WorldWideScience

Sample records for situ x-ray investigation

  1. Custom AFM for X-ray beamlines: in situ biological investigations under physiological conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gumí-Audenis, B. [ESRF, The European Synchrotron, Grenoble (France); Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Carlà, F. [ESRF, The European Synchrotron, Grenoble (France); Vitorino, M. V. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Panzarella, A. [ESRF, The European Synchrotron, Grenoble (France); Porcar, L. [Institut Laue-Langevin, Grenoble (France); Boilot, M. [ORTEC, Marseille (France); Guerber, S. [CEA, LETI Grenoble (France); Bernard, P. [ESRF, The European Synchrotron, Grenoble (France); Rodrigues, M. S. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Sanz, F.; Giannotti, M. I. [Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Costa, L., E-mail: luca.costa@esrf.fr [ESRF, The European Synchrotron, Grenoble (France)

    2015-09-30

    The performance of a custom atomic force microscope for grazing-incidence X-ray experiments on hydrated soft and biological samples is presented. A fast atomic force microscope (AFM) has been developed that can be installed as a sample holder for grazing-incidence X-ray experiments at solid/gas or solid/liquid interfaces. It allows a wide range of possible investigations, including soft and biological samples under physiological conditions (hydrated specimens). The structural information obtained using the X-rays is combined with the data gathered with the AFM (morphology and mechanical properties), providing a unique characterization of the specimen and its dynamics in situ during an experiment. In this work, lipid monolayers and bilayers in air or liquid environment have been investigated by means of AFM, both with imaging and force spectroscopy, and X-ray reflectivity. In addition, this combination allows the radiation damage induced by the beam on the sample to be studied, as has been observed on DOPC and DPPC supported lipid bilayers under physiological conditions.

  2. In-situ X-ray diffraction : a useful tool to investigate hydride-formation reactions

    NARCIS (Netherlands)

    Notten, P.H.L.; Daams, J.L.C.; Veirman, de A.E.M.; Staals, A.A.

    1994-01-01

    A high-pressure X-ray diffraction (XRD) cell has been designed which allowed us to study simultaneously hydrogen absorption/desorption isotherms and XRD powder diffraction patterns on (de)hydrided intermetallic compounds. The hydride formation reaction was investigated in the case of LaNi5 under

  3. Structural investigations of LiFePO4 electrodes and in situ studies by Fe X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Deb, Aniruddha; Bergmann, Uwe; Cramer, S.P.; Cairns, Elton J.

    2005-01-01

    Fe K-edge X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) have been performed on electrodes containing LiFePO 4 to determine the local atomic and electronic structure and their stability with electrochemical cycling. A versatile electrochemical in situ cell has been constructed for long-term soft and hard X-ray experiments for the structural investigation on battery electrodes during the lithium-insertion/extraction processes. The device is used here for an X-ray absorption spectroscopic study of lithium insertion/extraction in a LiFePO 4 electrode, where the electrode contained about 7.7 mg of LiFePO 4 on a 20 μm thick Al-foil. Fe K-edge X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) have been performed on this electrode to determine the local atomic and electronic structure and their stability with electrochemical cycling. The initial state (LiFePO 4 ) showed iron to be in the Fe 2+ state corresponding to the initial state (0.0 mAh) of the cell, whereas in the delithiated state (FePO 4 ) iron was found to be in the Fe 3+ state corresponding to the final charged state (3 mAh). XANES region of the XAS spectra revealed a high spin configuration for the two states (Fe (II), d 6 and Fe (III), d 5 ). The results confirm that the olivine structure of the LiFePO 4 and FePO 4 is retained by the electrodes in agreement with the XRD observations reported previously. These results confirm that LiFePO 4 cathode material retains good structural short-range order leading to superior cycling capability

  4. In situ X-ray investigations of oxygen precipitation in semiconductor silicon; In-situ-Roentgenuntersuchungen der Sauerstoffpraezipitation in Halbleitersilizium

    Energy Technology Data Exchange (ETDEWEB)

    Grillenberger, Hannes

    2011-03-04

    The precipitation of oxygen in Czochralski grown semiconductor silicon is investigated in situ during thermal treatments up to 1000 C with high energy X-rays. All investigations are performed with a focusing Laue diffractometer. The parameters of the diffraction curve are the relative full width at half maximum (rFHWM) and the enhancement of the integral intensity (EII). A readout software has been developed to extract these automatically from the detector image for the measured 220, -220 and 040 Bragg peaks. The sample thickness is set to 15 mm as this enhances the sensitivity of the method and the samples are processed after the strain-field diffraction (SFD) experiments to wafers for an ex situ characterization demanding wafers. Three experimental series with a total of 21 in situ SFD experiments with different thermal treatments have been performed. The slope of the initial temperature ramp is set to 1 K/min in the first and the third series to generate a high precipitate (Bulk Micro Defect, BMD) density. In the second series the slope is chosen as 10 K/min to generate a lower density in the same silicon material. It is shown with all experiments and with preliminary works that the built up of strain during the heat treatment is caused by BMDs during the high temperature period of the treatment. The detection limit of series 1 is found at 7 nm at a density of 10{sup 13}/cm{sup 3}, of series 2 at 40 nm at a density of 2 x 10{sup 8}/cm{sup 3}, and at 8 nm at a density of 4.8 x 10{sup 12}/cm{sup 3} for series 3. The local maximum of the EII at 450 C, which emerges coincident with a local minimum of the rFWHM in series 2 may be caused by thermal donors (TD). With the experiments is shown that SFD operates in the infrared-laser scattering tomography detection range, but also reaches in a region covered only by transmission electron microscopy (TEM) so far. In contrast to these methods SFD is not limited to low temperatures and in situ experiments can be done. Thus

  5. Structural Investigation of Sodium Layered Oxides Via in Situ Synchrotron X-Ray Diffraction

    DEFF Research Database (Denmark)

    Jung, Young Hwa; Christiansen, Ane Sælland; Johnsen, Rune

    2015-01-01

    electrochemical reaction is generally considered to be a pivotal feature for understanding the relationship between layered structures and electrochemical properties. Here the structure, phase stability, and electrochemical properties of two kinds of layered oxides, P2 and O3, are investigated through in......-situ synchrotron XRD experiments. A capillary Na-based cell is designed to minimize interference in other substances such as a separator or external battery parts. This approach could give us to obtain clear diffraction patterns with high intensity during electrochemical reaction in a short period of time without...... further relaxation step. We carefully scrutinized reversible structural phase transformations during electrochemical reaction of P2 and O3-layered compounds based on in situ analysis, and detailed results will be discussed....

  6. In situ grazing incidence small-angle X-ray scattering investigation of polystyrene nanoparticle spray deposition onto silicon.

    Science.gov (United States)

    Herzog, Gerd; Benecke, Gunthard; Buffet, Adeline; Heidmann, Berit; Perlich, Jan; Risch, Johannes F H; Santoro, Gonzalo; Schwartzkopf, Matthias; Yu, Shun; Wurth, Wilfried; Roth, Stephan V

    2013-09-10

    We investigated the spray deposition and subsequent self-assembly during drying of a polystyrene nanoparticle dispersion with in situ grazing incidence small-angle X-ray scattering at high time resolution. During the fast deposition of the dispersion and the subsequent evaporation of the solvent, different transient stages of nanoparticle assembly can be identified. In the first stage, the solvent starts to evaporate without ordering of the nanoparticles. During the second stage, large-scale structures imposed by the breakup of the liquid film are observable. In this stage, the solvent evaporates further and nanoparticle ordering starts. In the late third drying stage, the nanoparticles self-assemble into the final layer structure.

  7. Hydrogen Absorption in Metal Thin Films and Heterostructures Investigated in Situ with Neutron and X-ray Scattering

    Directory of Open Access Journals (Sweden)

    Sara J. Callori

    2016-05-01

    Full Text Available Due to hydrogen possessing a relatively large neutron scattering length, hydrogen absorption and desorption behaviors in metal thin films can straightforwardly be investigated by neutron reflectometry. However, to further elucidate the chemical structure of the hydrogen absorbing materials, complementary techniques such as high resolution X-ray reflectometry and diffraction remain important too. Examples of work on such systems include Nb- and Pd-based multilayers, where Nb and Pd both have strong affinity to hydrogen. W/Nb and Fe/Nb multilayers were measured in situ with unpolarized and polarized neutron reflectometry under hydrogen gas charging conditions. The gas-pressure/hydrogen-concentration dependence, the hydrogen-induced macroscopic film swelling as well as the increase in crystal lattice plane distances of the films were determined. Ferromagnetic-Co/Pd multilayers were studied with polarized neutron reflectometry and in situ ferromagnetic resonance measurements to understand the effect of hydrogen absorption on the magnetic properties of the system. This electronic effect enables a novel approach for hydrogen sensing using a magnetic readout scheme.

  8. Interdiffusion in nanometer-scale multilayers investigated by in situ low-angle x-ray diffraction

    Science.gov (United States)

    Wang, Wei-Hua; Bai, Hai Yang; Zhang, Ming; Zhao, J. H.; Zhang, X. Y.; Wang, W. K.

    1999-04-01

    An in situ low-angle x-ray diffraction technique is used to investigate interdiffusion phenomena in various metal-metal and metal-amorphous Si nanometer-scale compositionally modulated multilayers (ML's). The temperature-dependent interdiffusivities are obtained by accurately monitoring the decay of the first-order modulation peak as a function of annealing time. Activation enthalpies and preexponential factors for the interdiffusion in the Fe-Ti, Ag-Bi, Fe-Mo, Mo-Si, Ni-Si, Nb-Si, and Ag-Si ML's are determined. Activation enthalpies and preexponential factors for the interdiffusion in the ML's are very small compared with that in amorphous alloys and crystalline solids. The relation between the atomic-size difference and interdiffusion in the ML's are investigated. The observed interdiffusion characteristics are compared with that in amorphous alloys and crystalline α-Zr, α-Ti, and Si. The experimental results suggest that a collective atomic-jumping mechanism govern the interdiffusion in the ML's, the collective proposal involving 8-15 atoms moving between extended nonequilibrium defects by thermal activation. The role of the interdiffusion in the solid-state reaction in the ML's is also discussed.

  9. Texture evolution of orthorhombic α″ titanium alloy investigated by in situ X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Elmay, W., E-mail: wafa.elmay@ensam.eu [Laboratoire d' Etude des Microstructures et de Mécanique des Matériaux LEM3 (UMR CNRS 7239), 4 rue Augustin Fresne, 57078 Metz (France); Berveiller, S.; Patoor, E. [Laboratoire d' Etude des Microstructures et de Mécanique des Matériaux LEM3 (UMR CNRS 7239), 4 rue Augustin Fresne, 57078 Metz (France); Gloriant, T. [Chimie-Métallurgie (UMR CNRS 6226), 20, Avenue des Buttes de Coesmes, F-35043 Rennes (France); Prima, F. [Laboratoire de Physico-Chimie des Surfaces (UMR CNRS 7045), 11 Rue Pierre et Marie Curie, F-75231 Paris (France); Laheurte, P. [Laboratoire d' Etude des Microstructures et de Mécanique des Matériaux LEM3 (UMR CNRS 7239), 4 rue Augustin Fresne, 57078 Metz (France)

    2017-01-02

    The present paper deals with an in-situ X-ray diffraction analysis during cyclic tensile tests of a fully martensitic Ti-24Nb alloy. Texture evolution of martensite α″ phase was followed during loading-unloading cycles. Preferential formation and reverse transformation of particular martensite variants have been observed based on pole figure analysis. The occurrence of the deformation mechanisms for the martensitic Ti-24Nb alloy was also commented by coupling microstructural observations during in-situ experiments and additional cyclic tests followed by heating after each unloading. Through the study of the evolution of the lattice strain, it was found that under loading conditions, the {020} planes exhibit a large tension lattice strain while the {200} planes are subjected to a compression solicitation, which causes the lattice parameters a and c to be shrunk, and b to be elongated.

  10. Repeated sorption of water in SBA-15 investigated by means of in situ small-angle x-ray scattering

    International Nuclear Information System (INIS)

    Erko, M; Paris, O; Wallacher, D; Findenegg, G H

    2012-01-01

    The effect of repeated cycles of water adsorption/desorption on the structural stability of ordered mesoporous silica SBA-15 is studied by small-angle x-ray scattering (SAXS). In situ sorption measurements are conducted using a custom-built sorption apparatus in connection with a laboratory SAXS setup. Two striking irreversible changes are observed in the sorption isotherms as derived from the integrated SAXS intensity. First, the capillary condensation pressure shifts progressively to lower relative pressure values with increasing number of sorption cycles. This effect is attributed to chemisorption of water at the silica walls, resulting in a change of the fluid-wall interaction. Second, the sorption cycles do not close completely at vanishing vapour pressure, suggesting that progressively more water remains trapped within the porous material after each cycle. This effect is interpreted to be the result of an irreversible collapse of parts of mesopores, originating from pore wall deformation due to the large Laplace pressure of water acting on the pore walls at capillary condensation and capillary evaporation. (paper)

  11. In situ x-ray diffraction investigations during low energy ion nitriding of austenitic stainless steel grade 1.4571

    International Nuclear Information System (INIS)

    Manova, D; Mändl, S; Gerlach, J W; Hirsch, D; Neumann, H; Rauschenbach, B

    2014-01-01

    Insertion of nitrogen into austenitic stainless steel leads to anomalously fast nitrogen diffusion and the formation of an expanded face-centred cubic phase which is known to contain a large amount of mechanical stress. In situ x-ray diffraction (XRD) measurements during low energy nitrogen ion implantation into steel 316Ti at 300–550 °C allow a direct view into diffusion and phase formation. While the layer growth is directly observable from the decreasing substrate reflection intensity, the time evolution of the intensities for the expanded phase reflection is much more complex: several mechanisms including at least formation and annealing of defects, twinning, reduction of the crystal symmetry, or grain rotation may be active inside the expanded phase, besides the thermally activated decay of the metastable expanded phase. This locally varying coherence length or scattering intensity from the expanded phase is furthermore a function of temperature and time, additionally complicating the deconvolution of XRD spectra for stress and concentration gradients. As no concise modelling of this coherence length is possible at present, a simple qualitative model assuming a dependence of the scattering intensity on the depth, influence by stress and plastic flow during the nitriding process is proposed for understanding the underlying processes. (paper)

  12. In situ characterization of delamination and crack growth of a CGO–LSM multi-layer ceramic sample investigated by X-ray tomographic microscopy

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Esposito, Vincenzo; Lauridsen, Erik Mejdal

    2014-01-01

    The densification, delamination and crack growth behavior in a Ce0.9Gd0.1O1.95 (CGO) and (La0.85Sr0.15)0.9MnO3 (LSM) multi-layer ceramic sample was studied using in situ X-ray tomographic microscopy (microtomography) to investigate the critical dynamics of crack propagation and delamination...... in a multilayered sample. Naturally occurring defects, caused by the sample preparation process, are shown not to be critical in sample degradation. Instead defects are nucleated during the debinding step. Crack growth is significantly faster along the material layers than perpendicular to them, and crack growth...

  13. In situ investigation by X-ray tomography of the overall and local microstructural changes occurring during partial remelting of an Al-15.8 wt.% Cu alloy

    International Nuclear Information System (INIS)

    Limodin, Nathalie; Salvo, Luc; Suery, Michel; DiMichiel, Marco

    2007-01-01

    The paper is concerned with the study of the microstructural changes occurring during holding of an Al-15.8 wt.% Cu alloy in the semi-solid state. These changes are investigated in 3D by in situ X-ray tomography carried out at the temperature of the treatment. The studies are classified in two categories: overall changes by measuring average values of characteristic parameters, and local changes by considering the evolution of individual necks between particles. It is shown in particular that the size of the solid particles or the surface area of the solid-liquid interfaces do not follow the classical power laws but rather evolve in a slower manner. Local observations confirm that these results are due to the competition of two coarsening mechanisms of the solid particles that occur simultaneously: dissolution of a small particle to the benefit of one or several bigger ones by an Ostwald-type mechanism and the growth of necks between solid particles due to their coalescence. Complex variations of neck size result from these mechanisms which can be explained only by considering the neighbourhood of the particles under investigation. These observations confirm that in situ X-ray tomography is a very powerful tool to provide data that are representative of the semi-solid state and to observe in real time the mechanisms that act on the microstructure

  14. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

    DEFF Research Database (Denmark)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico

    2016-01-01

    at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.......The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing......-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments...

  15. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

    Science.gov (United States)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole

    2016-01-01

    The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles. PMID:26917133

  16. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering.

    Science.gov (United States)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole; Chorkendorff, Ib

    2016-03-01

    The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.

  17. Dehydrogenation kinetics of pure and nickel-doped magnesium hydride investigated by in situ time-resolved powder X-ray diffraction

    DEFF Research Database (Denmark)

    Jensen, T.R.; Andreasen, A.; Vegge, Tejs

    2006-01-01

    The dehydrogenation kinetics of pure and nickel (Ni)-doped (2w/w%) magnesium hydride (MgH2) have been investigated by in situ time-resolved powder X-ray diffraction (PXD). Deactivated samples, i.e. air exposed, are investigated in order to focus on the effect of magnesium oxide (MgO) surface layers......, which might be unavoidable for magnesium (Mg)-based storage media for mobile applications. A curved position-sensitive detector covering 120 degrees in 20 and a rotating anode X-ray source provide a time resolution of 45 s and up to 90 powder pattems collected during an experiment under isothermal...... by the Johnson-Mehi-Avrami formalism in order to derive rate constants at different temperatures. The apparent activation energies for dehydrogenation of pure and Ni-doped magnesium hydride were E-A approximate to 300 and 250 kJ/mol, respectively. Differential scanning calorimetry gave, E-A = 270 k...

  18. Investigation of the internal electric field distribution under in situ x-ray irradiation and under low temperature conditions by the means of the Pockels effect

    International Nuclear Information System (INIS)

    Prekas, G; Sellin, P J; Veeramani, P; Davies, A W; Lohstroh, A; Oezsan, M E; Veale, M C

    2010-01-01

    The internal electric field distribution in cadmium zinc telluride (CdZnTe) x-ray and γ-ray detectors strongly affects their performance in terms of charge transport and charge collection properties. In CdZnTe detectors the electric field distribution is sensitively dependent on not only the nature of the metal contacts but also on the working conditions of the devices such as the temperature and the rate of external irradiation. Here we present direct measurements of the electric field profiles in CdZnTe detectors obtained using the Pockels electo-optic effect whilst under in situ x-ray irradiation. These data are also compared with alpha particle induced current pulses obtained by the transient current technique, and we discuss the influence of both low temperature and x-ray irradiation on the electric field evolution. Results from these studies reveal strong distortion of the electric field consistent with the build-up of space charge at temperatures below 250 K, even in the absence of external irradiation. Also, in the presence of x-ray irradiation levels a significant distortion in the electric field is observed even at room temperature which matches well the predicted theoretical model.

  19. Investigation of the reversible sodiation of Sn foil by ex-situ X-ray diffractometry and Mössbauer effect spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Du, Zhijia [Department of Physics and Atmospheric Science, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Dunlap, R.A. [Department of Physics and Atmospheric Science, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Institute for Research in Materials, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); College of Sustainability, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Obrovac, M.N., E-mail: mobrovac@dal.ca [Department of Physics and Atmospheric Science, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Institute for Research in Materials, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Chemistry, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada)

    2014-12-25

    Highlights: • Mössbauer spectra of all phases formed during sodiation measured for the first time. • Center shifts correlated with metallurgically prepared samples. • Center shift correlated with Na content in Na–Sn. - Abstract: The reversible sodiation of Sn foil was investigated using ex-situ X-ray diffractometry (XRD) and Mössbauer effect spectroscopy. The measured voltage profile indicated that the sodiation process of Sn foil proceeded in three stages. Ex-situ XRD patterns demonstrated that Na{sub 4}Sn{sub 4}, Na{sub 5}Sn{sub 2} and Na{sub 15}Sn{sub 4} phases were formed at the end of each discharge plateau. Na{sub 5}Sn{sub 2}, Na{sub 4}Sn{sub 4} and β-Sn were formed at the end of each charge plateau. Three single-phase alloys, Na{sub 4}Sn{sub 4}, Na{sub 9}Sn{sub 4} and Na{sub 15}Sn{sub 4}, were prepared by annealing stoichiometric ratios of Na and Sn. The Mössbauer spectra of ex-situ samples at the end of each discharge plateau were collected and compared with the Mössbauer spectra of the three single phase alloys. The measured parameters for the Mössbauer effect spectra were consistent with an analysis of the crystal structures. The center shift became less positive with an increase of the sodium content in Na–Sn phases and this was shown to be a useful indicator of the degree of sodiation of Sn electrodes.

  20. Coupling in-situ X-ray micro- and nano-tomography and discrete element method for investigating high temperature sintering of metal and ceramic powders

    Directory of Open Access Journals (Sweden)

    Yan Zilin

    2017-01-01

    Full Text Available The behaviour of various powder systems during high temperature sintering has been investigated by coupling X-ray microtomography and discrete element method (DEM. Both methods are particularly relevant to analyse particle interactions and porosity changes occurring during sintering. Two examples are presented. The first one deals with a copper powder including artificially created pores which sintering has been observed in situ at the European synchrotron and simulated by DEM. 3D images with a resolution of 1.5 μm have been taken at various times of the sintering cycle. The comparison of the real displacement of particle centers with the displacement derived from the mean field assumption demonstrates significant particle rearrangement in some regions of the sample. Although DEM simulation showed less rearrangement, it has been able to accurately predict the densification kinetics. The second example concerns multilayer ceramic capacitors (MLCCs composed of hundreds of alternated metal electrode and ceramic dielectric layers. The observation of Ni-based MLCCs by synchrotron nanotomography at Argon National Laboratory with a spatial resolution between 10 and 50 nm allowed understanding the origin of heterogeneities formed in Ni layers during sintering. DEM simulations confirmed this analysis and provided clues for reducing these defects.

  1. New Pyrazole-Hydrazone Derivatives: X-ray Analysis, Molecular Structure Investigation via Density Functional Theory (DFT) and Their High In-Situ Catecholase Activity.

    Science.gov (United States)

    Karrouchi, Khalid; Yousfi, El Bekkaye; Sebbar, Nada Kheira; Ramli, Youssef; Taoufik, Jamal; Ouzidan, Younes; Ansar, M'hammed; Mabkhot, Yahia N; Ghabbour, Hazem A; Radi, Smaail

    2017-10-25

    The development of low-cost catalytic systems that mimic the activity of tyrosinase enzymes (Catechol oxidase) is of great promise for future biochemistry technologic demands. Herein, we report the synthesis of new biomolecules systems based on hydrazone derivatives containing a pyrazole moiety ( L1 - L6 ) with superior catecholase activity. Crystal structures of L1 and L2 biomolecules were determined by X-ray single crystal diffraction (XRD). Optimized geometrical parameters were calculated by density functional theory (DFT) at B3LYP/6-31G (d, p) level and were found to be in good agreement with single crystal XRD data. Copper (II) complexes of the compounds ( L1 - L6 ), generated in-situ, were investigated for their catalytic activities towards the oxidation reaction of catechol to ortho -quinone with the atmospheric dioxygen, in an attempt to model the activity of the copper containing enzyme tyrosinase. The studies showed that the activities depend on four parameters: the nature of the ligand, the nature of counter anion, the nature of solvent and the concentration of ligand. The Cu(II)-ligands, given here, present the highest catalytic activity (72.920 μmol·L -1 ·min -1 ) among the catalysts recently reported in the existing literature.

  2. Growth and structure of water on SiO2 films on Si investigated byKelvin probe microscopy and in situ X-ray Spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Verdaguer, A.; Weis, C.; Oncins, G.; Ketteler, G.; Bluhm, H.; Salmeron, M.

    2007-06-14

    The growth of water on thin SiO{sub 2} films on Si wafers at vapor pressures between 1.5 and 4 torr and temperatures between -10 and 21 C has been studied in situ using Kelvin Probe Microscopy and X-ray photoemission and absorption spectroscopies. From 0 to 75% relative humidity (RH) water adsorbs forming a uniform film 4-5 layers thick. The surface potential increases in that RH range by about 400 mV and remains constant upon further increase of the RH. Above 75% RH the water film grows rapidly, reaching 6-7 monolayers at around 90% RH and forming a macroscopic drop near 100%. The O K-edge near-edge X-ray absorption spectrum around 75% RH is similar to that of liquid water (imperfect H-bonding coordination) at temperatures above 0 C and ice-like below 0 C.

  3. X-ray investigation of Nb/O interfaces

    International Nuclear Information System (INIS)

    Delheusy, M.

    2008-01-01

    X-ray free electron lasers and the future International Linear Collider project are based on the performance of niobium superconducting RF cavities for efficient particle acceleration. A remarkable increase of the RF accelerating field is usually achieved by low-temperature annealing of the cavities (T≤150 C, several hours). The microscopic origin of this effect has remained unclear; however, it has been argued that a redistribution of subsurface interstitial oxygen into niobium is involved. In this study, the near surface structure of oxidized niobium single crystals and its evolution upon vacuum annealing has been studied by means of non-destructive in-situ surface sensitive x-ray techniques: x-ray reflectivity (XRR), grazing incidence x-ray diffraction (GIXD), diffuse scattering (GIDXS), crystal truncation rods measurements (CTRs), and high-resolution core-level spectroscopy (HRCLS). A first insight into the interplay between the oxide formation/dissolution and the occurrence of 181 subsurface interstitial oxygen has been given. The natural oxide on Nb(110) and Nb(100) surfaces is constituted of Nb 2 O 5 , NbO 2 and NbO, from the surface to the interface. It reduces progressively upon heating from Nb 2 O 5 to NbO 2 at low temperatures, and to NbO at 300 C. The Nb(110)/NbO(111) interface presents a Nishiyma-Wassermann epitaxial orientation relationship. The depth-distribution of interstitial oxygen has been established indicating that most of the oxygen is located in the direct vicinity of the oxide/niobium interface. No evidence of oxygen depletion below the oxide layer has been observed for the low temperature thermal treatments and surface preparations investigated in this study. (author) [fr

  4. X-ray investigation of Nb/O interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Delheusy, Melissa

    2008-07-07

    X-ray free electron lasers and the future International Linear Collider project are based on the performance of niobium superconducting rf cavities for efficient particle acceleration. A remarkable increase of the rf accelerating field is usually achieved by low-temperature annealing of the cavities (T<150 C, several hours). The microscopic origin of this effect has remained unclear; however, it has been argued that a redistribution of subsurface interstitial oxygen into niobium is involved. In this study, the near surface structure of oxidized niobium single crystals and its evolution upon vacuum annealing has been studied by means of non-destructive in-situ surface sensitive X-ray techniques: X-ray reflectivity (XRR), grazing incidence X-ray diffraction (GIXD), diffuse scattering (GIDXS), crystal truncation rods measurements (CTRs), and high-resolution core-level spectroscopy (HRCLS). A first insight into the interplay between the oxide formation/dissolution and the occurrence of subsurface interstitial oxygen has been given. The natural oxide on Nb(110) and Nb(100) surfaces is constituted of Nb{sub 2}O{sub 5}, NbO{sub 2} and NbO, from the surface to the interface. It reduces progressively upon heating from Nb{sub 2}O{sub 5} to NbO{sub 2} at low temperatures, and to NbO at 300 C. The Nb(110)/NbO(111) interface presents a Nishiyama-Wassermann epitaxial orientation relationship. The depth-distribution of interstitial oxygen has been established indicating that most of the oxygen is located in the direct vicinity of the oxide/niobium interface. No evidence of oxygen depletion below the oxide layer has been observed for the low temperature thermal treatments and surface preparations investigated in this study. (orig.)

  5. X-ray investigations of the hot ISM

    Science.gov (United States)

    Sanders, W. T.

    1993-01-01

    At energies less than one keV, the intensity of the galactic x-ray background dominates that of the extragalactic background in almost every direction on the sky. Below 1/4 keV, the galactic x-ray background has a galactic stellar component, but the dominant emitter seems to be hot interstellar matter. The origin of the general 3/4 keV x-ray background remains uncertain, but one component must also be the contribution from hot interstellar matter. An overview is given of recent x-ray investigations of the hot interstellar medium using data from the ROSAT X-ray Telescope/Position-Sensitive Proportional Counter (XRT/PSPC) instrument. Several prominent features in the low energy x-ray background that are interpreted as fossil supernova remnants are discussed.

  6. In situ X-ray near-edge absorption spectroscopy investigation of the state of charge of all-vanadium redox flow batteries.

    Science.gov (United States)

    Jia, Chuankun; Liu, Qi; Sun, Cheng-Jun; Yang, Fan; Ren, Yang; Heald, Steve M; Liu, Yadong; Li, Zhe-Fei; Lu, Wenquan; Xie, Jian

    2014-10-22

    Synchrotron-based in situ X-ray near-edge absorption spectroscopy (XANES) has been used to study the valence state evolution of the vanadium ion for both the catholyte and anolyte in all-vanadium redox flow batteries (VRB) under realistic cycling conditions. The results indicate that, when using the widely used charge-discharge profile during the first charge process (charging the VRB cell to 1.65 V under a constant current mode), the vanadium ion valence did not reach V(V) in the catholyte and did not reach V(II) in the anolyte. Consequently, the state of charge (SOC) for the VRB cell was only 82%, far below the desired 100% SOC. Thus, such incompletely charged mix electrolytes results in not only wasting the electrolytes but also decreasing the cell performance in the following cycles. On the basis of our study, we proposed a new charge-discharge profile (first charged at a constant current mode up to 1.65 V and then continuously charged at a constant voltage mode until the capacity was close to the theoretical value) for the first charge process that achieved 100% SOC after the initial charge process. Utilizing this new charge-discharge profile, the theoretical charge capacity and the full utilization of electrolytes has been achieved, thus having a significant impact on the cost reduction of the electrolytes in VRB.

  7. Application of the nuclear x-ray fluorescence method to prospecting for gold in-situ

    International Nuclear Information System (INIS)

    Zhang, Y.; Xie, T.; Zhou, S.; Ge, L.

    1989-01-01

    Arsenic and chalcophile elements are often associated with gold, and can be considered indicator elements when prospecting for gold deposits. The nuclear geophysics X-ray fluorescence method can be used to search for hidden gold deposits by measuring fluorescence intensities of the indicator elements in situ. The method can speed geologic investigation and reduce exploration cost. Three types of portable radioisotope X-ray fluorescence analyzers, designed and manufactured by Chengdu College of Geology and Chongqing Geological Instrument Factory, are briefly introduced. These analyzers are widely used in different stages of geologic investigation for gold in China. In the two case histories presented five anomalous zones of X-ray fluorescence intensity related to gold mineralization are located and one hidden gold deposit is discovered with gold content of 23 g/t

  8. Capillary based Li-air batteries for in situ synchrotron X-ray powder diffraction studies

    DEFF Research Database (Denmark)

    Storm, Mie Møller; Johnsen, Rune E.; Younesi, Reza

    2015-01-01

    For Li-air batteries to reach their full potential as energy storage system, a complete understanding of the conditions and reactions in the battery during operation is needed. To follow the reactions in situ a capillary-based Li-O2 battery has been developed for synchrotron-based in situ X......-ray powder diffraction (XRPD). In this article, we present the results for the analysis of 1st and 2nd deep discharge and charge for a cathode being cycled between 2 and 4.6 V. The crystalline precipitation of Li2O2 only is observed in the capillary battery. However, there are indications of side reactions...... of constant exposure of X-ray radiation to the electrolyte and cathode during charge of the battery was also investigated. X-ray exposure during charge leads to changes in the development of the intensity and the FWHM of the Li2O2 diffraction peaks. The X-ray diffraction results are supported by ex situ X...

  9. Investigation of a novel x-ray tube for the calibration of the x-ray crystal spectrometer in the KSTAR machine

    International Nuclear Information System (INIS)

    Bak, J.G.; Lee, S.G.

    2007-01-01

    A novel x-ray tube with a line filament has been developed for the in-situ calibration of the x-ray crystal spectrometer (XCS) in the KSTAR machine. The characteristics of the x-ray tube are investigated from the x-ray images obtained by using a pinhole and a CCD detector. It is found that the image has the width of about 0.1 mm, which is much improved as compared with the previous experimental results. In addition, there is a uniform region around the center of the image within its full length of 13.5 mm. This work may lead to the development of a novel x-ray tube with a line focus, which is required for the calibration of the XCS. Experimental results from the investigation of the x-ray tube are presented and the technical issues in a design of the in-situ calibration system using the x-ray tube for the KSTAR XCS are discussed. (author)

  10. X-ray fluorescence analyzers for investigating postmediaeval pottery from Southern Moravia

    International Nuclear Information System (INIS)

    Trojek, Tomas; Hlozek, Matin; Cechak, Tomas; Musilek, Ladislav

    2010-01-01

    This paper deals with an investigation of ceramic archaeological finds with the use of in-situ X-ray fluorescence analysis. Firstly, three configurations of X-ray fluorescence analyzers constructed and used at the Czech Technical University in Prague are described and compared for use in a non-destructive survey of siliceous materials. Detection limits, depth of analysis, the relation of the analyzed area, the homogeneity of the samples, and variations in the element concentrations are discussed. Secondly, many shards of postmediaeval pottery from Southern Moravia are analyzed with X-ray fluorescence analysis and some of them also with electron microprobe analysis. Selected results are described.

  11. In vivo and in situ investigative results of repair and recovery processes during ontogenesis, after X-ray irradiation of bean seeds

    International Nuclear Information System (INIS)

    Koeroesi, F.; Jezierska-Szabo, E.; Szoeke, P.

    1999-01-01

    When exposing plant organs to high doses of ionizing radiation, disorders in growth and development or even lethality may occur. With the aim of modelling this phenomenon, seeds of bean, variety Echo Elit, were irradiated with a 300 Gy dose of X-ray irradiation (120 kV; 4.5 mA). In order to characterize repair and recovery at plant level, the biological production and photosynthetic pigments of the plants during ontogenesis in vivo and changes in their electric capacitance were continuously monitored and recorded via a computer-aided and -controlled data acquisition system. According to the data obtained, the repair in the biosynthesis of photosynthetic pigments will have been completed by the beginning of flowering. It may be assumed from the capacitance measurements made at 11 a.m. According to this postulation the process of repairing X-ray injuries might be finished by the beginning of pod formation without the plants actually recovering. (author)

  12. In situ x-ray diffraction studies of three-dimensional C60 polymers

    International Nuclear Information System (INIS)

    Wood, R A; Lewis, M H; Bennington, S M; Cain, M G; Kitamura, N; Fukumi, A K

    2002-01-01

    In situ investigations into the P/T field of C 60 fullerene were performed using energy-dispersive x-ray diffraction techniques. Isobars were obtained at 11 and 9 GPa accompanied by isotherms at 750 and 800 K with pressure reaching 13 GPa. The P/T history and pressure isotropy were investigated with the aim of optimizing conditions for 3D polymer formation. Confirmation of the formation of 3D polymers was performed in situ; however, the reclaimed sample did not exhibit the expected high hardness value, due to depolymerization on pressure release. Isotropy in the pressure field promoted formation and retention of the face-centred-cubic structure

  13. Nanocalorimeter platform for in situ specific heat measurements and x-ray diffraction at low temperature

    Science.gov (United States)

    Willa, K.; Diao, Z.; Campanini, D.; Welp, U.; Divan, R.; Hudl, M.; Islam, Z.; Kwok, W.-K.; Rydh, A.

    2017-12-01

    Recent advances in electronics and nanofabrication have enabled membrane-based nanocalorimetry for measurements of the specific heat of microgram-sized samples. We have integrated a nanocalorimeter platform into a 4.5 T split-pair vertical-field magnet to allow for the simultaneous measurement of the specific heat and x-ray scattering in magnetic fields and at temperatures as low as 4 K. This multi-modal approach empowers researchers to directly correlate scattering experiments with insights from thermodynamic properties including structural, electronic, orbital, and magnetic phase transitions. The use of a nanocalorimeter sample platform enables numerous technical advantages: precise measurement and control of the sample temperature, quantification of beam heating effects, fast and precise positioning of the sample in the x-ray beam, and fast acquisition of x-ray scans over a wide temperature range without the need for time-consuming re-centering and re-alignment. Furthermore, on an YBa2Cu3O7-δ crystal and a copper foil, we demonstrate a novel approach to x-ray absorption spectroscopy by monitoring the change in sample temperature as a function of incident photon energy. Finally, we illustrate the new insights that can be gained from in situ structural and thermodynamic measurements by investigating the superheated state occurring at the first-order magneto-elastic phase transition of Fe2P, a material that is of interest for magnetocaloric applications.

  14. Synchrotron radiation microbeam X-ray fluorescence analysis of zinc concentration in remineralized enamel in situ.

    Science.gov (United States)

    Matsunaga, Tsunenori; Ishizaki, Hidetaka; Tanabe, Shuji; Hayashi, Yoshihiko

    2009-05-01

    Remineralization is an indispensable phenomenon during the natural healing process of enamel decay. The incorporation of zinc (Zn) into enamel crystal could accelerate this remineralization. The present study was designed to investigate the concentration and distribution of Zn in remineralized enamel after gum chewing. The experiment was performed at the Photon Factory. Synchrotron radiation was monochromatized and X-rays were focused into a small beam spot. The X-ray fluorescence (XRF) from the sample was detected with a silicon (Si) (lithium (Li)) detector. X-ray beam energy was tuned to detect Zn. The examined samples were small enamel fragments remineralized after chewing calcium phosphate-containing gum in situ. The incorporation of Zn atom into hydroxyapatite (OHAP), the main component of enamel, was measured using Zn K-edge extended X-ray absorption fine structure (EXAFS) with fluorescence mode at the SPring-8. A high concentration of Zn was detected in a superficial area 10-microm deep of the sectioned enamel after gum chewing. This concentration increased over that in the intact enamel. The atomic distance between Zn and O in the enamel was calculated using the EXAFS data. The analyzed atomic distances between Zn and O in two sections were 0.237 and 0.240 nm. The present experiments suggest that Zn is effectively incorporated into remineralized enamel through the physiological processes of mineral deposition in the oral cavity through gum-chewing and that Zn substitution probably occurred at the calcium position in enamel hydroxyapatite.

  15. Accelerators and x-rays in cultural heritage investigations

    International Nuclear Information System (INIS)

    Heinz-Eberhard, Mahnke; Salomon, J.; Heinz-Eberhard, Mahnke; Denker, A.; Heinz-Eberhard, Mahnke

    2009-01-01

    In the following article a review is given on the use of accelerators in studies connected to our cultural heritage. It focuses on making use of the production and detection of x-rays as a general tool. At 'small accelerators', the proton induced x-ray emission (PIXE), especially when combined with Rutherford backscattering spectroscopy (RBS), has been developed to a very versatile and powerful technique for near-surface investigations. It is well complemented by larger facilities, synchrotron radiation sources as well as medium energy ion accelerators for high energy PIXE. With the development of small compact electron accelerators, a new generation of mono-energetic high-energy high-intensity x-ray sources will add a very comfortable complement in cultural heritage studies

  16. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F.P., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Garraffo, S. [ITABC, CNR, Via Salaria km 29.300, 00016 Monterotondo, Roma (Italy); Pappalardo, L. [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Rizzo, F. [LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, 95123 Catania (Italy)

    2012-07-15

    The compositional analysis of archeological metals performed with the X-ray Fluorescence technique (XRF) provides information on the ancient technology. One of the most interesting case-study concerns the techniques used by Romans for silvering the surface of coins. Different metallurgical processes have been suggested in previous studies. Recently the investigation has been addressed to the mercury-silvering and to its possible use in the mass-production of coins minted during the late period (after 294 AD). In the present paper the non-destructive investigation of the silvering process used for manufacturing the Roman nummi - the important typology of coin introduced by Diocletian in his monetary reform - is approached by the combined use of the standard X-Ray Fluorescence (XRF) and the low energy micro-X-Ray Fluorescence (LE-{mu}XRF) portable methods. The research was focused on the systematic determination of the mercury presence in a large number of samples and on its correlation with silver in the surface of the coins. 1041 Roman nummi belonging to the Misurata Treasure were analyzed in situ, at the Leptis Magna Museum (Al Khums, Libya). The treasure, composed of about 108 thousand silvered coins, gives the unique opportunity to study the Roman coinage in a wide interval of time (about 40 years in the period 294-333 AD) and in almost all the imperial mints operating in the Roman world. - Highlights: Black-Right-Pointing-Pointer Custom-building of a high energy broad-beam and a low energy micro-beam XRF Black-Right-Pointing-Pointer In situ analysis of the silvering methods in late Roman nummi with plated surfaces Black-Right-Pointing-Pointer The broad-beam XRF was applied for the detection of mercury traces in the coin alloy. Black-Right-Pointing-Pointer The low energy micro-XRF was used to scan the surface patina of the coins. Black-Right-Pointing-Pointer The correlation between mercury and silver at the coin surface was evidenced.

  17. In situ X-ray diffraction studies on the piezoelectric response of PZT thin films

    Energy Technology Data Exchange (ETDEWEB)

    Davydok, A., E-mail: davydok@mpie.de [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Max-Planck-Institut für Eisenforschung, Department Structure and Nano-/Micromechanics of Materials, D-40237 Düsseldorf (Germany); Cornelius, T.W. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Mocuta, C. [SOLEIL Synchrotron, DiffAbs beamline, L' Orme des Merisiers, Saint-Aubin - BP 48, 91192 Gif-sur-Yvette Cedex (France); Lima, E.C. [Universidade Federal do Tocantins, 77500-000 Porto Nacional, TO (Brazil); Araujo, E.B. [Departamento de Fisica e Quimica, Universidade Estadual Paulista, Av. Brasil, 56 Centro, 15385-000 Ilha Solteira, SP (Brazil); Thomas, O. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France)

    2016-03-31

    Piezoelectric properties of randomly oriented self-polarized PbZr{sub 0.50}Ti{sub 0.50}O{sub 3} (PZT) thin films were investigated using in situ synchrotron X-ray diffraction. Possibilities for investigating the piezoelectric effect using micro-sized hard X-ray beams are demonstrated and perspectives for future dynamical measurements on PZT samples with variety of compositions and thicknesses are given. Studies performed on the crystalline [100, 110] directions evidenced piezoelectric anisotropy. The piezoelectric coefficient d{sub 33} was calculated in terms of the lab reference frame (d{sub perp}) and found to be two times larger along the [100] direction than along the [110] direction. The absolute values for the d{sub perp} amount to 120 and 230 pm/V being in good agreement with experimental and theoretical values found in literature for bulk PZT ceramics. - Highlights: • We performed in situ synchrotron X-ray diffraction studies on (PZT) thin films. • We discuss anisotropy of piezo effect in different crystallographic directions. • Perpendicular component Piezo coefficient of thin PZT layer is defined.

  18. Investigation of Pink Tourmalines by X-ray Fluorescent Technique

    International Nuclear Information System (INIS)

    Sangariyavanich, A.; Na Songkhla, S.; Pimjum, S.

    1998-01-01

    X-ray fluorescent technique has been employed in the study of trace elements in six samples of gamma irradiated pink tourmalines, namely, red-pink (rubellite), light-pink, orange-pink, brownish orange-pink, purple red and purple orange-pink. The analysis of their characteristic X-ray indicated the existence of manganese in all samples. Trace amounts of iron, zinc, lead, bismuth or gallium were also investigated in certain samples. Since these elements were not present in red-pink tourmaline, therefore, we believed that manganese is the major cause of pink color in tourmaline while other elements produce various types of pink color

  19. Experimental investigations of the dosimetric features of x-ray radiation used in x-ray diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Prostyakova, M A

    1975-10-01

    For radiation hygiene estimates of the extent of the irradiation of various organs and tissues in roentgenological investigations, the quality and quantity of the primary radiation beam and its behaviour in the irradiated medium are assessed. It is shown that the effective energy of x-rays generated at 50-100 kV and with different radiation field dimensions at different depths in a tissue-equivalent irradiated medium is more or less constant, varying within the range 25 to 32 keV. The constancy of effective x-ray energies in a tissue-equivalent medium enables one to use, for different x-ray tube regimes, constant values of the roentgen-rad conversion factor for soft tissue and bone tissue. The investigations confirm the desirability of using high voltages across the x-ray tube in practical x-ray work.

  20. X-Ray diffraction Investigation of Electrochemically Deposited Copper

    DEFF Research Database (Denmark)

    Pantleon, Karen; Jensen, Jens Dahl; Somers, Marcel A.J.

    2004-01-01

    by the determination of X-ray diffraction (XRD) pole figures and the calculation of the orientation distribution functions. XRD results are discussed in relation to the morphologies of the electrodeposits as investigated with light optical microscopy and correlated with the process parameters during electrodeposition....

  1. In Situ X-ray Diffraction Studies of (De)lithiation Mechanism in Silicon Nanowire Anodes

    KAUST Repository

    Misra, Sumohan; Liu, Nian; Nelson, Johanna; Hong, Seung Sae; Cui, Yi; Toney, Michael F.

    2012-01-01

    -Si product has been observed. In this work, we use an X-ray transparent battery cell to perform in situ synchrotron X-ray diffraction on SiNWs in real time during electrochemical cycling. At deep lithiation voltages the known metastable Li 15Si 4 phase forms

  2. Thermally stimulated investigations on diamond X-Ray detectors

    International Nuclear Information System (INIS)

    Tromson, D.; Bergonzo, P.; Brambilla, A.; Mer, C.; Foulon, F.; Amosov, V.N.

    1999-01-01

    Intrinsic diamond material is increasingly used for the fabrication of radiation detectors. However, the presence of inherent defects has a strong impact on the detector characteristics such as the time dependent stability of the detection signal. In order to draw better insights into this effect, comparative investigations of the X-ray responses with thermally stimulated current (TSC) measurements were carried out on natural diamond detectors. TSC revealed the presence of four peaks or shoulders on natural samples in the 200 to 500 K domain. Three energy levels were identified at about 0.7, 0.71 and 0.95 eV. Time dependent X-ray detector sensitivity was investigated for various initial conditions. The results give evidence of the improvement of the detection properties after having filled traps in the material by X-ray irradiation. The comparison between the X-ray response and the TSC spectra indicate that trapping levels emptied at room temperature appear to significantly affect the performance of radiation detectors. (authors)

  3. In-situ synchrotron X-Ray diffraction investigation of the fast recovery of microstructure during electropulse treatment of heavily cold drawn nanocrystalline Ni-Ti wires

    Czech Academy of Sciences Publication Activity Database

    Malard, B.; Pilch, Jan; Šittner, Petr; Delville, R.; Curfs, C.

    172-174, č. 6 (2011), s. 1243-1248 ISSN 1012-0394 R&D Projects: GA AV ČR(CZ) IAA200100627; GA MŠk(CZ) LA10010 Institutional research plan: CEZ:AV0Z10100520 Keywords : recovery process * electropulse treatment * in-situ analysis * superelasticity Subject RIV: BM - Solid Matter Physics ; Magnetism

  4. Setup for in situ X-ray diffraction studies of thin film growth by magnetron sputtering

    CERN Document Server

    Ellmer, K; Weiss, V; Rossner, H

    2001-01-01

    A novel method is described for the in situ-investigation of nucleation and growth of thin films during magnetron sputtering. Energy dispersive X-ray diffraction with synchrotron light is used for the structural analysis during film growth. An in situ-magnetron sputtering chamber was constructed and installed at a synchrotron radiation beam line with a bending magnet. The white synchrotron light (1-70 keV) passes the sputtering chamber through Kapton windows and hits one of the substrates on a four-fold sample holder. The diffracted beam, observed under a fixed diffraction angle between 3 deg. and 10 deg., is energy analyzed by a high purity Ge-detector. The in situ-EDXRD setup is demonstrated for the growth of tin-doped indium oxide (ITO) films prepared by reactive magnetron sputtering from a metallic target.

  5. Local detection of X-ray spectroscopies with an in-situ Atomic Force Microscope

    International Nuclear Information System (INIS)

    Rodrigues, M S; Dhez, O; Denmat, S Le; Felici, R; Comin, F; Chevrier, J

    2008-01-01

    The in situ combination of Scanning Probe Microscopies with X-ray microbeams adds a variety of new possibilities to the panoply of synchrotron radiation techniques. This paper describes an optics-free Atomic Force Microscope that can be directly installed on most of the synchrotron radiation end-stations for combined X-ray and atomic force microscopy experiments. The instrument can be used for atomic force imaging of the investigated sample or to locally measure the X-ray absorption or diffraction, or it can also be used to mechanically interact with the sample while simultaneously taking spectroscopy or diffraction measurements. The local character of these measurements is intrinsically linked with the use of the Atomic Force Microscope tip. It is the sharp tip that gives the opportunity to measure the photons flux impinging on it, or to locally measure the absorption coefficient or the shape of the diffraction pattern. At the end an estimation of the limits of the various techniques presented is also discussed.

  6. X-ray electron investigation of technetium compounds

    International Nuclear Information System (INIS)

    Gerasimov, V.N.; Kryuchkov, S.V.; Kuzina, A.F.; Kulakov, V.M.; Pirozhkov, S.V.; Spitsyn, V.I.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii)

    1982-01-01

    Investigation results of a number of technetium compounds using the method of X-ray electron spectroscopy have been presented for the first time. Calculation of effective charge for compounds without Tc-Tc bond and cluster complexes with strong Tc-Tc bond is made. Strong interdependence of effective charge and properties of technetium clusters is shown. Binding energies for certain cluster complexes of technetium with halides are given

  7. X-ray investigations in intensive care units

    Energy Technology Data Exchange (ETDEWEB)

    Pokieser, H.

    1981-10-01

    From special care following surgery and from arteficial respiration of polio patients the modern and very special intensive medical care has developed. At the same time the provisional bedside radiology was improved to one branch of clinical radiology with special organisation and methods of investigation. Importance and urgency of radiological information are requiring close cooperation of all medical branches. Functions of these different groups have to be defined. The movable X-ray apparatus of 20 kV output is necessary for every intensive care unit. Hard beam technique for lung X-rays, scattered radiation grids and adequate positioning of the patient are important to get the same high quality pictures than from the radiological department.

  8. X-ray investigations in intensive care units

    International Nuclear Information System (INIS)

    Pokieser, H.

    1981-01-01

    From special care following surgery and from arteficial respiration of polio patients the modern and very special intensive medical care has developed. At the same time the provisional bedside radiology was improved to one branch of clinical radiology with special organisation and methods of investigation. Importance and urgency of radiological information are requiring close cooperation of all medical branches. Functions of these different groups have to be defined. The movable X-ray apparatus of 20 kV output is necessary for every intensive care unit. Hard beam technique for lung X-rays, scattered radiation grids and adequate positioning of the patient are important to get the same high quality pictures than from the radiological department. (orig.) [de

  9. Application of in situ x-ray diffraction techniques in heterogenous catalytic systems

    International Nuclear Information System (INIS)

    Sharifah Bee Abd Hamid

    2002-01-01

    A broad range of techniques is available today for the characterisation of catalysts and the investigation of catalyst reaction mechanisms. However, only a limited number of those are suitable for in situ studies, i.e experiments performed in conditions mimicking or close as possible to real operating conditions. Various commercially and in-house developed in situ X-Ray diffraction (XRD) cells have been used to obtain information on the phase and structure of materials at the initial formation stage, activation methodology, calcination, reduction and carburization. A major advantage of the in situ X-ray cells is that it allows direct observations on the decomposition of precursors leading to various phases in a controlled environment, i.e. controlled temperature and pressure under specified gases. The cells can be operated both at high temperatures and high pressures, equipped with Position Sensitive Detector (PSD), feature which was used to study phase transformation occurring during the activation of various solids. In MoO 3 , XRD results provide detailed information on the hydrogen insertion into its lattice, followed by carburization providing good understanding on the mechanism in the solid transformation leading to the metastable MoC 1 -x phase. For the Bi-SnO x systems, the environmental cell coupled with XRD and PSD allow the design of activation procedure to obtain the active Bi 2 Sn 2 O 7 . The in situ XRD technique reveals crucial information on the initial stage of oxides formations prior to condensation reaction shown in MCM-41 and titania systems. In this presentation, discussions on general achievements and problems relating to the use of in situ XRD techniques as well as of specific examples selected to illustrate the use and potential of in situ XRD are made. It is not intended to be a review of the art but a highlight of the challenges which the catalytic and material scientists face when entering the avenue. (Author)

  10. Compact x-ray microradiograph for in situ imaging of solidification processes: Bringing in situ x-ray micro-imaging from the synchrotron to the laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Rakete, C.; Baumbach, C.; Goldschmidt, A.; Samberg, D.; Schroer, C. G. [Institut fuer Strukturphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Breede, F.; Stenzel, C. [Astrium-Space Transportation, Department: TO 611, Claude-Dornier-Strasse, D-88039 Friedrichshafen (Germany); Zimmermann, G.; Pickmann, C. [ACCESS e.V., Intzestrasse 5, D-52072 Aachen (Germany); Houltz, Y.; Lockowandt, C. [Science Services Division, SSC, Box 4207, SE-17104 Solna (Sweden); Svenonius, O.; Wiklund, P. [Scint-X AB, Torshamnsgatan 35, SE-164 40 Kista (Sweden); Mathiesen, R. H. [Inst. for Fysikk, NTNU, N-7491 Trondheim (Norway)

    2011-10-15

    A laboratory based high resolution x-ray radiograph was developed for the investigation of solidification dynamics in alloys. It is based on a low-power microfocus x-ray tube and is potentially appropriate for x-ray diagnostics in space. The x-ray microscope offers a high spatial resolution down to approximately 5 {mu}m. Dynamic processes can be resolved with a frequency of up to 6 Hz. In reference experiments, the setup was optimized to yield a high contrast for AlCu-alloys. With samples of about 150 {mu}m thickness, high quality image sequences of the solidification process were obtained with high resolution in time and space.

  11. In-situ X-ray diffraction system using sources and detectors at fixed angular positions

    Science.gov (United States)

    Gibson, David M [Voorheesville, NY; Gibson, Walter M [Voorheesville, NY; Huang, Huapeng [Latham, NY

    2007-06-26

    An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

  12. A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

    International Nuclear Information System (INIS)

    Eveno, Myriam; Duran, Adrian; Castaing, Jacques

    2010-01-01

    It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude. (orig.)

  13. A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

    Science.gov (United States)

    Eveno, Myriam; Duran, Adrian; Castaing, Jacques

    2010-09-01

    It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude.

  14. In situ anodization of aluminum surfaces studied by x-ray reflectivity and electrochemical impedance spectroscopy

    International Nuclear Information System (INIS)

    Bertram, F.; Evertsson, J.; Messing, M. E.; Mikkelsen, A.; Lundgren, E.; Zhang, F.; Pan, J.; Carlà, F.; Nilsson, J.-O.

    2014-01-01

    We present results from the anodization of an aluminum single crystal [Al(111)] and an aluminum alloy [Al 6060] studied by in situ x-ray reflectivity, in situ electrochemical impedance spectroscopy and ex situ scanning electron microscopy. For both samples, a linear increase of oxide film thickness with increasing anodization voltage was found. However, the slope is much higher in the single crystal case, and the break-up of the oxide film grown on the alloy occurs at a lower anodization potential than on the single crystal. The reasons for these observations are discussed as are the measured differences observed for x-ray reflectivity and electrochemical impedance spectroscopy.

  15. In Situ Ptychography of Heterogeneous Catalysts using Hard X-Rays

    DEFF Research Database (Denmark)

    Baier, Sina; Damsgaard, Christian Danvad; Scholz, Maria

    2016-01-01

    A new closed cell is presented for in situ X-ray ptychography which allows studies under gas flow and at elevated temperature. In order to gain complementary information by transmission and scanning electron microscopy, the cell makes use of a Protochips E-chipTM which contains a small, thin...... the same sample holder for ex situ electron microscopy before and after the in situ study underlines the unique possibilities available with this combination of electron microscopy and X-ray microscopy on the same sample....

  16. Methodology for studying strain inhomogeneities in polycrystalline thin films during in situ thermal loading using coherent x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Vaxelaire, N; Labat, S; Thomas, O [Aix-Marseille University, IM2NP, FST avenue Escadrille Normandie Niemen, F-13397 Marseille Cedex (France); Proudhon, H; Forest, S [MINES ParisTech, Centre des materiaux, CNRS UMR 7633, BP 87, 91003 Evry Cedex (France); Kirchlechner, C; Keckes, J [Erich Schmid Institute for Material Science, Austrian Academy of Science and Institute of Metal Physics, University of Leoben, Jahnstrasse 12, 8700 Leoben (Austria); Jacques, V; Ravy, S [Synchrotron SOLEIL, L' Orme des merisiers, Saint-Aubin BP 48, 91192 Gif-sur-Yvette Cedex (France)], E-mail: nicolas.vaxelaire@univ-cezanne.fr

    2010-03-15

    Coherent x-ray diffraction is used to investigate the mechanical properties of a single grain within a polycrystalline thin film in situ during a thermal cycle. Both the experimental approach and finite element simulation are described. Coherent diffraction from a single grain has been monitored in situ at different temperatures. This experiment offers unique perspectives for the study of the mechanical properties of nano-objects.

  17. Methodology for studying strain inhomogeneities in polycrystalline thin films during in situ thermal loading using coherent x-ray diffraction

    International Nuclear Information System (INIS)

    Vaxelaire, N; Labat, S; Thomas, O; Proudhon, H; Forest, S; Kirchlechner, C; Keckes, J; Jacques, V; Ravy, S

    2010-01-01

    Coherent x-ray diffraction is used to investigate the mechanical properties of a single grain within a polycrystalline thin film in situ during a thermal cycle. Both the experimental approach and finite element simulation are described. Coherent diffraction from a single grain has been monitored in situ at different temperatures. This experiment offers unique perspectives for the study of the mechanical properties of nano-objects.

  18. First use of portable system coupling X-ray diffraction and X-ray fluorescence for in-situ analysis of prehistoric rock art.

    Science.gov (United States)

    Beck, L; Rousselière, H; Castaing, J; Duran, A; Lebon, M; Moignard, B; Plassard, F

    2014-11-01

    Study of prehistoric art is playing a major role in the knowledge of human evolution. Many scientific methods are involved in this investigation including chemical analysis of pigments present on artefacts or applied to cave walls. In the past decades, the characterization of coloured materials was carried on by taking small samples. This procedure had two main disadvantages: slight but existing damage of the paintings and limitation of the number of samples. Thanks to the advanced development of portable systems, in-situ analysis of pigment in cave can be now undertaken without fear for this fragile Cultural Heritage. For the first time, a portable system combining XRD and XRF was used in an underground and archaeological environment for prehistoric rock art studies. In-situ non-destructive analysis of black prehistoric drawings and determination of their composition and crystalline structure were successfully carried out. Original results on pigments used 13,000 years ago in the cave of Rouffignac (France) were obtained showing the use of two main manganese oxides: pyrolusite and romanechite. The capabilities of the portable XRD-XRF system have been demonstrated for the characterization of pigments as well as for the analysis of rock in a cave environment. This first in-situ experiment combining X-ray diffraction and X-ray fluorescence open up new horizons and can fundamentally change our approach of rock art studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. In situ measurements of X-ray peak profile asymmetry from individual grains

    DEFF Research Database (Denmark)

    Wejdemann, Christian; Lienert, U.; Pantleon, Wolfgang

    2010-01-01

    Two copper samples, pre-deformed in tension to 5% plastic strain, are subjected to an in situ tensile deformation of 1% plastic strain while X-ray peak profiles from individual bulk grains are obtained. One sample is oriented with the in situ tensile axis parallel to the pre-deformation axis...

  20. X-ray topographic method of investigation of phase objects

    International Nuclear Information System (INIS)

    Levonyan, L.V.

    2001-01-01

    The intensity distribution of the monochromatized synchrotron radiation transmitting through the phase object and crystal-analyzer in Laue geometry is considered. It is shown that the local angular deviation of the incident radiation caused by the refraction on structural inhomogeneities of the object under investigation is directly transferred to the X-ray topographic image. In the absence of the phase object the latter consists of parallel straight fringes with a slowly decreasing period. The presence of the phase object changes the shape and period of fringes. The influence of the spatial and temporal coherence on the image is discussed. 5 refs

  1. A study of the reactivity of elemental Cr/Se/Te thin multilayers using X-ray reflectometry, in situ X-ray diffraction and X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Behrens, Malte; Tomforde, Jan; May, Enno; Kiebach, Ragnar; Bensch, Wolfgang; Haeussler, Dietrich; Jaeger, Wolfgang

    2006-01-01

    The reactivity of [Cr/Se/Te] multilayers under annealing was investigated using X-ray reflectometry, in situ X-ray diffraction, X-ray absorption fine structure (XAFS) measurements and transmission electron microscopy. For all samples, interdiffusion was complete at temperatures between 100 and 300 deg. C, depending on the repeating tri-layer thickness. A crystalline phase nucleated approximately 20 deg. C above the temperature where interdiffusion was finished. The first crystalline phase in a binary Cr/Te sample was layered CrTe 3 nucleating at 230 deg. C. In ternary samples (Se:Te=0.6-1.2), the low-temperature nucleation of such a layered CrQ 3 (Q=Se, Te) phase is suppressed and instead the phase Cr 2 Q 3 nucleates first. Interestingly, this phase decomposes around 500 deg. C into layered CrQ 3 . In contrast, binary Cr/Se samples form stable amorphous alloys after interdiffusion and Cr 3 Se 4 nucleates around 500 deg. C as the only crystalline phase. Evaluation of the XAFS data of annealed samples yield Se-Cr distances of 2.568(1) and 2.552(1) A for Cr 2 Q 3 and CrQ 3 , respectively. In the latter sample, higher coordination shells around Se are seen accounting for the Se-Te contacts in the structure. - Graphical abstract: The first step of the reaction of elemental Cr/Te/Se-multilayers is the interdiffusion of the elements as evidenced by the decay of the modulation peaks in the low-angle region of the X-ray diffraction patterns. The subsequent growth of Bragg peaks at higher scattering angles indicates crystallization of chromium chalcogenide Cr 2 Te 3- x Se x

  2. In-situ measurement of the strain relaxation of GaN nanograins during X-ray irradiation

    International Nuclear Information System (INIS)

    Choe, Hyeokmin; Lee, Sanghwa; Sohn, Yuri; Kim, Chinkyo

    2008-01-01

    GaN nanograins were grown on a c-plane sapphire substrate and their strain relaxation due to X-ray irradiation was investigated in-situ by utilizing synchrotron xray scattering. The GaN nanograins were constantly exposed to the synchrotron X-ray and θ-2θ scans through the (002) Bragg peak of GaN were repeatedly carried out during the irradiation. The Bragg peak of the compressively strained GaN nanograins gradually shifted toward higher angle, which implies that the GaN nanograins in compressive strain experienced strain relaxation during X-ray irradiation. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. New developments for the investigation of hard X-rays emitted by peeling adhesive tapes.

    Science.gov (United States)

    Krämer, D; Lützenkirchen-Hecht, D; Lühmann, B; Keite-Telgenbüscher, K; Frahm, R

    2013-05-01

    We realized an advanced apparatus for the investigation of emitted X-rays produced by peeling adhesive tape rolls under vacuum conditions. Two stepper motors can unwind and rewind a tape roll, and an additional roller with an optical encoder provides measurement and control of the tape speed. This way reproducible and consecutive experiments are feasible without having to change the tape or break the vacuum. The dependence of the X-ray emission on tape speed, gas pressure, type of adhesive tape, and detector angle has been investigated. The resulting spectra are continuous and span an X-ray energy range of typically 2-60 keV with high intensity. Furthermore, the new apparatus allows the in situ metalization of adhesive tape rolls by a gold sputter source. A significantly increased X-ray emission was observed for adhesive tapes with a metal coating. Thin metal foils have been placed between the tape and the detector, different K- and L-absorption edges could be measured. A considerable enhancement of the emission was achieved under the influence of the magnetic field of an NdFeB permanent magnet.

  4. Use of x-ray fluorescence for in-situ detection of metals

    Science.gov (United States)

    Elam, W. T. E.; Whitlock, Robert R.; Gilfrich, John V.

    1995-01-01

    X-ray fluorescence (XRF) is a well-established, non-destructive method of determining elemental concentrations at ppm levels in complex samples. It can operate in atmosphere with no sample preparation, and provides accuracies of 1% or better under optimum conditions. This report addresses two sets of issues concerning the use of x-ray fluorescence as a sensor technology for the cone penetrometer, for shipboard waste disposal, or for other in-situ, real- time environmental applications. The first issue concerns the applicability of XRF to these applications, and includes investigation of detection limits and matrix effects. We have evaluated the detection limits and quantitative accuracy of a sensor mock-up for metals in soils under conditions expected in the field. In addition, several novel ways of improving the lower limits of detection to reach the drinking water regulatory limits have been explored. The second issue is the engineering involved with constructing a spectrometer within the 1.75 inch diameter of the penetrometer pipe, which is the most rigorous physical constraint. Only small improvements over current state-of-the-art are required. Additional advantages of XRF are that no radioactive sources or hazardous materials are used in the sensor design, and no reagents or any possible sources of ignition are involved.

  5. Two-dimensional in situ metrology of X-ray mirrors using the speckle scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongchang, E-mail: hongchang.wang@diamond.ac.uk; Kashyap, Yogesh; Laundy, David; Sawhney, Kawal [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom)

    2015-06-06

    The two-dimensional slope error of an X-ray mirror has been retrieved by employing the speckle scanning technique, which will be valuable at synchrotron radiation facilities and in astronomical telescopes. In situ metrology overcomes many of the limitations of existing metrology techniques and is capable of exceeding the performance of present-day optics. A novel technique for precisely characterizing an X-ray bimorph mirror and deducing its two-dimensional (2D) slope error map is presented. This technique has also been used to perform fast optimization of a bimorph mirror using the derived 2D piezo response functions. The measured focused beam size was significantly reduced after the optimization, and the slope error map was then verified by using geometrical optics to simulate the focused beam profile. This proposed technique is expected to be valuable for in situ metrology of X-ray mirrors at synchrotron radiation facilities and in astronomical telescopes.

  6. In situ X-ray studies of film cathodes for solid oxide fuel cells

    International Nuclear Information System (INIS)

    Fuoss, Paul; Chang, Kee-Chul; You, Hoydoo

    2013-01-01

    Highlights: •Synchrotron X-rays are used to study in operando the structural and chemical changes of LSM and LSCF film cathodes during half-cell operations. •A-site and B-site cations actively segregate or desegregate on the changes of temperature, pO 2 , and electrochemical potential. •Chemical lattice expansions show that oxygen-cathode interface is the primary source of rate-limiting processes. •The surface and subsurface of the LSM and LSCF films have different oxidation-states due to vacancy concentration changes. •Liquid-phase infiltration and coarsening processes of cathode materials into porous YSZ electrolyte backbone were monitored by USAXS. -- Abstract: Synchrotron-based X-ray techniques have been used to study in situ the structural and chemical changes of film cathodes during half-cell operations. The X-ray techniques used include X-ray reflectivity (XR), total-reflection X-ray fluorescence (TXRF), high-resolution diffraction (HRD), ultra-small angle X-ray scattering (USAXS). The epitaxial thin film model cathodes for XR, TXRF, and HRD measurements are made by pulse laser deposition and porous film cathodes for USAX measurements are made by screen printing technique. The experimental results reviewed here include A-site and B-site segregations, lattice expansion, oxidation-state changes during cell operations and liquid-phase infiltration and coarsening of cathode to electrolyte backbone

  7. Hydride reorientation in Zircaloy-4 examined by in situ synchrotron X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Weekes, H.E. [Department of Materials, Royal School of Mines, Imperial College London, Prince Consort Road, London SW7 2BP (United Kingdom); Jones, N.G. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Lindley, T.C. [Department of Materials, Royal School of Mines, Imperial College London, Prince Consort Road, London SW7 2BP (United Kingdom); Dye, D., E-mail: david.dye@imperial.ac.uk [Department of Materials, Royal School of Mines, Imperial College London, Prince Consort Road, London SW7 2BP (United Kingdom)

    2016-09-15

    The phenomenon of stress-reorientation has been investigated using in situ X-ray diffraction during the thermomechanical cycling of hydrided Zircaloy-4 tensile specimens. Results have shown that loading along a sample’s transverse direction (TD) leads to a greater degree of hydride reorientation when compared to rolling direction (RD)-aligned samples. The elastic lattice micro-strains associated with radially oriented hydrides have been revealed to be greater than those oriented circumferentially, a consequence of strain accommodation. Evidence of hydride redistribution after cycling, to α-Zr grains oriented in a more favourable orientation when under an applied stress, has also been observed and its behaviour has been found to be highly dependent on the loading axis. Finally, thermomechanical loading across multiple cycles has been shown to reduce the difference in terminal solid solubility of hydrogen during dissolution (TSS{sub D,H}) and precipitation (TSS{sub P,H}).

  8. In situ X-ray polymerization: from swollen lamellae to polymer-surfactant complexes.

    Science.gov (United States)

    Agzenai, Yahya; Lindman, Björn; Alfredsson, Viveka; Topgaard, Daniel; Renamayor, Carmen S; Pacios, Isabel E

    2014-01-30

    The influence of the monomer diallyldimethylammonium chloride (D) on the lamellar liquid crystal formed by the anionic surfactant aerosol OT (AOT) and water is investigated, determining the lamellar spacings by SAXS and the quadrupolar splittings by deuterium NMR, as a function of the D or AOT concentrations. The cationic monomer D induces a destabilization of the AOT lamellar structure such that, at a critical concentration higher than 5 wt %, macroscopic phase separation takes place. When the monomer, which is dissolved in the AOT lamellae, is polymerized in situ by X-ray initiation, a new collapsed lamellar phase appears, corresponding to the complexation of the surfactant with the resulting polymer. A theoretical model is employed to analyze the variation of the interactions between the AOT bilayers and the stability of the lamellar structure.

  9. Hazard and efficiency of X-ray diagnostic investigations

    International Nuclear Information System (INIS)

    1984-01-01

    This symposium deals with the hazards and efficiency of biomedical X-ray examinations. The first articles are devoted to the effects of radiation on the human body. Special attention is paid to low dose irradiation. Later on the efficiency and necessity of X-ray examinations are discussed. Reference is made to the diagnosis of colon- and mammacarcinoma. (Auth.)

  10. The adsorption of methanol and water on SAPO-34: in situ and ex situ X-ray diffraction studies

    DEFF Research Database (Denmark)

    Wragg, David S.; Johnsen, Rune; Norby, Poul

    2010-01-01

    The adsorption of methanol on SAPO-34 has been studied using a combination of in situ synchrotron powder X-ray diffraction to follow the process and ex situ high resolution powder diffraction to determine the structure. The unit cell volume of SAPO-34 is found to expand by 0.5% during methanol ad...

  11. In Situ X-ray Diffraction Studies of Cathode Materials in Lithium Batteries

    International Nuclear Information System (INIS)

    Yang, X. Q.; Sun, X.; McBreen, J.; Mukerjee, S.; Gao, Yuan; Yakovleva, M. V.; Xing, X. K.; Daroux, M. L.

    1998-01-01

    system during charge and discharge. The in situ XRD technique was used by Reimers, Li,and Dahn to study the LiCoO 2 , LiNiO 2 , and LiMn 2 O 4 systems. Their results of these studies have demonstrated that in situ XRD can provide more detailed information about the cathode material structural changes during charge-discharge. Conventional x-ray sources were used in these studies and the beryllium windows were used in the in situ cells. Provisions were made to prevent corrosion of the beryllium windows during charge-discharge. For this reason, the in situ cells were often designed quite differently than a real battery. More seriously, the problem of beryllium corrosion restricted the voltage range of the cell below 4.5 V. This limited the use of this technique to study the effects of overcharge which is very important to the thermal stability of the cathodes. Using the plastic lithium battery technology, Amatucci, Tarascon, and Klein constructed an in situ XRD cell, which allows structural investigations at voltages greater than 5 V without any beryllium window corrosion. However, all of these in situ XRD studies using conventional x-ray sources probe the cell in reflection geometry. Therefore, the observed structural changes are predominantly from the top few microns of the electrode coating, which might not be representative for the whole coating during charge-discharge especially when the rate is high

  12. X-ray investigation of Nb/O interfaces

    International Nuclear Information System (INIS)

    Delheusy, Melissa

    2008-01-01

    X-ray free electron lasers and the future International Linear Collider project are based on the performance of niobium superconducting rf cavities for efficient particle acceleration. A remarkable increase of the rf accelerating field is usually achieved by low-temperature annealing of the cavities (T 2 O 5 , NbO 2 and NbO, from the surface to the interface. It reduces progressively upon heating from Nb 2 O 5 to NbO 2 at low temperatures, and to NbO at 300 C. The Nb(110)/NbO(111) interface presents a Nishiyama-Wassermann epitaxial orientation relationship. The depth-distribution of interstitial oxygen has been established indicating that most of the oxygen is located in the direct vicinity of the oxide/niobium interface. No evidence of oxygen depletion below the oxide layer has been observed for the low temperature thermal treatments and surface preparations investigated in this study. (orig.)

  13. Investigation of fetal weight determination in x-ray pelvimetry

    International Nuclear Information System (INIS)

    Chung, M. C.; Tae, S.; Lee, H. K.; Kwon, K. H.; Chung, W. K.; Kim, K. J.

    1981-01-01

    The x-ray pelvimetry is widely used for investigation of fetal weight determination by measuring the size of the fetal head. The report concerns 173 cases with Colcher-Sussman method from January, 1, 1977 to December, 31, 1980 at Soonchunhyang College Hospital. We measured fetal head diameter in both A-P and lateral projections. The brief results are as follows: 1) Among the total 173 cases, vaginal delivery is 88 cases and Cesarean section is 85 cases. 2) The rate of Cesarean section is increased over 35 year of age and 4,000 gm of birth weight. 3) The rate of Cesarean section is increased in abnormal presentation. 4) The relationship between the fetal head diameter and the fetal weight is more significant in A-P puus lateral projection tha A-P only. 5) The average size of the fetal head is 0.8 cm larger in Cesarean section than in vaginal delivery

  14. Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials.

    Science.gov (United States)

    Kulriya, P K; Singh, F; Tripathi, A; Ahuja, R; Kothari, A; Dutt, R N; Mishra, Y K; Kumar, Amit; Avasthi, D K

    2007-11-01

    An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90 MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T=255 K.

  15. Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials

    Science.gov (United States)

    Kulriya, P. K.; Singh, F.; Tripathi, A.; Ahuja, R.; Kothari, A.; Dutt, R. N.; Mishra, Y. K.; Kumar, Amit; Avasthi, D. K.

    2007-11-01

    An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T =255K.

  16. Solution spectroelectrochemical cell for in situ X-ray absorption fine structure

    International Nuclear Information System (INIS)

    Antonio, M.R.; Soderholm, L.

    1995-01-01

    A purpose-built spectroelectrochemical cell for in situ fluorescence XAFS (X-ray Absorption Fine Structure) measurements of bulk solution species during constant-potential electrolysis is described. The cell performance was demonstrated by the collection of europium L 3 -edge XANES (X-ray Absorption Near Edge Structure) throughout the course of electrolysis of an aqueous solution of EuCl 3 ·6H 2 O in 1 M H 2 SO 4 . The europium L 3 -edge resonances reported here for the Eu III and Eu II ions demonstrate that their 2p 3/2 → 5d electronic transition probabilities are not the same

  17. In situ X-ray probing reveals fingerprints of surface platinum oxide.

    Science.gov (United States)

    Friebel, Daniel; Miller, Daniel J; O'Grady, Christopher P; Anniyev, Toyli; Bargar, John; Bergmann, Uwe; Ogasawara, Hirohito; Wikfeldt, Kjartan Thor; Pettersson, Lars G M; Nilsson, Anders

    2011-01-07

    In situ X-ray absorption spectroscopy (XAS) at the Pt L(3) edge is a useful probe for Pt-O interactions at polymer electrolyte membrane fuel cell (PEMFC) cathodes. We show that XAS using the high energy resolution fluorescence detection (HERFD) mode, applied to a well-defined monolayer Pt/Rh(111) sample where the bulk penetrating hard X-rays probe only surface Pt atoms, provides a unique sensitivity to structure and chemical bonding at the Pt-electrolyte interface. Ab initio multiple-scattering calculations using the FEFF code and complementary extended X-ray absorption fine structure (EXAFS) results indicate that the commonly observed large increase of the white-line at high electrochemical potentials on PEMFC cathodes originates from platinum oxide formation, whereas previously proposed chemisorbed oxygen-containing species merely give rise to subtle spectral changes.

  18. In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk,Hans-Rudolf

    2007-06-29

    We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.

  19. In situ microfluidic dialysis for biological small-angle X-ray scattering

    DEFF Research Database (Denmark)

    Skou, Magda; Skou, Soren; Jensen, Thomas Glasdam

    2014-01-01

    Owing to the demand for low sample consumption and automated sample changing capabilities at synchrotron small-angle X-ray (solution) scattering (SAXS) beamlines, X-ray microfluidics is receiving continuously increasing attention. Here, a remote-controlled microfluidic device is presented for sim...... in incidental sample purification. Hence, this versatile microfluidic device enables investigation of experimentally induced structural changes under dynamically controllable sample conditions. (C) 2014 International Union of Crystallography......Owing to the demand for low sample consumption and automated sample changing capabilities at synchrotron small-angle X-ray (solution) scattering (SAXS) beamlines, X-ray microfluidics is receiving continuously increasing attention. Here, a remote-controlled microfluidic device is presented...

  20. Electrochemical cell for in situ x-ray diffraction under ultrapure conditions

    DEFF Research Database (Denmark)

    Koop, T.; Schindler, W.; Kazimirov, A.

    1998-01-01

    within a few seconds. The oxygen level in the electrolyte is reduced by continuous N(2) flow to less than 0.2% compared to that of a fresh electrolyte. This can be done while rotating the cell by 360 degrees about the surface normal. The electrode potential is accurately measured at the position......An electrochemical cell has been developed for in situ x-ray diffraction from a working electrode under clean conditions equivalent to ultrahigh vacuum conditions of 5 x 10(-10) mbar. The substrate crystals can be prepared ex situ and transferred into the cell under protection of ultrapure water...... of the crystal using a Luggin capillary and a standard reference electrode. We demonstrate the performance of our cell by in situ synchrotron x-ray diffraction measurements on ultrathin Co layers electrodeposited on Cu(001) in an aqueous H(2)SO(4)/CoSO(4) solution. (C) 1998 American Institute of Physics....

  1. Investigation of the human spleen by X-ray microanalysis

    International Nuclear Information System (INIS)

    Kopani, M.; Jakubovsky, J.; Polak, S.

    2001-01-01

    Qualitative and quantitative topographic analysis using X-ray fluorescence (XRF), X-ray powder diffraction (XRD) and scanning electron microscopy was performed in tissue samples of rat and human spleens. The presence of silico-aluminium and silico-calcareous particles of various sizes could be seen. The presence of the inorganic substances mentioned in the human red pulp cords is assumed to be a consequence of the purifying function of the spleen. (Authors)

  2. Investigation on diagnostic techniques of X-ray radiation characteristic from slit target

    International Nuclear Information System (INIS)

    Cheng Jinxiu; Miao Wenyong; Sun Kexu; Wang Hongbin; Cao Leifeng; Yang Jiamin; Chen Zhenglin

    2001-01-01

    On the Xingguang-II facility, X-ray transport process in a cavity target was simulated in a long cylindrical cavity with slits. High temporally and spatially resolved Microchannel Plate (MCP) gated X-ray picosecond frame camera and soft X-ray steak camera were used to investigate the temporal and spatial distribution of the soft X-ray emitted from the cavity wall through the slit. X-ray transport velocity, X-ray emission time and amount of intensity decay was obtained. X-ray CCD pinhole transmission grating spectrometer was used to investigate the spectrum change of the emitted X-ray versus its location. The change characteristic of the spectrum of X-ray absorbed and emitted again and again in transport was obtained. X-ray diodes and Dante spectrometer were used to measure X-ray flux and radiation temperature in the slit, the source and the transport end, respectively. The typical results in the experiment were given. A brief and essential analysis and discussion were made

  3. In situ surface/interface x-ray diffractometer for oxide molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H.; Freeland, J. W.; Hong, Hawoong, E-mail: hhong@aps.anl.gov [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Tung, I. C. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Chang, S.-H.; Bhattacharya, A.; Fong, D. D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2016-01-15

    In situ studies of oxide molecular beam epitaxy by synchrotron x-ray scattering has been made possible by upgrading an existing UHV/molecular beam epitaxy (MBE) six-circle diffractometer system. For oxide MBE growth, pure ozone delivery to the chamber has been made available, and several new deposition sources have been made available on a new 12 in. CF (ConFlat, a registered trademark of Varian, Inc.) flange. X-ray diffraction has been used as a major probe for film growth and structures for the system. In the original design, electron diffraction was intended for the secondary diagnostics available without the necessity of the x-ray and located at separate positions. Deposition of films was made possible at the two diagnostic positions. And, the aiming of the evaporation sources is fixed to the point between two locations. Ozone can be supplied through two separate nozzles for each location. Also two separate thickness monitors are installed. Additional features of the equipment are also presented together with the data taken during typical oxide film growth to illustrate the depth of information available via in situ x-ray techniques.

  4. In situ surface/interface x-ray diffractometer for oxide molecular beam epitaxy

    International Nuclear Information System (INIS)

    Lee, J. H.; Freeland, J. W.; Hong, Hawoong; Tung, I. C.; Chang, S.-H.; Bhattacharya, A.; Fong, D. D.

    2016-01-01

    In situ studies of oxide molecular beam epitaxy by synchrotron x-ray scattering has been made possible by upgrading an existing UHV/molecular beam epitaxy (MBE) six-circle diffractometer system. For oxide MBE growth, pure ozone delivery to the chamber has been made available, and several new deposition sources have been made available on a new 12 in. CF (ConFlat, a registered trademark of Varian, Inc.) flange. X-ray diffraction has been used as a major probe for film growth and structures for the system. In the original design, electron diffraction was intended for the secondary diagnostics available without the necessity of the x-ray and located at separate positions. Deposition of films was made possible at the two diagnostic positions. And, the aiming of the evaporation sources is fixed to the point between two locations. Ozone can be supplied through two separate nozzles for each location. Also two separate thickness monitors are installed. Additional features of the equipment are also presented together with the data taken during typical oxide film growth to illustrate the depth of information available via in situ x-ray techniques

  5. In situ synchrotron X-ray studies during metal-organic chemical vapor deposition of semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Carol [Northern Illinois Univ., DeKalb, IL (United States); Argonne National Lab., Argonne, IL (United States); Highland, Matthew J.; Perret, Edith; Fuoss, Paul H.; Streiffer, Stephen K.; Stephenson, G. Brian [Argonne National Lab., Argonne, IL (United States); Richard, Marie-Ingrid [Universite Paul Cezanne Aix-Marseille, Marseille (France)

    2012-07-01

    In-situ, time-resolved techniques provide valuable insight into the complex interplay of surface structural and chemical evolution occurring during materials synthesis and processing of semiconductors. Our approach is to observe the evolution of surface structure and morphology at the atomic scale in real-time during metal organic vapor phase deposition (MOCVD) by using grazing incidence x-ray scattering and X-ray fluorescence, coupled with visible light scattering. Our vertical-flow MOCVD chamber is mounted on a 'z-axis' surface diffractometer designed specifically for these studies of the film growth, surface evolution and the interactions within a controlled growth environment. These techniques combine the ability of X-rays to penetrate a complex environment for measurements during growth and processing, with the sensitivity of surface scattering techniques to atomic and nanoscale structure. In this talk, we outline our program and discuss examples from our in-situ and real-time X-ray diffraction and fluorescence studies of InN, GaN, and InGaN growth on GaN(0001).

  6. Cyclic olefin homopolymer-based microfluidics for protein crystallization and in situ X-ray diffraction

    International Nuclear Information System (INIS)

    Emamzadah, Soheila; Petty, Tom J.; De Almeida, Victor; Nishimura, Taisuke; Joly, Jacques; Ferrer, Jean-Luc; Halazonetis, Thanos D.

    2009-01-01

    A cyclic olefin homopolymer-based microfluidics system has been established for protein crystallization and in situ X-ray diffraction. Microfluidics is a promising technology for the rapid identification of protein crystallization conditions. However, most of the existing systems utilize silicone elastomers as the chip material which, despite its many benefits, is highly permeable to water vapour. This limits the time available for protein crystallization to less than a week. Here, the use of a cyclic olefin homopolymer-based microfluidics system for protein crystallization and in situ X-ray diffraction is described. Liquid handling in this system is performed in 2 mm thin transparent cards which contain 500 chambers, each with a volume of 320 nl. Microbatch, vapour-diffusion and free-interface diffusion protocols for protein crystallization were implemented and crystals were obtained of a number of proteins, including chicken lysozyme, bovine trypsin, a human p53 protein containing both the DNA-binding and oligomerization domains bound to DNA and a functionally important domain of Arabidopsis Morpheus’ molecule 1 (MOM1). The latter two polypeptides have not been crystallized previously. For X-ray diffraction analysis, either the cards were opened to allow mounting of the crystals on loops or the crystals were exposed to X-rays in situ. For lysozyme, an entire X-ray diffraction data set at 1.5 Å resolution was collected without removing the crystal from the card. Thus, cyclic olefin homopolymer-based microfluidics systems have the potential to further automate protein crystallization and structural genomics efforts

  7. In situ flash x-ray high-speed computed tomography for the quantitative analysis of highly dynamic processes

    Science.gov (United States)

    Moser, Stefan; Nau, Siegfried; Salk, Manfred; Thoma, Klaus

    2014-02-01

    The in situ investigation of dynamic events, ranging from car crash to ballistics, often is key to the understanding of dynamic material behavior. In many cases the important processes and interactions happen on the scale of milli- to microseconds at speeds of 1000 m s-1 or more. Often, 3D information is necessary to fully capture and analyze all relevant effects. High-speed 3D-visualization techniques are thus required for the in situ analysis. 3D-capable optical high-speed methods often are impaired by luminous effects and dust, while flash x-ray based methods usually deliver only 2D data. In this paper, a novel 3D-capable flash x-ray based method, in situ flash x-ray high-speed computed tomography is presented. The method is capable of producing 3D reconstructions of high-speed processes based on an undersampled dataset consisting of only a few (typically 3 to 6) x-ray projections. The major challenges are identified, discussed and the chosen solution outlined. The application is illustrated with an exemplary application of a 1000 m s-1 high-speed impact event on the scale of microseconds. A quantitative analysis of the in situ measurement of the material fragments with a 3D reconstruction with 1 mm voxel size is presented and the results are discussed. The results show that the HSCT method allows gaining valuable visual and quantitative mechanical information for the understanding and interpretation of high-speed events.

  8. Grain rotation and lattice deformation during photoinduced chemical reactions revealed by in situ X-ray nanodiffraction.

    Science.gov (United States)

    Huang, Zhifeng; Bartels, Matthias; Xu, Rui; Osterhoff, Markus; Kalbfleisch, Sebastian; Sprung, Michael; Suzuki, Akihiro; Takahashi, Yukio; Blanton, Thomas N; Salditt, Tim; Miao, Jianwei

    2015-07-01

    In situ X-ray diffraction (XRD) and transmission electron microscopy (TEM) have been used to investigate many physical science phenomena, ranging from phase transitions, chemical reactions and crystal growth to grain boundary dynamics. A major limitation of in situ XRD and TEM is a compromise that has to be made between spatial and temporal resolution. Here, we report the development of in situ X-ray nanodiffraction to measure high-resolution diffraction patterns from single grains with up to 5 ms temporal resolution. We observed, for the first time, grain rotation and lattice deformation in chemical reactions induced by X-ray photons: Br(-) + hv → Br + e(-) and e(-) + Ag(+) → Ag(0). The grain rotation and lattice deformation associated with the chemical reactions were quantified to be as fast as 3.25 rad s(-1) and as large as 0.5 Å, respectively. The ability to measure high-resolution diffraction patterns from individual grains with a temporal resolution of several milliseconds is expected to find broad applications in materials science, physics, chemistry and nanoscience.

  9. Structural study on Ni nanowires in an anodic alumina membrane by using in situ heating extended x-ray absorption fine structure and x-ray diffraction techniques

    International Nuclear Information System (INIS)

    Cai Quan; Chen Xing; Chen Zhongjun; Wang Wei; Mo Guang; Wu Zhonghua; Zhang Junxi; Zhang Lide; Pan Wei

    2008-01-01

    Polycrystalline Ni nanowires have been prepared by electrochemical deposition in an anodic alumina membrane template with a nanopore size of about 60 nm. In situ heating extended x-ray absorption fine structure and x-ray diffraction techniques are used to probe the atomic structures. The nanowires are identified as being mixtures of nanocrystallites and amorphous phase. The nanocrystallites have the same thermal expansion coefficient, of 1.7 x 10 -5 K -1 , as Ni bulk; however, the amorphous phase has a much larger thermal expansion coefficient of 3.5 x 10 -5 K -1 . Details of the Ni nanowire structures are discussed in this paper

  10. The Oxford-Diamond In Situ Cell for studying chemical reactions using time-resolved X-ray diffraction

    Science.gov (United States)

    Moorhouse, Saul J.; Vranješ, Nenad; Jupe, Andrew; Drakopoulos, Michael; O'Hare, Dermot

    2012-08-01

    A versatile, infrared-heated, chemical reaction cell has been assembled and commissioned for the in situ study of a range of chemical syntheses using time-resolved energy-dispersive X-ray diffraction (EDXRD) on Beamline I12 at the Diamond Light Source. Specialized reactor configurations have been constructed to enable in situ EDXRD investigation of samples under non-ambient conditions. Chemical reactions can be studied using a range of sample vessels such as alumina crucibles, steel hydrothermal autoclaves, and glassy carbon tubes, at temperatures up to 1200 °C.

  11. Investigation of fetal weight determination in X-ray pelvimetry

    Energy Technology Data Exchange (ETDEWEB)

    Chung, M. D.; Tae, S.; Lee, H. K.; Kwon, K. H.; Chung, W. K.; Kim, K. J. [Soon Chung Hyang College Hospital, Chunan (Korea, Republic of)

    1981-06-15

    The X-ray pelvimetry is widely used for investigation of fetal weight determination by measuring the size of the fetal head. The report concerns 173 cases with Colcher-Sussman method from January 1'77 to December 31'80 at Soon Chun Hyang college hospital. We measured fetal head diameter in both A-P and lateral projections. The brief results are as follows: 1)Among the total 173 cases, vaginal delivery is 88 cases and Cesarean section is 85 cases. 2) The rate of Cesarean section is increased over 35 years of age and 4,000 gm of birth weight. 3) The rate of Cesarean section is increased in abnormal presentation. 4) The relationship between the fetal head diameter and the fetal weight is more significant in A-P plus lateral projection than A-P only. 5) The average size of the fetal head is 0.8cm larger in Cesarean section than in vaginal delivery.

  12. Investigation of fetal weight determination in X-ray pelvimetry

    International Nuclear Information System (INIS)

    Chung, M. D.; Tae, S.; Lee, H. K.; Kwon, K. H.; Chung, W. K.; Kim, K. J.

    1981-01-01

    The X-ray pelvimetry is widely used for investigation of fetal weight determination by measuring the size of the fetal head. The report concerns 173 cases with Colcher-Sussman method from January 1'77 to December 31'80 at Soon Chun Hyang college hospital. We measured fetal head diameter in both A-P and lateral projections. The brief results are as follows: 1)Among the total 173 cases, vaginal delivery is 88 cases and Cesarean section is 85 cases. 2) The rate of Cesarean section is increased over 35 years of age and 4,000 gm of birth weight. 3) The rate of Cesarean section is increased in abnormal presentation. 4) The relationship between the fetal head diameter and the fetal weight is more significant in A-P plus lateral projection than A-P only. 5) The average size of the fetal head is 0.8cm larger in Cesarean section than in vaginal delivery

  13. Nanocalorimeter platform for in situ specific heat measurements and x-ray diffraction at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Willa, K. [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Diao, Z. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden; Laboratory of Mathematics, Physics and Electrical Engineering, Halmstad University, P.O. Box 823, SE-301 18 Halmstad, Sweden; Campanini, D. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden; Welp, U. [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Divan, R. [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Hudl, M. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden; Islam, Z. [X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Kwok, W. -K. [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Rydh, A. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden

    2017-12-01

    Recent advances in electronics and nanofabrication have enabled membrane-based nanocalorimetry for measurements of the specific heat of microgram-sized samples. We have integrated a nanocalorimeter platform into a 4.5 T split-pair vertical-field magnet to allow for the simultaneous measurement of the specific heat and x-ray scattering in magnetic fields and at temperatures as low as 4 K. This multi-modal approach empowers researchers to directly correlate scattering experiments with insights from thermodynamic properties including structural, electronic, orbital, and magnetic phase transitions. The use of a nanocalorimeter sample platform enables numerous technical advantages: precise measurement and control of the sample temperature, quantification of beam heating effects, fast and precise positioning of the sample in the x-ray beam, and fast acquisition of x-ray scans over a wide temperature range without the need for time-consuming re-centering and re-alignment. Furthermore, on an YBa2Cu3O7-delta crystal and a copper foil, we demonstrate a novel approach to x-ray absorption spectroscopy by monitoring the change in sample temperature as a function of incident photon energy. Finally, we illustrate the new insights that can be gained from in situ structural and thermodynamic measurements by investigating the superheated state occurring at the first-order magneto-elastic phase transition of Fe2P, a material that is of interest for magnetocaloric applications.

  14. Soft X-ray synchrotron radiation investigations of actinide materials systems utilizing X-ray emission spectroscopy and resonant inelastic X-ray scattering

    International Nuclear Information System (INIS)

    Shuh, D.K.; Butorin, S.M.; Guo, J.-H.; Nordgren, J.

    2004-01-01

    Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies

  15. Reduction of variable-truncation artifacts from beam occlusion during in situ x-ray tomography

    DEFF Research Database (Denmark)

    Borg, Leise; Jørgensen, Jakob Sauer; Frikel, Jürgen

    2017-01-01

    Many in situ x-ray tomography studies require experimental rigs which may partially occlude the beam and cause parts of the projection data to be missing. In a study of fluid flow in porous chalk using a percolation cell with four metal bars drastic streak artifacts arise in the filtered...... and artifact-reduction methods are designed in context of FBP reconstruction motivated by computational efficiency practical for large, real synchrotron data. While a specific variable-truncation case is considered, the proposed methods can be applied to general data cut-offs arising in different in situ x-ray...... backprojection (FBP) reconstruction at certain orientations. Projections with non-trivial variable truncation caused by the metal bars are the source of these variable-truncation artifacts. To understand the artifacts a mathematical model of variable-truncation data as a function of metal bar radius and distance...

  16. In situ X-ray powder diffraction, synthesis, and magnetic properties of InVO 3

    Science.gov (United States)

    Lundgren, Rylan J.; Cranswick, Lachlan M. D.; Bieringer, Mario

    2006-12-01

    We report the first synthesis and high-temperature in situ X-ray diffraction study of InVO 3. Polycrystalline InVO 3 has been prepared via reduction of InVO 4 using a carbon monoxide/carbon dioxide buffer gas. InVO 3 crystallizes in the bixbyite structure in space group Ia-3 (206) with a=9.80636(31) Å with In 3+/V 3+ disorder on the (8 b) and (24 d) cation sites. In situ powder X-ray diffraction experiments and thermal gravimetric analysis in a CO/CO 2 buffer gas revealed the existence of the metastable phase InVO 3. Bulk samples with 98.5(2)% purity were prepared using low-temperature reduction methods. The preparative methods limited the crystallinity of this new phase to approximately 225(50) Å. Magnetic susceptibility and neutron diffraction experiments suggest a spin-glass ground state for InVO 3.

  17. Chromosome translocations in chinese medical X-ray workers analyzed by fluorescence in situ hybridization

    International Nuclear Information System (INIS)

    Sun Yuanming; Li Jin; Wang Qin; Tang Weisheng; Wang Zhiquan

    2002-01-01

    Objective: To study long-term radiation effect in occupational workers exposed to low dose X-rays using the method of fluorescence in situ hybridization (FISH). Method: Chromosome translocations of 25 medical X-ray workers were analyzed by FISH with chromosome No. 4 and No. 7 probes according to PAINT (The Protocol for Aberration Identification and Nomenclature Terminology) system. Results: The frequency of genome translocation in X-ray workers was (13.14 ± 1.23)/1000 cells. The rate of complete and incomplete translocation was 1:1.7. According to the calendar year of entry before/after the year of 1965 as the border, the data showed that the incomplete translocation of the after 1965 group was obviously higher than those of the controls (P < 0.01 and P < 0.05, respectively). Conclusion: The chromosome translocation in early Chinese medical X-ray workers is mainly the incomplete one, the frequency of translocation does not dependent on chromosomal DNA content, and incomplete and complete ones increase along with prolongation of working years in their position

  18. Fusion bonding of Si wafers investigated by x ray diffraction

    DEFF Research Database (Denmark)

    Weichel, Steen; Grey, Francois; Rasmussen, Kurt

    2000-01-01

    The interface structure of bonded Si(001) wafers with twist angle 6.5 degrees is studied as a function of annealing temperature. An ordered structure is observed in x-ray diffraction by monitoring a satellite reflection due to the periodic modulation near the interface, which results from...

  19. Structural Investigations of Nanowires Using X-Ray Diffraction

    DEFF Research Database (Denmark)

    Stankevic, Tomas

    Advancements in growth of the nanowire-based devices opened another dimension of possible structures and material combinations, which nd their applications in a wide variety of elds, including everyday life. Characterization of such devices brings its own challenges and here we show that X-rays oer...

  20. Scanning small angle X-ray scattering investigations of bone

    International Nuclear Information System (INIS)

    Rinnerthaler, S.

    1998-06-01

    An important characteristic of bone is its strength, which is determined by bone mass, architecture and material quality. From a physical point of view bone is a composite material consisting of an organic matrix (collagen) and of inlets of mineral crystals (hydroxyapatite). These components build up a hierarchical, heterogeneous structure. The size of the mineral crystals lies in the nano-meter range and can be investigated by positionsensitive Small-Angle X-ray Scattering (Scanning-SAXS) in a non-destructive way. The average thickness, the degree and direction of the predominant orientation, as well as some information about shape and arrangement of the mineral crystals were determined in bones of humans, mice, and baboons by Scanning-SAXS with respect to age, bone diseases (osteogenesis imperfecta, pycnodysostosis) or medical treatments (fluoride or alendronate) of osteoporosis. The crystal thickness and the degree of orientation is much smaller in young individuals than in adults and the predominant orientation of the mineral crystals is different in a mixture of bone and mineralized cartilage compared to bone. Further, because position-resolved measurements are now possible, results from Scanning-SAXS measurements could be compared with the results of other position resolved methods. Due to this new feature it was possible, for the first time, to correlate directly 'mottled' bone visible in back-scattered electron imaging with small η-parameters evaluated from SAXS-patterns and the course of the collagen fibers with the predominant orientation of the mineral crystals. Scanning-SAXS proved to be a powerful tool to characterize bone nano-structure. (author)

  1. In-situ X-ray Nanocharacterization of Defect Kinetics in Chalcogenide Solar Cell Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bertoni, Mariana [Arizona State Univ., Tempe, AZ (United States); Lai, Barry [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Masser, Jorg [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Buonassisi, Tonio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2016-09-21

    For decades the optimization of polycrystalline absorbers has been done using an Edisonian approach, where trial and error and complex design of experiments in large parameter spaces have driven efficiencies to the record values we see today – CIGS at 22.5%, 22.1% for CdTe, 21.3% for high purity multi-crystalline silicon. Appropriate growth parameters are critical to ensure good quality crystals with low concentration of structural defects - low dislocation density and large grain sizes. However, to bridge the gap between the efficiencies today and the fundamental Shockley-Queisser limit for these materials a much more fundamental understanding of the role and interaction between composition, structure, defect density and electrical properties is required. In recent years multiple novel characterization techniques have shown the potential that nanoscale characterization can have in deciphering the composition of grain boundaries in materials like CIGS and CdTe. However, high resolution has come at the cost of small sampling areas and number of specimens, making it extremely difficult to draw conclusions based on the characteristic small sampling sizes. The missing links thus far have been: (1) the lack of statistical meaningfulness of the nanosclae studies and (2) the direct correlation of compositional variations to electrical performance with nanoscale resolution. In this work we present the use of synchrotron-based nano-X-ray fluorescence microscopy (nano-XRF), x-ray absorption nanospectroscopy (nano-XAS) coupled with nano-x-ray beam induced current (nano-XBIC) as ideal tools for investigating elemental, chemical and electrical properties of large areas of solar cell materials at the sub-micron scale with very high sensitivity. We show how the technique can provide statistical valuable information regarding the elemental segregation in CIGS and the direct correlation to current collection. For example, we demonstrate that Cu and Ga (and with that, CGI and GGI

  2. Investigation of the Microstructure Evolution in a Fe-17Mn-1.5Al-0.3C Steel via In Situ Synchrotron X-ray Diffraction during a Tensile Test.

    Science.gov (United States)

    Ma, Yan; Song, Wenwen; Bleck, Wolfgang

    2017-09-25

    The quantitative characterization of the microstructure evolution in high-Mn steel during deformation is of great importance to understanding its strain-hardening behavior. In the current study, in situ high-energy synchrotron X-ray diffraction was employed to characterize the microstructure evolution in a Fe-17Mn-1.5Al-0.3C steel during a tensile test. The microstructure at different engineering strain levels-in terms of ε-martensite and α'-martensite volume fractions, the stacking fault probability, and the twin fault probability-was analyzed by the Rietveld refinement method. The Fe-17Mn-1.5Al-0.3C steel exhibits a high ultimate tensile strength with a superior uniform elongation and a high strain-hardening rate. The remaining high strain-hardening rate at the strain level about 0.025 to 0.35 results from ε-martensite dominant transformation-induced-plasticity (TRIP) effect. The increase in the strain-hardening rate at the strain level around 0.35 to 0.43 is attributed to the synergetic α'-martensite dominant TRIP and twinning-induced-plasticity (TWIP) effects. An evaluation of the stacking fault energy (SFE) of the Fe-17Mn-1.5Al-0.3C steel by the synchrotron measurements shows good agreement with the thermodynamic calculation of the SFE.

  3. In situ alkali-silica reaction observed by x-ray microscopy

    International Nuclear Information System (INIS)

    Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.; Meyer-Ilse, W.

    1997-01-01

    In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques available for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction

  4. In situ alkali-silica reaction observed by x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kurtis, K.E.; Monteiro, P.J.M. [Univ. of California, Berkeley, CA (United States); Brown, J.T.; Meyer-Ilse, W. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques available for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.

  5. X-ray and Moessbauer investigations of isotropic barium ferrites

    International Nuclear Information System (INIS)

    Kirichok, P.P.; Pashchenko, V.A.; Dem'yaniv, T.O.; Ryabova, G.N.; Lisovskij, A.M.

    1984-01-01

    Using the methods of X-ray and γ-resonance spectroscopy the crystal chemical and magnetic structure of isotropic barium hexaferrites is studied. compacting pressure the lattice parameter c of ferrite of the BaOx5.7Fe 2 O 3 is decreased and the diffraction line width on its X-ray p attern is increased. Due to increasing the isoststical compacting pressure quadrupole splitting of the γ-resonance absorption spectrum of 57 Fe nuclei in tetrahedral positions 4f 1 and in positions 2a decreases. The sintering temperature growth leads to increasing the lattice parameter c and diffraction line widths and decreasing the effeutive field values and isomeric s hifts on 57 Fe nuclei. Isostatical compacting pressure does not affect the electron configuration of iron ions

  6. Calcified-tissue investigations using synchrotron x-ray microscopy

    International Nuclear Information System (INIS)

    Jones, K.W.; Spanne, P.; Schidlovsky, G.; Dejun, X.; Bockman, R.S.; Hammond, P.B.; Bornschein, R.L.; Hoeltzel, D.A.

    1990-10-01

    Synchrotron x-ray microscopy (SXRM) in both emission and absorption modes has been used to examine elemental distributions in specimens of rat tibia, human deciduous teeth, and an orthopedic implant phantom. The work was performed with a spatial resolution of 8 μm for the emission work and 25 μm for the absorption work. The results illustrate the usefulness of SXRM for measurements of different types of calcified tissue. 3 figs

  7. Instrument for x-ray absorption spectroscopy with in situ electrical control characterizations

    International Nuclear Information System (INIS)

    Huang, Chun-Chao; Chang, Shu-Jui; Yang, Chao-Yao; Tseng, Yuan-Chieh; Chou, Hsiung

    2013-01-01

    We report a synchrotron-based setup capable of performing x-ray absorption spectroscopy and x-ray magnetic circular dichroism with simultaneous electrical control characterizations. The setup can enable research concerning electrical transport, element- and orbital-selective magnetization with an in situ fashion. It is a unique approach to the real-time change of spin-polarized electronic state of a material/device exhibiting magneto-electric responses. The performance of the setup was tested by probing the spin-polarized states of cobalt and oxygen of Zn 1-x Co x O dilute magnetic semiconductor under applied voltages, both at low (∼20 K) and room temperatures, and signal variations upon the change of applied voltage were clearly detected

  8. In Situ X-ray Diffraction Studies of (De)lithiation Mechanism in Silicon Nanowire Anodes

    KAUST Repository

    Misra, Sumohan

    2012-06-26

    Figure Persented: Silicon is a promising anode material for Li-ion batteries due to its high theoretical specific capacity. From previous work, silicon nanowires (SiNWs) are known to undergo amorphorization during lithiation, and no crystalline Li-Si product has been observed. In this work, we use an X-ray transparent battery cell to perform in situ synchrotron X-ray diffraction on SiNWs in real time during electrochemical cycling. At deep lithiation voltages the known metastable Li 15Si 4 phase forms, and we show that avoiding the formation of this phase, by modifying the SiNW growth temperature, improves the cycling performance of SiNW anodes. Our results provide insight on the (de)lithiation mechanism and a correlation between phase evolution and electrochemical performance for SiNW anodes. © 2012 American Chemical Society.

  9. Instrumentation for in situ flow electrochemical Scanning Transmission X-ray Microscopy (STXM)

    Science.gov (United States)

    Prabu, Vinod; Obst, Martin; Hosseinkhannazer, Hooman; Reynolds, Matthew; Rosendahl, Scott; Wang, Jian; Hitchcock, Adam P.

    2018-06-01

    We report the design and performance of a 3-electrode device for real time in situ scanning transmission X-ray microscopy studies of electrochemical processes under both static (sealed, non-flow) conditions and with a continuous flow of electrolytes. The device was made using a combination of silicon microfabrication and 3D printing technologies. The performance is illustrated by results of a study of copper deposition and stripping at a gold working electrode. X-ray absorption spectromicroscopy at the Cu 2p edge was used to follow the evolution as a function of potential and time of the spatial distributions of Cu(0) and Cu(i) species electro-deposited from an aqueous solution of copper sulphate. The results are interpreted in terms of competing mechanisms for the reduction of Cu(ii).

  10. X-ray tomography investigations on pebble bed structures

    International Nuclear Information System (INIS)

    Reimann, J.; Rolli, R.; Pieritz, R.A.; Ferrero, C.; Di Michiel, M.

    2007-01-01

    Granular materials (pebbles) are used in present ceramic breeder blankets both for the ceramic breeder material and beryllium. The thermal-mechanical behaviour of these pebble beds strongly depends on the arrangement of the pebbles in the bed, their contacts and contact surfaces with other pebbles and with walls. The influence of these quantities is most pronounced for beryllium pebble beds because of the large thermal conductivity ratio of beryllium to helium gas atmosphere. At present, the data base for the pebble bed thermal conductivity (k) and heat transfer coefficient (h) is quite limited for compressed beds and significant discrepancies exist in respect to h. The detailed knowledge of the pebble bed topology is, therefore, essential to better understand the heat transfer mechanisms. In the present work, results from detailed X-ray tomography investigations are reported on pebble topology in i) the pebble bed bulk (which is relevant for k), and ii) the region close to walls with thicknesses of several pebble diameters (relevant for h). At Forschungszentrum Karlsruhe, pebble beds consisting of aluminium spheres with diameters of 2.3 and 5 mm, respectively, (simulating the blanket relevant 1 mm beryllium pebbles), were uniaxially compressed at different pressure levels. High resolution three-dimensional microtomography (MT) experiments were subsequently performed at the European Synchrotron Radiation Facility, Grenoble. Radial and axial void fraction distributions were found to be oscillatory next to the walls and non-oscillatory in the bulk. For non-compressed pebble beds, the bulk void fraction is fairly constant; for compressed beds, a gradient exists along the compression axis. In the bulk, the angular distribution of pebble contacts was found to be fairly constant, indicating that no regular packing structure is induced. In the wall region, the pebble layer touching the wall is composed of zones with hexagonal structures as shown clearly by MT images. This

  11. X-ray investigation of fatigued nickel monocrystals by an analysis of diffraction line profiles

    International Nuclear Information System (INIS)

    Schmidt, G.K.

    1988-01-01

    Using a statistics of the inhomogeneous plastic deformation of a fatigued FCC monocrystal it may be possible to analyse the intensity distributions of the X-ray reflections of this crystal with regard to the fatigue phenomena. The results of an X-ray investigation of a fatigued nickel monocrystal are desribed. 3 refs.; 1 figure; 1 table

  12. Thermal expansion and phase transformations of nitrogen-expanded austenite studied with in situ synchrotron X-ray diffraction

    DEFF Research Database (Denmark)

    Brink, Bastian; Ståhl, Kenny; Christiansen, Thomas Lundin

    2014-01-01

    Nitrogen-expanded austenite, _N, with high and low nitrogen contents was produced from AISI 316 grade stainless steel powder by gaseous nitriding in ammonia/hydrogen gas mixtures. In situ synchrotron X-ray diffraction was applied to investigate the thermal expansion and thermal stability...... as a fitting parameter. The stacking fault density is constant for temperatures up to 680 K, whereafter it decreases to nil. Surprisingly, a transition phase with composition M4N (M = Fe, Cr, Ni, Mo) appears for temperatures above 770 K. The linear coefficient of thermal expansion depends on the nitrogen...

  13. In situ x-ray reflectivity and grazing incidence x-ray diffraction study of L 1{sub 0} ordering in {sup 57}Fe/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Raghavendra Reddy, V; Gupta, Ajay; Gome, Anil [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore-452 017 (India); Leitenberger, Wolfram [Institute of Physics, University of Potsdam, 14469 Potsdam (Germany); Pietsch, U [Physics Department, University of Siegen, D-57068 Siegen (Germany)], E-mail: vrreddy@csr.ernet.in, E-mail: varimalla@yahoo.com

    2009-05-06

    In situ high temperature x-ray reflectivity and grazing incidence x-ray diffraction measurements in the energy dispersive mode are used to study the ordered face-centered tetragonal (fct) L 1{sub 0} phase formation in [Fe(19 A)/Pt(25 A)]{sub x 10} multilayers prepared by ion beam sputtering. With the in situ x-ray measurements it is observed that (i) the multilayer structure first transforms to a disordered FePt and subsequently to an ordered fct L 1{sub 0} phase, (ii) the ordered fct L 1{sub 0} FePt peaks start to appear at 320 deg. C annealing, (iii) the activation energy of the interdiffusion is 0.8 eV and (iv) ordered fct FePt grains have preferential out-of-plane texture. The magneto-optical Kerr effect and conversion electron Moessbauer spectroscopies are used to study the magnetic properties of the as-deposited and 400 deg. C annealed multilayers. The magnetic data for the 400 {sup 0}C annealed sample indicate that the magnetization is at an angle of {approx}50 deg. from the plane of the film.

  14. In Situ Soft X-ray Spectromicroscopy of Early Tricalcium Silicate Hydration

    Directory of Open Access Journals (Sweden)

    Sungchul Bae

    2016-12-01

    Full Text Available The understanding and control of early hydration of tricalcium silicate (C3S is of great importance to cement science and concrete technology. However, traditional characterization methods are incapable of providing morphological and spectroscopic information about in situ hydration at the nanoscale. Using soft X-ray spectromicroscopy, we report the changes in morphology and molecular structure of C3S at an early stage of hydration. In situ C3S hydration in a wet cell, beginning with induction (~1 h and acceleration (~4 h periods of up to ~8 h, was studied and compared with ex situ measurements in the deceleration period after 15 h of curing. Analysis of the near-edge X-ray absorption fine structure showed that the Ca binding energy and energy splitting of C3S changed rapidly in the early age of hydration and exhibited values similar to calcium silicate hydrate (C–S–H. The formation of C–S–H nanoseeds in the C3S solution and the development of a fibrillar C–S–H morphology on the C3S surface were visualized. Following this, silicate polymerization accompanied by C–S–H precipitation produced chemical shifts in the peaks of the main Si K edge and in multiple scattering. However, the silicate polymerization process did not significantly affect the Ca binding energy of C–S–H.

  15. Fabrication and testing of an electrochemical microcell for in situ soft X-ray microspectroscopy measurements

    Science.gov (United States)

    Gianoncelli, A.; Kaulich, B.; Kiskinova, M.; Mele, C.; Prasciolu, M.; Sgura, I.; Bozzini, B.

    2013-03-01

    In this paper we report on the fabrication and testing of a novel concept of electrochemical microcell for in-situ soft X-ray microspectroscopy in transmission. The microcell, fabricated by electron-beam lithography, implements an improved electrode design, with optimal current density distribution and minimised ohmic drop, allowing the same three-electrode electrochemical control achievable with traditional cells. Moreover standard electroanalytical measurements, such as cyclic voltammetry, can be routinely performed. As far as the electrolyte is concerned, we selected a room-temperature ionic-liquid. Some of the materials belonging to this class, in addition to a broad range of outstanding electrochemical properties, feature two highlights that are crucial for in situ, soft X-ray transmission work: spinnability, enabling accurate thickness control, and stability to UHV, allowing operation of an open cell in the analysis chamber vacuum (10-6 mbar). The cell can, of course, be used also with non-vacuum stable electrolytes in the sealed version developed in previous work in our group. In this study, the microcell designed, fabricated and tested in situ by applying an anodic polarisation to a Au electrode and following the formation of a distribution of corrosion features. This specific material combination presented in this work does not limit the cell concept, that can implement any electrodic material grown by lithography, any liquid electrolyte and any spinnable solid electrolyte.

  16. In-situ x-ray absorption study of copper films in ground water solutions

    International Nuclear Information System (INIS)

    Kvashnina, K.O.; Butorin, S.M.; Modin, A.; Soroka, I.; Marcellini, M.; Nordgren, J.; Guo, J.-H.; Werme, L.

    2007-01-01

    This study illustrates how the damage from copper corrosion can be reduced by modifying the chemistry of the copper surface environment. The surface modification of oxidized copper films induced by chemical reaction with Cl - and HCO 3 - in aqueous solutions was monitored by in situ X-ray absorption spectroscopy. The results show that corrosion of copper can be significantly reduced by adding even a small amount of sodium bicarbonate. The studied copper films corroded quickly in chloride solutions, whereas the same solution containing 1.1 mM HCO 3 - prevented or slowed down the corrosion processes

  17. Application of X-ray fluorescence in investigation of historical monuments

    International Nuclear Information System (INIS)

    Cechak, Tomas; Trojek, Tomas; Musilek, Ladislav; Paulusova, Hana

    2008-01-01

    Full text: Nuclear techniques represent invaluable tools in non-destructive diagnostics applied to archaeological findings and objects of arts, mainly for dating and determining the composition of materials used in the production of artefacts. In this work we present the application of X-ray fluorescence analysis (XRFA). The X-ray fluorescence apparatus built and operated in the Laboratory of Quantitative Methods in Research of Ancient Monuments, constituent part of the Department of Dosimetry and Application of Ionizing Radiation, FNSPE, was used for the purpose of old relics measurements. The X-ray sources (radionuclides) generate the characteristic X-ray photons from the sample. After processing the resulting signal, we obtain information about the chemical composition of the tested sample. These results give data for qualitative and quantitative analysis of samples. XRFA is relatively simple and non-destructive method. Capability of in-situ measurement is one of big advantages of this method. The radionuclide sources of exciting radiation (e.g. 55 Fe enables the excitation of elements with Z up to 23, 238 Pu is used in interval of Z from 20 to 39 etc.) and X-ray tube with Mo anode were used. Narrow collimation of the exciting beam makes it possible to select the measured area of e.g. pigments in old manuscripts. X-ray fluorescence analysis, both in its energy form and in its wave dispersive form, is one of the most widespread methods using ionising radiation to study the elemental composition of materials. It is frequently used for studies of various cultural and historic relicts and objects of art. This work summarizes the author's experience with X-ray fluorescence analysis in investigating historical relicts namely by means of portable spectroscopic devices. Utilization of these methods is demonstrated in the investigation of fresco paintings, metal objects and old manuscripts. The results of these measurements provide the information on the composition of

  18. Thermal expansion behavior study of Co nanowire array with in situ x-ray diffraction and x-ray absorption fine structure techniques

    Science.gov (United States)

    Mo, Guang; Cai, Quan; Jiang, Longsheng; Wang, Wei; Zhang, Kunhao; Cheng, Weidong; Xing, Xueqing; Chen, Zhongjun; Wu, Zhonghua

    2008-10-01

    In situ x-ray diffraction and x-ray absorption fine structure techniques were used to study the structural change of ordered Co nanowire array with temperature. The results show that the Co nanowires are polycrystalline with hexagonal close packed structure without phase change up until 700 °C. A nonlinear thermal expansion behavior has been found and can be well described by a quadratic equation with the first-order thermal expansion coefficient of 4.3×10-6/°C and the second-order thermal expansion coefficient of 5.9×10-9/°C. The mechanism of this nonlinear thermal expansion behavior is discussed.

  19. Combined in situ small and wide angle X-ray scattering studies of TiO2 nano-particle annealing to 1023 K

    DEFF Research Database (Denmark)

    Kehres, Jan; Andreasen, Jens Wenzel; Krebs, Frederik C

    2010-01-01

    Combined in situ small- and wide-angle X-ray scattering (SAXS/WAXS) studies were performed in a recently developed laboratory setup to investigate the dynamical properties of dry oleic acid-capped titanium dioxide nanorods during annealing in an inert gas stream in a temperature interval of 298-1...

  20. The effect of water on the stability of iron oxide and iron carbide nanoparticles in hydrogen and syngas followed by in situ X-ray absorption spectroscopy

    NARCIS (Netherlands)

    Thuene, P.C.; Moodley - Gengan, P.; Scheijen, F.J.E.; Fredriksson, H.O.A.; Lancee, R.J.; Kropf, J.; Miller, J.T.; Niemantsverdriet, J.W.

    2012-01-01

    The effect of water on iron-based nanoparticles under hydrogen and syngas was investigated by in situ X-ray absorption spectroscopy. The iron oxide (¿-Fe2O3) nanoparticles, dispersed as a monolayer on flat silica surfaces, were readily converted into metallic iron in dry hydrogen at 350 °C and into

  1. Investigations of X-ray irradiation of marine fish aboard

    International Nuclear Information System (INIS)

    Karnop, G.; Reinacher, E.; Antonacopoulos, N.; Meyer, V.

    1976-01-01

    Studies on X-ray irradiation of ocean perch, cod and coley (at doses of 50-150 krad) are described. The results show that irradiation within this dose range has no significant effect on the shelf-life of fish stored in ice. Although irradiation positively influenced bacteriological and chemical characteristics (e.g. reduction of total aerobic count, and inhibition of decomposition of N-containing compounds), the organoleptically-limited shelf-life of irradiated specimens was similar to that of non-irradiated specimens. Organoleptic changes in irradiated and in non-irradiated samples differed; this is attributed to the abnormal spoilage flora (mainly radiation-resistant Moraxella spp.) in the irradiated samples. (orig./HP) [de

  2. Shock Melting of Iron Silicide as Determined by In Situ X-ray Diffraction.

    Science.gov (United States)

    Newman, M.; Kraus, R. G.; Wicks, J. K.; Smith, R.; Duffy, T. S.

    2016-12-01

    The equation of state of core alloys at pressures and temperatures near the solid-liquid coexistence curve is important for understanding the dynamics at the inner core boundary of the Earth and super-Earths. Here, we present a series of laser driven shock experiments on textured polycrystalline Fe-15Si. These experiments were conducted at the Omega and Omega EP laser facilities. Particle velocities in the Fe-15Si samples were measured using a line VISAR and were used to infer the thermodynamic state of the shocked samples. In situ x-ray diffraction measurements were used to probe the melting transition and investigate the potential decomposition of Fe-15Si in to hcp and B2 structures. This work examines the kinetic effects of decomposition due to the short time scale of dynamic compression experiments. In addition, the thermodynamic data collected in these experiments adds to a limited body of information regarding the equation of state of Fe-15Si, which is a candidate for the composition in Earth's outer core. Our experimental results show a highly textured solid phase upon shock compression to pressures ranging from 170 to 300 GPa. Below 320 GPa, we observe diffraction peaks consistent with decomposition of the D03 starting material in to an hcp and a cubic (potentially B2) structure. Upon shock compression above 320 GPa, the intense and textured solid diffraction peaks give way to diffuse scattering and loss of texture, consistent with melting along the Hugoniot. When comparing these results to that of pure iron, we can ascertain that addition of 15 wt% silicon increases the equilibrium melting temperature significantly, or that the addition of silicon significantly increases the metastability of the solid phase, relative to the liquid. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  3. A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies

    Energy Technology Data Exchange (ETDEWEB)

    Kroner, Anna B., E-mail: anna.kroner@diamond.ac.uk; Gilbert, Martin; Duller, Graham; Cahill, Leo; Leicester, Peter; Woolliscroft, Richard; Shotton, Elizabeth J. [Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Chilton, Oxfordshire, OX110DE (United Kingdom); Mohammed, Khaled M. H. [UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX110FA (United Kingdom); School of Chemistry, University of Southampton, Southampton, SO17 1BJ (United Kingdom)

    2016-07-27

    A capillary-based sample environment with hot air blower and integrated gas system was developed at Diamond to conduct X-ray absorption spectroscopy (XAS) studies of materials under time-resolved, in situ conditions. The use of a hot air blower, operating in the temperature range of 298-1173 K, allows introduction of other techniques e.g. X-ray diffraction (XRD), Raman spectroscopy for combined techniques studies. The flexibility to use either quartz or Kapton capillaries allows users to perform XAS measurement at energies as low as 5600 eV. To demonstrate performance, time-resolved, in situ XAS results of Rh catalysts during the process of activation (Rh K-edge, Ce L{sub 3}-edge and Cr K-edge) and the study of mixed oxide membrane (La{sub 0.6}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3−δ}) under various partial oxygen pressure conditions are described.

  4. In meso in situ serial X-ray crystallography of soluble and membrane proteins

    International Nuclear Information System (INIS)

    Huang, Chia-Ying; Olieric, Vincent; Ma, Pikyee; Panepucci, Ezequiel; Diederichs, Kay; Wang, Meitian; Caffrey, Martin

    2015-01-01

    A method for performing high-throughput in situ serial X-ray crystallography with soluble and membrane proteins in the lipid cubic phase is described. It works with microgram quantities of protein and lipid (and ligand when present) and is compatible with the most demanding sulfur SAD phasing. The lipid cubic phase (LCP) continues to grow in popularity as a medium in which to generate crystals of membrane (and soluble) proteins for high-resolution X-ray crystallographic structure determination. To date, the PDB includes 227 records attributed to the LCP or in meso method. Among the listings are some of the highest profile membrane proteins, including the β 2 -adrenoreceptor–G s protein complex that figured in the award of the 2012 Nobel Prize in Chemistry to Lefkowitz and Kobilka. The most successful in meso protocol to date uses glass sandwich crystallization plates. Despite their many advantages, glass plates are challenging to harvest crystals from. However, performing in situ X-ray diffraction measurements with these plates is not practical. Here, an alternative approach is described that provides many of the advantages of glass plates and is compatible with high-throughput in situ measurements. The novel in meso in situ serial crystallography (IMISX) method introduced here has been demonstrated with AlgE and PepT (alginate and peptide transporters, respectively) as model integral membrane proteins and with lysozyme as a test soluble protein. Structures were solved by molecular replacement and by experimental phasing using bromine SAD and native sulfur SAD methods to resolutions ranging from 1.8 to 2.8 Å using single-digit microgram quantities of protein. That sulfur SAD phasing worked is testament to the exceptional quality of the IMISX diffraction data. The IMISX method is compatible with readily available, inexpensive materials and equipment, is simple to implement and is compatible with high-throughput in situ serial data collection at macromolecular

  5. In-situ oxidation study of Pd(100) by surface x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Volkan; Franz, Dirk; Stierle, Andreas [AG Grenzflaechen, Universitaet Siegen (Germany); Martin, Natalia; Lundgren, Edvin [Department of Synchrotron Radiation Research, Lund University (Sweden); Mantilla, Miguel [MPI fuer Metallforschung, Stuttgart (Germany)

    2011-07-01

    The oxidation of the Pd(100) surface at oxygen pressures in the 10{sup -6} mbar to 10{sup 3} mbar range and temperatures up to 1000 K has been studied in-situ by surface x-ray diffraction (SXRD). The SXRD experiments were performed at the MPI beamline at the Angstrom Quelle Karlsruhe (ANKA). We present the surface and crystal truncation rod (CTR) data from the ({radical}(5) x {radical}(5)) surface layer. We show that the transformation from the surface oxide to PdO bulk oxide can be observed in-situ under specific pressure and temperature conditions. We compare our results with previously proposed structure models based on low energy electron diffraction (LEED) I(V) curves and density functional theory calculations. Finally, we elucidate the question of commensurability of the surface oxide layer with respect to the Pd(100) substrate.

  6. In-situ reactive of x-ray optics by glow discharge

    International Nuclear Information System (INIS)

    Johnson, E.D.; Garrett, R.F.

    1987-01-01

    We have developed a method of in-situ reactive glow discharge cleaning of x-ray optical surfaces which is capable of complete removal of carbon contamination. Our work is the first to successfully clean an entire optical system in-situ and characterize its performance at short wavelengths (as low as 10 /angstrom/). The apparatus required is quite simple and can easily be fitted to most existing UHV (ultra high vacuum) mirror boxes of monochromators. The advantages of this technique over previously available methods include dramatic improvements in instrument performance and reductions in down time since the whole process typically takes a few days. This paper will briefly describe our results and detail the experimental considerations for application of the technique on different monochromator geometries. Possible improvements and extensions of the technique are also discussed

  7. Combining X-ray Absorption and X-ray Diffraction Techniques for in Situ Studies of Chemical Transformations in Heterogeneous Catalysis: Advantages and Limitations

    International Nuclear Information System (INIS)

    Frenkel, A.I.; Hanson, J.; Wang, Q.; Marinkovic, N.; Chen, J.G.; Barrio, L.; Si, R.; Lopez Camara, A.; Estrella, A.M.; Rodriguez, J.A.

    2011-01-01

    Recent advances in catalysis instrumentations include synchrotron-based facilities where time-resolved X-ray scattering and absorption techniques are combined in the same in situ or operando experiment to study catalysts at work. To evaluate the advances and limitations of this method, we performed a series of experiments at the new XAFS/XRD instrument in the National Synchrotron Light Source. Nearly simultaneous X-ray diffraction (XRD) and X-ray absorption fine-structure (XAFS) measurements of structure and kinetics of several catalysts under reducing or oxidizing conditions have been performed and carefully analyzed. For CuFe 2 O 4 under reducing conditions, the combined use of the two techniques allowed us to obtain accurate data on kinetics of nucleation and growth of metallic Cu. For the inverse catalyst CuO/CeO 2 that underwent isothermal reduction (with CO) and oxidation (with O 2 ), the XAFS data measured in the same experiment with XRD revealed strongly disordered Cu species that went undetected by diffraction. These and other examples emphasize the unique sensitivity of these two complementary methods to follow catalytic processes in the broad ranges of length and time scales.

  8. Development of an in situ temperature stage for synchrotron X-ray spectromicroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, R., E-mail: rupak@alum.mit.edu, E-mail: buonassisi@mit.edu; Serdy, J.; Culpepper, M. L.; Buonassisi, T., E-mail: rupak@alum.mit.edu, E-mail: buonassisi@mit.edu [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); West, B.; Stuckelberger, M.; Bertoni, M. I. [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Lai, B.; Maser, J. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2015-11-15

    In situ characterization of micro- and nanoscale defects in polycrystalline thin-film materials is required to elucidate the physics governing defect formation and evolution during photovoltaic device fabrication and operation. X-ray fluorescence spectromicroscopy is particularly well-suited to study defects in compound semiconductors, as it has a large information depth appropriate to study thick and complex materials, is sensitive to trace amounts of atomic species, and provides quantitative elemental information, non-destructively. Current in situ methods using this technique typically require extensive sample preparation. In this work, we design and build an in situ temperature stage to study defect kinetics in thin-film solar cells under actual processing conditions, requiring minimal sample preparation. Careful selection of construction materials also enables controlled non-oxidizing atmospheres inside the sample chamber such as H{sub 2}Se and H{sub 2}S. Temperature ramp rates of up to 300 °C/min are achieved, with a maximum sample temperature of 600 °C. As a case study, we use the stage for synchrotron X-ray fluorescence spectromicroscopy of CuIn{sub x}Ga{sub 1−x}Se{sub 2} (CIGS) thin-films and demonstrate predictable sample thermal drift for temperatures 25–400 °C, allowing features on the order of the resolution of the measurement technique (125 nm) to be tracked while heating. The stage enables previously unattainable in situ studies of nanoscale defect kinetics under industrially relevant processing conditions, allowing a deeper understanding of the relationship between material processing parameters, materials properties, and device performance.

  9. Thermal behaviour of molecular sieves (SAPO-11/AIPO-11 type) investigated by synchrotron radiation X-ray diffraction (SRXD)

    International Nuclear Information System (INIS)

    Neissendorfer, F.; Jahn, E.; Gusenko, S.N.; Sheromov, M.A.

    1991-01-01

    The structure of molecular sieves is important for a successful application as a catalyzer. The final structure of the synthetic product depends on the technological steps. This process was investigated by in-situ Synchrotron radiation X-ray diffraction. Structural changes in the molecular sieves exist not only during the heating process but also during the following cooling process. (author) 3 figs., 2 refs

  10. In situ synchrotron X-ray diffraction study on epitaxial-growth dynamics of III–V semiconductors

    Science.gov (United States)

    Takahasi, Masamitu

    2018-05-01

    The application of in situ synchrotron X-ray diffraction (XRD) to the molecular-beam epitaxial (MBE) growth of III–V semiconductors is overviewed along with backgrounds of the diffraction theory and instrumentation. X-rays are sensitive not only to the surface of growing films but also to buried interfacial structures because of their large penetration depth. Moreover, a spatial coherence length up to µm order makes X-rays widely applicable to the characterization of low-dimensional structures, such as quantum dots and wires. In situ XRD studies during growth were performed using an X-ray diffractometer, which was combined with an MBE chamber. X-ray reciprocal space mapping at a speed matching a typical growth rate was achieved using intense X-rays available from a synchrotron light source and an area detector. The importance of measuring the three-dimensional distribution of XRD intensity in a reciprocal space map is demonstrated for the MBE growth of two-, one-, and zero-dimensional structures. A large amount of information about the growth process of two-dimensional InGaAs/GaAs(001) epitaxial films has been provided by three-dimensional X-ray reciprocal mappings, including the anisotropic strain relaxation, the compositional inhomogeneity, and the evolution of surface and interfacial roughness. For one-dimensional GaAs nanowires grown in a Au-catalyzed vapor-liquid–solid mode, the relationship between the diameter of the nanowires and the formation of polytypes has been suggested on the basis of in situ XRD measurements. In situ three-dimensional X-ray reciprocal space mapping is also shown to be useful for determining the lateral and vertical sizes of self-assembled InAs/GaAs(001) quantum dots as well as their internal strain distributions during growth.

  11. X-ray investigation of CdSe nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kurtulus, Oezguel [Physics Division, Dogus University, Istanbul (Turkey); Li, Zhen [Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane (Australia); Mews, Alf [Physical Chemistry, University of Hamburg, Hamburg (Germany); Pietsch, Ullrich [Department of Physics, University of Siegen, Siegen (Germany)

    2009-08-15

    CdSe nanowires (NWs) have been prepared by a solution-liquid-solid (SLS) approach using Bi nanocatalysts. Structural characterization has been performed by X-ray powder diffraction providing an admixture of wurtzite and zinc-blende (ZB) structure units separated by different types of stacking faults. The relative contributions of ZB type stacking units within the NWs were determined to be in the order of 3-6% from a set of ratios of reflection intensities appearing in only wurtzite structure to those appearing in both ZB and wurtzite (W) structure. In addition, the anisotropy of domain size within the NWs was evaluated from the evolution of peak broadening for increasing scattering length. The coherence lengths along the growth direction are found to be changing between 16 and 21 nm, smaller than the results obtained from TEM measurement, while the NW diameters are determined to be between 5 and 8 nm which is in good agreement with TEM inspection. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  12. Speckle-based portable device for in-situ metrology of x-ray mirrors at Diamond Light Source

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Zhou, Tunhe; Sawhney, Kawal

    2017-09-01

    For modern synchrotron light sources, the push toward diffraction-limited and coherence-preserved beams demands accurate metrology on X-ray optics. Moreover, it is important to perform in-situ characterization and optimization of X-ray mirrors since their ultimate performance is critically dependent on the working conditions. Therefore, it is highly desirable to develop a portable metrology device, which can be easily implemented on a range of beamlines for in-situ metrology. An X-ray speckle-based portable device for in-situ metrology of synchrotron X-ray mirrors has been developed at Diamond Light Source. Ultra-high angular sensitivity is achieved by scanning the speckle generator in the X-ray beam. In addition to the compact setup and ease of implementation, a user-friendly graphical user interface has been developed to ensure that characterization and alignment of X-ray mirrors is simple and fast. The functionality and feasibility of this device is presented with representative examples.

  13. In situ observation of syntactic foams under hydrostatic pressure using X-ray tomography

    International Nuclear Information System (INIS)

    Lachambre, J.; Maire, E.; Adrien, J.; Choqueuse, D.

    2013-01-01

    Syntactic foams (hollow glass microspheres embedded in a polymeric matrix) are being used increasingly for the purpose of thermal insulation in ultradeep water. A better understanding of the damage mechanisms of these materials at the microsphere scale under such a hydrostatic loading condition is of prior importance in determining actual material limits, improving phenomenological modelling and developing novel formulations in the future. To achieve this goal, a study based on X-ray microtomography was performed on two syntactic foam materials (polypropylene and polyurethane matrix) and a standard foamed PP. A special set up has been designed in order to allow the X-ray microtomographic observation of the material during hydrostatic pressure loading using ethanol as the pressure fluid. Spatial resolution of (3.5 μm) 3 and in situ non-destructive scanning allowed a unique qualitative and quantitative analysis of the composite microstructure during stepwise isotropic compression by hydrostatic pressure up to 50 MPa. The collapse of weaker microspheres were observed during pressure increase and the damage parameters could be estimated. It is shown that the microspheres which are broken or the porosities which are close to the surface in the foamed PP are filled by a fluid (either the ethanol or the polymeric matrix itself). The hydrostatic pressure decreases the volume of the foam only slightly. In the PU matrix, ethanol diffusion is seen to induce swelling of the matrix, which is an unexpected phenomenon but reveals the high potential of X-ray microtomographic observation to improve diffusion analysis in complex media

  14. Structural investigation of GaInP nanowires using X-ray diffraction

    DEFF Research Database (Denmark)

    Kriegner, D.; Persson, Johan Mikael; Etzelstorfer, T.

    2013-01-01

    In this work the structure of ternary GaxIn1−xP nanowires is investigated with respect to the chemical composition and homogeneity. The nanowires were grown by metal–organic vapor-phase epitaxy. For the investigation of ensemble fluctuations on several lateral length scales, X-ray diffraction...... gradients along the sample by recording diffraction patterns at different positions. In addition, compositional variations were found also within single nanowires in X-ray energy dispersive spectroscopy measurements....

  15. Final Report on Developing Microstructure-Property Correlation in Reactor Materials using in situ High-Energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meimei [Argonne National Lab. (ANL), Argonne, IL (United States); Almer, Jonathan D. [Argonne National Lab. (ANL), Argonne, IL (United States); Yang, Yong [Univ. of Florida, Gainesville, FL (United States); Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-01

    This report provides a summary of research activities on understanding microstructure – property correlation in reactor materials using in situ high-energy X-rays. The report is a Level 2 deliverable in FY16 (M2CA-13-IL-AN_-0403-0111), under the Work Package CA-13-IL-AN_- 0403-01, “Microstructure-Property Correlation in Reactor Materials using in situ High Energy Xrays”, as part of the DOE-NE NEET Program. The objective of this project is to demonstrate the application of in situ high energy X-ray measurements of nuclear reactor materials under thermal-mechanical loading, to understand their microstructure-property relationships. The gained knowledge is expected to enable accurate predictions of mechanical performance of these materials subjected to extreme environments, and to further facilitate development of advanced reactor materials. The report provides detailed description of the in situ X-ray Radiated Materials (iRadMat) apparatus designed to interface with a servo-hydraulic load frame at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermal-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. We conducted several case studies using the iRadMat to obtain a better understanding of deformation and fracture mechanisms of irradiated materials. In situ X-ray measurements on neutron-irradiated pure metal and model alloy and several representative reactor materials, e.g. pure Fe, Fe-9Cr model alloy, 316 SS, HT-UPS, and duplex cast austenitic stainless steels (CASS) CF-8 were performed under tensile loading at temperatures of 20-400°C in vacuum. A combination of wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and imaging techniques were utilized to interrogate microstructure at different length scales in real time while the specimen was subject to thermal-mechanical loading. In addition, in situ X-ray studies were

  16. Bone structure investigation using X-ray and neutron radiography techniques

    International Nuclear Information System (INIS)

    Kamali Moghaddam, K.; Taheri, T.; Ayubian, M.

    2008-01-01

    In this paper we report a study of the periodic variation of bone tissue humidity immediately after death using both neutron and X-ray radiography techniques. After death, bone tissue experiences sequential change over time. This change consists of organic and inorganic phase variations of the bone structure, as well as gradual reduction of the bone's water content. These variations are investigated by periodically imaging dead bone using X-ray and neutron radiography. Chemical separation techniques such as calcification and decalcification were used to separate the organic and inorganic phases of the bone. Comparison between X-ray and neutron radiographs of bone following phase separation can be potentially used to investigate the bone disease or to determine a cause of death. In our experiments, we use adult rat femur bones, and the interpretations of these results are presented based on our understanding of bone structure and images produced by neutron and X-ray photon interactions

  17. Bone structure investigation using X-ray and neutron radiography techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kamali Moghaddam, K. [Nuclear Research Center (NRC), Atomic Energy Organization of Iran (AEOI), P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of)], E-mail: kkamali@aeoi.org.ir; Taheri, T.; Ayubian, M. [Nuclear Research Center (NRC), Atomic Energy Organization of Iran (AEOI), P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of)

    2008-01-15

    In this paper we report a study of the periodic variation of bone tissue humidity immediately after death using both neutron and X-ray radiography techniques. After death, bone tissue experiences sequential change over time. This change consists of organic and inorganic phase variations of the bone structure, as well as gradual reduction of the bone's water content. These variations are investigated by periodically imaging dead bone using X-ray and neutron radiography. Chemical separation techniques such as calcification and decalcification were used to separate the organic and inorganic phases of the bone. Comparison between X-ray and neutron radiographs of bone following phase separation can be potentially used to investigate the bone disease or to determine a cause of death. In our experiments, we use adult rat femur bones, and the interpretations of these results are presented based on our understanding of bone structure and images produced by neutron and X-ray photon interactions.

  18. Ion-induced nanopatterns on semiconductor surfaces investigated by grazing incidence x-ray scattering techniques

    Energy Technology Data Exchange (ETDEWEB)

    Carbone, D; Metzger, T H [ID01, ESRF, 6 rue Jules Horowitz, F-38043 Grenoble Cedex (France); Biermanns, A; Pietsch, U [Festkoerperphysik, Universitaet Siegen, D-57068 Siegen (Germany); Ziberi, B; Frost, F [Leibniz-Institut fuer Oberflaechenmodifizierung e.V., D-04318 Leipzig (Germany); Plantevin, O [Universite Paris-Sud, Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, UMR 8609, F-91405 Orsay (France)], E-mail: gcarbone@esrf.fr

    2009-06-03

    In this review we cover and describe the application of grazing incidence x-ray scattering techniques to study and characterize nanopattern formation on semiconductor surfaces by ion beam erosion under various conditions. It is demonstrated that x-rays under grazing incidence are especially well suited to characterize (sub)surface structures on the nanoscale with high spatial and statistical accuracy. The corresponding theory and data evaluation is described in the distorted wave Born approximation. Both ex situ and in situ studies are presented, performed with the use of a specially designed sputtering chamber which allows us to follow the temporal evolution of the nanostructure formation. Corresponding results show a general stabilization of the ordering wavelength and the extension of the ordering as a function of the ion energy and fluence as predicted by theory. The in situ measurements are especially suited to study the early stages of pattern formation, which in some cases reveal a transition from dot to ripple formation. For the case of medium energy ions crystalline ripples are formed buried under a semi-amorphous thick layer with a ripple structure at the surface being conformal with the crystalline/amorphous interface. Here, the x-ray techniques are especially advantageous since they are non-destructive and bulk-sensitive by their very nature. In addition, the GI x-ray techniques described in this review are a unique tool to study the evolving strain, a topic which remains to be explored both experimentally and theoretically.

  19. In-Situ X-ray Tomography Study of Cement Exposed to CO2 Saturated Brine

    DEFF Research Database (Denmark)

    Chavez Panduro, E. A.; Torsæter, M.; Gawel, K.

    2017-01-01

    For successful CO2 storage in underground reservoirs, the potential problem of CO2 leakage needs to be addressed. A profoundly improved understanding of the behavior of fractured cement under realistic subsurface conditions including elevated temperature, high pressure and the presence of CO2...... saturated brine is required. Here, we report in situ X-ray micro computed tomography (μ-CT) studies visualizing the microstructural changes upon exposure of cured Portland cement with an artificially engineered leakage path (cavity) to CO2 saturated brine at high pressure. Carbonation of the bulk cement......, self-healing of the leakage path in the cement specimen, and leaching of CaCO3 were thus directly observed. The precipitation of CaCO3, which is of key importance as a possible healing mechanism of fractured cement, was found to be enhanced in confined regions having limited access to CO2...

  20. Development of a combined portable x-ray fluorescence and Raman spectrometer for in situ analysis.

    Science.gov (United States)

    Guerra, M; Longelin, S; Pessanha, S; Manso, M; Carvalho, M L

    2014-06-01

    In this work, we have built a portable X-ray fluorescence (XRF) spectrometer in a planar configuration coupled to a Raman head and a digital optical microscope, for in situ analysis. Several geometries for the XRF apparatus and digital microscope are possible in order to overcome spatial constraints and provide better measurement conditions. With this combined spectrometer, we are now able to perform XRF and Raman measurements in the same point without the need for sample collection, which can be crucial when dealing with cultural heritage objects, as well as forensic analysis. We show the capabilities of the spectrometer by measuring several standard reference materials, as well as other samples usually encountered in cultural heritage, geological, as well as biomedical studies.

  1. In situ x-ray diffraction study on AgI nanowire arrays

    International Nuclear Information System (INIS)

    Wang Yinhai; Ye Changhui; Wang Guozhong; Zhang Lide; Liu Yanmei; Zhao Zhongyan

    2003-01-01

    The AgI nanowire arrays were prepared in the ordered porous alumina membrane by an electrochemical method. Transmission electron microscopy observation shows that the AgI nanowires are located in the channels of the alumina membrane. In situ x-ray diffractions show that the nanowire arrays possess hexagonal close-packed structure (β-AgI) at 293 K, orienting along the (002) plane, whereas at 473 K, the nanowire arrays possess a body-centered cubic structure (α-AgI), orienting along the (110) plane. The AgI nanowire arrays exhibit a negative thermal expansion property from 293 to 433 K, and a higher transition temperature from the β to α phase. We ascribe the negative thermal expansion behavior to the phase transition from the β to α phase, and the elevated transition temperature to the radial restriction by the channels of alumina membrane

  2. In situ X-ray and neutron diffraction study of Ba2In2O5

    International Nuclear Information System (INIS)

    Speakman, S.A.; Misture, S.T.

    2001-01-01

    Order-disorder transitions in barium indate, Ba 2 In 2 O 5 , have been studied using in-situ X-ray and neutron diffraction. At room temperature, the crystal structure is an orthorhombic brownmillerite structure. At 706 C, the crystal structure is orthorhombic, possibly of the Imma or Ibm2 space groups. At 900 C, oxygen vacancies begin to disorder. The order-disorder transition occurs slowly in two steps over a temperature range of 900 - 925 C. Above this temperature range, the crystal structure is tetragonal, most likely belonging to the space group I 4/mcm. A second order-disorder transition begins at 1040 C, and proceeds over the temperature range 1040 - 1065 C. Above this temperature range, the crystal structure is a cubic, oxygen-deficient perovskite structure, with space group Pm3m. At an undetermined temperature above 1200 C, Ba 2 In 2 O 5 begins to decompose. (orig.)

  3. In Situ High Resolution Synchrotron X-Ray Powder Diffraction Studies of Lithium Batteries

    DEFF Research Database (Denmark)

    Amri, Mahrez; Fitch, Andy; Norby, Poul

    2015-01-01

    allowing diffraction information to be obtained from only the active material during battery operation [2]. High resolution synchrotron x-ray powder diffraction technique has been undertaken to obtain detailed structural and compositional information during lithiation/delithiation of commercial LiFePO4...... materials [3]. We report results from the first in situ time resolved high resolution powder diffraction experiments at beamline ID22/31 at the European Synchrotron Radiation Facility, ESRF. We follow the structural changes during charge of commercial LiFePO4 based battery materials using the Rietveld...... method. Conscientious Rietveld analysis shows slight but continuous deviation of lattice parameters from those of the fully stoichiometric end members LiFePO4 and FePO4 indicating a subsequent variation of stoichiometry during cathode delithiation. The application of an intermittent current pulses during...

  4. In-situ x-ray characterization of wurtzite formation in GaAs nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Krogstrup, Peter; Hannibal Madsen, Morten; Nygaard, Jesper; Feidenhans' l, Robert [Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen (Denmark); Hu Wen [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1-1-1 Koto, Sayo, Hyogo 679-5148 (Japan); Kozu, Miwa; Nakata, Yuka [University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678-1297 (Japan); Takahasi, Masamitu [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1-1-1 Koto, Sayo, Hyogo 679-5148 (Japan); University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678-1297 (Japan)

    2012-02-27

    In-situ monitoring of the crystal structure formation during Ga-assisted GaAs nanowire growth on Si(111) substrates has been performed in a combined molecular beam epitaxy growth and x-ray characterization experiment. Under Ga rich conditions, we show that an increase in the V/III ratio increases the formation rate of the wurtzite structure. Moreover, the response time for changes in the structural phase formation to changes in the beam fluxes is observed to be much longer than predicted time scales of adatom kinetics and liquid diffusion. This suggests that the morphology of the growth interface plays the key role for the relative growth structure formation rates.

  5. X-ray Pump–Probe Investigation of Charge and Dissociation Dynamics in Methyl Iodine Molecule

    Directory of Open Access Journals (Sweden)

    Li Fang

    2017-05-01

    Full Text Available Molecular dynamics is of fundamental interest in natural science research. The capability of investigating molecular dynamics is one of the various motivations for ultrafast optics. We present our investigation of photoionization and nuclear dynamics in methyl iodine (CH3I molecule with an X-ray pump X-ray probe scheme. The pump–probe experiment was realized with a two-mirror X-ray split and delay apparatus. Time-of-flight mass spectra at various pump–probe delay times were recorded to obtain the time profile for the creation of high charge states via sequential ionization and for molecular dissociation. We observed high charge states of atomic iodine up to 29+, and visualized the evolution of creating these high atomic ion charge states, including their population suppression and enhancement as the arrival time of the second X-ray pulse was varied. We also show the evolution of the kinetics of the high charge states upon the timing of their creation during the ionization-dissociation coupled dynamics. We demonstrate the implementation of X-ray pump–probe methodology for investigating X-ray induced molecular dynamics with femtosecond temporal resolution. The results indicate the footprints of ionization that lead to high charge states, probing the long-range potential curves of the high charge states.

  6. Reduction of variable-truncation artifacts from beam occlusion during in situ x-ray tomography

    Science.gov (United States)

    Borg, Leise; Jørgensen, Jakob S.; Frikel, Jürgen; Sporring, Jon

    2017-12-01

    Many in situ x-ray tomography studies require experimental rigs which may partially occlude the beam and cause parts of the projection data to be missing. In a study of fluid flow in porous chalk using a percolation cell with four metal bars drastic streak artifacts arise in the filtered backprojection (FBP) reconstruction at certain orientations. Projections with non-trivial variable truncation caused by the metal bars are the source of these variable-truncation artifacts. To understand the artifacts a mathematical model of variable-truncation data as a function of metal bar radius and distance to sample is derived and verified numerically and with experimental data. The model accurately describes the arising variable-truncation artifacts across simulated variations of the experimental setup. Three variable-truncation artifact-reduction methods are proposed, all aimed at addressing sinogram discontinuities that are shown to be the source of the streaks. The ‘reduction to limited angle’ (RLA) method simply keeps only non-truncated projections; the ‘detector-directed smoothing’ (DDS) method smooths the discontinuities; while the ‘reflexive boundary condition’ (RBC) method enforces a zero derivative at the discontinuities. Experimental results using both simulated and real data show that the proposed methods effectively reduce variable-truncation artifacts. The RBC method is found to provide the best artifact reduction and preservation of image features using both visual and quantitative assessment. The analysis and artifact-reduction methods are designed in context of FBP reconstruction motivated by computational efficiency practical for large, real synchrotron data. While a specific variable-truncation case is considered, the proposed methods can be applied to general data cut-offs arising in different in situ x-ray tomography experiments.

  7. In-Situ Synchrotron X-ray Study of the Phase and Texture Evolution of Ceria and Superconductor Films Deposited by Chemical Solution Method

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; He, Dong

    2012-01-01

    In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry/differential ther......In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry...

  8. Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Maddox, B. R., E-mail: maddox3@llnl.gov; Akin, M. C., E-mail: akin1@llnl.gov; Teruya, A.; Hunt, D.; Hahn, D.; Cradick, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Morgan, D. V. [National Security Technologies LLC, Los Alamos, New Mexico 87544 (United States)

    2016-08-15

    Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from the sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10{sup 7} molybdenum Kα photons.

  9. Sulfur X-Ray Absorption Spectroscopy of Living Mammalian Cells: An Enabling Tool for Sulfur Metabolomics. in Situ Observation of Uptake of Taurine Into MDCK Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gnida, M.; Sneeden, E.Yu; Whitin, J.C.; Prince, R.C.; Pickering, I.J.; Korbas, M.; George, G.N.

    2009-06-01

    Sulfur is essential for life, with important roles in biological structure and function. However, because of a lack of suitable biophysical techniques, in situ information about sulfur biochemistry is generally difficult to obtain. Here, we present an in situ sulfur X-ray absorption spectroscopy (S-XAS) study of living cell cultures of the mammalian renal epithelial MDCK cell line. A great deal of information is retrieved from a characteristic sulfonate feature in the X-ray absorption spectrum of the cell cultures, which can be related to the amino acid taurine. We followed the time and dose dependence of uptake of taurine into MDCK cell monolayers. The corresponding uptake curves showed a typical saturation behavior with considerable levels of taurine accumulation inside the cells (as much as 40% of total cellular sulfur). We also investigated the polarity of uptake of taurine into MDCK cells, and our results confirmed that uptake in situ is predominantly a function of the basolateral cell surface.

  10. In-situ X-ray residual stress measurement on a peened alloy 600 weld metal at elevated temperature under tensile load

    International Nuclear Information System (INIS)

    Yunomura, Tomoaki; Maeguchi, Takaharu; Kurimura, Takayuki

    2014-01-01

    In order to verify stability of residual stress improvement effect of peeing for mitigation of stress corrosion cracking in components of PWR plant, relaxation behavior of residual stress induced by water jet peening (WJP) on surface of alloy 600 weld metal (alloy 132) was investigated by in-situ X-ray residual stress measurement under thermal aging and stress condition considered for actual plant operation. Surface residual stress change was observed at the early stage of thermal aging at 360°C, but no significant further stress relaxation was observed after that. Applied stress below yield stress does not significantly affect stress relaxation behavior of surface residual stress. For the X-ray residual stress measurement, X-ray stress constant at room temperature for alloy 600 was determined experimentally with several surface treatment and existence of applied strain. The X-ray stress constant at elevated temperatures were extrapolated theoretically based on the X-ray stress constant at room temperature for alloy 600. (author)

  11. Atoms in Action: Observing Atomic Motion with Dynamic in situ X-ray Diffraction

    Science.gov (United States)

    Cox, Jordan Michael

    Metal-organic framework (MOF) materials are rich in both structural diversity and application. These materials are comprised of metal atoms or clusters which are connected in a three-dimensional polymer-like network by bridging organic linker molecules. One of the major attractive features in MOFs is their permanent pore space which can potentially be used to adsorb or exchange foreign molecules from/with the surrounding environment. While MOFs are an active area of scientific interest, MOF materials are still relatively new, only 20 years old. As such, there is still much that needs to be understood about these materials before they can be effectively applied to widespread chemical problems like CO2 sequestration or low-pressure hydrogen fuel storage. One of the most important facets of MOF chemistry to understand in order to rationally design MOF materials with tailor-made properties is the relationship between the structural features in a MOF and the chemical and physical properties of that material. By examining in detail the atomic structure of a MOF with known properties under a variety of conditions, scientists can begin to unravel the guiding principles which govern these relationships. X-ray diffraction remains one of the most effective tools for determining the structure of a crystalline material with atomic resolution, and has been applied to the determination of MOF structures for years. Typically these experiments have been carried out using powder X-ray diffraction, but this technique lacks the high-resolution structural information found in single-crystal methods. Some studies have been reported which use specialized devices, sometimes called Environmental Control Cells, to study single crystalline MOFs under non-ambient chemical conditions in situ . However, these in situ studies are performed under static conditions. Even in cases where the ECC provides continued access to the local chemical environment during diffraction data collections, the

  12. XRMON-GF: A novel facility for solidification of metallic alloys with in situ and time-resolved X-ray radiographic characterization in microgravity conditions

    Science.gov (United States)

    Nguyen-Thi, H.; Reinhart, G.; Salloum Abou Jaoude, G.; Mathiesen, R. H.; Zimmermann, G.; Houltz, Y.; Voss, D.; Verga, A.; Browne, D. J.; Murphy, A. G.

    2013-07-01

    As most of the phenomena involved during the growth of metallic alloys from the melt are dynamic, in situ and time-resolved X-ray imaging should be retained as the method of choice for investigating the solidification front evolution. On Earth, the gravity force is the major source of various disturbing effects (natural convection, buoyancy/sedimentation, and hydrostatic pressure) which can significantly modify or mask certain physical mechanisms. Therefore solidification under microgravity is an efficient way to eliminate such perturbations to provide unique benchmark data for the validation of models and numerical simulations. Up to now, in situ observation during microgravity solidification experiments were limited to the investigations on transparent organic alloys, using optical methods. On the other hand, in situ observation on metallic alloys generally required synchrotron facilities. This paper reports on a novel facility we have designed and developed to investigate directional solidification on metallic alloys in microgravity conditions with in situ X-ray radiography observation. The facility consists of a Bridgman furnace and an X-ray radiography device specifically devoted to the study of Al-based alloys. An unprecedented experiment was recently performed on board a sounding rocket, with a 6 min period of microgravity. Radiographs were successfully recorded during the entire experiment including the melting and solidification phases of the sample, with a Field-of-View of about 5 mm×5 mm, a spatial resolution of about 4 µm and a frequency of 2 frames per second. Some preliminary results are presented on the solidification of the Al-20 wt% Cu sample, which validate the apparatus and confirm the potential of in situ X-ray characterization for the investigation of dynamical phenomena in materials processing, and particularly for the studying of metallic alloys solidification.

  13. Dynamics of barite growth in porous media quantified by in situ synchrotron X-ray tomography

    Science.gov (United States)

    Godinho, jose; Gerke, kirill

    2016-04-01

    Current models used to formulate mineral sequestration strategies of dissolved contaminants in the bedrock often neglect the effect of confinement and the variation of reactive surface area with time. In this work, in situ synchrotron X-ray micro-tomography is used to quantify barite growth rates in a micro-porous structure as a function of time during 13.5 hours with a resolution of 1 μm. Additionally, the 3D porous network at different time frames are used to simulate the flow velocities and calculate the permeability evolution during the experiment. The kinetics of barite growth under porous confinement is compared with the kinetics of barite growth on free surfaces in the same fluid composition. Results are discussed in terms of surface area normalization and the evolution of flow velocities as crystals fill the porous structure. During the initial hours the growth rate measured in porous media is similar to the growth rate on free surfaces. However, as the thinner flow paths clog the growth rate progressively decreases, which is correlated to a decrease of local flow velocity. The largest pores remain open, enabling growth to continue throughout the structure. Quantifying the dynamics of mineral precipitation kinetics in situ in 4D, has revealed the importance of using a time dependent reactive surface area and accounting for the local properties of the porous network, when formulating predictive models of mineral precipitation in porous media.

  14. Rapid thermal processing chamber for in-situ x-ray diffraction

    International Nuclear Information System (INIS)

    Ahmad, Md. Imteyaz; Van Campen, Douglas G.; Yu, Jiafan; Pool, Vanessa L.; Van Hest, Maikel F. A. M.; Toney, Michael F.; Fields, Jeremy D.; Parilla, Philip A.; Ginley, David S.

    2015-01-01

    Rapid thermal processing (RTP) is widely used for processing a variety of materials, including electronics and photovoltaics. Presently, optimization of RTP is done primarily based on ex-situ studies. As a consequence, the precise reaction pathways and phase progression during the RTP remain unclear. More awareness of the reaction pathways would better enable process optimization and foster increased adoption of RTP, which offers numerous advantages for synthesis of a broad range of materials systems. To achieve this, we have designed and developed a RTP instrument that enables real-time collection of X-ray diffraction data with intervals as short as 100 ms, while heating with ramp rates up to 100 °Cs −1 , and with a maximum operating temperature of 1200 °C. The system is portable and can be installed on a synchrotron beamline. The unique capabilities of this instrument are demonstrated with in-situ characterization of a Bi 2 O 3 -SiO 2 glass frit obtained during heating with ramp rates 5 °C s −1 and 100 °C s −1 , revealing numerous phase changes

  15. Rapid thermal processing chamber for in-situ x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Md. Imteyaz; Van Campen, Douglas G.; Yu, Jiafan; Pool, Vanessa L.; Van Hest, Maikel F. A. M.; Toney, Michael F., E-mail: mftoney@slac.stanford.edu [SSRL, SLAC National Accelerator Laboratory, 2575, Sand Hill Road, Menlo Park, California 94025 (United States); Fields, Jeremy D.; Parilla, Philip A.; Ginley, David S. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

    2015-01-15

    Rapid thermal processing (RTP) is widely used for processing a variety of materials, including electronics and photovoltaics. Presently, optimization of RTP is done primarily based on ex-situ studies. As a consequence, the precise reaction pathways and phase progression during the RTP remain unclear. More awareness of the reaction pathways would better enable process optimization and foster increased adoption of RTP, which offers numerous advantages for synthesis of a broad range of materials systems. To achieve this, we have designed and developed a RTP instrument that enables real-time collection of X-ray diffraction data with intervals as short as 100 ms, while heating with ramp rates up to 100 °Cs{sup −1}, and with a maximum operating temperature of 1200 °C. The system is portable and can be installed on a synchrotron beamline. The unique capabilities of this instrument are demonstrated with in-situ characterization of a Bi{sub 2}O{sub 3}-SiO{sub 2} glass frit obtained during heating with ramp rates 5 °C s{sup −1} and 100 °C s{sup −1}, revealing numerous phase changes.

  16. In Situ Synchrotron X-ray Study of Ultrasound Cavitation and Its Effect on Solidification Microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Jiawei; Tan, Dongyue; Lee, Tung Lik (Hull)

    2014-12-11

    Considerable progress has been made in studying the mechanism and effectiveness of using ultrasound waves to manipulate the solidification microstructures of metallic alloys. However, uncertainties remain in both the underlying physics of how microstructures evolve under ultrasonic waves, and the best technological approach to control the final microstructures and properties. We used the ultrafast synchrotron X-ray phase contrast imaging facility housed at the Advanced Photon Source, Argonne National Laboratory, US to study in situ the highly transient and dynamic interactions between the liquid metal and ultrasonic waves/bubbles. The dynamics of ultrasonic bubbles in liquid metal and their interactions with the solidifying phases in a transparent alloy were captured in situ. The experiments were complemented by the simulations of the acoustic pressure field, the pulsing of the bubbles, and the associated forces acting onto the solidifying dendrites. The study provides more quantitative understanding on how ultrasonic waves/bubbles influence the growth of dendritic grains and promote the grain multiplication effect for grain refinement.

  17. X-ray diffraction investigation of self-annealing in nanocrystalline copper electrodeposits

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.

    2006-01-01

    X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multip...... twinning during self-annealing. The kinetics of self-annealing depends on the layer thickness as well as on the orientation and/or the size of the as-deposited crystallites. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.......X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multiple...

  18. Electronic structure of nanoscale Cu/Pt alloys: A combined X-ray diffraction and X-ray absorption investigations

    International Nuclear Information System (INIS)

    Chen Xing; Chu Wangsheng; Cai Quan; Xia Dingguo; Wu Zhonghua; Wu Ziyu

    2006-01-01

    PVP-protected Cu/Pt clusters were prepared by glycol/water reduction method and characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD) and absorption spectra. TEM and XRD analysis show that the Cu/Pt clusters with different molar ratio have fcc structure with particle size of about 4 nm, while the lattice parameters in these clusters reduce with increasing Cu concentration. From the X-ray absorption near edge structure (XANES) at Cu-K edge and Pt-L 2,3 edge, we demonstrate that the d-electronic states of Cu and Pt are affected by the local environment as a function of Cu/Pt molar ratio. With increasing Cu concentration, Pt loses a fraction of 5d electrons and the hybridization between p- and d-states at Cu sites is enhanced

  19. Electronic structure of nanoscale Cu/Pt alloys: A combined X-ray diffraction and X-ray absorption investigations

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xing [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Graduate School of the Chinese Academy of Sciences, 100864 Beijing (China); Chu Wangsheng [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); University of Science and Technology of China, Hefei, 230036 (China); Cai Quan [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Graduate School of the Chinese Academy of Sciences, 100864 Beijing (China); Xia Dingguo [College of Environmental and Energy Engineering, Beijing University of Technology, 100022 Beijing (China); Wu Zhonghua [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Wu Ziyu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China) and National Center for Nanoscience and Technology (China)]. E-mail: wuzy@ihep.ac.cn

    2006-11-15

    PVP-protected Cu/Pt clusters were prepared by glycol/water reduction method and characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD) and absorption spectra. TEM and XRD analysis show that the Cu/Pt clusters with different molar ratio have fcc structure with particle size of about 4 nm, while the lattice parameters in these clusters reduce with increasing Cu concentration. From the X-ray absorption near edge structure (XANES) at Cu-K edge and Pt-L{sub 2,3} edge, we demonstrate that the d-electronic states of Cu and Pt are affected by the local environment as a function of Cu/Pt molar ratio. With increasing Cu concentration, Pt loses a fraction of 5d electrons and the hybridization between p- and d-states at Cu sites is enhanced.

  20. The effect of strain path change on subgrain volume fraction determined from in situ X-ray measurements

    DEFF Research Database (Denmark)

    Wejdemann, Christian; Poulsen, Henning Friis; Lienert, U.

    2009-01-01

    to additional 5% strain is performed in situ while mapping a selected X-ray reflection from one particular bulk grain with high angular resolution. The reciprocal space maps are analyzed with a recently developed fitting method, and a correlation is found between the evolution of the subgrain volume fraction...

  1. Methodology for in situ synchrotron X-ray studies in the laser-heated diamond anvil cell

    DEFF Research Database (Denmark)

    Mezouar, M.; Giampaoli, R.; Garbarino, G.

    2017-01-01

    A review of some important technical challenges related to in situ diamond anvil cell laser heating experimentation at synchrotron X-ray sources is presented. The problem of potential chemical reactions between the sample and the pressure medium or the carbon from the diamond anvils is illustrated...

  2. In-situ real-time x-ray scattering for probing the processing-structure-performance relation

    KAUST Repository

    Smilgies, Detlef-M.

    2014-01-01

    © 2014 Materials Research Society. In-situ X-ray scattering methodology is discussed, in order to analyze the microstructure development of soft functional materials during coating, annealing, and drying processes in real-time. The relevance of a fundamental understanding of coating processes for future industrial production is pointed out.

  3. Synchrotron-Radiation X-Ray Investigation of Li+/Na+ Intercalation into Prussian Blue Analogues

    Directory of Open Access Journals (Sweden)

    Yutaka Moritomo

    2013-01-01

    Full Text Available Prussian blue analogies (PBAs are promising cathode materials for lithium ion (LIB and sodium ion (SIB secondary batteries, reflecting their covalent and nanoporous host structure. With use of synchrotron-radiation (SR X-ray source, we investigated the structural and electronic responses of the host framework of PBAs against Li+ and Na+ intercalation by means of the X-ray powder diffraction (XRD and X-ray absorption spectroscopy (XAS. The structural investigation reveals a robust nature of the host framework against Li+ and Na+ intercalation, which is advantageous for the stability and lifetime of the batteries. The spectroscopic investigation identifies the redox processes in respective plateaus in the discharge curves. We further compare these characteristics with those of the conventional cathode materials, such as, LiCoO2, LiFePO4, and LiMn2O4.

  4. Effective X-ray elastic constant measurement for in situ stress measurement of biaxially strained AA5754-O

    International Nuclear Information System (INIS)

    Iadicola, Mark A.; Gnäupel-Herold, Thomas H.

    2012-01-01

    Accurate measurement of stresses by X-ray diffraction requires accurate X-ray elastic constants. Calibration experiments are one method to determine these for a specific material in a specific condition. In this paper, uniaxial tension experiments are used to investigate the variation of these constants after uniaxial and equal-biaxial plastic deformation for an aluminum alloy (AA5754-O) of interest to the automotive industry. These data are critical for accurate measurement of the biaxial mechanical properties of the material using a recent experimental method combining specialized sheet metal forming equipment with portable X-ray diffraction equipment. The measured effective X-ray elastic constants show some minor variation with increased plastic deformation, and this behavior was found to be consistent for both uniaxially and equal-biaxially strained samples. The use of two average values for effective X-ray elastic constants, one in the rolling direction and one transverse to the rolling direction of the sheet material, is shown to be of sufficient accuracy for the combined tests of interest. Comparison of uniaxial data measured using X-ray diffraction and standard methods show good agreement, and biaxial stress–strain results show good repeatability. Additionally, the calibration data show some non-linear behavior, which is analyzed in regards to crystallographic texture and intergranular stress effects. The non-linear behavior is found to be the result of intergranular stresses based on comparison with additional measurements using other X-ray diffraction equipment and neutron diffraction.

  5. X-ray detectors for structure investigations constructed at JINR

    Energy Technology Data Exchange (ETDEWEB)

    Chernenko, S P [LHE Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Cheremukhina, G A [LHE Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Fateev, O V [LHE Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Smykov, L P [LHE Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Vasiliev, S E [LHE Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Zanevsky, Yu V [LHE Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Kheiker, D M [Institute of Crystallography, Leninsky prosp. 59, 117333 Moscow (Russian Federation); Popov, A N [Institute of Crystallography, Leninsky prosp. 59, 117333 Moscow (Russian Federation)

    1994-09-01

    The performance characteristics of a few high resolution position-sensitive detectors constructed at JINR are presented. The detectors supplied with original software operate with an IBM PC/AT. One of these devices has been succesfully applied for protein molecule structure investigations and the other for studies of the structure-forming process during combustion. The preliminary parameters of the high count rate MWPC with parallel electronics and the testing results of the microstrip detector are given. ((orig.))

  6. Visualizing and measuring flow in shale matrix using in situ synchrotron X-ray microtomography

    Science.gov (United States)

    Kohli, A. H.; Kiss, A. M.; Kovscek, A. R.; Bargar, J.

    2017-12-01

    Natural gas production via hydraulic fracturing of shale has proliferated on a global scale, yet recovery factors remain low because production strategies are not based on the physics of flow in shale reservoirs. In particular, the physical mechanisms and time scales of depletion from the matrix into the simulated fracture network are not well understood, limiting the potential to optimize operations and reduce environmental impacts. Studying matrix flow is challenging because shale is heterogeneous and has porosity from the μm- to nm-scale. Characterizing nm-scale flow paths requires electron microscopy but the limited field of view does not capture the connectivity and heterogeneity observed at the mm-scale. Therefore, pore-scale models must link to larger volumes to simulate flow on the reservoir-scale. Upscaled models must honor the physics of flow, but at present there is a gap between cm-scale experiments and μm-scale simulations based on ex situ image data. To address this gap, we developed a synchrotron X-ray microscope with an in situ cell to simultaneously visualize and measure flow. We perform coupled flow and microtomography experiments on mm-scale samples from the Barnett, Eagle Ford and Marcellus reservoirs. We measure permeability at various pressures via the pulse-decay method to quantify effective stress dependence and the relative contributions of advective and diffusive mechanisms. Images at each pressure step document how microfractures, interparticle pores, and organic matter change with effective stress. Linking changes in the pore network to flow measurements motivates a physical model for depletion. To directly visualize flow, we measure imbibition rates using inert, high atomic number gases and image periodically with monochromatic beam. By imaging above/below X-ray adsorption edges, we magnify the signal of gas saturation in μm-scale porosity and nm-scale, sub-voxel features. Comparing vacuumed and saturated states yields image

  7. The x-ray time of flight method for investigation of ghosting in amorphous selenium-based flat panel medical x-ray imagers

    International Nuclear Information System (INIS)

    Rau, A.W.; Bakueva, L.; Rowlands, J.A.

    2005-01-01

    Amorphous selenium (a-Se) based real-time flat-panel imagers (FPIs) are finding their way into the digital radiology department because they offer the practical advantages of digital x-ray imaging combined with an image quality that equals or outperforms that of conventional systems. The temporal imaging characteristics of FPIs can be affected by ghosting (i.e., radiation-induced changes of sensitivity) when the dose to the detector is high (e.g., portal imaging and mammography) or the images are acquired at a high frame rate (e.g., fluoroscopy). In this paper, the x-ray time-of-flight (TOF) method is introduced as a tool for the investigation of ghosting in a-Se photoconductor layers. The method consists of irradiating layers of a-Se with short x-ray pulses. From the current generated in the a-Se layer, ghosting is quantified and the ghosting parameters (charge carrier generation rate and carrier lifetimes and mobilities) are assessed. The x-ray TOF method is novel in that (1) x-ray sensitivity (S) and ghosting parameters can be measured simultaneously (2) the transport of both holes and electrons can be isolated, and (3) the method is applicable to the practical a-Se layer structure with blocking contacts used in FPIs. The x-ray TOF method was applied to an analysis of ghosting in a-Se photoconductor layers under portal imaging conditions, i.e., 1 mm thick a-Se layers, biased at 5 V/μm, were irradiated using a 6 MV LINAC x-ray beam to a total dose (ghosting dose) of 30 Gy. The initial sensitivity (S 0 ) of the a-Se layers was 63±2 nC cm -2 cGy -1 . It was found that S decreases to 30% of S 0 after a ghosting dose of 5 Gy and to 21% after 30 Gy at which point no further change in S occurs. At an x-ray intensity of 22 Gy/s (instantaneous dose rate during a LINAC x-ray pulse), the charge carrier generation rate was 1.25±0.1x10 22 ehp m -3 s -1 and, to a first approximation, independent of the ghosting dose. However, both hole and electron transport showed a

  8. A quasi-monochromatic X-rays source for art painting pigments investigation

    Energy Technology Data Exchange (ETDEWEB)

    Albertin, F.; Franconieri, A.; Gambaccini, M.; Petrucci, F.; Chiozzi, S. [University of Ferrara, Department of Physics and INFN, Ferrara (Italy); Moro, D. [University of Padova, Department of Physics, Padova (Italy); LNL - INFN, Legnaro, Padova (Italy)

    2009-08-15

    Monochromatic X-ray sources can be used for several applications, like in medicine or in studying our cultural heritage. We are investigating imaging systems based on a tuneable energy band X-ray source, to obtain an element mapping of painting layers using the K-edge technique. The narrow energy band beams are obtained with conventional X-ray source via Bragg diffraction on a mosaic crystal; such an analysis has been performed at different diffraction angles, tuning the energy to investigate spectra of interest from the artistic point of view, like zinc and copper. In this paper the characteristics of the system in terms of fluence rate are reported, and first results of this technique on canvas samples and painting are presented. (orig.)

  9. Structural and microstructural changes during anion exchange of CoAl layered double hydroxides: an in situ X-ray powder diffraction study

    DEFF Research Database (Denmark)

    Johnsen, Rune; Krumeich, Frank; Norby, Poul

    2010-01-01

    Anion-exchange processes in cobalt-aluminium layered double hydroxides (LDHs) were studied by in situ synchrotron X-ray powder diffraction (XRPD). The processes investigated were CoAl-CO3 CoAl-Cl CoAl-CO3, CoAl-Cl CoAl-NO3 and CoAl-CO3 CoAl-SO4. The XRPD data show that the CoAl-CO3 CoAl-Cl process...

  10. Monte Carlo Investigation of Phosphor Screens for X-ray Imaging

    International Nuclear Information System (INIS)

    Lim, Chang Hwy; Cheong, Min Ho; Cho, Min Kook; Shon, Choel Soon; Kim, Ho Kyung

    2006-01-01

    In order to detect X rays with pixel detectors, there are two technical methods; a direct detection using photoconductive material that permits the conversion of the incident X rays into the signal charges, and an indirect detection using scintillation material that converts the incident X rays into the optical photons. Therefore, two-dimensional (2D) photosensitive pixel array is necessary for the indirect-detection scheme. Terbium-doped gadolinium oxysulfide (Gd 2 O 2 S:Tb) phosphor screen is the most popular X-ray converter, and often employed to the digital radiographic system owing to its well-known technology and easy handling in size, thickness, and flexibility. Furthermore, the cost is effective. In cascaded imaging chains of the indirect-detection system, the phosphor screen is served as the first stage. Since the image signal-to-noise ratio (SNR) is irreversible through the cascaded system, the phosphor screen is largely responsible for the eventual image quality. For the various radiation qualities suggested by IEC (International Electrotechnical Commission, Report 1267), we have investigated important physical quantities of Gd 2 O 2 S:Tb screen with a wide range of coverages (34 . 135 mg/cm 2 ) by using Monte Carlo calculations. The results will be useful for the optimal design of digital X-ray imaging systems

  11. Investigation of elemental distribution in lung samples by X-ray fluorescence microtomography

    International Nuclear Information System (INIS)

    Pereira, Gabriela R.; Rocha, Henrique S.; Lopes, Ricardo T.

    2007-01-01

    X-Ray Fluorescence Microtomography (XRFCT) is a suitable technique to find elemental distributions in heterogeneous samples. While x-ray transmission microtomography provides information about the linear attenuation coefficient distribution, XRFCT allows one to map the most important elements in the sample. The x-ray fluorescence tomography is based on the use of the X-ray fluorescence emitted from the elements contained in a sample so as to give additional information to characterize the object under study. In this work a rat lung and two human lung tissue samples have been investigated in order to verify the efficiency of the system in determination of the internal distribution of detected elements in these kinds of samples and to compare the elemental distribution in the lung tissue of an old human and a fetus. The experiments were performed at the X-Ray Fluorescence beamline (XRF) of the Brazilian Synchrotron Light Source (LNLS), Campinas, Brazil. A white beam was used for the excitation of the elements and the fluorescence photons have been detected by a HPGe detector. All the tomographies have been reconstructed using a filtered-back projection algorithm. It was possible to visualize the distribution of high atomic number elements on both, artificial and tissues samples. It was compared the quantity of Zn, Cu and Fe for the lung human tissue samples and verify that these elements have a higher concentration on the fetus tissue sample than the adult tissue sample. (author)

  12. Investigations of time resolved x-ray wide-angle scattering and x-ray small-angle scattering at DESY

    International Nuclear Information System (INIS)

    Zachmann, H.G.; Gehrke, R.; Prieske, W.; Riekel, C.

    1985-01-01

    Instrumentation is described for the simultaneous wide-angle and small-angle x-ray scattering. The method was applied to the study of the isothermal crystallization of polyethylene terephthalates. In agreement with the classical theories of crystallization, the data showed that the density difference between the crystals and the non-crystalline regions does not change with time. The mechanisms of melting, recrystallization, and crystal thickening were investigated by small-angle x-ray scattering with stepwise changes and continuous changes of temperature using polyethylene terephthalate

  13. An investigation of dose changes for therapeutic kilovoltage x-ray beams with underlying lead shielding

    International Nuclear Information System (INIS)

    Hill, Robin; Healy, Brendan; Holloway, Lois; Baldock, Clive

    2007-01-01

    Kilovoltage x-ray beams are used to treat cancer on or close to the skin surface. Many clinical cases use high atomic number materials as shielding to reduce dose to underlying healthy tissues. In this work, we have investigated the effect on both the surface dose and depth doses in a water phantom with lead shielding at depth in the phantom. The EGSnrc Monte Carlo code was used to simulate the water phantom and to calculate the surface doses and depth doses using primary x-ray beam spectra derived from an analytical model. The x-ray beams were in the energy range of 75-135 kVp with field sizes of 2, 5 and 8 cm diameter. The lead sheet was located beneath the water surface at depths ranging from 0.5-7.5 cm. The surface dose decreased as the lead was positioned closer to the water surface and as the field size was increased. The variation in surface dose as a function of x-ray beam energy was only small but the maximum reduction occurred for the 100 kVp x-ray beam. For the 8 cm diameter field with the lead at 1 cm depth and using the 100 kVp x-ray beam, the surface dose was reduced to 0.898 of the surface dose in the water phantom only. Measured surface dose changes, using a Farmer-type ionization chamber, agreed with the Monte Carlo calculated doses. Calculated depth doses in water with a lead sheet positioned below the surface showed that the dose fall-off increased as the lead was positioned closer to the water surface as compared to the depth dose in the water phantom only. Monte Carlo calculations of the total x-ray beam spectrum at the water surface showed that the total fluence decreased due to a reduction in backscatter from within the water and very little backscatter from the lead. The mean energy of the x-ray spectrum varied less than 1 keV, with the lead at 1 cm beneath the water phantom surface. As the Monte Carlo calculations showed good agreement with the measured results, this method can be used to verify surface dose changes in clinical situations

  14. Rapid detection of chromosome rearrangement in medical diagnostic X-ray workers by using fluorescence in situ hybridization and study on dose estimation

    International Nuclear Information System (INIS)

    Wang Zhiquan; Sun Yuanming; Li Jin

    1998-01-01

    Objective: Biological doses were estimated for medical diagnostic X-ray workers. Methods: Chromosome rearrangements in X-ray workers were analysed by fluorescence in situ hybridization (FISH) with composite whole chromosome paintings number 4 and number 7. Results: The frequency of translocation in medical diagnostic X-ray workers was much higher than that in control group (P<0.01). The biological doses to individual X-ray workers were calculated by their translocation frequency. The translocation frequencies of both FISH and G-banding were in good agreement. Conclusion: The biological doses to X-ray workers are estimated by FISH first when their dosimetry records are not documented

  15. Investigation of L X-ray intensity ratios in Pt induced by proton collisions

    International Nuclear Information System (INIS)

    Kaur, Manpuneet; Kaur, Mandeep; Mohan, Harsh; Jain, Arvind Kumar; Singh, Parjit S.; Vohra, Neelam; Sharma, Sunita

    2015-01-01

    A survey of literature on L X-ray parameters inspires us for taking up the present investigation. These parameters are useful to study atomic properties. In view of this, we report L X-ray intensity ratios for Pt, namely, L ℓ / L α , L β / L α and L γ / L α with proton collisions over the energy range 260 - 400 keV with an interval of 20 keV. The intention of research presented in this paper is to explore their energy dependence and comparison with theoretical calculations. These analyses will yield a data in the low energy region which assist in better clarity of proton induced X-ray emission phenomenon

  16. Pyrophosphate-Inhibition of Apatite Formation Studied by In Situ X-Ray Diffraction

    Directory of Open Access Journals (Sweden)

    Casper Jon Steenberg Ibsen

    2018-02-01

    Full Text Available The pathways to crystals are still under debate, especially for materials relevant to biomineralization, such as calcium phosphate apatite known from bone and teeth. Pyrophosphate is widely used in biology to control apatite formation since it is a potent inhibitor of apatite crystallization. The impacts of pyrophosphate on apatite formation and crystallization kinetics are, however, not fully understood. Therefore, we studied apatite crystallization in water by synchrotron in situ X-ray diffraction. Crystallization was conducted from calcium chloride (0.2 M and sodium phosphate (0.12 M at pH 12 where hydrogen phosphate is the dominant phosphate species and at 60 °C to allow the synchrotron measurements to be conducted in a timely fashion. Following the formation of an initial amorphous phase, needle shaped crystals formed that had an octacalcium phosphate-like composition, but were too small to display the full 3D periodic structure of octacalcium phosphate. At later growth stages the crystals became apatitic, as revealed by changes in the lattice constant and calcium content. Pyrophosphate strongly inhibited nucleation of apatite and increased the onset of crystallization from minute to hour time scales. Pyrophosphate also reduced the rate of growth. Furthermore, when the pyrophosphate concentration exceeded ~1% of the calcium concentration, the resultant crystals had reduced size anisotropy suggesting that pyrophosphate interacts in a site-specific manner with the formation of apatite crystals.

  17. Scanning of Adsorption Hysteresis In Situ with Small Angle X-Ray Scattering.

    Directory of Open Access Journals (Sweden)

    Athanasios Ch Mitropoulos

    Full Text Available Everett's theorem-6 of the domain theory was examined by conducting adsorption in situ with small angle x-ray scattering (SAXS supplemented by the contrast matching technique. The study focuses on the spectrum differences of a point to which the system arrives from different scanning paths. It is noted that according to this theorem at a common point the system has similar macroscopic properties. Furthermore it was examined the memory string of the system. We concluded that opposite to theorem-6: a at a common point the system can reach in a finite (not an infinite number of ways, b a correction for the thickness of the adsorbed film prior to capillary condensation is necessary, and c the scattering curves although at high-Q values coincide, at low-Q values are different indicating different microscopic states. That is, at a common point the system holds different metastable states sustained by hysteresis effects. These metastable states are the ones which highlight the way of a system back to a return point memory (RPM. Entering the hysteresis loop from different RPMs different histories are implanted to the paths toward the common point. Although in general the memory points refer to relaxation phenomena, they also constitute a characteristic feature of capillary condensation. Analogies of the no-passing rule and the adiabaticity assumption in the frame of adsorption hysteresis are discussed.

  18. In situ X-ray analysis of MoO3 reduction

    International Nuclear Information System (INIS)

    Leisegang, T.; Levin, A.A.; Meyer, D.C.; Walter, J.

    2005-01-01

    The reduction of MoO 3 to MoO 2 under hydrogen/argon atmosphere (5 vol. % H 2 /95 vol. % Ar) in the temperature range 323 K..623 K was studied in situ by means of wide-angle X-ray scattering. It has been found that the starting material, MoO 3 , consists of two different orthorhombic MoO 3 phases A and B with nearly the same structure parameters. The phase A (fraction of 37.1 wt%) describes the larger crystallites whereas the phase B (fraction of 62.9 wt.%) describes the smaller crystallites. Under the reduction to monoclinic MoO 2 phase during the heating, the thermal evolution of the phase fractions is different. A conclusion is drawn that MoO 2 is formed preferably in big crystallites. About 10 wt. % of MoO 2 has been found to form at 623 K resulting in about 69 wt. % after cooling to room temperature followed by holding in Ar/H 2 atmosphere about 24 h. Additionally, about 4.4 wt. % of the Mo 4 O 11 oxide probably formed in large crystallites was detected in the reduced powder after the cooling. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Uranium oxidation kinetics monitored by in-situ X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Zalkind, S., E-mail: shimonzl@nrcn.org.il; Rafailov, G.; Halevy, I.; Livneh, T.; Rubin, A.; Maimon, H.; Schweke, D.

    2017-03-15

    The oxidation kinetics of U-0.1 wt%Cr at oxygen pressures of 150 Torr and the temperature range of 90–150 °C was studied by means of in-situ X-ray diffraction (XRD). A “breakaway” in the oxidation kinetics is found at ∼0.25 μm, turning from a parabolic to a linear rate law. At the initial stage of oxidation the growth plane of UO{sub 2}(111) is the prominent one. As the oxide thickens, the growth rate of UO{sub 2}(220) plane increases and both planes grow concurrently. The activation energies obtained for the oxide growth are Q{sub parabolic} = 17.5 kcal/mol and Q{sub linear} = 19 kcal/mol. Enhanced oxidation around uranium carbide (UC) inclusions is clearly observed by scanning electron microscopy (SEM).

  20. In situ synchrotron X-ray diffraction study of hydrides in Zircaloy-4 during thermomechanical cycling

    Energy Technology Data Exchange (ETDEWEB)

    Cinbiz, Mahmut N., E-mail: cinbizmn@ornl.gov [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA, 16802 (United States); Koss, Donald A., E-mail: koss@ems.psu.edu [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, 16802 (United States); Motta, Arthur T., E-mail: atm2@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA, 16802 (United States); Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, 16802 (United States); Park, Jun-Sang, E-mail: parkjs@aps.anl.gov [Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439 (United States); Almer, Jonathan D., E-mail: almer@aps.anl.gov [Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439 (United States)

    2017-04-15

    The d-spacing evolution of both in-plane and out-of-plane hydrides has been studied using in situ synchrotron radiation X-ray diffraction during thermo-mechanical cycling of cold-worked stress-relieved Zircaloy-4. The structure of the hydride precipitates is such that the δ{111} d-spacing of the planes aligned with the hydride platelet face is greater than the d-spacing of the 111 planes aligned with the platelet edges. Upon heating from room temperature, the δ{111} planes aligned with hydride plate edges exhibit bi-linear thermally-induced expansion. In contrast, the d-spacing of the (111) plane aligned with the hydride plate face initially contracts upon heating. These experimental results can be understood in terms of a reversal of stress state associated with precipitating or dissolving hydride platelets within the α-zirconium matrix. - Highlights: •The δ{111} d-spacings aligned with the hydride plate edges exhibit a bi-linear thermal expansion. •Stress state reversal is predicted with the onset of hydride dissolution. •During dissolution, the δ{111} planes oriented parallel to the hydride plate face initially contract upon heating. •Hydride d-spacings indicate that both in-plane (circumferential) and out-of-plane (radial) hydrides are in the same strain-state and likely in the same stress state as well.

  1. Scanning of Adsorption Hysteresis In Situ with Small Angle X-Ray Scattering

    Science.gov (United States)

    Mitropoulos, Athanasios Ch.; Favvas, Evangelos P.; Stefanopoulos, Konstantinos L.; Vansant, Etienne F.

    2016-01-01

    Everett’s theorem-6 of the domain theory was examined by conducting adsorption in situ with small angle x-ray scattering (SAXS) supplemented by the contrast matching technique. The study focuses on the spectrum differences of a point to which the system arrives from different scanning paths. It is noted that according to this theorem at a common point the system has similar macroscopic properties. Furthermore it was examined the memory string of the system. We concluded that opposite to theorem-6: a) at a common point the system can reach in a finite (not an infinite) number of ways, b) a correction for the thickness of the adsorbed film prior to capillary condensation is necessary, and c) the scattering curves although at high-Q values coincide, at low-Q values are different indicating different microscopic states. That is, at a common point the system holds different metastable states sustained by hysteresis effects. These metastable states are the ones which highlight the way of a system back to a return point memory (RPM). Entering the hysteresis loop from different RPMs different histories are implanted to the paths toward the common point. Although in general the memory points refer to relaxation phenomena, they also constitute a characteristic feature of capillary condensation. Analogies of the no-passing rule and the adiabaticity assumption in the frame of adsorption hysteresis are discussed. PMID:27741263

  2. In situ x-ray scattering studies of the Au(111)/electrolyte interface

    International Nuclear Information System (INIS)

    Wang, Jia; Ocko, B.M.; Davenport, A.J.; Isaacs, H.S.

    1991-01-01

    The adsorption of anions at the Au(111) electrode and the subsequent effect on the gold surface structure have been investigated using x-ray specular reflectivity and grazing incident angle diffraction techniques. The top layer of gold atoms undergoes a reversible phase transition between the (1x1) bulk termination and a (23x√ bar 3) reconstructed phase on changing the potential. The shifts of the phase transition potential in NaCland NaBr solutions from the one in NaF can be understood by the anion adsorption induced charge effect. The reconstruction formation rate increases in chloride and bromide solutions due to an increase in the surface mobility with anion adsorption. Adsorbed chloride and bromide monolayers can be monitored during a potential scan by the specular reflectivity

  3. A rotational and axial motion system load frame insert for in situ high energy x-ray studies

    Energy Technology Data Exchange (ETDEWEB)

    Shade, Paul A., E-mail: paul.shade.1@us.af.mil; Schuren, Jay C.; Turner, Todd J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Blank, Basil [PulseRay, Beaver Dams, New York 14812 (United States); Kenesei, Peter; Goetze, Kurt; Lienert, Ulrich; Almer, Jonathan [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Suter, Robert M. [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Bernier, Joel V.; Li, Shiu Fai [Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lind, Jonathan [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-09-15

    High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability.

  4. X-ray diffraction investigation of spin reorientation in SmFe2

    International Nuclear Information System (INIS)

    Gaviko, V.S.; Korolyov, A.V.; Mushnikov, N.V.

    1996-01-01

    Spontaneous magnetoelastic crystal lattice distortions in the spin reorientation region of high magnetostrictive SmFe 2 have been investigated by X-ray diffraction in the temperature range 80-300 K. Comparison of experimental shapes of X-ray diffraction lines with calculated shapes shows that, in the region of the spin reorientation transition, a mixture of left angle 110 right angle and left angle 111 right angle phases rather than the angular left angle uuw right angle -type phase is realized. The temperature dependence of the relative volume content of left angle 110 right angle and left angle 111 right angle phases is determined using least-squares fitting. (orig.)

  5. Investigation of surface residual stress profile on martensitic stainless steel weldment with X-ray diffraction

    Directory of Open Access Journals (Sweden)

    I.I. Ahmed

    2018-04-01

    Full Text Available The development of residual stresses during fabrication is inevitable and often neglected with dire consequences during the service life of the fabricated components. In this work, the surface residual stress profile following the martensitic stainless steel (MSS pipe welding was investigated with X-ray diffraction technique. The results revealed the presence of residual stresses equilibrated across the weldment zones. Tensile residual stress observed in weld metal was balanced by compressive residual stresses in the parent material on the opposing sides of weld metal. Keywords: Residual stress, Weld, Stainless steel, X-ray, HAZ

  6. X-Ray Diffraction for In-Situ Mineralogical Analysis of Planetesimals.

    Science.gov (United States)

    Sarrazin, P.; Blake, D. F.; Dera, P.; Downs, R. T.; Taylor, J.

    2017-12-01

    X-ray diffraction (XRD) is a general purpose technique for definitive, quantitative mineralogical analysis. When combined with XRF data for sample chemistry, XRD analyses yield as complete a characterization as is possible by any spacecraft-capable techniques. The MSL CheMin instrument, the first XRD instrument flown in space, has been used to establish the quantitative mineralogy of the Mars global soil, to discover the first habitable environment on another planet, and to provide the first in-situ evidence of silicic volcanism on Mars. CheMin is now used to characterize the depositional and diagenetic environments associated with the mudstone sediments of lower strata of Mt. Sharp. Conventional powder XRD requires samples comprised of small grains presented in random orientations. In CheMin, sample cells are vibrated to cause loose powder to flow within the cell, driven by granular convection, which relaxes the requirement for fine grained samples. Nevertheless, CheMin still requires mechanisms to collect, crush, sieve and deliver samples before analysis. XTRA (Extraterrestrial Regolith Analyzer) is an evolution of CheMin intended to analyze fines in as-delivered surface regolith, without sample preparation. Fine-grained regolith coats the surfaces of most airless bodies in the solar system, and because this fraction is typically comminuted from the rocky regolith, it can often be used as a proxy for the surface as a whole. HXRD (Hybrid-XRD) is concept under development to analyze rocks or soils without sample preparation. Like in CheMin, the diffracted signal is collected with direct illumination CCD's. If the material is sufficiently fine-grained, a powder XRD pattern of the characteristic X-ray tube emission is obtained, similar to CheMin or XTRA. With coarse grained crystals, the white bremsstrahlung radiation of the tube is diffracted into Laue patterns. Unlike typical Laue applications, HXRD uses the CCD's capability to distinguish energy and analyze the

  7. An investigation of infection control for x-ray cassettes in a diagnostic imaging department

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Matthew [School of Allied Health Professions and Science, Faculty of Health, Wellbeing and Science, University Campus Suffolk, Rope Walk, Ipswich, Suffolk, IP4 1LT (United Kingdom); Harvey, Jane M. [School of Allied Health Professions and Science, Faculty of Health, Wellbeing and Science, University Campus Suffolk, Rope Walk, Ipswich, Suffolk, IP4 1LT (United Kingdom)], E-mail: j.harvey@ucs.ac.uk

    2008-11-15

    Introduction: This research was conducted to investigate if X-ray cassettes could be a possible source of pathogens capable of causing nosocomial infections, and if they could be a possible vector for cross infection within the hospital environment. Method: The research involved the swabbing of X-ray cassettes in a Diagnostic Imaging Department of a large hospital in the east of England. Two areas of the Diagnostic Imaging Department were included in the study. Research concentrated on X-ray cassettes used for mobile radiography, accident and emergency and inpatient use. Forty cassettes were swabbed in total specifically for general levels of bacterial contamination, also for the presence or absence of methicillin-resistant Staphylococcus aureus (MRSA). A mapping exercise was completed following the location of an X-ray cassette typically used in mobile radiography. The exercise noted the level of direct contact with patient's skin and other possible routes of infection. Results: The results demonstrated that there were large levels of growth of samples taken from cassettes and developed in the Microbiology Department. Coagulase-negative Staphylococcus, Micrococci, Diptheroids and species of Bacillus were all identified. The mapping exercise in which the journey of a 35/43 cm cassette used for mobile radiography was tracked found that contact with patient's skin and potential pathogens or routes of cross infection was a common occurrence whilst undertaking mobile radiography. Conclusion: The research has identified the presence of bacterial contamination on cassettes. The research established that X-ray cassettes/imaging plates are often exposed to pathogens and possible routes of cross infection; also that patient's skin often comes directly in contact with the X-ray cassette/imaging plate. The research also shows that as cassettes/imaging plates are a potential source of cross infection, the Diagnostic Imaging Department may be partly responsible

  8. An investigation of infection control for x-ray cassettes in a diagnostic imaging department

    International Nuclear Information System (INIS)

    Fox, Matthew; Harvey, Jane M.

    2008-01-01

    Introduction: This research was conducted to investigate if X-ray cassettes could be a possible source of pathogens capable of causing nosocomial infections, and if they could be a possible vector for cross infection within the hospital environment. Method: The research involved the swabbing of X-ray cassettes in a Diagnostic Imaging Department of a large hospital in the east of England. Two areas of the Diagnostic Imaging Department were included in the study. Research concentrated on X-ray cassettes used for mobile radiography, accident and emergency and inpatient use. Forty cassettes were swabbed in total specifically for general levels of bacterial contamination, also for the presence or absence of methicillin-resistant Staphylococcus aureus (MRSA). A mapping exercise was completed following the location of an X-ray cassette typically used in mobile radiography. The exercise noted the level of direct contact with patient's skin and other possible routes of infection. Results: The results demonstrated that there were large levels of growth of samples taken from cassettes and developed in the Microbiology Department. Coagulase-negative Staphylococcus, Micrococci, Diptheroids and species of Bacillus were all identified. The mapping exercise in which the journey of a 35/43 cm cassette used for mobile radiography was tracked found that contact with patient's skin and potential pathogens or routes of cross infection was a common occurrence whilst undertaking mobile radiography. Conclusion: The research has identified the presence of bacterial contamination on cassettes. The research established that X-ray cassettes/imaging plates are often exposed to pathogens and possible routes of cross infection; also that patient's skin often comes directly in contact with the X-ray cassette/imaging plate. The research also shows that as cassettes/imaging plates are a potential source of cross infection, the Diagnostic Imaging Department may be partly responsible for adding to

  9. X-rays Provide a New Way to Investigate Exploding Stars

    Science.gov (United States)

    2007-05-01

    exhausted. The duration of this X-ray emission traces the amount of material left on the white dwarf after the nova explosion. Optical Image of Andromeda Galaxy (M31) Optical Image of Andromeda Galaxy (M31) A well determined start time of the optical nova outburst and the X-ray turn-on and turn-off times are therefore important benchmarks for replication in computer models of novae. Whilst monitoring the M31 novae, frequently over several months, for the appearance and subsequent disappearance of the X-rays, Pietsch made an important discovery. Some novae start to emit X-rays and then turn them off again within just a few months. "These novae are a new class. They would have been overlooked before," says Pietsch. That's because previous surveys looked only every six months or so. Within that time, the fast X-ray novae could have blinked both on and off. In addition to discovering the short-lived ones, the new survey also confirms that other novae generate X-rays over a much longer time. XMM-Newton detected seven novae that were still shining X-rays into space, up to a decade after the original eruption. The differing lengths of times are thought to reflect the masses of the white dwarfs at the heart of the nova explosion. The fastest evolving novae are thought to be those coming from the most massive white dwarfs. To investigate further, the team have been awarded more XMM-Newton and Chandra observing time. They now plan to monitor M31's novae every ten days for several months, starting in November 2007 to glean more information about these puzzling stellar explosions. Notes for editors: X-ray monitoring of optical novae in M31 from July 2004 to February 2005 by W. Pietsch et al. is published in Astronomy and Astrophysics, 465, 375-392 (2007). For more information: Wolfgang Pietsch wnp@mpe.mpg.de Norbert Schartel Norbert.Schartel@sciops.esa.int

  10. Adsorbate induced surface alloy formation investigated by near ambient pressure X-ray photoelectron spectroscopy

    DEFF Research Database (Denmark)

    Nierhoff, Anders Ulrik Fregerslev; Conradsen, Christian Nagstrup; McCarthy, David Norman

    2014-01-01

    for engineering of more active or selective catalyst materials. Dynamical surface changes on alloy surfaces due to the adsorption of reactants in high gas pressures are challenging to investigate using standard characterization tools. Here we apply synchrotron illuminated near ambient pressure X-ray photoelectron...

  11. Small angle X ray diffraction investigation of twinned opal_like structures

    NARCIS (Netherlands)

    Samusev, A.K.; Sinev, I.S.; Samusev, K.B.; Rybin, M.V.; Mistonov, A.A.; Grigoryeva, N.A.; Grigoriev, S.V.; Petukhov, A.V.; Byelov, D.; Trofimova, E.Y.; Kurdyukov, D.A.; Golubev, V.G.; Limonov, M.F.

    2012-01-01

    Small angle X ray diffraction from synthetic opal films has been investigated as a function of the orientation of the sample. All the observed (hkl) diffraction reflections have been interpreted. The reconstruct tion of the reciprocal lattice of the studied opal films has been carried out. The

  12. Investigation of nanoscale structures by small-angle X-ray scattering in a radiochromic dosimeter

    DEFF Research Database (Denmark)

    Skyt, Peter Sandegaard; Jensen, Grethe Vestergaard; Wahlstedt, Isak Hannes

    2014-01-01

    This study examines the nanoscale structures in a radiochromic dosimeter that was based on leuco-malachite-green dye and the surfactant sodium dodecyl sulfate (SDS) suspended in a gelatin matrix. Small-angle X-ray scattering was used to investigate the structures of a range of compositions...

  13. Extended X-ray absorption fine structure investigation of nitrogen stabilized expanded austenite

    DEFF Research Database (Denmark)

    Oddershede, Jette; Christiansen, Thomas; Ståhl, Kenny

    2010-01-01

    As-delivered austenitic stainless steel and nitrogen stabilized expanded austenite, both fully nitrided and denitrided (in H2), were investigated with Cr, Fe and Ni extended X-ray absorption fine structure. The data shows pronounced short-range ordering of Cr and N. For the denitrided specimen...

  14. Investigation of atomic correlations in amorphous substances in the event of x-ray diffraction

    International Nuclear Information System (INIS)

    Birkelund, K.; Dahl Jensen, K.

    1990-06-01

    The aim was to determine a procedure for the experimental investigation of atomic correlations in monatomic amorphous substances (exemplified in amorphic germanium) that occur in relation to X-ray diffractometry, based on the classic theory of spreading. The underlying theory and a description of the experimental procedures are presented. (AB)

  15. Non-destructive in situ study of “Mad Meg” by Pieter Bruegel the Elder using mobile X-ray fluorescence, X-ray diffraction and Raman spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Van de Voorde, Lien, E-mail: lien.vandevoorde@ugent.be [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); Van Pevenage, Jolien [Ghent University, Department of Analytical Chemistry, Raman Spectroscopy Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); De Langhe, Kaat [Ghent University, Department of Archaeology, Archaeometry Research Group, Sint-Pietersnieuwstraat 35, B-9000 Gent (Belgium); De Wolf, Robin; Vekemans, Bart; Vincze, Laszlo [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Archaeometry Research Group, Sint-Pietersnieuwstraat 35, B-9000 Gent (Belgium); Martens, Maximiliaan P.J. [Ghent University, Department of Art, Music and Theatre Sciences, Blandijnberg 2, B-9000 Gent (Belgium)

    2014-07-01

    “Mad Meg”, a figure of Flemish folklore, is the subject of a famous oil-on-panel painting by the Flemish renaissance artist Pieter Bruegel the Elder, exhibited in the Museum Mayer van den Bergh (Antwerp, Belgium). This article reports on the in situ chemical characterization of this masterpiece by using currently available state-of-the-art portable analytical instruments. The applied non-destructive analytical approach involved the use of a) handheld X-ray fluorescence instrumentation for retrieving elemental information and b) portable X-ray fluorescence/X-ray diffraction instrumentation and laser-based Raman spectrometers for obtaining structural/molecular information. Next to material characterization of the used pigments and of the different preparation layers of the painting, also the verification of two important historical iconographic hypotheses is performed concerning the economic way of painting by Brueghel, and whether or not he used blue smalt pigment for painting the boat that appears towards the top of the painting. The pigments identified are smalt pigment (65% SiO{sub 2} + 15% K{sub 2}O + 10% CoO + 5% Al{sub 2}O{sub 3}) for the blue color present in all blue areas of the painting, probably copper resinate for the green colors, vermillion (HgS) as red pigment and lead white is used to form different colors. The comparison of blue pigments used on different areas of the painting gives no differences in the elemental fingerprint which confirms the existing hypothesis concerning the economic painting method by Bruegel. - Highlights: • In situ, non-destructive investigation of a famous painting by Pieter Bruegel. • Use of a new, commercial available, portable XRF/XRD instrumentation. • Multi-methodological approach: make also use of a mobile Raman spectrometer. • Used pigments and different preparation layers of the painting are characterized. • The verification of two important historical iconographic hypotheses are performed.

  16. Non-destructive in situ study of “Mad Meg” by Pieter Bruegel the Elder using mobile X-ray fluorescence, X-ray diffraction and Raman spectrometers

    International Nuclear Information System (INIS)

    Van de Voorde, Lien; Van Pevenage, Jolien; De Langhe, Kaat; De Wolf, Robin; Vekemans, Bart; Vincze, Laszlo; Vandenabeele, Peter; Martens, Maximiliaan P.J.

    2014-01-01

    “Mad Meg”, a figure of Flemish folklore, is the subject of a famous oil-on-panel painting by the Flemish renaissance artist Pieter Bruegel the Elder, exhibited in the Museum Mayer van den Bergh (Antwerp, Belgium). This article reports on the in situ chemical characterization of this masterpiece by using currently available state-of-the-art portable analytical instruments. The applied non-destructive analytical approach involved the use of a) handheld X-ray fluorescence instrumentation for retrieving elemental information and b) portable X-ray fluorescence/X-ray diffraction instrumentation and laser-based Raman spectrometers for obtaining structural/molecular information. Next to material characterization of the used pigments and of the different preparation layers of the painting, also the verification of two important historical iconographic hypotheses is performed concerning the economic way of painting by Brueghel, and whether or not he used blue smalt pigment for painting the boat that appears towards the top of the painting. The pigments identified are smalt pigment (65% SiO 2 + 15% K 2 O + 10% CoO + 5% Al 2 O 3 ) for the blue color present in all blue areas of the painting, probably copper resinate for the green colors, vermillion (HgS) as red pigment and lead white is used to form different colors. The comparison of blue pigments used on different areas of the painting gives no differences in the elemental fingerprint which confirms the existing hypothesis concerning the economic painting method by Bruegel. - Highlights: • In situ, non-destructive investigation of a famous painting by Pieter Bruegel. • Use of a new, commercial available, portable XRF/XRD instrumentation. • Multi-methodological approach: make also use of a mobile Raman spectrometer. • Used pigments and different preparation layers of the painting are characterized. • The verification of two important historical iconographic hypotheses are performed

  17. Room temperature redox reaction by oxide ion migration at carbon/Gd-doped CeO2 heterointerface probed by an in situ hard x-ray photoemission and soft x-ray absorption spectroscopies

    Directory of Open Access Journals (Sweden)

    Takashi Tsuchiya, Shogo Miyoshi, Yoshiyuki Yamashita, Hideki Yoshikawa, Kazuya Terabe, Keisuke Kobayashi and Shu Yamaguchi

    2013-01-01

    Full Text Available In situ hard x-ray photoemission spectroscopy (HX-PES and soft x-ray absorption spectroscopy (SX-XAS have been employed to investigate a local redox reaction at the carbon/Gd-doped CeO2 (GDC thin film heterointerface under applied dc bias. In HX-PES, Ce3d and O1s core levels show a parallel chemical shift as large as 3.2 eV, corresponding to the redox window where ionic conductivity is predominant. The window width is equal to the energy gap between donor and acceptor levels of the GDC electrolyte. The Ce M-edge SX-XAS spectra also show a considerable increase of Ce3+ satellite peak intensity, corresponding to electrochemical reduction by oxide ion migration. In addition to the reversible redox reaction, two distinct phenomena by the electrochemical transport of oxide ions are observed as an irreversible reduction of the entire oxide film by O2 evolution from the GDC film to the gas phase, as well as a vigorous precipitation of oxygen gas at the bottom electrode to lift off the GDC film. These in situ spectroscopic observations describe well the electrochemical polarization behavior of a metal/GDC/metal capacitor-like two-electrode cell at room temperature.

  18. Analysis of biological slurry samples by total x-ray fluorescence after in situ microwave digestion

    International Nuclear Information System (INIS)

    Lue-Meru, M.P.; Capote, T.; Greaves, E.

    2000-01-01

    Biological slurry samples were analyzed by total reflection x-ray fluorescence (TXRF) after an in situ microwave digestion procedure on the quartz reflector. This method lead to the removal of the matrix by the digestion and permits the enrichment of the analites by using sample amounts higher than those normally used in TXRF for the thin layer requirement since the organic matrix is removed. In consequence, the pre-concentration of sample is performed and the detection capability is increased by a quasi direct method. The samples analyzed were the international IAEA blood standard, the SRM bovine liver 1577-a standard and fresh onion tissues. Slurries were prepared in three ways: a.- weighing a sample amount on the reflector and adding suprapure nitric acid and internal standard followed by microwave digestion, b.-weighing a sample amount and water with an appropriate concentration of the internal standard in an Eppendorf vial, taking then an aliquot to the quartz reflector for microwave digestion with suprapure nitric acid, c.- weighing a sample amount of fresh tissue, homogenising with high speed homegenator to obtain a slurry sample which can be diluted in an ependorf vial with water an the internal standard. Then an aliquot is taken to the reflector for microwave digestion with suprapure nitric acid. Further details of sample preparation procedures will be discussed during presentation. The analysis was carried out in a Canberra spectrometer using the Kalpha lines of the Ag and Mo tubes. The elements Ca, K, Fe, Cu, Zn, Se, Mn, Rb, Br, Sr were determined. The effect of the preparation procedure was evaluated by the accuracy and precision of the results for each element and the percent of recovery. (author)

  19. Perspectives of in situ/operando resonant inelastic X-ray scattering in catalytic energy materials science

    International Nuclear Information System (INIS)

    Liu, Yi-Sheng; Glans, Per-Anders; Chuang, Cheng-Hao; Kapilashrami, Mukes; Guo, Jinghua

    2015-01-01

    Highlights: • In-situ/operando soft X-ray RXES and RIXS offer unique perspectives in the energy material science. - Abstract: Growing environmental concerns have renewed the interest for light induced catalytic reactions to synthesize cleaner chemical fuels from syngas. This, however, requires a sound understanding for the dynamics taking place at molecular level as a result of light – matter interaction. We present herein the principles of soft X-ray resonant emission spectroscopy (RXES) and resonant inelastic scattering (RIXS) and the importance of these spectroscopic techniques in materials science in light of their unique ability to emanate characteristic fingerprints on the geometric structure, chemical bonding charge and spin states in addition to chemical sensitivity. The addition of in situ/operando RXES and RIXS capability offers new opportunities to project important material properties and functionalities under conditions nearly identical to the operational modes.

  20. Perspectives of in situ/operando resonant inelastic X-ray scattering in catalytic energy materials science

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi-Sheng; Glans, Per-Anders [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Chuang, Cheng-Hao [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Physics, Tamkang University, Tamsui 250, Taiwan, ROC (China); Kapilashrami, Mukes [Center for Engineering Concepts Development, Department of Mechanical Engineering, University of Maryland, College Park, MD 20742 (United States); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Guo, Jinghua, E-mail: jguo@lbl.gov [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064 (United States)

    2015-04-15

    Highlights: • In-situ/operando soft X-ray RXES and RIXS offer unique perspectives in the energy material science. - Abstract: Growing environmental concerns have renewed the interest for light induced catalytic reactions to synthesize cleaner chemical fuels from syngas. This, however, requires a sound understanding for the dynamics taking place at molecular level as a result of light – matter interaction. We present herein the principles of soft X-ray resonant emission spectroscopy (RXES) and resonant inelastic scattering (RIXS) and the importance of these spectroscopic techniques in materials science in light of their unique ability to emanate characteristic fingerprints on the geometric structure, chemical bonding charge and spin states in addition to chemical sensitivity. The addition of in situ/operando RXES and RIXS capability offers new opportunities to project important material properties and functionalities under conditions nearly identical to the operational modes.

  1. Investigation of optimal scanning protocol for X-ray computed tomography polymer gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Sellakumar, P. [Bangalore Institute of Oncology, 44-45/2, II Cross, RRMR Extension, Bangalore 560 027 (India)], E-mail: psellakumar@rediffmail.com; James Jebaseelan Samuel, E. [School of Science and Humanities, VIT University, Vellore 632 014 (India); Supe, Sanjay S. [Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Hosur Road, Bangalore 560 027 (India)

    2007-11-15

    X-ray computed tomography is one of the potential tool used to evaluate the polymer gel dosimeters in three dimensions. The purpose of this study is to investigate the factors which affect the image noise for X-ray CT polymer gel dosimetry. A cylindrical water filled phantom was imaged with single slice Siemens Somatom Emotion CT scanner. The imaging parameters like tube voltage, tube current, slice scan time, slice thickness and reconstruction algorithm were varied independently to study the dependence of noise on each other. Reductions of noise with number of images to be averaged and spatial uniformity of the image were also investigated. Normoxic polymer gel PAGAT was manufactured and irradiated using Siemens Primus linear accelerator. The radiation induced change in CT number was evaluated using X-ray CT scanner. From this study it is clear that image noise is reduced with increase in tube voltage, tube current, slice scan time, slice thickness and also reduced with increasing the number of images averaged. However to reduce the tube load and total scan time, it was concluded that tube voltage of 130 kV, tube current of 200 mA, scan time of 1.5 s, slice thickness of 3 mm for high dose gradient and 5 mm for low dose gradient were optimal scanning protocols for this scanner. Optimum number of images to be averaged was concluded to be 25 for X-ray CT polymer gel dosimetry. Choice of reconstruction algorithm was also critical. From the study it is also clear that CT number increase with imaging tube voltage and shows the energy dependency of polymer gel dosimeter. Hence for evaluation of polymer gel dosimeters with X-ray CT scanner needs the optimization of scanning protocols to reduce the image noise.

  2. Instability of cyclic superelastic deformation of NiTi investigated by synchrotron X-ray diffraction

    Czech Academy of Sciences Publication Activity Database

    Sedmák, P.; Šittner, Petr; Pilch, Jan; Curfs, C.

    2015-01-01

    Roč. 94, Aug (2015), s. 257-270 ISSN 1359-6454 R&D Projects: GA ČR GB14-36566G; GA ČR GPP108/12/P111; GA ČR GA14-15264S; GA ČR GAP107/12/0800 Institutional support: RVO:68378271 Keywords : shape memory alloy * NiTi * superelasticity * cyclic deformation * in situ X-ray diffraction Subject RIV: JG - Metallurgy Impact factor: 5.058, year: 2015

  3. In Situ X-ray Diffraction Study of Cesium Exchange in Synthetic Umbite

    International Nuclear Information System (INIS)

    Fewox, C.; Clearfield, A.; Celestian, A.

    2011-01-01

    The exchange of Cs + into H 1.22 K 0.84 ZrSi 3 O 9 · 2.16H 2 O (umbite-(HK)) was followed in situ using time-resolved X-ray diffraction at the National Synchrotron Light Source. The umbite framework (space group P2 1 /c with cell dimensions of a = 7.2814(3) (angstrom), b = 10.4201(4) (angstrom), c = 13.4529(7) (angstrom), and β = 90.53(1) o ) consists of wollastonite-like silicate chains linked by isolated zirconia octahedra. Within umbite-(HK) there are two unique ion exchange sites in the tunnels running parallel to the a-axis. Exchange Site 1 is marked by 8 member-ring (MR) windows in the bc-plane and contains K + cations. Exchange Site 2 is marked by a larger 8-MR channel parallel to [100], and contains H 2 O molecules. The occupancy of the Cs + cations through these channels was modeled by Rietveld structure refinements of the diffraction data and demonstrated that there is a two-step exchange process. The incoming Cs + ions populated the larger 8-MR channel (Exchange Site 2) first and then migrated into the smaller 8-MR channel. During the exchange process a structural change occurs, transforming the exchanger from monoclinic P2 1 /c to orthorhombic P2 1 2 1 2 1 . This structural change occurs when Cs + occupancy in the small cavity becomes greater than 0.50. The final in situ ion exchange diffraction pattern was refined to yield umbite-(CsK) with the molecular formula H 0.18 K 0.45 Cs 1.37 ZrSi 3 O 9 · 0.98H 2 O and possessing an orthorhombic unit cell with dimensions a = 10.6668(8) (angstrom), b = 13.5821(11) (angstrom), c = 7.3946(6) (angstrom). Solid state 133 Cs MAS NMR showed there is only a slight difference between the two cavities electronically. Valence bond sums for the completely occupied Exchange Site 1 demonstrate that Cs-O bonds of up to 3.8 (angstrom) contribute to the coordination of the Cs + cation.

  4. Investigation of Deuterium Loaded Materials Subject to X-Ray Exposure

    Science.gov (United States)

    Benyo, Theresa L.; Steinetz, Bruce M.; Hendricks, Robert C.; Martin, Richard E.; Forsley, Lawrence P.; Daniels, Christopher C.; Chait, Arnon; Pines, Vladimir; Pines, Marianna; Penney, Nicholas; hide

    2017-01-01

    Results are presented from an exploratory study involving x-ray irradiation of select deuterated materials. Titanium deuteride plus deuterated polyethylene, deuterated polyethylene alone, and for control, hydrogen-based polyethylene samples and nondeuterated titanium samples were exposed to x-ray irradiation. These samples were exposed to various energy levels from 65 to 280 kV with prescribed electron flux from 500 to 9000 µA impinging on a tungsten braking target, with total exposure times ranging from 55 to 280 min. Gamma activity was measured using a high-purity germanium (HPGe) detector, and for all samples no gamma activity above background was detected. Alpha and beta activities were measured using a gas proportional counter, and for select samples beta activity was measured with a liquid scintillator spectrometer. The majority of the deuterated materials subjected to the microfocus x-ray irradiation exhibited postexposure beta activity above background and several showed short-lived alpha activity. The HPE and nondeuterated titanium control samples exposed to the x-ray irradiation showed no postexposure alpha or beta activities above background. Several of the samples (SL10A, SL16, SL17A) showed beta activity above background with a greater than 4s confidence level, months after exposure. Portions of SL10A, SL16, and SL17A samples were also scanned using a beta scintillator and found to have beta activity in the tritium energy band, continuing without noticeable decay for over 12 months. Beta scintillation investigation of as-received materials (before x-ray exposure) showed no beta activity in the tritium energy band, indicating the beta emitters were not in the starting materials.

  5. Development of high-performance X-ray transparent crystallization plates for in situ protein crystal screening and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, Ahmed S. M.; Warkentin, Matthew [Cornell University, Ithaca, New York (United States); Apker, Benjamin [MiTeGen LLC, Ithaca, New York (United States); Thorne, Robert E., E-mail: ret6@cornell.edu [Cornell University, Ithaca, New York (United States); MiTeGen LLC, Ithaca, New York (United States)

    2011-07-01

    An optically, UV and X-ray transparent crystallization plate suitable for in situ analysis has been developed. The plate uses contact line pinning rather than wells to confine the liquids. X-ray transparent crystallization plates based upon a novel drop-pinning technology provide a flexible, simple and inexpensive approach to protein crystallization and screening. The plates consist of open cells sealed top and bottom by thin optically, UV and X-ray transparent films. The plates do not need wells or depressions to contain liquids. Instead, protein drops and reservoir solution are held in place by rings with micrometre dimensions that are patterned onto the bottom film. These rings strongly pin the liquid contact lines, thereby improving drop shape and position uniformity, and thus crystallization reproducibility, and simplifying automated image analysis of drop contents. The same rings effectively pin solutions containing salts, proteins, cryoprotectants, oils, alcohols and detergents. Strong pinning by rings allows the plates to be rotated without liquid mixing to 90° for X-ray data collection or to be inverted for hanging-drop crystallization. The plates have the standard SBS format and are compatible with standard liquid-handling robots.

  6. In situ SERS and X-ray photoelectron spectroscopy studies on the pH-dependant adsorption of anthraquinone-2-carboxylic acid on silver electrode

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dan, E-mail: dany@sit.edu.cn [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Jia, Shaojie [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Fodjo, Essy Kouadio [Laboratory of Physical Chemistry, University Felix Houphouet Boigny, 22 BP 582, Abidjan 22, Cote d’Ivoire (Cote d' Ivoire); Xu, Hu [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Wang, Yuhong, E-mail: yuhong_wang502@sit.edu.cn [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Deng, Wei [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China)

    2016-03-30

    Graphical abstract: The orientation of anthraquinone-2-carboxylic acid (AQ-2-COOH) has been investigated by in situ surface-enhanced Raman scattering (in situ SERS) spectroelectrochemistry and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) on silver surface. - Highlights: • The adsorption behavior of anthraquinone-2-carboxylic acid (AQ-2-COOH) on Ag electrode is influenced by the pH. • The pH-dependant adsorption of AQ-2-COOH has been confirmed by in situ surface-enhanced Raman scattering (in situ SERS) spectroelectrochemistry and angle-resolved X-ray photoelectron spectroscopy (AR-XPS). • The results can provide insights into electron transfer reactions of AQ-2-COOH in biological systems. - Abstract: In this study, in situ surface-enhanced Raman scattering (SERS) spectroelectrochemistry and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) are used to investigate the redox reaction and adsorption behavior of anthraquinone-2-carboxylic acid (AQ-2-COOH) on an Ag electrode at different pH values. The obtained results indicate that AQ-2-COOH is adsorbed tilted on the Ag electrode through O-atom of ring carbonyl in a potential range from −0.3 to −0.5 V vs. SCE, but the orientation turns to more tilted orientation with both O-atom of the ring carbonyl and carboxylate group in positive potential region for pH 6.0 and 7.4. However, at pH 10.0, the orientation adopts tilted conformation constantly on the Ag electrode with both O-atom of the anthraquinone ring and carboxylate group in the potential range from −0.3 to −0.5 V vs. SCE or at positive potentials. Moreover, the adsorption behavior of AQ-2-COOH has been further confirmed by AR-XPS on the Ag surface. Proposed reasons for the observed changes in orientation are presented.

  7. X-ray investigation of intermetallides and their hydrides under hydrogen pressure in H2-LaNi5 system

    International Nuclear Information System (INIS)

    Karonik, V.V.; Tsypin, M.I.; Prokof'ev, M.V.; Kazakov, D.N.

    1983-01-01

    X-ray phase analysis has been used to investigate phase composition of LaNi 5 -H 2 system; comparison of X-ray diffraction data with the results of plotting absorption and desorption isotherms is conducted. Technique of the X-ray diffraction study of intermetallide-hydrogen system using special X-ray chamber to diffractometer DRON-1.5 (GUR-5) is worked out. The parameters of elementary cell of the LaNisub(5)Hsub(6.2) hydride are determined: a=0.541(2) pm, c=0.430(2) nm, c/a=0.795, V=0.109 nm 3 (hexagonal syngony)

  8. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A., E-mail: abazylak@mie.utoronto.ca [Dept. of Mechanical & Industrial Engineering, Faculty of Applied Science & Engineering, University of Toronto, Toronto, Ontario (Canada); Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N. [Canadian Light Source, Saskatoon, Saskatchewan (Canada); Tabuchi, Y.; Kotaka, T. [EV System Laboratory, Research Division 2, Nissan Motor Co., Ltd., Yokosuka, Kanagawa (Japan)

    2016-07-27

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  9. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    International Nuclear Information System (INIS)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A.; Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N.; Tabuchi, Y.; Kotaka, T.

    2016-01-01

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  10. Insight into the structure of Pd/ZrO2 during the total oxidation of methane using combined in situ XRD, X.-ray absorption and Raman spectroscopy

    DEFF Research Database (Denmark)

    Grunwaldt, Jan-Dierk; van Vegten, Niels; Baiker, Alfons

    2009-01-01

    The structure of palladium during the total combustion of methane has been studied by a combination of the complementary in situ techniques X-ray absorption spectroscopy, Raman spectroscopy and X-ray diffraction. The study demonstrates that finely dispersed and oxidized palladium is most active f...

  11. Combining x-ray diffraction contrast tomography and mesoscale grain growth simulations in strontium titanate: An integrated approach for the investigation of microstructure evolution

    DEFF Research Database (Denmark)

    Syha, Melanie; Baürer, Michael; Rheinheimer, Wolfgang

    2013-01-01

    Motivated by the recently reported a growth anomaly in strontium titatate bulk samples1, the microstructure of bulk strontium titanate has been investigated by an integrated approach comprising conventional metallography, three dimensional X-ray diffraction contrast tomography (DCT)2, and the obs......Motivated by the recently reported a growth anomaly in strontium titatate bulk samples1, the microstructure of bulk strontium titanate has been investigated by an integrated approach comprising conventional metallography, three dimensional X-ray diffraction contrast tomography (DCT)2......, and the observation of pore shapes in combination with mesoscale grain growth simulations. The microstructural evolution in strontium titanate has been characterized alternating ex-situ annealing and high energy X-ray DCT measurements, resulting in three dimensional microstructure reconstructions which...

  12. Evaluation of an in-situ x-ray fluorescence analyzer for inorganic pollutants in sediments and water columns

    International Nuclear Information System (INIS)

    Wogman, N.A.

    1979-09-01

    The applicability of an energy dispersive x-ray fluorescence spectrometer for measurement of trace elements in sediments and in water columns from Coast Guard vessels has been investigated. This investigation was conducted in both freshwater and saltwater areas and included Puget Sound, Lake Washington, Lake Union, and the ship canal in the State of Washington. The spectrometer system consisted of a solid cryogen-cooled Si(Li) detector and a 109 Cd excitation source. Sediments and water columns were viewed through a 0.2 mm Be window. This study showed the feasibility of measuring trace elements at concentrations ranging from 20 to about 100 ppM. Measurements of this sensitivity with a 100 mCi 109 Cd source are possible for time intervals as short as 5 minutes. This in-situ measurement capability permits the on-site mapping of pollution and avoids the problem of sediment disturbance which is inherent in the collection of grab samples of the sediment surface. Recommendations for an improved analyzer system included a detector assembly which could be towed, or allow continuous sediment surface analysis thereby recording the average composition of a large area

  13. Stress-dependent crystal structure of lanthanum strontium cobalt ferrite by in situ synchrotron X-ray diffraction

    Science.gov (United States)

    Geiger, Philipp T.; Khansur, Neamul H.; Riess, Kevin; Martin, Alexander; Hinterstein, Manuel; Webber, Kyle G.

    2018-02-01

    Lanthanum strontium cobalt ferrite La1-xSrxCo1-yFeyO3-δ (LSCF) is one of the most studied mixed ionic-electronic conductor materials due to electrical and transport properties, which are attractive for intermediate temperature solid oxide fuel cells (SOFCs), oxygen permeation membranes, and catalysis. The integration of such materials, however, depends on the thermal as well as mechanical behavior. LSCF exhibits nonlinear hysteresis during compressive stress-strain measurements, marked by a remanent strain and coercive stress, i.e., ferroelasticity. However, the origin of ferroelastic behavior has not been investigated under high compressive stress. This study, therefore, investigates the microscopic origin of stress-induced mechanical behavior in polycrystalline (La0.6Sr0.4)0.95Co0.2Fe0.8O3-δ using in situ synchrotron x-ray diffraction. The data presented here reveals that the strain response originates from the intrinsic lattice strain as well as the extrinsic domain switching strain without any apparent change in crystallographic symmetry. A comparison of the calculated microscopic strain contribution with that of a macroscopic measurement indicates a significant change in the relative contributions of intrinsic and extrinsic strain depending on the applied stress state, i.e., under maximum stress and after unloading. Direct evidence of the microscopic origin of stress-strain response outlined in this paper may assist in guiding materials design with the improved mechanical reliability of SOFCs.

  14. Ultrahigh-vacuum in situ electrochemistry with solid polymer electrolyte and x-ray photoelectron spectroscopy studies of polypyrrole

    International Nuclear Information System (INIS)

    Skotheim, T.A.; Florit, M.I.; Melo, A.; O'Grady, W.E.

    1984-01-01

    A new in situ combined electrochemistry and x-ray-photoelectron-spectroscopy (XPS) technique using solid polymer electrolytes has been used to characterize electrically conducting films of polypyrrole perchlorate. The technique allows in situ electrochemical oxidation and reduction (doping and undoping) in ultrahigh vacuum and the simultaneous study of the polymer with XPS as a function of its electrochemical potential. We demonstrate that some anion species interact strongly electrostatically with the nitrogen heteroatoms. We also show conclusively that the electrochemistry of polypyrrole is highly irreversible

  15. Note: A novel method for in situ loading of gases via x-ray induced chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan (UNLV); (CIW)

    2011-12-14

    We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO{sub 3}) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

  16. Note: A novel method for in situ loading of gases via x-ray induced chemistry

    Science.gov (United States)

    Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan

    2011-10-01

    We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO3) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

  17. Reflection-mode x-ray powder diffraction cell for in situ studies of electrochemical reactions

    International Nuclear Information System (INIS)

    Roberts, G.A.; Stewart, K.D.

    2004-01-01

    The design and operation of an electrochemical cell for reflection-mode powder x-ray diffraction experiments are discussed. The cell is designed for the study of electrodes that are used in rechargeable lithium batteries. It is designed for assembly in a glove box so that air-sensitive materials, such as lithium foil electrodes and carbonate-based electrolytes with lithium salts, can be used. The cell uses a beryllium window for x-ray transmission and electrical contact. A simple mechanism for compressing the electrodes is included in the design. Sample results for the cell are shown with a Cu Kα source and a position-sensitive detector

  18. Non-destructive investigations of Swiss museums objects with neutron and x-ray imaging methods

    International Nuclear Information System (INIS)

    Lehmann, E.H.; Deschler, E.; Pernet, L.; Vontobel, P.

    2004-01-01

    Many objects of archaeological relevance found in Switzerland are from the Celtic and Roman era. Because of their uniqueness in most cases it is demanded to perform any investigation with such samples non-destructively. Depending on the structure and size of the objects a transmission experiment performed either with X-ray or neutron can alight inner structures, composition, defects or the principles of the manufacturing procedures. Furthermore, the treatment by conservators and restaurateurs becomes visible in many cases. This report describes some examples of such investigations. In the case of neutron investigations, beside the transmission imaging as a radiograph the three-dimensional structure was observed with a tomography technique. For X-ray radiography, the images were obtained in the same digital format because the similar experimental method (imaging plates) was applied. It becomes evident in the described examples that the combination and complementary use of both methods (neutrons and X-ray) brings insights in different aspects of the samples properties and treatment. This approach to study museums objects stored and exhibit in Switzerland can be extrapolated to other countries where these techniques are also simultaneously available in order to investigate other objects of relevance. The European network COST-G8 entitled 'Non-destructive analysis and testing of museum objects' can help to support initiatives in this direction. (author)

  19. Non-thermal electron populations in microwave heated plasmas investigated with X-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Belapure, Jaydeep Sanjay

    2013-04-15

    An investigation of the generation and dynamics of superthermal electrons in fusion plasma is carried out. A SDD+CsI(Tl) based X-ray diagnostic is constructed, characterized and installed at ASDEX Upgrade. In various plasma heating power and densities, the fraction and the energy distribution of the superthermal electrons is obtained by a bi-Maxwellian model and compared with Fokker-Planck simulations.

  20. Soft X-ray spectroscopic investigations in experiments on Z-pinch stabilization

    International Nuclear Information System (INIS)

    Pikuz, S.A.; Skobelev, I.Yu.

    1996-01-01

    X-ray spectroscopic methods were used to investigate the spatial distribution of Z-pinch plasma parameters. Experiments were carried out on the GAEL pulse line generator in Ecole Polytechnique (France) with different types of load. Obtained results for the concentration of electrons and plasma temperature showed that higher plasma homogeneity was obtained in experiments with complex load. Spectrograms demonstrate the stabilization effect of the A1-jet. (orig.)

  1. Soft X-ray spectroscopic investigations in experiments on Z-pinch stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Pikuz, S.A. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.; Shelkovenko, T.A. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.; Romanova, V.M. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.; Etlicher, B. [Ecole Polytechnique, Palaseau (France). Lab. de Phys. des Mililux Ionises; Attelan, S. [Ecole Polytechnique, Palaseau (France). Lab. de Phys. des Mililux Ionises; Chuvatin, A.S. [Ecole Polytechnique, Palaseau (France). Lab. de Phys. des Mililux Ionises; Faenov, A.Ya. [MISDC VNIIFTRI, Moscow (Russian Federation); Skobelev, I.Yu. [MISDC VNIIFTRI, Moscow (Russian Federation)

    1996-04-01

    X-ray spectroscopic methods were used to investigate the spatial distribution of Z-pinch plasma parameters. Experiments were carried out on the GAEL pulse line generator in Ecole Polytechnique (France) with different types of load. Obtained results for the concentration of electrons and plasma temperature showed that higher plasma homogeneity was obtained in experiments with complex load. Spectrograms demonstrate the stabilization effect of the A1-jet. (orig.).

  2. In situ chemical state analysis of buried polymer/metal adhesive interface by hard X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Ozawa, Kenichi; Kakubo, Takashi; Shimizu, Katsunori; Amino, Naoya; Mase, Kazuhiko; Ikenaga, Eiji; Nakamura, Tetsuya; Kinoshita, Toyohiko; Oji, Hiroshi

    2014-01-01

    Highlights: • Chemical state analysis of the buried rubber/brass interface is conducted by HAXPES. • Ultrathin rubber films are prepared on the brass surface by two methods. • A high density of Cu 2 S is found on the rubber side of the buried adhesive layer. • The chemical states of the buried and exposed interfaces are compared. - Abstract: Chemical state analysis of adhesive interfaces is important to understand an adhesion mechanism between two different materials. Although photoelectron spectroscopy (PES) is an ideal tool for such an analysis, the adhesive interfaces must be exposed to the surface because PES is essentially a surface sensitive technique. However, an in situ observation is possible by hard X-ray PES (HAXPES) owing to its large probing depth. In the present study, HAXPES is applied to investigate the adhesive interface between rubber and brass without exposing the interface. It is demonstrated that copper sulfides formed at the buried rubber/brass interface are distinguished from S-containing species in the rubber overlayer. The chemical state of the buried interface is compared with that of the “exposed” interface prepared by so-called a filter-paper method

  3. Phase transformation in δ-Pu alloys at low temperature: An in situ microstructural characterization using X-ray diffraction

    International Nuclear Information System (INIS)

    Ravat, B.; Platteau, C.; Texier, G.; Oudot, B.; Delaunay, F.

    2009-01-01

    In order to investigate the martensitic transformation, an isothermal hold at -130 deg. C for 48 h was performed on a highly homogenized PuGa alloy. The modifications of the microstructure were characterized in situ thanks to a specific tool. This device was developed at the CEA-Valduc to analyze the crystalline structure of plutonium alloys as a function of temperature and more especially at low temperature using X-ray diffraction. The analysis of the recorded diffraction patterns highlighted that the martensitic transformation for this alloy is the result of a direct δ → α' + δ phase transformation. Moreover, a significant Bragg's peaks broadening corresponding to the δ-phase was observed. A microstructural analysis was made to characterize anisotropic microstrain resulting from the stress induced by the unit cell volume difference between the δ and α' phases. The amount of α'-phase evolved was analyzed within the framework of the Avrami theory in order to characterize the nucleation process. The results suggested that the growth mechanism corresponded to a general mechanism where the nucleation sites were in the δ-grain edges and the α'-phase had a plate-like morphology.

  4. Phase transformation in δ-Pu alloys at low temperature: An in situ microstructural characterization using X-ray diffraction

    Science.gov (United States)

    Ravat, B.; Platteau, C.; Texier, G.; Oudot, B.; Delaunay, F.

    2009-09-01

    In order to investigate the martensitic transformation, an isothermal hold at -130 °C for 48 h was performed on a highly homogenized PuGa alloy. The modifications of the microstructure were characterized in situ thanks to a specific tool. This device was developed at the CEA-Valduc to analyze the crystalline structure of plutonium alloys as a function of temperature and more especially at low temperature using X-ray diffraction. The analysis of the recorded diffraction patterns highlighted that the martensitic transformation for this alloy is the result of a direct δ → α' + δ phase transformation. Moreover, a significant Bragg's peaks broadening corresponding to the δ-phase was observed. A microstructural analysis was made to characterize anisotropic microstrain resulting from the stress induced by the unit cell volume difference between the δ and α' phases. The amount of α'-phase evolved was analyzed within the framework of the Avrami theory in order to characterize the nucleation process. The results suggested that the growth mechanism corresponded to a general mechanism where the nucleation sites were in the δ-grain edges and the α'-phase had a plate-like morphology.

  5. Phase transformation in delta-Pu alloys at low temperature: An in situ microstructural characterization using X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Ravat, B., E-mail: brice.ravat@cea.f [CEA, Valduc, F-21120 Is-sur-Tille (France); Platteau, C.; Texier, G.; Oudot, B.; Delaunay, F. [CEA, Valduc, F-21120 Is-sur-Tille (France)

    2009-09-15

    In order to investigate the martensitic transformation, an isothermal hold at -130 deg. C for 48 h was performed on a highly homogenized PuGa alloy. The modifications of the microstructure were characterized in situ thanks to a specific tool. This device was developed at the CEA-Valduc to analyze the crystalline structure of plutonium alloys as a function of temperature and more especially at low temperature using X-ray diffraction. The analysis of the recorded diffraction patterns highlighted that the martensitic transformation for this alloy is the result of a direct delta -> alpha' + delta phase transformation. Moreover, a significant Bragg's peaks broadening corresponding to the delta-phase was observed. A microstructural analysis was made to characterize anisotropic microstrain resulting from the stress induced by the unit cell volume difference between the delta and alpha' phases. The amount of alpha'-phase evolved was analyzed within the framework of the Avrami theory in order to characterize the nucleation process. The results suggested that the growth mechanism corresponded to a general mechanism where the nucleation sites were in the delta-grain edges and the alpha'-phase had a plate-like morphology.

  6. Fluid adsorption in ordered mesoporous solids determined by in situ small-angle X-ray scattering.

    Science.gov (United States)

    Findenegg, Gerhard H; Jähnert, Susanne; Müter, Dirk; Prass, Johannes; Paris, Oskar

    2010-07-14

    The adsorption of two organic fluids (n-pentane and perfluoropentane) in a periodic mesoporous silica material (SBA-15) is investigated by in situ small-angle X-ray scattering (SAXS) using synchrotron radiation. Structural changes are monitored as the ordered and disordered pores in the silica matrix are gradually filled with the fluids. The experiments yield integrated peak intensities from up to ten Bragg reflections from the 2D hexagonal pore lattice, and additionally diffuse scattering contributions arising from disordered (mostly intrawall) porosity. The analysis of the scattering data is based on a separation of these two contributions. Bragg scattering is described by adopting a form factor model for ordered pores of cylindrical symmetry which accounts for the filling of the microporous corona, the formation of a fluid film at the pore walls, and condensation of the fluid in the core. The filling fraction of the disordered intrawall pores is extracted from the diffuse scattering intensity and its dependence on the fluid pressure is analyzed on the basis of a three-phase model. The data analysis introduced here provides an important generalisation of a formalism presented recently (J. Phys. Chem. C, 2009, 13, 15201), which was applicable to contrast-matching fluids only. In this way, the adsorption behaviour of fluids into ordered and disordered pores in periodic mesoporous materials can be analyzed quantitatively irrespective of the fluid density.

  7. Investigating Students' Ideas About X-rays While Developing Teaching Materials for a Medical Physics Course

    International Nuclear Information System (INIS)

    Kalita, Spartak; Zollman, Dean

    2007-01-01

    The goal of the Modern Miracle Medical Machines project is to promote pre-med students' interest in physics by using the context of contemporary medical imaging. The X-ray medical imaging learning module will be a central part of this effort. To investigate students' transfer of learning in this context we have conducted a series of clinical and teaching interviews. In the latter interview, some of the proposed learning materials were used. The students brought to our discussion pieces of knowledge transferred from very different sources such as their own X-ray experiences, previous learning and the mass media. This transfer seems to result in more or less firm mental models which often are not always internally consistent or coherent

  8. Investigation of mosaicity of epitaxic multilayers by the statistical theory of X-ray dynamical diffraction

    International Nuclear Information System (INIS)

    Li Ming; Mai Zhenhong; Li Jianhua; Li Chaorong; Cui Shufan

    1995-01-01

    Based on the statistical theory of X-ray dynamical diffraction for thin films, the mosaicity of three types of semiconductor epitaxic layers has been investigated by analyzing their rocking curves by the X-ray double-crystal diffraction method. It is shown that the statistical theory can provide quantitative information on the mosaicity of the epitaxic layers such as the mean size and the mean disorientation of mosaic blocks in the layers. Some misunderstandings in interpreting experimental data are cleared up by taking into account the effect of diffuse scattering. It is emphasized that attempts to obtain structural parameters of specimens from their rocking curves by means of the Takagi-Taupin equations for coherent fields only are not strictly correct since diffuse scattering causes additional changes in the tails of the rocking curves. (orig.)

  9. In-situ high-P, T X-ray microtomographic imaging during large deformation

    DEFF Research Database (Denmark)

    Wang, Y; Lesher, Charles

    2011-01-01

    We have examined the microstructural evolution of a two-phase composite (olivine + Fe-Ni-S) during large shear deformation, using a newly developed high-pressure X-ray tomography microscope. Two samples were examined: a load-bearing framework–type texture, where the alloy phase (Fe-Ni-S) was pres...

  10. In situ x-ray imaging of nanoparticle agglomeration in fluidized beds

    International Nuclear Information System (INIS)

    Jenneson, Paul Michael; Gundogdu, Ozcan

    2006-01-01

    A high spatial (down to 400 nm) and temporal resolution (down to 1 ms) x-ray imaging apparatus has been designed to study the agglomeration of arc plasma synthesized zinc oxide nanoparticles (average diameter of 50 nm) in fluidized beds under different gas flow velocities. The mean volume distribution of the nanoparticle agglomerates was determined with x-ray microtomography and found to correspond to a lognormal distribution with a mean value of 0.70x10 9 μm 3 and a variance of 3.6x10 21 (μm 3 ) 2 . The average density of the agglomerates was found to be 2.9 g cm -3 compared to 5.6 g cm -3 for the individual nanoparticles. The powder assembly was then dynamically imaged using an x-ray image intensifier coupled to a digital camera using a field of view of 24.20 mm by 32.25 mm and a temporal resolution of 40 ms. Sequential frames were captured into computer memory for a range of gas flow velocities from 0.026 ms -1 to 0.313 ms -1 . The breakup energy of the agglomerates was calculated to be approximately 2x10 -8 J using a combination of dynamic observations and physical properties of the agglomerate system extracted from the x-ray microtomographic data

  11. In situ surface X-ray diffraction studies of the copper-electrolyte interface. Atomic structure and homoepitaxial grwoth

    Energy Technology Data Exchange (ETDEWEB)

    Golks, Frederik

    2011-05-19

    Copper electrodeposition is the predominantly used technique for on-chip wiring in the fabrication of ultra-large scale integrated (ULSI) microchips. In this 'damascene copper electroplating' process, multicomponent electrolytes containing organic additives realize void-free filling of trenches with high aspect ratio ('superconformal deposition'). Despite manifold studies, motivated by the continuous trend to shrink wiring dimensions and thus the demand of optimized plating baths, detailed knowledge on the growth mechanism - in presence and absence of additives - is still lacking. Using a recently developed hanging meniscus X-ray transmission cell, brilliant synchrotron x-rays and a fast, one-dimensional detector system, unique real-time in situ surface X-ray diffraction studies of copper electrodeposition were performed under realistic reaction conditions, approaching rates of technological relevance. Preparatory measurements of the electrochemical dissolution of Au(001) in chloride-containing electrolyte demonstrated the capability of this powerful technique, specifically the possibility to follow atomic-scale deposition or dissolution processes with a time resolution down to five milliseconds. The electrochemical as well as structural characterization of the Cu(001)- and Cu(111)-electrolyte interfaces provided detailed insight into the complex atomic-scale structures in presence of specifically adsorbed chloride on these surfaces. The interface of Cu(001) in chloride-containing electrolyte exhibits a continuous surface phase transition of a disordered Cl adlayer to a c(2 x 2) Cl adlayer with increasing potential. The latter was found to induce a small vertical corrugation of substrate atoms, which can be ascribed to lattice relaxations induced by the presence of coadsorbed water molecules and cations in the outer part of the electrochemical double layer. The study of the specific adsorption of chloride on Cu(111) from acidic aqueous

  12. In situ surface X-ray diffraction studies of the copper-electrolyte interface. Atomic structure and homoepitaxial grwoth

    Energy Technology Data Exchange (ETDEWEB)

    Golks, Frederik

    2011-05-19

    Copper electrodeposition is the predominantly used technique for on-chip wiring in the fabrication of ultra-large scale integrated (ULSI) microchips. In this 'damascene copper electroplating' process, multicomponent electrolytes containing organic additives realize void-free filling of trenches with high aspect ratio ('superconformal deposition'). Despite manifold studies, motivated by the continuous trend to shrink wiring dimensions and thus the demand of optimized plating baths, detailed knowledge on the growth mechanism - in presence and absence of additives - is still lacking. Using a recently developed hanging meniscus X-ray transmission cell, brilliant synchrotron x-rays and a fast, one-dimensional detector system, unique real-time in situ surface X-ray diffraction studies of copper electrodeposition were performed under realistic reaction conditions, approaching rates of technological relevance. Preparatory measurements of the electrochemical dissolution of Au(001) in chloride-containing electrolyte demonstrated the capability of this powerful technique, specifically the possibility to follow atomic-scale deposition or dissolution processes with a time resolution down to five milliseconds. The electrochemical as well as structural characterization of the Cu(001)- and Cu(111)-electrolyte interfaces provided detailed insight into the complex atomic-scale structures in presence of specifically adsorbed chloride on these surfaces. The interface of Cu(001) in chloride-containing electrolyte exhibits a continuous surface phase transition of a disordered Cl adlayer to a c(2 x 2) Cl adlayer with increasing potential. The latter was found to induce a small vertical corrugation of substrate atoms, which can be ascribed to lattice relaxations induced by the presence of coadsorbed water molecules and cations in the outer part of the electrochemical double layer. The study of the specific adsorption of chloride on Cu(111) from acidic aqueous electrolyte revealed a

  13. EPR and X-ray diffraction investigation of some Greek marbles and limestones

    International Nuclear Information System (INIS)

    Duliu, Octavian; Grecu, Maria Nicoleta; Cristea, Corina

    2009-01-01

    Twelve different marble and limestone samples collected from well-known Greek quarries have been investigated by X-ray diffraction and electron paramagnetic resonance (EPR). X-ray diffraction spectra permitted to determine both major (calcite and dolomite) and minor (quartz or magnesite) mineralogical components. EPR has been used to investigate the same samples unirradiated and after 10 kGy gamma-ray irradiation. The unirradiated samples display typical EPR spectra of Mn 2+ in calcite and dolomite as well as a superposition of these while some samples displayed EPR free radicals signals of centers (low field signal) and centers (high field signal). From X-ray diffraction and EPR spectra it was possible to extract numerical values of several numerical parameters such as dolomite to calcite ratio, EPR intensity parameter, and low field to high field EPR signals intensity ratio. These values as well as the correlation coefficients between the digital functions that described the low field Mn 2+ ions EPR line have been used as entry data for cluster analysis to quantify the resemblance and differences between analyzed samples. (authors)

  14. Investigation of electronic order using resonant soft X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Schlappa, J.

    2006-12-01

    The aim of this PhD work was the application of resonant soft X-ray diffraction technique for the investigation of electronic order in transition metal oxides at the TM L{sub 2,3}-edge, trying to obtain a quantitative understanding of the data. The method was first systematically explored through application to a model system in order to test the feasibility of the technique and to understand of how X-ray optical effects have to be taken into account. Two more complex systems were investigated; stripe order in La{sub 1.8}Sr{sub 0.2}NiO{sub 4} and charge and orbital order in Fe{sub 3}O{sub 4}. The main focus of the work was on the spectroscopic potential of the technique, trying to obtain a level of quantitative description of the data. For X-ray absorption spectroscopy (XAS) from transition metal oxides, cluster configuration interaction calculation provides a powerful and realistic microscopic theory. In the frame work of this thesis cluster theory, considering explicit hybridization effects between the TM-ion and the surrounding oxygen ligands, has been applied for the first time to describe resonant diffraction data. (orig.)

  15. Investigation of electronic order using resonant soft X-ray diffraction

    International Nuclear Information System (INIS)

    Schlappa, J.

    2006-01-01

    The aim of this PhD work was the application of resonant soft X-ray diffraction technique for the investigation of electronic order in transition metal oxides at the TM L 2,3 -edge, trying to obtain a quantitative understanding of the data. The method was first systematically explored through application to a model system in order to test the feasibility of the technique and to understand of how X-ray optical effects have to be taken into account. Two more complex systems were investigated; stripe order in La 1.8 Sr 0.2 NiO 4 and charge and orbital order in Fe 3 O 4 . The main focus of the work was on the spectroscopic potential of the technique, trying to obtain a level of quantitative description of the data. For X-ray absorption spectroscopy (XAS) from transition metal oxides, cluster configuration interaction calculation provides a powerful and realistic microscopic theory. In the frame work of this thesis cluster theory, considering explicit hybridization effects between the TM-ion and the surrounding oxygen ligands, has been applied for the first time to describe resonant diffraction data. (orig.)

  16. Intrinsic stress in ZrN thin films: Evaluation of grain boundary contribution from in situ wafer curvature and ex situ x-ray diffraction techniques

    International Nuclear Information System (INIS)

    Koutsokeras, L. E.; Abadias, G.

    2012-01-01

    Low-mobility materials, like transition metal nitrides, usually undergo large residual stress when sputter-deposited as thin films. While the origin of stress development has been an active area of research for high-mobility materials, atomistic processes are less understood for low-mobility systems. In the present work, the contribution of grain boundary to intrinsic stress in reactively magnetron-sputtered ZrN films is evaluated by combining in situ wafer curvature measurements, providing information on the overall biaxial stress, and ex situ x-ray diffraction, giving information on elastic strain (and related stress) inside crystallites. The thermal stress contribution was also determined from the in situ stress evolution during cooling down, after deposition was stopped. The stress data are correlated with variations in film microstructure and growth energetics, in the 0.13-0.42 Pa working pressure range investigated, and discussed based on existing stress models. At low pressure (high energetic bombardment conditions), a large compressive stress is observed due to atomic peening, which induces defects inside crystallites but also promotes incorporation of excess atoms in the grain boundary. Above 0.3-0.4 Pa, the adatom surface mobility is reduced, leading to the build-up of tensile stress resulting from attractive forces between under-dense neighbouring column boundary and possible void formation, while crystallites can still remain under compressive stress.

  17. Chandra and the VLT Jointly Investigate the Cosmic X-Ray Background

    Science.gov (United States)

    2001-03-01

    Summary Important scientific advances often happen when complementary investigational techniques are brought together . In the present case, X-ray and optical/infrared observations with some of the world's foremost telescopes have provided the crucial information needed to solve a 40-year old cosmological riddle. Very detailed observations of a small field in the southern sky have recently been carried out, with the space-based NASA Chandra X-Ray Observatory as well as with several ground-based ESO telescopes, including the Very Large Telescope (VLT) at the Paranal Observatory (Chile). Together, they have provided the "deepest" combined view at X-ray and visual/infrared wavelengths ever obtained into the distant Universe. The concerted observational effort has already yielded significant scientific results. This is primarily due to the possibility to 'identify' most of the X-ray emitting objects detected by the Chandra X-ray Observatory on ground-based optical/infrared images and then to determine their nature and distance by means of detailed (spectral) observations with the VLT . In particular, there is now little doubt that the so-called 'X-ray background' , a seemingly diffuse short-wave radiation first detected in 1962, in fact originates in a vast number of powerful black holes residing in active nuclei of distant galaxies . Moreover, the present investigation has permitted to identify and study in some detail a prime example of a hitherto little known type of object, a distant, so-called 'Type II Quasar' , in which the central black hole is deeply embedded in surrounding gas and dust. These achievements are just the beginning of a most fruitful collaboration between "space" and "ground". It is yet another impressive demonstration of the rapid progress of modern astrophysics, due to the recent emergence of a new generation of extremely powerful instruments. PR Photo 09a/01 : Images of a small part of the Chandra Deep Field South , obtained with ESO telescopes

  18. Investigation of chemical vapour deposition diamond detectors by X-ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    International Nuclear Information System (INIS)

    Olivero, P.; Manfredotti, C.; Vittone, E.; Fizzotti, F.; Paolini, C.; Lo Giudice, A.; Barrett, R.; Tucoulou, R.

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the large hadron collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of 'detector grade' artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro-beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitative study of the inhomogeneity of the charge transport parameter defined as the product of mobility and lifetime for both electron and holes. XBIL represents a technique complementary to ion beam induced luminescence (IBIL), which has already been used by our group, since X-ray energy loss profile in the material is different from that of MeV ions. X-ray induced luminescence maps have been performed simultaneously with induced photocurrent maps, to correlate charge transport and induced luminescence properties of diamond. Simultaneous XBICC and XBIL maps exhibit features of partial complementarity that have been interpreted on the basis of considerations on radiative and non-radiative recombination processes which compete with charge transport efficiency

  19. In situ analyses of Ag speciation in tissues of cucumber and wheat using synchrotron-based X-ray absorption spectroscopy

    Data.gov (United States)

    U.S. Environmental Protection Agency — In situ analyses of Ag speciation in tissues of cucumber and wheat using synchrotron-based X-ray absorption spectroscopy showing spectral fitting and linear...

  20. Structural changes of polymer-coated microgranules and excipients on tableting investigated by microtomography using synchrotron X-ray radiation.

    Science.gov (United States)

    Kajihara, Ryusuke; Noguchi, Shuji; Iwao, Yasunori; Suzuki, Yoshio; Terada, Yasuko; Uesugi, Kentaro; Itai, Shigeru

    2015-03-15

    Multiple-unit tablets consisting of polymer-coated microgranules and excipients have a number of advantageous pharmaceutical properties. Polymer-coated microgranules are known to often lose their functionality because of damage to the polymer coating caused by tableting, and the mechanism of polymer coating damage as well as the structural changes of excipients upon tableting had been investigated but without in-situ visualization and quantitative analysis. To elucidate the mechanism of coating damage, the internal structures of multiple-unit tablets were investigated by X-ray computed microtomography using synchrotron X-rays. Cross sectional images of the tablets with sub-micron spatial resolution clearly revealed that void spaces remained around the compressed excipient particles in the tablets containing an excipient composed of cellulose and lactose (Cellactose(®) 80), whereas much smaller void spaces remained in the tablets containing an excipient made of sorbitol (Parteck(®) SI 150). The relationships between the void spaces and the physical properties of the tablets such as hardness and disintegration were investigated. Damage to the polymer coating in tablets was found mainly where polymer-coated microgranules were in direct contact with each other in both types of tablets, which could be attributed to the difference in hardness of excipient particles and the core of the polymer-coated microgranules. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Probing the influence of X-rays on aqueous copper solutions using time-resolved in situ combined video/X-ray absorption near-edge/ultraviolet-visible spectroscopy

    NARCIS (Netherlands)

    Mesu, J. Gerbrand; Beale, Andrew M.; de Groot, Frank M. F.; Weckhuysen, Bert M.

    2006-01-01

    Time-resolved in situ video monitoring and ultraviolet-visible spectroscopy in combination with X-ray absorption near-edge spectroscopy (XANES) have been used for the first time in a combined manner to study the effect of synchrotron radiation on a series of homogeneous aqueous copper solutions in a

  2. A Next-Generation Hard X-Ray Nanoprobe Beamline for In Situ Studies of Energy Materials and Devices

    Science.gov (United States)

    Maser, Jörg; Lai, Barry; Buonassisi, Tonio; Cai, Zhonghou; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Jacobsen, Chris; Preissner, Curt; Roehrig, Chris; Rose, Volker; Shu, Deming; Vine, David; Vogt, Stefan

    2014-01-01

    The Advanced Photon Source is developing a suite of new X-ray beamlines to study materials and devices across many length scales and under real conditions. One of the flagship beamlines of the APS upgrade is the In Situ Nanoprobe (ISN) beamline, which will provide in situ and operando characterization of advanced energy materials and devices under varying temperatures, gas ambients, and applied fields, at previously unavailable spatial resolution and throughput. Examples of materials systems include inorganic and organic photovoltaic systems, advanced battery systems, fuel cell components, nanoelectronic devices, advanced building materials and other scientifically and technologically relevant systems. To characterize these systems at very high spatial resolution and trace sensitivity, the ISN will use both nanofocusing mirrors and diffractive optics to achieve spots sizes as small as 20 nm. Nanofocusing mirrors in Kirkpatrick-Baez geometry will provide several orders of magnitude increase in photon flux at a spatial resolution of 50 nm. Diffractive optics such as zone plates and/or multilayer Laue lenses will provide a highest spatial resolution of 20 nm. Coherent diffraction methods will be used to study even small specimen features with sub-10 nm relevant length scale. A high-throughput data acquisition system will be employed to significantly increase operations efficiency and usability of the instrument. The ISN will provide full spectroscopy capabilities to study the chemical state of most materials in the periodic table, and enable X-ray fluorescence tomography. In situ electrical characterization will enable operando studies of energy and electronic devices such as photovoltaic systems and batteries. We describe the optical concept for the ISN beamline, the technical design, and the approach for enabling a broad variety of in situ studies. We furthermore discuss the application of hard X-ray microscopy to study defects in multi-crystalline solar cells, one

  3. In Situ Local Contact Angle Measurement in a CO2-Brine-Sand System Using Microfocused X-ray CT.

    Science.gov (United States)

    Lv, Pengfei; Liu, Yu; Wang, Zhe; Liu, Shuyang; Jiang, Lanlan; Chen, Junlin; Song, Yongchen

    2017-04-11

    The wettability of porous media is of major interest in a broad range of natural and engineering applications. The wettability of a fluid on a solid surface is usually evaluated by the contact angle between them. While in situ local contact angle measurements are complicated by the topology of porous media, which can make it difficult to use traditional methods, recent advances in microfocused X-ray computed tomography (micro-CT) and image processing techniques have made it possible to measure contact angles on the scale of the pore sizes in such media. However, the effects of ionic strength, CO 2 phase, and flow pattern (drainage or imbibition) on pore-scale contact angle distribution are still not clear and have not been reported in detail in previous studies. In this study, we employed a micro-CT scanner for in situ investigation of local contact angles in a CO 2 -brine-sand system under various conditions. The effects of ionic strength, CO 2 phase, and flow pattern on the local contact-angle distribution were examined in detail. The results showed that the local contact angles vary over a wide range as a result of the interaction of surface contaminants, roughness, pore topology, and capillarity. The wettability of a porous surface could thus slowly weaken with increasing ionic strength, and the average contact angle could significantly increase when gaseous CO 2 (gCO 2 ) turns into supercritical CO 2 (scCO 2 ). Contact angle hysteresis also occurred between drainage and imbibition procedures, and the hysteresis was more significant under gCO 2 condition.

  4. Investigation of radiation absorption and X-ray fluorescence properties of medical imaging scintillators by Monte Carlo methods

    International Nuclear Information System (INIS)

    Nikolopoulos, D.; Kandarakis, I.; Cavouras, D.; Valais, I.; Linardatos, D.; Michail, C.; David, S.; Gaitanis, A.; Nomicos, C.; Louizi, A.

    2006-01-01

    X-ray absorption and X-ray fluorescence properties of medical imaging scintillating screens were studied by Monte Carlo methods as a function of the incident photon energy and screen-coating thickness. The scintillating materials examined were Gd 2 O 2 S (GOS) Gd 2 SiO 5 (GSO) YAlO 3 (YAP), Y 3 Al 5 O 12 (YAG), LuSiO 5 (LSO), LuAlO 3 (LuAP) and ZnS. Monoenergetic photon exposures were modeled in the range from 10 to 100 keV. The corresponding ranges of coating thicknesses of the investigated scintillating screens ranged up to 200 mg cm -2 . Results indicated that X-ray absorption and X-ray fluorescence are affected by the incident photon energy and the screen's coating thickness. Regarding incident photon energy, this X-ray absorption and fluorescence was found to exhibit very intense changes near the corresponding K edge of the heaviest element in the screen's scintillating material. Regarding coating thickness, thicker screens exhibited higher X-ray absorption and X-ray fluorescence. Results also indicated that a significant fraction of the generated X-ray fluorescent quanta escape from the scintillating screen. This fraction was found to increase with screen's coating thickness. At the energy range studied, most of the incident photons were found to be absorbed via one-hit photoelectric effect. As a result, the reabsorption of scattered radiation was found to be of rather minor importance; nevertheless this was found to increase with the screen's coating thickness. Differences in X-ray absorption and X-ray fluorescence were found among the various scintillators studied. LSO scintillator was found to be the most attractive material for use in many X-ray imaging applications, exhibiting the best absorption properties in the largest part of the energy range studied. Y-based scintillators were also found to be of significant absorption performance within the low energy ranges

  5. AN X-RAY INVESTIGATION OF THREE SUPERNOVA REMNANTS IN THE LARGE MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Klimek, Matthew D.; Points, S. D.; Smith, R. C.; Shelton, R. L.; Williams, R.

    2010-01-01

    We have investigated three supernova remnants (SNRs) in the LMC using multi-wavelength data. These SNRs are generally fainter than the known sample (see Section 4) and may represent a previously missed population. One of our SNRs is the second LMC remnant analyzed which is larger than any Galactic remnant for which a definite size has been established. The analysis of such a large remnant contributes to the understanding of the population of highly evolved SNRs. We have obtained X-ray images and spectra of three of these recently identified SNRs using the XMM-Newton observatory. These data, in conjunction with pre-existing optical emission-line images and spectra, were used to determine the physical conditions of the optical- and X-ray-emitting gas in the SNRs. We have compared the morphologies of the SNRs in the different wavebands. The physical properties of the warm ionized shell were determined from the Hα surface brightness and the SNR expansion velocity. The X-ray spectra were fit with a thermal plasma model and the physical conditions of the hot gas were derived from the model fits. Finally, we have compared our observations with simulations of SNR evolution.

  6. Ion backscattering and X-ray investigations of violin varnish and wood

    International Nuclear Information System (INIS)

    Sigurd, D.; Tove, P.A.; Petersson, S.

    1980-01-01

    The use of Rutherford backscattering (RBS) of ions (i.e. α-particles) and excitation of characteristic X-rays by protons, for determining the elemental composition of the top layers of violin varnish and wood is described. The amount of elements such as C, O, Si, S, Ca, Cu, Fe, Ni, Zn, Pb has been measured, on the varnished and unvarnished sides of wood samples from old instrument makers such as A. Stradivari, G. Guarneri del Gesu, Santo Serafin, C. Tononi etc. Differences in both the shape of the RBS spectra and in the presence of different elements are found and discussed. The use of X-ray excitation by ions (i.e. protons) helps in assessing the presence of the different elements. X-ray investigations can be done with instruments in air while RBS (at least in the presently used form) has to be performed in a vacuum chamber. Apart from offering an aid in determining the materials and procedures which were used in fabricating acoustically excellent instruments, the method could be of value for identifying their authenticity. (orig.)

  7. Ion backscattering and x-ray investigations of violin varnish and wood

    Science.gov (United States)

    Arne Tove, Per; Sigurd, Dag; Petersson, Sture

    1980-01-01

    The use of Rutherford backscattering (RBS) of ions (i.e. α-particles) and excitation of characteristic X-rays by protons, for determining the elemental composition of the top layers of violin varnish and wood is described. The amount of elements such as C, O, Si, S, Ca, Cu, Fe, Ni, Zn, Pb has been measured, on the varnished and unvarnished sides of wood samples from old instrument makers such as A. Stradivari, G. Guarneri del Gesu, Santo Serafin, C. Tononi etc. Differences in both the shape of the RBS spectra and in the presence of different elements are found and discussed. The use of X-ray excitation by ions (i.e. protons) helps in assessing the presence of the different elements. X-ray investigations can be done with instruments in air while RBS (at least in the presently used form) has to be performed in a vacuum chamber. Apart from offering an aid in determining the materials and procedures which were used in fabricating acoustically excellent instruments, the method could be of value for identifying their authenticity.

  8. Investigation of water seepage through porous media using X-ray imaging technique

    Science.gov (United States)

    Jung, Sung Yong; Lim, Seungmin; Lee, Sang Joon

    2012-07-01

    SummaryDynamic movement of wetting front and variation of water contents through three different porous media were investigated using X-ray radiography. Water and natural sand particles were used as liquid and porous media in this study. To minimize the effects of minor X-ray attenuation and uneven illumination, the flat field correction (FFC) was applied before determining the position of wetting front. In addition, the thickness-averaged (in the direction of the X-ray penetration) water content was obtained by employing the Beer-Lambert law. The initial inertia of water droplet influences more strongly on the vertical migration, compared to the horizontal migration. The effect of initial inertia on the horizontal migration is enhanced as sand size decreases. The pattern of water transport is observed to be significantly affected by the initial water contents. As the initial water contents increases, the bulb-type transport pattern is shifted to a trapezoidal shape. With increasing surface temperature, water droplets are easily broken on the sand surface. This consequently decreases the length of the initial inertia region. Different from the wetting front migration, the water contents at the initial stage clearly exhibit a preferential flow along the vertical direction. The water transport becomes nearly uniform in all directions beyond the saturation state.

  9. Investigations of some regional river systems by INAA and X-ray fluorescence

    International Nuclear Information System (INIS)

    Drazhkovich, R.J.; Kukoch, A.

    1985-01-01

    Distribution of Zn, Hg, Sb, Cr, Fe, Sc and Co has been investigated in materials dissolved and suspended in the rivers Ibar, Zapadna Morava and Kamenica by means of INAA and X-ray fluorescence. Irradiation was made in VKG-channels of RA-nuclear reactor Vincha. Distribution coefficients were calculated, as well as contamination factors for investigated river regional systems in comparison to the uncontaminated water system. Data obtained indicate the possibility of utilization of these two analytical methods for investigation and control of biogeochemical and contamination processes in small regional water systems, especially important for modern studies in life sciences

  10. Estimation of bearing contact angle in-situ by X-ray kinematography

    Science.gov (United States)

    Fowler, P. H.; Manders, F.

    1982-01-01

    The mounted, preloaded contact angle of the structural bearings in the assembled design mechanical assembly was measured. A modification of the Turns method is presented, based upon the clarity and definition of moving parts achieved with X-ray technique and cinematic display. Contact angle is estimated by counting the number of bearings passing a given point as a function of number of turns of the shaft. Ball and pitch diameter variations are discussed. Ball train and shaft angle uncertainties are also discussed.

  11. In situ stress determination by X-ray diffractometry and its prospects

    International Nuclear Information System (INIS)

    Castex, Louis

    The mechanical behavior of the metallic construction generally relates to the amount of the residual stress which reigned in the constitutive material. It is then essential to evaluate the residual stress inside the material without destruction. The X-ray diffractometry apparatus which we have developed for this study consisted of the use of the linear sensitive detector, the special psi-goniometer and the programming computer [fr

  12. Synchrotron-based in situ soft X-ray microscopy of Ag corrosion in aqueous chloride solution

    International Nuclear Information System (INIS)

    Bozzini, B; D'Urzo, L; Gianoncelli, A; Kaulich, B; Kiskinova, M; Prasciolu, M; Tadjeddine, A

    2009-01-01

    In this paper we report an in situ X-ray microscopy study of a model metal electrochemistry system, incorporating faradaic reactivity: the anodic corrosion and cathodic electrodeposition of Ag in aqueous systems. The information at sub-μm scale about morpho-chemical evolution of the electrified interface, provided by this novel electroanalytical approach fosters fundamental understanding of important issues concerning material fabrication and stability, which are crucial in developing the next generation electrochemical technologies, such as fuel cells and biosensors. The key methodology challenge faced in this pilot electrochemical experiments is combining a three-electrode configuration and wet environment, which required metal electrodes suitable for transmitting soft X-rays and a sealed cell allowing working in high vacuum. This has been solved via lithographic fabrication route fabricating 75 nm thick Ag electrodes and using Si 3 N 4 membranes as X-ray windows and electrode support. Imaging in the STXM mode with phase contrast allowed us to monitor the corrosion morphologies and metal outgrowth features. Localised thickness variation and the build-up of reaction products of electron density different from that of the starting material have been detected with high sensitivity.

  13. In situ X-ray powder diffraction studies of the synthesis of graphene oxide and formation of reduced graphene oxide

    International Nuclear Information System (INIS)

    Storm, Mie Møller; Johnsen, Rune E.; Norby, Poul

    2016-01-01

    Graphene oxide (GO) and reduced graphene oxide (rGO) are important materials in a wide range of fields. The modified Hummers methods, for synthesizing GO, and subsequent thermal reduction to rGO, are often employed for production of rGO. However, the mechanism behinds these syntheses methods are still unclear. We present an in situ X-ray diffraction study of the synthesis of GO and thermal reduction of GO. The X-ray diffraction revealed that the Hummers method includes an intercalation state and finally formation of additional crystalline material. The formation of GO is observed during both the intercalation and the crystallization stage. During thermal reduction of GO three stages were observed: GO, a disordered stage, and the rGO stage. The appearance of these stages depends on the heating ramp. The aim of this study is to provide deeper insight into the chemical and physical processes during the syntheses. - Graphical abstract: In situ X-ray diffraction results for of the modified Hummers synthesis and the thermal reduction of graphene oxide, revealing three stages for both syntheses as well as new GO diffraction peaks and unidentified crystalline material for the Hummers synthesis and a disordered stage for the thermal reduction of graphene oxide. Display Omitted - Highlights: • Hummers synthesis consists of three stages: dissolution, intercalation and crystal. • GO is produced early on during the synthesis and display new diffraction peaks. • An unidentified triclinic phase is observed for the Hummers synthesis. • Thermal reduction of GO display three stages: GO, a disordered stage and rGO. • In situ XRD indicate reformation of rGO even for fast heated thermal reduction.

  14. In situ X-ray powder diffraction studies of the synthesis of graphene oxide and formation of reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Storm, Mie Møller, E-mail: mmst@dtu.dk; Johnsen, Rune E.; Norby, Poul

    2016-08-15

    Graphene oxide (GO) and reduced graphene oxide (rGO) are important materials in a wide range of fields. The modified Hummers methods, for synthesizing GO, and subsequent thermal reduction to rGO, are often employed for production of rGO. However, the mechanism behinds these syntheses methods are still unclear. We present an in situ X-ray diffraction study of the synthesis of GO and thermal reduction of GO. The X-ray diffraction revealed that the Hummers method includes an intercalation state and finally formation of additional crystalline material. The formation of GO is observed during both the intercalation and the crystallization stage. During thermal reduction of GO three stages were observed: GO, a disordered stage, and the rGO stage. The appearance of these stages depends on the heating ramp. The aim of this study is to provide deeper insight into the chemical and physical processes during the syntheses. - Graphical abstract: In situ X-ray diffraction results for of the modified Hummers synthesis and the thermal reduction of graphene oxide, revealing three stages for both syntheses as well as new GO diffraction peaks and unidentified crystalline material for the Hummers synthesis and a disordered stage for the thermal reduction of graphene oxide. Display Omitted - Highlights: • Hummers synthesis consists of three stages: dissolution, intercalation and crystal. • GO is produced early on during the synthesis and display new diffraction peaks. • An unidentified triclinic phase is observed for the Hummers synthesis. • Thermal reduction of GO display three stages: GO, a disordered stage and rGO. • In situ XRD indicate reformation of rGO even for fast heated thermal reduction.

  15. A geometrical approach for semi-automated crystal centering and in situ X-ray diffraction data collection

    International Nuclear Information System (INIS)

    Mohammad Yaser Heidari Khajepour; Ferrer, Jean-Luc; Lebrette, Hugo; Vernede, Xavier; Rogues, Pierrick

    2013-01-01

    High-throughput protein crystallography projects pushed forward the development of automated crystallization platforms that are now commonly used. This created an urgent need for adapted and automated equipment for crystal analysis. However, first these crystals have to be harvested, cryo-protected and flash-cooled, operations that can fail or negatively impact on the crystal. In situ X-ray diffraction analysis has become a valid alternative to these operations, and a growing number of users apply it for crystal screening and to solve structures. Nevertheless, even this shortcut may require a significant amount of beam time. In this in situ high-throughput approach, the centering of crystals relative to the beam represents the bottleneck in the analysis process. In this article, a new method to accelerate this process, by recording accurately the local geometry coordinates for each crystal in the crystallization plate, is presented. Subsequently, the crystallization plate can be presented to the X-ray beam by an automated plate-handling device, such as a six-axis robot arm, for an automated crystal centering in the beam, in situ screening or data collection. Here the preliminary results of such a semi-automated pipeline are reported for two distinct test proteins. (authors)

  16. Determination of existing exposure level of population during X ray investigations

    International Nuclear Information System (INIS)

    Tselinov, N.V.; Kudritskij, Yu.K.

    1978-01-01

    The distribution of X ray procedures among 500 inhabitants of the city of Vorkuta in 1975 is studied. Data on the distribution of the subjects by age group and type of X ray procedure are presented. The results obtained broaden the existing concepts on hygienic importance of radiation received by the population of the country during X ray studies. It is proposed that these results be used in developing methods for standardizing X ray procedures

  17. Experimental investigation of void coalescence in a dual phase steel using X-ray tomography

    International Nuclear Information System (INIS)

    Landron, C.; Bouaziz, O.; Maire, E.; Adrien, J.

    2013-01-01

    In situ tensile tests were carried out during X-ray microtomography imaging of a smooth and a notched specimen of dual phase steel. The void coalescence was first qualitatively observed and quantitative data concerning this damage step was then acquired. The void coalescence criteria of Brown and Embury and of Thomason were then tested against the experimental data at both the macroscopic and local levels. Although macroscopic implementation of the criteria gave acceptable results, the local approach was probably closest to the real nature of void coalescence, because it takes into account local coalescence events observed experimentally before final fracture. The correlation between actual coalescing couples of cavities and local implementation of the two criteria showed that the Thomason criterion is probably the best adapted to predict the local coalescence events in the case of the material studied

  18. A Rotational and Axial Motion System Load Frame Insert for In Situ High Energy X-Ray Studies (Postprint)

    Science.gov (United States)

    2015-09-08

    Paul A. Shade, Jay C. Schuren, and Todd J. Turner AFRL/RX Basil Blank PulseRay Peter Kenesei, Kurt Goetze, Ulrich Lienert, and Jonathan Almer...AFRL/RX 2) Basil Blank – PulseRay (continued on page 2) 5d. PROJECT NUMBER 4349 5e. TASK NUMBER 0001 5f...2015) A rotational and axial motion system load frame insert for in situ high energy x-ray studies Paul A. Shade,1,a) Basil Blank,2 Jay C. Schuren,1,b

  19. In situ multi-axial loading frame to probe elastomers using X-ray scattering.

    Science.gov (United States)

    Pannier, Yannick; Proudhon, Henry; Mocuta, Cristian; Thiaudière, Dominique; Cantournet, Sabine

    2011-11-01

    An in situ tensile-shear loading device has been designed to study elastomer crystallization using synchrotron X-ray scattering at the Synchrotron Soleil on the DiffAbs beamline. Elastomer tape specimens of thickness 2 mm can be elongated by up to 500% in the longitudinal direction and sheared by up to 200% in the transverse direction. The device is fully automated and plugged into the TANGO control system of the beamline allowing synchronization between acquisition and loading sequences. Experimental results revealing the evolution of crystallization peaks under load are presented for several tension/shear loading sequences.

  20. In-situ observation of deuteride formation in palladium electrochemical cathode by X-ray diffraction method

    International Nuclear Information System (INIS)

    Yamamoto, Takao; Oka, Takashi; Taniguchi, Ryoichi

    1990-01-01

    In-situ X-ray diffraction observation of palladium foil cathode (10 μm) was carried out during electrolysis of 0.1N-LiOD heavy water solution in order to estimate the deuterium content in palladium during the detection of charged particles in our previous work. A complete transformation into β-palladium deuteride phase was observed, and its maximum lattice constant 4.06 A was evaluated as corresponding to D/Pd = 0.73. The deuterium concentration in the previous work was estimated as higher than this considering the difference in cell conditions. (author)

  1. Strength of shock-loaded single-crystal tantalum [100] determined using in situ broadband x-ray Laue diffraction.

    Science.gov (United States)

    Comley, A J; Maddox, B R; Rudd, R E; Prisbrey, S T; Hawreliak, J A; Orlikowski, D A; Peterson, S C; Satcher, J H; Elsholz, A J; Park, H-S; Remington, B A; Bazin, N; Foster, J M; Graham, P; Park, N; Rosen, P A; Rothman, S R; Higginbotham, A; Suggit, M; Wark, J S

    2013-03-15

    The strength of shock-loaded single crystal tantalum [100] has been experimentally determined using in situ broadband x-ray Laue diffraction to measure the strain state of the compressed crystal, and elastic constants calculated from first principles. The inferred strength reaches 35 GPa at a shock pressure of 181 GPa and is in excellent agreement with a multiscale strength model [N. R. Barton et al., J. Appl. Phys. 109, 073501 (2011)], which employs a hierarchy of simulation methods over a range of length scales to calculate strength from first principles.

  2. Measurement of ZnO/Al2O3 Heterojunction Band Offsets by in situ X-Ray Photoelectron Spectroscopy

    International Nuclear Information System (INIS)

    Lei Hong-Wen; Zhang Hong; Wang Xue-Min; Zhao Yan; Yan Da-Wei; Jiang Zhong-Qian; Yao Gang; Zeng Ti-Xian; Wu Wei-Dong

    2013-01-01

    ZnO films are grown on c-sapphire substrates by laser molecular beam epitaxy. The band offsets of the ZnO/Al 2 O 3 heterojunction are studied by in situ x-ray photoelectron spectroscopy. The valence band of Al 2 O 3 is found to be 3.59±0.05eV below that of ZnO. Together with the resulting conduction band offset of 2.04±0.05eV, this indicates that a type-I staggered band line exists at the ZnO/Al 2 O 3 heterojunction

  3. Investigation of HF-plasma-treated soft x-ray optical elements

    Science.gov (United States)

    Eggenstein, F.; Krivenkov, M.; Rudolph, I.; Sertsu, M. G.; Sokolov, A.; Varykhalov, A.; Wolf, J.; Zeschke, T.; Schäfers, F.

    2017-09-01

    The contamination of optical elements (mirrors and gratings) with carbon still is an issue when using soft x-ray synchrotron radiation. With an in-house developed HF-plasma treatment we are able to decontaminate our optics in-situ from carbon very efficiently. The cleaning device, a simple Al-antenna, is mounted in situ inside the mirror- and grating vacuum chambers. A systematic study of the HF-plasma cleaning efficiency was performed acquired with in-situ and exsitu methods for monitoring: An atomic force microscope (AFM) and a scanning tunneling microscope (STM) were used before and after the cleaning process to determine the surface morphology and roughness. Reflectivity angular scans using the reflectometer at the BESSY-II Metrology Station [1-3] allowed to estimate the thickness of the remaining Clayer after different cleaning steps and thereby helped us to determine the etching rate. Reflection spectra measurements in the range of 200 eV - 900 eV show the complete removal of Carbon from the optics without contaminating it with any other elements due to the plasma treatment. The data show that the plasma process improves the reflectivity and reduces the roughness of the surface. In addition to that, the region of the optical surface where the carbon has been removed becomes passivated.

  4. Investigation of hepatic fibrosis with synchrotron X-ray diffraction enhanced imaging

    International Nuclear Information System (INIS)

    Li Hui; Beijing Univ., Health Science Center, Beijing; Wang Xueyan; Zhao Tao; Hu Chunhong; Lu Weiyuan; Luo Shuqian; Wang Tailing; Wang Baoen; Zhao Xinyan; Zhu Peiping; Huang Wanxia; Yuan Qingxi; Wang Junyue

    2008-01-01

    In this paper, imaging investigation of hepatic fibrosis in rats induced by human albumin with hard X-ray diffraction enhanced imaging (DEI) is reported. The experiments were performed at 4W1A beamline of Beijing Synchrotron Radiation Facility (BSRF). The results show that great differences can be observed in DEI images between the normal and diseased rats in different stages of liver fibrosis. The difference can also be revealed by the profile curve and texture measurements on regions of interest. The results show that DEI may be a potential way for diagnosis of hepatic fibrosis. (authors)

  5. Phase transition sequence in ferroelectric Aurivillius compounds investigated by single crystal X-ray diffraction

    Science.gov (United States)

    Boullay, P.; Tellier, J.; Mercurio, D.; Manier, M.; Zuñiga, F. J.; Perez-Mato, J. M.

    2012-09-01

    The investigation of the phase transition sequence in SrBi2Ta2O9 (SBT) and SrBi2Nb2O9 (SBN) is reported using single-crystal X-ray diffraction. By monitoring specific reflections as a function of temperature, sensitive either to the superstructure formation or to polar displacements, it was possible to check the existence or not of an intermediate phase. This latter was confirmed in SBT, but within experimental accuracy could not be detected in SBN.

  6. X-ray structural investigation into complexes of p-aminobenzoic acid and metals

    International Nuclear Information System (INIS)

    Amiraslanov, I.R.; Musaev, F.N.; Mamedov, Kh.S.

    1982-01-01

    X-ray structural investigation of p-aminobenzoatodiaqua-strontium Sr(H 2 NC 6 H 4 COO) 2 x2H 2 o' was carried out. Crystals were rhombic: a=6.86(1), b=13.39(2), c=18.58(2) A, V=1705 A, Z=4, space group P2 1 2 1 2 1 . The basis of the structure was formed by infinite along the axis a chains of strontium atom octavertices articulated with common oxygen vertices. Sr-O bond lengths were 2.46-2.74 A; the distance between strontium neighbour - ring atom 4.07(1) A. Bond angles were presented

  7. X-ray absorption spectroscopy study of the LixFePO4 cathode during cycling using a novel electrochemical in situ reaction cell

    International Nuclear Information System (INIS)

    Deb, A.; Bergmann, U.; Cairns, E.L.; California Univ., Berkeley, CA; Cramer, S.P.; California Univ., Davis, CA

    2004-01-01

    The extraction and insertion of lithium in LiFePO 4 has been investigated in practical Li-ion intercalation electrodes for Li-ion batteries using Fe K-edge X-ray absorption spectroscopy (XAS). A versatile electrochemical in situ reaction cell was utilized, specifically designed for long-term X-ray experiments on battery electrodes during the lithium-extraction/insertion process in electrode materials for Li-ion batteries. The electrode contained about 7.7 mg of LiFePO 4 on a 20 μm-thick Al foil. In order to determine the charge compensation mechanism and structural perturbations occurring in the system during cycling, in situ X-ray absorption fine-structure spectroscopy (XAFS) measurements were conducted on the cell at a moderate rate using typical Li-ion battery operating voltages (3.0-4.1 V versus Li/Li + ).XAS studies of the LiFePO 4 electrode measured at the initial state (LiFePO 4 ) showed iron to be in the Fe(II) state corresponding to the initial state (0.0 mAh) of the battery, whereas in the delithiated state (FePO 4 ) iron was found to be in the FE(III) state corresponding to the final charged state (3 m Ah) of the battery. The X-ray absorption near-edge structure (XANES) region of the XAS spectra revealed a high-spin configuration for the two states [Fe(II), d 6 and Fe(III), d 5 ]. The XAFS data analysis confirmed that the olivine structure of the LeFePO 4 and FePO 4 is retained by the electrodes, which is in agreement with the X-ray diffraction observations on these compounds. The XAFS data that were collected continuously during cycling revealed details about the response of the cathode to Li insertion and extraction. These measurements on the LiFePO 4 cathode show that the material retains good structural short-range order leading to superior cycling

  8. Investigation of the hard x-ray background in backlit pinhole imagers

    Energy Technology Data Exchange (ETDEWEB)

    Fein, J. R., E-mail: jrfein@umich.edu; Holloway, J. P. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States); Peebles, J. L. [Center for Energy Research, University of California, San Diego, La Jolla, California 92093 (United States); Keiter, P. A.; Klein, S. R.; Kuranz, C. C.; Manuel, M. J.-E.; Drake, R. P. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States)

    2014-11-15

    Hard x-rays from laser-produced hot electrons (>10 keV) in backlit pinhole imagers can give rise to a background signal that decreases signal dynamic range in radiographs. Consequently, significant uncertainties are introduced to the measured optical depth of imaged plasmas. Past experiments have demonstrated that hard x-rays are produced when hot electrons interact with the high-Z pinhole substrate used to collimate the softer He-α x-ray source. Results are presented from recent experiments performed on the OMEGA-60 laser to further study the production of hard x-rays in the pinhole substrate and how these x-rays contribute to the background signal in radiographs. Radiographic image plates measured hard x-rays from pinhole imagers with Mo, Sn, and Ta pinhole substrates. The variation in background signal between pinhole substrates provides evidence that much of this background comes from x-rays produced in the pinhole substrate itself. A Monte Carlo electron transport code was used to model x-ray production from hot electrons interacting in the pinhole substrate, as well as to model measurements of x-rays from the irradiated side of the targets, recorded by a bremsstrahlung x-ray spectrometer. Inconsistencies in inferred hot electron distributions between the different pinhole substrate materials demonstrate that additional sources of hot electrons beyond those modeled may produce hard x-rays in the pinhole substrate.

  9. On-line and in-situ x-ray diffraction analysis of the crystallisation of important pharmaceutical materials

    International Nuclear Information System (INIS)

    Hastings, S.

    1999-01-01

    Full text: The crystallisation process is an important unit operation for the separation and purification of many chemical products, particularly in the pharmaceutical industry. Variations in the conditions of crystallisation can lead to the formation of different polymorphic forms which are often meta-stable phases which results in phase conversion at different rates to the stable form. Our group, in collaboration with many industrial sponsors, have developed a number of online techniques which help to optimise the processing conditions of many of these specialty materials. In particular, on-line and in-situ X-ray diffraction (XRD) has been used to monitor the crystallisation of pharmaceutical materials. Several novel in-situ X-ray cells have been developed, in particular; a solution cell, which allows us to control and hence optimise crystallographic conditions such as temperature and pH whilst monitoring the crystal structure of the sample as it crystallises from solution. In conjunction with XRD data information on turbidity (% light transmittance) is taken to analyse solvent-mediated crystallisation. This technique gives information on the temperatures at which the system crystallises and dissolves. From this the meta-stable zone width (MSZW) can be calculated and then directly related to the crystal structure of the particles formed. The current system being studied is the crystallisation of stearic acid, a common pharmaceutical excipient, in various polar and non-polar solvents in order to ascertain the effect that the polarity of the solvent has on the polymorphic form crystallised. By combining such kinetic assessment with measurements of resulting particle structure the potential to optimise the process to produce optimal particle properties is obtainable. Copyright (1999) Australian X-ray Analytical Association Inc

  10. Probing Stress States in Silicon Nanowires During Electrochemical Lithiation Using In Situ Synchrotron X-Ray Microdiffraction

    Directory of Open Access Journals (Sweden)

    Imran Ali

    2018-04-01

    Full Text Available Silicon is considered as a promising anode material for the next-generation lithium-ion battery (LIB due to its high capacity at nanoscale. However, silicon expands up to 300% during lithiation, which induces high stresses and leads to fractures. To design silicon nanostructures that could minimize fracture, it is important to understand and characterize stress states in the silicon nanostructures during lithiation. Synchrotron X-ray microdiffraction has proven to be effective in revealing insights of mechanical stress and other mechanics considerations in small-scale crystalline structures used in many important technological applications, such as microelectronics, nanotechnology, and energy systems. In the present study, an in situ synchrotron X-ray microdiffraction experiment was conducted to elucidate the mechanical stress states during the first electrochemical cycle of lithiation in single-crystalline silicon nanowires (SiNWs in an LIB test cell. Morphological changes in the SiNWs at different levels of lithiation were also studied using scanning electron microscope (SEM. It was found from SEM observation that lithiation commenced predominantly at the top surface of SiNWs followed by further progression toward the bottom of the SiNWs gradually. The hydrostatic stress of the crystalline core of the SiNWs at different levels of electrochemical lithiation was determined using the in situ synchrotron X-ray microdiffraction technique. We found that the crystalline core of the SiNWs became highly compressive (up to -325.5 MPa once lithiation started. This finding helps unravel insights about mechanical stress states in the SiNWs during the electrochemical lithiation, which could potentially pave the path toward the fracture-free design of silicon nanostructure anode materials in the next-generation LIB.

  11. Inhomogeneous thermal expansion of metallic glasses in atomic-scale studied by in-situ synchrotron X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Taghvaei, Amir Hossein, E-mail: amirtaghvaei@gmail.com [Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Shakur Shahabi, Hamed [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Bednarčik, Jozef [Photon Science DESY, Notkestraße 85, 22603 Hamburg (Germany); Eckert, Jürgen [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); TU Dresden, Institute of Materials Science, 01062 Dresden (Germany)

    2015-01-28

    Numerous investigations have demonstrated that the elastic strain in metallic glasses subjected to mechanical loading could be inhomogeneous in the atomic-scale and it increases with distance from an average atom and eventually reaches the macroscopic strain at larger inter-atomic distances. We have observed a similar behavior for the thermal strain imposed by heating of Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} glassy particles below the glass transition temperature by analysis of the scattering data obtained by in-situ high-energy synchrotron X-ray diffraction (XRD). The results imply that the volumetric thermal strains calculated from the shift in position of the principal diffraction maximum and reduced pair correlation function (PDF) peaks are in good agreement for the length scales beyond 0.6 nm, corresponding to the atoms located over the third near-neighbor shell. However, smaller and even negative volumetric thermal strains have been calculated based on the shifts in the positions of the second and first PDF peaks, respectively. The structural changes of Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} glassy particles are accompanied by decreasing the average coordination number of the first near-neighbor shell, which manifests the occurrence of local changes in the short-range order upon heating. It is believed that the detected length-scale dependence of the volumetric thermal strain is correlated with the local atomic rearrangements taking place in the topologically unstable regions of the glass governed by variations in the atomic-level stresses.

  12. Interaction between U/UO2 bilayers and hydrogen studied by in-situ X-ray diffraction

    Science.gov (United States)

    Darnbrough, J. E.; Harker, R. M.; Griffiths, I.; Wermeille, D.; Lander, G. H.; Springell, R.

    2018-04-01

    This paper reports experiments investigating the reaction of H2 with uranium metal-oxide bilayers. The bilayers consist of ≤ 100 nm of epitaxial α-U (grown on a Nb buffer deposited on sapphire) with a UO2 overlayer of thicknesses of between 20 and 80 nm. The oxides were made either by depositing via reactive magnetron sputtering, or allowing the uranium metal to oxidise in air at room temperature. The bilayers were exposed to hydrogen, with sample temperatures between 80 and 200 C, and monitored via in-situ x-ray diffraction and complimentary experiments conducted using Scanning Transmission Electron Microscopy - Electron Energy Loss Spectroscopy (STEM-EELS). Small partial pressures of H2 caused rapid consumption of the U metal and lead to changes in the intensity and position of the diffraction peaks from both the UO2 overlayers and the U metal. There is an orientational dependence in the rate of U consumption. From changes in the lattice parameter we deduce that hydrogen enters both the oxide and metal layers, contracting the oxide and expanding the metal. The air-grown oxide overlayers appear to hinder the H2-reaction up to a threshold dose, but then on heating from 80 to 140 C the consumption is more rapid than for the as-deposited overlayers. STEM-EELS establishes that the U-hydride layer lies at the oxide-metal interface, and that the initial formation is at defects or grain boundaries, and involves the formation of amorphous and/or nanocrystalline UH3. This explains why no diffraction peaks from UH3 are observed.

  13. In situ X-ray synchrotron study of organic semiconductor ultra-thin films growth

    International Nuclear Information System (INIS)

    Moulin, J.-F.; Dinelli, F.; Massi, M.; Albonetti, C.; Kshirsagar, R.; Biscarini, F.

    2006-01-01

    In this work we present an X-ray diffraction study of the early stages of growth of an organic semiconductor (sexithiophene, T 6 ) thin film prepared by high vacuum sublimation. Specular reflectometry and grazing incidence X-ray diffraction were used to monitor the formation of T 6 films on silicon oxide. Our results show that T 6 grows as a crystalline layer from the beginning of the evaporation. The reflectometry analysis suggests that, in the range of rates and temperatures studied, the growth is never layer by layer but rather 3D in nature. In-plane GIXD has allowed us to observe for the first time a thin film phase of T 6 formed of molecules standing normal to the substrate and arranged in a compressed unit cell with respect to the bulk, i.e. the unit cell parameters b and c are relatively smaller. We have followed the dynamics of formation of this new phase and identified the threshold of appearance of the bulk phase, which occurs above ∼5-6 monolayers. These results are relevant to the problem of organic thin film transistors, for which we have previously demonstrated experimentally that only the first two monolayers of T 6 films are involved in the electrical transport. The layers above the second one do not effectively contribute to charge mobility, either because they are more 'disordered' or because of a screening of the gate field

  14. Characterization by X-ray tomography of granulated alumina powder during in situ die compaction

    Energy Technology Data Exchange (ETDEWEB)

    Cottrino, Sandrine; Jorand, Yves, E-mail: yves.jorand@insa-lyon.fr; Maire, Eric; Adrien, Jérôme

    2013-07-15

    Compaction process, the aim of which being to obtain green bodies with low porosity and small size, is often used before sintering treatment. Prior to die filling, the ceramic powder is generally granulated to improve flowability. However during compaction, density heterogeneity and critical size defects may appear due to intergranule and granule-die wall frictions. In this work, the influence of granule formulation on the compact morphology has been studied. To do so, a compaction setup was installed inside an X-ray tomography equipment so that the evolution of the compact morphology could be analysed during the whole compaction process. We have demonstrated that high humidity rate and the addition of binder in the granule formulation increase density heterogeneity and generate larger defects. - Highlights: • An original compaction set up was installed inside an X-Ray tomography equipment. • The compaction process of granulated ceramic powder is imaged. • The compact green microstructure is quantified and related to the compaction stages. • The most detrimental defects of dry-pressed parts are caused by hollow granules. • Formulations without binder allow a reduction of the number of large defects.

  15. Investigation of multilayered nanocomposites as low energy X-Rays attenuators

    International Nuclear Information System (INIS)

    Silva, Liliane; Batista, Adriana S.M.; Nascimento, Jefferson P.; Furtado, Clascídia A.; Faria, Luiz O.

    2017-01-01

    The development of radiation attenuating materials has application in radioprotection and conditioning of short-lived waste. Polymeric materials can serve as a matrix for the dispersion of nanomaterials with good attenuation features, resulting in lightweight, conformable, flexible and easy-to-process materials. Thus, some well-known shielding materials could be used in low proportion for the formation of new materials. On the other hand, nanostructured carbon materials, such as graphene oxide (GO) and carbon nanotubes (NTCs), have been reported recently to show enhanced attenuation properties. In this sense, polymeric matrixes provide the necessary flexibility for use in various applications that require molding. For the present work, poly(vinylidene fluoride) [PVDF] homopolymers and its fluorinated copolymers were filled with nanosized metallic and graphene oxides in order to produce nanocomposites with increased low energy X-ray attenuation efficiency. Film samples of PVDF/reduced Graphene Oxide [PVDF/rGO] and Poly(vinylidene fluoride – tryfluorethylene)/Barium Oxide [P(VDF-TrFE)/BaO] were synthesized. In a second step, the samples were then sandwiched between Kapton® layers and exposed to X-rays source (8.5 keV). The samples were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The attenuation coefficient was evaluated and compared with the attenuation of the individual constituents. It was observed an increase in the linear attenuation coefficient of the layered materials, justifying further investigation of these nanostructured composites as X-ray or gamma radiation attenuators. (author)

  16. Investigation of multilayered nanocomposites as low energy X-Rays attenuators

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Liliane; Batista, Adriana S.M.; Nascimento, Jefferson P.; Furtado, Clascídia A.; Faria, Luiz O., E-mail: asfisica@gmail.com, E-mail: adriananuclear@yahoo.com.br, E-mail: farialo@cdtn.br, E-mail: nascimentopatricio@yahoo.com.br, E-mail: clas@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    The development of radiation attenuating materials has application in radioprotection and conditioning of short-lived waste. Polymeric materials can serve as a matrix for the dispersion of nanomaterials with good attenuation features, resulting in lightweight, conformable, flexible and easy-to-process materials. Thus, some well-known shielding materials could be used in low proportion for the formation of new materials. On the other hand, nanostructured carbon materials, such as graphene oxide (GO) and carbon nanotubes (NTCs), have been reported recently to show enhanced attenuation properties. In this sense, polymeric matrixes provide the necessary flexibility for use in various applications that require molding. For the present work, poly(vinylidene fluoride) [PVDF] homopolymers and its fluorinated copolymers were filled with nanosized metallic and graphene oxides in order to produce nanocomposites with increased low energy X-ray attenuation efficiency. Film samples of PVDF/reduced Graphene Oxide [PVDF/rGO] and Poly(vinylidene fluoride – tryfluorethylene)/Barium Oxide [P(VDF-TrFE)/BaO] were synthesized. In a second step, the samples were then sandwiched between Kapton® layers and exposed to X-rays source (8.5 keV). The samples were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The attenuation coefficient was evaluated and compared with the attenuation of the individual constituents. It was observed an increase in the linear attenuation coefficient of the layered materials, justifying further investigation of these nanostructured composites as X-ray or gamma radiation attenuators. (author)

  17. Investigation of X-ray permeability of surgical gloves coated with different contrast agents

    Science.gov (United States)

    Kayan, Mustafa; Yaşar, Selçuk; Saygın, Mustafa; Yılmaz, Ömer; Aktaş, Aykut Recep; Kayan, Fatmanur; Türker, Yasin; Çetinkaya, Gürsel

    2016-01-01

    Objective: We aimed to investigate the effectiveness and radiation protection capability of latex gloves coated with various contrast agents as an alternative to lead gloves. Methods: The following six groups were created to evaluate the permeability of X-ray in this experimental study: lead gloves, two different non-ionic contrast media (iopromide 370/100 mg I/mL and iomeprol 400/100 mg I/mL), 10% povidone–iodine (PV–I), 240/240 g/mL barium sulphate and a mixture of equal amounts of all contrast agents. A radiation dose detector was placed in coated latex gloves for each one. The absorption values of radiation from latex gloves coated with various contrast agents were measured and compared with the absorption of radiation from lead gloves. This study was designed as an ‘experimental study’. Results: The mean absorption value of X-ray from lead gloves was 3.0±0.08 µG/s. The mean absorption values of X-ray from latex gloves coated with various contrast agents were 3.7±0.09 µG/s (iopromide 370/100 mg I/mL), 3.6±0.09 µG/s (iomeprol 400/100 mg I/mL), 3.7±0.04 µG/s (PV–I), 3.1±0.07 µG/s (barium sulphate) and 3.8±0.05 µG/s (mixture of all contrast agents). Latex gloves coated with barium sulphate provided the best radiation absorption compared with latex gloves coated with other radiodense contrast agents. Conclusion: Latex gloves coated with barium sulphate may provide protection equivalent to lead gloves. PMID:26680548

  18. Radiobiological investigations of soft X-rays near carbon, nitrogen, oxygen K-shell edges on Aspergillus oryzae spores

    International Nuclear Information System (INIS)

    Chen, L.; Jiang, S. P.; Wan, L. B.; Ma, X. D.; Li, M. F.

    2008-01-01

    Soft X-rays at carbon, nitrogen, oxygen K-shell edges have special radiobiological effects. Using Aspergillus oryzae spores as sample, the radiation effects of soft X-rays near the K-shell edges of C, N and O elements from synchrotron radiation were investigated. Also the dose depositions of different X-ray energies in spore were discussed. At the same time, the spores were irradiated by gamma rays from 60 Co and relative biological effects were compared with those produced by soft X-rays. The results showed that soft X-rays near K-shell edges of O element had higher ability of radiation damage than that of X-rays near K-shell edges of C and N elements as compared with one another. But they all had higher killing abilities per unit dose than that of gamma rays from 60 Co. The relative biological effects (RBEs), the comparison of dose to gamma rays at 10% survival level, of the three soft X-rays were 1.65, 1.73 and 1.91, respectively. (authors)

  19. Structural investigation of semi-conductor nanostructures by x-ray diffraction

    International Nuclear Information System (INIS)

    Stangl, J.

    2003-01-01

    Full text: Semiconductor nanostructures present a topic of increasing interest due to their potential for new device concepts, as well as from a scientific point of view. In structures with dimensions smaller than the DeBroglie wavelength of electrons or holes, quantum confinement effects determine the electronic and optical properties. For the understanding of such structures, their structural investigation, i.e., the determination of size, shape, chemical composition and strain state is mandatory. X-ray diffraction is a powerful technique for this purpose. In particular, the strain fields within nanostructures as well as in the surrounding matrix can be determined with high precision. Using synchrotron radiation sources, also the distribution of chemical composition within objects with typically several nm height and 10 to 100 nm width can be established. With x-ray diffraction, the non-destructive investigation of uncapped and buried structures is possible. The latter is important, as for applications buried structures are needed, and during capping the structural properties may change considerably. Here, we will focus on so-called self-assembled nanostructures, which form during the deposition of different semiconductors on top of each other. In contrast to structures etched after growth of planar layers, self organized islands or wires are virtually defect-free and hence promising for applications. Different scattering techniques sensitive to shape and/or composition and strain will be discussed. (author)

  20. In situ x-ray fluorescence and californium-252 neutron activation analysis for marine and terrestrial mineral exploration

    International Nuclear Information System (INIS)

    Wogman, N.A.

    1976-12-01

    Instrumentation has been designed for in situ analysis of marine and terrestrial minerals using the techniques of x-ray fluorescence and neutron activation analysis. The energy-dispersive x-ray fluorescence analyzer allows more than 20 elements to be quantitatively measured at the 10 ppM level in water depths to 300 m. The analyzer consists of a solid cryogen-cooled Si(Li) detector, a 50 mCi 109 Cd or 57 Co excitation source, and an analyzer-computer system for data storage and manipulation. The neutron activation analysis, which is designed to measure up to 30 elements at parts per hundred to ppM levels, utilizes the man-made element 252 Cf as its neutron activation source. The resulting radioelements which emit characteristic gamma radiation are then analyzed in situ during 2- to 200-s counting intervals with Ge(Li) or NaI(T1) detector systems. An extension of this latter technique, which uses a 252 Cf- 235 U fueled subcritical multiplier, is also being studied. The subcritical facility allows the neutrons from the 252 Cf source to be multiplied, thus providing greater neutron flux. Details of these in situ analysis systems, actual in situ spectra, and recorded data are discussed with respect to the detection of minerals at their varying concentration levels. The system response of each illustrates its usefulness for various rapid environmental mineral exploration studies. These techniques can be utilized on terrestrial surfaces and marine or fresh water sediments. 5 figures, 2 tables

  1. In Situ Identification of Mineral Resources with an X-Ray-Optical "Hands-Lens" Instrument

    Science.gov (United States)

    Marshall, J.; Koppel, L.; Bratton, C.; Metzger, E.; Hecht, M.

    1999-09-01

    The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56). While a sample is being x-rayed, the instrument simultaneously acquires an optical image of the sample surface at magnifications from lx to at least 50x (200x being feasible, depending on the sample surface). We believe that imaging the sample is extremely important as corroborative sample-identification data (the need for this capability having been illustrated by the experience of the Pathfinder rover). Very few geologists would rely on instrument data for sample identification without having seen the sample. Visual inspection provides critical recognition data such as texture, crystallinity, granularity, porosity, vesicularity, color, lustre, opacity, and

  2. In situ observation of Cu-Ni alloy nanoparticle formation by X-ray diffraction, X-ray absorption spectroscopy, and transmission electron microscopy: Influence of Cu/Ni ratio

    DEFF Research Database (Denmark)

    Wu, Qiongxiao; Duchstein, Linus Daniel Leonhard; Chiarello, Gian Luca

    2014-01-01

    Silica-supported, bimetallic Cu-Ni nanomaterials were prepared with different ratios of Cu to Ni by incipient wetness impregnation without a specific calcination step before reduction. Different in situ characterization techniques, in particular transmission electron microscopy (TEM), X-ray...... diffraction (XRD), and X-ray absorption spectroscopy (XAS), were applied to follow the reduction and alloying process of Cu-Ni nanoparticles on silica. In situ reduction of Cu-Ni samples with structural characterization by combined synchrotron XRD and XAS reveals a strong interaction between Cu and Ni species......, which results in improved reducibility of the Ni species compared with monometallic Ni. At high Ni concentrations silica-supported Cu-Ni alloys form a homogeneous solid solution of Cu and Ni, whereas at lower Ni contents Cu and Ni are partly segregated and form metallic Cu and Cu-Ni alloy phases. Under...

  3. High pressure in-situ X-ray diffraction study on Zn-doped magnetite nanoparticles

    Science.gov (United States)

    Ferrari, S.; Bilovol, V.; Pampillo, L. G.; Grinblat, F.; Errandonea, D.

    2018-03-01

    We have performed high pressure synchrotron X-ray powder diffraction experiments on two different samples of Zn-doped magnetite nanoparticles (formula Fe(3-x)ZnxO4; x = 0.2, 0.5). The structural behavior of then a noparticles was studied up to 13.5 GPa for x = 0.2, and up to 17.4 GPa for x = 0.5. We have found that both systems remain in the cubic spinel structure as expected for this range of applied pressures. The analysis of the unit cell volume vs. pressure results in bulk modulus values lower than in both end-members, magnetite (Fe3O4) and zinc ferrite (ZnFe2O4), suggesting that chemical disorder may favor compressibility, which is expected to improve the increase of the Neel temperature under compression.

  4. In Situ X-Ray Photoelectron Spectroscopy of Model Catalysts: At the Edge of the Gap

    Science.gov (United States)

    Blomberg, S.; Hoffmann, M. J.; Gustafson, J.; Martin, N. M.; Fernandes, V. R.; Borg, A.; Liu, Z.; Chang, R.; Matera, S.; Reuter, K.; Lundgren, E.

    2013-03-01

    We present high-pressure x-ray photoelectron spectroscopy (HP-XPS) and first-principles kinetic Monte Carlo study addressing the nature of the active surface in CO oxidation over Pd(100). Simultaneously measuring the chemical composition at the surface and in the near-surface gas phase, we reveal both O-covered pristine Pd(100) and a surface oxide as stable, highly active phases in the near-ambient regime accessible to HP-XPS. Surprisingly, no adsorbed CO can be detected during high CO2 production rates, which can be explained by a combination of a remarkably short residence time of the CO molecule on the surface and mass-transfer limitations in the present setup.

  5. The swelling behavior of montmorillonite as affected by the grain size by in situ X-ray diffraction experiments

    International Nuclear Information System (INIS)

    Morodome, S.; Kawamura, K.; Owada, H.; Yahagi, R.; Kobayashi, I.

    2012-01-01

    Document available in extended abstract form only. In many existing researches, the swelling behavior and impermeability of smectitic engineered barrier materials in disposal facilities of radioactive waste was investigated. In the RWMC-project, the effect of smectite content on the mechanical and hydraulic behavior of smectitic materials is investigated and modeled to introduce into THMC analysis. However, since smectite is a natural resource, physical and chemical properties are different with places of production. In order to model the swelling behavior and impermeability of smectitic materials, not only the smectite content but also layer charge and crystal size will be the primary factors. In addition, smectite types and impurity minerals contents or soluble salts affect bentonite characteristic, as well. In this research, in order to focus on the effect of grain size of smectite, the swelling behavior of smectitic materials which are the same place of production but are different grain size were investigated. The smectitic material used in this study was Kunipia-F (Kunimine Industry Co. Ltd., Japan), which is from the Tukinuno Mine, Yamagata prefecture, Japan, and is purified montmorillonite produced by hydraulic elutriation. It is considered that the montmorillonite, Kunipia-F, has large crystal size, and for example Kunipia-F is able to make a sheet when drying weak solution. The grain size was conditioned by jet mill pulverizer. The pulverizing was conducted by making each other collide with high speed. The grain size of the intact and pulverized samples was measured by using of the laser scattering particle distribution analyzer and SEM. The swelling behavior was measured by in situ X-ray diffraction using of a sample chamber which can control the temperature and humidity precisely. The result of the laser scattering analysis denoted that the pulverized sample fined down expressly. The difference of the crystal aspect ratio of the pre- and post

  6. In situ X-ray absorption fine structure studies on the structure of nickel phosphide catalyst supported on K-USY

    CERN Document Server

    Kawai, T; Suzuki, S

    2003-01-01

    Local structure around Ni in a nickel phosphide catalyst supported on K-USY was investigated by an situ X-ray absorption fine structure (XAFS) method during the reduction process of the catalyst and the hydrodesulfurization (HDS) reaction of thiophene. In the passivated sample, Ni phosphide was partially oxidized but after the reduction, 1.1 nm diameter Ni sub 2 P particles were formed with Ni-P and Ni-Ni distances at 0.218 and 0.261 nm, respectively, corresponding to those of bulk Ni sub 2 P. In situ XAFS cleary revealed that the Ni sub 2 P structure was stable under reaction conditions and was an active structure for the HDS process.

  7. Glass sample preparation and performance investigations. [solar x-ray imager

    Science.gov (United States)

    Johnson, R. Barry

    1992-01-01

    This final report details the work performed under this delivery order from April 1991 through April 1992. The currently available capabilities for integrated optical performance modeling at MSFC for large and complex systems such as AXAF were investigated. The Integrated Structural Modeling (ISM) program developed by Boeing for the U.S. Air Force was obtained and installed on two DECstations 5000 at MSFC. The structural, thermal and optical analysis programs available in ISM were evaluated. As part of the optomechanical engineering activities, technical support was provided in the design of support structure, mirror assembly, filter wheel assembly and material selection for the Solar X-ray Imager (SXI) program. As part of the fabrication activities, a large number of zerodur glass samples were prepared in different sizes and shapes for acid etching, coating and polishing experiments to characterize the subsurface damage and stresses produced by the grinding and polishing operations. Various optical components for AXAF video microscope and the x-ray test facility were also fabricated. A number of glass fabrication and test instruments such as a scatter plate interferometer, a gravity feed saw and some phenolic cutting blades were fabricated, integrated and tested.

  8. Investigation of plasma dynamics and x-ray emission in'ATON'plasma focus

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.

    1995-01-01

    The experimental studies on 20 kJ 'Aton' plasma focus device are presented in this paper. The plasma sheath structure has been investigated by means of the measurements of the axial and azimuthal magnetic fields along the coaxial electrodes. The operating gas was hydrogen with pressures in the range of 0.62 torr to 6 torr. The intensity of visible radiation emitted by the plasma sheath was measured as a function of axial distances along the coaxial electrodes. The results showed that the visible radiation intensity is increased with axial distances until a position near the muzzle, then it decreased and has a minimum value at the coaxial electrode muzzle. The main parameters contributing to the behavior of the distribution are the plasma sheath density and the impurities from the eroded materials of the discharge electrodes. An x-ray pulse has been detected along the coaxial electrodes and extended up to the expansion chamber. At a distance near the muzzle two x-ray pulses have been detected, the second one has intensity relative to the first one with time lag of 11μs. 8 fig

  9. X-ray photoelectron spectroscopy investigation of the carburization of 310 stainless steel

    International Nuclear Information System (INIS)

    Tabet, N.; Allam, I.; Yin, R.C.

    2003-01-01

    The surface of 310 stainless steel (310SS) samples was investigated by X-ray photoelectron spectroscopy (XPS) after 500 h cyclic exposure to two carburizing atmospheres: CH 4 (2%)-H 2 (98%) at 800 deg. C, and CH 4 (10%)-H 2 (90%) at 1100 deg. C. The depth distribution of various elements in the surface region was obtained by XPS after successive cycles of argon etching. The microstructure of the alloy was observed by scanning electron microscopy (SEM) and the phases formed during the exposure were analyzed by X-ray diffraction (XRD). The results showed that the major phases that were formed within few micrometer depth during exposure at 800 deg. C include both iron and chromium carbides. (Mn, Cr) oxide was also formed as a result of the reaction with the residual oxygen of the atmosphere. A region of few microns width that was relatively depleted of chromium was formed under the surface as a result of the outwards diffusion of chromium. The exposure to the reducing atmosphere at 1100 deg. C led to the formation of various iron and chromium carbides. No oxide was formed during exposure. In all exposed samples, the surface was Cr enriched while nickel remained buried under the surface region that reacted with the atmosphere

  10. X-ray investigations for determining the aspect ratio in CdSe nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, Ullrich; Kurtulus, Oezguel [Festkoerperphysik, Universitaet Siegen (Germany)

    2008-07-01

    Semiconductor based 1D nanostructures are of high technological interest due to potential application in 1D conductivity measurements and optical devices. Catalyst assisted solution-liquid-solid synthesis is a new method where nanocrystal catalysts are used to grow CdSe nanorods (NR) from solution. The aim of this study is to investigate CdSe samples prepared with this new method by means of X-ray diffraction. The measurements have been performed at DELTA synchrotron using a beam of wavelength 1.127A and an image plate system. It is found that the CdSe NRs have a crystal structure of wurtzite with an aspect ratio changing between 2 and 10. This is in contradiction with the results obtained from TEM measurements, according to which the lengths of the NRs are in the order of 1 {mu} and the widths are around 20 nm. Presently the results are interpreted by the appearance of stacking faults which separate uniformly stacked AB, AB layers from each other. It is planned to measure an individual NR using a nanofocused X-ray beam. Once an individual NR could be observed, the next step is to measure the powder spectrum using a CCD as a function of the position of the beam spot along the nanorod. Depending on this information, the parameters affecting the structure of the NRs would be clear by making experiments with samples prepared in different conditions.

  11. Static tensile deformation behavior of a lean duplex stainless steel studied by in situ neutron diffraction and synchrotron radiation white x-rays

    International Nuclear Information System (INIS)

    Tsuchida, Noriyuki; Kawahata, Taiji; Ishimaru, Eiichiro; Takahashi, Akihiko; Suzuki, Hiroshi; Shobu, Takahisa

    2013-01-01

    To investigate the tensile deformation behavior of a lean duplex stainless steel (S32101) from the viewpoints of plastic deformability among phases or grains, we performed static tensile tests, in situ neutron diffraction, and white x-ray diffraction experiments at room temperature. In the static tensile tests, the S32101 steel displayed a larger uniform elongation and a better tensile strength-uniform elongation balance than a commercial SUS329J4L duplex stainless steel. A larger uniform elongation of S32101 is associated with the macroscopic work hardening behavior that a work hardening rate higher than the flow stress can maintain up until high true strains. From the experimental results of synchrotron radiation white x-ray diffraction experiments, the hard phase of S32101 was changed from the ferrite (α) phase to austenite (γ) one during tensile deformation. This led to a larger stress partitioning between the phases at the latter stage of deformation. From the experimental results of in situ neutron diffraction, it was found that the stress partitioning of the γ phase in the S32101 was the largest among the present results. Therefore, the larger work hardening rate of S32101 can be explained by the large stress partitioning of the γ phase, that between γ and α phases and γ volume fraction. (author)

  12. MapX An In Situ, Full-frame X-Ray Spectroscopic Imager for Planetary Science and Astrobiology

    Science.gov (United States)

    Blake, David; Sarrazin, Philippe; Thompson, Kathleen; Bristow, Thomas

    2017-01-01

    Microbial life exploits micron-scale disequilibria at boundaries where valence, chemical potential, pH, Eh, etc. vary on a length scale commensurate with the organisms - 10's to 100's of microns. The detection of accumulations of the biogenic elements C,N,O,P,S at appropriate concentrations on or in a mineral/ice substrate would constitute permissive evidence of extant life, but context is also required. Does the putative biosignature exist under habitable conditions? Under what conditions of P, T, and chemical potential was the host mineralogy formed? MapX is an in situ robotic spacecraft instrument that images the biogenic elements C, N, O, P, S, as well as the cations of the rock-forming minerals (Na, Mg, Al, Si, K, Ca, Ti, Cr, Mn, Fe) and important anions such as Cl, Fl. MapX provides element maps with less than or equal to100 microns resolution over a 2.5 cm X 2.5 cm area, as well as quantitative XRF spectra from ground- or instrument-selected Regions of Interest (ROI). XRF spectra are converted to mineralogies using ground- or instrument-based algorithms. Either X-ray tube or radioisotope sources such as 244Cm (Alpha-particle and gamma- ray fluorescence) can be used. Fluoresced sample Xrays are imaged onto an X-ray sensitive CCD through an X-ray MicroPore Optic (MPO). The MapX design as well as baseline performance requirements for a MapX instrument intended for life detection / identification of habitable environments will be presented.

  13. Proteins on surfaces investigated by microbeam grazing incidence small angle X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gebhardt, Ronald; Riekel, Christian; Burghammer, Manfred [European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex (France); Vendrely, Charlotte [Universite de Cergy-Pontoise, ERRMECE, F-95000, Cergy-Pontoise (France); Mueller-Buschbaum, Peter [TU Muenchen, Physik Department E13, Muenchen (Germany)

    2009-07-01

    Grazing incidence small angle scattering with a 1 micron x-ray beam ({mu}GISAXS) is applied to study structural ordering of casein micelles and fibroin in solution cast films. {mu}GISAXS scans provide the possibility to locate highly ordered areas and to investigate variation in the molecular packing. In the case of the casein micelles, ordered film structures have been generated by decreasing their natural size dispersion. While dynamic light scattering was used to characterize the different size fractions in solution, {mu}GISAXS and roughness are measured on the resulting casein films. GISAXS-Patterns are analyzed by simulations providing the dimension and nearest neighbor distances of casein micelles. In the case of fibroin, ordering of nano-fibers formed during the drying process is investigated. The experimental data are analyzed by simulations and compared to SEM, AFM and Raman scattering experiments.

  14. The isotope X-ray fluorescence analysis and its application in geochemical investigations in Greenland

    International Nuclear Information System (INIS)

    Kunzendorf, H.

    1973-01-01

    The applicability of the isotope X-ray fluorescence analysis (IRFA) in the geochemical exploration was investigated. Detection limits of about 0.1% for the elements Ti, Zr, Nb, Mo and La+Ce were achieved in terrain measurements. Detection limits of 0.05% were found in the analysis of Cr, Ni, Cu, Zn, Zr, Nb, Mo, La+Ce and Pb in finely grinded rock samples. Geochemical investigations were carried out in the Ilimaussag-Intrusion in south Greenland as well as on the Mo deposits Malmbjerg and the heavy mineral occurence 'kote 800' in East Greenland. The use of portable IRFA equipment proved to be particularly suitable in the analysis of bed rocks, loose rock samples such as moraine material, in the semi-quantitative analysis of heavy mineral concentrates, the analysis of bored cores during the boring programme, as well as the analysis of finely grinded rock samples. (ORU) [de

  15. In situ X-ray diffraction study of crystallization process of GeSbTe thin films during heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Naohiko [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)]. E-mail: e0957@mosk.tytlabs.co.jp; Konomi, Ichiro [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Seno, Yoshiki [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Motohiro, Tomoyoshi [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

    2005-05-15

    The crystallization processes of the Ge{sub 2}Sb{sub 2}Te{sub 5} thin film used for PD and DVD-RAM were studied in its realistic optical disk film configurations for the first time by X-ray diffraction using an intense X-ray beam of a synchrotron orbital radiation facility (SPring-8) and in situ quick detection with a Position-Sensitive-Proportional-Counter. The dependence of the amorphous-to-fcc phase-change temperature T{sub 1} on the rate of temperature elevation R{sub et} gave an activation energy E{sub a}: 0.93 eV much less than previously reported 2.2 eV obtained from a model sample 25-45 times thicker than in the real optical disks. The similar measurement on the Ge{sub 4}Sb{sub 1}Te{sub 5} film whose large reflectance change attains the readability by CD-ROM drives gave E{sub a}: 1.13 eV with larger T{sub 1} than Ge{sub 2}Sb{sub 2}Te{sub 5} thin films at any R{sub et} implying a lower sensitivity in erasing as well as a better data stability of the phase-change disk.

  16. Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials

    Energy Technology Data Exchange (ETDEWEB)

    Weber, J. K. R.; Alderman, O. L. G. [Materials Development, Inc., Arlington Heights, Illinois 60004 (United States); Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Tamalonis, A.; Sendelbach, S. [Materials Development, Inc., Arlington Heights, Illinois 60004 (United States); Benmore, C. J. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Hebden, A.; Williamson, M. A. [Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2016-07-15

    An aerodynamic levitator with carbon dioxide laser beam heating was integrated with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. The chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The sample environment was integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. The system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions.

  17. In situ X-ray diffraction study of crystallization process of GeSbTe thin films during heat treatment

    International Nuclear Information System (INIS)

    Kato, Naohiko; Konomi, Ichiro; Seno, Yoshiki; Motohiro, Tomoyoshi

    2005-01-01

    The crystallization processes of the Ge 2 Sb 2 Te 5 thin film used for PD and DVD-RAM were studied in its realistic optical disk film configurations for the first time by X-ray diffraction using an intense X-ray beam of a synchrotron orbital radiation facility (SPring-8) and in situ quick detection with a Position-Sensitive-Proportional-Counter. The dependence of the amorphous-to-fcc phase-change temperature T 1 on the rate of temperature elevation R et gave an activation energy E a : 0.93 eV much less than previously reported 2.2 eV obtained from a model sample 25-45 times thicker than in the real optical disks. The similar measurement on the Ge 4 Sb 1 Te 5 film whose large reflectance change attains the readability by CD-ROM drives gave E a : 1.13 eV with larger T 1 than Ge 2 Sb 2 Te 5 thin films at any R et implying a lower sensitivity in erasing as well as a better data stability of the phase-change disk

  18. Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques

    Directory of Open Access Journals (Sweden)

    Abhisakh Sarma

    2014-09-01

    Full Text Available In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 107. This value remain almost constant over a frequency range from 1Hz to 106 Hz even at 80 K temperature.

  19. Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sarma, Abhisakh; Sanyal, Milan K., E-mail: milank.sanyal@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

    2014-09-15

    In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 10{sup 7}. This value remain almost constant over a frequency range from 1Hz to 10{sup 6} Hz even at 80 K temperature.

  20. In situ X-ray scattering studies of protein solution droplets drying on micro- and nanopatterned superhydrophobic PMMA surfaces.

    Science.gov (United States)

    Accardo, Angelo; Gentile, Francesco; Mecarini, Federico; De Angelis, Francesco; Burghammer, Manfred; Di Fabrizio, Enzo; Riekel, Christian

    2010-09-21

    Superhydrophobic poly(methyl methacrylate) surfaces with contact angles of ∼170° and high optical and X-ray transparencies have been fabricated through the use of optical lithography and plasma etching. The surfaces contain either a microscale pattern of micropillars or a random nanofibrillar pattern. Nanoscale asperities on top of the micropillars closely resemble Nelumbo nucifera lotus leaves. The evolution of the contact angle of water and lysozyme solution droplets during evaporation was studied on the micro- and nanopatterned surfaces, showing in particular contact-line pinning for the protein solution droplet on the nanopatterned surface. The microstructural evolution of lysozyme solution droplets was studied on both types of surfaces in situ under nearly contact-free conditions by synchrotron radiation microbeam wide-angle and small-angle X-ray scattering revealing the increasing protein concentration and the onset of precipitation. The solid residuals show hollow sphere morphologies. Rastermicrodiffraction of the detached residuals suggests about a 1/3 volume fraction of ≥17 nm lysozyme nanocrystalline domains and about a 2/3 short-range-order volume fraction. About 5-fold larger nanocrystalline domains were observed at the attachment points of the sphere to the substrates, which is attributed to particle growth in a shear flow. Such surfaces represent nearly contact-free sample supports for studies of inorganic and organic solution droplets, which find applications in biochips.

  1. In situ synchrotron x-ray characterization of microstructure formation in solidification processing of Al-based metallic alloys

    International Nuclear Information System (INIS)

    Billia, Bernard; Nguyen-Thi, Henri; Mangelinck-Noel, Nathalie

    2010-01-01

    The microstructure formed during the solidification step has a major influence on the properties of materials processed by major techniques (casting, welding ...). In situ and real-time characterization by synchrotron X-ray imaging is the method of choice to unveil the dynamical formation of the solidification microstructure in metallic alloys, and thus provide precise data for the critical validation of the theoretical predictions that is needed for sound advancement of modeling and numerical simulation. After a description of the experimental procedure used at the European Synchrotron Radiation Facility (ESRF), dynamical phenomena in the formation of the grain structure and dendritic or equiaxed solidification microstructure in Al-based alloys are presented. Beyond fluid flow interaction, earth gravity induces stresses, deformation and fragmentation in the dendritic mush. Settling of dendrite arms and equiaxed grains thus occurs, in particular in the columnar to equiaxed transition. Other types of stresses and strains are caused by the mere formation of the solidification microstructure itself. In white-beam X-ray topography, stresses and strains are manifested by specific contrasts and breaking of the Laue images into several pieces. Finally, quantitative analysis of the grey level in radiographs enables the analysis of solute segregation, which noticeably results in solutal poisoning of growth when equiaxed grains are interacting. (author)

  2. In-situ characterization of highly reversible phase transformation by synchrotron X-ray Laue microdiffraction

    International Nuclear Information System (INIS)

    Chen, Xian; Tamura, Nobumichi; MacDowell, Alastair; James, Richard D.

    2016-01-01

    The alloy Cu_2_5Au_3_0Zn_4_5 undergoes a huge first-order phase transformation (6% strain) and shows a high reversibility under thermal cycling and an unusual martensitc microstructure in sharp contrast to its nearby compositions. This alloy was discovered by systematically tuning the composition so that its lattice parameters satisfy the cofactor conditions (i.e., the kinematic conditions of compatibility between phases). It was conjectured that satisfaction of these conditions is responsible for the enhanced reversibility as well as the observed unusual fluid-like microstructure during transformation, but so far, there has been no direct evidence confirming that these observed microstructures are those predicted by the cofactor conditions. To verify this hypothesis, we use synchrotron X-ray Laue microdiffraction to measure the orientations and structural parameters of variants and phases near the austenite/martensite interface. The areas consisting of both austenite and multi-variants of martensite are scanned by microLaue diffraction. The cofactor conditions have been examined from the kinematic relation of lattice vectors across the interface. The continuity condition of the interface is precisely verified from the correspondent lattice vectors between two phases.

  3. Investigation of cavitating flows by X-ray and optical imaging

    Science.gov (United States)

    Coutier-Delgosha, Olivier; Fuzier, Sylvie; Khlifa, Ilyass; Fezzaa, Kamel

    2015-11-01

    Hydrodynamic cavitation is the partial vaporization of high speed liquid flows. The turbulent, compressible and unsteady character of these flows makes their study unusually complex and challenging. Instabilities generated by the occurrence of cavitation have been investigated in the last years in the LML laboratory by various non-intrusive measurements including X-ray imaging (to obtain the fields of void fraction and velocity in both phases), and PIV with fluorescent particles (to obtain the velocity fields in both phases). It has been shown that cavitation is characterized by significant slip velocities between liquid and vapor, especially in the re-entrant jet area and the cavity wake. This results suggests some possible improvements in the numerical models currently used for CFD of cavitating flows. Professor at Arts et Metiers ParisTech, Director of the LML laboratory.

  4. Differential thermal, Thermogravimetric and X-ray diffraction investigation of hydration phases in cementitious waste form

    International Nuclear Information System (INIS)

    Khalil, M.Y.; Nagy, M.E.; El-Sourougy, M.R.; Zaki, A.A.

    1996-01-01

    Hydration phases of cement determine the final properties of the product. Adding other components to the cement paste may alter the final phases formed and affect properties of the hardened products. In this work ordinary portland cement and/or blast furnace slag cement were hardened with low-or intermediate-level radioactive liquid wastes and different additives. Hydration phases were investigated using differential thermal, thermogravimetric, and X-ray diffraction techniques. Low-and intermediate-level liquid wastes were found not to affect the hydration phases of cement. The addition of inorganic exchangers and latex were found to affect the hydration properties of the cement waste system. This resulted in a reduction of compressive strength. On the contrary, addition of epoxy also affected the hydration causing increase in compressive strength. 10 figs., 2 tabs

  5. Neonatal anthropometrics and body composition in obese children investigated by dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Lausten-Thomsen, Ulrik; Nielsen, Tenna Ruest Haarmark; Thagaard, Ida Näslund

    2014-01-01

    index (BFMI), and fat free mass index (FFMI) in obese children and the preceding in utero conditions expressed by birth weight, birth length, and birth weight for gestational age. The study cohort consisted of 776 obese Danish children (median age 11.6 years, range 3.6-17.9) with a mean Body Mass Index......UNLABELLED: Epidemiological and animal studies have suggested an effect of the intrauterine milieu upon the development of childhood obesity. This study investigates the relationship between body composition measured by dual energy X-ray absorptiometry expressed as body fat percent, body fat mass...... Standard Deviation Score (BMI SDS) of 2.86 (range 1.64-5.48) treated in our national referral centre. In a linear general regression model adjusted for age, gender, socioeconomic status, and duration of breastfeeding, we found the body fat percent, FFMI, and BFMI at the time of enrolment in childhood...

  6. Lyophilized histidine investigated using X-ray photoelectron spectroscopy and cryogenics: Deprotonation in vacuum

    International Nuclear Information System (INIS)

    Cardenas, Juan F.; Groebner, Gerhard

    2005-01-01

    Lyophilized histidine samples were investigated using X-ray photoelectron spectroscopy (XPS). Lyophilized samples were prepared from aqueous solutions at a pH in the range between ∼1.5 and ∼10, and with no further addition of electrolyte. The use of cryogenics allowed the determination of protonated to unprotonated molar ratios of sites in L-histidine, which correlates well with the dissociation constants of the residual amino acid sites. When cryogenics was not used deprotonation of the lyophilized samples occurred, where the degree and the total concentration of deprotonated sites correlates well with the formation constants and the decrease in Cl concentration, respectively. This later relation clearly indicates a correlation between deprotonation and the desorption of HCl from lyophilized samples

  7. Investigation of mineral distribution in bone by synchrotron X-ray fluorescence microscopy after tibolone therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I. [Rio de Janeiro State Univ., Nova Friburgo, RJ (Brazil). Dept. of Mechanical Engineering and Energy; Federal Univ. of Rio de Janeiro, RJ (Brazil). Nuclear Instrumentation Lab. - COPPE; Carvalho, A.C.B.; Henriques, H.N.; Guzman-Silva, M.A. [Fluminense Federal Univ., Niteroi, RJ (Brazil). Lab. of Experimental Pathology; Sales, E.; Lopes, R.T. [Federal Univ. of Rio de Janeiro, RJ (Brazil). Nuclear Instrumentation Lab. - COPPE; Granjeiro, J.M. [Fluminense Federal Univ., Niteroi, RJ (Brazil). Dept. of Cellular and Molecular Biology

    2011-07-01

    Tibolone is a synthetic steroid with estrogenic, androgenic, and progestagenic properties used for the prevention of postmenopausal osteoporosis and treatment of climacteric symptoms. Tibolone shows almost no action on breast and endometrium, which are target-organs for estrogens and progesterone activity. The aim of this work was to investigate the spatial distribution of calcium and zinc minerals in the femoral head of ovariectomized rat in order to evaluate the effects of the long-term administration of tibolone. For that purpose X-ray microfluorescence was used with synchrotron radiation imaging technique which was performed at Brazilian Light Synchrotron Laboratory, Campinas, SP. Minerals were not homogeneously distributed in trabecular bone areas; a higher concentration of calcium in the trabecular regions at femoral heads was found in ovariectomized and tibolone-treated rats compared to ovariectomized and control groups. (orig.)

  8. Synthesis, X-ray crystallography, thermal studies, spectroscopic and electrochemistry investigations of uranyl Schiff base complexes.

    Science.gov (United States)

    Asadi, Zahra; Shorkaei, Mohammad Ranjkesh

    2013-03-15

    Some tetradentate salen type Schiff bases and their uranyl complexes were synthesized and characterized by UV-Vis, NMR, IR, TG, C.H.N. and X-ray crystallographic studies. From these investigations it is confirmed that a solvent molecule occupied the fifth position of the equatorial plane of the distorted pentagonal bipyramidal structure. Also, the kinetics of complex decomposition by using thermo gravimetric methods (TG) was studied. The thermal decomposition reactions are first order for the studied complexes. To examine the properties of uranyl complexes according to the substitutional groups, we have carried out the electrochemical studies. The electrochemical reactions of uranyl Schiff base complexes in acetonitrile were reversible. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Lyophilized histidine investigated using X-ray photoelectron spectroscopy and cryogenics: Deprotonation in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, Juan F. [Inorganic Chemistry, Umeaa University, 90187 Umeaa (Sweden)]. E-mail: juan.cardenas@chem.umu.se; Groebner, Gerhard [Biophysical Chemistry, Umeaa University, 90187 Umeaa (Sweden)

    2005-08-15

    Lyophilized histidine samples were investigated using X-ray photoelectron spectroscopy (XPS). Lyophilized samples were prepared from aqueous solutions at a pH in the range between {approx}1.5 and {approx}10, and with no further addition of electrolyte. The use of cryogenics allowed the determination of protonated to unprotonated molar ratios of sites in L-histidine, which correlates well with the dissociation constants of the residual amino acid sites. When cryogenics was not used deprotonation of the lyophilized samples occurred, where the degree and the total concentration of deprotonated sites correlates well with the formation constants and the decrease in Cl concentration, respectively. This later relation clearly indicates a correlation between deprotonation and the desorption of HCl from lyophilized samples.

  10. In situ time-resolved X-ray near-edge absorption spectroscopy of selenite reduction by siderite

    International Nuclear Information System (INIS)

    Badaut, V.; Schlegel, M.L.; Descostes, M.; Moutiers, G.

    2012-01-01

    The reduction oxidation-reaction between aqueous selenite (SeO 3 2- ) and siderite (FeCO 3 (s)) was monitored by in situ, time-resolved X-ray absorption near-edge structure (XANES) spectroscopy at the selenium K edge in a controlled electrochemical environment. Spectral evolutions showed that more than 60% of selenite was reduced at the siderite surface after 20 h of experiment, at which time the reaction was still incomplete. Fitting of XANES spectra by linear combination of reference spectra showed that selenite reaction with siderite is essentially a two-step process, selenite ions being immobilized on siderite surface prior to their reduction. A kinetic model of the reduction step is proposed, allowing to identify the specific contribution of surface reduction. These results have strong implications for the retention of selenite by corrosion products in nuclear waste repositories and in a larger extent for the fate of selenium in the environment. (authors)

  11. High-temperature dehydration of talc: a kinetics study using in situ X-ray powder diffraction

    Science.gov (United States)

    Wang, Duojun; Yi, Li; Huang, Bojin; Liu, Chuanjiang

    2015-06-01

    High-temperature in situ X-ray powder diffraction patterns were used to study the dehydration kinetics of natural talc with a size of 10-15 µm. The talc was annealed from 1073 to 1223 K, and the variations in the characteristic peaks corresponding to talc with the time were recorded to determine the reaction progress. The decomposition of talc occurred, and peaks corresponding to talc and peaks corresponding to enstatite and quartz were observed. The enstatite and talc exhibited a topotactic relationship. The dehydration kinetics of talc was studied as a function of temperature between 1073 and 1223 K. The kinetics data could be modeled using an Avrami equation that considers nucleation and growth processes ? where n varies from 0.4 to 0.8. The rate constant (k) equation for the natural talc is ? The reaction mechanism for the dehydration of talc is a heterogeneous nucleation and growth mechanism.

  12. In-situ early stage electromigration study in Al line using synchrotron polychromatic X-ray microdiffraction

    International Nuclear Information System (INIS)

    Chen, Kai; Tamura, Nobumichi; Tu, King-Ning

    2007-01-01

    Electromigration is a phenomenon that has attracted much attention in the semiconductor industry because of its deleterious effects on electronic devices (such as interconnects) as they become smaller and current density passing through them increases. However, the effect of the electric current on the microstructure of interconnect lines during the very early stage of electromigration is not well documented. In the present report, we used synchrotron radiation based polychromatic X-ray microdiffraction for the in-situ study of the electromigration induced plasticity effects on individual grains of an Al (Cu) interconnect test structure. Dislocation slips which are activated by the electric current stressing are analyzed by the shape change of the diffraction peaks. The study shows polygonization of the grains due to the rearrangement of geometrically necessary dislocations (GND) in the direction of the current. Consequences of these findings are discussed

  13. Phase transformation in sol-gel prepared zirconia using in-situ high temperature X-ray diffraction

    International Nuclear Information System (INIS)

    Srinivasan, R.; Davis, B.H.; Hubbard, C.R.; Cavin, O.B.; Porter, W.D.

    1991-01-01

    Zirconia was precipitated at a pH of 10.5 by admixing a solution of ZrCl 4 and NH 4 OH both rapidly (∼ 1 min) and slowly (∼ 8 hr). The precipitate was calcined at 500C for 5 hours and then furnace cooled. The former exhibited monoclinic phase while the latter yielded tetragonal phase. The pathway from amorphous to crystalline form was followed by in-situ high temperature X-ray diffraction in flowing air and in He. The data showed the evolution of the tetragonal crystalline phase on heating. On rapid cooling the tetragonal phase is retained at R.T., and on slow cooling the transformation to monoclinic phase occurs in air

  14. Oxygen partial pressure control during in-situ high temperature X-ray diffraction on cerium dioxide

    International Nuclear Information System (INIS)

    Strach, M.; Belin, R.C.; Richaud, J-C.; Rogez, J.

    2014-01-01

    Cerium dioxide is widely used as a surrogate for plutonium dioxide in the studies of MOX type nuclear fuel. Thus, obtaining an accurate description of the structures present in this system in a range of temperatures is of importance to the development of fuel for the IV. generation of nuclear reactors. However, such a study requires appropriate scientific tools, in particular regarding the control and monitoring of the oxygen partial pressure (pO 2 ). Here we discuss several in-situ X-ray diffraction experiments performed to determine the phases present in the hypo-stoichiometric CeO 2-x region of the phase diagram and clearly demonstrate the need for controlling the pO 2 . (authors)

  15. In-situ early stage electromigration study in Al line using synchrotron polychromatic X-ray microdiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kai; Tamura, Nobumichi; Tu, King-Ning

    2007-10-31

    Electromigration is a phenomenon that has attracted much attention in the semiconductor industry because of its deleterious effects on electronic devices (such as interconnects) as they become smaller and current density passing through them increases. However, the effect of the electric current on the microstructure of interconnect lines during the very early stage of electromigration is not well documented. In the present report, we used synchrotron radiation based polychromatic X-ray microdiffraction for the in-situ study of the electromigration induced plasticity effects on individual grains of an Al (Cu) interconnect test structure. Dislocation slips which are activated by the electric current stressing are analyzed by the shape change of the diffraction peaks. The study shows polygonization of the grains due to the rearrangement of geometrically necessary dislocations (GND) in the direction of the current. Consequences of these findings are discussed.

  16. Design of a miniature flow cell for in situ x-ray imaging of redox flow batteries

    Science.gov (United States)

    Jervis, Rhodri; Brown, Leon D.; Neville, Tobias P.; Millichamp, Jason; Finegan, Donal P.; Heenan, Thomas M. M.; Brett, Dan J. L.; Shearing, Paul R.

    2016-11-01

    Flow batteries represent a possible grid-scale energy storage solution, having many advantages such as scalability, separation of power and energy capabilities, and simple operation. However, they can suffer from degradation during operation and the characteristics of the felt electrodes are little understood in terms of wetting, compression and pressure drops. Presented here is the design of a miniature flow cell that allows the use of x-ray computed tomography (CT) to study carbon felt materials in situ and operando, in both lab-based and synchrotron CT. Through application of the bespoke cell it is possible to observe felt fibres, electrolyte and pore phases and therefore enables non-destructive characterisation of an array of microstructural parameters during the operation of flow batteries. Furthermore, we expect this design can be readily adapted to the study of other electrochemical systems.

  17. Design of a miniature flow cell for in situ x-ray imaging of redox flow batteries

    International Nuclear Information System (INIS)

    Jervis, Rhodri; Brown, Leon D; Neville, Tobias P; Millichamp, Jason; Finegan, Donal P; Heenan, Thomas M M; Brett, Dan J L; Shearing, Paul R

    2016-01-01

    Flow batteries represent a possible grid-scale energy storage solution, having many advantages such as scalability, separation of power and energy capabilities, and simple operation. However, they can suffer from degradation during operation and the characteristics of the felt electrodes are little understood in terms of wetting, compression and pressure drops. Presented here is the design of a miniature flow cell that allows the use of x-ray computed tomography (CT) to study carbon felt materials in situ and operando , in both lab-based and synchrotron CT. Through application of the bespoke cell it is possible to observe felt fibres, electrolyte and pore phases and therefore enables non-destructive characterisation of an array of microstructural parameters during the operation of flow batteries. Furthermore, we expect this design can be readily adapted to the study of other electrochemical systems. (paper)

  18. X-ray interferometers

    International Nuclear Information System (INIS)

    Franks, A.

    1980-01-01

    An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

  19. Investigation of bone morphology using X-ray microfluorescence bidimensional mapping

    International Nuclear Information System (INIS)

    Lima, I.; Sales, E.; Anjos, M.J.; Assis, J.T.; Lopes, R.T.

    2008-01-01

    Full text: The utilization of radiation for medical purposes is an important tool that has been helping in finding the causes of several illnesses. In relation to application of radioisotope in medicine, it has been making a great contribution to the development of analytical techniques that can help diagnostic illness. The X-ray fluorescence technique is within this context providing identification of chemical elements, and moreover, it can provide its spatial concentrations and distributions in several kinds of biological tissues, such as bone. Several issues concerning bone metabolism are still under study, and the investigation of its morphology, in relation to mineral distribution, can be useful. The aim of this study is to characterize trabecular bone samples in order to verify the influence of the chemical elemental distribution in bone morphology through bi-dimensional mapping obtained through X-ray fluorescence technique with synchrotron radiation. The measurements were performed at Brazilian Synchrotron Light National Laboratory (XRF beam line). This line is equipped with an HPGe detector with a resolution of 150 eV at 5.9 keV, a white beam, and the sample holder is placed at 45 deg in relation to the detector and the incident beam. The beam is focused by a fine conical capillary which provides X-ray microbeam of 20 μm diameter. To perform the experiment, the samples were placed in a mylar adhesive tape, positioned in the experimental set up and their measurements was taken into account in the calculation of concentration. The spectra were acquired in 10 s and 200 s to perform 2D images and single profiles respectively. No sample preparation was required and the experiment was performed in vertebrae and femur bone sites (in several positions) with 150 μm of thickness approximately. It was measured NIST Standard Reference Material (bone ash and bone meal - SRM 1400 and SRM 1486) in order to evaluate our experimental method. The sample holder has complete

  20. Investigation of Co nanoparticle formation using time-dependent and spatially-resolved X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zinoveva, S.

    2008-04-15

    A crucial step towards controlled synthesis of nanoparticles is the detailed understanding of the various chemical processes that take place during the synthesis. X-ray Absorption Spectroscopy (XAS) is especially suitable for elucidating the type and structure of the intermediate metal species. It is applicable to materials that have no long range order and provides information on both electronic and geometric structures. Here a comparative study is reported of the formation of cobalt nanoparticles via thermolysis of two organometallic precursors dicobalt octacarbonyl (DCO) and alkyne-bridged dicobalt hexacarbonyl (ADH) in the presence of aluminum organics. Using time-dependent XAS a reaction pathway different from both the atom based La Mer model and the Watzky and Finsky autocatalytic surface growth model is observed. Where prior to the nucleation several intermediates are formed and the initial nucleus is composed of Co atoms coordinated with ligands Co{sub n}(CO){sub m} with n=2-3, m=3-5. The formation of Co nanoparticles was also investigated using a reaction different from thermolysis of cobalt carbonyls, namely reduction of Co (II) acetate by sodium borohydrate. Here the combination of microreactor system and spatially resolved XAS allowed ''in situ'' monitoring of the wet chemical synthesis. Several steps of the reaction were spatially resolved in the microreactor. The vertical size of the X-ray beam (50 {mu}m) focused with Kirkpatrick-Baez mirror system, determines the time resolution (better than 2 ms). The results provide direct insight into rapid process of nanoparticles formation and demonstrate the potential of this new technique for the fundamental studies of such type of processes where miniaturization and timeresolution are important. Like in the carbonyls thermolysis no evidence for the reduction of the starting complex to isolated Co{sup 0} atoms followed by nucleation of Co{sup 0} atoms was observed. (orig.)

  1. Investigation of Co nanoparticle formation using time-dependent and spatially-resolved X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zinoveva, S

    2008-04-15

    A crucial step towards controlled synthesis of nanoparticles is the detailed understanding of the various chemical processes that take place during the synthesis. X-ray Absorption Spectroscopy (XAS) is especially suitable for elucidating the type and structure of the intermediate metal species. It is applicable to materials that have no long range order and provides information on both electronic and geometric structures. Here a comparative study is reported of the formation of cobalt nanoparticles via thermolysis of two organometallic precursors dicobalt octacarbonyl (DCO) and alkyne-bridged dicobalt hexacarbonyl (ADH) in the presence of aluminum organics. Using time-dependent XAS a reaction pathway different from both the atom based La Mer model and the Watzky and Finsky autocatalytic surface growth model is observed. Where prior to the nucleation several intermediates are formed and the initial nucleus is composed of Co atoms coordinated with ligands Co{sub n}(CO){sub m} with n=2-3, m=3-5. The formation of Co nanoparticles was also investigated using a reaction different from thermolysis of cobalt carbonyls, namely reduction of Co (II) acetate by sodium borohydrate. Here the combination of microreactor system and spatially resolved XAS allowed ''in situ'' monitoring of the wet chemical synthesis. Several steps of the reaction were spatially resolved in the microreactor. The vertical size of the X-ray beam (50 {mu}m) focused with Kirkpatrick-Baez mirror system, determines the time resolution (better than 2 ms). The results provide direct insight into rapid process of nanoparticles formation and demonstrate the potential of this new technique for the fundamental studies of such type of processes where miniaturization and timeresolution are important. Like in the carbonyls thermolysis no evidence for the reduction of the starting complex to isolated Co{sup 0} atoms followed by nucleation of Co{sup 0} atoms was observed. (orig.)

  2. Ex-situ time-lapse x-ray CT study of 3D micro-structural fatigue damage evolution in uni-directional composites

    DEFF Research Database (Denmark)

    Jespersen, Kristine Munk; Wang, Ying; Zangenberg Hansen, Jens

    2016-01-01

    In this study, the progress of damage under tension-tension fatigue of a uni-directional (UD) glass fibre composite made from a non-crimp fabric is studied using transilluminated white light imaging (TWLI) and X-ray computed tomography (CT). TWLI images are automatically captured throughout...... to initiate already after the first cycle, whereas some grow gradually and others appear suddenly during cycling. The off-axis cracks are observed to saturate after a few thousand cycles. The UD fibre fracture damage in the region observed by X-ray CT is probably already saturated at the first interruption...... point, as no significant change is seen between the two X-ray images. However, the study indicates how TWLI can be used as an initial indicator to locate damage regions at an early stage for the future ex-situ X-ray CT experiments....

  3. Investigation of liquid water in gas diffusion layers of polymer electrolyte fuel cells using X-ray tomographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Flueckiger, Reto [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Marone, Federica [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Stampanoni, Marco [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, CH-8092 Zurich (Switzerland); Wokaun, Alexander [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Buechi, Felix N., E-mail: felix.buechi@psi.c [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2011-02-01

    In polymer electrolyte fuel cells (PEFCs), condensation of water within the pore network of the gas diffusion layers (GDL) can influence the gas transport properties and thus reduce the electrochemical conversion rates. The use of X-ray tomographic microscopy (XTM), which allows for a resolution in the order of one micrometer is investigated for studying ex situ the local saturation in GDL's. The strength of XTM is the high spatial resolution with simultaneous contrast for water and carbon, allowing for non-destructive 3D-imaging of the solid and the contained water. The application of this method for imaging the ex situ water intrusion into the porous network of GDLs is explored using absorption and phase contrast methods. It is shown that the inhomogeneous filling behavior of GDL materials can indeed be visualized with sufficient resolution. For Toray paper TGP-H-060 the local saturation was measured as function of the water pressure. The results, evaluated in 1D, 2D and 3D show a liquid water retention effect at the denser layers near the surface. A comparison with established capillary pressure functions is presented. Altogether, the results show the potential of the XTM-method as a tool for studying the liquid water behavior in PEFC on a microscopic scale.

  4. Investigation of liquid water in gas diffusion layers of polymer electrolyte fuel cells using X-ray tomographic microscopy

    International Nuclear Information System (INIS)

    Flueckiger, Reto; Marone, Federica; Stampanoni, Marco; Wokaun, Alexander; Buechi, Felix N.

    2011-01-01

    In polymer electrolyte fuel cells (PEFCs), condensation of water within the pore network of the gas diffusion layers (GDL) can influence the gas transport properties and thus reduce the electrochemical conversion rates. The use of X-ray tomographic microscopy (XTM), which allows for a resolution in the order of one micrometer is investigated for studying ex situ the local saturation in GDL's. The strength of XTM is the high spatial resolution with simultaneous contrast for water and carbon, allowing for non-destructive 3D-imaging of the solid and the contained water. The application of this method for imaging the ex situ water intrusion into the porous network of GDLs is explored using absorption and phase contrast methods. It is shown that the inhomogeneous filling behavior of GDL materials can indeed be visualized with sufficient resolution. For Toray paper TGP-H-060 the local saturation was measured as function of the water pressure. The results, evaluated in 1D, 2D and 3D show a liquid water retention effect at the denser layers near the surface. A comparison with established capillary pressure functions is presented. Altogether, the results show the potential of the XTM-method as a tool for studying the liquid water behavior in PEFC on a microscopic scale.

  5. In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Patridge, Christopher J. [NRC/NRL Cooperative Research Associate, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Love, Corey T., E-mail: corey.love@nrl.navy.mil [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Swider-Lyons, Karen E. [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Twigg, Mark E. [Electronics Science and Technology Division, Code 6812, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Ramaker, David E. [Chemistry Division, Code 6189, U.S. Naval Research laboratory, Washington, DC 20375 (United States)

    2013-07-15

    The local structure of nanoscale (∼10–40 nm) LiCoO{sub 2} is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO{sub 2} nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO{sub 2} metal-oxide bond lengths, structural disorder, and chemical state are tracked during cycling by adapting the delta mu (Δμ) technique in complement with comprehensive extended X-ray absorption fine structure (EXAFS) modeling. For the first time, we use a Δμ EXAFS method, and by comparison of the difference EXAFS spectra, extrapolate significant coordination changes and reduction of cobalt species with cycling. This combined approach suggests Li–Co site exchange at the surface of the nanoscale LiCoO{sub 2} as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO{sub 2}. - Graphical abstract: Electrochemical cycling of Li-ion batteries has strong impact on the structure and integrity of the cathode active material particularly near the surface/electrolyte interface. In developing a new method, we have used in-situ X-ray absorption spectroscopy during electrochemical cycling of nanoscale LiCoO{sub 2} to track changes during charge and discharge and between subsequent cycles. Using difference spectra, several small changes in Co-O bond length, Co-O and Co-Co coordination, and site exchange between Co and Li sites can be tracked. These methods show promise as a new technique to better understand processes which lead to capacity fade and loss in Li-ion batteries. - Highlights: • A new method is developed to understand capacity fade in Li-ion battery cathodes. • Structural changes are tracked during Li intercalation/deintercalation of LiCoO{sub 2}. • Surface structural changes are emphasized using nanoscale-LiCoO{sub 2} and difference spectra. • Full multiple

  6. In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO2

    International Nuclear Information System (INIS)

    Patridge, Christopher J.; Love, Corey T.; Swider-Lyons, Karen E.; Twigg, Mark E.; Ramaker, David E.

    2013-01-01

    The local structure of nanoscale (∼10–40 nm) LiCoO 2 is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO 2 nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO 2 metal-oxide bond lengths, structural disorder, and chemical state are tracked during cycling by adapting the delta mu (Δμ) technique in complement with comprehensive extended X-ray absorption fine structure (EXAFS) modeling. For the first time, we use a Δμ EXAFS method, and by comparison of the difference EXAFS spectra, extrapolate significant coordination changes and reduction of cobalt species with cycling. This combined approach suggests Li–Co site exchange at the surface of the nanoscale LiCoO 2 as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO 2 . - Graphical abstract: Electrochemical cycling of Li-ion batteries has strong impact on the structure and integrity of the cathode active material particularly near the surface/electrolyte interface. In developing a new method, we have used in-situ X-ray absorption spectroscopy during electrochemical cycling of nanoscale LiCoO 2 to track changes during charge and discharge and between subsequent cycles. Using difference spectra, several small changes in Co-O bond length, Co-O and Co-Co coordination, and site exchange between Co and Li sites can be tracked. These methods show promise as a new technique to better understand processes which lead to capacity fade and loss in Li-ion batteries. - Highlights: • A new method is developed to understand capacity fade in Li-ion battery cathodes. • Structural changes are tracked during Li intercalation/deintercalation of LiCoO 2 . • Surface structural changes are emphasized using nanoscale-LiCoO 2 and difference spectra. • Full multiple scattering calculations are used to

  7. X-ray in-situ study of copper electrodeposition on UHV prepared GaAs(001) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gruender, Yvonne

    2008-06-02

    For this work a unique setup for in-situ electrochemical studies was employed and improved. This setup permits UHV preparation of the GaAs(001) surface with a defined surface termination (arsenic-rich or gallium-rich) and its characterization by SXRD in UHV, under ambient pressure in inert gas and in electrolyte under potential control without passing through air. The GaAs(001) surfaces were capped by amorphous arsenic. This permitted to ship them through ambient air. Afterwards smooth well defined GaAs(001) surfaces could be recovered by thermal annealing in UHV. A first investigation of the arsenic capped sample was done by atomic force microscopy (AFM) and Surface X-Ray Diffraction (SXRD). The non bulk like termination of the arsenic buried GaAs(001) surface was revealed. For the electrochemical metal deposition, arsenic terminated (2 x 4) reconstructed and gallium terminated (4 x 2) reconstructed GaAs(001) surfaces were employed. These surfaces were characterized by STM, LEED and a first time by SXRD. The surfaces are smooth, however, a higher degree of disorder than for MBE prepared reconstructed GaAs(001) is found. After exposure of the sample to nitrogen, the surfaces were then again studied by SXRD. These two steps characterizing the bare GaAs(001) surfaces permitted us to get a better knowledge of the starting surface and its influence on the later electrodeposited copper. At ambient pressure both reconstructions are lifted, but the surface is not bulk-like terminated as can be deduced from the crystal truncation rods. Epitaxial copper clusters grow upon electrodeposition on the UHV prepared GaAs(001) surface. The copper lattice is rotated and inclined with respect to the GaAs substrate lattice, leading to eight symmetry equivalent domains. The influence of the surface termination as well as the nucleation potential on the structure of the electrodeposited copper were investigated. The tilt and rotation angles do not depend on the deposition potential but

  8. Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated

    Science.gov (United States)

    Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.

    1999-01-01

    Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

  9. In situ X-ray diffraction study of the electrochemical reaction on lead electrodes in sulphate electrolytes

    International Nuclear Information System (INIS)

    Angerer, P.; Mann, R.; Gavrilovic, A.; Nauer, G.E.

    2009-01-01

    The anodic oxidation of pure lead in two acidic sulphate electrolytes with identical ionic strength (pH ∼ 0 and pH ∼ -0.1) was studied by in situ grazing incidence X-ray diffraction method (GIXD). Crystalline products such as lead sulphate (anglesite, PbSO 4 , orthorhombic), α- and β-lead dioxide (α-PbO 2 , orthorhombic, and β-PbO 2 , tetragonal), and tribasic lead sulphate hydrate with the stoichiometric composition 3PbO.PbSO 4 .H 2 O (triclinic) were detected at defined potentials. A method for the semi-quantitative determination of the thickness of the deposited layer from diffraction data is described. After the in situ measurement, the washed and dried working electrodes were additionally characterized ex situ by GIXD measurements at different angles of incidence. The phase litharge (lead oxide, t-PbO, tetragonal) and lead sulphate were observed at the surface of the lead substrate. The quantitative evaluation of the diffraction intensity of this measurement series enables the modelling of a qualitative depth profile of the layer generated during the electrochemical treatment. The anglesite phase is located in the uppermost layer, while the litharge phase was detected closer to the lead substrate

  10. In situ X-ray ptychography imaging of high-temperature CO2 acceptor particle agglomerates

    DEFF Research Database (Denmark)

    Høydalsvik, Kristin; Fløystad, Jostein Bø; Zhao, Tiejun

    2014-01-01

    be used for in situ phase contrast imaging in structure studies at atmospheric pressure and elevated temperatures. Lithium zirconate, a candidate CO2 capture material, was studied at a pressure of one atmosphere in air and in CO2, at temperatures exceeding 600 °C. Images with a spatial resolution better...

  11. Elemental investigation of talcum baby powder by X-Ray florescence and fast neutron activation Techniques

    International Nuclear Information System (INIS)

    Hassan, M. F.; Abd El Wahab, M.; Nada, A.

    2008-01-01

    Different samples of Egyptian and Hungarian talcum powders were studied, using X-ray florescence (XRF) and Fast Neutron Activation Analysis (FNAA) techniques to ensure the safety of its use. The K (X-rays) and the gamma-rays were measured, using Si(Li) and high-purity germanium (HPGe) spectrometers to detect and determine qualitatively and quantitatively the constituents of the studied samples. The concentrations of the elements (Mg, Si, Al, Fe, Zn, and Ba) were measured and their presence was confirmed by X-ray, lifetime and/or XRF measurements. One of these samples was also studied, using the Environmental Scanning Electron Microscope (ESEM)

  12. In situ analysis of elemental depth distributions in thin films by combined evaluation of synchrotron x-ray fluorescence and diffraction

    International Nuclear Information System (INIS)

    Mainz, R.; Klenk, R.

    2011-01-01

    In this work we present a method for the in situ analysis of elemental depth distributions in thin films using a combined evaluation of synchrotron x-ray fluorescence and energy-dispersive x-ray diffraction signals. We recorded diffraction and fluorescence signals simultaneously during the reactive annealing of thin films. By means of the observed diffraction signals, the time evolution of phases in the thin films during the annealing processes can be determined. We utilized this phase information to parameterize the depth distributions of the elements in the films. The time-dependent fluorescence signals were then taken to determine the parameters representing the parameterized depth distributions. For this latter step, we numerically calculated the fluorescence intensities for a given set of depth distributions. These calculations handle polychromatic excitation and arbitrary functions of depth distributions and take into account primary and secondary fluorescence. Influences of lateral non-uniformities of the films, as well as the accuracy limits of the method, are investigated. We apply the introduced method to analyze the evolution of elemental depth distributions and to quantify the kinetic parameters during a synthesis process of CuInS 2 thin films via the reactive annealing of Cu-In precursors in a sulfur atmosphere.

  13. An in situ near-ambient pressure X-ray Photoelectron Spectroscopy study of Mn polarised anodically in a cell with solid oxide electrolyte

    International Nuclear Information System (INIS)

    Bozzini, Benedetto; Amati, Matteo; Bocchetta, Patrizia; Dal Zilio, Simone; Knop-Gericke, Axel; Vesselli, Erik; Kiskinova, Maya

    2015-01-01

    This paper reports an in situ study of the anodic behavior of a model solid oxide electrolysis cell (SOEC) by means of near-ambient pressure X-ray Photoelectron Spectroscopy (XPS) combined with near edge X-ray absorption fine structure (NEXAFS) measurements. The focus is on the anodic surface chemistry of MnO x , a model anodic material already considered in cognate SOFC-related studies, during electrochemical operation in CO 2 , CO 2 /H 2 O and H 2 O ambients. The XPS and NEXAFS results we obtained, complemented by electrochemical measurements and SEM characterisation, reveal the chemical evolution of Mn under electrochemical control. MnO is the stable chemical form at open-circuit potential (OCP), while Mn 3 O 4 forms under anodic polarisation in all the investigated gas ambients. Carbon deposits are present on the Mn electrode at OCP, but they are readily oxidised under anodic conditions. Prolonged operation of the MnO x anode leads to pitting of the Mn films, damaging of the triple-phase boundary region and also to formation of discontinuities in the Mn patch. This is accompanied by chemical transformations of the electrolyte and formation of ZrC without impact on the surface chemistry of the Mn-based anode

  14. Effects of quartz particle size and water-to-solid ratio on hydrothermal synthesis of tobermorite studied by in-situ time-resolved X-ray diffraction

    International Nuclear Information System (INIS)

    Kikuma, J.; Tsunashima, M.; Ishikawa, T.; Matsuno, S.; Ogawa, A.; Matsui, K.; Sato, M.

    2011-01-01

    Hydrothermal synthesis process of tobermorite (5CaO.6SiO 2 .5H 2 O) has been investigated by in-situ X-ray diffraction using high-energy X-rays from a synchrotron radiation source in combination with a purpose-build autoclave cell. Dissolution rates of quartz were largely affected by its particle size distribution in the starting mixtures. However, the composition (Ca/Si) of non-crystalline C-S-H at the start of tobermorite formation was identical regardless of the quartz dissolution rate. An effect of water-to-solid ratio (w/s) was investigated for samples using fine particle quartz. Tobermorite did not occur with w/s of 1.7 but occurred with w/s higher than 3.0. Surprisingly, however, the dissolution curves of quartz were nearly identical for all samples with w/s from 1.7 to 9, indicating that the dissolution rate is predominated by surface area. Possible reaction mechanism for tobermorite formation will be discussed in terms of Ca and/or silicate ion concentration in the liquid phase and distribution of Ca/Si in non-crystalline C-S-H. - Graphical abstract: Time-resolved XRD data set was obtained at up to 190 deg. C under a saturated steam pressure. Tobermorite (5CaO.6SiO 2 .5H 2 O) formation reaction was investigated in detail for several different starting materials. Highlights: → Hydrothermal formation of tobermorite was monitored by in-situ XRD. → Ca/Si of C-S-H at the start time of tobermorite formation was determined. → The Ca/Si value was identical regardless of the quartz particle size in the starting mixture.

  15. Fatigue History and in-situ Loading Studies of the overload Effect Using High Resolution X-ray Strain Profiling

    International Nuclear Information System (INIS)

    Croft, M.; Jisrawi, N.; Zhong, Z.; Holtz, R.; Sadananda, K.; Skaritka, J.; Tsakalakos, T.

    2007-01-01

    High-energy synchrotron X-ray diffraction experiments are used to perform local crack plane strain profiling of 4140 steel compact tension specimens fatigued at constant amplitude, subjected to a single overload cycle, then fatigued some more at constant amplitude. X-ray strain profiling results on a series of samples employing in-situ load cycling are correlated with the crack growth rate (da/dN) providing insight into the da/dN retardation known as the 'overload effect'. Immediately after the overload, the strain under maximum load is greatly reduced but the range of strain, between zero and maximum load, remains unchanged compared to the pre-overload values. At the point of maximum retardation, it is the strain range that is greatly reduced while the maximum-load strain has begun to recover to the pre-overload value. For a sample that has recovered to approximately half of the original da/dN value following the overload, the strain at maximum load is fully recovered while the strain range, though partially recovered, is still substantially reduced. The dominance of the strain range in the overload effect is clearly indicated. Subject to some assumptions, strong quantitative support for a crack growth rate driving force of the suggested form [(K max ) -p (ΔK) p ] γ is found. A dramatic nonlinear load dependence in the spatial distribution of the strain at maximum retardation is also demonstrated: at low load the response is dominantly at the overload position; whereas at high loads it is dominantly at the crack tip position. This transfer of load response away from the crack tip to the overload position appears fundamental to the overload effect for high R-ratio fatigue as studied here

  16. Mechanistic studies of chemical looping desulfurization of Mn-based oxides using in situ X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    König, C.F.J.; Nachtegaal, M.; Seemann, M.; Clemens, F.; Garderen, N. van; Biollaz, S.M.A.; Schildhauer, T.J.

    2014-01-01

    Highlights: • Mn sorbents remove H 2 S from hot syngas in chemical looping desulfurization process. • State of Mn followed by in situ X-ray absorption spectroscopy and mass spectrometry. • Two-step mechanism explains the formation of SO 2 under reducing conditions. - Abstract: Cleaning of producer gas from biomass gasification is required for further processing, e.g. to avoid catalyst poisoning in subsequent conversion steps. High-temperature gas cleaning, of which sulfur removal is an important part, is a promising way to improve the overall efficiency of biomass conversion. In a high temperature “chemical looping desulfurization” process, a sorbent material, here manganese oxide, is cycled between producer gas from the gasifier to remove sulfur species, and an oxidizing atmosphere, in which the sulfur species are released as SO 2 . Alternatively, the use of such material as reactive bed material could be integrated into an allothermal dual fluidized bed gasifier. In a laboratory reactor, we subjected manganese-based materials to a periodically changing gas atmosphere, simulating a “chemical looping desulfurization” reactor. The “fuel reactor” gas contained H 2 , CO, CH 4 and H 2 S, similar as in the producer gas, and the “oxidizing reactor” contained diluted O 2 . Mass spectrometry showed that most of the H 2 S is taken up by the sample in the “fuel reactor” part, while also some unwanted SO 2 is generated in the “fuel reactor” part. Most of the sulfur is released in the oxidizing reactor. Simultaneous in situ X-ray absorption spectroscopy (XAS) of the Mn materials during different stages of the chemical looping desulfurization process showed that the initial Mn 3 O 4 is transformed in the presence of H 2 S to MnS via a MnO intermediate in the fuel reactor. Oxygen from the reduction of Mn 3 O 4 oxidizes some H 2 S to the undesired SO 2 in the fuel reactor. Upon exposure to O 2 , MnS is again oxidized to Mn 3 O 4 via MnO, releasing SO

  17. Thermal expansion behavior of empressite, AgTe: A structural study by means of in situ high-temperature single-crystal X-ray diffraction

    International Nuclear Information System (INIS)

    Bindi, Luca

    2009-01-01

    The crystal structure of empressite, AgTe, a rare silver telluride, has been investigated by in situ X-ray single-crystal diffraction methods within the temperature range 298-463 K. AgTe remains orthorhombic, space group Pmnb (Pnma as standard), and shows only normal thermal expansion over the entire temperature range. The unit-cell parameters show a gradual increase with the increase of temperature. Slight adjustments in the geometry of Ag-tetrahedra and in the crystal-chemical environment of tellurium atoms occur in a continuous way without abrupt structural changes. The coefficients of thermal expansion along various axes are: α a = 1.5 x 10 -5 K -1 , α b = 3.0 x 10 -5 K -1 , α c = 2.2 x 10 -5 K -1 , and the bulk thermal expansion coefficient α V is 5.4 x 10 -5 K -1 for the temperature range 298-463 K

  18. Investigating high speed phenomena in laser plasma interactions using dilation x-ray imager (invited).

    Science.gov (United States)

    Nagel, S R; Hilsabeck, T J; Bell, P M; Bradley, D K; Ayers, M J; Piston, K; Felker, B; Kilkenny, J D; Chung, T; Sammuli, B; Hares, J D; Dymoke-Bradshaw, A K L

    2014-11-01

    The DIlation X-ray Imager (DIXI) is a new, high-speed x-ray framing camera at the National Ignition Facility (NIF) sensitive to x-rays in the range of ≈2-17 keV. DIXI uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps, a ≈10× improvement over conventional framing cameras currently employed on the NIF (≈100 ps resolution), and otherwise only attainable with 1D streaked imaging. The pulse-dilation technique utilizes a voltage ramp to impart a velocity gradient on the signal-bearing electrons. The temporal response, spatial resolution, and x-ray sensitivity of DIXI are characterized with a short x-ray impulse generated using the COMET laser facility at Lawrence Livermore National Laboratory. At the NIF a pinhole array at 10 cm from target chamber center (tcc) projects images onto the photocathode situated outside the NIF chamber wall with a magnification of ≈64×. DIXI will provide important capabilities for warm-dense-matter physics, high-energy-density science, and inertial confinement fusion, adding important capabilities to temporally resolve hot-spot formation, x-ray emission, fuel motion, and mix levels in the hot-spot at neutron yields of up to 10(17). We present characterization data as well as first results on electron-transport phenomena in buried-layer foil experiments.

  19. Simultaneous investigation of parent electrons and bremsstrahlung x rays by rocket-borne detectors

    International Nuclear Information System (INIS)

    Vij, K.K.; Venkatesan, D.; Sheldon, W.R.; Kern, J.W.; Benbrook, J.R.; Whalen, B.A.

    1975-01-01

    Simultaneous measurements of the energy spectrum of precipitating electrons and the resulting bremsstrahlung X ray spectrum were carried out during an auroral event on March 3, 1971, at the Churchill Research Range, Manitoba, Canada. The electron data were obtained with detectors on a Black Brant VB sounding rocket (275-km apogee), while the X ray flux was measured by an instrument package that was boosted to 60 km on an Arcas rocket. The X ray package was deployed on a parachute at apogee to provide a slow descent through the atmosphere. Thick target bremsstrahlung theory is used to calculate the X ray flux produced by the incident electrons, and a Monte Carlo method is used to predict the X ray spectrum at various altitudes appropriate for comparison with the measured X ray data. Satisfactory agreement between theory and experiment is obtained, and the value of the constant in the thick target theory has been estimated to be (2plus-or-minus0.5) times10 -5

  20. Simultaneous investigation of parent electrons and bremsstrahlung x rays by Rocket--Borne detectors

    International Nuclear Information System (INIS)

    Vij, K.K.; Venkatesan, D.; Sheldon, W.R.; Kern, J.W.; Benbrook, J.R.; Whalen, B.A.

    1975-01-01

    Simultaneous measurements of the energy spectrum of precipitating electrons and the resulting bremsstrahlung X ray spectrum were carried out during an auroral event on March 3, 1971, at the Churchill Research Range, Manitoba, Canada. The electron data were obtained with detectors on a Black Brant VB sounding rocket (275-km apogee), while the X ray flux was measured by an instrument package that was boosted to 60 km on an Arcas rocket. The X ray package was deployed on a parachute apogee to provide a slow descent through the atmosphere. Thick target bremsstrahlung theory is used to calculate the X ray flux produced by the incident electrons, and a Monte Carlo method is used to predict the X ray spectrum at various altitudes appropriate for comparison with the measured X ray data. Satisfactory agreement between theory and experiment is obtained, and the value of the constant in the thick target theory has been estimated to be (2plus-or-minus0.5) times10 -5 . (auth)

  1. [Experimental investigation of laser plasma soft X-ray source with gas target].

    Science.gov (United States)

    Ni, Qi-liang; Gong, Yan; Lin, Jing-quan; Chen, Bo; Cao, Jian-lin

    2003-02-01

    This paper describes a debris-free laser plasma soft X-ray source with a gas target, which has high operating frequency and can produce strong soft X-ray radiation. The valve of this light source is drived by a piezoelectrical ceramic whose operating frequency is up to 400 Hz. In comparison with laser plasma soft X-ray sources using metal target, the light source is debris-free. And it has higher operating frequency than gas target soft X-ray sources whose nozzle is controlled by a solenoid valve. A channel electron multiplier (CEM) operating in analog mode is used to detect the soft X-ray generated by the laser plasma source, and the CEM's output is fed to to a charge-sensitive preamplifier for further amplification purpose. Output charges from the CEM are proportional to the amplitude of the preamplifier's output voltage. Spectra of CO2, Xe and Kr at 8-14 nm wavelength which can be used for soft X-ray projection lithography are measured. The spectrum for CO2 consists of separate spectral lines originate mainly from the transitions in Li-like and Be-like ions. The Xe spectrum originating mainly from 4d-5f, 4d-4f, 4d-6p and 4d-5p transitions in multiply charged xenon ions. The spectrum for Kr consists of separate spectral lines and continuous broad spectra originating mainly from the transitions in Cu-, Ni-, Co- and Fe-like ions.

  2. Investigating high speed phenomena in laser plasma interactions using dilation x-ray imager (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, S. R., E-mail: nagel7@llnl.gov; Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Piston, K.; Felker, B. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Hilsabeck, T. J.; Kilkenny, J. D.; Chung, T.; Sammuli, B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Hares, J. D.; Dymoke-Bradshaw, A. K. L. [Kentech Instruments Ltd., Wallingford, Oxfordshire OX10 (United Kingdom)

    2014-11-15

    The DIlation X-ray Imager (DIXI) is a new, high-speed x-ray framing camera at the National Ignition Facility (NIF) sensitive to x-rays in the range of ≈2–17 keV. DIXI uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps, a ≈10× improvement over conventional framing cameras currently employed on the NIF (≈100 ps resolution), and otherwise only attainable with 1D streaked imaging. The pulse-dilation technique utilizes a voltage ramp to impart a velocity gradient on the signal-bearing electrons. The temporal response, spatial resolution, and x-ray sensitivity of DIXI are characterized with a short x-ray impulse generated using the COMET laser facility at Lawrence Livermore National Laboratory. At the NIF a pinhole array at 10 cm from target chamber center (tcc) projects images onto the photocathode situated outside the NIF chamber wall with a magnification of ≈64×. DIXI will provide important capabilities for warm-dense-matter physics, high-energy-density science, and inertial confinement fusion, adding important capabilities to temporally resolve hot-spot formation, x-ray emission, fuel motion, and mix levels in the hot-spot at neutron yields of up to 10{sup 17}. We present characterization data as well as first results on electron-transport phenomena in buried-layer foil experiments.

  3. Silver in geological fluids from in situ X-ray absorption spectroscopy and first-principles molecular dynamics

    Science.gov (United States)

    Pokrovski, Gleb S.; Roux, Jacques; Ferlat, Guillaume; Jonchiere, Romain; Seitsonen, Ari P.; Vuilleumier, Rodolphe; Hazemann, Jean-Louis

    2013-04-01

    The molecular structure and stability of species formed by silver in aqueous saline solutions typical of hydrothermal settings were quantified using in situ X-ray absorption spectroscopy (XAS) measurements, quantum-chemical modeling of near-edge absorption spectra (XANES) and extended fine structure spectra (EXAFS), and first-principles molecular dynamics (FPMD). Results show that in nitrate-bearing acidic solutions to at least 200 °C, silver speciation is dominated by the hydrated Ag+ cation surrounded by 4-6 water molecules in its nearest coordination shell with mean Ag-O distances of 2.32 ± 0.02 Å. In NaCl-bearing acidic aqueous solutions of total Cl concentration from 0.7 to 5.9 mol/kg H2O (m) at temperatures from 200 to 450 °C and pressures to 750 bar, the dominant species are the di-chloride complex AgCl2- with Ag-Cl distances of 2.40 ± 0.02 Å and Cl-Ag-Cl angle of 160 ± 10°, and the tri-chloride complex AgCl32- of a triangular structure and mean Ag-Cl distances of 2.60 ± 0.05 Å. With increasing temperature, the contribution of the tri-chloride species decreases from ˜50% of total dissolved Ag in the most concentrated solution (5.9m Cl) at 200 °C to less than 10-20% at supercritical temperatures for all investigated solutions, so that AgCl2- becomes by far the dominant Ag-bearing species at conditions typical of hydrothermal-magmatic fluids. Both di- and tri-chloride species exhibit outer-sphere interactions with the solvent as shown by the detection, using FPMD modeling, of H2O, Cl-, and Na+ at distances of 3-4 Å from the silver atom. The species fractions derived from XAS and FPMD analyses, and total AgCl(s) solubilities, measured in situ in this work from the absorption edge height of XAS spectra, are in accord with thermodynamic predictions using the stability constants of AgCl2- and AgCl32- from Akinfiev and Zotov (2001) and Zotov et al. (1995), respectively, which are based on extensive previous AgCl(s) solubility measurements. These data

  4. X-ray and scanning electron microscopic investigation of porous silicon and silicon epitaxial layers grown on porous silicon

    International Nuclear Information System (INIS)

    Wierzchowski, W.; Pawlowska, M.; Nossarzewska-Orlowska, E.; Brzozowski, A.; Wieteska, K.; Graeff, W.

    1998-01-01

    The 1 to 5 μm thick layers of porous silicon and epitaxial layers grown on porous silicon were studied by means of X-ray diffraction methods, realised with a wide use of synchrotron source and scanning microscopy. The results of x-ray investigation pointed the difference of lateral periodicity between the porous layer and the substrate. It was also found that the deposition of epitaxial layer considerably reduced the coherence of porous fragments. A number of interface phenomena was also observed in section and plane wave topographs. The scanning electron microscopic investigation of cleavage faces enabled direct evaluation of porous layer thickness and revealed some details of their morphology. The scanning observation of etched surfaces of epitaxial layers deposited on porous silicon revealed dislocations and other defects not reasonable in the X-ray topographs. (author)

  5. Portable and micro x-ray fluorescence investigations of the wall paintings belonging to different periods of anatolian history

    International Nuclear Information System (INIS)

    Zararsiz, A.; Ozen, L.; Kalayci, Y.

    2014-01-01

    Full text: In this study portable x-ray fluorescence spectrometer and micro x-ray fluorescence spectrometer were used for investigating the pigments on the Chatalhoyuk wall paintings from the neolithic period which are located in Museum of Anatolian Civilizations. Totally 15 artifacts were investigated in this study and the elemental compositions of the pigments were identified on this paintings. The communities which have lived in different periods of time have revealed different cultures during the 12 000 years old cultural heritage in our country

  6. Beamline electrostatic levitator for in situ high energy x-ray diffraction studies of levitated solids and liquids

    Energy Technology Data Exchange (ETDEWEB)

    Gangopadhyay, A.K.; Lee, G.W.; Kelto, K.F.; Rogers, J.R.; Goldman, A.I.; Robinson, D.S.; Rathz, T.J.; Hyers, R.W. (WU); (UAB); (NASA); (UMASS, Amherst)

    2010-07-19

    Determinations of the phase formation sequence, crystal structures and the thermo-physical properties of materials at high temperatures are hampered by contamination from the sample container and environment. Containerless processing techniques, such as electrostatic (ESL), electromagnetic, aerodynamic, and acoustic levitation, are most suitable for these studies. An adaptation of ESL for in situ structural studies of a wide range of materials using high energy (30-130 keV) x rays at a synchrotron source is described here. This beamline ESL (BESL) allows the in situ determination of the atomic structures of equilibrium solid and liquid phases, undercooled liquids and time-resolved studies of solid-solid and liquid-solid phase transformations. The use of area detectors enables the rapid acquisition of complete diffraction patterns over a wide range (0.5-14 {angstrom}{sup -1}) of reciprocal space. The wide temperature range (300-2500 K), containerless processing environment under high vacuum (10{sup -7}-10{sup -8} Torr), and fast data acquisition capability, make BESL particularly well suited for phase stability studies of high temperature solids and liquids. An additional, but important, feature of BESL is the capability for simultaneous measurements of a host of thermo-physical properties including the specific heat, enthalpy of transformation, solidus and liquidus temperatures, density, viscosity, and surface tension, all on the same sample during the structural measurements.

  7. Formation and texture of palladium germanides studied by in situ X-ray diffraction and pole figure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Geenen, F.A., E-mail: Filip.Geenen@UGent.be [Ghent University, Department of Solid-State Sciences, Krijgslaan 281 (S1), 9000 Gent (Belgium); Knaepen, W.; De Keyser, K. [Ghent University, Department of Solid-State Sciences, Krijgslaan 281 (S1), 9000 Gent (Belgium); Opsomer, K. [Interuniversitair Micro-Electronica Centrum (IMEC), Kapeldreef 75, 3001 Leuven (Belgium); Vanmeirhaeghe, R.L. [Ghent University, Department of Solid-State Sciences, Krijgslaan 281 (S1), 9000 Gent (Belgium); Jordan-Sweet, J.; Lavoie, C. [IBM T.J. Watson Research Center, Yorktown (United States); Detavernier, C. [Ghent University, Department of Solid-State Sciences, Krijgslaan 281 (S1), 9000 Gent (Belgium)

    2014-01-31

    The solid state reaction between 30 nm Pd films and various Ge substrates (Ge(100), Ge(111), polycrystalline Ge and amorphous Ge) was studied by means of in situ X-ray diffraction and in situ sheet resistance measurements. The reported phase sequence of Pd{sub 2}Ge followed by PdGe was verified on all substrates. The texture of the germanides was analysed by pole figure measurements on samples quenched in the Pd{sub 2}Ge and in the PdGe phase on both Ge(100) and (111) substrates. We report an epitaxial growth of Pd{sub 2}Ge on Ge(111) and on Ge(100). The formed PdGe has an axiotaxial alignment on Ge(111). On Ge(100), the axiotaxial texture is observed together with a fibre texture. The higher formation temperature of PdGe on Ge(111) could be related to the epitaxial alignment of the Pd{sub 2}Ge parent phase on Ge(111). - Highlights: • Solid-state reaction is studied on a Pd film with Ge substrates. • Pd2Ge grains have an epitaxial texture on both Ge 100 and Ge 111. • PdGe grains are found to grow with an axiotaxial texture. • Retarded PdGe formation on Ge111 is related with strong epitaxy of Pd2Ge.

  8. An in situ grazing incidence x-ray scattering study of block copolymer thin films during solvent vapor annealing

    Science.gov (United States)

    Gu, Xiaodan; Gunkel, Ilja; Hexemer, Alexander; Russell, Thomas

    2014-03-01

    Although solvent vapor annealing (SVA) has been widely applied to block copolymer (BCP) thin films to obtain well-ordered microdomains, the mechanism of enhancing lateral order is not well understood. Here, we used real time in situ grazing-incidence small-angle x-ray scattering (in situGISAXS) to study the self-assembly of PS-b-P2VP BCP BCPs with different molecular weights thin films in THF vapor, a near neutral solvent for both blocks. Both swelling and deswelling behavior of BCP thin films were examined. The extent of swellingand the solvent removal rate not only affect the domain spacing of BCPs but also dictate the extent of lateral ordering of the BCP microdomains. Larger grains were observed at higher values of the swelling ratio (close to disordering). To preserve the maximal lateral ordering of the microdomains in the swollen state, the fastest solvent removal rate is required to freeze in the ordered microdomain structure of the swollen BCP film. We thanks support from U.S. Department of Energy BES under contract BES-DE-FG02-96ER45612 and ALS doctoral fellowship.

  9. An in-situ X-ray diffraction study on the electrochemical formation of PtZn alloys on Pt(1 1 1) single crystal electrode

    Energy Technology Data Exchange (ETDEWEB)

    Drnec, J., E-mail: drnec@esrf.fr [ESRF, Grenoble (France); Bizzotto, D. [Department of Chemistry, AMPEL, University of British Columbia, Vancouver, BC (Canada); Carlà, F. [ESRF, Grenoble (France); Fiala, R. [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Sode, A. [Ruhr-Universität Bochum, Bochum (Germany); Balmes, O.; Detlefs, B.; Dufrane, T. [ESRF, Grenoble (France); Felici, R., E-mail: felici@esrf.fr [ESRF, Grenoble (France)

    2015-11-01

    Highlights: • PtZn electrochemical alloying is observed on single crystal Pt electrodes. • In-situ X-ray characterization during alloy formation and dissolution is provided. • Structural model of the surface during alloying and dissolution is discussed. • X-ray based techniques can be used in in-operando studies of bimetallic fuel cell catalysts. - Abstract: The electrochemical formation and dissolution of the oxygen reduction reaction (ORR) PtZn catalyst on Pt(1 1 1) surface is followed by in-situ X-ray diffraction (XRD) and X-ray reflectivity (XRR) measurements. When the crystalline Pt surface is polarized to sufficiently negative potential values, with respect to an Ag/AgCl|KCl reference electrode, the electrodeposited zinc atoms diffuse into the bulk and characteristic features are observed in the X-ray patterns. The surface structure and composition during deposition and dissolution is determined from analysis of XRR curves and measurements of crystal truncation rods. Thin Zn-rich surface layer is present during the alloy formation while a Zn-depleted layer forms during dissolution.

  10. Ex-situ X-ray computed tomography data for a non-crimp fabric based glass fibre composite under fatigue loading

    DEFF Research Database (Denmark)

    Jespersen, Kristine Munk; Mikkelsen, Lars Pilgaard

    2017-01-01

    The data published with this article are high resolution X-ray computed tomography (CT) data obtained during an ex-situ fatigue test of a coupon test specimen made from a non-crimp fabric based glass fibre composite similar to those used for wind turbine blades. The fatigue test was interrupted...

  11. Electronic structure and optical properties of CdS{sub x}Se{sub 1−x} solid solution nanostructures from X-ray absorption near edge structure, X-ray excited optical luminescence, and density functional theory investigations

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M. W. [DESY (Deutsches Elektronen-Synchrotron), FS-PEX, Notkestrasse 85, 22607 Hamburg (Germany); Yiu, Y. M., E-mail: yyiu@uwo.ca; Sham, T. K. [Department of Chemistry, University of Western Ontario, London, ON N6A5B7 (Canada); Ward, M. J. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); Liu, L. [Institute of Functional Nano and Soft Materials (FUNSOM) and Soochow University-Western University Center for Synchrotron Radiation Research, Soochow University, Suzhou, Jiangsu, 215123 (China); Hu, Y. [Canadian Light Source, University of Saskatchewan, Saskatoon, SK S7N2V3 (Canada); Zapien, J. A. [Center Of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (China); Liu, Yingkai [Institute of Physics and Electronic Information, Yunnan Normal University, Kunming, Yunnan, 650500 (China)

    2014-11-21

    The electronic structure and optical properties of a series of iso-electronic and iso-structural CdS{sub x}Se{sub 1−x} solid solution nanostructures have been investigated using X-ray absorption near edge structure, extended X-ray absorption fine structure, and X-ray excited optical luminescence at various absorption edges of Cd, S, and Se. It is found that the system exhibits compositions, with variable local structure in-between that of CdS and CdSe accompanied by tunable optical band gap between that of CdS and CdSe. Theoretical calculation using density functional theory has been carried out to elucidate the observations. It is also found that luminescence induced by X-ray excitation shows new optical channels not observed previously with laser excitation. The implications of these observations are discussed.

  12. Effect of Pressure on Valence and Structural Properties of YbFe2Ge2 Heavy Fermion Compound A Combined Inelastic X-ray Spectroscopy, X-ray Diffraction, and Theoretical Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ravhi S.; Svane, Axel; Vaitheeswaran; #8741; , Ganapathy; Kanchana, Venkatakrishnan; Antonio, Daniel; Cornelius, Andrew L.; Bauer, Eric D.; Xiao, Yuming; Chow, Paul (Aarhus); (CIW); (Hyderabad - India); (IIT-India); (LANL); (UNLV)

    2016-06-03

    The crystal structure and the Yb valence of the YbFe2Ge2 heavy fermion compound was measured at room temperature and under high pressures using high-pressure powder X-ray diffraction and X-ray absorption spectroscopy via both partial fluorescence yield and resonant inelastic X-ray emission techniques. Furthermore, the measurements are complemented by first-principles density functional theoretical calculations using the self-interaction corrected local spin density approximation investigating in particular the magnetic structure and the Yb valence. While the ThCr2Si2-type tetragonal (I4/mmm) structure is stable up to 53 GPa, the X-ray emission results show an increase of the Yb valence from v = 2.72(2) at ambient pressure to v = 2.93(3) at ~9 GPa, where at low temperature a pressure-induced quantum critical state was reported.

  13. In situ and ex situ electron microscopy and X-ray diffraction characterization of the evolution of a catalytic system - from synthesis to deactivation

    DEFF Research Database (Denmark)

    Gardini, Diego

    Heterogeneous catalysis represents a research field of undeniable importance for a multitude of technological and industrial processes. Supported catalysts are nowadays at the base of the large-scale production of most chemicals and are used for the removal of air pollutants from automotive engines...... the understanding of the structural properties and mechanisms at the origin of catalytic activity. This thesis presents the potential and uniqueness of ex situ and in situ transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques in the characterization of several supported material systems...... TEM (HRTEM) and electron energy loss spectroscopy (EELS) revealed the degradation of the supported carbide particles probably due to the formation of volatile molybdenum hydroxide species. The activity of silver nanoparticles as catalyst for soot oxidation was studied in operative conditions...

  14. X-Ray-induced Deuterium Enrichment of N-rich Organics in Protoplanetary Disks: An Experimental Investigation Using Synchrotron Light

    Energy Technology Data Exchange (ETDEWEB)

    Gavilan, Lisseth; Carrasco, Nathalie [LATMOS, Université Versailles St Quentin, UPMC Université Paris 06, CNRS, 11 blvd d’Alembert, F-78280 Guyancourt (France); Remusat, Laurent; Roskosz, Mathieu [IMPMC, CNRS UMR 7590, Sorbonne Universités, UPMC Université Paris 06, IRD, Muséum National d’Histoire Naturelle, CP 52, 57 rue Cuvier, Paris F-75231 (France); Popescu, Horia; Jaouen, Nicolas [SEXTANTS beamline, SOLEIL synchrotron, L’Orme des Merisiers, F-91190 Saint-Aubin (France); Sandt, Christophe [SMIS beamline, SOLEIL synchrotron, L’Orme des Merisiers, F-91190 Saint-Aubin (France); Jäger, Cornelia [Laboratory Astrophysics and Cluster Physics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University and Institute of Solid State Physics, Helmholtzweg 3, D-07743 Jena (Germany); Henning, Thomas [Max-Planck Institute for Astronomy Königstuhl 17, D-69117 Heidelberg (Germany); Simionovici, Alexandre [Institut des Sciences de la Terre, Observatoire des Sciences de l’Univers de Grenoble, BP 53, F-38041 Grenoble (France); Lemaire, Jean Louis [Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris Sud, Université Paris-Saclay, F-91405 Orsay (France); Mangin, Denis, E-mail: lisseth.gavilan@latmos.ipsl.fr [Institut Jean Lamour, CNRS, Université de Lorraine, F-54011 Nancy (France)

    2017-05-01

    The deuterium enrichment of organics in the interstellar medium, protoplanetary disks, and meteorites has been proposed to be the result of ionizing radiation. The goal of this study is to simulate and quantify the effects of soft X-rays (0.1–2 keV), an important component of stellar radiation fields illuminating protoplanetary disks, on the refractory organics present in the disks. We prepared tholins, nitrogen-rich organic analogs to solids found in several astrophysical environments, e.g., Titan’s atmosphere, cometary surfaces, and protoplanetary disks, via plasma deposition. Controlled irradiation experiments with soft X-rays at 0.5 and 1.3 keV were performed at the SEXTANTS beamline of the SOLEIL synchrotron, and were immediately followed by ex-situ infrared, Raman, and isotopic diagnostics. Infrared spectroscopy revealed the preferential loss of singly bonded groups (N–H, C–H, and R–N≡C) and the formation of sp{sup 3} carbon defects with signatures at ∼1250–1300 cm{sup −1}. Raman analysis revealed that, while the length of polyaromatic units is only slightly modified, the introduction of defects leads to structural amorphization. Finally, tholins were measured via secondary ion mass spectrometry to quantify the D, H, and C elemental abundances in the irradiated versus non-irradiated areas. Isotopic analysis revealed that significant D-enrichment is induced by X-ray irradiation. Our results are compared to previous experimental studies involving the thermal degradation and electron irradiation of organics. The penetration depth of soft X-rays in μ m-sized tholins leads to volume rather than surface modifications: lower-energy X-rays (0.5 keV) induce a larger D-enrichment than 1.3 keV X-rays, reaching a plateau for doses larger than 5 × 10{sup 27} eV cm{sup −3}. Synchrotron fluences fall within the expected soft X-ray fluences in protoplanetary disks, and thus provide evidence of a new non-thermal pathway to deuterium fractionation of

  15. X-Ray-induced Deuterium Enrichment of N-rich Organics in Protoplanetary Disks: An Experimental Investigation Using Synchrotron Light

    Science.gov (United States)

    Gavilan, Lisseth; Remusat, Laurent; Roskosz, Mathieu; Popescu, Horia; Jaouen, Nicolas; Sandt, Christophe; Jäger, Cornelia; Henning, Thomas; Simionovici, Alexandre; Lemaire, Jean Louis; Mangin, Denis; Carrasco, Nathalie

    2017-05-01

    The deuterium enrichment of organics in the interstellar medium, protoplanetary disks, and meteorites has been proposed to be the result of ionizing radiation. The goal of this study is to simulate and quantify the effects of soft X-rays (0.1-2 keV), an important component of stellar radiation fields illuminating protoplanetary disks, on the refractory organics present in the disks. We prepared tholins, nitrogen-rich organic analogs to solids found in several astrophysical environments, e.g., Titan’s atmosphere, cometary surfaces, and protoplanetary disks, via plasma deposition. Controlled irradiation experiments with soft X-rays at 0.5 and 1.3 keV were performed at the SEXTANTS beamline of the SOLEIL synchrotron, and were immediately followed by ex-situ infrared, Raman, and isotopic diagnostics. Infrared spectroscopy revealed the preferential loss of singly bonded groups (N-H, C-H, and R-N≡C) and the formation of sp3 carbon defects with signatures at ˜1250-1300 cm-1. Raman analysis revealed that, while the length of polyaromatic units is only slightly modified, the introduction of defects leads to structural amorphization. Finally, tholins were measured via secondary ion mass spectrometry to quantify the D, H, and C elemental abundances in the irradiated versus non-irradiated areas. Isotopic analysis revealed that significant D-enrichment is induced by X-ray irradiation. Our results are compared to previous experimental studies involving the thermal degradation and electron irradiation of organics. The penetration depth of soft X-rays in μm-sized tholins leads to volume rather than surface modifications: lower-energy X-rays (0.5 keV) induce a larger D-enrichment than 1.3 keV X-rays, reaching a plateau for doses larger than 5 × 1027 eV cm-3. Synchrotron fluences fall within the expected soft X-ray fluences in protoplanetary disks, and thus provide evidence of a new non-thermal pathway to deuterium fractionation of organic matter.

  16. Investigation of polyelectrolytes by total reflection x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Varga, I.; Nagy, M.

    2000-01-01

    Water soluble polyelectrolyte samples containing mono-, bi- and trivalent metal ions were investigated without any pretreatment. Acid digestion of linear polymers may lead to a product insoluble in water so the digestion has to be avoided. The aim of this paper was the determination of analytical characteristics and limitations of the total reflection x-ray fluorescence (TXRF) analysis for poly (vinylalcohol-vinylsulphate) salts and poly (acrylic acid, acrylamide) copolymers containing the following cations: K + , Cs + , Ba 2+ , Cu 2+ and La 3+ . On the basis of our results efficiency of ion-exchange during preparation of polyelectrolytes and stoichiometry of the end-product were determined. TXRF results were compared with data gained by inductively coupled plasma atomic emission spectrometry (ICP-AES) measurements except in the case of Cs + which has poor sensitivity in ICP-AES. Good agreement was found between the results of the two techniques and calculations from titrimetric data. Concentration of Li + and Mg 2+ in polymer samples was measured by ICP-AES. In majority of cases film-like dry residues of aqueous solutions of polyelectrolytes can be characterized by homogeneous spatial distribution of metal ions within the organic matrix. This is because the migration of the ions is hindered during drying process. Determination of metals in polyelectrolyte films by TXRF is quite ideal as model for analysis of plant, animal or human tissues which is a frequent task in environmental and inorganic biomedical analytical chemistry. (author)

  17. Non-destructive investigation of a time capsule using neutron radiography and X-ray fluorescence

    Science.gov (United States)

    MacDonald, B. L.; Vanderstelt, J.; O'Meara, J.; McNeill, F. E.

    2016-01-01

    Non-destructive analytical techniques are becoming increasingly important for the study of objects of cultural heritage interest. This study applied two techniques: X-ray fluorescence and neutron radiography, for the investigation of a capped, tubular metal object recovered from an urban construction site in Gore Park, Hamilton, Canada. The site is an urban park containing a World War I commemorative monument that underwent renovation and relocation. Historical documentation suggested that the object buried underneath the monument was a time capsule containing a paper document listing the names of 1800 Canadians who died during WWI. The purpose of this study was to assess the condition of the object, and to verify if it was what the historical records purported. XRF analysis was used to characterize the elemental composition of the metal artifact, while neutron radiography revealed that its contents were congruent with historical records and remained intact after being interred for 91 years. Results of this study demonstrate the value of non-destructive techniques for the analysis and preservation of cultural heritage.

  18. Investigation into structure of berylliumaluminium silicate glasses and crystals by X-ray spectroscopy

    International Nuclear Information System (INIS)

    Tykachinskij, I.D.; Gorbachev, V.V.; Petrakov, V.N.; Varshal, B.G.; Bystrakov, A.S.; Dmitriev, I.D.; Zatsepin, A.F.; Blaginina, L.A.

    1983-01-01

    For the purpose of elucidating the structural state of Be 2+ and Al 3+ ions as well as the nature of Be-O bond the investigation of glasses obtained from BeO, Al 2 O 3 and SiO 2 with different component composition is undertaken by X-ray spectroscopy. In three-component beryllium alumosilicate glasses at the ratio γ=Al 2 O 3 /BeO=0.34-1.92 the main part of Al 3+ cations forms AlO 4 groups. Be 2+ cations probably occupy several non-equivalent states. At the ''crystal-glass'' transition the reorganization of near structure of beryllium alumosilicate frame with appearance in a glass in contrast to crystal analog of beryllium cations playing the role of a glass former (being a part of glass net) as well as a modifier role occurs. For compositions with γ=1 the degree of ionic character of the Be-O bond is the greatest. The increase of Be 2+ cations fraction being a part of the glass net is characteristic feature of the glasses with parameter values γ not equal to 1

  19. X-ray fluorescence in investigations of cultural relics and archaeological finds

    Energy Technology Data Exchange (ETDEWEB)

    Musilek, Ladislav, E-mail: musilek@fjfi.cvut.cz [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 7, 115 19 Praha 1 (Czech Republic); Cechak, Tomas; Trojek, Tomas [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 7, 115 19 Praha 1 (Czech Republic)

    2012-07-15

    Some characteristic features of X-ray fluorescence (XRF) analysis make it an ideal method for investigations of cultural relics and archaeological finds. It has therefore become a standard method used in archaeometry. Paintings, frescos, manuscripts, pottery, metalwork, glass, and many other objects are analysed with the aim of recognising their materials, production technologies and origin, and for identifying counterfeits. This paper reviews various techniques used in XRF analyses of works of art, summarises the advantages and limitations of the method, and presents some typical examples of its use. The general review is supplemented by some techniques used and some results achieved at CTU-FNSPE in Prague. - Highlights: Black-Right-Pointing-Pointer Review of XRF analysis in archaeometry. Black-Right-Pointing-Pointer Instrumentation for XRF analysis with various sources of radiation. Black-Right-Pointing-Pointer Materials and artefacts, which can be measured and information, which can be obtained. Black-Right-Pointing-Pointer XRF analysis of artworks at the CTU Prague.

  20. Structural investigation of spherical hollow excipient Mannit Q by X-ray microtomography.

    Science.gov (United States)

    Kajihara, Ryusuke; Noguchi, Shuji; Iwao, Yasunori; Yasuda, Yuki; Segawa, Megumi; Itai, Shigeru

    2015-11-10

    The structure of Mannit Q particles, an excipient made by spray-drying a d-mannitol solution, and Mannit Q tablets were investigated by synchrotron X-ray microtomography. The Mannit Q particles had a spherical shape with a hollow core. The shells of the particles consisted of fine needle-shaped crystals, and columnar crystals were present in the hollows. These structural features suggested the following formation mechanism for the hollow particles:during the spray-drying process, the solvent rapidly evaporated from the droplet surface, resulting in the formation of shells made of fine needle-shaped crystals.Solvent remaining inside the shells then evaporated slowly and larger columnar crystals grew as the hollows formed. Although most of the Mannit Q particles were crushed on tableting, some of the particles retained their hollow structures, probably because the columnar crystals inside the hollows functioned as props. This demonstrated that the tablets with porous void spaces may be readily manufactured using Mannit Q. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Non-destructive investigation of a time capsule using neutron radiography and X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, B.L., E-mail: macdonbl@mcmaster.ca [McMaster University, Department of Medical Physics and Applied Radiation Sciences, Hamilton (Canada); Vanderstelt, J., E-mail: joshv@nray.ca [Nray Services Inc., 56A Head Street, Dundas, ON (Canada); O’Meara, J. [University of Guelph, Department of Physics, Guelph (Canada); McNeill, F.E. [McMaster University, Department of Medical Physics and Applied Radiation Sciences, Hamilton (Canada)

    2016-01-15

    Non-destructive analytical techniques are becoming increasingly important for the study of objects of cultural heritage interest. This study applied two techniques: X-ray fluorescence and neutron radiography, for the investigation of a capped, tubular metal object recovered from an urban construction site in Gore Park, Hamilton, Canada. The site is an urban park containing a World War I commemorative monument that underwent renovation and relocation. Historical documentation suggested that the object buried underneath the monument was a time capsule containing a paper document listing the names of 1800 Canadians who died during WWI. The purpose of this study was to assess the condition of the object, and to verify if it was what the historical records purported. XRF analysis was used to characterize the elemental composition of the metal artifact, while neutron radiography revealed that its contents were congruent with historical records and remained intact after being interred for 91 years. Results of this study demonstrate the value of non-destructive techniques for the analysis and preservation of cultural heritage.

  2. FT-IR and X-ray spectroscopic investigations of Na-diclofenac-cyclodextrins interactions

    Science.gov (United States)

    Bratu, I.; Astilean, S.; Ionesc, Corina; Indrea, E.; Huvenne, J. P.; Legrand, P.

    1998-01-01

    The association of DCF-Na (the salt of the 2-[(2,6-dichlorophenyl)amino]-phenyl-acetic acid) with β-CD (cyclodextrin) in some therapeutic formulas can contribute to the optimisation of the physico-chemical and pharmaceutical properties of the parent drug. The understanding of the interaction between DCF with β-CD represents the objective of this study. FT-IR spectroscopy is one of the methods which clarify the nature of these interactions in complexes of such type. Therefore the changes in FT-IR spectra of binary dispersed systems DCF/ β-CD in physical mixture and coprecipitate from methanol (molar ratios: 1/1, 1/2, 2/3, 3/4, 7/4) were analysed. The analysis of the broadening of the X-ray powder diffraction line has been applied to investigate the average effective crystallite size, the mean square of the microstrain caused by distortions within β-CD crystallite and the fault probability in the binary dispersed DCF/ β-CD coprecipitate system.

  3. Yeast cell metabolism investigated by CO{_2} production and soft X-ray irradiation

    Science.gov (United States)

    Masini, A.; Batani, D.; Previdi, F.; Milani, M.; Pozzi, A.; Turcu, E.; Huntington, S.; Takeyasu, H.

    1999-01-01

    Results obtained using a new technique for studying cell metabolism are presented. The technique, consisting in CO2 production monitoring, has been applied to Saccharomyces cerevisiae yeast cells. Also the cells were irradiated using the soft X-ray laser-plasma source at Rutherford Appleton Laboratory with the aim of producing a damage of metabolic processes at the wall level, responsible for fermentation, without great interference with respiration, taking place in mitochondria, and DNA activity. The source was calibrated with PIN diodes and X-ray spectrometers and used Teflon stripes as target, emitting X-rays at about 0.9 keV, with a very low penetration in biological material. X-ray doses delivered to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. Immediately after irradiation, the damage to metabolic activity was measured again by monitoring CO2 production. Results showed a general reduction in gas production by irradiated samples, together with non-linear and non-monotone response to dose. There was also evidence of oscillations in cell metabolic activity and of X-ray induced changes in oscillation frequency.

  4. In situ dehydration behavior of zeolite-like pentagonite: A single-crystal X-ray study

    International Nuclear Information System (INIS)

    Danisi, Rosa Micaela; Armbruster, Thomas; Lazic, Biljana

    2013-01-01

    The structural modifications upon heating of pentagonite, Ca(VO)(Si 4 O 10 )·4H 2 O (space group Ccm2 1 , a=10.3708(2), b=14.0643(2), c=8.97810(10) Å, V=1309.53(3) Å 3 ) were investigated by in situ temperature dependent single-crystal X-ray structure refinements. Diffraction data of a sample from Poona district (India) have been measured in steps of 25 up to 250 °C and in steps of 50 °C between 250 and 400 °C. Pentagonite has a porous framework structure made up by layers of silicate tetrahedra connected by V 4+ O 5 square pyramids. Ca and H 2 O molecules are extraframework occupants. Room temperature diffraction data allowed refinement of H positions. The hydrogen-bond system links the extraframework occupants to the silicate layers and also interconnects the H 2 O molecules located inside the channels. Ca is seven-fold coordinated forming four bonds to O of the tetrahedral framework and three bonds to extraframework H 2 O. The H 2 O molecule at O9 showing a high displacement parameter is not bonded to Ca. The dehydration in pentagonite proceeds in three steps. At 100 °C the H 2 O molecule at O8 was released while O9 moved towards Ca. As a consequence the displacement parameter of H 2 O at O9 halved compared to that at room temperature. The unit-cell volume decreased to 1287.33(3) Å 3 leading to a formula with 3H 2 O per formula unit (pfu). Ca remained seven-fold coordinated. At 175 °C Ca(VO)(Si 4 O 10 )·3H 2 O transformed into a new phase with 1H 2 O molecule pfu characterized by doubling of the c axis and the monoclinic space group Pn. Severe bending of specific T--O--T angles led to contraction of the porous three-dimensional framework. In addition, H 2 O at O9 was expelled while H 2 O at O7 approached a position in the center of the channel. The normalized volume decreased to 1069.44(9) Å 3 . The Ca coordination reduced from seven- to six-fold. At 225 °C a new anhydrous phase with space group Pna2 1 but without doubling of c had formed. Release of

  5. In situ dehydration behavior of zeolite-like pentagonite: A single-crystal X-ray study

    Energy Technology Data Exchange (ETDEWEB)

    Danisi, Rosa Micaela, E-mail: rosa.danisi@krist.unibe.ch [Mineralogical Crystallography, Institute of Geological Sciences, University of Bern, Freiestrasse 3, Bern CH-3012 (Switzerland); Armbruster, Thomas; Lazic, Biljana [Mineralogical Crystallography, Institute of Geological Sciences, University of Bern, Freiestrasse 3, Bern CH-3012 (Switzerland)

    2013-01-15

    The structural modifications upon heating of pentagonite, Ca(VO)(Si{sub 4}O{sub 10}){center_dot}4H{sub 2}O (space group Ccm2{sub 1}, a=10.3708(2), b=14.0643(2), c=8.97810(10) A, V=1309.53(3) A{sup 3}) were investigated by in situ temperature dependent single-crystal X-ray structure refinements. Diffraction data of a sample from Poona district (India) have been measured in steps of 25 up to 250 Degree-Sign C and in steps of 50 Degree-Sign C between 250 and 400 Degree-Sign C. Pentagonite has a porous framework structure made up by layers of silicate tetrahedra connected by V{sup 4+}O{sub 5} square pyramids. Ca and H{sub 2}O molecules are extraframework occupants. Room temperature diffraction data allowed refinement of H positions. The hydrogen-bond system links the extraframework occupants to the silicate layers and also interconnects the H{sub 2}O molecules located inside the channels. Ca is seven-fold coordinated forming four bonds to O of the tetrahedral framework and three bonds to extraframework H{sub 2}O. The H{sub 2}O molecule at O9 showing a high displacement parameter is not bonded to Ca. The dehydration in pentagonite proceeds in three steps. At 100 Degree-Sign C the H{sub 2}O molecule at O8 was released while O9 moved towards Ca. As a consequence the displacement parameter of H{sub 2}O at O9 halved compared to that at room temperature. The unit-cell volume decreased to 1287.33(3) A{sup 3} leading to a formula with 3H{sub 2}O per formula unit (pfu). Ca remained seven-fold coordinated. At 175 Degree-Sign C Ca(VO)(Si{sub 4}O{sub 10}){center_dot}3H{sub 2}O transformed into a new phase with 1H{sub 2}O molecule pfu characterized by doubling of the c axis and the monoclinic space group Pn. Severe bending of specific T--O--T angles led to contraction of the porous three-dimensional framework. In addition, H{sub 2}O at O9 was expelled while H{sub 2}O at O7 approached a position in the center of the channel. The normalized volume decreased to 1069.44(9) A{sup 3

  6. Investigation of pulse shape analyzers for phoswich detectors in space-borne hard X-ray experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bleeker, J A.M.; Overtoom, J M [Huygens Lab., Leiden (Netherlands). Cosmic Ray Working Group

    1979-12-01

    A low-background telescope for hard X-ray astronomy (15-250 keV), comprising arrays of NaI(Tl)/CsI(Na) phoswiches as photon collectors, was recently developed. The background rejection efficiency of such a telescope, and hence the minimum source in a given time, critically depends on the performance of the phoswich pulse shape analyzer (PSA) in a space radiation environment. Results from theoretical and experimental work on analyzer configurations based on zero-crossing detection are presented. This led to the selection of an optimum configuration for space application. The in-situ performance of this analyzer was evaluated in a balloon-borne hard X-ray experiment, showing excellent discrimination efficiency throughout the entire energy regime.

  7. Film-based X-ray tomography combined with digital image processing: investigation of an ancient pattern-welded sword

    International Nuclear Information System (INIS)

    Lindegaard-Andersen, A.; Vedel, T.; Jeppesen, L.; Gottlieb, B.

    1988-01-01

    Film-based X-ray tomography and digital image processing have been used to investigate an inhomogeneous object of non-circular cross-section. The feasibility of using digital image processing to compensate for the poor contrast resolution inherent in film-based tomography has been demonstrated. (author)

  8. Experimental investigation of the diffusion coefficients in porous media by application of X-ray computer tomography

    DEFF Research Database (Denmark)

    Zhelezny, Petr; Shapiro, Alexander

    2006-01-01

    The present work describes a new experimental method that makes it possible to investigate diffusion coefficients in a porous medium. The method is based on application of X-ray computed tomography (CT). The general applicability of this method for the determination of diffusion coefficients...

  9. Systematic investigation of lard polymorphism using combined DSC and time-resolved synchrotron X-ray diffraction

    NARCIS (Netherlands)

    Kalnin, D.J.E.; Lesieur, P.; Artzner, F.; Keller, G.; Ollivon, M.

    2005-01-01

    The polymorphic behavior of lard was systematically investigated by differential scanning calorimetry (DSC) while simultaneously monitoring the formation of the different crystal forms with X-ray diffraction (XRDT). To interpret the complex polymorphic evolution of the sample analyzed by regular

  10. Structure investigation of metal ions clustering in dehydrated gel using x-ray anomalous dispersion effect

    CERN Document Server

    Soejima, Y; Sugiyama, M; Annaka, M; Nakamura, A; Hiramatsu, N; Hara, K

    2003-01-01

    The structure of copper ion clusters in dehydrated N-isopropylacrylamide/sodium acrylate (NIPA/SA) gel has been studied by means of small angle X-ray scattering (SAXS) method. In order to distinguish the intensity scattered by Cu ions, the X-ray anomalous dispersion effect around the Cu K absorption edge has been coupled with SAXS. It is found that the dispersion effect dependent on the incident X-ray energy is remarkable only at the momentum transfer q = 0.031 A sup - sup 1 , where a SAXS peak is observed. The results indicate that copper ions form clusters in the dehydrated gel, and that the mean size of clusters is the same as that of SA clusters produced by microphase separation. It is therefore naturally presumed that copper ions are adsorbed into the SA molecules. On the basis of the presumption, a mechanism is proposed for microphase-separation and clustering of Cu ions.

  11. Preliminary investigation of changes in x-ray multilayer optics subjected to high radiation flux

    International Nuclear Information System (INIS)

    Hockaday, M.P.; Blake, R.L.; Grosso, J.S.; Selph, M.M.; Klein, M.M.; Matuska, W. Jr.; Palmer, M.A.; Liefeld, R.J.

    1985-01-01

    A variety of metal multilayers was exposed to high x-ray flux using Sandia National Laboratories' PROTO II machine in the gas puff mode. Fluxes incident on the multilayers above 700 MW/cm 2 in total radiation, in nominal 20 ns pulses, were realized. The neon hydrogen- and helium-like resonance lines were used to probe the x-ray reflectivity properties of the multilayers as they underwent change of state during the heating pulse. A fluorescer-fiber optic-streak camera system was used to monitor the changes in x-ray reflectivity as a function of time and irradiance. Preliminary results are presented for a W/C multilayer. Work in progress to model the experiment is discussed. 13 refs., 4 figs

  12. Development of a new micro-furnace for "in situ" high-temperature single crystal X-ray diffraction measurements

    Science.gov (United States)

    Alvaro, Matteo; Angel, Ross J.; Marciano, Claudio; Zaffiro, Gabriele; Scandolo, Lorenzo; Mazzucchelli, Mattia L.; Milani, Sula; Rustioni, Greta; Domeneghetti, Chiara M.; Nestola, Fabrizio

    2015-04-01

    Several experimental methods to reliably determine elastic properties of minerals at non-ambient conditions have been developed. In particular, different techniques for generating high-pressure and high-temperature have been successfully adopted for single-crystal and powder X-ray diffraction measurements. High temperature devices for "in-situ" measurements should provide the most controlled isothermal environment as possible across the entire sample. It is intuitive that in general, thermal gradients across the sample increase as the temperature increases. Even if the small isothermal volume required for single-crystal X-ray diffraction experiments makes such phenomena almost negligible, the design of a furnace should also aim to reduce thermal gradients by including a large thermal mass that encloses the sample. However this solution often leads to complex design that results in a restricted access to reciprocal space or attenuation of the incident or diffracted intensity (with consequent reduction of the accuracy and/or precision in lattice parameter determination). Here we present a newly-developed H-shaped Pt-Pt/Rh resistance microfurnace for in-situ high-temperature single-crystal X-ray diffraction measurements. The compact design of the furnace together with the long collimator-sample-detector distance allows us to perform measurements up to 2θ = 70° with no further restrictions on any other angular movement. The microfurnace is equipped with a water cooling system that allows a constant thermal gradient to be maintained that in turn guarantees thermal stability with oscillations smaller than 5°C in the whole range of operating T of room-T to 1200°C. The furnace has been built for use with a conventional 4-circle Eulerian geometry equipped with point detector and automated with the SINGLE software (Angel and Finger 2011) that allows the effects of crystal offsets and diffractometer aberrations to be eliminated from the refined peak positions by the 8

  13. X-ray and radionuclide investigations of the bones and joints in psoriasis

    International Nuclear Information System (INIS)

    Spuzyak, M.I.; Vasil'ev, A.A.; Belyaev, G.M.; Vikman, Ya.Eh.

    1990-01-01

    Radiography of the bones and joints was performed in 133 psoriatic patients; osteoscintigraphy with 99m Tc-phosphate compounds was also performed in 42 of them. On the basis of x-ray findings 3 types of osteoarticular psoriasis were singled out: psoriatic polyarthritis, psoriatic polyarthrosis and psoriatic arthropathy. The most ample information on the type, activity and spreading of a pathological process in the bones and joints in psoriasis can be obtained from the combination of the x-ray and radionuclide methods

  14. Investigation of Lecturer's Chalk by x-ray Florescence and Fast Neutron Activation Techniques

    International Nuclear Information System (INIS)

    Hassan, M.F.

    2011-01-01

    Different samples of lecturer's chalk were studied, using X-ray florescence (XRF) and Fast Neutron Activation Analysis (FNAA) techniques to ensure the safety of its use. The K (X-rays) and the gamma-rays were measured, using Si(Li) and high-purity germanium (HPGe) spectrometers to detect and determine qualitatively and quantitatively the constituents of the studied samples. The concentrations of the elements (Ca and small traces of Al, Fe, Mg and Si) were measured and their presence was confirmed by gamma-ray, lifetime and/or XRF measurements.

  15. Probing Structural Changes in Poly(3-hexylthiophene) (P3HT) During Electrochemical Oxidation with In Situ X-ray Scattering

    Science.gov (United States)

    Thelen, Jacob L.; Patel, Shrayesh N.; Javier, Anna E.; Balsara, Nitash P.

    2014-03-01

    Mixtures of poly(3-hexylthiophene)-b-poly(ethylene oxide) (P3HT-b-PEO) block copolymer and lithium bis(trifluromethanesulfonyl) imide (LiTFSI) salt can microphase separate into electron (P3HT) and ion (PEO/LiTFSI) conducting domains. P3HT is a semicrystalline polymer with intrinsically semiconducting electronic properties. Electrochemical oxidation (doping) of the P3HT block provides the P3HT-b-PEO/LiTFSI mixtures with electronic conductivity suitable for lithium battery operation. Due to the presence of the solid-state electrolyte (PEO/LiTFSI) in intimate contact with the microphase separated P3HT domains, electrochemical oxidation of P3HT can be performed entirely in the solid state; therefore, P3HT-b-PEO/LiTFSI provides a unique opportunity to study the structural changes in P3HT induced by oxidation. We use in situ x-ray scattering techniques to probe structural changes in P3HT during electrochemical oxidation and correlate these changes with previously observed enhancements in electron mobility. Supported by the Joint Center for Energy Storage Research (JCESR).

  16. In Situ Ambient Pressure X-ray Photoelectron Spectroscopy of Cobalt Perovskite Surfaces under Cathodic Polarization at High Temperatures

    KAUST Repository

    Crumlin, Ethan J.; Mutoro, Eva; Hong, Wesley T.; Biegalski, Michael D.; Christen, Hans M.; Liu, Zhi; Bluhm, Hendrik; Shao-Horn, Yang

    2013-01-01

    Heterostructured oxide interfaces have demonstrated enhanced oxygen reduction reaction rates at elevated temperatures (∼500-800 C); however, the physical origin underlying this enhancement is not well understood. By using synchrotron-based in situ ambient pressure X-ray photoelectron spectroscopy (APXPS), we focus on understanding the surface electronic structure, elemental composition, and chemical nature of epitaxial La0.8Sr 0.2CoO3-δ (LSC113), (La 0.5Sr0.5)2CoO4±δ (LSC214), and LSC214-decorated LSC113 (LSC 113/214) thin films as a function of applied electrical potentials (0 to -800 mV) at 520 C and p(O2) of 1 × 10-3 atm. Shifts in the top of the valence band binding energy and changes in the Sr 3d and O 1s spectral components under applied bias reveal key differences among the film chemistries, most notably in the degree of Sr segregation to the surface and quantity of active oxygen sites in the perovskite termination layer. These differences help to identify important factors governing the enhanced activity of oxygen electrocatalysis observed for the LSC113/214 heterostructured surface. © 2013 American Chemical Society.

  17. Facile Low Temperature Hydrothermal Synthesis of BaTiO3 Nanoparticles Studied by In Situ X-ray Diffraction

    Directory of Open Access Journals (Sweden)

    Ola G. Grendal

    2018-06-01

    Full Text Available Ferroelectric materials are crucial for today’s technological society and nanostructured ferroelectric materials are important for the downscaling of devices. Controlled and reproducible synthesis of these materials are, therefore, of immense importance. Hydrothermal synthesis is a well-established synthesis route, with a large parameter space for optimization, but a better understanding of nucleation and growth mechanisms is needed for full utilization and control. Here we use in situ X-ray diffraction to follow the nucleation and growth of BaTiO3 formed by hydrothermal synthesis using two different titanium precursors, an amorphous titania precipitate slurry and a Ti-citric acid complex solution. Sequential Rietveld refinement was used to extract the time dependency of lattice parameters, crystallite size, strain, and atomic displacement parameters. Phase pure BaTiO3 nanoparticles, 10–15 nm in size, were successfully synthesized at different temperatures (100, 125, and 150 °C from both precursors after reaction times, ranging from a few seconds to several hours. The two precursors resulted in phase pure BaTiO3 with similar final crystallite size. Finally, two different growth mechanisms were revealed, where the effect of surfactants present during hydrothermal synthesis is discussed as one of the key parameters.

  18. Selective molecular annealing: in situ small angle X-ray scattering study of microwave-assisted annealing of block copolymers.

    Science.gov (United States)

    Toolan, Daniel T W; Adlington, Kevin; Isakova, Anna; Kalamiotis, Alexis; Mokarian-Tabari, Parvaneh; Dimitrakis, Georgios; Dodds, Christopher; Arnold, Thomas; Terrill, Nick J; Bras, Wim; Hermida Merino, Daniel; Topham, Paul D; Irvine, Derek J; Howse, Jonathan R

    2017-08-09

    Microwave annealing has emerged as an alternative to traditional thermal annealing approaches for optimising block copolymer self-assembly. A novel sample environment enabling small angle X-ray scattering to be performed in situ during microwave annealing is demonstrated, which has enabled, for the first time, the direct study of the effects of microwave annealing upon the self-assembly behavior of a model, commercial triblock copolymer system [polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene]. Results show that the block copolymer is a poor microwave absorber, resulting in no change in the block copolymer morphology upon application of microwave energy. The block copolymer species may only indirectly interact with the microwave energy when a small molecule microwave-interactive species [diethylene glycol dibenzoate (DEGDB)] is incorporated directly into the polymer matrix. Then significant morphological development is observed at DEGDB loadings ≥6 wt%. Through spatial localisation of the microwave-interactive species, we demonstrate targeted annealing of specific regions of a multi-component system, opening routes for the development of "smart" manufacturing methodologies.

  19. Automated scanning electron microscopy and x-ray microanalysis for in situ quantification of gadolinium deposits in skin

    International Nuclear Information System (INIS)

    Thakral, Charu; Abraham, Jerrold L.

    2007-01-01

    Gadolinium (Gd) has been identified as a possible causative agent of an emerging cutaneous and systemic fibrosing disorder, nephrogenic systemic fibrosis (NSF), which can cause serious disability and even death. To date, there are only two known associations with this disorder - renal insufficiency and Gd enhanced magnetic resonance imaging (MRI). We developed an automated quantitative scanning electron microscopy (SEM) and Energy dispersive x-ray spectroscopy (EDS) method for Gd in tissue of NSF patients. Freshly cut paraffin block surfaces examined using the variable pressure mode under standardized conditions and random search of the tissue area allow in situ detection and semiquantitative morphometric (volumetric) analysis of insoluble higher atomic number features using backscattered electron imaging. We detected Gd ranging from 1 to 2270 cps/mm 2 in 57 cutaneous biopsies of NSF. Gd was associated with P, Ca, and usually Na in tissue deposits. Our method reproducibly determines the elemental composition, relative concentration, and spatial distribution of detected features within the tissue. However, we cannot detect features below our spatial resolution, nor concentrations below the detection limit of our SEM/EDS system. The findings confirm transmetallation and release of toxic Gd ions in NSF and allow dose-response analysis at the histologic level. (author)

  20. In situ surface X-ray diffraction study of ultrathin epitaxial Co films on Au(111) in alkaline solution

    International Nuclear Information System (INIS)

    Reikowski, Finn; Maroun, Fouad; Di, Nan; Allongue, Philippe; Ruge, Martin; Stettner, Jochim; Magnussen, Olaf M.

    2016-01-01

    The oxidation behavior of ultrathin electrodeposited Co films on Au(111) in alkaline electrolyte was studied using in situ surface X-ray scattering techniques employing synchrotron radiation and complementary optical reflectivity and electrochemical measurements. The films are formed at pH 4 and consist of (001)-oriented hcp Co crystallites that are several nm high, a few ten nm in diameter, and remain largely unchanged after electrolyte exchange to pH 12 solution. In the pre-oxidation peak only minor changes were observed in the diffraction studies, excluding the formation of Co(OH)_2 layers. In the potential regime of Co hydroxide formation a rapid reduction of the amount of Co is observed, while the characteristic height of the islands decreases only slightly. On longer times scales, growth of 3D crystals of Co(OH)_2 occurs as well as irreversible Co dissolution into the electrolyte is found. On the basis of the structural observations oxidation of the Co film is proposed to proceed via fast formation of an ultrathin passivating layer, followed by nucleation and growth of 3D hydroxide crystals at the grain boundaries in the Co deposit.

  1. In Situ Ambient Pressure X-ray Photoelectron Spectroscopy of Cobalt Perovskite Surfaces under Cathodic Polarization at High Temperatures

    KAUST Repository

    Crumlin, Ethan J.

    2013-08-08

    Heterostructured oxide interfaces have demonstrated enhanced oxygen reduction reaction rates at elevated temperatures (∼500-800 C); however, the physical origin underlying this enhancement is not well understood. By using synchrotron-based in situ ambient pressure X-ray photoelectron spectroscopy (APXPS), we focus on understanding the surface electronic structure, elemental composition, and chemical nature of epitaxial La0.8Sr 0.2CoO3-δ (LSC113), (La 0.5Sr0.5)2CoO4±δ (LSC214), and LSC214-decorated LSC113 (LSC 113/214) thin films as a function of applied electrical potentials (0 to -800 mV) at 520 C and p(O2) of 1 × 10-3 atm. Shifts in the top of the valence band binding energy and changes in the Sr 3d and O 1s spectral components under applied bias reveal key differences among the film chemistries, most notably in the degree of Sr segregation to the surface and quantity of active oxygen sites in the perovskite termination layer. These differences help to identify important factors governing the enhanced activity of oxygen electrocatalysis observed for the LSC113/214 heterostructured surface. © 2013 American Chemical Society.

  2. Bone Implant Interface Investigation by Synchrotron Radiation X-Ray Microfluorescence

    International Nuclear Information System (INIS)

    Calasans-Maia, M.; Sales, E.; Lopes, R. T.; Granjeiro, J. M.; Lima, I.

    2010-01-01

    Zinc is known to play a relevant role in growth and development; it has stimulatory effects on in vitro and in vivo bone formation and an inhibitory effect on in vitro osteoclastic bone resorption. The inorganic component of the bone tissue is nonstoichiometric apatite; changes in the composition of hidroxyapatite are subject of studies in order to improve the tissue response after implantation. The objective of this study was to investigate the effect of 0.5% zinc-containing hydroxyapatite in comparison to hydroxyapatite on osseous repair of rabbit's tibia. Cylinders (2x6 mm) of both materials were produced according to the specification of the International Organization for Standardization. Ethics Commission on Teaching and Research in Animals approved this project (HUAP-195/06). Fifteen White New Zealand rabbits were submitted to general anesthesia and two perforations (2 mm) were made in each tibia for implantation of zinc-containing hydroxyapatite cylinders (left tibia) and hydroxyapatite cylinders (right tibia). After 1, 2 and 4 weeks, the animals were killed and one fragment of each tibia with the cylinder was collected and embedded in a methacrylate-based resin and cut into slices (∼200 μm thickness), parallel to the implant's long axis with a precision diamond saw for Synchrotron Radiation X-ray Microfluorescence investigation. The accomplishment of the standard procedures helped the planning, execution and the comparative analysis of the results. The chemical and physical properties of the biomaterials were modified after its implantation and the incorporation of zinc. Both materials are biocompatible and promote osteoconduction and favored bone repair.

  3. NOTE: An innovative phantom for quantitative and qualitative investigation of advanced x-ray imaging technologies

    Science.gov (United States)

    Chiarot, C. B.; Siewerdsen, J. H.; Haycocks, T.; Moseley, D. J.; Jaffray, D. A.

    2005-11-01

    Development, characterization, and quality assurance of advanced x-ray imaging technologies require phantoms that are quantitative and well suited to such modalities. This note reports on the design, construction, and use of an innovative phantom developed for advanced imaging technologies (e.g., multi-detector CT and the numerous applications of flat-panel detectors in dual-energy imaging, tomosynthesis, and cone-beam CT) in diagnostic and image-guided procedures. The design addresses shortcomings of existing phantoms by incorporating criteria satisfied by no other single phantom: (1) inserts are fully 3D—spherically symmetric rather than cylindrical; (2) modules are quantitative, presenting objects of known size and contrast for quality assurance and image quality investigation; (3) features are incorporated in ideal and semi-realistic (anthropomorphic) contexts; and (4) the phantom allows devices to be inserted and manipulated in an accessible module (right lung). The phantom consists of five primary modules: (1) head, featuring contrast-detail spheres approximate to brain lesions; (2) left lung, featuring contrast-detail spheres approximate to lung modules; (3) right lung, an accessible hull in which devices may be placed and manipulated; (4) liver, featuring conrast-detail spheres approximate to metastases; and (5) abdomen/pelvis, featuring simulated kidneys, colon, rectum, bladder, and prostate. The phantom represents a two-fold evolution in design philosophy—from 2D (cylindrically symmetric) to fully 3D, and from exclusively qualitative or quantitative to a design accommodating quantitative study within an anatomical context. It has proven a valuable tool in investigations throughout our institution, including low-dose CT, dual-energy radiography, and cone-beam CT for image-guided radiation therapy and surgery.

  4. An innovative phantom for quantitative and qualitative investigation of advanced x-ray imaging technologies

    International Nuclear Information System (INIS)

    Chiarot, C B; Siewerdsen, J H; Haycocks, T; Moseley, D J; Jaffray, D A

    2005-01-01

    Development, characterization, and quality assurance of advanced x-ray imaging technologies require phantoms that are quantitative and well suited to such modalities. This note reports on the design, construction, and use of an innovative phantom developed for advanced imaging technologies (e.g., multi-detector CT and the numerous applications of flat-panel detectors in dual-energy imaging, tomosynthesis, and cone-beam CT) in diagnostic and image-guided procedures. The design addresses shortcomings of existing phantoms by incorporating criteria satisfied by no other single phantom: (1) inserts are fully 3D-spherically symmetric rather than cylindrical; (2) modules are quantitative, presenting objects of known size and contrast for quality assurance and image quality investigation; (3) features are incorporated in ideal and semi-realistic (anthropomorphic) contexts; and (4) the phantom allows devices to be inserted and manipulated in an accessible module (right lung). The phantom consists of five primary modules: (1) head, featuring contrast-detail spheres approximate to brain lesions; (2) left lung, featuring contrast-detail spheres approximate to lung modules; (3) right lung, an accessible hull in which devices may be placed and manipulated; (4) liver, featuring conrast-detail spheres approximate to metastases; and (5) abdomen/pelvis, featuring simulated kidneys, colon, rectum, bladder, and prostate. The phantom represents a two-fold evolution in design philosophy-from 2D (cylindrically symmetric) to fully 3D, and from exclusively qualitative or quantitative to a design accommodating quantitative study within an anatomical context. It has proven a valuable tool in investigations throughout our institution, including low-dose CT, dual-energy radiography, and cone-beam CT for image-guided radiation therapy and surgery. (note)

  5. Development of a laser-based heating system for in situ synchrotron-based X-ray tomographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fife, Julie L., E-mail: julie.fife@psi.ch [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Computational Materials Laboratory, Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland); Rappaz, Michel [Computational Materials Laboratory, Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland); Pistone, Mattia [Institute for Geochemistry and Petrology, Swiss Federal Institute of Technology of Zurich, Zurich (Switzerland); Celcer, Tine [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); The Centre of Excellence for Biosensors, Instrumentation and Process Control, Solkan (Slovenia); Mikuljan, Gordan [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Stampanoni, Marco [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Institute for Biomedical Engineering, Swiss Federal Institute of Technology and University of Zurich, Zurich (Switzerland)

    2012-05-01

    A laser-based heating system has been developed at the TOMCAT beamline of the Swiss Light Source for in situ observations of moderate-to-high-temperature applications of materials. Understanding the formation of materials at elevated temperatures is critical for determining their final properties. Synchrotron-based X-ray tomographic microscopy is an ideal technique for studying such processes because high spatial and temporal resolutions are easily achieved and the technique is non-destructive, meaning additional analyses can take place after data collection. To exploit the state-of-the-art capabilities at the tomographic microscopy and coherent radiology experiments (TOMCAT) beamline of the Swiss Light Source, a general-use moderate-to-high-temperature furnace has been developed. Powered by two diode lasers, it provides controlled localized heating, from 673 to 1973 K, to examine many materials systems and their dynamics in real time. The system can also be operated in various thermal modalities. For example, near-isothermal conditions at a given sample location can be achieved with a prescribed time-dependent temperature. This mode is typically used to study isothermal phase transformations; for example, the formation of equiaxed grains in metallic systems or to nucleate and grow bubble foams in silicate melts under conditions that simulate volcanic processes. In another mode, the power of the laser can be fixed and the specimen moved at a constant speed in a user-defined thermal gradient. This is similar to Bridgman solidification, where the thermal gradient and cooling rate control the microstructure formation. This paper details the experimental set-up and provides multiple proofs-of-concept that illustrate the versatility of using this laser-based heating system to explore, in situ, many elevated-temperature phenomena in a variety of materials.

  6. Investigation of photon counting pixel detectors for X-ray spectroscopy and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Talla, Patrick Takoukam

    2011-04-07

    The Medipix2 and Medipix3 detectors are hybrid pixelated photon counting detectors with a pixel pitch of 55 {mu}m. The sensor material used in this thesis was silicon. Because of their small pixel size they suffer from charge sharing i.e. an incoming photon can be registered by more than one pixel. In order to correct for charge sharing due to lateral diffusion of charge carriers, the Medipix3 detector was developed: with its Charge Summing Mode, the charge collected in a cluster of 2 x 2 pixel is added up and attributed to only one pixel whose counter is incremented. The adjustable threshold of the detectors allows to count the photons and to gain information on their energy. The main purposes of the thesis are to investigate spectral and imaging properties of pixelated photon counting detectors from the Medipix family such as Medipix2 and Medipix3. The investigations are based on simulations and measurements. In order to investigate the spectral properties of the detectors measurements were performed using fluorescence lines of materials such as molybdenum, silver but also some radioactive sources such as Am-241 or Cd-109. From the measured data, parameters like the threshold dispersion and the gain variation from pixel-to-pixel were extracted and used as input in the Monte Carlo code ROSI to model the responses of the detector to monoenergetic photons. The measured data are well described by the simulations for Medipix2 and for Medipix3 operating in Charge Summing Mode. Due to charge sharing and due to the energy dependence of attenuation processes in silicon and to Compton scattering the incoming and the measured spectrum differ substantially from each other. Since the responses to monoenergetic photons are known, a deconvolution was performed to determine the true incoming spectrum. Several direct and iterative methods were successfully applied on measured and simulated data of an X-ray tube and radioactive sources. The knowledge of the X-ray spectrum is

  7. Investigation of photon counting pixel detectors for X-ray spectroscopy and imaging

    International Nuclear Information System (INIS)

    Talla, Patrick Takoukam

    2011-01-01

    The Medipix2 and Medipix3 detectors are hybrid pixelated photon counting detectors with a pixel pitch of 55 μm. The sensor material used in this thesis was silicon. Because of their small pixel size they suffer from charge sharing i.e. an incoming photon can be registered by more than one pixel. In order to correct for charge sharing due to lateral diffusion of charge carriers, the Medipix3 detector was developed: with its Charge Summing Mode, the charge collected in a cluster of 2 x 2 pixel is added up and attributed to only one pixel whose counter is incremented. The adjustable threshold of the detectors allows to count the photons and to gain information on their energy. The main purposes of the thesis are to investigate spectral and imaging properties of pixelated photon counting detectors from the Medipix family such as Medipix2 and Medipix3. The investigations are based on simulations and measurements. In order to investigate the spectral properties of the detectors measurements were performed using fluorescence lines of materials such as molybdenum, silver but also some radioactive sources such as Am-241 or Cd-109. From the measured data, parameters like the threshold dispersion and the gain variation from pixel-to-pixel were extracted and used as input in the Monte Carlo code ROSI to model the responses of the detector to monoenergetic photons. The measured data are well described by the simulations for Medipix2 and for Medipix3 operating in Charge Summing Mode. Due to charge sharing and due to the energy dependence of attenuation processes in silicon and to Compton scattering the incoming and the measured spectrum differ substantially from each other. Since the responses to monoenergetic photons are known, a deconvolution was performed to determine the true incoming spectrum. Several direct and iterative methods were successfully applied on measured and simulated data of an X-ray tube and radioactive sources. The knowledge of the X-ray spectrum is

  8. Effects of X-Ray Dose On Rhizosphere Studies Using X-Ray Computed Tomography

    Science.gov (United States)

    Zappala, Susan; Helliwell, Jonathan R.; Tracy, Saoirse R.; Mairhofer, Stefan; Sturrock, Craig J.; Pridmore, Tony; Bennett, Malcolm; Mooney, Sacha J.

    2013-01-01

    X-ray Computed Tomography (CT) is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such as root washing. However, one routinely unreported aspect of X-ray CT is the potential effect of X-ray dose on the soil-borne microorganisms and plants in rhizosphere investigations. Here we aimed to i) highlight the need for more consistent reporting of X-ray CT parameters for dose to sample, ii) to provide an overview of previously reported impacts of X-rays on soil microorganisms and plant roots and iii) present new data investigating the response of plant roots and microbial communities to X-ray exposure. Fewer than 5% of the 126 publications included in the literature review contained sufficient information to calculate dose and only 2.4% of the publications explicitly state an estimate of dose received by each sample. We conducted a study involving rice roots growing in soil, observing no significant difference between the numbers of root tips, root volume and total root length in scanned versus unscanned samples. In parallel, a soil microbe experiment scanning samples over a total of 24 weeks observed no significant difference between the scanned and unscanned microbial biomass values. We conclude from the literature review and our own experiments that X-ray CT does not impact plant growth or soil microbial populations when employing a low level of dose (<30 Gy). However, the call for higher throughput X-ray CT means that doses that biological samples receive are likely to increase and thus should be closely monitored. PMID:23840640

  9. Structural investigation of bistrifluron using x-ray crystallography, NMR spectroscopy, and molecular modeling

    CERN Document Server

    Moon, J K; Rhee, S K; Kim, G B; Yun, H S; Chung, B J; Lee, S S; Lim, Y H

    2002-01-01

    A new insecticide, bistrifluron acts as an inhibitor of insect development and interferes with the cuticle formation of insects. Since it shows low acute oral and dermal toxicities, it can be one of potent insecticides. Based on X-ray crystallography, NMR spectroscopy and molecular modeling, the structural studies of bistrifluron have been carried out.

  10. Investigations of Caenorhabditis Elegans Using Soft X-ray Contact Microscopy

    Czech Academy of Sciences Publication Activity Database

    Desai, T.; Batani, D.; Bernardinello, A.; Poletti, G.; Orsini, F.; Ullschmied, Jiří; Skála, Jiří; Králiková, Božena; Krouský, Eduard; Mocek, Karel; Pfeifer, Miroslav; Kadlec, Christelle; Mocek, Tomáš; Präg R., Ansgar; Renner, Oldřich; Juha, Libor; Cotelli, F.; Lamia, C. L.; Zullini, A.

    2004-01-01

    Roč. 20, č. 3 (2004), s. 121-125 ISSN 1120-1797 R&D Projects: GA MŠk LN00A100 Keywords : C. elegans * soft X-ray contact microscopy * intense laser plasma * gold target Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.341, year: 2004

  11. X-ray Photoelectron Spectroscopy Investigation on Electrochemical Degradation of Proton Exchange Membrane Fuel Cell Electrodes

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Dhiman, Rajnish; Skou, Eivind Morten

    2015-01-01

    X-ray photoelectron spectroscopy studies were systematically carried out on the electrodes before and after the electrochemical stress tests in an aqueous electrolyte at 20 °C and 70 °C. The electrodes have different ionomer structures (no ionomer, only ionomer, physically mixed ionomer and hot p...

  12. X-ray diffraction investigation of the sulphur induced 4x1 reconstruction of Ni(110)

    DEFF Research Database (Denmark)

    Foss, M.; Feidenhans'l, R.; Nielsen, M.

    1993-01-01

    The atomic structure of the Ni(110)4 x 1-S reconstruction has been determined on the basis of surface X-ray diffraction measurements. An analysis of the in-plane diffraction data shows that the model consists of Ni rows along the [001] direction, two for every 4 x 1 unit cell, corresponding to 0....

  13. A Variable-Energy Soft X-Ray Microprobe to Investigate Mechanisms of the Radiation-Induced Bystander Effect

    International Nuclear Information System (INIS)

    Folkard, Melvyn; Vojnovic, Borivoj; Schettino, Giuseppe; Atkinson, Kirk; Prise, Kevin M.; Michael, Barry D.

    2007-01-01

    The Gray Cancer Institute has pioneered the use of X ray focusing techniques to develop systems for micro irradiating individual cells and sub cellular targets in vitro. Cellular micro irradiation is now recognized as a highly versatile technique for understanding how ionizing radiation interacts with living cells and tissues. The strength of the technique lies in its ability to deliver precise doses of radiation to selected individual cells (or sub cellular targets). The application of this technique in the field of radiation biology continues to be of great interest for investigating a number of phenomena currently of concern to the radiobiological community. One important phenomenon is the so called ''bystander effect'' where it is observed that unirradiated cells can also respond to signals transmitted by irradiated neighbors. Clearly, the ability of a microbeam to irradiate just a single cell or selected cells within a population is well suited to studying this effect. Our prototype ''tabletop'' X-ray microprobe was optimized for focusing 278 eV C-K X rays and has been used successfully for a number of years. However, we have sought to develop a new variable energy soft X-ray microprobe capable of delivering focused CK (0.28 keV), Al-K (1.48 keV) and notably, Ti-K (4.5 keV) X rays. Ti-K X rays are capable of penetrating several cell layers and are therefore much better suited to studies involving tissues and multi cellular layers. In our new design, X-rays are generated by the focused electron bombardment of a material whose characteristic-K radiation is required. The source is mounted on a 1.5 x 1.0 meter optical table. Electrons are generated by a custom built gun, designed to operate up to 15 kV. The electrons are focused using a permanent neodymium iron boron magnet assembly. Focusing is achieved by adjusting the accelerating voltage and by fine tuning the target position via a vacuum position feedthrough. To analyze the electron beam properties, a custom

  14. X-ray photoelectron spectroscopy (XPS) investigation of the surface film on magnesium powders.

    Science.gov (United States)

    Burke, Paul J; Bayindir, Zeynel; Kipouros, Georges J

    2012-05-01

    Magnesium (Mg) and its alloys are attractive for use in automotive and aerospace applications because of their low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. Powder metallurgy may be a suitable solution for forming near-net-shape parts. However, sintering pure magnesium presents difficulties due to surface film that forms on the magnesium powder particles. The present work investigates the composition of the surface film that forms on the surface of pure magnesium powders exposed to atmospheric conditions and on pure magnesium powders after compaction under uniaxial pressing at a pressure of 500 MPa and sintering under argon at 600 °C for 40 minutes. Initially, focused ion beam microscopy was utilized to determine the thickness of the surface layer of the magnesium powder and found it to be ~10 nm. The X-ray photoelectron analysis of the green magnesium sample prior to sintering confirmed the presence of MgO, MgCO(3)·3H(2)O, and Mg(OH)(2) in the surface layer of the powder with a core of pure magnesium. The outer portion of the surface layer was found to contain MgCO(3)·3H(2)O and Mg(OH)(2), while the inner portion of the layer is primarily MgO. After sintering, the MgCO(3)·3H(2)O was found to be almost completely absent, and the amount of Mg(OH)(2) was also decreased significantly. This is postulated to occur by decomposition of the compounds to MgO and gases during the high temperature of sintering. An increase in the MgO content after sintering supports this theory.

  15. Synthesis of 1 nm Pd Nanoparticles in a Microfluidic Reactor: Insights from in Situ X ray Absorption Fine Structure Spectroscopy and Small-Angle X ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Ayman M.; Al Hasan, Naila M.; Ivanov, Sergei A.; Siefert, Soenke; Kelly, Ryan T.; Hallfors, Nicholas G.; Benavidez, Angelica D.; Kovarik, Libor; Jenkins, Aaron; Winans, R. E.; Datye, Abhaya K.

    2015-06-11

    In this paper we show that the temporal separation of nucleation and growth is not a necessary condition for the colloidal synthesis of monodisperse nanoparticles. The synthesis mechanism of Pd nanoparticles was determined by in situ XAFS and SAXS in a microfluidic reactor capable of millisecond up to an hour time resolution. The SAXS results showed two autocatalytic growth phases, a fast growth phase followed by a very slow growth phase. The steady increase in the number of particles throughout the two growth phases indicates the synthesis is limited by slow continuous nucleation. The transition from fast to slow growth was caused by rapid increase in bonding with the capping agent as shown by XAFS. Based on this fundamental understanding of the synthesis mechanism, we show that 1 nm monodisperse Pd nanoparticles can be synthesized at low temperature using a strong binding capping agent such as trioctylphosphine (TOP).

  16. A reference sample for investigating the stability of the imaging system of x-ray computed tomography

    International Nuclear Information System (INIS)

    Sun, Wenjuan; Brown, Stephen; Flay, Nadia; McCarthy, Michael; McBride, John

    2016-01-01

    The use of x-ray computed tomography for dimensional measurements associated with engineering applications has flourished in recent years. However, error sources associated with the technology are not well understood. In this paper, a novel two-sphere reference sample has been developed and used to investigate the stability of the imaging system that consists of an x-ray tube and a detector. In contrast with other research work reported, this work considered relative positional variation along the x -, y - and z -axes. This sample is a significant improvement over the one sphere sample proposed previously, which can only be used to observe the stability of the imaging system along x - and y -axes. Temperature variations of different parts of the system have been monitored and the relationship between temperature variations and x-ray image stability has been studied. Other effects that may also influence the stability of the imaging system have been discussed. The proposed reference sample and testing method are transferable to other types of x-ray computed tomography systems, for example, systems with transmission targets and systems with sub-micrometre focal spots. (paper)

  17. Comparative investigation of two-dimensional imaging methods and X-ray tomography in the characterization of microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Bacaicoa, Inigo; Luetje, Martin [Kassel Univ. (Germany). Inst. of Materials Engineering, Quality and Reliability; Saelzer, Philipp [Kassel Univ. (Germany). Abt. Materialentwicklung und Verbundwerkstoffe; Umbach, Cristin [Kassel Univ. (Germany). Inst. for Structural Engineering; Brueckner-Foit, Angelika [Kassel Univ. (Germany). Inst. of Materials Engineering; Heim, Hans-Peter [Kassel Univ. (Germany). Plastics Engineering; Middendorf, Bernhard [Kassel Univ. (Germany). Dept. of Building Materials and Construction Chemistry

    2017-11-01

    The microstructural features of three different materials have been quantified by means of 2D image analysis and X-ray micro-computer tomography (CT) and the results were compared to determine the reliability of the 2D analysis in the material characterization. The 3D quantification of shrinkage pores and Fe-rich inclusions of an Al-Si-Cu alloy by X-ray tomography was compared with the statistical analysis of the 2D metallographic pictures and a significant difference in the results was found due to the complex morphology of shrinkage pores and Fe-rich particles. Furthermore, wood particles of a wood-plastic composite were measured by dynamic image analysis and X-ray tomography. Similar results were obtained for the maximum length of the particles, although the results of width differ considerably, which leads to a miscalculation of the particles aspect ratio. Finally, air voids of a foam concrete were investigated by the analysis of the 2D pictures in ImageJ and the results of the 2D circularity were compared with the values of the 3D elongation obtained by micro-computed tomography. The 3D analysis of the air voids in the foam concrete showed a more precise description of the morphology, although the 2D result are in good agreement with the results obtained by X-ray micro-tomography.

  18. Comparative investigation of two-dimensional imaging methods and X-ray tomography in the characterization of microstructure

    International Nuclear Information System (INIS)

    Bacaicoa, Inigo; Luetje, Martin; Saelzer, Philipp; Umbach, Cristin; Brueckner-Foit, Angelika; Heim, Hans-Peter; Middendorf, Bernhard

    2017-01-01

    The microstructural features of three different materials have been quantified by means of 2D image analysis and X-ray micro-computer tomography (CT) and the results were compared to determine the reliability of the 2D analysis in the material characterization. The 3D quantification of shrinkage pores and Fe-rich inclusions of an Al-Si-Cu alloy by X-ray tomography was compared with the statistical analysis of the 2D metallographic pictures and a significant difference in the results was found due to the complex morphology of shrinkage pores and Fe-rich particles. Furthermore, wood particles of a wood-plastic composite were measured by dynamic image analysis and X-ray tomography. Similar results were obtained for the maximum length of the particles, although the results of width differ considerably, which leads to a miscalculation of the particles aspect ratio. Finally, air voids of a foam concrete were investigated by the analysis of the 2D pictures in ImageJ and the results of the 2D circularity were compared with the values of the 3D elongation obtained by micro-computed tomography. The 3D analysis of the air voids in the foam concrete showed a more precise description of the morphology, although the 2D result are in good agreement with the results obtained by X-ray micro-tomography.

  19. A flow cell for transient voltammetry and in situ grazing incidence X-ray diffraction characterization of electrocrystallized cadmium(II) tetracyanoquinodimethane

    Energy Technology Data Exchange (ETDEWEB)

    Veder, Jean-Pierre [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Nafady, Ayman [School of Chemistry, Monash University, Clayton, Victoria 3800 (Australia); Clarke, Graeme [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Williams, Ross P. [Centre for Materials Research, Department of Imaging and Applied Physics, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); De Marco, Roland, E-mail: r.demarco@curtin.edu.a [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Bond, Alan M. [School of Chemistry, Monash University, Clayton, Victoria 3800 (Australia)

    2011-01-01

    An easy to fabricate and versatile cell that can be used with a variety of electrochemical techniques, also meeting the stringent requirement for undertaking cyclic voltammetry under transient conditions in in situ electrocrystallization studies and total external reflection X-ray analysis, has been developed. Application is demonstrated through an in situ synchrotron radiation-grazing incidence X-ray diffraction (SR-GIXRD) characterization of electrocrystallized cadmium (II)-tetracyanoquinodimethane material, Cd(TCNQ){sub 2}, from acetonitrile (0.1 mol dm{sup -3} [NBu{sub 4}][PF{sub 6}]). Importantly, this versatile cell design makes SR-GIXRD suitable for almost any combination of total external reflection X-ray analysis (e.g., GIXRF and GIXRD) and electrochemical perturbation, also allowing its application in acidic, basic, aqueous, non-aqueous, low and high flow pressure conditions. Nevertheless, the cell design separates the functions of transient voltammetry and SR-GIXRD measurements, viz., voltammetry is performed at high flow rates with a substantially distended window to minimize the IR (Ohmic) drop of the electrolyte, while SR-GIXRD is undertaken using stop-flow conditions with a very thin layer of electrolyte to minimize X-ray absorption and scattering by the solution.

  20. Support Effects in Catalysis Studied by in-situ Sum Frequency Generation Vibrational Spectroscopy and in-situ X-Ray Spectroscopies

    Science.gov (United States)

    Kennedy, Griffin John

    Kinetic measurements are paired with in-situ spectroscopic characterization tools to investigate colloidally based, supported Pt catalytic model systems in order to elucidate the mechanisms by which metal and support work in tandem to dictate activity and selectivity. The results demonstrate oxide support materials, while inactive in absence of Pt nanoparticles, possess unique active sites for the selective conversion of gas phase molecules when paired with an active metal catalyst. In order to establish a paradigm for metal-support interactions using colloidally synthesized Pt nanoparticles the ability of the organic capping agent to inhibit reactivity and interaction with the support must first be assessed. Pt nanoparticles capped by poly(vinylpyrrolidone) (PVP), and those from which the PVP is removed by UV light exposure, are investigated for two reactions, the hydrogenation of ethylene and the oxidation of methanol. It is shown that prior to PVP removal the particles are moderately active for both reactions. Following removal, the activity for the two reactions diverges, the ethylene hydrogenation rate increases 10-fold, while the methanol oxidation rate decreases 3-fold. To better understand this effect the capping agent prior to, and the residual carbon remaining after UV treatment are probed by sum frequency generation vibrational spectroscopy. Prior to removal no major differences are observed when the particles are exposed to alternating H2 and O2 environments. When the PVP is removed, carbonaceous fragments remain on the surface that dynamically restructure in H2 and O2. These fragments create a tightly bound shell in an oxygen environment and a porous coating of hydrogenated carbon in the hydrogen environment. Reaction rate measurements of thermally cleaned PVP and oleic acid capped particles show this effect to be independent of cleaning method or capping agent. In all this demonstrates the ability of the capping agent to mediate nanoparticle catalysis

  1. Investigations of the phase transition in V3O5 using energy dispersive X-ray diffraction and synchrotron radiation white beam X-ray topography

    International Nuclear Information System (INIS)

    Asbrink, S.; Gerward, L.; Staun Olsen, J.

    1985-01-01

    The reversible first order phase transition in V 3 O 5 at T t =155 0 C has been studied using a specially constructed oven, where the temperature can be kept constant within a few hundredths of a degree for several hours. Energy dispersive diffraction measurements have beem made in a temperature region around the phase transition with the fixed crystal method and the θ/2θ scanning method. White beam X-ray topographs have been obtained from the same crystal in the same temperature region using synchrotron radiation. The integrated intensities of the strong h 0 0 reflections show anomalies that are correlated with the corresponding X-ray topographs. Thus, an unexpected increase of crystal perfection is observed a few hundredths of a degree below T t . The energy dependence of the intensity maximum at T t for strong reflections has been determined and semi-quantitatively explained on the basis of extinction theory. (orig.)

  2. Hydration forces between aligned DNA helices undergoing B to A conformational change: In-situ X-ray fiber diffraction studies in a humidity and temperature controlled environment.

    Science.gov (United States)

    Case, Ryan; Schollmeyer, Hauke; Kohl, Phillip; Sirota, Eric B; Pynn, Roger; Ewert, Kai E; Safinya, Cyrus R; Li, Youli

    2017-12-01

    Hydration forces between DNA molecules in the A- and B-Form were studied using a newly developed technique enabling simultaneous in situ control of temperature and relative humidity. X-ray diffraction data were collected from oriented calf-thymus DNA fibers in the relative humidity range of 98%-70%, during which DNA undergoes the B- to A-form transition. Coexistence of both forms was observed over a finite humidity range at the transition. The change in DNA separation in response to variation in humidity, i.e. change of chemical potential, led to the derivation of a force-distance curve with a characteristic exponential decay constant of∼2Å for both A- and B-DNA. While previous osmotic stress measurements had yielded similar force-decay constants, they were limited to B-DNA with a surface separation (wall-to-wall distance) typically>5Å. The current investigation confirms that the hydration force remains dominant even in the dry A-DNA state and at surface separation down to∼1.5Å, within the first hydration shell. It is shown that the observed chemical potential difference between the A and B states could be attributed to the water layer inside the major and minor grooves of the A-DNA double helices, which can partially interpenetrate each other in the tightly packed A phase. The humidity-controlled X-ray diffraction method described here can be employed to perform direct force measurements on a broad range of biological structures such as membranes and filamentous protein networks. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. The development of in situ photon-in/photon-out soft X-ray spectroscopy on beamline 7.0.1 at the ALS

    International Nuclear Information System (INIS)

    Guo, Jinghua

    2013-01-01

    Highlights: ► Development of various cells for in-situ electronic structure study. ► Gas cell for study of gas molecules and catalytic reactions. ► Liquid cell for study of molecular liquids and ion salvation. ► In-situ cell for study of electrochemical reactions. -- Abstract: This is a mini-review about the development of various cells built over the years for in situ electronic structure study of gas molecules, molecular liquids, gas/solid and liquid/solid interfaces. In the study of gas molecules, the role of the parity selection rule in the case of homonuclear diatomic molecules (N 2 and O 2 ) is revealed and illustrated by the resonant X-ray emission spectra, while the occurrence of forbidden transitions in CO 2 is explained in terms of dynamical symmetry breaking due to vibronic coupling. X-ray emission spectroscopy has been used to elucidate the molecular structure of liquid water, liquid methanol, methanol–water mixtures, as well as cation–water solutions, and to reveal the influence of the intermolecular interaction on the local electronic structure of water molecules. The in situ soft X-ray spectroscopy experimental studies of electrochemical reactions were also performed under ambient conditions

  4. In situ ultra-small-angle X-ray scattering study under uniaxial stretching of colloidal crystals prepared by silica nanoparticles bearing hydrogen-bonding polymer grafts

    Directory of Open Access Journals (Sweden)

    Ryohei Ishige

    2016-05-01

    Full Text Available A molded film of single-component polymer-grafted nanoparticles (SPNP, consisting of a spherical silica core and densely grafted polymer chains bearing hydrogen-bonding side groups capable of physical crosslinking, was investigated by in situ ultra-small-angle X-ray scattering (USAXS measurement during a uniaxial stretching process. Static USAXS revealed that the molded SPNP formed a highly oriented twinned face-centered cubic (f.c.c. lattice structure with the [11−1] plane aligned nearly parallel to the film surface in the initial state. Structural analysis of in situ USAXS using a model of uniaxial deformation induced by rearrangement of the nanoparticles revealed that the f.c.c. lattice was distorted in the stretching direction in proportion to the macroscopic strain until the strain reached 35%, and subsequently changed into other f.c.c. lattices with different orientations. The lattice distortion and structural transition behavior corresponded well to the elastic and plastic deformation regimes, respectively, observed in the stress–strain curve. The attractive interaction of the hydrogen bond is considered to form only at the top surface of the shell and then plays an effective role in cross-linking between nanoparticles. The rearrangement mechanism of the nanoparticles is well accounted for by a strong repulsive interaction between the densely grafted polymer shells of neighboring particles.

  5. X-ray photoemission electron microscopy, a tool for the investigation of complex magnetic structures

    International Nuclear Information System (INIS)

    Scholl, Andreas; Ohldag, Hendrik; Nolting, Frithjof; Stohr, Joachim; Padmore, Howard A.

    2001-01-01

    X-ray Photoemission Electron Microscopy unites the chemical specificity and magnetic sensitivity of soft x-ray absorption techniques with the high spatial resolution of electron microscopy. The discussed instrument possesses a spatial resolution of better than 50 nm and is located at a bending magnet beamline at the Advanced Light Source, providing linearly and circularly polarized radiation between 250 and 1300 eV. We will present examples which demonstrate the power of this technique applied to problems in the field of thin film magnetism. The chemical and elemental specificity is of particular importance for the study of magnetic exchange coupling because it allows separating the signal of the different layers and interfaces in complex multi-layered structures

  6. Soft X-ray spectroscopic investigation of a plasma focus operated in pure neon

    International Nuclear Information System (INIS)

    Presura, R.; Zoita, V.; Paraschiv, I.

    1996-01-01

    The soft X-ray emission of the medium-energy plasma focus device IPF-2/20 operated in pure neon was studied with spectral resolution. The spectra of H- and He-like Ne ions were recorded by means of a de Broglie spectrograph for initial filling pressures in the range 1.3 to 7 torr. Both the soft X-ray emission characteristics and the plasma parameters are strongly dependent on the working gas pressure. The intensity of the He-like neon ions lines increases when the working gas pressure is raised, while for the H-like ions it has a maximum for about 5 torr filling. The electron density has values of the order of 10 20 cm -3 . The electron temperature ranges between 300 and 350 eV. Both the plasma density and the plasma temperature decrease when the initial gas pressure is increased. (author). 2 figs., 9 refs

  7. Elemental investigation on Spanish dinosaur bones by x-ray fluorescence

    International Nuclear Information System (INIS)

    Brunetti, Antonio; Golosio, Bruno; Stegel, Giovanni; Piga, Giampaolo; Lasio, Barbara; Oliva, Piernicola; Enzo, Stefano

    2013-01-01

    In this paper we examine the chemical composition results obtained on a collection of 18 dinosaur fossil bones from Spain studied using a portable x-ray fluorescence spectrometer together with a reverse Monte Carlo numerical technique of data analysis. This approach is applied to the hypothesis of arbitrarily rough surfaces in order to account for the influence of the surface state of specimens on the chemical content evaluation. It is confirmed that the chemical content of elements is essential for understanding the changes brought about by diagenetic and taphonomic processes. However, for precise knowledge of what changes fossil bones have undergone after animal life and burial, it is necessary to use a multi-technique approach making use of other instruments like x-ray diffraction in order to describe accurately the transformations undergone by the mineralogical and bioinorganic phases and the properties of specific molecular groups. (paper)

  8. Soft X-ray spectroscopic investigation of a plasma focus operated in pure neon

    Energy Technology Data Exchange (ETDEWEB)

    Presura, R; Zoita, V; Paraschiv, I [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania)

    1997-12-31

    The soft X-ray emission of the medium-energy plasma focus device IPF-2/20 operated in pure neon was studied with spectral resolution. The spectra of H- and He-like Ne ions were recorded by means of a de Broglie spectrograph for initial filling pressures in the range 1.3 to 7 torr. Both the soft X-ray emission characteristics and the plasma parameters are strongly dependent on the working gas pressure. The intensity of the He-like neon ions lines increases when the working gas pressure is raised, while for the H-like ions it has a maximum for about 5 torr filling. The electron density has values of the order of 10{sup 20} cm{sup -3}. The electron temperature ranges between 300 and 350 eV. Both the plasma density and the plasma temperature decrease when the initial gas pressure is increased. (author). 2 figs., 9 refs.

  9. Structural and microstructural changes during anion exchange of CoAl layered double hydroxides. An in situ X-ray powder diffraction study

    International Nuclear Information System (INIS)

    Johnsen, Rune E.; Krumeich, Frank; Norby, Poul

    2010-01-01

    Anion-exchange processes in cobalt-aluminium layered double hydroxides (LDHs) were studied by in situ synchrotron X-ray powder diffraction (XRPD). The processes investigated were CoAl-CO 3 →CoAl-Cl →CoAl-CO 3 , CoAl-Cl→CoAl-NO 3 and CoAl-CO 3 →CoAl-SO 4 . The XRPD data show that the CoAl-CO 3 →CoAl-Cl process is a two-phase transformation, where the amount of the CoAl-CO 3 phase decreases exponentially while that of the CoAl-Cl phase increases exponentially. Energy-dispersive X-ray spectroscopy (EDXS) studies of a partially chloride-exchanged CoAl-CO 3 LDH sample along with in situ XRPD data suggested that the individual particles in the CoAl-CO 3 sample are generally anion-exchanged with chloride one at a time. In contrast with the CoAl-CO 3 →CoAl-Cl transformation, the XRPD data show that the reverse CoAl-Cl→CoAl-CO 3 process is a one-phase transformation. Rietveld refinements indicate that the occupancy factors of the carbon and oxygen sites of the carbonate group increase, while that of the chloride site decreases. In the CoAl-Cl→CoAl-NO 3 anion-exchange reaction, the XRPD patterns reveal the existence of two intermediate phases in addition to the initial CoAl-Cl and final CoAl-NO 3 phases. The in situ data indicate that one of these intermediates is a mixed nitrate- and chloride-based LDH phase, where the disorder decreases as the nitrate content increases. The XRPD data of the partial CoAl-CO 3 →CoAl-SO 4 anion-exchange reaction show that the process is a two-phase transformation involving a sulfate-containing LDH with a 1H polytype structure. (orig.)

  10. Theoretical x-ray absorption investigation of high pressure ice and compressed graphite

    International Nuclear Information System (INIS)

    Shaw, Dawn M; Tse, John S

    2007-01-01

    The x-ray absorption spectra (XAS) of high pressure ices II, VIII, and IX have been computed with the Car-Parrinello plane wave pseudopotential method. XAS for the intermediate structures obtained from uniaxial compression of hexagonal graphite along the c-axis are also studied. Whenever possible, comparisons to available experimental results are made. The reliability of the computational methods for the XAS for these structures is discussed

  11. Synchrotron X-ray Investigations of Mineral-Microbe-Metal Interactions

    International Nuclear Information System (INIS)

    Kemner, Kenneth M.; O'Loughlin, Edward J.; Kelly, Shelly D.; Boyanov, Maxim I.

    2005-01-01

    Interactions between microbes and minerals can play an important role in metal transformations (i.e. changes to an element's valence state, coordination chemistry, or both), which can ultimately affect that element's mobility. Mineralogy affects microbial metabolism and ecology in a system; microbes, in turn, can affect the system's mineralogy. Increasingly, synchrotron-based X-ray experiments are in routine use for determining an element's valence state and coordination chemistry, as well as for examining the role of microbes in metal transformations.

  12. X-ray Computed Tomographic Investigation of the Porosity and Morphology of Plasma Electrolytic Oxidation Coatings

    Czech Academy of Sciences Publication Activity Database

    Zhang, X.; Aliasghari, S.; Němcová, A.; Burnett, T.L.; Kuběna, Ivo; Šmíd, Miroslav; Thompson, G.; Skeldon, P.; Withers, P.J.

    2016-01-01

    Roč. 8, č. 13 (2016), s. 8801-8810 ISSN 1944-8244 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : plasma electrolytic oxidation * porosity * scanning electron microscopy * titanium * X-ray computed tomography Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 7.504, year: 2016 http://pubs.acs.org/doi/abs/10.1021/acsami.6b00274

  13. X-ray photoelectron spectrometer calibration and thin film investigations on germanium oxides

    OpenAIRE

    Deegan, Terri

    1998-01-01

    The first aim of this project was the characterisation of the VG Scientific Clam 100 based, XPS (X-ray Photoelectron Spectroscopy). Spectrometer in the Physics department at Dublin City University Detailed energy scale and intensity scale calibrations were carried out using sputter-cleaned Au (Gold), Ag (Silver), Cu (Copper) and Pd (Palladium) foil samples. Analysis of these calibration spectra against standard reference spectra led to an accurate energy calibration and the production of indi...

  14. Application of instrumental neutron activation analysis and X-ray fluorescence analysis in art pieces investigation

    International Nuclear Information System (INIS)

    Panczyk, E.; Kierzek, J.; Walis, L.; Ligeza, M.

    1996-01-01

    The application of instrumental neutron activation analysis have been shown for the trace element identification in dyes of old painting and other art objects. The recognition of their composition is a important measure for attribution. Also the X-ray fluorescence analysis has been frequently used for examination of art objects. The age determination of the old chinese porcelain is a good example described in the paper. 20 refs, 4 figs

  15. Diagnostic reference levels for X-ray investigations in pain management units in Belgium

    International Nuclear Information System (INIS)

    Lichtherte, S.; Le Polain de Waroux, B.

    2008-01-01

    X-rays are commonly used in pain treatment centres where infiltrative techniques are performed. Although X-rays are useful in increasing the precision of infiltrative techniques, their use puts patients and staff at risk of radiation exposure. As a result, medical staff now have to obtain a certificate of training on the use of X-rays before being allowed to use X-rays in practice. This analysis was based on 373 detailed registrations of procedure-related parameters in the six centres that participated in this study between January 2009 and July 2009. Examinations chosen for inclusion in this study were the most commonly performed fluoroscopic imaging-guided procedures in a pain management unit: epidural (cervical/lumbar), facet joint nerve blocks (cervical/lumbar) and trans-foraminal (cervical/lumbar). The sample size, the dose-area product (DAP) range for whole population, the mean and the third quartile DAP corrected for patient size (DAP corr ), the screening time range, the mean and the third quartile screening time are presented. The proposed DRLs for epidural, facet joint nerve blocks and trans-foraminal are 0.5, 2.5 and 3 Gy cm 2 for DAP values and 12, 60 and 50 s for screening times, respectively. In the absence of national diagnostic reference levels (DRLs) for pain management fluoroscopic procedures, these DAP and screening time values provide a possible way of establishing provisional DRLs for local use. The values for each examination type could be used as a baseline against which to monitor the effectiveness of dose reduction strategies as part of the optimisation process that is the goal of any quality control and patient dose monitoring system. (authors)

  16. Formation of tavorite-type LiFeSO4F followed by in situ X-ray diffraction

    Science.gov (United States)

    Eriksson, Rickard; Sobkowiak, Adam; Ångström, Jonas; Sahlberg, Martin; Gustafsson, Torbjörn; Edström, Kristina; Björefors, Fredrik

    2015-12-01

    The tavorite-type polymorph of LiFeSO4F has recently attracted substantial attention as a positive electrode material for lithium ion batteries. The synthesis of this material is generally considered to rely on a topotactic exchange of water (H2O) for lithium (Li) and fluorine (F) within the structurally similar hydrated iron sulfate precursor (FeSO4·H2O) when reacted with lithium fluoride (LiF). However, there have also been discussions in the literature regarding the possibility of a non-topotactic reaction mechanism between lithium sulfate (Li2SO4) and iron fluoride (FeF2) in tetraethylene glycol (TEG) as reaction medium. In this work, we use in situ X-ray diffraction to continuously follow the formation of LiFeSO4F from the two suggested precursor mixtures in a setup aimed to mimic the conditions of a solvothermal autoclave synthesis. It is demonstrated that LiFeSO4F is formed directly from FeSO4·H2O and LiF, in agreement with the proposed topotactic mechanism. The Li2SO4 and FeF2 precursors, on the other hand, are shown to rapidly transform into FeSO4·H2O and LiF with the water originating from the highly hygroscopic TEG before a subsequent formation of LiFeSO4F is initiated. The results highlight the importance of the FeSO4·H2O precursor in obtaining the tavorite-type LiFeSO4F, as it is observed in both reaction routes.

  17. Investigation of clinical conditions affecting quality control in a dental X-ray unit

    International Nuclear Information System (INIS)

    Akiyama, Hironori; Koseki, Takakazu; Itagaki, Keisuke; Yotsui, Yoritaka; Gamoh, Shoko; Shimizutani, Kimishige

    2011-01-01

    In this study, to clarify quality control issues in a dental X-ray unit, we surveyed the uniformity and safety of absorbed doses and exposure time from dental X-ray units, and evaluated image quality of intraoral radiography at Osaka Dental University Hospital. Measurements of dose and exposure time were carried out five times and the mean was calculated at twenty-two dental X-ray units in our university hospital using the standard parameters for the mandibular molar region in adults. Intraoral radiography for evaluation of image quality was taken using D-speed films under the standard parameters for the mandibular molar region in adults and E-speed films for pediatric patients. Evaluation of image quality was performed by three oral radiologists. Dose and exposure time differed significantly among units. Image quality of intraoral radiography using D-speed films was not significantly better than that of E-speed films. This study demonstrated that it is necessary to establish a uniform dose and exposure time and to change D-speed films to E-speed films when obtaining intraoral radiography in our hospital. (author)

  18. Investigation Biological And Medical Specimen Using X-Ray Dark Field Imagine

    International Nuclear Information System (INIS)

    Pattanasiriwisawa, Wanwisa; Sugiyama, Hiroshi; Maksimenko, Anton; Kazuyuki, Hyodo; Ando, Masami

    2005-10-01

    X-ray dark-field imaging (DFI) and bright-field imaging (BFI) in the Laue geometry has been successfully demonstrated. Using a Bragg-case asymmetric monochromator which produces an x-ray beam with a 0.3 μrad divergence incident onto an object and a Laue geometry analyzer that can simultaneously provide DFI and BFI. The imaging technique of DFI is quite novel one that we did not have before in that the central bright line satisfying the Bragg condition is removed by the analyzer crystal and the background radiation obscuring the image of the object does not come to record film. This is not the case in BFI and the strong background radiation obscures the real image of the object. X-ray optics comprising two Laue case diffraction wafers working at 35 keV has been successfully applied to some biological samples such as ivory, tusk, horn, tooth and a phantom of breast cancer. Images of ivory and others have shown very clear and informative inside structure. All pieces of the breast cancer phantom provide us with very fine images to simulate cancer

  19. Quantitative investigation of two metallohydrolases by X-ray absorption spectroscopy near-edge spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, W. [Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027 (China); Chu, W.S.; Yang, F.F.; Yu, M.J.; Chen, D.L.; Guo, X.Y. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhou, D.W.; Shi, N. [Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027 (China); Marcelli, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, P.O. Box 13, Frascati 00044 (Italy); Niu, L.W.; Teng, M.K. [Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027 (China); Gong, W.M. [Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Benfatto, M. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, P.O. Box 13, Frascati 00044 (Italy); Wu, Z.Y. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, P.O. Box 13, Frascati 00044 (Italy)], E-mail: wuzy@ihep.ac.cn

    2007-09-21

    The last several years have witnessed a tremendous increase in biological applications using X-ray absorption spectroscopy (BioXAS), thanks to continuous advancements in synchrotron radiation (SR) sources and detector technology. However, XAS applications in many biological systems have been limited by the intrinsic limitations of the Extended X-ray Absorption Fine Structure (EXAFS) technique e.g., the lack of sensitivity to bond angles. As a consequence, the application of the X-ray absorption near-edge structure (XANES) spectroscopy changed this scenario that is now continuously changing with the introduction of the first quantitative XANES packages such as Minut XANES (MXAN). Here we present and discuss the XANES code MXAN, a novel XANES-fitting package that allows a quantitative analysis of experimental data applied to Zn K-edge spectra of two metalloproteins: Leptospira interrogans Peptide deformylase (LiPDF) and acutolysin-C, a representative of snake venom metalloproteinases (SVMPs) from Agkistrodon acutus venom. The analysis on these two metallohydrolases reveals that proteolytic activities are correlated to subtle conformation changes around the zinc ion. In particular, this quantitative study clarifies the occurrence of the LiPDF catalytic mechanism via a two-water-molecules model, whereas in the acutolysin-C we have observed a different proteolytic activity correlated to structural changes around the zinc ion induced by pH variations.

  20. Quantitative investigation of two metallohydrolases by X-ray absorption spectroscopy near-edge spectroscopy

    International Nuclear Information System (INIS)

    Zhao, W.; Chu, W.S.; Yang, F.F.; Yu, M.J.; Chen, D.L.; Guo, X.Y.; Zhou, D.W.; Shi, N.; Marcelli, A.; Niu, L.W.; Teng, M.K.; Gong, W.M.; Benfatto, M.; Wu, Z.Y.

    2007-01-01

    The last several years have witnessed a tremendous increase in biological applications using X-ray absorption spectroscopy (BioXAS), thanks to continuous advancements in synchrotron radiation (SR) sources and detector technology. However, XAS applications in many biological systems have been limited by the intrinsic limitations of the Extended X-ray Absorption Fine Structure (EXAFS) technique e.g., the lack of sensitivity to bond angles. As a consequence, the application of the X-ray absorption near-edge structure (XANES) spectroscopy changed this scenario that is now continuously changing with the introduction of the first quantitative XANES packages such as Minut XANES (MXAN). Here we present and discuss the XANES code MXAN, a novel XANES-fitting package that allows a quantitative analysis of experimental data applied to Zn K-edge spectra of two metalloproteins: Leptospira interrogans Peptide deformylase (LiPDF) and acutolysin-C, a representative of snake venom metalloproteinases (SVMPs) from Agkistrodon acutus venom. The analysis on these two metallohydrolases reveals that proteolytic activities are correlated to subtle conformation changes around the zinc ion. In particular, this quantitative study clarifies the occurrence of the LiPDF catalytic mechanism via a two-water-molecules model, whereas in the acutolysin-C we have observed a different proteolytic activity correlated to structural changes around the zinc ion induced by pH variations

  1. Plutonium-uranium mixed oxide characterization by coupling micro-X-ray diffraction and absorption investigations

    Science.gov (United States)

    Degueldre, C.; Martin, M.; Kuri, G.; Grolimund, D.; Borca, C.

    2011-09-01

    Plutonium-uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The potential differences of metal redox state and microstructural developments of the matrix before and after irradiation are commonly analysed by electron probe microanalysis. In this work the structure and next-neighbor atomic environments of Pu and U oxide features within unirradiated homogeneous MOX and irradiated (60 MW d kg -1) MOX samples was analysed by micro-X-ray fluorescence (μ-XRF), micro-X-ray diffraction (μ-XRD) and micro-X-ray absorption fine structure (μ-XAFS) spectroscopy. The grain properties, chemical bonding, valences and stoichiometry of Pu and U are determined from the experimental data gained for the unirradiated as well as for irradiated fuel material examined in the center of the fuel as well as in its peripheral zone (rim). The formation of sub-grains is observed as well as their development from the center to the rim (polygonization). In the irradiated sample Pu remains tetravalent (>95%) and no (oxidation in the rim zone. Any slight potential plutonium oxidation is buffered by the uranium dioxide matrix while locally fuel cladding interaction could also affect the redox of the fuel.

  2. In situ study of the growth and degradation processes in tetragonal lysozyme crystals on a silicon substrate by high-resolution X-ray diffractometry

    Science.gov (United States)

    Kovalchuk, M. V.; Prosekov, P. A.; Marchenkova, M. A.; Blagov, A. E.; D'yakova, Yu. A.; Tereshchenko, E. Yu.; Pisarevskii, Yu. V.; Kondratev, O. A.

    2014-09-01

    The results of an in situ study of the growth of tetragonal lysozyme crystals by high-resolution X-ray diffractometry are considered. The crystals are grown by the sitting-drop method on crystalline silicon substrates of different types: both on smooth substrates and substrates with artificial surface-relief structures using graphoepitaxy. The crystals are grown in a special hermetically closed crystallization cell, which enables one to obtain images with an optical microscope and perform in situ X-ray diffraction studies in the course of crystal growth. Measurements for lysozyme crystals were carried out in different stages of the crystallization process, including crystal nucleation and growth, developed crystals, the degradation of the crystal structure, and complete destruction.

  3. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  4. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  5. In situ 3D characterization of high temperature fatigue damage mechanisms in a cast aluminum alloy using synchrotron X-ray tomography

    International Nuclear Information System (INIS)

    Dezecot, Sebastien; Buffiere, Jean-Yves; Koster, Alain; Maurel, Vincent; Szmytka, Fabien; Charkaluk, Eric; Dahdah, Nora; El Bartali, Ahmed; Limodin, Nathalie; Witz, Jean-Francois

    2016-01-01

    Fatigue tests were performed at 250 °C on a cast AlSi7Cu3Mg aluminum alloy and monitored with Synchrotron in situ X-ray tomography in order to understand the micro-mechanisms of crack initiation and propagation. The analysis of the 3D images reveals that internal shrinkage pores are responsible for the main crack initiation. Crack propagation is mainly due to the complex and highly interconnected network of hard particles of the eutectic regions.

  6. In situ analysis of the Zn(S,O) buffer layer preparation for chalcopyrite solar cells by Zn L-edge X-ray absorption spectroscopy.

    Science.gov (United States)

    Lauermann, Iver; Kropp, Timo; Vottier, Damien; Ennaoui, Ahmed; Eberhardt, Wolfgang; Aziz, Emad F

    2009-02-23

    Bridging the gap between high-vacuum soft X-ray absorption spectroscopy and real systems under ambient conditions probes chemical reactions in situ during deposition and annealing processes. The origin of highly efficient buffer layers in Zn(S,O) is the complex formation between Zn(2+) and the S=C group of thiourea (see schematic), which allows ligand-to-metal and metal-to-ligand charge transfer (LMCT and MLCT).

  7. Investigation of molecular mechanisms of action of chelating drugs on protein-lipid model membranes by X-ray fluorescence

    International Nuclear Information System (INIS)

    Novikova, N. N.; Zheludeva, S. I.; Koval'chuk, M. V.; Stepina, N. D.; Erko, A. I.; Yur'eva, E. A.

    2009-01-01

    Protein-lipid films based on the enzyme alkaline phosphatase were subjected to the action of chelating drugs, which are used for accelerating the removal of heavy metals from the human body, and the elemental composition of the resulting films was investigated. Total-reflection X-ray fluorescence measurements were performed at the Berlin Electron Storage Ring Company for Synchrotron Radiation (BESSY) in Germany. A comparative estimation of the protective effect of four drugs (EDTA, succimer, xydiphone, and mediphon) on membrane-bound enzymes damaged by lead ions was made. The changes in the elemental composition of the protein-lipid films caused by high doses of chelating drugs were investigated. It was shown that state-of-the-art X-ray techniques can, in principle, be used to develop new methods for the in vitro evaluation of the efficiency of drugs, providing differential data on their actions.

  8. In-situ X-ray diffraction activation study on an Fe/TiO2 pre-catalyst.

    Science.gov (United States)

    Rayner, Matthew K; Billing, David G; Coville, Neil J

    2014-06-01

    This study focuses on the use of in situ powder X-ray diffraction (PXRD) and quantitative phase analysis using the Rietveld method to monitor the structural properties of a titania-supported iron (10% Fe/TiO2) pre-catalyst during calcination (oxidation) and activation (reduction) in the temperature range 25-900°C. The TiO2 oxidation study revealed an increase in anatase particle size before the anatase to rutile phase transformation, lending credibility to the bridging mechanism proposed by Kim et al. [(2007), Mater. Sci. Forum, 534-536, 65-68]. Pre-catalyst oxidation experiments allowed for the determination of a suitable calcination temperature (450°C) of the pre-catalyst in terms of maximum hematite concentration and appropriate particle size. These experiments also confirmed that the anatase to rutile phase transformation occurred at higher temperatures after Fe addition and that anatase was the sole donor of Ti(4+) ions, which are known to migrate into hematite (Gennari et al., 1998), during the formation of pseudobrookite (Fe2TiO5) at temperatures above 690°C. Using the results from the oxidation experiments, two pre-catalyst samples were calcined at different temperatures; one to represent the preferred case and one to represent a case where the pre-catalyst had been excessively heated. Samples of the excessively heated catalysts were exposed to different reducing gas atmospheres (5, 10 and 100% H2/N2) and heated in the in situ PXRD reactor, so that diffraction data could be collected during the activation process. The results show that reduction with gases containing low concentrations of H2 (5 and 10%) led to the formation of ilmenite (FeTiO3) and we were able to show that both anatase and rutile are consumed in the reaction. Higher concentrations of H2 led to the formation of magnetite (Fe3O4) and metallic iron (Fe(0)). We also noted a decrease in the anatase to rutile transformation temperature under reducing atmospheres when compared with the pre

  9. Soft x-ray lasers

    International Nuclear Information System (INIS)

    Matthews, D.L.; Rosen, M.D.

    1988-01-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs

  10. In situ electrochemical high-energy X-ray diffraction using a capillary working electrode cell geometry

    Energy Technology Data Exchange (ETDEWEB)

    Young, Matthias J.; Bedford, Nicholas M.; Jiang, Naisheng; Lin, Deqing; Dai, Liming

    2017-05-26

    The ability to generate new electrochemically active materials for energy generation and storage with improved properties will likely be derived from an understanding of atomic-scale structure/function relationships during electrochemical events. Here, the design and implementation of a new capillary electrochemical cell designed specifically forin situhigh-energy X-ray diffraction measurements is described. By increasing the amount of electrochemically active material in the X-ray path while implementing low-Zcell materials with anisotropic scattering profiles, an order of magnitude enhancement in diffracted X-ray signal over traditional cell geometries for multiple electrochemically active materials is demonstrated. This signal improvement is crucial for high-energy X-ray diffraction measurements and subsequent Fourier transformation into atomic pair distribution functions for atomic-scale structural analysis. As an example, clear structural changes in LiCoO2under reductive and oxidative conditions using the capillary cell are demonstrated, which agree with prior studies. Accurate modeling of the LiCoO2diffraction data using reverse Monte Carlo simulations further verifies accurate background subtraction and strong signal from the electrochemically active material, enabled by the capillary working electrode geometry.

  11. Laboratory and In-Flight In-Situ X-ray Imaging and Scattering Facility for Materials, Biotechnology and Life Sciences

    Science.gov (United States)

    2003-01-01

    We propose a multifunctional X-ray facility for the Materials, Biotechnology and Life Sciences Programs to visualize formation and behavior dynamics of materials, biomaterials, and living organisms, tissues and cells. The facility will combine X-ray topography, phase micro-imaging and scattering capabilities with sample units installed on the goniometer. This should allow, for the first time, to monitor under well defined conditions, in situ, in real time: creation of imperfections during growth of semiconductors, metal, dielectric and biomacromolecular crystals and films, high-precision diffraction from crystals within a wide range of temperatures and vapor, melt, solution conditions, internal morphology and changes in living organisms, tissues and cells, diffraction on biominerals, nanotubes and particles, radiation damage, also under controlled formation/life conditions. The system will include an ultrabright X-ray source, X-ray mirror, monochromator, image-recording unit, detectors, and multipurpose diffractometer that fully accommodate and integrate furnaces and samples with other experimental environments. The easily adjustable laboratory and flight versions will allow monitoring processes under terrestrial and microgravity conditions. The flight version can be made available using a microsource combined with multilayer or capillary optics.

  12. Laboratory micro- and nanoscale X-ray tomographic investigation of Al–7 at.%Cu solidification structures

    International Nuclear Information System (INIS)

    Patterson, B.M.; Henderson, K.C.; Gibbs, P.J.; Imhoff, S.D.; Clarke, A.J.

    2014-01-01

    X-ray computed tomography across multiple length scales provides an opportunity to non-destructively visualize and quantify the micro- to nano-scale microstructural features of solidification structures in three dimensions. Aluminum–7 at.%copper samples were directionally solidified at three cooling rates (0.44, 0.67, and 1.33 °C/s), resulting in systematic changes in the as-solidified microstructure, which are difficult to quantify using traditional microscopic techniques. The cooling rate of a material affects its ultimate microstructure, and characterizing that microstructure is key to predicting and understanding its bulk properties. Here, two different laboratory X-ray computed tomography instruments were used to characterize as-solidified microstructures, including micro-scale computed tomography with approximately 1 mm field-of-view, ∼ 1.7 μm resolution, and nano-scale X-ray computed tomography ∼ 65 μm FOV, 150 nm resolution. Micro-scale X-ray radiography and computed tomography enabled a quantitative investigation of changes in the primary dendritic solidification structure with increasing cooling rate. Nano-scale absorption contrast X-ray computed tomography resolved the distinct phases of the lamellar eutectic structure and three dimensional measurements of the ∼ 1 μm interlamellar spacing. It is found that the lamella eutectic structure thickness is inversely proportional to the cooling rate. Nano-scale Zernike phase contrast was also used to image voids at eutectic colony boundaries. The application and resolution of these two instruments are discussed with respect to the resolvable features of the solidification structures. - Highlights: • Al–Cu eutectic is a model system for studying solidification microstructure. • X-ray computed tomography provides a 3D picture of these complex structures. • Micro-scale tomography images the primary and secondary dendritic structures. • Nano-scale tomography images the eutectic lamella and

  13. Laboratory micro- and nanoscale X-ray tomographic investigation of Al–7 at.%Cu solidification structures

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, B.M., E-mail: bpatterson@lanl.gov; Henderson, K.C.; Gibbs, P.J.; Imhoff, S.D.; Clarke, A.J.

    2014-09-15

    X-ray computed tomography across multiple length scales provides an opportunity to non-destructively visualize and quantify the micro- to nano-scale microstructural features of solidification structures in three dimensions. Aluminum–7 at.%copper samples were directionally solidified at three cooling rates (0.44, 0.67, and 1.33 °C/s), resulting in systematic changes in the as-solidified microstructure, which are difficult to quantify using traditional microscopic techniques. The cooling rate of a material affects its ultimate microstructure, and characterizing that microstructure is key to predicting and understanding its bulk properties. Here, two different laboratory X-ray computed tomography instruments were used to characterize as-solidified microstructures, including micro-scale computed tomography with approximately 1 mm field-of-view, ∼ 1.7 μm resolution, and nano-scale X-ray computed tomography ∼ 65 μm FOV, 150 nm resolution. Micro-scale X-ray radiography and computed tomography enabled a quantitative investigation of changes in the primary dendritic solidification structure with increasing cooling rate. Nano-scale absorption contrast X-ray computed tomography resolved the distinct phases of the lamellar eutectic structure and three dimensional measurements of the ∼ 1 μm interlamellar spacing. It is found that the lamella eutectic structure thickness is inversely proportional to the cooling rate. Nano-scale Zernike phase contrast was also used to image voids at eutectic colony boundaries. The application and resolution of these two instruments are discussed with respect to the resolvable features of the solidification structures. - Highlights: • Al–Cu eutectic is a model system for studying solidification microstructure. • X-ray computed tomography provides a 3D picture of these complex structures. • Micro-scale tomography images the primary and secondary dendritic structures. • Nano-scale tomography images the eutectic lamella and

  14. An experimental investigation on reduced radiological penumbra for intermediate energy x-rays: Implications for small field radiosurgery

    Science.gov (United States)

    Keller, Brian Michael

    Current day external beam radiation therapy typically uses x-ray energies in the megavoltage (6--18 MV) or in the superficial/orthovoltage (80--350 kVp) energy ranges. It has been found that intermediate energy x-rays (those greater than orthovoltage but sub-megavoltage) may offer an advantage in the field of high precision radiation therapy such as in radiosurgery. This advantage is a reduction in the radiological penumbra associated with small (less than about 3 cm) radiation dose fields. A consequence of reduced radiological penumbra is a more homogenous, conformal dose distribution in the patient with dose escalation and organ sparing made more feasible. The objectives of this thesis were as follows: to produce and to characterize an intermediate energy x-ray beam, to establish a method of accurate penumbra measurement at the micron level for millimeter size fields, to measure the radiological penumbra of single small intermediate energy x-ray fields, and to show the clinical consequences of a multiple beam irradiation in a stereotactic head phantom. A maximum photon energy of 1.2 +/- 0.1 MeV was determined for the intermediate energy x-ray spectrum at the expense of a low dose rate. A digital microscope with a computer controlled translation stage was investigated for its ability to resolve steep dose gradients in Gafchromic EBT film for field sizes as small as 1 mm and for photon energies as low as 100 kVp. The microscope-film system resolved gradients to within about 30 mum, limited by the inherent spatial resolution of the film, the noise of the system, and the uncertainties of measurement. Penumbra widths were compared for 1.2 MV versus 6 MV for identical irradiation conditions. In some instances, there was a five-fold reduction in the radiological penumbra of single 1.2 MV x-ray beams. A multiple beam arc irradiation demonstrated that the advantages seen with single beams carry over to multiple beams. The benefits of reduced radiological penumbra for

  15. In situ micro-focused X-ray beam characterization with a lensless camera using a hybrid pixel detector

    International Nuclear Information System (INIS)

    Kachatkou, Anton; Marchal, Julien; Silfhout, Roelof van

    2014-01-01

    Position and size measurements of a micro-focused X-ray beam, using an X-ray beam imaging device based on a lensless camera that collects radiation scattered from a thin foil placed in the path of the beam at an oblique angle, are reported. Results of studies on micro-focused X-ray beam diagnostics using an X-ray beam imaging (XBI) instrument based on the idea of recording radiation scattered from a thin foil of a low-Z material with a lensless camera are reported. The XBI instrument captures magnified images of the scattering region within the foil as illuminated by the incident beam. These images contain information about beam size, beam position and beam intensity that is extracted during dedicated signal processing steps. In this work the use of the device with beams for which the beam size is significantly smaller than that of a single detector pixel is explored. The performance of the XBI device equipped with a state-of-the-art hybrid pixel X-ray imaging sensor is analysed. Compared with traditional methods such as slit edge or wire scanners, the XBI micro-focused beam characterization is significantly faster and does not interfere with on-going experiments. The challenges associated with measuring micrometre-sized beams are described and ways of optimizing the resolution of beam position and size measurements of the XBI instrument are discussed

  16. Absolute dose calibration of an X-ray system and dead time investigations of photon-counting techniques

    CERN Document Server

    Carpentieri, C; Ludwig, J; Ashfaq, A; Fiederle, M

    2002-01-01

    High precision concerning the dose calibration of X-ray sources is required when counting and integrating methods are compared. The dose calibration for a dental X-ray tube was executed with special dose calibration equipment (dosimeter) as function of exposure time and rate. Results were compared with a benchmark spectrum and agree within +-1.5%. Dead time investigations with the Medipix1 photon-counting chip (PCC) have been performed by rate variations. Two different types of dead time, paralysable and non-paralysable will be discussed. The dead time depends on settings of the front-end electronics and is a function of signal height, which might lead to systematic defects of systems. Dead time losses in excess of 30% have been found for the PCC at 200 kHz absorbed photons per pixel.

  17. INVESTIGATIONS THE EFFECT OF EOSIN B DYE ON X- RAY DIFFRACTION PATTERN OF SILVER NITRATE DOPED PVP FILMS

    Directory of Open Access Journals (Sweden)

    Mahasin F. Hadi Al-Kadhemy

    2017-07-01

    Full Text Available In this research, X-ray diffraction of the powder (PVP polymer, Eosin B dye, and silver nitrate and (EB/PVP, AgNO3/PVP, EB/AgNO3/PVP films have been studied. Casting method is used to prepare homogeneous films on plastic petri dishes. All parameters accounted for the X-ray diffraction; full width half maximum (FWHM, Miller indices (hkl, size of crystalline (D, Specific Surface Area (S and Dislocation Density (δ.The nature of the structural of materials and films will be investigated. The XRD pattern of PVP polymer was amorphous structure with two broader peaks and the Eosin B dye and silver nitrate have crystalline structure. While the mixture between these materials led to appearing some crystalline peaks into XRD pattern of PVP polymer.

  18. Design and theoretical investigation of a digital x-ray detector with large area and high spatial resolution

    Science.gov (United States)

    Gui, Jianbao; Guo, Jinchuan; Yang, Qinlao; Liu, Xin; Niu, Hanben

    2007-05-01

    X-ray phase contrast imaging is a promising new technology today, but the requirements of a digital detector with large area, high spatial resolution and high sensitivity bring forward a large challenge to researchers. This paper is related to the design and theoretical investigation of an x-ray direct conversion digital detector based on mercuric iodide photoconductive layer with the latent charge image readout by photoinduced discharge (PID). Mercuric iodide has been verified having a good imaging performance (high sensitivity, low dark current, low voltage operation and good lag characteristics) compared with the other competitive materials (α-Se,PbI II,CdTe,CdZnTe) and can be easily deposited on large substrates in the manner of polycrystalline. By use of line scanning laser beam and parallel multi-electrode readout make the system have high spatial resolution and fast readout speed suitable for instant general radiography and even rapid sequence radiography.

  19. Investigation of periodically driven systems by x-ray absorption spectroscopy using asynchronous data collection mode

    Science.gov (United States)

    Singh, H.; Donetsky, D.; Liu, J.; Attenkofer, K.; Cheng, B.; Trelewicz, J. R.; Lubomirsky, I.; Stavitski, E.; Frenkel, A. I.

    2018-04-01

    We report the development, testing, and demonstration of a setup for modulation excitation spectroscopy experiments at the Inner Shell Spectroscopy beamline of National Synchrotron Light Source - II. A computer algorithm and dedicated software were developed for asynchronous data processing and analysis. We demonstrate the reconstruction of X-ray absorption spectra for different time points within the modulation pulse using a model system. This setup and the software are intended for a broad range of functional materials which exhibit structural and/or electronic responses to the external stimulation, such as catalysts, energy and battery materials, and electromechanical devices.

  20. Comparative investigations of high resolution scanning systems for digitising X-ray films

    International Nuclear Information System (INIS)

    Wessel, H.; Rose, P.

    1992-01-01

    The visual or computer-aided evaluation of digitised X-ray films in non-destructive material testing requires highly sensitive scanning systems. They must be able to resolve differences in blackening and convert them into digital data without loss, if possible. Only in this way is the detection of the finest cracks in weld seams or contraction in areas of great sudden changes in blackening of cast parts guaranteed. In the context of this work, measurements were carried out which describe the reproduction properties of different scanning systems. After a short explanation of the different scanning systems, the results of the measurements are shown and evaluated. (orig.) [de

  1. Investigation of hepatic fibrosis in rats with x-ray diffraction enhanced imaging

    International Nuclear Information System (INIS)

    Li Hui; Zhang Lu; Wang Xueyan; Luo Shuqian; Wang Tailing; Wang Baoen; Zhao Xinyan

    2009-01-01

    X-ray diffraction enhanced imaging (DEI) is a phase contrast technique that generates excellent contrast of biological soft tissues compared to conventional absorption radiography. We explore the application of DEI in the diagnosis of hepatic fibrosis. The produced refraction contrast images of fibrous rat liver samples show clearly abnormal liver architectures. Moreover, by comparing to histological pictures, different stages of fibrosis are discriminated, and the corresponding morphological features are analyzed. Besides, quantitative analyses of texture features are presented. The results reported herein show that DEI can be a potential noninvasive technique to diagnose and stage hepatic fibrosis

  2. Sum rules application to reflectometry of X-ray resonant radiation for magnetic multilayer investigation

    International Nuclear Information System (INIS)

    Smekhova, A.G.; Andreeva, M.A.

    2005-01-01

    One elaborated the general formalism on the basis of which one derived the clear expressions for reflection factors of X-ray radiation with a circular polarization from medium magnetized both within surface plane and within reflection plane both for grazing angles and for high grazing angles. The asymmetry of reflection spectra for right- and left-polarized radiation is shown to depend both on nondiagonal components of a susceptibility tensor and on other components in contrast to absorption spectra, so the sum rule to determine the orbital and the spin magnetic moments can not be applied directly to the experimental spectra of reflection [ru

  3. X-raying investigation into complexes of n-aminobenzoic acid with metals

    International Nuclear Information System (INIS)

    Amiraslanov, I.R.; Mamedov, Kh.S.; Movsumov, Eh.M.; Musaev, F.N.; Magerramov, A.I.; Nadzhafov, G.N.; AN Azerbajdzhanskoj SSR, Baku. Inst. Fiziki)

    1979-01-01

    The X-ray structural study of triaqua-bis(p-aminobenzoate) of cadmium(2)Cd(H 2 NC 6 H 4 COO) 2 x3H 2 O is carried out. The crystals are triclinic. The coordination number of cadmium atom is 7, it forms two chelate cycles with two carboxylate ligands, and in axial positions is coordinated by nitrogen atoms of aminogroups of the two neighbouring complexes, forming a polymeric chain. Coordination is added up to 7 by one water molecule, which together with other water molecules not entering in the coordination sphere, sew together polymeric chains by hydrogen bonds

  4. Fractal morphology in lignite coal: a small angle x-ray scattering investigation

    International Nuclear Information System (INIS)

    Chitra, R.; Sen, D.; Mazumder, S.; Chandrasekaran, K.S.

    1999-01-01

    Small angle x-ray scattering technique has been used to study the pore morphology in lignite coal from Neyveli lignite mine (Tamilnadu, India). The sample were collected from three different locations of the same mine. SAXS profiles from all the three samples show almost identical functionality, irrespective of the locations from where the samples were collected. SAXS experiment using two different wavelengths also exhibit same functionality indicating the absence of multiple scattering. The analysis indicates the surface fractal nature of the pore morphology. The surface fractal dimension is calculated to be 2.58. (author)

  5. Ion track annealing in quartz investigated by small angle X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Schauries, D.; Afra, B.; Rodriguez, M.D. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601 (Australia); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64287 Darmstadt (Germany); Hawley, A. [Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168 (Australia); Kluth, P. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601 (Australia)

    2015-12-15

    We report on the reduction of cross-section and length of amorphous ion tracks embedded within crystalline quartz during thermal annealing. The ion tracks were created via Au ion irradiation with an energy of 2.2 GeV. The use of synchrotron-based small angle X-ray scattering (SAXS) allowed characterization of the latent tracks, without the need for chemical etching. Temperatures between 900 and 1000 °C were required to see a notable change in track size. The shrinkage in cross-section and length was found to be comparable for tracks aligned perpendicular and parallel to the c-axis.

  6. X-ray topographic investigation of the deformation field around spots irradiated by FLASH single pulses

    Czech Academy of Sciences Publication Activity Database

    Wierzchowski, W.; Wieteska, K.; Balcer, T.; Klinger, D.; Sobierajski, R.; Zymierska, D.; Chalupský, Jaromír; Hájková, Věra; Burian, Tomáš; Gleeson, A.J.; Juha, Libor; Tiedtke, K.; Toleikis, S.; Vyšín, Luděk; Wabnitz, H.; Gaudin, J.

    2011-01-01

    Roč. 80, č. 10 (2011), s. 1036-1040 ISSN 0969-806X R&D Projects: GA AV ČR KAN300100702; GA MŠk LC510; GA ČR(CZ) GAP108/11/1312; GA MŠk(CZ) LC528; GA MŠk LA08024; GA AV ČR IAAX00100903; GA MŠk(CZ) ME10046 Institutional research plan: CEZ:AV0Z10100523 Keywords : silicon * FLASH irradiation * x-ray topography * deformation fields Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.227, year: 2011

  7. X-ray and neutron scattering investigations of YCo sub 3 -H

    Energy Technology Data Exchange (ETDEWEB)

    Benham, M J; Bennington, S M; Ross, D K [Birmingham Univ. (UK). School of Physics and Space Research; Noreus, D [Stockholm Univ. (Sweden). Dept. of Structural Chemistry; Yamaguchi, M [Yokohoma National Univ. (Japan). Dept. of Electrical and Computer Engineering

    1989-01-01

    Various structural studies of YCo{sub 3}H(D){sub x} in the {beta}-phase (0X-ray diffraction measurements determined that the expansion of the lattice is localised to components of the structure which are related to the Laves phase, YCo{sub 2}. Neutron diffraction and inelastic neutron scattering were also used in tandem, and hydrogen occupation of a single (36i) tetrahedral site was inferred for the entire concentration range. (orig.).

  8. X-ray film interferometer as an instrument for semiconductor heterostructure investigation

    CERN Document Server

    Vasilenko, A P; Nikitenko, S G; Fedorov, A A; Sokolov, L V; Nikiforov, A I; Trukhanov, E M

    2001-01-01

    Translation Moire pictures were first observed in interference topographs obtained using Synchrotron radiation. A film interferometer was prepared on the base of the GeSi heterosystem. Another film interferometer, which presents the heterosystem of epitaxial Si/ porous Si/ substrate Si, permitted us to observe a decrease in the bending of the film atomic planes at annealing of the heterosystem. This bend smoothing was calculated with the sensitivity better than 1 A with the use of X-ray interference topographs. Contrast peculiarities in Moire pictures are discussed for nondiffracting layers and crystal quantum wells.

  9. Investigation by laser induced breakdown spectroscopy, X-ray fluorescence and X-ray powder diffraction of the chemical composition of white clay ceramic tiles from Veliki Preslav

    International Nuclear Information System (INIS)

    Blagoev, K.; Grozeva, M.; Malcheva, G.; Neykova, S.

    2013-01-01

    The paper presents the results of the application of laser induced breakdown spectroscopy, X-ray fluorescence spectrometry, and X-ray powder diffraction in assessing the chemical and phase composition of white clay decorative ceramic tiles from the medieval archaeological site of Veliki Preslav, a Bulgarian capital in the period 893–972 AC, well-known for its original ceramic production. Numerous white clay ceramic tiles with highly varied decoration, produced for wall decoration of city's churches and palaces, were found during the archaeological excavations in the old capital. The examination of fourteen ceramic tiles discovered in one of the city's monasteries is aimed at characterization of the chemical profile of the white-clay decorative ceramics produced in Veliki Preslav. Combining different methods and comparing the obtained results provides complementary information regarding the white-clay ceramic production in Veliki Preslav and complete chemical characterization of the examined artefacts. - Highlights: ► LIBS, XRF and XRD analyses of medieval white-clay ceramic tiles fragments are done. ► Different elements and phases, presented in the ceramics fragments were determined. ► Differences in the tiles' raw material mineral composition are found. ► Information of the tiles' production process and the raw clay deposits is obtained

  10. Investigation by laser induced breakdown spectroscopy, X-ray fluorescence and X-ray powder diffraction of the chemical composition of white clay ceramic tiles from Veliki Preslav

    Energy Technology Data Exchange (ETDEWEB)

    Blagoev, K., E-mail: kblagoev@issp.bas.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Grozeva, M., E-mail: margo@issp.bas.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Malcheva, G., E-mail: bobcheva@issp.bas.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Neykova, S., E-mail: sevdalinaneikova@abv.bg [National Institute of Archaeology with Museum, Bulgarian Academy of Sciences, 2 Saborna, 1000 Sofia (Bulgaria)

    2013-01-01

    The paper presents the results of the application of laser induced breakdown spectroscopy, X-ray fluorescence spectrometry, and X-ray powder diffraction in assessing the chemical and phase composition of white clay decorative ceramic tiles from the medieval archaeological site of Veliki Preslav, a Bulgarian capital in the period 893–972 AC, well-known for its original ceramic production. Numerous white clay ceramic tiles with highly varied decoration, produced for wall decoration of city's churches and palaces, were found during the archaeological excavations in the old capital. The examination of fourteen ceramic tiles discovered in one of the city's monasteries is aimed at characterization of the chemical profile of the white-clay decorative ceramics produced in Veliki Preslav. Combining different methods and comparing the obtained results provides complementary information regarding the white-clay ceramic production in Veliki Preslav and complete chemical characterization of the examined artefacts. - Highlights: ► LIBS, XRF and XRD analyses of medieval white-clay ceramic tiles fragments are done. ► Different elements and phases, presented in the ceramics fragments were determined. ► Differences in the tiles' raw material mineral composition are found. ► Information of the tiles' production process and the raw clay deposits is obtained.

  11. Electronic properties of Nd2−xCexCuO4+δ: A hard X-ray photoemission investigation

    International Nuclear Information System (INIS)

    Guarino, A.; Panaccione, G.; Offi, F.; Monaco, G.; Fondacaro, A.; Torelli, P.; Fittipaldi, R.; Vecchione, A.; Pace, S.; Nigro, A.

    2016-01-01

    Highlights: • We grow and characterize Nd 2−x Ce x CuO 4+δ samples as thin film and single crystal. • We study the Cu 2p levels of our samples by hard X-ray photoemission spectroscopy. • We investigate bulk features of the Nd 2−x Ce x CuO 4+δ samples. • Signature of the bulk response is correlated with the crystallinity of the samples. - Abstract: Cu 2p core levels spectra measured by X-ray photoemission spectroscopy of selected as-grown Nd 2−x Ce x CuO 4+δ samples are presented and discussed. The presence of a satellite peak in the 2p core level of Nd 2−x Ce x CuO 4+δ single crystal by hard X-ray photoemission is confirmed in all non-superconducting samples, films and single crystals investigated in this work. The comparison of the spectral features of the different samples suggests that the presence and the intensity of this satellite peak is not related to the electric transport properties, but to the texture characteristics.

  12. Effect of bainitic transformation temperature on the mechanical behavior of cold-rolled TRIP steels studied with in-situ high-energy X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Fu, B. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Yang, W.Y., E-mail: wyyang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Li, L.F.; Sun, Z.Q. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-05-01

    The effect of bainitic transformation temperature (400 and 450 °C) after intercritical annealing on the mechanical behavior of a low alloyed C–Mn–Al–Si cold-rolled TRIP steel was investigated using the in-situ high-energy X-ray diffraction technique. It was found that the mechanical behaviors of TRIP steels were dominated by the micromechanical behaviors of constituent phases, such as yield strength of each phase and stress partitioning among different phases, as well as the transformation kinetics of retained austenite during plastic deformation. The microstructures obtained at different bainitic transformation temperatures were similar, but exhibited obviously different mechanical behaviors. The retained austenite in the sample treated at 450 °C with lower carbon content and yield strength was less stable and transformed into martensite at a relatively faster speed during deformation leading to a higher ultimate tensile strength but a smaller uniform elongation. In addition, stress partitioning among constituent phases was also obtained for the investigated steels in such a way that the ferrite matrix undertook smaller stresses and the bainitic ferrite, martensite and retained austenite bore larger ones during plastic deformation. The retained austenite in the sample treated at 400 °C with higher carbon content displayed significantly higher strength and relatively stronger work-hardening capabilities during deformation in comparison to those of the sample treated at 450 °C.

  13. The application of in-situ 3D X-ray diffraction in annealing experiments: First interpretation of substructure development in deformed NaCl

    DEFF Research Database (Denmark)

    Borthwick, Verity; Schmidt, Søren; Piazolo, Sandra

    2012-01-01

    In-situ 3D X-ray diffraction (3DXRD) annealing experiments were conducted at the ID-11 beamline at the European Synchrotron Radiation Facility in Grenoble. This allowed us to nondestructively document and subsequently analyse the development of substructures during heating, without the influence...... subgrain boundary formation. These results demonstrate that 3DXRD coupled with in-situ heating is a successful non-destructive technique for examining real-time postdeformational annealing in strongly deformed crystalline materials with complicated microstructures. © (2012) Trans Tech Publications...

  14. SO3 formation from the X-ray photolysis of SO2 astrophysical ice analogues: FTIR spectroscopy and thermodynamic investigations.

    Science.gov (United States)

    de Souza Bonfim, Víctor; Barbosa de Castilho, Roberto; Baptista, Leonardo; Pilling, Sergio

    2017-10-11

    In this combined experimental-theoretical work we focus on the physical and chemical changes induced by soft X-rays on sulfur dioxide (SO 2 ) ice at a very low temperature, in an attempt to clarify and quantify its survival and chemical changes in some astrophysical environments. SO 2 is an important constituent of some Jupiter moons and has also been observed in ices around protostars. The measurements were performed at the Brazilian Synchrotron Light Source (LNLS/CNPEM), in Campinas, Brazil. The SO 2 ice sample (12 K) was exposed to a broadband beam of mainly soft X-rays (6-2000 eV) and in situ analyses were performed by IR spectroscopy. The X-ray photodesorption yield (upper limit) was around 0.25 molecules per photon. The values determined for the effective destruction (SO 2 ) and formation (SO 3 ) cross sections were 2.5 × 10 -18 cm 2 and 2.1 × 10 -18 cm 2 , respectively. The chemical equilibrium (88% of SO 2 and 12% of SO 3 ) was reached after the fluence of 1.6 × 10 18 photons cm -2 . The SO 3 formation channels were studied at the second-order Møller-Plesset perturbation theory (MP2) level, which showed the three most favorable reaction routes (ΔH < -79 kcal mol -1 ) in simulated SO 2 ice: (i) SO + O 2 → SO 3 , (ii) SO 2 + O → SO 3 , and (iii) SO 2 + O + → SO 3 + + e - → SO 3 . The amorphous solid environment effect decreases the reactivity of intermediate species towards SO 3 formation, and ionic species are even more affected. The experimentally determined effective cross sections and theoretical reaction channels identified in this work allow us to better understand the chemical evolution of certain sulfur-rich astrophysical environments.

  15. A reaction cell with sample laser heating for in situ soft X-ray absorption spectroscopy studies under environmental conditions.

    Science.gov (United States)

    Escudero, Carlos; Jiang, Peng; Pach, Elzbieta; Borondics, Ferenc; West, Mark W; Tuxen, Anders; Chintapalli, Mahati; Carenco, Sophie; Guo, Jinghua; Salmeron, Miquel

    2013-05-01

    A miniature (1 ml volume) reaction cell with transparent X-ray windows and laser heating of the sample has been designed to conduct X-ray absorption spectroscopy studies of materials in the presence of gases at atmospheric pressures. Heating by laser solves the problems associated with the presence of reactive gases interacting with hot filaments used in resistive heating methods. It also facilitates collection of a small total electron yield signal by eliminating interference with heating current leakage and ground loops. The excellent operation of the cell is demonstrated with examples of CO and H2 Fischer-Tropsch reactions on Co nanoparticles.

  16. X-ray absorption spectroscopy investigation of structurally modified lithium niobate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vitova, Tonya

    2008-02-15

    The type and concentration of impurity centers in different valence states are crucial for tuning the photorefractive properties of doped Lithium Niobate (LN) crystals. X-ray Absorption Spectroscopy (XAS) is an appropriate tool for studying the local structure of impurity centers. XAS combined with absorption in UV/VIS/IR and High Resolution X-ray Emission Spectroscopy (HRXES) provide information about the valence state of the dopant ions in as-grown, reduced or oxidized doped LN crystals. Cu (Cu{sup 1+} and Cu{sup 2+}) and Fe (Fe{sup 2+} and Fe{sup 3+}) atoms are found in two different valence states, whereas there are indications for a third Mn valency, in addition to Mn{sup 2+} and Mn{sup 3+} in manganese-doped LN crystals. One of the charge compensation mechanisms during reduction of copper- doped LN crystals is outgassing of oxygen atoms. Cu ions in the reduced crystals have at least two different site symmetries: twofold (Cu{sup 1+}) and sixfold (Cu{sup 2+}) coordinated by O atoms. Fe and Mn atoms are coordinated by six O atoms. Cu and Fe ions are found to occupy only Li sites, whereas Mn ions are also incorporated into Li and Nb sites. The refractive index change in LN crystals irradiated with {sup 3}He{sup 2+} ions is caused by structurally disordered centers, where Nb atoms are displaced from normal crystallographic sites and Li or/and O vacancies are present. (orig.)

  17. Small-angle x-ray scattering investigation of the solution structure of troponin C

    International Nuclear Information System (INIS)

    Hubbard, S.R.; Hodgson, K.O.; Doniach, S.

    1988-01-01

    X-ray crystallographic studies of troponin C have revealed a novel protein structure consisting of two globular domains, each containing two Ca 2+ -binding sites, connected via a nine-turn alpha-helix, three turns of which are fully exposed to solvent. Since the crystals were grown at pH approximately 5, it is of interest to determine whether this structure is applicable to the protein in solution under physiological conditions. We have used small-angle x-ray scattering to examine the solution structure of troponin C at pH 6.8 and the effect of Ca 2+ on the structure. The scattering data are consistent with an elongated structure in solution with a radius of gyration of approximately 23.0 A, which is quite comparable to that computed for the crystal structure. The experimental scattering profile and the scattering profile computed from the crystal structure coordinates do, however, exhibit differences at the 40-A level. A weak Ca 2+ -facilitated dimerization of troponin C was observed. The data rule out large Ca 2+ -induced structural changes, indicating rather that the molecule with Ca 2+ bound is only slightly more compact than the Ca 2+ -free molecule

  18. X-ray absorption spectroscopy investigation of structurally modified lithium niobate crystals

    International Nuclear Information System (INIS)

    Vitova, Tonya

    2008-02-01

    The type and concentration of impurity centers in different valence states are crucial for tuning the photorefractive properties of doped Lithium Niobate (LN) crystals. X-ray Absorption Spectroscopy (XAS) is an appropriate tool for studying the local structure of impurity centers. XAS combined with absorption in UV/VIS/IR and High Resolution X-ray Emission Spectroscopy (HRXES) provide information about the valence state of the dopant ions in as-grown, reduced or oxidized doped LN crystals. Cu (Cu 1+ and Cu 2+ ) and Fe (Fe 2+ and Fe 3+ ) atoms are found in two different valence states, whereas there are indications for a third Mn valency, in addition to Mn 2+ and Mn 3+ in manganese-doped LN crystals. One of the charge compensation mechanisms during reduction of copper- doped LN crystals is outgassing of oxygen atoms. Cu ions in the reduced crystals have at least two different site symmetries: twofold (Cu 1+ ) and sixfold (Cu 2+ ) coordinated by O atoms. Fe and Mn atoms are coordinated by six O atoms. Cu and Fe ions are found to occupy only Li sites, whereas Mn ions are also incorporated into Li and Nb sites. The refractive index change in LN crystals irradiated with 3 He 2+ ions is caused by structurally disordered centers, where Nb atoms are displaced from normal crystallographic sites and Li or/and O vacancies are present. (orig.)

  19. Investigation of annealed and metamict pyrochlore minerals by x-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Greegor, R.B.; Lytle, F.W.; Ewing, R.C.; Chakoumakos, B.C.; Lumpkin, G.R.

    1984-01-01

    Materials of the pyrochlore structure type exhibit a variety of interesting properties including phases capable of acting as hosts for actinides in radioactive wastes. Studies of curium doped gadolinium titanate phases (Gd 2 Ti 2 O 7 ) have been made which showed that the radiation damage ingrowth followed an exponential relationship. For the study reported here a series of synthetic pyrochlores were produced having the titanate phase with the general formula (RE) 2 Ti 2 O 7 , RE = Er, Y 2 , Gd 2 , Dy, La. Additionally a set of metamict (radiation damaged) pyrochlores was examined in both a natural and post temperature annealed state. Experiments were conducted on these samples using the Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Absorption Near Edge Structure (XANES) techniques. In summary, these studies show that in pyrochlore structure types the Ti-O cage undergoes changes due to radiation damage. The individual Ti-O bonds become more disordered which leads to a loss of short and long range order and, ultimately, to expansion of the bulk material. 2 refs., 2 figs

  20. Ultra-short period X-ray mirrors: Production and investigation

    International Nuclear Information System (INIS)

    Bibishkin, M.S.; Chkhalo, N.I.; Fraerman, A.A.; Pestov, A.E.; Prokhorov, K.A.; Salashchenko, N.N.; Vainer, Yu.A.

    2005-01-01

    Technological problems that deal with manufacturing of highly effective ultra-short (d=0.7-3.2 nm) period X-ray multilayer mirrors (MLM) are discussed in the article. In an example of Cr/Sc and W/B 4 C MLM it is experimentally shown, that the problem of periodicity and selectivity for multilayer dispersive X-ray elements has been generally solved by now. However, the problem of short-period MLM reflectivity increase related to existing of transitive borders between layers in structures remains rather urgent. The new technique of tungsten deposition using the RF source in order to decrease roughness in borders is discussed and tested. The results of measurements on wavelengths of 0.154, 0.834 and 1.759 nm are given. The RbAP crystals ordinary used in experiments and short-period W/B 4 C MLM produced are compared. The specular and non-specular characteristics of scattering on the 0.154 nm wavelengths are also measured in order to study transitive borders structures

  1. Effect of Cobalt Fillers on Polyurethane Segmentations Investigated by Synchrotron Small Angle X-Ray Scattering

    Directory of Open Access Journals (Sweden)

    Krit Koyvanich

    2013-01-01

    Full Text Available The segmentation between rigid and rubbery chains in polyurethanes (PUs influences polymeric properties and implementations. Several models have successfully been proposed to visualize the configuration between the hard segment (HS and soft segment (SS. For particulate PU composites, the arrangement of HS and SS is more complicated because the fillers tend to disrupt the chain formation and segmentation. In this work, the effect of ferromagnetic cobalt (Co powders (average diameter 2 μm on PU synthesized from a reaction between polyether polyol (soft segment and diphenylmethane-4,4′-diisocyanate (hard segment was studied with varying loadings (0, 20, 40, and 60 wt.%. The 300 μm thick PU/Co samples were tape-casted and then received heat treatment at 80°C for 180 min. From synchrotron small angle X-ray scattering (SAXS, the plot of the X-ray scattering intensity (I against the scattering vector (q exhibited a typical single peak of PU whose intensity was reduced by the increase in the Co loading. Characteristic SAXS peaks in the case of 0-20 wt.% Co agreed well with the scattering by globular hard segment domains according to Zernike-Prins and Percus-Yevick models. The higher Co loadings led to larger deviations from all theoretical models.

  2. Investigation of organ dose difference of age phantoms for medical X-ray examinations

    International Nuclear Information System (INIS)

    Park, Sang Hyun; Kim, Woo Ran; Lee, Jai Ki; Lee, Choon Sik

    2003-01-01

    Methodology for calculating the organ equivalent doses and the effective doses of pediatric and adult patients undergoing medical X-ray examinations were established. The MIRD-type mathematical phantoms of 4 age groups were constructed with addition of the esophagus to the same phantoms. Two typical examination procedures, chest PA and abdomen AP, were simulated for the pediatric patients as well as the adult as illustrative examples. The results confirmed that patients pick up approximate 0.03 mSv of effective dose from a single chest PA examination, and 0.4 to 1.7 mSv from an abdomen AP examination depending on the ages. For dose calculations where irradiation is made with a limited field, the details of the position, size and shape of the organs and the organ depth from the entrance surface considerably affect the resulting doses. Therefore, it is important to optimize radiation protection by control of X-ray properties and beam examination field. The calculation result, provided in this study, can be used to implement optimization for medical radiation protection

  3. Recipe Book for Larger Benthic Foraminifera X-ray Investigation: a Process Approach

    Science.gov (United States)

    Wolfgring, E.; Briguglio, A.; Hohenegger, J.

    2012-04-01

    During the past years X-ray microtomography (microCT) has become an essential tool in imaging procedures in micropaleontology. Apart from highest standards in accuracy, well conducted microCT scans aim to resolve the whole specimen in constant quality and free from any artifacts or visual interferences. Normally, to get used to X-ray techniques and get usable results, countless attempts are needed, resulting in enormous waste of time. This work tries to provide an insight into how best exploitable results can be obtained from the scanning process concerning Larger Benthic Foraminifera (LBF). As each specimen features different characteristics regarding substantial composition, density and conservation status, it is impossible and probably erroneous to give standardized guidelines even within this systematic group. Depending on the attributes of the specimen and on the desired visualization, several details have to be taken into account. Samples preparation: to get sharp images the X-ray has to cross the specimen along its shortest diameter, for LBF the equatorial view is almost always the best positioning (not for alveolinids!). The container itself has to be chosen wisely as well; it must not affect a flawless penetration of the specimen by the X-ray and has to provide a high degree of stability. Small plastic pipettes are perfect to store the specimen (or specimens) and some cardboard may help in keeping the position. The nature and quality of the paste used to fixate the object and its container are essential in ensuring a smooth rotation of the specimen which is inevitable for the consistent quality of the image and to avoid vibrations. Scan parameters: beside the correct choice of dedicated filters (which are always different depending on the working station), settings for kv, µA and resolution might have to be revised for each new object to deliver optimal results. Standard values for hyaline forms with empty chambers are normally around 80 Kv and 100 u

  4. The use of x-ray interferometry to investigate the linearity of the NPL Differential Plane Mirror Optical Interferometer

    Science.gov (United States)

    Yacoot, Andrew; Downs, Michael J.

    2000-08-01

    The x-ray interferometer from the combined optical and x-ray interferometer (COXI) facility at NPL has been used to investigate the performance of the NPL Jamin Differential Plane Mirror Interferometer when it is fitted with stabilized and unstabilized lasers. This Jamin interferometer employs a common path design using a double pass configuration and one fringe is realized by a displacement of 158 nm between its two plane mirror retroreflectors. Displacements over ranges of several optical fringes were measured simultaneously using the COXI x-ray interferometer and the Jamin interferometer and the results were compared. In order to realize the highest measurement accuracy from the Jamin interferometer, the air paths were shielded to prevent effects from air turbulence and electrical signals generated by the photodetectors were analysed and corrected using an optimizing routine in order to subdivide the optical fringes accurately. When an unstabilized laser was used the maximum peak-to-peak difference between the two interferometers was 80 pm, compared with 20 pm when the stabilized laser was used.

  5. Investigations of X-ray response of single wire anode Ar-N2 flow type gas scintillation proportional counters

    International Nuclear Information System (INIS)

    Garg, S.P.; Sharma, R.C.

    1984-01-01

    The X-ray response of single wire anode gas scintillation proportional counters of two different geometries operated with argon+nitrogen gases in continuous flow has been investigated with wire anodes of diameters 25 μm to 1.7 mm. An energy resolution of 19% is obtained for 5.9 keV X-rays entering the counter perpendicular to the anode in pill-box geometry with 25 μm diameter anode. With cylindrical geometry counters energy obtained at 5.9 keV are 18%, 24% and 33% for 50 μm, 0.5 mm and 1.7 mm diameter anodes respectively. An analysis of the observed resolution shows that the contribution from photon counting statistics to the relative variance of scintillation pulses even for X-rays in Ar-N 2 single wire anode gas scintillation proportional counters is small and is not a limiting factor. The energy resolution with thicker anodes, where the contribution from the variance of the charge multiplication factor also has been minimised, is found to deteriorate mainly by the interaction in the scintillation production region. Comments are made on the possibility of improvement in energy resolution by suppression of pulses due to such interactions with the help of the pulse risetime discrimination technique. (orig.)

  6. Induced magnetism at the interfaces of a Fe/V superlattice investigated by resonant magnetic x-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Magnuson, Martin, E-mail: Martin.Magnuson@ifm.liu.se

    2017-01-15

    The induced magnetic moments in the V 3d electronic states of interface atomic layers in a Fe(6ML)/V(7ML) superlattice was investigated by x-ray resonant magnetic scattering. The first V atomic layer next to Fe was found to be strongly antiferromagnetically polarized relatively to Fe and the magnetic moments of the next few atomic layers in the interior V region decay exponentially with increasing distance from the interface, while the magnetic moments of the Fe atomic layers largely remain bulk-like. The induced V moments decay more rapidly as observed by x-ray magnetic scattering than in standard x-ray magnetic circular dichroism. The theoretical description of the induced magnetic atomic layer profile in V was found to strongly rely on the interface roughness within the superlattice period. These results provide new insight into interface magnetism by taking advantage of the enhanced depth sensitivity to the magnetic profile over a certain resonant energy bandwidth in the vicinity of the Bragg angles. - Highlights: • Magnetic moments of buried layers are probed by XRMS in a Fe/V superlattice. • The induced V magnetic moments in XRMS are more rapidly decaying than previously observed by XMCD. • The magnetic depth profile sensitivity is enhanced at an energy bandwidth in the vicinity of the Bragg angles.

  7. Planetesimal core formation with partial silicate melting using in-situ high P, high T, deformation x-ray microtomography

    Science.gov (United States)

    Anzures, B. A.; Watson, H. C.; Yu, T.; Wang, Y.

    2017-12-01

    Differentiation is a defining moment in formation of terrestrial planets and asteroids. Smaller planetesimals likely didn't reach high enough temperatures for widescale melting. However, we infer that core formation must have occurred within a few million years from Hf-W dating. In lieu of a global magma ocean, planetesimals likely formed through inefficient percolation. Here, we used in-situ high temperature, high pressure, x-ray microtomography to track the 3-D evolution of the sample at mantle conditions as it underwent shear deformation. Lattice-Boltzmann simulations for permeability were used to characterize the efficiency of melt percolation. Mixtures of KLB1 peridotite plus 6.0 to 12.0 vol% FeS were pre-sintered to achieve an initial equilibrium microstructure, and then imaged through several consecutive cycles of heating and deformation. The maximum calculated melt segregation velocity was found to be 0.37 cm/yr for 6 vol.% FeS and 0.61 cm/year for 12 vol.% FeS, both below the minimum velocity of 3.3 cm/year required for a 100km planetesimal to fully differentiate within 3 million years. However, permeability is also a function of grain size and thus the samples having smaller grains than predicted for small planetesimals could have contributed to low permeability and also low migration velocity. The two-phase (sulfide melt and silicate melt) flow at higher melt fractions (6 vol.% and 12 vol.% FeS) was an extension of a similar study1 containing only sulfide melt at lower melt fraction (4.5 vol.% FeS). Contrary to the previous study, deformation did result in increased permeability until the sample was sheared by twisting the opposing Drickamer anvils by 360 degrees. Also, the presence of silicate melt caused the FeS melt to coalesce into less connected pathways as the experiment with 6 vol.% FeS was found to be less permeable than the one with 4.5 vol.% FeS but without any partial melt. The preliminary data from this study suggests that impacts as well as

  8. In-situ and operando characterization of batteries with energy-dispersive synchrotron x-ray diffraction

    Science.gov (United States)

    Paxton, William Arthur

    Batteries play a pivotal role in the low-carbon society that is required to thwart the effects of climate change. Alternative low-carbon energy sources, such as wind and solar, are often intermittent and unreliable. Batteries are able capture their energy and deliver it later when it is needed. The implementation of battery systems in grid-level and transportation sectors is essential for efficient use of alternative energy sources. Scientists and engineers need better tools to analyze and measure the performance characteristics of batteries. One of the main hindrances in the progress of battery research is that the constituent electrode materials are inaccessible once an electrochemical cell is constructed. This leaves the researcher with a limited number of available feedback mechanisms to assess the cell's performance, e.g., current, voltage, and impedance. These data are limited in their ability to reveal the more-localized smaller-scale structural mechanisms on which the batteries' performance is so dependent. Energy-dispersive x-ray diffraction (EDXRD) is one of the few techniques that can internally probe a sealed battery. By analyzing the structural behavior of battery electrodes, one is able to gain insight to the physical properties on which the battery's performance is dependent. In this dissertation, EDXRD with ultrahigh energy synchrotron radiation is used to probe the electrodes of manufactured primary and secondary lithium batteries under in-situ and operando conditions. The technique is then applied to solve specific challenges facing lithium ion batteries. Diffraction spectra are collected from within a battery at 40 micrometer resolution. Peak-fitting is used to quantitatively estimate the abundance of lithiated and non-lithiated phases. Through mapping the distribution of phases within, structural changes are linked to the battery's galvanic response. A three-dimensional spatial analysis of lithium iron phosphate batteries suggests that evolution

  9. Corrosion and Corrosion-Fatigue Behavior of 7075 Aluminum Alloys Studied by In Situ X-Ray Tomography

    Science.gov (United States)

    Stannard, Tyler

    7XXX Aluminum alloys have high strength to weight ratio and low cost. They are used in many critical structural applications including automotive and aerospace components. These applications frequently subject the alloys to static and cyclic loading in service. Additionally, the alloys are often subjected to aggressive corrosive environments such as saltwater spray. These chemical and mechanical exposures have been known to cause premature failure in critical applications. Hence, the microstructural behavior of the alloys under combined chemical attack and mechanical loading must be characterized further. Most studies to date have analyzed the microstructure of the 7XXX alloys using two dimensional (2D) techniques. While 2D studies yield valuable insights about the properties of the alloys, they do not provide sufficiently accurate results because the microstructure is three dimensional and hence its response to external stimuli is also three dimensional (3D). Relevant features of the alloys include the grains, subgrains, intermetallic inclusion particles, and intermetallic precipitate particles. The effects of microstructural features on corrosion pitting and corrosion fatigue of aluminum alloys has primarily been studied using 2D techniques such as scanning electron microscopy (SEM) surface analysis along with post-mortem SEM fracture surface analysis to estimate the corrosion pit size and fatigue crack initiation site. These studies often limited the corrosion-fatigue testing to samples in air or specialized solutions, because samples tested in NaCl solution typically have fracture surfaces covered in corrosion product. Recent technological advancements allow observation of the microstructure, corrosion and crack behavior of aluminum alloys in solution in three dimensions over time (4D). In situ synchrotron X-Ray microtomography was used to analyze the corrosion and cracking behavior of the alloy in four dimensions to elucidate crack initiation at corrosion pits

  10. Experimental issues in in-situ synchrotron x-ray diffraction at high pressure and temperature by using a laser-heated diamond-anvil cell

    International Nuclear Information System (INIS)

    Yoo, C.S.

    1997-01-01

    An integrated technique of diamond-anvil cell, laser-heating and synchrotron x-ray diffraction technologies is capable of structural investigation of condensed matter in an extended region of high pressures and temperatures above 100 GPa and 3000 K. The feasibility of this technique to obtain reliable data, however, strongly depends on several experimental issues, including optical and x-ray setups, thermal gradients, pressure homogeneity, preferred orientation, and chemical reaction. In this paper, we discuss about these experimental issues together with future perspectives of this technique for obtaining accurate data

  11. Electrochemical kinetics and X-ray absorption spectroscopy investigations of select chalcogenide electrocatalysts for oxygen reduction reaction applications

    International Nuclear Information System (INIS)

    Ziegelbauer, Joseph M.; Murthi, Vivek S.; O'Laoire, Cormac; Gulla, Andrea F.; Mukerjee, Sanjeev

    2008-01-01

    Transition metal-based chalcogenide electrocatalysts exhibit a promising level of performance for oxygen reduction reaction applications while offering significant economic benefits over the state of the art Pt/C systems. The most active materials are based on Ru x Se y clusters, but the toxicity of selenium will most likely limit their embrace by the marketplace. Sulfur-based analogues do not suffer from toxicity issues, but suffer from substantially less activity and stability than their selenium brethren. The structure/property relationships that result in these properties are not understood due to ambiguities regarding the specific morphologies of Ru x S y -based chalcogenides. To clarify these properties, an electrochemical kinetics study was interpreted in light of extensive X-ray diffraction, scanning electron microscopy, and in situ X-ray absorption spectroscopy evaluations. The performance characteristics of ternary M x Ru y S z /C (M = Mo, Rh, or Re) chalcogenide electrocatalysts synthesized by the now-standard low-temperature nonaqueous (NA) route are compared to commercially available (De Nora) Rh- and Ru-based systems. Interpretation of performance differences is made in regards to bulk and surface properties of these systems. In particular, the overall trends of the measured activation energies in respect to increasing overpotential and the gross energy values can be explained in regards to these differences

  12. A study on the phase transformation of the nanosized hydroxyapatite synthesized by hydrolysis using in situ high temperature X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Shih, W.-J. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan, 70101, Taiwan (China); Wang, J.-W. [Department of Enviromental and Safety Engineering, Chung Hwa College of Medical Technology, 89 Wen-Hua 1st St., Rende Shiang, Tainan, 71703, Taiwan (China); Wang, M.-C. [Department of Materials Science and Engineering, National United University, 1 Lien-Da, Kung-Ching Li, Miao Li 360, Taiwan (China)]. E-mail: mcwang@nuu.edu.tw; Hon, M.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan, 70101, Taiwan (China); Dayeh University, 112 Shan-Jiau Road, Da-Tsuen, Changhua 515, Taiwan (China)

    2006-09-15

    The biodegradable hydroxyapatite (HA) was synthesized by hydrolysis and characterized using high temperature X-ray diffraction (HT-XRD), differential thermal analysis and thermogravimetry (DTA/TG), and scanning electron microscopy (SEM). The in situ phase transformation of the HA synthesized from CaHPO{sub 4}.2H{sub 2}O (DCPD) and CaCO{sub 3} with a Ca / P = 1.5 in 2.5 M NaOH{sub (aq)} at 75 deg. C for 1 h was investigated by HT-XRD between 25 and 1500 deg. C. The HA was crystallized at 600 deg. C and maintained as the major phase until 1400 deg. C. The HA steadily transformed to the {alpha}-tricalcium phosphate ({alpha}-TCP) which became the major phosphate phase at 1500 deg. C. At 700 deg. C, the minor CaO phase appeared and vanished at 1300 deg. C. The Na{sup +} impurity from the hydrolysis process was responsible for the formation of the NaCaPO{sub 4} phase, which appeared above 800 deg. C and disappeared at 1200 deg. C.

  13. Structural evaluation of reduced graphene oxide in graphene oxide during ion irradiation: X-ray absorption spectroscopy and in-situ sheet resistance studies

    Science.gov (United States)

    Saravanan, K.; Jayalakshmi, G.; Suresh, K.; Sundaravel, B.; Panigrahi, B. K.; Phase, D. M.

    2018-03-01

    We report the structural evolution of reduced graphene oxide (rGO) in graphene oxide (GO) flakes during 1 MeV Si+ ion irradiation. In-situ electrical resistivity measurements facilitate monitoring the sheet resistance with the increase in the fluence. The electrical sheet resistance of the GO flake shows the exponential decay behaviour with the increasing ion fluence. Raman spectra of the GO flake reveal the increase in the ID/IG ratio, indicating restoration of the sp2 network upon irradiation. The C/O ratio estimated from resonant Rutherford backscattering spectrometry analysis directly evidenced the reduction of oxygen moieties upon irradiation. C K-edge X-ray absorption near edge structure spectra reveal the restoration of C=C sp2-hybridized carbon atoms and the removal of oxygen-containing functional groups in the GO flake. STM data reveal the higher conductance in the rGO regime in comparison with the regime, where the oxygen functional groups are present. The experimental investigation demonstrates that the ion irradiation can be employed for efficient reduction of GO with tunable electrical and structural properties.

  14. In situ X-ray diffraction study of irradiation-induced lattice expansion in Al foils by MeV-energy heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Minagawa, Hideaki [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Tsuchida, Hidetsugu, E-mail: tsuchida@nucleng.kyoto-u.ac.jp [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan); Murase, Ryu [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Itoh, Akio [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan)

    2016-04-01

    Using in situ X-ray diffraction measurements, we investigate lattice deformations of a free-standing aluminum foil induced by irradiation with MeV-energy heavy projectiles (C, O, and Si ions). The dependence of the ion-beam flux on the lattice expansion is analyzed in terms of two types of irradiation effects: (i) electronic excitation collision-induced lattice heating and (ii) elastic collision-induced displacement damage. We observe that the change in the lattice parameter is proportional to the energy in lattice heating, irrespective of projectile species. This result is in good agreement with a model calculation for thermal lattice expansion caused by beam heating. Moreover, with the correlation between lattice expansion and displacement damage, we consider a simple model for lattice expansion originating from the accumulation of Frenkel defects. From the model, we obtained the relationship between the relative changes in lattice parameter and the value of displacement per atom (dpa) rate. A comparison of the results from model calculations and experiments shows that the dpa rate calculated from the model, which takes account of athermal defect-recombination, is strongly correlated with the change in lattice parameter. This result suggests that the concentration of surviving defects under irradiation diminishes because of spontaneous recombination of defects produced.

  15. Molybdenum Cluster Chalcogenides: In Situ X-Ray Studies on the Formation of Cu xMo 6S 8 via Electron/Ion Transfer

    Science.gov (United States)

    Fischer, C.; Gocke, E.; Stege, U.; Schöllhorn, R.

    1993-01-01

    Systematic structural investigation have been performed on the formation of the ternary Chevrel phase system CuxMo6S8 by topotactic intercalation of copper into Mo6S8 via electron/ion transfer reactions. In high-temperature synthesis the homogeneity range of CuxMo6S8 formation corresponds to 1.8 ≤ x ≤ 3.66, while by galvanostatic or potentiostatic reduction of binary Mo6S8 at ambiet temperature in aqueous CuSO4 or aprotic CuCl/Ch3CN electrolyte the terminal rhombohedral phase Cu4Mo6S8 with the maximum number of electrons per Mo6 cluster can be obtained. The phase range 1 ≤ x ≤ 4 of CuxMo6S8 as obtained by galvanostatic reduction of Mo6S8 in aqueous CuSO4 electrolyte has been determined by in situ X-ray experiments. Warburg oxygen manometry has proved to be a new and powerful analytical tool for examination of the Cu content of ternary phase CuxMo6S8. Thermodiffractometry and 63 Cu NMR studies of Cu2Mo6S8 (high-temperature phase) reveal a phase-transition rhombohedral/triclinic in a broad temperature range between 285 and 200 K. Superconducting properties (temperature-dependent ac susceptibility) of high temperature and electrochemically prepared Cu phases are reported.

  16. Thermal expansion behavior of empressite, AgTe: A structural study by means of in situ high-temperature single-crystal X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Bindi, Luca [Museo di Storia Naturale, sez. di Mineralogia, Universita di Firenze, Via La Pira 4, I-50121 Firenze (Italy)], E-mail: luca.bindi@unifi.it

    2009-04-03

    The crystal structure of empressite, AgTe, a rare silver telluride, has been investigated by in situ X-ray single-crystal diffraction methods within the temperature range 298-463 K. AgTe remains orthorhombic, space group Pmnb (Pnma as standard), and shows only normal thermal expansion over the entire temperature range. The unit-cell parameters show a gradual increase with the increase of temperature. Slight adjustments in the geometry of Ag-tetrahedra and in the crystal-chemical environment of tellurium atoms occur in a continuous way without abrupt structural changes. The coefficients of thermal expansion along various axes are: {alpha}{sub a} = 1.5 x 10{sup -5} K{sup -1}, {alpha}{sub b} = 3.0 x 10{sup -5} K{sup -1}, {alpha}{sub c} = 2.2 x 10{sup -5} K{sup -1}, and the bulk thermal expansion coefficient {alpha}{sub V} is 5.4 x 10{sup -5} K{sup -1} for the temperature range 298-463 K.

  17. Microstructure selection in thin-sample directional solidification of an Al-Cu alloy: In situ X-ray imaging and phase-field simulations

    International Nuclear Information System (INIS)

    Clarke, A. J.; Tourret, D.; Song, Y.; Imhoff, S. D.; Gibbs, P. J.

    2017-01-01

    We study microstructure selection during during directional solidification of a thin metallic sample. We combine in situ X-ray radiography of a dilute Al-Cu alloy solidification experiments with three-dimensional phase-field simulations. Here we explore a range of temperature gradient G and growth velocity V and build a microstructure selection map for this alloy. We investigate the selection of the primary dendritic spacing Λ and tip radius ρ. While ρ shows a good agreement between experimental measurements and dendrite growth theory, with ρ~V"-"1"/"2, Λ is observed to increase with V (∂Λ/∂V > 0), in apparent disagreement with classical scaling laws for primary dendritic spacing, which predict that ∂Λ/∂V<0. We show through simulations that this trend inversion for Λ(V) is due to liquid convection in our experiments, despite the thin sample configuration. We use a classical diffusion boundary-layer approximation to semi-quantitatively incorporate the effect of liquid convection into phase-field simulations. This approximation is implemented by assuming complete solute mixing outside a purely diffusive zone of constant thickness that surrounds the solid-liquid interface. This simple method enables us to quantitatively match experimental measurements of the planar morphological instability threshold and primary spacings over an order of magnitude in V. Lastly, we explain the observed inversion of ∂Λ/∂V by a combination of slow transient dynamics of microstructural homogenization and the influence of the sample thickness.

  18. In situ SERS and X-ray photoelectron spectroscopy studies on the pH-dependant adsorption of anthraquinone-2-carboxylic acid on silver electrode

    Science.gov (United States)

    Li, Dan; Jia, Shaojie; Fodjo, Essy Kouadio; Xu, Hu; Wang, Yuhong; Deng, Wei

    2016-03-01

    In this study, in situ surface-enhanced Raman scattering (SERS) spectroelectrochemistry and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) are used to investigate the redox reaction and adsorption behavior of anthraquinone-2-carboxylic acid (AQ-2-COOH) on an Ag electrode at different pH values. The obtained results indicate that AQ-2-COOH is adsorbed tilted on the Ag electrode through O-atom of ring carbonyl in a potential range from -0.3 to -0.5 V vs. SCE, but the orientation turns to more tilted orientation with both O-atom of the ring carbonyl and carboxylate group in positive potential region for pH 6.0 and 7.4. However, at pH 10.0, the orientation adopts tilted conformation constantly on the Ag electrode with both O-atom of the anthraquinone ring and carboxylate group in the potential range from -0.3 to -0.5 V vs. SCE or at positive potentials. Moreover, the adsorption behavior of AQ-2-COOH has been further confirmed by AR-XPS on the Ag surface. Proposed reasons for the observed changes in orientation are presented.

  19. Interface electronic properties of co-evaporated MAPbI3 on ZnO(0001): In situ X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy study

    International Nuclear Information System (INIS)

    Zhou, Xianzhong; Li, Xiaoli; Huang, Feng; Zhong, Dingyong; Liu, Yuan

    2016-01-01

    In this work, the interface electronic properties of ZnO(0001)/CH 3 NH 3 PbI 3 were investigated by both X-ray and ultraviolet photoelectron spectroscopy. The CH 3 NH 3 PbI 3 thin films were grown on single crystalline ZnO(0001) substrate in situ by co-evaporation of PbI 2 and CH 3 NH 3 I at room temperature with various thickness from 1.5 nm to 190 nm. It was found that the conduction band minimum of ZnO lies 0.3 eV below that of CH 3 NH 3 PbI 3 , while the valence band maximum of ZnO lies 2.1 eV below that of CH 3 NH 3 PbI 3 , implying that the electrons can be effectively transported from CH 3 NH 3 PbI 3 to ZnO, and the holes can be blocked in the same time. A PbI 2 rich layer was initially formed at the interface of ZnO(0001)/CH 3 NH 3 PbI 3 during the growth. As a consequence, an interface barrier was built up which may prevent the electron transport at the interface.

  20. In situ electrochemical impedance spectroscopy/synchrotron radiation grazing incidence X-ray diffraction-A powerful new technique for the characterization of electrochemical surfaces and interfaces

    Energy Technology Data Exchange (ETDEWEB)

    De Marco, Roland [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia)]. E-mail: r.demarco@exchange.curtin.edu.au; Jiang, Z.-T. [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Martizano, Jay [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Lowe, Alex [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Pejcic, Bobby [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Riessen, Arie van [Materials Research Group, Department of Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia)

    2006-08-15

    A marriage of electrochemical impedance spectroscopy (EIS) and in situ synchrotron radiation grazing incidence X-ray diffraction (SR-GIXRD) has provided a powerful new technique for the elucidation of the mechanistic chemistry of electrochemical systems. In this study, EIS/SR-GIXRD has been used to investigate the influence of metal ion buffer calibration ligands, along with natural organic ligands in seawater, on the behaviour of the iron chalcogenide glass ion-selective electrode (ISE). The SR-GIXRD data demonstrated that citrate - a previously reported poor iron calibration ligand for the analysis of seawater - induced an instantaneous and total dissolution of crystalline GeSe and Sb{sub 2}Se{sub 3} in the modified surface layer (MSL) of the ISE, while natural organic ligands in seawater and a mixture of ligands in a mimetic seawater ligand system protected the MSL's crystalline inclusions of GeSe and Sb{sub 2}Se{sub 3} from oxidative attack. Expectedly, the EIS data showed that citrate induced a loss in the medium frequency time constant for the MSL of the ISE, while seawater's natural organic ligands and the mimetic ligand system preserved the medium frequency EIS response characteristics of the ISE's MSL. The new EIS/SR-GIXRD technique has provided insights into the suitability of iron calibration ligands for the analysis of iron in seawater.

  1. Investigation of some ancient opaque glasses in the archaeological museums of Istanbul by x-ray radiography technique

    International Nuclear Information System (INIS)

    Tugrul, B.; Sungur, F.; Atik, S.

    1986-01-01

    In this study, opaque glass samples of which interiors is invisible, investigated by the x-ray radiography technique. In the evaluation,some knowledge has been extracted about the glass base and mold technique. Furthermore,it was shown that ornamental attachments have been fixed on the glass artifacts by techniques different than what it appears to be. In addition to that, joining edges of restorated opaque glass samples can be investigated and quality of the restoration can be evaluated. Therefore, the opaque glass samples were investigated non-destructively a short period of time, much like transparent glass could be studied. (author)

  2. Spectroscopic Investigations of Highly Charged Ions using X-Ray Calorimeter Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Thorn, Daniel Bristol [Univ. of California, Davis, CA (United States)

    2008-11-19

    Spectroscopy of K-shell transitions in highly charged heavy ions, like hydrogen-like uranium, has the potential to yield information about quantum electrodynamics (QED) in extremely strong nuclear fields as well as tests of the standard model, specifically parity violation in atomic systems. These measurements would represent the 'holy grail' in high-Z atomic spectroscopy. However, the current state-of-the-art detection schemes used for recording the K-shell spectra from highly charged heavy ions does not yet have the resolving power to be able to attain this goal. As such, to push the field of high-Z spectroscopy forward, new detectors must be found. Recently, x-ray calorimeter spectrometers have been developed that promise to make such measurements. In an effort to make the first steps towards attaining the 'holy grail', measurements have been performed with two x-ray calorimeter spectrometers (the XRS/EBIT and the ECS) designed and built at Goddard Space Flight Center in Greenbelt, MD. The calorimeter spectrometers have been used to record the K-shell spectra of highly charged ions produced in the SuperEBIT electron beam ion trap at Lawrence Livermore National Laboratory in Livermore, CA. Measurements performed with the XRS/EBIT calorimeter array found that the theoretical description of well-above threshold electron-impact excitation cross sections for hydrogen-like iron and nickel ions are correct. Furthermore, the first high-resolution spectrum of hydrogen-like through carbon-like praseodymium ions was recorded with a calorimeter. In addition, the new high-energy array on the EBIT Calorimeter Spectrometer (ECS) was used to resolve the K-shell x-ray emission spectrum of highly charged xenon ions, where a 40 ppm measurement of the energy of the K-shell resonance transition in helium-like xenon was achieved. This is the highest precision result, ever, for an element with such high atomic number. In addition, a first-of-its-kind measurement of

  3. Spectroscopic Investigations of Highly Charged Ions using X-Ray Calorimeter Spectrometers

    International Nuclear Information System (INIS)

    Thorn, D. B.

    2008-01-01

    Spectroscopy of K-shell transitions in highly charged heavy ions, like hydrogen-like uranium, has the potential to yield information about quantum electrodynamics (QED) in extremely strong nuclear fields as well as tests of the standard model, specifically parity violation in atomic systems. These measurements would represent the 'holy grail' in high-Z atomic spectroscopy. However, the current state-of-the-art detection schemes used for recording the K-shell spectra from highly charged heavy ions does not yet have the resolving power to be able to attain this goal. As such, to push the field of high-Z spectroscopy forward, new detectors must be found. Recently, x-ray calorimeter spectrometers have been developed that promise to make such measurements. In an effort to make the first steps towards attaining the 'holy grail', measurements have been performed with two x-ray calorimeter spectrometers (the XRS/EBIT and the ECS) designed and built at Goddard Space Flight Center in Greenbelt, MD. The calorimeter spectrometers have been used to record the K-shell spectra of highly charged ions produced in the SuperEBIT electron beam ion trap at Lawrence Livermore National Laboratory in Livermore, CA. Measurements performed with the XRS/EBIT calorimeter array found that the theoretical description of well-above threshold electron-impact excitation cross sections for hydrogen-like iron and nickel ions are correct. Furthermore, the first high-resolution spectrum of hydrogen-like through carbon-like praseodymium ions was recorded with a calorimeter. In addition, the new high-energy array on the EBIT Calorimeter Spectrometer (ECS) was used to resolve the K-shell x-ray emission spectrum of highly charged xenon ions, where a 40 ppm measurement of the energy of the K-shell resonance transition in helium-like xenon was achieved. This is the highest precision result, ever, for an element with such high atomic number. In addition, a first-of-its-kind measurement of the effect of the

  4. High Pressure In Situ X-ray Diffraction Study of MnO to 120 GPa and Comparison with Shock Compression Experiment

    Science.gov (United States)

    Yagi, Takehiko; Kondo, Tadashi; Syono, Yasuhiko

    1997-07-01

    In order to clarify the nature of the phase transformation in MnO observed at around 90 GPa by shock compression experiment (Syono et al., this symposium), high pressure in situ x-ray experiments were carried out up to 120 GPa. Powdered sample was directly compressed in Mao-Bell type diamond anvil and x-ray experiments were carried out using angle dispersive technique by combining synchrotron radiation and imaging plate detector. Distortion of the B1 structured phase into hexagonal unit cell was observed from 25-40 GPa, which continues to increase up to 90 GPa. At around 90 GPa, discontinuous change of the diffraction was observed. This new phase cannot be explained by a simple B2 structure and the analysis of this phase is in progress. This high pressure phase has metallic appearance, which reverses to transparent MnO on release of pressure.

  5. Applications of x ray absorption fine structure to the in situ study of the effect of cobalt in nickel hydrous oxide electrodes for fuel cells and rechargeable batteries

    Science.gov (United States)

    Kim, Sunghyun; Tryk, Donald A.; Scherson, Daniel A.; Antonio, Mark R.

    1993-01-01

    Electronic and structural aspects of composite nickel-cobalt hydrous oxides have been examined in alkaline solutions using in situ X-ray absorption fine structure (XAFS). The results obtained have indicated that cobalt in this material is present as cobaltic ions regardless of the oxidation state of nickel in the lattice. Furthermore, careful analysis of the Co K-edge Extended X-ray absorption fine structure data reveals that the co-electrodeposition procedure generates a single phase, mixed metal hydrous oxide, in which cobaltic ions occupy nickel sites in the NiO2 sheet-like layers and not two intermixed phases each consisting of a single metal hydrous oxide.

  6. Frequencies of X-ray and fast neutron induced chromosome translocations in human peripheral blood lymphocytes as detected by in situ hybridization using chromosome specific DNA libraries

    International Nuclear Information System (INIS)

    Natarajan, A.T.; Darroudi, F.; Vermeulen, S.; Wiegant, J.

    1992-01-01

    DNA libraries of six human chromosomes were used to detect translocations in human lymphocytes induced by different doses of X-rays and fast neutrons. Results show that with X-rays, one can detect about 1.5 to 2.0 fold more translocations in comparison to dicentrics, whereas following fast neutron irradiation, the difference between these two classes of aberrations are significantly different at high doses. In addition, triple fluorescent in situ hybridization technique was used to study the frequencies of radiation-induced translocations involving a specific chromosome. Chromosome number 1 was found to be involved in translocations more frequently than chromosomes number 2, 3, 4, 8 and X. (author). 10 refs., 1 fig., 2 tabs

  7. In situ determination of K, Ca, S and Si in fresh sugar cane leaves by handheld Energy Dispersive X-Ray Fluorescence Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Marcelo B.B.; Adame, Andressa; Almeida, Eduardo de; Brasil, Marcos A.S.; Krug, Francisco J., E-mail: fjkrug@cena.usp.br [Centro de Energia Nuclear na Agricultura, Piracicaba, SP (Brazil); Schaefer, Carlos E.G.R. [Departamento de Solos, Universidade Federal de Viçosa, MG (Brazil)

    2018-05-01

    A portable energy dispersive X-ray fluorescence spectrometer was evaluated in the in situ analysis of fresh sugar cane leaves for real time plant nutrition diagnosis. Fresh leaf fragments (n = 10 sugar cane varieties; 20 fragments per leaf; 2 measurement sites per fragment) were irradiated and the averaged data from X-ray characteristic emission lines intensities (for K, Ca, S and Si Kα lines) were in close agreement with mass fraction data obtained by a validated comparative method. The linear correlation coefficients (r) ranged from 0.9575 for Ca to 0.9851 for Si. The obtained limits of detection were at least two-fold lower than the critical nutrient levels. Manganese can also be properly determined, but validation still requires more robust calibration models. The proposed method is a straightforward approach towards the fast evaluation of the nutritional profile of plants avoiding time-consuming steps, which involve drying, grinding, weighing, and acid digestion. (author)

  8. Application of micron X-ray CT based on micro-PIXE to investigate the distribution of Cs in silt particles for environmental remediation in Fukushima Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Keizo, E-mail: keizo.ishii@qse.tohoku.ac.jp [Research Center for Remediation Engineering of Environments Contaminated with Radioisotopes, Graduate School of Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Hatakeyama, Taisuke; Itoh, Shin; Sata, Daichi [Department of Quantum Science and Energy Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Ohnuma, Tohru; Yamaguchi, Toshiro; Arai, Hiromu; Arai, Hirotsugu [Research Center for Remediation Engineering of Environments Contaminated with Radioisotopes, Graduate School of Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Matsuyama, Shigeo; Terakawa, Atsuki; Kim, Seong-Yun [Department of Quantum Science and Energy Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan)

    2016-03-15

    We used X-ray computed tomography (CT) using characteristic X-rays produced in micro-particle-induced X-ray emission (PIXE) to investigate the internal structure of silt particles and develop new methods to decontaminate soil containing radioactive cesium. We obtained 3D attenuation coefficient images of silt particles with a diameter of approximately 100 μm for V K and Cr K X-rays. Owing to the absorption edges of the Cs L-shell, the differences between the V K and Cr K X-ray images revealed the spatial distribution of Cs atoms in the silt particles. Cs atoms were distributed over the surfaces of the silt particles to a thickness of approximately 10 μm. This information is useful for the decontamination of silt contaminated by radiation from the Fukushima Daiichi nuclear disaster.

  9. Hydrogen absorption in epitaxial W/Nb(001) and polycrystalline Fe/Nb(110) multilayers studied in-situ by X-ray/neutron scattering techniques and X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Klose, F.; Rehm, C.; Fieber-Erdmann, M.; Holub-Krappe, E.; Bleif, H. J.; Sowers, H.; Goyette, R.; Troger, L.; Maletta, H.

    1999-01-01

    Hydrogen can be absorbed in large quantities by 100 A thin Nb layers embedded in epitaxial W/Nb and polycrystalline Fe/Nb multilayers. The solubility and the hydrogen-induced structural changes of the host lattice are explored in-situ by small-angle neutron/X-ray reflectometry and high-angle diffraction. These measurements reveal for both systems that the relative out-of-plane expansion of the Nb layers is considerably larger than the relative increase of the Nb interplanar spacing indicating two distinctly different mechanisms of hydrogen absorption. In Fe/Nb multilayers, hydrogen expands the Nb interplanar spacing in a continuous way as function of the external pressure. In contrast, the Nb lattice expansion is discontinuous in epitaxial W/Nb multilayers: A jump in the Nb(002) Bragg reflection position occurs at a critical hydrogen pressure of 1 mbar. In-situ EXAFS spectroscopy also exhibits an irreversible expansion of the Nb lattice in the film plane for p H2 > 1 mbar. This can be regarded as a structural phase transition from an exclusively out-of-plane to a three-dimensionally expanded state at low and high hydrogen pressures, respectively

  10. Investigation of solar flares in X-ray and optical spectral region

    International Nuclear Information System (INIS)

    Kurt, V.; Kurochka, L.N.; Zenchenko, V.M.

    1989-01-01

    Measurements of hard X h radiation of 180 solar flares carried out on board of the space probes Venera-13,-14, were compared with measurements of optical and thermal X t radiation. Values of total energy release during a flare in these regions are calculated, and correlation analysis is carried out. The bond correlations found have shown that total energy of fast electrons, caused X h -flare in the flare pulse phase, and thermal energy at the end of a pulse phase are practically connected with each othesr functionally. Quantitative connection between a flare ball in H α -line and the most probable energy values, being in different radiation regions calculated in the scope of generally accepted models, is established. The total energy of an optical (cold) part of the flare, radiation energy in X-ray region and the energy introduced to the flare volume by energy particles are shown to be compared between each other

  11. Investigation of biomedical inner microstructures with hard X-ray phase-contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shu Hang [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Graduate University of the Chinese Academy of Sciences, 100864 Beijing (China); Zhu Peiping [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Chen Bo [Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Liu Bo; Yin Hongxia [Capital University of Medical Sciences, 100054 Beijing (China); Li Enrong [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Graduate University of the Chinese Academy of Sciences, 100864 Beijing (China); Liu Yijin [Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Wang Junyue [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Graduate University of the Chinese Academy of Sciences, 100864 Beijing (China); Yuan Qingxi; Huang Wanxia; Fang Shouxian [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Wu Ziyu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); National Center for NanoScience and Technology, 100080 Beijing (China)], E-mail: wuzy@ihep.ac.cn

    2007-09-21

    Hard X-ray Phase-Contrast Imaging (HX-PCI) is a new and valuable method that may provide information of the inner parts of an opaque object. Previous reports demonstrated its applicability in soft and hard tissue imaging. Here we provide further evidence for improved image quality and the effective capability to distinguish inner microstructures in real biomedical systems such as cochlea. Experiments performed both at the 4W1A beamline of the Beijing Synchrotron Radiation Facility (BSRF) and at the Taiwan National Synchrotron Radiation Research Center (NSRRC) clearly show details of samples' inner microstructure with a resolution of a few microns. The improved spatial resolution is a relevant achievement for future improved understanding and clinical trials.

  12. Investigation on the properties of a laminar grating as a soft x-ray beam splitter

    International Nuclear Information System (INIS)

    Liu Ying; Fuchs, Hans-Joerg; Liu Zhengkun; Chen Huoyao; He Shengnan; Fu Shaojun; Kley, Ernst-Bernhard; Tuennermann, Andreas

    2010-01-01

    Laminar-type gratings as soft x-ray beam splitters for interferometry are presented. Gold-coated grating beam splitters with 1000 lines/mm are designed for grazing incidence operation at 13.9nm. They are routinely fabricated using electron beam lithography and ion etching techniques. The laminar grating is measured to have almost equal absolute efficiencies of about 20% in the zeroth and -1st orders, which enables a fringe visibility up to 0.99 in the interferometer. The discrepancy of the grating profiles between the optimized theoretical and the experimental results is analyzed according to the comparison of the optimized simulation results and the measurement realization of the grating efficiencies. By a precise control of the grating profile, the grating efficiency in the -1st order and the fringe visibility could be improved to 25% and 1, respectively.

  13. X-ray electron density investigation of chemical bonding in van der Waals materials

    Science.gov (United States)

    Kasai, Hidetaka; Tolborg, Kasper; Sist, Mattia; Zhang, Jiawei; Hathwar, Venkatesha R.; Filsø, Mette Ø.; Cenedese, Simone; Sugimoto, Kunihisa; Overgaard, Jacob; Nishibori, Eiji; Iversen, Bo B.

    2018-03-01

    Van der Waals (vdW) solids have attracted great attention ever since the discovery of graphene, with the essential feature being the weak chemical bonding across the vdW gap. The nature of these weak interactions is decisive for many extraordinary properties, but it is a strong challenge for current theory to accurately model long-range electron correlations. Here we use synchrotron X-ray diffraction data to precisely determine the electron density in the archetypal vdW solid, TiS2, and compare the results with density functional theory calculations. Quantitative agreement is observed for the chemical bonding description in the covalent TiS2 slabs, but significant differences are identified for the interactions across the gap, with experiment revealing more electron deformation than theory. The present data provide an experimental benchmark for testing theoretical models of weak chemical bonding.

  14. Investigating the suitability of GaAs:Cr material for high flux X-ray imaging

    Science.gov (United States)

    Veale, M. C.; Bell, S. J.; Duarte, D. D.; French, M. J.; Hart, M.; Schneider, A.; Seller, P.; Wilson, M. D.; Kachkanov, V.; Lozinskaya, A. D.; Novikov, V. A.; Tolbanov, O. P.; Tyazhev, A.; Zarubin, A. N.

    2014-12-01

    Semi-insulating wafers of GaAs material with a thickness of 500μm have been compensated with chromium by Tomsk State University. Initial measurements have shown the material to have high resistivity (3 × 109Ωcm) and tests with pixel detectors on a 250 μm pitch produced uniform spectroscopic performance across an 80 × 80 pixel array. At present, there is a lack of detectors that are capable of operating at high X-ray fluxes (> 108 photons s-1 mm-2) in the energy range 5-50 keV. Under these conditions, the poor stopping power of silicon, as well as issues with radiation hardness, severely degrade the performance of traditional detectors. While high-Z materials such as CdTe and CdZnTe may have much greater stopping power, the formation of space charge within these detectors degrades detector performance. Initial measurements made with GaAs:Cr detectors suggest that many of its material properties make it suitable for these challenging conditions. In this paper the radiation hardness of the GaAs:Cr material has been measured on the B16 beam line at the Diamond Light Source synchrotron. Small pixel detectors were bonded to the STFC Hexitec ASIC and were irradiated with 3 × 108 photons s-1 mm-2 monochromatic 12 keV X-rays up to a maximum dose of 0.6 MGy. Measurements of the spectroscopic performance before and after irradiation have been used to assess the extent of the radiation damage.

  15. Crystallization kinetics of Fe-B based amorphous alloys studied in-situ using X-rays diffraction and differential scanning calorimetry

    Directory of Open Access Journals (Sweden)

    Santos D.R. dos

    2001-01-01

    Full Text Available The crystallization processes for the amorphous metallic alloys Fe74B17Si2Ni4Mo3 and Fe86B6Zr7Cu1 (at. % were investigated using X-rays diffraction measurements performed in-situ during Joule-heating, with simultaneous monitoring of the electrical resistance. We determined the main structural transitions and crystalline phases formed during heating, and correlated these results to the observed resistance variations. As the annealing current is increased, the resistance shows an initial decrease due to stress relaxation, followed by a drop to a minimum value due to massive nucleation and growth of alpha-Fe nanocrystals. Further annealing causes the formation of small fractions of Fe-B, B2Zr or ZrO2, while the resistance increases due to temperature enhancement. In situ XRD measurements allowed the identification of metastable phases, as the gamma-Fe phase which occurs at high temperatures. The exothermal peaks observed in the differential scanning calorimetry (DSC for each alloy corroborate the results. We also have performed DSC measurements with several heating rates, which allowed the determination of the Avrami exponent and crystallization activation energy for each alloy. The obtained activation energies (362 and 301 kJ/mol for Fe-B-Zr-Cu; 323 kJ/mol for Fe-B-Si-Ni-Mo are comparable to reported values for amorphous iron alloys, while the Avrami exponent values (n = 1.0 or n = 1.2 are consistent with diffusion controlled crystallization processes with nucleation rates close to zero.

  16. Investigation of the interaction of high intensity laser light with solids and hot plasma using X-ray spectroscopic technique

    International Nuclear Information System (INIS)

    Zigler, A.

    1978-06-01

    This work investigates the properties of high power laser-produced plasmas by developing and applying x-ray spectroscopic methods which utilize spatial resolution. The shadow techniques which were developed in this work yield a high spatial resolution of 5-15μm together with an adequate X-ray spectral resolution for single shots of laser power flux of 2.10 13 W/cm -2 . The intensity distribution in the source is calculated from the partial shadow by numerical differentiation. The main advantage of the present method is the ability to obtain spatial information simultaneously for strong and weak spectral lines for a single shot of medium power laser. Plasma parameters were derived from H-like and He-like lines and their inner-shell satellites, which were obtained from Mg, Al and Si targets. Using shadow techniques, the sizes of the emitting regions of the various spectral lines were measured; the spatial variation of the ionization stage, the electron temperature and density were investigated. A constant electron temperature of (250+-50)eV and electron density scale-length of about 50μm were derived for an expanding plasma. An experimental investigation of the possible origin and the mechanisms responsible for the Ksub(α) radiation in laser-produced plasma was carried out. It is shown that the Ksub(α) radiation was generated by fast suprathermal electrons and originated inside the target behind the interaction zone of the shock and heat waves. Energy penetration depth and hot plasma expansion were tested by using multilayer targets, thin foils and achieving a two-dimensional spatially resolved X-ray Al spectrum. (B.G.)

  17. Operando X-ray investigation of solid oxide fuel cell model electrodes

    International Nuclear Information System (INIS)

    Volkov, Sergey Aleksandrovic

    2017-04-01

    A detailed study of three solid oxide fuel cells (SOFCs) related model systems is presented in this work with the aim of the better understanding of the structural changes in cell components associated with their operation. The first model system is an La_0_._6Sr_0_._4CoO_3_-_d (LSC) on yttria-stabilized zirconia (YSZ). Changes in the YSZ(100) single crystal surface structure buried under the squared LSC microelectrode were studied at a synchrotron under operational conditions. High flux photon beam at the synchrotron allowed access to the LSC/YSZ interface. Structural information from the substrate surface at an atomic scale was acquired. Element-specific anomalous XRD data allowed to distinguish between Y and Zr scattering contributions. For the first time, it was shown that the Y cation concentration at the electrode/electrolyte interface strongly depends on the sample environment and the applied potential. The second model system is a Pt/YSZ. Buried YSZ(111) surface and dense Pt film morphology changes under operational conditions were addressed. High-energy X-ra