ara Russia's gold reserves guarantee reliable protection from Western sanctions By english.pravda.ru Published On :: Thu, 21 Mar 2024 18:49:00 +0300 Russia's gold reserves have become the "magic wand” with the help of which Russia easily survived the "hellish” sanctions of the West and achieved economic growth. The West admires Russia's policy of pegging the ruble to gold The Russian economy showed unprecedented growth of 3.6 percent in 2023 against the backdrop of more than 16,000 sanctions, as well as huge expenses for carrying out the special military operation in Ukraine. Russia's GDP is to grow by another 2.6 percent in 2024, the IMF said. Russia has been able to achieve that with the help of its "gold strategy,” The Conversation. com website said. The strategy is about pegging the ruble to gold and liberalising gold trade. Full Article Russia
ara Exjugador de la NFL se declara culpable por reclamaciones médicas fraudulentas de más de $29,000 By www.tdi.texas.gov Published On :: Fri, 4 Nov 2022 00:00:00 CDT El caso fue dirigido por los investigadores del Departamento de Seguros de Texas (TDI por su nombre y siglas en inglés) y los fiscales trabajando con la Oficina del Fiscal del condado Harris. Full Article
ara El personal de TDI estará ofreciendo ayuda en persona para los dueños de vivienda con daños por el tornado By www.tdi.texas.gov Published On :: Fri, 27 Jan 2023 00:00:00 CST Si su casa sufrió daños por el severo estado del tiempo que impactó el sureste de Texas esta semana, contacte a su compañía de seguros para presentar una reclamación lo antes posible. Full Article
ara Consejos para las reclamaciones al seguro por los incendios forestales de Texas By www.tdi.texas.gov Published On :: Mon, 4 Mar 2024 00:05:00 CST Los residentes cuyas propiedades hayan sufrido daños por los incendios forestales de Texas deben llamar a su compañía de seguros para presentar una reclamación lo antes posible. Full Article
ara Consejos de reclamaciones de seguros para los Texanos con daños por inundación By www.tdi.texas.gov Published On :: Tue, 7 May 2024 00:00:00 CDT El Departamento de Seguros de Texas (Texas Department of Insurance, TDI, por su nombre y siglas en inglés) les recuerda a las víctimas de las inundaciones que deben documentar los daños y presentar las reclamaciones al seguro de inmediato. Full Article
ara ¿Conoce usted las alertas sobre las estafas de contratistas? Consejos para evitar las estafas después de Beryl By www.tdi.texas.gov Published On :: Mon, 15 Jul 2024 00:00:00 CDT El Departamento de Seguros de Texas (Texas Department of Insurance, TDI, por su nombre y siglas en inglés) tiene consejos para ayudarle a reconocer y evitar las estafas comunes de contratistas. Full Article
ara El Departamento de Seguros de Texas recomienda a los residentes costeros a estar preparados para los huracanes By www.tdi.texas.gov Published On :: Tue, 10 Sep 2024 00:00:00 CDT Septiembre se considera la etapa cumbre de la actividad ciclónica, pero es importante recordar que la temporada de huracanes se extiende hasta noviembre. Full Article
ara First launch of Angara-A5 heavy-class rocket from Vostochny Cosmodrome aborted By english.pravda.ru Published On :: Tue, 09 Apr 2024 14:37:00 +0300 The first launch of the Angara-A5 heavy launch vehicle from the newly built launch complex at the Vostochny Cosmodrome was aborted two minutes before lift off. The rocket with the Orion upper stage and test payload was supposed to take off for the first time from Vostochny on Tuesday, April 9, at 12:00. The launch was postponed. The launch of the Angara rocket was postponed till Wednesday, April 10, Roscosmos chief Yuri Borisov said. Full Article Science
ara Russia's first Angara space launch vehicle finally launched at third attempt By english.pravda.ru Published On :: Thu, 11 Apr 2024 16:11:00 +0300 The Orion upper stage of the Angara-A5 heavy rocket launched the Gagarinets small satellite into low Earth orbit, Roscosmos said on its Telegram channel. "The Cubesat 3U format satellite was created by Russian private company Avant Space and is intended to test elements of the service platform,” the state corporation said. After the launch of the Gagarinets, the upper stage continued its work. Full Article Science
ara Zara and Bershka to return to Russia as Z and Br By english.pravda.ru Published On :: Thu, 10 Nov 2022 16:23:00 +0300 Spanish brands Zara and Bershka that left the Russian market after the start of the special operation in Ukraine plan to return. It is believed that their stores will reopen in Russia in early 2023, Mash Telegram channel reports. According to the channel, Bershka's new name will be Br, and Zara's — Z. The new owners of the business thus want to keep part of the former name in order to attract customers' attention. Other brands that are part of Inditex, such as Pull&Bear and Stradivarius, will return to the country as well. Full Article Business
ara McDonald's restaurants in Kazakhstan reopen as 'I am Daniyar,' 'I am Yulia,' 'I am Aray' etc By english.pravda.ru Published On :: Wed, 16 Aug 2023 16:52:00 +0300 Former McDonald's restaurants in Kazakhstan have changed signs yet again. "We're Open" signs have been replaced with new "I am…" signs that contain proper names (in Kazakh language). For example, the signs of a restaurant in the city of Alma-Ata says "I am Madiyar." Other restaurants were called "I am Daniyar," I am Yulia," "I am Aray," I am Alexander," etc. Food Solutions KZ restaurant management company confirmed that the signs of former McDonald's restaurants were changed in six cities. Full Article Business
ara Perguntas e Respostas da Mayo Clinic: Utilizando radioterapia para tratar tumores cerebrais By www.newswise.com Published On :: Tue, 12 Nov 2024 13:25:18 EST A radioterapia tem sido usada para tratar o cancer desde o inicio do seculo 20. Este tipo de tratamento continua sendo um dos tratamentos mais eficazes para tumores cerebrais cancerigenos (malignos) e nao cancerigenos (benignos). A forma como ele e ministrado -- e a tecnologia utilizada -- continuou evoluindo e melhorando. Full Article
ara Idina Menzel to Celebrate the Debut of the Bronx Zoo at the 98th Macy's Thanksgiving Day Parade(r) with a Special Performance From Her New Broadway Musical "Redwood" By www.newswise.com Published On :: Tue, 12 Nov 2024 08:40:41 EST Today, the Bronx Zoo announced that Idina Menzel, Tony Award-winner, actress, philanthropist and multi-platinum-selling singer/songwriter, will perform in the 98th Macy's Thanksgiving Day Parade(r) on the zoo's new "Wondrous World of Wildlife" float. Full Article
ara Barbara Brizuela Embraces Interdisciplinarity as Dean of the School of Arts and Sciences By www.newswise.com Published On :: Mon, 04 Nov 2024 13:50:52 EST Barbara Brizuela, who has been named dean of the School of Arts and Sciences, is a big believer in interdisciplinary research. "Knowledge-seeking has no disciplinary boundaries," says Brizuela. "We're going to need broad and connected perspectives to be able to solve the world's biggest problems." The dean of the Graduate School of Arts and Sciences (GSAS) and professor of education served as the school's dean ad interim since July. Her appointment to lead the School of Arts and Sciences builds on a long and distinguished career as a teacher, mentor, researcher, and administrator. Full Article
ara Kim Young-gun Wins South Korea's Sixth Gold at Paris Paralympics By world.kbs.co.kr Published On :: Sun, 08 Sep 2024 12:32:18 +0900 [Sports] : Kim Young-gun won the gold medal in men's table tennis at the Paris Paralympics, bringing the sixth gold to South Korea. Kim, ranked second in the world, grabbed the gold on Saturday after beating top-ranked Wanchai Chaiwut of Thailand three to two in the final of the men's singles MS4 event at ...[more...] Full Article Sports
ara 2024 Paris Paralympics Ends with Closing Ceremony By world.kbs.co.kr Published On :: Mon, 09 Sep 2024 10:42:05 +0900 [Sports] : The 2024 Paris Paralympics came to a close on Sunday after a 12-day run. The global sports festival wrapped up Sunday night with a glitzy closing ceremony at the Stade de France in Saint-Denis, near Paris. About 44-hundred athletes with disabilities competed in 22 sporting events, representing 169 ...[more...] Full Article Sports
ara Quarantine Agency Develops Differential Diagnosis Technology for Lumpy Skin Disease By world.kbs.co.kr Published On :: Wed, 25 Sep 2024 16:57:36 +0900 [Science] : The Animal and Plant Quarantine Agency says it has developed, for the first time in the world, a differential diagnosis technology for lumpy skin disease(LSD), a viral disease that affects cattle. With the technology, jointly developed with Median Diagnostics, it can be determined within eight hours if a ...[more...] Full Article Science
ara You Don't Want to Know How Maraschino Cherries Are Made By recipes.howstuffworks.com Published On :: Tue, 20 Feb 2024 18:43:02 -0500 The expression "the cherry on top" refers to a very good thing. You may think differently once you learn how maraschino cherries are actually made. Full Article
ara Exploiting fourth-generation synchrotron radiation for enzyme and photoreceptor characterization By journals.iucr.org Published On :: (Time-resolved) macromolecular crystallography at the new ESRF-ID29 beamline is described. Full Article text
ara Density functional theory investigation of the phase transition, elastic and thermal characteristics for AuMTe2(M = Ga, In) chalcopyrite compounds By journals.iucr.org Published On :: This study presents the first theoretical predictions of the phase transitions, elastic properties, and thermal behavior of AuMTe2 (M = Ga, In) chalcopyrite compounds. Using density functional theory and the quasi-harmonic Debye model, key mechanical and thermodynamic properties are analyzed, offering insights valuable for future experimental validation. Full Article text
ara Parameterized absorptive electron scattering factors By journals.iucr.org Published On :: 2024-01-25 In electron diffraction, thermal atomic motion produces incoherent scattering over a relatively wide angular range, which appears as a diffuse background that is usually subtracted from measurements of Bragg spot intensities in structure solution methods. The transfer of electron flux from Bragg spots to diffuse scatter is modelled using complex scattering factors f + if' in the Bloch wave methodology. In a two-beam Einstein model the imaginary `absorptive' scattering factor f' can be obtained by the evaluation of an integral containing f over all possible scattering angles. While more sophisticated models of diffuse scatter are widely used in the electron microscopy community, it is argued in this paper that this simple model is appropriate for current structure solution and refinement methods. The two-beam model is a straightforward numerical calculation, but even this simplistic approach can become time consuming for simulations of materials with large numbers of atoms in the unit cell and/or many incident beam orientations. Here, a parameterized form of f' is provided for 103 elements as neutral, spherical atoms that reduces calculation time considerably. Full Article text
ara Universal parameters of bulk-solvent masks By journals.iucr.org Published On :: 2024-02-09 The bulk solvent is a major component of biomacromolecular crystals that contributes significantly to the observed diffraction intensities. Accurate modelling of the bulk solvent has been recognized as important for many crystallographic calculations. Owing to its simplicity and modelling power, the flat (mask-based) bulk-solvent model is used by most modern crystallographic software packages to account for disordered solvent. In this model, the bulk-solvent contribution is defined by a binary mask and a scale (scattering) function. The mask is calculated on a regular grid using the atomic model coordinates and their chemical types. The grid step and two radii, solvent and shrinkage, are the three parameters that govern the mask calculation. They are highly correlated and their choice is a compromise between the computer time needed to calculate the mask and the accuracy of the mask. It is demonstrated here that this choice can be optimized using a unique value of 0.6 Å for the grid step irrespective of the data resolution, and the radii values adjusted correspondingly. The improved values were tested on a large sample of Protein Data Bank entries derived from X-ray diffraction data and are now used in the computational crystallography toolbox (CCTBX) and in Phenix as the default choice. Full Article text
ara Structural and biochemical characterization of the M405S variant of Desulfovibrio vulgaris formate dehydrogenase By journals.iucr.org Published On :: 2024-05-01 Molybdenum- or tungsten-dependent formate dehydrogenases have emerged as significant catalysts for the chemical reduction of CO2 to formate, with biotechnological applications envisaged in climate-change mitigation. The role of Met405 in the active site of Desulfovibrio vulgaris formate dehydrogenase AB (DvFdhAB) has remained elusive. However, its proximity to the metal site and the conformational change that it undergoes between the resting and active forms suggests a functional role. In this work, the M405S variant was engineered, which allowed the active-site geometry in the absence of methionine Sδ interactions with the metal site to be revealed and the role of Met405 in catalysis to be probed. This variant displayed reduced activity in both formate oxidation and CO2 reduction, together with an increased sensitivity to oxygen inactivation. Full Article text
ara Understanding secondary order parameters in perovskites with tilted octahedra By journals.iucr.org Published On :: A symmetry guide for the secondary structural degrees of freedom and related physical properties generated by tilts of BX6 octahedra in perovskites is proposed. Full Article text
ara Characterization and calibration of DECTRIS PILATUS3 X CdTe 2M high-Z hybrid pixel detector for high-precision powder diffraction measurements By journals.iucr.org Published On :: The performance of a high-Z photon-counting detector for powder diffraction measurements at high (>50 keV) energies is characterized, and the appropriate corrections are described in order to obtain data of higher quality than have previously been obtained from 2D detectors in these energy ranges. Full Article text
ara Understanding secondary order parameters in perovskites with tilted octahedra By journals.iucr.org Published On :: 2024-10-16 In the family of perovskite materials, the tilts of BX6 octahedra are the most common type of structural distortion. Conventionally, the formation of low-symmetry perovskite phases with tilted octahedra is analyzed by considering only primary order parameters. However, octahedral tilting also gives rise to secondary order parameters which contribute to additional atomic displacements, ordering and lattice distortions. Our study highlights the significant impact of secondary order parameters on the structural formation and emergent physical properties of perovskites. Through group-theoretical and crystallographic analyses, we have identified all secondary order parameters within Glazer-type tilt systems and clarified their physical manifestations. We explore the fundamental symmetry relationships among various structural degrees of freedom in perovskites, including tilt-induced ferroelasticity, correlations between displacements and ordering of atoms occupying different positions, and the potential for rigid unit rotations and unconventional octahedral tilts. Particular emphasis is placed on the emergence of secondary order parameters and their coupling with primary order parameters, as well as their symmetry-based hierarchy, illustrated through a modified Bärnighausen tree. We applied our theoretical insights to elucidate phase transitions in well known perovskites such as CaTiO3 and RMnO3 (where R = La and lanthanide ions), thereby demonstrating the significant influence of secondary order parameters on crystal structure formation. Our results serve as a symmetry-based guide for the design, identification and structural characterization of perovskites with tilted octahedra, and for understanding tilt-induced physical properties. Full Article text
ara Similarity score for screening phase-retrieved maps in X-ray diffraction imaging – characterization in reciprocal space By journals.iucr.org Published On :: 2024-01-01 X-ray diffraction imaging (XDI) is utilized for visualizing the structures of non-crystalline particles in material sciences and biology. In the structural analysis, phase-retrieval (PR) algorithms are applied to the diffraction amplitude data alone to reconstruct the electron density map of a specimen particle projected along the direction of the incident X-rays. However, PR calculations may not lead to good convergence because of a lack of diffraction patterns in small-angle regions and Poisson noise in X-ray detection. Therefore, the PR calculation is still a bottleneck for the efficient application of XDI in the structural analyses of non-crystalline particles. For screening maps from hundreds of trial PR calculations, we have been using a score and measuring the similarity between a pair of retrieved maps. Empirically, probable maps approximating the particle structures gave a score smaller than a threshold value, but the reasons for the effectiveness of the score are still unclear. In this study, the score is characterized in terms of the phase differences between the structure factors of the retrieved maps, the usefulness of the score in screening the maps retrieved from experimental diffraction patterns is demonstrated, and the effective resolution of similarity-score-selected maps is discussed. Full Article text
ara Heitt Mjölnir: a heated miniature triaxial apparatus for 4D synchrotron microtomography By journals.iucr.org Published On :: 2024-01-01 Third- and fourth-generation synchrotron light sources with high fluxes and beam energies enable the use of innovative X-ray translucent experimental apparatus. These experimental devices access geologically relevant conditions whilst enabling in situ characterization using the spatial and temporal resolutions accessible at imaging beamlines. Here, Heitt Mjölnir is introduced, a heated miniature triaxial rig based on the design of Mjölnir, but covering a wider temperature range and larger sample volume at similar pressure capacities. This device is designed to investigate coupled thermal, chemical, hydraulic and mechanical processes from grain to centimetre scales using cylindrical samples of 10 mm × 20 mm (diameter × length). Heitt Mjölnir can simultaneously reach confining (hydraulic) pressures of 30 MPa and 500 MPa of axial stress with independently controlled sample pore fluid pressure < 30 MPa. This internally heated apparatus operates to temperatures up to 573 K with a minimal vertical thermal gradient in the sample of <0.3 K mm−1. This new apparatus has been deployed in operando studies at the TOMCAT (Swiss Light Source), I12 JEEP (Diamond Light Source) and PSICHÉ (Synchrotron SOLEIL) beamlines for 4D X-ray microtomography with scan intervals of a few minutes. Heitt Mjölnir is portable and modular, allowing a wide range of 4D characterizations of low-grade metamorphism and deformational processes. It enables spatially and temporally resolved fluid–rock interaction studies at conditions of crustal reservoirs and is suitable for characterization of material properties in geothermal, carbonation or subsurface gas storage applications. Technical drawings and an operation guide are included in this publication. Full Article text
ara In situ characterization of stresses, deformation and fracture of thin films using transmission X-ray nanodiffraction microscopy By journals.iucr.org Published On :: 2024-01-01 The use of hard X-ray transmission nano- and microdiffraction to perform in situ stress and strain measurements during deformation has recently been demonstrated and used to investigate many thin film systems. Here a newly commissioned sample environment based on a commercially available nanoindenter is presented, which is available at the NanoMAX beamline at the MAX IV synchrotron. Using X-ray nanoprobes of around 60–70 nm at 14–16 keV and a scanning step size of 100 nm, we map the strains, stresses, plastic deformation and fracture during nanoindentation of industrial coatings with thicknesses in the range of several micrometres, relatively strong texture and large grains. The successful measurements of such challenging samples illustrate broad applicability. The sample environment is openly accessible for NanoMAX beamline users through the MAX IV sample environment pool, and its capability can be further extended for specific purposes through additional available modules. Full Article text
ara Investigation of structural and reflective characteristics of short-period Mo/B4C multilayer X-ray mirrors By journals.iucr.org Published On :: 2024-02-09 The results of a study of the structural and reflective characteristics of short-period multilayer X-ray mirrors based on Mo/B4C at wavelengths 1.54 Å, 9.89 Å and 17.59 Å are presented. The period of the samples varied in the range 8–35 Å. The average widths of the interfaces were ∼3.5 and 2.2 Å at one and the other boundaries, with a tendency for weak growth with any decrease in the period. The interlayer roughness was ∼1 Å. The research results indicate promising prospects for the use of multilayer Mo/B4C mirrors for synchrotron applications. Full Article text
ara Optimization of synchrotron radiation parameters using swarm intelligence and evolutionary algorithms By journals.iucr.org Published On :: 2024-02-22 Alignment of each optical element at a synchrotron beamline takes days, even weeks, for each experiment costing valuable beam time. Evolutionary algorithms (EAs), efficient heuristic search methods based on Darwinian evolution, can be utilized for multi-objective optimization problems in different application areas. In this study, the flux and spot size of a synchrotron beam are optimized for two different experimental setups including optical elements such as lenses and mirrors. Calculations were carried out with the X-ray Tracer beamline simulator using swarm intelligence (SI) algorithms and for comparison the same setups were optimized with EAs. The EAs and SI algorithms used in this study for two different experimental setups are the Genetic Algorithm (GA), Non-dominated Sorting Genetic Algorithm II (NSGA-II), Particle Swarm Optimization (PSO) and Artificial Bee Colony (ABC). While one of the algorithms optimizes the lens position, the other focuses on optimizing the focal distances of Kirkpatrick–Baez mirrors. First, mono-objective evolutionary algorithms were used and the spot size or flux values checked separately. After comparison of mono-objective algorithms, the multi-objective evolutionary algorithm NSGA-II was run for both objectives – minimum spot size and maximum flux. Every algorithm configuration was run several times for Monte Carlo simulations since these processes generate random solutions and the simulator also produces solutions that are stochastic. The results show that the PSO algorithm gives the best values over all setups. Full Article text
ara ForMAX – a beamline for multiscale and multimodal structural characterization of hierarchical materials By journals.iucr.org Published On :: 2024-02-22 The ForMAX beamline at the MAX IV Laboratory provides multiscale and multimodal structural characterization of hierarchical materials in the nanometre to millimetre range by combining small- and wide-angle X-ray scattering with full-field microtomography. The modular design of the beamline is optimized for easy switching between different experimental modalities. The beamline has a special focus on the development of novel fibrous materials from forest resources, but it is also well suited for studies within, for example, food science and biomedical research. Full Article text
ara Scattered high-energy synchrotron radiation at the KARA visible-light diagnostic beamline By journals.iucr.org Published On :: 2024-03-26 To characterize an electron beam, visible synchrotron light is often used and dedicated beamlines at synchrotron sources are becoming a more common feature as instruments and methods for the diagnostics are, along with the accelerators, further developed. At KARA (Karlsruhe Research Accelerator), such a beamline exists and is based on a typical infrared/visible-light configuration. From experience at such beamlines no significant radiation was expected (dose rates larger than 0.5 µSv h−1). This was found not to be the case and a higher dose was measured which fortunately could be shielded to an acceptable level with 0.3 mm of aluminium foil or 2.0 mm of Pyrex glass. The presence of this radiation led to further investigation by both experiment and calculation. A custom setup using a silicon drift detector for energy-dispersive spectroscopy (Ketek GmbH) and attenuation experiments showed the radiation to be predominantly copper K-shell fluorescence and is confirmed by calculation. The measurement of secondary radiation from scattering of synchrotron and other radiation, and its calculation, is important for radiation protection, and, although a lot of experience exists and methods for radiation protection are well established, changes in machine, beamlines and experiments mean a constant appraisal is needed. Full Article text
ara Characterization of silicon pore optics for the NewAthena X-ray observatory in the PTB laboratory at BESSY II By journals.iucr.org Published On :: 2024-06-24 The New Advanced Telescope for High ENergy Astrophysics (NewAthena) will be the largest space-based X-ray observatory ever built. It will have an effective area above 1.1 m2 at 1 keV, which corresponds to a polished mirror surface of about 300 m2 due to the grazing incidence. As such a mirror area is not achievable with an acceptable mass even with nested shells, silicon pore optics (SPO) technology will be utilized. In the PTB laboratory at BESSY II, two dedicated beamlines are in use for their characterization with monochromatic radiation at 1 keV and a low divergence well below 2 arcsec: the X-ray Pencil Beam Facility (XPBF 1) and the X-ray Parallel Beam Facility (XPBF 2.0), where beam sizes up to 8 mm × 8 mm are available while maintaining low beam divergence. This beamline is used for characterizing mirror stacks and controlling the focusing properties of mirror modules (MMs) – consisting of four mirror stacks – during their assembly at the beamline. A movable CCD based camera system 12 m from the MM registers the direct and the reflected beams. The positioning of the detector is verified by a laser tracker. The energy-dependent reflectance in double reflection through the pores of an MM with an Ir coating was measured at the PTB four-crystal monochromator beamline in the photon energy range 1.75 keV to 10 keV, revealing the effects of the Ir M edges. The measured reflectance properties are in agreement with the design values to achieve the envisaged effective area. Full Article text
ara X-ray scattering based scanning tomography for imaging and structural characterization of cellulose in plants By journals.iucr.org Published On :: 2024-06-25 X-ray and neutron scattering have long been used for structural characterization of cellulose in plants. Due to averaging over the illuminated sample volume, these measurements traditionally overlooked the compositional and morphological heterogeneity within the sample. Here, a scanning tomographic imaging method is described, using contrast derived from the X-ray scattering intensity, for virtually sectioning the sample to reveal its internal structure at a resolution of a few micrometres. This method provides a means for retrieving the local scattering signal that corresponds to any voxel within the virtual section, enabling characterization of the local structure using traditional data-analysis methods. This is accomplished through tomographic reconstruction of the spatial distribution of a handful of mathematical components identified by non-negative matrix factorization from the large dataset of X-ray scattering intensity. Joint analysis of multiple datasets, to find similarity between voxels by clustering of the decomposed data, could help elucidate systematic differences between samples, such as those expected from genetic modifications, chemical treatments or fungal decay. The spatial distribution of the microfibril angle can also be analyzed, based on the tomographically reconstructed scattering intensity as a function of the azimuthal angle. Full Article text
ara New achievements in orbital angular momentum beam characterization using a Hartmann wavefront sensor and the Kirkpatrick–Baez active optical system KAOS By journals.iucr.org Published On :: 2024-08-16 Advances in physics have been significantly driven by state-of-the-art technology, and in photonics and X-ray science this calls for the ability to manipulate the characteristics of optical beams. Orbital angular momentum (OAM) beams hold substantial promise in various domains such as ultra-high-capacity optical communication, rotating body detection, optical tweezers, laser processing, super-resolution imaging etc. Hence, the advancement of OAM beam-generation technology and the enhancement of its technical proficiency and characterization capabilities are of paramount importance. These endeavours will not only facilitate the use of OAM beams in the aforementioned sectors but also extend the scope of applications in diverse fields related to OAM beams. At the FERMI Free-Electron Laser (Trieste, Italy), OAM beams are generated either by tailoring the emission process on the undulator side or, in most cases, by coupling a spiral zone plate (SZP) in tandem with the refocusing Kirkpatrick–Baez active optic system (KAOS). To provide a robust and reproducible workflow to users, a Hartmann wavefront sensor (WFS) is used for both optics tuning and beam characterization. KAOS is capable of delivering both tightly focused and broad spots, with independent control over vertical and horizontal magnification. This study explores a novel non-conventional `near collimation' operational mode aimed at generating beams with OAM that employs the use of a lithographically manufactured SZP to achieve this goal. The article evaluates the mirror's performance through Hartmann wavefront sensing, offers a discussion of data analysis methodologies, and provides a quantitative analysis of these results with ptychographic reconstructions. Full Article text
ara In situ characterization of stresses, deformation and fracture of thin films using transmission X-ray nanodiffraction microscopy. Corrigendum By journals.iucr.org Published On :: 2024-08-06 Errors in variable subscripts, equations and Fig. 8 in Section 3.2 of the article by Lotze et al. [(2024). J. Synchrotron Rad. 31, 42–52] are corrected. Full Article text
ara Characterizing electron-collecting CdTe for use in a 77 ns burst-rate imager By journals.iucr.org Published On :: 2024-08-07 The Keck-PAD (pixel array detector) was developed at Cornell as a burst-rate imager capable of recording images from successive electron bunches (153 ns period) from the Advanced Photon Source (APS). Both Si and hole-collecting Schottky CdTe have been successfully bonded to this ASIC (application-specific integrated circuit) and used with this frame rate. The facility upgrades at the APS will lower the bunch period to 77 ns, which will require modifications to the Keck-PAD electronics to image properly at this reduced period. In addition, operation at high X-ray energies will require a different sensor material having a shorter charge collection time. For the target energy of 40 keV for this project, simulations have shown that electron-collecting CdTe should allow >90% charge collection within 35 ns. This collection time will be sufficient to sample the signal from one frame and prepare for the next. 750 µm-thick electron-collecting Schottky CdTe has been obtained from Acrorad and bonded to two different charge-integrating ASICs developed at Cornell, the Keck-PAD and the CU-APS-PAD. Carrier mobility has been investigated using the detector response to single X-ray bunches at the Cornell High Energy Synchrotron Source and to a pulsed optical laser. The tests indicate that the collection time will meet the requirements for 77 ns imaging. Full Article text
ara Synthesis, characterization and structural analysis of complexes from 2,2':6',2''-terpyridine derivatives with transition metals By journals.iucr.org Published On :: 2024-05-16 The synthesis and structural characterization of three families of coordination complexes synthesized from 4'-phenyl-2,2':6',2''-terpyridine (8, Ph-TPY), 4'-(4-chlorophenyl)-2,2':6',2''-terpyridine (9, ClPh-TPY) and 4'-(4-methoxyphenyl)-2,2':6',2''-terpyridine (10, MeOPh-TPY) ligands with the divalent metals Co2+, Fe2+, Mn2+ and Ni2+ are reported. The compounds were synthesized from a 1:2 mixture of the metal and ligand, resulting in a series of complexes with the general formula [M(R-TPY)2](ClO4)2 (where M = Co2+, Fe2+, Mn2+ and Ni2+, and R-TPY = Ph-TPY, ClPh-TPY and MeOPh-TPY). The general formula and structural and supramolecular features were determinated by single-crystal X-ray diffraction for bis(4'-phenyl-2,2':6',2''-terpyridine)nickel(II) bis(perchlorate), [Ni(C21H15N3)2](ClO4)2 or [Ni(Ph-TPY)2](ClO4)2, bis[4'-(4-methoxyphenyl)-2,2':6',2''-terpyridine]manganese(II) bis(perchlorate), [Mn(C22H17N3O)2](ClO4)2 or [Mn(MeOPh-TPY)2](ClO4)2, and bis(4'-phenyl-2,2':6',2''-terpyridine)manganese(II) bis(perchlorate), [Mn(C21H15N3)2](ClO4)2 or [Mn(Ph-TPY)2](ClO4)2. In all three cases, the complexes present distorted octahedral coordination polyhedra and the crystal packing is determined mainly by weak C—H⋯π interactions. All the compounds (except for the Ni derivatives, for which FT–IR, UV–Vis and thermal analysis are reported) were fully characterized by spectroscopic (FT–IR, UV–Vis and NMR spectroscopy) and thermal (TGA–DSC, thermogravimetric analysis–differential scanning calorimetry) methods. Full Article text
ara Synthesis, spectroscopic and crystallographic characterization of various cymantrenyl thioethers [Mn{C5HxBry(SMe)z}(PPh3)(CO)2] By journals.iucr.org Published On :: 2024-07-05 Starting from [Mn(C5H4Br)(PPh3)(CO)2] (1a), the cymantrenyl thioethers [Mn(C5H4SMe)(PPh3)(CO)2] (1b) and [Mn{C5H4–nBr(SMe)n}(PPh3)(CO)2] (n = 1 for compound 2, n = 2 for 3 and n = 3 for 4) were obtained, using either n-butyllithium (n-BuLi), lithium diisopropylamide (LDA) or lithium tetramethylpiperidide (LiTMP) as base, followed by electrophilic quenching with MeSSMe. Stepwise consecutive reaction of [Mn(C5Br5)(PPh3)(CO)2] with n-BuLi and MeSSMe led finally to [Mn{C5(SMe)5}(PPh3)(CO)2] (11), only the fifth complex to be reported containing a perthiolated cyclopentadienyl ring. The molecular and crystal structures of 1b, 3, 4 and 11 were determined and were studied for the occurrence of S⋯S and S⋯Br interactions. It turned out that although some interactions of this type occurred, they were of minor importance for the arrangement of the molecules in the crystal. Full Article text
ara 3-[(Benzo-1,3-dioxol-5-yl)amino]-4-methoxycyclobut-3-ene-1,2-dione: polymorphism and twinning of a precursor to an antimycobacterial squaramide By journals.iucr.org Published On :: 2024-07-05 The title compound, 3-[(benzo-1,3-dioxol-5-yl)amino]-4-methoxycyclobut-3-ene-1,2-dione, C12H9NO5 (3), is a precursor to an antimycobacterial squaramide. Block-shaped crystals of a monoclinic form (3-I, space group P21/c, Z = 8, Z' = 2) and needle-shaped crystals of a triclinic form (3-II, space group P-1, Z = 4, Z' = 2) were found to crystallize concomitantly. In both crystal forms, R22(10) dimers assemble through N—H⋯O=C hydrogen bonds. These dimers are formed from crystallographically unique molecules in 3-I, but exhibit crystallographic Ci symmetry in 3-II. Twinning by pseudomerohedry was encountered in the crystals of 3-II. The conformations of 3 in the solid forms 3-I and 3-II are different from one another but are similar for the unique molecules in each polymorph. Density functional theory (DFT) calculations on the free molecule of 3 indicate that a nearly planar conformation is preferred. Full Article text
ara 2,4-Diarylpyrroles: synthesis, characterization and crystallographic insights By journals.iucr.org Published On :: 2024-08-08 Three 2,4-diarylpyrroles were synthesized starting from 4-nitrobutanones and the crystal structures of two derivatives were analysed. These are 4-(4-methoxyphenyl)-2-(thiophen-2-yl)-1H-pyrrole, C15H13NOS, and 3-(4-bromophenyl)-2-nitroso-5-phenyl-1H-pyrrole, C16H11BrN2O. Although pyrroles without substituents at the α-position with respect to the N atom are very air sensitive and tend to polymerize, we succeeded in growing an adequate crystal for X-ray diffraction analysis. Further derivatization using sodium nitrite afforded a nitrosyl pyrrole derivative, which crystallized in the triclinic space group Poverline{1} with Z = 6. Thus, herein we report the first crystal structure of a nitrosyl pyrrole. Interestingly, the co-operative hydrogen bonds in this NO-substituted pyrrole lead to a trimeric structure with bifurcated halogen bonds at the ends, forming a two-dimensional (2D) layer with interstitial voids having a radius of 5 Å, similar to some reported macrocyclic porphyrins. Full Article text
ara Characterization of novel mevalonate kinases from the tardigrade Ramazzottius varieornatus and the psychrophilic archaeon Methanococcoides burtonii By journals.iucr.org Published On :: 2024-02-27 Mevalonate kinase is central to the isoprenoid biosynthesis pathway. Here, high-resolution X-ray crystal structures of two mevalonate kinases are presented: a eukaryotic protein from Ramazzottius varieornatus and an archaeal protein from Methanococcoides burtonii. Both enzymes possess the highly conserved motifs of the GHMP enzyme superfamily, with notable differences between the two enzymes in the N-terminal part of the structures. Biochemical characterization of the two enzymes revealed major differences in their sensitivity to geranyl pyrophosphate and farnesyl pyrophosphate, and in their thermal stabilities. This work adds to the understanding of the structural basis of enzyme inhibition and thermostability in mevalonate kinases. Full Article text
ara Refining short-range order parameters from the three-dimensional diffuse scattering in single-crystal electron diffraction data By journals.iucr.org Published On :: 2024-01-01 Our study compares short-range order parameters refined from the diffuse scattering in single-crystal X-ray and single-crystal electron diffraction data. Nb0.84CoSb was chosen as a reference material. The correlations between neighbouring vacancies and the displacements of Sb and Co atoms were refined from the diffuse scattering using a Monte Carlo refinement in DISCUS. The difference between the Sb and Co displacements refined from the diffuse scattering and the Sb and Co displacements refined from the Bragg reflections in single-crystal X-ray diffraction data is 0.012 (7) Å for the refinement on diffuse scattering in single-crystal X-ray diffraction data and 0.03 (2) Å for the refinement on the diffuse scattering in single-crystal electron diffraction data. As electron diffraction requires much smaller crystals than X-ray diffraction, this opens up the possibility of refining short-range order parameters in many technologically relevant materials for which no crystals large enough for single-crystal X-ray diffraction are available. Full Article text
ara Structural characterization of TIR-domain signalosomes through a combination of structural biology approaches By journals.iucr.org Published On :: 2024-08-27 The TIR (Toll/interleukin-1 receptor) domain represents a vital structural element shared by proteins with roles in immunity signalling pathways across phyla (from humans and plants to bacteria). Decades of research have finally led to identifying the key features of the molecular basis of signalling by these domains, including the formation of open-ended (filamentous) assemblies (responsible for the signalling by cooperative assembly formation mechanism, SCAF) and enzymatic activities involving the cleavage of nucleotides. We present a historical perspective of the research that led to this understanding, highlighting the roles that different structural methods played in this process: X-ray crystallography (including serial crystallography), microED (micro-crystal electron diffraction), NMR (nuclear magnetic resonance) spectroscopy and cryo-EM (cryogenic electron microscopy) involving helical reconstruction and single-particle analysis. This perspective emphasizes the complementarity of different structural approaches. Full Article text
ara Synthesis, structural and spectroscopic characterization of defect-rich forsterite as a representative phase of Martian regolith By journals.iucr.org Published On :: 2024-10-28 Regolith draws intensive research attention because of its importance as the basis for fabricating materials for future human space exploration. Martian regolith is predicted to consist of defect-rich crystal structures due to long-term space weathering. The present report focuses on the structural differences between defect-rich and defect-poor forsterite (Mg2SiO4) – one of the major phases in Martian regolith. In this work, forsterites were synthesized using reverse strike co-precipitation and high-energy ball milling (BM). Subsequent post-processing was also carried out using BM to enhance the defects. The crystal structures of the samples were characterized by X-ray powder diffraction and total scattering using Cu and synchrotron radiation followed by Rietveld refinement and pair distribution function (PDF) analysis, respectively. The structural models were deduced by density functional theory assisted PDF refinements, describing both long-range and short-range order caused by defects. The Raman spectral features of the synthetic forsterites complement the ab initio simulation for an in-depth understanding of the associated structural defects. Full Article text
ara Synthesis and characterization of an organic–inorganic hybrid crystal: 2[Co(en)3](V4O13)·4H2O By journals.iucr.org Published On :: 2024-09-03 Organic–inorganic hybrid crystals have diverse functionalities, for example in energy storage and luminescence, due to their versatile structures. The synthesis and structural characterization of a new cobalt–vanadium-containing compound, 2[Co(en)3]3+(V4O13)6−·4H2O (1) is presented. The crystal structure of 1, consisting of [Co(en)3]3+ complexes and chains of corner-sharing (VO4) tetrahedra, was solved by single-crystal X-ray diffraction in the centrosymmetric space group P1. Phase purity of the bulk material was confirmed by infrared spectroscopy, scanning electron microscopy, elemental analysis and powder X-ray diffraction. The volume expansion of 1 was found to be close to 1% in the reported temperature range from 100 to 300 K, with a volume thermal expansion coefficient of 56 (2) × 10−6 K−1. The electronic band gap of 1 is 2.30 (1) eV, and magnetic susceptibility measurements showed that the compound exhibits a weak paramagnetic response down to 1.8 K, probably due to minor CoII impurities (<1%) on the CoIII site. Full Article text
ara A comprehensive characterization of thiophosgene in the solid state By journals.iucr.org Published On :: 2024-09-05 Thiophosgene is one of the principal C=S building blocks in synthetic chemistry. At room temperature, thiophosgene is a red liquid. While its properties in the liquid and gaseous states are well known, a comprehensive characterization of thiophosgene in its solid state is presented here. Differential scanning calorimetry shows that thiophosgene forms a supercooled melt before rapidly crystallizing. Its melting point is 231.85 K (−41.3 °C). At 80 K, thiophosgene crystallizes in space group P63/m [No. 174, a = b = 5.9645 (2), c = 6.2835 (3) Å, V = 193.59 (2) Å3]. The molecule shows a distinct rotational disorder: all S and Cl positions are of mixed occupancy and the disorder does not resolve at temperatures as low as 10 K, as was shown by neutron powder diffraction. Infrared, Raman and inelastic neutron scattering spectra were collected and assigned with the aid of quantum chemical calculations. A larger ordered structural model allowed for better agreement between the measured and calculated spectra, further indicating that disorder is an inherent feature of solid-state thiophosgene. Full Article text
ara Synthesis and crystallographic characterization of 6-hydroxy-1,2-dihydropyridin-2-one By journals.iucr.org Published On :: 2023-11-14 The title compound, C5H5NO2, is a hydroxylated pyridine ring that has been studied for its involvement in microbial degradation of nicotinic acid. Here we describe its synthesis as a formic acid salt, rather than the standard hydrochloride salt that is commercially available, and its spectroscopic and crystallographic characterization. Full Article text
ara New copper carboxylate pyrene dimers: synthesis, crystal structure, Hirshfeld surface analysis and electrochemical characterization By journals.iucr.org Published On :: 2024-01-01 Two new copper dimers, namely, bis(dimethyl sulfoxide)tetrakis(μ-pyrene-1-carboxylato)dicopper(Cu—Cu), [Cu2(C17H9O2)4(C2H6OS)2] or [Cu2(pyr-COO−)4(DMSO)2] (1), and bis(dimethylformamide)tetrakis(μ-pyrene-1-carboxylato)dicopper(Cu—Cu), [Cu2(C17H9O2)4(C3H7NO)2] or [Cu2(pyr-COO−)4(DMF)2] (2) (pyr = pyrene), were synthesized from the reaction of pyrene-1-carboxylic acid, copper(II) nitrate and triethylamine from solvents DMSO and DMF, respectively. While 1 crystallized in the space group Poverline{1}, the crystal structure of 2 is in space group P21/n. The Cu atoms have octahedral geometries, with four oxygen atoms from carboxylate pyrene ligands occupying the equatorial positions, a solvent molecule coordinating at one of the axial positions, and a Cu⋯Cu contact in the opposite position. The packing in the crystal structures exhibits π–π stacking interactions and short contacts through the solvent molecules. The Hirshfeld surfaces and two-dimensional fingerprint plots were generated for both compounds to better understand the intermolecular interactions and the contribution of heteroatoms from the solvent ligands to the crystal packing. In addition, a Cu2+/Cu1+ quasi-reversible redox process was identified for compound 2 using cyclic voltammetry that accounts for a diffusion-controlled electron-donation process to the Cu dimer. Full Article text