k The use of ethanol as contrast enhancer in Synchrotron X-ray phase-contrast imaging leads to heterogeneous myocardial tissue shrinkage: a case report By journals.iucr.org Published On :: In this work, we showed that the use of ethanol to increase image contrast when imaging cardiac tissue with synchrotron X-ray phase-contrast imaging (X-PCI) leads to heterogeneous tissue shrinkage, which has an impact on the 3D organization of the myocardium. Full Article text
k Development and testing of a dual-frequency, real-time hardware feedback system for the hard X-ray nanoprobe beamline of the SSRF By journals.iucr.org Published On :: we introduce a novel approach for a real-time dual-frequency feedback system, which has been firstly used at the hard X-ray nanoprobe beamline of SSRF. The BiBEST can then efficiently stabilize X-ray beam position and stability in parallel, making use of different optical systems in the beamline. Full Article text
k Van Vleck analysis of angularly distorted octahedra using VanVleckCalculator By journals.iucr.org Published On :: 2024-02-01 Van Vleck modes describe all possible displacements of octahedrally coordinated ligands about a core atom. They are a useful analytical tool for analysing the distortion of octahedra, particularly for first-order Jahn–Teller distortions, but determination of the Van Vleck modes of an octahedron is complicated by the presence of angular distortion of the octahedron. This problem is most commonly resolved by calculating the bond distortion modes (Q2, Q3) along the bond axes of the octahedron, disregarding the angular distortion and losing information on the octahedral shear modes (Q4, Q5 and Q6) in the process. In this paper, the validity of assuming bond lengths to be orthogonal in order to calculate the Van Vleck modes is discussed, and a method is described for calculating Van Vleck modes without disregarding the angular distortion. A Python package for doing this, VanVleckCalculator, is introduced and some examples of its use are given. Finally, it is shown that octahedral shear and angular distortion are often, but not always, correlated, and a parameter η is proposed as the shear fraction. It is demonstrated that η can be used to predict whether the values will be correlated when varying a tuning parameter such as temperature or pressure. Full Article text
k Operation model of a skew-symmetric split-crystal neutron interferometer By journals.iucr.org Published On :: 2024-02-01 The observation of neutron interference using a triple Laue interferometer formed by two separate crystals opens the way to the construction and operation of skew-symmetric interferometers with extended arm separation and length. The specifications necessary for their successful operation are investigated here: most importantly, how the manufacturing tolerance and crystal alignments impact the interference visibility. In contrast with previous studies, both incoherent sources and the three-dimensional operation of the interferometer are considered. It is found that, with a Gaussian Schell model of an incoherent source, the integrated density of the particles leaving the interferometer is the same as that yielded by a coherent Gaussian source having a radius equal to the coherence length. Full Article text
k A note on the Hendrickson–Lattman phase probability distribution and its equivalence to the generalized von Mises distribution By journals.iucr.org Published On :: 2024-02-16 Hendrickson & Lattman [Acta Cryst. (1970), B26, 136–143] introduced a method for representing crystallographic phase probabilities defined on the unit circle. Their approach could model the bimodal phase probability distributions that can result from experimental phase determination procedures. It also provided simple and highly effective means to combine independent sources of phase information. The present work discusses the equivalence of the Hendrickson–Lattman distribution and the generalized von Mises distribution of order two, which has been studied in the statistical literature. Recognizing this connection allows the Hendrickson–Lattman distribution to be expressed in an alternative form which is easier to interpret, as it involves the location and concentration parameters of the component von Mises distributions. It also allows clarification of the conditions for bimodality and access to a simplified analytical method for evaluating the trigonometric moments of the distribution, the first of which is required for computing the best Fourier synthesis in the presence of phase, but not amplitude, uncertainty. Full Article text
k Convolutional neural network approach for the automated identification of in cellulo crystals By journals.iucr.org Published On :: 2024-02-23 In cellulo crystallization is a rare event in nature. Recent advances that have made use of heterologous overexpression can promote the intracellular formation of protein crystals, but new tools are required to detect and characterize these targets in the complex cell environment. The present work makes use of Mask R-CNN, a convolutional neural network (CNN)-based instance segmentation method, for the identification of either single or multi-shaped crystals growing in living insect cells, using conventional bright field images. The algorithm can be rapidly adapted to recognize different targets, with the aim of extracting relevant information to support a semi-automated screening pipeline, in order to aid the development of the intracellular protein crystallization approach. Full Article text
k A workflow for single-particle structure determination via iterative phasing of rotational invariants in fluctuation X-ray scattering By journals.iucr.org Published On :: 2024-03-15 Fluctuation X-ray scattering (FXS) offers a complementary approach for nano- and bioparticle imaging with an X-ray free-electron laser (XFEL), by extracting structural information from correlations in scattered XFEL pulses. Here a workflow is presented for single-particle structure determination using FXS. The workflow includes procedures for extracting the rotational invariants from FXS patterns, performing structure reconstructions via iterative phasing of the invariants, and aligning and averaging multiple reconstructions. The reconstruction pipeline is implemented in the open-source software xFrame and its functionality is demonstrated on several simulated structures. Full Article text
k Simulations of dislocation contrast in dark-field X-ray microscopy By journals.iucr.org Published On :: 2024-03-21 Dark-field X-ray microscopy (DFXM) is a full-field imaging technique that non-destructively maps the structure and local strain inside deeply embedded crystalline elements in three dimensions. In DFXM, an objective lens is placed along the diffracted beam to generate a magnified projection image of the local diffracted volume. This work explores contrast methods and optimizes the DFXM setup specifically for the case of mapping dislocations. Forward projections of detector images are generated using two complementary simulation tools based on geometrical optics and wavefront propagation, respectively. Weak and strong beam contrast and the mapping of strain components are studied. The feasibility of observing dislocations in a wall is elucidated as a function of the distance between neighbouring dislocations and the spatial resolution. Dislocation studies should be feasible with energy band widths of 10−2, of relevance for fourth-generation synchrotron and X-ray free-electron laser sources. Full Article text
k Millisecond X-ray reflectometry and neural network analysis: unveiling fast processes in spin coating By journals.iucr.org Published On :: 2024-03-15 X-ray reflectometry (XRR) is a powerful tool for probing the structural characteristics of nanoscale films and layered structures, which is an important field of nanotechnology and is often used in semiconductor and optics manufacturing. This study introduces a novel approach for conducting quantitative high-resolution millisecond monochromatic XRR measurements. This is an order of magnitude faster than in previously published work. Quick XRR (qXRR) enables real time and in situ monitoring of nanoscale processes such as thin film formation during spin coating. A record qXRR acquisition time of 1.4 ms is demonstrated for a static gold thin film on a silicon sample. As a second example of this novel approach, dynamic in situ measurements are performed during PMMA spin coating onto silicon wafers and fast fitting of XRR curves using machine learning is demonstrated. This investigation primarily focuses on the evolution of film structure and surface morphology, resolving for the first time with qXRR the initial film thinning via mass transport and also shedding light on later thinning via solvent evaporation. This innovative millisecond qXRR technique is of significance for in situ studies of thin film deposition. It addresses the challenge of following intrinsically fast processes, such as thin film growth of high deposition rate or spin coating. Beyond thin film growth processes, millisecond XRR has implications for resolving fast structural changes such as photostriction or diffusion processes. Full Article text
k Unlocking the surface chemistry of ionic minerals: a high-throughput pipeline for modeling realistic interfaces By journals.iucr.org Published On :: 2024-03-15 A systematic procedure is introduced for modeling charge-neutral non-polar surfaces of ionic minerals containing polyatomic anions. By integrating distance- and charge-based clustering to identify chemical species within the mineral bulk, our pipeline, PolyCleaver, renders a variety of theoretically viable surface terminations. As a demonstrative example, this approach was applied to forsterite (Mg2SiO4), unveiling a rich interface landscape based on interactions with formaldehyde, a relevant multifaceted molecule, and more particularly in prebiotic chemistry. This high-throughput method, going beyond techniques traditionally applied in the modeling of minerals, offers new insights into the potential catalytic properties of diverse surfaces, enabling a broader exploration of synthetic pathways in complex mineral systems. Full Article text
k Laue microdiffraction on polycrystalline samples above 1500 K achieved with the QMAX-µLaue furnace By journals.iucr.org Published On :: 2024-03-31 X-ray Laue microdiffraction aims to characterize microstructural and mechanical fields in polycrystalline specimens at the sub-micrometre scale with a strain resolution of ∼10−4. Here, a new and unique Laue microdiffraction setup and alignment procedure is presented, allowing measurements at temperatures as high as 1500 K, with the objective to extend the technique for the study of crystalline phase transitions and associated strain-field evolution that occur at high temperatures. A method is provided to measure the real temperature encountered by the specimen, which can be critical for precise phase-transition studies, as well as a strategy to calibrate the setup geometry to account for the sample and furnace dilation using a standard α-alumina single crystal. A first application to phase transitions in a polycrystalline specimen of pure zirconia is provided as an illustrative example. Full Article text
k Neural network analysis of neutron and X-ray reflectivity data incorporating prior knowledge By journals.iucr.org Published On :: 2024-03-31 Due to the ambiguity related to the lack of phase information, determining the physical parameters of multilayer thin films from measured neutron and X-ray reflectivity curves is, on a fundamental level, an underdetermined inverse problem. This ambiguity poses limitations on standard neural networks, constraining the range and number of considered parameters in previous machine learning solutions. To overcome this challenge, a novel training procedure has been designed which incorporates dynamic prior boundaries for each physical parameter as additional inputs to the neural network. In this manner, the neural network can be trained simultaneously on all well-posed subintervals of a larger parameter space in which the inverse problem is underdetermined. During inference, users can flexibly input their own prior knowledge about the physical system to constrain the neural network prediction to distinct target subintervals in the parameter space. The effectiveness of the method is demonstrated in various scenarios, including multilayer structures with a box model parameterization and a physics-inspired special parameterization of the scattering length density profile for a multilayer structure. In contrast to previous methods, this approach scales favourably when increasing the complexity of the inverse problem, working properly even for a five-layer multilayer model and a periodic multilayer model with up to 17 open parameters. Full Article text
k The pypadf package: computing the pair angle distribution function from fluctuation scattering data By journals.iucr.org Published On :: 2024-05-17 The pair angle distribution function (PADF) is a three- and four-atom correlation function that characterizes the local angular structure of disordered materials, particles or nanocrystalline materials. The PADF can be measured using X-ray or electron fluctuation diffraction data, which can be collected by scanning or flowing a structurally disordered sample through a focused beam. It is a natural generalization of established pair distribution methods, which do not provide angular information. The software package pypadf provides tools to calculate the PADF from fluctuation diffraction data. The package includes tools for calculating the intensity correlation function, which is a necessary step in the PADF calculation and also the basis for other fluctuation scattering analysis techniques. Full Article text
k Tracking copper nanofiller evolution in polysiloxane during processing into SiOC ceramic By journals.iucr.org Published On :: 2024-06-18 Polymer-derived ceramics (PDCs) remain at the forefront of research for a variety of applications including ultra-high-temperature ceramics, energy storage and functional coatings. Despite their wide use, questions remain about the complex structural transition from polymer to ceramic and how local structure influences the final microstructure and resulting properties. This is further complicated when nanofillers are introduced to tailor structural and functional properties, as nanoparticle surfaces can interact with the matrix and influence the resulting structure. The inclusion of crystalline nanofiller produces a mixed crystalline–amorphous composite, which poses characterization challenges. With this study, we aim to address these challenges with a local-scale structural study that probes changes in a polysiloxane matrix with incorporated copper nanofiller. Composites were processed at three unique temperatures to capture mixing, pyrolysis and initial crystallization stages for the pre-ceramic polymer. We observed the evolution of the nanofiller with electron microscopy and applied synchrotron X-ray diffraction with differential pair distribution function (d-PDF) analysis to monitor changes in the matrix's local structure and interactions with the nanofiller. The application of the d-PDF to PDC materials is novel and informs future studies to understand interfacial interactions between nanofiller and matrix throughout PDC processing. Full Article text
k TORO Indexer: a PyTorch-based indexing algorithm for kilohertz serial crystallography By journals.iucr.org Published On :: 2024-06-18 Serial crystallography (SX) involves combining observations from a very large number of diffraction patterns coming from crystals in random orientations. To compile a complete data set, these patterns must be indexed (i.e. their orientation determined), integrated and merged. Introduced here is TORO (Torch-powered robust optimization) Indexer, a robust and adaptable indexing algorithm developed using the PyTorch framework. TORO is capable of operating on graphics processing units (GPUs), central processing units (CPUs) and other hardware accelerators supported by PyTorch, ensuring compatibility with a wide variety of computational setups. In tests, TORO outpaces existing solutions, indexing thousands of frames per second when running on GPUs, which positions it as an attractive candidate to produce real-time indexing and user feedback. The algorithm streamlines some of the ideas introduced by previous indexers like DIALS real-space grid search [Gildea, Waterman, Parkhurst, Axford, Sutton, Stuart, Sauter, Evans & Winter (2014). Acta Cryst. D70, 2652–2666] and XGandalf [Gevorkov, Yefanov, Barty, White, Mariani, Brehm, Tolstikova, Grigat & Chapman (2019). Acta Cryst. A75, 694–704] and refines them using faster and principled robust optimization techniques which result in a concise code base consisting of less than 500 lines. On the basis of evaluations across four proteins, TORO consistently matches, and in certain instances outperforms, established algorithms such as XGandalf and MOSFLM [Powell (1999). Acta Cryst. D55, 1690–1695], occasionally amplifying the quality of the consolidated data while achieving superior indexing speed. The inherent modularity of TORO and the versatility of PyTorch code bases facilitate its deployment into a wide array of architectures, software platforms and bespoke applications, highlighting its prospective significance in SX. Full Article text
k The master key: structural science in unlocking functional materials advancements By journals.iucr.org Published On :: 2024-05-24 From the historical roots of metalworking to the forefront of modern nanotechnology, functional materials have played a pivotal role in transforming societies, and their influence is poised to persist into the future. Encompassing a wide array of solid-state materials, spanning semiconductors to polymers, molecular crystals to nanoparticles, functional materials find application in critical sectors such as electronics, computers, information, communication, biotechnology, aerospace, defense, environment, energy, medicine and consumer products. This feature article delves into diverse instances of functional materials, exploring their structures, their properties and the underlying mechanisms that contribute to their outstanding performance across fields like batteries, photovoltaics, magnetics and heterogeneous catalysts. The field of structural sciences serves as the cornerstone for unraveling the intricate relationship between structure, dynamics and function. Acting as a bridge, it connects the fundamental understanding of materials to their practical applications. Full Article text
k Neural networks for rapid phase quantification of cultural heritage X-ray powder diffraction data By journals.iucr.org Published On :: 2024-05-31 Recent developments in synchrotron radiation facilities have increased the amount of data generated during acquisitions considerably, requiring fast and efficient data processing techniques. Here, the application of dense neural networks (DNNs) to data treatment of X-ray diffraction computed tomography (XRD-CT) experiments is presented. Processing involves mapping the phases in a tomographic slice by predicting the phase fraction in each individual pixel. DNNs were trained on sets of calculated XRD patterns generated using a Python algorithm developed in-house. An initial Rietveld refinement of the tomographic slice sum pattern provides additional information (peak widths and integrated intensities for each phase) to improve the generation of simulated patterns and make them closer to real data. A grid search was used to optimize the network architecture and demonstrated that a single fully connected dense layer was sufficient to accurately determine phase proportions. This DNN was used on the XRD-CT acquisition of a mock-up and a historical sample of highly heterogeneous multi-layered decoration of a late medieval statue, called `applied brocade'. The phase maps predicted by the DNN were in good agreement with other methods, such as non-negative matrix factorization and serial Rietveld refinements performed with TOPAS, and outperformed them in terms of speed and efficiency. The method was evaluated by regenerating experimental patterns from predictions and using the R-weighted profile as the agreement factor. This assessment allowed us to confirm the accuracy of the results. Full Article text
k Accessing self-diffusion on nanosecond time and nanometre length scales with minute kinetic resolution By journals.iucr.org Published On :: 2024-06-07 Neutron spectroscopy uniquely and non-destructively accesses diffusive dynamics in soft and biological matter, including for instance proteins in hydrated powders or in solution, and more generally dynamic properties of condensed matter on the molecular level. Given the limited neutron flux resulting in long counting times, it is important to optimize data acquisition for the specific question, in particular for time-resolved (kinetic) studies. The required acquisition time was recently significantly reduced by measurements of discrete energy transfers rather than quasi-continuous neutron scattering spectra on neutron backscattering spectrometers. Besides this reduction in acquisition times, smaller amounts of samples can be measured with better statistics, and most importantly, kinetically changing samples, such as aggregating or crystallizing samples, can be followed. However, given the small number of discrete energy transfers probed in this mode, established analysis frameworks for full spectra can break down. Presented here are new approaches to analyze measurements of diffusive dynamics recorded within fixed windows in energy transfer, and these are compared with the analysis of full spectra. The new approaches are tested by both modeled scattering functions and a comparative analysis of fixed energy window data and full spectra on well understood reference samples. This new approach can be employed successfully for kinetic studies of the dynamics focusing on the short-time apparent center-of-mass diffusion. Full Article text
k Determination of α lamellae orientation in a β-Ti alloy using electron backscatter diffraction By journals.iucr.org Published On :: 2024-06-27 The spatial orientation of α lamellae in a metastable β-Ti matrix of Timetal LCB (Ti–6.8 Mo–4.5 Fe–1.5 Al in wt%) was examined and the orientation of the hexagonal close-packed α lattice in the α lamella was determined. For this purpose, a combination of methods of small-angle X-ray scattering, scanning electron microscopy and electron backscatter diffraction was used. The habit planes of α laths are close to {111}β, which corresponds to (1320)α in the hexagonal coordinate system of the α phase. The longest α lamella direction lies approximately along one of the 〈110〉β directions which are parallel to the specific habit plane. Taking into account the average lattice parameters of the β and α phases in aged conditions in Timetal LCB, it was possible to index all main axes and faces of an α lath not only in the cubic coordinate system of the parent β phase but also in the hexagonal system of the α phase. Full Article text
k Quality assessment of the wide-angle detection option planned at the high-intensity/extended Q-range SANS diffractometer KWS-2 combining experiments and McStas simulations By journals.iucr.org Published On :: 2024-06-27 For a reliable characterization of materials and systems featuring multiple structural levels, a broad length scale from a few ångström to hundreds of nanometres must be analyzed and an extended Q range must be covered in X-ray and neutron scattering experiments. For certain samples or effects, it is advantageous to perform such characterization with a single instrument. Neutrons offer the unique advantage of contrast variation and matching by D-labeling, which is of great value in the characterization of natural or synthetic polymers. Some time-of-flight small-angle neutron scattering (TOF-SANS) instruments at neutron spallation sources can cover an extended Q range by using a broad wavelength band and a multitude of detectors. The detectors are arranged to cover a wide range of scattering angles with a resolution that allows both large-scale morphology and crystalline structure to be resolved simultaneously. However, for such analyses, the SANS instruments at steady-state sources operating in conventional monochromatic pinhole mode rely on additional wide-angle neutron scattering (WANS) detectors. The resolution must be tuned via a system of choppers and a TOF data acquisition option to reliably measure the atomic to mesoscale structures. The KWS-2 SANS diffractometer at Jülich Centre for Neutron Science allows the exploration of a wide Q range using conventional pinhole and lens focusing modes and an adjustable resolution Δλ/λ between 2 and 20%. This is achieved through the use of a versatile mechanical velocity selector combined with a variable slit opening and rotation frequency chopper. The installation of WANS detectors planned on the instrument required a detailed analysis of the quality of the data measured over a wide angular range with variable resolution. This article presents an assessment of the WANS performance by comparison with a McStas [Willendrup, Farhi & Lefmann (2004). Physica B, 350, E735–E737] simulation of ideal experimental conditions at the instrument. Full Article text
k DFT2FEFFIT: a density-functional-theory-based structural toolkit to analyze EXAFS spectra By journals.iucr.org Published On :: 2024-07-17 This article presents a Python-based program, DFT2FEFFIT, to regress theoretical extended X-ray absorption fine structure (EXAFS) spectra calculated from density functional theory structure models against experimental EXAFS spectra. To showcase its application, Ce-doped fluorapatite [Ca10(PO4)6F2] is revisited as a representative of a material difficult to analyze by conventional multi-shell least-squares fitting of EXAFS spectra. The software is open source and publicly available. Full Article text
k Coherent X-ray diffraction imaging of single particles: background impact on 3D reconstruction By journals.iucr.org Published On :: 2024-08-30 Coherent diffractive imaging with X-ray free-electron lasers could enable structural studies of macromolecules at room temperature. This type of experiment could provide a means to study structural dynamics on the femtosecond timescale. However, the diffraction from a single protein is weak compared with the incoherent scattering from background sources, which negatively affects the reconstruction analysis. This work evaluates the effects of the presence of background on the analysis pipeline. Background measurements from the European X-ray Free-Electron Laser were combined with simulated diffraction patterns and treated by a standard reconstruction procedure, including orientation recovery with the expand, maximize and compress algorithm and 3D phase retrieval. Background scattering did have an adverse effect on the estimated resolution of the reconstructed density maps. Still, the reconstructions generally worked when the signal-to-background ratio was 0.6 or better, in the momentum transfer shell of the highest reconstructed resolution. The results also suggest that the signal-to-background requirement increases at higher resolution. This study gives an indication of what is possible at current setups at X-ray free-electron lasers with regards to expected background strength and establishes a target for experimental optimization of the background. Full Article text
k Low-dose electron microscopy imaging for beam-sensitive metal–organic frameworks By journals.iucr.org Published On :: 2024-09-05 Metal–organic frameworks (MOFs) have garnered significant attention in recent years owing to their exceptional properties. Understanding the intricate relationship between the structure of a material and its properties is crucial for guiding the synthesis and application of these materials. (Scanning) Transmission electron microscopy (S)TEM imaging stands out as a powerful tool for structural characterization at the nanoscale, capable of detailing both periodic and aperiodic local structures. However, the high electron-beam sensitivity of MOFs presents substantial challenges in their structural characterization using (S)TEM. This paper summarizes the latest advancements in low-dose high-resolution (S)TEM imaging technology and its application in MOF material characterization. It covers aspects such as framework structure, defects, and surface and interface analysis, along with the distribution of guest molecules within MOFs. This review also discusses emerging technologies like electron ptychography and outlines several prospective research directions in this field. Full Article text
k The AUREX cell: a versatile operando electrochemical cell for studying catalytic materials using X-ray diffraction, total scattering and X-ray absorption spectroscopy under working conditions By journals.iucr.org Published On :: 2024-09-20 Understanding the structure–property relationship in electrocatalysts under working conditions is crucial for the rational design of novel and improved catalytic materials. This paper presents the Aarhus University reactor for electrochemical studies using X-rays (AUREX) operando electrocatalytic flow cell, designed as an easy-to-use versatile setup with a minimal background contribution and a uniform flow field to limit concentration polarization and handle gas formation. The cell has been employed to measure operando total scattering, diffraction and absorption spectroscopy as well as simultaneous combinations thereof on a commercial silver electrocatalyst for proof of concept. This combination of operando techniques allows for monitoring of the short-, medium- and long-range structure under working conditions, including an applied potential, liquid electrolyte and local reaction environment. The structural transformations of the Ag electrocatalyst are monitored with non-negative matrix factorization, linear combination analysis, the Pearson correlation coefficient matrix, and refinements in both real and reciprocal space. Upon application of an oxidative potential in an Ar-saturated aqueous 0.1 M KHCO3/K2CO3 electrolyte, the face-centered cubic (f.c.c.) Ag gradually transforms first to a trigonal Ag2CO3 phase, followed by the formation of a monoclinic Ag2CO3 phase. A reducing potential immediately reverts the structure to the Ag (f.c.c.) phase. Following the electrochemical-reaction-induced phase transitions is of fundamental interest and necessary for understanding and improving the stability of electrocatalysts, and the operando cell proves a versatile setup for probing this. In addition, it is demonstrated that, when studying electrochemical reactions, a high energy or short exposure time is needed to circumvent beam-induced effects. Full Article text
k Link between b.c.c.–f.c.c. orientation relationship and austenite morphology in CF8M stainless steel By journals.iucr.org Published On :: 2024-10-01 Slow-cooled CF8M duplex stainless steel is used for critical parts of the primary coolant pipes of nuclear reactors. This steel can endure severe service conditions, but it tends to become more brittle upon very long-term aging (tens of years). Therefore, it is essential to understand its specific microstructure and temporal evolution. As revealed by electron backscatter diffraction (EBSD) analyses, the microstructure consists of millimetre-scale ferritic grains within which austenite lath packets have grown with preferred crystallographic orientations concerning the parent ferritic phase far from the ferrite grain boundaries. In these lath packets where the austenite phase is nucleated, the lath morphology and crystal orientation accommodate the two ferrite orientations. Globally, the Pitsch orientation relationship appears to display the best agreement with the experimental data compared with other classical relationships. The austenite lath packets are parallel plate-shaped laths, characterized by their normal n. A novel methodology is introduced to elucidate the expected relationship between n and the crystallographic orientation given the coarse interfaces, even though n is only partly known from the observation surface, in contrast to the 3D crystal orientations measured by EBSD. The distribution of retrieved normals n is shown to be concentrated over a set of discrete orientations. Assuming that the ferrite and austenite obey the Pitsch orientation relationship, the determined lath normals are close to an invariant direction of the parent phase given by the same orientation relationship. Full Article text
k distect: automatic sample-position tracking for X-ray experiments using computer vision algorithms By journals.iucr.org Published On :: 2024-10-30 Soft X-ray spectroscopy is an important technique for measuring the fundamental properties of materials. However, for measurements of samples in the sub-millimetre range, many experimental setups show limitations. Position drifts on the order of hundreds of micrometres during thermal stabilization of the system can last for hours of expensive beam time. To compensate for drifts, sample tracking and feedback systems must be used. However, in complex sample environments where sample access is very limited, many existing solutions cannot be applied. In this work, we apply a robust computer vision algorithm to automatically track and readjust the sample position in the dozens of micrometres range. Our approach is applied in a complex sample environment, where the sample is in an ultra-high vacuum chamber, surrounded by cooled thermal shields to reach sample temperatures down to 2.5 K and in the center of a superconducting split coil. Our implementation allows sample-position tracking and adjustment in the vertical direction since this is the dimension where drifts occur during sample temperature change in our setup. The approach can be easily extended to 2D. The algorithm enables a factor of ten improvement in the overlap of a series of X-ray absorption spectra in a sample with a vertical size down to 70 µm. This solution can be used in a variety of experimental stations, where optical access is available and sample access by other means is reduced. Full Article text
k Formulation of perfect-crystal diffraction from Takagi–Taupin equations: numerical implementation in the crystalpy library By journals.iucr.org Published On :: 2024-10-29 The Takagi–Taupin equations are solved in their simplest form (zero deformation) to obtain the Bragg-diffracted and transmitted complex amplitudes. The case of plane-parallel crystal plates is discussed using a matrix model. The equations are implemented in an open-source Python library crystalpy adapted for numerical applications such as crystal reflectivity calculations and ray tracing. Full Article text
k Foreword to the special virtual issue dedicated to the proceedings of the PhotonMEADOW2023 Joint Workshop By journals.iucr.org Published On :: 2024-10-11 Full Article text
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k Emerging Technologies and Trends in Identity Verification, KYC, and KYB Report 2024 By thepaypers.com Published On :: Thu, 16 May 2024 09:00:00 +0100 The inaugural edition of the Emerging Technologies and Trends in Identity Verification (IDV), KYC, and KYB Report 2024 offers a comprehensive overview of the key technology trends and best practices in digital onboarding for consumers and businesses in 2024. Full Article
k Fintech for Marketplaces and Platforms Report 2024 By thepaypers.com Published On :: Tue, 28 May 2024 07:24:00 +0100 The 1st edition of the Fintech for Marketplaces and Platforms Report covers essential ecommerce trends and future perspectives. Full Article
k Key Players In the EU Payments Landscape – 2024 Edition By thepaypers.com Published On :: Tue, 02 Jul 2024 08:30:00 +0100 The 2024 'Key Players in the EU Payments Landscape' report by PA EU, Deloitte, and The Paypers ranks key players in EU's payments markets. Full Article
k Unlocking the Potential of A2A Payments Report 2024 By thepaypers.com Published On :: Wed, 03 Jul 2024 14:44:00 +0100 The first edition of the Unlocking the Potential of A2A Payments Report 2024 provides the latest insights into the A2A space. Full Article
k Embedded Finance and Banking-as-a-Service Report 2024 By thepaypers.com Published On :: Mon, 05 Aug 2024 11:52:00 +0100 Unlock unparalleled insights into the transformative world of Embedded Finance and Banking-as-a-Service (BaaS) with The Paypers' latest report. Dive deep into essential business models, key players, and the latest trends reshaping industries with our comprehensive guide, curated by industry experts and leading companies. Full Article
k FilmWeek: ‘The Courier,’ ‘Zack Snyder’s Justice League,’ ‘City Of Lies’ And More By www.scpr.org Published On :: Fri, 19 Mar 2021 09:28:00 -0700 Benedict Cumberbatch in “The Courier”; Credit: LIAM DANIEL / LIONSGATE / ROADSIDE ATTRACTIONS FilmWeek MarqueeLarry Mantle and KPCC film critics Tim Cogshell, Lael Loewenstein and Andy Klein review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Tina,’ ‘The Marijuana Conspiracy,’ ‘The Vault’ And More By www.scpr.org Published On :: Fri, 26 Mar 2021 08:57:00 -0700 Tina Turner performing, used in the documentary "Tina." ; Credit: Dave Hogan/Getty Images/HBO FilmWeek MarqueeLarry Mantle and KPCC film critics Wade Major, Claudia Puig, Peter Rainer and Charles Solomon review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Godzilla Vs. Kong,’ ‘The Outside Story,’ ‘Shiva Baby’ And More By www.scpr.org Published On :: Fri, 02 Apr 2021 09:54:00 -0700 Still from "Godzilla vs. Kong"; Credit: Courtesy of Warner Bros. Entertainment Inc. All Rights Reserved. FilmWeek MarqueeLarry Mantle and KPCC film critics Amy Nicholson, Angie Han and Charles Solomon review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Thunder Force,’ ‘Voyagers,’ ‘Honeydew’ And More By www.scpr.org Published On :: Fri, 09 Apr 2021 09:37:00 -0700 MELISSA MCCARTHY and OCTAVIA SPENCER in "Thunder Force."; Credit: HOPPER STONE/NETFLIX © 2021 FilmWeek MarqueeLarry Mantle and KPCC film critics Christy Lemire and Andy Klein review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘We Broke Up,’ ‘Reefa,’ ‘Hope,’ And More By www.scpr.org Published On :: Fri, 16 Apr 2021 09:22:00 -0700 William Jackson Harper and Aya Cash in “We Broke Up.”; Credit: Vertical Entertainment FilmWeek MarqueeLarry Mantle and KPCC film critics Claudia Puig, Tim Cogshell and Charles Solomon review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Demon Slayer the Movie: Mugen Train,’ Street Gang: How We Got to Sesame Street,’ ‘Together Together’ And More By www.scpr.org Published On :: Fri, 23 Apr 2021 10:25:00 -0700 Archival still from the documentary "Street Gang: How We Got to Sesame Street"; Credit: HBO FilmWeek MarqueeLarry Mantle and KPCC film critics Claudia Puig and Charles Solomon review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Mortal Kombat,’ ‘Four Good Days,’ ‘Limbo’ And More By www.scpr.org Published On :: Fri, 30 Apr 2021 09:11:00 -0700 Tadanobu Asano (L) and Chin Han (R) in "Mortal Kombat."; Credit: Warner Bros. Pictures FilmWeek MarqueeLarry Mantle and KPCC film critics Wade Major and Angie Han review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Wrath Of Man,’ ‘Here Today,’ ‘The Paper Tigers’ And More By www.scpr.org Published On :: Fri, 07 May 2021 09:30:00 -0700 Jason Statham's character H in the film "Wrath of Man"; Credit: Metro Goldwyn Mayer Pictures FilmWeek MarqueeLarry Mantle and KPCC film critics Christy Lemire and Tim Cogshell review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Spiral,’ ‘The Woman In The Window,’ ‘Profile,’ And More By www.scpr.org Published On :: Fri, 14 May 2021 14:33:00 -0700 Chris Rock as Detective Zeke Banks in the film "Spiral."; Credit: Lionsgate FilmWeek MarqueeGuest host John Horn and KPCC film critics Claudia Puig, Amy Nicholson and Andy Klein review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘Dream Horse,’ ‘The Dry,’ ‘MilkWater’ And More By www.scpr.org Published On :: Fri, 21 May 2021 14:13:00 -0700 Toni Collette (center) in the film "Dream Horse." FilmWeek MarqueeLarry Mantle and KPCC film critics Angie Han, Wade Major and Peter Rainer review this weekend’s new movie releases.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘A Quiet Place Part II,’ ‘Cruella,’ ‘Moby Doc’ And More By www.scpr.org Published On :: Fri, 28 May 2021 11:00:00 -0700 Millicent Simmonds, Noah Jupe and Emily Blunt return in “A Quiet Place, Part II.”; Credit: Paramount Pictures FilmWeek MarqueeLarry Mantle and KPCC film critics Lael Loewenstein, Christy Lemire and Charles Solomon review this weekend’s new movie releases on streaming and on demand platforms.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘The Conjuring: The Devil Made Me Do It,’ ‘Spirit Untamed,’ ‘Edge Of The World’ And More By www.scpr.org Published On :: Fri, 04 Jun 2021 09:33:00 -0700 Vera Farmiga and Patrick Wilson in "The Conjuring: The Devil Made Me Do It"; Credit: Warner Bros. Pictures FilmWeek MarqueeLarry Mantle and KPCC film critics Amy Nicholson, Wade Major and Charles Solomon review this weekend’s new movie releases on streaming and on demand platforms.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
k FilmWeek: ‘In The Heights,’ ‘Holler,’ ‘Wish Dragon’ And More By www.scpr.org Published On :: Fri, 11 Jun 2021 09:02:00 -0700 ANTHONY RAMOS as Usnavi and MELISSA BARRERA as Vanessa in “IN THE HEIGHTS.”; Credit: Macall Polay/Warner Bros. Pictures’ FilmWeek MarqueeLarry Mantle and KPCC film critics Angie Han, Andy Klein, Tim Cogshell and Charles Solomon review this weekend’s new movie releases on streaming and on demand platforms.This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article