TY - JOUR A1 - Döhler, Michael A1 - Hille, Falk A1 - Mevel, L. A1 - Rücker, Werner T1 - Structural health monitoring with statistical methods during progressive damage test of S101 Bridge N2 - For the last decades vibration based damage detection of engineering structures has become an important issue for maintenance operations on transport infrastructure. Research in vibration based structural damage detection has been rapidly expanding from classic modal parameter estimation to modern operational monitoring. Since structures are subject to unknown ambient excitation in operation conditions, all estimates from the finite data measurements are of statistical nature. The intrinsic uncertainty due to finite data length, colored noise, non-stationary excitations, model order reduction or other operational influences needs to be considered for robust and automated structural health monitoring methods. In this paper, two subspace-based methods are considered that take these statistical uncertainties into account, first modal parameter and their confidence interval estimation for a direct comparison of the structural states, and second a statistical null space based damage detection test that completely avoids the identification step. The performance of both methods is evaluated on a large scale progressive damage test of a prestressed concrete road bridge, the S101 Bridge in Austria. In an on-site test, ambient vibration data of the S101 Bridge was recorded while different damage scenarios were introduced on the bridge as a benchmark for damage identification. It is shown that the proposed damage detection methodology is able to clearly indicate the presence of structural damage, if the damage leads to a change of the structural system. KW - Subspace methods KW - Operational modal analysis KW - Uncertainty bounds KW - Damage detection KW - Prestressed concrete bridge PY - 2014 DO - https://doi.org/10.1016/j.engstruct.2014.03.010 SN - 0141-0296 VL - 69 SP - 183 EP - 193 PB - Elsevier CY - Oxford AN - OPUS4-30665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döhler, M. A1 - Hille, Falk A1 - Lam, X.-B. A1 - Mevel, L. A1 - Rücker, Werner ED - Proulx, T. T1 - Confidence intervals of modal parameters during progressive damage test N2 - In Operational Modal Analysis, the modal parameters (natural frequencies, damping ratios and mode shapes) obtained from Stochastic Subspace Identification (SSI) of a structure, are afflicted with statistical uncertainty. For evaluating the quality of the obtained results it is essential to know the respective confidence intervals of these figures. In this paper we present algorithms that automatically compute the confidence intervals of modal parameters obtained from covarianceand data-driven SSI of a structure based on vibration measurements. They are applied to the monitoring of the modal parameters of a prestressed concrete highway bridge during a progressive damage test that was accomplished within the European research project IRIS. Results of the covariance- and data-driven SSI are compared. T2 - 29th IMAC - Conference on structural dynamics CY - Jacksonville, FL, USA DA - 31.01.2011 KW - Stochastische subspace basierte Identifikation KW - Schadensdetektion KW - Spannbetonbrücke PY - 2011 SN - 978-1-4419-9304-5 DO - https://doi.org/10.1007/978-1-4419-9305-2_17 SN - 2191-5644 N1 - Serientitel: Conference Proceedings of the Society for Experimental Mechanics Series – Series title: Conference Proceedings of the Society for Experimental Mechanics Series VL - 4 SP - 237 EP - 250 PB - Springer AN - OPUS4-24335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lempke, L. A1 - Fischer, Tobias A1 - Bell, Jérémy A1 - Kraus, Werner A1 - Rurack, Knut A1 - Krause, N. T1 - Gold-catalyzed allene cycloisomerization for pyrrole synthesis: towards highly fluorinated BODIPY dyes N2 - A novel synthetic strategy toward highly fluorinated BODIPY dyes with exceptional photostabilities relying on sustainable gold catalysis has been developed. A key to the tailored pyrrole precursors is the gold catalysis performed in ionic liquids as the reaction medium, allowing a facile recycling of the catalysts. The dyes prepared are well-matching with the spectral windows of popular rhodamine dyes and possess high brightness while showing a distinctly higher photostability than the rhodamines especially in aprotic solvents. KW - Gold-Katalyse KW - BODIPY-Farbstoffe KW - Photostabilität KW - Fluor-Substitution KW - Fluoreszenz PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-344692 DO - https://doi.org/10.1039/c4ob02671c SN - 1477-0520 SN - 1477-0539 VL - 13 IS - 12 SP - 3787 EP - 3791 PB - RSC CY - Cambridge AN - OPUS4-34469 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sanayei, Mohammad Hassan A1 - Farhat, A. A1 - Luu, Li-Hua A1 - Werner, L. A1 - Rettinger, C. A1 - Philippe, P. A1 - Cuéllar, Pablo T1 - Micromechanical framework for a 3D solid cohesion model - Implemantation, validation and perspectives N2 - This article presents a solid cohesion model for the simulation of bonded granular assemblies in the frame of 3D discrete element approaches (DEM). A simple viscoplastic cohesion model for 2D geometries is extended to 3D conditions, while its yield criterion is generalized as a hyper-surface in the space of bond solicitations to include torsional moments. The model is then calibrated using experimental results of uniaxial traction at both the microscopic and macroscopic scales with an artificial granular cohesive soil. The paper finally presents some simulated results on the macromechanical sample traction application and briefly discusses the model's current limitations and promising prospects for subsequent works. T2 - VII International Conference on Particle-Based Methods PARTICLES 2021 CY - Hamburg, Germany DA - 04.10.2021 KW - Granular Cohesive Materials, KW - DEM KW - Micromechanical Tensile Failure KW - Macromechanical Sample Strength PY - 2021 AN - OPUS4-53726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kratz, S. A1 - Beerbaum, B. A1 - Elsner, H. A1 - Reuvers, J. A1 - Dockhorn, T. A1 - Rechberger, H. A1 - Werner, W. A1 - Knudsen, L. A1 - Flachowsky, G. A1 - Rodehutscord, M. A1 - Adam, Christian A1 - Steingrobe, B. A1 - Schick, J. A1 - Albert, E. A1 - Leinweber, P. A1 - Ekardt, F. A1 - Embert, G. T1 - Ressourcen schonender Einsatz von Phosphor in der Landwirtschaft - Symposium des Institutes für Pflanzenbau und Bodenkunde des JKI in Braunschweig - eine Synopse KW - Klärschlamm KW - Phosphor KW - Ressource KW - Klärschlammasche KW - P-Düngemittel KW - Demonstrationsanlage PY - 2009 SN - 1867-0911 SN - 1867-0938 SN - 1865-4371 VL - 61 IS - 2 SP - 69 EP - 71 PB - Ulmer CY - Stuttgart AN - OPUS4-18928 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Werner, L. A1 - Tetz, M. A1 - Feldmann, Ines A1 - Bücker, Michael T1 - Evaluating and defining the sharpness of intraocular lenses: Microedge structure of commercially available square-edged hydrophilic intraocular lenses KW - ESEM KW - Intraocularlinse KW - IOL PY - 2009 DO - https://doi.org/10.1016/j.jcrs.2008.11.042 SN - 0886-3350 VL - 35 IS - 3 SP - 556 EP - 566 PB - Elsevier CY - New York, NY, USA AN - OPUS4-19228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bykov, M. A1 - Yusenko, Kirill A1 - Bykova, E. A1 - Pakhomova, A. A1 - Kraus, Werner A1 - Dubrovinskaia, N. A1 - Dubrovinsky, L. T1 - Synthesis of arsenopyrite-type rhodium pernitride RhN2 from a single-source azide precursor N2 - Nitrogen-rich noble metal nitrides possess unique mechanical and catalytic properties, therefore their synthesis and characterization is of interest for fundamental solid state chemistry and materials science. In this study we have synthesized a singlesource precursor [Rh(NH3)6]3(N3)5Cl4 (Rh:N ratio 1:11). Its controlled decomposition in a laser-heated diamond anvil cell at 39 GPa resulted in a formation of rhodium pernitride, RhN2. According to the results of single-crystal X-ray diffraction RhN2 has arsenopyrite structure type crystal structure previously unknown for this compound (P21/c (no. 14). KW - EOS KW - High-pressure KW - Nitrides PY - 2019 DO - https://doi.org/10.1002/ejic.201900488 IS - 32 SP - 3667 EP - 3671 PB - Wiley AN - OPUS4-48924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hachmöller, O. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Aichler, M. A1 - Radtke, Martin A1 - Dietrich, D. A1 - Schwamborn, K. A1 - Lutz, L. A1 - Werner, M. A1 - Sperling, M. A1 - Walch, A. A1 - Karst, U. T1 - Elemental bioimaging and speciation analysis for the investigation of Wilsons disease using μXRF and XANES N2 - A liver biopsy specimen from a Wilson’s disease (WD) patient was analyzed by means of micro-X-ray fluorescence (mXRF) spectroscopy to determine the elemental distribution. First, bench-top mXRF was utilized for a coarse scan of the sample under laboratory conditions. The resulting distribution maps of copper and iron enabled the determination of a region of interest (ROI) for further analysis. In order to obtain more detailed elemental information, this ROI was analyzed by synchrotron radiation (SR)-based mXRF with a beam size of 4 mm offering a resolution at the cellular level. Distribution maps of additional elements to copper and iron like zinc and manganese were obtained due to a higher sensitivity of SR-mXRF. In addition to this, X-ray absorption near edge structure spectroscopy (XANES) was performed to identify the oxidation states of copper in WD. This speciation analysis indicated a mixture of copper(I) and copper(II) within the WD liver tissue. KW - progressive hepatolenticular degeneration KW - mXRF Micro-X-ray fluorescence spectroscopy KW - XANES X-ray absorption near edge structure spectroscopy PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-360811 DO - https://doi.org/10.1039/C6MT00001K SN - 1756-5901 SN - 1756-591X PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-36081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Bricks, J. L. A1 - Resch-Genger, Ute A1 - Kraus, Werner A1 - Schulz, Burkhard A1 - Li, Yanqin A1 - Reck, Günter T1 - Influence of the donor substituent and acceptor alkylation on the structure-analytical properties of mono- and bifunctional biphenyl-type fluorescent reporters N2 - A systematic structural investigation of R-phenyl-substituted 2,2':6',2"-terpyridines, a family of mono- and bifunctional charge transfer (CT)-operated fluorescent reporters for protons and metal ions, is presented. These molecules are equipped with non-binding and analyte coordinating donor substituents R (R = CF3, H, OMe, OH, DMA, A15C5 equaling monoaza-15-crown-5) of various donor strength and display CT-controlled spectroscopic properties and communication of analyte–receptor interactions. The crystal structures of the neutral fluorescent probes are compared to the structures of their terpyridine-alkylated or -protonated counterparts that represent model systems for acceptor protonation or cation coordination. The aim is here a better understanding of the complexation-induced structural and spectroscopic changes and the identification of common packing motifs of bpb-R thereby taking into account the importance of terpyridine building blocks for the construction of supramolecular systems and coordination arrays revealing π–π interactions. KW - Biphenyl KW - Terpyridine KW - Crystal structure KW - Fluorescent probe KW - Charge transfer KW - Bifunctional PY - 2008 DO - https://doi.org/10.1016/j.molstruc.2007.03.025 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 874 IS - 1-3 SP - 14 EP - 27 PB - Elsevier CY - Amsterdam AN - OPUS4-17087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A.I. A1 - Smolin, A.Y. A1 - Psakhie, S.G. A1 - Österle, Werner A1 - Kloß, Heinz A1 - Popov, V.L. T1 - Computer modeling of local tribological contacts by the example of the automotive brake friction pair N2 - In the paper the method of discrete modeling (movable cellular automata method) and combined discrete-continuous description of the simulated medium are used to analyze processes occurring in the local contact of the automotive brake system. The characteristic size of the considered region is 1.5 ?m. The following contact situation is simulated: steel fiber coated by an iron oxide film as the brake pad and pearlitic steel also coated by an iron oxide layer as the disc. On the assumption of oxide layer wearing we simulate the iron oxide - iron oxide, iron oxide - metal and metal - metal contacts. The calculation results for the friction coefficient for various contact situations give quite adequate values. For example, for the oxide - oxide system the calculated coefficient is approximately equal to 0.4, while for the metal - metal contact the obtained value varies from 0.7 to 0.9. Analysis of a set of the obtained results allows concluding that oxide is formed more rapidly than the sliding layer, which in turn makes the friction coefficient value stabilized. PY - 2008 DO - https://doi.org/10.1016/j.physme.2008.03.008 SN - 1029-9599 VL - 11 IS - 1-2 SP - 73 EP - 84 PB - Inst. of Strength Physics and Materials Science SB RAS CY - Tomsk AN - OPUS4-18698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - CONF A1 - Cristol, A.L. A1 - Desplanques, Y. A1 - Österle, Werner A1 - Degallaix, G. T1 - Coupling between thermal localisation and friction mechanisms: heat accumulation effect N2 - Heat accumulation induced by a succession of railway brakings leads to changes of the friction conditions occurring in pad-disc contact. Infrared thermography observations show a progressive increase of surface temperature over the succession, as well as a modification of the hot band migration phenomenon. From a tribological point of view, the heat accumulation, accompanied by a wear increase, progressively modifies the friction behaviour from one braking to the next. Post-mortem observations of pads are performed on surface by scanning electron microscopy and in depth after Focus Ion Beam cut by scanning ion microscopy. Observations show that, with heat accumulation, the third body quantity rises inside the contact, in accordance with wear increase. It is concluded that source flows of third body, which increase with temperature, feed aplenty the contact and modify its load-bearing capacity. T2 - JEF 2010 - 6th European conference on braking CY - Lille, France DA - 2010-11-24 KW - Successive braking KW - Heat accumulation KW - Thermal localisation KW - Wear KW - SEM KW - FIB PY - 2010 SP - 61 EP - 69 AN - OPUS4-22729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Dörfel, Ilona A1 - Prietzel, Claudia A1 - Rooch, Heidemarie A1 - Cristol-Bulthé, A.-L. A1 - Defallaix, G. A1 - Desplanques, Y. T1 - A comprehensive microscopic study of third body formation at the interface between a brake pad and brake disc during the final stage of a pin-on-disc test KW - Brake KW - Third body KW - Wear KW - Friction KW - Nano-scale KW - TEM PY - 2009 DO - https://doi.org/10.1016/j.wear.2008.11.023 SN - 0043-1648 VL - 267 IS - 5-8 SP - 781 EP - 788 PB - Elsevier CY - Amsterdam AN - OPUS4-19450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Österle, Werner A1 - Kaiander, I. A1 - Sellin, R.L. A1 - Bimberg, D. T1 - BAM-L002 - A new type of certified reference material for length calibration and testing of lateral resolution in the nanometre range N2 - A new type of test sample for the determination of lateral resolution in surface analysis is presented. The certified reference material BAM-L002 Nanoscale strip pattern for length calibration and testing of lateral resolution is an embedded cross-section of epitaxially grown layers of AlxGa1-xAs and InxGa1-xAs on GaAs substrate. The surface of the sample provides a flat pattern with strip widths of 0.4-500 nm. The combination of gratings, isolated narrow strips and sharp edges of wide strips offers improved possibilities for the calibration of a length scale, the determination of lateral resolution and the optimization of instrument settings. The feasibility of the reference material for an analysis of lateral resolution is demonstrated for SIMS. PY - 2004 DO - https://doi.org/10.1002/sia.1936 SN - 0142-2421 SN - 1096-9918 VL - 36 SP - 1423 EP - 1426 PB - Wiley CY - Chichester AN - OPUS4-4696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mantouvalou, I. A1 - Bauer, L.J. A1 - Truong, V.-B. A1 - Wagener, Y. A1 - Förste, F. A1 - Maruchenko, O. A1 - Werner, S. A1 - Lizzi, F. A1 - Wieder, Frank A1 - Wolff, T. A1 - Kanngießer, B. A1 - Zaslansky, P. T1 - Quantitative micro-XRF combined with X-ray imaging reveals correlations between Zn concentration and dentin tubule porosity across entire teeth N2 - Bony materials are biogenic composites of protein fibers and mineral that create hierarchical structures. In the case of teeth, dentin is the main component and similar to other bones, it contains porosity at multiple length scales. It is traversed by micron-sized hollow channels known as dentinal tubules, essential for temperature and pain sensation. Tubule density and thus porosity vary throughout the macroscopic three-dimensional (3D) structure, with porosity increasing toward the pulp. The different densities in teeth are easily revealed non-destructively in 3D by X-ray imaging using computer tomography (CT). Yet elemental composition analysis is more difficult to obtain from within the centimeter-sized heterogeneous bulk material. We describe an approach of merging CT measurements of healthy, intact bovine teeth with micro-X-ray fluorescence (micro-XRF) images of matching serially sectioned slices. Through the combination of multi-resolution quantitative CT measurements with elemental mass fraction derivation, gradients in density and element distributions such as calcium (Ca), phosphorus (P), and zinc (Zn) are revealed across entire teeth in 3D. While the main constituents (Ca and P) are homogeneously distributed in the matrix, Zn concentration increases significantly and exponentially toward the pulp. We find an inverse association between dentin tissue density and Zn concentration localizing this element in or around tubules. Our data serve as a quantitative reference for density and Zn mass fractions in healthy, neither carious nor hypermineralized dentin, as a basis for comparisons across species in health and disease states. KW - Dentin density KW - Micro-computer tomography KW - Quantitative micro-X-ray fluorescence KW - Tubule porosity KW - Zn distribution PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654215 DO - https://doi.org/10.1002/VIW.20250173 SN - 2688-3988 SN - 2688-268X SP - 1 EP - 14 PB - Wiley Online Library AN - OPUS4-65421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -