TY - CONF A1 - Reiche, I. A1 - Berger, Achim A1 - Duval, A. A1 - Görner, Wolf A1 - Guicharnaud, H. A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riederer, J. A1 - Riesemeier, Heinrich A1 - Roth, M. ED - Marabelli, M. ED - Tabaso, M. T1 - Spatially resolved SR-XRF analyses of complex drawings of the Holbein family T2 - 8th International Conference on "Non-Destructive Investigations and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage" CY - Lecce, Italy DA - 2005-05-15 KW - X-ray spectrometry KW - XRF KW - Röntgenfluoreszenzanalyse KW - RFA KW - Silverpoint drawing KW - Silberstiftzeichnung PY - 2005 SP - 7 pages PB - Italian Society of Non Destructive Testing CY - Lecce AN - OPUS4-7677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reiche, I. A1 - Berger, Achim A1 - Görner, Wolf A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riederer, J. A1 - Riesemeier, Heinrich A1 - Roth, M. T1 - Following the traces of Albrecht Dürer: analysis of silverpoint drawings by spatially resolved synchrotron-induced X-ray fluorescence analysis N2 - Spatially resolved X-ray fluorescence analysis using synchrotron radiation (SR-XRF) at the wavelength shifter beamline, BAMline, at BESSY was used to investigate Renaissance silverpoint drawings as it is extremely sensitive, non-destructive and can be carried out in air using an excitation spot in the hundred micrometer range. This paper deals with first results of the study of silverpoint drawings of Albrecht Dürer (1471–1528) belonging to the sketchbook that Albrecht Dürer used during a travel to the Netherlands in 1520/21. These results are compared to a PIXE study performed on drawings from the same sketchbook. The minor element composition of the silverpoint used for the drawings in the sketchbook was (10.6 ± 3.5) wt.% of Cu and traces of Zn. Mercury was found in the marks but does not belong to the initial composition of the silverpoint as it is attributed to an alteration phenomenon. One drawing of the sketchbook represents an exception. It consists of silver marks containing an additional minor element, Zn, in the marks and was, therefore, created with another silverpoint, probably at a different time than the other drawings. KW - Synchrotron KW - SR-XRF analysis KW - Drawing KW - Silverpoint KW - Albrecht Dürer PY - 2004 DO - https://doi.org/10.1016/j.nimb.2004.03.081 SN - 0168-583X SN - 1872-9584 VL - 226 IS - 1-2 SP - 83 EP - 91 PB - Elsevier CY - Amsterdam AN - OPUS4-4574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reiche, I. A1 - Berger, Achim A1 - Bevers, H. A1 - Dupuis, G. A1 - Duval, A. A1 - Görner, Wolf A1 - Guicharnaud, H. A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riederer, J. A1 - Riesemeier, Heinrich A1 - Roth, M. T1 - Spatially resolved SR-XRF analyses of complex drawings by the Holbein family and silverpoint drawings by Rembrandt KW - X-ray spectrometry KW - XRF KW - Röntgenfluoreszenzanalyse KW - RFA KW - Silverpoint drawing KW - Silberstiftzeichnung PY - 2005 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2004.pdf#page=491 SN - 0179-4159 SP - 491 EP - 493 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-7380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wilde, L. A1 - Radnik, J. A1 - Schneider, M. A1 - Herein, D. A1 - Riesemeier, Heinrich A1 - Radtke, Martin T1 - In situ TEY cell for XAS measurements at the BAMline PY - 2004 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2003.pdf#page=283 SN - 0179-4159 SP - 283 EP - 285 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-3508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reiche, I. A1 - Berger, Achim A1 - Duval, A. A1 - Görner, Wolf A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riederer, J. A1 - Riesemeier, Heinrich T1 - Metallstiftzeichnungen Albrecht Dürers KW - Synchrotron KW - XRF analysis KW - Drawings KW - Archaeometry KW - Röntgenfluoreszenzanalyse (RFA) KW - Zeichnungen KW - Archäometrie KW - Albrecht Dürer PY - 2004 SN - 1563-2628 VL - 5 IS - 2 SP - 30 EP - 38 PB - Foto Text Verl. CY - Stuttgart AN - OPUS4-3570 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Görner, Wolf A1 - Berger, Achim A1 - Merchel, Silke A1 - Pernicka, E. A1 - Radtke, Martin A1 - Reiche, I. A1 - Reinholz, Uwe A1 - Riederer, J. A1 - Riesemeier, Heinrich A1 - Wunderlich, C. H. T1 - Kunst- und Kulturgüter unter "Beschuss" T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2004 CY - Salzburg, Österreich DA - 2004-05-17 KW - SY-RFA KW - PIXE KW - PIGE KW - PAA KW - Zerstörungsfreie Analyse KW - Silberstiftzeichnungen KW - Himmelsscheibe von Nebra KW - Indische Moghulmalereien PY - 2004 UR - http://www.ndt.net/article/dgzfp04/papers/p46/p46.htm SN - 3-931381-55-2 SP - 1(?) EP - 11(?) PB - DGZfP CY - Berlin AN - OPUS4-6897 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reiche, I. A1 - Berger, Achim A1 - Duval, A. A1 - Görner, Wolf A1 - Guicharnaud, H. A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riederer, J. A1 - Riesemeier, Heinrich A1 - Roth, M. ED - Denker, A. ED - Adriaens, A. ED - Dowsett, M. ED - Giumlia-Mair, A. T1 - Synchrotron radiation and protons on the traces of famous artists - Non-destructive analyses of silverpoint drawings by Albrecht Dürer KW - X-ray spectrometry KW - XRF KW - Röntgenfluoreszenzanalyse KW - RFA KW - Silverpoint drawing KW - Silberstiftzeichnung PY - 2006 SN - 3-8167-7178-5 SP - 91 EP - 101 PB - Fraunhofer-IRB-Verl. CY - Stuttgart AN - OPUS4-14190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brücher, M. A1 - von Bohlen, A. A1 - Jacob, P. A1 - Franzke, J. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Müller, Bernd R. A1 - Scharf, Oliver A1 - Hergenröder, R. T1 - The charge of solid-liquid interfaces measured by X-ray standing waves and streaming current N2 - Measurements of ion distributions at a charged solid–liquid interface using X-ray standing waves (XSW) are presented. High energy synchrotron radiation (17.48 keV) is used to produce an XSW pattern inside a thin water film on a silicon wafer. The liquid phase is an aqueous solution containing Br and Rb ions. The surface charge is adjusted by titration. Measurements are performed over a pH range from 2.2–9, using the native Si oxide layer and functional (amine) groups as surface charge. The Debye length, indicating the extension of the diffuse layer, could be measured with values varying between 1–4 nm. For functionalized wafers, the pH dependent change from attraction to repulsion of an ion species could be detected, indicating the isoelectric point. In combination with the measurement of the streaming current, the surface charge of the sample could be quantified. KW - Interfacial charge KW - Solid/liquid interfaces KW - Surface analysis KW - Surface functionalization KW - X-ray spectrometry KW - X-ray KW - Standing waves KW - XSW KW - Streaming current KW - Synchrotron radiation PY - 2010 DO - https://doi.org/10.1002/cphc.201000166 SN - 1439-4235 SN - 1439-7641 VL - 11 IS - 10 SP - 2118 EP - 2123 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-22057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nikolic, Nela A1 - Dal Co, Alma A1 - Kiviet, Daniel J. A1 - Bergmiller, Tobias A1 - Littmann, Sten A1 - Kuypers, Marcel M. M. A1 - Ackermann, Martin A1 - Schreiber, Frank T1 - Cell-to-cell variation and specialization in sugar metabolism in clonal bacterial populations N2 - While we have good understanding of bacterial metabolism at the population level, we know little about the metabolic behavior of individual cells: do single cells in clonal populations sometimes specialize on different metabolic pathways? Such metabolic specialization could be driven by stochastic gene expression and could provide individual cells with growth benefits of specialization. We measured the degree of phenotypic specialization in two parallel metabolic pathways, the assimilation of glucose and arabinose. We grew Escherichia coli in chemostats, and used isotope-labeled sugars in combination with nanometer-scale secondary ion mass spectrometry and mathematical modeling to quantify sugar assimilation at the single-cell level. We found large variation in metabolic activities between single cells, both in absolute assimilation and in the degree to which individual cells specialize in the assimilation of different sugars. Analysis of transcriptional reporters indicated that this variation was at least partially based on cell-to-cell variation in gene expression. Metabolic differences between cells in clonal populations could potentially reduce metabolic incompatibilities between different pathways, and increase the rate at which parallel reactions can be performed. KW - Metabolism KW - Escherichia coli KW - Phenotypic diversity KW - Phenotypic heterogeneity PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-438873 UR - http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007122 DO - https://doi.org/10.1371/journal.pgen.1007122 SN - 1553-7404 VL - 13 IS - 12 SP - e1007122, 1 EP - e1007122, 24 PB - Public Library of Science CY - Cambridge, United Kingdom AN - OPUS4-43887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, M. A1 - Schreiner, M. A1 - Mäder, M. A1 - Melcher, M. A1 - Guerra, M. A1 - Salomon, J. A1 - Radtke, Martin A1 - Alram, M. A1 - Schindel, N. T1 - The hoard of Becin - non-destructive analysis of the silver coins N2 - We report the results of an analytical investigation on 416 silver-copper coins stemming from the Ottoman Empire (end of 16th and beginning of 17th centuries), using synchrotron micro X-ray fluorescence analysis (SRXRF). In the past, analyses had already been conducted with energy dispersive X-ray fluorescence analysis (EDXRF), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM/EDX) and proton induced X-ray emission spectroscopy (PIXE).With this combination of techniques it was possible to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. For the interpretation of the data statistical analysis (principal component analysis—PCA) has been performed. A definite local assignment was explored and significant clustering was obtained regarding the minor and trace elements composing the coin alloys. KW - SRXRF KW - Silber KW - Archaeometrie PY - 2010 DO - https://doi.org/10.1007/s00339-010-5627-y SN - 0947-8396 VL - 99 IS - 2 SP - 351 EP - 356 PB - Springer CY - Berlin AN - OPUS4-23170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, M. A1 - Schreiner, M. A1 - Melcher, M. A1 - Guerra, M. A1 - Salomon, J. A1 - Radtke, Martin A1 - Alram, M. A1 - Schindel, N. T1 - Analysis of the hoard of Becin using X-ray-based techniques N2 - Four hundred and sixteen silver coins stemming from the Ottoman Empire (16th and 17th centuries) were analyzed to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. As most of the coins showed the typical green patina on their surfaces due to corrosion processes that have led to the depletion of copper in the near surface domains of the silver coins in comparison to their core composition, small samples had to be taken, embedded in synthetic resin, and cross sectioned to investigate the true-heart metal composition. µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission were applied to determine the silver contents as well as the minor and trace elements. The type of the alloy was investigated as well as if coins minted in different locations demonstrated homogeneous traits concerning the predominant impurities (Au and Bi), which could suggest a common ore. Finally, energy-dispersive microanalysis in a scanning electron microscope was applied to study the homogeneity/heterogeneity of the coins and the presence of surface enrichments and to explain differences between the µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission measurements concerning the main component. In general, the silver content of the analyzed specimen varies between 90 and 95%. These outcomes have not supported the historical interpretations, which predict that during the period studied, a debasement of approximately 44% of the silver content of the coins should have occurred. KW - SRXRF KW - Silber KW - BAMline PY - 2012 DO - https://doi.org/10.1002/xrs.2415 SN - 0049-8246 VL - 41 IS - 6 SP - 416 EP - 424 PB - Wiley CY - Chichester AN - OPUS4-27723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Margreiter, R. A1 - Baumann, J. A1 - Mantouvalou, I. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Strub, E. T1 - Investigations on fire-gilding N2 - Fire-gilding is a historic technique for the application of golden layers on a number of different base materials utilizing a gold amalgam. This technique leaves a significant amount of Hg in the golden layer, giving archeometrists a reliable indicator to identify firegildings. Recent findings on presumably fire-gilded objects have shown in several cases significantly lower Hg content than previously studied objects. This prompted a synchrotron-based X-ray fluorescence investigation into the Hg distribution along the material–gilding interface, as well as a series of measurements regarding the Hg content development in fire-gilded samples during artificial aging. This work presents findings on laboratory-prepared fire-gildings, indicating an Hg enrichment at the interface of firegilded silver samples. Notably, such an enrichment is missing in fire-gilded copper samples. Further, it is confirmed that fire-gilded layers typically do not undercut an Hg bulk content of 5%. In this light, it seems improbable that ancient samples that contain <5% Hg are fire-gilded. The results presented in this study might lead to a non-destructive method to identify the Hg enrichment at the interface. This might be obtained by a combination of different non-destructive measurements and might also work unambiguously in samples in which the gold top layer is altered. KW - BAMline KW - X-Ray Fluorescence KW - Gilding KW - Depth profile KW - Archaeometry PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552885 DO - https://doi.org/10.1111/arcm.12797 SN - 0003-813X SP - 1 EP - 14 PB - Wiley online library AN - OPUS4-55288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, Junhao A1 - Klahn, Marcus A1 - Tian, Xinxin A1 - Bartling, Stephan A1 - Zimina, Anna A1 - Radtke, Martin A1 - Rockstroh, Nils A1 - Naliwajko, Pawel A1 - Steinfeldt, Norbert A1 - Peppel, Tim A1 - Grunwaldt, Jan‐Dierk A1 - Logsdail, Andrew J. A1 - Jiao, Haijun A1 - Strunk, Jennifer T1 - Fundamental Structural and Electronic Understanding of Palladium Catalysts on Nitride and Oxide Supports N2 - The nature of the support can fundamentally affect the function of a heterogeneous catalyst. For the novel type of isolated metal atom catalysts, sometimes referred to as single‐atom catalysts, systematic correlations are still rare. Here, we report a general finding that Pd on nitride supports (non‐metal and metal nitride) features a higher oxidation state compared to that on oxide supports (non‐metal and metal oxide). Through thorough oxidation state investigations by X‐ray absorption spectroscopy (XAS), X‐ray photoelectron spectroscopy (XPS), CO‐DRIFTS, and density functional theory (DFT) coupled with Bader charge analysis, it is found that Pd atoms prefer to interact with surface hydroxyl group to form a Pd(OH)x species on oxide supports, while on nitride supports, Pd atoms incorporate into the surface structure in the form of Pd−N bonds. Moreover, a correlation was built between the formal oxidation state and computational Bader charge, based on the periodic trend in electronegativity. KW - BAmline KW - XANES KW - Catalyst PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608341 DO - https://doi.org/10.1002/anie.202400174 SN - 1433-7851 VL - 63 IS - 20 SP - 1 EP - 9 PB - Wiley AN - OPUS4-60834 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fortes Martin, R. A1 - Thünemann, Andreas A1 - Stockmann, Jörg Manfred A1 - Radnik, Jörg A1 - Koetz, J. T1 - From Nanoparticle Heteroclusters to Filament Networks by Self-Assembly at the Water–Oil Interface of Reverse Microemulsions N2 - Surface self-assembly of spherical nanoparticles of sizes below 10 nm into hierarchical heterostructures is under arising development despite the inherent difficulties of obtaining complex ordering patterns on a larger scale. Due to template-mediated interactions between oil-dispersible superparamagnetic nanoparticles (MNPs) and polyethylenimine-stabilized gold nanoparticles (Au(PEI)NPs) at the water–oil interface of microemulsions, complex nanostructured films can be formed. Characterization of the reverse microemulsion phase by UV–vis absorption revealed the formation of heteroclusters from Winsor type II phases (WPII) using Aerosol-OT (AOT) as the surfactant. SAXS measurements verify the mechanism of initial nanoparticle clustering in defined dimensions. XPS suggested an influence of AOT at the MNP surface. Further, cryo-SEM and TEM visualization demonstrated the elongation of the reverse microemulsions into cylindrical, wormlike structures, which subsequently build up larger nanoparticle superstructure arrangements. Such WPII phases are thus proven to be a new form of soft template, mediating the self-assembly of different nanoparticles in hierarchical network-like filaments over a substrate during solvent evaporation. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Nano structure PY - 2021 DO - https://doi.org/10.1021/acs.langmuir.1c01348 VL - 37 IS - 29 SP - 8876 EP - 8885 PB - American Chemical Society AN - OPUS4-53034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krause, Martin A1 - Kurz, J.H. A1 - Lanata, F. A1 - Krstevska, L. A1 - Cavalli, A. T1 - Needs for further developing monitoring- and NDT-methods for timber structures N2 - For the assessmentand for monitoring of timber structures there are numerous promising methods that enable the quantitative description of the current condition of construction elements or parts of a structure. This concerns material properties like modulus of elasticity, moisture content and density as well as structural properties like dynamic characteristics, localization of inhomogeneities, cracks, and biological attack. During the work in COST Action FP 1101, since 2012 the capability of experimental methods are discussed and compared. This covers electrical and electromagnetic wave methods (resistivity, microwave, Radar, X-Ray), elastic waves (ultrasound, pile testing) and mechanical testing (static and dynamic). Describing and collecting the use of the experimental methods for monitoring purposes was the objective of working group 3 "Monitoring of Timber Structures" of the COST Action. Monitoring capabilities will extend the use of timber structures to further applications in civil engineering. So far, no standard exists but collections of application examples and review papers representing the state of the art. From there needs for further developments regarding monitoring and NDT methods for timber structures can be identified and these are described in this paper. T2 - SHATIS 2015 - 3rd International conference on structural health assessment of timber structures CY - Wroclaw, Poland DA - 09.09.2015 KW - Holz Konstruktionen KW - Monitoring KW - Langzeitverhalten KW - Erdbebensicherheit KW - Historische Bauwerke KW - Ultrasonic echo imaging KW - Historical timber structures KW - Seismic investigation KW - Dynamic tests KW - Anisotropic wave propagation KW - Extending service life PY - 2015 VL - 1 SP - 1 EP - 12 AN - OPUS4-35178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuhne, Maren A1 - Dippong, Martin A1 - Flemig, Sabine A1 - Hoffmann, Katrin A1 - Petsch, K. A1 - Schenk, J.A. A1 - Kunte, Hans-Jörg A1 - Schneider, Rudolf T1 - Comparative characterization of mAb producing hapten-specific hybridoma cells by flow cytometric analysis and ELISA N2 - A novel method that optimizes the screening for antibody-secreting hapten-specific hybridoma cells by using flow cytometry is described. Cell clones specific for five different haptens were analyzed. We selectively double stained and analyzed fixed hybridoma cells with fluorophore-labeled haptens to demonstrate the target-selectivity, and with a fluorophore-labeled anti-mouse IgG antibody to characterize the level of surface expression of membrane-bound IgGs. ELISA measurements with the supernatants of the individual hybridoma clones revealed that antibodies from those cells, which showed the highest fluorescence intensities in the flow cytometric analysis, also displayed the highest affinities for the target antigens. The fluorescence intensity of antibody-producing cells corresponded well with the produced antibodies' affinities toward their respective antigens. Immunohistochemical staining verified the successful double labeling of the cells. Our method makes it possible to perform a high-throughput screening for hybridoma cells, which have both an adequate IgG production rate and a high target affinity. KW - Immunization KW - Hapten KW - Monoclonal antibodies KW - Hybridoma KW - Flow cytometry KW - ELISA KW - Estradiol KW - Estrone KW - Digoxigenin KW - Zearalenone KW - Aflatoxin KW - CLSM PY - 2014 DO - https://doi.org/10.1016/j.jim.2014.07.004 SN - 0022-1759 SN - 1872-7905 VL - 413 SP - 45 EP - 56 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-32322 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 - JOUR A1 - Krause, Martin A1 - Milmann, Boris A1 - Mielentz, Frank A1 - Streicher, Doreen A1 - Redmer, Bernhard A1 - Mayer, K. A1 - Langenberg, K.-J. A1 - Schickert, M. T1 - Ultrasonic Imaging Methods for Investigation of Post-tensioned Concrete Structures: A Study of Interfaces at Artificial Grouting Faults and Its Verification N2 - This paper presents the progress of successful location of grouting faults in tendon ducts with ultrasonic imaging. The examples were obtained in the research group FOR 384 funded by DFG (German Research Foundation). The co-operation of experimental research and modeling allowed imaging and identification of grouted and ungrouted areas of tendon ducts (including strands) in a large test specimen (40 m²). In addition to the criteria for indicating grouting faults in post-tensioned ducts known until now the phase evaluation of reflected ultrasonic pulses is described. Experiments and modeling of wave propagation are presented for reflections at metal plates in concrete (thickness range 0.5 mm to 40 mm) and for tendon ducts including strands. The main part of the progress was achieved by automated measurements using dry contact transducers, 3D-SAFT reconstruction including phase evaluation and modeling considering wave propagation for typical elastic parameters and exact experimental site conditions. The results for shear waves as well as for pressure waves are compared in the frequency range from 50 kHz to 120 kHz. KW - Non-destructive testing KW - Tendons KW - Prestressed concrete bridges KW - Ultrasonic echo KW - Reconstruction calculation KW - 3D-SAFT KW - Modeling (EFIT) PY - 2008 DO - https://doi.org/10.1007/s10921-008-0033-5 SN - 0195-9298 SN - 1573-4862 VL - 27 IS - 1-3 SP - 67 EP - 82 PB - Plenum Press CY - New York, NY AN - OPUS4-17922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mayer, K. A1 - Langenberg, K.-J. A1 - Krause, Martin A1 - Milmann, Boris A1 - Mielentz, Frank T1 - Characterization of reflector types by phase-sensitive ultrasonic data processing and imaging N2 - Ultrasonic and radar imaging techniques are limited in resolution by the wavelength in the material, yet information beyond those limits is hidden in complex frequency dependent reflection coefficients. The analysis of the phase of complex reflection coefficients together with the properties of imaging algorithms can help to characterize and to classify indications of defects in concrete buildings. This paper describes a method to extract phase information from measurements and SAFT reconstructed images. The influencing factors like material properties, transducer characteristics, and imaging algorithms based on Born or Physical Optics approximations are elaborated. Simulated and experimental results are briefly discussed. KW - NDT KW - Imaging KW - Flaw characterization KW - Tendon ducts KW - Phase analysis KW - Ultrasonic echo KW - SAFT KW - FT-SAFT KW - EFIT-modeling KW - Modellierung KW - EFIT KW - Spannbeton KW - Ultraschallecho KW - Spannkanäle KW - Verpressfehler KW - Zerstörungsfreie Prüfung im Bauwesen KW - ZfP-Bau PY - 2008 DO - https://doi.org/10.1007/s10921-008-0035-3 SN - 0195-9298 SN - 1573-4862 VL - 27 IS - 1-3 SP - 35 EP - 45 PB - Plenum Press CY - New York, NY AN - OPUS4-17926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mero, M. A1 - Clapp, B. A1 - Jasapara, J.C. A1 - Rudolph, W. A1 - Ristau, D. A1 - Starke, K. A1 - Krüger, Jörg A1 - Martin, Sven A1 - Kautek, Wolfgang T1 - On the damage behavior of dielectric films when illuminated with multiple femtosecond laser pulses N2 - The physical effects reducing the damage threshold of dielectric films when exposed to multiple femtosecond pulses are investigated. The measured temperature increase of a Ta2O5 film scales exponentially with the pulse fluence. A polarized luminescence signal is observed that depends quadratically on the pulse fluence and is attributed to twophoton excitation of self-trapped excitons that form after band-to-band excitation. The damage fluence decreases with increasing pulse number, but is independent of the repetition rate from 1 Hz to 1 kHz at a constant pulse number. The repetition rate dependence of the breakdown threshold is also measured for TiO2 , HfO2, Al2O3, and SiO2 films. A theoretical model is presented that explains these findings. KW - Laser-induced damage KW - Laser materials KW - Ultrafast phenomena KW - Coatings PY - 2005 DO - https://doi.org/10.1117/1.1905343 SN - 0892-354X VL - 44 IS - 5 SP - 051107-1-051107-7 PB - Dekker CY - New York, NY AN - OPUS4-7406 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Haardt, P. A1 - Krause, Martin A1 - Streicher, Doreen A1 - Krause, H.-J. ED - Watanabe, E. ED - Frangopol, D. T1 - Scanning NDT-Methods for the Inspection of Highway Structures T2 - 2nd International Conference on Bridge Maintenance, Safety and Management CY - Kyoto, Japan DA - 2004-10-19 KW - ZfPBau KW - Ingenieurbauwerke KW - Automatisierung KW - Laserscanner KW - Ultraschallecho KW - Impuls Radar KW - Impact-Echo PY - 2004 SN - 90-5809-680-7 SP - 8 pages PB - Balkema CY - Leiden AN - OPUS4-5201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kroggel, O. A1 - Krause, Martin A1 - Schickert, M. A1 - Langenberg, K.-J. T1 - Moderne Verfahren der Bauwerksdiagnose, Entwicklung und Anwendung - Die DFG-Forschergruppe FOR384 stellt ihre Ergebnisse vor - Ultraschall T2 - Fachtagung 2005 des Deutschen Ausschusses für Stahlbeton in Zusammenarbeit mit der Bundesanstalt für Materialforschung und -prüfung "Zerstörungsfreie Prüfverfahren und Bauwerksdiagnose im Betonbau" CY - Berlin, Deutschland DA - 2005-03-10 KW - Ultraschallecho-Verfahren KW - Beton KW - Fundamente KW - Erhärtungsverhalten KW - Tomographie PY - 2005 SP - A5 EP - A10 PB - BAM CY - Berlin AN - OPUS4-11718 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mayer, K. A1 - Langenberg, K.-J. A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Milmann, Boris A1 - Kohl, Christoph T1 - Characterization of ultrasonic and radar reflector types in concrete by phase evaluation of the signal and the reconstructed image T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - NDT-CE KW - Ultrasonic echo KW - Radar KW - Phase evaluation KW - Modeling of wave propagation KW - Reconstruction calculation PY - 2006 SN - 3-931381-86-2 SP - 1 EP - 8(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bothe, Martin A1 - Mya, K.Y. A1 - Lin, E.M.J. A1 - Yeo, C. C. A1 - Lu, X. A1 - He, C. A1 - Pretsch, Thorsten T1 - Triple-shape properties of star-shaped POSS-polycaprolactone polyurethane networks N2 - Here, we present an investigation of the triple-shape properties of star-shaped polyhedral oligomeric silsesquioxane-poly(ε-caprolactone) polyurethanes (SPOSS-PUs), which have three-dimensional network structures. In a typical 'triple-shape functionalization process', mostly consisting of two tensile deformations at different temperatures, chain immobilization of the polymer network component poly(ε-caprolactone) (PCL) was successfully realized first through crystallization and then through vitrification. Subsequently, large parts of the respective strains were released under stress-free recovery conditions. The two-fold fixed ('programmed') specimens responded to heating with two independent length contractions (switching steps); the first shape change was associated with PCL devitrification and the second one with the melting of hitherto crystalline PCL. It was revealed that the triple-shape properties of SPOSS-PU networks considerably depend on PCL network chain length. When applying exactly the same 'triple-shape creation procedure', larger strain releases were detected in the first transition for polymers with a higher PCL network chain length, whereas the second transition was more accentuated for SPOSS-PU networks with a shorter PCL chain length. In the course of thermo-mechanical cycling, the formation of a neck during the second tensile deformation was repeatedly detected for SPOSS-PUs with higher PCL network chain length; in the subsequent recovery process the specimens even exhibited the highest total strain recoverability. Finally, gradual strain release could be achieved at temperatures below the PCL melting transition through the selection of up to four temperature holding steps, at which every time stable shapes were formed. KW - Shape memory polymer KW - Active polymer KW - Triple-shape polymer KW - Hybrid star-shaped polymer KW - POSS-polycaprolactone polyurethanes KW - Thermo-mechanical properties PY - 2012 DO - https://doi.org/10.1039/c1sm06474f SN - 1744-683X VL - 8 IS - 4 SP - 965 EP - 972 PB - RSC Publ. CY - Cambridge AN - OPUS4-25260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Colla, Camilla A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Höhberger, H.-J. A1 - Sommer, H. T1 - Combination of NDT techniques for site investigation of non-ballasted railway tracks N2 - Today's civil engineering NDT needs are for quantitative, fast to apply and easy to interpret methods. They are required on site both for evaluation of existing structures/infrastructure and for quality control in new construction. With this purpose, BAM has carried out in-situ feasibility studies, using radar, impact-echo and ultrasonic-echo methods. Two examples are given of their combined application on different railway slab–track constructions, using high frequency radar, scanning impact-echo and ultrasonic array methods. The aim was to evaluate limitations and advantages, comparability and complementarity of these methods. The on-site measurements demonstrated the possibility to investigate, with good accuracy via NDT, the bonding conditions between sleepers and slab, to locate voids and measure layer thickness. The acoustic and electromagnetic methods used, were found to be complementary. KW - Concrete KW - NDT KW - Impact echo KW - Ultrasonics KW - Radar KW - Railway PY - 2002 DO - https://doi.org/10.1016/S0963-8695(01)00033-0 SN - 0963-8695 VL - 35 SP - 95 EP - 105 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-1858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -