TY - CONF A1 - Österle, Werner A1 - Müller, Urs A1 - Desplanques, Y. A1 - Bulthé, A.-L. A1 - Degallaix, G. A1 - Dmitriev, A.I. T1 - 3rd Body formation of two different brake pad materials designed for railway application T2 - 5th European Conference on Braking (JEF 2006) CY - Lille, France DA - 2006-11-08 PY - 2006 SP - 107 EP - 115 AN - OPUS4-18699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Gardei, André A1 - Garcia, O. A1 - Riedl, Martin A1 - Vanhellemond, I. A1 - Suput, J.S. A1 - Santarelli, M.-L. A1 - Rodríguez-Maribona, I. A1 - Müller, Urs ED - Jadwiga W. Lukaszewicz, ED - Piotr Niemcewicz, T1 - Performance and durability of a new antigraffiti system for cultural heritage - the EC project GRAFFITAGE T2 - 11th International Congress on Deterioration and Conservation of Stone CY - Torun, Poland DA - 2008-09-15 KW - Cultural heritage KW - Antigraffiti system KW - Sandstone KW - Limestone KW - Brick KW - Monument KW - Cleaning KW - Historische Baustoffe PY - 2008 SN - 978-83-231-2237-1 VL - II SP - 889 EP - 897 PB - Nicolaus Copernicus University Press CY - Torun, Poland AN - OPUS4-18844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chabrelie, A. A1 - Müller, Urs A1 - Scrivener, K.L. ED - Palomo, Á. ED - Zaragoza, A. ED - Agüí, J. C. L. T1 - Mechanisms of degradation of concrete by external sufate ions under laboratory and field conditions N2 - The durability of concrete is a major challenge for the construction, which devotes one third to one half of its annual investment to building maintenance. The lack of fieid data regarding concrete durability, especially in the case of exposure to Sulfate ions (“sulfate attack”) makes it dijficult to determine the appropriate fest methods andperformance criteria. Additionally, the increased use of sustainable blends (cement with mineral admixtures, typically slag from the iron industiy) suffers from a lack of experience regarding their long-term performance. Most results for sulfate resistance are derived from accelerated laboratoiy tests xvhere performance criteria are based only on macroscopic properties, especially expansion. To fill this gap and better widerstand the mechanisms of sulfate attack under real conditions, a parallel study of laboratoiy micro-concrete and fieid concrete samples under sulfate exposure was undertaken, focussing on microstructural changes in addition to the conventional macroscopic characterisation. Four exposure regimes were designed in the laboratoiy: full immersion (ponding), pH-control, semi-immersion and wet/diy cycles. Pure Portland blends and slag blends witli high level of slag replacement (70 wt.-%) were investigated. The exposure regime has been found to play a major role in the damage process. In ponding conditions, the damage process takes place in three stages characterised by a first period of induction, followed by surface damage thatfinally extends to the bulle of the material. Paradoxically, the w/c-ratio does not seem to have much impact on the ionic transport phenomena but might be more decisive in the microstructure mechanical strength against local stresses. The slag blends, considered as sulfate resistant in ponding exposure, revealed badperformances under wet/diy cycles. This beliaviour was attributed to poor proper physical resistance of the slag hydrates against diying. The fieid concretes selected for the comparison with the laboratoiy cases were partially buried in a sulfate-enriched soil in Argentina. A pure Portland blend and a slag blends with high level of slag replacement (80 wt.-%) were investigated. The submerged part of the samples could be compared to the laboratoiy ponding exposure, wliile the upper layer of the samples subjected to weathering could be compared to the laboratoiy wet/diy cycles exposure. The fieid obsen’ations tend to confirm the laboratoiy results and validate the fest settings. It has been underlined that a direct relationship between damage (e.g.; cracking/expansion) andphase assemblage was not evident. However, the study highlights that sulfate combination with the hydrates of the cement (e.g.; C-S-H) and with those of the slag would play a rote in the initiation of the expansion, which would be attributed to a swelling of the hydrates or to the precipitation offine ettringite after the Saturation level in sulfate of the hydrates has been reached. T2 - 13th International congress on the chemistry of cement - XIII ICCC CY - Madrid, Spain DA - 03.07.2011 KW - Sulfate attack KW - Exposure conditions KW - Concrete KW - Laboratory test KW - Field KW - Phase assemblage KW - Microstructure KW - XRD KW - SEM KW - SCM KW - Slag PY - 2011 SN - 978-84-7292-400-0 SP - 1 EP - 14 CY - Madrid AN - OPUS4-24810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kirilina, E. A1 - Helbling, S. A1 - Morawski, M. A1 - Pine, K. A1 - Reimann, K. A1 - Jankuhn, S. A1 - Dinse, J. A1 - Deistung, A. A1 - Reichenbach, J. R. A1 - Trampel, R. A1 - Geyer, S. A1 - Müller, Larissa A1 - Jakubowski, Norbert A1 - Arendt, T. A1 - Bazin, P.-L. A1 - Weiskopf, N. T1 - Superficial white matter imaging: Contrast mechanisms and whole-brain in vivo mapping N2 - Superficial white matter (SWM) contains the most cortico-cortical white matter connections in the human brain encompassing the short U-shaped association fibers. Despite its importance for brain connectivity, very little is known about SWM in humans, mainly due to the lack of noninvasive imaging methods. Here, we lay the groundwork for systematic in vivo SWM mapping using ultrahigh resolution 7 T magnetic resonance imaging. Using biophysical modeling informed by quantitative ion beam microscopy on postmortem brain tissue, we demonstrate that MR contrast in SWM is driven by iron and can be linked to the microscopic iron distribution. Higher SWM iron concentrations were observed in U-fiber–rich frontal, temporal, and parietal areas, potentially reflecting high fiber density or late myelination in these areas. Our SWM mapping approach provides the foundation for systematic studies of interindividual differences, plasticity, and pathologies of this crucial structure for cortico-cortical connectivity in humans. KW - Magnetic resonance imaging KW - Laser ablation KW - ICP-MS KW - Brain KW - Imaging PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514430 DO - https://doi.org/10.1126/sciadv.aaz9281 SN - 2375-2548 VL - 6 IS - 41 SP - eaaz9281 PB - American Association for the Advancement of Science (Science/AAAS) CY - Washington, DC, USA AN - OPUS4-51443 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinsch, Stefan A1 - Nascimento, M.L.F. A1 - Müller, Ralf A1 - Zanotto, E. D. T1 - Crystal growth kinetics in cordierite and diopside glasses in wide temperature ranges N2 - We measured and collected literature data for the crystal growth rate, u(T), of µ-cordierite (2MgO · 2Al2O3 · 5SiO2) and diopside (CaO · MgO · 2SiO2) in their isochemical glass forming melts. The data cover exceptionally wide temperature ranges, i.e. 800–1350 °C for cordierite and 750–1378 °C for diopside. The maximum of u(T) occurs at about 1250 °C for both systems. A smooth shoulder is observed around 970 °C for µ-cordierite. Based on measured and collected viscosity data, we fitted u(T) using standard crystal growth models. For diopside, the experimental u(T) fits well to the 2D surface nucleation model and also to the screw dislocation growth mechanism. However, the screw dislocation model yields parameters of more significant physical meaning. For cordierite, these two models also describe the experimental growth rates. However, the best fittings of u(T) including the observed shoulder, were attained for a combined mechanism, assuming that the melt/crystal interface growing from screw dislocations is additionally roughened by superimposed 2D surface nucleation at large undercoolings, starting at a temperature around the shoulder. The good fittings indicate that viscosity can be used to assess the transport mechanism that determines crystal growth in these two systems, from the melting point Tm down to about Tg, with no sign of a breakdown of the Stokes–Einstein/Eyring equation. KW - Crystal growth KW - Oxide glasses KW - Silicates KW - Kristallwachstumsgeschwindigkeit KW - Kinetik KW - Silikatgläser PY - 2008 DO - https://doi.org/10.1016/j.jnoncrysol.2008.09.007 SN - 0022-3093 VL - 354 IS - 52-54 SP - 5386 EP - 5394 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-18383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Nascimento, M.L.F. A1 - Zanotto, E. D. T1 - Crystal Growth Mechanism in Cordierite and Diopside Glasses in Wide Temperature Ranges T2 - XX. International Congress on Glass CY - Kyoto, Japan DA - 2004-09-26 KW - Cordierite KW - Diopside KW - Glass KW - Crystal growth PY - 2004 SP - 6 pages PB - Ceramic Society of Japan CY - Tokio AN - OPUS4-4389 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bauer, L.J. A1 - Wieder, Frank A1 - Truong, V. A1 - Förste, F. A1 - Wagener, Y. A1 - Jonas, A. A1 - Praetz, S: A1 - Schlesiger, C. A1 - Kupsch, Andreas A1 - Müller, Bernd R. A1 - Kanngießer, B. A1 - Zaslansky, P. A1 - Mantouvalou, I. T1 - Absorption Correction for 3D Elemental Distributions of Dental Composite Materials Using Laboratory Confocal Micro-X-ray Fluorescence Spectroscopy N2 - Confocal micro-X-ray fluorescence (micro-XRF) spectroscopy facilitates three-dimensional (3D) elemental imaging of heterogeneous samples in the micrometer range. Laboratory setups using X-ray tube excitation render the method accessible for diverse research fields but interpretation of results and quantification remain challenging. The attenuation of X-rays in composites depends on the photon energy as well as on the composition and density of the material. For confocal micro-XRF, attenuation severely impacts elemental distribution information, as the signal from deeper layers is distorted by superficial layers. Absorption correction and quantification of fluorescence measurements in heterogeneous composite samples have so far not been reported. Here, an absorption correction approach for confocal micro-XRF combining density information from microcomputed tomography (micro-CT) data with laboratory X-ray absorption spectroscopy (XAS) and synchrotron transmission measurements is presented. The energy dependency of the probing volume is considered during the correction. The methodology is demonstrated on a model composite sample consisting of a bovine tooth with a clinically used restoration material. KW - Micro X-ray fluorescence spectroscopy KW - Dental composite materials KW - Computed tomography KW - Absorption correction PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601630 DO - https://doi.org/10.1021/acs.analchem.4c00116 SN - 0003-2700 SN - 1520-6882 VL - 96 IS - 21 SP - 8441 EP - 8449 PB - American Chemical Society Publications CY - Washington, DC AN - OPUS4-60163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -