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Search results for: X-RAY CRYSTAL STRUCTURES
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Inner-shell fragmentation of molecules into neutral fragments in high-Rydberg states induced by soft X-ray excitation with pulsed-field ionization
PublicationIn the present communication, we will show the results of measurements probing the production of neutral high-Rydberg fragments at the K edges of the molecules containing oxygen and nitrogen atoms. The experiments were performed at the Gas Phase beamline of the Elettra synchrotron radiation laboratory (Trieste, Italy), exploiting a combined soft X-ray excitation with pulsed-field ionization and ion time-of-flight (TOF) spectrometry...
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Study of microstress state of P91 steel using complementary mechanical Barkhausen, magnetoacoustic emission, and X-ray diffraction techniques
PublicationThe paper deals with assessment of microstress state of martensite P91 steel using three complementary techniques: mechanical Barkhausen emission, magnetoacoustic emission (MAE), and X-ray diffraction (XRD) profile analysis. Magnetic coercivity Hc and microstructure were investigated with inductive magnetometry and magnetic force microscopy (MFM), respectively. Internal stress level of P91 steel was modified by heat treatment....
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Mechanical and fracture properties of concrete reinforced with recycled and industrial steel fibers using Digital Image Correlation technique and X-ray micro computed tomography
PublicationPaper presents investigation of fracture phenomenon in plain concrete and in concrete reinforced with both recycled steel fibers (RSF) and industrial steel fibers (ISF). The wedge splitting test (WST), which enables stable crack propagation for quasi-brittle materials, was carried out on 75 75 75 mm cube samples. Initially, fracture process zone development was investigated only on the surface of samples using Digital Image Correlation...
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Pyrrole azocrown ethers - synthesis, crystal structures, and fluorescence properties
PublicationZsyntezowano nowe związki makrocykliczne zawierające w makropierścieniu pierścień pirolowy, grupy azowe oraz reszty chromoforowe i fluorescencyjne. Scharakteryzowano strukturę krystaliczną dwóch spośród otrzymanych makrocykli metodą rentgenografii strukturalnej. Stwierdzono, że zaprezentowane pirolowe azokorony to związki czułe i selektywne na jony ołowiu(II) oraz, że mogą być użyte jako chemosensory zarówno w spektroskopii UV-Vis,...
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A study on the interaction of rhodamine B with methylthioadenosine phosphorylase protein sourced from an Antarctic soil metagenomic library.
PublicationThe presented study examines the phenomenon of the fluorescence under UV light excitation (312 nm) of E. coli cells expressing a novel metagenomic-derived putative methylthioadenosine phosphorylase gene, called rsfp, grown on LB agar supplemented with a fluorescent dye rhodamine B. For this purpose, an rsfp gene was cloned and expressed in an LMG194 E. coli strain using an arabinose promoter. The resulting RSFP protein was purified...
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Chalcogen bonding interactions in a series of aromatic selenocyanates
PublicationSelenium atoms in aromatic selenocyanates are characterized by the occurrence of two σ-holes, a stronger one in the prolongation of the NC–Se bond and a weaker one in the prolongation of the Ar–Se bond. The crystal structures of several bis(selenocyanato) derivatives, prepared by a method originally developed for ortho bis-substituted derivatives, illustrate very well this difference, with a short NC–Se⋯NC ChB interaction organizing...
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Enhancing electrical properties through in-situ controlled nanocrystallization of V2O5–TeO2 glass
PublicationV2O5–TeO2 glass–ceramics (VTGC) were prepared by controlled annealing of the V2O5–TeO2 glass (VTG), which illustrates a parent glass matrix with a single charge carrier. The annealing proceeded at six temperatures selected between the glass transition and the maximum of the frst crystallization process to obtain various nanocrystallite sizes. Heat treatment caused an increase in DC conductivity by 2.5–3.5 (250–285 °C) order of...
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Use of X-Ray Computed Tomography for Ice Detection Applied to Organ Cryopreservation
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Ovarian tissue cryopreservation by stepped vitrification and monitored by X-ray computed tomography
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Structure of Kα1,2 - and Kβ1,3 -emission x-ray spectra for Se, Y, and Zr
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Precise x-ray energies of gadolinium determined by a combined experimental and theoretical approach
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Two-photon double ionization of atoms in attosecond x-ray radiation fields
PublicationWe consider two-photon double ionization of helium with 100, 200, and 400 eV excess energy for the two ejected electrons, corresponding to photon energies of 89.5, 139.5, and 239.5 eV, respectively. We focus on the case of ultrashort pulses (two oscillations of the field) and develop an approach to calculate the two-photon transition matrix elements within the lowest order of the time-dependent perturbation theory. One of the...
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X-ray and NMR structural studies of the series of porphyrazines with peripheral pyrrolyl groups
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BIOLOGICAL AGE ASSESSMENT ALGORITHMS BASED ON X-RAY IMAGES OF BONE TISSUE
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Testing interaction models by using x-ray absorption spectroscopy: solid Pb
PublicationPraca prezentuje zastosowanie metody EXAFS jako narzędzia do testowania potencjałów oddziaływań międzyatomowych używanych w symulacjach dynamiczno-molekularnych na przykładzie czystego ołowiu w fazie stałej (od temperatury pokojowej do temperatury topnienia). Testowaniu poddano następujące potencjały: dwuciałowy empiryczny potencjał Dzugutova, Larssona i Ebbsjo (DLE), potencjał ciasnego wiązania (TB) i potencjał w modelu osadzonego...
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Mechanical and radiation shielding properties of concrete reinforced with boron--basalt fibers using Digital Image Correlation and X--ray micro--computed tomography
PublicationThe paper presents experimental investigations of the radiation shielding, mechanical and fracture properties of concrete reinforced with 5 kg/m3 of novel basalt fibers infused with boron oxide (BBF). However, further studies concerning other dosages i.e. 1 kg/m3, 10 kg/m3, 15 kg/m3 and 20 kg/m3 are currently carried out. Experiments with neutron source revealed that addition of BBF as a dispersed concrete reinforcement could improve...
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Structural features responsible for control of the eukaryotic GlcN-6-P synthase activity
PublicationGlucosamine-6-phosphate (GlcN-6-P) synthase is responsible for catalysis of the first and practically irreversible step in hexosamine metabolism. As UDP-GlcNAc, the final product of the hexosamine path, constitutes one of the essential substrates for assembly of bacterial and fungal cell walls, the enzyme is an interesting target for antimicrobial therapy.The structure of E. coli enzyme, known since 2001, forms a dimer of two identical...
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Reactivity of Diimido Complexes of Molybdenum and Tungsten towards Lithium Derivatives of Diphosphanes and Triphosphanes
PublicationThe reaction of R2P–P(SiMe3)Li (R = tBu, iPr) with the diimido molybdenum complex [(ArN)2MoCl2·dme] (Ar = 2,6-iPr2C6H3; dme = 1,2-dimethoxyethane) yielded the side-oncoordinated phosphanylphosphinidene anionic complexes [(2,6-iPr2C6H3N)2Mo(Cl)(η2-P=PR2)]– (7Mo, 8Mo). The thermal decomposition of [(2,6-iPr2C6H3N)2M(Cl)(η2-P=PR2)]–[M = Mo (7Mo), W (8W)] to [(2,6-iPr2C6H3N)2M(Cl)(1,2-η-tBu2P=P–PtBu2)] [M = Mo (3Mo), W (3W)] was investigated...
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Monitoring the fracture process of concrete during splitting using integrated ultrasonic coda wave interferometry, digital image correlation and X-ray micro-computed tomography
PublicationThe paper deals with the continuous-time monitoring of mechanical degradation in concrete cubes under splitting. A series of experiments performed with integrated coda wave interferometry (CWI) and digital image correlation (DIC), supported with X-ray micro-computed tomography (micro-CT) is reported. DIC and micro-CT techniques were used to characterize the fracture process in detail. CWI method was proved to be effective in the...
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Enhancing Luminescence and X-ray Absorption Capacity of Eu3+:LaF3 Nanoparticles by Bi3+ Codoping
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On the interpretation of high-resolution x-ray spectra from JET with an ITER-like wall
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Experimental investigations on water sorptivity in mortars with the use of X-ray micro-CT system.
PublicationW pracy doswiadczalnej zbadano zjawisko sorpcji wody w pryzmatycznych próbkach zapraw, które jest ściśle powiązane z trwałością materiału. Sorpcyjność oceniana na etapie ustalonym w połączeniu z warunkami zewnętrznymi może być wykorzystana do przewidywania okresu użytkowania. Sorpcyjność początkową i wtórną wody w próbkach zapraw nienasyconych zmierzono w badaniach laboratoryjnych zgodnie z normą amerykańską ASTM C 1585–04. Wpływ...
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Experimental investigations of fracture process in concrete by means of x-ray micro-computed tomography
PublicationW artykule pokazano doświadczalne wyniki badań procesu pękania w betonie stosując mikro-tomografię. Doświadczenia wykonano dla zginanych belek betonowych. Wyniki doświadczalne modelowano stosując MES na bazie modelu z degradacją sztywności sprężystej z nielokalnym osłabieniem. Beton symulowano jako materiał 4-fazowy. Uzyskano dobra zgodność wyników MES z doświadczeniami.
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The bismuth atom neighbourhood in bismuth-silicate glasses from X-ray absorption experiment
PublicationPraca zawiera wyniki strukturalnej analizy EXAFS lokalnego otoczenia atomów bizmutu w krystalicznym tlenku bizmutu (odmiana alfa) i w szklach bizmutowo-krzemianowych o składzie xBi2O3 (1-x)SiO2,x=0.3, 0.4, 0.5, 0.6. Analizę XA- FS realizowano w oparciu o metodę GNXAS. Otrzymane wyniki porównano z danymi literaturowym.
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approximation of photonic crystal fibres with large air holes by the step index fibre model
PublicationAn equivalent step index fibre with a silica core and air cladding is used to model photonic crystal fibres with large air holes. We model this fibre for linear polarisation (we focus on the lowest few transverse modes of the electromagnetic field). The equivalent step index radius is obtained by equating the lowest two eigenvalues of the model to those calculated numerically for the photonic crystal fibres. The step index parameters...
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Enhancement of the Magnetic Coupling in Exfoliated CrCl 3 Crystals Observed by Low‐Temperature Magnetic Force Microscopy and X‐ray Magnetic Circular Dichroism
PublicationMagnetic crystals formed by 2D layers interacting by weak van der Waals forces are currently a hot research topic. When these crystals are thinned to nanometric size, they can manifest strikingly different magnetic behavior compared to the bulk form. This can be the result of, for example, quantum electronic confinement effects, the presence of defects, or pinning of the crystallographic structure in metastable phases induced by...
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Novel primosomal protein B from Clostridium pastuerianum
PublicationPriB is a primosomal protein that catalyzes DNA replication in Procaryota. The replication pathway starts with PriA protein - the initiator protein that binds to a DNA replication fork, unwinds double-stranded DNA and role of PriB is to stabilize PriA on the DNA. However there are many biochemical differences in replication mechanism in bacteria and only some of them use PriB proteins. A few of PriB proteins were published and...
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Novel primosomal protein B from Clostridium pasteurianum
PublicationPriB is a primosomal protein that catalyzes DNA replication in Procaryota. The replication pathway starts with PriA protein - the initiator protein that binds to a DNA replication fork, unwinds double-stranded DNA and role of PriB is to stabilize PriA on the DNA. However there are many biochemical differences in replication mechanism in bacteria and only some of them use PriB proteins. A few of PriB proteins were published and...
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Torsional elasticity and energetics of F1-ATPase
PublicationFoF1-ATPase is a rotary motor protein synthesizing ATP from ADP driven by a cross-membrane proton gradient. The proton flow through the membrane-embedded Fo generates the rotary torque that drives the rotation of the asymmetric shaft of F1. Mechanical energy of the rotating shaft is used by the F1 catalytic subunit to synthesize ATP. It was suggested that elastic power transmission with transient storage of energy in some compliant...
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Method for prediction of the frost resistance ability of air‐entrained concrete based on the 3D air void characteristics by x‐ray micro‐CT
PublicationIn modern construction, one of the most important factors in the execution of contracts is time. Standard procedures for assessing the frost resistance or concrete are usually very time-consuming and can take up to 40 days. The current paper is experimentally and practically oriented. It presents an alternative testing method, based on air void network, that allows to assess the frost resistance of concrete within just a few days...
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Assessment of the cryoprotectant concentration inside a bulky organ for cryopreservation using X-ray computed tomography
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Modelling of the soft X-ray tungsten spectra expected to be registered by GEM detection system for WEST
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Structure of high-resolution Kβ1,3 x-ray emission spectra for the elements from Ca to Ge
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The X-ray photoelectron spectroscopy of surface composition of aged mixed copper manganese oxide catalysts
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Fracture evolution in concrete compressive fatigue experiments based on X-ray micro-CT images
PublicationArtykuł omawia ewolucje pękania w betonie podczas cyklicznego ściskania betonu. Przestrzenną ewolucję pękania zobrazowano stosując mikro-tomograf rentgenowski. Zdjęcia wykonano dla różnych cykli zmęczeniowych. Wyniki porównano z testami monotonicznymi. Jakościowa ewolucja objętości pękania ze wzrostem zmęczeniowego zniszczenia pokazała silnie nieliniowy kształt.
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Crystal structures of the Bacillus subtilis prophage lytic cassette proteins XepA and YomS
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Shear fracture of longitudinally reinforced concrete beams under bending using Digital Image Correlation and FE simulations with concrete micro-structure based on X-ray micro-computed tomography images
PublicationThe paper presents experimental and numerical investigations of the shear fracture in rectangular concrete beams longitudinally reinforced with steel or basalt bar under quasi-static three point bending. Shear fracture process zone formation and development on the surface of beams was investigated by Digital Image Correlation (DIC) whereas thorough analyses of 3D material micro-structure, air voids, width and curvature of shear...
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Imaging polarimeter with high-accuracy measuring principles in crystal optics
PublicationAn imaging polarimeter based on the principles of high-accuracy polarimetry well known in crystal optics is proposed. The application of scientific digital cameras for performance light measurements leads to precise data on polarizers quality, i.e., maps of extinction ratio and transmission axis. Processing of numerous images, acquired at various settings in the polarizer-sample-analyser system, allows to determine the two-dimensional...
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Exploring the Antitumor Efficacy of N-Heterocyclic Nitrilotriacetate Oxidovanadium(IV) Salts on Prostate and Breast Cancer Cells
PublicationThe crystal structures of two newly synthesized nitrilotriacetate oxidovanadium(IV) salts, namely [QH][VO(nta)(H2O)](H2O)2 (I) and [(acr)H][VO(nta)(H2O)](H2O)2 (II), were determined. Additionally, the cytotoxic effects of four N-heterocyclic nitrilotriacetate oxidovanadium(IV) salts— 1,10-phenanthrolinium, [(phen)H][VO(nta)(H2O)](H2O)0.5 (III), 2,2′-bipyridinium [(bpy)H][VO(nta)(H2O)](H2O) (IV), and two newly synthesized compounds...
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Effect of different crystalline structures on W/O and O/W/O wax emulsion stability
PublicationtThe possibility of emulsion stabilization using mineral and vegetable wax particles only (without sur-factant) was investigated. Mineral waxes, paraffin wax and ceresin, and a vegetable wax, carnauba wax,were used. The content of the wax particles and the water to oil proportion were found crucial for thestability of all emulsions. Some emulsions were also produced with a liquid wax (i.e. jojoba oil). Themultiple light scattering...
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Mechanism of recognition of parallel G-quadruplexes by DEAH/RHAU helicase DHX36 explored by molecular dynamics simulations
PublicationBecause of high stability and slow unfolding rates of G-quadruplexes (G4), cells have evolved specialized helicases that disrupt these non-canonical DNA and RNA structures in an ATP-dependent manner. One example is DHX36, a DEAH-box helicase, which participates in gene expression and replication by recognizing and unwinding parallel G4s. Here, we studied the molecular basis for the high affinity and specificity of DHX36 for parallel-type...
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Analysis of the bulk solid flow during gravitational silo emptying using X-ray and ECT tomography
PublicationW pracy przedstawiono wyniki pomiarów zmian koncentracji piasku bezkohezyjnego zachodzących w prostokątnym modelu silosu opróżnianym grawitacyjnie. Pomiary wykonano z zastosowaniem kontynualnego promieniowania rentgenowskiego oraz z użyciem tomografii pojemnościowej. Badania wykonano dla zróżnicowanego zagęszczenia początkowego piasku oraz różnego stopnia szorstkości ścian. Szczególny nacisk położono na zachowanie sie materiału...
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Detection of Cystic Fibrosis Symptoms Based on X-Ray Images Using Machine Learning- Pilot Study
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Inelastic X-Ray Scattering Studies of Phonon Dispersion in PbTe and (Pb,Cd)Te Solid Solution
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Diagnostics of the plasma parameters based on the K X-ray line positions for various 4d and 4f metals
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FPGA-based LLRF control module for x-ray free electron laser and TESLA feedback system
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Quantitative estimation of volume changes of granular materials during silo flow using X-ray tomography.
PublicationW artykule przedstawiono wyniki badań doświadczalnych nad zmianami objętościowymi materiału granulowanego podczas przepływu silosowego. Badania wykonano przy zastosowaniu tomografii rentgenowskiej. Wyniki porównano z wynikami doświadczalnymi przy zastosowaniu cyfrowej obróbki zdjęć płynącego materiału.
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High-accuracy polarimetric studies on lead germanate single crystals
PublicationA high-accuracy polarimetric technique has been used for the characterization of a lead germanate ferroelectric single crystal. The measurement results of the linear and circular birefringence in the [010] direction at a wavelength of 633 nm under the influence of an electric field are presented. Gyration–electric field hysteresis loops at alternative crystal positions in the polarization system have been used to determine the...
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Adsorption behavior and corrosion inhibitive characteristics of newly synthesized cyano-benzylidene xanthenes on copper/sodium hydroxide interface: Electrochemical, X-ray photoelectron spectroscopy and theoretical studies
PublicationElegant process for synthesis of 3-(7H-dibenzo[c,h]xanthen-7-yl)benzaldehyde (3), as new starting material to create a set of novel xanthene analogues, 2-(3-(7H-dibenzo[c,h]xanthen-7-yl)benzylidene)malononitrile (4), 3-(3-(7H-dibenzo[c,h]xanthen-7-yl)phenyl)-2-cyanoacrylic acid (5), and Ethyl-3-(3-(7H-dibenzo[c,h]xanthen-7-yl)phenyl)-2-cyanoacrylate (6), was achieved starting with available materials under mild conditions. Various...
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Individual contributions of M X-ray line from Cu- and Co-like tungsten ions and L X-ray line from Ne-like molybdenum ions – Benchmarks for new approach to determine the high-temperature tokamak plasma parameters
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