TY - JOUR A1 - Williams, S. H. A1 - Hilger, A. A1 - Kardjilov, N. A1 - Manke, I. A1 - Strobl, M. A1 - Douissard, P.A. A1 - Martin, T. A1 - Riesemeier, Heinrich A1 - Banhart, J. T1 - Detection system for microimaging with neutrons N2 - A new high-resolution detector setup for neutron imaging has been developed based on infinity-corrected optics with high light collection, combined with customized mounting hardware. The system can easily be installed, handled and fitted to any existing facility, avoiding the necessity of complex optical systems or further improved electronics (CCD). This is the first time optical magnification higher than 1:1 has been used with scintillator-based neutron detectors, as well as the first implementation of infinity corrected optics for neutron imaging, achieving the smallest yet reported effective pixel size of 3.375 µm. A novel transparent crystal scintillator (GGG crystal) has been implemented with neutrons for the first time to overcome limitations of traditional powder scintillators (Li6/ZnS, Gadox). The standardized procedure for resolution measurements with the Modulation Transfer Function (MTF) is summarized to facilitate comparison between instruments and facilities. Using this new detector setup, a resolution of 14.8 µm with a field of view of 6 mm × 6 mm has been achieved while maintaining reasonable count times. These advances open a wide range of new possible research applications and allow the potential for additional future developments. KW - Instrumentation for neutron sources KW - Neutron radiography KW - Neutron detectors (cold, thermal, fast neutrons) PY - 2012 DO - https://doi.org/10.1088/1748-0221/7/02/P02014 SN - 1748-0221 VL - 7 IS - P02014 SP - 1 EP - 26 PB - Inst. of Physics Publ. CY - London AN - OPUS4-26433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schott, M. A1 - Szczerba, Wojciech A1 - Posset, U. A1 - Vuk, A.S. A1 - Beck, M. A1 - Riesemeier, Heinrich A1 - Thünemann, Andreas A1 - Kurth, D. G. T1 - In operando XAFS experiments on flexible electrochromic devices based on Fe(II)-metallo-supramolecular polyelectrolytes and vanadium oxides N2 - Flexible electrochromic devices (ECDs) based on Fe(II)-metallo-supramolecular polyelectrolytes (Fe-MEPE) and vanadium oxide are studied in operando by means of x-ray absorption fine structure (XAFS) spectroscopy. The ECDs are blue-purple in the colored state at 0.0 V and become light yellow when a voltage of 1.6 V is applied. The XAFS studies at the K-edge of Fe(II) reveals that the absorption edge is shifted toward higher energies by 1.8 eV in the transparent state. Comparison of two different ECDs and different charge cycles demonstrates the reversibility and repeatability of the process. We attribute the shift to a charge transfer and a change of oxidation state of the ions from Fe2+ to Fe3+. The transition is not accompanied by a noticeable structural change of the octahedral coordination geometry as confirmed by analysis of the extended x-ray absorption fine structure (EXAFS) data. (C) 2015 Elsevier B.V. All rights reserved. KW - Metallo-supramolecular polyelectrolytes KW - Vanadium oxide KW - Electrochromism KW - Electrochromic device KW - Cyclic voltammetry KW - XAFS PY - 2016 DO - https://doi.org/10.1016/j.solmat.2015.10.015 SN - 0927-0248 VL - 147 SP - 61 EP - 67 PB - Elsevier B.V. CY - Amsterdam [u.a.] AN - OPUS4-35251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Markötter, Henning A1 - Manke, I. A1 - Haußmann, J. A1 - Arlt, Tobias A1 - Klages, M. A1 - Krüger, P. A1 - Hartnig, C. A1 - Scholta, J. A1 - Müller, Bernd R. A1 - Riesemeier, Heinrich A1 - Banhart, J. T1 - Combined synchrotron X-ray radiography and tomography study of water transport in gas diffusion layers N2 - Synchrotron X-ray radiography and tomography investigations of a custom-made polymer electrolyte membrane fuel cell optimised for visualisation purposes are presented. The 3D water distribution and transport pathways in the porous carbon fibre gas diffusion layers (GDLs) were investigated. The authors found that water is not only moving from the GDL into the channel, but can also take the opposite way, that is, from the channel into free pore space of the GDL. Such movement of water into the opposite direction has been subject of speculations but has so far not yet been reported and might bring new insights into the general water transport behaviour, which might give new aspects to the general description of water transport processes and influence modelling assumptions to describe the process taking place in the GDL. KW - Synchrotron radiography KW - Synchrotron tomography KW - Gas diffusion layers KW - Water transport PY - 2012 DO - https://doi.org/10.1049/mnl.2012.0410 SN - 1750-0443 VL - 7 IS - 7 SP - 689 EP - 692 PB - IET CY - London AN - OPUS4-26282 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Vincze, L. A1 - Reuter, Dirk T1 - X-ray scattering in X-ray fluorescence spectra with X-ray monochromatic, polarised excitation - modelling, experiment, and Monte-Carlo simulation N2 - A systematic series of measurements has been carried out with monochromatic X-ray excitation with synchrotron radiation in order to check a physical model on X-ray scattering. The model has recently been successfully tested for the case of polychromatic, unpolarised excitation emitted by an X-ray tube. Our main purpose is the modelling of a physical background in X-ray fluorescence spectra, so that improved quantitative results can be achieved especially for strongly scattering specimens. The model includes single Rayleigh and Compton scattering in the specimen, the effect of bound electrons, the challenging Compton broadening and the polarisation degree. Representative specimens, measurement geometries and excitation energies have been selected with synchrotron monochromatic light at BAMline/BESSY II. Monte-Carlo simulations have been also carried out in order to evaluate the quality of the results achieved with the model. KW - X-ray scattering KW - Monochromatic excitation KW - Polarisation KW - Modelling KW - Monte-Carlo simulation PY - 2011 DO - https://doi.org/10.1016/j.nimb.2011.04.009 SN - 0168-583X SN - 1872-9584 VL - 269 IS - 13 SP - 1493 EP - 1498 PB - Elsevier CY - Amsterdam AN - OPUS4-23765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Alrwashdeh, S. S. A1 - Markötter, Henning A1 - Haußmann, J. A1 - Hilger, A. A1 - Klages, M. A1 - Müller, Bernd R. A1 - Kupsch, Andreas A1 - Riesemeier, Heinrich A1 - Scholta, J. A1 - Manke, I. T1 - Investigation of water transport in newly developed micro porous layers for polymer electrolyte membrane fuel cells N2 - In this investigation, synchrotron X-ray imaging was used to investigate the water distribution inside newly developed gas diffusion media in polymer electrolyte membrane fuel cells. In-situ radiography was used to reveal the relationship between the structure of the microporous layer (MPL) and the water flow in a newly developed MPL equipped with randomly arranged holes. A strong influence of these holes on the overall water transport was found. This contribution provides a brief overview to some of our recent activities on this research field. KW - Polymer electrolyte membrane fuel cell KW - Microporous layer KW - Water distribution KW - Radiography KW - Synchrotron X-ray imaging PY - 2017 DO - https://doi.org/10.9729/AM.2017.47.3.101 SN - 2287-4445 SN - 2287-5123 VL - 47 IS - 3 SP - 101 EP - 104 AN - OPUS4-43356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - De Samber, B. A1 - Scharf, Oliver A1 - Buzanich, Günter A1 - Garrevoet, J. A1 - Tack, P. A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe A1 - Evens, R. A1 - De Schamphelaere, K. A1 - Falkenberg, G. A1 - Janssen, C. A1 - Vincze, L. T1 - Three-dimensional X-ray fluorescence imaging modes for biological specimens using a full-field energy dispersive CCD camera N2 - Besides conventional scanning X-ray fluorescence imaging at synchrotron sources, full-field X-ray fluorescence (FF-XRF) imaging techniques that do not implicitly require spatial scanning of the sample have become available. FF-XRF has become achievable thanks to the development of a new type of energy dispersive CCD-based 2D detector, also referred to as a 'color X-ray camera (CXC)' or 'SLcam'. We report on different imaging schemes for biological samples using FF-XRF imaging: (a) 2D 'zoom' imaging with pinhole optics using the 'camera obscura' principle; (b) 2D 'fixed magnification' imaging using magnifying polycapillary optics; and (c) 3D-FF-XRF imaging using an X-ray sheet beam or computed tomography (CT). The different FF-XRF imaging modes are illustrated using the crustacean Daphnia magna, a model organism for investigating the effects of metals on organism/ecosystem health, and foraminifera, a class of amoeboid protist. Detailed analytical characterization of the set-up is performed through analyzing various reference materials in order to determine limits of detection (LODs) and sensitivities. Experiments were performed using the BAMline at the BESSY synchrotron (Berlin, Germany) and using the P06 Hard X-ray Microprobe at the PETRAIII synchrotron (Hamburg, Germany). KW - CXC KW - BAMline KW - Maia detector KW - Synchrotron PY - 2019 DO - https://doi.org/10.1039/c9ja00198k VL - 34 IS - 10 SP - 2083 EP - 2093 PB - Royal Society of Chemistry CY - Cambridge, United Kingdom AN - OPUS4-49359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Markötter, Henning A1 - Haußmann, J. A1 - Alink, R. A1 - Dittmann, K. A1 - Tötzke, C. A1 - Krüger, P. A1 - Klages, M. A1 - Arlt, Tobias A1 - Müller, Bernd R. A1 - Riesemeier, Heinrich A1 - Scholta, J. A1 - Gerteisen, D. A1 - Manke, I. A1 - Banhart, J. T1 - Investigation of fuel cell materials and liquid water transport by means of synchrotron imaging N2 - Synchrotron imaging allows addressing various important issues in fuel cell research, for example water distribution and transport. The water distribution in polymer electrolyte membrane fuel cells (PEMFCs) was observed quasi in-situ directly after operation by means of synchrotron tomography. The 3D data set was compared with the tomogram of a dry cell in order to separate the water distribution from cell materials. Engineered transport pathways realized by perforating holes through the gas diffusion layer (GDL) are a recent approach to optimize water transport and cell performance. For some parameter sets a cell performance increase and an improvement of stabilization have already been proven. We present high resolution investigations of the water distribution in perforated GDLs of operating PEMFCs by means of in-situ synchrotron radiography. The surrounding areas of the holes exhibited a distinct hydrophilic character. KW - Gas-diffusion layers KW - Resolution neutron-radiography KW - X-ray radiography KW - Visualization KW - PEMFC PY - 2013 DO - https://doi.org/10.1149/04529.0195ecst SN - 1938-6737 SN - 1938-5862 VL - 45 IS - 29 SP - 195 EP - 202 CY - Pennington, NJ, USA AN - OPUS4-30545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Markötter, Henning A1 - Manke, I. A1 - Krüger, P. A1 - Arlt, Tobias A1 - Huassmann, J. A1 - Klages, M. A1 - Riesemeier, Heinrich A1 - Hartnig, C. A1 - Scholta, J. A1 - Banhart, J. T1 - Investigation of 3D water transport paths in gas diffusion layers by combined in-situ synchrotron X-ray radiography and tomography N2 - The three-dimensional water distribution and water transport paths in the gas diffusion layer (GDL) and the adjacent micro-porous layer (MPL) of a polymer electrolyte membrane fuel cell (PEMFC) were analyzed during cell operation. The technique of quasi in-situ X-ray tomography was used for a 3D visualization of the water distribution and the structure of the GDL at different operating conditions. Based on findings from in-situ radiographic measurements water transport paths were detected and subsequently examined by tomography. The combination of these 2D and 3D techniques allows for a fully three-dimensionally resolved visualization of transport paths through the GDL. KW - Polymer electrolyte membrane fuel cell (PEMFC) KW - Radiography KW - Tomography KW - Synchrotron X-ray imaging KW - Gas diffusion layer (GDL) KW - Water transport paths PY - 2011 DO - https://doi.org/10.1016/j.elecom.2011.06.023 SN - 1388-2481 VL - 13 IS - 9 SP - 1001 EP - 1004 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-25244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arlt, Tobias A1 - Manke, I. A1 - Wippermann, K. A1 - Tötzke, C. A1 - Markötter, Henning A1 - Riesemeier, Heinrich A1 - Mergel, J. A1 - Banhart, J. T1 - Investigation of the three-dimensional ruthenium distribution in fresh and aged membrane electrode assemblies with synchrotron X-ray absorption edge tomography N2 - Synchrotron X-ray absorption edge imaging was used to investigate the ruthenium distribution in both fresh and aged Pt/Ru-based membrane electrode assemblies (MEA) of direct methanol fuel cells. MEAs aged in different ways were analyzed: artificially aged by MeOH depletion and aged for 1700 h in an operating fuel cell stack. An element sensitive tomographic technique – differential X-ray absorption edge tomography – was applied allowing for a 3D-visualization of the ruthenium distribution within the MEA. We found a markedly changed Ru distribution after aging which is correlated to the GDL structure, the flow field geometry, and CO2 transport in the methanol solution. KW - Edge tomography KW - Ruthenium distribution KW - Direct methanol fuel cells KW - Synchrotron X-ray KW - PtRu corrosion PY - 2011 DO - https://doi.org/10.1016/j.elecom.2011.05.013 SN - 1388-2481 VL - 13 IS - 8 SP - 826 EP - 829 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-25243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Markötter, Henning A1 - Manke, I. A1 - Hartnig, C. A1 - Krüger, P. A1 - Wippermann, K. A1 - Arlt, Tobias A1 - Choinka, G. A1 - Riesemeier, Heinrich A1 - Banhart, J. T1 - Hochauflösende Synchrotron-Radiografie KW - PEM Fuel-cells KW - Local current distribution KW - Neutron imaging technique KW - Water transport PY - 2010 SN - 0025-5300 VL - 52 IS - 10 SP - 698 EP - 704 PB - Hanser CY - München AN - OPUS4-23046 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Markötter, Henning A1 - Haußmann, J. A1 - Alink, R. A1 - Tötzke, C. A1 - Arlt, Tobias A1 - Klages, M. A1 - Riesemeier, Heinrich A1 - Scholta, J. A1 - Gerteisen, D. A1 - Banhart, J. A1 - Manke, I. T1 - Influence of cracks in the microporous layer on the water distribution in a PEM fuel cell investigated by synchrotron radiography N2 - Water evolution in the gas diffusion layer of a polymer electrolyte membrane fuel cell was visualized in situ by means of synchrotron X-ray radiography. Cracks in the microporous layer were identified as start points of efficient liquid water transfer paths through the gas diffusion layer. Quantitative analysis of the water flow rate through those arbitrarily distributed cracks into the gas channel revealed that they have a strong influence on the overall liquid water transport. This could find entry into future material design and simulation. KW - Polymer electrolyte membrane fuel cell (PEMFC) KW - Radiography KW - Synchrotron X-ray imaging KW - Microporous layer (MPL) KW - Water transport KW - Liquid water flow rate PY - 2013 DO - https://doi.org/10.1016/j.elecom.2013.04.006 SN - 1388-2481 VL - 34 SP - 22 EP - 24 PB - Elsevier CY - Amsterdam AN - OPUS4-30548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riesemeier, Heinrich T1 - Combined synchrotron X-ray and neutron imaging for the characterization of fuel cells T2 - Third Joint BER II and BESSY II Users´ Meeting CY - Berlin, Germany DA - 2011-11-30 PY - 2011 AN - OPUS4-25125 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radtke, Martin A1 - Reiche, I. A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Guerra, M.F. T1 - Beyond the Great Wall: Gold of the silk roads and the first empire of the Steppes N2 - Fingerprinting ancient gold work requires the use of nondestructive techniques with high spatial resolution (down to 25 µm) and good detection limits (micrograms per gram level). In this work experimental setups and protocols for synchrotron radiation induced X-ray fluorescence (SRXRF) at the BAMline of the Berlin electron storage ring company for synchrotron radiation (BESSY) in Berlin for the measurement of characteristic trace elements of gold are compared considering the difficulties, shown in previous works, connected to the quantification of Pt. The best experimental conditions and calculation methods were achieved by using an excitation energy of 11.58 keV, a silicon drift chamber detector (SDD) detector, and pure element reference standards. A detection limit of 3 µg/g has been reached. This newly developed method was successfully applied to provenancing the Xiongnu gold from the Gol Mod necropolis, excavated under the aegis of the United Nations Educational, Scientific and Cultural Organization (UNESCO). The composition of the base alloys and the presence of Pt and Sn showed that, contrary to what is expected, the gold foils from the first powerful empire of the steppes along the Great Wall were produced with alluvial gold from local placer deposits located in Zaamar, Boroo, and in the Selenga River. KW - Synchrotron radiation KW - X-ray fluorescence KW - Limit of detection KW - Platinum KW - Silicon drift detector KW - SR-microXRF KW - Elemental imaging KW - Gold PY - 2013 DO - https://doi.org/10.1021/ac3025416 SN - 0003-2700 SN - 1520-6882 VL - 85 IS - 3 SP - 1650 EP - 1656 PB - American Chemical Society CY - Washington, DC AN - OPUS4-30224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Thünemann, Andreas A1 - Streli, C. T1 - Impurities in multicrystalline silicon wafers for solar cells detected by synchrotron micro-beam X-ray fluorescence analysis N2 - We report on the trace analysis of copper and iron impurities in multicrystalline silicon wafers with the microbeam X-ray fluorescence (µ-XRF) technique. The efficiency of solar cells, which are based on multicrystalline silicon wafers, is strongly influenced by minor contamination with metals such as copper and iron. Application of compound refractive lenses (CRLs) in µ-XRF allows versatile two-dimensional mapping of relevant contaminations and localization of their sites of deposition. In this context, the measured bulk average limit of detection (LOD) was one picogram of iron and copper per gram of silicon. We suggest that µ-XRF is a valuable tool for non-destructive spatial (3D) quantification of metal impurities in a wide range of materials and devices whose functioning could be critically affected by impurities. KW - X-ray micro beam KW - Compound refractive lens KW - Solar cell KW - Silicon impurities PY - 2012 DO - https://doi.org/10.1039/c2ja30188a SN - 0267-9477 SN - 1364-5544 VL - 27 IS - 11 SP - 1875 EP - 1881 PB - Royal Society of Chemistry CY - London AN - OPUS4-26791 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bjeoumikhov, A. A1 - Bjeoumikhova, Zemfira A1 - Riesemeier, Heinrich A1 - Radtke, Martin A1 - Wedell, R. T1 - Propagation of synchrotron radiation through nanocapillary structures N2 - The propagation of synchrotron radiation through nanocapillary structures with channel sizes of 200 nm and periods in the micrometer size has been studied experimentally. It was shown that the propagation through individual capillary channels has a mode formation character. Furthermore it was shown that during the propagation through capillary channels the coherence of synchrotron radiation is partially conserved. Interference of beams propagating through different capillary channels is observed which leads to a periodically modulated distribution of the radiation intensity in a plane far from the exit of the structure. These investigations are of high relevance for the understanding of X-ray transmission through nanocapillaries and the appearance of wave properties at this size scale. KW - Polycapillary structure KW - Nanocapillary KW - X-ray optics KW - Wave properties KW - Synchrotron radiation KW - X-ray diffraction PY - 2007 DO - https://doi.org/10.1016/j.physleta.2007.01.092 SN - 0031-9163 SN - 0375-9601 VL - 366 IS - 4-5 SP - 283 EP - 288 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-20580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brieger, C. A1 - Melke, J. A1 - van der Bosch, N. A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - de Oliveira Guilherme Buzanich, Ana A1 - Krishna Kayarkatte, M. A1 - Derr, I. A1 - Schökel, A. A1 - Roth, C. ED - de Oliveira Guilherme Buzanich, Ana T1 - A combined in-situ XAS–DRIFTS study unraveling adsorbate induced changes on Pt nanoparticle structure N2 - The adsorption behavior of Platinum nanoparticles was studied for the as-received catalyst (under inert gas), under hydrogen and CO atmosphere using our newly designed in-situ cell. X-ray Absorption Spectroscopy (XAS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) experiments were performed simultaneously with high data quality. Structural information and the type of adsorbate could be revealed via Extended X-ray Absorption Fine Structure (EXAFS) analysis, Δμ X-ray Absorption Near Edge Structure analysis (Δμ XANES) and in-situ DRIFTS. The as-received catalyst showed sub-surface oxygen and O(n-fold). Under CO atmosphere only CO(atop) was found. Reversible adsorbate induced changes of the Pt nanoparticle structure were derived from changes in the Pt-Pt coordination number and the corresponding bond distance. Under reducing conditions (H2, CO) a significant increase in both values occurred. Temperature dependent desorption of CO revealed a gradual shift from Pt-CO to Pt-O. Reoxidation was clearly assigned to strong metal support interaction from the SiO2 support. KW - X-ray absorption spectroscopy KW - DRIFTS KW - XANES KW - CO adsoprtion KW - Platinum KW - String metal support interaction KW - Silica support KW - Adsorbates KW - Infrared spectroscopy PY - 2016 DO - https://doi.org/10.1016/j.jcat.2016.03.034 SN - 0021-9517 VL - 339 SP - 57 EP - 67 PB - Elsevier AN - OPUS4-38367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strub, Erik A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Reznikova, E. T1 - Measurements with compound refractive lenses at the "BAMline" N2 - A set of compound refractive lenses (CRLs), mounted on a silicon wafer, was obtained from the Institut für Mikrostrukturtechnik Karlsruhe. The CRLs were characterized at the BAMline at the synchrotron BESSYII in Berlin. It could be demonstrated that beam diameters below 1 µm can be obtained. The beam size accepted by the lenses is (140 × 140) µm2, thus the intensity gain in the micrometer spot, including absorption, is about 15,000. It is possible to switch between different beam energies within a few minutes. First results of scans and the application of the lenses for MicroXANES (X-ray absorption near-edge structure) measurements are presented in this paper. Also, the possibility of MicroEXAFS (extended X-ray absorption fine structure) measurements is discussed. KW - X-ray optics KW - XANES KW - EXAFS KW - XAS KW - XRF KW - Speciation PY - 2008 DO - https://doi.org/10.1016/j.nimb.2008.02.057 SN - 0168-583X SN - 1872-9584 VL - 266 IS - 10 SP - 2165 EP - 2168 PB - Elsevier CY - Amsterdam AN - OPUS4-17554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich T1 - Spatially-resolved detection of iodine in natural plantinum-palladium nuggets: a comparison of PIXE and XRF T2 - European Conference on X-ray Spectrometry CY - Figueira da Foz, Portugal DA - 2010-06-20 PY - 2010 AN - OPUS4-21073 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El-Hasan, T. A1 - Szczerba, Wojciech A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Kersten, M. T1 - Cr(VI)/Cr(III) and As(V)/As(III) ratio assessments in Jordanian spent oil shale produced by aerobic combustion and anaerobic pyrolysis N2 - With the increase in the awareness of the public in the environmental impact of oil shale utilization, it is of interest to reveal the mobility of potentially toxic trace elements in spent oil shale. Therefore, the Cr and As oxidation state in a representative Jordanian oil shale sample from the El-Lajjoun area were investigated upon different lab-scale furnace treatments. The anaerobic pyrolysis was performed in a retort flushed by nitrogen gas at temperatures in between 600 and 800 °C (pyrolytic oil shale, POS). The aerobic combustion was simply performed in porcelain cups heated in a muffle furnace for 4 h at temperatures in between 700 and 1000 °C (burned oil shale, BOS). The high loss-on-ignition in the BOS samples of up to 370 g kg–1 results from both calcium carbonate and organic carbon degradation. The LOI leads to enrichment in the Cr concentrations from 480 mg kg–1 in the original oil shale up to 675 mg kg–1 in the ≥850 °C BOS samples. Arsenic concentrations were not much elevated beyond that in the average shale standard (13 mg kg–1). Synchrotron-based X-ray absorption near-edge structure (XANES) analysis revealed that within the original oil shale the oxidation states of Cr and As were lower than after its aerobic combustion. Cr(VI) increased from 0% in the untreated or pyrolyzed oil shale up to 60% in the BOS ash combusted at 850 °C, while As(V) increased from 64% in the original oil shale up to 100% in the BOS ash at 700 °C. No Cr was released from original oil shale and POS products by the European compliance leaching test CEN/TC 292 EN 12457-1 (1:2 solid/water ratio, 24 h shaking), whereas leachates from BOS samples showed Cr release in the order of one mmol L–1. The leachable Cr content is dominated by chromate as revealed by catalytic adsorptive stripping voltammetry (CAdSV) which could cause harmful contamination of surface and groundwater in the semiarid environment of Jordan. KW - Trace-elements KW - Fly-ash KW - Speciation KW - Chromium KW - Sediments KW - Behavior KW - Metals KW - Xanes KW - Cr KW - Transformation PY - 2011 DO - https://doi.org/10.1021/es200695e SN - 0013-936X SN - 1520-5851 VL - 45 IS - 22 SP - 9799 EP - 9805 PB - ACS Publ. CY - Washington, DC AN - OPUS4-25290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grunewald, Christian A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Buzanich, Günter A1 - Riesemeier, Heinrich T1 - SRXRF-measurements at non-planar objects: automatic determination of the angle of incidence of the exciting X-ray N2 - For quantitative SRXRF measurements the angle of incidence of the incoming X-ray beam is an important factor. When the sample is focused by a long-range-microscope, the determination of the angle can be automatized using a simple algorithm. This was developed to improve the orientation of especially round or ornate samples. As a side effect the three dimensional surface can be reconstructed, too. KW - X-ray fluorescence KW - Synchrotron radiation KW - Long-range microscope PY - 2011 DO - https://doi.org/10.1039/c0ja00237b SN - 0267-9477 SN - 1364-5544 VL - 26 IS - 5 SP - 1088 EP - 1089 PB - Royal Society of Chemistry CY - London AN - OPUS4-23193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -