TY - CONF A1 - Altmann, Korinna A1 - Braun, U. T1 - Monitoring von Mikroplastik N2 - Der Vortrag gibt einen Überblick was bei der Analyse von Mikroplastik zu beachten ist und beschreibt die Vor- und Nachteile der TED-GC/MS. T2 - Abschlusstreffen MikroPlaTas CY - Online meeting DA - 23.06.2021 KW - Mikroplastik KW - TED-GC/MS KW - Mikroplastik-Analytik PY - 2021 AN - OPUS4-52916 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna A1 - Ciornii, Dmitri A1 - Hodoroaba, Vasile-Dan A1 - Braun, U. T1 - Requirements for inter-lab comparison studies and cooperation with CUSP and JRC N2 - Results from different methods applied to micro- and nanoplastics (MNPs) analysis show that there are large gaps in harmonisation with respect to terminology, size classes, sample preparation protocols and, finally, to the comparability of the measurands and descriptors. Within the European research cluster to understand the health impacts of micro- and nanoplastics (CUSP) working group WG3-Inter-Laboratory Comparisons an overview of the existing detection methods revealing advantages and disadvantages regarding the analytical tasks is being compiled. There is a clear need to develop high class characterized reference materials for MNPs in the size ranges of 100-10 µm and smaller than 10 µm, so that these can be used to validate methods and to make results comparable. Inter-laboratory comparisons (ILCs) on model samples with complex matrices regarding mass, or water samples for number-based methods, will help us to advance the process of harmonization as well as to train users early in process of developing new methods. We plan to keep all five CUSP projects well-connected also with the 'outside' MNP projects and ILCs and to extract the optimum of needs, capabilities, and efforts in order to launch new VAMAS ILCs which should expand already available ones. T2 - CUSP Meeting and General Assembly of PlasticsFatE CY - Online meeting DA - 13.12.2021 KW - CUSP KW - Microplastic KW - Inter-lab comparison KW - VAMAS KW - Reference materials PY - 2021 UR - https://cusp-research.eu/about/ AN - OPUS4-54036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna A1 - Hodoroaba, Vasile-Dan A1 - Braun, U. T1 - CUSP inter-laboratory comparisons N2 - In this breakout session first, an introduction is given on the planning and organisation of an inter-laboratory comparison (ILC) under the pre-standardisation plattform VAMAS within the newly formed technical working area TWA 45 Micro and Nano Plastics in the Environment. An update with the ILCs on micro- and nanoplastic performed so far is also given. In the third part, the requirements for a reference materials are presented. The needs from the different H2020 micro- and nanoplastic projects are collected and compiled in an ILC matrix for joint activities as the next steps. T2 - The European Research Cluster to Understand the Health Impact of Micro- and Nanoplastics (CUSP) Launching Event CY - Online meeting DA - 10.06.2021 KW - Microplastic KW - Nanoplastic KW - Inter-laboratory comparison KW - VAMAS KW - Reference material PY - 2021 AN - OPUS4-52808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altstädt, V. A1 - Köppl, T. A1 - Krämer, J. A1 - Wolff-Fabris, F. A1 - Döring, M. A1 - Pospiech, D. A1 - Schartel, Bernhard T1 - Phosphorous-based flame retardants for thermoplastic polyesters and carbon fibre reinforced epoxy composites T2 - 11th Annual UNESCO/IUPAC workshop & conference on functional polymeric materials & composites CY - Stellenbosch, South Africa DA - 2011-04-27 PY - 2011 AN - OPUS4-23416 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Annie Biwen A1 - Deland, Eric A1 - Kleinbub, Sherin A1 - Koerdt, Andrea T1 - Standardization of MIC laboratory testing: with a special focus on corrosive methanogens N2 - Microbiologically influenced corrosion (MIC) is a highly unpredictable process involving a complex group of microorganisms, including sulfate-reducing bacteria and methanogens. Standard laboratory MIC testing using static serum bottle enrichments is an easy but limited method, offering poor resolution on the biomineralization process of corrosion products. An example of this is the presumed corrosion product siderite by corrosive methanogens (Mi-MIC). Previous publications reported siderite was the sole corrosion product of M. maripaludis using metal coupons incubated under stationary conditions. However, the formation of siderite is closely related to the surrounding environmental conditions, i.e. pH, CO2 concentration, flow and temperature. Thus, siderite as the sole corrosion product of Mi-MIC remain inconclusive and questionable. To study Mi-MIC effectively, a novel versatile multiport flow-column corrosion monitoring system (MFC) was developed. MFC allows sectional corrosion rate determination under flow conditions using different types of material, inoculum and packing material. MFC offers great flexibility, ease of operation and accurate corrosion measurements that can be combined with many other techniques. Using MFC, we studied multiple strains of methanogens and compared it with sulfate-reducing bacteria under neutral and low pH conditions. It was revealed by MFC that corrosive methanogens have equally high corrosion potential as sulfate-reducing bacteria. Additionally, siderite is not the dominant nor sole corrosion product of Mi-MIC. Thus, effective corrosion monitoring and establishing standard laboratory practices, i.e. incorporating MFC as part of regular testing process, will provide deeper understanding of MIC. This will allow further microbial electrophysiology understandings, contributing to effective mitigation strategy development. T2 - EUROPEAN MIC NETWORK WEBINAR CY - Online meeting DA - 19.05.2020 KW - MIC KW - Methanogen KW - FIB/SEM KW - Corrosion products KW - Microbiologically influenced corrosion KW - Flow Model KW - Modelling KW - Korrosion PY - 2020 AN - OPUS4-51554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Biwen Annie A1 - Koerdt, Andrea A1 - Brüggemann, Kristin A1 - Wurzler, Nina A1 - Kleinbub, Sherin A1 - Özcan Sandikcioglu, Özlem T1 - Effect of biocides on highly corrosive methanogenic Archaea N2 - Biocide mitigation strategies of microbiologically influenced corrosion (MIC) in the oil and gas industry have been primarily used to eliminate the growths of sulfate-reducing microorganisms (SRM). However, methanogenic Archaea (MA) can also be highly corrosive by using iron as an electron source for methanogenesis. Because of the fundamental physiological differences between archaea and bacteria, responses of MA towards SRM-specific biocides cannot be deduced using SRM. Due to the lack of information available on the effect of biocides on corrosive MA, we selected THPS, glutaraldehyde, nitrate and perchlorate to compare against corrosive SRM. Preliminary results showed that at low concentrations of THPS (0-10 ppm), growth of MA was not affected, methane production and corrosion rates (0.1 mm/yr) were comparable between the different THPS concentrations. On the contrary, the SRM strain showed decreased corrosion rates (0.18 mm/yr to 0.03 mm/yr) with increasing THPS concentrations. Further corrosion tests including electrochemical measurements of different biocides on the growth of MA and SRM will be conducted. Such knowledge not only provide important insights on the physiological response of MA to biocides but also contribute to more effective mitigation strategies that can be both economic and environmentally beneficial. T2 - 25th Annual Reservoir Microbiology Forum CY - London, UK DA - 20.11.2019 KW - Corrosion KW - Methanogen KW - Microorganism KW - Biocide PY - 2019 AN - OPUS4-49788 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Biwen Annie A1 - Koerdt, Andrea A1 - Özcan Sandikcioglu, Özlem A1 - Schreiber, Frank A1 - Kleinbub, Sherin T1 - The study of methanogen-induced microbiologically influenced corrosion under flow conditions N2 - Microbiologically influenced corrosion (MIC) is an expensive but unpredictable problem for the industries. The most well-known culprit for MIC is the sulfate-reducing microorganisms (SRM), such as members from the genus Desulfovibrio. It has been widely accepted that SRM can contribute significantly to MIC through the production of hydrogen sulfide (HS-) or in some cases a direct electron uptake from the metal surface. However, in a real environmental system, SRM is not exclusive and often involved with other microorganisms that may also contribute to MIC, such as methanogens. Methanogenic archaea can produce methane (CH4) using H2+CO2, formate, methylated amines or acetate. Methanogens are highly abundant in the environment and many are found in very extreme conditions, such as high temperature and high salinity. Previous researches have demonstrated that methanogens are capable of MIC, though the specific mechanisms are still under investigation. In the oil and gas industry, methanogens are not considered as the main contributor for MIC since the corrosion rates are often too low. However, the tests for methanogen-induced MIC are usually performed at static conditions, which cannot represent the system accurately. Here, we developed a novel anaerobic system to evaluate the corrosion potential of methanogens under flow conditions. We will use the Methanococcus maripaludis KA1 strain, which was isolated from a crude oil tank, as the organism of interest. A separate system for Desulfovibrio alaskensis will be established for corrosion rate comparisons. Furthermore, we will study the synergistic effects of M. maripaludis and D. alaskensis on MIC under flow. T2 - Eurocorr 2018 CY - Krakow, Poland DA - 09.09.2018 KW - Mikrobiell beeinflusste Korrosion KW - Methanogen KW - Korrosion KW - Microbiologically influenced corrosion KW - Methanogenesis KW - Flow system KW - Model PY - 2018 AN - OPUS4-46012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anders, Stefan A1 - Mair, Georg A1 - Novak, Pavel T1 - Safety aspects of storage cylinders and their consequences on regulations T2 - StorHy 2006 StorHy EUROCOURSE Train-IN 2006 CY - Ingolstadt, Germany DA - 2006-09-25 PY - 2006 AN - OPUS4-14165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anders, Stefan T1 - Thermal loading cases of hydrogen high pressure storage cylinders T2 - ICHS International Conference on Hydrogen Safety CY - San Sebastián, Spain DA - 2007-09-11 PY - 2007 AN - OPUS4-15806 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anders, Stefan T1 - Besondere Aspekte des Eigenspannungszustandes in Compositeflaschen für Wasserstofffahrzeuge T2 - BAM-Kolloquium CY - Berlin, Germany DA - 2007-06-06 PY - 2007 AN - OPUS4-15809 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anders, Stefan T1 - Residual stresses in composite-metal structures for high pressure H2 gas cylinders T2 - CANCOM Conferenz CY - Winnipeg, Canada DA - 2007-08-14 PY - 2007 AN - OPUS4-15810 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anders, Stefan T1 - Betrachtungen zum Eigenspannunszustand von Typ-III Hochdruckbehältern T2 - CNG Round Table, BAM CY - Berlin, Germany DA - 2008-06-19 PY - 2008 AN - OPUS4-17668 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anders, Stefan A1 - Mair, Georg A1 - Novak, Pavel T1 - Composite Druckgasspeicher für Treibgas und Gefahrgut T2 - Behörden-Erfahrungsaustausch, BAM CY - Berlin, Germany DA - 2005-06-01 PY - 2005 AN - OPUS4-11268 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andres Arcones, Daniel A1 - Weiser, M. A1 - Koutsoureladkis, D.-S. A1 - Unger, Jörg F. T1 - Evaluation of Model Bias Identification Approaches Based on Bayesian Inference and Applications to Digital Twins N2 - In recent years, the use of simulation-based digital twins for monitoring and assessment of complex mechanical systems has greatly expanded. Their potential to increase the information obtained from limited data makes them an invaluable tool for a broad range of real-world applications. Nonetheless, there usually exists a discrepancy between the predicted response and the measurements of the system once built. One of the main contributors to this difference in addition to miscalibrated model parameters is the model error. Quantifying this socalled model bias (as well as proper values for the model parameters) is critical for the reliable performance of digital twins. Model bias identification is ultimately an inverse problem where information from measurements is used to update the original model. Bayesian formulations can tackle this task. Including the model bias as a parameter to be inferred enables the use of a Bayesian framework to obtain a probability distribution that represents the uncertainty between the measurements and the model. Simultaneously, this procedure can be combined with a classic parameter updating scheme to account for the trainable parameters in the original model. This study evaluates the effectiveness of different model bias identification approaches based on Bayesian inference methods. This includes more classical approaches such as direct parameter estimation using MCMC in a Bayesian setup, as well as more recent proposals such as stat- FEM or orthogonal Gaussian Processes. Their potential use in digital twins, generalization capabilities, and computational cost is extensively analyzed. T2 - 5th ECCOMAS Thematic Conference on Uncertainty Quantificationin Computational Sciences and Engineering CY - Athens, Greece DA - 12.06.2023 KW - Digital Twin KW - Simulation Models KW - Uncertainty Quantification KW - Model Bias PY - 2023 UR - https://2023.uncecomp.org/ AN - OPUS4-58226 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andresen, Elina A1 - Frenzel, Florian A1 - Würth, Christian A1 - Resch-Genger, Ute T1 - Upconversion for security tags and future applications N2 - NIR-excitable lanthanide nanocrystals (LnNC) show multi-color emission pattern composed of a multitude of narrow bands of varying intensity in the ultraviolet, visible, near-infrared, and short-wave infrared detectable with miniaturized optical instruments and simple color (RGB) cameras in complex environments. This makes these chemically inert luminescent materials ideal candidates for anticounterfeiting and authentication applications as well as for modules in optical sensors in which the LnNCs can be used as nanolamps in combination with analyte-sensitive fluorophores or the temperature sensitivity of defined emission bands can be utilized. Therefore, we are building up and exploring a platform of LnNC with application-specifically tuned size, composition, and surface chemistry. T2 - SHIFT 2022 CY - La Laguna, Tenerife, Spain DA - 10.10.2022 KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence PY - 2022 AN - OPUS4-56229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andresen, Elina A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Prinz, Carsten T1 - Assessing dissolution of upconverting nanoparticles by TEM, EDXS, potentiometry and fluorometry N2 - Inorganic lanthanide-doped upconversion nanoparticles (UCNP) constitute an emerging class of near-infrared (NIR)-excitable luminescent reporters for bioimaging, fluorescence assays, sensors in bioanalysis, and optical thermometry as well as phosphors for photovoltaic and security applications.1 However, the use of UCNPs in bioimaging and cellular studies requires biocompatible particles. One possible cause of UCNP toxicity is the release of potentially harmful fluoride fluoride and lanthanide ions as revealed by dilution studies in aqueous environments, particularly under high dilution conditions.2-5 To address this issue, suitable surface coatings preventing such effects in combination with fast screening methods suited for online in situ analysis are desired. Here we present a systematic study of differently sized β-NaYF4:Yb,Er nanocrystals stabilized with different surface coatings and different hydrophilic ligands varying in binding strength to the surface atoms in various aqueous environments at different temperatures. T2 - E-MRS Fall Meeting 2021 CY - Online meeting DA - 20.09.2021 KW - Dissolution KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence PY - 2021 AN - OPUS4-56231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andrés Arcones, Daniel A1 - Weiser, M. A1 - s Koutsourelakis, F. A1 - Unger, Jörg F. T1 - A Bayesian Framework for Simulation-based Digital Twins of Bridges N2 - Simulation-based digital twins have emerged as a powerful tool for evaluating the mechanical response of bridges. As virtual representations of physical systems, digital twins can provide a wealth of information that complements traditional inspection and monitoring data. By incorporating virtual sensors and predictive maintenance strategies, they have the potential to improve our understanding of the behavior and performance of bridges over time. However, as bridges age and undergo regular loading and extreme events, their structural characteristics change, often differing from the predictions of their initial design. Digital twins must be continuously adapted to reflect these changes. In this article, we present a Bayesian framework for updating simulation-based digital twins in the context of bridges. Our approach integrates information from measurements to account for inaccuracies in the simulation model and quantify uncertainties. Through its implementation and assessment, this work demonstrates the potential for digital twins to provide a reliable and up-to-date representation of bridge behavior, helping to inform decision-making for maintenance and management. T2 - EUROSTRUCT 2023 CY - Vienna, Austria DA - 25.09.2023 KW - Digital Twin KW - Simulation Models KW - Uncertainty Quantification KW - Model Bias PY - 2023 UR - https://eurostruct.org/eurostruct-2023/ AN - OPUS4-58663 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Angurel, L.A. A1 - Cubero, A. A1 - Martínez, E. A1 - de la Fuente, G.F. A1 - Navarro, R. A1 - Legall, Herbert A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Effects of laser surface processing under different atmospheres on the superconducting properties of pure niobium N2 - Niobium metal is the pure element with the highest superconducting critical temperature (T_c = 9.2 K), which is present in many applications. Particularly, in superconducting radio frequency (SRF) cavities of particle accelerators, the control of the surface characteristics of pure Nb is crucial, as the presence of defects may generate magnetic flux pinning that can increase by more than two orders of magnitude the surface critical current, ic. Several procedures such as chemical- or electro-polishing have been used aiming at cleaning surface contamination and decreasing its roughness. Sub-nanosecond lasers can be applied to generate a broad range of micro and nanostructures (e.g. Laser-Induced Periodic Surface Structures, LIPSS) that strongly modify the materials properties - as wettability, color, oxidation resistance or antibacterial behavior. In this work, we analyze a variety of surface structures generated on pure Nb sheets with different laser systems (UV, Vis and n-IR, fs and ps) by exploring a range of processing parameters. These include pulse overlap, irradiance or the effective number of pulses, under different atmospheres (air, N2, Ar, vacuum). The effects on Tc, critical currents and critical fields (Bc1, Bc2 and Bc3) have been obtained from magnetization, ac susceptibility and heat capacity measurements, revealing their dependence with the different surface nanostructures and the chemical changes generated with these laser treatments. T2 - E-MRS Spring Meeting 2021 CY - Online meeting DA - 31.05.2021 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Niobium KW - Superconductivity PY - 2021 AN - OPUS4-52730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anschütz, Franziska A1 - Schneider, Rudolf A1 - Franke, M. A1 - Bräutigam, P. A1 - Ondruschka, B. T1 - Innovative Wastewater Treatment with Cavitation Technologies: Removal of 17a-Ethinyl Estradiol in Aquatic System by Hydrodynamic-Acoustiv-Cavitation (HAC) T2 - 1st International Conference on Ultrasonic-based Applications: from Analysis to Synthesis CY - Lisbon, Portugal DA - 2014-09-15 PY - 2014 AN - OPUS4-32060 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Apel, Andreas A1 - Ballheimer, Viktor A1 - Kuschke, Christian A1 - Schubert, Sven A1 - Wille, Frank T1 - Approach for the use of Acceleration Values for Packages of Radioactive Material under Routine Conditions of Transport T2 - Radioactive Materials Transport and Storage Conference 2012 (RAMtransport 2012) CY - London, England DA - 2012-05-22 PY - 2012 AN - OPUS4-26610 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Apel, Andreas A1 - Ballheimer, Viktor A1 - Kuschke, Christian A1 - Schubert, Sven A1 - Wille, Frank T1 - Proposal for Regulatory Improvement on Load Assumption for Routine Conditions of Transport T2 - International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2013) CY - San Francisco, CA, USA DA - 2013-08-18 PY - 2013 AN - OPUS4-30272 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appajaiah, Anilkumar A1 - Kretzschmar, Hans-Jürgen T1 - Climatic Aging or Degradation of Plastic Optical Fibres (POFs): Chemical Analysis T2 - 11th International POF Conference 2002 CY - Tokyo, Japan DA - 2002-09-18 PY - 2002 AN - OPUS4-3550 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appajaiah, Anilkumar A1 - Kretzschmar, Hans-Jürgen T1 - Climating aging of PMMA based polymer optical fibres (POF): Analysis of polymer degradation T2 - 3th International IEEE Conference on polymers and adhesives in microelectronics and photonics (Polytronic 2003) CY - Montreux, Switzerland DA - 2003-10-21 PY - 2003 AN - OPUS4-5104 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appajaiah, Anilkumar T1 - Climating aging of polymer optical fibres (POF) - Chemical investigations T2 - 17. Fachgruppentreffen der ITG-Fachgruppe 5.4.1 "Optische Polymerfasern", Institut für Mikrotechnik CY - Mainz, Germany DA - 2003-11-04 PY - 2003 AN - OPUS4-5106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arconada, N. A1 - Ortel, Erik A1 - Hodoroaba, Vasile-Dan A1 - Gómez, E. A1 - Blanco, M. A1 - Goitandia, A. A1 - Haizea, Z. A1 - Erkiaga, A. A1 - Aranzabe, E. A1 - Stanciu, D. A1 - Isopescu, R. T1 - Synthsis of TiO2 Nanoparticles with controlled Characteristics by Sol-Gel Technology T2 - International summer workshop NANOSCIENCE meets METROLOGY CY - Erice, Italy DA - 2015-07-27 PY - 2015 AN - OPUS4-33872 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Zertifizierung nach Druckgeräte-Richtlinien und Überschneidung mit anderen Richtlinien N2 - Die BAM ist als Benannte Stelle im Rahmen der europäischen Richtlinien 97/23/EG über Druckgeräte (PED) [1] und 1999/36/EG über ortsbewegliche Druckgeräte (TPED) [2] bei der Zertifizierung von Ausrüstungsteilen für Druckgefäße (PED und TPED), Baugruppen (PED) und der Neubewertung von Baumustern (TPED) tätig. In diesem Beitrag wird die Zertifizierung einschließlich der dabei gewonnenen Erfahrungen und in der Praxis auftretenden Problemen auf Seiten der Hersteller und Benannten Stellen bei der Zertifizierung nach diesen europäischen Richtlinien vorgestellt. Die wesentlichen Probleme ergeben sich aus der Zuordnung der Druckgeräte zu entsprechenden Kategorien innerhalb der Richtlinien und aus der Überschneidung mit anderen europäischen und nationalen Richtlinien. T2 - 10. Kolloquium zu Fragen der chemischen und physikalischen Sicherheitstechnik, BAM CY - Berlin, Germany DA - 2004-06-17 PY - 2004 AN - OPUS4-4851 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Einfluss Europäischer Richtlinien und Nationaler Gesetze auf Tauchgeräte T2 - Taucher-Tage 2008 Aufkirchen CY - Munich, Germany DA - 2008-04-25 PY - 2008 AN - OPUS4-17691 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Die neue Europäische Richtlinie über ortsbewegliche Druckgeräte - Was kommt, was geht, was bleibt? T2 - 14. Gefahrgutkongress Mecklenburg-Vorpommern CY - Rostock, Germany DA - 2010-10-27 PY - 2010 AN - OPUS4-22319 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Neue Informationen und Erfahrungsaustausch zu in Feuerlöschern verwendeten ortsbeweglichen Druckgeräten N2 - Im Vortrag werden die aktuellen Anforderungen an die Beförderung von Feuerlöschern UN 1044 und an in tragbaren/fahrbaren Feuerlöschern verwendete Treibgasflaschen vorgestellt. Es wird auf die damit verbundenen praktischen Probleme sowie aktuelle Lösungsansätze eingegangen. T2 - Fortbildung GRIF CY - Prichsenstadt, Germany DA - 07.09.2021 KW - ADR KW - Ortsbewegliche Druckgeräte KW - TPED KW - Tragbare Feuerlöscher KW - Treibgasflaschen PY - 2021 AN - OPUS4-53265 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Atemschutzflaschen und Atemschutzgeräte im Blickpunkt Europäischer Richtlinien T2 - 17. Fachtagung "Seminar Atemschutz" der Landesfeuerwehrschule Sachsen CY - Hoyerswerda, Germany DA - 2014-02-20 PY - 2014 AN - OPUS4-30254 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Normung von Gasflaschenventilen im ISO/TC 58, CEN/TC 23 und DIN/NDG/AA03 T2 - 23. BAM-DIN-IGV-Jahrestreffen CY - Berlin, Germany DA - 2014-02-19 PY - 2014 AN - OPUS4-30256 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Atemschutzflaschen und Atemschutzgeräte im Blickpunkt Europäischer Richtlinien T2 - Fortbildung für Ausbilder von Atemschutzgerätewarten der Deutschen Landesfeuerwehrschulen CY - Kassel, Germany DA - 2013-05-13 PY - 2013 AN - OPUS4-31088 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Aktuelle Entwicklungen im Bereich der Druckgeräterichtlinien PED und TPED T2 - 8. Europäische Druckgerätetage CY - Fürstenfeldbruck, Germany DA - 2009-06-24 PY - 2009 AN - OPUS4-19558 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Atemschutzflaschen im Blickpunkt der Europäischen Richtlinien über Druckgeräte T2 - Fortbildung der Ausbilder von Atemschutzgerätewarten der Deutschen Landesfeuerwehrschulen CY - Kassel, Germany DA - 2011-05-03 PY - 2011 AN - OPUS4-23650 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Aktueller Stand der Normung von Gasflaschenventilen N2 - Im Vortrag wird der aktuelle Stand der Normung von Gasflaschenventilen vorgestellt. Dieser umfasst nationale, europäische und internationale Normen, die größtenteils im Bereich der Gefahrgutbeförderung verbindlich anzuwenden sind. T2 - 25. Jahrestreffen BAM/DIN/DVFG/IGV CY - Berlin, Germany DA - 21.02.2018 KW - Gasflaschenventile KW - Normung KW - ADR PY - 2018 AN - OPUS4-44330 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Konformitätsbewertung von ortsbeweglichen Druckgeräten nach Richtlinie 2010/35/EU (TPED) N2 - Im Vortrag wird auf die rechtlichen Grundlagen der Richtlinie 2010/35/EU eingegangen. Dies umfasst die Definition von ortsbeweglichen Druckgeräten, die an sie gestellten technischen Anforderungen und die Anforderungen an deren Konformitätsbewertung. Des Weiteren wird die Anwendung der Richtlinie auf Feuerlöscher und deren Treibgasflaschen diskutiert T2 - Fortbildung GRIF CY - Würzburg, Germany DA - 15.09.2017 KW - Ortsbewegliche Druckgeräte KW - Tragbare Feuerlöscher KW - Treibgasflaschen PY - 2017 AN - OPUS4-43957 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Quick-release cylinder valves according to EN ISO 17871 and EN 12094-4 N2 - The presentation deals with the different requirements for quick-release cylinder valves used for transport of dangerous goods (TPED/ADR) and construction products (CPR) and the posssibility for a future harmonization. T2 - Normungssitzung CEN/TC 191/WG 6 CY - Berlin, Germany DA - 27.06.2018 KW - Construction products KW - Quick-release cylinder valves KW - Transport of dangerouss goods PY - 2018 AN - OPUS4-45440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Regelsetzung zu Ventilschutz und Sicherheitsventilen N2 - Im Vortrag wird auf die aktuellen Anforderungen aus dem Gefahrgutbeförderungsrecht an Ventilschutz einschließlich Schutzkragen als integraler Bestandteil einiger Gasflaschen und LPG-Sicherheitsventilen eingegangen. Des Weiteren werden die aktuell laufenden Revisionen der Normen EN ISO 11117 für Ventilschutz und EN 13953 für LPG-Sicherheitsventile diskutiert. T2 - DVFG Forum Flüssiggas 2018 CY - Leipzig, Germany DA - 12.06.2018 KW - Ventilschutz KW - Sicherheitsventile KW - Flüssiggas PY - 2018 AN - OPUS4-45192 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Konformitätsbewertung von ortsbeweglichen Druckgeräten - speziell Treibgasflaschen - nach Richtlinie 2010/35/EU (TPED) N2 - Im Vortrag wird auf die rechtlichen Grundlagen der Richtlinie 2010/35/EU eingegangen. Dies umfasst die Definition von ortsbeweglichen Druckgeräten, die an sie gestellten technischen Anforderungen und die Anforderungen an deren Konformitätsbewertung. Des Weiteren wird die Anwendung der Richtlinie auf Feuerlöscher und deren Treibgasflaschen sowie die damit verbundenen Probleme in der Praxis diskutiert. T2 - Fortbildung GRIF CY - Prichsenstadt, Germany DA - 11.09.2019 KW - Ortsbewegliche Druckgeräte KW - Treibgasflaschen KW - Tragbare Feuerlöscher KW - TPED KW - ADR KW - Konformitätsbewertung PY - 2019 AN - OPUS4-49024 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Neue Informationen und Erfahrungsaustausch zu in Feuerlöschern verwendeten ortsbeweglichen Druckgeräten N2 - Im Vortrag werden die aktuellen Anforderungen an die Beförderung von Feuerlöschern UN 1044 und an in tragbaren/fahrbaren Feuerlöschern verwendete Treibgasflaschen vorgestellt. Es wird auf die damit verbundenen praktischen Probleme sowie aktuelle Lösungsansätze eingegangen. T2 - Fortbildung GRIF CY - Online meeting DA - 08.09.2020 KW - ADR KW - Ortsbewegliche Druckgeräte KW - TPED KW - Tragbare Feuerlöscher KW - Treibgasflaschen PY - 2020 AN - OPUS4-51232 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Aktueller Stand der Normung von Gasflaschenventilen N2 - Im Vortrag wird der aktuelle Stand der Normung von Gasflaschenventilen vorgestellt. Dieser umfasst nationale, europäische und internationale Normen, die größtenteils im Bereich der Gefahrgutbeförderung verbindlich anzuwenden sind. T2 - 27. Jahrestreffen BAM/DIN/DVFG/IGV CY - Berlin, Germany DA - 27.02.2020 KW - ADR KW - Gasflaschenventile KW - Normung PY - 2020 AN - OPUS4-50701 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Konformitätsbewertung von ortsbeweglichen Druckgeräten nach Richtlinie 2010/35/EU (TPED) N2 - Im Vortrag werden die Anforderungen und das Konformitätsbewertungsverfahren für ortsbewegliche Druckgeräte nach Richtlinie 2010/35/EU (TPED) vorgestellt. Dabei werden auch aktuell bekannte Probleme mit ortsbeweglichen Druckgeräten als Input für die Marktüberwachung angesprochen. T2 - Schulung ODV/ADR CY - Potsdam, Germany DA - 07.08.2019 KW - Ortsbewegliche Druckgeräte KW - TPED KW - ODV KW - ADR KW - Konformitätsbewertung KW - Marktüberwachung PY - 2019 AN - OPUS4-48697 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Aktueller Stand der Normung von Gasflaschenventilen N2 - Im Vortrag wird der aktuelle Stand der Normung von Gasflaschenventilen vorgestellt. Dieser umfasst nationale, europäische und internationale Normen, die größtenteils im Bereich der Gefahrgutbeförderung verbindlich anzuwenden sind. T2 - 28. Jahrestreffen BAM/DIN/DVFG/IGV CY - Online meeting DA - 24.02.2021 KW - ADR KW - Gasflaschenventile KW - Normung PY - 2021 AN - OPUS4-52115 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Aktueller Stand der Normung von Gasflaschenventilen N2 - Der Vortrag gibt einen Überblick über den aktuellen Stand der Normung von Gasflaschenventilen im Bereich des Gefahrgutbeförderungsrechts. T2 - 24. Jahrestreffen BAM/DIN/IGV CY - Berlin, Germany DA - 15.02.2017 KW - Gasflaschenventile KW - Normung PY - 2017 AN - OPUS4-39236 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Konformitätsbewertung von ortsbeweglichen Druckgeräten - speziell Treibgasflaschen - nach Richtlinie 2010/35/EU (TPED) N2 - Im Vortrag wird auf die rechtlichen Grundlagen der Richtlinie 2010/35/EU eingegangen. Dies umfasst die Definition von ortsbeweglichen Druckgeräten, die an sie gestellten technischen Anforderungen und die Anforderungen an deren Konformitätsbewertung. Des Weiteren wird die Anwendung der Richtlinie auf Feuerlöscher und deren Treibgasflaschen sowie die damit verbundenen Probleme in der Praxis diskutiert. T2 - Fortbildung GRIF CY - Prichsenstadt, Germany DA - 11.09.2018 KW - Ortsbewegliche Druckgeräte KW - Treibgasflaschen KW - Tragbare Feuerlöscher KW - TPED PY - 2018 AN - OPUS4-45962 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aris, Stephan T1 - Aktueller Stand der Normung von Gasflaschenventilen N2 - Im Vortrag wird der aktuelle Stand der Normung von Gasflaschenventilen vorgestellt. Dieser umfasst nationale, europäische und internationale Normen, die größtenteils im Bereich der Gefahrgutbeförderung verbindlich anzuwenden sind. T2 - 26. Jahrestreffen BAM/DIN/DVFG/IGV CY - Berlin, Germany DA - 27.02.2019 KW - Normung KW - ADR KW - Gasflaschenventile PY - 2019 AN - OPUS4-47470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela T1 - Polyaniline/SiO2 Containing Coatings for Geothermal Application N2 - Geothermal brine is considered to be an aggressive environment as it contains various dissolved salts. Even though carbon steel is commonly used as a construction material due to its machinability and economical reason, it is susceptible to uniform and localized corrosion in a high temperature and high pressure system. Therefore, a coating system is introduced to protect the carbon steel against corrosion in such environment. 1. Carbon steel is susceptible to uniform corrosion in presence of oxygen, with corrosion rate of immersion at 150 °C of 0.39 mm/a. 2. Exposure test of carbon steel at 150°C and 10 bar (pressurized by Ar) results in pitting corrosion with depth of 19 µm and width 4 µm on average. 3. OCP measurement shows that the stability of measurement is reached after 40 hours of immersion in the solution. 4. EIS measurement is useful to observe the effect of temperature, immersion time, and coating composition on the corrosion processes of coated metals for use in geothermal application. T2 - FU Forschungsseminar CY - Berlin, Germany DA - 28.11.2017 KW - Geothermal KW - Corrosion KW - Coating PY - 2017 AN - OPUS4-43363 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Bäßler, Ralph A1 - Roth, C. T1 - Electrochemical measurement of polyaniline containing coating at high temperature: PROBLEMS AND CHALLENGES N2 - This presentation describes special aspects when performing measurements at high temperatures. Especially electrochemical issues are addressed for impedance spectroscopy, like overlapping time constants, handling of noise etc. T2 - Electrochemical Doctoral School “Corrosion: from analysis to modelling” CY - Brussels Belgium DA - 04.02.2019 KW - Polyaniline KW - Geothermal KW - Electrochemical impedance spectroscopy PY - 2019 AN - OPUS4-47917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Bäßler, Ralph A1 - Roth, C. T1 - Polyaniline/silicon dioxide containing coating for use in artificial geothermal brines N2 - Geothermal brine is a complex system containing a wide variety of dissolved salts resulting from the condition s in a geothermal well. These fluids lead to corrosion in pipes and other parts of geothermal system construction and necessitate intense research efforts in finding new suitable materials. Carbon steel is susceptible to corrosion in geothermal brine especially when it is exposed to a high temperature and high-pressure medium, which is considered to be an aggressive environment. An artificial geothermal water, bas ed on a brine composition found in Indonesia, was used to investigate the performance of high alloyed materials. The electrolyte has pH 4 and contains 1,500 mg/l Cl-, 20 mg/l SO4 2-, 15 mg/l HCO3 -, 200 mg/l Ca 2+, 250 mg/l K+, and 600 mg/l Na+. In order to protect the bare material in geothermal application, it is necessary to either use high alloyed material s or coatings. In this research, a coating system consisting of polyaniline and silicon dioxide was investigated regarding its behavior to protect carbon steel. In detail, the effect of SiO2 and polyaniline (PANi) addition was evaluated by exposure and electrochemical tests for 7 days, i.e. electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) at room temperature and 150 °C with 1 MPa pressure. T2 - NACE International Annual Corrosion Conference CY - Phoenix, AZ, USA DA - 15.04.2018 KW - Geothermal KW - Coating KW - SiO2 KW - Polyaniline KW - Corrosion PY - 2018 AN - OPUS4-44919 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela T1 - Corrosion study of carbon steel in Indonesian geothermal brine N2 - Results of corrosion studies performed on carbon steel in saline brine are presented and discussed. T2 - PhD-Seminar at Institut Teknologi Sepuluh Nopember (ITS) CY - Surabaya, Indonesia DA - 09.11.2018 KW - Corrosion KW - Electrochemistry PY - 2018 AN - OPUS4-46743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela T1 - Fenomena Korosi pada aplikasi panas bumi N2 - To accelerate the development of Indonesian geothermal energy, progress should be done in all aspects. Corrosion is an important part on the technological development to ensure the safety and longevity of a power plant. T2 - Fireside Chat der Indonesischen Botschaft CY - Berlin, Germany DA - 21.11.2019 KW - Corrosion KW - Korosi KW - Korrosion PY - 2019 AN - OPUS4-49735 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Electrochemical deposition of polyaniline on carbon steel for corrosion study in geothermal solution N2 - Polyaniline has been widely developed for many applications, e.g., sensor, supercapacitor component, electrochromic devices, and anticorrosion pigments [1]. Although the addition of polyaniline pigment in organic coatings has been an alternative for corrosion protection in industrial application, the protection mechanism is still not fully understood [2]. Herein in this study, as a part of the development of polyaniline/silicon dioxide coating for geothermal application, polyaniline has been deposited electrochemically on carbon steel surface and tested in geothermal solution to study the contribution of polyaniline in the corrosion protection of a polyaniline-based composite in the geothermal system. The electrochemical deposition was carried out by immersing carbon steel in 0.1 M oxalic acid and 0.05 M aniline, with the polarization potential of -0.6 – 1.5 V vs. Ag/AgCl, and a scan rate of 10 mV/s. To observe the surface/interface reaction between the electrolyte and electrode surface during the electrochemical polymerization, electrochemical impedance spectroscopy (EIS) measurement was applied after each cycle. For corrosion study in the geothermal application, this experiment used an artificial geothermal solution with the composition of 1,500 mg/l Cl-, 20 mg/l SO42-, 15 mg/l HCO3-, 200 mg/l Ca2+, 250 mg/l K+, and 600 mg/l Na+, and pH 4 to simulate a geothermal brine found in Sibayak, Indonesia. Electrochemical measurements were performed by monitoring the open circuit potential over seven days, with the interruption of EIS every 22 hours. The experiments were performed at room temperature and 150 °C (1 MPa) in a free oxygen environment. Polyaniline coated carbon steel is more durable in a room temperature environment compared to 150 °C, which could be caused by the iron oxalate dissolution at elevated temperature. This degradation was further proven by the impedance spectra, which showed a reduction of approximately ten times for specimens measured at 150 °C as compared to the specimens measured at room temperature. T2 - 4th International Conference on Functional Materials Science 2018 (ICFMS 2018) CY - Bali, Indonesia DA - 13.11.2018 KW - Polyaniline KW - Electrochemical deposition KW - Corrosion PY - 2018 AN - OPUS4-46742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Roth, C. T1 - The Effect of Different Polyaniline Types in Silicon Dioxide Containing Coatings for Carbon Steel Protection in Artificial Geothermal Brines N2 - According to the results of the experiments carried out, the following points can be concluded: 1. Exposure tests showed that specimens with the addition of SiO2 particles and polyaniline particles exhibit better corrosion resistance than specimens with the addition of only polyaniline particles or binder only. 2. Open circuit potential measurements showed that in the beginning of the experiments, both coatings had an open circuit potential 100 mV higher than carbon steel. Within one day of immersion, the potential of carbon steel increased significantly, indicating the formation of oxide layer. After extended exposure the carbon steel potential sat between PS1 (which had higher potential) and PS2 (which had a lower potential) and all three were in the range –600 mV to –500 mV vs Ag/AgCl. 3. Both coatings PS-1 and PS-2 were degraded with increasing exposure time, shown by the decrease of absolute impedance value at low frequency range after 2, 4, and 6 days exposure. 4. Potentiodynamic test was performed after 3 hours and 6 days exposure, and it was shown that the coating in the initial stage exhibited more passive behavior than the specimens exposed for 6 days. T2 - NACE International Corrosion Conference 2019 CY - Nashville, TN, USA DA - 24.03.2019 KW - Geothermal KW - Coating KW - Polyaniline KW - Corrosion PY - 2019 AN - OPUS4-47914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela T1 - Fireside Chat - Sharing PhD N2 - Erfahrung einer indonesischen Stipendiatin beim Aufenthalt in Deutschland als Doktorandin; Hinweise und Empfehlungen für indonesische Jungwissenschaftler und Studenten T2 - Fireside Chat der Indonesischen Botschaft CY - Berlin, Germany DA - 21.11.2019 KW - Indonesien PY - 2019 AN - OPUS4-49737 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Weritz, Friederike A1 - Wiggenhauser, Herbert T1 - Ortung von Putzablösungen auf Beton und Mauerwerk mit der Puls-Phasen-Thermografie T2 - DACH-Jahrestagung 2004: ZfP in Forschung, Entwicklung und Anwendung CY - Salzburg, Austria DA - 2004-05-17 PY - 2004 AN - OPUS4-4016 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Weritz, Friederike A1 - Wiggenhauser, Herbert T1 - Structural investigation of concrete and masonry structures behind plaster by means of pulse phase thermography T2 - The 7th International Conference on Quantitative Infrared Thermography (QIRT) 2004, Karman Institute CY - Sint-Genesius-Rode, Belgium DA - 2004-07-05 PY - 2004 AN - OPUS4-4020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Helmerich, Rosemarie A1 - Maierhofer, Christiane A1 - Röllig, Mathias T1 - Quantitative pulse-phase-thermography for composites and concrete structures T2 - Structural Faults & Repair 2006 CY - Edinburgh, Scotland DA - 2006-06-13 PY - 2006 AN - OPUS4-12441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf T1 - Impuls-Thermografie und Puls-Phasen-Thermografie zur Qualitätssicherung von Beschichtungen T2 - Workshop zur Anwendung der Impuls-Thermografie im Bauwesen CY - Berlin, Germany DA - 2005-04-21 PY - 2005 AN - OPUS4-11288 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf T1 - Square pulse thermography in frequency domain T2 - Thermosense XXX 2008 as part of the SPIE DSS Symposium CY - Orlando, FL, USA DA - 2008-03-18 PY - 2008 AN - OPUS4-17478 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Gaulke, A. T1 - Thermography investigations and numerical analysis of turbulent and laminar flow at light weight structures T2 - Thermosense XXX 2008 as part of the SPIE DSS Symposium CY - Orlando, FL, USA DA - 2008-03-18 PY - 2008 AN - OPUS4-17479 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Helmerich, Rosemarie A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Wiggenhauser, Herbert T1 - Adaptation of pulsed phase thermography for quantitative NDT in civil engineering T2 - INDE07- Imaging NDE 2007, Application of Thermal Imaging CY - Kalpakkam, India DA - 2007-04-25 PY - 2007 AN - OPUS4-16017 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arnold, B. A1 - Burger, H. A1 - Drott, U. A1 - Hahn, Oliver A1 - Kaun, S. A1 - Laue, S. A1 - Noll-Minor, M. A1 - Raue, J. A1 - Schlütter, F. A1 - Ziemann, M. T1 - Pigmentveränderungen - Verschwärzen von Bleizinngelb T2 - Jahrestagung Archäometrie und Denkmalpflege 2010 CY - Bochum, Germany DA - 2010-09-15 PY - 2010 AN - OPUS4-21777 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arrigoni, M. A1 - Bedon, C. A1 - Larcher, M. A1 - van Doormaal, A. A1 - Haberacker, C. A1 - Hüsken, Götz A1 - Millon, O. A1 - Saarenheimo, A. A1 - Solomos, G. A1 - Thamie, L. A1 - Valsamos, G. A1 - Williams, A. A1 - Stolz, A. T1 - Recommendations for a new generation of standards for testing numerical assessment of blast-loaded glass windows N2 - The determination of the blast protection level of civil engineering buildings components against explosive effects represents a topic of crucial importance, in current practice. However, some key aspects of blast resistant structures design have been only marginally considered in the last decade, and currently still require appropriate regulations. This is especially true in the case of windows and facades, where the intrinsic material brittleness is the major influencing parameter for blast-resistant assemblies. While blast assessment of buildings and systems is usually achieved by means of experimental investigations, as well as numerical simulations, general regulations and guidelines are currently missing. In this regard, the European Reference Network for Critical Infrastructure Protection (ERNCIP) Thematic Group “Resistance of Structures to Explosion Effects” attempts to develop guidelines and recommendations aimed to harmonise test procedures in experimental testing of glass windows under blast, as well as standardized approaches for their vulnerability assessment via numerical modelling. In this paper, major Thematic Group outcomes and next challenges are briefly summarized. T2 - International Conference on Structural and Mechanical Engineering for Security and Prevention - ICSMESP 2017 CY - Prague, Czech Republic DA - 14.06.2017 KW - Blast protection KW - Blast loaded glass windows KW - Experimental testing KW - Finite element numerical modelling KW - Standardisation PY - 2017 AN - OPUS4-41926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arroyo-Abad, Uriel A1 - Piechotta, Christian A1 - Mattusch, J. T1 - Arsenolipids in marine fish: Occurence and Perspective T2 - Anakon 2015 CY - Graz, Austria DA - 2015-03-23 PY - 2015 AN - OPUS4-33647 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arroyo-Abad, Uriel A1 - Piechotta, Christian A1 - Mattusch, J. T1 - Arsenolipids in marine fish: Occurence and Perspective T2 - CANAS - Colloquium Analytische Atomspektroskopie CY - Leipzig, Germany DA - 2015-03-08 PY - 2015 AN - OPUS4-33648 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Mathematical analysis of the bulging effect in high power laser beam welding of thick steel sheets N2 - The present work is devoted to the mathematical analysis of the bulging effect in high-power laser beam welding of thick steel sheets. The numerical results are based upon experimental results from previous studies, revealing the relationships between the bulging effect, the hot cracking formation, and the distribution of alloying elements in the weld pool. The widening of the molten pool in its middle area is observed for both complete and partial penetration welding of 8 mm - 15 mm thick structural steel sheets. The weld pool shape is extracted from the simulations to evaluate the extent of the necking and bulging of the solidification isotherm and their influence on the hot cracking formation and the mixing behavior of the weld pool. Relying on an earlier numerical study utilizing a fixed keyhole, simulation models considering a dynamic keyhole are developed thereto. The link between the bulge and the studied phenomena is found to be significant. T2 - Beam Technologies & Laser Applications CY - Saint Petersburg, Russia DA - 20.09.2021 KW - Deep penetration laser beam welding KW - Bulge effect KW - Numerical modelling KW - Hot cracking KW - Necking KW - Mixing behavior PY - 2021 AN - OPUS4-53375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Numerical study of the bulging effect in deep penetration laser beam welding N2 - This article is devoted to the study of the bulging effect in deep penetration laser beam welding. The numerical results of the investigations are based upon experimental results from previous studies to reveal the relationship between the bulging effect and the hot cracking formation, as well as the mixing of alloying elements in the weld pool. The widening of the molten pool in its center area can be observed in full penetration as well as in partial penetration welds on 8 mm and 12 mm thick structural steel plates, respectively. The weld pool shape is extracted from the simulations to evaluate the extent of the necking of the solidification line as well as the bulging phenomena and its influence on the hot cracking phenomena. Relying on an earlier numerical study utilizing a fixed keyhole, simulation models considering a dynamic keyhole are developed thereto. Additionally, the mixing behavior of alloying elements during partial penetration is investigated. The link between the bulge and the studied phenomena is found to be significant. T2 - Lasers in Manufacturing Conference 2021 CY - Online meeting DA - 21.06.2021 KW - Deep penetration laser beam welding KW - Welding simulation KW - Solidification cracking KW - Bulging effect PY - 2021 AN - OPUS4-52847 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Numerical study on the formation of a bulging region in partial penetration laser beam welding N2 - A transient three-dimensional thermo-fluid dynamics numerical model was developed to study the formation of a bulging region in partial penetration laser beam welding. The model accounts for the coupling between the fluid flow, the heat transfer, and the keyhole dynamics by considering the effects of multiple reflections and Fresnel absorption of the laser beam in the keyhole, the phase transitions during melting and evaporating, the thermo-capillary convection, the natural convection, and the phase-specific and temperature-dependent material properties up to the evaporation temperature. The validity of the model was backed up by experimentally obtained data, including the drilling time, the weld pool length, the local temperature history outside the weld pool, the process efficiency, and a range of metallographic cross-sections. The model was applied for the cases of partial penetration laser beam welding of 8 mm and 12 mm thick unalloyed steel sheets. The obtained experimental and numerical results reveal that the bulging region forms transiently depending on the penetration depth of the weld, showing a tendency to transition from a slight bulging to a fully developed bulging region between penetration depths of 6 mm and 9 mm, respectively. T2 - The 13th International Seminar "Numerical Analysis of Weldability" CY - Graz - Castle Seggau, Austria DA - 04.09.2022 KW - Laser beam welding KW - Deep penetration KW - Bulge formation KW - Numerical modeling PY - 2022 AN - OPUS4-55719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Meng, Xiangmeng A1 - Karkhin, Victor A1 - Rethmeier, Michael T1 - On the relationship between the bulge effect and the hot cracking formation during deep penetration laser beam welding N2 - Recent studies have confirmed the widening of the weld pool interface, known as a bulge effect, during deep penetration high power laser beam welding. The link between such geometric particularities of the weld pool shape and the hot cracking phenomena is significant. The present work seeks to extend the level of understanding by investigating their relationship. A coupled multiphysics, multiscale numerical framework is developed, comprising a series of subsequent analyses. The study examines the influences of the bulge on the three most dominant effects causing hot cracking, namely the thermal cycles, the mechanical loading, and the local microstructure. The bulge in the weld pool shape forms approximately in the middle of the plate, thus correlating with the location of hot cracking. It increases the hot cracking susceptibility by enhancing the three dominant effects. The numerical results are backed up by experimental data. T2 - 11th CIRP Conference on Photonic Technologies [LANE 2020] CY - Online meeting DA - 07.09.2020 KW - Hot cracking KW - Bulge effect KW - Numerical modelling KW - Laser beam welding KW - Deep penetration PY - 2020 AN - OPUS4-51277 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - A decoupling numerical approach for the study of hot cracking formation during high power keyhole mode welding of steel plates with a high sheet thickness N2 - The weld pool dynamics and shape play a fundamental role in keyhole mode welding. The presented work aims the experimental and numerical investigation of the influence of the weld pool characteristics on the formation of hot cracking. The experimental procedure allows recording the molten pool in the longitudinal section of a butt joint configuration of 15 mm thick structural steel and transparent quartz glass by using a high-speed video camera and two thermal imaging cameras. The observations show that the dimensions of the weld pool vary depending on the depth. The regions close to the surface form a teardrop-shaped weld pool. A bulge-region and its temporal evolution are observed approximately in the middle of the depth of the weld pool, where hot cracking appears. A numerical framework including models for the weld pool dynamics, global temperature field, transient stress state, crystal growth, diffusion and macro-segregation and subroutines for their one-way couplings is developed. The numerically obtained and experimentally observed results are in a good agreement. It is shown that the bulge-region leads to a delay in the solidification behavior, increased temporal tensile stresses and accumulation of impurities in the defect region and hence enhance the probability of hot cracking formation. T2 - Colloquium, National Institute of Standards and Technology, Physical Measurements Laboratory, Applied Physics Division CY - Boulder, Colorado, USA DA - 15.10.2019 KW - Keyhole mode welding KW - Weld pool shape KW - Bulge KW - Hot cracking PY - 2019 AN - OPUS4-49338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - A decoupling numerical approach for the study of hot cracking formation during high power keyhole mode welding of steel plates with a high sheet thickness N2 - The weld pool dynamics and shape play a fundamental role in keyhole mode welding. The presented work aims the experimental and numerical investigation of the influence of the weld pool characteristics on the formation of hot cracking. The experimental procedure allows recording the molten pool in the longitudinal section of a butt joint configuration of 15 mm thick structural steel and transparent quartz glass by using a high-speed video camera and two thermal imaging cameras. The observations show that the dimensions of the weld pool vary depending on the depth. The regions close to the surface form a teardrop-shaped weld pool. A bulge-region and its temporal evolution are observed approximately in the middle of the depth of the weld pool, where hot cracking appears. A numerical framework including models for the weld pool dynamics, global temperature field, transient stress state, crystal growth, diffusion and macro-segregation and subroutines for their one-way couplings is developed. The numerically obtained and experimentally observed results are in a good agreement. It is shown that the bulge-region leads to a delay in the solidification behavior, increased temporal tensile stresses and accumulation of impurities in the defect region and hence enhance the probability of hot cracking formation. T2 - Colloquium, Dept. Materials Science & Engineering, The Ohio State University CY - Columbus, Ohio, USA DA - 18.10.2019 KW - Keyhole mode welding KW - Weld pool shape KW - Bulge KW - Hot cracking PY - 2019 AN - OPUS4-49339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Rethmeier, Michael A1 - Karkhin, V. T1 - Mathematical modeling of the geometrical differences between the weld end crater and the steady-state weld pool N2 - The geometrical characteristics of the weld end crater are commonly used for the validation of numerical results in welding simulation. A semi-analytical model calculating the cooling stage of the welding process after the moving energy source is turned off has been developed. A solution for various combinations of heat sources and workpieces has been found. The theoretical limits for the heat transfer of the absorbed energy during cooling in a thin plate and a semi-infinite body were studied. It is shown that after turning off the energy source, an additional melting of the base material in longitudinal direction may occur. The developed technique is applied to complete-penetration keyhole laser beam welding of a 2 mm thick austenitic chromium-nickel 316L steel plate at a welding speed of 20 mm/s and a laser power of 2.3 kW. The results show a theoretical increase of the weld end crater length in comparison to the length of the steady-state weld pool of up to 19 %. A shift of the centre of the end crater, in which the solidification of the liquid metal ends, towards the tail of the end crater relative to the axis of the heat source at the time of its termination, was computed. The speed and the direction of crystallization of the molten material in the weld pool and the end crater were found to be different. A good agreement between the computational results and the welding experiments was achieved. T2 - ICALEO 2019 - The International Congress on Applications of Lasers & Electro-Optics CY - Orlando, FL, USA DA - 07.10.2019 KW - Keyhole mode welding KW - Weld pool shape KW - End-crater KW - Heat conduction PY - 2019 AN - OPUS4-49341 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Karkhin, Victor A1 - Khomich, P. A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Assessment of welding thermal cycles by boundary element method N2 - A numerical framework simulation of the steady-state thermal behaviour in keyhole mode welding has been developed. It is based on the equivalent heat source concept and consists of two parts: computational thermo-fluid dynamics and heat conduction. The solution of the thermo-fluid dynamics problem by the finite element method for a bounded domain results in a weld pool interface geometry being the input data for a subsequent heat conduction problem solved for a workpiece by proposed boundary element method. The main physical phenomena, such as keyhole shape, thermo-capillary and natural convection and temperaturedependent material properties are taken into consideration. The developed technique is applied to complete-penetration keyhole laser beam welding of a 15 mm thick low-alloyed steel plate at a welding speed of 33 mm/s and a laser power of 18 kW. The fluid flow of the molten metal has a strong influence on the weld pool geometry. The thermo-capillary convection is responsible for an increase of the weld pool size near the plate surfaces and a bulge formation near the plate middle plane. The numerical and experimental molten pools, cross-sectional weld dimensions and thermal cycles of the heat affected zone are in close agreement. T2 - 72nd IIW Annual Assembly and International Conference CY - Bratislava, Slovakia DA - 07.07.2019 KW - Numerical simulation KW - Boundary element method KW - Themral cycles KW - Keyhole mode welding KW - Bulging PY - 2019 AN - OPUS4-48467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Berechnung des transienten Temperaturfeldes beim Laserstrahlschweißen mit einer modellierten äquivalenten Wärmequelle N2 - Ein neuartiger Modellierungsansatz für die Berechnung des transienten Temperaturfeldes beim Laserstrahlschweißen mit einer äquivalenten Wärmequelle wurde vorgestellt. Das numerische Modell wurde in zwei Studien unterteilt. Im ersten Teil wurde der Laserstrahlschweißprozess in einer stationären Schmelzbadsimulation untersucht. Die lokale Schmelzbadgeometrie und das Temperaturfeld wurden unter Berücksichtigung der Effekte der thermokapillaren und freien Konvektion, der latenten Wärme und der temperaturabhängigen Materialeigenschaften bis hin zur Verdampfungstemperatur ermittelt. Die Ergebnisse wurden benutzt, um eine äquivalente volumetrische Wärmequelle zu definieren. In der folgenden Studie wurde damit das transiente Temperaturfeld im geschweißten Bauteil berechnet. Die numerischen Ergebnisse wurden durch parallel laufende Experimente validiert. T2 - BAM Alumni Kolloquium 9.3 CY - Berlin, Germany DA - 24.11.2017 KW - Simulation KW - Transientes Temperaturfeld KW - Laserstrahlschweißen KW - Äquivalente Wärmequelle PY - 2017 AN - OPUS4-43555 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Transient process simulation of heat transfer in laser beam welding with an equivalent heat source N2 - A multi-physics modelling framework developed for the prediction of the three-dimensional transient temperature field of the laser welding process is presented. The numerical model consists of two studies. In the first study, a steady-state CFD process simulation of full-penetration keyhole laser beam welding was performed. Considering the effects of latent heat, natural and thermo-capillary convection and temperature-dependent material properties up to evaporation temperature the local weld pool geometry and temperature field were obtained. These results were used in the second subsequent study, as an equivalent volumetric heat source, by the prediction of the transient thermal cycle during and after fusion welding. Here the energy input and the movement of the heat source were realized by a novel technique, making use of pointwise constraints and a moving mesh provided with helper lines and additional remeshing condition. The numerically calculated results were compared to experimentally observed weld pool shapes and time-temperature curves and show a very good agreement. T2 - COMSOL Conference CY - Rotterdam, The Netherlands DA - 18.10.2017 KW - High power laser beam welding KW - Equivalent volumetric heat source KW - Transient heat transfer KW - Moving mesh KW - Pointwise constraints PY - 2017 AN - OPUS4-42607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Ivanov, S. A1 - Valdaytseva, E. T1 - A simplified model for numerical simulation of laser metal deposition process with beam oscillation N2 - A simplified model for the numerical simulation of the laser metal deposition process with beam oscillation is proposed. The model studies circular and lateral oscillations in order to reduce the porosity of the deposited part, to increase the process efficiency and the gap bridging ability as well. The deposition rate is increased by modifying the shape and the width of the molten pool through an optimized laser beam power distribution and oscillation amplitude. The relationship between the process conditions and the shape of the fabricated part are determined. It is found that an increase of the amplitude by a lateral oscillation of the beam reduces the heat flux and hence the shape of the deposited wall. A good correlation between the numerically calculated results and the experimental measurements is obtained. T2 - 9th International Conference on Beam Technologies and Laser Applications CY - St. Petersburg, Russia DA - 17.09.2018 KW - Numerical modelling KW - Laser metal deposition KW - Beam oscillations PY - 2018 AN - OPUS4-46017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Karkhin, V. A1 - Rethmeier, Michael T1 - A novel approach for calculating the thermal cycle of a laser beam welding process using a stationary CFD model N2 - This work aims to find the thermal cycles during and after fusion welding through simulation by first calculating the resulting local temperature field in the quasi-stationary part of the process. Here complete-penetration keyhole laser beam welding with a laser power of 18 kW on a 15 mm thick slab of a low-alloyed steel at a welding speed of 2 m/min is considered. In order to physically depict the laser material interaction a multi-physics numerical model including the effects of phase transformation, thermo-capillary convection, natural convection and temperature-dependent material properties up to evaporation temperature is developed. It uses a fixed keyhole geometry with a right truncated circular cone shape to introduce the laser beam energy to the workpiece. In a subsequent study, the resulting local temperature field is then used as an equivalent heat source in order to predict the unsteady thermal cycle during and after fusion welding. The translational movement of the laser beam through the workpiece is represented by a moving mesh approach. For the simulation, stationary heat transfer and fluid dynamics are described by a system of strongly coupled partial differential equations. These are solved with the commercial finite element software COMSOL Multiphysics 5.0. The results of the numerical simulation are validated by experiments, where the weld bead shapes and the thermal cycles show good correlation. T2 - 12th International Seminar "Numerical Analysis of Weldability" CY - Graz-Seggau, Austria DA - 23.09.2018 KW - Equivalent volumetric heat source KW - Process simulation KW - Laser beam welding KW - Transient heat transfer KW - Moving mesh PY - 2018 AN - OPUS4-46037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bakir, Nasim A1 - Bachmann, Marcel A1 - Gumenyuk, Andrey A1 - Na, S.-J. A1 - Retmeier, Michael T1 - On the search for the origin of the bulge effect in high power laser beam welding N2 - The shape of the weld pool in laser beam welding plays a major role to understand the dynamics of the melt and its solidification behavior. The aim of the present work was its experimental and numerical investigation. To visualize the geometry of the melt pool in the longitudinal section a butt joint configuration of 15 mm thick structural steel and transparent quartz glass was used. The weld pool shape was recorded by means of a high-speed video camera and two thermal imaging MWIR and VIS cameras. The observations show that the dimensions of the weld pool vary depending on the depth. The regions close to the surface form a teardrop shaped weld pool. A bulge-region and its temporal evolution were observed approximately in the middle of the depth of the weld pool. Additionally, a transient numerical simulation was performed until reaching a steady state to obtain the weld pool shape and to understand the formation mechanism of the observed bulging phenomena. A fixed keyhole with an experimentally obtained shape was used to represent the full-penetration laser beam welding process. The model considers the local temperature field, the effects of phase transition, thermo-capillary convection, natural convection and temperature-dependent material properties up to evaporation temperature. It was found that the Marangoni convection and the movement of the laser heat source are the dominant factors for the formation of the bulging-region. Good correlation between the numerically calculated and the experimentally observed weld bead shapes and the time-temperature curves on the upper and bottom surface were found. T2 - International Congress on Applications of Lasers & Electro-Optics (ICALEO®) CY - Orlando, FL, USA DA - 14.10.2018 KW - High power laser beam welding KW - Solidification cracking KW - Bulging effect KW - Numerical modelling PY - 2018 AN - OPUS4-46339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Äquivalente Wärmequellenmodellierung beim Hochleistungslaserstrahlschweißen dicker Bleche N2 - Der vorgestellte Modellierungsprozess dient zur Abschätzung einer geeigneten äquivalenten Wärmequelle und Berechnung des thermischen Verhaltens beim Laserstrahlschweißen. Die Methode Kombiniert die Vorteile von gägngigen Simulationsverfahren und reduziert die berücksichtigte Anzahl an physikalischen Aspekten und Kalibrierungsparameter. Durch die modellierten physikalischen Phänomene konnten die Informationen über die Strömung im Schmelzbad und dessen Einfluss auf die resultierende lokale Temperaturverteilung und folglich auf das transiente Temperaturfeld gewonnen werden. Dadurch wurde die Simulatioszeit(inkl. Kalibrierungsaufwand) auf weniger als einen Tag Rechenzeit verringert. T2 - Assistentenseminar 2017 der Wissenschaftlichen Gesellschaft Fügetechnik e.V. im DVS CY - Rabenau bei Dresden, Sachsen, Germany DA - 06.09.2017 KW - Hochleistungslaserstrahlschweißen KW - Prozesssimulation KW - Äquivalente Wärmequelle KW - Knotenweise Zwangsbedingungen KW - Bewegtes Gitter PY - 2017 AN - OPUS4-42085 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni T1 - Modeling the Relationship between Weld Pool Dynamics and Centerline Solidification Cracking in High Power Laser Beam Welding N2 - The present work deals with the recently confirmed widening of the weld pool interface, known as a bulging effect, and its relevance in high power laser beam welding. A combined experimental and numerical approach is utilized to study the influence of the bulge on the hot cracking formation and the transport of alloying elements in the molten pool. A technique using a quartz glass, a direct-diode laser illumination, a high-speed camera, and two thermal imaging cameras is applied to visualize the weld pool geometry in the longitudinal section. The study examines the relevance of the bulging effect on both, partial and complete penetration, as well as for different sheet thicknesses ranging from 8 mm to 25 mm. The numerical analysis shows that the formation of a bulge region is highly dependent on the penetration depth and occurs above 10 mm penetration depth. The location of the bulge correlates strongly with the cracking location. The obtained experimental and numerical results reveal that the bulging effect increases the hot cracking susceptibility and limits the transfer of alloying elements from the top of the weld pool to the weld root. T2 - Gastvortrag an der Universität Innsbruck, Institut für Konstruktion und Materialwissenschaften CY - Innsbruck, Austria DA - 18.06.2023 KW - Laser beam welding KW - Centerline solidification cracking KW - Bulging KW - Numerical simulation PY - 2024 AN - OPUS4-60333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Artinov, Antoni A1 - Lange, Fritz A1 - Bachmann, Marcel A1 - Rethmeier, Michael A1 - Hilgenberg, Kai T1 - Numerical simulation of the weld pool dynamics during pulsed laser welding using adapted heat source and vaporization models N2 - A transient simulation including the impact of the laser energy, the melting of the metal and the development of the weld pool was conducted to observe the evolution of the vapor capillary and the solidification of the melt in pulsed laser beam welding of AISI 304 steel. The phase field method was implemented to investigate the evolution and behavior of the liquid-gas interface during welding and to describe the condensed and vapor phases. The effects of phase transition, recoil pressure, thermo-capillary and natural convection, vaporization and temperature dependent material properties were taken into account. A Gaussian-like heat source under consideration of the Fresnel absorption model was used to model the energy input of the laser beam. The heat source model was extended by a newly developed empirical approach of describing multiple beam reflections in the keyhole. To validate this new model, the numerical results were compared to experimental data and good agreement regarding the size and shape of the weld pool was observed. T2 - LANE Conference 2018 CY - Fürth, Germany DA - 03.09.2018 KW - Pulsed laser beam welding KW - Weld pool dynamics KW - Multiple reflections KW - Vaporization PY - 2018 AN - OPUS4-45873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Asadujjaman, Asad A1 - Bertin, Annabelle T1 - Aggregation behavior of UCST-Type Poly(Acrylamide-co-Acrylonitrile) copolymer N2 - Thermoresponsive polymers have shown great potential in applications such as bioseparation, drug delivery and diagnostic. Only few thermoresponsive polymers that present an upper critical solution temperature (UCST) in a relevant temperature range, i.e. phase separate from solution upon cooling, have been reported so far. Moreover, the most studied UCST type polymers namely polybetaines are difficult to use under physiological conditions, which significantly restricts their potential applications. Therefore, UCST polymers with sharp and robust phase transition in physiological conditions (in the presence of salts, ions etc.) are highly needed in order to extend the range of applications of this class of polymers. Herein, a robust UCST-type copolymer of acrylamide (AAm) and acrylonitrile (AN) (poly(AAm-co-AN)) was prepared by reversible addition fragmentation chain transfer (RAFT) polymerization and its thermo-induced aggregation behavior in aqueous media was studied. At temperature below the UCST, the copolymer chains were aggregated together. The aggregate size was found to be larger with increasing AN contents and became smaller upon dilution of the copolymer solutions. While above the UCST, the copolymer chains were expanded and weekly associated in solution. The association between the copolymer chains formed smaller aggregates with increasing the AN contents or the dilution of the solutions. A model is proposed to explain such aggregation-association behavior of the Fig. 1. Figure 1. Schematic illustration of the proposed thermos-induced aggregation behavior of the poly(AAm-co-AN) in aqueous solution. T2 - World Congress on Living Polymerizations and Polymers 2016 CY - Budapest, Hungry DA - 29.05.2016 - 03.06.2016 KW - Polymer KW - UCST PY - 2016 AN - OPUS4-36491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ascher, Lena A1 - Häckel, A. A1 - Schellenberger, E. A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Bildgebung von Eu-dotierten sehr kleinen Eisenoxid-Nanopartikeln in atherosklerotischen Plaques mittels LA-ICP-MS N2 - Atherosklerotische Läsionen können durch Magnetresonanztomographie (MRT) unter Verwendung von sehr kleinen Eisenoxidnanopartikeln (VSOP) sichtbar gemacht werden. VSOP akkumulieren in atherosklerotischen Plaques und dienen somit als Atherosklerosesonde. Das Ziel dieses Projektes war die Abbildung der Verteilung von Europium-dotierten VSOP (Eu-VSOP) durch Laserablation ICP-MS in histologischen Dünnschnitten der Aortenwurzelregion des ApoE-Knockout-Mausmodells, das reich an atherosklerotischen Plaques ist. Darüber hinaus wurde untersucht, ob die VSOP-Akkumulation in den Plaques mit anderen Biomarkern der Entzündung wie Makrophagen und verändertem Endothel korreliert. Somit wäre eine Beurteilung, ob es sich hierbei um instabile bzw. vulnerable Plaque-Regionen handelt möglich. Zu diesem Zweck wurden Antikörper mit verschiedenen Lanthaniden markiert und mit der Eu-VSOP-Verteilung unter Verwendung von LA-ICP-MS in einem Multiplex-Messmodus korreliert. Eine mögliche Korrelation von reaktiven Stickstoffspezies (RNS) mit endogenem Eisen oder Eu-VSOP kann ebenfalls durch LA-ICP-MS nachgewiesen werden. Zu diesem Zweck wurden RNS-spezifische Antikörper auch mit Lanthaniden markiert. T2 - 26. ICPMS-Anwendertreffen CY - Berlin, Germany DA - 03.09.2018 KW - Bioimaging KW - LA-ICP-MS KW - Nanopartikel KW - Antikörpermarkierung PY - 2018 AN - OPUS4-45921 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ashokkumar, Pichandi A1 - Rurack, Knut T1 - Organic-Inoranic hybrid host materials for fluorescence sensing of anions in aqueous media T2 - Netzwerktagung der Alexander von Humboldt-Stiftung CY - Karlsruhe, Germany DA - 2012-11-28 PY - 2012 AN - OPUS4-27229 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Holtappels, Kai T1 - Messunsicherheit bei der Bestimmung von Explosionsgrenzen T2 - 5. Fachtagung "Messunsicherheit praxisgerecht bestimmen" CY - Erfurt, Germany DA - 2011-11-08 PY - 2011 AN - OPUS4-24821 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Sicherheitstechnische Fragestellungen im Zusammenhang mit Elektrolyseanlagen N2 - Im Vortrag werden aktuelle Entwicklungen bei verschiedenen Elektrolysetechnologien kurz vorgestellt. Dann werden für Elektrolyseanlagen spezifische Gefährdungen diskutiert, v.a. die im Zusammenhang mit den Eigenschaften der Gase Wasserstoff und Sauerstoff stehen. Dabei wird auch Bezug auf die Normung- und Regelsetzung genommen und Sicherheitskonzepte werden beispielhaft kurz vorgestellt. Abschließend wird auf Unfallereignisse im Zusammenhang mit der Elektrolyse eingegangen. T2 - BAM/UBA-Behördenerfahrungsaustausch CY - Berlin, Germany DA - 27.06.2022 KW - Explosionsschutz KW - Wasserstofferzeugung KW - Sauerstoff KW - Sicherheit PY - 2022 AN - OPUS4-55220 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Grunewald, Thomas T1 - Experimentelle Untersuchung von Zündwahrscheinlichkeiten bei mechanischen Schlagvorgängen in wasserstoffhaltigen Atmosphären N2 - Im Projekt HySpark wird die Wirksamkeit mechanischer Schlagvorgänge beim Aufprall von unterschiedlichen Werkstoffen als Zündquelle für wasserstoffhaltige Atmosphären experimentell untersucht. Zum Einen wird die Zündwirksamkeit bei Wasserstoff/Luft-Gemischen in Abhängigkeit der Werkstoffpaarung untersucht. Dabei konnte v.a. festgestellt werden, dass bei Schlagvorgängen von Nicht-Eisen-Metallen mit verschiedenen Stahlsorten die wirksame Zündung vermieden werden kann. Jedoch können bei Schlagvorgängen mit Estrichbeton hohe Zündwahrscheinlichkeiten beobachtet werden. Zum anderen wird der Einfluss von Wasserstoffbeimischungen im Erdgasnetz auf die Zündwirksamkeit von mechanischen Schlägen untersucht. Bei Anteilen bis 25% Wasserstoff konnte bei den Versuchen kein Erhöhung der Zündwahrscheinlichkeit festgestellt werden. T2 - H2-Kolloquium des Kompetenzzentrums „H2Safety@BAM” CY - Online meeting DA - 04.07.2022 KW - Explosionsschutz KW - Zündquellen KW - Schlagfunken KW - Erdgas PY - 2022 AN - OPUS4-55224 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Hydrogen Safety - Explosion Protection for Hydrogen Applications N2 - In this lecture the safety related properties og hydrogen compared to other fuel gases and the explosion protection measures of avoiding flammable mixtures, avoiding ignition sources and mitigating the consequences of explosions when handling hydrogen and hydrogen mixtures are presented. The Joint European Summer School JESS 2021 addresses these issues by offering high quality graduate level courses on selected topics of vehicle technology, innovation & business development, safe handling of hydrogen, and modelling. The course content is tailored to the needs of a diverse audience: newcomers to the field, experienced students, and young professionals working at the forefront of fuel cell and hydrogen applications. T2 - Joint European Summer School (JESS) CY - Online meeting DA - 06.09.2021 KW - Explosionsschutz KW - Explosionsgrenzen KW - Zündenergie KW - Zündquellen KW - Auswirkung von Explosionen PY - 2021 AN - OPUS4-53808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Sicherheitstechnische Eigenschaften von Erdgas/Wasserstoff-Gemischen - Auswirkungen auf den Explosionsschutz N2 - Hinsichtlich ihrer sicherheitstechnischen Kenngrößen (STK) unterscheiden sich Wasserstoff und Erdgas zum Teil stark. Im Vortrag werden verschiedene STK von Erdgas/Wasserstoff-Gemischen im Abhängigkeit des Wasserstoffanteils vorgestellt und die Auswirkung der Beimischung von Wasserstoff zum Erdgas auf die Wirksamkeit von Explosionsschutzmaßnahmen erläutert. T2 - DVGW-Kongress 2021 "Gasinfrastruktur für Erdgas-H2-Gemische" CY - Online meeting DA - 07.10.2021 KW - Explosionsschutz KW - Explosionsgrenzen KW - Zündenergie KW - Power to Gas KW - Erdgasnetz KW - Zündquellen PY - 2021 AN - OPUS4-53725 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Hydrogen safety - Explosion protection for hydrogen applications N2 - In this lecture the safety related properties of hydrogen and hydrogen mixtures and explosion protection measures are shown and compared with other fuel gases. Measures for primary explosion protection (avoiding flammable mixtures), secondary explosion protection (avoiding ignition sources) and constructive explosion protection (mitigating the consequences of explosions) when handling hydrogen and hydrogen mixtures are presented. The Joint European Summer School JESS 2022 addresses these issues by offering high quality graduate level courses on selected topics of vehicle technology, innovation & business development, safe handling of hydrogen, and modelling. The course content is tailored to the needs of a diverse audience: newcomers to the field, experienced students, and young professionals working at the forefront of fuel cell and hydrogen applications. T2 - Joint European Summer School (JESS) on Fuel Cell, Electrolyser and Battery Technologies CY - Athens, Greece DA - 11.09.2022 KW - Ignition source KW - ATEX KW - Explosion limits KW - Hazardous areas KW - Hydrogen accidents KW - Detonation PY - 2022 AN - OPUS4-57066 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Habib, Abdel Karim A1 - Tashqin, Temir A1 - Seemann, A. A1 - Schütz, S. T1 - Explosion protection for mixtures of hydrogen and natural gas N2 - The effects of hydrogen admixture to natural gas on explosion regions, explosion group classification, explosion severity and on areas with explosive mixtures in case of gas release was studied experimentally. With increasing hydrogen fractions the mixtures become mainly more "critical", but up to 10 mole% hydrogen the influence on the safety characteristics are very low. By using appropriate calculation methods some of the safety characteristics could be calculated with good accuracy. T2 - 21st World Hydrogen Energy Conference 2016 (WHEC) CY - Zaragoza, Spain DA - 13.06.2016 KW - power-to-gas KW - explosion limits KW - explosion groups KW - model of constant adiabatic flame temperatures (CAFT) KW - methane PY - 2016 AN - OPUS4-37232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Seemann, A. A1 - Schütz, S. T1 - Power-to-Gas: Safety characteristics of hydrogen/natural-gas-mixtures N2 - LEL, UEL LOC, MESG, pmax and (dp/dt)max of hydrogen/natural gas-mixtures were determined systematically according to international standards. Mixtures of natural gas and hydrogen mainly become more „critical“ with increasing hydrogen fraction. The effect of up to 10 Vol% H2–admixture to natural gas on safety characteristics is very low, no major adaption of existing measures for explosion protection is necessary. More substantial adjustment of measures for explosion protection is necessary at hydrogen fractions of more than 25 Vol%. Some of the safety characteristics can be estimated with good accuracy by calculation methods. T2 - 15th International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Freiburg, Germany DA - 05.06.2016 KW - explosion protection KW - hydrogen enriched natural gas KW - methane/hydrogen-mixtures KW - hydrogen safety KW - energy storage PY - 2016 AN - OPUS4-36717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Steinbach, J. T1 - Calculation of Explosion Regions of Gas Mixtures T2 - 13th International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Bruges, Belgium DA - 2010-06-07 PY - 2010 AN - OPUS4-21585 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Gasgemische mit geringen Anteilen an Brenngasen in Distickstoffoxid / Sicherheitstechnische Beurteilung von Gasgemischen mit brennbaren und oxidierenden Bestandteilen N2 - Im Vortrag werden zum einen sicherheitstechnische Aspekte bei der Herstellung von Gasgemischen aus geringen Anteilen an Lachgas und brennbaren Gasen diskutiert. Zum anderen werden allgemein Vorgehensweisen und Berechnungsmethoden zur sicherheitstechnischen Beurteilung der Herstellung von Gasgemischen mit brennbaren und oxidierenden Komponenten vorgestellt. T2 - 17. Sitzung der Expertengruppe Spezialgase des IGV CY - Berlin, Germany DA - 11.02.2016 KW - Explosionsschutz KW - Herstellung von Gasgemischen KW - Chemisch instabile Gase KW - Spezialgase PY - 2016 AN - OPUS4-38008 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schröder, Volkmar T1 - Flamox-Gas Mixtures - Herstellbarkeit und Füllung N2 - Im Vortrag wird auf die sicherheitstechnische Beurteilung in Hinblick auf den Explosionsschutz bei der Herstellung und Füllung von Gasgemischen mit brennbaren und mit oxidierenden Komponenten eingegangen. Anhand von Beispielen werden u.a. Vorgehensweisen und Berechnungsmethoden beschrieben, anhand derer beurteilt werden kann, ob Gasgemische überhaupt sicher hergestellt werden können und in welcher Reihenfolge die Komponenten zur sicheren Herstellung der Gemische gefüllt werden sollten. T2 - Workshop der Linde AG CY - Unterschleißheim, Germany DA - 14.04.2016 KW - Explosionsschutz KW - Herstellung von Gasgemischen KW - Spezialgase KW - Sicherheit KW - Gefahrstoffe PY - 2016 AN - OPUS4-38004 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Tashqin, Temir T1 - Sicherheitstechnische Kenngrößen von Erdgas/Wasserstoff-Gemischen bei der Power-to-Gas-Technologie T2 - Forschungsbeirat "Sicherheitstechnische Kenngrößen von Wasserstoff-Erdgas-Gemischen" CY - BG ETEM, Köln DA - 2015-09-02 PY - 2015 AN - OPUS4-33928 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Wasserstoffsicherheitsfragen - Sicherheitstechnische Kenngrößen von Wasserstoff und Gemischen von Wasserstoff mit Erdgas N2 - Wasserstoff unterscheidet sich hinsichtlich der sicherheitstechnischen Eigenschaften von anderen brennbaren Gassen, v.a. durch die sehr niedrige Mindestzündenergie und die sehr hohe Flammengeschwindigkeit. Durch Beimischung von Wasserstoff zum Erdgas ändern sich die sicherheitstechnischen Eigenschaften zum Teil in kritischer Richtung. Bis zu einem Wasserstoffanteil von 10 Mol-% im Erdgas ist aber keine wesentliche Anpassung der Maßnahmen für den Explosionsschutz erforderlich. Synthesgas ist ein weiteres Wasserstoffgemisch das in Zukunft vermutlich zunehmend relevant sein wird. Die beiden Komponenten Wasserstoff und Kohlenmonoxid haben zwar in mancher Hinsicht ähnliche sicherheitstechnische Eigenschaften unterscheiden sich aber auch sehr stark bzgl. der Mindestzündenergie und der Flammengeschwindigkeit. T2 - 9. HYPOS-Dialog: Grüner Wasserstoff, aber sicher! - Sicherheitsaspekte im Umgang mit Wasserstoff CY - Magdeburg, Germany DA - 11.09.2020 KW - Explosionsschutz KW - Zündenergie KW - Explosionsgrenzen KW - Zündquellen KW - Synthesegas PY - 2020 AN - OPUS4-51264 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schröder, Volkmar T1 - The influence of strong ignition sources on the explosion and decomposition limits of gases N2 - Explosion and decomposition limits of flammable and chemically unstable gases were determined experimentally in a dosed autoclave with varying ignition energy up to 1000 J. The ignition source was a lightning arc caused by an exploding wire igniter as described in EN 1839 B .. In case of methane only the upper explosion limit was influenced significantly by the ignition energy, whereas the lower explosion limit was constant. In case of R32 however. it was the lower explosion limit that was influenced significantly by the ignition energy and not the upper explosion limit. A particularly strong dependency from the ignition energy was found for the decomposition limits of the chemically unstable gases in nitrogen. T2 - 16th International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Delft, The Netherlands DA - 16.06.2019 KW - Explosionsgrenzen KW - Zündenergie KW - Chemisch instabile Gase KW - Kältemittel KW - Zündquellen PY - 2019 AN - OPUS4-48993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Göpfert, T. A1 - Winterleitner, E. A1 - Schwarze, M. T1 - Safety related properties of low-GWP refrigerants N2 - Most fluorinated hydrocarbons that shall replace refrigerants with high GWP. like R134a. are flammable. For evaluating inertization measures for explosion protection. flammability of low-GWP refrigerants R1234yf, R32 and R1132a blended with carbon dioxide. Nitrogen and argon were studied experimentally in a closed autoclave at atmospheric conditions. Furthermore, a calculation method was adapted to reduce the experimental costs for flammability studies on these gas mixtures. For igniting R1234yf in the closed autoclave a newly developed ignition system was used that allows generating electric arcs with high ignition energy. Gas mixtures containing the mildly flammable R1234yf and R32 could be inerted by adding much less inert gas than mixtures containing R1132a, which is more similar to unfluorinated hydrocarbons regarding the explosion regions. By using the adapted model of constant adiabatic flame temperature profiles estimating the explosion limits of fluorinated hydrocarbons was possible with similar accuracy as for unf luorinated hydrocarbons. T2 - 25th IIR International Congress of refrigeration CY - Montreal, Canada DA - 24.08.2019 KW - Explosionsgrenzen KW - Inertisierung KW - Entzündbarkeit KW - Kältemittel KW - R1234f, R32, R1132a PY - 2019 AN - OPUS4-48994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Untersuchungen zum Zündverhalten von N2O/CO2/Öl-Gemischen in Kältemaschinen N2 - Lachgas kann als Medium in Kälteanwendungen unter -50 °C eingesetzt werden. Da ein explosionsartiger Zerfall von Lachgas bei erhöhtem Druck möglich ist, sind bei entsprechenden Anwendungen Explosionsgefahren zu beachten. Im Vortrag wurden die Voraussetzungen und die Einflussgrößen für den explosionsartigen Zerfall von Lachgas, wie Temperatur, Druck, Geometrie und Zündenergie vorgestellt und diskutiert. Weiterhin wurden Versuchsergebnisse zur Untersuchung des Einflusses geringer Mengen an brennbaren Komponenten (Propan und Öl-Nebel) auf die Explosionseigenschaften vorgestellt und die Stabilisierung der Gemische durch Beimischung von Kohlendioxid diskutiert. T2 - Informations-Treffen Kälteanwendungen unter -50 °C CY - Karlsruhe, Germany DA - 05.02.2019 KW - Lachgas KW - Kältemaschinen KW - Explosionsschutz PY - 2019 AN - OPUS4-48558 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -