TY - JOUR A1 - Kailasam, K. A1 - Mesch, M. B. A1 - Möhlmann, Lennart A1 - Baar, M. A1 - Blechert, S. A1 - Schwarze, M. A1 - Schröder, M. A1 - Schomäcker, R. A1 - Senker, J. A1 - Thomas, A. T1 - Donor–acceptor-type heptazine-based polymer networks for photocatalytic hydrogen evolution N2 - A heptazine-based polymer network (HMP-3) with a donor–acceptor (D–A) structure was prepared and tested as catalyst for photocatalytic hydrogen evolution from water. Compared to other heptazine-based materials, which are typically prepared at high temperatures and have recently received much interest as metal-free photocatalysts, the low-temperature protocol applied here allows the defined introduction of organic functional groups within the polymer backbone. The structure of HMP-3 contains alternating heptazine and benzothiadiazole moieties as electron acceptors connected by aminobenzene bridges as electron donors. The resulting material leads to enhanced hydrogen evolution compared to graphitic carbon nitride materials prepared at high temperatures (>500 8C) most probably because of the stabilization of photogenerated charge carriers in the D–A structure. KW - Photocatalysis KW - Water splitting KW - Water reduction KW - Carbon nitride PY - 2016 DO - https://doi.org/10.1002/ente.201500478 VL - 4 IS - 6 SP - 744 EP - 750 PB - Wiley AN - OPUS4-36915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Algernon, D. A1 - Arndt, R.W. A1 - Denzel, W. A1 - Ebsen, B. A1 - Feistkorn, S. A1 - Friese, M. A1 - Große, C.U. A1 - Kathage, S. A1 - Keßler, S. A1 - Köpp, Christian A1 - Küttenbaum, Stefan A1 - Lohse, C. A1 - Maack, Stefan A1 - Niederleithinger, Ernst A1 - Schickert, M. A1 - Schröder, G. A1 - Taffe, A. A1 - Timofeev, Juri A1 - Walther, A. A1 - Wilcke, M. A1 - Wolf, J. A1 - Wöstmann, Jens T1 - Test specimen concepts in regard to quality assurance and validation of nondestructive testing in civil engineering N2 - The process of ensuring reliability of NDT applications contains various aspects, such as determining the performance and probability of success, the uncertainty in measurement, the provision of clear and functional procedures and ensuring the correct application accordingly. Test specimens have become powerful elements in supporting many of these aspects. Within the committee for NDT in Civil Engineering (NDT-CE) of the German Society for Nondestructive Testing (DGZfP), the subcommittee on Quality Assurance (UA-QS) therefore addresses the design and the integration of test specimens in the quality assurance process. Depending on the specific purpose, the requirements on test specimens can vary significantly based on the defined simulated scenario. The most prominent purposes of test specimens might be seen in providing references for inspection systems in regard to function control, calibration and validation. Further aspects can be parametric studies, basic investigation of physical principles related to NDT or a simplified and therefore comprehensive demonstration of inspection concepts (e.g. for teaching purposes). The specific purpose of a test specimen dictates the requirements regarding its conception, including the exact design, the material or the fabrication accuracy and the conditioning. In the development of a general guideline by the UA-QS for application-specific procedures and their validation, the use of test specimens is addressed and specific concepts for the design of test specimens are made. This includes the analysis of the measurement process regarding any given application, deriving an adequate calibration approach for it and designing test specimens (calibration specimens) accordingly. Furthermore, it includes the validation of the procedure taking into account all conditions related to the specific application in the field. The validation requires a statistically sufficient number of trials. Thorough evaluation of each trial can only be established if the ground-truth is known. Therefore, test specimens providing a realistic but controlled simulation of the inspection problem are valuable and indispensable elements in the validation process. The requirement of being fully realistic will often not be possible to fulfill due to practical restrictions. Any aspect that cannot be included in the simulation realistically needs to be simulated conservatively. This again, requires a sufficient understanding of the inspection principle and technique to ensure conservativeness. Among other quality-assurance-related aspects, the UA-QS establishes concepts and guidelines regarding sound and efficient approaches for the specific purposes of test specimens. This subcommittee brings together representatives of different Groups along the entire value chain of NDT-CE, including researchers, practitioners, manufacturers and clients. They all work together in establishing a common understanding and level of quality assurance in the industry. T2 - SMT and NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.08.2018 KW - Quality assurance KW - Procedure KW - Reliability KW - Validation KW - Reference specimen PY - 2019 UR - https://asnt.org/smt18papers SN - 978-1-57117-456-7 VL - 11/19 SP - 39 EP - 48 PB - The American Society for Nondestructive Testing, Inc. CY - Columbus, OH, USA AN - OPUS4-47240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Algernon, D. A1 - Arndt, R.W. A1 - Denzel, W. A1 - Ebsen, B. A1 - Feistkorn, S. A1 - Friese, M. A1 - Große, C.U. A1 - Kathage, S. A1 - Keßler, S. A1 - Köpp, Christian A1 - Küttenbaum, Stefan A1 - Lohse, C. A1 - Maack, Stefan A1 - Niederleithinger, Ernst A1 - Schickert, M. A1 - Schröder, G. A1 - Taffe, A. A1 - Timofeev, Juri A1 - Walther, A. A1 - Wilcke, M. A1 - Wolf, J. A1 - Wöstmann, Jens T1 - NDT procedures in relation to quality assurance and validation of nondestructive testing in civil engineering N2 - The field of non-destructive testing of civil structures (NDT-CE) has been continuously growing. Due to the complexity and diversity of civil constructions as well as the heterogeneity of concrete, specific standards or guidelines for the application of modern NDT-CE are still missing. The development of individual solutions is the current approach, which is just as challenging as it is common for NDT-CE. With the increasing development and commercialization of NDT-CE technology, the group of practitioners is growing. To ensure a good level of quality in the industry, it appears necessary to establish adequate means. Naturally, the performance of NDT-CE methods regarding a specific application is strongly dependent on choosing the most suitable inspection technique and applying it correctly, generally referred to as the inspection procedure in the field of NDT. There are well-defined guidelines regarding procedure documentation and handling in many fields of NDT (e.g. nuclear, aerospace or automotive) according to the high importance of procedures in assuring a successful and reliable application. For a long time, this has not always been the case with NDT-CE, which is still considered a unique discipline of NDT. Part of the reason for that might be the young development state of NDTCE, the heterogeneity of building materials like concrete, timber or masonry as a material and the diversity of civil structures. In consequence, NDT-CE procedure development is considered challenging. Among other aspects, addressed in the subcommittee on Quality Assurance (UA-QS) within the committee for NDT-CE of the German Society for Nondestructive Testing (DGZfP), part of its work aims at establishing an adequate basis for NDT-CE procedure development. While some of the highly developed approaches from other industries are taken into consideration, they need to be analyzed regarding their suitability for NDT-CE and adapted accordingly. For a procedure to be as defined as possible, it needs to contain sufficient information, such as the scope and limitations regarding material, geometry and condition of the test object, inspection parameters, calibration, data acquisition, analysis criteria as well as requirements regarding the inspection personnel. For a successful implementation in the field, it is important to define the specific procedure as precisely as possible. Despite the necessity of a great amount of information to be included, the procedure needs to be suitable for efficient field application. The UA-QS is developing a guideline for NDT-CE procedures suitable for application in this field of NDT to ensure correct and reproducible application. To demonstrate and evaluate this concept, specific examples of procedures are also produced. In particular, the UA-QS has developed a procedure for the detection and positioning of tendon ducts using Ground Penetrating Radar (GPR). This procedure is tested regarding the practical applicability in a roundrobin on a defined type of reference test block. T2 - SMT and NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.08.2018 KW - Quality assurance KW - Procedure KW - Reliability KW - Validation KW - Reference specimen PY - 2019 UR - https://asnt.org/smt18papers SN - 978-1-57117-456-7 VL - 11/19 SP - 31 EP - 38 PB - The American Society for Nondestructive Testing, Inc. CY - Columbus, OH, USA AN - OPUS4-47239 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Algernon, D. A1 - Arndt, R. A1 - Ebsen, B. A1 - Feistkorn, S. A1 - Friese, M. A1 - Große, C. A1 - Kathage, S. A1 - Keßler, S. A1 - Kurz, J. A1 - Küttenbaum, Stefan A1 - Lohse, C. A1 - Maack, Stefan A1 - Niederleithinger, Ernst A1 - Schickert, M. A1 - Schröder, G. A1 - Taffe, A. A1 - Walther, A. A1 - Wilcke, M. A1 - Wolf, J. A1 - Wöstmann, Jens T1 - Richtlinie B-LF 01: Leitfaden zur Erstellung von Prüfanweisungen für die Zerstörungsfreie Prüfung im Bauwesen (ZfP Bau) N2 - Der vorliegende Leitfaden dient zur Unterstützung der Entwicklung und Umsetzung von Prüfanweisungen für ZfP-Verfahren im Bauwesen. Er gibt einen Überblick über Verwendungszweck, Erstellung und Inhalte von Prüfanweisungen unter Berücksichtigung einheitlicher Standardisierungsziele. KW - Prüfanweisung KW - Beton KW - Leitfaden PY - 2022 SN - 978-3-947971-23-7 SP - 1 EP - 9 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung e.V. (DGZfP) CY - Berlin ET - 1. Aufl., April 2022 AN - OPUS4-54985 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waegner, M. A1 - Schröder, M. A1 - Suchaneck, G. A1 - Sturm, Heinz A1 - Weimann, Christiane A1 - Eng, L.M. A1 - Gerlach, G. T1 - Domain formation in nano-patterned PZT thin films N2 - In this work, reactive magnetron-sputtered Pb(Zr,Ti)O3 thin films were used to fabricate well-ordered nanodot arrays by means of nanosphere lithography (NSL). NSL is based on a two-step etch process by means of, firstly adjusting the diameter of polystyrene spheres in the self-assembled polymeric nanosphere mask using reactive ion etching, and secondly transferring the mask to the substrate by ion milling with adjusted heights. Hence, structures with different aspect ratios can be fabricated. Piezoresponse force microscopy was used as the inspection tool on both non-patterned and patterned films. Both the topography and polarization out of plane and in plane was deduced in this mode. Grains of nanodots with low aspect ratio form domain structures comparable to domains in non-patterned films. In contrast to that, nanodots with a higher aspect ratio form particular structures. The in-plane amplitude images show mostly a bisectioned domain assembly, while the out-of-plane amplitude images show in some cases more complex structures like 'c'-shaped domains or multi-domains around a center domain. The patterning of the ferroelectric material was shown to affect the formation of ferroelectric domains. The initial polycrystalline, randomly-ordered films are re-oriented and show domain structures depending on nanodisc diameter and aspect ratio. This may enable tailoring of ferroelectric materials in their piezoelectric and pyroelectric properties by patterning. T2 - MRS Spring meeting 2012 CY - San Francisco, CA, USA DA - 2012-04-09 KW - Nanostructure KW - Piezoresponse KW - Ferroelectric KW - Piezo response force microscopy KW - Nanodots PY - 2012 DO - https://doi.org/10.1557/opl.2012.1230 SN - 1946-4274 SN - 0272-9172 VL - 1454 SP - 1 EP - 6(?) PB - Mater. Res. Soc CY - Warrendale, Pa. AN - OPUS4-26521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waegner, M. A1 - Schröder, M. A1 - Suchaneck, G. A1 - Sturm, Heinz A1 - Weimann, Christiane A1 - Eng, L.M. A1 - Gerlach, G. T1 - Enhanced piezoelectric response in nano-patterned lead zirconate titanate thin films N2 - In this work, Pb(Zr,Ti)O3 thin films were used to fabricate well-ordered nanodot arrays by means of nanosphere lithography. This technique is based on a two-step etch process that enables excellent control of the fabrication of ordered nanodisc arrays of defined height, diameter, and pitch. Piezoresponse force microscopy was used to investigate both non-patterned and patterned films. The topography and both the out-of-plane and the in-plane polarization were deduced in this mode. Grains of nanodots with a low aspect ratio form domain structures comparable to domains in non-patterned two-dimensional films. In contrast, nanodots with a higher aspect ratio form particular structures like bi-sectioned domain assemblies, c-shaped domains or multi-domains surrounding a center domain. The patterning of the ferroelectric material was shown to affect the formation of ferroelectric domains. The initial polycrystalline films with random polarization orientation re-orient upon patterning and then show domain structures dependent on the nanodisc diameter and aspect ratio. PY - 2012 DO - https://doi.org/10.1143/JJAP.51.11PG04 SN - 0021-4922 VL - 51 SP - 11PG04-1 - 11PG04-5 CY - Tokyo AN - OPUS4-27697 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weh, K. A1 - Noack, M. A1 - Hoffmann, Katrin A1 - Schröder, K.-P. A1 - Caro, J. T1 - Change of gas permeation by photoinduced switching of zeolite-azobenzene membranes of type MFI and FAU N2 - FAU membranes of type Na–X and MFI membranes of type silicalite-1 which contain adsorbed azobenzene (AZB), have photoswitchable permeation properties due to the trans–cis photoisomerization of AZB. The change of gas permeation through these host–guest composite membranes depends on the irradiation wavelength, the quality of the membranes and the amount of adsorbed AZB. The permeances of the gases in the trans-form of the zeolite-encapsulated AZB were higher than those in the cis-form. The separation factors of equimolar mixtures of N2/CO2 and CH4/CO2 fed through the FAU–AZB membrane were higher at trans-switching than at cis-switching. The changes of the permeances of single gases and of the separation factors of equimolar gas mixtures by photoinduced trans–cis switching were found to be reversible over numerous switching cycles. The experimental results are in agreement with predictions made by Monte Carlo simulations for passing of permeant gases through these host–guest systems with the zeolite-hosted AZB in the trans- and in the cis-configuration. PY - 2002 DO - https://doi.org/10.1016/S1387-1811(02)00331-1 SN - 1387-1811 SN - 1873-3093 VL - 54 IS - 1-2 SP - 15 EP - 26 PB - Elsevier CY - Amsterdam AN - OPUS4-1752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bresch, Harald A1 - Meyer-Plath, Asmus A1 - Burgdorf, T. A1 - Packroff, R. A1 - Apel, P. A1 - Adolf, P. A1 - Jesse, A. A1 - Leuschner, C. A1 - Bosse, H. A1 - Dubbert, W. A1 - Epp, A. A1 - Gebel, T. A1 - Götz, M. A1 - Herzberg, F. A1 - Hornbogen, T. A1 - Kersten, N. A1 - Kneuer, C. A1 - Kujath, P. A1 - Pipke, R. A1 - Plitzko, s. A1 - Schlesier, K. A1 - Schröder, F. A1 - Schwirn, K. A1 - Sommer, Y. A1 - Tentschert, J. A1 - Völker, D. A1 - Wolf, T. T1 - 1. Bilanz zur gemeinsamen Forschungsstrategie der Ressortforschungseinrichtungen des Bundes 'Nanotechnologie - Gesundheits- und Umweltrisiken von Nanomaterialien' (2007 - 2011) KW - Nanotechnologie KW - Nanopartikel KW - Nanomaterial KW - Bundesoberbehörden KW - Forschungsstrategie PY - 2013 SP - 1 EP - 124 CY - Berlin AN - OPUS4-28538 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Holtappels, Kai A1 - Schröder, Volkmar A1 - Kobiera, A. A1 - Wolanski, P. A1 - Braithwaite, M. A1 - Pasman, H. T1 - Gas explosion safety characteristics and anomalies at unusual conditions T2 - 12th International Symposium on Loss and Safety Promotion in the Process Industries CY - Edinburgh, Scotland, UK DA - 2007-05-22 KW - Process safety KW - Hydrocarbon oxidation KW - Combustion phenomena KW - Combustion regions PY - 2007 SN - 978-0-85295-508-6 SN - 0307-0492 N1 - Serientitel: IChemE symposium series – Series title: IChemE symposium series IS - 153 SP - 1 EP - 7(?) PB - IChemE CY - Rugby, Warwickshire AN - OPUS4-14849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Barbier, J.-P. A1 - Bissolotti, G. A1 - Christian, S. A1 - Cleaver, K. A1 - Heller, D. A1 - Injaian, M. A1 - Schröder, Volkmar A1 - Witte, F. T1 - Safe preparation of compressed oxidant-fuel gas mixtures in cylinders KW - Sicherheitstechnik KW - Biogas KW - Explosionsgrenzen KW - Prozesssicherheit PY - 2007 IS - 139/07/E SP - 1 EP - 36 PB - European Industrial Gases Association (EIGA) CY - Brussels AN - OPUS4-16501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sloniec, Jagoda A1 - Schnurr, M. A1 - Witte, C. A1 - Resch-Genger, Ute A1 - Schröder, L. A1 - Hennig, Andreas T1 - Biomembrane interactions of functionalized cryptophane-A: combined fluorescence and 129Xe NMR studies of a bimodal contrast agent N2 - Fluorescent derivatives of the 129Xe NMR contrast agent cryptophane-A were obtained by functionalization with near infrared fluorescent dyes DY680 and DY682. The resulting conjugates were spectrally characterized, and their interaction with giant and large unilamellar vesicles of varying phospholipid composition was analyzed by fluorescence and NMR spectroscopy. In the latter, a chemical exchange saturation transfer with hyperpolarized 129Xe (Hyper-CEST) was used to obtain sufficient sensitivity. To determine the partitioning coefficients, we developed a method based on fluorescence resonance energy transfer from Nile Red to the membrane-bound conjugates. This indicated that not only the hydrophobicity of the conjugates, but also the phospholipid composition, largely determines the membrane incorporation. Thereby, partitioning into the liquid-crystalline phase of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine was most efficient. Fluorescence depth quenching and flip-flop assays suggest a perpendicular orientation of the conjugates to the membrane surface with negligible transversal diffusion, and that the fluorescent dyes reside in the interfacial area. The results serve as a basis to differentiate biomembranes by analyzing the Hyper-CEST signatures that are related to membrane fluidity, and pave the way for dissecting different contributions to the Hyper-CEST signal. KW - Biosensors KW - Fluorescence KW - FRET KW - Hyperpolarization KW - Lipids KW - Xenon PY - 2013 DO - https://doi.org/10.1002/chem.201203773 SN - 0947-6539 SN - 1521-3765 VL - 19 IS - 9 SP - 3110 EP - 3118 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-28980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Giurcan, V. A1 - Razus, D. A1 - Mitu, M. A1 - Schröder, Volkmar T1 - Limiting oxygen concentration and minimum inert concentration of fuel-air-inert gaseous mixtures evaluation by means of adiabatic flame temperatures and measured fuel-air lower flammability limits N2 - The present paper aims to re-examine the validity of the linear correlation found between AFTLOC, the adiabatic flame temperature at the apex of the flammability range of fuel-air-inert mixtures (where LOC, the Limiting Oxygen Concentration, is measured) and AFTLFL, the adiabatic flame temperature at the lower flammability limit of fuel-air mixtures (LFL). New sets of experimental measurements of LFL and LOC referring to fuel-air mixtures diluted with N2, CO2 and H2O(vap) from trusted literature sources form a comprehensive database for such evaluation. Both the slope and intercept of correlations AFTLOC = a + b*AFTLFL are dependent on the nature of inert gas and on initial temperature. Based on the linear correlation between AFTLOC and AFTLFL, a procedure for calculation of LOC and MIC (Minimum Inert Concentration) of fuel-air-inert mixtures is presented, using measured or calculated LFL of fuel-air mixtures and their corresponding AFT. The method predicts with reasonable accuracy LOC and MIC of fuel-air-inert mixtures (relative deviations ranging between -14 and +17% when calculated and measured LOC and MIC for fuelair-nitrogen and fuel-air-carbon dioxide at ambient initial conditions are examined). KW - Fuel KW - Limiting oxygen concentration KW - Minimum inert concentration KW - Adiabatic flame temperature KW - Flammability limit PY - 2013 UR - http://www.revistadechimie.ro/pdf/GIURCAN%20V.pdf%2012%2013.pdf SN - 0034-7752 VL - 64 IS - 12 SP - 1445 EP - 1453 PB - sti CY - Bucure AN - OPUS4-29997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Volkmar A1 - Schalau, Bernd A1 - Molnarne, M. T1 - Explosion protection in biogas and hybrid power plants N2 - Renewable energies became more and more important in the last years. The production of biogas using agricultural waste and the use of wind and solar energy in combination with water electrolysis is one way to substitute natural gas. Therefore the number of biogas plants is growing very fast in Germany. In the meantime, the operation of such plants is responsible for a significant number of accidents. New safety regulations on biogas plants and a short statistical summary of accidents in Germany are presented in the first part of this presentation. The main focus of the paper is the principle hazards arising from the substances and materials in biogas and hybrid power plants. Primarily, these are the hazards of fire and explosion induced by flammable methane gas. However, further hazards are the dangers of asphyxiation and poisoning by gases such as carbon dioxide, hydrogen sulphide and ammonia. Furthermore, hydrogen is produced by water electrolysis in hybrid power plants and mixed with bio methane in some cases. In order to prevent explosions when handling biogas and hydrogen it is necessary to know the explosion limits of gas and gas mixtures in mixture with air. However, biogas from agricultural plants can vary significantly in its composition. Therefore, for each gas composition the explosion limits would have to be determined. This would require a considerable amount of time and effort. Due to this fact, the explosion limits of biogas are frequently referred to only by the methane fraction of the gas mixture in the safety-relevant literature. In reality as biogas can consist of methane, carbon dioxide and further residual gases the explosion limits are generally over or underestimated. A calculation method for explosion limits was developed by means of explosion diagrams to avoid such errors. In a last topic methods are shown for the calculation of gas spreading in case of leakages in gas buffers for risk evaluation and land use planning. For this purpose the German directive VDI 3783 was evaluated. KW - Biogas KW - Explosion protection KW - Hybrid power plants KW - Safety characteristics KW - Technical regulations PY - 2014 DO - https://doi.org/10.1016/j.proeng.2014.10.433 SN - 1877-7058 VL - 84 SP - 259 EP - 272 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-32085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Molnarne, M. A1 - Seifert, Alexander A1 - Schröder, Volkmar T1 - Explosion protection according to the EU directives using the data from CHEMSAFE database N2 - For international trade and production of machinery used in potentially explosive atmospheres it is important to know about the regulations within the European Union. This paper presents an application of CHEMSAFE flammability data for fulfilling the requirements of the EU explosion protection directives. Most of the published data for flammability of substances are measured under atmospheric conditions although chemical processes operate often under non-atmospheric conditions. A couple of R&D projects were initiated in Germany to get more knowledge on explosion characteristics for non-atmospheric conditions. The explosion protection for machinery operated under non-atmospheric conditions is defined in the 2006/42/EU Directive. CHEMSAFE fulfills this requirement while it contains data of flammable compounds measured under non-atmospheric conditions and with other oxidizers than air. Furthermore it includes flammability data for gas mixtures consisting of flammable, inert, and different oxidizing components and most of the data are measured according to international standards. Safety data on flammable dusts - such as minimum ignition energy, maximum explosion pressure, ignition temperatures - represents also an important part of the database. The potentially explosive atmospheres are defined in revised Directive 2014/34/EU. For preparing risk assessment documents the following data for flammable gases and vapors, relating to the use of equipment, among others are necessary: Flammability limit, flash point, temperature class - auto-ignition temperature, maximum experimental safe gap. CHEMSAFE'2013 includes not only these data but also more than 200 triangular explosion diagrams, e.g. the newly measured methane/nitrogen/oxygen system under pressures up to 50 bars. The international standard Draft of IEC 80079-1-1 publishes data tables for flammable substances originated from CHEMSAFE which represents the international acceptance of these data. KW - Flammability limits KW - Gas and dust explosion KW - Explosion protection KW - Safety characteristics KW - Technical regulations KW - Safety data KW - CHEMSAFE database PY - 2014 DO - https://doi.org/10.1016/j.proeng.2014.10.432 SN - 1877-7058 VL - 84 SP - 247 EP - 258 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-32086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Molnarne, M. A1 - Schröder, Volkmar T1 - Flammability of Gases in Focus of European and US Standards N2 - The presentation will discuss the difference between EU and US standards for the determination of explosion (flammability) limits and limiting oxygen concentration. Small differences observed in measured values can be traced back to the different test apparatuses and criteria. The discrepancies can be much greater in the case of limiting oxygen concentration because of the high amount of inert gases and the corresponding low laminar burning velocities. The paper describes some examples and the influence of the chosen criteria on the results. The European and US standards use the criteria of flame propagation in open test vessels and of pressure rise in closed ones. The examples discussed show that flame propagation is still possible at very small pressure rise values, as observed much below the pressure rise criterion of usual standards. However, flame propagation in a process plant can cause an accident or explosion and must be avoided. Therefore, the flame propagation criterion is recommended to be used in chemical safety engineering. The European safety database CHEMSAFE contains expert-evaluated safety data for cases where the determination method and criteria are known. Flammability characteristics based on the pressure rise criterion may suffice in certain cases, e.g. for explosion protection in closed vessels without any connecting pipes. T2 - 2016 International Symposium on Safety Science and Technology CY - Kunming, China DA - 17.10.2016 KW - Flammability KW - Limiting oxygen concentration KW - Standardization KW - Explosion protection KW - Test methods PY - 2016 VL - Vol. XI SP - 400 EP - 409 AN - OPUS4-37951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Priebe, Nsesheye Susan A1 - Vogler, Nico A1 - Sturm, Patrick A1 - Neubert, M. A1 - Schröder, H.-J. A1 - Kühne, Hans-Carsten A1 - Hünger, K.-J. A1 - Gluth, Gregor T1 - Calcined brick clays and mixed clays as supplementary cementitious materials: Effects on the performance of blended cement mortars N2 - While calcined clays in general have been credited with a great potential to mitigate CO2 emissions related to cement production and consumption, calcined brick clays are currently understudied in this regard. In the present work, two brick clays, a low-grade kaolinitic clay, and a mixed clay composed of 50% brick clay and 50% low-grade kaolinitic clay were studied regarding transformations on calcination, and strength and durability performance as well as pore structure of mortars made with the blended cements. All calcined clays exhibited pozzolanic reactivity, with the performance of the brick clays inferior to the low-grade kaolinitic clay. However, the mixed clay performed very similar to the low-grade kaolinitic clay, which points to a viable option for optimal use of brick clays in cementitious systems. The carbonation resistance of the blended cement mortars was generally worse than that of the plain Portland cement mortar, as expected, but the former exhibited a significantly improved chloride penetration resistance. The latter improvement was due to pore structure refinement in the blended cement mortars, compared to the Portland cement mortar. KW - Brick clay KW - Illitic clay KW - Calcined clay KW - Blended cement KW - Supplementary cementitous materials PY - 2021 DO - https://doi.org/10.1016/j.conbuildmat.2020.120990 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. VL - 266 SP - 120990 PB - Elsevier Ltd. AN - OPUS4-51362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Volkmar A1 - Molnarne, M. T1 - Hazardous properties of hydrogen and hydrogen containing fuel gases N2 - The paper provides a summary of safety characteristics of hydrogen and hydrogen fuel gases. The inves-tigations focus on water electrolysis, the feeding of hydrogen into the natural gas grid and the use ofhydrogen for the fermentation process in biogas plants. The safety characteristics of hydrogen such as avery low minimum ignition energy, very large explosion range and high flame velocity with the resultingrapid pressure increase of hydrogen explosions are of particular importance for explosion protection andthey differ strongly from those of natural gas. Explosion ranges of hydrogen-methane-carbon dioxidemixtures have been measured for the use of hydrogen in biomethane production. The paper also showsand discusses explosion ranges of hydrogen and hydrogen-natural gas mixtures. Pressure and tempera-ture dependencies of the explosion limits of mixtures were investigated. Furthermore, pressure rise rates(KGvalues) were measured with regard to constructive explosion protection. The maximum experimen-tal safe gaps were determined for the classification of the mixtures and assignment to explosion groupsaccording to the European ATEX directives. It was found that admixture of 10% hydrogen to natural gashas only a minor influence on the safety characteristics of gas explosions. KW - Hydrogen safety KW - Biogas KW - Renewable energy KW - Natural gas mixtures KW - Flammability PY - 2019 DO - https://doi.org/10.1016/j.psep.2019.07.012 SN - 0957-5820 VL - 130 SP - 1 EP - 5 PB - Elsevier AN - OPUS4-49032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krietsch, Arne A1 - Kwangvitayanon, Yolada A1 - Schmidt, Martin A1 - Klippel, Alexander A1 - Schröder, Volkmar A1 - Scheid, M. T1 - Validation of the new ignition source 'exploding wire' for dust explosion testing in the 20-L-sphere N2 - The safety characteristics Maximum Explosion Pressure pniB, Maximum Explosion Pressure Rise (dp/dt)™* and Lower Explosion Limit LEL are determined in closed vessels such as the 20-L-sphere according to international Standards. Dust ignition is carried out using pyrotechnical igniters which are defined in the Standards. Due to various disadvantages of pyrotechnical igniters the need for alternative ignition sources arises again and again. Studies at the Federal Institute for Material Research and Testing (BAM) with ignition units which were able to generate ignition energies up to 2000 J showed that the so-called “exploding wire” or “fuse wire“ is suitable as an alternative ignition source. The paper presents further test results for the Validation of the exploding wire for the determination of Pm» and (dp/dt)mx in the 20-L-sphere. The tests were performed with a new ignition unit and improved electrodes which allowed ignition energies up to 10000 J. The paper also analyses propagation of flame and electrical arc on basis of high speed camera recordings. Turbulence measurements with a LDA System in the 20-L-sphere allowed investigation whether the activation of the ignition sources has an influence on the turbulence field generated during dust dispersion and whether the influence differs depending on the ignition source. T2 - Hazards 24 Symposium CY - Edinburgh, UK DA - 07.05.2014 KW - Dust explosion testing KW - Exploding wire KW - Explosion characteristics KW - Ignition source PY - 2014 SN - 978-0-85295-582-6 N1 - Serientitel: IChemE Symposium Series – Series title: IChemE Symposium Series VL - 159 SP - 1 EP - 7 AN - OPUS4-31145 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 unfluorinated hydrocarbons. Keywords: Explosion Protection, Inertization, Flammability, HFOs, HFC., R1234yf, R32, R1132a T2 - 25th IIR Internationa Congress of Refrigeration CY - Montreal, Canada DA - 24.08.2019 KW - Explosion Protection KW - Inertization KW - Flammability KW - HFOs KW - R1234yf KW - R1132a KW - R32 KW - HFC PY - 2019 SN - 978-2-36215-035-7 DO - https://doi.org/10.18462/iir.icr.2019.0767 SN - 1025-9031 SP - 1 EP - 9 AN - OPUS4-49546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Jakob A1 - Mishurova, Tatiana A1 - Fritsch, Tobias A1 - Serrano Munoz, Itziar A1 - Evans, Alexander A1 - Sprengel, Maximilian A1 - Klaus, M. A1 - Genzel, C. A1 - Schneider, J. A1 - Bruno, Giovanni T1 - On the influence of heat treatment on microstructure and mechanical behavior of laser powder bed fused Inconel 718 N2 - A range of heat treatments have been developed for wrought Inconel 718 to obtain desired properties. For additively manufactured Inconel 718, the recently developed standard ASTM F3301 provides guidance for heat treatment of powder bed fusion specimens. Although this standard is based on standards developed for wrought Inconel 718, it does not include direct aging. Since direct aging reduces the number of processing steps, it can result in a post processing cost reduction if the desired properties are obtained. In this study, we characterized the microstructure and tensile behavior of Inconel 718 specimens produced by a laser powder bed fusion process. The specimens were heat treated according to two different routines after stress relieving: a full heat Treatment versus a one-step direct aging process. Differences in the resulting texture and grain morphology were observed. The ex-situ stress-strain behavior was broadly similar. However, a slight increase in yield strength was observed for the direct aged specimen. In order to understand this behavior, investigations with in-situ synchrotron Energy dispersive X-ray diffraction tensile testing revealed differences in the load partitioning among different Crystal directions. Importantly, the elastic anisotropy expressed by the magnitude of the diffraction elastic constants showed a dependency on the microstructures. KW - Electron microscopy KW - X-ray analysis KW - Inconel 718 KW - Additive Manufacturing KW - Mechanical behavior KW - Diffraction elastic constants PY - 2021 DO - https://doi.org/10.1016/j.msea.2020.140555 VL - 805 SP - 40555 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-52142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Schmid, T. A1 - Schwarze, M. T1 - Explosion characteristics of mildly flammable refrigerants ignited with high-energy ignition sources in closed systems N2 - For evaluation of explosion scenarios in closed systems involving the mildly flammable refrigerants R1234yf, R1234ze and R32 dependent on the ignition energy, ignitions were carried out in a closed autoclave. A newly developed ignition system was used, which allows generating electric arcs with defined energies in a range between 3 J and 1000 J. The lower explosion limit of R32 decreases with increasing ignition energy. R32-explosions can be more severe than explosions involving highly flammable substances. However, in case of R1234yf and R1234ze, the ignition energy had to be increased to more than 100 J and more than 500 J to detect explosions in the closed system at all, although flame Propagation phenomena can already be observed if these substances are ignited with much weaker ignition sources in open glass tubes. The explosions were very mild with these substances. KW - Flammability limits KW - Explosion severity KW - R1234yf KW - R1234ze KW - R32 KW - Hydrofluoroolefin (HFO) PY - 2018 DO - https://doi.org/10.1016/j.ijrefrig.2018.04.009 SN - 0140-7007 SN - 1879-2081 VL - 90 SP - 249 EP - 256 PB - Elsevier Ltd and IIR AN - OPUS4-45879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mitu, M. A1 - Razus, D. A1 - Schröder, Volkmar T1 - Laminar burning velocities of hydrogen-blended methane-air and natural gas-air mixtures, calculated from the early stage of p(t) records in a spherical vessel N2 - The flammable hydrogen-blended methane–air and natural gas–air mixtures raise specific safety and environmental issues in the industry and transportation; therefore, their explosion characteristics such as the explosion limits, explosion pressures, and rates of pressure rise have significant importance from a safety point of view. At the same time, the laminar burning velocities are the most useful parameters for practical applications and in basic studies for the validation of reaction mechanisms and modeling turbulent combustion. In the present study, an experimental and numerical study of the effect of hydrogen addition on the laminar burning velocity (LBV) of methane–air and natural gas–air mixtures was conducted, using mixtures with equivalence ratios within 0.90 and 1.30 and various hydrogen fractions rH within 0.0 and 0.5. The experiments were performed in a 14 L spherical vessel with central ignition at ambient initial conditions. The LBVs were calculated from p(t) data, determined in accordance with EN 15967, by using only the early stage of flame propagation. The results show that hydrogen addition determines an increase in LBV for all examined binary flammable mixtures. The LBV variation versus the fraction of added hydrogen, rH, follows a linear trend only at moderate hydrogen fractions. The further increase in rH results in a stronger variation in LBV, as shown by both experimental and computed LBVs. Hydrogen addition significantly changes the thermal diffusivity of flammable CH4–air or NG–air mixtures, the rate of heat release, and the concentration of active radical species in the flame front and contribute, thus, to LBV variation. KW - Hydrogen KW - Methane KW - Natural gas KW - Laminar burning velocity (LBV) KW - Closed vessel combustion PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569083 DO - https://doi.org/10.3390/en14227556 SN - 1996-1073 VL - 14 IS - 22 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-56908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Jakob A1 - Heldmann, A. A1 - Hofmann, M. A1 - Evans, Alexander A1 - Petry, W. A1 - Bruno, Giovanni T1 - Determination of diffraction and single-crystal elastic constants of laser powder bed fused Inconel 718 N2 - High energy X-ray synchrotron diffraction is used to investigate the elastic anisotropy of the nickel-based superalloy IN718 produced by laser powder bed fusion (PBF-LB). This material is characterized by a columnar grain morphology with some crystallographic texture. The material is subjected to elastic loading to determine the diffraction elastic constants (DECs). Furthermore, the single-crystal elastic constants (SCEC) are refined from these experiments using different micromechanical models. The results show that each micromechanical model predicts a specific set of SCEC that well describes the elastic anisotropy of PBF-LB/IN718. KW - Mechanical Engineering KW - Mechanics of Materials KW - Condensed Matter Physics KW - General Materials Science PY - 2023 DO - https://doi.org/10.1016/j.matlet.2023.135305 SN - 0167-577X VL - 353 SP - 1 EP - 5 PB - Elsevier B.V. AN - OPUS4-58477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hempel, M. A1 - Ziegler, Mathias A1 - Schwirzke-Schaaf, S. A1 - Tomm, J.W. A1 - Jankowski, D. A1 - Schröder, D. T1 - Spectroscopic analysis of packaging concepts for high-power diode laser bars N2 - Double-side cooled high-power diode laser bars packaged by different techniques on different types of passive heat sinks are analyzed in terms of packaging-induced strain. Reference data from standard devices being single-side cooled only and packaged by conventional soft and hard soldering are also presented. Thermal profiling across the devices complements the results. The most suitable packaging architecture and technique for double-side cooled bars is identified. Measurements of the laser emission near field and electroluminescence pattern provide direct reference to the functionality of the devices. Furthermore, a type of cross calibration of the methods used for strain analysis is made, since all techniques are applied to the same set of bars. This involves micro photoluminescence, micro Raman, and degree-of-polarization electroluminescence spectroscopy. KW - Spectroscopy KW - Semiconductor laser KW - Thermography KW - High-power diode lasers KW - Non-destructive testing PY - 2012 DO - https://doi.org/10.1007/s00339-012-6799-4 SN - 0947-8396 VL - 107 IS - 2 SP - 371 EP - 377 PB - Springer CY - Berlin AN - OPUS4-25789 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hsuan, Y.G. A1 - Schröder, Hartmut A1 - Rowe, K. A1 - Müller, Werner A1 - Greenwood, J. A1 - Cazzuffi, D. A1 - Koerner, R.M. ED - Neil Dixon, T1 - Long-term performance and lifetime prediction of geosynthetics N2 - To properly understand and assess the long-term behaviour of geosynthetic materials it is necessary to investigate the various types of possible degradation mechanims. This includes both chemical and mechanical behaviour, and sometimes even their interactions with one another. Clearly, chemical degradation of geosynthetics depends on the polymer type. For example, polyolefins are vulnerable to oxidation; polyesters are susceptible to hydrolysis; and plasticizers can leach from polyvinyl chloride. This paper describes the concept of these three types of degradation, but focuses on the oxidation of polyolefins since the majority of the geosynthetics is made from this type of polymer. The methods used to predict the lifetime of antioxidants and service life of the geosynthetic material will be illustrated. Furthermore, the influence of temperature, pressure, and ultraviolet light on the service life are also demonstrated. Finally, the current specifications targeting the longevity of different geosynthetics are presented. Regarding mechanical degradation, the paper mainly focuses upon the creep deformation of geogrids and stress crack resistance (SCR) of polyethylene geomembranes and geopipe. The method to assess stress crack resistance is described, and the microscopic mechanisms that lead to such failure are explained. For creep evaluation, different acceleration tests are presented and their applicability with respect to the different types of polymers is illustrated. In addition, the long-term shear behaviour of geocomposites and geosynthetic clay liners is presented. T2 - 4th European Geosynthetics Conference - EuroGeo4 CY - Edinburgh, Scotland, UK DA - 2008-09-07 KW - Geosynthetic KW - Durability KW - Degradation KW - Antioxidant KW - Weathering PY - 2008 SP - 1 EP - 41 AN - OPUS4-17975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -