TY - CONF A1 - Radtke, Martin T1 - Between the Eurasien steppes and China: provenancing the Xiongnu gold by IBA and SRXRF T2 - Fifth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 2013-12-04 PY - 2013 AN - OPUS4-29905 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - News from the BAMline N2 - A presentation of recent measurements at the BAMline with focus on AI and ML applications T2 - Seminar: Strahlenphysikalische Anwendungen in Technik und Medizin CY - Vienna, Austria DA - 18.05.2022 KW - Synchrotron KW - BAMline KW - Bayesian Statistics KW - Gold KW - X-ray fluorescence PY - 2022 AN - OPUS4-56253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Big to Small - Getting Smarter@BAMline N2 - In this talk an overview about artificial intelligence/machine learning applications @BAMline is given. In the first part, the use of neural networks for the quantification of XRF measurements and the decoding of coded-aperture measurements are shown. Then it is shown how Gaussian processes and Bayesian statistics can be used to achieve an optimal alignment of the set-up and in general for optimization of measurements. T2 - Forschungsseminar Institut für Optik und Atomare Physik TU Berlin CY - Berlin, Germany DA - 25.10.2022 KW - Artificial Inelligence KW - Machine Learning KW - Bayesian Statistics KW - Gaussian process KW - Neural network KW - BAMline KW - Synchrotron PY - 2022 AN - OPUS4-56249 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - ML@BAMLINE N2 - An overview of the machine learning methods used at BAMline. Examples of automatic alignment and optimisation based on Gaussian processes are discussed. Quantification of XRF measurements and reconstruction for coded aperture imaging based on neural networks are also presented. T2 - Machine Learning Workshop BAM CY - Online meeting DA - 18.03.2021 KW - Artificial Intelligence KW - Machine learning KW - Bayesian Optimization KW - Gaussian process KW - Neural Network PY - 2021 AN - OPUS4-54142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Constantinescu, B. A1 - Vasilescu, A. A1 - Radtke, Martin A1 - Reinholz, Uwe T1 - Micro-SR-XRF studies for archaeological gold identification - the case of carpathian gold and romanian museal objects N2 - In the determination of the provenance of gold in archaeological artifacts, trace elements are more significant than the main components. Several minute fragments of natural Carpathian gold-placer and primary-and some very small (a few milligrams) fragments of archaeological items were studied using micro Synchrotron Radiation X-Ray Fluorescence (micro SR-XRF) at the BESSY Synchrotron Facility in Berlin, Germany. The goal of the study was to identify the trace elements characterizing Carpathian gold, looking especially at Sn, Sb, Pb and Te, and to determine if the gold in the archaeological items is native or refined. Applications to the authentication and provenance of nine Dacian gold bracelets, koson coins and two Bronze Age items are presented. KW - Gold KW - Provenance KW - Archeometry KW - Sy-XRF PY - 2010 DO - https://doi.org/10.1007/s00339-010-5624-1 SN - 0947-8396 VL - 99 IS - 2 SP - 383 EP - 389 PB - Springer CY - Berlin AN - OPUS4-21395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - ABSORBTION OF THE PRIMARY BEAM IN SR-TXRF ANALYSIS: EXPERIMENTAL VISUALIZATION USING A COLOR X-RAY CAMERA T2 - International Congress on X-Ray Optics and Microanalysis CY - Hamburg, Germany DA - 2013-09-02 PY - 2013 AN - OPUS4-29898 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Analysis of trace elements in gold alloys by SR-XRF at high energy at the BAMline T2 - Ecaart 9 (European conference on accelerators in applied research and technology) CY - Florence, Italy DA - 2007-09-03 PY - 2007 AN - OPUS4-16399 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Strub, Erik A1 - Born, H. T1 - Neues vom Berliner Goldhut: Materialanalysen mit Synchrotronstrahlung KW - Sy-RFA KW - Berliner Goldhut PY - 2009 SN - 0341-1184 VL - 41 SP - 29 EP - 35 PB - Marie Leidorf GmbH CY - Berlin AN - OPUS4-20271 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - THE IDEAL SPECIMENT FOR TOTAL REFLECTION X-RAY FLUORESCENCE (TXRF) ANALYSIS: RESULTS FROM SIMULATIONS AND EXPERIMENTAL EVALUATION T2 - International Congress on X-Ray Optics and Microanalysis CY - Hamburg, Germany DA - 2013-09-02 PY - 2013 AN - OPUS4-29871 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin A1 - Holtappels, Kai T1 - Pressure resistance of glass capillary structures for gas storage purposes T2 - First International Conference on Materials for Energy CY - Karlsruhe, Germany DA - 2010-07-04 PY - 2010 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, Martin - Birth name of Kluge, Martin: Beckmann-Kluge, Martin AN - OPUS4-24056 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holtappels, Kai A1 - Kluge, Martin T1 - Pressure resistance of glass capillaries for hydrogen storage T2 - Workshop "Materials challenges for clean enery" im Rahmen des 3rd World Materials Research Institute Forum, NIST CY - Washington, D.C., USA DA - 2009-06-22 PY - 2009 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. AN - OPUS4-19677 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - The Color X-Ray Camera: Imaging and Beyond T2 - ANKA/KNMF User Meeting 2013 CY - 76646 Bruchsal, Deutschland DA - 2013-09-26 PY - 2013 AN - OPUS4-29900 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Neues vom Berliner Goldhut: Analyse mit Sy-RFA T2 - Deutsche Tagung für Forschung mit Synchrotronstrahlung, Neutronen und Ionenstrahlen, SNI 2010 CY - Berlin, Germany DA - 2010-02-24 PY - 2010 AN - OPUS4-20097 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Von der Bronzezeit ins 21. Jahrhundert - Materialcharakterisierung mit SyXRF an der BAMline T2 - 17. Sitzung des Fachausschusses Zerstörungsfreie Materialcharakterisierung, DGZFP CY - Berlin, Germany DA - 2009-11-10 PY - 2009 AN - OPUS4-20772 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Das Hiddensee-Projekt T2 - Kulturgut durchleutet - Strahlung trifft Kulturgut (Symposium) CY - Berlin, Germany DA - 2009-11-04 PY - 2009 AN - OPUS4-20771 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - SRXRF examples from the BAMline N2 - Synchrotron radiation sources with their unique properties in terms of intensity, polarization and adjustability offer a wide range of possibilities in materials research. A basic introduction about the creation and special properties of synchrotron radiation will be given. Examples of current work at BAMline, the high-energy measuring facility of the Federal Institute for Materials Research and Testing at the synchrotron BESSY, are used to illustrate the possibilities and limitations of existing measuring methods. T2 - Better with Scattering CY - Online meeting DA - 16.03.2020 KW - Synchrotron KW - BAMline KW - XRF PY - 2020 AN - OPUS4-51895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - X-ray camera with high energy and spital resolution: Sterography with a colour X-ray camera T2 - European Conference on X-ray Spectrometry CY - Figueira da Foz, Portugal DA - 2010-06-20 PY - 2010 AN - OPUS4-21205 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Von Ägypten bis Hiddensee – Analyse von Gold mit Synchrotronstrahlung - Update 2018 N2 - Gold ist eines der sieben schon im Altertum bekannten Metalle und wurde wg. seines Glanzes und seiner Seltenheit von alters her als Tauschmittel und zur Herstellung von Schmuck benutzt. Außerdem ist es einfach bearbeitbar und weitestgehend gegen chemische Einflüsse resistent. Die Untersuchungen von Gold mit synchrotronstrahlungsangeregter Röntgenfluoreszenzanalyse sind zerstörungsfrei und geben Auskunft über die in der untersuchten Probe vorhandenen chemischen Elemente. Bei den hier vorgestellten Untersuchungen an der BAMline stehen Fragestellungen wie Herkunft, Herstellungsverfahren und Zusammengehörigkeit von Goldfunden im Vordergrund. Die verschiedenen Fragestellungen werden an einer Reihe von Beispielen erläutert die vom Wikingerschatz aus Hiddensee über die Himmelsscheibe von Nebra bis hin zu Funden aus Ägypten langen. Zusätzlich werden die modernen Messmethoden vorgestellt, die am Synchrotron heutzutage zur Verfügung stehen. T2 - Vorlesung FU Berlin Einführung in die Archäometrie CY - Berlin, Germany DA - 01.11.2018 KW - Gold KW - Synchrotron KW - XRF KW - BAMline PY - 2018 AN - OPUS4-46451 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Tragbare RFA an Gläsern: Ergebnisse und Grenzen N2 - Vorstellung der Ergebnisse der Messungen an Gläsern von Goethes Prismen. T2 - 3. Goethe/Ritter-Workshop CY - Berlin, Germany DA - 25.05.2018 KW - Goethe KW - Farbenlehre KW - Prisma KW - Handheld KW - XRF PY - 2018 AN - OPUS4-46369 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Röntgenfluoreszenzanalyse mit Synchrotronstrahlung an der Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin T2 - Seminar: "Strahlenphysikalische Anwendungen in Technik und Medizin" CY - Wien, Österreich DA - 2015-01-14 PY - 2015 AN - OPUS4-34014 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Experiences with the Color X-Ray Camera at the BAMline T2 - X-ray Spectroscopy Detectors for Present and Future Synchrotron Storage rings: Opportunities for Horizon 2020 CY - Paris, Frankreich DA - 2015-03-16 PY - 2015 AN - OPUS4-34009 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Double Dispersive X-ray Fluorescence T2 - EXRS 2014 CY - Bologna (Italien) DA - 2014-06-15 PY - 2014 AN - OPUS4-32370 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Imaging with the Color X-ray Camera - Basics and Examples T2 - HZB Industry Workshop CY - Berlin DA - 2015-02-19 PY - 2015 AN - OPUS4-34023 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Wolf, Martin T1 - Zur Phänomenologie der Heißrissbildung beim Schweißen und Entwicklung aussagekräftiger Prüfverfahren N2 - Zur Ermittlung der Heißrissresistenz beim Schweißen metallischer Werkstoffe können Heißrisstests eingesetzt werden. Obwohl bislang zahlreiche Heißrisstestverfahren entwickelt wurden, kann eine unerwartete Heißrissbildung während der Durchführung von Bauteilschweißungen oftmals nicht verhindert werden. Dies ist einerseits darauf zurückzuführen, dass sich die Bedingungen im Heißrisstest von den thermomechanischen Beanspruchungen einer Bauteilschweißung zu sehr unterscheiden. Andererseits erfolgt die Auswertung der meisten Heißrissversuche mit Hilfe empirischer Parameter, mit denen die eigentlichen Mechanismen der Heißrissentstehung jedoch nur unzureichend quantifiziert werden können. Ein wesentliches Ziel war es daher, aussagekräftige Methoden zur Quantifizierung des Heißrissverhaltens beim Schweißen zu entwickeln und damit einen Beitrag zur Erhöhung der Heißrisssicherheit geschweißter Bauteile zu leisten. N2 - For determining the hot cracking resistance of materials during welding of metallic materials it is possible to employ hot cracking tests. Despite numerous hot cracking tests have been developed till now, unexpected hot cracking during welding cannot always be avoided. This is on the one hand ascribed to the fact that the conditions prevalent in hot cracking testing differ too strongly from the thermomechanical loads imposed during component welding. On the other hand, evaluation of most hot cracking tests is carried out using empiric parameters which, however, fall short of adequate quantification of the actual hot cracking mechanism. A key aim of this study was therefore to develop convincing methods for quantifying the hot cracking behaviour during welding, and thus to make a contribution towards improving the hot cracking resistance of welded components. As a prerequisite, the Modified Varestraint Transvarestraint-Test (MVT-Test) was first upgraded with a view to varying the specimen loading rate over a very wide range up to quasi-instantaneous loading. As test material, Alloy 602 CA was chosen which exhibits a pronounced dependence of hot cracking resistance on the respective shielding gas. With the use of Ar 4.8 and Ar + 1% N2 as shielding gases, hot crack-critical as well as hot crack-uncritical material behaviour could be investigated. For further elucidation of the solidification cracking mechanism, a combined model was first developed which can be used to demonstrate that the solidification crack-critical limiting temperature TER and the solidification crack-critical strain rate (dε/dt)krit are largely independent of each other and must be determined using various test concepts. Numerical temperature calculations with first implementation of the reproduced real weld pool geometries helped to determine the solidification crack-critical limiting temperature for Alloy 602 CA as a function of different welding parameters and of the investigated shielding gases. It is demonstrated that the solidification crack-critical limiting temperature rises significantly with the use of Ar + 1% N2. In addition to this, the solidification crack-critical limiting temperature is significantly dependent on the applied welding parameters. The MVTTest was also used to conduct experiments with variable specimen loading rate in both the Varestraint and the Transvarestraint mode. Various hot cracking parameters determined in these experiments were evaluated quantitatively. With regard to exclusively qualitative determination of the hot cracking resistance of materials it was found that the measurable differences are more distinct in the Varestraint mode than in the Transvarestraint mode. For hot cracking test transferability investigations, the very critical specimen loading rates at which solidification cracking does not occur yet, were experimentally determined in MVTTests. Using the obtained results in conjunction with thermomechanical simulations, the local critical strain rates in the immediate vicinity of the weld pool were calculated. It is shown that the local critical strains and strain rates constitute a crack criterion for the transferability to the newly developed Controlled Tensile Weldability Test (CTW-Test). Keywords: Solidification cracking, liquation cracking, global strain, local strain, transferability, Modified Varestraint Transvarestraint Test, weld pool geometry, hot cracking parameter, Controlled Tensile Weldability Test, Alloy 602 CA. T3 - BAM Dissertationsreihe - 19 KW - Phänomenologie Heißrissbildung KW - Schweißen und Entwicklung aussagekräftiger Prüfverfahren PY - 2006 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-1395 SN - 978-3-86509-599-2 SN - 1613-4249 VL - 19 SP - 1 EP - 218 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-139 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krentel, Daniel A1 - Tschirschwitz, Rico A1 - Kluge, Martin A1 - Askar, Enis A1 - Habib, Abdel Karim A1 - Kohlhoff, Harald A1 - Mair, Georg W. A1 - Neumann, Patrick P. A1 - Rudolph, Michael A1 - Schoppa, André A1 - Storm, Sven-Uwe A1 - Szczepaniak, Mariusz T1 - Auswirkungen von unfallbedingtem Behälterversagen bei alternativen Pkw-Antrieben - Teil 1: Problemstellung, Stand der Technik und Voruntersuchungen N2 - Flüssige und komprimierte Gase sind in Deutschland, Europa und der Welt vielfältig als alternative Kraftstoffe im Einsatz. Diese werden unter teilweise hohem Druck in robusten Behältern an Bord gespeichert. Ein Versagen des Treibstoffbehälters im Schadensfall sollen verschiedene Sicherheitseinrichtungen, auch bei einem eventuell unfallbedingt auftretenden Fahrzeugbrand, verhindern. Sind diese Sicherheitseinrichtungen unfallbedingt beschädigt oder liegen die Belastungen dieser Einrichtung außerhalb ihres Auslegungsbereichs, ist ein Versagen des Behälters dennoch möglich. Dadurch kann es zur Bildung eines explosionsfähigen Brennstoff-Luft-Gemischs mit den entsprechenden Folgen für Fahrgäste, Einsatzkräfte und Umfeld kommen. Die Bundesanstalt für Materialforschung und -prüfung (BAM) untersucht im Forschungsprojekt "CoFi-ABV" mit umfangreichen zerstörenden Versuchsreihen im Realmaßstab die Folgen des unfallbedingten Versagens von Behältern für alternative Kraftstoffe und Maßnahmen zur Reduktion dieser Folgen im Rahmen einer ganzheitlichen Auswirkungsbetrachtung. Dieser Beitrag ist der Start einer Reihe und soll die Problemstellung sowie die Projektinhalte umfassend erläutern. KW - Alternative Antriebe KW - Alternative Kraftstoffe KW - Behälterversagen KW - Fahrzeugbrand PY - 2016 SN - 2191-0073 VL - 6 IS - 9 SP - 39 EP - 46 PB - Springer-VDI-Verlag CY - Düsseldorf AN - OPUS4-37360 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tschirschwitz, Rico A1 - Krentel, Daniel A1 - Kluge, Martin A1 - Habib, Abdel Karim A1 - Askar, Enis A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. A1 - Rudolph, Michael A1 - Schoppa, André A1 - Szczepaniak, Mariusz T1 - Versagen von Gasbehältern für alternative Treibstoffe N2 - Im Rahmen des Projekts „Complex Fires – Auswirkung von Behälterversagen“ (CoFi-ABV) sollen die Auswirkungen des Versagens von Gasbehältern für alternative Treibstoffe in Fahrzeugen unter Berücksichtigung komplexer Brand- und Explosionsszenarien untersucht werden. Es wird der aktuelle Hintergrund des Forschungsvorhabens erläutert sowie die geplanten Untersuchungen und beabsichtigten Ergebnisse vorgestellt. Hauptbestandteil des Projekts ist eine Vielzahl von zerstörenden Großversuchen. Im Vorfeld dieser Großversuche werden zur Weiterentwicklung und Adaptierung von Messtechnik Versuche im kleineren Maßstab durchgeführt. Im Folgenden werden Teile dieser Ver-suchsaufbauten im „mid-scale“ sowie die dabei verwendete Messtechnik dargestellt. Weiterhin werden erste Ergebnisse aus Wärmeeintragsversuchen zur Quantifizierung verschiedener Unterfeuerungsmethoden für die zerstörenden Großversuche vorgestellt. T2 - 14. Kolloquium zur chemischen und physikalischen Sicherheitstechnik (BAM-PTB-Kolloquium) CY - Berlin, Germany DA - 14.06.2016 KW - Explosion KW - alternative Treibstoffe KW - Behälterversagen KW - Composite PY - 2016 SN - 978-3-9817853-5-7 SN - 0938-5533 SP - 1 EP - 143 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) AN - OPUS4-37172 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Stelling, Karen A1 - Böllinghaus, Thomas A1 - Wolf, Martin A1 - Schöler, Annett A1 - Burkert, Andreas A1 - Isecke, Bernd ED - Böllinghaus, Thomas ED - Herold, H. T1 - Hot cracks as stress corrosion cracking initiation sites in laser welded corrosion resistant alloys N2 - Although hot cracks at weld surfaces of corrosion resistant alloys (CRAs) might provide access to respective aggressive media and thus, might provide the conditions for a local potential and pH drop, the interaction between hot cracking and corrosion phenomena has not been investigated up to the present. This particularly concerns the initiation of stress corrosion cracking inside such crevices. As a first approach to clarify the influence of hot cracks on corrosion resistance, considering particularly stress corrosion cracking, hot crack afflicted laser welds of three different CRAs have been subjected to a series of different corrosion tests. Besides the fact that the Drop Evaporation (DE) Test represents a more realistic procedure than standard immersion tests it turned out that hot cracks can obviously represent an initiation site of stress corrosion cracking in the austenitic stainless steel AISI 309 (German No. 1.4828). The susceptibility of such hot crack afflicted laser welds to stress corrosion cracking (SCC) significantly depends on temperature and chloride concentration of the test environment In comparison, the high nitrogen austenitic stainless steel AISI S 34565 (German No. 1.4565) did not exhibit any stress corrosion cracking associated with hot cracking. This material exhibited pitting corrosion and stress corrosion only in the base material. The Alloy 50 (German No. 2.4850), a Nickel based material, was susceptible to pitting corrosion, but showed no tendency towards stress corrosion cracking at all. T2 - International Workshop "Hot Cracking Phenomena in Welds" CY - Berlin, Germany DA - 2004-03-04 KW - Ni-Base Alloy KW - Stress corrosion Cracking KW - Hot Cracking KW - Laser Welding KW - Austenitic Stainless Steel KW - Drop Evaporation Test PY - 2005 SN - 3-540-22332-0 DO - https://doi.org/10.1007/3-540-27460-X_10 SP - 165 EP - 182 PB - Springer CY - Berlin AN - OPUS4-11852 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Constantinescu, B. A1 - Vasilescu, A. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Pacheco, C. A1 - Pichon, L. A1 - Oberländer-Târnoveanu, E. T1 - SR XRF and micro-PIXE studies on ancient metallurgy of thirteen Dacian gold bracelets N2 - A thorough microscopic investigation by SR XRF and micro-PIXE brings insight into the probable techniques used in the manufacture of thirteen Dacian gold bracelets, one of the most spectacular archaeological finds ever on the territory of Romania. KW - Micro-SR-XRF KW - Micro-PIXE KW - Archaeometry KW - Gold KW - Romania PY - 2012 DO - https://doi.org/10.1007/s00339-012-7306-7 SN - 0947-8396 VL - 109 IS - 2 SP - 395 EP - 402 PB - Springer CY - Berlin AN - OPUS4-26902 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 - GEN A1 - Raedel, Martina A1 - Sabel, Martin A1 - Bücker, Michael A1 - Unger, Brita ED - Meeks, N. ED - Cartwright, C. ED - Meek, A. ED - Mongiatti, A. T1 - ESEM-EDX analyses for the characterisation and reproduction of nineteenth-century gold tesserae N2 - Environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM-EDX) is a versatile working tool for the examination of gold tesserae as well as for the selection of suitable materials for their reproduction. In this paper, the ESEM-EDX analyses of original gold tesserae and their damage types are presented. These analytical results form the basis for further calculations of glass properties and experiments. These calculated values enable the determination of the relevant glass properties and allow us to choose the appropriate type of modern glass for further experiments. Subsequent experiments convert this knowledge into practice. By comparing the analytical results from the original glasses and the replicas the accuracy and precision will be shown. KW - Gold mosaics KW - Tesserae KW - ESEM-EDX KW - Glass analyses KW - Damage mechanism PY - 2012 SN - 978-1-904982-65-4 SP - 107 EP - 113 PB - Archetype publications Ltd. AN - OPUS4-27641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rua-Ibarz, Ana A1 - Nakadi, Flávio V. A1 - Bolea-Fernandez, Eduardo A1 - Bazo, Antonio A1 - Battistella, Beatrice A1 - Matiushkina, Anna A1 - Resch-Genger, Ute A1 - Abad Andrade, Carlos Enrique A1 - Resano, Martín T1 - Discrete entity analysis via microwave-induced nitrogen plasma–mass spectrometry in single-event mode N2 - In this work, single-event microwave-induced nitrogen plasma–mass spectrometry (single-event MINP-MS) was evaluated for the first time for the analysis of discrete entities such as nanoparticles, biological cells, and microplastics. Nitrogen (N2) effectively overcomes Ar-based polyatomic interferences, enabling (ultra)trace element determination of Fe and Se using their most abundant isotopes, 56Fe (91.66%) and 80Se (49.82%). Iron oxide nanoparticles (Fe2O3 NPs) ranging from 20 to 70 nm were accurately characterized, with excellent agreement with established sizing techniques, such as transmission electron microscopy (TEM) and dynamic light scattering (DLS). A limit of detection (LoD) of 8.6 ag for Fe─equivalent to an LoDsize of 19 nm for Fe2O3─was achieved, which is significantly lower than recent values reported for high-end quadrupole-based ICP-MS. Selenium nanoparticles (SeNPs) of 150 and 250 nm were also accurately characterized, without the N2-based plasma experiencing issues handling relatively large metallic NPs (linearity, R2 = 0.9994). Se-enriched yeast cells (SELM-1 certified reference material) were successfully analyzed via single-cell MINP-MS using external calibration based on SeNPs and a transport efficiency-independent approach. In addition, 2–3 μm polystyrene (PS) and polytetrafluoroethylene (PTFE) were accurately sized by monitoring 12C+, confirming the method’s suitability for handling micrometer-sized polymeric materials (microplastics). The average duration of individual events (680 ± 160 μs) suggests that the digestion of individual entities in N2-based plasmas is comparable to that in Ar-based plasmas. These results open new avenues for this instrumentation as an alternative to ICP ionization sources, also in the context of discrete entity analysis. KW - Microwave-Induced Nitrogen Plasma KW - Discrete entity analysis KW - Particle/droplet event counting KW - Comparison to SP-ICP-MS methodologies KW - Nitrogen plasma vs. argon ICP trade-offs KW - Trace elemental quantification at the single-entity level KW - Time-resolved mass spectrometry for discrete entities PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643825 DO - https://doi.org/10.1021/acs.analchem.5c04341 SN - 0003-2700 SP - 1 EP - 8 PB - American Chemical Society (ACS) AN - OPUS4-64382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Patrick P. A1 - Kohlhoff, Harald A1 - Hüllmann, Dino A1 - Kluge, Martin A1 - Askar, Enis A1 - Habib, Abdel Karim A1 - Krentel, Daniel A1 - Mair, Georg W. A1 - Rudolph, Michael A1 - Schoppa, André A1 - Szczepaniak, Mariusz A1 - Storm, Sven-Uwe A1 - Tschirschwitz, Rico T1 - Auswirkungen von Behälterversagen bei alternativen PKW-Antrieben - Teil 2: UAV-basierte Fernerkundung von Gaswolken N2 - Verkehrsunfälle unter Beteiligung von Fahrzeugen mit alternativen Kraftstoffen wie LPG („Autogas“, Liquefied Petroleum Gas), CNG (Compressed Natural Gas, komprimiertes Erdgas) oder CGH2 (Compressed Gas Hydrogen, komprimierter Wasserstoff), bergen neue, komplexe Risiken für Passagiere, Einsatzkräfte und deren Umfeld. Im Rahmen des Projektes „CoFi-ABV“ beschäftigt sich die Bundesanstalt für Materialforschung und -prüfung (BAM) unter Berücksichtigung komplexer Brand- und Explosionsszenarien mit einer ganzheitlichen Betrachtung der Auswirkungen des unfallbedingten Versagens von Gasbehältern für alternative Kraftstoffe. Ein wichtiger Teil des Forschungsvorhabens umfasst Entwicklung, Aufbau und Validierung einer unbemannten Flugplattform (Unmanned Aerial Vehicle, UAV) zur Ferndetektion von Gaswolken. Für das sogenannte gassensitive Mini-UAV wird ein robuster Open-Path-Gasdetektor auf einer Sensorbewegungsplattform in Form eines modifizierten Kamera-Gimbals, integriert. Ziel ist es, ein leistungsfähiges und robustes Werkzeug zu entwickeln, welches Einsatzkräften im Falle eines Unfalls als Hilfe zur Abschätzung der Gefahr durch Gaswolken, ihrer Ausbreitung und der notwendigen Absperrbereiche zur Verfügung steht. Dieser Artikel ist der zweite der Reihe und legt, nach Projektvorstellung im ersten Teil, nun den Schwerpunkt auf das gassensitive Mini-UAV. KW - UAV KW - Fernerkundung KW - Open-Path-Gasdetektor KW - Alternative Antriebe/Kraftstoffe KW - Behälterversagen PY - 2016 SN - 2191-0073 VL - 6 IS - 11/12 SP - 23 EP - 28 PB - Springer-VDI-Verlag CY - Düsseldorf AN - OPUS4-38517 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krentel, Daniel A1 - Tschirschwitz, Rico A1 - Kluge, Martin A1 - Askar, Enis A1 - Habib, Abdel Karim A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. A1 - Rudolph, Michael A1 - Schoppa, André A1 - Storm, Sven-Uwe A1 - Szczepaniak, Mariusz T1 - Experimental investigation of failure of LPG gas tanks in passenger cars during full fire development N2 - In continuation of a preceding test series involving sole LPG vehicle tanks, three passenger cars equipped with identical toroidal steel LPG tanks were set on fire. The tanks were installed in the space normally reserved for the spare tyre, in the car boot. No safety device was installed on the tank, in order to force critical failure of the cylinder. Two of the cars were equipped with a tank filled with liquefied propane to a level of 20 % (5.3 kg), the third one was filled completely (25.5 kg). The partially filled tanks failed critically within a time period of more than 20 min after the initiation of the fire. The fully-filled tank did not rupture; the propane was released continuously through a small leak that appeared during the fire. Comprehensive equipment was used to procure measurement data, enabling an analysis of potential consequences and hazards to humans and infrastructure within the vehicle surroundings. The inner status of the tank (pressure, temperature of the liquid phase and the steel casing), the development of the fire (temperature inside and around the vehicle) and the pressure induced in the near-field in case of tank rupture were recorded. The results were analysed in detail and compared against the data gained in tests involving sole, but identical LPG tanks. T2 - FIVE 2018 CY - Boras, Sweden DA - 03.10.2018 KW - Behälterversagen KW - LPG KW - Alternative Antriebe KW - Fahrzeugbrand KW - Auswirkungsbetrachtung PY - 2018 SN - 978-91-88695-95-6 VL - 51 SP - 123 EP - 131 PB - RISE Safety CY - Boras AN - OPUS4-46310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krentel, Daniel A1 - Rudolph, Michael A1 - Tschirschwitz, Rico A1 - Kluge, Martin A1 - Askar, Enis A1 - Habib, Abdel Karim A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. A1 - Schalau, Bernd A1 - Schoppa, André A1 - Storm, Sven-Uwe A1 - Szczepaniak, Mariusz A1 - Mair, Georg W. T1 - Infrared radiation measurement at failure of mobile gas vessels N2 - 15 identical off-the-shelf propane cylinders (m = 11 kg liquid propane) were underfired. The infrared Radiation of the Explosion, that occurred in the aftermath of the vessel failure, was recorded using four bolometers. These measurements are compared with an estimation of the Maximum intensity gained by an Analysis of the Video data, an Extended Version of the Stefan-Boltzmann law and a BLEVE model. T2 - 26th International Colloquium on the Dynamics of Explosions and Reactive Systems CY - Boston, USA DA - 30.07.2017 KW - Failure of gas vessels KW - Propane cylinder KW - Gas explosion KW - Consequences KW - Infrared radiation PY - 2017 SP - 1 EP - 6 PB - FM Global CY - Seattle, USA AN - OPUS4-41993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeps, Robert A1 - Askar, Enis A1 - Ferrero, Fabio A1 - Kluge, Martin T1 - Zündtemperatur von Gasen/ Gasgemischen bei erhöhten Anfangsdrücken in Abhängigkeit vom Behältervolumen N2 - Zur Einschätzung der Wirksamkeit einer heißen Oberfläche als Zündquelle für ein Gas oder ein Gasgemisch werden in der Praxis Zündtemperaturen experimentell bestimmt. Die Zündtemperatur gemäß dem europäischen Standardverfahren EN 14522 wird bei Atmosphärendruck bestimmt und ist vor allem dazu geeignet die Wirksamkeit einer heißen Oberfläche als Zündquelle bei einem unerwünschten Stoffaustritt aus einer geschlossenen Anlage einzuschätzen. Eine Aussage bzgl. der der Zündfähigkeit an heißen Oberflächen innerhalb einer geschlossenen Anlage, z. B. in größeren Behältern bei bestimmten Gemischzusammensetzungen und höheren Anfangsdrücken, kann anhand der Zündtemperatur gemäß EN 14522 nicht getroffen werden. Die Bestimmung nach dem europäischen Standard erfolgt in einem offenen System, bei atmosphärischem Druck und in Luft als Oxidationsmittel. T2 - 11. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 07.11.2013 KW - Sicherheitstechnische Kenngrößen KW - Chemisch instabile Gase KW - Zerfallsfähige Gase KW - Explosion KW - Ethylenoxid KW - Tetrafluorethylen KW - Acetylen PY - 2013 SN - 978-3-86011-058-4 IS - F-02 SP - 1 EP - 14 AN - OPUS4-29534 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werrel, Martin T1 - Ventilation vs. Vitiation Effects on the CO Pruduktion in a Controlled-atmosphere Cone Calorimeter T2 - IAFSS International Symposium on Fire Safety Science CY - Christchurch, New Zealand DA - 2014-02-10 PY - 2014 AN - OPUS4-30291 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bevilacqua, Tommaso A1 - Gumenyuk, Andrey A1 - Habibi, Niloufar A1 - Hartwig, Philipp A1 - Klawonn, Axel A1 - Lanser, Martin A1 - Rethmeier, Michael A1 - Scheunemann, Lisa A1 - Schröeder, Jöerg T1 - Large-scale thermo-mechanical simulation of laser beam welding using high-performance computing: A qualitative reproduction of experimental results N2 - Laser beam welding (LBW) is a non-contact joining technique that has gained significant importance in modern industrial manufacturing. One potential problem, however, is the formation of solidification cracks, which particularly affects alloys with a pronounced melting range. The aim of the present work is the development of computational methods and software tools to numerically simulate LBW. In order to obtain a sufficiently accurate solution, a large number of finite elements has to be used. Therefore, a highly parallel scalable solver framework, based on the software library PETSc, was used to solve this computationally challenging problem on a high-performance computing architecture. Finally, the experimental results and the numerical simulations are compared. They are found to be in good qualitative agreement, which confirms the validity of the numerical simulations and allows for a better interpretation of the experimentally observed strain distribution. KW - Laser beam welding KW - Termo-mechanical processes KW - Solidification cracking KW - High-performance computing KW - Domain decomposition methods PY - 2025 DO - https://doi.org/10.1016/j.rineng.2025.108827 SN - 2590-1230 SP - 1 EP - 33 PB - Elsevier B.V. AN - OPUS4-65290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martin, Nathan A1 - Nota, Kevin A1 - Aumont, Cédric A1 - Marchand, Grégor A1 - Marguerie, Dominique T1 - Anthropic and climatic impacts on biodiversity during the Mesolithic-Neolithic transition in North-Western France N2 - The Neolithic transition, which began around 10,000 BCE in Western Asia, has significantly impacted the biodiversity dynamics and the hunter-gatherer communities due to the beginning of anthropization and climate fluctuations during this period. Neolithic farmers gradually spread to the Atlantic margins of North-Western Europe during the 6th millennium BCE, arriving later than in other parts of the continent. This systematic review aims to shed a light on the landscape transformations and shifts in the ecological niches that occurred during neolithization in the Armorican Massif, driven by human and climatic influences, through an interdisciplinary examination of palynology, archaeology and palaeogenomics. This Massif is situated in North-Western France which hosted well established Mesolithic and Neolithic societies that have been extensively studied. However, recent research has called into question the coexistence of these two cultural groups in this area, necessitating a reevaluation of the literature in light of these new findings. This systematic review coupled with an analysis of pollen sequences reveals spatial and temporal heterogeneity in vegetation composition, openness, and the gradual introduction of domesticated taxa into the region. This analysis should be seen in the context of the delayed adoption of the agro-pastoral lifestyle in North-Western Europe, attributed to the different climatic conditions encountered, which required time for these societies and their domesticated taxa to adapt. Further investigation is needed to clearly differentiate between anthropogenic and climatic impacts and paleoclimatic reconstruction based on pollen sequences looks promising for addressing this issue. KW - Armorican massif KW - Neolithic transition KW - Anthropization KW - Climate KW - Palynology KW - Biodiversity dynamics PY - 2024 DO - https://doi.org/10.1016/j.quaint.2024.11.004 SN - 1040-6182 VL - 714 SP - 1 EP - 19 PB - Elsevier CY - Amsterdam AN - OPUS4-65313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feller, Viktor A1 - Mielentz, Frank A1 - Klewe, T. A1 - Krause, Martin A1 - Orglmeister, R. A1 - Pflugradt, M. T1 - Ultrasonic phased array for investigations of concrete components N2 - This paper describes an innovation of a phased array using dry contact probes to test concrete components. Based on preceding work on pressure waves, a low-frequency ultrasonic phased array consisting of shear wave probes is used in the experiments. This configuration allows the variation and control of the sound field directivity during the measurement. The measurements are carried out on a concrete test block using a scanning laservibrometer and a scanner system in transmission mode. The laboratory measurements are compared to theoretical calculations to investigate the influence of the probes shape and dimension on the resulting sound field patterns. The comparison of the modelling and the measurements demonstrates the suitability of the point source synthesis as a tool for the optimization of probe array designs. Methods of coded are used to improve the signal to noise ratio. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Ultrasonic KW - Phased array KW - Concrete KW - Point source synthesis PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-350417 UR - http://www.ndt.net/article/ndtce2015/papers/059_feller_viktor.pdf SN - 1435-4934 SP - 1 EP - 5 PB - Technische Universität Berlin / Bundesanstalt für Materialforschung und -prüfung AN - OPUS4-35041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dey, Anika A1 - Casperson, Ralf A1 - Pohl, Rainer A1 - Thomas, Hans-Martin T1 - Die Wirbelstromprüfung als Hilfsmittel für die Schieneninstandhaltung N2 - Die zerstörungsfreie Oberflächenprüfung an verlegten Eisenbahnschienen mit Wirbelstrom hat in den letzten Jahren durch ständige Weiterentwicklung und Verifizierung enorm an Bedeutung gewonnen. Es wurde u.a. angestrebt zuverlässige Planungsgrößen für den Einsatz von Instandhaltungsmaßnahmen zu erhalten, durch deren gezielten Einsatz Risswachstum unterbunden werden kann. Die Ursache für das Wachstum von Rissen in der Schiene liegt in der Materialermüdung des Werkstoffes infolge der Betriebsbelastungen im RadSchiene-Kontakt. Nach einer gewissen Beanspruchungsdauer kommt es an den Kontaktflächen der Fahrkante zu einer Kaltverfestigung des Schienenstahls. Durch fortschreitende Verfestigung des kontaktbeanspruchten Oberflächenbereichs der gehärteten Schicht wird der Werkstoff spröde und es bilden sich feine Risse aus. Die Risse wachsen anfangs unter einem flachen Winkel in das Schieneninnere hinein, neigen dann aber ab einem gewissen Stadium dazu in das Innere des Schienenkopfes abzukippen, was im Extremfall zu einem Schienenbruch führen kann. Diese Rollkontaktermüdungsrisse, auch genannt Head Checks, entstehen bevorzugt in der Fahrkante von bogenäußeren Schienen. Die Anwendung der Wirbelstromprüfung an der Schiene wurde bisher zur Ermittlung der Schädigungstiefe dieser Rollkontaktermüdungsrisse eingesetzt. Das Wirbelstromverfahren besitzt die Eigenschaft, sehr empfindlich auf alle Veränderungen der Materialeigenschaften an der Oberfläche zu reagieren. Daher wurde festgestellt, dass sich neben der Detektion von Rissen auch Fehler wie Eindrückungen oder Schlupfwellen, bis hin zu Materialveränderungen durch Schweißen oder Aufhärtungen in der Schienenoberfläche bestimmen lassen. Die Wirbelstromprüfung besitzt daher das Potenzial, mögliche Orte der Entstehung von Ermüdungsrissen in einem extrem frühzeitigen Stadium nachzuweisen. Ziel ist es, die rissgefährdeten Zonen schon im Zustand der Kaltverfestigung zu identifizieren. Dadurch können sich neue Aspekte für die präventive Schieneninstandhaltung ergeben. T2 - DGZfP-Jahrestagung 2010 - Zerstörungsfreie Materialprüfung ZfP in Forschung, Entwicklung und Anwendung CY - Erfurt, Germany DA - 10.05.2010 PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-214813 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-21481 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krause, Martin A1 - Effner, Ute A1 - Müller, Sabine A1 - Nowak, Thomas Rudolf A1 - Vergin, Dirk T1 - 3D-SAFT Imaging von Streuern in Brettschichtholz N2 - Aktuell wird die Ultraschallechotechnik für Holzbauteile genutzt, indem aus der Abschattung eines ansonsten stabilen Rückwandechos auf Auffälligkeiten im Holzbauteil geschlossen wird. Dabei werden Transversalwellen (Mittenfrequenz 50 kHz) mit der Polarisationsrichtung in Faserrichtung (L) angewendet. In einem 2012 abgeschlossenen Forschungsvorhaben wurde nun die direkte Abbildung von Streuern durch anisotrope SAFT-Rekonstruktion entwickelt. Dazu werden flächig aufgenommene Ultraschallmessdaten mit automatisiert scannenden Druck- und Scherwellenköpfen erzeugt und auf Basis anisotroper Geschwindigkeitsverteilungen rekonstruiert. Benutzt werden die auch häufig für Beton eingesetzten trocken ankoppelnden Punktkontakt-Prüfköpfe. Da damit auch intensive Wellen an der Oberfläche erzeugt werden, entstehen im Material zusätzliche Kopfwellen, die ebenfalls bei der Rekonstruktion berücksichtigt werden. Da die Wellengeschwindigkeiten in Holz individuell stark schwanken, wird eine interaktive Auswertetechnik zur Ermittlung der Materialkonstanten benutzt. Für die Messungen werden Druckwellen sowie Scherwellen in zwei Polarisationsrichtungen verwendet. Die Messungen erfolgen sowohl mit automatischen Scannersystemen als auch mit einem linearen Prüfkopf-Array (kommerziell erhältlicher multistatischer Messkopf). Gezeigt werden Ergebnisse an Bauteilen mit künstlichen und realen Fehlstellen. Das Forschungsprojekt wurde gefördert vom Bundesamt für Bau- und Raumordnung (BBR, Zukunft Bau). T2 - DGZfP-Jahrestagung 2013 CY - Dresden, Germany DA - 06.05.2013 KW - Holz KW - Ultraschallecho KW - Anisotropie KW - Rekonstruktionsrechnung KW - Fehlstellenortung PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-293509 SN - 978-3-940283-49-8 IS - Poster 8 SP - 1 EP - 9 AN - OPUS4-29350 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krause, Martin A1 - Mauke, R. A1 - Effner, Ute A1 - Milmann, Boris A1 - Völker, Christoph A1 - Wiggenhauser, Herbert T1 - Ultrasonic testing of a sealing construction made of salt concrete in an underground disposal facility for radioactive waste N2 - For the closure of radioactive waste disposal facilities engineered barriers- so called “drift seals” are used. The purpose of these barriers is to constrain the possible infiltration of brine and to prevent the migration of radionuclides into the biosphere. In a rock salt mine a large scale in-situ experiment of a sealing construction made of salt concrete was set up to prove the technical feasibility and operability of such barriers. In order to investigate the integrity of this structure, non-destructive ultrasonic measurements were carried out. Therefore two different methods were applied at the front side of the test-barrier: 1 Reflection measurements from boreholes 2 Ultrasonic imaging by means of scanning ultrasonic echo methods This extended abstract is a short version of an article to be published in a special edition of ASCE Journal that will briefly describe the sealing construction, the application of the non-destructive ultrasonic measurement methods and their adaptation to the onsite conditions -as well as parts of the obtained results. From this a concept for the systematic investigation of possible contribution of ultrasonic methods for quality assurance of sealing structures may be deduced. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 2015-09-15 KW - Ultrasonic reflection measurement KW - Dry contact transducers in boreholes KW - Interface salt-concrete / rock salt KW - Ultrasonic imaging of internal reflectors PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346203 UR - http://www.ndt.net/?id=18304 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Babutzka, Martin A1 - Heyn, A. T1 - Dynamic tafel factor adaption for the evaluation of instantaneous corrosion rates on zinc by using gel-type electrolytes N2 - The paper presents a new method for the determination and evaluation of tafel factors using gel-type electrolytes and electrochemical frequency modulation technique (EFM). This relatively new electrochemical method offers the possibility to determine both polarization resistances and tafel factors within one measurement and in short measuring intervals. Starting from a comprehensive parameter study it is shown that a direct relationship between the two values exists that can be described mathematically. This contribution presents the determined tafel factors for the system gel-type electrolyte/zinc and discusses their applicability and their limits. T2 - 19th Chemnitz Seminar on Materials Engineering – 19. Werkstofftechnisches Kolloquium CY - Chemnitz, Germany DA - 16.03.2017 KW - Gel-type electrolytes KW - Gelartige Elektrolyte KW - Zinc KW - Zink KW - Stern Geary constant KW - Stern-Geary-Konstante PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-394324 UR - http://iopscience.iop.org/article/10.1088/1757-899X/181/1/012021/pdf DO - https://doi.org/10.1088/1757-899X/181/1/012021 SN - 1757-899X SN - 1757-8981 VL - 181 IS - Conference 1 SP - Article UNSP 012021, 1 EP - 11 PB - IOP Publishing CY - Bristol, UK AN - OPUS4-39432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilhelm, Stefan A1 - Kaiser, Martin A1 - Würth, Christian A1 - Heiland, J. A1 - Carrillo-Carrion, C. A1 - Muhr, V. A1 - Wolfbeis, Otto S. A1 - Parak, W.J. A1 - Resch-Genger, Ute A1 - Hirsch, T. T1 - Water dispersible upconverting nanoparticles: effects of surface modification on their luminescence and colloidal stability N2 - We present a systematic study on the effect of surface ligands on the luminescence properties and colloidal stability of β-NaYF4:Yb3+,Er3+ upconversion nanoparticles (UCNPs), comparing nine different surface coatings to render these UCNPs water-dispersible and bioconjugatable. A prerequisite for this study was a large-scale synthetic method that yields ~2 g per batch of monodisperse oleate-capped UCNPs providing identical core particles. These ~23 nm sized UCNPs display an upconversion quantum yield of ~0.35% when dispersed in cyclohexane and excited with a power density of 150 W cm-2, underlining their high quality. A comparison of the colloidal stability and luminescence properties of these UCNPs, subsequently surface modified with ligand exchange or encapsulation protocols, revealed that the ratio of the green (545 nm) and red (658 nm) emission bands determined at a constant excitation power density clearly depends on the surface chemistry. Modifications relying on the deposition of additional (amphiphilic) layer coatings, where the initial oleate coating is retained, show reduced non-radiative quenching by water as compared to UCNPs that are rendered water-dispersible via ligand exchange. Moreover, we could demonstrate that the brightness of the upconversion luminescence of the UCNPs is strongly affected by the type of surface modification, i.e., ligand exchange or encapsulation, yet hardly by the chemical nature of the ligand. KW - upconverting nanoparticles (UCNPs) KW - Luminescence KW - surface modification PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-324071 DO - https://doi.org/10.1039/c4nr05954a SN - 2040-3364 SN - 2040-3372 VL - 7 IS - 4 SP - 1403 EP - 1410 PB - RSC Publ. CY - Cambridge AN - OPUS4-32407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Hensel, Christina A1 - Kreißig, Michael A1 - Schmidtchen, Ulrich A1 - Holtappels, Kai T1 - Unterfeuerung von Acetylendruckgasbehältern T2 - 10. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Deutschland DA - 2010-11-04 KW - Sicherheit KW - Acetylen KW - Feuer KW - Wasserkühlung KW - Wärmeübertragung PY - 2010 SN - 978-3-89746-119-2 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. IS - Paper N-02 SP - 1 EP - 20 CY - Frankfurt/M. AN - OPUS4-22351 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Schmidtchen, Ulrich A1 - Holtappels, Kai T1 - Modeling the heat transfer in acetylene cylinders during and after the exposure to fire N2 - In this paper two different approaches for predicting the heating-up of an acetylene cylinder involved in a fire and the afterward cooling with water are presented. In the simulations polynomial functions were used to describe the temperature dependency of the thermal properties of the cylinder interior, which is a complex system composed by a solid porous material, a solvent (typically acetone) and acetylene dissolved in it. Model equations covered heat conduction in the cylinder interior and at its walls. In the first approach the cylinder surroundings were simulated as a further domain constituted by CO2, during the fire exposure, and for water, during the cooling. In this domain the coupled heat transfer (convection and conduction) and the momentum equation (Navier-Stokes) were solved. In the second approach no further domain was considered but boundary conditions were set directly on the cylinder walls. Results of the calculations performed with both approaches are presented. This work could prove helpful in predicting to which extent the interior of an acetylene cylinder exposed to fire reaches temperatures capable of initiating the decomposition of acetylene and to determine how long a water cooling should be applied, so that the system is brought again under non-critical conditions. KW - Safety KW - Acetylene KW - Heat transfer KW - Fire KW - Water cooling PY - 2010 DO - https://doi.org/10.1016/j.jlp.2010.06.012 SN - 0950-4230 SN - 1873-3352 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. VL - 23 SP - 654 EP - 661 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-21808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeps, Robert A1 - Rosenow, B. A1 - Kluge, Martin A1 - Blanchard, R. A1 - Holtappels, Kai T1 - Druckentlastungsvorgänge in großvolumigen Behältern N2 - Es wurden Druckentlastungsvorgänge in einem 5 m³ Autoklav mit einem L/D-Verhältnis von 1,14 nach der Zündung von Methan-Luft-Gemischen untersucht. Schwerpunkt der Arbeit war die Bestimmung der Explosionsdrücke, der zeitlichen Druckanstiege bzw. der KG-Werte und der reduzierten Explosionsdrücke in Abhängigkeit der Methankonzentration. Im geschlossenen Behälter wurden die Explosionsdrücke und zeitlichen Druckanstiege für Methan-Luft-Gemische mit Methankonzentrationen von 5,9 Vol-% bis 13,5 Vol-% ermittelt. Die Ergebnisse zeigen gute Übereinstimmung mit den Literaturwerten. Weiter wurden Druckentlastungsversuche mit einer kreisrunden Entlastungsfläche von 0,011 m² und einer Druckentlastungsfolie mit einem statischen Ansprechdruck von 1,94 bar durchgeführt. Hierbei wurden Gemische mit Methankonzentrationen von 5,9 Vol-% bis 14,3 Vol-% untersucht. Dabei zeigte sich, dass die vergleichsweise kleine Entlastungsfläche nur dann zu reduzierten Explosionsdrücken gleich dem statischen Ansprechdruck der Berstfolie führte, wenn die Methankonzentration ≤ 5,9 Vol-% oder ≥ 14,0 Vol-% betrug. Bei allen anderen untersuchten Methankonzentrationen führten die durch die Druckentlastung induzierten Turbulenzen zu einer Beschleunigung der Verbrennungsreaktion und zu Explosionsdrücken vergleichbar denen im geschlossenen Behälter. T2 - 14. Kolloquium zur chemischen und physikalischen Sicherheitstechnik (BAM-PTB-Kolloquium) CY - Berlin, Germany DA - 14.06.2016 KW - Druckentlastung KW - Up-Scale KW - Deflagration KW - Sicherheitstechnik PY - 2016 SN - 978-3-9817853-5-7 SN - 0938-5533 VL - 2016 SP - 21 EP - 28 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-37176 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Kreißig, Michael A1 - Hensel, Christina A1 - Schmidtchen, Ulrich A1 - Holtappels, Kai T1 - Preventing the explosion of acetylene cylinders involved in fire with help of numerical modeling N2 - The current paper describes a mathematical model, which was developed to simulate the heat transfer in acetylene cylinders during exposure to a fire. The cases of a direct engulfment of the cylinder in the flames and of exposure to a distant fire were considered. Furthermore, the model was also applied to the prediction of the heat transfer during the cooling with water of heated acetylene cylinders, in order to assess the effectiveness of this procedure as a measure to prevent the burst of the cylinder. To provide data for the definition and validation of the model a total of 13 bonfire tests with 8.9-, 10- and 50-dm³-cylinders were performed, where pressure and temperature measurements in the samples were performed. During 5 experiments the fire was extinguished before the expected cylinder burst and a cooling with water was applied. In the paper a short description of the experimental set-up and of the test results is given. Finally, a comparison with the model predictions is provided, showing reasonable agreement. KW - Acetylene cylinders KW - Fire KW - Explosion KW - Cooling KW - Numerical model PY - 2012 DO - https://doi.org/10.1016/j.jlp.2011.10.006 SN - 0950-4230 SN - 1873-3352 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. VL - 25 IS - 2 SP - 364 EP - 372 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-25137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Holtappels, Kai A1 - Kluge, Martin A1 - Ferrero, Fabio A1 - Schmidtchen, Ulrich T1 - Acetylenflaschen im Feuer N2 - Acetylen ist eines der wichtigsten technischen Gase und findet insbesondere Anwendung beim Schweißen und Schneiden verschiedener Werkstoffe. Damit Acetylen in entsprechenden Mengen vor Ort zur Verfügung gestellt werden kann, wird es in Druckgasbehälter abgefüllt. Im Falle eines Brandes stehen Acetylenflaschen im Verdacht, jederzeit – auch nach Löschen des Feuers – aufgrund einer möglicherweise initiierten Zerfallsreaktion zu bersten. Um insbesondere Personenschäden zu vermeiden, evakuieren und sperren die Rettungskräfte einen Sicherheitsbereich mit einem Radius von mindestens 200 m um die verdächtige Flasche ab. Gleichzeitig wird umgehend mit der Kühlung der Flasche begonnen. Wie lange muss aber eine Acetylenflasche gekühlt werden, bis sie sicher abtransportiert werden kann, und wie lange muss der Sicherheitsbereich mit dem großen Radius aufrecht erhalten werden? Diesen Fragen ist die BAM in den vergangenen Jahren im Rahmen verschiedener Untersuchungen und Projekte nachgegangen. KW - Acetylen KW - Druckbehälter KW - Poröses Material KW - Lösungsmittel PY - 2012 SN - 2191-0073 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. VL - 2 IS - 4 SP - 19 EP - 25 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-25902 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Schalau, Bernd A1 - Schulze, Marcel A1 - Kant, Hanjo A1 - Orchini, Alessandro ED - Ruggiero, Eric J. T1 - Experimental investigation of large-scale hydrogen diffusion jet flames N2 - Hydrogen is a promising alternative to natural gas in industrial energy applications which would serve the goal of limiting global warming. However, wide application of hydrogen requires specific safety considerations taking into account that hydrogen is stored and transported under much higher pressure than natural gas. Thus, one scenario to be considered for hazard assessment is a sudden release of hydrogen from a leakage or safety valve and its subsequent ignition. For hydrocarbon flames, various jet flame models are available. However, hydrogen flames significantly differ from hydrocarbon flames in their combustion behavior, so that the applicability of these models to hydrogen has to be investigated. For that purpose, reals scale tests were carried out at the BAM Test Site Technical Safety. In addition, hydrocarbon jet flames (methane) were investigated. In these tests, the flame geometry and the thermal heat radiation were investigated for a release angle of 90°, for different release pressures (up to 220 bar) and mass flows (up to 0.175 kg/s). While existing heat radiation data from the literature are mostly based on unsteady outflow conditions and/or releases in still air, the experiments presented here are focused on ensuring a constant mass flow over the release duration under realistic free field conditions (with wind influence). This allows a better comparability with the stationary jet flame models and assessment of wind influence on model predictions. A number of parameters such as the surface emissive power of the jet flame and the radiant heat fraction were determined. A detailed comparison of the obtained experimental results with literature radiation models was performed. Good agreement between experimental and literature data was found for hydrogen whereas significant differences were identified for methane. Based on the investigations, empirical equations for modelling jet flames could be derived. T2 - American Society of Mechanical Engineers - Turbomachinery Technical Conference & Exposition GT2025 CY - Memphis, TN, USA DA - 16.06.2025 KW - Hydrogen release KW - Jet flame KW - Radiant heat fraction KW - Thermal radiation PY - 2025 SN - 978-0-7918-8877-3 DO - https://doi.org/10.1115/GT2025-FM2 SP - 1 EP - 11 PB - The American Society of Mechanical Engineers CY - Livingston AN - OPUS4-64098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -