ero Ukraine Commander: Numerous Reports of N. Korean Soldiers Preparing to Participate in Combat Operations By world.kbs.co.kr Published On :: Sun, 10 Nov 2024 12:56:09 +0900 [International] : Ukraine's top military commander, Oleksandr Syrskyi, reportedly said that his country has numerous reports of North Korean soldiers preparing to participate in combat operations alongside Russian forces. Reuters said on Sunday that Syrskyi made the remarks in a Facebook post on Saturday. In the ...[more...] Full Article International
ero 10 Most Dangerous Cities in the World, Based on Homicide Rate By people.howstuffworks.com Published On :: Tue, 05 Nov 2024 10:15:03 -0500 The most dangerous cities in the world are a major concern for residents, visitors, law enforcement and policymakers. While crime exists everywhere, some cities statistically experience consistently high crime levels. We turned to Statista, a global data and business intelligence platform, to find the hard numbers on the murder rate per capita in cities worldwide. Full Article
ero 20 Most Dangerous Cities in California By people.howstuffworks.com Published On :: Thu, 07 Nov 2024 10:15:02 -0500 Whether you're looking for adventure, work opportunities, new scenery or better weather conditions, California cities represent a special, sunny place in the popular imagination. But before packing your bags and heading to the Golden State, you'll want to know which is the most dangerous city in California. Full Article
ero [4K] SEVENTEEN, CNBLUE, AB6IX, Billlie, SAY MY NAME, YENA, EPEX, VANNER, Xdinary Heroes, JD1 | On the way to music bank 241018 By world.kbs.co.kr Published On :: 2024-10-18 +09:00 On the morning of October 18, at Yeoido KBS HallKBS WORLD Radio filmed K-pop stars making their way to attend rehearsals for Music Bank.[more...] Full Article Economy&It
ero Climate change and coastal erosion - British Geological Survey By news.google.com Published On :: Mon, 29 Jan 2024 05:54:58 GMT Climate change and coastal erosion British Geological Survey Full Article
ero Spotlight on BGS coastal erosion data - British Geological Survey By news.google.com Published On :: Thu, 18 Jul 2024 07:00:00 GMT Spotlight on BGS coastal erosion data British Geological Survey Full Article
ero Symmetry, magnetic transitions and multiferroic properties of B-site-ordered A2MnB'O6 perovskites (B' = [Co, Ni]) By journals.iucr.org Published On :: A comparative description is presented of the symmetry and the magnetic structures found in the family of double perovskites A2MnB'O6 (mainly B' = Co and some Ni compounds for comparative purposes). Full Article text
ero Superstructure reflections in tilted perovskites By journals.iucr.org Published On :: 2024-07-26 The superstructure spots that appear in diffraction patterns of tilted perovskites are well documented and easily calculated using crystallographic software. Here, by considering a distortion mode as a perturbation of the prototype perovskite structure, it is shown how the structure-factor equation yields Boolean conditions for the presence of superstructure reflections. This approach may have some advantages for the analysis of electron diffraction patterns of perovskites. Full Article text
ero The structure of a pectin-active family 1 polysaccharide lyase from the marine bacterium Pseudoalteromonas fuliginea By journals.iucr.org Published On :: 2024-06-27 Pseudoalteromonas fuliginea sp. PS47 is a recently identified marine bacterium that has extensive enzymatic machinery to metabolize polysaccharides, including a locus that targets pectin-like substrates. This locus contains a gene (locus tag EU509_03255) that encodes a pectin-degrading lyase, called PfPL1, that belongs to polysaccharide lyase family 1 (PL1). The 2.2 Å resolution X-ray crystal structure of PfPL1 reveals the compact parallel β-helix fold of the PL1 family. The back side of the core parallel β-helix opposite to the active site is a meandering set of five α-helices joined by lengthy loops. A comparison of the active site with those of other PL1 enzymes suggests a catalytic mechanism that is independent of metal ions, such as Ca2+, but that substrate recognition may require metal ions. Overall, this work provides the first structural insight into a pectinase of marine origin and the first structure of a PL1 enzyme in subfamily 2. Full Article text
ero X-ray crystal structure of proliferating cell nuclear antigen 1 from Aeropyrum pernix By journals.iucr.org Published On :: 2024-10-09 Proliferating cell nuclear antigen (PCNA) plays a critical role in DNA replication by enhancing the activity of various proteins involved in replication. In this study, the crystal structure of ApePCNA1, one of three PCNAs from the thermophilic archaeon Aeropyrum pernix, was elucidated. ApePCNA1 was cloned and expressed in Escherichia coli and the protein was purified and crystallized. The resulting crystal structure determined at 2.00 Å resolution revealed that ApePCNA1 does not form a trimeric ring, unlike PCNAs from other domains of life. It has unique structural features, including a long interdomain-connecting loop and a PIP-box-like sequence at the N-terminus, indicating potential interactions with other proteins. These findings provide insights into the functional mechanisms of PCNAs in archaea and their evolutionary conservation across different domains of life. A modified medium and protocol were used to express recombinant protein containing the lac operon. The expression of the target protein increased and the total incubation time decreased when using this system compared with those of previous expression protocols. Full Article text
ero 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
ero Small-angle scattering and dark-field imaging for validation of a new neutron far-field interferometer By journals.iucr.org Published On :: A neutron far-field interferometer is under development at NIST with the aim of enabling a multi-scale measurement combining the best of small-angle neutron scattering (SANS) and neutron imaging and tomography. We use the close relationship between SANS, ultra-SANS, spin-echo SANS and dark-field imaging and measurements of monodisperse spheres as a validation metric, highlighting the strengths and weaknesses of each of these neutron techniques. Full Article text
ero Small-angle scattering and dark-field imaging for validation of a new neutron far-field interferometer By journals.iucr.org Published On :: 2024-11-08 The continued advancement of complex materials often requires a deeper understanding of the structure–function relationship across many length scales, which quickly becomes an arduous task when multiple measurements are required to characterize hierarchical and inherently heterogeneous materials. Therefore, there are benefits in the simultaneous characterization of multiple length scales. At the National Institute of Standards and Technology, a new neutron far-field interferometer is under development that aims to enable a multi-scale measurement combining the best of small-angle neutron scattering (SANS) and neutron imaging and tomography. Spatially resolved structural information on the same length scales as SANS (0.001–1 µm) and ultra-small-angle neutron scattering (USANS, 0.1–10 µm) will be collected via dark-field imaging simultaneously with regular attenuation radiography (>10 µm). The dark field is analogous to the polarization loss measured in spin-echo SANS (SESANS) and is related to isotropic SANS through a Hankel transform. Therefore, we use this close relationship and analyze results from SANS, USANS, SESANS and dark-field imaging of monodisperse spheres as a validation metric for the interferometry measurements. The results also highlight the strengths and weaknesses of these neutron techniques for both steady-state and pulsed neutron sources. Finally, we present an example of the value added by the spatial resolution enabled by dark-field imaging in the study of more complex heterogeneous materials. This information would otherwise be lost in other small-angle scattering measurements averaged over the sample. Full Article text
ero 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
ero Combination of XEOL, TR-XEOL and HB-T interferometer at the TPS 23A X-ray nanoprobe for exploring quantum materials By journals.iucr.org Published On :: 2024-01-19 In this study, a combination of X-ray excited optical luminescence (XEOL), time-resolved XEOL (TR-XEOL) and the Hanbury-Brown and Twiss (HB-T) interferometer at the Taiwan Photon Source (TPS) 23A X-ray nanoprobe beamline for exploring quantum materials is demonstrated. On the basis of the excellent spatial resolution rendered using a nano-focused beam, emission distributions of artificial micro-diamonds can be obtained by XEOL maps, and featured emission peaks of a selected local area can be obtained by XEOL spectra. The hybrid bunch mode of the TPS not only provides a sufficiently high peak power density for experiments at each beamline but also permits high-quality temporal domain (∼200 ns) measurements for investigating luminescence dynamics. From TR-XEOL measurements, the decay lifetime of micro-diamonds is determined to be approximately 16 ns. Furthermore, the XEOL spectra of artificial micro-diamonds can be investigated by the HB-T interferometer to identify properties of single-photon sources. The unprecedented strategy of combining XEOL, TR-XEOL and the HB-T interferometer at the X-ray nanoprobe beamline will open new avenues with significant characterization abilities for unraveling the emission mechanisms of single-photon sources for quantum materials. Full Article text
ero Enhancing electrospray ionization efficiency for particle transmission through an aerodynamic lens stack By journals.iucr.org Published On :: 2024-02-02 This work investigates the performance of the electrospray aerosol generator at the European X-ray Free Electron Laser (EuXFEL). This generator is, together with an aerodynamic lens stack that transports the particles into the X-ray interaction vacuum chamber, the method of choice to deliver particles for single-particle coherent diffractive imaging (SPI) experiments at the EuXFEL. For these experiments to be successful, it is necessary to achieve high transmission of particles from solution into the vacuum interaction region. Particle transmission is highly dependent on efficient neutralization of the charged aerosol generated by the electrospray mechanism as well as the geometry in the vicinity of the Taylor cone. We report absolute particle transmission values for different neutralizers and geometries while keeping the conditions suitable for SPI experiments. Our findings reveal that a vacuum ultraviolet ionizer demonstrates a transmission efficiency approximately seven times greater than the soft X-ray ionizer used previously. Combined with an optimized orifice size on the counter electrode, we achieve >40% particle transmission from solution into the X-ray interaction region. These findings offer valuable insights for optimizing electrospray aerosol generator configurations and data rates for SPI experiments. Full Article text
ero A versatile sample-delivery system for X-ray photoelectron spectroscopy of in-flight aerosols and free nanoparticles at MAX IV Laboratory By journals.iucr.org Published On :: 2024-08-07 Aerosol science is of utmost importance for both climate and public health research, and in recent years X-ray techniques have proven effective tools for aerosol-particle characterization. To date, such methods have often involved the study of particles collected onto a substrate, but a high photon flux may cause radiation damage to such deposited particles and volatile components can potentially react with the surrounding environment after sampling. These and many other factors make studies on collected aerosol particles challenging. Therefore, a new aerosol sample-delivery system dedicated to X-ray photoelectron spectroscopy studies of aerosol particles and gas molecules in-flight has been developed at the MAX IV Laboratory. The aerosol particles are brought from atmospheric pressure to vacuum in a continuous flow, ensuring that the sample is constantly renewed, thus avoiding radiation damage, and allowing measurements on the true unsupported aerosol. At the same time, available gas molecules can be used for energy calibration and to study gas-particle partitioning. The design features of the aerosol sample-delivery system and important information on the operation procedures are described in detail here. Furthermore, to demonstrate the experimental range of the aerosol sample-delivery system, results from aerosol particles of different shape, size and composition are presented, including inorganic atmospheric aerosols, secondary organic aerosols and engineered nanoparticles. Full Article text
ero Hyperspectral full-field quick-EXAFS imaging at the ROCK beamline for monitoring micrometre-sized heterogeneity of functional materials under process conditions By journals.iucr.org Published On :: 2024-08-23 Full-field transmission X-ray microscopy has been recently implemented at the hard X-ray ROCK–SOLEIL quick-EXAFS beamline, adding micrometre spatial resolution to the second time resolution characterizing the beamline. Benefiting from a beam size versatility due to the beamline focusing optics, full-field hyperspectral XANES imaging has been successfully used at the Fe K-edge for monitoring the pressure-induced spin transition of a 150 µm × 150 µm Fe(o-phen)2(NCS)2 single crystal and the charge of millimetre-sized LiFePO4 battery electrodes. Hyperspectral imaging over 2000 eV has been reported for the simultaneous monitoring of Fe and Cu speciation changes during activation of a FeCu bimetallic catalyst along a millimetre-sized catalyst bed. Strategies of data acquisition and post-data analysis using Jupyter notebooks and multivariate data analysis are presented, and the gain obtained using full-field hyperspectral quick-EXAFS imaging for studies of functional materials under process conditions in comparison with macroscopic information obtained by non-spatially resolved quick-EXAFS techniques is discussed. Full Article text
ero Synthesis of organotin(IV) heterocycles containing a xanthenyl group by a Barbier approach via ultrasound activation: synthesis, crystal structure and Hirshfeld surface analysis By journals.iucr.org Published On :: 2024-07-25 A series of organotin heterocycles of general formula [{Me2C(C6H3CH2)2O}SnR2] [R = methyl (Me, 4), n-butyl (n-Bu, 5), benzyl (Bn, 6) and phenyl (Ph, 7)] was easily synthesized by a Barbier-type reaction assisted by the sonochemical activation of metallic magnesium. The 119Sn{1H} NMR data for all four compounds confirm the presence of a central Sn atom in a four-coordinated environment in solution. Single-crystal X-ray diffraction studies for 17,17-dimethyl-7,7-diphenyl-15-oxa-7-stannatetracyclo[11.3.1.05,16.09,14]heptadeca-1,3,5(16),9(14),10,12-hexaene, [Sn(C6H5)2(C17H16O)], 7, at 100 and 295 K confirmed the formation of a mononuclear eight-membered heterocycle, with a conformation depicted as boat–chair, resulting in a weak Sn⋯O interaction. The Sn and O atoms are surrounded by hydrophobic C—H bonds. A Hirshfeld surface analysis of 7 showed that the eight-membered heterocycles are linked by weak C—H⋯π, π–π and H⋯H noncovalent interactions. The pairwise interaction energies showed that the cohesion between the heterocycles are mainly due to dispersion forces. Full Article text
ero The interoperability of crystallographic data and databases By journals.iucr.org Published On :: 2024-01-01 Interoperability of crystallographic data with other disciplines is essential for the smooth and rapid progress of structure-based science in the computer age. Within crystallography and closely related subject areas, there is already a high level of conformance to the generally accepted FAIR principles (that data be findable, accessible, interoperable and reusable) through the adoption of common information exchange protocols by databases, publishers, instrument vendors, experimental facilities and software authors. Driven by the success within these domains, the IUCr has worked closely with CODATA (the Committee on Data of the International Science Council) to help develop the latter's commitment to cross-domain integration of discipline-specific data. The IUCr has, in particular, emphasized the need for standards relating to data quality and completeness as an adjunct to the FAIR data landscape. This can ensure definitive reusable data, which in turn can aid interoperability across domains. A microsymposium at the IUCr 2023 Congress provided an up-to-date survey of data interoperability within and outside of crystallography, expounded using a broad range of examples. Full Article text
ero Chaperone-mediated MHC-I peptide exchange in antigen presentation By journals.iucr.org Published On :: 2024-04-24 This work focuses on molecules that are encoded by the major histocompatibility complex (MHC) and that bind self-, foreign- or tumor-derived peptides and display these at the cell surface for recognition by receptors on T lymphocytes (T cell receptors, TCR) and natural killer (NK) cells. The past few decades have accumulated a vast knowledge base of the structures of MHC molecules and the complexes of MHC/TCR with specificity for many different peptides. In recent years, the structures of MHC-I molecules complexed with chaperones that assist in peptide loading have been revealed by X-ray crystallography and cryogenic electron microscopy. These structures have been further studied using mutagenesis, molecular dynamics and NMR approaches. This review summarizes the current structures and dynamic principles that govern peptide exchange as these relate to the process of antigen presentation. Full Article text
ero Roodmus: a toolkit for benchmarking heterogeneous electron cryo-microscopy reconstructions By journals.iucr.org Published On :: 2024-10-15 Conformational heterogeneity of biological macromolecules is a challenge in single-particle averaging (SPA). Current standard practice is to employ classification and filtering methods that may allow a discrete number of conformational states to be reconstructed. However, the conformation space accessible to these molecules is continuous and, therefore, explored incompletely by a small number of discrete classes. Recently developed heterogeneous reconstruction algorithms (HRAs) to analyse continuous heterogeneity rely on machine-learning methods that employ low-dimensional latent space representations. The non-linear nature of many of these methods poses a challenge to their validation and interpretation and to identifying functionally relevant conformational trajectories. These methods would benefit from in-depth benchmarking using high-quality synthetic data and concomitant ground truth information. We present a framework for the simulation and subsequent analysis with respect to the ground truth of cryo-EM micrographs containing particles whose conformational heterogeneity is sourced from molecular dynamics simulations. These synthetic data can be processed as if they were experimental data, allowing aspects of standard SPA workflows as well as heterogeneous reconstruction methods to be compared with known ground truth using available utilities. The simulation and analysis of several such datasets are demonstrated and an initial investigation into HRAs is presented. Full Article text
ero A short note on the use of irreducible representations for tilted octahedra in perovskites By journals.iucr.org Published On :: 2024-08-08 It is pointed out that many authors are unaware that the particular choice of unit-cell origin determines the irreducible representations to which octahedral tilts in perovskites belong. Furthermore, a recommendation is made that the preferred option is with the origin at the B-cation site rather than that of the A site. Full Article text
ero New insights into the magnetism and magnetic structure of LuCrO3 perovskite By journals.iucr.org Published On :: 2024-09-03 A polycrystalline sample LuCrO3 has been characterized by neutron powder diffraction (NPD) and magnetization measurements. Its crystal structure has been Rietveld refined from NPD data in space group Pnma; this perovskite contains strongly tilted CrO6 octahedra with extremely bent Cr—O—Cr superexchange angles of ∼142°. The NPD data show that below Néel temperature (TN ≃ 131 K), the magnetic structure can be defined as an A-type antiferromagnetic arrangement of Cr3+ magnetic moments, aligned along the b axis, with a canting along the c axis. A noticeable magnetostrictive effect is observed in the unit-cell parameters and volume upon cooling down across TN. The AC magnetic susceptibility indicates the onset of magnetic ordering below 112.6 K; the magnetization isotherms below TN show a nonlinear behaviour that is associated with the described canting of the Cr3+ magnetic moments. From the Curie–Weiss law, the effective moment of the Cr3+ sublattice is found to be μeff = 3.55 μB (calculated 3.7 μB) while the ΘCW parameter yields a value of −155 K, indicating antiferromagnetic interactions. There is a conspicuous increase of TN upon the application of external pressure, which must be due to shortening of the Cr—O bond length under compression that increases the orbital overlap integral. Full Article text
ero Structural characterization of a new samarium–sodium heterometallic coordination polymer By journals.iucr.org Published On :: 2024-02-06 Lanthanide-containing materials are of interest in the field of crystal engineering because of their unique properties and distinct structure types. In this context, a new samarium–sodium heterometallic coordination polymer, poly[tetrakis(μ2-2-formyl-6-methoxyphenolato)samarium(III)sodium(I)], {[SmNa(C8H7O3)4]·solvent}n (Sm-1), was synthesized and crystallized via slow evaporation from a mixture of ethanol and acetonitrile. The compound features alternating SmIII and NaI ions, which are linked by ortho-vanillin (o-vanillin) ligands to form a mono-periodic chain-like coordination polymer. The chains propagate along the [001] direction. Residual electron density of disordered solvent molecules in the void space could not be reasonably modeled, thus the SQUEEZE function was applied. The structural, vibrational, and optical properties are reported. Full Article text
ero Crystal structure of the tetraethylammonium salt of the non-steroidal anti-inflammatory drug nimesulide (polymorph II) By journals.iucr.org Published On :: 2024-02-20 The crystal structure of the tetraethylammonium salt of the non-steroidal anti-inflammatory drug nimesulide (polymorph II) (systematic name: tetraethylammonium N-methanesulfonyl-4-nitro-2-phenoxyanilinide), C8H20N+·C13H11N2O5S−, was determined using single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P21/c with one tetraethylammonium cation and one nimesulide anion in the asymmetric unit. In the crystal, the ions are linked by C—H⋯N and C—H⋯O hydrogen bonds and C—H⋯π interactions. There are differences in the geometry of both the nimesulide anion and the tetraethylammonium cation in polymorphs I [Rybczyńska & Sikorski (2023). Sci. Rep. 13, 17268] and II of the title compound. Full Article text
ero Synthesis and crystal structures of two racemic 2-heteroaryl-3-phenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4-ones By journals.iucr.org Published On :: 2024-06-04 3-Phenyl-2-(thiophen-3-yl)-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4-one (C17H12N2OS2, 1) and 2-(1H-indol-3-yl)-3-phenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4-one 0.438-hydrate (C21H15N3OS·0.438H2O, 2) crystallize in space groups P21/n and C2/c, respectively. The asymmetric unit in each case is comprised of two parent molecules, albeit of mixed chirality in the case of 1 and of similar chirality in 2 with the enantiomers occupying the neighboring asymmetric units. Structure 2 also has water molecules (partial occupancies) that form continuous channels along the b-axis direction. The thiazine rings in both structures exhibit an envelope conformation. Intermolecular interactions in 1 are defined only by C—H⋯O and C—H⋯N hydrogen bonds between crystallographically independent molecules. In 2, hydrogen bonds of the type N—H⋯O between independent molecules and C—H⋯N(π) type, and π–π stacking interactions between the pyridine rings of symmetry-related molecules are observed. Full Article text
ero Crystal structure and Hirshfeld surface analysis of 2-bromoethylammonium bromide – a possible side product upon synthesis of hybrid perovskites By journals.iucr.org Published On :: 2024-06-18 This study presents the synthesis, characterization and Hirshfeld surface analysis of a small organic ammonium salt, C2H7BrN+·Br−. Small cations like the one in the title compound are considered promising components of hybrid perovskites, crucial for optoelectronic and photovoltaic applications. While the incorporation of this organic cation into various hybrid perovskite structures has been explored, its halide salt counterpart remains largely uninvestigated. The obtained structural results are valuable for the synthesis and phase analysis of hybrid perovskites. The title compound crystallizes in the solvent-free form in the centrosymmetric monoclinic space group P21/c, featuring one organic cation and one bromide anion in its asymmetric unit, with a torsion angle of −64.8 (2)° between the ammonium group and the bromine substituent, positioned in a gauche conformation. The crystal packing is predominantly governed by Br⋯H interactions, which constitute 62.6% of the overall close atom contacts. Full Article text
ero Two chromium(II) acetate complexes with N-heterocyclic carbene (NHC) coligands By journals.iucr.org Published On :: 2024-06-28 Tetrakis(μ-acetato-κ2O:O')bis{[1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-κC2]chromium(II)} tetrahydrofuran disolvate, [Cr2(C2H3O2)4(C27H36N4)2]·2C4H8O or [Cr2(OAc)4(IDipp)2]·2C4H8O (1), and tetrakis(μ-acetato-κ2O:O')bis{[1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene-κC2]chromium(II)}, {Cr2(C2H3O2)4(C21H24N2)2] or [Cr2(OAc)4(IMes)2] (2), were synthesized from anhydrous chromium(II) acetate [Cr2(OAc)4] and the corresponding NHC (NHC = N-heterocyclic carbene) in toluene as solvent. Both complexes crystallize in the triclinic system, space group Poverline{1}. The molecular structures consist of Cr2(OAc)4 paddle-wheels that carry two terminal NHC ligands. This leads to a square-pyramidal coordination of the chromium atoms. Full Article text
ero Crystal structure and supramolecular features of a host–guest inclusion complex based on A1/A2-hetero-difunctionalized pillar[5]arene By journals.iucr.org Published On :: 2024-09-24 A host–guest supramolecular inclusion complex was obtained from the co-crystallization of A1/A2-bromobutoxy-hydroxy difunctionalized pillar[5]arene (PilButBrOH) with adiponitrile (ADN), C47H53.18Br0.82O10·C6H8N2. The adiponitrile guest is stabilized within the electron-rich cavity of the pillar[5]arene host via multiple C—H⋯O and C—H⋯π interactions. Both functional groups on the macrocyclic rim are engaged in supramolecular interactions with an adjacent inclusion complex via hydrogen-bonding (O—H⋯N or C—H⋯Br) interactions, resulting in the formation of a supramolecular dimer in the crystal structure. Full Article text
ero Crystal structure and Hirshfeld surface analysis of the salt 2-iodoethylammonium iodide – a possible side product upon synthesis of hybrid perovskites By journals.iucr.org Published On :: 2024-10-31 The title organic–inorganic hybrid salt, C2H7IN+·I−, is isotypic with its bromine analog, C2H7BrN+·Br− [Semenikhin et al. (2024). Acta Cryst. E80, 738–741]. Its asymmetric unit consists of one 2-iodoethylammonium cation and one iodide anion. The NH3+ group of the organic cation forms weak hydrogen bonds with four neighboring iodide anions, leading to the formation of supramolecular layers propagating parallel to the bc plane. Hirshfeld surface analysis reveals that the most important contribution to the crystal packing is from N—H⋯I interactions (63.8%). The crystal under investigation was twinned by a 180° rotation around [001]. Full Article text
ero 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
ero 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
ero Fast nanoscale imaging of strain in a multi-segment heterostructured nanowire with 2D Bragg ptychography By journals.iucr.org Published On :: 2024-02-01 Developing semiconductor devices requires a fast and reliable source of strain information with high spatial resolution and strain sensitivity. This work investigates the strain in an axially heterostructured 180 nm-diameter GaInP nanowire with InP segments of varying lengths down to 9 nm, simultaneously probing both materials. Scanning X-ray diffraction (XRD) is compared with Bragg projection ptychography (BPP), a fast single-projection method. BPP offers a sufficient spatial resolution to reveal fine details within the largest segments, unlike scanning XRD. The spatial resolution affects the quantitative accuracy of the strain maps, where BPP shows much-improved agreement with an elastic 3D finite element model compared with scanning XRD. The sensitivity of BPP to small deviations from the Bragg condition is systematically investigated. The experimental confirmation of the model suggests that the large lattice mismatch of 1.52% is accommodated without defects. Full Article text
ero Revealing nanoscale sorption mechanisms of gases in a highly porous silica aerogel By journals.iucr.org Published On :: 2024-08-19 Geological formations provide a promising environment for the long-term and short-term storage of gases, including carbon dioxide, hydrogen and hydrocarbons, controlled by the rock-specific small-scale pore structure. This study investigates the nanoscale structure and gas uptake in a highly porous silica aerogel (a synthetic proxy for natural rocks) using transmission electron microscopy, X-ray diffraction, and small-angle and ultra-small-angle neutron scattering with a tracer of deuterated methane (CD4) at pressures up to 1000 bar. The results show that the adsorption of CD4 in the porous silica matrix is scale dependent. The pore space of the silica aerogel is fully accessible to the invading gas, which quickly equilibrates with the external pressure and shows no condensation on the sub-nanometre scale. In the 2.5–50 nm pore size region a classical two-phase adsorption behaviour is observed. The structure of the aerogel returns to its original state after the CD4 pressure has been released. Full Article text
ero Towards Seamless Payment Interoperability – Thunes Report By thepaypers.com Published On :: Fri, 11 Oct 2024 09:24:00 +0100 ‘The Road Ahead: Towards Seamless Payments Interoperability’, an eBook from Thunes, Visa, and The Paypers, explores how payments interoperability is reshaping the future of cross-border transactions. Full Article
ero The general equation of δ direct methods and the novel SMAR algorithm residuals using the absolute value of ρ and the zero conversion of negative ripples By journals.iucr.org Published On :: The general equation of the δ direct methods is established and applied in its difference form to the definition of one of the two residuals that constitute the SMAR phasing algorithm. These two residuals use the absolute value of ρ and/or the zero conversion of negative Fourier ripples (≥50% of the unit-cell volume). Alternatively, when solved for ρ, the general equation provides a simple derivation of the already known δM tangent formula. Full Article text
ero A Treacherous SVD By blogs.mathworks.com Published On :: Mon, 15 Jul 2024 15:39:04 +0000 A few days ago, a bug report from our office in Cambridge caught my attention. Computing the singular values and singular vectors of a particular matrix would sometimes cause MATLAB to crash.... read more >> Full Article Numerical Analysis Programming Singular Values
ero Zero Day Response: Strategies for the Newest Innovation in Corporate Defense By www.itsecurity.com Published On :: Fri, 26 Mar 2010 23:04:02 +0000 On-Demand Webinar > Watch Now!>>SPONSORED BY: TripwireResearch shows that over a third of organizations are not prepared for breaches while the average cost per breach in 2009 was $6.7 millio... Full Article
ero The Hero That Nobody Sees By enewsletter.catawbacountync.gov Published On :: Wed, 17 Apr 2013 18:09:37 +0000 Everyone sees the bright shiny fire truck arrive on the scene to put out the fire. Everyone sees the EMS units rushing to help. Everyone sees the Rescue units as they respond throughout the community. Everyone sees the flashing blue lights as law enforcement work to keep our community safe. Everyone sees State Highway Patrol [...] Full Article Citizen Interaction People Public Safety
ero Micromax releases AI powered mobile launcher, Steroid By cio.economictimes.indiatimes.com Published On :: Wed, 04 Jul 2018 07:00:00 +0530 Micromax forays in the race of in-house mobile launcher driven by Machine Learning and AI to enhance the user experience. Full Article
ero How QR codes work and what makes them dangerous: A computer scientist explains By cio.economictimes.indiatimes.com Published On :: Fri, 08 Apr 2022 15:28:35 +0530 The data in a QR code is a series of dots in a square grid. Each dot represents a one and each blank a zero in binary code, and the patterns encode sets of numbers, letters or both, including URLs. Full Article
ero Cold War Chemical Tests Over American Cities Were Far Below Dangerous Levels By Published On :: Wed, 14 May 1997 04:00:00 GMT A series of secret tests conducted by the U.S. Army in the 1950s and 1960s did not expose residents of the United States and Canada to chemical levels considered harmful, according to a new report from a committee of the National Research Council. Full Article
ero MMR Vaccine and Thimerosal-Containing Vaccines Are Not Associated With Autism, IOM Report Says By Published On :: Tue, 18 May 2004 04:00:00 GMT Based on a thorough review of clinical and epidemiological studies, neither the mercury-based vaccine preservative thimerosal nor the measles-mumps-rubella (MMR) vaccine are associated with autism, says a new report from the Institute of Medicine of the National Academies. Full Article
ero National Academy of Medicine Publication Outlines Use of Procurement Requirements to Drive Interoperability in Health Care By Published On :: Fri, 12 Oct 2018 05:00:00 GMT While health care has made great strides in recent years with the proliferation of electronic health records (EHRs), establishment of regional health information exchanges, and development of data exchange standards and interfaces, interoperability among health care technologies remains very limited, says a new National Academy of Medicine (NAM) special publication. Full Article
ero New Report Charts Path to Net-Zero Carbon Emissions by 2050, Recommends Near-Term Policies to Ensure Fair and Equitable Economic Transition and Revitalization of Manufacturing Industry By Published On :: Tue, 02 Feb 2021 05:00:00 GMT Achieving net-zero carbon emissions in the U.S. by 2050 is feasible and would not only help address climate change but also build a more competitive economy, increase high-quality jobs, and help address social injustice in the energy system, says a new report from the National Academies of Sciences, Engineering, and Medicine. Full Article
ero Zero Emission Vehicles Represent the Future of Energy Efficiency, Petroleum and Emissions Reductions in 2025-2035, New Report Says By Published On :: Wed, 31 Mar 2021 04:00:00 GMT Increased use of zero emission vehicles (ZEVs) presents the greatest opportunity to improve the energy efficiency of light-duty vehicles — i.e., passenger vehicles and light trucks — over the period of 2025-2035, says a new congressionally mandated report from the National Academies of Sciences, Engineering, and Medicine. Full Article
ero Science Academies of G-7 Nations Call for Action to Reach Net-Zero Emissions, Reverse Declines in Biodiversity, and Improve Data-Sharing to Prepare for Future Health Emergencies By Published On :: Wed, 31 Mar 2021 04:00:00 GMT Science academies from the G-7 nations today issued three statements recommending that their governments take urgent action to build a net-zero emissions, climate-resilient future, reverse global declines in biodiversity, and improve data-sharing for future health emergencies. Full Article
ero Engineering the Transition to Net-Zero Carbon Emissions By Published On :: Tue, 27 Sep 2022 04:00:00 GMT In an interview, NAE President John Anderson discusses the national and global transition to net-zero carbon emissions and how engineers — and NAE in particular — can support that shift. Energy Transitions is the theme of NAE’s annual meeting this year, taking place Oct. 2-3. Full Article
ero Secretaries of Energy and Transportation Discuss Getting to ‘Net-Zero’ in U.S. Transportation During TRB’s 2023 Annual Meeting By Published On :: Thu, 12 Jan 2023 05:00:00 GMT Energy Secretary Jennifer M. Granholm and Transportation Secretary Pete Buttigieg took the stage at the 2023 annual meeting of the Transportation Research Board to discuss the federal government’s plan to reach “net-zero” carbon emissions in the U.S. transportation sector by 2050. Full Article