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Abstract: Uncovering lead-free materials with an exceptionally high recoverable energy density is vital for the creation of future pulse power capacitors. This study determined that introducing Tungsten (W) and Tantalum (Ta) into the Nb-site of AgNbO3 lead-free antiferroelectric ceramics, while offsetting this with vacancies at the Ag-site, can effectively maintain the electrical homogeneity. Additionally, employing this co-doping approach can secure the antiferroelectric phases by lowering the necessary temperatures for M1-M2 and M2-M3 phase transitions. This may prove advantageous in the creation of novel AgNbO3-based energy storage ceramics. The use of in-situ high-resolution synchrotron powder x-ray diffraction (SPXD) at varying temperatures revealed for the first time that in 10 at% W doped AgNbO3, the M1 and M2 phases in the temperature range of −193 to ∼150 °C are more appropriately fitted as the non-polar Pbcm space group, whereas the M3 phase aligns with the mixed of non-polar Pbcm and polar Pmc21 space groups.

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Abstract: Carbon fibre composites are widely used in low specific stiffness and high strength structures such as airframes. Compressive loading of these assemblies can lead to buckling and localised deformation around defects and imperfections that can hinder performance and lead to overengineering via excessive safety factors. Synchrotron X-Ray Diffraction (SXRD) has recently been shown to be capable of performing lattice strain mapping within carbon fibre composites at the microscale, a previously unprecedented resolution. In this study SXRD and radiography was performed on carbon fibre composite columns produced via two different methods (standard lamination and half square) at a range of different load states: unbuckled, one-third of the buckling load and post buckling. The results provide quantitative insights into the impact of these different production methods on lattice strain and fibre orientation, as well as the influence these factors have on reducing buckling load (by up to 22%). As well as being the first use of SXRD on industrially representative full-size carbon fibre samples, these insights provide invaluable detail into the factors which limit performance and the origins of column failure; crucial factors required to optimise structural design, production and loading capability.

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Abstract: Serial crystallography has emerged as an important tool for structural studies of integral membrane proteins. The ability to collect data from micrometre-sized weakly diffracting crystals at room temperature with minimal radiation damage has opened many new opportunities in time-resolved studies and drug discovery. However, the production of integral membrane protein microcrystals in lipidic cubic phase at the desired crystal density and quantity is challenging. This paper introduces VIALS (versatile approach to high-density microcrystals in lipidic cubic phase for serial crystallography), a simple, fast and efficient method for preparing hundreds of microlitres of high-density microcrystals suitable for serial X-ray diffraction experiments at both synchrotron and free-electron laser sources. The method is also of great benefit for rational structure-based drug design as it facilitates in situ crystal soaking and rapid determination of many co-crystal structures. Using the VIALS approach, room-temperature structures are reported of (i) the archaerhodopsin-3 protein in its dark-adapted state and 110 ns photocycle intermediate, determined to 2.2 and 1.7 Å, respectively, and (ii) the human A2A adenosine receptor in complex with two different ligands determined to a resolution of 3.5 Å.

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Abstract: In situations where the stereoregularity of the polymer chains permits, crystals can form in synthetic or natural polymers. These crystals have an immense impact on the properties of the polymeric material. Typically polymers crystallized from a quiescent melt form spherulites, but where the melt exhibits a level of anisotropy, the crystalline morphology, is quite different to the spherulitic structure, although it may well contain chain-folded lamellar crystals. We consider a number of different systems in which the anisotropy has developed in different ways. Despite these differences, there are strong features in common within the semi-crystalline polymer morphology. We consider the strain-induced crystallization in deformed natural rubber, in sheared melts containing both self-assembling nanoparticles and engineered nanoparticles, and during extrusion as part of fused granular deposition-based 3D printing.

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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.