TY - JOUR A1 - Marchant, H. K. A1 - Tegetmeyer, H. E. A1 - Ahmerkamp, S. A1 - Holtappels, M. A1 - Lavik, G. A1 - Graf, J. A1 - Schreiber, Frank A1 - Mussmann, M. A1 - Strous, M. A1 - Kuypers, M. M. M. T1 - Metabolic specialization of denitrifiers in permeable sediments controls N2O emissions N2 - Coastal oceans receive large amounts of anthropogenic fixed nitrogen (N), most of which is denitrified in the sediment before reaching the open ocean. Sandy sediments, which are common in coastal regions, seem to play an important role in catalysing this N‐loss. Permeable sediments are characterized by advective porewater transport, which supplies high fluxes of organic matter into the sediment, but also leads to fluctuations in oxygen and nitrate concentrations. Little is known about how the denitrifying communities in these sediments are adapted to such fluctuations. Our combined results indicate that denitrification in eutrophied sandy sediments from the world's largest tidal flat system, the Wadden Sea, is carried out by different groups of microorganisms. This segregation leads to the formation of N2O which is advectively transported to the overlying waters and thereby emitted to the atmosphere. At the same time, the production of N2O within the sediment supports a subset of Flavobacteriia which appear to be specialized on N2O reduction. If the mechanisms shown here are active in other coastal zones, then denitrification in eutrophied sandy sediments may substantially contribute to current marine N2O emissions. KW - Nitrous oxide KW - Denitrification KW - Cross-feeding PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-463061 UR - https://onlinelibrary.wiley.com/doi/full/10.1111/1462-2920.14385 DO - https://doi.org/10.1111/1462-2920.14385 SN - 1462-2920 SN - 1462-2912 VL - 20 IS - 12 SP - 4486 EP - 4502 PB - John Wiley & Sons Ltd AN - OPUS4-46306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jordan, T. A1 - Askar, Enis A1 - Holtappels, Kai A1 - Deeg, S. A1 - Jopen, M. A1 - Stoll, U. A1 - Reinecke, E.-A. A1 - Krause, U. A1 - Beyer, M. A1 - Markus, D. T1 - Stand der Kenntnisse und Technik bezüglich Wasserstoffsicherheit N2 - Die Einführung von Wasserstoff als sicherer Energieträger braucht eine robuste Wissensbasis, darauf aufgebaute Werkzeuge zur Auslegung und Sicherheitsbewertung von Wasserstofftechnologien und ein international harmonisiertes Regelwerk. Viele der innovativen Technologien implizieren Wasserstoff bei hohen Drücken und/oder kryogenen Temperaturen, mit denen in verteilten Anwendungen erstmalig private Nutzer in Kontakt kommen. Um überkonservative, teure Sicherheitslösungen zu vermeiden, gleichzeitig aber die Einsetzbarkeit und Sicherheit von Wasserstoffanwendungen zu demonstrieren und die Akzeptanz für die Technologie aufrecht zu halten, muss auch die Sicherheitsforschung mit den Trends der technologischen Entwicklung Schritt halten, oder sie besser noch antizipieren. So beschreibt dieser Überblicksartikel nicht nur den gegenwärtigen Stand der Kenntnisse und Technik bezüglich Wasserstoffsicherheit, sondern auch ihre Weiterentwicklung. KW - Alternative Energieträger KW - Explosionsschutz KW - Flüssigwasserstoff KW - Unfallszenarien KW - Wasserstoffspeicherung KW - Sicherheitsbewertung KW - Regelsetzung KW - Gefährdungs- und Risikobeurteilung PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593629 DO - https://doi.org/10.1002/cite.202300141 SN - 0009-286X VL - 96 IS - 1-2 SP - 1 EP - 20 PB - Wiley-VCH AN - OPUS4-59362 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prewitz, M. A1 - Gaber, M. A1 - Müller, Ralf A1 - Marotzke, C. A1 - Holtappels, Kai T1 - Polymer coated glass capillaries and structures for high-pressure hydrogen storage: Permeability and hydrogen tightness N2 - The hydrogen tightness of high-pressure hydrogen storage is a Basic criterion for long-term storage. The H2 permeation coefficients of epoxy resin and a glass lacquer were determined to enable the geometric optimization of a glass capillary storage. It was found that the curing conditions have no significant influence on the H2 permeation coefficient of resin. The H2 permeation coefficient of epoxy resin is only about three orders of Magnitude greater than that of borosilicate glass. This suggests that the initial pressure of 700 bar takes about 2.5 years to be halved in capillary array storage. Therefore, a high-pressure hydrogen storage tank based on glass capillaries is ideally suited for long-term storage in mobile applications. KW - Permeability KW - Glass capillaries KW - Coating KW - Hydrogen storage KW - Long-term calculation KW - Epoxy resin PY - 2018 DO - https://doi.org/10.1016/j.ijhydene.2017.12.092 SN - 0360-3199 VL - 43 IS - 11 SP - 5637 EP - 5644 PB - Elsevier AN - OPUS4-44327 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -