TY - CONF A1 - Rauchegger, Christian A1 - Schalau, Bernd A1 - Schmidt, Dirk A1 - Lohse, Volkmar A1 - Schröder, Volkmar A1 - Thévenin, D. T1 - Experimental results from heavy gas dispersions (R134a) N2 - Heavy gases in large quantities are used worldwide in various industries. Past incidents, such as the liquefied gas disaster in Viareggio (2009) have shown that these materials are difficult to handle in a safe manner. According to the German Hazardous Incident Ordinance (StörfallVO 2000 - 12. BIMSchV), plant operators with extended responsibilities must produce a report in which they verify that , in the event of an unintentional gas release, the surrounding area will not be aversely affected. Essential elements of this report are calculations of both the released mass flow and the gas dispersion. Using models such as the VDI guideline 3783 (state of the art in Germany) plant operators are able to predict the characteristics of likely gas dispersions. The presented experimental investigations were carried out at the BAM better understand heavy gas dispersion with high gas concentrations in the air (≥ 1 Vol.-%), as well as concentrations with approximately neutral density characteristics (≤ 3000ppm) in order to test the accuracy of the VDI guideline. The starting point for experimental trials was the heavy gas releases resulting from pipeline, vessel or standard gas bottle leaks, with mass flows of between 20 and 100 g s-1. Investigations on the gas-phase release process focused on the unsteady mass flow associated with releases from standard gas bottles. The experimental results will be used as comparative parameters for future simulations. The goal of these simulations is to develop a model with which calculation of the unsteady mass flow, based on the material characteristics for any gas, is possible. T2 - 7th Global congress on process safety - 2011 Spring meeting CY - Chicago, Illinois, USA DA - 13.03.2011 KW - Heavy gas KW - Gas releases KW - Dispersion KW - Measurement KW - VDI guideline 3783 PY - 2011 SP - 1 EP - 12 AN - OPUS4-23532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rauchegger, Christian A1 - Schröder, Volkmar A1 - Lohse, Volkmar A1 - Schmidt, Dirk A1 - Thévenin, D. T1 - Release and dispersion of heavy gases - experimental results and numerical simulations N2 - Heavy gases in large quantities are used worldwide in various industries. Past incidents, such as the liquefied gas disaster in Viareggio (2009) have shown that these materials are difficult to handle in a safe manner. According to the German Hazardous Incident Ordinance (StörfallVO 2000 - 12. BImSchV) plant operators with 'extended responsibilities' must produce a report in which they verify that, in the event of an unintentional gas release, the surrounding area will not be aversely affected. The essential elements of this report include calculations of both releasedmass flow and gas dispersion. Using models such as the VDI guideline 3783 (state of the art in Germany) plant operators are able to predict the characteristics of likely gas dispersions. Within the framework of the reported experimental trials, the release process of heavy gases from standard gas cylinders was investigated. Using the results of this investigation a calculation methodology has been developed which is able to predict the mass flow of a gas-phase release. As input parameters only the geometry of the gas cylinder, the material properties of the respective fluid as well as the environmental parameters such as velocity of approach and air temperature are required. In the course of modeling various approaches for nucleate boiling have been tested for their applicability. Both the calculation methodology and a comparison between the calculated and experimental results will be presented. Within the same framework of experimental trials, the dispersion process of the aforementioned heavy gases was also investigated. The dispersed gas cloud in this case was considered as originating from a continuous point source under ambient conditions. For the various Trials concentrations both in the heavy gas (≥ 1 vol.-%) and in the neutral gas field (≤ 3000 ppm) were measured. In the immediate area of the release the length, width and height of the heavy gas cloud were evaluated. The experimental results, comparison calculations and the measurement techniques will be presented. T2 - 8th Global congress on process safety (GCPS) CY - Houston, TX, USA DA - 01.04.2012 KW - Heavy gases KW - Gas releases KW - Gas Dispersion KW - VDI Guideline 3783 PY - 2012 UR - https://www.researchgate.net/publication/267345315_Release_and_Dispersion_of_Heavy_Gases_-_Experimental_Results_and_Numerical_Simulations SN - 978-0-8169-1071-7 IS - Paper 104aq SP - 1 EP - 16 AN - OPUS4-25772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Beck, Uwe A1 - Negendank, Detlef A1 - Lohse, Volkmar A1 - Kormunda, M. A1 - Esser, N. T1 - Dependence of the optical constants and the performance in the SPREE gas measurement on the thickness of doped tin oxide over coatings N2 - In this study, thickness related changes of the optical properties of doped tin oxide were studied. Two different sets of samples were prepared. The first set was doped with iron or nickel on silicon substrate with thicknesses of 29–56 nm, the second was iron doped on gold/glass substrate with 1.6–6.3 nm. The optical constants were determined by using spectral ellipsometry (SE) followed by modelling of the dielectric function with an oscillator model using Gaussian peaks. The analysis of the optical constants shows a dependence of the refraction and the absorption on the thickness of the doped tin oxide coating. In addition to the tin oxide absorption in the UV, one additional absorption peak was found in the near-IR/red which is related to plasmonic effects due to the doping. This peak shifts from the near-IR to the red part of the visible spectrum and becomes stronger by reducing the thickness, probably due to the formation of metal nanoparticles in this layer. These results were found for two different sets of samples by using the same optical model. Afterwards the second sample set was tested in the Surface Plasmon Resonance Enhanced Ellipsometric (SPREE) gas measurement with CO gas. It was found that the thickness has significant influence on the sensitivity and thus the adsorption of the CO gas. By increasing the thickness from 1.6 nm to 5.1 nm, the sensing ability is enhanced due to a higher coverage of the surface with the over coating. This is explained by the high affinity of CO molecules to the incorporated Fe-nanoparticles in the tin oxide coating. By increasing the thickness further to 6.3 nm, the sensing ability drops because the layer disturbs the SPR sensing effect too much. T2 - 7th International Conference on Spectroscopic Ellipsometry (ICSE-7) DA - 06.06.2016 KW - Surface plasmon resonance KW - Spectroscopic ellipsometry KW - Doped tin oxide KW - Gas sensing KW - Plasmonic absorption PY - 2017 DO - https://doi.org/10.1016/j.apsusc.2016.11.188 SN - 0169-4332 VL - 421, Teil B SP - 480 EP - 486 PB - Elsevier B.V. AN - OPUS4-42692 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohse, Volkmar T1 - Stand der Normung zur Messfunktion und funktionalen Sicherheit von Gaswarngeräten für die Durchführung von Konformitätsverfahren nach Richtlinie 94/9/EG (ATEX) T2 - Erfahrungsaustauschkreis Explosionsschutz der deutschen, für Richtlinie 94/9/EG notifizierten Stellen (EK4) CY - Reinhardsbrunn DA - 2015-05-12 PY - 2015 AN - OPUS4-33522 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohse, Volkmar T1 - Auswahl, Installation und Einsatz von Gaswarnsystemen unter Berücksichtigung des Merkblatts T 023 der deutschen BG-Chemie und der neuen ÖVE/ÖNorm EN 60079-29-2 T2 - Seminar MSA Auer Austria CY - Vienna, Austria DA - 2009-10-28 PY - 2009 AN - OPUS4-19908 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohse, Volkmar T1 - Betreiben von Gaswarnanlagen unter Berücksichtigung der Merkblätter T 021 und T 023 der BG RCI (BG-Chemie) sowie der TRBS 1201 Teil 3 T2 - MSA Austria Seminar CY - Vienna, Austria DA - 2010-06-01 PY - 2010 AN - OPUS4-21381 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nooke, Alida A1 - Beck, Uwe A1 - Hertwig, Andreas A1 - Krause, Andreas A1 - Krüger, Hannes A1 - Lohse, Volkmar A1 - Negendank, Detlef A1 - Steinbach, J. T1 - On the application of gold based SPR sensors for the detection of hazardous gases N2 - A gas sensor system based on the surface plasmon resonance (SPR) effect in a 44 nm Au layer was studied. The usability of this sensor system was investigated for several analyte gases and gas mixtures which are interesting due to their flammability, toxicity or greenhouse effect. The SPR effect of gold was measured in nitrogen and compared with the gaseous alkane series which caused a shift of the position of the SPR effect. For in situ measurements, the phase shift Δ at the SPR angle (ψ minimum) in the analyte gas mixtures was measured for investigated gases in comparison with nitrogen. With this method, detection limits of different gases could be determined, which lie in a range interesting for safety engineering. Furthermore the aging effect of the gold layers which leads to loss in sensitivity of the sensor was investigated. KW - Ellipsometry KW - SPR effect KW - Gas sensing KW - Gold layer PY - 2010 DO - https://doi.org/10.1016/j.snb.2010.05.061 SN - 0925-4005 SN - 1873-3077 VL - 149 IS - 1 SP - 194 EP - 198 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-21673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohse, Volkmar T1 - Auswahl, Einsatz und Instandhaltung von Gaswarnsystemen unter Berücksichtigung der Merkblätter T 021 und T 023 der BG-Chemie und der neuen DIN EN 60079-29-2 T2 - Kundenseminar MSA Auer GmbH CY - Berlin, Germany DA - 2008-04-08 PY - 2008 AN - OPUS4-17336 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohse, Volkmar T1 - Explosionsschutz - Gefährdungsanalyse und Explosionsschutzdokument T2 - Hauptvortrag bei Kundenseminar MSA Auer GmbH CY - Berlin, Germany DA - 2009-04-29 PY - 2009 AN - OPUS4-19169 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohse, Volkmar T1 - Auswahl, Einsatz und Betrieb von Gaswarnanlagen unter Berücksichtigung der DIN EN 60079-29-2 und des ergänzenden Merkblatts T 023 der BG-Chemie T2 - Seminar für Honeywell Analytics CY - Bad Hersfeld, Germany DA - 2009-11-27 PY - 2009 AN - OPUS4-20370 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Negendank, Detlef A1 - Lohse, Volkmar T1 - Gaswarnsysteme in der Sicherheitstechnik - Anforderungen an Messfunktion und funktionale Sicherheit T2 - 12. BAM/PTB-Kolloquium zu Fragen der chemischen und physikalischen Sicherheitstechnik, BAM CY - Berlin, Germany DA - 2010-06-15 PY - 2010 AN - OPUS4-21006 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -