TY - GEN A1 - Ferrero, Fabio A1 - Noll, Matthias A1 - Schmidt, Bernd A1 - Malow, Marcus A1 - Schmidt, Martin T1 - Experimentelle und numerische Analyse des Selbstentzündungsverhalten von Holzhalden T2 - 9. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit" CY - Köthen, Deutschland DA - 2008-11-06 KW - Brandvermeidung KW - Biomasse KW - Lagerung KW - Schüttgüter KW - Selbstentzündung PY - 2008 SN - 978-3-89746-099-7 SP - 1 EP - 21 PB - VDI, Hallescher Bezirksverein CY - Halle AN - OPUS4-18305 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, C. A1 - Hensen, C. A1 - Wallmann, K. A1 - Liebetrau, V. A1 - Tatzel, Michael A1 - Schurr, S. L. A1 - Kutterolf, S. A1 - Haffert, L. A1 - Geilert, Sonja A1 - Hübscher, C. A1 - Lebas, E. A1 - Heuser, A. A1 - Schmidt, M. A1 - Strauss, H. A1 - Vogl, Jochen A1 - Hansteen, T. T1 - Origin of High Mg and SO4 Fluids in Sediments of the Terceira Rift, Azores‐Indications for Caminite Dissolution in a Waning Hydrothermal System N2 - During R/V Meteor cruise 141/1, pore fluids of near surface sediments were investigated to find indications for hydrothermal activity in the Terceira Rift (TR), a hyperslow spreading center in the Central North Atlantic Ocean. To date, submarine hydrothermal fluid venting in the TR has only been reported for the D. João de Castro seamount, which presently seems to be inactive. Pore fluids sampled close to a volcanic cone at 2,800‐m water depth show an anomalous composition with Mg, SO4, and total alkalinity concentrations significantly higher than seawater and a nearby reference core. The most straightforward way of interpreting these deviations is the dissolution of the hydrothermally formed mineral caminite (MgSO4 0.25 Mg (OH)2 0.2H2O). This interpretation is corroborated by a thorough investigation of fluid isotope systems (δ26Mg, δ30Si, δ34S, δ44/42Ca, and 87Sr/86Sr). Caminite is known from mineral assemblages with anhydrite and forms in hydrothermal recharge zones only under specific conditions such as high fluid temperatures and in altered oceanic crust, which are conditions generally met at the TR. We hypothesize that caminite was formed during hydrothermal activity and is now dissolving during the waning state of the hydrothermal system, so that caminite mineralization is shifted out of its stability zone. Ongoing fluid circulation through the basement is transporting the geochemical signal via slow advection toward the seafloor. KW - Isotope ratio KW - Delta value KW - Pore fluids KW - Magnesium KW - Hydrothermal fluid PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503430 DO - https://doi.org/10.1029/2019GC008525 VL - 20 IS - 12 SP - 6078 EP - 6094 PB - Wiley AN - OPUS4-50343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Bohraus, Stephan A1 - Schmidt, Rüdiger A1 - Portella, Pedro Dolabella ED - Lohrmann, M. ED - Rettenmayr, P. T1 - Aufbau einer fraktographischen online-Datenbank N2 - Fraktographischen Daten aus Schadensanalysen, Vergleichsversuchen und Vorhaben könnten der Fachöffentlichkeit im Bereich Fraktographie zur Verfügung gestellt werden, sofern das Urheberrecht es zulässt und außerdem ein geeignetes Medium existiert. Ein solches Medium könnte eine offene fraktographische online-Datenbank sein. Eine solche wird im Rahmen der AG Fraktographie im DVM-DGM Gemeinschaftsausschuss "Rasterelektronenmikroskopie in der Materialprüfung" zurzeit erarbeitet. T2 - Metallographietagung 2013 CY - Friedrichshafen, Germany DA - 18.09.2013 KW - Datenbank KW - Fraktographie KW - Schadensanalyse PY - 2013 SN - 978-3-88355-398-6 VL - 45 SP - 19 EP - 24 PB - Inventum CY - Bonn AN - OPUS4-50598 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, C. A1 - Schierack, P. A1 - Gerber, U. A1 - Schröder, C. A1 - Choi, Youngeun A1 - Bald, Ilko A1 - Lehmann, W. A1 - Rödiger, S. T1 - Streptavidin Homologues for Applications on Solid Surfaces at High Temperatures N2 - One of the most commonly used bonds between two biomolecules is the bond between biotin and streptavidin (SA) or streptavidin homologues (SAHs). A high dissociation constant and the consequent high-temperature stability even allows for its use in nucleic acid detection under polymerase chain reaction (PCR) conditions. There are a number of SAHs available, and for assay design, it is of great interest to determine as to which SAH will perform the best under assay conditions. Although there are numerous single studies on the characterization of SAHs in solution or selected solid phases, there is no systematic study comparing different SAHs for biomolecule-binding, hybridization, and PCR assays on solid phases. We compared streptavidin, core streptavidin, traptavidin, core traptavidin, neutravidin, and monomeric streptavidin on the surface of microbeads (10–15 μm in diameter) and designed multiplex microbead-based experiments and analyzed simultaneously the binding of biotinylated oligonucleotides and the hybridization of oligonucleotides to complementary capture probes. We also bound comparably large DNA origamis to capture probes on the microbead surface. We used a real-time fluorescence microscopy imaging platform, with which it is possible to subject samples to a programmable time and temperature profile and to record binding processes on the microbead surface depending on the time and temperature. With the exception of core traptavidin and monomeric streptavidin, all other SA/SAHs were suitable for our investigations. We found hybridization efficiencies close to 100% for streptavidin, core streptavidin, traptavidin, and neutravidin. These could all be considered equally suitable for hybridization, PCR applications, and melting point analysis. The SA/SAH–biotin bond was temperature-sensitive when the oligonucleotide was mono-biotinylated, with traptavidin being the most stable followed by streptavidin and neutravidin. Mono-biotinylated oligonucleotides can be used in experiments with temperatures up to 70 °C. When oligonucleotides were bis-biotinylated, all SA/SAH–biotin bonds had similar temperature stability under PCR conditions, even if they comprised a streptavidin variant with slower biotin dissociation and increased mechanostability. KW - Biopolymers Probes KW - Hybridization KW - Fluorescence KW - Genetics PY - 2020 DO - https://doi.org/10.1021/acs.langmuir.9b02339 VL - 36 IS - 2 SP - 628 EP - 636 PB - American Chemical Society Publication CY - Washington AN - OPUS4-50357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kondo, M. A1 - Melzer, Michael A1 - Karnaushenko, D. A1 - Uemura, T. A1 - Yoshimoto, S. A1 - Aklyama, M. A1 - Noda, Y. A1 - Araki, T. A1 - Schmidt, O. G. A1 - Sekitani, T. T1 - Imperceptible magnetic sensor matrix system integrated with organic driver and amplifier circuits N2 - Artificial electronic skins (e-skins) comprise an integrated matrix of flexible devices arranged on a soft, reconfigurable surface. These sensors must perceive physical interaction spaces between external objects and robots or humans. Among various types of sensors, flexible magnetic sensors and the matrix configuration are preferable for such position sensing. However, sensor matrices must efficiently map the magnetic field with real-time encoding of the positions and motions of magnetic objects. This paper reports an ultrathin magnetic sensor matrix system comprising a 2 × 4 array of magnetoresistance sensors, a bootstrap organic shift register driving the sensor matrix, and organic signal amplifiers integrated within a single imperceptible platform. The system demonstrates high magnetic sensitivity owing to the use of organic amplifiers. Moreover, the shift register enabled real-time mapping of 2D magnetic field distribution. KW - Imperceptible electronics KW - Magnetic sensor system KW - Electronic skin KW - Organic electronics KW - Giant magnetoresistance PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503855 DO - https://doi.org/10.1126/sciadv.aay6094 SN - 2375-2548 VL - 6 IS - 4 SP - Paper eaay6094, 1 EP - 10 PB - American Association for the Advancement of Science AN - OPUS4-50385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Martin A1 - Wu, Dejian A1 - Zhao, P. A1 - Tan, X. A1 - Huang, W. A1 - Qianc, X. T1 - Minimum explosion concentrations of coal dusts with CH4/H2/CO below the gas lower explosion limit N2 - A 20-L spherical explosion chamber was used to investigate the explosion characteristics of dust clouds in air with the presence of flammable gas which is lower than its lower explosion limit (LEL). including minimum explosion concentration (MEC) of dust. Explosion pressure (Pex) and explosion pressure rise (dp/dt)ex). Two dust samples (anthracite coal, bituminous coal) and were three flammable gases (CH4, H2 and CO) were tested. Experimental results showed that the explosion of hybrid mixtures occurs when both dust and gas concentrations are lower than the LEL/MEC of the single substances. Meanwhile. all flammable gases with different volume fractions have distinct effects on the MEC. Pex and (dp/dt)ex of the dust samples. With the increase of the flammable gas concentration. either the Pex and (dp/dt)ex increase or the MEC decreases for all the hybrid mixtures of both two dust samples. At the same concentration of coal dusts. the addition of CH4 promotes higher explosion risks than the other two flammable gases. The distribution of (dp/dt)ex is quite different with the restricted area defined by empirical formulas. These results improve our understanding of the explosion behaviour and the explosion risk of hybrid dust-gas mixtures in air. KW - Dust explosions KW - Gas explosions KW - Minimum explosible concentration KW - Lower explosion limit KW - Hybrid mixtures PY - 2020 DO - https://doi.org/10.1016/j.fuel.2019.116401 SN - 0032-5910 VL - 260 SP - UNSP 116401 PB - Elsevier Sci. Ltd. AN - OPUS4-49956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Schmidt, Martin A1 - Tan, X. A1 - Zhao, P. A1 - Huang, W. A1 - Qian, X. T1 - Minimum ignition temperature of carbonaceous dust clouds in air with CH4/H-2/CO below the gas lower explosion limit N2 - Godbert-Greenwald furnace was used to investigate the minimum ignition temperature of dust clouds (MITC) in air with the presence of flammable gas which is lower than its lower explosion limit (LEL). Three flammable gases (CH4, H2 and CO) and three carbonaceous dusts (anthracite coal, bituminous coal and sweet potato starch) were tested. Results showed that all flammable gases have distinct effects on the MITC of the dust samples and volatile matter content of dust plays an important role during the ignition process. Specifically, the MITC of anthracite coal dust decreased from 610 °C to 560 °C, 580 °C and 570 °C with 3% CH4, 3% CO and 2.5% H2, respectively. Moreover, a heterogeneous ignition mechanism model was proposed to verify the equally global ignition characteristic between hybrid anthracite coal-CxHy mixture and bituminous coal. All three gases had an ignorable effect on the MITC of starch dust considering the experimental error. The presence of CO and H2 slightly promoted the ignition of bituminous coal dust, but the addition of CH4 showed a distinct concentration effect on the MITC of bituminous coal: the MITC decreased with 1% CH4 while increased with 2% and 3% CH4. This negative-effect of flammable gases at such low concentrations on ignition temperature of bituminous coal dusts was found for the first time. Furthermore, the presence of the 2nd flammable gas had a smaller effect on the MITC of dust samples with a higher volatile content, resulted from the competition of heterogeneous and homogeneous ignition mechanisms. KW - Dust explosions KW - Gas explosions KW - Minimum ignition temperature KW - Hybrid mixtures PY - 2020 DO - https://doi.org/10.1016/j.fuel.2019.116811 SN - 0016-2361 VL - 264 SP - 116811 PB - Elsevier Ltd. AN - OPUS4-50856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Benita A1 - Pergantis, S. A. A1 - Esteban-Fernández, Diego A1 - Jakubowski, Norbert A1 - Günther, D. T1 - Investigation of a combined microdroplet generator and pneumatic nebulization system for rapid quantitative determination of metal-containing nanoparticles using ICP-MS N2 - In this work, a routinely applicable approach is presented to characterize metal NPs. Individual droplets generated from a microdroplet generator (MDG) were merged into an aerosol generated by a pneumatic nebulizer (PN) and introduced into an ICPMS. The MDG offers high transport efficiency of individual and discrete droplets and was therefore used to establish a calibration function for mass quantification of NPs which were introduced through the PN following the single particle procedure as described elsewhere. The major advantages of such a combined configuration include fast processing of large sample volumes, fast exchanges of different sample matrixes, and the calibration of the NP signal using traceable elemental standards, thus avoiding the need to use NP reference materials or other, not always thoroughly characterized, commercially available NPs. The transport efficiency of the sample introduction is calculated based on the fact that 100% of the calibrant reaches the plasma through the MDG, whereas for the PN a NP suspension containing a known number concentration is used. Alternatively, bulk analysis of the NP material allows transport efficiency determination without any additional information from reference NPs. With this method, we could determine the size of standard silver NPs at 60.4 ± 1.0 nm and 80.0 ± 1.4 nm, respectively, which agrees with the size ranges given by the supplier (60.8 ± 6.6 nm and 79.8 ± 5.4 nm). Furthermore, we were also able to determine the NPs number concentration of the sample (Ag/Au) with a deviation of 3.2% the expected value. KW - Nanoparticles KW - ICP-MS KW - Microdroplet generator PY - 2015 DO - https://doi.org/10.1021/acs.analchem.5b01604 SN - 0003-2700 SN - 1520-6882 VL - 87 IS - 17 SP - 8687 EP - 8694 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Der Einfluss des Staubungsverhaltens auf druckentlastete Staubexplosionen T2 - 12. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen DA - 2015-11-05 PY - 2015 AN - OPUS4-34789 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knechtel, Sophie A1 - Schmidt, Simon A1 - Mishra, K. B. A1 - Wehrstedt, Klaus-Dieter T1 - Modellierung der Hauptbrandszenarien von flüssigem Wasserstoff (LH2) mittels CFD N2 - Die sichere Lagerung und der Transport von Flüssigwasserstoff (LH2) verlangen nach verlässlichen Abschätzungen möglicher Risiken durch Feuer oder Explosion. Aufgrund des breiten Explosionsbereichs (4 Vol.-% - 74 Vol.-%) reagiert Wasserstoff sehr schnell und produziert hohe Flammentemperaturen. Da Wasserstoffflammen ruß- bzw. farblos sind, ist Wärmestrahlung im Fernfeld kein Risikofaktor. Allerdings stellen die hohe lokale Wärmestrahlung und die nicht sichtbaren Flammen eine Gefahr für Menschen und Infrastruktur in der Nähe dar. Es ist daher notwendig die Gefahren von LH2-Feuern sorgfältig zu bewerten. Einerseits sind experimentelle Untersuchungen verschiedener Szenarien teuer, andererseits können sie teilweise auch praktisch nicht durchführbar sein. Numerische Simulationen dieser Szenarien können ein Ausweg aus diesem Problem sein. In der vorliegenden Arbeit wird ein solcher Ansatz genutzt, um große Brandszenarien mit LH2 mittels CFD (Computational Fluid Dynamics) zu modellieren und so die notwendigen Sicherheitsabstände abzuschätzen. Der Fokus liegt dabei auf der Simulation von Jet- und Pool-Feuerszenarien mit einem kommerziellen CFD-Code (Ansys CFX). Die benötigten geometrischen Modelle werden für Jet- und Pool-Feuer erstellt und mit den nötigen Randbedingungen implementiert. Wichtige Submodelle für chemische Reaktionen (Einschritt- und detaillierte Modelle), Verbrennung (Eddy-Dissipation- und Flamelet-Modell) und Strahlung (Discrete-Transfer-Modell) werden genutzt. Die maximal simulierten Flammentemperaturen liegen bei ~2100 K für Jet-Feuer und ~2300 K für Pool-Feuer. Um Aussagen zu thermischen Sicherheitsabständen zu treffen, wurden die Spezifischen Ausstrahlungen (SEP) ermittelt und anschließend entsprechende Positionsfaktoren gewählt, um verlässliche Sicherheitsabstände zu berechnen. Je nach Bedarf können CFD-Modelle sowohl für qualitative als auch für quantitative Risikobewertungen von LH2-Großbränden genutzt werden. T2 - 12. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 05.11.2015 KW - Flüssigwasserstoff KW - Großbrand KW - Poolfeuer KW - Jet-Feuer KW - CFD KW - Sicherheitsabstand PY - 2015 SN - 978-3-86011-091-1 SP - Paper P-11, 1 EP - 8 AN - OPUS4-34827 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -