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Abstract: Machine learning techniques are being increasingly applied in medical and physical sciences across a variety of imaging modalities; however, an important issue when developing these tools is the availability of good quality training data. Here we present a unique, multimodal synchrotron dataset of a bespoke zinc-doped Zeolite 13X sample that can be used to develop advanced deep learning and data fusion pipelines. Multi-resolution micro X-ray computed tomography was performed on a zinc-doped Zeolite 13X fragment to characterise its pores and features before spatially resolved X-ray diffraction computed tomography was carried out to characterise the topographical distribution of sodium and zinc phases. Zinc absorption was controlled to create a simple, spatially isolated, two-phase material. Both raw and processed data are available as a series of Zenodo entries. Altogether we present a spatially resolved, three-dimensional, multimodal, multi-resolution dataset that can be used to develop machine learning techniques. Such techniques include the development of super-resolution, multimodal data fusion, and 3D reconstruction algorithms.

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Abstract: The plumes of Enceladus contain a non-ice component that originates from aqueous processes occurring within the interior 1,2. The ocean of Enceladus is thought to be connected to the surface across a range of time scales. These processes range from the rapid eruption of cryovolcanic plumes to slow crustal convection on geological timescales3,4. In every case, the system will have a temperature and geochemical evolution as it freezes, with the history of evolution recorded in the sequence of mineral precipitation. Analogously to igneous and metamorphic petrology, we can explore the mineralogy and its context to reconstruct the history of that sample. Most importantly, for astrobiological investigations, the formation and cryo-petrological study of inorganic salts can be used to identify sites of recent exposure on the surface. Synchrotron X-ray techniques allow fast, high-resolution probing of these systems with X-ray light. By exploring large, multi-component samples with multiple techniques, with variable temperature over time we can reveal many emergent processes that may not be predictable with simple phase diagrams. We use a combination of synchrotron powder X-ray diffraction (PXRD) and X-ray microtomography (µCT) across multiple beamlines at Diamond Light Source (I11, I12 and DIAD). Using a multi-modal approach, we present an in-situ study of the low-temperature phase behaviour of Na-Cl-HCO3 fluids. We employ K11-DIAD (Dual Imaging and Diffraction) to carry out ‘image-guided diffraction’ on an Enceladus-type sample frozen in real-time. DIAD’s unique capabilities allow us not only to study microstructure down to 1 µm but also to carry out spatially resolved XRD and identify solid phases present. We present, for the first time, the use of dual imaging and diffraction of a Na-Cl-CO₃ solution frozen in real time in 3 dimensions [Figure 1]. DIAD’s imaged guided diffraction provides spatially-resolved XRD, allowing us to probe different regions of our sample and identify the formation of Na2CO₃ hydrates. We show the influence of carbonate chemistry on the sequence of cryogenic precipitation and the development of complex microstructures. These results provide insights into crustal transport processes and will help with interpreting observational data from upcoming Galilean missions.

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Abstract: Controllable sorption selectivity in zeolites is crucial for their application in catalysis, gas separation and ion-exchange. Whilst existing approaches to achieving sorption selectivity with natural zeolites typically rely on screening for specific geological deposits, here we develop partial interzeolite transformation as a straightforward and highly tuneable method to achieve sorption selectivity via forming dual-phase composites with simultaneous control of both phase-ratio and morphology. The dual-cation (strontium and caesium) exchange properties of a series of granular mordenite/zeolite P composites formed from a parent natural mordenite material are demonstrated in complex, industrially relevant multi-ion environments pertinent to nuclear waste management. The relative uptake of caesium and strontium is controlled via the extent of transformation: composites exhibit significantly increased ion-exchange affinity for strontium compared to both the parent mordenite and physical mixtures of mordenite/zeolite P phases with similar phase ratios. The composite with a 40[thin space (1/6-em)]:[thin space (1/6-em)]60 mordenite[thin space (1/6-em)]:[thin space (1/6-em)]zeolite P ratio composite achieves higher uptake rates than the natural clinoptilolite material currently used to decontaminate nuclear waste streams at the Sellafield site, UK. In situ X-ray image-guided diffraction experiments during caesium exchange demonstrate that the mordenite core retains rapid caesium uptake likely responsible for the unique ion-exchange chemistry achievable through the partial inter-zeolite transformation. These results offer a straightforward and controllable route to optimised zeolite functionality and a strategy to engineer composites from low-grade natural sources at low cost and with formulation advantages for industrial deployment.

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Abstract: Diamond is home to an ever-evolving array of beamlines and instruments, allowing scientists from a wide variety of disciplines to collect high-quality, high-resolution data for their groundbreaking research. In materials science, X-ray imaging and tomography experiments can determine the 3D microstructure of samples, while X-ray diffraction techniques offer the phase composition and stress distribution. Most synchrotron beamlines are designed to offer one or the other, with a few that can do both – but not at the same time. Switching between the modes can be complicated and time consuming. Diamond’s Dual Imaging and Diffraction beamline (DIAD) provides both imaging and diffraction capabilities in one instrument. Its novel dual beam design operates with two independent beams meeting at the sample position, one setup for imaging and one for diffraction. By constantly switching between the two modes, DIAD enables in situ and in operando measurements and time-resolved studies. Understanding the complex structure of tooth enamel, the factors involved in its decay and potential strategies for its remineralisation exemplify some outstanding tasks in biomedical materials science that can benefit from the dual beamline approach. In work recently published in Chemical & Biomedical Imaging, a group of researchers from the University of Oxford and the University of Birmingham (led by Professor Alexander Korsunsky) detail a proof-of-concept study that demonstrated how the unique capabilities of DIAD can be used to consider different options for remineralisation and to grade them in terms of how well they work.

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Abstract: Purpose / Aim: Dentine hypersensitivity (DH) is a commonly occurring dental condition where sharp pain derived from exposed dentine in response to stimuli that cannot be ascribed to any other dental diseases. It is highly prevalent affecting up to 69% of the UK population and has a significant impact on the quality of life. Bioactive glasses that degrade in oral environment and form apatite are thought to be beneficial in occluding the exposed open dentine tubules and have been introduced to toothpastes, e.g. Novamin® (45S5 Bioglass) for Sensodyne by GSK, fluoride containing bioactive glass for BioMin® F by BioMin Technologies Ltd. Post-mortem characterisations evidenced tubule occlusion (Fig.1) but failed in providing dynamic history. Therefore, this study aimed to monitor dentine tubule occlusion with bioactive glasses using an operando time-lapse X-ray diffraction tomography experiment. Materials & Methods: Disinfected Teeth (collected under REC reference 16/SW/0220) were sectioned mesio-distally into discs approximately 500 μm thick using a precision diamond saw, polished down to 300 μm manually. Matchstick specimens (5 mm length x 3 mm width) prepared were brushed for 2 mins with bioactive glasses pastes, housed in a modified Eppendorf tube and positioned on the tomography stage of the Dual Imaging and Diffraction (DIAD) beamline at Diamond Light Source (UK’s national synchrotron). A baseline X-ray tomography (pink beam, 0-180°, detector exposure of 0.01 and 5,000 projections) and X-ray diffraction mapping (matrix scan with 10x10 points, 20 s exposure) were collected before artificial saliva was introduced. Time-lapse X-ray tomography and X-ray diffraction mapping using the same parameters as baseline scan were carried out consecutively for 8 h allowing the visualisation of tubule occlusion and changes of mineral density as well as monitor the phase evolution from glass to apatite. Artificial saliva was manually replenished. Monochromatic beam with an energy of 20 keV was used and calibrations were performed. Results: The collected tomography data allow visualisation of dentine tubule occlusion showing improved occlusion with time. 2D XRD data provide qualitative and quantitative information relates to glass dissolution and apatite formation as a function of time. Conclusions: The Dual Imaging and Diffraction (DIAD) beamline correlates X-ray tomography and X-ray diffraction mapping offers the opportunity to study dentine occlusion by bioactive glasses in a time evolving manner that is not available via other techniques. Although in vitro but clinically relevant. The results will potentially provide a guidance for optimising and designing products for dentine tubule occlusion/treating dentine hypersensitivity – one of the most prevalent global diseases with healthy ageing.