TY - JOUR A1 - Arndt, Ralf A1 - Hillemeier, B. A1 - Maierhofer, Christiane A1 - Rieck, C. A1 - Röllig, Mathias A1 - Scheel, H. A1 - Walther, A. T1 - Zerstörungsfreie Ortung von Fehlstellen und Inhomogenitäten in Bauteilen mit der Impuls-Thermografie KW - Impuls-Thermografie KW - Puls-Phasen-Thermografie KW - Zerstörungsfreie Prüfung KW - Ortung von Fehlstellen KW - Ablösungen und Verpressfehler PY - 2004 SN - 0005-6820 SN - 1437-0999 SN - 0341-1052 SN - 0932-6359 SN - 0932-8351 VL - 81 IS - 10 SP - 786 EP - 793 PB - Ernst CY - Berlin AN - OPUS4-4572 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Arndt, Ralf A1 - Röllig, Mathias A1 - Rieck, C. A1 - Walther, A. A1 - Scheel, H. A1 - Hillemeier, B. T1 - Application of impulse-thermography for non-destructive assessment of concrete structures N2 - Impulse-thermography is an active method for quantitative investigations of the near surface region of various structures. It has recently been applied and optimised to applications in civil engineering. By using either an internal or external heat source, parts of the structure under investigation are heated up and the transient heat flux is observed by recording the temperature change at the surface as a function of time. This method is very well suited for the detection of voids and honeycombing in concrete, up to concrete covers of 10 cm as well as for the location of delaminations in multi-layered systems (e.g. plaster on concrete, CFRP-laminates on concrete, asphalt on concrete). Also safety relevant defects like voids in tendon ducts and cracks in concrete could be recognised. KW - Non-destructive testing KW - Impulse-thermography KW - Concrete KW - CFRP-laminates KW - Delamination KW - Tendon duct KW - Voids KW - Compaction faults PY - 2006 DO - https://doi.org/10.1016/j.cemconcomp.2006.02.011 SN - 0958-9465 SN - 1873-393X VL - 28 IS - 4 SP - 393 EP - 401 PB - Elsevier CY - Barking, Essex AN - OPUS4-12359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maierhofer, Christiane A1 - Hasenstab, A. A1 - Arndt, Ralf ED - Michaelsen, H. T1 - Mit Radar und Wärme - Zerstörungsfreie Untersuchung am Spindlerboden im Ovalen Kabinett KW - Parkett KW - Neues Palais KW - Radar KW - Aktive Thermografie PY - 2010 SN - 978-3-86568-462-2 SP - 245 EP - 250 PB - Michael Imhof AN - OPUS4-22356 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hasenstab, A. A1 - Neumann, H.-H. A1 - Maierhofer, Christiane A1 - Arndt, Ralf A1 - Bluhm, J. T1 - Praktische Untersuchungen an Kulturgütern und Verkehrsbauten in der Baudenkmalpflege T2 - Fachtagung Bauwerksdiagnose - Praktische Anwendungen zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Deutschland DA - 2010-02-18 KW - ZfPBau KW - Kulturgüter KW - Fallstudien KW - Radar KW - Aktive Thermografie KW - Endoskopie PY - 2010 SN - 978-3-940283-24-5 IS - DGZfP-BB 121 (Vortrag 11) SP - 1 EP - 14 CY - Berlin AN - OPUS4-21065 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - C. Pardo Pérez, L. A1 - Arndt, A. A1 - Stojkovikj, S. A1 - Y. Ahmet, I. A1 - T. Arens,, J. A1 - Dattila, F. A1 - Wendt, R. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Davies, V. A1 - Höflich, K. A1 - Köhnen, E. A1 - Tockhorn, P. A1 - Golnak, R. A1 - Xiao, J. A1 - Schuck, G. A1 - Wollgarten, M. A1 - López, N. A1 - T. Mayer, M. T1 - Determining Structure-Activity Relationships in Oxide Derived CuSn Catalysts During CO2 Electroreduction Using X-Ray Spectroscopy N2 - The development of earth-abundant catalysts for selective electrochemical CO2 conversion is a central challenge. Cu-Sn bimetallic catalysts can yield selective CO2 reduction toward either CO or formate. This study presents oxide-derived Cu-Sn catalysts tunable for either product and seeks to understand the synergetic effects between Cu and Sn causing these selectivity trends. The materials undergo significant transformations under CO2 reduction conditions, and their dynamic bulk and surface structures are revealed by correlating observations from multiple methods—X-ray absorption spectroscopy for in situ study, and quasi in situ X-ray photoelectron spectroscopy for surface sensitivity. For both types of catalysts, Cu transforms to metallic Cu0 under reaction conditions. However, the Sn speciation and content differ significantly between the catalyst types: the CO-selective catalysts exhibit a surface Sn content of 13 at. % predominantly present as oxidized Sn, while the formate-selective catalysts display an Sn content of ≈70 at. % consisting of both metallic Sn0 and Sn oxide species. Density functional theory simulations suggest that Snδ+ sites weaken CO adsorption, thereby enhancing CO selectivity, while Sn0 sites hinder H adsorption and promote formate production. This study reveals the complex dependence of catalyst structure, composition, and speciation with electrochemical bias in bimetallic Cu catalysts. KW - Electrochemical CO2 conversion KW - Cu catalysts KW - X-ray absorption spectroscopy PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547116 DO - https://doi.org/10.1002/aenm.202103328 SN - 1614-6832 VL - 12 IS - 5 SP - 2103328 PB - Wiley-VCH GmbH AN - OPUS4-54711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -