TY - GEN A1 - Weidemann, Gerd A1 - Goebbels, Jürgen A1 - Wolk, Thomas A1 - Riesemeier, Heinrich T1 - Computed tomography experiments at BAMline PY - 2003 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2002.pdf#page=299 SN - 0179-4159 SP - 299 EP - 300 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-2494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riesemeier, Heinrich T1 - Analytik Röntgenstrahlung in der BAMline T2 - Seminar der Abteilung I, BAM CY - Berlin, Germany DA - 2002-11-11 PY - 2002 AN - OPUS4-3002 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klobes, Peter A1 - Riesemeier, Heinrich A1 - Meyer, Klaus A1 - Goebbels, Jürgen A1 - Hellmuth, k.-H. T1 - Rock porosity determination by combination of X-ray computerized tomography with mercury porosimetry N2 - Abstract First results are described of coupling of mercury porosimetry with X-ray computerized tomography (CT) as a new combination technique for rock porosity studies. This technique is suitable for rock samples with a pronounced mercury intrusion-extrusion hysteresis and includes CT measurements before and after mercury intrusion. The entrapped portion of mercury, when the pressure after the intrusion into the rock sample is reduced to 0.1 MPa, serves as a contrast agent in the porous network to localize spatial distribution of rock porosity by CT. The results obtained show that the mercury intrusion and therefore the porosity were quite different for the separate mineral phases. Therefore the combination of mercury porosimetry and computer tomography can give 3-D data on mineral-specific porosity distributions with additional pore size information. In contrast to mercury porosimetry as a single method, results of the combination technique with CT represent a direct visualization of porosity variation and do not depend on any special pore network model. PY - 1997 SN - 0937-0633 VL - 357 IS - 5 SP - 543 EP - 547 PB - Springer CY - Berlin AN - OPUS4-11970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Klobes, Peter A1 - Riesemeier, Heinrich A1 - Meyer, Klaus A1 - Goebbels, Jürgen A1 - Siitari-Kauppi, M. A1 - Hellmuth, K.-H. ED - Gray, W. T1 - Investigation of rock samples using x-ray-microcomputer-tomography before and after mercury intrusion porosimetry N2 - A new method for the physical characterization of rock matrices for use in site investigations of nuclear waste repositories has been developed. The method can provide information needed in the assessment of the performance of the geosphere working as a natural barrier retarding the migration of radionuclides by diffusion into the rock matrix. Most conventional methods for the physical characterization of rocks give only bulk information. The combination of mercury porosimetry and computer tomography can give 3-D data on mineral-specific porosity distributions with additional pore size information. Additionally, limits for mineral-specific internal surface areas can be estimated, which is essential for the assessment of water-rock interaction and reactive interaction with radionuclides (sorption). Results of measurements on granitic rock (granodiorite) from the Baltic shield are discussed and integrated with results by complementary methods. T2 - 20th Materials Research Society Symposium on the Scientific Basis for Nuclear Waste Management CY - Boston, MA, USA DA - 1996-12-02 PY - 1997 SN - 1-558-99369-X SN - 0272-9172 N1 - Serientitel: Materials Research Society symposium proceedings – Series title: Materials Research Society symposium proceedings IS - 465 SP - 863 EP - 870 PB - Materials Research Society CY - Pittsburgh, Pa. AN - OPUS4-11971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zabler, S. A1 - Riesemeier, Heinrich A1 - Fratzl, P. A1 - Zaslansky, P. T1 - Fresnel-propagated imaging for the study of human tooth dentin by partially coherent x-ray tomography N2 - Recent methods of phase imaging in x-ray tomography allow the visualization of features that are not resolved in conventional absorption microtomography. Of these, the relatively simple setup needed to produce Fresnel-propagated tomograms appears to be well suited to probe tooth-dentin where composition as well as microstructure vary in a graded manner. By adapting analytical propagation approximations we provide predictions of the form of the interference patterns in the 3D images, which we compare to numerical simulations as well as data obtained from measurements of water immersed samples. Our observations reveal details of the tubular structure of dentin, and may be evaluated similarly to conventional absorption tomograms. We believe this exemplifies the power of Fresnel-propagated imaging as a form of 3D microscopy, well suited to quantify gradual microstructural-variations in teeth and similar tissues. KW - Fourier optics KW - Partial coherence in imaging KW - Tomography KW - X-ray imaging KW - Phase modulation KW - Dentistry KW - High resolution Sy-CT KW - Microstructure in human Teeth PY - 2006 DO - https://doi.org/10.1364/OE.14.008584 SN - 1094-4087 VL - 14 IS - 19 SP - 8584 EP - 8597 PB - Optical Society of America CY - Washington, DC AN - OPUS4-13869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paris, O. A1 - Li, C. A1 - Siegel, S. A1 - Weseloh, G. A1 - Emmerling, Franziska A1 - Riesemeier, Heinrich A1 - Erko, A. A1 - Fratzl, P. T1 - A new experimental station for simultaneous X-ray microbeam scanning for small- and wide-angle scattering and fluorescence at BESSY II N2 - A new instrument for simultaneous microbeam small- and wide-angle X-ray scattering and X-ray fluorescence (SAXS/WAXS/XRF) is presented. The instrument is installed at the microfocus beamline at BESSY II and provides a beam of 10 µm size with a flux of about 109 photons s-1. A SAXS resolution up to 500 Å d-spacing and a range of scattering vectors of almost three orders of magnitude are reached by using a large-area high-resolution CCD-based detector for simultaneous SAXS/WAXS. The instrument is particularly suited for scanning SAXS/WAXS/XRF experiments on hierarchically structured biological tissues. The necessary infrastructure, such as a cryo-stream facility and an on-site preparation laboratory for biological specimens, are available. KW - Scanning SAXS KW - Scanning WAXS KW - Microbeam KW - Synchrotron radiation PY - 2007 SN - 0021-8898 SN - 1600-5767 VL - 40 IS - Supplement SP - s466 EP - s470 PB - Blackwell CY - Oxford AN - OPUS4-15049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maier, W. A1 - Arlt, Tobias A1 - Wannek, C. A1 - Manke, I. A1 - Riesemeier, Heinrich A1 - Krüger, P. A1 - Scholta, J. A1 - Lehnert, W. A1 - Banhart, J. A1 - Stolten, D. T1 - In-situ synchrotron X-ray radiography on high temperature polymer electrolyte fuel cells N2 - In contrast to classical low temperature polymer electrolyte fuel cells (LT-PEFCs), the membrane conductivity in high temperature polymer electrolyte fuel cells (HT-PEFCs) (operating temperature ~ 160 °C) is based on proton transport within phosphorus-oxygen acids at different levels of hydration, orthophosphoric acid (H3PO4) being the simplest example. We present for the first time in-situ synchrotron X-ray radiography measurements applied to a HT-PEFC to gain insight into the local composition of the membrane electrode assembly (MEA) under dynamic operating conditions. Transmission changes during the radiographic measurements exhibit a clear influence of the formation of product water on the membrane composition. KW - HT-PEFC KW - Synchrotron x-ray radiography KW - Membrane electrode assembly (MEA) KW - Phosphoric acid PY - 2010 DO - https://doi.org/10.1016/j.elecom.2010.08.002 SN - 1388-2481 VL - 12 IS - 10 SP - 1436 EP - 1438 PB - Elsevier CY - Amsterdam AN - OPUS4-23962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reiche, I. A1 - Müller, K. A1 - Staude, Andreas A1 - Goebbels, Jürgen A1 - Riesemeier, Heinrich T1 - Synchrotron radiation and laboratory micro X-ray computed tomography - useful tools for the material identification of prehistoric objects made of ivory, bone or antler N2 - Archaeological bone, ivory and antler, as well as objects manufactured from them, are largely studied to extract as much information as possible from these materials. Among others, one key question in archaeology is the exact identification of the material. Even if the identification of different kinds of osseous material seems to be trivial in many cases, it can be a difficult issue when small, heavily carved and more or less altered ancient objects are concerned. This study was focused on the determination of parameters allowing the distinction of archaeological ivory, bone and antler in order to identify the raw material used for the manufacture of prehistoric objects. The high performance of synchrotron radiation (SR) and laboratory-based micro X-ray computed tomography (microCT), providing highly resolved three-dimensional information on the micromorphology, permitted the establishment of such distinctive features of modern references of ivory, antler, land mammal and whale bones: ivory shows characteristic tubular pores with a diameter of about 1 to 2 µm, bone and antler show typical osteon structures. In our measured references, antler shows on average larger and more elongated shaped pores of the osteons compared to terrestrial mammal bone. This feature however depends very much on the original localization of the studied sample within the antler. Whale bones can be distinguished from the other osseous materials by a cancellous, osteoporotic-like structure with irregularly distributed rounded porosities with diameters reaching up to 500 µm. These characteristics have also been tested on determined Palaeolithic fragments, as diagenetic changes during burial have to be considered and may lead to the modification of the parameters established on the basis of modern bone references. In general, the chemical composition of bone objects can change drastically over time while micromorphological features, as evidenced by microCT, seem to be less susceptible to such alterations. In addition, microCT enables the comparison of inner and possibly less altered parts of the objects, and can be considered as completely non-destructive for small mineralised prehistoric objects. In this study, specific morphological features allowing the distinction of ivory and of whale bone from other bone and antler material were determined, even for altered materials dating back to Palaeolithic periods. Thus, we provide, in addition to archaeozoological, chemical and isotopic markers, a new non-destructive tool to identify some raw materials used for the fabrication of osseous objects ranging from recent to prehistoric periods. PY - 2011 DO - https://doi.org/10.1039/c0ja00246a SN - 0267-9477 SN - 1364-5544 VL - 26 IS - 9 SP - 1802 EP - 1812 PB - Royal Society of Chemistry CY - London AN - OPUS4-24338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rack, A. A1 - Weitkamp, T. A1 - Zanette, I. A1 - Morawe, C. A1 - Vivo Rommeveaux, A. A1 - Tafforeau, P. A1 - Cloetens, P. A1 - Ziegler, E. A1 - Rack, T. A1 - Cecilia, A. A1 - Vagovic, P. A1 - Harmann, E. A1 - Dietsch, R. A1 - Riesemeier, Heinrich T1 - Coherence preservation and beam flatness of a single-bounce multilayer monochromator (beamline ID19-ESRF) N2 - Larger spectral bandwidth and higher photon flux density are the major advantages of multilayer monochromators over crystal-based devices. Especially for synchrotron-based hard X-ray microimaging applications the increased photon flux density is important in order to achieve high contrast and resolution in space and/or time. However, the modifications on the beam profile induced by reflection on a multilayer are a drawback which can seriously harm the performance of such a monochromator. A recent study [A. Rack, T. Weitkamp, M. Riotte, D. Grigoriev, T. Rack, L. Helfen, T. Baumbach, R. Dietsch, T. Holz, M. Krämer, F. Siewert, M. Meduna, P. Cloetens, E. Ziegler, J. Synchrotron Radiat. 17 (2010) 496–510] has shown that the modifications in terms of beam flatness and coherence preservation can be influenced via the material composition of the multilayer coating. The present article extends this knowledge by studying further material compositions used on a daily basis for hard X-ray monochromatization at the beamline ID19 of the European Synchrotron Radiation Facility. KW - Multilayer mirrors KW - X-rays KW - X-ray optics KW - Coherence KW - X-ray monochromators KW - X-ray imaging KW - X-ray phase contrast KW - Synchrotron radiation PY - 2011 DO - https://doi.org/10.1016/j.nima.2010.11.069 SN - 0168-9002 SN - 0167-5087 VL - 649 IS - 1 SP - 123 EP - 127 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-25240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rack, T. A1 - Zabler, S. A1 - Rack, C. A1 - Stiller, M. A1 - Riesemeier, Heinrich A1 - Cecilia, A. A1 - Nelson, K. T1 - Coherent synchrotron-based micro-imaging employed for studies of micro-gap formation in dental implants N2 - Biocompatible materials such as titanium are regularly applied in oral surgery. Titanium-based implants for the replacement of missing teeth demand a high mechanical precision in order to minimize micro-bacterial leakage, especially when two-piece concepts are used. Synchrotron-based hard x-ray radiography, unlike conventional laboratory radiography, allows high spatial resolution in combination with high contrast even when micro-sized features in such highly attenuating objects are visualized. Therefore, micro-gap formation at interfaces in two-piece dental implants with the sample under different mechanical loads can be studied. We show the existence of micro-gaps in implants with conical connections and study the mechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential source of implant failure, i.e., bacterial leakage, which can be a stimulus for an inflammatory process. T2 - 10th International conference on X-ray microscopy CY - Chicago, Illinois, USA DA - 15.08.2010 KW - X-ray imaging KW - Dental implants KW - Digital radiography KW - Implant-abutment interface KW - Synchrotron radiation KW - X-ray phase contrast PY - 2011 SN - 978-0-7354-0925-5 DO - https://doi.org/10.1063/1.3625398 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1365 SP - 445 EP - 448 AN - OPUS4-25347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -