ANSTO User Meeting 2021

Name: ANSTO User Meeting 2021
Start: 2021-11-24T09:00:00+11:00
End: 2021-11-26T17:20:00+11:00
Location: Online

24 Nov 2021, 09:00 → 26 Nov 2021, 17:20 Australia/Sydney

Online

Description

ABSTRACT SUBMISSION NOW CLOSED

Due to various covid restrictions the comittee has decided to change this to an online only event, ANSTO hopes we can commence face to face meetings next year.

A schedule of online webinars allows scientists who have accessed any of ANSTO’s research infrastructure, and includes the beamlines of the Australian Synchrotron, neutron scattering instruments at the Australian Centre for Neutron Scattering, instruments the Centre for Accelerator Science and deuterated products from the National Deuteration Facility, to showcase their work during the last year.

The event will coincide with the combined annual meetings of the Australian Neutron Beam Users Group (ANBUG) and the Australian Synchrotron Users Advisory Committee (UAC).

The announcement of excellence in neutron and synchrotron research awards takes place during the meeting.

Investigations using the instruments extend to a diverse range of scientific areas including advanced materials, biomedicine, life sciences, food science, physics, surface and condensed matter, chemistry, soft matter and crystallography, manufacturing and engineering, earth, environment and cultural heritage and research relating to the instruments and instrument techniques.

Student Funding

AINSE is offering up to 100 student registrations for students from AINSE Member Universities to attend this event with preference given to students that are presenting either an oral or poster.

Contact

aum2021@ansto.gov.au

02 9717 9770

Wednesday, 24 November
- 09:00 → 09:15
  
  Welcome Address
- 09:15 → 10:00
  
  Update: Organisational
- 10:00 → 10:30
  Plenary
  - 10:00
    
    Prof Despina Louca - Plenary 30m
    
    To be supplied
    
    Speaker: Prof. Despina Louca (University of Virginia)
- 10:30 → 11:00
  
  Morning Tea 30m
- 11:00 → 12:50
  Advanced Materials
  - 11:00
    
    Structural studies of solid-state ionic conductors at the limits of diffraction and beyond 20m
    
    The structures of solid-state ionic conductors are a compromise between long-range (and hence long-term) lattice stability and short-range coordinative flexibility. To rationally design improved versions for applications such as fuel cells and batteries, we need to understand how this compromise is reached. Diffraction methods alone are inadequate – whether using X-rays or neutrons, ex situ or operando, conventional crystallography or total scattering analysis – because of their dynamic nature. The time-averaged structure is not the whole story. In this talk I will show how we use experimental X-ray and neutron spectroscopy, and computational structure and dynamics calculations, to supplement diffraction when studying solid-state oxide, proton and lithium ionic conductors. We can then validate the insights gained by making targeted chemical modifications and testing their effects on structure and functional physical properties.
    
    Speaker: Chris Ling (University of Sydney)
  - 11:20
    
    Magnetoelastic coupling as a relaxation pathway for single ion magnets observed using inelastic neutron scattering. 15m
    
    Single ion magnets (SIM's), are materials that show an energy barrier to spin reorientation without long range magnetic order. Such materials have been postulated to be useful as potential materials for high density data storage or to be used as Qubits. The origin of the effect lies in the crystal field splitting of the central lanthanoid ion. The determination of crystal field splitting has long been performed using INS and this has been readily extended to SIM's [1]. In recent years the operating temperature of these SIM's has increased dramatically with magnetic hysteresis observed above liquid nitrogen temperatures [2]. The limiting factor is no longer the height of the energy barrier for reorientation, but minimization of relaxation by varying methods such as quantum tunneling of magnetization and Orbach relaxation. Such phenomena have previously been shown to be measurable using INS and QENS techniques [3,4,5]. In our recent work we have revisited the INS of Na9[Ho(W5O18)2] to analyse both the presence or absence of a QENS signal to determine whether Orbach relaxation occurs [3]. We have also performed an analysis of the peak widths of the crystal field excitations and modelled these using a magnetoelastic model [4]. This reanalysis demonstrates that INS holds more information than just the energy scale of the system for single ion magnets.
    
    [1] M. A. Dunstan et al, European Journal of Inorganic Chemistry 1089 (2019).
    [2] F-S. Guo,et al, Science, 362, 1400 (2018)
    [3] M. Roepke, et al, Physical Review B, 60, 9793 (1999)
    [4] S.W. Lovesey, U. Staub, Physical Review B, 61, 9130 (2000)
    [5] M. Ruminy, et. al, Physical Review B 95, 060414(R) (2017)
    
    Speaker: Richard Mole (ANSTO)
  - 11:35
    
    Total scattering: science that’s better than average 15m
    
    Local-scale defects and disorder are essential in the development of new advanced functional materials. However, such features are often difficult to characterize and understand without suitable probes. Powder diffraction is a powerful technique for understanding atomic structures, however, Bragg peaks alone are limited to information regarding the “average” or long-range structure. The presence of local-scale disorder results in diffuse features that occur beneath and between the Bragg peaks. Hence, the chracterisation of nano-scale (0.1 – 3 nm) features in functional materials demands an alternative approach.
    Total scattering involves the collection of both Bragg and diffuse data over a wide Q-range. This can be Fourier transformed to generate the pair distribution function (PDF), which corresponds to an interatomic histogram of atom-atom pairs in real space. Analyzing such data can enable the development of atomic models that capture the local- and long-range structural features. Such measurements require the use of high energy x-rays and/or neutrons. With the development of the advanced diffraction and scattering beamline at the Australian synchrotron, such measurements will become viable in Australia.
    This presentation will show case clear-cut examples of the application of total scattering in materials chemistry. This will show the necessity for local structure analysis in developing a complete understanding of structure-property relationships.
    
    Speaker: Frederick Marlton (University of Sydney)
  - 11:50
    
    Single-Crystal-to-Single-Crystal Transformations of Metal–Organic-Framework-Supported, Site-Isolated Trigonal-Planar Cu(I) Complexes with Labile Ligands 15m
    
    Transition-metal complexes bearing labile ligands can be difficult to isolate and study in solution because of unwanted dinucleation or ligand substitution reactions. Metal–organic frameworks (MOFs) provide a unique matrix that allows site isolation and stabilization of well-defined transition-metal complexes that may be of importance as moieties for gas adsorption or catalysis.
    
    Herein we report the development of an in situ anion metathesis strategy that facilitates the postsynthetic modification of Cu(I) complexes appended to a porous, crystalline MOF. By exchange of coordinated chloride for weakly coordinating anions in the presence of carbon monoxide (CO) or ethylene, a series of labile MOF-appended Cu(I) complexes featuring CO or ethylene ligands are prepared and structurally characterized using X-ray crystallography. These complexes have an uncommon trigonal planar geometry because of the absence of coordinating solvents. The porous host framework allows small and moderately sized molecules to access the isolated Cu(I) sites and displace the “place-holder” CO ligand, mirroring the ligand-exchange processes involved in Cu-centered catalysis.
    
    Speaker: Ricardo Peralta (University of Adelaide)
  - 12:05
    
    Deuteration of Rec1-Resilin and its hydrogel for biomedical applications 15m
    
    Rec1-resilin is a highly hydrophilic protein that exudes a vast range of multi-responsiveness, well known for its superelasticity. Self-assembly of Rec1-resilin has been studied in vitro, however, it is difficult to understand the interaction and molecular organisation of the protein with varying biological environments due to the presence of complex systems. Therefore, it is critical to synthesise Rec1-resilin in deuterated form, which would enable a unique neutron scattering length density for neutron scattering experiments. With a view to understand the self-assembly and co-assembly of Rec1-resilin and tailor its responsiveness, we successfully synthesised deuterated Rec1-resilin using a modified protocol. Utilising this modified protocol, we hope to develop modular versions of Rec1-resilin with hydrophobic segment to explore its unique properties from its conformational structure, binding and organisation with complementary and contrasting neutron scattering techniques with intentions to develop biomimetic gels for adhesion and repair of tissue. Ultimately, this will show the impact of deuteration on the protein through a comparison of the structure and organisation of the deuterated and unlabelled modular versions of Rec1-resilin in different environments, which will not only provide a fundamental understanding of phase behaviour but also lead to utilisation of isotopically-labelled modular Rec1-resilin protein and its hydrogels for biomedical applications.
    
    Speaker: Nisal Wanasingha
  - 12:20
    
    Interfacial spin-structures in Pt/Tb3Fe5O12 bilayer films on Gd3Ga5O12 substrates 15m
    
    The insulating ferrimagnets of rare-earth iron garnets (ReIG) are researched intensively owing to their strong magneto-electric responses. Proximity coupling between an insulating ReIG and a heavy metal, such as Pt has been shown to lead to an Anomalous Hall effect (AHE). Amongst the ReIG family, TbIG is less explored than the well-known YIG films. In this article, we report thin films (40 nm) of ferrimagnetic insulator Tb3Fe5O12 (TbIG) were grown on (111) oriented Gd3Ga5O12 (GGG) substrates by using pulsed laser deposition technique, some of which were capped by a thin Pt layer. Scanning transmission electron microscopy and X-ray diffraction show that the oxide films are epitaxial with high crystalline quality and sharp interfaces. Detailed polarized neutron reflectometry was used to study the spin structure above, below and near the compensation to search for interfacial spin effects. The neutron reflectivity with different states (spin up (R+) and spin down (R-)) and the spin asymmetry (SA = (R+ - R-)/ (R+ + R-)) shows trends above 100 K consistent with the weak ferrimagnetic moment and compensation point. Remarkably, the PNR spectra at 7 K shows additional splitting of R+ and R- indicating strong magnetization on the magnetic film showing a new magnetic layer that arise, additional STEM mapping elucidate that this additional layer occurs at the TbIG/GGG interface, where a chemical difference in the ratio of Gd:Ga occurs as product of the growth conditions. This effect appears in both capped and Pt-free TbIG films. Reversal of AHE sign occurred between 145 K and room temperature. The peculiar behavior of AHE loop around 220 K is related to the compensation point of TbIG.
    
    Speaker: Ms Roshni Yadav
  - 12:35
    
    Operando investigation of a lead-acid battery with the IMBL. 15m
    
    Lead-acid batteries play a key role in the energy storage marketplace. They are often cheaper, safer and more recyclable than alternative electrochemical energy storage systems. Under traditional energy storage applications such as starting, lighting and ignition batteries, they provide a great balance of affordability, lifespan and performance to the consumer. However, as the demands placed on energy storage systems have increased over recent decades, lead-acid batteries have been shown to have a markedly shortened lifespan. Investigations have found the cause of this failure is related to an uneven utilization of active material in the Pb electrode. Although, the process whereby uneven utilization of active material leads to a significant reduction in cycle-life has yet to be determined. Typically, investigations of uneven material utilization are conducted after the fact and are destructive (EPMA, SEM, XRD etc.). Our project aimed to determine whether the IMBL could be a suitable candidate for non-destructive, operando investigations into active material utilization. To achieve this, a lead-acid cell was designed specifically for the IMBL. It was cycled whilst being simultaneously imaged at 85 keV, with an exposure time of 0.8 s at a resolution of 5.8 µm. Results show that key reaction products could be observed in-situ and furthermore they could be localized within certain regions within the Pb electrode. We show that the IMBL could be a powerful tool to further the current understanding of lead-acid batteries.
    
    Speaker: Mr Chad Stone (Swinburne University of Technology)
- 11:00 → 12:50
  Biomedicine, Life science & Food Science
  - 11:00
    
    The Death Kiss: understanding how the zombie protein, MLKL, is triggered to kill cells by necroptosis 20m
    
    In 2012, Mixed lineage kinase domain-like (MLKL), a catalytically-dead (“zombie”) cousin of conventional protein kinases, termed a pseudokinase, was implicated as the key effector in the programmed necrosis (or necroptosis) cell death pathway. This pathway has been implicated in innate immunity, the pathogenesis of inflammatory diseases, and tissue injury arising from ischemia-reperfusion. As a result, an improved fundamental knowledge of MLKL’s activation mechanism is of enormous interest as we and others look to target the pathway therapeutically.
    
    Here, I will describe our recent work dissecting the chronology of events in this pathway using novel tools, biochemistry, microscopy, proteomics and structural biology methods. Our structural studies were enabled by the MX and SAXS beamlines at the Australian Synchrotron and isotopic protein labelling at the National Deuteration Facility.
    
    Speaker: Dr James Murphy (Walter and Eliza Hall Institute of Medical Research)
  - 11:20
    
    Structures of biliary micelles during solubilisation of lipids mimicking the digestion products of human and bovine milk 15m
    
    Milk is our sole source of nutrition for the first six months of life and milk lipids carry fat-soluble nutrients through the gut as well as providing most of the energy we consume with milk. The digestion and absorption of lipids, predominantly triglycerides, and entrained nutrients is therefore important for survival and growth. Milk triglycerides are regarded amongst the most chemically complex mixtures, their composition is species-dependent and determines the mixture of fatty acids and monoglycerides that form during their digestion. Most lipid digestion takes place in the small intestines where bile salts mixed with phospholipids in the intestinal fluids form a colloidal sink into which the poorly-soluble digestion products can partition and be absorbed at the intestinal walls. This work describes attempts to simulate how the structures of biliary micelles change when they absorb milk digestion products under intestinal conditions. Mixtures of fatty acids and monoglycerides were prepared to mimic the digestion products of human and bovine milk. The chemical complexity of the mixtures was varied by including between four and eight different lipid chain types in the digestion product mixtures. The effect of pH on micelle structure was also studied within the range of pH 6.4-7.7, consistent with the increase in pH along the intestinal tract. The structural differences when these complex lipid mixtures were solubilised by bile salt/phospholipid micelles were identified using the SAXS/WAXS beamline at the ANSTO Australian Synchrotron. The lipid composition was found to be a primary driver of micelle shape and size, with pH having a secondary affect in reducing aggregate formation at higher pH.
    
    Speaker: Dr Andrew Clulow (ANSTO Australian Synchrotron)
  - 11:35
    
    Hepatic lipid composition in dietary models of high iron NAFLD investigated with Synchrotron Infrared and X-Ray Fluorescence microscopy 15m
    
    Hepatocytes are essential for maintaining homeostasis of mammalian iron and lipid metabolism. Serious health consequences have been linked to dysregulation of both areas. One such consequence is non-alcoholic fatty liver disease (NAFLD). Approximately 30% of individuals with NAFLD demonstrate a moderate increase in hepatic iron; however, the mechanism and metabolic consequences remain under-investigated. We assessed the metabolic consequences using mice fed either a control or high fat (HF) diet, with or without high iron. Attenuated Total Reflection Infrared Microscopy (Macro-ATR) at the Australian Synchrotron was used to investigate lipid composition and distribution, and X-Ray Fluorescence Microscopy (XRF) at the Diamond Light Source (UK) was used to determine subcellular iron concentration and distribution. Peri-portal hepatocytes of HF fed animals exhibited elevated lipid parameters, including ester and free fatty acid concentrations ~7x that of controls (P<0.005). The increase was seen within lipid droplets, which were primarily composed of cholesteryl esters and triglycerides. When HF livers were iron loaded, reductions in all lipid parameters were observed, with ~2.6x lower relative ester concentration (P<0.05) compared to HF only. Iron loaded HF peri-portal hepatocytes exhibited shorter chain lengths (P<0.005) and a shift in the olefinic peak (3011 cm-1) compared to HF (3007 cm-1) (P<0.05), suggesting the shorter chains were more polyunsaturated. Iron accumulated within mitochondria of peri-portal hepatocytes of animals fed high iron diets. Poly-unsaturated lipids are strong activators of hepatic lipid breakdown and this study suggests a role for iron in reducing the lipid burden by remodelling hepatic lipids in NAFLD.
    
    Speakers: Mr Clinton Kidman (Curtin University), Dr Cyril Mamotte (Curtin University)
  - 11:50
    
    Investigating the Therapeutic Benefit of Spermidine in a Pre-Clinical Model of Muscular Dystrophy 15m
    
    Research into treatment for Duchenne Muscular Dystrophy (DMD) typically focuses on deterioration of muscle, however bone health is also severely compromised. Current treatment with corticosteroids exacerbate bone loss, so novel therapies targeting both muscle and bone are needed. Studies on bone health in a pre-clinical model, mdx mice, are limited and have conflicting results.
    Objective of study: To characterise aspects of bone health in mdx mice and investigate whether spermidine might attenuate disease symptoms and spare bone.
    Bone structure and function were assessed in 16-week-old mdx mice femurs by three-point bending, microarchitectural assessment using the Imaging and Medical Beamline (IMBL) at the Australian Synchrotron, and by histological analysis. Cortical thickness and cortical bone area fraction were lower in dystrophic mice compared to wild-type controls (WT). No differences were observed in metaphyseal trabecular bone morphometry. Three-point bending indicated that mdx femurs required less stress to reach yield point and failure but were able to sustain damage for a longer period (post-yield displacement) compared to WT mice. Despite this, mdx femurs required more energy to reach failure. Histology revealed lower osteoblast numbers in mdx mice. Spermidine treatment did not appear to compromise bone health in either WT or mdx mice which is important as current treatments typically worsen bone quality. This study provides novel data about aspects of skeletal morphology in mdx mice at 16 weeks of age, and provides new techniques using pre-clinical models to investigate potential therapies for DMD patients that might target both muscle and bone.
    
    Speaker: Lauryn Schaddee Van Dooren (University of Melbourne)
  - 12:05
    
    Structural insights into the ferroxidase and iron sequestration mechanisms of ferritin from Caenorhabditis elegans 15m
    
    Iron is an essential trace element that, when in excess, becomes highly toxic [1]. Intracellular iron concentration must be strictly regulated by a network of interacting mechanisms [2]. Ferritin is a ubiquitous iron-storage protein that forms a highly conserved 24-subunit spherical cage-like structure. Ferritin catalyses the oxidation of iron (II) to iron (III) and sequesters the newly oxidised iron (III) as a mineral core to prevent cellular damage [3]. In this study, we use the model organism, Caenorhabditis elegans, to investigate iron uptake, oxidation, storage and release by ferritin.
    C. elegans expresses two ferritin proteins, FTN-1 and FTN-2, which both exhibit ferroxidase activity [4]. FTN-2 functions at a rate significantly faster than FTN-1 despite conservation of all catalytic residues, suggesting that structural differences at a location distinct to the ferroxidase centre may influence catalytic activity. We solved the X-ray crystal structures of FTN-1 (1.84 Å) and FTN-2 (1.47 Å), and the cryo-EM structure of FTN-2 (1.88 Å). FTN-1 and FTN-2 both adopt the conserved 24-subunit cage-like structure and bind one iron (II) in the ferroxidase centre of each chain. We postulate that iron (II) accesses the ferroxidase centre through a three-fold symmetrical pore. This pore is notably larger and more negatively charged in the FTN-2 structure and may facilitate easier access of iron (II) to the ferroxidase centre, resulting in a faster catalysis rate.
    These structural insights further our understanding of the mechanisms used by ferritin to regulate iron storage and the overall role of ferritin in iron homeostasis.
    
    Speaker: Tess Malcolm (Bio21 Molecular Science and Biotechnology Institute)
  - 12:20
    
    Spectroscopic Analysis of Age-Related Changes in the Brain Lateral Ventricles During Ageing 15m
    
    Alzheimer’s disease is the most common form of dementia and poses significant health and economic concerns. Currently, the disease has no cure, and it is expected that over 1 million people could be affected by 2058 in Australia alone. The content and distribution of metals such as Fe, Cu, Zn is known to change in the ageing brain and thus, increased understanding of the mechanistic role of metal dis-homeostasis may illuminate new therapeutic strategies. The brain lateral ventricles, which play a role in controlling metal and ion transport, have shown increasing levels of copper surrounding their walls with ageing. As a redox active metal, copper can induce oxidative stress which is a process that occurs during Alzheimer’s disease onset and progression. Our research group has been interested in determining whether the age-related elevation of copper surrounding the lateral ventricles is inducing oxidative stress in that region. In this study, we have utilised X-Ray Absorption Spectroscopy (XAS) at the Stanford Synchrotron Radiation Lightsource to analyse different chemical forms of sulfur and measure oxidative stress by analysis of disulfides. Additionally, we used the infrared microscopy beamline at the Australian Synchrotron to identify whether any other markers of oxidative stress were present around the ventricles. Further insights into metal dis-homeostasis and its influence on other biochemical pathways, may help to reveal some of the neurochemical mechanisms involved in progression of Alzheimer’s disease. In turn, this may help pave the way for potential preventative or therapeutic models.
    
    Speaker: Ms Ashley Hollings (School of Molecular and Life Sciences, Curtin University, GPOBox U1987, Bentley Western Australia 6845, Australia. Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia 6102, Australia.)
  - 12:35
    
    Imaging Breast Microcalcifications Using Dark-Field Signal in Propagation-Based Phase-Contrast Tomography 15m
    
    Breast microcalcifications are an important primary radiological indicator of breast cancer. However, microcalcification classification and diagnosis can be still challenging for radiologists due to limitations of the standard 2D mammography technique, including spatial and contrast resolution. In this study, we propose an approach to improve the detection of microcalcifications in propagation-based phase-contrast X-ray tomography (PB-CT) of breast tissues. Five fresh mastectomies containing microcalcifications were scanned at the Imaging and Medical beamline of the Australian Synchrotron at different X-ray energies and radiation doses. Both bright-field and dark-field images were extracted from the same data sets using different image processing methods [1]. A quantitative analysis was performed in terms of visibility and contrast-to-noise ratio of microcalcifications. The results show that the visibility of the microcalcifications in the dark-field images is more than two times higher compared to the bright-field images. Dark-field images have also provided more accurate information about the size and shape of the microcalcifications [2]. Therefore, dark-field PB-CT images are likely to help radiologists evaluate the probability of breast cancer more effectively. This work has been conducted in the course of developing a medical imaging facility at the Australian Synchrotron for advanced breast cancer imaging.
    References:
    [1] T. E. Gureyev, et al., Phys. Med. Biol. 65, 215029, 2020.
    [2] A. Aminzadeh et al., submitted.
    
    Speaker: Alaleh Amin zadeh
- 11:00 → 12:50
  Instruments & Techniques
  
  Convener: Andrew Clulow (ANSTO Australian Synchrotron)
  - 11:00
    
    From Niche to Mainstream: Ptychography Comes of Age. 20m
    
    In the space of a few short years, ptychography has moved from a niche method1,2 to emerging as a mainstream technique for user science3,4. Until recently, ptychography required significant expert user experience to collect and reconstruct useable data, with a field of view often limited to a small area (such as a single cell)5 by data collection and reconstruction limitations6. Now however, ptychography data can be collected at high speed7 complementary to modern X-ray fluorescence fly-scanning8, with data-pipelines providing results within a few hours using GPU enabled reconstruction algorithms9. These advances allow ptychography to be applied to larger areas and sample replicates10, allowing statistically significant user science to be done in a reasonable timeframe while simultaneously collecting X-ray fluorescence data11-13. In this presentation, I highlight key milestones on the ptychography journey as it makes its way into the mainstream, as well as looking towards the future.
    
    Michael W. M. Jones1, Grant A. van Riessen2,3, Christoph E. Schrank4, Nicholas W. Phillips5, Gerard N. Hinsley2, Martin D. de Jonge6, Cameron M. Kewish2,6
    
    1Central Analytical Research Facility, Queensland University of Technology, Brisbane QLD 4000, Australia
    2Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora VIC 3086, Australia
    3Melbourne Centre for Nanofabrication, Clayton VIC 3168, Australia
    4School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane QLD 4000, Australia
    5Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
    6Australian Nuclear Science and Technology Organisation, Australian Synchrotron, Clayton VIC 3168, Australia
    
    Speaker: Michael Jones (QUT)
  - 11:20
    
    How to take a perfect image with DINGO 15m
    
    Neutron tomography is a powerful non-destructive technique used to study the internal structure of opaque objects. Neutron images are obtained by exposing an object to a uniform neutron beam. The transmitted neutrons interact with a phosphor which converts from neutrons to visible light, which is then demagnified on to a CCD camera.
    The modulation transfer function (MTF) is routinely used to determine the sharpness of an image, i.e. the ability of the imaging system to transfer information from an object to an image. The spatial frequency (SF) is the rate of transition between light and dark features in the image. For a perfect system where all of the frequency information is passed from object to image equally, the MTF of the will be 1 or 100% for all spatial frequencies and all features and contrast in the object will be transferred to the image.
    We performed a series of measurements to optimise the time necessary to obtain high-resolution radiographs with the DINGO instrument. We determined the MTF over a range of experimental conditions to understand the various contributions of DINGO’s imaging system variables to radiograph resolution. The system components varied in this study are the two beam modes, different scintillator screens, and pixel resolution of different cameras and lenses. We also compared the different exposure times of the object to the neutron beam to try to understand the minimum exposure time that will generate good resolution radiographs.
    Details of the use of this method for determining the quality of a neutron tomographic imaging system will be presented and the MTF data will be used to determine the optimal operating arrangement.
    
    Speaker: Vili Grigorova (Macquarie University)
  - 11:35
    
    The Imaging and Medical Beamline is expanding 15m
    
    Synchrotron radiation has many advantages, but it is also flawed. And its biggest flaw happens to be its fundamental intrinsic property! The radiation is emitted in the plane of the stored beam and we are stuck with the infamous ‘letterbox door’ beam profile. At least when not tinkering with focused undulator beams.
    In clinical imaging research, this beam shape is a serious disadvantage. In fact, when compared with the field of view of commercial medical imaging devices, it is often the showstopper when engaging with a clinician to discuss medical application of the IMBL.
    So how will we image human patients in 2022, as part of our world leading research project in breast CT imaging and cancer detection? Our vertical ‘letter box opening’ at 135 meter is 3 cm, at 35 keV, with a roll off of 50%. This is far from ideal for imaging the breasts of a patient lying in a prone position on our robotic positioning and scanning stage. Consequently, we have designed and tested a Bragg-Bragg beam expander to be placed downstream of our double-bent-Laue primary monochromator. The net result is an 8 cm vertical beam profile at 135 meter, with minimal roll off, to match the vertical field of view of our new EIGER2 CdTe X 3M clinical detector.
    This paper will present the design of our beam expander and the results of our in-air tests. This device will be installed in vacuum in the next machine shutdown.
    
    Speaker: Daniel Hausermann (Australian Synchrotron (ANSTO))
  - 11:50
    
    Quantifying the x-ray dark-field signal in single-grid imaging 15m
    
    X-ray imaging has progressed in recent decades to capture not only a conventional attenuation image, but also a ‘phase-contrast’ image that visualises those features that are difficult to see with attenuation. More recently, techniques have been developed to capture a ‘dark-field’ signal. The dark-field signal is generated by ultra-small-angle x-ray scattering from unresolved sample features, such as bubbles, powders or fibres, providing information about sample microstructure that is inaccessible using full-field conventional or phase-contrast x-ray imaging. Dark-field imaging can be useful in a range of fields, including medical diagnosis, materials science and airport screening.
    
    Single-grid imaging is an emerging x-ray imaging technique that only requires one optical element – a grid or, in the speckle-based variant, a piece of sandpaper. The grid or sandpaper generate a reference pattern that is warped and blurred when the sample is introduced, revealing phase and dark-field respectively. This technique is suitable for dynamic imaging since the three complementary image signals can be extracted from single sample exposure, unlike previous methods. Until now, this technique has primarily been applied in phase-contrast imaging.
    
    In this work, we derive a method to extract and quantify a dark-field signal from single-grid imaging, relating the signal to the number of sample microstructures. We also apply our method of analysis to images captured at the Australian Synchrotron’s Imaging and Medical Beamline to evaluate how our measurements align with theoretical predictions. Future directions include investigating how the sample microstructure size affects the dark-field signal strength.
    
    Speaker: Ying Ying How
  - 12:05
    
    Total Scattering Measurements at the Australian Synchrotron Powder Diffraction Beamline: Capabilities and Limitations 15m
    
    The PD beamline at the Australian Synchrotron (ANSTO) consistently receives requests to carry out total scattering experiments for various materials including battery electrodes, piezoelectrics and coordination frameworks. In this study we describe the capabilities and limitations of carrying out total scattering experiments on the Powder Diffraction beamline. A maximum instrument momentum transfer of 19 Å-1 can be achieved. Our results detail how the pair distribution function is affected by Qmax, absorption, and counting time duration at the PD beamline. We also trial a variable counting time strategy using the Mythen II detector. Refined structural parameters exemplify how the PDF is affected by these parameters. Total scattering experiments can be carried out at PD although there are limitations. These are: (1) only measurements on stable systems and at non-ambient conditions is possible if the temperature is held during data collection, (2) it is essential to dilute highly absorbing samples (µR>1), and (3) only correlation lengths >0.35 Å may be resolved. A case study comparing the PDF atom-atom correlation lengths with EXAFS derived radial distances of Ni and Pt nanoparticles is also presented, which shows good agreement between the two techniques. The results here can be used as a guide for researchers considering total scattering experiments at the PD beamline.
    
    Speaker: Dr Anita D'Angelo (Australian Synchrotron)
  - 12:20
    
    Update on Polarised Neutron Capabilities at the Australian Centre for Neutron Scattering 15m
    
    The Australian Centre for Neutron Scattering offers neutron polarisation capabilities which are compatible with six different neutron scattering instruments, using a combination of polarising supermirrors and $^3$He cell spin filters. An overview of these capabilities will be given, followed by a description of some recent experiments which make use of a variety of these capabilities on instruments, including the cold triple-axis spectrometer Sika, and the small-angle neutron scattering instrument Quokka with a recently-commissioned 7 T compensated vertical magnet. Finally, current and future work to expand capabilities will be outlined, such as a new system for polarisation analysis experiments with magnetic fields controlled in 3D for the time-of-flight spectrometer Pelican which will soon be offered to the user community, and a bespoke 0.5 T horizontal magnet system for the thermal triple-axis spectrometer Taipan.
    
    Speaker: Andrew Manning (ANSTO)
  - 12:35
    
    KOALA 2: Implications for magnetic structural and exotic studies 15m
    
    The KOALA single-crystal diffractometer has now been operating for more than a decade and is now nearing retirement (mid-2022). The technical improvements of the new KOALA 2 diffractometer, and the implications for conventional chemical crystallography are described in separate presentations at this meeting.
    In this presentation we will present the implications for less conventional studies, such as: magnetic structures; incommensurate and other complex structures; very small samples; high-pressure experiments; studies over many temperatures; various preparatory studies of inelastic and diffuse scattering.
    
    Speaker: Dr Ross Piltz (ACNS, ANSTO)
- 12:50 → 13:20
  
  Lunch 30m
- 13:20 → 13:40
  Update: ACNS
  - 13:20
    
    Australian Centre for Neutron Scattering Update 20m
    
    The Australian Centre for Neutron Scattering (ACNS) utilises neutrons from Australia's multi-purpose research reactor, OPAL, to solve complex research and industrial problems for Australian and international users via merit-based access and user-pays programs. Neutron scattering techniques provide the research community and industry with unique tools to study the structure, dynamics and properties of a range of materials, helping scientists understand why materials have the properties they do, and helping tailor new materials.
    
    An update will be given on the OPAL reactor and its neutron beam facilities, the status of the neutron beam instruments and supporting capabilities, user program, and future plans.
    
    Speaker: Jamie Schulz (ANSTO)
- 13:40 → 14:00
  Update: NDF
  - 13:40
    
    Deuteration at the NDF: facility overview and update on diversity of capabilities, user program and impact. 15m
    
    Deuteration can provide contrast and improved resolution to assist investigations into the relationship between molecular structure and function of molecules of both biological and synthetic origin. Molecular deuteration of organic compounds and biomolecules increases options available in characterisation and complex structure function investigations using neutron scattering and reflectometry, nuclear magnetic resonance (NMR), mass spectrometry (MS) and other techniques and also creates functional materials with superior properties in life sciences, pharmaceutical and advanced technology applications.
    The National Deuteration Facility (NDF) at the Australian Nuclear Science and Technology Organisation (ANSTO) has the specialised expertise and infrastructure to deliver deuteration through both biological and chemical molecular deuteration techniques to provide for a range of experimental and research applications that benefit from availability of custom deuterated molecules. The NDF has developed a suite of capabilities supporting researcher and industry access to a diversity of molecules. Capabilities include production of isotopically labelled proteins (variably deuterated, multiple-labelled - 2H, 13C, 15N) and cholesterol-d45 through bacterial recombinant expression and bio-engineered yeast growth respectively and catalysed 1H/2H exchange and chemical synthesis of a wide range of small organic molecules using tailored deuteration approaches to provide bespoke deuterated molecules generally unavailable commercially. This includes a range of deuterated lipids, unsaturated phospholipids (e.g. POPC and DOPC), surfactants, ionic liquids, fatty acids and detergents. Availability of these molecules widens the breadth of systems that can be investigated with applications across multiple research fields.
    An overview and update on the NDF will be provided including details on the NDF User Program and modes of access, capability advancements and brief highlights of research enabled through utilisation of deuterated molecules produced by the NDF.
    
    Speaker: Karyn Wilde (National Deuteration Facility, ANSTO)
- 14:00 → 15:00
  Advanced Materials
  - 14:00
    
    In-situ X-ray diffaction for hydrogen sorption study of Mg-La alloys 15m
    
    Trace Na additions can enhance the reaction kinetics of Mg-5%La (wt.%) alloys, resulting in a potential hydrogen storage material. In this study, we used in-situ synchrotron Powder X-ray Diffraction (PXRD) to examine the hydrogen sorption behaviour of the Na-modified Mg-5%La. A setup equipped with a hydrogen gas flow cell and a hot air blower at the Powder Diffraction beamline of the Australian Synchrotron facility is used to allow for PXRD data collection during hydrogen sorption reactions to study the phase evolutions and the cyclability of the alloy. To shed light on the underlying processes during the reactions, in-situ desorption and absorption were performed in a hydrogen atmosphere between 30-480 °C and atmospheric pressure to 2MPa H2. Rietveld refinement was conducted using the TOPAS-Academic V6 software to calculate the weight percentage and lattice expansion of each phase in the sample. In addition, in-situ High Voltage Transmission Electron Microscopy (HVTEM) was used as a complementary technique to study the volume expansion properties during desorption as a function of temperature.
    
    Speaker: Manjin Kim
  - 14:15
    
    Natural ageing behaviour in Al-Cu alloys containing Sc and Zr 15m
    
    The 2xxx series Al-Cu alloys have been extensively used as engineering structures and components of lightweight vehicles due to their excellent strength-to-weight ratio. Recent research has demonstrated that further substantial enhancement in the strength of Al-Cu alloys could be achieved by adding Sc and Zr by forming nano-sized Al3(Sc, Zr) dispersoids. However, further development and manufacturing of these new Sc and Zr-containing Al-Cu alloys are limited by a lack of basic understanding of the effect of Al3(Sc, Zr) dispersoids on the microstructural evolution during room temperature storage after quenching from solution treatment (called natural ageing). In this work, therefore, we have studied the effect of Al3(Sc, Zr) dispersoids on natural ageing behaviour in an Al-4wt.%Cu-0.1wt.%Sc-0.1wt.%Zr alloy using small-angle neutron and x-ray scattering (SANS and SAXS). The hardness measurement shows that the presence of Al3(Sc, Zr) dispersoids significantly delays the natural ageing kinetics of Al-Cu alloys. SANS was used to quantify the size distribution of Al3(Sc, Zr) dispersoids which is ~ 25 ± 3 nm. In-situ SAXS results show that the presence of Al3(Sc, Zr) dispersoids results in a significant delay in the solute clustering formation during natural ageing. This is attributed to the suppression of the natural ageing kinetics in the Al-Cu-Sc-Zr alloys. These results were confirmed by differential scanning calorimetry (DSC) and high resolution transmission electron microscopy (TEM). The suppression mechanism is hypothesized to come from the dispersoids and Sc solute acting as vacancy sinks which slows down the diffusion of solute at room temperatures.
    
    Speaker: Lu Jiang (Deakin University)
  - 14:30
    
    Magnetic Nanochain Formation Studied by Small-Angle Scattering 15m
    
    Self-assembly of magnetic nanoparticles is of interest due to the broad range of applications in material science and biomedical engineering. Parameters that affect self-assembly in nanoparticles include particle size, the applied magnetic field profile, concentration and synthesis routines. A range of different sizes of magnetic nanoparticles between 5 and 27 nm were investigated using polarized small-angle neutron scattering (SANS) at the KWS-1 instrument operated by the Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany and the Quokka instrument operated by the Australian Centre for Neutron Scattering (ACNS) at ANSTO in Lucas Heights, Australia. Iron oxide nanoparticles were dispersed in toluene and measured at room temperature in applied fields between ±2.2 T. The observed self-assembly strongly depended on both nanoparticle size and applied field. For smaller particles (diameter ≤ 20 nm) there was no indication of self-assembly, while 27 nm nanoparticles assemble into linear chains even in low concentrations (0.42% v/v) and low field (4 mT).
    
    The magnetization profile within the cores of the smaller nanoparticles could be extracted with high-resolution when using a spin-polarized incident neutron beam. For larger nanoparticle, the structural and form factors were obtained by sector analysis of the 2-D SANS patterns. The extracted structure factors suggest that the chains grow longer and straighter and align more closely with the field direction up until application of the maximum field. This is understood in terms of a minimization of the dipole energy of the nanoparticles in the presence of the applied field and neighbouring particles. Preliminary results from experiments studying self-assembly of more complex nanoparticles (including gold-iron dumbbell nanoparticles) will be discussed.
    
    Speaker: Dr Lester Barnsley (ANSTO)
- 14:00 → 15:00
  Biomedicine, Life science & Food Science
  - 14:00
    
    Neutron Reflectometry Unravels Allergen-Lung Surfactant Monolayer Interactions in the Development of Pollen-Induced Thunderstorm Asthma 15m
    
    Pollen-induced thunderstorm asthma outbreaks affect thousands of individuals globally. Australians in particular suffer from it every year. Pollens, the major culprit in thunderstorm asthma, are biological microparticles produced by flowering species of the plants. Pollens encounter stormy environments including lightning and humidity in thunderstorms, which results in liberation of associated allergen proteins and probable reactions with reactive oxygen nitrogen species (RONS) from the environment, before inhalation. Since allergen proteins are much smaller in size than whole pollen, they can travel deep down in the lower airways where they initially interact with the lung surfactant monolayer present within the lumen of alveoli. Although meteorological, pathological and immunological analyses support the role of pollen allergens in exacerbating asthma, the physicochemical basis of this phenomenon is underinvestigated.
    
    In this talk, we present a model system to study the interactions between an allergen protein and a lung surfactant monolayer composed of solid-supported dipalmiptoylphosphatidylcholine (DPPC) monolayer. We mimic the stormy environment with plasma-activated water (PAW) and employ advanced analytical tools and techniques such as quartz crystal microbalance with dissipation (QCM-D) and neutron reflectometry (NR) to investigate the effect of RONS on the allergen protein and its subsequent interactions with the DPPC monolayer. Our experimental analysis revealed the attachment of RONS on the allergens when exposed to the PAW, and QCM-D showed mass adsorption profiles. Furthermore, NR showed the monolayer insertion and aggregation propensity of the allergens, providing a deeper mechanistic insight into these interactions. The findings of this research will enable effective diagnostic strategies and therapeutics for the treatment of thunderstorm asthma.
    
    Speaker: Mr Arslan Siddique (UNSW Sydney)
  - 14:15
    
    Investigating the role of Zn in glucose regulation using X-ray Fluorescence Microscopy and X-ray absorption near-edge structure spectroscopy 15m
    
    Zinc plays an important function in glucose regulation, particularly within pancreatic islets, the anatomical home of the glucose regulating hormones insulin and glucagon. Glucose dysregulation is a significant contributor to the epidemic of metabolic diseases, including diabetes, that affect an increasing number of people. Zn is found in very high (mM) concentrations in insulin-secreting β-cells, where it facilitates insulin synthesis and storage, and is co-secreted with insulin, subsequently acting as a signalling molecule. Zn dysregulation is often coincident with impairment of insulin secretion, but little is known about the nature of the changes. Since a subset of the pool of Zn in islets is labile, it is difficult to image in its in vivo situation using conventional techniques such as histochemistry. Not only do preparation steps such as washing displace Zn, but some forms in which it exists are not readily discernible using conventional microscopy techniques. X-ray fluorescence microscopy (XFM) and X-ray absorption near-edge structure spectroscopy (XANES) offer several advantages in that tissue preparation is minimal, facilitating the conservation of native states, and all forms of Zn are not only detectable, but are able to be discriminated by matching spectra against an existing library of Zn forms. Here we report the preliminary results from our study of Zn speciation and elemental mapping in murine islets from healthy or diabetes-prone animals in two age groups, 14 (denoted young) or 28 (old) weeks. This work uses a library of biologically relevant Zn forms created in our laboratory, and contributes to our understanding of the role of Zn in glucose regulation in health and disease, including aging.
    
    Speaker: Dr Gaewyn Ellison (Curtin Innovation Health Research Institute (CHIRI), Curtin University)
  - 14:30
    
    Gd-TPP-DOTA reduces cell viability in cancer cells via synchrotron radiotherapy 15m
    
    High-Z elements have been proposed as radiosensitisers in X-ray photon radiotherapy due to their emission of multiple high-LET photo- and Auger electrons following X-ray irradiation. Gadolinium is a particularly attractive candidate radiosensitiser, since it can also be used as an MRI contrast agent. In this study, we report on the efficacy of Gd-triphenylphosphonium salt-DOTA (Gd(III)-TPP-DOTA) for synchrotron microbeam radiation therapy dose enhancement. The compound utilises the mitochondrial targeting moiety triphenylphosphonium (TPP) to accumulate Gd in the inner mitochondrial membrane.
    
    Experiments were conducted using the dynamic mode option at hutch 2B of the Imaging and Medical Beamline at the Australian Synchrotron. Human glioblastoma multiforme cells (T98G cell line) were cultured to 80-90% confluence in T12.5 flasks. Approximately 24 hours prior to irradiation, the cultures were either treated with a 500 μM solution of Gd(III)DOTA-TPP or a vehicle control. Spatial dose distribution of synchrotron broad beam (BB) and single/multiple microbeams were measured using a micron-scale X-Tream dosimetry system and Gafchromic films in air and at 2 cm depth in solid water (same depth as the monolayer of cells in T12.5 flasks). A total of 96 flasks were irradiated, with doses of 0, 1, 2, 3, 4, 5, 10 and 16 Gy delivered in valley (MRT) or uniformly (BB). Post irradiation, each flask was re-seeded into 7 x 96 well-plates to perform the resazurin cell proliferation assay up to 7 days after irradiation.
    
    Our preliminary analysis indicates that for cells irradiated by 3 Gy of BB or MRT radiation, the addition of Gd(III)DOTA-TPP results in a reduction in viable cell mass by 24.25% and 25.79%, respectively, compared with untreated flasks.
    
    Speaker: Dr Ryan Middleton (ANSTO)
  - 14:45
    
    Structural, Biochemical and Functional characterization of Salmonella BcfH: an unusual Dsb-like fimbrial protein 15m
    
    Bacteria use folding enzymes to produce functional virulence factors. These foldases include the Dsb family of proteins, which catalyze a key step in the protein-folding pathway, the introduction of disulfide bonds. The Dsb oxidative system, which includes an oxidative DsbA/DsbB pathway and an isomerase DsbC/DsbD pathway, is present in numerous bacterial species. Conventionally, Dsb proteins have specific redox functions with monomeric and dimeric Dsbs exclusively catalyzing thiol oxidation and disulfide isomerization, respectively. This contrasts with the eukaryotic disulfide forming machinery where the modular thioredoxin protein PDI mediates thiol oxidation and disulfide reshuffling. In this study, we identified and structurally and biochemically characterized a novel Dsb-like protein from Salmonella enterica termed BcfH and defined its role in virulence. Encoded by a highly conserved bcf (bovine colonization factor) fimbrial operon, the Dsb-like enzyme BcfH forms a trimeric structure, exceptionally uncommon among the large and evolutionary conserved thioredoxin superfamily. BcfH also displays very unusual catalytic redox centers, including an unwound α-helix holding the redox active site and a trans proline instead of the conserved cis proline active site loop. Remarkably, BcfH displays both thiol oxidase and disulfide isomerase activities contributing to Salmonella fimbrial biogenesis. Typically, oligomerization of bacterial Dsb proteins modulates their redox function, with monomeric and dimeric Dsbs mediating thiol oxidation and disulfide isomerization, respectively. The present study demonstrates a further structural and functional malleability in the thioredoxin-fold protein family. BcfH trimeric architecture and unconventional catalytic sites permit multiple redox functions emulating in bacteria the eukaryotic protein disulfide isomerase dual oxido-reductase activity.
    
    Speaker: Pramod Subedi (La Trobe University)
    
    almonella enterica BcfH Is a Trimeric Thioredoxin-Like Bifunctional Enzyme with Both Thiol Oxidase and Disulfide Isomerase Activities
- 14:00 → 15:00
  Instruments & Techniques
  - 14:00
    
    Precision Measurement of the Complex Fine Structure at the Australian Synchrotron 15m
    
    Current applications of X-ray Absorption Fine Structure (XAFS) to low absorbing samples such as ultra-thin films in semiconductor and nano-devices have been limited. This is expected to not be the case for the phase component of the fine structure as it is generally orders of magnitude larger than the absorption component in the x-ray regime. Here, we present details of precision measurements of both the phase and absorption components of the atomic fine structure across the K-edge of thin copper and iron foils. The experiments applied Fourier Transform Holography with an extended reference in spectroscopy mode and were conducted at the XFM and the SAXS/WAXS beamlines of the Australian Synchrotron. The results provide critical experimental benchmark for further theoretical development and has potential to delve into the phase equivalent of XAFS related techniques.
    
    Speaker: Tony Kirk (La Trobe University)
  - 14:15
    
    X-ray dark-field imaging without optics 15m
    
    X-ray image contrast can be generated via three mechanisms: (i) attenuation, (ii) phase contrast and (iii) most recently, the dark-field signal, which arises due to the incoherent scattering of the incident x-ray wavefield by unresolved sub-pixel features (microstructure) present in the sample. These contrast mechanisms can be realised using emerging x-ray imaging techniques, such as analyser-based and grid-based imaging, each of which require the use of specialised optics and carefully aligned setups. In this work, we focus on a technique which has not been used to capture quantitative dark-field contrast – propagation-based imaging. Propagation-based imaging requires no specialist optics and operates on the principle that phase variations induced in the x-ray wavefield by the sample manifest as intensity variations at the detector plane, some metres downstream, due to the self-interference of the wavefield. We describe a new approach to analysing propagation-based images, derived from the x-ray Fokker-Planck Equation, which enables dark-field images to be extracted. All that is required is two exposures, captured at two different propagation distances, which enable our algorithm to separate phase and dark-field effects to recover sample thickness and microstructure distribution. We demonstrate, using images captured at the Australian Synchrotron’s Imaging and Medical Beamline, that it is possible to capture dark-field images without having to introduce specialised optics or spend extensive time on optics alignment. This new technique could be applied to study biomedical microstructures, like the alveoli in the lung, or manufactured parts, capturing porosity or carbon fibre.
    
    Speaker: Mr Thomas Leatham (Monash University)
  - 14:30
    refnx - The Next Generation of Reflectometry Analysis Software 15m
    
    refnx [1] is a next generation reflectometry analysis package, building on its predecessor, Motofit. It has undergone a large amount of collaborative development over the last five years, introducing innovative features that greatly aid the national and international neutron and X-ray reflectometry community:
    
    a Bayesian statistics core with comprehensive uncertainty analyses and model selection ("how many layers can the data justify").
    
    quantitative introduction of prior information into the modelling system (information known from other sources)
    
    modular construction of structural models, ranging from a basic Slab up to freeform SLD profiles and Lipid membrane leaflets. These components are easily extensible.
    
    co-refinement of multiple contrast datasets.
    
    mixed Area models.
    
    Python based with analyses performed in Jupyter notebooks or a Qt GUI.
    
    Here we give a brief introduction to how these aspects advance the reflectometry technique. In addition, refnx is designed to enable reproducible research. We also discuss what reproducible research means in the context of a neutron scattering study, outlining how this is achieved with refnx, and how these practices could (should) be taken up by neutron scatterers in general.
    
    [1] Nelson, Andrew RJ, and Stuart W. Prescott. "refnx: neutron and X-ray reflectometry analysis in Python." Journal of applied crystallography 52.1 (2019): 193-200.
    
    Speaker: Andrew Nelson (ANSTO)
  - 14:45
    
    Micro-Computed Tomography (MCT) beamline at ANSTO/Australian Synchrotron: A progress report 15m
    
    The Micro-Computed Tomography (MCT) beamline is one of the first new beamlines to be constructed at the Australian Synchrotron as part of the BRIGHT program. MCT will complement the existing X-ray imaging/tomography capability provided by the Imaging and Medical Beamline (IMBL), and will target applications requiring higher (sub-micron) spatial resolution and involving smaller samples. MCT will be a bending-magnet beamline, operating in the 8 to 40 keV range, based on a double-multilayer monochromator. Filtered white and pink beams will also be available, the latter utilising a single-(vertical)bounce mirror. MCT will benefit from X-ray phase-contrast modalities (such as propagation-based, grating-based and speckle) in addition to conventional absorption contrast, and be equipped with a robotic stage for rapid sample exchange. A higher-resolution CT configuration based on the use of a Fresnel zone plate system will also be available. A number of sample environmental stages, such as for high temperature and the application of loads, are planned in collaboration with certain groups in the user community.
    
    Anticipated application areas for non-destructive 3D sample characterisation include biomedical/ health science, food, materials science, and palaeontology. This presentation will provide an update on the progress of the MCT project, including the procurement of three state-of-the-art X-ray detector systems, and the significant scientific-computing effort required to meet the demands of this high-performance imaging beamline.
    
    Speaker: Andrew Stevenson (Australian Synchrotron)
- 15:00 → 15:30
  
  Afternoon Tea 30m
- 15:30 → 17:05
  Chemistry, Soft Matter & Crystallography
  - 15:30
    
    Elucidating the Structures and Behaviour of Therapeutic Delivery Platforms with Non-interfering Techniques 20m
    
    Preamble: Anton is the Leader of the Applied Chemistry and Translational Biomaterials Group. His research focuses on the development of innovative chemistries, delivery systems and biotechnologies to address challenges in the biomedical, mining, and environmental sectors.
    Abstract: Self-assembled polymeric delivery platforms based on colloidal aggregates have promise for the delivery of therapeutics and cells, and their morphology in solution strongly influences their behaviour in a biological context (e.g., cellular uptake). In turn, the composition and microstructure of the individual polymers play a defining role in their self-assembly and the morphology of the resulting colloidal aggregates. Observing the behaviour and precise morphology of these systems in solution using non-interfering techniques allows them to be studied in their native state. In this presentation, Anton will discuss the application of diffusion nuclear magnetic resonance spectroscopy and Synchrotron small-angle X-ray scattering for the elucidation of colloidal aggregate structure and morphology.
    
    Speaker: Anton Blencowe (University of South Australia)
  - 15:50
    
    Quantifying the robustness of neutron reflectometry for analysing polymer brush structure 15m
    
    Surfaces covered with densely tethered polymer chains possess desirable properties and are ubiquitous in natural and human-made systems. These properties stem from the diffuse structure of these polymer brush interfaces; consequently, resolving their structure is key to designing systems with better performance. NR has been widely used for studying these systems as it is the only technique that can resolve the detailed structure of these films, the polymer volume fraction profile.
    
    However, the analysis of collected reflectometry data has significant challenges; inflexible models preclude viable structures and the uncertainty around accepted profiles (spread) is challenging to quantify. Furthermore, there is no guarantee of profile uniqueness in reflectivity analysis - multiple structures may match the data equally well (multimodality). Quantifying these uncertainties has not been attempted on brush systems, but is a vital part of validating the application of NR for structural characterisation. Historically, data analyses have used least-squares approaches, which can’t satisfactorily determine profile uncertainty.
    
    Here we outline the methodology we have developed for modelling NR data. We model our brush with a freeform profile that minimises assumptions regarding polymer conformation while enforcing physically reasonable structures. We employ a Bayesian statistical framework that enables the characterisation of structural uncertainty and multimodality through Markov Chain Monte Carlo sampling. The Bayesian approach lets us introduce prior knowledge into the analysis procedure; the amount of grafted polymer should remain constant under different conditions.
    
    The rigour of our approach is demonstrated via a round-trip analysis of a simulated system, as well as data collected on thermoresponsive brushes. A low level of uncertainty was observed, confirming the validity of NR for examining polymer brush systems.
    
    Speaker: Dr Andrew Nelson (ANSTO)
  - 16:05
    
    Muti-Scale Dynamic Study on The Amphiphilic Nanostructure of Protic Ionic Liquids 15m
    
    Ionic liquids are a novel class of solvents with ultra-low vapour pressure and tunable liquid properties. Among them, protic ionic liquids (PILs) are particularly effective solvents for self-assembly of surfactants and lipids into micelles, vesicles, liquid crystals and microemulsions. This is exemplified by alkylammonium PILs, which are also cheap, easily prepared and can be readily deuterated. Over the past decade, much is learnt about the static structure of alkylammonium PILs, however, virtually nothing is known about their dynamics, both the single ion diffusion and the collective motion of clusters. This is due to the complex and disordered nature of liquid nanostructure, which is expected to display a range of dynamic behaviors on different time and length scale. In this study, we have examined ethanolammonium nitrate, ethylammonium nitrate and propylammonium nitrate, using a variety of dynamic techniques. We employed multi-contrast wide-angle neutron spin echo spectroscopy (WASP, ILL) to capture the nanosecond relaxations across 0.1 – 1.4 Å^-1, and pulse-field gradient NMR to track molecular diffusion. Combined with their known averaged liquid nanostructures, we have now characterized the static and dynamic nanostructure of three protic ionic liquids, carefully chosen to demonstrate different degrees of ordering, at multiple temperatures. This allows us to understand the structure-property relationship of alkylammonium PILs across a wide space and time scale, which has the potential to unlock rational design of job-specific PIL-based solvent systems.
    
    Speaker: Shurui Miao (The University of Sydney)
  - 16:20
    Maximum flux: Using time-resolved neutron reflectometry to improve our understanding of surface-initiated polymerisation 15m
    
    Polymer brushes are dense arrays of surface-tethered polymers that possess desirable qualities, such as lubricity and fouling resistance, provided that their structure and chemistry are correctly tuned [1]. Surface-initiated polymerisation (SIP) is the primary method for synthesising these brushes with the physicochemical properties required to imbue surfaces with the aforementioned qualities. However, previous work [2,3] indicates that polymers synthesised by SIP deviate from polymers produced via solution polymerisation, likely due to the proximity of initiators in the tethered case. This deviation is not well understood, which impedes the structural characterisation of the resulting brushes. As structure dictates behaviour [1], understanding the nature of the brushes produced by SIP facilitates the rational design of functional brush coatings.
    
    Here we present a study of brushes synthesised via SIP of the well-characterised polymer poly(N-isopropyl acrylamide) (PNIPAM) using time-resolved neutron reflectometry (NR). First, we demonstrate that we can control the polymer initiator density and examine the relationship between molecular weight and grafting density. We then observe a series of SIP reactions from surfaces with different initiator densities in situ using time-resolved NR. To our knowledge, this is the first time that the structure of a growing polymer brush has been directly observed. The results confirm that a high initiator density leads to poor control early in the reaction, and explain several phenomena observed by previous NR experiments [4,5]. This experiment paves the way for further kinetic experiments on Platypus and will be of interest to anyone interested in the dynamic assembly of interfaces over timescales of 10 minutes to several hours.
    
    10.1021/acs.macromol.7b00450
    
    10.1021/acs.macromol.5b02261
    
    10.1021/acs.macromol.7b01572
    
    10.1021/acs.macromol.6b01001
    
    10.1021/acs.langmuir.0c01502
    
    Speaker: Isaac Gresham (The University of New South Wales)
  - 16:35
    
    Elucidation of the electronic structure in lanthanoid-radical systems by inelastic neutron scattering 15m
    
    Single-molecule magnets (SMMs) are metal organic compounds which exhibit magnetic hysteresis and slow magnetic relaxation at low temperature. They have potential applications in high density data storage, quantum computing, and molecular spintronics. Coordination complexes of the trivalent lanthanoid (Ln(III)) ions are the current best performing SMMs, with examples showing hysteresis above liquid nitrogen temperature.[1]
    
    The magnetic properties of Ln(III) ions stems from the crystal field (CF) splitting of the ground Russel-Saunders state. These CF states give rise to the energy barrier to reversal of magnetisation, and can be tuned by modification of the ligand environment around the Ln(III) centre. Slow magnetic relaxation in Ln-SMMs can also be modulated by the introduction of magnetic exchange coupling with another magnetic moment, such as that of an organic radical ligand.[2] Quantifying the magnitude of magnetic exchange coupling in many Ln(III) systems is, however, difficult using conventional magnetometric techniques, due to the often large spin-orbit coupling.
    
    Inelastic neutron scattering (INS) is an ideal spectroscopic tool to measure both CF splitting and magnetic exchange coupling in Ln(III) systems.[3] We have used INS measurements to elucidate the magnetic exchange coupling and CF splitting in Ln(III)-semiquinonate complexes. Using this information we have rationalised the magnetic properties of these compounds, with the hope that a better understanding of the magnetic exchange in these systems can be used to design SMMs with improved performance.
    
    [1] Guo et al. Science 2018, 362 (6421), 1400–1403
    [2] Demir et al. Coord. Chem. Rev. 2015, 289–290, 149–176
    [3] Dunstan et al. Eur. J. Inorg. Chem. 2019, 8, 1090–1105
    
    Speaker: Maja Dunstan (University of Melbourne)
  - 16:50
    Characterisation of Ionic Liquids and Their Ability to Stabilise Proteins 15m
    
    Proteins are an important part of biotechnology and can be utilised for a range of applications and industries1. But the stability and solubility of the protein is often a limiting factor, so ionic liquids (ILs) have been tested as an alternative solvent due to their wide scope and tailorable properties. They are reported to increase protein activity2, solubility, long term and thermal stability. However, the relationship between the structure of an IL and how it interacts with proteins in solution is unknown.
    In this study 52 ammonium based ILs and 14 common salts were prepared with HEWL and human lysozyme. Physicochemical, and thermal properties of the neat ILs were characterised, while SAXS was used to characterise protein stability. High concentrations of IL (>50 mol%) were often not conducive with the native structure of the protein, while lower concentrations (1-10 mol%) can support native protein structures with minimal to no aggregation. It was also found that additional alkyl chains on the cation, and the presence of hydroxyl groups reduced lysozyme’s radius of gyration, preserving its native structure.
    
    Egorova, K. S.; Gordeev, E. G.; Ananikov, V. P., Biological Activity of Ionic Liquids and Their Application in Pharmaceutics and Medicine. Chemical Reviews 2017, 117 (10), 7132-7189.
    
    Mann, J. P.; McCluskey, A.; Atkin, R., Activity and thermal stability of lysozyme in alkylammonium formate ionic liquids—influence of cation modification. Green Chemistry 2009, 11 (6), 785-792.
    
    Speaker: Stuart Brown (RMIT)
- 15:30 → 17:05
  Earth, Environment & Cultural Heritage
  - 15:30
    
    From deep time to the present: An exploration of Aboriginal connections to South Australia’s Riverland region 20m
    
    This keynote address will explore a range of cultural heritage projects relating to collaborations between ANSTO, Flinders University and the River Murray and Mallee Aboriginal Corporation. From rare artefacts to earthen cooking mounds and ancient shell middens this presentation considers the contribution of radiocarbon dating within a broader research program that has investigated Aboriginal connections to Country from deep time to the present in South Australia’s Riverland region.
    
    Speaker: Prof. Amy Roberts (Flinders University)
  - 15:50
    
    The structure and spectroscopy of solid propanal: A potential mineral for planetary astrobiology 15m
    
    Aldehydes are considered an important species toward astrobiology, acting as a primary reagent for the Strecker synthesis of amino acids in aqueous media. However, within the cold, icy surfaces of planetary bodies and interstellar dust particles, chemical reactions that lead to these biological-building blocks can still unfold. Here, "non-thermal equilibrium" chemistry is driven by harsh radiation environments, which produce populations of radicals and charged species in the icy matrix. It is these short-lived intermediates that then on-react with ammonia and cyanides to form of higher-order organics.
    
    For the possible detection of proteinogenic amino acids in space environments it is important to first locate their more abundant amino acid precursors. However, only formaldehyde and acetaldehyde has been observed by telescope and spacecraft reconnaissance to date. The search for other simple aldehydes has been hampered by a general lack of fundamental data including crystal structure and spectroscopic signatures.
    
    In a combined neutron scattering (ANSTO Wombat Instrument) and x-ray diffraction study, we have determined the crystal structure of propanal (CH3CH2CHO)-under planetary ice surface conditions-for the first time. This new structure allowed for the DFT simulation of its vibrational frequencies, which was then applied to assign its far-infrared spectrum collected at the Australian Synchrotron THz Beamline. This critical structural and spectroscopic data will enable the search for this species during future surveys and spacecraft exploration of distant icy worlds in our quest to uncover the molecular origins-of-life.
    
    Speaker: Courtney Ennis (University of Otago)
  - 16:05
    
    Pioneer plant driven primary mineral weathering and secondary mineral formation in Fe ore tailings 15m
    
    Eco-engineering tailings into soil-like substrates is an emerging technology to rehabilitate the tailings landscapes. Pioneer plants play an important role in mineral weathering and secondary mineral formation, which are pre-requisites for aggregate formation and pedogenesis in the tailings. The present study aimed to characterise the direct role of pioneer plant roots in tailing mineral weathering and secondary mineral formation in a compartmented cultivation system [1]. It was found that root activities accelerated the weathering of Fe bearing primary minerals (e.g., biotite) via Fe(II) oxidation coupled with Fe(III) and Si dissolution. Numerous nanosized Fe-Si rich amorphous minerals and vermiculite were neo-formed in the tailings subject to rhizosphere activities, as revealed by various micro-spectroscopic analysis. The Fe-Si rich secondary amorphous minerals may have resulted from co-precipitation of dissolved Fe(III) and Si on mineral surfaces under alkaline and circumneutral pH conditions. The roots of Gramineae plant Sorghum spp. developed most extensively in the tailings, leading to more efficient mineral weathering and secondary mineral formation than Halophyte plant Atriplex amnicola and Leguminous plant Acacia chisholmii. Overall, the study has unravelled the pioneer plant role in tailing mineral (biotite dominant) weathering and secondary Fe-Si mineral formation. These findings also indicate that tolerant pioneer plants may act as integral components in designing the eco-engineering processes for soil formation in Fe ore tailings.
    References:
    [1] Wu, S., Liu, Y., ... & Huang, L. (2021). Rhizosphere Drives Biotite-Like Mineral Weathering and Secondary Fe–Si Mineral Formation in Fe Ore Tailings. ACS Earth and Space Chemistry, 5(3), 618-631.
    
    Speaker: Dr Songlin Wu (The University of Queensland)
  - 16:20
    
    Cuatros Amigos- the four stromatolites in a row. The first 3D image of the oldest evidence of life in the geologic record 15m
    
    The 3.48 Ga Dresser Formation, Pilbara Craton, Western Australia provides the Earth’s most convincing evidence of early life through a diverse array of biosignatures. However, identifying biosignatures in Archean rocks is difficult due to billions of years of erosion, deformation, and metamorphic alteration. Characterisation of community-accepted biosignatures also remains challenging, particularly the robustness of textural biosignatures as indicators of early life in Archean rocks. The textural biosignatures identified in the Dresser Formation are identified in surface outcrops that are weathered. Therefore, in May 2019, fresh Dresser deposits were drilled to aid in a better understanding of these ancient biosignatures and to provide validity to a biogenic origin.
    
    Three well-preserved cores of 5-30 m thickness and 8 cm in diameter were extracted from ~70 m beneath the land surface. The cores provide excellent preservation of biosignatures, including the preservation of fossilized, pyritized, stromatolites. One stromatolite horizon within the core exhibits extraordinary morphological structures. Here we present preliminary results of the 3D geometry of these fossil stromatolites. 3D structures were obtained using the neutron imaging station DINGO at ANSTO. A full tomography of a first sample has been scanned with 1896 projection with an angular step of 0.19° and an exposure time of 60 seconds per projection. The data was reconstructed using filtered backprojection technique with Pydingo (a free in-house developed python toolbox). 3D-rendering was done with VG-Studio. This horizon aids in better defining the biogenicity of these textural biosignatures.
    
    Speaker: Ms Michaela J Dobson (The University of Auckland, ANSTO)
  - 16:35
    
    High-resolution high throughput thermal neutron tomographic imaging of fossiliferous cave breccias from Sumatra 15m
    
    We employ high-throughput thermal-neutron tomographic imaging to visualise internal diagnostic features of dense fossiliferous breccia from three Pleistocene cave localities in Sumatra, Indonesia. We demonstrate that these seemingly homogeneous breccias are an excellent source of data to aid in determining taphonomic and depositional histories of complex depositional sites such as tropical caves. X-ray Computed Tomographic (CT) imaging is gaining importance amongst palaeontologists as a non-destructive approach to studying fossil remains. Traditional methods of fossil preparation risk damage to the specimen and may destroy contextual evidence in the surrounding matrix. CT imaging can reveal the internal composition and structure of fossils contained within consolidated sediment/rock matrices prior to any destructive mechanical or chemical preparation. Neutron tomography (NT) provides an alternative contrast to X-rays, and in some circumstances, is capable of discerning denser matrices impenetrable to or yielding no contrast with CT imaging. High throughput neutron imaging reduces neutron fluence during scanning which means there is less residual neutron-induced radioactivation in geological samples; allowing for earlier subsequent analyses. However, this approach remains unutilised in palaeontology, archaeology or geological surveys. Results suggest that the primary agents in the formation of the breccias and concentration of incorporated vertebrate remains are several rapid depositional phases of water and sediment gravity flow. This study highlights the potential for future analyses of breccia deposits in palaeontological studies in caves around the world.
    
    Speaker: Ms Holly Ellen Smith (Griffith University)
  - 16:50
    
    Pressure-dependent changes in Zr coordination in silicate liquid: in vs. ex situ measurements 15m
    
    Changes in the coordination of elements in silicate melts as a function of pressure impact their geochemical behaviour and are key to understanding processes such as planetary differentiation. Questions persist as to the extent to which the coordination environment of elements in silicate melts at high pressure and temperature can be preserved in glasses recovered to ambient conditions.
    
    The only method to unambiguously measure the coordination environment of trace elements in a silicate liquid at high pressure is via in situ measurements such as x-ray absorption spectroscopy, preferably in large volume apparatus that can simulate the environment of the upper mantle such as the Macquarie D-DIA apparatus. These measurements are difficult and only possible at a handful of facilities worldwide, so most experimental data are derived from ex situ measurements of recovered glasses.
    
    We made Zr K-edge XANES measurements in situ at conditions simulating the mantle, showing a pressure-dependent change consistent with an earlier ex situ study on samples recovered from piston-cylinder experiments in which glasses were annealed close to their glass transition temperature (Burnham et al. 2019). We plan further XAS experiments measuring samples recovered from our in situ experiments to determine the differences between quenched glasses, annealed glasses, and in situ measurements.
    
    We propose that changes in Zr XANES correspond to an increase in the coordination number of Zr with pressure. This could explain previously observed changes in Zr solubility at high pressure not predicted by current models, and changes in Zr olivine/melt partition coefficients at mantle pressures.
    
    Speaker: Nicholas Farmer (Macquarie University)
- 15:30 → 17:05
  Physics, Surface & Condensed Matter
  - 15:30
    
    Good vibrations: phonons in topological thermoelectrics 20m
    
    Thermoelectric materials harness a temperature gradient to produce a voltage via the Seebeck effect, providing a way to harvest and recycle heat. Recently a new generation of thermoelectrics has been developed that offer unprecedented performance by leveraging topological physics. The key to their functionality is their robust high electronic conductivity in tandem with their low thermal conductivity. The latter can be engineered by controlling the lattice vibrations or “phonons”. Here I will discuss recent neutron spectroscopy experiments at the Australian Centre for Neutron Scattering, ANSTO, which offer unique insights into the differences between “good” optical and “bad” acoustic phonon vibrations in thermoelectrics. I will show how these experiments are complemented by large-scale molecular dynamic simulations on the GADI supercomputer within the National Computing Infrastructure. Time permitting, I will also briefly demonstrate how we use the Centre for Accelerator Science and neutron reflectometry to enable surface-engineering in these novel crystals for microelectronic applications.
    
    References:
    N. Islam, D. L. Cortie et, Acta Materialia 215, 117026 (2021)
    W. Zhao, Cortie, Wang et al, Physical Review B 104 (8), 085153 (2021)
    D.L et al. Cortie Applied Physics Letters 116 (19), 192410 (2020)
    
    Speaker: Dr David David Cortie
  - 15:50
    
    Characterization of MOSFET sensors for dosimetry in alpha particle therapy 15m
    
    Alpha particle therapy, such as diffusing alpha-emitters radiation therapy (DaRT) and targeted alpha-particle therapy (TAT), exploits the short-range and high linear energy transfer (LET) of alpha particles to destroy cancer cells locally with minimal damage to surrounding healthy cells. Dosimetry for DaRT and TAT is challenging, as their radiation sources produce mixed radiation fields of α particles, β particles, and γ rays. There is currently no dosimeter for real-time in vivo dosimetry of DaRT or TAT. Metal-oxide-semiconductor field-effect transistors (MOSFETs) have features that are ideal for this scenario. Owing to their compactness, MOSFETs can fit into fine-gauge needle applicators, such as those used to carry the radioactive seeds into the tumour. This study characterized the response of MOSFETs designed at the Centre for Medical and Radiation Physics, University of Wollongong. MOSFETs with three different gate oxide thicknesses (0.55 µm, 0.68 µm, and 1.0 µm) were irradiated with a 5.5 MeV mono-energetic helium ion beam (He2+) using SIRIUS 6MV accelerator tandem at the Australian Nuclear Science and Technology Organization (ANSTO) and an Americium-241 (241Am) source. The sensitivity and dose-response linearity were assessed by analysing the spatially resolved median energy maps of each device and their corresponding voltage shift values. The results showed that the response of the MOSFET detectors was linear with alpha dose up to 25.68 Gy. Also, it was found that a gate bias of between 15 V and 60 V would optimize the sensitivity of the detectors to alpha particles with energy of 5.5 MeV.
    
    Speaker: Ms Fang-Yi Su (Centre for Medical Radiation Physics, University of Wollongong)
  - 16:05
    
    Magnetic Ordering in Superconducting Sandwiches 15m
    
    Our cuprate-manganite ‘superconducting sandwich’ multilayers exhibit a highly unusual magnetic-field induced insulating-to-superconducting transition (IST), contrary to the commonly held understanding that magnetic fields are detrimental to superconductivity [1, 2]. This new behaviour is a result of the specific magnetic and electronic properties of the manganite coupling with the high-Tc cuprate (YBa2Cu3O7-δ, YBCO). Due to the specific manganite composition, Nd0.65(Ca0.7Sr0.3)0.35MnO3 (NCSMO), we hypothesize the behaviour to originate from CE-type antiferromagnetic ordering as well as charge and orbital ordering [3].
    
    The magnetic data presented here will focus on polarized neutron reflectometry (PNR) and elastic neutron scattering on a YBCO-NCSMO trilayer and superlattice. The model that best described the PNR data for the trilayer had antiparallel moments at the YBCO-NCSMO interfaces. In the superlattice, the direction of moments at NCSMO interfaces were found to alternate with film depth whose long-ranged ordering was broken below 35 K in a 1 T applied field. The stability of the AFM order in the superlattice was further supported by a robustness of magnetic in-plane half-order elastic scattering peaks at 9 T. This evidences the interplay of magnetism and superconductivity that play a role in realizing the IST effect in our superconducting sandwiches.
    
    REFERENCES
    [1] B. Mallett et al. Phys. Rev. B. 94, 180503(R) (2016)
    [2] E. Perret et al. Comms. Phys. 45, 1-10 (2018)
    [3] Y. Tokura. Rep. Prog. Phys. 69, 797-851 (2006).
    
    Speaker: Andrew Chan (The University of Auckland)
  - 16:20
    
    Neutron and synchrotron characterisation techniques for hydrogen fuel cell materials 15m
    
    Hydrogen fuel cells and other renewable energy technologies have specific materials and functional needs which can be more fully understood using neutron and synchrotron characterisation techniques. In this presentation, a materials which has applications in proton exchange membranes is studied with a variety to techniques to develop a comprehensive understanding of the functional-structural relationship. The materials used here is phosphotungstic acid (HPWA) stabilised in an ‘inert’ mesoporous silica host material. This aim of this research is to develop an understanding of the interaction between the HPWA and the silica and whether different structures or surface chemistries have advantageous or detrimental effects.
    Two silica symmetries used were Ia3 ̅d (face centred cubic bi-continuous) and P6mm (2D hexagonal with cylindrical pores) which were vacuum impregnated with solutions of HPWA in a range of concentrations. The resulting powder samples were then analysed using small angle x-ray scattering (SAXS), inductively coupled plasma emissions spectroscopy (ICP-OES), nitrogen gas adsorption/desorption, near edge X-ray absorption fine structure (NEXAFS/X-ray absorption near edge structure/XANES) of the O and Si k-edges, Fourier transform infra-red spectroscopy (FTIR), Raman spectroscopy, and then formed into a disk using polyethylene as the binder for electrical impedance spectroscopy (EIS).
    The insights gained from this systematic study indicate that the surface chemistry of the silica host has a significant effect on the performance, uptake and interactions with the HPWA anions, where lower concentrations of HPWA result in stronger host:HPWA interactions but lower conductivity
    
    Speaker: Krystina Lamb (ANSTO)
  - 16:35
    
    Towards fast dose calculations for novel radiotherapy treatments with generative adversarial networks 15m
    
    Introduction
    Existing approximations used in clinical treatment planning are either not fast or not accurate enough for some novel irradiation techniques like microbeam radiation therapy (MRT), which relies on arrays of sub-mm synchrotron-generated, polarized X-ray beams. We present studies using generative adversarial networks (GANs) to mimic full Monte Carlo simulations of radiation transport to achieve a compromise of fast and accurate dose computation for variable phantoms and irradiation scenarios.
    
    Materials & Methods
    To obtain a generalised model for the dose prediction a conditional GAN using a 3D-UNet architecture is developed. As proof of concept, we predict the simulated dose depositions of a bone slab inside a water phantom with variable rotation angles and thicknesses. Subsequently, we demonstrate that our model is generalisable by applying it to a simplified head phantom simulation.
    All Monte Carlo simulations are performed with Geant4 using a phase space file obtained from a validated simulation at the Australian Synchrotron.
    
    Results
    The trained model predicts for both the bone slab inside the water phantom and the simple head phantom dose distributions with deviations of less than 1% of the maximum dose for over 94% of the simulated voxels in the beam. Dose predictions near material interfaces are accurate on a voxel-by-voxel basis with less than 5% deviation in most cases. Dose predictions can be produced in less than a second on a desktop PC compared to approximately 50 CPU hours needed for the corresponding Geant4 simulation.
    
    Speaker: Florian Mentzel
- 17:05 → 17:35
  
  Update: AINSE
Thursday, 25 November
- 09:00 → 09:15
  
  Welcome Address: Day 2 Opening Remarks
- 09:15 → 09:45
  
  Awards: UAC | Research Award
- 09:45 → 10:15
  
  Awards: Stephen Wilkins Medal
- 10:15 → 10:45
  
  Morning Tea 30m
- 10:45 → 12:20
  Advanced Materials
  - 10:45
    
    Delivery of antimicrobials to bacteria by cubosome nanocarriers 20m
    
    Dyett, B.; Meikle, T.G.; Yu, H.; Strachan, J.B.; Lakic, B.; White, J.; Drummond, C.J. and Conn, C.E
    
    The increasing prevalence of antibiotic resistant bacteria, in part due to overuse and misuse of antibiotics over the past decades, is one of the key global health challenges. Some gram-negative strains have already been found to be resistant even to last resort antibiotics. This is partially due to their ability to hinder the transport of antimicrobials through their outer membrane structure. One proposed strategy to combat this issue is via the use of lipid nanocarriers as drug delivery vehicles. These nanocarriers are known to interact with the outer lipid membrane via a unique fusion-type mechanism which can improve transport of antimicrobials into Gram-negative bacteria (Figure 1). In this talk I will discuss the mechanism of interaction of cubosome lipid nanocarriers with both Gram-positive and Gram-negative bacteria and discuss recent advances in the use of lipid-based nanocarriers to deliver antibiotics.
    Synchrotron SAXS is used to characterise the internal nanostructure of the particles before and after encapsulation of a range of antimicrobials including metal nanocrystals,[1] antimicrobial peptides [2] and small molecule drugs.[3] Synchrotron CD is used to confirm retention of secondary structure following encapsulation for antimicrobial peptides.[2] The mechanism of uptake of cubosomes into both Gram-positive and Gram-negative bacteria is demonstrated using TIRF microscopy in combination with synchrotron FTIR.[3.4] Fundamental differences in the uptake mechanism between Gram-positive and Gram-negative bacteria will be described.[3]
    
    (more)
    
    Speaker: Charlotte Conn (RMIT)
  - 11:05
    
    Chemical expansion and proton conductivity in vanadium-substituted variants of γ-Ba4Nb2O9 15m
    
    Complex perovskite derived oxides are an important emerging class of ionic conducting materials with potential applications in energy technologies including fuel cells, batteries, and separation membranes. The high temperature phase γ-Ba4Nb2O9 is one such complex oxide which shows proton and oxide ionic conduction.
    
    Recently we have shown that two new compositional series with the previously unique γ-Ba4Nb2O9 type structure, γ-Ba4VxTa2-xO9 and γ-Ba4VxNb2-xO9 (x = 0-2/3),can form [1]. Undoped Ba4Ta2O9 forms a 6H-perovskite type phase, but with sufficient V doping the γ-type phase is thermodynamically preferred and possibly more stable than γ-Ba4Nb2O9, forming at a 200 °C lower synthesis temperature. This is explained by the fact that Nb5+ ions in γ-Ba4Nb2O9 simultaneously occupy 4-, 5- and 6-coordinate sites in the oxide sublattice, which is less stable than allowing smaller V5+ to occupy the former and larger Ta5+ to occupy the latter. We characterised the structures of the new phases using a combination of X-ray and neutron powder diffraction. All compositions hydrate rapidly and extensively (up to 1/3 H2O per formula unit) under ambient conditions, like the parent γ-Ba4Nb2O9 phase, and show moderate but improved mixed-ionic electronic conduction. At lower temperatures the ionic conduction is significantly protonic, where hydration is maintained. We also show that these new vanadium containing phases have higher total conductivities than the parent γ-Ba4Nb2O9 compound.
    
    [1] AJ Brown, B Schwaighofer, M Avdeev, B Johannessen, IR Evans and CD Ling, Chemistry of Materials, available online (2021). DOI: 10.1021/acs.chemmater.1c02340
    
    Speaker: Mr Alex Brown (The University of Sydney)
  - 11:20
    
    Shape of nanopores in track-etched polycarbonate membranes 15m
    
    Small angle X-ray scattering (SAXS) has been used over the past decade for characterizing track etched nanopores in a variety of organic and inorganic materials. In the present study, synchrotron based SAXS was used to study the morphology and size variation of the nanopores in polycarbonate (PC) as a function of the etching time and ion fluence. The shape of the nanopores fabricated through track-etch technology was found to be consistent with cylindrical pores with ends tapering off towards the two polymer surfaces in the last ~1.6 μm. The tapered structure of the nanopores in track-etched PC membranes was first observed more than 40 years ago followed by many other studies suggesting that the shape of nanopores in PC membranes deviates from a perfect cylinder and nanopores narrow towards both membrane surfaces. However, quantification of the shape of nanopores has remained elusive due to inherent difficulties in imaging the pores using microscopy techniques. This study reports on the quantitative measurement of the tapered structure of nanopores using SAXS[1]. Determination of this structure was enabled by obtaining high-quality SAXS data and the development of appropriate form-factor model. The etch rates for both the radius at the polymer surface and the radius of the pore in bulk were calculated. Both etch rates decrease slightly with increasing fluence. This behavior is ascribed to the overlap of track halos which are characterized by cross-linking of the polymer chains. The results enable a better understanding of track-etched membranes and facilitate improved pore design for many applications.
    
    References:
    [1] Dutt, S. et al. J. Membr. Sci. 638, 119681 (2021)
    
    Speaker: Shankar Dutt (Australian National University)
  - 11:35
    
    Application of Inelastic Neutron Scattering for Thermoelectric Materials Study 15m
    
    Research on thermoelectric (TE) materials have been an active field for the past decade as TE material can potentially be used in many niche areas such as to power space probe and convert waste-heat into electricity. Continuing developments are undergoing in the search for advanced TE materials that could play significant role in sustainable technology. One of the strategies in improving the performance of a thermoelectric material is to decrease the thermal conductivity, which is directly related to the lattice dynamics of the materials. Measurement of phonon density of states and phonon dispersion as a function of temperature can provide deep insight of the thermal conductivity in terms of, for example, anharmonic vibrations and low energy rattling modes. PELICAN, a time of fight neutron spectrometer at ACNS, has been actively used for such kind of studies. In this presentation, I will give a brief introduction and the current status of TE material research, followed by the link to material lattice dynamics and explore how inelastic neutron scattering can help in fundamental understanding of the thermoelectric properties with a couple of study cases.
    
    Speaker: Dehong Yu (Australian Nuclear Science and Technology Organisation)
  - 11:50
    
    Origin of vertical slab orientation in blade-coated layered hybrid perovskite films revealed with in-situ synchrotron X-ray scattering 15m
    
    Controlling the vertical orientation of perovskite slabs in layered hybrid perovskite films is key for enabling further optimization of photovoltaic device performance. However, the mechanism explaining vertical orientation control in such films remains under debate. Here, we present an in-situ grazing-incidence wide-angle X-ray scattering (GIWAXS) study on the formation of BA2MAn-1PbnI3n+1 perovskite films during blade-coating where BA, MA and n denote butylammonium, methylammonium and thickness of perovskite slabs. The evolution of grazing-incidence transmission wide-angle X-ray scattering (GTWAXS) signal is also monitored to reveal the specific vertically-oriented low-n phases formed in such films. We find that the blade-coating temperature greatly influences the crystallization dynamics of BA2MAn-1PbnI3n+1 perovskite films and perovskite slab orientation via intermediate phase and low-n phase formation. For the perovskite film with targeted dimensionality of n = 4, blade-coating films at higher temperatures suppresses the formation of the 2MAI∙3PbI2∙2DMF intermediate phase. This in turn suppresses the formation of the n = 2 phase that adopts an undesired horizontal perovskite slab orientation, instead favouring the formation of the n = 3 phase that adopts the desired vertical perovskite slab orientation. Further analysis on the microstructural evolution of films with near-perfect vertical orientation reveals that the formation mechanism proceeds through several stages: (i) sol-gel, (ii) weakly-texture 3D-like perovskite, (iii) n = 3 phase, and finally, (iv) crystallite reorientation into the near-perfect texture. The findings from this in-situ simultaneous GIWAXS and GTWAXS study provide improved understanding of the film formation mechanism for layered hybrid perovskite films with near-perfect vertical orientation.
    
    Speaker: Mr Wen Liang Tan (Monash University Australia)
- 10:45 → 12:20
  Biomedicine, Life science & Food Science
  - 10:45
    
    Membrane permeabilisation is mediated by distinct epitopes in mouse and human orthologs of the necroptosis effector, MLKL 15m
    
    Necroptosis is a lytic programmed cell death pathway with origins in innate immunity that is frequently dysregulated in inflammatory diseases. The terminal effector of the pathway, MLKL, is licensed to kill following phosphorylation of its pseudokinase domain by the upstream regulator, RIPK3 kinase. Phosphorylation provokes the unleashing of MLKL’s N-terminal four-helix bundle (4HB or HeLo) domain, which binds and permeabilises the plasma membrane to cause cell death. The precise mechanism by which the 4HB domain permeabilises membranes, and how the mechanism differs between species, remains unclear. Here, we identify the membrane binding epitope of mouse MLKL using NMR spectroscopy. Using liposome permeabilisation and cell death assays, we validate K69 in the α3 helix, W108 in the α4 helix, and R137/Q138 in the first brace helix as crucial residues for necroptotic signaling. This epitope differs from the phospholipid binding site reported for human MLKL, which comprises basic residues primarily located in the α1 and α2 helices. In further contrast to human and plant MLKL orthologs, in which the α3-α4 loop forms a helix, this loop is unstructured in mouse MLKL in solution. Together, these findings illustrate the versatility of the 4HB domain fold, whose lytic function can be mediated by distinct epitopes in different orthologs.
    
    Speaker: Chris Horne (WEHI)
  - 11:00
    
    Disulfide bond formation between T-cell receptor and peptide antigen lowers the threshold of T cell activation 15m
    
    The immune system is vigilant in detecting foreign pathogens. Our cells present peptides (p), small fragments of proteins, atop Major Histocompatibility Complex (MHC) glycoproteins. These pMHC molecules are displayed on the cell’s surface and monitored by T cells of the immune system that patrol the body. T cells use their specialized T cell receptors (TCRs) to recognize and bind to pMHCs, where the quality of binding influences T cell activation. Activated T cells are responsible for killing off infected cells and clearing infection. The contribution of individual parameters that dictate activation for this cell-to-cell TCR-pMHC interaction are unclear. However, a long reigning hypothesis is that the threshold of T cell activation can be determined by the dissociation constant or binding affinity. We have engineered a disulfide bond (DSB) between two cysteine residues introduced into a TCR and peptide that are known to form a TCR-pMHC complex. The formation of the DSB was validated using biophysical assays and X-ray crystallography. This approach represents a model in which the covalently bonded TCR-pMHC do not dissociate, prolonging the confinement time of the interaction almost indefinitely. When this TCR and pMHC model were reproduced in T cells, we discovered that the DSB interaction was 10,000-fold more sensitive in activating T cells than the wild-type counterpart without altering binding affinity. Thus, we show that confinement time plays an important role in the activation of T cells, which could be useful in designing T cell therapies or peptide vaccines.
    
    Speaker: Dr Christopher Szeto (La Trobe Institute for Molecular Science)
  - 11:15
    
    A Comparison of Different Approaches to Image Quality Assessment in Phase-Contrast Mammography 15m
    
    Propagation-based phase-contrast computed tomography (PB-CT) has the potential to improve breast cancer detection and characterisation compared to established mammography techniques. The aim of this work is to find a quantitative image quality metric which could accurately predict the subjective clinical image quality assessment of PB-CT images made by radiologists as described in Taba et al. [1].
    
    The experimental data analysed in this study included PB-CT scans, which were obtained for 12 full intact mastectomy samples at Imaging and Medical beamline (IMBL) of the Australian Synchrotron at different monochromatic X-ray energies and clinically relevant radiation doses. Quantitative image quality metrics including visibility, signal to noise ratio (SNR), and spatial resolution, were calculated for all PB-CT and conventional CT image sets using the open-source 3D Slicer (https://www.slicer.org/) software. For each metric, an objective image quality “score” was generated to match the subjective scoring provided by the radiologists. Weighting factors were then applied to the scores and a weighted contrast to noise to resolution (CNR/res) score was calculated.
    
    The unscaled contrast and spatial resolution scores were both found to have a significant correlation with the radiologists’ scores with R values of 0.9223 and 0.8360 respectively, while SNR had an insignificant correlation, with an R value of -0.6785. The weighted CNR/res score showed a significant correlation to the radiologists’ scores with an R value of 0.9681.
    
    [1] S. T. Taba et al., Academic radiology 28.1 (2021): e20-e26.
    
    Speaker: Jesse Reynolds (University of Canterbury)
  - 11:30
    
    Human MLKL is maintained by RIPK3 in an inactive conformation prior to disengagement and cell death by necroptosis 15m
    
    Necroptosis is a caspase-independent form of programmed cell death that results in the compromise of plasma membranes and release of inflammatory cellular contents. Dysregulated necroptosis has been shown to play a role in a range of different human pathologies, including ischemia-reperfusion injury, inflammatory diseases, and inflammatory bowel disease. Phosphorylation of MLKL by the RIPK3 kinase leads to MLKL oligomerization, translocation to, and permeabilization of, the plasma membrane to induce necroptotic cell death. The precise choreography of MLKL activation remains incompletely understood. Here, we used Monobodies, synthetic binding proteins, that bind the pseudokinase domain of MLKL to detect endogenous protein interactions within human cells. We showed that MLKL is stably bound by RIPK3 prior to their disengagement upon necroptosis induction. Crystal structures of MLKL pseudokinase domain in complex with two different monobodies or RIPK3 kinase domain identified two distinct conformations of MLKL pseudokinase domain. These structures support that human RIPK3 maintains MLKL in an inactive conformation prior to the induction of necroptosis. These studies provide further evidence that MLKL undergoes a large conformational change upon activation and identify MLKL disengagement from RIPK3 as a key regulatory step in the necroptosis pathway.
    
    Speaker: Mr Yanxiang Meng (WEHI)
  - 11:45
    
    The silver bullet: using silver doped lanthanum manganite to selectively target deadly brain cancer 15m
    
    Introduction
    Treatment of deadly cancers that are deep-seated within sensitive healthy tissue is limited to adequate targeting strategies. More specifically, brain and central nervous system cancers can be the most aggressive, have higher mortality rates and lower accessibility to chemotherapeutic drugs. This study introduces the first in-depth analysis doped lanthanum manganite (LAGMO) nanoparticles (NPs) as a brain cancer selective chemotherapeutic and radiation dose enhancer
    
    Method
    The magnetic, chemical and biological properties of LAGMO NPs at silver dopant levels of 0-10% were investigated. Magnetic and chemical phases of LAGMO NPs were analysed with neutron diffraction using the ECHIDNA High-Resolution Powder Diffractometer. Biocompatibility and combinational treatment strategies involved in vitro biological endpoint clonogenic assays, live cell imaging and a cancer cell selectivity investigation.
    
    Results
    Neutron diffraction revealed that 10% LAGMO NPs exhibit residual ferromagnetism at 300 K suggesting potential hyperthermia cancer treatment strategies. Biocompatibility studies of LAGMO NPs with cancerous and non-cancerous cells displayed completely cancer cell selective toxic response while non-cancerous cell growth was promoted. Clonogenic assays revealed a significant decrease in long-term survival of cancer cells with NPs and radiation therapy compared to radiation alone.
    
    Conclusion
    LAGMO NPs have potential to significantly improve targeted cancer treatment strategies. Their unique magnetic properties introduce a potential to induce cancer cell hyperthermia alongside radiation treatment and improve clinical outcomes. Furthermore, they promote non-cancerous cell growth while severely damaging cancer cells alongside radiation.
    
    References
    Khochaiche, Abass, et al. "First extensive study of silver-doped lanthanum manganite nanoparticles for inducing selective chemotherapy and radio-toxicity enhancement." Materials Science and Engineering: C 123 (2021): 111970.
    
    Speaker: Mr Abass Khochaiche (University of Wollongong)
  - 12:00
    
    Determining the role of protein aggregation in COVID-19 15m
    
    COVID-19 is primarily known as a respiratory disease caused by the virus SARS-CoV-2. However, neurological symptoms such as memory loss, sensory confusion, cognitive and psychiatric issues, severe headaches, and even stroke are reported in as many as 30 % of cases and can persist even after the infection is over (so-called ‘long COVID’). These neurological symptoms are thought to be caused by brain inflammation and toxicity, triggered by the virus infecting the central nervous system of COVID-19 patients, however we still don’t understand the molecular mechanisms underpinning this neurotoxicity. The neurological effects of COVID-19 share many similarities to neurodegenerative diseases such as Alzheimer's and Parkinson’s in which the presence of cytotoxic self-assembled protein aggregates, known as amyloid nanofibrils are a common hallmark. This led us to hypothesise that self-assembled amyloid aggregates maybe present in the proteome of SARS-CoV-2 and responsible for some of the neurological symptoms of COVID-19. In this work we identified several peptides sequences within the proteome of SARS-CoV-2 that have a strong tendency to spontaneously self-assemble into amyloid aggregates. We performed an extensive characterisation of the in vitro toxicity and biophysical properties of these assemblies using a variety of techniques. We used data recorded at the SAXS/WAXS beamline at the Australian Synchrotron to provide insights into the nanoscale morphology and molecular structure of these assemblies. Based on these results we introduce the idea that cytotoxic amyloid aggregates of SARS-CoV-2 proteins are causing some of the neurological symptoms commonly found in COVID-19 and contributing to long COVID.
    
    Speaker: Nicholas Reynolds (La Trobe University)
- 10:45 → 12:20
  Instruments & Techniques
  - 10:45
    
    Small Angle Neutron Scattering Capability at ANSTO 15m
    
    The ANSTO Lucas Heights campus is home to three world-class small angle neutron scattering (SANS) instruments: Bilby, a time-of-flight SANS instrument [1], Kookaburra, an Ultra-Small Angle Neutron scattering instrument [2] and Quokka, a monochromatic SANS instrument [3]. Together they cover the structure of materials from 1 nm to > 20 microns. As well as recent scientific highlights, we here outline the updates from the group since the last ANSTO user meeting, notably:
    - The replacement of our lab-based small angle X-ray instrument with a state-of-the-art instrument along with a range of dedicated sample environments, currently being procured and due for installation early 2022.
    - The new rheometer for in-situ measurements on the three neutron instruments.
    - Our recently developed GiSANS setup, funded by the National Synchrotron Radiation Research Center.
    
    [1] A. Sokolova, A. E. Whitten, L. de Campo, J. Christoforidis, A. Eltobaji, J. Barnes, F. Darmann and A. Berry, Performance and characteristics of the BILBY time-of-flight small-angle neutron scattering instrument, J Appl Crystallogr, 2019, 52, 1-12.
    [2] Rehm, C.; Campo, L. d.; Brûlé, A.; Darmann, F.; Bartsch, F.; Berry, A., Design and performance of the variable-wavelength Bonse–Hart ultra-small-angle neutron scattering diffractometer KOOKABURRA at ANSTO. J Appl Crystallogr, 2018, 51 (1), 1-8.
    [3] K. Wood, J. P. Mata, C. J. Garvey, C. M. Wu, W. A. Hamilton, P. Abbeywick,[..] and E. P. Gilbert, QUOKKA, the pinhole small-angle neutron scattering instrument at the OPAL Research Reactor, Australia: design, performance, operation and scientific highlights, J Appl Crystallogr, 2018, 51, 294-314.
    
    Speaker: Kathleen Wood (Australian Nuclear Science and Technology Organisation)
  - 11:00
    
    New developments in neutron imaging at DINGO 15m
    
    The neutron radiography / tomography / imaging instrument DINGO is operational since October 2014 to support research at ANSTO. DINGO provides a useful tool to give a different insight into objects. A major part of applications from research and industrial users was demanding high resolution setup and fast scans on DINGO. The neutron beam size can be adjusted to the sample size from 25 x 25 mm 2 to 200 x 200 mm 2 with a resulting pixel size from 12µm to ~100µm. Depending on the sample composition a full tomography has been taken in 10 minute – 36 hours. During the recent OPAL long shutdown, a new sapphire filter has been installed to reduce the amount of epithermal and fast neutrons at the sample position. These high energy neutrons do not contribute to the image, only as noise, and increasing the radiation levels around the CMOS camera. This update will improve the image quality as well as the reliability of the whole instrument.
    In addition, we implement a new type of neutron tomography scan to address long samples like in drill cores. These samples can now be scanned horizontal up two 1.2 meter in length. For small core sizes we can run up to three cores in one scan, which makes DINGO a very competitive instrument for fast high throughput imaging.
    A new software package for 3D reconstruction has been developed as well. It is an open source package based on the python toolbox “tomopy” with a GUI custom made for DINGO to enable users to run the reconstruction on their own computing environment.
    
    Speaker: Dr Ulf Garbe (ANSTO)
  - 11:15
    
    A study of the intrinsic background from the Beryllium Filter Spectrometer on Taipan 15m
    
    The Beryllium filter spectrometer on Taipan is a low-energy band-pass spectrometer that employs a number of materials to effectively scatter out neutrons of higher energies and transmit only neutrons in the energy range, ef=1.2±0.5 meV. Here in this study the spectrometer response is studied in order to understand and identify the inherent background from the spectrometer itself.
    
    Ambient air and nickel are used as scatterers in this study as the former gives a reasonable detection limit of the spectrometer and the latter gives enough scatter to observe the inelastic signal but not too much to swamp out the inherent signal produced by the spectrometer itself. The background shape is found to be hull-like that reflects the total scattering cross-sections of the filter materials themselves and that of the copper cooling frame and the iron found in the stainless steel collimator. Furthermore the detailed inelastic signals from the last set of Beryllium blocks next to the detector bank are identifiable as low intensity parts of the spectra.
    
    A simple experimental method using the collected spectra are used to identify features associated with scatter from the spectrometer and those from the sample under investigation which can then be used to potentially effectively strip-out the spectrometer profile from collected spectra. Further work is discussed to minimise the scatter generated from the spectrometer filter blocks and frames in order to reduce the background to the ultimate minimum limit.
    
    Speaker: Dr Anton Stampfl (Australian Nuclear Science and Technology Organisation)
  - 11:30
    
    BioSAXS: The future of solution scattering at the Australian Synchrotron 15m
    
    BioSAXS is one of the new beamlines to be constructed at the Australian Synchrotron within the BRIGHT program. The beamline is currently under construction and it is scheduled to phase into user operations in mid-late 2022. BioSAXS will be a high-flux (~5 x 1014 ph/sec) small angle X-ray scattering beamline dedicated to all sorts of solution scattering including dispersions, gels and soft matter, covering a variety of disciplines from biology to chemistry and material sciences. The high flux of the beamline will provide enhanced data quality and kinetic resolution, allowing for time-resolved studies on the millisecond timescale, as well as the measurement of weak scatterers and low concentrations that wouldn’t otherwise be possible to measure. The in-vacuum detector system at the end station will provide quick and highly automated camera changes, a q range of ~0.0015 – 3 Å-1 and low background in collected data. The CoFlow, a pioneering development of the Australian Synchrotron, will be the primary autoloading device for high throughput experiments. Other sample environment options will include a stopped-flow and rheometer, temperature-controlled capillary stages, a shear cell as well as a versatile magnetic-array system, optimized for experiments on magnetic nanoparticles used in biomedical applications. The beamline’s sample platform will also accommodate the installation of user equipment. The objective of this presentation is to demonstrate BioSAXS’ final design and capabilities that will allow it to develop into a highly-automated and versatile beamline that can accommodate a wide-range of solution scattering experiments, complementing the existing SAXS/WAXS beamline to ensure the world-leading capabilities of the SAXS offering at the Australian Synchrotron.
    
    Speaker: Dr Christina Kamma-Lorger (ANSTO Australian Synchrotron)
  - 11:45
    
    ACNS SAMPLE ENVIRONMENT UPDATE 15m
    
    Since the last ANSTO User Meeting the sample environment group at ACNS has supported our facility users with a range of unique developments and set ups. We have had a change in structure with the laboratory group forming and working alongside us. We will report on the progress on our ongoing projects on Direct Laser Melting (DLM) deposition system co-funded by a NSW RAAP grant. Also underway are LIEF grants with equipment for use at ACNS, one includes a rheometer for use on ACNS beam instruments.
    This presentation will also cover our new equipment projects funded by the NCRIS RIIP scheme. This includes new cryofurnaces, a new type of furnace, a universal testing machine and other equipment. This funding will maintain and improve our existing capabilities and increase the redundancy across the SE suite to better service competing requests.
    
    Speaker: Rachel White (ANSTO)
  - 12:00
    
    High-Resolution Macro ATR-FTIR Chemical Imaging Capability at Australian Synchrotron Infrared Microspectroscopy (IRM) Beamline 15m
    
    This presentation aims to provide a summary on technical aspects and applications of our synchrotron macro ATR-FTIR microspectroscopy, unique to the Infrared Microspectroscopy (IRM) beamline at ANSTO–Australian Synchrotron.¹ The device was developed by modifying the cantilever arm of a standard macro-ATR unit to accept Ge-ATR elements. Coupling synchrotron-IR beam to the Ge-ATR element (n=4), reduces the beam focus size by a factor of 4 (improving lateral resolution), and the mapping step size by 4 times relative to the stage step motion. As a result, the macro ATR-FTIR measurement at our IRM beamline can be performed at minimum projected aperture (sampling spot size) of 1-2 μm using a 20x objective, and minimum mapping step size of 250 nm, allowing high-resolution chemical imaging analysis with the resolution limit beyond those allowed for standard synchrotron-FTIR transmission and reflectance setups.
    
    The technique has facilitated many experiments in a diverse range of research disciplinary. Here, there will be presentations based on macro ATR-FTIR technique in archaeology, electrochemistry (battery), biomedical and forensic sciences. Apart from these, we will provide additional applications in the fields of food and pharmaceutical science,^2-4 single-fibre analysis,^5-6 and dentistry.⁷
    
    References:
    [1] J. Vongsvivut, et al., Analyst 144, 10, 3226-323 (2019).
    [2] A.P. Pax, et al., Food Chemistry, 291, 214-222 (2019).
    [3] Y.P. Timilsena, et al., Food Chemistry, 275, 457-466 (2019).
    [4] D.M. Silva, et al., Journal of Colloid and Interface Science, 587, 499-509 (2021).
    [5] S. Nunna, et al., Journal of Materials Chemistry A, 5, 7372-7382 (2017).
    [6] C. Haynl, et al., Scientific Reports, 10, 17624 (2020).
    [7] P.V. Seredin, et al., International Journal of Molecular Sciences, 22, 6510 (2021).
    
    Speaker: Jitraporn (Pimm) Vongsvivut (Australian Synchrotron)
- 12:20 → 13:30
  
  Lunch 1h 10m
- 13:30 → 14:20
  Biomedicine, Life science & Food Science
  - 13:30
    
    Jaws caught on the IMBL 15m
    
    Maturational changes in feeding behaviour among sharks are associated with increased mineralisation of the teeth and jaws, but this relationship has only been demonstrated in a few species. Large, highly mobile shark species are rarely available for detailed anatomical study, despite their importance for ecological health and widespread interest among the general population. We examined the crania, jaws, and teeth of two great white sharks (Carcharodon carcharias), a 2.3 m juvenile and a 3.2 m young adult.
    
    The CT scans used a 230 keV (mean energy) polychromatic beam from the 4 Tesla wiggler, with a filtration of 6mmAl, 6mmCu, 3mmMo and 3mmPb. The detector was a Teledyne-Dalsa Xineos 3030HR with 100µm pixels, a width of 300mm, and a 1mm CsI converter for high efficiency at high energy. Image noise was reduced by collecting 18,000 projections per rotation to deliver an image quality good enough to segment out different tissue types. With a beam size of 300mm x 35mm, the shark head was covered by ‘tiling’, and stitching the tiles, with the full-head image made up of two columns and 21 tiles, to image a 600mm x 520mm area. Total scan time was 9 hours.
    
    The heads were also imaged using conventional CT and 7 Tesla MRI for finite element modelling of bite forces produced by the jaw musculature. These results will be compared with measurements of the difference in mineralisation of tooth and jaw cartilage between the two specimens to assess developmental changes in tooth and jaw hardness as the animals shift their diets from largely fish-based (juvenile) to larger prey, such as seals, scavenged whales and surfers (adults).
    
    Speaker: Dr Daniel Hausermann (Australian Synchrotron (ANSTO))
- 13:30 → 14:20
  Earth, Environment & Cultural Heritage
  - 13:30
    
    Use of high-resolution technologies to understand the broken past 20m
    
    Our understanding of material culture and past environmental contexts have been utterly transformed over the last two decades by new and greatly improved scientific methods. Innovative investigations revolve around refinement of methods for chronological dating, characterization and provenancing, bioarchaeology, geoarchaeology and the emerging sub-discipline of cyber-archaeology. As ever, when dealing with the past, 'meaning' remains more difficult and we are always be limited by what little we can know. With the help of multi-scalar, high-resolution techniques, there at least exists potential for useful and even groundbreaking information to be retrieved from material culture, the absence of which might inhere a sense of doubt. This talk will illustrate some applications of science and technology that are proving valuable in Australian archaeology, drawing from my own studies at ANSTO and the Australian Synchrotron as well as other novel multi-scientific projects. At the heart of these is an interdisciplinary approach and an aim to provide the most accurate understanding of the dynamic past from what is often a very fragmentary record.
    
    Speaker: Dr Ingrid Ward (University of Western Australia)
  - 13:50
    Leaving a mark on forensic science: Using synchrotron microscopy and spectroscopy to explore fingermark chemistry 15m
    
    Fingermarks are an important tool in forensic investigations however, a large number are not successfully recovered and are never used as evidence.(1) A significant challenge in their detection is the chemical variability of fingermark deposits. This research aims to answer important questions in fingermark chemistry using synchrotron sourced analysis including x-ray fluorescence microscopy (XFM), infrared microspectroscopy (IRM) and THz-Far infrared (Far-IR) spectroscopy to deepen the understanding of fingermark residue and improve recovery methods.
    
    First, what is the chemical composition of a fingermark? We explored the distribution of inorganic material using XFM to discriminate between the endogenous and exogenous metals present in a natural fingermark, with multimodal studies using IRM connecting this distribution to the organic material.(2,3) Further investigation of the transfer and persistence of exogenous metals demonstrated how handling different metal objects can affect fingermark chemistry, suggesting daily activities can influence the material present in a fingermark.
    Second, what happens to this material as the fingermarks age? The material deposited in a fingermark is not static and changes over time, with the rate of change being influenced by the environment and surface. We have directly imaged the rate of change post deposition using IRM, demonstrating the dehydration of hydrophilic material in a fingermark droplet over time. To volumetrically measure this rate of change we have measured the water evaporating off a fingermark in the gas phase using Far-IR, providing important insight into the water content in fingermark residue.
    
    S. Chadwick et al. Forensic Science International, 2018, 289, 381-389.
    
    B. N. Dorakumbura et al. Analyst, 2018, 143, 4027-4039.
    
    R. E. Boseley et al. Analytical Chemistry, 2019, 91, 10622-10630.
    
    Speaker: Rhiannon Boseley (Curtin University)
  - 14:05
    
    Understanding the generation and evolution of reaction-induced porosity in the replacement of calcite by gypsum: A combined microscopy, X-ray micro-tomography, and USANS/SANS study 15m
    
    Fluid-mediated mineral replacement reactions are common in natural systems and are essential for geological and engineering processes. In these reactions, a primary mineral is replaced by a product mineral via a mechanism called coupled dissolution-reprecipitation. This mechanism leads to the preservation of the shape of the primary mineral into the product mineral. The product mineral includes reaction-induced porosity contributing to enhanced permeability, which is crucial for the replacement reaction to progress from the surface to the core of the primary mineral grain. These reaction-induced pores are complex in size, shape and connectivity, and can evolve with time. However, the mechanisms of the creation and evolution of such pores are still poorly understood. Therefore, we investigated the replacement of calcite (CaCO₃) by gypsum (CaSO₄.2H₂O) to understand porosity creation in the replacement stage and the evolution of such porosity after complete replacement. This replacement reaction is important for the applications such as groundwater reservoir evaluation, CO₂ sequestration, cultural heritage preservation, and acid mine drainage remediation. Samples collected at various reaction stages over 18 months were characterised by ultra-small-angle neutron scattering and small-angle neutron scattering (USANS/SANS), ultra-high-resolution electron microscopy (UHR-SEM), and X-ray micro-computed tomography (X-μCT). Results show the formation of micro-voids in the core of the gypsum grain and the generation of nanometre-sized elongated pores in the newly formed gypsum crystals. Micrometre-sized pores were mostly open, while pores smaller than 30 nm were mainly closed. After complete replacement, continued porosity coarsening occurred in the 18 months’ time, driven by Ostwald ripening.
    
    Speaker: Muhammet Kartal (Murdoch University)
- 13:30 → 14:20
  Physics, Surface & Condensed Matter
  - 13:30
    
    Scattering or spectroscopy? Both! 20m
    
    In this presentation I will discuss the development of resonant tender X-ray diffraction to study the molecular packing of semiconducting polymers. Semiconducting polymers are being developed for application in a wide range of optoelectronic devices including solar cells, LED and transistors. Being polymeric materials they offer advantages over traditional semiconductors including ease of processing and mechanical flexibility. Most semiconducting polymers are semicrystalline, with the way in which polymer chains pack strongly affecting their optoelectronic performance. Unlike small molecule crystals whose structure can be directly solved using crystallographic methods, semiconducting polymers are more disordered meaning that there are not enough diffraction peaks available. To squeeze more information from the diffraction peaks that are present, we have turned to resonant diffraction: By varying the X-ray energy across an elemental absorption edge, the variations in diffraction intensity that are observed can provide additional information. Also known as anomalous diffraction this technique has been applied in other fields including protein crystallography. As many semiconducting polymers utilise sulfur as heteroatoms, we have studied resonant diffraction effects at the sulfur K-edge in the tender X-ray regime. Furthermore we have adopted a spectroscopic approach exploiting anisotropic near-edge X-ray absorption features at the sulfur K-edge that produce highly anisotropic resonant diffraction effects. This marrying of spectroscopy and scattering enables us not only to infer information about the position of the resonant atoms within the unit cell, but also to deduce the orientation of molecular bonds and orbitals within the unit cell.
    
    Speaker: Prof. Chris McNeill (Monash University)
  - 13:50
    
    Wavefield Characterisation of MHz XFEL Pulse Trains 15m
    
    X-ray Free Electron Laser (XFEL) light sources present new opportunities in the imaging of single particles and biomolecules. The interpretation and analysis of XFEL imaging data depends critically on a fundamental understanding of the characteristics of the inherently stochastic XFEL pulses delivered to the instrument. Exploiting the unique MHz repetition rate of the European XFEL to image single particles requires an improved understanding of both the inter- and intra-train fluctuations in pulse structure and beam pointing, which are frequently implicated in the loss of information in XFEL single particle imaging (SPI) and other classes of coherent diffraction experiment. Failure to account for fluctuations of the electron bunch phase-space and/or trajectory within a pulse train can result in deviations of the recorded wavefront and intensity statistics from theoretical behaviour and lead to conflation of the structure of the source and sample in single particle reconstruction.
    
    Contrary to expectations, X-ray optical data collected at the SPB-SFX instrument of the European XFEL demonstrates a sensitivity of inter- and intra-train variations in beam pointing to beam delivery parameters, including the order of a pulse within a train. This data is presented in comparison to a partially coherent wave optical simulation of the SPB-SFX instrument, through which photon diagnostics have been designed and developed, with the goal of improving the stability and subsequent imaging quality of the user-end photon beam. We describe these preliminary results within the scope of developing a novel phase-retrieval method applicable to the study of MHz repetition rate XFEL sources, using nearfield speckle-tracking measurements.
    
    Speaker: Mr Trey Guest (La Trobe University, European XFEL)
  - 14:05
    
    Verification of L-alanine single-crystallinity for anisotropic synchrotron terahertz measurements 15m
    
    One way to probe the molecular interactions of a material is by using terahertz (THz) spectroscopy, which has been used to study L-alanine in detail [1]. However, isotropic THz spectroscopy has limitations in identifying the origin of vibrational modes since the direction of the associated dipole moment is random in an isotropic THz measurement. Therefore, there is a benefit to performing anisotropic (polarised) THz measurements. This work represents the first anisotropic measurements performed on L-alanine, the simplest chiral amino acid, and one of the earliest amino acids fundamental to early life on Earth [2].
    
    An appropriate sample for anisotropic measurements must be highly single-crystalline. This presentation describes a method to prepare and test a sample for anisotropic THz measurements. Samples have been grown at the University of Wollongong, and sample verification has been done at ACNS’s Taipan triple-axis spectrometer. Using Taipan, a narrow mosaic spread of ~0.8° was determined, and single, well-fitted Gaussian peaks were observed in both sample rotation and Q-space scans, suggesting high single-crystallinity in our L-alanine samples. Additionally, the Taipan measurements were able to verify the orientation of the L-alanine single crystals with respect to their crystallographic axes.
    
    Anisotropic THz measurements were taken on the THz – Far Infrared beamline at the Australian Synchrotron using a wire-grid polariser. Distinct absorption bands were observed for different crystal orientations, further confirming single-crystallinity, and identifying the dipole moment directions for the observed modes. We thus demonstrate a method of performing anisotropic THz measurements.
    
    [1] T. J. Sanders et al., J. Chem. Phys., 154, 244311 (2021)
    [2] V. Kubyshkin and N. Budisa, Int. J. Mol. Sci., 20, 5507 (2019)
    
    Speaker: Jackson Allen (UOW)
- 14:25 → 14:50
  
  Afternoon Tea 25m
- 14:50 → 15:10
  
  Awards: ANBUG | Technical Award
- 15:10 → 15:30
  
  Awards: ANBUG | Student Award
- 15:30 → 15:50
  
  Awards: ANBUG | Neutron Award
- 15:50 → 16:10
  
  Awards: ANBUG | Young Scientist Award
- 16:10 → 16:30
  
  Awards: ANBUG | Career Award
- 16:30 → 17:00
  
  Update: Career Progress & Poster Slam
- 17:00 → 17:30
  
  Break 30m
- 17:30 → 20:30
  Poster Session
  - 17:30
    
    EMU cold-neutron backscattering spectrometer at ACNS, ANSTO 1m
    
    EMU is the high-resolution neutron spectrometer installed at the OPAL reactor, ANSTO, which delivers 1 µeV FWHM energy transfer resolution for an accessible ±31 µeV energy transfer range. The spectral resolution is achieved by neutron backscattering from Si (111) crystals on the primary and secondary flight paths, allowing up to 1.95 Å-1 momentum transfer range. The spectrometer is well for suited quasi-elastic and inelastic neutron scattering studies, notably in the field of soft-condensed mater including biophysics and polymer science, chemistry and materials science, and geosciences.
    Most experiments are carried out with standard cryo-furnaces (2 to 800 K temperature range). Spectrometer beam-time access is merit-based, thus welcoming experiments as well in other materials research areas, and including experiments that may require e.g., other ancillary equipment such as existing controlled-gas delivery, and potentially pressure, applied field set-ups, etc. We will present examples of the spectrometer capabilities through select case studies.
    
    Speaker: Alice Klapproth (ANSTO)
  - 17:31
    
    Full Hemisphere Photoemission Using the Toroidal Analyser 1m
    
    The toroidal analyser at the Australian Synchrotron is an angle-resolving photoelectron spectrometer capable of mapping the full hemisphere of emitted photoelectrons from a sample. This measurement capability is unusual amongst conventional photoelectron spectrometers, and permits a number unique techniques for the electronic and structural characterization of surfaces. This presentation will detail the operating principles of the spectrometer, with particular reference to the angular detection geometry, and will describe the three modes of full hemisphere photoemission (i) Fermi Surface Mapping (ii) Molecular Tomography and (iii) Photoelectron Diffraction.
    
    Speaker: Anton Tadich
  - 17:32
    
    Status, statistics, and recent research highlights from Echidna 1m
    
    The Echidna high-resolution powder diffractometer remains a reliable and productive ACNS instrument contributing annually to about 50 published studies done on a wide range of topics, from magnetic, energy and planetary materials to cultural heritage and additive manufacturing. We will discuss how Echidna has been affected by COVID-19 measures, latest and planned developments, user programme statistics, and recent research highlights.
    
    Speakers: Max Avdeev (Australian Nuclear Science and Technology Organisation, Australian Centre for Neutron Scattering), James Hester (ANSTO), Chin-Wei Wang (NSRRC)
  - 17:33
    
    Scientific computing support for neutron scattering experiments at ANSTO 1m
    
    The purpose of the scientific computing support at ANSTO is to aid in the interpretation of both structural and dynamical data from the neutron scattering instruments using atomistic modelling calculations. Most of these calculations are done with ab initio scientific software packages based on Density Functional Theory, including VASP, WIEN2K, ABINIT, SIESTA, PHONON, and QUANTUM ESPRESSO, although some are performed with packages based on classical force fields, such as LAMMPS, DL_POLY, NAMD, and GULP. Analysis of the results of these calculations exploits tools such as VMD, NMOLDYN, XCRYSDEN, and ISAACS, in addition to in-house code. Calculations and analysis are carried out locally on a scientific computing Linux cluster comprising both ACNS dedicated cores and ANSTO shared ones, with jobs managed by PBS. We give a brief overview of all of the above capabilities and an example of a typical calculation/analysis.
    
    Speaker: Dr RAMZI KUTTEH (ANSTO/ACNS)
  - 17:34
    
    Fusion Peptide Interactions with the Lipidic Cubic Phase 1m
    
    Despite the fact that membrane fusion is a key step in many biological processes, the underlying mechanism still remains elusive. The bicontinuous cubic phases are a perfect medium for the delivery of therapeutic proteins owing to their enhanced solubility, sustained release and reduced toxicity. It has been suggested that the fusion event of viruses is tightly regulated by specialized fusion proteins which are responsible for protein-lipid interactions or protein-protein interactions. The fusion components of enveloped viral fusion involve viral proteins that insert hydrophobic sequences into the target membrane and refold to drive merging of the lipid bilayers which can be utilized to enhance drug delivery. By using high throughput methodology to prepare and characterize viral fusion peptide interactions based on lipid composition, our study has revealed that the N-terminal charge of the viral fusion peptide has a significant effect on lattice parameter of the cubic phases. Induced curvature depends on peptide concentration but the mechanism was observed to be viral dependent. We investigated the phase behaviour which represents its fusion function and bilayer destabilizing effect, upon encapsulation in bicontinuous cubic phases with and without phospholipid using synchrotron SAXS. We also used TOF-SANS and contrast-matching of the lipid membrane to investigate the phase behaviour of the mixed lipid systems. This is crucial for better understanding of the fundamental physiochemical parameters of the lipid mesophase in response to peptide encapsulation and dependency of the peptide structural conformation.
    
    Speaker: Ms Izabela Milogrodzka (Monash University)
  - 17:35
    
    Recent highlights from the Pelican spectrometer 1m
    
    The cold-neutron time-of-flight spectrometer Pelican has been in operation since 2014. Pelican is well suited to the measurement of quasielastic and inelastic scattering in the low energy region, as a result Pelican is sensitive to many phenomena including self-diffusion of molecular species, low energy phonons, crystal field excitation's and spin waves. While use of the neutron energy gain portion of the spectrum allows the detailed measurement of the phonon density of states. The spectrometer is well equipped with a wide range of sample environment which allows measurements in applied magnetic fields, milli Keliven temperatures and applied pressure. In this contribution we will show results from recent publications highlighting the diverse science and application of the Pelican spectrometer.
    
    Speakers: Richard Mole (ANSTO), Dehong Yu (Australian Nuclear Science and Technology Organisation)
  - 17:36
    
    Kowari residual stress diffractometer 1m
    
    Kowari is a residual stress diffractometer which can be used for ‘strain scanning’ of large engineering components as large as one ton. The integrity of engineering components often depends on strains and stresses inside the material. For example, rails can fail if stresses exceed the ‘ultimate tensile stress’.
    
    Speaker: Mark Reid (ANSTO)
  - 17:37
    
    Current Facilities on the Soft X-ray Beamline 1m
    
    The soft X-ray beamline at the Australian Synchrotron has been operating with users since 2008. The beamline offers three different systems for users; A full Ultra High Vacuum surface science system with Nexafs and Photo-emission capabilities, an Angle Resolved Photoelectron Spectroscopy (ARPES) system operated with La Trobe University and a High Throughput system exclusively for Nexafs but with vacuum pressure restrictions relaxed from UHV to lie in the 10-7 to 10-8 mbar range. The current specific capability of all three instruments will be presented.
    
    Speaker: Dr Bruce Cowie (ANSTO)
  - 17:38
    
    ATOS-GOM structured light 3D scanner, replacement new for old or intriguing possibilities! 1m
    
    The ATOS-GOM structured light 3D scanner is a replacement for the laser scanner previously used on the Kowari instrument. In addition to outlining its operation, this talk will address some exciting possibilities this new piece of equipment brings to the Kowari instrument.
    
    Speaker: Mark Reid (ANSTO)
  - 17:39
    
    ADS-1 and ADS-2: New high-energy X-ray beamlines at the Australian Synchrotron 1m
    
    Eight new beamlines are currently under design or construction at the Australian Synchrotron as part of the BRIGHT project. Included among them are the Advanced Diffraction and Scattering beamlines, ADS-1 and ADS-2, which will offer high-energy X-rays (45-150 keV) for a variety of diffraction, imaging and tomography experiments. ADS will benefit users from the materials, minerals and engineering research communities who wish to study bulky or strongly absorbing samples and/or perform in situ measurements using complex sample environments. We present an update on the progress of the ADS project, including the latest design features of the two beamline endstations and the planned range of experimental capabilities.
    
    Speaker: Josie Auckett (Australian Synchrotron)
  - 17:40
    
    Getting better statistics: variable count time data collection with large linear detectors. 1m
    
    X-ray diffraction data are normally collected with a fixed count time (FCT) per step. With this data, the intensities of the diffraction peaks decrease with increasing angle,primarily due to the effects of atomic scattering factors, Lorentz-polarisation, atomic displacement parameters, and absorption. In diffractometers with point or small linear detectors, these changes can be counteracted by systematically varying the counting time as a function of diffraction angle.This variable-count-time (VCT) approach has been shown to produce data of superior quality for structure determination and refinement, as all peaks have similar intensities, allowing them to contribute equally
    to the analysis process.
    
    With the advent of large linear detectors, the ability to change the counting time as a function of angle has been removed. A computer program has been written to construct a VCT diffraction pattern by the progressive summation of a series of conventional FCT diffraction patterns. This approach extends the collection of VCT data to large linear detectors, where traditional VCT is impossible. The program can also be used to simulate the construction process as an aid in experimental planning. An example application is given.
    
    Speaker: Dr Matthew Rowles (Curtin University)
  - 17:41
    
    Enhancing synchrotron modulated Microbeam Radiation Therapy in vivo with novel high Z nanoparticles 1m
    
    With limited improvement in brain cancer patient survival in the last 30 years, the search for a treatment strategy that is targeted and effective continues. This study is harnessing the unique properties of synchrotron radiation for anti-cancer radiotherapy. The Imaging and Medical Beamline (IMBL) at the ANSTO Australian Synchrotron (AS) offers the possibility to perform pre-clinical synchrotron radiation trials using extremely high dose-rates, sparing normal tissue whilst delivering large doses to the tumour site. This study focused on patient specific treatments combining Microbeam Radiation Therapy (MRT) with novel high Z nanoparticles (NPs), and was the largest rodent survival study utilising nanoparticle enhancement ever undertaken at AS. Thulium oxide NPs (Z=69) are a promising sensitising and imaging agent with limited cytotoxicity and proven synchrotron enhancement. 32 Fischer 344 rats were inoculated with 9L gliosarcoma in the right caudate nucleus of the brain. 11 days later, the rats were imaged with Computed Tomography (CT) to locate the tumour in relation to bony anatomy. The following day, nanoparticles were injected directly to the tumour of each rat. Using the CT scans, the rats were aligned in-beam, and a bolus was placed over the irradiation site. One radiation fraction was given to different treatment groups at valley doses of 8, 14 or 15Gy, with a radiation field of 8mm by 8mm and microbeams produced using the 4T magnet and Al/Al filtration. Utilising a heavily improved oedema protocol, seizure symptoms and adverse events immediately post MRT were significantly reduced. Overall survival compared to rodents with MRT alone was found to be improved when considering the tumour to brain volume.
    
    Speaker: Sarah Vogel (University of Wollongong)
  - 17:42
    
    Structural basis of the Trichoplax adhaerens Scribble and Dlg interactions with the PDZ-binding motif of Vangl 1m
    
    Maintenance of multicellular tissue architecture is conserved process which is regulated by a highly
    conserved set of proteins. The interacting partners of these regulators are also conserved across the
    animal kingdom. Scribble and Dlg are two such key polarity regulators that involve in the establishment
    and maintenance of multicellular apical-basal cell polarity in epithelial cells. These are scaffolding
    proteins bearing multiple PDZ domains that mediate most of their interactions. Complex multicellular
    organisms evolved from the simple primitive forms; therefore, we examined Scribble and Dlg mediated
    cell polarity in the simplest metazoan living on earth, Placazoa, Trichoplax adhaerens. Despite its
    extreme simplicity, Trichoplax contains all polarity regulators that are fundamental to instruct the body
    plans in higher animals; thus, making it an ideal candidate to use as a polarity studying model. We now
    show biochemically that a key interaction for the establishment of cell polarity between Scribble and
    Dlg PDZ domains and Vangl in mammals is fully recapitulated in Trichoplax. We found that Scribble
    PDZ1, PDZ2 and PDZ3 interact with Vangl with affinities comparable to the human interaction, with
    a similar hierarchy in affinities. We also found that all three PDZ domains of Dlg interact with Vangl
    with no hierarchy of their affinities. We then show using crystal structures of Scribble PDZ1, PDZ2 and
    Dlg PDZ1, PDZ2 bound to the C-terminal PDZ binding motif of Vangl that in addition to the binding
    affinities, the detailed interactions between Scribble/Vangl and Dlg/Vangl are also conserved at the
    atomic level between Trichoplax and human.
    
    Speaker: Mrs Janesha Maddumage (1Department of Biochemistry and Genetics, La Trobe University)
  - 17:43
    
    Platypus Neutron Reflectometer 1m
    
    PLATYPUS is the initial neutron reflectometer at the Australian Centre for Neutron Scattering with a capability to study surfaces and interface systems ranging from biomolecules, soft matter through to magnetic thin films [1-3]. There have been a number of significant improvements to both the instrument and data reduction and treatment software [4] over the last two years. On the hardware front the original detector has been replaced [5] enabling higher count rate capabilities, greater detection efficiency at shorter wavelengths and significantly lower background. The slits which define the neutron beam have been replaced with upgraded positioning mechanisms enabling greater flexibility in experimental setup. These changes have significantly enhanced the instrument performance with improved reproducibility.
    
    [1] M. James et al., J. Neutron Research 14, 91 - 108 (2006)
    [2] M. James et al., Nuclear Inst. and Methods in Physics Research A, 632, 112 - 123 (2011)
    [3] T. Saerbeck et al., Rev. Sci. Instrum. 83, 081301 (2012)
    [4] A. Nelson et al., J. Appl. Crystallography, 52, 193 - 200 (2019)
    [5] L. Abuel et al., Journal of Neutron Research, 23(1), 53 – 67, (2021).
    
    Speaker: Dr Stephen Holt (Australian Nuclear Science and Technology Organisation)
  - 17:44
    
    Demonstrated enantioselective adsorption with cobalt 1D coordination polymers 1m
    
    Chiral coordination polymers have recently been explored as potential stationary phases for enantioselective separations.1 However, the chiral resolution ability of non-porous coordination polymers is not often tested.
    
    In this work, two chiral 1D cobalt coordination polymers have been synthesised with an amino acid functionalized diimde ligand. The coordination polymers, which have little free pore space, have been tested for their chiral resolution abilities with 1-phenylethanol. Coordination polymer 1 shows a preference for one enantiomer over the other in both soaking experiments and preliminary ‘mini columns’, whereas a second structurally similar polymer shows no enantioselectivity thus far. Analyses are currently underway to further probe the chiral separation ability of the systems.
    
    References
    1 Turner, D. R., Chirality in Network Solids. In Chirality in Supramolecular Assemblies: Causes and Consequences, Keene, R. F., Ed. 2016
    
    Speaker: Winnie Cao (Monash University)
  - 17:45
    
    Complex Coacervates as encapsulation system 1m
    
    Complex coacervates are oppositely charged self-assembled biopolymers such as proteins and polysaccharides. They can be used both as a delivery system of bioactive materials, and for improving the structural and textural functionalities of the final food products. The functionalities of the coacervates are dependent on their microstructures, which are determined on a case-by-case basis depending on the combination of protein, polysaccharide, and bioactive. The encapsulation approach developed in this work incorporates the binding of the bioactives to proteins prior to forming complex coacervates with pectin. This was compared to the coacervate structures formed without the bioactives.
    Structural characterization using SANS showed that protein-bioactive complexes could effectively self-assemble with pectin to form complex coacervates making them suitable to be considered as effective encapsulating systems that can used as value added products such as fat and meat analogous.
    
    Speakers: Sunandita Ghosh, Andrew Whitten (ANSTO), Jitendra Mata (ANSTO)
  - 17:46
    
    A multi-analyser upgrading possibility for the thermal-neutron triple-axis spectrometer Taipan 1m
    
    Taipan is a high-flux thermal-neutron triple-axis spectrometer with a traditional single-detector design. Taipan has been working as the work horse for inelastic neutron scattering experiments at ACNS for the last ten years, generating numerous beautiful scientific highlights. Following the trend of the neuron instrumentation, it is interesting to consider the future upgrade of Taipan to increase its data acquisition efficiency with a multi-analyser design. In this research, the possibility of upgrading Taipan into a multi-analyser triple-axis spectrometer is discussed. The simulation of the 21 analyser channels with a 2 degree gap in-between is demonstrated. The simulated result shows that the data acquisition efficiency can be substantially enhanced on Taipan and the multi-analyser design is also very suitable for magnetic diffraction measurement at the low Q range.
    
    Speaker: Dr Guochu Deng (Australian Nuclear Science and Technology Organization)
    
    Mutli-analyzer upgrade of Taipan Taipan_MultiAna_V3.pdf
  - 17:47
    
    Taipan – a versatile thermal neutron scattering instrument for materials research. 1m
    
    Located on the OPAL reactor face, Taipan is the highest flux, thermal neutron scattering instrument at ANSTO. Originally, Taipan was built as a traditional triple-axis spectrometer for inelastic neutron scattering studies with energy transfers up to 70meV. Since its inclusion in the ANSTO user program in 2010, Taipan has undergone a number of upgrades and improvements, including new shielding, new primary optics and the installation of a Cu-monochromator extending energy transfers up to 200meV. An additional secondary spectrometer, the Be-filter analyser, was also developed and integrated in 2015, offering a new way to measure excitations and vibrations in polycrystalline materials.
    This poster will present some recent highlights at Taipan – both as a TAS, and a Be-filter analyser spectrometer.
    
    Speaker: Kirrily Rule (ANSTO)
  - 17:48
    
    Diffuse Scattering Studies from a Martensitic Fe-Pd Alloy 1m
    
    From literature reports, Fe-Pd alloys in the vicinity of Fe-30at%Pd exhibit two martensitic transformations on being cooled from just above room temperature to about 100 K. A preliminary study of a large single crystal of this composition at the KOALA beamline, not only showed evidence for these transformations but also revealed most interesting satellite reflections around certain Bragg spots. The crystal was then studied further in two triple-axis experiments. The first was at TAIPAN, specifically to study elastic scattering and the second, at SIKA, to study quasi-elastic scattering both in the vicinity of certain Bragg peaks but also around the satellite reflections observed at KOALA. During a parallel experiment to the SIKA one, an ideally small piece of the crystal was studied at KOALA but the interesting satellites found for the large crystal were not present. As a result, in a further experiment on the large crystal at KOALA, completed in early 2021, diffraction patterns were collected with the aim of surveying the whole of the large crystal, particularly in the vicinity of the edge from which the ideally small crystal piece had been extracted by electro-discharge machining. The results from this last experiment will be summarised and discussed in relation to the earlier triple-axis and KOALA results.
    
    Speaker: Trevor Finlayson (University of Melbourne)
  - 17:49
    
    Spin Dynamics, Critical Scattering and Magnetoelectric Coupling Mechanism of Mn$_4$Nb$_2$O$_9$ 1m
    
    The spin dynamics of Mn$_4$Nb$_2$O$_9$ were studied by using inelastic neutron scattering. A spin-dynamic model is proposed to explain the observed spin-wave excitation spectrum. The model indicates that the exchange interactions along the chain direction are weakly ferromagnetic while the exchange interactions between the neighbour chains are strongly antiferromagnetic. Such a antiferromagnetic configuration in the hexagonal plane cause spin frustration with a spin gap of about 1.4 meV at the zone centre. The Mn$^{2+}$ ions in this material demonstrate a very weak easy-axis single-ion anisotropy. Critical scattering in the vicinity of T$_{N}$ was studied. On the basis of the magnetic structure and spin-dynamic models, the weak magnetoelectric coupling effect in Mn$_4$Nb$_2$O$_9$ is ascribed to the weak magnetostriction due to the subtle difference between Mn$^{2+}$ ions on the Mn$_{I}$ and Mn$_{II}$ sites.
    
    Speaker: Guochu Deng (Australian Nuclear Science and Technology Organization)
    
    MNO_UserMeeting2021.pdf Spin Dynamics of Mn4Nb2O9
  - 17:50
    
    Exploring Amine-based MOFs for Electrochemical Water Splitting 1m
    
    Electrochemical water splitting is one of the widely studied routes to developing sustainable energy systems. Energy in the form of hydrogen has been gaining attention since it can be easily converted, stored, and transported. In order to improve efficiency, an electrocatalyst will be needed to aid the slow kinetics of the oxygen evolution reaction (OER) process. Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are generally considered to have inferior electrocatalytic performance relative to noble metal oxides, however, in this study using a 2D Co-framework of 1,4,7-tris(4’-methylbiphenyl-4-carboxylic)-1,4,7-triazacyclononane deposited onto nickel foam has shown a promising catalytic activity. The fabricated electrode with a loading of 0.25 mg cm-2 has shown a low overpotential of 259 mV at the current density of 20 mA cm-2 in alkaline conditions. The electrochemical stability of the electrode was evaluated and showed continuous electrolysis with no decay for several hours at room temperature. These initial results not only provide a good design for fabricating MOF-based catalysts but also opens up more ideas for tuning and enhancing the electrochemical performance of amine-based MOFs.
    
    Speaker: Jade Ang (Monash University)
  - 17:51
    
    Chain alignment and charge transport anisotropy in blade-coated N2200/PS blend films 1m
    
    Semiconducting polymers offer the potential of low-cost flexible electronics. To improve the processability and mechanical flexibility of semiconducting polymers, blending with commodity polymers is an attractive strategy. Understanding how blending affects the resulting microstructure in aligned samples produced by directional coating techniques such as blade coating is important to optimize device performance. This presentation will discuss the microstructure of blade-coated blends of the semiconducting polymer N2200 with polystyrene (PS) using a range of techniques. In particular, we have investigated the degree of alignment of chains of the semiconducting polymer N2200 at the surface and in the bulk. UV-vis spectroscopy and surface-sensitive NEXAFS spectroscopy show that blade coating induces the preferential orientation of N2200 chains parallel to the coating direction. Angle-dependent NEXAFS enables the averaged tilt angle of the planar backbone of N2200 to be determined, revealing improved edge-on configuration at the surface with reduced N2200 content. By deconvoluting the spectra of N2200/PS blend film, the concentration of N2200 at the surface was determined, showing its tendency of segregating at the surface. Another synchrotron-based technique, grazing-incidence wide-angle X-ray scattering (GIWAXS) was used to selectively probe the crystalline phase of N2200. The GIWAXS results confirm the directional alignment of N2200 crystallites with backbone stacking direction to be parallel to the coating direction. From the analysis of crystallite orientation (texture), a transition from preferential face-on orientation to edge-on orientation at low N2200 content was seen. Finally, charge transport anisotropy was investigated by measuring organic field-effect transistors based on blade-coated N2200/PS blend films with conductive channel length parallel or perpendicular to the coating direction.
    
    Speaker: Ms Lin-jing Tang (Monash University)
  - 17:52
    
    Investigation of the Diffusion of Cr2O3 into different phases of TiO2 upon Annealing 1m
    
    Chromium oxide (Cr2O3) can be used as a protective layer for photocatalysts to improve photocatalytic water splitting activity and is commonly photodeposited. However, it is not known how the conditions of the Cr2O3 formation affect the formation of the protective layer and potential diffusion into the substate onto which the Cr2O3 has been deposited. We have investigated the stability of Cr2O3 photodeposited onto the surface of different crystal phases of TiO2 with subsequent annealing at a range of temperatures up to 600⁰C. X-ray photoelectron spectroscopy and synchrotron near-edge X-ray absorption fine structure were used to analyse the chemical composition of the sample, Neutral impact collision ion scattering spectroscopy was used to study the concentration depth profile of the elements in the sample and atomic force microscopy was used to investigate the morphology of the surface. Under annealing conditions, the Cr2O3 layer diffuses into the amorphous and anatase phases of TiO2 but remains at the surface of the rutile phase. This finding is attributed to differences in surface energy with Cr2O3 being higher in surface energy than the amorphous and anatase phases of TiO2 but lower in surface energy than the rutile phase of TiO2. Reduction of Cr2O3 to Cr metal was observed after annealing with no observation of the formation of higher oxidised forms of chromium oxide like CrO2 and CrO3. These findings are of general interest to researchers utilising a protective overlayer to augment photocatalytic water splitting.
    
    Speaker: Abdulrahman Alotabi (Flinders University)
  - 17:53
    
    Energy Storage Rocks: Metal Carbonates as Thermochemical Energy Storage Materials 1m
    
    The intermittent nature of renewable energy is a major challenge that can be overcome via cheap and effective energy storage [1]. Thermochemical energy storage is an upcoming technology that can improve efficiency in applications such as concentrated solar power[2]. Metal carbonates have great potential as thermochemical energy storage materials, through the reversible endo/exothermic desorption/absorption of carbon dioxide (CO₂)[3]. However, major challenges include the loss of cyclic capacity and slow reaction kinetics[3].
    Recently, it has been established that raw unrefined dolomite, CaMg(CO₃)₂, performed significantly better than laboratory synthesized dolomite due to the positive effect of chemically inert impurities present in the sample[4] However, increasing its relatively low operational temperature (550 °C) will improve efficiency[4]. The present research explores reactive metal carbonate composites, which consist of barium carbonate destabilised using titanium (IV) oxide (TiO₂) or barium silicate (BaSiO₃)[5]. This reduces the operating temperature from 1400 °C to, more suitable temperatures of 1100 °C and 850 °C, respectively, and improves kinetics of CO₂ release and uptake. The reactions are explored using in situ synchrotron XRD combined with a variety of other characterisation techniques.
    [1] T. Sweetnam and C. Spataru, in Storing Energy, edited by T.M. Letcher (Elsevier, Oxford, 2016), pp. 501–508.
    [2] C. Prieto, P. Cooper, A.I. Fernández, and L.F. Cabeza, Renew. Sustain. Energy Rev. 60, 909 (2016).
    [3] L. André, S. Abanades, and G. Flamant, Renew. Sustain. Energy Rev. 64, 703 (2016).
    [4] T.D. Humphries, K.T. Møller, W.D.A. Rickard, M.V. Sofianos, S. Liu, C.E. Buckley, and M. Paskevicius, J. Mater. Chem. A 7, 1206 (2019).
    [5] K.T. Møller, K. Williamson, C.E. Buckley, and M. Paskevicius, J. Mater. Chem. A 8, 10935 (2020).
    
    Speaker: Mr Kyran Williamson (Department of Physics and Astronomy, Curtin University,)
  - 17:54
    
    Data processing technique for the Taipan Be-filter spectrometer 1m
    
    Taipan, the highest flux thermal neutron scattering instrument at ACNS, was originally built as a traditional triple-axis spectrometer. In 2016 a beryllium filter analyser spectrometer was added for increased versatility. The Be-filter acts like a low-energy band-pass filter ideal for investigating lattice dynamics and molecular vibrations over a wide energy range. It is particularly well suited to measuring the motion within materials containing light elements such as hydrogen.
    We have successfully created a robust method of treating data from the Taipan filter-analyser and present the method within this poster [1]. The data-treatment process includes correction for the non-linear energy variation of a particular monochromator, removal of higher-order wavelength contamination, and estimation of low-energy multiple-scattering. The steps described here can be utilized by all users of the Australian Nuclear Science and Technology Organisation “Be-filter”—past, present, and future.
    
    [1] G.N. Iles, K.C. Rule, V.K. Peterson, A.P.J. Stampfl and M.M. Elcombe, Rev. Sci. Instrum. 92, 073304 (2021); doi: 10.1063/5.0054786
    
    Speaker: Kirrily Rule (ANSTO)
  - 17:55
    
    Discovering peptide inhibitors against FtsY, an antibiotic target 1m
    
    The rapid rise of antibiotic resistance has caused an urgent demand for new antibiotics. One way to address this is by manipulating essential bacterial interactions not targeted by current antibiotics. The interaction between the Signal Recognition Particle (SRP) and its receptor (FtsY) is critical for cell viability but is mediated by RNA:protein interactions in bacteria versus protein:protein interactions in eukaryotes. We have used a new technology known as RaPID (Randomised non-standard Peptide Integrated Discovery) to identify cyclic peptides that bind to FtsY. Sequence enrichment was observed after seven rounds of selection and eight representative peptides were selected for further characterisation.
    
    To determine whether the peptides can bind the intended RNA-binding interface on FtsY, Nuclear Magnetic Resonance Spectroscopy (NMR) spectra were collected on ²H¹³C¹⁵N-FtsY produced by ANSTO. High deuteration level has facilitated good quality NMR spectra despite the large size of FtsY (35 kDa). In total, ~220 amide groups were mapped onto the “fingerprint” ¹⁵N-¹H-HSQC spectrum with >75% of backbone resonances assigned. Following peptide synthesis, we will titrate selected peptides into labelled FtsY for chemical shift perturbation experiments. This will provide binding affinity data for the different peptides and enable the mapping of binding residues onto our previously solved crystal structure. The highest affinity binders will be subjected to soaking and co-crystallisation experiments with FtsY to further characterise the mode of interaction. Taken together, the data obtained will inform the future development of cyclic peptides into FtsY inhibitors with high affinity and specificity as potential antibiotic leads.
    
    Speaker: Jennifer Zhao (University of Sydney)
  - 17:56
    
    Zeolitic imidazolate frameworks (ZIFs) structure and properties correlation to nucleic acid delivery 1m
    
    In regenerative medicine, (intra)cellular delivery of genetic material can be used to introduce functional copies of a gene that is defective and responsible for disease development. To avoid nuclease- and lysosome-mediated degradation of the gene, drug delivery systems / carriers need to be developed. Recently, non-viral delivery systems are being developed, such as microinjection, or various chemical approaches (e.g. liposomes, polymers, lipids); due to their economical synthesis, biocompatibility and ability to transfer a variety of genetic materials and gene editing tools.1 Zeolite imidazole framework (ZIF) is a well-studied non-viral polymeric delivery system where coordination between Zn(II) and imidazolate forms a highly organised framework in aqueous solution. ZIFs offer advantageous physicochemical properties for bio-delivery applications and have been shown to encapsulate a wide range of biomolecules, including nucleic acids, via biomimetic mineralisation. Such ZIF-based delivery systems provide protection of the gene cargo and were shown to result in endocytosis-mediated cellular uptake. Further, ZIFs degrade in the acidic microenvironments of cancer cells, releasing their cargo at the target site.2,3 Both cellular uptake and release of ZIF encapsulated biomolecules are determined by the framework structure, and its crystal phase. In our work, a series of ZIF preparation methods are studied for the encapsulation of a circular plasmid. The resulting ZIF structures are characterised via FTIR, SEM, synchrotron PXRD. The aim of this project is to establish structure–property relationships to gene loading efficiency, cellular uptake and cargo release profiles.
    
    References:
    1. Sung et al. 2019, Biomater Res, 23(1), 1-7, doi: 10.1186/s40824-019-0156-z.
    2. Poddar et al. 2020, Small, 15(36), 1902268, doi: 10.1002/smll.201902268.
    3. Poddar et al. 2021, Chem Com, 56(98),15406-15409, doi: 10.1039/d0cc06241c.
    
    Speaker: Shakil Ahmed Polash (PhD candidate, School of Science, RMIT University, Melbourne, Victoria 3000, Australia)
  - 17:57
    
    Inelastic Neutron Scatterings Reveal Intense Ferromagnetic Fluctuations Preceding Magnetoelastic First-Order Transitions in LaFe13−xSix 1m
    
    First-order magnetic transitions are of both fundamental and technological interest. Of particular interest are giant magnetocaloric effects, which are attributed to first-order magnetic transitions and have attracted great attention for solid-state refrigeration applications. Here, we present a systematic study, with inelastic and quasielastic neutron scatterings, on the lattice and spin dynamics in intermetallic LaFe11.6Si1.4 and LaFe11.2Si1.8, which represent one of the most classical giant magnetocaloric systems and undergo first-order and second-order magnetic transitions, respectively. While the two samples show similar spin-phonon coupling effect, LaFe11.6Si1.4 exhibits a much stronger magnetic diffuse scattering in the paramagnetic state preceding its first-order magnetic transition, correlating closely to picosecond ferromagnetic fluctuations. These dynamic insights suggest that the spin dynamics dominate the magnetoelastic transition and ferromagnetic fluctuations may be universally relevant for magnetocaloric materials [1].
    
    [1] Zhao Zhang, et al. PHYSICAL REVIEW MATERIALS 5, L071401 (2021).
    
    Speaker: Dehong Yu (Australian Nuclear Science and Technology Organisation)
  - 17:58
    
    Characterisation of an Antimony-based Catalysts for Acid Water Oxidation Catalysis – Insights through X-ray Absorption Spectroscopy and the challenges of multi-metal systems 1m
    
    Electrochemical water splitting with a proton-exchange membrane electrolyte provides many advantages for the energy-efficient production of high-purity dihydrogen in a sustainable manner, but the current technology relies on high loadings of expensive and scarce iridium at the anodes, which are also often insufficiently stable in operation. A common strategy to achieve stability is to synthesise composite oxides composed of multiple components, for example [M]SbOx, [M]PbOx, [M]BiOx. Yet, these materials pose a challenge in that it is not well understand how the mixed metal works to stabilise the material under acidic conditions. The present work presents an efficient ruthenium antimony oxide (RuSbOx) electrocatalyst synthesised as a thin film on fluorine-doped tin oxide (FTO). Comprehensive physical characterisation by X-ray absorption spectroscopy (XAS) and transmission electron microscopy (TEM) reveals important insights into the structure and mechanism of the examined materials while simultaneously highlighting how structural effects, such as disorder, may impact the observation and interpretation of EXAFS data.
    
    Speaker: Brittany Kerr (Swinburne University of Technology)
  - 17:59
    
    Biocompatible ionic liquids as designer solvents for the formation of non-lamellar lyotropic liquid crystalline nanoparticles as drug delivery vehicles 1m
    
    Ionic liquids (ILs) have emerged as a remarkable class of green solvents with unique characteristics, and feasible task-specific tailoring of their properties. The application of ILs has extended to facilitate amphiphile self-assembly. ILs not only support the self-assembly of amphiphiles, they can also be used as designer solvents(1).
    Lipid amphiphiles can assemble into a wide range of lyotropic liquid crystalline mesophases possessing unique highly ordered multidimensional structures. The bulk phases can be further broken into nanoparticle dispersions (LCNPs),for examples cubosomes and hexosomes, that are characterised by their high surface to volume ratio. These particles are receiving growing interest due to their great potential as drug delivery vehicles for both hydrophilic and hydrophobic drugs(2).
    Our recent small angle X ray scattering (SAXS) results revealed a wide range of LCNPs such as cubosomes and hexosomes obtained in various biocompatible ILs-water solvents. A strong correlation exists between the pH of the solutions and the adapted phases.
    
    References:
    1. Zhai, J.; Sarkar, S.; Tran, N.; Pandiancherri, S.; Greaves, T. L.; Drummond, C. J., Tuning Nanostructured Lyotropic Liquid Crystalline Mesophases in Lipid Nanoparticles with Protic Ionic Liquids. The Journal of Physical Chemistry Letters 2021, 12 (1), 399-404.
    2. Zhai, J.; Fong, C.; Tran, N.; Drummond, C. J., Non-Lamellar Lyotropic Liquid Crystalline Lipid Nanoparticles for the Next Generation of Nanomedicine. ACS Nano 2019, 13 (6), 6178-6206.
    
    Speaker: Mr Mohamad El Mohamad (RMIT university)
  - 18:00
    
    Understanding the structural basis of TIR-domain assembly formation in TRAM- and TRIF- dependent TLR signalling 1m
    
    Toll-like receptors (TLRs) detect pathogens and endogenous danger, initiating immune responses that lead to the production of pro-inflammatory cytokines. At the same time, TLR-mediated inflammation is associated with a number of pathological states, including infectious, autoimmune, inflammatory, cardiovascular and cancer-related disorders. This dual role of the pathways has attracted widespread interest from pharmaceutical industries. Cytoplasmic signalling by TLRs starts by their TIR (Toll/interleukin-1 receptor) domain interacting with TIR domain-containing adaptor proteins MyD88, MAL, TRIF and TRAM. Combinatorial recruitment of these adaptors via TIR:TIR domain interactions orchestrates downstream signalling pathways, leading to induction of the pro-inflammatory genes. Although many constituents of the TLR pathways have been identified, the available information on their coordinated interactions is limited. Such information is crucial for a mechanistic understanding of TLR signalling, development of therapeutic strategies, and understanding of the molecular basis of the consequences for human disease of adaptor polymorphic variants. We have discovered that TIR domains can form large assemblies. We hypothesized that TIR domain signalling occurs through a mechanism involving higher-order assembly formation. In this study we aim to determine the molecular architecture of higher-order assemblies formed by TIR domains with a focus on TRAM-TRIF assemblies in the TLR4 and TLR3 pathway.
    
    Speaker: Ms Mengqi Pan
  - 18:01
    
    Structural basis of coronavirus E protein interactions with human PALS1 PDZ domain 1m
    
    SARS-CoV-2 infection leads to coronavirus disease 2019 (COVID-19), which is associated with severe and life-threatening pneumonia and respiratory failure. However, the molecular basis of these symptoms remains unclear. SARS-CoV-1 E protein interferes with control of cell polarity and cell-cell junction integrity in human epithelial cells by binding to the PALS1 PDZ domain, a key component of the Crumbs polarity complex. We show that C-terminal PDZ binding motifs of SARS-CoV-1 and SARS-CoV-2 E proteins bind the PALS1 PDZ domain with 29.6 and 22.8 μM affinity, whereas the related sequence from MERS-CoV did not bind. We then determined crystal structures of PALS1 PDZ domain bound to both SARS-CoV-1 and SARS-CoV-2 E protein PDZ binding motifs. Our findings establish the structural basis for SARS-CoV-1/2 mediated subversion of Crumbs polarity signalling and serve as a platform for the development of small molecule inhibitors to suppress SARS-CoV-1/2 mediated disruption of polarity signalling in epithelial cells.
    
    Speaker: Mrs Airah Javorsky (La Trobe University)
  - 18:02
    
    Crystal Structures of Protic Ionic Liquids and their hydrates 1m
    
    Protic Ionic Liquids (PILs) are a class of tailorable solvents made up of fused salts with melting points below 100 °C, which are formed through a Brønsted acid-base reaction involving proton exchange[1]. These solvents have applications as lubricants, electrolytes, and many other uses[2]. Although they are quite similar to molten salts, their crystal structures have not been explored in-depth, with only ethylammonium nitrate (EAN) having a reported crystal structure[3, 4].
    Ten alkylammonium-based protic ionic liquids at both neat (<1 wt% water) and 90 mol% PIL, 10 mol% water concentrations were selected. Diffraction patterns were collected at the Australian Synchrotron ANSTO while attempting to crystallise the samples by cooling to 120 K. Five samples crystallised (3 neat, 2 dilute), where the temperature of the system was then increased at a rate of 6 K/min to room temperature. From these patterns we have identified a number of crystal phases, identifying their stability ranges and lattice constant variation from 120 K to room temperature.
    [1] Hallett, J.P. and Welton, T. (2011). Chemical Reviews. 111, 3508–3576.
    [2] Greaves, T.L. and Drummond, C.J. (2008). Chemical Reviews. 108, 206–237.
    [3] Abe, H. (2020). Journal of Molecular Liquids. 6.
    [4] Henderson, W.A., et al. (2012). Physical Chemistry Chemical Physics. 14, 16041.
    
    Speaker: Michael Hassett (RMIT University)
  - 18:03
    
    Ocean acidification alters the nutritional value of Antarctic diatoms 1m
    
    The cold waters of the Southern Ocean (SO) are acknowledged as a major hotspot for atmospheric CO2 uptake and is anticipated to be one of first regions to be affected by Ocean acidification (OA). Primary production in the SO is dominated by diatom-rich phytoplankton assemblages, whose individual physiologies and community composition are strongly shaped by the environment, yet knowledge on how diatoms allocate cellular energy in response to OA is limited. Using Synchrotron based FTIR-Microspectroscopy at the Australian Synchrotron, we analysed the macromolecular content of selected individual diatom taxa from a natural Antarctic phytoplankton community exposed to a gradient of fCO2 levels (288 – 1263 µatm). We found strong species-specific differences in macromolecular partitioning under OA. Larger taxa showed preferential energy allocation towards proteins, while smaller taxa increased both lipid and protein stores. Our study also revealed an OA-induced community shift towards smaller taxa and lower silicification rates at high fCO2. If these changes are representative of future Antarctic diatom physiology, we may expect a shift away from lipid rich large diatoms towards a community dominated by smaller, less silicified taxa, but with higher lipid and protein stores than their present-day contemporaries, a response that could have cascading effects on foodweb dynamics in the Antarctic marine ecosystem.
    
    Speaker: Ms Rebecca Duncan (University of Technology Sydney and UNIS Svalbard)
  - 18:04
    
    Synchrotron Light for Exploring Arsenic Environments in Arsenian Pyrite 1m
    
    Substitution of arsenic in pyrite called arsenian pyrite is often accompanied by concentration of valuable metals such as gold in some deposits. In such mineralogical occurrence, a concentration-driven substitution of As encapsulating ‘pure’ pyrite is typical. Although knowledge of As substitution environment in pyrite is important in determining surface characteristics, and interactions in chemical processes such as oxidation, they are widely varied in nature with paucity of information in existing literature. The current study employed synchrotron X-ray spectroscopy (SXPS), using tunable excitation energy to study vacuum-fractured surfaces of arsenian pyrite. SXPS As 3d of arsenian pyrite suggest the existence of an As-As dimer in arsenian pyrite, characterised by a shift in bulk binding energy to 0.6 eV lower than the As-S dimer of arsenopyrite. Possible As cluster formation was also proposed. The high binding energy contribution at excitation energy of 100 and 210 eV were resolved into two surface components that may have formed from possible surface reconstruction or polymerisation.
    
    Speaker: Philip Forson (University of South Australia, Future Industries Institute-STEM)
  - 18:05
    
    Acidophilic iron- and sulfur-oxidizing bacteria driven primary mineral weathering and secondary mineral formation in Fe ore tailings 1m
    
    Direct phytostabilisation of Fe ore tailings is typically unfeasible due to its harsh environment, which includes strongly alkaline pH conditions, deficient available nutrients and organic matter and poor physical structure, hindering microbial and plant colonisation. Eco-engineering Fe ore tailings into a soil-like substrate (or technosol) is an emerging technology to rehabilitate tailings landscapes sustainably, involving a suite of abiotic and biotic inputs (organic matter, functional microorganisms and pioneer plants). However, the extreme alkalinity and the lack of secondary Fe-rich minerals are critical barriers to transforming Fe ore tailings into soil.
    Using a microcosm experiment amendment with elemental sulfur (S0), Acidithiobacillus ferrooxidans demonstrated the capacity to generate acid that neutralised alkaline tailings and accelerated primary mineral weathering, i.e., technosol formation. [1] The effects of biological S0 oxidation on the weathering of alkaline Fe ore tailings were examined using several high-resolution micro-spectroscopic techniques, including synchrotron-based X-ray absorption fine structure spectroscopy (XAFS) and electron microscopy. It is found that: 1) A. ferrooxidans inoculum together with S0 amendment facilitated fast neutralisation of the alkaline Fe ore tailings; 2) A. ferrooxidans activities induced Fe-bearing primary mineral (e.g., biotite) weathering and nano-sized secondary mineral (e.g., ferrihydrite and jarosite) formation; 3) the association between bacterial cells and tailing minerals were facilitated by extracellular polymeric substances (EPS). The behaviour and biogeochemical functionality of A. ferrooxidans in the tailings provide a fundamental basis for developing bacterial based technologies towards eco-engineering tailings into a soil-like substrate for sustainable mine site rehabilitation.
    
    Speaker: Mr QING YI (The University of Queensland)
    
    AUM2021_QingYI_Poster-20210926.pdf
  - 18:06
    
    Comparison between calculated texture-derived velocities and laboratory measurements conducted on samples from a gold-hosting structure. 1m
    
    Most lode gold deposits worldwide are associated with structures such as shear zones. Thanks to their capacity to couple resolution and depth of investigation, seismic methods can identify these indirect indicators of mineralization and help extend gold exploration targets to greater depths. Rocks from shear zones are usually seismically anisotropic. Seismic anisotropy is generally related to the intrinsic texture of the rock and the presence of cracks at depth. Determining seismic anisotropy in relation to the texture of the rock, and its evolution with depth (pressure) is therefore necessary to help interpret exploratory seismic surveys. We report here the results of such a correlation conducted in the laboratory with rock samples extracted from the Thunderbox Gold Mine in Western Australia. Four samples — including two from the shear zone — were selected to assess the pressure and directional dependency of the P-wave velocities. In addition, an independent texture analysis was carried out on the two samples from the shear zone using the quantitative Neutron diffraction method. We then computed the texture-derived velocities using as inputs the mineralogy and texture of the samples. The good agreement between calculated texture-derived velocities with experimental measurements shows that the texture of the shear zone samples is the main source of seismic anisotropy. This study seeks to improve the understanding of the seismic response across mineral deposits that are structurally controlled by shear zones.
    
    Speaker: Mr Andre Eduardo Calazans Matos de Souza (Curtin University)
  - 18:07
    
    Towards real-time analysis of liquid jet alignment in SFX 1m
    
    Serial femtosecond crystallography (SFX) enables atomic scale imaging of protein structures via X-ray diffraction measurements from large numbers of small crystals intersecting intense X-ray Free Electron Laser (XFEL) pulses. Sample injection typically involves continuous delivery of crystals to the pulsed XFEL beam via a liquid jet. Due to movement of the jet, which is often focused to further reduce its diameter using a gas virtual dynamic nozzle (GVDN), jet position is often adjusted multiple times during the experiment. This can result in loss of beamtime and significant manual intervention. Here we present a novel approach to the problem of liquid jet misalignment in SFX based on machine vision. We demonstrate automatic identification and classification of when there is overlap (‘hit’) and when there is not overlap (‘miss’) between the XFEL beam and jet. Our algorithm takes as its input optical images from the ‘side microscope’ located inside the X-ray hutch. This algorithm will be incorporated into the control system at the SFX/SPB beamline at the European XFEL where it will be used for in-situ ‘alignment correction’ via a continuous feedback loop with the stepper motors controlling the location of the nozzle within the chamber. Full automation of this process will result in a larger volume of useful data being collected. By increasing the efficiency and reducing the per experiment operational cost of SFX at the European XFEL a higher volume of experiments can be performed. In addition, via analysis of the feedback metrology we anticipate that optimised nozzle designs and jetting conditions could be achieved further benefitting the end user.
    
    Speaker: Mr Jaydeep Jaydeep Patel (La Trobe University)
  - 18:08
    
    Combating “fishy” seafood using nuclear techniques 1m
    
    Food provenance is a global concern due to rising instances of food fraud, costing the global food industry over 50 billion USD per annum and leading to consumers getting lower quality produce. Seafood is a high value food product, and the Australian seafood industry is worth 4 billion AUD by 2023. Most Australian seafood is exported, and complex supply chains can leave it susceptible to seafood fraud. Accurate and reliable methods of determining seafood provenance is necessary to deter fraud in the supply chain. While conventional techniques can be used for determining seafood provenance, there is no single method that accurately determines both the geographic and production origin of seafood.
    
    This is where nuclear techniques can play a vital role, the ANSTO led seafood provenance consortium has partnered with university, industry, and government agencies to develop a method for determining seafood provenance using iso-elemental fingerprinting. This work also highlights the utilisation of ANSTO’s multi-platform analysis capabilities including x-ray fluorescence through Itrax, accelerator-based ion beam analysis and stable isotope analysis that allow provenance to be determined with >80% accuracy when combined with machine learning based models.
    
    This research is expected to provide the industry and regulatory bodies with an effective way of determining seafood provenance. Furthermore, the iso-elements fingerprints are unique to each grower and has the potential to be used as a tool to protect their brands. It also ensures that the Australian export industry is protected and allow consumers to make informed decisions when purchasing seafood.
    
    Speaker: Mr Karthik Gopi (UNSW)
  - 18:09
    
    Effect of different cladding alloys and grinding on residual stress in laser clad light rail components using neutron diffraction 1m
    
    One of the greatest challenges threatening Australia’s railway infrastructure is the rapid rate of rail degradation. Wear and rolling contact fatigue occur due to increasing speeds and tonnages of rollingstock, requiring significant funding by the Australian government to maintain. Light rail is particularly susceptible to degradation due to low carbon steel used in tram switch blades.
    
    Laser cladding is a repair strategy which applies a metallic deposition by melting a cladding powder with the substrate using a high energy laser. This process forms a metallurgical bonded layer whilst generating a heat affected zone (HAZ) containing a redistribution of residual stress due to phase changes and solidification shrinkage from the thermal inputs.
    
    During operation, cyclic wheel-rail contact stress is superimposed on the residual stress leading to fatigue. The ability to accurately measure residual stresses non-destructively, made possible using neutron diffraction, is critical in experimentally obtaining stress data for fatigue assessment. Laser cladding has been carried out on ex-service switch blades using a martensitic stainless steel and two Stellite alloys. A standard grinding procedure has been performed to replicate the stress conditions experienced in-field after cladding repairs.
    
    Strain measurements were undertaken on the Kowari strain scanner at ANSTO to determine the tri-axial stress across the cladding, HAZ and substrate. The locations of the fusion boundary and HAZ have been identified through correlation of the stress, microstrain and full width at half maximum profiles. These findings accompany extensive evaluation of microstructure and mechanical properties to optimise laser cladding repairs in light rail components.
    
    Speaker: Prof. Ralph Abrahams (Monash University)
  - 18:10
    
    Data Constrained Modelling with multi-energy X-ray computed microtomography to evaluate the porosity of plasma sprayed ceramic coatings 1m
    
    Coatings of the materials zirconium boride (ZrB2) and hydroxyapatite (HAp) underwent X-ray micro-Computed Tomography (X-ray μ-CT) scanning at the Australian Synchrotron. The Data Constrained Modelling (DCM) approach was used to reconstruct 3D models and assess porosity and void distributions. The results from the 3D analysis were compared to a 2D porosity and void distribution assessment, determined from image analysis of the coatings. It was found that the 3D and 2D porosity quantifications were in moderate to good agreement. The 3D porosity determined from the ZrB2-1 model, 24.7%, was within the range determined from 2D analysis, 22.1 ± 2.6%. Alternatively, the 3D porosity determined from the HAp-1 model, 22.8%, was marginally greater than the determined 2D porosity, 19.8 ± 2.1%. However, a comparison of the 2D and 3D void distributions revealed that a 2D assessment poorly predicts the 3D microstructure of coatings and cannot be used to infer properties strongly dependent on the 3D void network. Furthermore, the 3D analysis demonstrated the deficiencies in typical CT segmentation methods applied to data with a moderate CT resolution size of 5.4 μm. The DCM methodology can quantify fine-structure details below the resolution of the performed CT and thus assess the multi-scale porosity and void networks within atmospheric plasma spray (APS) deposited coatings. The superior DCM approach enabled the quantification of pores below the CT resolution limit and revealed that approximately 91.5% and 81.0% of the ZrB2-1 model and the HAp-1 models, respectively, would not have been accurately modelled using typical CT segmentation methods.
    
    Speaker: Mr Bruno Kahl (Swinburne University of Technology)
  - 18:11
    
    Microbeam radiation therapy in a heart beat 1m
    
    Non-small-cell lung carcinomas are highly radioresistant and so, of potential interest for treatment with Microbeam Radiation Therapy. In the thoracic cavity, the therapeutic dose is limited largely by the heart; one of the most important organs of risk.
    We developed an ex vivo protocol to study the acute response of the cardiac impulse conduction system to microbeam radiotherapy with high peak doses, combining physiology measurements in the Langendorff model of the isolated beating heart with world-leading real-time small volume dosimetry.
    The study was performed in Hutch 2B of the Imaging and Medical Beam Line (IMBL) of the Australian Synchrotron.
    The acute physiological response of the heart was measured for 60 minutes post-irradiation.
    With no arrhythmia or ventricle pressure drop, results place the upper limit for normal functioning of the heart between 400 – 4,000 Gy
    
    Speaker: Jason Paino (UOW)
  - 18:12
    
    Using low energy ion beams to pattern the surface of novel semiconductors 1m
    
    A wide range of ion energies (KeV- MeV), ion species, and ion fluences achievable by ion beam implantation, which allows fabrication of highly customized patterned subsurface structures in materials. This advanced material processing technology allows tuning of specific magnetic, and electronic properties with the aim of achieving a wide range of functionalities in electronics. Magnetic ions implantation has been actively used for functionalising semiconductor materials in recent few years in attempt to fabricate magnetic semiconductors for spintronic applications. [1, 2] Ion beam patterning, like electron-beam lithography, able to fabricate customised geometryies on a surface of a semiconductor to create a functionalised region with desired electronic and magnetic properties. By using low energy ion beam implanter at Center of Accelerator Science (CAS) at Australian Nueclear Science and Technology Organisation (ANSTO), we demonstrate that the current method has the potential application in the integrated circuitry processing industry with the ability to “write” very small features down to few tens of nanometers.
    
    Speaker: Abuduliken Bake (University of Wollongong)
  - 18:13
    
    Characterising the temperature dependent spectra of polyethylene for terahertz optics 1m
    
    Polyethylene is a highly transparent material in the terahertz (THz) region (1-200 cm$^{-1}$). This makes it ideal for lenses and windows, especially for cryostats. It is also often used as a binding medium in sample pellets to dilute trace amounts of optically thick samples.
    
    One caveat for this extremely useful material, however, is an absorption at 73 cm$^{-1}$, often overlooked when utilising polyethylene for terahertz optics. This mode was first studied during the 1960’s [1,2] but has sparsely been mentioned in scientific literature since, most recently in 2019, being described as “elusive” [3].
    
    To determine the effects of this absorption on terahertz optics we have quantified the intensity and frequency of this mode from 6-300 K for different sample thicknesses on the THz beamline at the Australaian Synchrotron. We have observed a large redshift of 6.7 cm$^{-1}$ (79.9-73.2 cm$^{-1}$) with heating over this temperature range, as well as significant reductions in the peak intensity. These results indicate that for thin samples (<2 mm) of polyethylene this mode is negligible at room temperature, however, at cryogenic temperatures this mode causes a notable drop in transmission, even for samples as thin as 0.5 mm. This warrants caution, especially when selecting cryostat windows and observing weak features near this mode.
    
    [1] R. V. McKnight et al., “Far-infrared spectrum of polyethylene, and quartz-crystal plates”, J. Opt. Soc. Am., 54(1), 132-133, 1964.
    
    [2] S. Krimm et al., “Assignment of the 71-cm-1 band in polyethylene”, J. Chem. Phys., 42(11), 4059-4060, 1965.
    
    [3] K. Zhou et al., “Transmittance of high-density polyethylene from 0.1 THz to 15 THz”, Proc. SPIE 11196, Infrared, Millimeter-Wave, and Terahertz Technologies VI, 2019.
    
    Speaker: Thomas Sanders (University of Wollonogong)
  - 18:14
    
    Inelastic Neutron Scattering of Liquid Metal Gallium 1m
    
    Liquid metals (LMs) – metals that are liquid near room temperature – have fascinated scientists for centuries. In the last few decades, in particular, the extent of their peculiar properties has been highlighted. Properties such as low melting point, high flexibility and stretchability, excellent thermal and electrical conductivities, and biocompatibility have led LMs to a wide variety of applications. While LMs have proven to be an exceptionally useful class of materials, their unique properties also speak to various fundamental physical phenomena. In particular, the (hydro)dynamics of LMs is of interest as they have a uniquely challenging nature: possessing the complex nature of regular fluids as well as a “sea” of electrons – giving rise to unique hydrodynamic effects. Inelastic neutron scattering (INS) is a particularly well-suited technique to investigate such effects as it probes the microscopic hydrodynamic origins in the nanometer-terahertz regime. In this presentation, we shall report our preliminary investigations on Ga across the phase transition from solid to liquid as a function of temperature using inelastic neutron scattering. The analysis of the energy dependence of the phonon density of states at low energy region reveals the transition from E^2 for the solid state to a more or less linear relationship corresponding to the liquid state. The dynamic changes will be further discussed in the content of atomic diffusive properties of the system through analysis of the quasielastic neutron scattering in combination with molecular dynamic simulations.
    
    Speaker: Caleb Stamper (University of Wollongong)
  - 18:15
    
    Understanding and controlling the formation of photonic crystals from polydisperse colloidal systems 1m
    
    The fundamentals of crystallisation and glass formation are not yet fully understood. Colloidal suspensions have been shown to be promising model systems for understanding these processes. As colloidal motion is Brownian, rather than ballistic, kinetics and dynamics can be studied in real-time. It is well documented that colloidal suspensions can “successfully crystallise” when the particles in the system have sufficiently low polydispersity.[1,2] This means that the particles must have a similar average size and shape. If a system is highly polydisperse, this will hinder the solidification process.
    
    In this work we will explore colloidal nanodiamonds. Nanodiamonds are a topic of interest in many material studies due to their wide variety, and unique mechanical and optical properties.[3,4] Detonation nanodiamonds (DNDs) are of particular interest due to their unique fabrication process. Due the detonation synthesis method, the particles are small (several nm) and faceted, but in solution self-assemble into highly irregular fractal shapes.[5] Despite this high polydispersity, when centrifuged, these types of DNDs can yield incredibly ordered structures and form iridescent photonic crystals – this is highly surprising given the highly irregular structures of these materials. These photonic crystals were first discovered by Grichko et al.,[5] however, the mechanisms behind these highly ordered structures are still unknown. With a combination of lab techniques and beam time allocations at the Australian Synchrotron, ANSTO and potentially overseas neutron facilities, we will systematically investigate these nanodiamond photonic crystals, and examine their structure and formation kinetics.
    
    Speaker: Katherine Chea (RMIT University)
  - 18:16
    
    Radiation monitor for astronaut safety and prediction of electronic failure in the space mission 1m
    
    Astronauts travelling through space are at risk of exposure to radiation arising from Galactic Cosmic Rays (GCRs) and Solar particle events (SPE) which possess a significant radiobiological effect. GCR is mostly made up of protons with a small proportion of GCR being high atomic number energetic particles, which are difficult to shield while SPEs are events which occasionally eject large number of protons on top of a steady stream of photons and electrons. The composition of GCRs and SPE creates a complex radiation field which becomes difficult to characterize in real time due to the large variety of ions and radiation types. The ability to measure the dose equivalent in real time received by astronauts with high efficiency and accuracy is of great importance, as the risk of excessive exposure can be monitored and minimized. A novel large area microdosimeter has been developed at the Centre for Medical Radiation Physics, University of Wollongong – named the Octobox, for monitoring the dose equivalent and radiobiological risk to astronauts in a mixed radiation field environment, typical to the one encountered in space. The Octobox’s response to 290 MeV/u 12C ion, 230 and 490 MeV/u 28Si, 400 MeV/u 20Ne at the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan was studied. Both experimental and GEANT4 simulation data are showing that the Octobox is suitable for mixed radiation field monitoring for space application with real-time readout of dose equivalent values aiding in protection of astronauts on space missions.
    
    Speaker: Vladimir Pan (University of Wollongong)
  - 18:17
    
    Canine osteosarcoma positioning and dosimetry study 1m
    
    Appendicular osteosarcoma is a highly destructive malignant primary bone tumour occurring in both canine and human patients. Clinically, amputation is the most common outcome, however, Synchrotron generated radiotherapy may provide a preferable alternative.
    Building from a body of knowledge acquired in small animal models, client-owned dogs with spontaneously developing tumours would be an excellent translational model to assess novel radiation therapies, moving toward the ultimate goal of human patients.
    
    This work presents a positioning and dosimetry study using a canine cadaver as a proof-of-concept for veterinary trials at the imaging and medical beamline of the Australian Synchrotron. This included x-ray imaging, alignment to the treatment beam, simulation and prescription of a therapeutic dose and finally the delivery of said prescription.
    
    Speaker: Jason Paino (UOW)
  - 18:18
    
    Lithium Lanthanide Halides: A New Family of Solid Electrolytes 1m
    
    The growing need for safe and reliable energy storage has brought the search for stable, high performance solid electrolytes to the forefront of battery materials research. Recently, it has been shown that lithium lanthanide halides (Li$_3$MX$_6$, M = La-Lu, X = Cl, Br, I) with high ionic conductivities can be synthesized through mechanochemical and water mediated routes, creating renewed interest in the family of compounds. However, Li$_3$MX$_6$ compounds have only been synthesised with the late lanthanides (Eu-Lu), apart from the isolated case of samarium bromide, and of these compounds, only Li$_3$MX$_6$ (X = Cl, Br, I) and Li$_3$YbCl$_6$ have had their crystal structures reported. This leaves a large gap in the literature that is yet to be explored. The family of Li$_3$MX$_6$ compounds share properties that make them highly appealing for use in all-solid-state batteries. Their structural properties, namely disordered lithium sites and soft anion lattices, allow for Li$_3$MX$_6$ compounds to have excellent ionic conductivities of ~1 mS/cm, comparable to garnet Li$_7$La$_3$Zr$_2$O$_{12}$, one of the most promising solid electrolytes for lithium batteries. Additionally, halides have a favourable decomposition against lithium metal electrodes, forming ionically conductive and electronically insulating LiX interphase materials. These interphase materials are stable during cycling and impede any further electrolyte decomposition, allowing for excellent cyclic stability. These properties, along with the large gaps that are yet to be explored, make research into Li$_3$MX$_6$ compounds imperative for the continued development of solid-state electrolytes for all-solid-state batteries.
    
    Speaker: Michael Brennan (University of Sydney)
  - 18:19
    
    Wombat – the high intensity diffractometer at OPAL 1m
    
    Wombat is a high intensity neutron diffractometer located in the OPAL Neutron Guide Hall. It is primarily used as a high-speed powder diffractometer, but has also expanded into texture characterisation and single-crystal measurement, particularly diffuse scattering. The high performance comes from the combination of the best area detector ever constructed for neutron diffraction with the largest beam guide yet put into any research reactor and a correspondingly large crystal monochromator, all combine with the centre’s polarisation capability to provide an instrument which is unique within the Southern hemisphere.
    
    Wombat has been used to explore a broad range of materials, including: novel hydrogen-storage materials, negative-thermal-expansion materials, methane-ice clathrates, piezoelectrics, high performance battery anodes and cathodes, high strength alloys, multiferroics, superconductors and novel magnetic materials. Our poster will highlight both the capacity of the instrument, and some recent results.
    
    Speaker: Helen Maynard-Casely (Australian Nuclear Science and Technology Organisation)
  - 18:20
    
    Investigating negative thermal expansion in aliphatic metal-organic frameworks 1m
    
    Negative thermal expansion (NTE) involves the unconventional behaviour of material contraction upon heating and has been observed in some metal organic frameworks (MOFs). Investigations into the mechanism governing NTE are highly important for practical applications for when it is undesirable for materials to expand upon heating. Previous investigations focused on aromatic and single component frameworks, our goal is to expand into the realm of aliphatic linkers such as cubane-1,4-dicarboxylate (1,4-cdc) and bicyclo[1.1.1]pentane-1,3-dicarboxylate (1,3-pdc), which may introduce unencountered dynamic motions.^[1]
    
    Single-component aliphatic MOFs, 3DL-MOF-1 ([Zn4O(1,3-pdc)₃]) and CUB-5 ([Zn4O(1,4-cdc)₃]) were explored using powder diffraction (PD) techniques.^[2] The aliphatic MOFs demonstrated enhanced NTE, in comparison to its aromatic MOF-5 analogue . Investigations on the host-guest effects on NTE behaviour^[3] were explored using neutron PD at the ACNS by charging 3DL-MOF-1 with CO2 guest molecules. Successful NTE quenching was achieved at higher CO2 loading.
    
    To extend our understanding of aliphatic influences on NTE behaviour, we study a series of moisture stable multicomponent frameworks.^[4] Using synchrotron PD and single crystal X-ray diffraction we investigate the NTE behaviour of quaternary MOFs (three linkers and one node) by varying the aliphatic linker in each system. We hope to identify the key characteristics of aliphatic linkers that dictates NTE behaviour.
    
    [1] J. Perego et al., Nature Chemistry 2020, 12, 845.
    [2] L. K. Macreadie et al., ACS Applied Materials & Interfaces 2021, 13, 30885.
    [3] J. E. Auckett et al., Nature communications 2018, 9, 1.
    [4] L. K. Macreadie, et al., Angewandte Chemie International Edition 2020, 59, 6090.
    
    Speaker: Ms Celia Chen (The University of Sydney)
  - 18:21
    
    Chiral CPs formed using chiral heterotopic ligands 1m
    
    The use of heterotopic ligands in the synthesis of coordination polymers (CPs) using pyridyl groups and carboxylates have been extensive. But the use of chiral heterotopic ligands using pyridyl groups and phthalimide groups has not been explored. Chiral coordination polymers have been formed using leucine, phenylalanine and cysteine substituted pyridylphthalimide cores (L3pyph, M3pyph and L4pyph), where the pyridyl groups have been substituted in the 3 and 4 positions. One dimensional coordination polymers have been formed using L3pyph and P3pyph, where there are π-π interactions between parallel 1D chains. However, the use of more exotic amino acids such cysteine, C3pyph, has allowed for a 2D coordination polymer to be formed through the formation of disulphide bonds between 1D chains. A two fold interpenetrated 2D dimensional coordination polymer has been formed using L4pyph and P4pyph. These illustrates that the substitution of the pyridyl group between the 3 and the 4 position has a major influence with the coordination polymers formed.
    
    Speaker: Mr Nicholas Kyratzis (Monash University)
  - 18:22
    
    The N-methyl-D-aspartate receptor ligand binding domain and the interactivity with ion-channel control 1m
    
    Encephalopathies are a group of brain dysfunctions which leads to cognitive, sensory, and motor impairments. Recent developments in the field have led to the identification of several mutations within the N-methyl-D-aspartate receptor as one of the possible culprits for this group of conditions. However, understanding of the underlying changes to the receptor due to these mutations has been elusive to date. We aimed to determine the effects of one of the first mutations identified within the N-methyl-D-aspartate receptor GluN1 ligand binding domain, Ser688Tyr. This mutation was identified and associated with early onset encephalopathy. We performed molecular docking, randomly seeded molecular dynamics simulations, and binding free energy calculations to determine the behaviour of the 2 main co-agonists: glycine and D-serine and their effects on ion channel function. We determined that the Ser688Tyr mutation leads to instability of both ligands within the ligand binding site due to changes within the ligand binding domain associated with the mutation. Associated binding free energy for both ligands also increased significantly in the mutated receptor. These results reinforce previously observed in vitro electrophysiology data and provides additional information on ligand behaviour. Upcoming studies involve the use of crystallography and neutron scattering to determine the effects of this mutation on ion-channel function. This study provides valuable insight into the consequences of mutations within the N-methyl-D-aspartate receptor GluN1 ligand binding domain.
    
    Speaker: Zheng Chen (The University of Sydney)
  - 18:23
    
    Chiral Detection with Fluorescent Coordination Polymers 1m
    
    Chirality is an intrinsic property of life on Earth. Biological systems have evolved alongside chiral molecules like proteins, DNA, and sugars, which all exist as pairs of nonsuperimposable mirror images. These mirror images, called enantiomers, are chemically indistinguishable, except when they interact with other chiral systems. Chiral drugs like ibuprofen differ in their effectiveness based on the chiral purity of the dose, and artificial sweeteners like aspartame can taste bitter if unwanted enantiomers are not filtered out prior to consumption, owing to the human body’s inherent chirality. The need to differentiate and separate the enantiomers of chiral compounds has led to the development of chiral sensors: molecular systems that can identify the enantiomeric purity of a sample.
    
    Coordination polymers (CPs) and metal-organic frameworks (MOFs) are ideally suited to chiral sensing. These crystalline frameworks consist of extended structures of organic linkers bridging metal centres, and are both easily tuned and potentially porous, enabling the incorporation of small guest compounds into their internal voids. When the parent framework is chiral,1 one enantiomer of a chiral guest molecule will have a stronger interaction with the structure than its opposite. This dichotomy in binding strength can be paired with methods like circular dichroism (CD) spectroscopy and fluorescent techniques to assess a sample’s enantiomeric composition.2
    
    This poster presentation will describe the synthesis of a chiral, fluorescent CP and its crystal structure, recorded on the MX1 beamline at the Australian Synchrotron. The ability of this framework to differentiate the enantiomers of chiral guest compounds through fluorescent quenching measurements will also be highlighted.
    
    Speaker: Shannon Thoonen (The University of Melbourne)
  - 18:24
    
    The investigation of structural and electronic configurations of noble-metal free nanocomposite and electrocatalytic oxides for acidic water electrolysis 1m
    
    The development of in situ XAS for water electrolysis applications, such as sustainable hydrogen production, is integral towards the accurate characterisation of state-of-the-art electrocatalytic materials. As this field continues to uncover a breadth of earth-abundant and high performance electrocatalysts, the understanding of their operando structures and electronic states is required to not only understand the true nature of these electromaterials, but also precisely bench-mark emerging catalysts and catalytic mechanisms against already industrially dominant electrocatalysts. Due to its intrinsically conductive nature, and the purity of hydrogen that is produced at industrially relevant current densities, acidic water electrolysis presents one of the most capable modes of producing hydrogen sustainably at the terawatt scale. It is from these perspectives that the development of cost effective, acid stable and highly active catalytic materials must be developed and characterised in order to make this technology increasingly feasible for deployment at the global scale. Operando XAS has been instrumental in our recent developments towards two intrinsically stable electrocatalysts that are based off cobalt-rion-lead and silver-bismuth mixed oxides, and the now refined understanding of "catalyst-in-matrix" mechanisms of operation. During our XAS work at ANSTO we have been successful in collecting high quality XANES and EXAFS data on the two acid stable materials described, whereby structural and electronic information would not have been uncovered under ex situ XAS experimental designs. From the detailed results obtained, we are now refining our in situ XAS technique for a breadth of acid-stabe materials that have been developed within our team at Monash University and believe that this will benefit the field towards precise bench-marking metrics for cost effective electrocatalysis.
    
    Speaker: Darcy Simondson-Tammer (Monash University)
  - 18:25
    
    Investigating the dielectric properties of the cornea and tympanic membrane using Synchrotron ATR and transmission at THz frequencies 1m
    
    High GHz and THz frequencies are becoming important in the communication, security, and industrial fields. With the increasing use of THz technology, the skin, cornea, and tympanic membrane will be subjected to increased incidental and purposeful THz radiation. There is an urgent need to adequately characterise the way the cornea and tympanic membrane interact with THz radiation to understand potential THz exposure hazards and refine dosimetry guidelines. The understanding of the complex permittivity of the cornea and tympanic membrane at THz frequencies may lead to the development of THz-based diagnostic techniques and therapeutic techniques based on the differences of permittivity at THz between normal and pathological states.
    
    THz is highly absorbed by liquid water. The cornea and tympanic membrane are “high bulk water content” tissues (over 70% water). We have devised innovative approaches to interrogate biological samples with attenuated total reflection (ATR) apparatus at THz frequencies at THz/far-infrared beamline in the Australian Synchrotron. One new method extends the capabilities of the ATR apparatus to a partial reflection/partial transmission mode (APR). A second method was to vary the temperature of biological tissues whilst continually scanning the sample. The combination of the methods brought a very accurate determination of the temperature-dependent variation of the refractive index. The last technique extends the useful range of the apparatus to exploring samples with refractive index beyond the maximum possible with attenuated total reflection, bringing water-based biological samples within the capacity of the diamond crystal ATR at the Australian Synchrotron.
    
    Speaker: Ms Negin Foroughimehr (Swinburne University of Technology)
  - 18:26
    
    Ruthenium-Based Pyrochlore Oxides for Improved Electrocatalysis 1m
    
    Energy security during the transition to a low-carbon economy is one of society’s grand challenges. One possible method of developing carbon-neutral energy generation is through the combustion of hydrogen and oxygen gas. However, these gases must be able to be sustainably sourced using low-emission technologies.
    
    One such method is using electrocatalysts – catalysts capable of splitting water into hydrogen and oxygen gas in the presence of electricity. Currently, industry standard electrocatalysts contain a high noble metal content, such as ruthenium and iridium. These metals are extremely expensive and their performance can degrade over time. Recently, pyrochlore oxides have emerged as promising alternatives due to their low noble metal content, extreme stability, and high oxygen evolution activity in acidic environments. However, despite this, debate currently exists in the literature as to what specific structural properties of these materials lead to their superior electrocatalytic performance.
    
    This work presents full structural models of various ruthenium pyrochlore oxides of the form (Y$_{2-x}M_{x}$)Ru$_{2}$O$_{7-d}$ ($M$ = Mn-Zn) based on various diffraction and spectroscopic studies. X-ray and neutron diffraction, as well as X-ray absorption spectroscopy, have been used to determine the short-range local and long-range average structures of these electrocatalysts. Cyclic voltammetry measurements have further shown significant oxygen evolution reaction activity compared to industry-standard ruthenium oxide, despite containing substantially less ruthenium. This has allowed us to establish structure-functionality relationships for these electrocatalysts, further developing and improving them for overall water splitting reactions.
    
    Speaker: Bryce Mullens (University of Sydney)
  - 18:27
    
    SNAKE VENOM-CONTRLLED 3D FIBRIN ARCHITECTURE REVEALED BY SANS/USANS DICTATES FIBROBLAST DIFFERENTATION 1m
    
    Fibrin is the founding matrix after injury, delivering the key biophysical cues to promote wound healing in a timely and coordinated manner. The effect of the fibrin architecture on wound healing hasn’t been studied due to a lack of control over the enzyme-catalyzed polymerization of the fibrin network in vitro. Here, we establish a new defined snake venom-controlled fibrin system with precisely and independently controlled architectural and mechanical properties. By utilising combined small-angle neutron scattering (SANS) and ultra-small angle neutron scattering (USANS) techniques, we characterize the full-scale architectural properties of the new system from the internal structure of the individual fibres to the structure of the fibrin networks and compare them to super-resolution optical methods. This very precise set of neutron scattering data confirms our full control over the network’s architectural features, which serves as a foundation for the application of this defined system. The subsequent cell differentiation studies reveal that fibrin architecture has prevailing control over fibroblast spreading phenotypes and long-term myofibroblast differentiation. These findings implicate matrix architecture as a key activator of fibroblast differentiation and provide new biophysical strategies in the design of biomaterials to promote scarless wound healing.
    
    Speaker: Mr Zhao Wang (1Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Australia.)
    
    Poster ANSTO annual users' meeting 2021-Jeff.pdf
  - 18:28
    
    Physical insights into self-assembly of enzymatic protein particles using Small-Angle X-ray Scattering (SAXS) 1m
    
    Assembled protein particles are emerging as advanced protein biomaterials with significant impact in areas of vaccine development, biocatalysis, drug delivery and biosensing. To date, assembled protein particles primarily serve as scaffold to tether functional entities for various applications. Since they lack inherent functional properties, subsequent functionalisation of protein particles is essential. In this work, we present a simple approach using self-assembling peptides to form particles of protein of interest in the presence of stimuli.[1] We demonstrate this by a model protein-peptide module using enzyme bovine carbonic anhydrase (BCA) fused with self-assembling peptide (P114) via GS-linker and expressed in E. coli. The BCA-P114 self-assembles into particles in response to two different stimuli i.e., pH and magnesium ions. Through dynamic light scattering we showed that BCA-P114 particles form spontaneously, and particle size can be controlled with the extent of stimuli.[2] Using SAXS (SAXS/WAXS beamline at the Australian Synchrotron), we studied the self-assembly kinetics and the timescales of BCA-P114 particle formation using magnesium ions as stimuli. The SAXS analysis of particle formation kinetics exhibited the particle formation to occurs within 10 secs of exposure to magnesium ions. Furthermore, the structure and function of BCA-P114 particle were confirmed by transmission electron microscopy and enzyme assay respectively. Our self-assembling strategy provides a platform for the spontaneous formation and customisation of particles of desired functional protein.[3] This platform technology will open-up new opportunities to adapt functional proteins into particles for use as advanced biomaterial.
    
    Speakers: Dr Bhuvana Shanbhag (Monash University), Dr Tayyaba Younas (Monash University)
  - 18:29
    
    A precisely piezo-controlled macro-ATR for characterizing the dynamic behaviour electrolyte/electrode interface 1m
    
    In all battery systems, electrolyte plays a vital role in determining the stability of the electrodes, as well as the safety of the battery uses. The good solid electrolyte interphase (SEI) protective layer formed at the first cycling process of the battery, rather than continually accumulating on the electrode surface, and is not dissoluble in electrolytes, making its properties highly dependent on the chemical structure. Therefore, further development of safe battery technology strongly requires a better understanding of the chemistry and formation mechanism of the SEI, which remains largely unknown due to their complex structure and a lack of reliable in situ experimental techniques. Based on the above, a novel piezo-controlled macro-ATR (within a precise controlling thickness of 100 nm above the electrode surface) is successfully developed for battery research in the IRM beamline in the Australian Synchrotron. This innovation enables probing the real-time reaction inside a battery at the micro-scale with an accurate controlled detecting movement to the electrode surface. Changes in functional groups and their distribution observed will be complementary with the ex-situ results to provide a better understanding of the mechanisms occurring in different electrolytes at different stages, which will subsequently be correlated to their stability and charging performance. Such knowledge will be critical for optimizing the ingredients of non-flammable electrolytes to support further development of more stable and high-performance batteries and enable scientific design principles of non-flammable electrolytes.
    
    Speaker: Ms SAILIN LIU (University of Wollongong)
  - 18:30
    
    Analysis of Thermoresponsive Dextrans via Small-Angle X-ray Scattering 1m
    
    Thermoresponsive polymers have gained significant interest over recent years due to their potential use in a wide range of applications, including drug delivery, cell therapies, pharmaceuticals, tissue engineering, and mineral processing [1]. Of particular interest are thermoresponsive polysaccharides, which are generally biocompatible and biodegradable, unlike their synthetic counterparts. This is particularly important when considering biomedical applications, such as drug delivery, as biodegradability allows for the clearance of the drug delivery system from the body and can help to facilitate drug release. We have developed a novel family of thermoresponsive polysaccharides with tunable transition temperatures via functionalisation of non-thermoresponsive dextran with a series of alkylamides [2]. By altering the composition and degree of substitution of the alkylamide groups on the dextran backbone, the temperature at which phase transition occurs can be tuned. Upon heating, solutions of thermoresponsive dextrans undergo a reversable phase transition to afford colloidal suspensions. The nature of the solution-to-colloid transition was investigated by UV-visible spectrophotometry to determine the transition temperature and hysteretic effects, and via dynamic light scattering to determine changes in particle size and dispersity. To further interrogate the phase transitions and conformational changes occurring upon heating and cooling, Synchrotron small-angle X-ray scattering (SAXS) was conducted as a function of temperature. Taken together, these results provide a fundamental platform to further study the behaviour of these novel thermoresponsive dextrans when applied to specific applications, such as drug delivery or mineral processing.
    1. Graham, S, et al., 2019, Carbohydrate Polymers, 207, p.143-159.
    2. Otto, S, et al., 2021, Carbohydrate Polymers, 254, p.117280.
    
    Speaker: Sarah Otto (University of South Australia)
  - 18:31
    
    Exploring the Surface of Vanadium Phosphate Cathode Materials 1m
    
    In this study, we used a combination of synchrotron soft X-ray absorption spectroscopy (XAS), lab-scale experimental techniques and first principles computation to critically examine and validate the surface and bulk electronic structure of prototypical vanadium (III) phosphate intercalation cathode materials, Na3V2(PO4)3, Li3V2(PO4)3 and K3V3(PO4)4• H2O. Using a combination of XPS, Raman UV-Vis -NIR, UPS and DFT calculations, a full picture of each AVPs electronic structure was developed and validated using both experimental and calculated electronic structure and density of states data. From our synchrotron data, XAS fluorescence yield and electron yield measurements reveal substantial variation in surface-to-bulk atomic structure, vanadium oxidation states and density of oxygen hole states across all AVP samples. We attribute this variation to an intrinsic alkali metal surface depletion layer identified across these alkali metal vanadium (III) phosphates. We propose that an alkali-depleted surface provides a beneficial interface with the bulk structure(s) that raises the Fermi level and improves surface charge transfer kinetics at the surface of this family of materials. This surface depletion phenomenon has been previously reported in other prominent transition metal phosphate intercalation cathodes, such as LiFePO4 and its general presence here suggests wider ubiquity amongst alkali transition metal phosphate materials.
    
    Speaker: Mr Tristram Jenkins (Queensland University of Technology)
  - 18:32
    
    Synthesis and structural characterisation of novel perovskite-type Na-ion conductors 1m
    
    The development of new solid electrolytes is becoming increasingly important, e.g., for rechargeable batteries for electric vehicles, where current liquid organic electrolytes cause major safety concerns. Some ABO3 perovskite metal oxides have shown excellent lithium and sodium ion conductivity owing to their chemical and structural flexibility. This has led to the development of several perovskite-type solid electrolytes such as Li3xLa2/3-xTiO3 (LLTO) and Na1/2-xLa1/2-xSr2xZrO3 (NLSZ), which have shown high ionic conductivities [1-3].
    Starting from the x = 1/6 member of NLSZ, a new series of sodium perovskite-type solid electrolytes with the formula Na1/3La1/3-x/3Sr1/3Zr1-xNbxO3 (0 ≤ x ≤ 0.8) (NLSZN) was synthesised. Structural characterisation was carried using a combination of synchrotron and neutron powder diffraction data, which revealed both first- and second-order phase transitions as a function of temperature. For some samples the symmetry appeared higher in synchrotron data than neutron data, owing to the higher relative sensitivity of neutron data to scattering from oxygen atoms in the structure [4]. As observed for other defect perovskites, there is a tendency to higher symmetry with increasing A-site vacancy concentration [5].
    
    [1] Y. Inaguma, L.Q. Chen, M. Itoh, T. Nakamura, T. Uchida, H. Ikuta, M. Wakihara, Solid State Commun. 86, 689–693 (1993).
    [2] Y.Z. Zhao, Z.Y. Liu, J.X. Xu, T.F. Zhang, F. Zhang, X.G. Zhang, J. Alloy. Compd. 783, 219–225 (2019).
    [3] F. Z. T. Yang, V. K. Peterson, S. Schmid, J. Alloy. Compd. 863, 158500 (2021).
    [4] S. Schmid, R. L. Withers. J. Solid State Chem. 191, 63 ─ 70 (2012).
    [5] T. A. Whittle, W. R. Brant, J. R. Hester, Q. Gu., S. Schmid, Dalton Trans. 46, 7253 ─ 7260 (2017).
    
    Speaker: Frederick Yang (University of Sydney)
  - 18:33
    
    Self-Assembly of Carbon Dioxide Nonionic Surfactants in Ionic Liquids 1m
    
    The diverse and tuneable intermolecular interactions present in ionic liquids (ILs) make them excellent media for surfactant self-assembly. Previous studies of polyoxyethylene alkyl ether nonionic surfactants, in ethylammonium nitrate and propylammonium nitrate have shown they can support the full range of amphiphilic self-assembly behaviour of nonionic surfactants for various applications. However, the head group of these nonionic surfactant, ethylene oxide (EO), is a petrochemical product, prompting us to seek bio-renewable substitutes, amongst which carbon dioxide stands out. Recent studies of nonionic surfactants incorporating CO2 (partly substituted for EO) have shown they are promising surface-active molecules. Small angle neutron scattering (QUOKKA, ANSTO) showed a single CO2 unit per surfactant can have an enormous impact on phase behaviour of dodecyl surfactants in water. The formation of gel-like liquid crystalline phases was completely suppressed through reduced hydration of the headgroups. This study is directed at understanding self-assembly behaviour of CO2 nonionic surfactants in ILs. We have examined the structure of surfactant-IL solutions using small angle neutron scattering as a function of surfactant concentration, solvent composition and temperature. Results shown that unlike water, solvation of nonionic headgroup is mostly unaffected by incorporation of CO2 units in pure ILs. However, this can be easily regulated through water dilution or mixing ILs. This demonstrates the composition of surfactant headgroup and the solvent can be used as tools to engineer solvent-headgroup interactions in formulating non-aqueous soft matter.
    
    Speaker: Shurui Miao (The University of Sydney)
  - 18:34
    
    Scaling behaviour of the skyrmions lattices in Cu2OSeO3 single crystals from small angle neutron scattering 1m
    
    Skyrmions are topologically protected spin vortices in the nanometre scale that behave like particles. In chiral crystals, competing magnetic interactions may induce 2D skyrmion lattices [1-2]. In the multiferroic insulator Cu$_2$OSeO$_3$, the skyrmion lattice responds to electric/magnetic fields suggesting applications in data storage [3]. These applications crucially depend on the stability conditions of the skyrmion phase. Notably, Cu$_2$OSeO$_3$ is the only material in which the appearance of two different skyrmion phases has been reported in its phase diagram. However, the quantum mechanisms of these phases and their thermodynamic connection are still under debate [4-6]. Hence, we used Small Angle Neutron Scattering and Lorentz Transmission Electron Microscopy to study the skyrmion stabilisation in single crystals of Cu$_2$OSeO$_3$ [7]. In this work, we report the field, temperature, and sample alignment dependence of the scaling behaviour of skyrmions as an order parameter for the emergence of the two skyrmion phases.
    
    [1] S. Muehlbauer et al., Science 323, 915 (2009)
    [2] S. Seki, X. Z. Yu, S. Ihiwata, and Y. Tokura, Science 336, 198 (2009)
    [3] A. Fert, N. Reyren, V. Cros, Nat. Rev. Mats. 2, 01731 (2017)
    [4] A. Chacon, L. Heinen et al., Nat. Phys. 14, 936-941 (2018)
    [5] F. Qian, L. J. Bannenberg et al., Sci. Adv. 4, eaat7323 (2018)
    [6] L. J. Bannenberg, H. Wilhelm et al., npj Quantum Mater. 4, 11 (2019)
    [7] M.-G. Han, et al., Sci. Adv. 6, eaax2138 (2020)
    
    Speaker: Mr Jorge Arturo Sauceda Flores (School of Physics, University of New South Wales, Sydney 2052, Australia)
  - 18:35
    
    Structural basis of higher-order assembly formation in Toll-like receptor 1,2 and 6 signaling pathway 1m
    
    Innate immunity represents a typical and widely distributed form of immunity. Innate immune responses are the first line of defense against pathogens, which can help destroy invaders invertebrate animals, invertebrates, and plants. The innate immune system recognizes microorganisms via pattern-recognition receptors (PRRs). The family of Toll-like receptors (TLRs) is a distinct group of PRRs. They detect the microbial components known as pathogen-associated molecular patterns (PAMPs), activate downstream transcription factors such as nuclear factor-κB (NF-κB), resulting in a pro-inflammatory response. 10 TLRs have been identified in the human TLR family. In humans, TLR2 can form heterodimers with TLR1 and TLR6 when binding different types of ligands. The cytoplasmic Toll/interleukin-1 receptor (TIR) domain can be found in all TLRs and is responsible for transmitting extracellular signals to intracellular cytoplasmic TIR domain-containing adaptor proteins through TIR: TIR domain interactions, thus initiating downstream signaling. Two TIR-domain containing adaptor proteins, Myeloid differentiation primary response 88 (MyD88) and MyD88 adaptor-like (MAL) mediate downstream signaling in the TLR2-TLR1/6 signaling pathway. It has been previously demonstrated that higher-order assembly formation occurs in the TLR4 signaling pathway. The mechanism, which is known as signaling by cooperative assembly formation (SCAF), may occur in all TLR signal transduction. To date, the transduction mechanisms of TLR2-TLR1/6 signaling are still unclear. This research aims to determine the structural basis of higher-order assemblies formed by TIR domains with a focus on assemblies in the TLR2-TLR1/6 signaling.
    
    Speaker: YAN LI (The University of Queensland)
  - 18:36
    
    Cholesterol catabolism: An exploitable weakness in mycobacterial infections? 1m
    
    Following the development of modern antibiotics and the net improvement of health care systems globally, tuberculosis (TB), a contagious and pathogenic bacterial infection caused by Mycobacterium tuberculosis, has been largely eliminated from developed countries. Despite this improvement TB remained a top 10 cause of death globally in 2020, which, when combined with the rise in multi-drug resistant tuberculosis (MDR-TB), represents an urgent global health concern. Other pathogenic mycobacteria including Mycobacterium ulcerans, the causative agent of Buruli Ulcer and Mycobacterium abscessus, a bacterium that affects cystic fibrosis patients, are also emerging public health threats. Mycobacteria are unique in their ability to metabolise host cell cholesterol, and this pathway has become a target for new antibiotic treatments to drug-resistant infections. The cytochrome P450 enzymes of the CYP125, CYP142 and CYP124 families initiate cholesterol metabolism. There are different numbers of cholesterol metabolising P450s in each Mycobacterium species. For example, Mycobacterium ulcerans and Mycobacterium tuberculosis have one of each CYP125, CYP142 and CYP124 enzymes, while Mycobacterium abscessus has four different CYP125 enzymes and no copies of CYP142 and CYP124. The reasons for different P450 profiles between mycobacteria remain unknown, as does a mechanistic understanding of the P450-mediated cholesterol oxidation. This project aims to understand the structural, evolutionary and mechanistic differences between enzymes of these three families. Also, screening of these enzymes as targets for a new class of cholesterol-based, anti-tubercular inhibitors will be undertaken.
    
    Speaker: Mr Daniel Doherty (The University of Adelaide)
  - 18:37
    
    X-ray structure of a transmembrane domain from an ABC-transporter dependent system from Neisseria meningitidis in a non-biological state 1m
    
    Molecular replacement (MR) is the most commonly used method in crystallography to solve the phase problem required to obtain the three dimensional structure of a protein. Traditionally MR uses a search model from a previously determined protein structure. One of the requirements for success by MR is that the amino acid sequences of the search model and the unknown structure should be have at least 35 % identity. When this is not possible, an ab initio model can be generated using the sequence of the unsolved protein. In this project, we used the algorithm, tr-Rosetta, from the Rosetta server to obtain ab initio models used for use in MR.
    CtrC is part of an ABC transporter dependent complex in Neisseria meningitis, important for capsule polysaccharide transport. It constitutes the transmembrane domain and associates with a separate nucleotide binding domain, CtrD, making a heterotetramer. CtrC, has been crystallised using the lipidic cubic phase (LCP) method. After data collection using the MX2 beamline at the Australian Synchrotron, the structure has been solved at 2.87 Å by MR using an ab initio derived search model.
    The structure of CtrC shows a monomeric arrangement in the crystal lattice, unusual for an ABC transporter. A single molecule of the monoolein lipid used in the LCP matrix was found bound within the protein structure. We hypothesize that the presence of the monoolein ligand, and possibly the absence of CtrD, abrogates the ability of CtrC to form the expected dimeric structure.
    
    Speaker: Lorelei Masselot--Joubert (University of Western Australia)
  - 18:38
    
    Size, shape and colloidal stability of fluorescent nanodiamonds in aqueous suspension 1m
    
    Fluorescent nanodiamonds (FNDs) containing negatively charged nitrogen-vacancy (NV–) centres have outstanding optical, photostability and spin properties which make them promising candidates as nanoscale sensors, and for quantum computing and bioimaging in biological media.
    
    The location of NV atoms relative to the surface of the particles is essential for these applications – if the NV atoms are buried too deeply, this will lead to lower brightness3. To optimize these properties, the particles must either be small or must have at least one dimension which is thin (eg plate shaped particles). The size and shape are therefore vital parameters to be investigated. Our collaborators4 examined the size effect on the optical properties of a wide range of FND particles, however, their 3D structure and colloidal stability have not been widely studied and are not well understood.
    
    Here, we systematically investigate the 3D shape of FNDs in water for a range of sizes and investigate the colloidal stability of these particles using dynamic light scattering, depolarised dynamic light scattering and synchrotron-based small-angle X-ray scattering (SAXS). Initial (SAXS) results suggest an interesting relation between the reported shape, DLS size of FND particles and emitted fluorescence.
    
    Speaker: Mr samir samir eldemrdash (School of science, RMIT University, Melbourne, Victoria 3001, Australia)
  - 18:39
    
    Breaking boundaries, or is it? Physical disruption at the nano- and micro scales for an in situ flow setup 1m
    
    For various soft and hard matter systems, reduction in sample particle size could be an effective method for producing homogeneous samples, eliminating trapped air bubbles, facilitating sample preparation (e.g., gel loading), or meeting the requirements of a specific sample environment. Due to the experimental constraints of small-angle scattering, such as the limited width (1 or 2 mm) of the sample cell, time-dependent characterisation of larger samples in real time is often not possible. Physical disruption of samples into smaller sized particles at a macro scale would allow simultaneous characterisation of a variety of systems, such as facilitating the flow of polymers, gels, aggregates, and minerals. While physical crushing or blending may appear to be a straightforward solution to the problem, a lack of knowledge about the effect on the nano- and microstructure precludes its widespread adoption.
    
    In this study, a yoghurt-like transglutaminase-induced acid gel (TG), was blended as a method of disruption, allowing the gel particles to flow freely in the newly developed recirculated flow set-up designed for the in situ analysis of gel devolution over time. The study has demonstrated that mechanical disruption to form TG particle distributions within the 5-6 µm to ~3.5 mm size range had no effect on the micro- and nanostructure of the gel. This work could benefit several studies, including dynamics of hydrogel swelling, characterisation of particles in motion, digestion or changes in structure when exposed to different environmental conditions, as well as the implementation of newly developed setups in several neutron scattering studies.
    
    Speaker: Meltem Bayrak
  - 18:40
    Small Angle Neutron Scattering instrument Bilby: capabilities to study mainstream and complex systems 1m
    
    ANSTO for more than ten years successfully operates the Small Angle Neutron Scattering (SANS) instrument Quokka[1] and in 2016 commenced the user operation of the second SANS instrument, Bilby[2]. The Ultra-small angle scattering instrument Kookaburra[3] is completing the set of the SANS instruments at ANSTO.
    
    Bilby exploits neutron Time-of-Flight (ToF) to extend the simultaneous measurable Q-range over and above what is possible on a conventional reactor-based monochromatic SANS instrument. In ToF mode, choppers are used to create neutron pulses comprising wavelengths between 2 and 20 Å of variable wavelength resolution (~3% ‒ 30%). In addition, Bilby can operate in monochromatic mode using a velocity selector.
    
    Two arrays of position sensitive detectors in combination with utilizing the wide wavelength range provide the capability to collect scattering data of a wide simultaneous angular range without changing the experimental set-up (maximum accessible Q on the instrument is 0.001-1.8Å-1).
    
    Additionally, there is a range of sample environment available allowing to change sample conditions in situ, which is priceless for the study of a wide variety of samples ranging from colloids and hierarchical materials to metals. Here we present some recent examples.
    
    References
    
    K. Wood et al, QUOKKA, the pinhole small-angle neutron scattering instrument at the OPAL Research Reactor, Australia: design, performance, operation and scientific highlights. J. Appl. Crystallogr. 51 (2018) 294-341.
    
    A. Sokolova et al, Performance and characteristics of the BILBY time-of-flight small-angle neutron scattering instrument. J. Appl. Crystallogr. 52 (2019) 1-12.
    
    C. Rehm et al, Design and performance of the variable-wavelength Bonse-Hart ultra-small-angle neutron scattering diffractometer KOOKABURRA at ANSTO. J. Appl. Crystallogr. 51 (2018) 1-8.
    
    Speakers: Anna Sokolova (Dr), Andrew Whitten (ANSTO), Liliana de Campo (ANSTO), Chun-Ming Wu (NSRRC)
  - 18:41
    
    Continuous chemical redistribution following amorphous-to-crystalline structural ordering in a Zr-Cu-Al bulk metallic glass 1m
    
    Bulk metallic glasses (BMGs) are thermodynamically metastable. As such, crystallization occurs when a BMG is thermally annealed at a temperature above the glass transition temperature. While extensive studies have been performed on the crystallization kinetics of BMGs, most of them have focused on the amorphous-to-crystalline structural ordering, and little attention has been paid to chemical distribution and its relationship with the structural ordering during the crystallization process. In this paper, a new approach, with simultaneous differential scanning calorimetry (DSC) and small angle neutron scattering (SANS) measurements, was applied to study in situ the crystallization of a Zr45.5Cu45.5Al9 BMG upon isothermal annealing at a temperature in the supercooled liquid region. Quantitative analysis of the DSC and SANS data showed that the structural evolution during isothermal annealing could be classified into three stages: (I) incubation; (II) amorphous-to-crystalline structural ordering; (III) continuous chemical redistribution. This finding was validated by composition analysis with atom probe tomography (APT), which further identified a transition region formed by expelling Al into the matrix. The transition region, with a composition of (Cu,Al)50Zr50, served as an intermediate step facilitating the formation of a thermodynamically stable crystalline phase with a composition of (Cu,Al)10Zr7.
    
    Speaker: Xuelian Wu
  - 18:42
    
    Working Mechanisms of Conversion-Type Metaphosphate Electrodes for Lithium/Sodium-Ion Batteries 1m
    
    The development of novel high-performance electrodes is crucial for the next generation of lithium/sodium-ion batteries (LIBs/SIBs) that can charge rapidly while maintaining high lithium/sodium storage capacity. One of the major research directions to achieve improved energy/power densities of LIBs/SIBs has, thus far, focused on electrode materials that can store Li+/Na+ through conversion reactions. Our group has discovered and systematically studied a new family of conversion-type electrode materials, the transition metal metaphosphates [M(PO3)n (M = Mn, Fe, Co, Ni and Cu; n = 1, 2, 3)]. Unlike traditional conversion-type monoanionic compounds such as oxides, nitrides and fluorides which rely on nanomaterials engineering, these metaphosphates can achieve full capacities and fast Li+/Na+ diffusion kinetics from micro-sized samples synthesised by conventional solid-state methods. We studied their conversion reactions using a combination of in situ x-ray powder diffraction (XRPD), in/ex situ X-ray absorption near-edge spectroscopy (XANES), and ex situ high resolution transmission electron microscopy (HRTEM). During the initial discharging, these compounds convert into amorphous ceramic composites with high electrochemical activities in which fine transition metal nanograins are embedded in a glassy LiPO3 matrix. Glassy LiPO3 is an excellent Li+ conductor due to the low iconicity of PO3-, and it can buffer the volume change of the electrode to maintain its integrity, thus leading to much better electrochemical reversibility and cycling stability than monoanionic compounds. In the following first charge, the electrode converts back to a metaphosphate in terms of its composition but does not recrystallise. In subsequent cycles, the metaphosphate electrodes in an amorphous form continue to react with Li+/Na+ reversibly.
    
    Speaker: Dr Qingbo Xia (The University of Sydney)
  - 18:43
    
    A photon counting detector for x-ray imaging: advantages and challenges 1m
    
    X-ray sensitive area detectors comprised of arrays of photon counting elements have been under development for decades. The difficult and expensive technological development of integrating readout electronic chips with a converter has been substantially supported by areas of science other than synchrotron radiation research. For instance, such innovation is vital in large scale high energy physics detectors. Synchrotron radiation research has benefited from this technology being spun-out into the market.
    IMBL has purchased a photon counting array detector: the Eiger2, from the Swiss company Dectris. It will be used in our human radiography programme. An NHMRC grant was awarded to pursue the use of computed tomography in mammography (breast imaging) using the IMBL. Funds were provided for a 3 mega-pixel array detector, with 75 micron pitch pixels. Similar devices have been used in SR x-ray scattering stations for a sometime, but have not yet found extensive use in radiography. The exquisite sensitivity is a great advantage for imaging live subjects; keeping the required dose to a minimum. However they do have field coverage limitations. These are being addressing as part of the human imaging project. In all photon counting detectors currently on the market, the active area is not continuous. The boundaries between IC chips, and multi-chip modules create gaps. For diffraction these missing pixels may be less important, since reflections are often duplicated, or radial integration reduces their effect. In imaging however, every pixel carries potentially important clinical information.
    Some initial data from the IMBL Eiger2 is presented, along with ideas for ameliorating the effect of the missing pixels on the radiological information.
    
    Speaker: Chris Hall (Australian Synchrotron)
  - 18:44
    
    Kookaburra, the ultra-small-angle neutron scattering instrument at ANSTO: design and recent applications 1m
    
    The double-crystal ultra-small-angle neutron scattering (USANS) diffractometer KOOKABURRA at ANSTO was made available for user experiments in 2014. KOOKABURRA allows the characterisation of microstructures covering length scales in the range of 0.1–20 µm. Use of the first- and second-order reflections coming off a doubly curved highly oriented mosaic pyrolytic graphite pre-monochromator at a fixed Bragg angle, in conjunction with two interchangeable pairs of Si(111) and Si(311) quintuple-reflection channel-cut crystals, permits operation of the instrument at two individual wavelengths, 4.74 and 2.37 Å (see more details https://www.ansto.gov.au/our-facilities/australian-centre-for-neutron-scattering/neutron-scattering-instruments/kookaburra). This unique feature among reactor-based USANS instruments allows optimal accommodation of a broad range of samples, both weakly and strongly scattering, in one sample setup [1,2]. The versatility and capabilities of KOOKABURRA have already resulted in a number of research papers, including studies on hard matter systems like rocks and coal [3,4], as well as soft matter systems like hydrogels or milk [5,6]. This clearly demonstrates that this instrument has a major impact in the field of large-scale structure determination. Some of the recent examples will be presented here.
    
    References:
    [1] Rehm, C. et al, J. Appl. Cryst., 2013, 46 1699-1704.
    [2] Rehm, C. et al, J. Appl. Cryst., 2018, 51, 1-8.
    [3] Blach, T. et al, Journal of Coal Geology, 2018, 186, 135-144.
    [4] Sakurovs, R.et al, Energy & Fuels, 2017, 31(1), 231-238.
    [5] Whittaker, J. et al, Int. J. Biol. Macromol., 2018, 114, 998-1007.
    [6] Li, Z. et al, Food Hydrocolloid, 2018, 79, 170-178.
    
    Speaker: Jitendra Mata (ANSTO)
  - 18:45
    
    Quokka, the Pinhole Small-Angle Neutron Scattering Instrument at ANSTO 1m
    
    Quokka was the first SANS instrument to be in operation at the Australian research reactor, OPAL [1]. It is a 40 m pinhole instrument operating with a neutron velocity selector, an adjustable collimation system providing source-sample distances of up to 20 m and a two dimensional 1 m squared position-sensitive state-of-the-art detector, capable of measuring neutrons scattered from the sample over a secondary flight path of up to 20 m. Also offering incident beam polarization and analysis capability as well as lens focusing optics, Quokka has been designed as a general purpose SANS instrument with a large sample area, capable of accommodating a variety of sample environments. Some of these sample environments are, a Rapid Heat Quench Cell enabling a sample to be studied in situ following a thermal shock (-120°C to 220°C); The neutron Rapid Visco Analyser (nRVA) which enables SANS to be measured simultaneously with viscosity via an RVA – an instrument widely used within the food industry; In-situ Differential Scanning Calorimetry (DSC); A stopped flow cell, and RheoSANS.
    In early 2021 Quokka achieved the milestone of 200 peer-reviewed publications in a variety of research fields. Here we cover some of the research highlights along with Quokka’s performance and operation.
    
    [1] K. Wood, J. P. Mata, C. J. Garvey, C. M. Wu, W. A. Hamilton,[..]and E. P. Gilbert, QUOKKA, the pinhole small-angle neutron scattering instrument at the OPAL Research Reactor, Australia: design, performance, operation and scientific highlights, J Appl Crystallogr, 2018, 51, 294-314.
    
    Speaker: Kathleen Wood (Australian Nuclear Science and Technology Organisation)
  - 18:46
    
    Novel techniques with ATR apparatus at THz frequencies 1m
    
    A new method is presented which extends the capabilities of attenuated total reflection (ATR) apparatus to a partial reflection/partial transmission mode, which also delivers the complex dielectric values of samples. The technique involves placing a mirror at a known distance from the sample/crystal interface to reflect the transmitted portion of the incident signal back to the detector. The attenuation of this signal reflected is dependent on the absorption coefficient of the sample.
    The method is well suited to biological samples in the terahertz radiation frequency band range 1.0 THz to 2.0 THz, with a diamond crystal ATR.
    The 2.0 THz range biological data is poorly represented in literature, since most THz data on biological tissues has 1.2 to 1.5 THz as the upper limit. A demonstration of the technique was performed using water and water based gel at the Australian Synchrotron FIR/THz beamline.
    At frequencies of 3.0 to 5.0 THz, a paradoxical region was noted where the total reflectance of the signal reflected at the initial crystal/sample interface plus the signal reflected from the mirror was less than the reflected at the initial crystal/sample interface alone. The destructive interference is in the region where the effective path length of the transmitted signal through the sample is in the region of 1.3 λ to 1.7 λ. Significance and potential uses of this region are still being investigated.
    Since many cancers have higher water content than normal tissue, the extension of the ATR apparatus capacity promises to establish a new diagnostic modality.
    
    Speaker: Zoltan Vilagosh (Swinburne University of Technology)
  - 18:47
    
    Structural characterization of SARS-Cov-2 spike derived peptides presented by the Human Leukocyte Antigen A*29:02. 1m
    
    The rapid emergence of SARS-Cov-2 out of Wuhan, China, in late 2019 has resulted in the current outbreak that has crippled social and economic development worldwide. With over four million deaths, significant efforts are being made to generate a viable treatment option. It has been well established that T lymphocytes destroy infected cells. These T cells also produce long lasting immunity through the proliferation of memory cells which recognize future viral invasion.
    
    Activation of T lymphocytes is achieved through the recognition of Human Leukocyte Antigens (HLA) surface receptors on infected cells. These HLA molecules present viral peptides to T cells which are able to recognize and activate against these antigens.
    
    However, due to the highly polymorphic nature of HLA molecules, it remains unclear how different peptides bind to the vast number of HLA molecules affect the stimulation of the adaptive immune response.
    
    The focus of this project is on a singular HLA, HLA-A29:02, found in approximately 3% of the world’s population. We wish to structurally analyse various peptides presented by HLA-A29:02 derived from the SARS-Cov-2 spike protein and determine how COVID-19 variants and their mutations might different in their presentation to T cells.
    
    Through the use of X-ray crystallography, we will gain deeper insights into how theses peptides are presented. This will further our understanding of how our own immune system responds to these antigens and may also help to in designing long lasting therapies such as peptide vaccines.
    
    Speaker: Lawton Murdolo (La Trobe University)
  - 18:48
    
    Understanding and controlling the formation of photonic crystals from polydisperse colloidal systems 1m
    
    The fundamentals of crystallisation and glass formation are not yet fully understood. Colloidal suspensions have been shown to be promising model systems for understanding these processes. As colloidal motion is Brownian, rather than ballistic, kinetics and dynamics can be studied in real-time. It is well documented that colloidal suspensions can “successfully crystallise” when the particles in the system have sufficiently low polydispersity.[1,2] This means that the particles must have a similar average size and shape. If a system is highly polydisperse, this will hinder the solidification process.
    
    In this work we will explore colloidal nanodiamonds. Nanodiamonds are a topic of interest in many material studies due to their wide variety, and unique mechanical and optical properties.[3,4] Detonation nanodiamonds (DNDs) are of particular interest due to their unique fabrication process. Due the detonation synthesis method, the particles are small (several nm) and faceted, but in solution self-assemble into highly irregular fractal shapes.[5] Despite this high polydispersity, when centrifuged, these types of DNDs can yield incredibly ordered structures and form iridescent photonic crystals – this is highly surprising given the highly irregular structures of these materials. These photonic crystals were first discovered by Grichko et al.,[5] however, the mechanisms behind these highly ordered structures are still unknown. With a combination of lab techniques and beam time allocations at the Australian Synchrotron, ANSTO and potentially overseas neutron facilities, we will systematically investigate these nanodiamond photonic crystals, and examine their structure and formation kinetics.
    
    Speaker: Katherine Chea (RMIT University)
  - 18:49
    
    Synthesis and characterization of K2YbF5 upconversion nanoparticles 1m
    
    Many avenues exist for synthesizing upconversion nanoparticles (UCNPs), such as hydrothermal, solvothermal, solid-state reactions, thermal decomposition, amongst others. Here we compare three hydro-solvothermal synthesis processes for producing K2YbF5:Er and K2YbF5:Tm UCNPs, each having a different order of addition of reagents. The first method (A) adds together potassium hydroxide, oleic acid, and ethanol; followed by the lanthanide ions, and finally potassium fluoride. The second method (B) mixes the lanthanide ions, oleic acid, and ethanol first; followed by potassium hydroxide, and finally potassium fluoride. The third method (C) is similar to the second one, except that potassium hydroxide and potassium fluoride are mixed together first before being introduced into the system. The resulting nanoparticles were characterized via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), photoluminescence spectra (PL), and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy on the Australian synchrotron soft-X ray beam line. SEM images reveal that all particles are crystalline with shapes ranging from microrods to hexagonal. EDS confirmed presence of dopant ions only for particles produced via method A, while NEXAFS spectra confirmed presence of dopant ions in all doped crystals, with their expected NEXAFS structure confirming the oxidation state of the ion within the nanocrystal. Thus there is evidence of dopant ions incorporated within the crystal; however, more quantitative techniques must be applied to properly ascertain the doping concentration and the quantum efficiency of the upconversion processes occurring within the synthesized particles.
    
    Speaker: John Arnold Ambay (University of Technology Sydney)
    
    ANSTO User Meeting Poster: Synthesis and characterization of K2YbF5 upconversion nanoparticles Google Drive folder for poster poster final ver.mp4
  - 18:50
    
    Effects of Mn and Co Ion Implantation on Pseudocapacitive Performance of Ceria-Nanostructures on Ni-Foam 1m
    
    Metal oxides have shown incredible potential as electrode materials for pseudocapacitive applications due to their high capacitance, good conductivity, electrochemical reversibility, and long cyclability. Through the engineering and manipulation of defect types and their concentrations, it is possible to enhance the kinetics of charge transfer and charge-discharge process to optimize redox and intercalation capacitances. Ion implantation is an advanced technique to uniformly introduce a desired concentration of dopants into nanostructures. The present work explores the pseudocapacitive performance of nanostructured cerium oxide (ceria, CeO_2-x) films on nickel foam electrodes (synthesized using electrodeposition), followed by implantation individually with Mn and Co ions. The implanted samples were annealed in nitrogen atmosphere to promote the diffusion and incorporation of implanted dopants in the ceria lattice and to modify the nanostructural features. The films were characterised using SEM, EDS, Raman spectroscopy, and XPS analyses to determine the role of the mineralogy, composition, surface chemistry, and nanostructure on the performance. The pseudocapacitive performance was determined using cyclic voltammetry (CV), charge-discharge, electrochemical impedance spectroscopy (EIS), and stability tests. After preliminary CV testing, the Co-implanted samples (1 x 10¹⁵ ions/cm²) annealed at 300℃ for 3 h in a nitrogen atmosphere showed an improvement in specific capacitance (495 F/g) compared to the non-implanted ceria samples (427 F/g).
    
    Speaker: Mr Ewing Y. Chen (UNSW)
  - 18:51
    
    The Nanoprobe beamline at the Australian Synchrotron: towards day #1, July 2024 1m
    
    A hard x-ray Nanoprobe beamline is under construction at the Australian Synchrotron, aiming to accept first users for operation in July, 2024. In this presentation we will outline the science case for the Nanoprobe along with the anticipated performance parameters and show examples of measurements that will be enabled by the facility. In particular, core methods supported by the Nanoprobe include: trace elemental mapping and spectroscopy at the 60-300 nm length-scale using x-ray fluorescence; absorption, differential phase contrast and ptychography using x-ray transmission, and; SAXS/WAXS and micro-diffraction.
    
    A number of substantial challenges must be overcome in order to reach the ultimate resolution, and these will be described along with the optical and operational design of the beamline. Cryogenic capabilities may present too great a challenge for the first-generation implementation but are keenly desired and firmly on the instrument development curve. The Nanoprobe endstation instrument will be located within a purpose-built satellite building at around 100 m from the source location. Although still deep in design phase, we will outline the building design and welcome comment from future potential users of the beamline particularly with regards to the instrument capabilities and the experimental support that is required from the ancillary services within the building and the larger Australian Synchrotron facility.
    
    Speaker: Martin de Jonge (ANSTO)
  - 18:52
    
    Investigation of Residual Stress and Mechanical Properties of Steelwork After Laser Cleaning 1m
    
    Surface preparation of steelwork for structural repainting is often conducted by sandblasting method in which abrasives (sands) are blasted onto the painted surface at high speed, removing the old paint and rust/dirt by the impact of the blast. This conventional method would cause irreversible damage to the underlying substrate, deteriorating its mechanical and fatigue performance. Laser cleaning has attracted attention as an alternative to conventional cleaning methods as an environmentally friendly and economical technology that removes paint and corrosion efficiently while inducing minimal damage to the surface of the material.
    This research investigates the mechanical properties and residual stresses of the laser cleaned steel samples from the Sydney Harbour Bridge. Laser cleaning using nanosecond laser was performed on the structural steel plates removed from the Sydney Harbour Bridge. The plates were then tested at the Australian Nuclear Science and Technology Organisation (ANSTO) for residual stress measurement and the University of Sydney for the microstructure characterisation and microhardness testing.
    Results of the residual stress measurements indicated that the residual stress profile changes at the surface after cleaning. This study enhances the understanding of changes in residual stress and mechanical properties at the surface of a steel subjected to laser cleaning.
    
    Speaker: Yutaka Tsumura (Sydney University)
  - 18:53
    
    Medium Energy Spectroscopy (MEX) – The spectroMEX High Resolution Crystal Spectrometer 1m
    
    The MEX1 beamline high resolution crystal spectrometer, spectroMEX, comprises a Johann-type point-to-point focusing geometry crystal spectrometer employing five spherically bent crystals on a 0.5 m diameter Rowland circle. The primary application of spectroMEX is high energy resolution fluorescence-detected (HERFD) XANES, wherein fluorescence XANES is collected with an energy resolution of the order of the core-hole lifetime broadening. HERFD XANES spectra contain additional spectral information when compared to conventional fluorescence or transmission XANES. spectroMEX also facilitates collection of high quality x-ray emission spectroscopy data, including the weak, but chemically sensitive valence-to-core emission lines (vtc-XES). This talk will describe the spectroMEX spectrometer design, progress to date, and present examples of the new spectroscopic techniques available to synchrotron users employing spectroMEX at the MEX1 beamline.
    
    Speaker: Jeremy Wykes (Australian Synchrotron)
  - 18:54
    
    Stability and Applications of Model Membranes 1m
    
    Biological cell membranes are a critical component of all living organisms. The cell membrane is a semi-permeable lipid bilayer controlling movement of ions and other molecules from one of the cell side to the other, and is primarily made up of amphiphilic lipid molecules.
    
    Our research group has previously developed a model system whereby a lipid bilayer is tethered to a solid supporting structure. The resulting tethered-bilayer lipid membranes (tBLMs) are highly stable in aqueous solution and the tethering region provides a reservoir under the bilayer to allow protein incorporation and minimise bilayer/substrate interactions. In the presence of an aqueous solution tBLMs have been shown to be stable for periods as long as multiple weeks with only minor degradation.
    
    This project is focused on understanding the effects that drying a model membrane out can have on its structure. This work is important for better understanding the water retention properties of tBLMs in order to determine their suitability for use in biosensing, where they may not be able to be completely submerged in solution, and whether additional protective coatings may be necessary to improve retention. Similar work has already been performed on other model systems such as black lipid membranes, but only tentatively in the field of tBLMs.
    
    Electrochemical impedance spectroscopy (EIS) has been used to model changes in membrane structure through the rehydration process as well as the resulting functionality, with neutron reflectometry approved to be performed in future to determine more layer-specific effects.
    
    Speaker: Alex Ashenden (Flinders University)
  - 18:55
    
    A high-temperature furnace for MEX 1m
    
    The Medium Energy X-ray Absorption Spectroscopy (MEX) Beamline at the Australian Synchrotron is currently being commissioned and is due to start running user experiments in the second half of 2022.
    The facility will provide a series of specialised sample environments for users to conduct in situ measurements of important scientific processes. One of these sample environments will be a high-temperature furnace, which will provide users with world-class experimental conditions and bring MEX in line with the capabilities of other synchrotron facilities.
    Based on the requirements specified by users in a 2020 survey of the Australian Synchrotron user community, the furnace will be designed to heat samples to ̴ 500 – 1500 °C, and will be compatible with a range of gases, including He, N2, CO2, O2, CO, and Ar.
    The high-temperature, controlled-atmosphere experimental conditions that such a furnace will provide are useful in Earth science for examining processes occurring in silicate melts, emulating conditions in the Earth’s crust. Some of the processes occurring at crustal conditions can only be observed in situ, rather than in the quenched products of experiments.
    The furnace will also be useful in materials science and chemistry for examining the behaviour of metals at high temperatures in a controlled atmosphere.
    
    Speaker: Emily Finch (Australian Synchrotron)
  - 18:56
    
    Do reduced aggregation and crystallinity really help to improve the photovoltaic performance of terpolymer acceptors in all-polymer solar cells? 1m
    
    Terpolymerization is a widely used method to control crystallinity of the semiconducting polymers which has been exploited to improve the photovoltaic performance of all-polymer solar cells (all-PSCs). Applying this strategy to the well-studied n-type polymer acceptor PNDI2OD-T2, different amounts of 3-n-octylthiophene (OT) are used to partially replace the bithiophene (T2) unit, resulting in three newly-synthesized terpolymer acceptors PNDI-OTx where x = 5%, 10%, or 15%. Another copolymer, namely PNDI2OD-C8T2, consisting of naphthalene diimide (NDI) copolymerised with 3-n-octylbithiophene (C8T2) is also synthesized for comparison. The experimental X-ray characterizations suggest that the molecular orientation of π-conjugated backbone in PNDI-OTx is slightly impacted and thin film crystallinity is systematically tuned by varying x, evidenced by near edge X-ray absorption fine structure (NEXAFS) and grazing incidence wide angle X-ray scattering (GIWAXS) measurements, respectively. However, the photovoltaic performance of all-PSCs based on J71:PNDI-OTx and J71:PNDI2OD-C8T2 blends are much lower than that of the reference J71:PNDI2OD-T2 system. Extensive morphological studies suggest that reduced crystallinity is likely to have a little influence on vertical phase separation and crystallinity of resulting blends as revealed by peak fits from NEXAFS and GIWAXS experiments. However, the reduced crystallinity is detrimental for morphology of the blend films, with coarser phase separation found in J71:PNDI-OTx and J71:PNDI2OD-C8T2 blends compared to J71:PNDI2OD-T2 blends, confirmed by resonant soft X-ray scattering. The results here challenge the common view that reduced crystallinity is the key parameter in controlling the morphology for enabling high-performing all-PSCs.
    
    Speaker: Doan Vu (Monash University)
  - 18:57
    
    Current and future capabilities of the IRM beamline at the Australian Synchrotron, and guidance on applying for use of the facility. 1m
    
    Infrared (IR) spectroscopy provides information on the chemical composition of materials, based on the absorption of infrared light by the vibrating bonds within molecular groups. IR microspectroscopy, using synchrotron light as the infrared source, enables this analysis to be performed on samples as small as 1 – 2 $\mu$m in size, with a sensitivity not possible in the laboratory. ANSTO’s synchrotron infrared microspectroscopy (IRM) beamline is equipped with a suite of accessories to enable the study of a diverse range of materials. This includes a sample heating and cooling stage, micro-compression cells for improved IR light transmission of dense materials, a liquid flow cell for the study of living organisms in a natural environment, and grazing angle optics for the analysis of thin film coatings on surfaces. The IRM beamline also has several attenuated total internal reflection (ATR) accessories that have been used for the study of challenging materials such biofilms, carbon fibre, leaf surfaces and battery materials, where a thin section of the sample can not be prepared. More recent developments on the IRM beamline include the use of polarisation optics to determine molecular orientation in materials and operation with a far-IR detector to extend the spectral range to 260 cm^-1. Future plans for the IRM beamline include the motorisation of additional functions to assist with mail-in experiments and, in the longer term, the additional of nano-IR capability to the experimental endstation. Scientists interested in accessing the IRM beamline are encouraged to contact the IRM beamline team to discuss their research proposals.
    
    Speaker: Dr Mark Tobin (ANSTO)
  - 18:58
    
    KOALA 2: making a good instrument better! 1m
    
    At the time that the KOALA Laue single-crystal neutron diffractometer came into service at ANSTO, a review of VIVALDI, the progenitor instrument at the ILL led to its deletion from their User program. Against this background, we were seeing a dearth of single-crystal neutron studies published in the literature. To our joy, in usage, we found the instrument to be readily applicable to the problems which our future users had identified in the planning workshops for the first suite of neutron beam instruments at ANSTO. A User base has been built which has resulted in a steady flow of rapidly cited publications across a wide range of journals - focussed on reaching the optimum scientific audience.
    KOALA is a copy of the ILL instrument VIVALDI purchased from the same vendor, and outside the standardisation of construction which has underpinned the reliability of the ANSTO neutron beam instrument suite. At ten years use, spare parts became a significant issue, and a review of the control systems revealed that the cost of refitting the existing instrument approached the cost of building a replacement instrument. The decision to build KOALA2 has provided opportunities to optimise the initial design with significant operational enhancements. COVID has meant that we were initially on track to achieve the instrument implementation in mid 2022 (component issues now mean this will be late 2022), and we will continue to operate KOALA 1 until KOALA 2 is ready to install.
    As time permits we will outline the range of science available and the enhancements KOALA 2.0 will bring.
    
    Speakers: Alison Edwards (ACNS, ANSTO), Ross Piltz (ACNS, ANSTO)
  - 18:59
    
    High crystallinity nitrogen doping of ALaTiO4 and A2La2Ti3O10 (A = Na¬+, K+) photocatalysts 1m
    
    Global warming is a current hot topic due to its potential for irreversible environmental damage. Ambitions were made within the Paris agreement to limit the temperature rise to be below 1.5 ºC pre-industrial level. Therefore, alternative fuel sources are needed to replace fossil fuel, with hydrogen gas is one popular choice due to its high energy density per unit weight, and technologies utilising hydrogen already developed. Hydrogen can be generated renewably by sunlight driven, photocatalytic water-splitting. Metal oxides, including those with a Ruddlesden-Popper type structures are being studied as potential photocatalysts. KLaTiO4 is a n=1 Ruddlesden-Popper type layered perovskite. KLaTiO4 can be used as a Hydrogen Evolution Catalyst (HEC), producing 9.540 μmol of H2 gas per hour from 20 mg of catalyst, when using methanol as sacrificial electron donor and platinum co-catalyst. The main issue of KLaTiO4 is its high bandgap (4.09 eV) meant it is incapable of absorbing visible light.
    The two main factors important for the synthesis of ALaTiO4 and A2La2Ti3O10 (A = Na¬+, K+) was discussed: volatility of alkaline metal ions at elevated temperatures and sintering temperature. Multiple samples of NaLaTiO4 or Na2La2Ti3O10 were made using traditional solid-state synthesis methods at temperature between 750 °C to 950 °C. Bandgap was tuned by doping nitrogen into the structure of ALaTiO4 during the synthesis process, as opposed to replacing oxygen atoms with nitrogen by post treatment of ALaTiO4. This was achieved by replacing a portion of TiO2 reagent used for TiN, and the sample was synthesised as normal. The resultant ALaTiO4-xNx¬ sample retained good crystallinity and have reduced bandgap, but at a cost of reduction in hydrogen evolution rate.
    
    Speaker: Mr Junwei Junwei Li (The University of Sydney)
    
    AUM2021_reduced.pdf
  - 19:00
    
    Completing the library of amino-acid neutron structures 1m
    
    Accurate neutron structures of the 20 naturally occurring amino acids that are the building blocks of proteins are key to investigations of polymorphism, condensed-phase NMR analysis, periodic density-functional-theory calculations, as restraints in X-ray protein refinements, and as initial structures in the computer modelling of proteins. The first 16 members of the family were determined in the 1970s by groups at Brookhaven National Laboratory and the Indian Atomic Energy Laboratory, but the last four proved to be elusive due to the lack of single crystals large enough for the monochromatic neutron diffractometers of the time. State-of-the-art reactor-based neutron Laue diffractometers, such as Koala on OPAL, allow high-precision structural investigations of single crystals with volumes around 0.1 mm3. This opens the door to completing the library of high-precision amino-acid neutron structures.
    
    Here we describe variable-temperature studies of three naturally-occurring amino acids using Koala, L-leucine [1] which is one of the four missing members and the two polymorphs of L-histidine. The data on the orthorhombic form of L-histidine greatly improve on the precision of a previous monochromatic neutron study. The second, monoclinic, form has been studied with neutrons for the first time [2]. Both studies were complemented by interaction-energy calculations using the Pixel method, and, for L-histidine, Hirshfeld Atom Refinement against X-ray data at the same temperatures. The resulting neutron structures yield geometric parameters with sufficient precision and accuracy for inclusion in restraint libraries of macromolecular structure refinements.
    
    The search continues for neutron-quality crystals of L-isoleucine, L-methionine and L-tryptophan.
    
    [1] J. Binns et al. Acta Cryst. B72 (2016) 885.
    [2] G. Novelli et al. Acta Cryst B. In press.
    
    Speaker: Prof. Garry McIntyre (Australian Nuclear Science and Technology Organisation)
Friday, 26 November
- 09:40 → 09:45
  
  Welcome Address
- 09:45 → 10:15
  Plenary
  - 09:45
    
    Accelerating Australia: Perspectives on future particle accelerators and their applications 30m
    
    There are over 50,000 particle accelerators in the world used for everything from treating cancer to finding out the secrets of the Universe. Australia has a long history in this area and excels in accelerator-based science: nowhere is this clearer than in the science carried out at our world-class infrastructure. That said, we have barely scratched the surface of what might be possible with beams of ions or electrons. Potential uses of particle beams are growing every day – from mining to archaeology to high-tech factories – enabled by breakthroughs in accelerator science and technology. In light of this, a new research group in accelerator physics was created at the University of Melbourne in 2019, who collaborate with ANSTO in a number of areas: from compact X-band electron accelerators to next-generation particle therapy. In this talk I will give an overview of some of the vast array of applications of accelerators and introduce the cutting-edge accelerator development research now happening in Australia. With strong collaboration between end-users and accelerator experts, together we can create a step-change in Australia’s capacity to deliver real-world impact using particle beams.
    
    Speaker: Suzie Sheehy (University of Melbourne)
- 10:15 → 10:45
  
  Morning Tea 30m
- 10:45 → 12:20
  Biomedicine, Life science & Food Science
  - 10:45
    
    Synchrotron CT dosimetry at the IMBL for low wiggler magnetic field strength and spatial modulation with bow tie filters 15m
    
    Synchrotron CT dose reduction was investigated for the IMBL wiggler source operated at lower magnetic field strength and for beam modulation with spatial filters placed upstream from the sample. Beam quality at 25-30 keV for 1.4-3.0 T was assessed using transmission measurements with copper to quantify the influence of third harmonic radiation. The low energy operational limit is 24-28 keV for 0.1-1% transmission by added filters, 2 mm path length through silicon and 25 m of air. The upper limit is near 80 keV for wiggler field 1.4 T, approximately 100 keV for 2.0 T and extend beyond 100 keV for 3.0-4.2 T. The harmonic radiation contribution is reduced for lower field strengths. Measured dose rates suggest the influence of harmonics is insignificant above approximately 26 keV at 1.4 T and above 33 keV at 2.0 T. Relative to 3 T operation, the mean dose rate in air is reduced to approximately 12% at 2 T and 4% at 1.4 T. Spatial filters were constructed from blocks of perspex with circular voids of diameter matching the CT dosimetry test objects. A calibrated ion chamber integrated absorbed dose to the phantom during 360o rotation. CT dose indices (CTDI) were measured at 25-100 keV for 3.0T only, at the centre and periphery for 35-160 mm diameter perspex phantoms. Beam shaping filters offer protection to the sample by reducing the peripheral and volumetric CTDI by about 10% for small objects and 20-30% for the larger samples.
    
    Speaker: Dr Stewart Midgley (Canberra Hospital)
  - 11:00
    
    Magnetically-guided particle delivery to airway surfaces for cystic fibrosis gene therapy: Synchrotron-based visualisation and optimisation for improved in vivo lentiviral gene transfer 15m
    
    Gene vectors to treat cystic fibrosis lung disease should be targeted to the conducting airways, as peripheral lung transduction does not offer therapeutic benefit. Viral transduction efficiency is directly related to the vector residence time. However, delivered fluids such as gene vectors naturally spread to the alveoli during inspiration. Extending gene vector residence time within the conducting airways is important, but hard to achieve.
    
    Gene vector conjugated magnetic particles that can be guided to the conducting airway surfaces could improve targeting. Due to the challenges of in vivo visualisation, the behaviour of small magnetic particles on the airway surface in the presence of an applied magnetic field is poorly understood. The aim of this study was to use synchrotron imaging to visualise the in vivo motion of a range of magnetic particles in live rat trachea to examine the dynamics and patterns of individual and bulk particle behaviour in vivo.
    
    Synchrotron X-ray imaging revealed the behaviour of magnetic particles in stationary and moving magnetic fields, both in vitro and in vivo. Particles could not be dragged along the live airway surface with the magnet, but during delivery deposition was focussed within the field of view where the magnetic field was the strongest.
    
    These results show that magnetic particles and magnetic fields may be a valuable approach for improving gene vector targeting to the conducting airways in vivo.
    
    Speaker: Martin Donnelley (University of Adelaide)
  - 11:15
    
    Biochemical Interaction of Few Layer Black Phosphorus with Microbial Cells Using Synchrotron macro- ATR-FTIR 15m
    
    In the fight against drug resistant pathogenic bacterial and fungal cells, low dimensional materials have been shown as a promising form of alternative treatment method. Specifically, few-layer black phosphorus (BP) has demonstrated its effectiveness against a wide range of pathogenic bacteria and fungal cells. In this work, the complex biochemical interaction of BP with a series of microbial cells is investigated to provide a greater understanding of the antimicrobial mechanism. Synchrotron macro-attenuated total reflection–Fourier transform infrared (ATR-FTIR) spectroscopy is used to elucidate the chemical changes occurring outside and within the cell of interested after exposure to BP nanoflakes. The ATR-FTIR data, coupled with advanced, high-resolution microscopy, reveals noticeable differences to the polysaccharide and nucleic acid spectral maps, along with changes in amide protein structure when compared to untreated cells. This study provides a greater insight into the biochemical interaction of BP nanoflakes with microbial cells is given, allowing for a better understanding of the antimicrobial mechanism of action.
    
    Speaker: Zoe Shaw (School of Engineering, RMIT University)
  - 11:30
    
    Using X-ray crystallography to understand bushfire-induced seed germination 15m
    
    Passing the site of a bushfire a couple of weeks after it has burnt itself out, you may notice a mass seed germination event taking place, allowing the bush to completely come back to life. This fascinating phenomenon occurs due to compounds in bushfire smoke called karrikins, which act as triggers for seed germination.
    
    Although we know this process occurs, we don’t understand how karrikins interact with seeds or seedlings, and what the little molecular machines – known as proteins – inside individual cells do to allow a seed to germinate.
    
    X-ray crystallography is a technique where the atomic structure of a crystal can be determined via its diffraction pattern when placed in the beam of an X-ray source. By crystallising the proteins involved in karrikin signalling and shooting them at the MX beamlines at the Australian Synchrotron, we are able to determine their structure and hence their function; allowing us to piece together a complete picture of how karrikins work.
    
    Overall, by understanding processes that control a plant’s growth and development, we have new avenues to explore in terms of finding sustainable agricultural techniques and effective methods of conservation and restoration.
    
    Speaker: Sabrina Davies (The University of Western Australia)
  - 11:45
    
    Regional lung volume measures in small animal models from single projection X-ray images 15m
    
    Regional Lung volume is a key parameter in assessing lung function and health. Computed Tomography (CT) is considered the gold standard for measuring lung volume; however, it requires a relatively high radiation dose and typically has associated lower spatial and temporal resolution than X-ray projection imaging. In this work, we investigate whether regional lung volumes can be determined using 2D X-ray projections. The idea is that as the lung inflates with air, the attenuating tissue is displaced leading to a localised increase in X-ray intensity. We imaged 13 New Zealand white rabbit kittens using high-resolution X-ray imaging and CT at the IMBL at various airway pressures. From the 2D projections, we converted changes in regional X-ray intensity through the lungs to changes in lung air volume using the Beer-Lambert law, under the assumption that the lungs of the animal were comprised of a single material (water). We measured the true air volumes from CT data for comparison. We found that relative changes in regional lung air volume derived from the 2D x-ray projections showed a coefficient of determination ($\mathrm{R}^2$) of 0.97 with CT data. This technique, therefore, provides a high speed, low dose method for measuring regional changes in lung volume that we are now using for studying lung aeration at birth in preclinical animal models.
    
    Speaker: Dylan O'Connell (Monash University)
  - 12:00
    
    Sub cellular scale mapping of deuterated compounds by nanoSIMS 15m
    
    High resolution imaging mass spectrometry by nanoSIMS (nano scale secondary ion mass spectrometry) is a valuable method to observe deuterium accumulation in any number of sample types. NanoSIMS analysis is a high resolution isotope and elemental imaging technique for solid sample surfaces, allows for spatial resolution as low as 50nm and has high sensitivity which makes it an ideal method for observing deuterium accumulation in sub cellular features of any number of sample types. The nanoSIMS method allows for simultaneous analysis of up to seven ion species, meaning there is capacity to pair deuterium analysis with other elemental or isotopic inquiry. In this presentation, fundamentals of nanoSIMS analysis are explained with emphasis on application to deuterium observation. The Microscopy Australia supported nanoSIMS facility at The University of Western Australia has recently begun collaboration with users that have sourced deuterated compounds from ANSTO based National Deuteration Facility and these examples will be discussed in detail.
    
    Speaker: Dr jeremy bougoure (University of Western Australia)
- 10:45 → 12:20
  Chemistry, Soft Matter & Crystallography
  - 10:45
    
    Molecular binding and exchange between model membranes and biologically relevant lipid assemblies 20m
    
    Model cellular membranes are often used to understand the interactions with biomolecules and nanoparticles[1], but the effects of such interactions go beyond molecular binding and include processes such as biomembrane restructuring and molecular exchange that may lead to changes in the structure and composition of the interacting nanoparticles.
    Here I will present our most recent work aiming at increasing the understanding of the role of biomembrane structure and composition on the function of lipoproteins. Lipoproteins are nanoemulsion-like particles composed of fats and proteins (apolipoproteins).[2] The complexity of lipoproteins is great,with different amounts and types of fats and proteins. We use lipoproteins from human healthy adults and look systematically at their capacity to exchange lipids as a function of membrane composition. We find that membrane charge, level of unsaturation in the acyl tails and presence of cholesterol all regulate lipoprotein function[3]–[5]. We also show significant differences in the exchange capacity of synthetic lipoproteins reconstituted with a single apolipoprotein type[6].
    Further, we show that the incubation with SARS CoV2 Spike proteins affects the exchange capacity of lipoproteins[7] that may be linked to the altered cholesterol metabolism in COVID19 patients.
    Finally, apolipoproteins also exchange and we demonstrate that their binding to Lipid-based nanoparticles (LNPs) affect the structure and composition of these particles[8]. The extent to which this component redistribution takes place may be correlated with the LNP’s capacity for protein expression and thus their therapeutic efficiency.
    All these experiments are possible thanks to neutron scattering combined with deuteration, since this an ideal approach to study the structure and dynamics of multicomponent systems where different parts of the system can be highlighted individually[8]–[11].
    
    Speaker: Prof. Marité Cárdenas (Malmö University and Nanyang Technological University)
  - 11:05
    
    High viscosity injector effects on the phase behaviour of lipidic cubic phase 15m
    
    In serial crystallography of membrane protein crystals, high-viscosity flow injectors deliver micron-sized crystals to the x-ray beam. The protein crystals are often injected embedded in the lipidic cubic phase (LCP) media, monoolein (MO), in which they were grown. The self-assembled structure of this media is easily impacted by the performance of the injector, e.g. pressure and gas flow surround the sample injection. However, it is not yet well understood how the continuous injection impacts the phase of the monoolein and how this influences the sample stream stability. In the present work, we report on observations of the structure of MO/water and MO/buffer mixtures during continuous flow injection at atmospheric pressure and in vacuum. These observations include x-ray diffraction data taken at the Australian Synchrotron (AS) and the Linac Coherent Light Source (LCLS), as well as optical polarisation measurements. We observe the coexistence of a cubic phase and lamellar phase within the sample stream. The lattice parameters are stable over typical changes in reservoir pressure that occur during injector operation. While the degree to which the lamellar phase is formed is found to depend strongly on the co-flowing gas used to stabilise the lipid stream. We further observe sharp transitions between diamond cubic and gyroid cubic phases that do not correlate with changes in pressure applied to the reservoir. In vacuum, we observe the coexistence of the gyroid cubic, the diamond-cubic and the lamellar phase simultaneously. The existence of LCP and lamellar phase at the experimental temperature, 26 degC and pressure ranges within the reservoir is unexpected and we investigate this observation using optical imaging.
    
    Speaker: Daniel Wells (La Trobe University)
  - 11:20
    
    Self-assembly of surfactants in protic ionic liquids 15m
    
    Protic ionic liquids (PILs) are the largest known solvent class capable of promoting surfactant self-assembly. However, PILs are increasingly used as mixtures with molecular solvents, such as water, to reduce their cost, viscosity and melting point, and the self-assembly promoting properties of these mixtures are largely unknown. Here we investigated the critical micelle concentration (CMC) of ionic and non-ionic amphiphiles in two ionic liquids, ethylammonium nitrate (EAN) and ethanolammonium nitrate (EtAN), to gain insight into the role of solvent species, and effect of solvent ionicity on the self-assembly process. The amphiphiles used were the cationic cetyltrimethylammonium bromide (CTAB), anionic sodium octanoate sulfate (SOS), and the non-ionic surfactant tetraethylene glycol monododecyl ether (C12E4). Surface tensiometry was used to obtain the CMCs and free energy parameters of micelle formation, and Small angle x-ray scattering (SAXS) was used to characterise the micelle shape and size. For CTAB, the trend in the CMC observed indicated that at low concentrations of the PIL, the ionic liquids acted as free ions, decreasing the CMC due to charge screening effects. This effect was not observed in C12E4 due to its neutral overall charge. Micelle formation of the anionic amphiphile was found to be more complex than initially hypothesised in ionic liquids. It was discovered that EtAN, the less cationic ionic liquid was able to facilitate self-assembly of SOS, whereas in EAN mixtures micelles could not be confirmed. The findings from this study gives insight into how solvent interactions are modified from solvents rich in water to rich in a PIL.
    
    Speaker: Sachini Kadaoluwa Pathirannahalage (RMIT University)
  - 11:35
    
    Deuterated Phospholipids to Study the Structure, Function and Dynamics of Membrane Proteins Using Neutron Scattering 15m
    
    Contrast matching and contrast variation in neutron scattering provide unparalleled power for understanding the structure, function, and dynamics of a selected component in a multicomponent system. A sophisticated contrast study often requires the availability of deuterated molecules in which deuterium atoms are introduced in a predictable and controlled fashion to replace protons. This can be achieved by direct deuteration of precursors followed by custom chemical synthesis, for which expertise and capabilities have been developed at facility (NDF), ANSTO.
    It this paper we will discuss recent high impact research output using deuterated phospholipids produced by NDF/ANSTO. We will describe the synthesis and applications of selectively or perdeuterated unsaturated phospholipids to contrast match out the whole lipid bilayer or nano disks within a multicomponent system. Further, we also describe their role in investigations related to membrane lipoproteins (ApoE) exchange in relation to lipid unsaturation,[1] effect of membrane composition,[2] and conformational analysis Mg+2 channel by neutron scattering techniques.[2, 3]
    
    References:
    1. Waldie, S., et al., Lipoprotein ability to exchange and remove lipids from model membranes as a function of fatty acid saturation and presence of cholesterol. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids, 2020. 1865(10): p. 158769.
    2. Waldie, S., et al., ApoE and ApoE Nascent-Like HDL Particles at Model Cellular Membranes: Effect of Protein Isoform and Membrane Composition. Frontiers in Chemistry, 2021. 9(249).
    3. Johansen, N.T., et al., Mg2+-dependent conformational equilibria in CorA: an integrated view on transport regulation. bioRxiv, 2021: p. 2021.08.20.457080.
    
    Speaker: Rao Yepuri (Australian Nuclear Science and Technology Organisation)
  - 11:50
    
    Investigating the interactions of monoolein liquid crystals with human microbiomes 15m
    
    Lipid-based liquid-crystals are biocompatible nanomaterials offering selective and ‘smart’ drug-release properties which are an emerging technology in the research and development pipeline. Over the last decade, research on these nanomaterials has focused on their behaviour in response to physicochemical phenomena and after loading with pharmaceutical cargo. Over the next decade, research aims to address our lack of understanding about how these prospective drug-carriers are influenced by physiological environments. This study explored members of the human microbiome as a potential candidate. Bacterial species which inhabit popular sites of drug administration were mixed with monoolein cubosomes and bulk cubic phase gels. The effects on liquid crystal structure and drug release profile were examined using benchtop and synchrotron SAXS, cross-polarized light microscopy, and fluorescence measurements. Particle mixing with bacterial cell membrane components induced a transformation to hexagonal structure, consistent with the transfer of bacterial phospholipids to the matrix. Similarly, exposure to the representative skin bacteria S. aureus induced the transformation to hexagonal structure after 8 hours. S. aureus exposure also reduced the rate of hydrophilic dye release from bulk monoolein cubic phase over a similar timeframe. This transformation was consistent with an increase in oleic acid content by lipolysis of monoolein by lipase. This research demonstrates the influence that bacteria can have on the structure and drug release properties of monoolein liquid-crystalline drug-delivery systems. These findings are hoped to inform future research throughout the development of these prospective drug-carrier nanomaterials for healthcare applications and commercially viable products.
    
    Speaker: Mr Jonathan Caukwell (The University of Newcastle)
  - 12:05
    
    How Do Ion Specific Effects Operate in Ionic Liquids? 15m
    
    Recent work has found that the identity of a surfactant's counter-ion can affect the critical micelle concentration, and the size and shape of resultant micelles in ionic liquid (IL) and choline-based deep eutectic solvents.[1,2] This indicates the presence of ion specific effects for micellisation in these neoteric solvents despite their high ionic strength.[3] This project examines this phenomenon further, by investigating a range of choline salts (chloride, bromide, and nitrate) in different nitrate-based ILs (ethylammonium, propylammonium, and ethanolammonium nitrate) via measurements taken on the Small Angle Neutron Diffractometer for Amorphous and Liquid Samples (SANDALS) beamline at ISIS. These results bring new insight into how ion specific effects can exist in high ionic strength neoteric solvents, and the parameters involved in controlling this surprising phenomenon.
    
    (1) Dolan, A.; Atkin, R.; G. Warr, G. The Origin of Surfactant Amphiphilicity and Self-Assembly in Protic Ionic Liquids. Chemical Science 2015, 6 (11), 6189–6198. https://doi.org/10.1039/C5SC01202C.
    (2) Sanchez-Fernandez, A.; S. Hammond, O.; J. Edler, K.; Arnold, T.; Doutch, J.; M. Dalgliesh, R.; Li, P.; Ma, K.; J. Jackson, A. Counterion Binding Alters Surfactant Self-Assembly in Deep Eutectic Solvents. Physical Chemistry Chemical Physics 2018, 20 (20), 13952–13961. https://doi.org/10.1039/C8CP01008K.
    (3) Warr, G. G.; Atkin, R. Solvophobicity and Amphiphilic Self-Assembly in Neoteric and Nanostructured Solvents. Current Opinion in Colloid & Interface Science 2020, 45, 83–96. https://doi.org/10.1016/j.cocis.2019.12.009.
    
    Speaker: Dr Joshua Marlow (University of Sydney)
- 10:45 → 12:20
  Instruments & Techniques
  - 10:45
    
    The new external ion beam capability for testing of electronics suitable for harsh space radiation environments 20m
    
    In 2019, the Australian Space Agency made its debut in the international scene of the space exploration. Securing the future of Australia’s space sector is the core of the Advancing Space: Australian Civil space Strategy 2019-2028. This Government plan reminds that space-based technology and services not only interests space missions, but benefits all Australians daily as for weather forecasting, GPS, internet access, online banking, emergency response tracking bushfires, monitoring of farming crops, etc.
    To further increase capability, the Space Infrastructure Fund (SIF) investment was issued to target 7 space infrastructure projects that involve several industries, organisations, universities, laboratories, all around the country. Mission control and tracking facilities, robotic & automation, AI command and control, space data analysis facilities, space manufacturing capabilities, and space payload qualification facilities, are the topics under study.
    ANSTO together with other 5 fund recipients engaged its resources in the last-mentioned project (space payload qualification facilities), with the aim to establish the National Space Qualification Network (NSQN).
    Particularly, the three ASNTO facilities Centre for Accelerator Science (CAS), the Australian Synchrotron and the Gamma Technology Research Irradiator (GATRI) will focus on enhancing and improving their capabilities for space radiation damage testing of electronics used in space and ensure they meet international standards in this area.
    Space technology can be affected by cosmic radiation when Single Event Upset (SEU) occurs, knocking out temporary or permanently the instrumentation that is paramount for the successful accomplishment of a mission, a test, or simply the usual functionality of a service.
    We need to deep understand the cause and the frequency of these events, in order to reduce the risk of component failure and to consequently optimizse the electronics. Tests must be performed in ground-based facilities before commercialization of any device.
    ANSTO facilities use accelerators to perform radiation tests with different beams (gamma-rays, x-rays, protons and heavy ions) to eventually provide international standards of Total Ionisation Dosage (TID) radiation testing for products that can enter faster into global supply chains.
    Because of the limitations encountered while performing tests in vacuum, at the CAS facility, the High Energy Heavy Ion Microprobe (HIM) of the 10MV ANTARES accelerator has recently been upgraded to an external chamber for testing standard electronic chips in an ambient-in-air environment. Advantages of an ex-vacuum microprobe are: ease of handling the sample with no limits to the dimension of the sample itself, no charge effects, more effective target heat dissipation, sampling is not required, gain in terms of time used for pump-up and down the chamber, and possibility to irradiate living system without compromising them.
    
    Stefania Peracchi1,*, David Cohen1, Zeljko Pastuovic1, Nikolas Paneras1, David Button1, Chris Hall2, Justin Davies3, Michael Mann1, David Cookson4, Michael Hotchkis1, Ceri Brenner1.
    
    1 Centre for Accelerator Science, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
    2 IMBL, Australian Synchrotron, Clayton, VIC 3168, Australia
    3 Gamma Technology Research Irradiator, Lucas Heights, NSW 2234, Australia
    4 NSTLI Industry and Stakeholder Engagement, Lucas Heights, NSW 2234, Australia
    
    Speaker: Dr Stefania Peracchi (ANSTO)
  - 11:05
    Tomographic X-ray phase and attenuation extraction for a sample composed of unknown materials 15m
    
    Propagation-based phase-contrast X-ray imaging (PB-PCXI) is a technique suitable for imaging weakly-attenuating objects, e.g., biological samples, as it utilizes both attenuation and refraction effects. Such effects are material dependent, and described by the X-ray’s complex refractive index n=1-δ+iβ, where β and δ describe attenuation, and refraction, respectively. Phase retrieval algorithms are typically applied to PB-PCXI images to recover lost phase information. A single-material reconstruction, based on the transport-of-intensity equation, has been published by Paganin et al. [1] and has proven useful in diverse fields. This approach has been extended to consider multi-material objects [2], and partially-coherent X-ray sources [3]. The described phase-retrieval algorithms can successfully recover the projected-phase information of an object, however, they require a priori knowledge of the sample materials. We present an algorithm capable of extracting β and δ functions for a sample that is composed of unknown materials. The essence of the approach is based on curve-fitting an error-function to each interface between distinct materials in a computed tomographic reconstruction [4], where the fit parameters are then used to calculate δ and β for composite materials. This approach requires no a priori sample information, making it broadly applicable, particularly in cases where exact sample composition is unknown. We have applied this method to a breast-tissue sample, where the δ for composite materials was calculated to 0.6% - 2.5% accuracy, compared to theoretical values.
    
    D. M. Paganin et al., J.Microsc. 206, 33 (2002)
    
    M. A. Beltran et al., Opt.Express 18, 6423 (2010)
    
    M. A. Beltran et al., J.Opt. 20, 055605 (2018)
    
    D. A. Thompson et al., J.Synchrotron.Radiat. 26, 825-838 (2019)
    
    Speaker: Samantha Alloo
  - 11:20
    
    High speed free-run ptychography at the Australian Synchrotron 15m
    
    The Australian Synchrotron X-ray Fluorescence Microscopy (XFM) beamline has recently implemented fast-scanning ptychography, a scanning X-ray diffraction microscopy method. Ptychography creates super-resolution images from transmitted microdiffraction patterns acquired as the sample is scanned through the beam. High-speed detectors and high-performance computers are required to iteratively reconstruct these complex images. The experimental methods and reconstruction algorithms have significantly evolved over the last decade and a half into a mature and user-friendly complementary imaging method to XFM.
    
    Here we present the implementation of high speed ptychography at the XFM beamline, which includes a free-run data collection mode where detector dead time is eliminated, and the scan time is optimized. We show that free-run data collection is viable for fast and high-quality ptychography by demonstrating extremely high data rate acquisition covering areas up to 352,000 µm2 at up to 140 µm2/s, with 18× spatial resolution enhancement compared to the beam size. With these improvements, ptychography at velocities up to 250 µm/s is approaching speeds compatible with fast-scanning X-ray fluorescence microscopy. The combination of these methods provides morphological context for elemental and chemical information, enabling unique scientific outcomes.
    
    Speaker: Cameron Kewish (Australian Synchrotron)
  - 11:35
    
    Medium Energy Spectroscopy (MEX) - Sample environments and supporting infrastructure 15m
    
    The Medium Energy Spectroscopy (MEX) beamline aims to facilitate a wide variety of ex- and in-situ experimental work from a variety of research areas. As such, we will provide a number of sample environments as standard set-up, in addition to ancillary equipment that can be used with custom or BYO sample environments. Sample environments will likely include; room temperature cell, electrochemical flow cell, micro-fluidic cell, flammable gas cell, furnace with gas environments,and a battery testing cell. In addition, supporting infrastructure and ancillary equipment will likely include; flammable and toxic gas handling (flow and pressure control), gas and vapor ventilation, electrochemical testing station (Autolab or similar), fluid (gas or vapour) syringe pumps with pressure monitoring. Most, if not all, of the sample environments and supporting infrastructure will be controlled with the beamline systems, enabling integration and triggering for maximum achievable automation of experiments.
    
    Speaker: Krystina Lamb (ANSTO)
  - 11:50
    
    Medium Energy Spectroscopy (MEX) - Opportunities for Microspectroscopy 15m
    
    The medium energy range offers unique opportunities for synchrotron-based X-ray absorption spectroscopy across the sciences. In particular, the K-absorption edges of alkali and alkali earth elements, e.g. K and Ca, s-group elements, e.g. S, P and Se, along with d-block elements, e.g. Mn, Fe, Cu all fall within this energy range. As do various L- and M-edges for heavier elements, e.g. Pb and U. The nascent Medium Energy X-ray Spectroscopy (MEX) beamlines will access these edges and offer unique opportunities to study the local structure, speciation, and chemistry of compounds and systems critical to biological, environmental, geological and industrial processes.
    
    Typically, characterisation of specific metal-ligand species requires isolation of the complex, necessitating disruption of native systems despite the attendant risk of redistribution and loss of chemical context. Despite the confounding potential of typical preparation methodologies, the tools available to coordination chemistry in situ have remained limited. The continuing synergy between synchrotron-based X-ray fluorescence microscopy (XFM) and X-ray absorption near edge structure (XANES) spectroscopy represents a powerful new analytical approach for studying chemistry in context.
    
    Using illustrative examples and highlighting particular techniques, this presentation will introduce one of MEX's major end stations, the scanning X-ray fluorescence microprobe ($\mu$MEX). To be installed on the MEX1 beamline, operating between 2 and 13.6 keV and focusing X-rays into a spot, less than 5 microns in diameter $\mu$MEX will offer unique opportunities for synchrotron-based X-ray microspectroscopy. To date, the scarcity of such optimised facilities leaves many exciting scientific questions to be explored though such measurements also involve unique experimental challenges.
    
    Speakers: Dr Simon James (ANSTO Australian Synchrotron), Mr Simon Pocock (ANSTO)
  - 12:05
    
    Hot Commissioning and First User Experiments on the Spatz Neutron Reflectometer 15m
    
    The Spatz neutron beam instrument is the latest to be installed and commissioned in the Neutron Guide Hall at the 20 MW OPAL Research Reactor. Spatz is a time-of-flight neutron reflectometer used for studying nanoscale structures at surfaces and interfaces and utilises a vertical sample geometry / horizontal scattering geometry. The instrument is situated at the end position of the CG2B neutron guide and views the cold-neutron source (CNS). The disc chopper cascade that pulses the neutron beam to produce the time-of-flight is very configurable to provide a wavelength resolution between 1 to 12 %. The detector is a helium-3 two-dimensional detector that is capable of measuring both specular and off-specular reflectivity. The sample stage can support a range of different sample environments including multiple solid-liquid cells, an atmospheric chamber with temperature control, the ATR-FT-IR spectrometer for simultaneous infra-red spectroscopy and neutron reflectometry measurements, electrochemical cells, etc. The geometry of the instrument and the sample environment available means that Spatz is well suited to studying phenomena at the gas-solid interface and solid-liquid interface. The Spatz instrument has been fully commissioned with neutrons and the results of the commissioning are presented. This includes measurements using the ‘Bragg mirror’ consisting of 25 bilayers of nickel and titanium, different solid substrates of silicon, quartz and sapphire, spin-coated polymer samples, and films under liquid. Reflectivity down to 10-7 can be achieved within 1 hour measuring time with good counting statistics in most cases. Early user experiments cover a range of science including investigating the thermal stability of organic solar cell materials and proteins interacting with biomimetic phospholipid cell membranes.
    
    Speaker: Anton Le Brun (ANSTO)
- 12:20 → 12:50
  
  Lunch 30m
- 12:50 → 13:10
  
  Update: CAS
- 13:10 → 13:30
  Update: AS
  - 13:10
    
    15 Years of Brilliance at the Australian Synchrotron 20m
    
    The Australia Synchrotron achieved first light in August 2006, and since then has operated 10 individual beamlines as part of Australia's largest standalone scientific research facility. In a typical year, the facility conducts up to 1000 individual experiment, and hosts more than 5000 User visits. Although modest compared to international synchrotron facilities in terms of the size of our storage ring, our staffing levels and the number of beamlines, the Australian Synchrotron's research community is one of the most productive in the world; generating more than 650 peer-reviewed journal articles in 2020. Over the past 15 years the Australian Synchrotron has supported the development of the scientific careers of thousands of students, researchers, and our staff. This presentation celebrates some of the highlights in beamline and technique development, as well as showcasing trends in high impact research outcomes from the Australian Synchrotron.
    
    Speaker: Michael James (ANSTO)
- 13:30 → 14:50
  Biomedicine, Life science & Food Science
  - 13:30
    
    Studying Polysaccharides in Solution with SAXS and Molecular Dynamics 20m
    
    Polysaccharides are semi-flexible polymers composed of sugar residues with a myriad of important functions in-vivo, including structural support, energy storage and immunogenicity. The local conformation of such chains is a crucial factor governing their interactions. Traditionally this conformation has only been directly accessible in the solid-state, using crystallographic techniques such as fibre diffraction. However, improvements in the quality of synchrotron-based X-ray scattering data means that conformation-dependent features can now be measured in solution. In tandem, scattering predictions based on structures initiated from existing fibre x-ray diffraction data, and then re-animated using molecular dynamics, can now be performed.
    
    Our group has recently measured the detailed small-angle x-ray scattering from a variety of anionic oligo- and poly-saccharides in solution. This talk will specifically present data obtained from experiments carried out on homogalacturonan, alginate and carrageenan and discuss their comparison with predictions based on our molecular dynamics simulations. The remarkable agreement found provides unequivocal evidence for the validity of our real-space atomistic models of the solution state structures. This technique is expected to be universally applicable for polysaccharides that consist of comparatively stiff glycosidic linkages, and to have extensive relevance for a number of biological macromolecules, including glycosylated proteins.
    
    Speaker: Prof. Martin (Bill) Williams (Massey University, MacDiarmid Institute, NZ)
  - 13:50
    
    SPACE RADIATION AND INDIVIDUAL RADIOSENSITIVITY- ANSTO CAS & HUMAN HEALTH IN AIR BEAM EXPERIMENTS 15m
    
    Radiation exposure is a major limiting factor for long duration manned space flights.
    Radiation protection standards are based on the assumption that individuals are equally resistant to ionizing radiation. However, for over a century, there is evidence that humans do not respond equally to radiation. Particularly, the studies of secondary effects post-radiotherapy have shown a great variability among individuals. More specifically, large discrepancies among astronauts after the same flight were observed. Recently, from a collection of hundreds of fibroblast cell lines derived from patients suffering from genetic disease or post-radiotherapy radiosensitivity, we have shown that the delay in the nucleoshuttling of the ATM protein may cause a lack of double strand break (DSB) recognition, incomplete DSB repair and radiosensitivity. Interestingly, the model of the ATM nucleoshuttling was shown to be relevant not only for low-dose and repeated exposures, but also for high-LET particles, which renders this model compatible with space radiation exposure scenarios. Lastly, this model could lead to a novel approach for radiation protection, consisting of interventions to accelerate ATM nucleoshuttling. Such an approach may help in developing efficient countermeasures that could assist with manned space flights. In 2019-2021, teams from ANSTO CAS and Human Health have been collaborating to adapt the ANTARES beamline for in air irradiation of living matter and study the effects of secondary radiation produced by interraction of cosmic and galactic rays with spacecraft shielding. DNA repair and mitochondrial activity processes will be studied.
    
    Speaker: Dr Melanie Lydia Ferlazzo (ANSTO)
  - 14:05
    
    Antimicrobial and Anti-Inflammatory Gallium Implanted ‘Trojan Horse’ Surfaces for Implantable Devices 15m
    
    A rapidly aging population, high incidence of osteoporosis and trauma-related fractures, and better health care access explain rapid surge in utilisation of orthopedic implantable devices. Unfortunately, many implants fail without strategies that synergistically prevent infections and enhance the implant’s integration with host tissues. Here, we propose a solution that builds on our pioneering work on gallium (Ga)-enhanced biomaterials, which show exceptional antimicrobial activity, and combined it with defensin (De, hBD-1), which has potent anti-microbial activity in vivo as part of the innate immune system. Our aim was to simultaneously impart antimicrobial activity and anti-inflammatory properties to polymer-based implantable devices through the modification of the surfaces with Ga ions and immobilisation of De. Poly-lactic acid (PLA) films were modified using Ga implantation using the Surface Engineering Beamline of the 6MV SIRIUS tandem accelerator at ANSTO Australia, and subsequently functionalised with De. Ga ion implantation increased surface roughness and increased stiffness of treated PLA surfaces and led to the reduction in foreign body giant cell formation and expression of pro-inflammatory cytokine IL-1β. Ga implantation and defensin immobilization both independently and synergistically introduced antimicrobial activity to the surfaces, significantly reducing total live biomass. We demonstrated, for the first time, that antimicrobial effects of De were enhanced by its surface immobilization. Cumulatively, the Ga-De surfaces were able to kill bacteria and reduce inflammation in comparison to the untreated control. These innovative surfaces have the potential to prevent biofilm formation without inducing cellular toxicity or inflammation, which is essential in enhancing integration of implantable devices with host tissues and hence, ensure their longevity.
    
    Speaker: Shiva Kamini Divakarla (The University of Sydney, Sydney Nano Institute, Faculty of Medicine and Health, Sydney Pharmacy School, Sydney, NSW 2006, Australia)
  - 14:20
    
    Structural insights into the unique modes of relaxin-binding and tethered-agonist mediated activation of RXFP1 and RXFP2 15m
    
    Our poor understanding of the mechanism by which the peptide-hormone H2 relaxin activates its G protein-coupled receptor, RXFP1 and the related receptor RXFP2, has hindered progress in its therapeutic development. Both receptors possess unique ectodomains that comprise of an N-terminal LDLa module joined by a linker to a Leucine Rich Repeat (LRR) domain. Truncation of the N-terminal LDLa module abolishes signalling for both receptors suggesting that the LDLa module is essential for activation and is postulated as a tethered agonist, induced to undergo a conformational change upon H2 relaxin binding.
    
    Here, we use Small Angle X-ray Scattering (SAXS), NMR spectroscopy, cell-based receptor signalling assays to show that it is not the LDLa module, but rather a conserved motif (GDxxGWxxxF), immediately C-terminal to the LDLa, that is the essential tethered agonist. Importantly, this motif associates with the LDLa module of both RXFP1 and RXFP2, in different manners suggesting distinct mechanisms of activation. For RXFP1, the motif is flexible, weakly associates with the LDLa module, and requires H2 relaxin binding to stabilize an active-state conformation. Conversely, the motif in RXFP2 does not possess the same flexibility as it does in RXFP1, and appears to be more structured and closely associated with the LDLa module, forming an essential binding interface for H2 relaxin. H2 relaxin binding to RXFP2 needs both the LDLa module and the motif, distinct to RXFP1 and the tethered agonist activity of the motif is not driven by an induced conformational change in RXFP2, also distinct to RXFP1. These results highlight distinct differences in relaxin mediated activation mechanism of RXFP1 and RXFP2 which will aid drug development targeting these receptors.
    
    Speaker: Dr Ashish Sethi (University of Melbourne)
  - 14:35
    
    Synchrotron infrared characterisation of SARS-CoV-2 virions for a new COVID-19 saliva test 15m
    
    In response to the COVID-19 pandemic the Biospectroscopy group within the Monash School of Chemistry have become part of a research working group headed by Prof. Dale Godfrey and Prof. Damian Purcell at the Doherty Institute to develop a new IR diagnostic for the detection of COVID-19. An infrared-based test would be reagent-less, able to test hundreds of thousands using the same instrument, be highly sensitive and inexpensive, producing results in minutes. This is cogent especially given the worldwide shortage of conventional testing kits and the long delays in getting results that in the case of virulent variants such as Delta, are costing lives. The talk will focus on new developments in the arena of point-of-site COVID testing highlighting rapid diagnostic-based tests and our new infrared based saliva screening test. We have modified a portable infrared spectrometer with purpose-built transflection accessory for rapid point-of-care detection of COVID-19 markers in saliva. Initially, purified virion particles were characterized with Raman spectroscopy, synchrotron infrared (IR) and AFM-IR. A data set comprising 171 transflection infrared spectra from 29 patients testing positive for SARS-CoV-2 by RT-qPCR and 28 testing negative, was modeled using Monte Carlo Double Cross Validation with 50 randomized test and model sets. The testing sensitivity was 93 % (27/29) with a specificity of 82 % (23/28) that included positive samples on the limit of detection for RT-qPCR. This high throughput infrared COVID-19 test is rapid, inexpensive, portable and utilizes sample self-collection, thus minimizing the risk to healthcare workers and is ideally suited to mass or personalised screening in public and private settings.
    
    Speaker: Prof. Bayden Wood (Centre for Biospectroscopy, School of Chemistry, Monash University)
- 13:30 → 14:50
  
  Chemistry, Soft Matter & Crystallography
- 13:30 → 14:50
  Instruments & Techniques
  - 13:30
    
    The recent progress of polarized neutron scattering techniques at SIKA 15m
    
    SIKA, the cold-neutron triple-axis spectrometer is on the CG4 beam port at the OPAL reactor, ACNS, ANSTO. We have reported the capabilities and status of SIKA in the last several user's meetings.
    In this meeting, we discuss the recent development of polarized neutron scattering experiments on SIKA. A 3He polarization analysis system is available for SIKA. We have performed several user experiments and commissioning experiments in the last two years. We would like to present some results by introducing the techniques we are trying to implement. In addition, we discuss our plan for the polarized neutron scattering experiment on the SIKA.
    
    Speaker: Shinichiro Yano (NSRRC)
  - 13:45
    MyD88 TIR domain higher-order assembly interactions revealed by serial femtosecond crystallography 15m
    
    Serial Synchrotron Crystallography (SSX) is rapidly emerging as a promising technique for collecting data for time-resolved structural studies or for performing room temperature micro-crystallography measurements using micro-focused beamlines. When performed using ultra-bright X-ray Free Electron Laser (XFEL) sources serial crystallography typically involves a process known as ’diffract-and-destroy’ where each crystal is measured just once before it is destroyed by the intense XFEL pulse. It’s the small and intense beam focus of XFELs that make it possible to determine structures from nanocrystals where conventional crystallography techniques fail. Only through thorough synchrotron investigation, can we achieve successful XFEL beamtime proposals. Here we investigate the important role of the MX2 beamline at the Australian Synchrotron played in the successful XFEL proposal which resulted in the structure of the Myeloid differentiation primary response gene 88 (MyD88) and MyD88 adaptor-like/TIRAP (MAL), Toll-like receptor (TLR) adaptor proteins which play an important role in inflammatory disease . The data generated at the Linac Coherent Light Source provided structural and mechanistic insight into TLR signal transduction[1].
    
    Clabbers, M., Holmes, S. et.al. MyD88 TIR domain higher-order assembly interactions revealed by microcrystal electron diffraction and serial femtosecond crystallography. Nature Communications, Nature communications 12 (1), 1-14, 2021.
    
    Speakers: Connie Darmanin (La Trobe), Dr Mark Hunter (Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California, USA)
  - 14:00
    
    The High Performance Macromolecular Crystallography (MX3) Beamline 15m
    
    The MX3 beamline will extend the capabilities of the existing suite of MX beamlines at the Australian Synchrotron. It will allow collection on crystals that are too small or weakly diffracting for the current beamlines. A high level of automation will transform membrane protein micro crystal collection and high throughput projects such as drug and fragment screening. Sample positioning will be provided via an MD3-UP goniometer and an ISARA robot will allow 6 second sample exchange. Serial crystallography capability will be provided using in-tray screening and collection and fixed target silicon chip scanning stages. A dedicated cluster will provide real-time data processing and automated data collection will be standard. This will include automated location of crystals from a rastered volume with subsequent data collection on each crystal with resulting automated data merging from multiple crystals.
    
    Some outstanding questions for the user community relate to time-resolved crystallography, and injector experiment capabilities; options will be presented and discussed.
    
    Speaker: Daniel Eriksson (Australian Synchrotron)
- 14:50 → 15:20
  
  Afternoon Tea 30m
- 15:20 → 17:05
  
  Biomedicine, Life science & Food Science
- 15:20 → 17:05
  Chemistry, Soft Matter & Crystallography
  - 15:25
    SAXS investigation of protic ionic liquid-water mixtures, and their application to protein crystallisation 15m
    
    Protic ionic liquids (PILs) are cost efficient “designer” solvents which can be tailored to have properties suitable for a broad range of applications. PILs are also being combined with molecular solvents to enable more control over the solvent environment, driven by a need to reduce their cost and viscosity. This also leads to greater biocompatability.
    In this presentation I will discuss our ongoing work into designing PIL solvents for proteins, with a focus on lysozyme as a model protein 1. We have recently been using SAXS to explore the effect of PILs on lysozyme from dilute to neat IL concentrations in water. This naturally leads to a discussion on the difficulties in obtaining SAXS data of proteins in viscous media, and of analysis the data where the solvent is also nanostructured. However, despite these challenges, we are beginning to develop design rules which can be used to select ILs for specific applications.
    One application that we are developing PIL solvents for is in protein crystallisation. We have used MX1&2 data to solve lysozyme crystal structures with 7 PILs present. Preliminary results will be presented where we have used SAXS to monitor the initial stages of lysozyme crystallisation in PIL-water solutions, using ethylammonium nitrate as the PIL.
    
    Qi, H.; Smith, K. M.; Darmanin, C.; Ryan, T. M.; Drummond, C. J.; Greaves, T. L., Lysozyme conformational changes with ionic liquids: spectroscopic, small angle x-ray scattering and crystallographic study. Journal of Colloid and Interface Science 2021, 585, 433-443.
    
    Speaker: Tamar Greaves (RMIT University)
  - 15:40
    
    Stimuli Responsive Switchable Chemical Sensors 15m
    
    The development of real-time, highly sensitive chemical sensors for the detection of very low analyte concentrations is of significant interest and importance for monitoring levels of harmful chemicals in the environment. The unique properties of the rare-earth metals enables sharp and narrow luminescent signals to be obtained. The incorporation of rare-earth ions into sensor systems offers significant advantages for enhancing the sensor response, allowing greater discrimination between chemical analytes.
    
    Coordination polymers (CPs) and Metal-Organic Frameworks (MOFs) are crystalline materials containing inorganic nodes bridged by multidentate ligands. The high porosity and tunability of CPs enable the systematic modification of pore chemistry and size. Tailored pore environments can be designed, making these materials well-suited to act as chemical sensors. Rare-earth coordination polymers remain relatively less explored than transition metal coordination polymers due to their higher coordination numbers and unpredictable coordination environments. Reports of rare-earth coordination polymers containing a redox-active ligand are still relatively scarce in the literature despite the potential they present for enhanced chemical sensing and the development of magnetic and switchable materials.
    
    This presentation will discuss the synthesis and properties of an isostructural series of rare-earth coordination polymers containing a redox-active viologen ligand. The viologen moiety is able to undergo a reversible one electron reduction upon exposure to a light or electrochemical stimulus. The electrochemical, photochromic and sensing ability of the materials will be discussed and their potential for application in the development of chemical sensors highlighted.
    
    Speaker: Carol Hua (University of Melbourne)
  - 15:55
    
    Influencing lipid hydrolysis by minute molecular changes 15m
    
    Designer lipid colloids are being increasingly studied for the delivery of drugs and nutrients. These nanoparticles can have different internal nanostructures and different lipidic composition. Cyclopropanated derivatives of commonly used monoacylglycerols show substantial differences in self-assembled structures, and formations of nanostructured nanoparticles. Most remarkably, small differences in the hydrophobic tail affect the packing of the lipids, sufficient to alter the availability of the lipid headgroups to be hydrolysed by interfacial enzymes. We employed small angle X-ray scattering and acid/base titration at the Australian Synchrotron SAXS/WAXS beamline to monitor the nanostructural changes during hydrolysis and the digestion rate. These fundamental characteristics are of interest for the smart design of lipidic nanoparticles for drug or nutrients delivery.
    
    Salvati Manni L. et al. (2021) J. Colloid Interface Sci. 588, 767-775
    
    Speaker: Livia Salvati Manni (University of Sydney)
  - 16:10
    
    Insight into the Variations of ABO4 Structures: Combined Experimental and Computational Studies 15m
    
    The development of carbon-neutral energy-generation is critical to combatting climate change. One such technology is the development of next-generation ion conductors for solid-oxide fuel cells (SOFCs). SOFCs offer a more efficient method of extracting energy from hydrogen or hydrocarbon fuels than current combustion engines due to their one-step chemical process. However, a bottleneck to the large-scale uptake of SOFCs is the poor performance of the conducting electrolytes that separate the anode from the cathode. Various $AB\text{O}_{4}$ structures have recently been proposed as solid electrolyte candidates in SOFCs, with increased high-temperature ionic conductivity being measured in chemically doped LaNbO$_{4}$. However, the various phase transitions of these materials within the operational temperature of SOFCs makes them non-ideal.
    
    To understand the effects of chemical doping on the structure and electrochemical properties, several complex $AB\text{O}_{4}$ structures have been investigated. In this work, we present the solid-solution series $Ln$(Nb$_{1-x}$Ta$_{x}$)O$_{4}$ (Ln = La-Lu). Using a combination of synchrotron X-ray and neutron powder diffraction methods, these studies have revealed several anomalies across the series. The structures appear to be sensitive to the size of the Ln cation and their synthesis conditions, with a difference in ionic conduction performance being observed. This experimental data has been further reinforced by ground state energy calculations performed using density functional theory. This is a landmark accomplishment that has not been previously used in similarly studied structures. These insights can be used in the development and engineering of novel and advanced electrolyte materials for SOFCs.
    
    Speaker: Bryce Mullens (University of Sydney)
  - 16:25
    
    Understanding Order and Correlation in Liquid Crystals by Fluctuation Scattering 15m
    
    Characterising the supramolecular organisation of macromolecules in the presence of varying degrees of disorder remains one of the challenges of macromolecular research. Discotic liquid crystals (DLCs) are an ideal model system for understanding the role of disorder on multiple length scales. Consisting of rigid aromatic cores with flexible alkyl fringes, they can be considered as one-dimensional fluids along the stacking direction and they have attracted attention as molecular wires in organic electronic components and photovoltaic devices.
    
    With its roots in single-particle imaging, fluctuation x-ray scattering (FXS) is a method that breaks free of the requirement for periodic order. However, the interpretation of FXS data has been limited by difficulties in analysing intensity correlations in reciprocal space.
    
    Recent work has shown that these correlations can be translated into a three-and four-body distribution in real space called the pair-angle distribution function (PADF) – an extension of the familiar pair distribution function into a three-dimensional volume. The analytical power of this technique has already been demonstrated in studies of disordered porous carbons and self-assembled lipid phases.
    
    Here we report on the investigation of order-disorder transitions in liquid crystal materials utilising the PADF technique and the development of facilities for FXS measurements at the Australian Synchrotron.
    
    Speaker: Jack Binns (RMIT University)
  - 16:40
    
    Automation of liquid crystal phase analysis for SAXS 15m
    
    Lyotropic liquid crystal phases (LCPs) are widely studied for diverse applications, including protein crystallization and drug delivery. The structure and properties of LCPs vary widely depending on composition, temperature and pressure. Therefore, high-throughput structural characterisation, such as small-angle x-ray scattering (SAXS), is important to cover meaningfully large compositional spaces. Currently there are well established methods for high-throughput LCP synthesis using automated methods, and for high throughput SAXS data collection with synchrotron sources. However, high-throughput LCP phase analysis for SAXS data is currently lacking, particularly for patterns containing multiple phases. Using SAXS data, we have developed a high throughput LCP phase identification procedure. The accuracy and time-saving capabilities of the identification procedure were validated on a total of 668 diffraction patterns for the amphiphile hexadecyltrimethylammonium bromide (CTAB), in 53 acidic or basic solvents containing ethylammonium nitrate (EAN) or ethanolammonium nitrate (EtAN). The thermal stability ranges and lattice parameters for the obtained LCP systems showed equivalent accuracy to manual analysis. A time comparison demonstrated that the high throughput phase identification procedure was over 20 times faster than manual analysis. We then applied the high throughput identification procedure to 332 diffraction patterns of sodium dodecyl sulfate (SDS) in the same EAN and EtAN based solvents to produce previously unreported phase diagrams that exhibit phase transitions between hexagonal, lamellar, primitive cubic and diamond cubic LCPs. The accuracy and significant time decrease of the high throughput identification procedure validates a new, unrestricted analytical method for the description of LCP phase transitions.
    
    Speaker: Stefan Paporakis (RMIT)
- 15:20 → 17:10
  Manufacturing & Engineering
  - 15:20
    
    New insight in corrosion mechanisms of nuclear fuel cladding using synchrotron x-rays 20m
    
    In water-cooled nuclear reactors zirconium alloys have been the material of choice to encapsulate the fuel due to a combination of low neutron cross-section, excellent corrosion performance and good mechanical properties. However, fuel cladding performance, or our ability to predict its performance, remains the limiting factor in an effort to push for increased fuel burnup, i.e. the energy extracted from a fuel assembly before it is removed from the core.
    Aqueous corrosion, and the associated hydrogen pick up, remains one of the limiting factors to take nuclear fuel assemblies to higher fuel burnup. Even slight variation in alloy chemistry is known to greatly affect the corrosion performance of a Zr-alloy. Michael will discuss the application of synchrotron x-ray diffraction and scattering techniques together with other advanced characterisation techniques to provide new understanding of the integrity and therefore passivation capability of the oxide that forms during aqueous corrosion.
    
    Speaker: Prof. Michael Preuss (Monash University)
  - 15:40
    
    Thermal evolution in metals as revealed by in-situ neutron diffraction 15m
    
    The thermal evolution in metals plays an utmost important role in thermo-mechanical processing. Lattice expansion not only reveals conventional thermal expansion but moreover gives insight to order parameters, change of chemical composition and pressure. Peak widths reveal microstructural changes, as well as texture evolution, while primary extinction can be used to study defect mechanisms. Quantifying anisotropic and phase related expansion mismatch allows to design alloys with better mechanical properties. Here I give an overview with selected examples on bulk zirconium alloys, aluminium alloys. Focus will be given on materials after severe plastic deformation, in which different states of thermal stress relaxation, microstructural recovery and recrystallization can be distinguished.
    
    Speaker: Klaus-Dieter Liss (GTIIT)
  - 15:55
    
    In-situ X-ray imaging of transient liquid phase (TLP) bonding in solder joints 15m
    
    The demand for Pb-free solder interconnections that can operate reliably at high service temperatures has motivated the development of transient liquid phase (TLP) bonding as an alternative soldering method. The capability of TLP bonding to be processed at a lower temperature while creating a joint composed of high melting temperature intermetallic compounds (IMCs) makes it a promising method. Sn/Cu-based systems are commonly used in electronic packaging due to their low melting point and cost benefits. However, the slow kinetics of the IMC growth and uncontrolled formation of porosity in Sn/Cu-based systems remain challenging issues in practical applications. The addition of Ni to the Cu substrate can minimize the time required for TLP bonding . In this study, the rapid growth of (Cu,Ni)6Sn5 during TLP bonding of Cu-Ni/Sn-0.7Cu/Cu-Ni joints was observed in real-time using the synchrotron X-ray microradiography technique at BL20XU beamline at SPring-8 Synchrotron, Japan. The joints were constructed to be approximately 100 μm thick to facilitate X-ray transmission and clamped in between silica slides to facilitate X-ray transmission and held isothermally at 240 °C bonding until the reaction was completed. The formation of voids and cracks and the kinetics of the TLP soldering process were investigated using a monochromatised X-ray energy of 21 keV. These firsthand observations contributed to a better understanding of the creation and distribution of porosity, which will aid in the development of high reliablility TLP bonding techniques for the production of high-temperature interconnections.
    
    Speaker: Ms Nurul Razliana Abdul Razak (The University of Queensland)
  - 16:10
    
    The use of variable temperature synchrotron XRD to characterise the behaviour of low temperature solder alloys 15m
    
    During the soldering process and the daily operation of the electronic devices, solder alloys experience temperature variation frequently. The mismatch in volume expansion of the solder alloys and the interconnected components can result in stresses which lead to failure. In a solder alloy system with high solubility of one element in another, the effects of thermal expansion and temperature dependent solubility limits are both important contributing factors to the thermally induced volume changes. In this study, Sn-57wt%Bi and Sn-37wt%Bi alloys which are promising materials for low-temperature solders were investigated by in-situ heating synchrotron powder X-ray diffraction (PXRD) to reveal the changes of the lattice parameters of Sn and Bi.
    The lattice parameters were derived by the Rietveld refinement of the PXRD patterns using TOPAS Academic V6 and following analyzed by the Coefficient of Thermal Expansion Analysis Suite (CTEAS) package using a tensor method to get the coefficient of the thermal expansion (CTE). Density functional theory (DFT) calculations were adopted to reveal the influence of the solid solution of Bi (or βSn) on the lattice parameters of βSn (or Bi), thereby decoupling the effects of thermal expansion and solid solution of Bi (or βSn) on the thermally induced volume change of βSn (or Bi).
    
    Speaker: Mr Qichao Hao (The University of Queensland)
  - 16:25
    
    Radiation test of Rad-Hard ICs for space applications 15m
    
    Conventional Integrated Circuits (IC) are highly sensitive to radiation effects and can operate only in environments with a very low level of radiation. High radiation environments such as space need custom-designed ICs with dedicated radiation-hardened architectures. Our research is focused on the development and test of radiation-hardened ICs in nanoscale and ultra-low-power semiconductor technologies for high radiation environments such as in space and particle physics experiments. The University of Melbourne and Ansto developed a strategic collaboration to enable the ANSTO's heavy ion microprobe beamline for radiation test of custom-designed ICs for space applications. In our presentation, we provide an overview of our collaboration outcome and our roadmap for further developments in future.
    
    Speaker: Dr Jafar Shojaii (The University of Melbourne)
  - 16:40
    One layer at a time: Unlocking Novel Materials and Structures for Neutron Radiation Environments through Additive Manufacturing 15m
    
    The UOW-ANSTO Seed Funding program is an initiative aimed at encouraging new collaborations between researchers at the University of Wollongong and ANSTO - bringing together teams with diverse and complementary skillsets to tackle questions that require multi-disciplinary approaches.
    
    In 2019, a team of researchers from ANSTO's Australian Centre for Neutron Scattering (ACNS), UOW's Australian Institute for Innovative Materials (AIIM) and the Translational Research Initiative for Cell Engineering and Printing (TRICEP) came together to tackle the question “Can the structures and materials made possible by additive manufacturing enable novel solutions for neutron radiation environments?”
    
    To explore this question, we undertook activities in three themes:
    
    THEME 1 – Polymers for neutron shielding and collimation
    
    THEME 2 – Low-hydrogen polymers for neutron sample environments
    
    THEME 3 – Metals and alloys for neutron sample environments
    
    This presentation will discuss activities undertaken in these themes, including:
    
    THEME 1: investigating novel boron nitride/polyurethane materials developed by the UOW for use in neutron shielding and collimation applications via experiments on the Taipan, Pelican, Bilby and Platypus facilities at ANSTO;
    
    THEME 2: the development of a custom low-hydrogen polymer (FEP) printing apparatus and optimised print procedure, to our knowledge one of the first such facilities. This has resulted in the production of low-hydrogen sample holders for use in ANSTO neutron environments; and
    
    THEME 3: leveraging the world-class facilities and expertise in metal additive manufacturing at TRICEP to produce 'sample can' components in titanium and aluminium for validation and as a platform for future customised sample environment devices.
    
    This presentation will also discuss possibilities and future plans for work in this exciting area.
    
    Speaker: Jonathan Knott (University of Wollongong)
  - 16:55
    
    Microstructure and residual stress interactions in metal additive manufacturing: post-build assessment and new in-situ methods 15m
    
    Layer-wise addition of metal to directly form components or add coatings via laser powder bed fusion (LPBF) or laser directed energy deposition (DED) can generate very high levels of residual stress which affect component durability if not adequately addressed. These techniques also result in novel, non-equilibrium microstructures, sometimes with desirable features, that interact with traditional residual stress relief and microstructure manipulation heat treatments.
    
    In LPBF nickel superalloy 718, neutron diffraction was used to demonstrate that a complex residual stress state can persist through a non-recrystallising heat treatment at 960 ºC plus subsequent ageing. The same treatment has been previously shown to relieve residual stresses and promote grain growth in conventionally manufactured material. This discrepancy is attributed to the presence of nano-scale intercellular precipitates and a large concentration of existing dislocations, both consequences of the LPBF process, which act to impede recrystallisation and creep processes. The residual stress state is shown to influence the long-crack fatigue threshold at low stress ratios. Higher temperature annealing successfully relieved residual stresses but resulted in recrystallisation and grain growth which reduced the yield stress.
    
    To further explore residual stress and phase evolution during additive manufacturing, an in-beamline laser DED capability is being developed at ANSTO for both neutron and synchrotron use.
    
    Speaker: Halsey Ostergaard (University of Sydney)
- 17:05 → 17:20
  
  Welcome Address: Closing Remarks & Prizes

ANSTO User Meeting 2021

Online

Student Funding

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