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1. Aspects in Classification Learning - Review of Recent Developments in Learning Vector Quantization

Author

Kaden M., Lange M., Nebel D., Riedel M., Geweniger T., and Villmann T.

Subjects
learning vector quantization, non-standard metrics, classification, classification certainty, statistics, Electronic computers. Computer science, QA75.5-76.95
Abstract

.Classification is one of the most frequent tasks in machine learning. However, the variety of classification tasks as well as classifier methods is huge. Thus the question is coming up: which classifier is suitable for a given problem or how can we utilize a certain classifier model for different tasks in classification learning. This paper focuses on learning vector quantization classifiers as one of the most intuitive prototype based classification models. Recent extensions and modifications of the basic learning vector quantization algorithm, which are proposed in the last years, are highlighted and also discussed in relation to particular classification task scenarios like imbalanced and/or incomplete data, prior data knowledge, classification guarantees or adaptive data metrics for optimal classification.

Published
2014
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2. Rare HCV subtypes and retreatment outcomes in a cohort of European DAA-experienced patients

Author

Antoni, C., Teufel, A., Vogelmann, R., Ebert, M., Balavoine, J., Giostra, E., Berning, M., Hampe, J., Boettler, T., Neumann-Haefelin, C., Thimme, R., De Gottardi, A., Rauch, A., Semmo, N., Ellenrieder, V., Gress, M., Herrmann, A., Stallmach, A., Hoffmann, D., Protzer, U., Kodal, A., Löbermann, M., Götze, T., Keitel-Anselmino, V., Lange, C.M., Zachoval, R., Mayerle, J., Maieron, A., Michl, P., Merle, U., Moradpour, D., Chave, J.-P., Muche, M., Epple, H.-J., Müller-Schilling, M., Kocheise, F., Müller, T., Tacke, F., Roeb, E., Rissland, J., Krawczyk, M., Schulze, P., Semela, D., Spengler, U., Rockstroh, J., Strassburg, C.P., Siebler, J., Schulze zur Wiesch, J., Piecha, F., von Felden, J., Jordan, S., Lohse, A., Sprinzl, M., Galle, P., Stauber, R., Strey, B., Steckstor, W., Schmiegel, W., Brockmeyer, N.H., Canbay, A., Trautwein, C., Uschner, F., Trebicka, J., Weber, T., Wedemeyer, H., Cornberg, M., Manns, M., Wietzke-Braun, P., Günther, R., Willuweit, K., Hilgard, G., Schmidt, H., Zizer, E., Backhus, J., Seufferlein, T., Al-Taie, O., Angeli, W., Beckebaum, S., Erhardt, A., Garrido-Lüneburg, A., Gattringer, H., Genné, D., Gschwantler, M., Gundling, F., Hametner, S., Schöfl, R., Haag, S., Heinzow, H., Heyer, T., Hirschi, C., Jussios, A., Kanzler, S., Kordecki, N., Kraus, M., Kullig, U., Wollschläger, S., Magenta, L., Beretta-Piccoli, B. Terziroli, Menges, M., Mohr, L., Muehlenberg, K., Niederau, C., Paulweber, B., Petrides, A., Pinkernell, M., Piso, R., Rambach, W., Reinhardt, L., Reiser, M., Riecken, B., Rieke, A., Roth, J., Schelling, M., Schlee, P., Schneider, A., Scholz, D., Schott, E., Schuchmann, M., Schulten-Baumer, U., Seelhoff, A., Stich, A., Stickel, F., Ungemach, J., Walter, E., Weber, A., Wege, H., Winzer, T., Abels, W., Adler, M., Audebert, F., Baermann, C., Bästlein, E., Barth, R., Barthel, K., Becker, W., Behrends, J., Benninger, J., Berger, F., Berzow, D., Beyer, T., Bierbaum, M., Blaukat, O., Bodtländer, A., Böhm, G., Börner, N., Bohr, U., Bokemeyer, B., Bruch, H.R., Bucholz, D., Buggisch, P., Matschenz, K., Petersen, J., Burkhard, O., Busch, N., Chirca, C., Delker, R., Diedrich, J., Frank, M., Diehl, M., Tal, A.O., Schneider, M., Dienethal, A., Dietel, P., Dikopoulos, N., Dreck, M., Dreher, F., Drude, L., Ende, K., Ehrle, U., Baumgartl, K., Emke, F., Glosemeyer, R., Felten, G., Hüppe, D., Fischer, J., Fischer, U., Frederking, D., Frick, B., Friese, G., Gantke, B., Geyer, P., Schwind, H.R., Glas, M., Glaunsinger, T., Goebel, F., Göbel, U., Görlitz, B., Graf, R., Gruber, H., Hartmann, C., Klag, C., Härter, G., Herder, M., Heuchel, T., Heuer, S., Hinrichsen, H., Seegers, B., Höffl, K.-H., Hörster, H., Sonne, J.-U., Hofmann, W.P., Holst, F., Hunstiger, M., Hurst, A., Jägel-Guedes, E., John, C., Jung, M., Kallinowski, B., Kapzan, B., Kerzel, W., Khaykin, P., Klarhof, M., Klüppelberg, U., Wolfratshausen, Klugewitz, K., Knapp, B., Knevels, U., Kochsiek, T., Körfer, A., Köster, A., Kuhn, M., Langekamp, A., Künzig, B., Link, R., Littman, M., Löhr, H., Lutz, T., Gute, P., Knecht, G., Lutz, U., Mainz, D., Mahle, I., Maurer, P., Mauss, S., Mayer, C., Möller, H., Heyne, R., Moritzen, D., Mroß, M., Mundlos, M., Naumann, U., Nehls, O., K, Ningel, R., Oelmann, A., Olejnik, H., Gadow, K., Pascher, E., Philipp, A., Pichler, M., Polzien, F., Raddant, R., Riedel, M., Rietzler, S., Rössle, M., Rufle, W., Rump, A., Schewe, C., Hoffmann, C., Schleehauf, D., Schmidt, W., Schmidt-Heinevetter, G., Fabris, J. Schmidtler-von, Schneider, L., Schober, A., Niehaus-Hahn, S., Schwenzer, J., Seidel, T., Seitel, G., Sick, C., Simon, K., Stähler, D., Stenschke, F., Steffens, H., Stein, K., Steinmüller, M., Sternfeld, T., Svensson, K., Tacke, W., Teuber, G., Teubner, K., Thieringer, J., Tomesch, A., Trappe, U., Ullrich, J., Urban, G., Usadel, S., von Lucadou, A., Weinberger, F., Werheid-Dobers, M., Werner, P., Winter, T., Zehnter, E., Zipf, A., Dietz, Julia, Graf, Christiana, Berg, Christoph P., Port, Kerstin, Deterding, Katja, Buggisch, Peter, Peiffer, Kai-Henrik, Vermehren, Johannes, Dultz, Georg, Geier, Andreas, Reiter, Florian P., Bruns, Tony, Schattenberg, Jörn M., Durmashkina, Elena, Gustot, Thierry, Moreno, Christophe, Trauth, Janina, Discher, Thomas, Fischer, Janett, Berg, Thomas, Kremer, Andreas E., Müllhaupt, Beat, Zeuzem, Stefan, and Sarrazin, Christoph

Published
2024
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3. Numerical investigation of cavitation flow in journal bearing geometry

Author

Stücke P., Schmidt M., and Riedel M.

Subjects
Physics, QC1-999
Abstract

The appearance of cavitation is still a problem in technical and industrial applications. Especially in automotive internal combustion engines, hydrodynamic journal bearings are used due to their favourable wearing quality and operating characteristics. Cavitation flows inside the bearings reduces the load capacity and leads to a risk of material damages. Therefore an understanding of the complex flow phenomena inside the bearing is necessary for the design development of hydrodynamic journal bearings. Experimental investigations in the fluid domain of the journal bearing are difficult to realize founded by the small dimensions of the bearing. In the recent years more and more the advantages of the computational fluid dynamics (CFD) are used to investigate the detail of the cavitation flows. The analysis in the paper is carried out in a two-step approach. At first an experimental investigation of journal bearing including cavitation is selected from the literature. The complex numerical model validated with the experimental measured data. In a second step, typically design parameters, such as a groove and feed hole, which are necessary to distribute the oil supply across the gap were added into the model. The paper reflects on the influence of the used design parameters and the variation of the additional supply flow rate through the feed hole regarding to cavitation effects in the bearing. Detailed pictures of the three-dimensional flow structures and the cavitation regions inside the flow film of the bearing are presented.

Published
2013
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4. Laser-optical and numerical Research of the flow inside the lubricating gap of a journal bearing model

Author

Riedel M., Schmidt M., Stücke P., and Nobis M.

Subjects
Physics, QC1-999
Abstract

The laser-optical research of the flow inside the lubricating gap of a journal bearing model is one important task in a larger overall project. The long-term objective is the development of an easy-to-work calculation tool which delivers information about the causes and consequences of cavitation processes in hydrodynamically lubricated journal bearings. Hence, it will be possible to find statements for advantageous and disadvantageous geometrical shapes of the bushings. In conclusion such a calculation tool can provide important insights for the construction and design of future journal bearings. Current design programs are based on a two-dimensional approach for the lubricating gap. The first dimension is the breath of the bearing and the second dimension is the circumferential direction of the bearing. The third dimension, the expansion of the gap in radial direction, will be neglected. Instead of an exact resolution of the flow pattern inside the gap, turbulence models are in use. Past studies on numerical and experimental field have shown that inside the lubricating gap clearly organized and predominantly laminar flow structures can be found. Thus, for a detailed analysis of the reasons and effects of cavitation bubbles, a three-dimensional resolution of the lubricating gap is inevitable. In addition to the qualitative evaluation of the flow with visualization experiments it is possible to perform angle-based velocity measurements inside the gap with the help of a triggered Laser-Doppler- Velocimeter (LDV). The results of these measurements are used to validate three-dimensional CFD flow simulations, and to optimize the numerical mesh structure and the boundary conditions. This paper will present the experimental setup of the bearing model, some exemplary results of the visualization experiments and LDV measurements as well as a comparison between experimental and numerical results.

Published
2013
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5. Gas hydrate dissociation off Svalbard induced by isostatic rebound rather than global warming.

Author

Wallmann, Klaus, Riedel, M, Hong, W, Patton, H, Hubbard, A, Pape, T, Hsu, C, Schmidt, C, Johnson, J, Torres, M, Andreassen, K, Berndt, C, and Bohrmann, G

Abstract

Methane seepage from the upper continental slopes of Western Svalbard has previously been attributed to gas hydrate dissociation induced by anthropogenic warming of ambient bottom waters. Here we show that sediment cores drilled off Prins Karls Foreland contain freshwater from dissociating hydrates. However, our modeling indicates that the observed pore water freshening began around 8 ka BP when the rate of isostatic uplift outpaced eustatic sea-level rise. The resultant local shallowing and lowering of hydrostatic pressure forced gas hydrate dissociation and dissolved chloride depletions consistent with our geochemical analysis. Hence, we propose that hydrate dissociation was triggered by postglacial isostatic rebound rather than anthropogenic warming. Furthermore, we show that methane fluxes from dissociating hydrates were considerably smaller than present methane seepage rates implying that gas hydrates were not a major source of methane to the oceans, but rather acted as a dynamic seal, regulating methane release from deep geological reservoirs.

Published
2018

6. Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1–3 Infections

Author

Balavoine, J., Giostra, E., Berning, M., Hampe, J., De Gottardi, A., Rauch, A., Semmo, N., Discher, T., Trauth, J., Fischer, J., Gress, M., Günther, R., Heinzow, H., Schmidt, J., Herrmann, A., Stallmach, A., Hilgard, G., Deterding, K., Lange, C.M., Ciesek, S., Wedemeyer, H., Hoffmann, D., Klinker, H., Schulze, P., Kocheise, F., Müller-Schilling, M., Kodal, A., Kremer, A., Ganslmayer, M., Siebler, J., Lammert, F., Rissland, J., Löbermann, M., Götze, T., Canbay, A., Lohse, A., von Felden, J., Jordan, S., Maieron, A., Moradpour, D., Chave, J.-P., Moreno, C., Müller, T., Muche, M., Epple, H.-J., Port, K., von Hahn, T., Cornberg, M., Manns, M., Reinhardt, L., Ellenrieder, V., Rockstroh, J., Schattenberg, J., Sprinzl, M., Galle, P., Roeb, E., Steckstor, M., Schmiegel, W., Brockmeyer, N.H., Seufferlein, T., Stremmel, W., Strey, B., Thimme, R., Teufel, A., Vogelmann, R., Ebert, M., Tomasiewicz, K., Trautwein, C., Tacke, F., Koenen, T., Weber, T., Zachoval, R., Mayerle, J., Raziorrouh, B., Angeli, W., Beckebaum, S., Doberauer, C., Durmashkina, E., Hackelsberger, A., Erhardt, A., Garrido-Lüneburg, A., Gattringer, H., Genné, D., Gschwantler, M., Gundling, F., Hametner, S., Schöfl, R., Hartmann, C., Heyer, T., Hirschi, C., Jussios, A., Kanzler, S., Kordecki, N., Kraus, M., Kullig, U., Wollschläger, S., Magenta, L., Beretta-Piccoli, B. Terziroli, Menges, M., Mohr, L., Muehlenberg, K., Niederau, C., Paulweber, B., Petrides, A., Pinkernell, M., Piso, R., Rambach, W., Reiser, M., Riecken, B., Rieke, A., Roth, J., Schelling, M., Schlee, P., Schneider, A., Scholz, D., Schott, E., Schuchmann, M., Schulten-Baumer, U., Seelhoff, A., Stich, A., Stickel, F., Ungemach, J., Walter, E., Weber, A., Winzer, T., Abels, W., Adler, M., Audebert, F., Baermann, C., Bästlein, E., Barth, R., Barthel, K., Becker, W., Behrends, J., Benninger, J., Berger, F., Berzow, D., Beyer, T., Bierbaum, M., Blaukat, O., Bodtländer, A., Böhm, G., Börner, N., Bohr, U., Bokemeyer, B., Bruch, H.R., Bucholz, D., Burkhard, O., Busch, N., Chirca, C., Delker, R., Diedrich, J., Frank, M., Diehl, M., Dienethal, A., Dietel, P., Dikopoulos, N., Dreck, M., Dreher, F., Drude, L., Ende, K., Ehrle, U., Baumgartl, K., Emke, F., Glosemeyer, R., Felten, G., Hüppe, D., Fischer, U., Frederking, D., Frick, B., Friese, G., Gantke, B., Geyer, P., Schwind, H.R., Glas, M., Glaunsinger, T., Goebel, F., Göbel, U., Görlitz, B., Graf, R., Gruber, H., Härter, G., Herder, M., Heuchel, T., Heuer, S., Höffl, K.-H., Hörster, H., Sonne, J.-U., Hofmann, W.P., Holst, F., Hunstiger, M., Hurst, A., Jägel-Guedes, E., John, C., Jung, M., Kallinowski, B., Kapzan, B., Kerzel, W., Khaykin, P., Klarhof, M., Klüppelberg, U., Klugewitz, K., Knapp, B., Knevels, U., Kochsiek, T., Körfer, A., Köster, A., Kuhn, M., Langekamp, A., Künzig, B., Link, R., Littman, M., Löhr, H., Lutz, T., Knecht, G., Lutz, U., Mainz, D., Mahle, I., Maurer, P., Mayer, C., Meister, V., Möller, H., Heyne, R., Moritzen, D., Mroß, M., Mundlos, M., Naumann, U., Nehls, O., Ningel, K.&R., Oelmann, A., Olejnik, H., Gadow, K., Pascher, E., Petersen, J., Philipp, A., Pichler, M., Polzien, F., Raddant, R., Riedel, M., Rietzler, S., Rössle, M., Rufle, W., Rump, A., Schewe, C., Hoffmann, C., Schleehauf, D., Schmidt, K.J., Schmidt, W., Schmidt-Heinevetter, G., Schmidtler-von Fabris, J., Schnaitmann, E., Schneider, L., Schober, A., Niehaus-Hahn, S., Schwenzer, J., Seidel, T., Seitel, G., Sick, C., Simon, K.G., Stähler, D., Stenschke, F., Steffens, H., Stein, K., Steinmüller, M., Sternfeld, T., Svensson, K., Tacke, W., Teuber, G., Teubner, K., Thieringer, J., Tomesch, A., Trappe, U., Ullrich, J., Urban, G., Usadel, S., von Lucadou, A., Weinberger, F., Werheid-Dobers, M., Werner, P., Winter, T., Zehnter, E., Zipf, A., Dietz, Julia, Spengler, Ulrich, Müllhaupt, Beat, Schulze zur Wiesch, Julian, Piecha, Felix, Mauss, Stefan, Seegers, Barbara, Hinrichsen, Holger, Antoni, Christoph, Wietzke-Braun, Perdita, Peiffer, Kai-Henrik, Berger, Annemarie, Matschenz, Katrin, Buggisch, Peter, Backhus, Johanna, Zizer, Eugen, Boettler, Tobias, Neumann-Haefelin, Christoph, Semela, David, Stauber, Rudolf, Berg, Thomas, Berg, Christoph, Zeuzem, Stefan, Vermehren, Johannes, and Sarrazin, Christoph

Published
2021
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8. Towards magnetic slowing of atoms and molecules

Author

Narevicius, E., Parthey, C. G., Libson, A., Riedel, M. F., Even, U., and Raizen, M. G.

Subjects
Physics - Atomic and Molecular Clusters
Abstract

We outline a method to slow paramagnetic atoms or molecules using pulsed magnetic fields. We also discuss the possibility of producing trapped particles by adiabatic deceleration of a magnetic trap. We present numerical simulation results for the slowing and trapping of molecular oxygen.

Published
2007
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9. Coherent Slowing of a Supersonic Beam with an Atomic Paddle

Author

Narevicius, E., Libson, A., Riedel, M. F., Parthey, C. G., Chavez, I., Even, U., and Raizen, M. G.

Subjects
Physics - Atomic Physics
Abstract

We report the slowing of a supersonic beam by elastic reflection from a receding atomic mirror. We use a pulsed supersonic nozzle to generate a 511 +/- 9 m/s beam of helium that we slow by reflection from a Si(111)-H(1x1) crystal placed on the tip of a spinning rotor. We were able to reduce the velocity of helium by 246 m/s and show that the temperature of the slowed beam is lower than 250 mK in the co-moving frame.

Published
2006

10. UNICORE - From Project Results to Production Grids

Author

Streit, A., Erwin, D., Lippert, Th., Mallmann, D., Menday, R., Rambadt, M., Riedel, M., Romberg, M., Schuller, B., and Wieder, Ph.

Subjects
Computer Science - Distributed, Parallel, and Cluster Computing, Computer Science - Operating Systems
Abstract

The UNICORE Grid-technology provides a seamless, secure and intuitive access to distributed Grid resources. In this paper we present the recent evolution from project results to production Grids. At the beginning UNICORE was developed as a prototype software in two projects funded by the German research ministry (BMBF). Over the following years, in various European-funded projects, UNICORE evolved to a full-grown and well-tested Grid middleware system, which today is used in daily production at many supercomputing centers worldwide. Beyond this production usage, the UNICORE technology serves as a solid basis in many European and International research projects, which use existing UNICORE components to implement advanced features, high level services, and support for applications from a growing range of domains. In order to foster these ongoing developments, UNICORE is available as open source under BSD licence at SourceForge, where new releases are published on a regular basis. This paper is a review of the UNICORE achievements so far and gives a glimpse on the UNICORE roadmap., Comment: 21 pages, 3 figures

Published
2005

11. Patterns of Resistance-Associated Substitutions in Patients With Chronic HCV Infection Following Treatment With Direct-Acting Antivirals

Author

Antoni, C., Vogelmann, R., Ebert, M., Backhus, J., Seufferlein, T., Balavoine, J., Giostra, E., Berg, C., Cornberg, M., Wedemeyer, H., Manns, M., De Gottardi, A., Esteban, R., Discher, T., Roeb, E., Gress, M., Günther, R., Wietzke-Braun, P., Herrmann, A., Stallmach, A., Hoffmann, D., Klinker, H., Kodal, A., Lammert, F., Löbermann, M., Schulze zur Wiesch, J., von Felden, J., Piecha, F., Lohse, A., Götze, T., Malfertheiner, P., Mayerle, J., Moradpour, D., Moreno, C., Neumann-Haefelin, C., Thimme, R., Reinhardt, L., Ellenrieder, V., Schattenberg, J., Sprinzl, M., Galle, P., Schmidt, J., Schott, E., Epple, H.-J., Siebler, J., Stauber, R., Steckstor, M., Schmiegel, W., Stremmel, W., Strey, B., Tomasiewicz, K., Trautwein, C., Zachoval, R., Angeli, W., Beckebaum, S., Doberauer, C., Ende, K., Erhardt, A., Garrido-Lüneburg, A., Gattringer, H., Genné, D., Gschwantler, M., Gundling, F., Hartmann, C., Heyer, T., Hirschi, C., Kanzler, S., Kordecki, N., Kraus, M., Kullig, U., Magenta, L., Terziroli Beretta-Piccoli, B., Menges, M., Mohr, L., Muehlenberg, K., Niederau, C., Paulweber, B., Petrides, A., Piso, R., Rambach, W., Reiser, M., Riecken, B., Roth, J., Schöfl, R., Maieron, A., Schneider, A., Schuchmann, M., Schulten-Baumer, U., Seelhoff, A., Semela, D., Stich, A., Vollmer, C., Brückner, J., Ungemach, J., Walter, E., Weber, A., Winzer, T., Abels, W., Adler, M., Audebert, F., Baermann, C., Bästlein, E., Barth, R., Barthel, K., Baumgartl, K., Becker, W., Benninger, J., Beyer, T., Bodtländer, A., Böhm, G., Bohr, U., Moll, A., Naumann, U., Börner, N., Bruch, H.R., Busch, N., Burkhard, O., Chirca, C., Dienethal, A., Dietel, P., Dreher, F., Efken, P., Ehrle, U., Emke, F., Fischer, J., Fischer, U., Frederking, D., Frick, B., Gantke B, B., Geyer, P., Glaunsinger, T., Goebel, F., Göbel, U., Graf, R., Herder, M., Heuchel, T., Heuer, S., Heyne, R., Höffl, K.H., Hofmann, W.P., Holst, F., Hörster, H., John, C., Jung, M.C., Kallinowski, B., Kerzel, W., Khaykin, P., Klarhof, M., Knapp, B., Knevels, U., Körfer, A., Köster, A., Künzig, B., Langenkamp, A., Kuhn, M., Littman, M., Löhr, H., Ludwig, L., Lutz, U., Maurer, P., Mayer, C., Meister, V., Moritzen, D., Mroß, M., Mundlos, M., Nehls, O., Ningel, K., Oelmann, A., Olejnik, H., Pascher, E., Philipp, A., Pichler, M., Polzien, F., Raddant, R., Riedel, M., Rietzler, S., Rump, A., Schmidt, W., Schmidtler-von Fabris, J., Schneider, L., Schober, A., Schwenzer, J., Seidel, T., Seitel, G., Sick, C., Simon, K., Stähler, D., Steffens, H., Svensson, K., Tacke, W., Teubner, K., Thieringer, J., Trappe, U., Ullrich, J., Usadel, S., von Lucadou, A., Werheid-Dobers, M., Zehnter, E., Zipf, A., Dietz, Julia, Susser, Simone, Vermehren, Johannes, Peiffer, Kai-Henrik, Grammatikos, Georgios, Berger, Annemarie, Ferenci, Peter, Buti, Maria, Müllhaupt, Beat, Hunyady, Bela, Hinrichsen, Holger, Mauss, Stefan, Petersen, Jörg, Buggisch, Peter, Felten, Gisela, Hüppe, Dietrich, Knecht, Gaby, Lutz, Thomas, Schott, Eckart, Berg, Christoph, Spengler, Ulrich, von Hahn, Thomas, Berg, Thomas, Zeuzem, Stefan, and Sarrazin, Christoph

Published
2018
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16. The Global Heat Flow Database: Update 2023

Author

Fuchs, S., Neumann, F., Norden, B., Beardsmore, G., Chiozzi, P., Colgan, W., Anguiano Dominguez, A., Duque, M., Ojeda Espinoza, O., Forster, F., Förster, A., Fröhder, R., Fuentes-Bustillos, K., Hajto, M., Harris, R., Jõeleht, A., Liebing, H., Liu, S., Lüdtke, G., Madon, M., Negrete-Aranda, R., Poort, J., Reznik, I., Riedel, M., Rolandone, F., Stål, T., Verdoya, M., and Wu, J.

Abstract

The data publication contains the compilation of global heat-flow data by the International Heat Flow Commission (IHFC; www.ihfc-iugg.org) of the International Association of Seismology and Physics of the Earth's Interior (IASPEI). The presented data update 2023 contains data generated between 1939 and 2022 and constitutes the first intermediate update benefiting from the global collaborative assessment and quality control of the Global Heat Flow Database running since May 2021 (http://assessment.ihfc-iugg.org).

Published
2023

23. Barkley Canyon Gas Hydrates: A Synthesis Based on Two Decades of Seafloor Observation and Remote Sensing

Author

Riedel, M., primary, Scherwath, M., additional, Römer, M., additional, Paull, C. K., additional, Lundsten, E. M., additional, Caress, D., additional, Brewer, P. G., additional, Pohlman, J. W., additional, Lapham, L. L., additional, Chapman, N. R., additional, Whiticar, M. J., additional, Spence, G. D., additional, Enkin, R. J., additional, and Douglas, K., additional

Published
2022
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24. Crustal Structure of the Niuafo'ou Microplate and Fonualei Rift and Spreading Center in the Northeastern Lau Basin, Southwestern Pacific

Author

Schmid, F., Kopp, H., Schnabel, M., Dannowski, A., Heyde, I., Riedel, M., Hannington, M. D., Engels, M., Beniest, A., Klaucke, I., Augustin, N., Brandl, P. A., Devey, C., Geology and Geochemistry, Kopp, H., 1 GEOMAR, Helmholtz Centre for Ocean Research Kiel Germany, Schnabel, M., 3 BGR, Federal Institute for Geosciences and Natural Resources Hanover Germany, Dannowski, A., Heyde, I., Riedel, M., Hannington, M. D., Engels, M., Beniest, A., 5 Department of Earth Sciences Vrije Universiteit Amsterdam Amsterdam The Netherlands, Klaucke, I., Augustin, N., Brandl, P. A., and Devey, C.

Subjects
back-arc basin, 551.8, back‐arc basin, Lau Basin, SDG 14 - Life Below Water
Abstract

The northeastern Lau Basin is one of the fastest opening and magmatically most active back‐arc regions on Earth. Although the current pattern of plate boundaries and motions in this complex mosaic of microplates is reasonably understood, the internal structure and evolution of the back‐arc crust are not. We present new geophysical data from a 290 km long east‐west oriented transect crossing the Niuafo'ou Microplate (back‐arc), the Fonualei Rift and Spreading Center (FRSC) and the Tofua Volcanic Arc at 17°20′S. Our P wave tomography model and density modeling suggest that past crustal accretion inside the southern FRSC was accommodated by a combination of arc crustal extension and magmatic activity. The absence of magnetic reversals inside the FRSC supports this and suggests that focused seafloor spreading has until now not contributed to crustal accretion. The back‐arc crust constituting the southern Niuafo'ou Microplate reveals a heterogeneous structure comprising several crustal blocks. Some regions of the back‐arc show a crustal structure similar to typical oceanic crust, suggesting they originate from seafloor spreading. Other crustal blocks resemble a structure that is similar to volcanic arc crust or a “hydrous” type of oceanic crust that has been created at a spreading center influenced by slab‐derived water at distances, Key Points: First insights into the crustal structure of the northeastern Lau Basin, along a 290 km transect at 17°20′S. Crust in southern Fonualei Rift and Spreading Center was created by extension of arc crust and variable amount of magmatism. Magmatic underplating is present in some parts of the southern Niuafo'ou Microplate., Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347

Published
2020
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31. High-resolution quantitative phase-contrast x-ray imaging for biomedical samples at PETRA III

Author

Riedel, M., Gustschin, A., Ushakov, L., Noichl, W., Taphorn, K., Busse, M., Beckmann, F., Hammel, J., Moosmann, J., and Herzen, J.

Abstract

Phase-contrast imaging is one of the standard X-ray imaging methods at synchrotron beamlines and has already proven to be beneficial for soft-tissue visualization. However, most implementations use single-distance inline phase-contrast techniques, and are thus not able to provide quantitative information. To access these, grating-based imaging (GBI) setups or, rather recently, speckle-based imaging (SBI) methods can be used. We built a new grating-based setup at the beamline P05 operated by HZG at the storage ring PETRA III / DESY. This new setup overcomes the previously reported limitations in spatial resolution compared to inline phase-contrast imaging. Furthermore, it allows for accurate quantitative phase contrast micro computed tomography of biological soft tissue. We replaced the typically used sandpaper by a 2D phase-grating as a wavefront marker, which increased the visibility and allowed for using fewer phase steps. Combined with an existing SBI phase-retrieval algorithm, the so-called Unified Modulated Pattern Analysis (UMPA) and an optimized scan protocol, we reached a resolution below 4 microns in scan times less than two hours. We investigated stained and unstained tissue samples, to quantify the staining process of different tissue types and were able to observe an increase in electron density, dependent on the stain and tissue type. By this, we could show the successful operation of our setup to quantitatively investigate samples on a micro meter scale at the beamline P05.

Published
2021
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32. Association of Institutes for Bee Research Report of the 55th Seminar in Hohen Neuendorf 11–13March 2008

Author

Scheiner, R., Alkattea, R., Steidle, H., Rosenkranz, P., Grünewald, B., Bartsch, C., Giurfa, M., Devaud, J. -M., Lein, J., Becher, M., Moritz, R. F. A., Fuchs, S., Riessberger-Gallé, U., Vollmann, J., Brodschneider, R., Aupinel, P., Crailsheim, K., Elmi, M. Pour, Haddad, N., de Miranda, J. R., Siede, R., König, M., Büchler, R., Thiel, H. -J., Gisder, S., Aumeier, P., Yue, C., Genersch, E., Šekulja, D., Garrido, C., Bienefeld, K., Ehrhardt, K., Ziegelmann, B., Steidle, J., Joachimsmeier, I., Kirchner, W. H., Ashiralieva, A., Fünfhaus, A., Borriss, R., Randolt, K., Gimple, O., Gätschenberger, H., Beier, H., Tautz, J., Loncaric, I., Derakhshifar, I., Köglberger, H., Moosbeckhofer, R., Oberlerchner, J., Riedel, M., Yue, D., Nordhoff, M., Wieler, L. H., Harz, M., Rademacher, E., Berg, S., Schürzinger, F., Illies, I., Radtke, J., Neuberger, P., Kovac, H., Bartzsch, C., Trompelt, J., Feller, K. -H., Schmidt, W., and Etzold, E.

Published
2008
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33. Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Author

Dietz, Julia, Spengler, Ulrich, Mullhaupt, Beat, zur Wiesch, Julian Schulze, Piecha, Felix, Mauss, Stefan, Seegers, Barbara, Hinrichsen, Holger, Antoni, Christoph, Wietzke-Braun, Perdita, Peiffer, Kai-Henrik, Berger, Annemarie, Matschenz, Katrin, Buggisch, Peter, Backhus, Johanna, Zizer, Eugen, Boettler, Tobias, Neumann-Haefelin, Christoph, Semela, David, Stauber, Rudolf, Berg, Thomas, Berg, Christoph, Zeuzem, Stefan, Vermehren, Johannes, Sarrazin, Christoph, Balavoine, J., Giostra, E., Berning, M., Hampe, J., De Gottardi, A., Rauch, A., Semmo, N., Discher, T., Trauth, J., Fischer, J., Gress, M., Guenther, R., Heinzow, H., Schmidt, J., Herrmann, A., Stallmach, A., Hilgard, G., Deterding, K., Lange, C. M., Ciesek, S., Wedemeyer, H., Hoffmann, D., Klinker, H., Schulze, P., Kocheise, F., Mueller-Schilling, M., Kodal, A., Kremer, A., Ganslmayer, M., Siebler, J., Lammert, F., Rissland, J., Loebermann, M., Goetze, T., Canbay, A., Lohse, A., von Felden, J., Jordan, S., Maieron, A., Moradpour, D., Chave, J. -P., Moreno, C., Mueller, T., Muche, M., Epple, H. -J., Port, K., von Hahn, T., Cornberg, M., Manns, M., Reinhardt, L., Ellenrieder, V., Rockstroh, J., Schattenberg, J., Sprinzl, M., Galle, P., Roeb, E., Steckstor, M., Schmiegel, W., Brockmeyer, N. H., Seufferlein, T., Stremmel, W., Strey, B., Thimme, R., Teufel, A., Vogelmann, R., Ebert, M., Tomasiewicz, K., Trautwein, C., Tacke, F., Koenen, T., Weber, T., Zachoval, R., Mayerle, J., Raziorrouh, B., Angeli, W., Beckebaum, S., Doberauer, C., Durmashkina, E., Hackelsberger, A., Erhardt, A., Garrido-Luneburg, A., Gattringer, H., Genne, D., Gschwantler, M., Gundling, F., Hametner, S., Schofl, R., Hartmann, C., Heyer, T., Hirschi, C., Jussios, A., Kanzler, S., Kordecki, N., Kraus, M., Kullig, U., Wollschlager, S., Magenta, L., Beretta-Piccoli, B. Terziroli, Menges, M., Mohr, L., Muehlenberg, K., Niederau, C., Paulweber, B., Petrides, A., Pinkernell, M., Piso, R., Rambach, W., Reiser, M., Riecken, B., Rieke, A., Roth, J., Schelling, M., Schlee, P., Schneider, A., Scholz, D., Schott, E., Schuchmann, M., Schulten-Baumer, U., Seelhoff, A., Stich, A., Stickel, F., Ungemach, J., Walter, E., Weber, A., Winzer, T., Abels, W., Adler, M., Baermann, C., Bastlein, E., Barth, R., Barthel, K., Becker, W., Behrends, J., Benninger, J., Berger, F., Berzow, D., Beyer, T., Bierbaum, M., Blaukat, O., Bodtlander, A., Bohm, G., Borner, N., Bohr, U., Bokemeyer, B., Bruch, H. R., Bucholz, D., Burkhard, O., Busch, N., Chirca, C., Delker, R., Diedrich, J., Frank, M., Diehl, M., Dienethal, A., Dietel, P., Dikopoulos, N., Dreck, M., Dreher, F., Drude, L., Ende, K., Ehrle, U., Baumgartl, K., Emke, F., Glosemeyer, R., Felten, G., Huppe, D., Fischer, U., Frederking, D., Frick, B., Friese, G., Gantke, B., Geyer, P., Schwind, H. R., Glas, M., Glaunsinger, T., Goebel, F., Gobel, U., Gorlitz, B., Graf, R., Gruber, H., Harter, G., Herder, M., Heuchel, T., Heuer, S., Hoffl, K. -H., Horster, H., Sonne, J. -U., Hofmann, W. P., Holst, F., Hunstiger, M., Hurst, A., Jagel-Guedes, E., John, C., Jung, M., Kallinowski, B., Kapzan, B., Kerzel, W., Khaykin, P., Klarhof, M., Kluppelberg, U., Klugewitz, K., Knapp, B., Knevels, U., Kochsiek, T., Korfer, A., Koster, A., Kuhn, M., Langekamp, A., Kunzig, B., Link, R., Littman, M., Lohr, H., Lutz, T., Knecht, G., Lutz, U., Mainz, D., Mahle, I., Maurer, P., Mayer, C., Meister, V., Moller, H., Heyne, R., Moritzen, D., Mross, M., Mundlos, M., Naumann, U., Nehls, O., Ningel, R., Oelmann, A., Olejnik, H., Gadow, K., Pascher, E., Petersen, J., Philipp, A., Pichler, M., Polzien, F., Raddant, R., Riedel, M., Rietzler, S., Rossle, M., Rufle, W., Rump, A., Schewe, C., Hoffmann, C., Schleehauf, D., Schmidt, K. J., Schmidt, W., Schmidt-Heinevetter, G., Schmidtler-von Fabris, J., Schnaitmann, E., Schneider, L., Schober, A., Niehaus-Hahn, S., Schwenzer, J., Seidel, T., Seitel, G., Sick, C., Simon, K. G., Stahler, D., Stenschke, F., Steffens, H., Stein, K., Steinmuller, M., Sternfeld, T., Svensson, K., Tacke, W., Teuber, G., Teubner, K., Thieringer, J., Tomesch, A., Trappe, U., Ullrich, J., Urban, G., Usadel, S., von Lucadou, A., Weinberger, F., Werheid-Dobers, M., Werner, P., Winter, T., Zehnter, E., Zipf, A., Dietz, Julia, Spengler, Ulrich, Mullhaupt, Beat, zur Wiesch, Julian Schulze, Piecha, Felix, Mauss, Stefan, Seegers, Barbara, Hinrichsen, Holger, Antoni, Christoph, Wietzke-Braun, Perdita, Peiffer, Kai-Henrik, Berger, Annemarie, Matschenz, Katrin, Buggisch, Peter, Backhus, Johanna, Zizer, Eugen, Boettler, Tobias, Neumann-Haefelin, Christoph, Semela, David, Stauber, Rudolf, Berg, Thomas, Berg, Christoph, Zeuzem, Stefan, Vermehren, Johannes, Sarrazin, Christoph, Balavoine, J., Giostra, E., Berning, M., Hampe, J., De Gottardi, A., Rauch, A., Semmo, N., Discher, T., Trauth, J., Fischer, J., Gress, M., Guenther, R., Heinzow, H., Schmidt, J., Herrmann, A., Stallmach, A., Hilgard, G., Deterding, K., Lange, C. M., Ciesek, S., Wedemeyer, H., Hoffmann, D., Klinker, H., Schulze, P., Kocheise, F., Mueller-Schilling, M., Kodal, A., Kremer, A., Ganslmayer, M., Siebler, J., Lammert, F., Rissland, J., Loebermann, M., Goetze, T., Canbay, A., Lohse, A., von Felden, J., Jordan, S., Maieron, A., Moradpour, D., Chave, J. -P., Moreno, C., Mueller, T., Muche, M., Epple, H. -J., Port, K., von Hahn, T., Cornberg, M., Manns, M., Reinhardt, L., Ellenrieder, V., Rockstroh, J., Schattenberg, J., Sprinzl, M., Galle, P., Roeb, E., Steckstor, M., Schmiegel, W., Brockmeyer, N. H., Seufferlein, T., Stremmel, W., Strey, B., Thimme, R., Teufel, A., Vogelmann, R., Ebert, M., Tomasiewicz, K., Trautwein, C., Tacke, F., Koenen, T., Weber, T., Zachoval, R., Mayerle, J., Raziorrouh, B., Angeli, W., Beckebaum, S., Doberauer, C., Durmashkina, E., Hackelsberger, A., Erhardt, A., Garrido-Luneburg, A., Gattringer, H., Genne, D., Gschwantler, M., Gundling, F., Hametner, S., Schofl, R., Hartmann, C., Heyer, T., Hirschi, C., Jussios, A., Kanzler, S., Kordecki, N., Kraus, M., Kullig, U., Wollschlager, S., Magenta, L., Beretta-Piccoli, B. Terziroli, Menges, M., Mohr, L., Muehlenberg, K., Niederau, C., Paulweber, B., Petrides, A., Pinkernell, M., Piso, R., Rambach, W., Reiser, M., Riecken, B., Rieke, A., Roth, J., Schelling, M., Schlee, P., Schneider, A., Scholz, D., Schott, E., Schuchmann, M., Schulten-Baumer, U., Seelhoff, A., Stich, A., Stickel, F., Ungemach, J., Walter, E., Weber, A., Winzer, T., Abels, W., Adler, M., Baermann, C., Bastlein, E., Barth, R., Barthel, K., Becker, W., Behrends, J., Benninger, J., Berger, F., Berzow, D., Beyer, T., Bierbaum, M., Blaukat, O., Bodtlander, A., Bohm, G., Borner, N., Bohr, U., Bokemeyer, B., Bruch, H. R., Bucholz, D., Burkhard, O., Busch, N., Chirca, C., Delker, R., Diedrich, J., Frank, M., Diehl, M., Dienethal, A., Dietel, P., Dikopoulos, N., Dreck, M., Dreher, F., Drude, L., Ende, K., Ehrle, U., Baumgartl, K., Emke, F., Glosemeyer, R., Felten, G., Huppe, D., Fischer, U., Frederking, D., Frick, B., Friese, G., Gantke, B., Geyer, P., Schwind, H. R., Glas, M., Glaunsinger, T., Goebel, F., Gobel, U., Gorlitz, B., Graf, R., Gruber, H., Harter, G., Herder, M., Heuchel, T., Heuer, S., Hoffl, K. -H., Horster, H., Sonne, J. -U., Hofmann, W. P., Holst, F., Hunstiger, M., Hurst, A., Jagel-Guedes, E., John, C., Jung, M., Kallinowski, B., Kapzan, B., Kerzel, W., Khaykin, P., Klarhof, M., Kluppelberg, U., Klugewitz, K., Knapp, B., Knevels, U., Kochsiek, T., Korfer, A., Koster, A., Kuhn, M., Langekamp, A., Kunzig, B., Link, R., Littman, M., Lohr, H., Lutz, T., Knecht, G., Lutz, U., Mainz, D., Mahle, I., Maurer, P., Mayer, C., Meister, V., Moller, H., Heyne, R., Moritzen, D., Mross, M., Mundlos, M., Naumann, U., Nehls, O., Ningel, R., Oelmann, A., Olejnik, H., Gadow, K., Pascher, E., Petersen, J., Philipp, A., Pichler, M., Polzien, F., Raddant, R., Riedel, M., Rietzler, S., Rossle, M., Rufle, W., Rump, A., Schewe, C., Hoffmann, C., Schleehauf, D., Schmidt, K. J., Schmidt, W., Schmidt-Heinevetter, G., Schmidtler-von Fabris, J., Schnaitmann, E., Schneider, L., Schober, A., Niehaus-Hahn, S., Schwenzer, J., Seidel, T., Seitel, G., Sick, C., Simon, K. G., Stahler, D., Stenschke, F., Steffens, H., Stein, K., Steinmuller, M., Sternfeld, T., Svensson, K., Tacke, W., Teuber, G., Teubner, K., Thieringer, J., Tomesch, A., Trappe, U., Ullrich, J., Urban, G., Usadel, S., von Lucadou, A., Weinberger, F., Werheid-Dobers, M., Werner, P., Winter, T., Zehnter, E., and Zipf, A.

Published
2021

35. Distributed natural gas venting offshore along the Cascadia margin

Author

Riedel, M., Scherwath, M., Römer, M., Veloso, M., Heesemann, M., and Spence, G. D.

Subjects
Carbonic acid, Science, Water, lcsh:Q, Natural gas, lcsh:Science, Methane, Article
Abstract

Widespread gas venting along the Cascadia margin is investigated from acoustic water column data and reveals a nonuniform regional distribution of over 1100 mapped acoustic flares. The highest number of flares occurs on the shelf, and the highest flare density is seen around the nutrition-rich outflow of the Juan de Fuca Strait. We determine ∼430 flow-rates at ∼340 individual flare locations along the margin with instantaneous in situ values ranging from ∼6 mL min−1 to ∼18 L min−1. Applying a tidal-modulation model, a depth-dependent methane density, and extrapolating these results across the margin using two normalization techniques yields a combined average in situ flow-rate of ∼88 × 106 kg y−1. The average methane flux-rate for the Cascadia margin is thus estimated to ∼0.9 g y−1m−2. Combined uncertainties result in a range of these values between 4.5 and 1800% of the estimated mean values., Methane venting is a widespread phenomenon at the Cascadia margin, however a comprehensive database of methane vents at this margin is lacking. Here the authors show that the margin-wide average methane flow-rate ranges from ~4 × 106 to ~1590 × 106 kg y−1 and is on average around 88 ± 6 × 106 kg y−1.

Published
2018

40. Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1–3 Infections

Author

Dietz, Julia, primary, Spengler, Ulrich, additional, Müllhaupt, Beat, additional, Schulze zur Wiesch, Julian, additional, Piecha, Felix, additional, Mauss, Stefan, additional, Seegers, Barbara, additional, Hinrichsen, Holger, additional, Antoni, Christoph, additional, Wietzke-Braun, Perdita, additional, Peiffer, Kai-Henrik, additional, Berger, Annemarie, additional, Matschenz, Katrin, additional, Buggisch, Peter, additional, Backhus, Johanna, additional, Zizer, Eugen, additional, Boettler, Tobias, additional, Neumann-Haefelin, Christoph, additional, Semela, David, additional, Stauber, Rudolf, additional, Berg, Thomas, additional, Berg, Christoph, additional, Zeuzem, Stefan, additional, Vermehren, Johannes, additional, Sarrazin, Christoph, additional, Balavoine, J., additional, Giostra, E., additional, Berning, M., additional, Hampe, J., additional, De Gottardi, A., additional, Rauch, A., additional, Semmo, N., additional, Discher, T., additional, Trauth, J., additional, Fischer, J., additional, Gress, M., additional, Günther, R., additional, Heinzow, H., additional, Schmidt, J., additional, Herrmann, A., additional, Stallmach, A., additional, Hilgard, G., additional, Deterding, K., additional, Lange, C.M., additional, Ciesek, S., additional, Wedemeyer, H., additional, Hoffmann, D., additional, Klinker, H., additional, Schulze, P., additional, Kocheise, F., additional, Müller-Schilling, M., additional, Kodal, A., additional, Kremer, A., additional, Ganslmayer, M., additional, Siebler, J., additional, Lammert, F., additional, Rissland, J., additional, Löbermann, M., additional, Götze, T., additional, Canbay, A., additional, Lohse, A., additional, von Felden, J., additional, Jordan, S., additional, Maieron, A., additional, Moradpour, D., additional, Chave, J.-P., additional, Moreno, C., additional, Müller, T., additional, Muche, M., additional, Epple, H.-J., additional, Port, K., additional, von Hahn, T., additional, Cornberg, M., additional, Manns, M., additional, Reinhardt, L., additional, Ellenrieder, V., additional, Rockstroh, J., additional, Schattenberg, J., additional, Sprinzl, M., additional, Galle, P., additional, Roeb, E., additional, Steckstor, M., additional, Schmiegel, W., additional, Brockmeyer, N.H., additional, Seufferlein, T., additional, Stremmel, W., additional, Strey, B., additional, Thimme, R., additional, Teufel, A., additional, Vogelmann, R., additional, Ebert, M., additional, Tomasiewicz, K., additional, Trautwein, C., additional, Tacke, F., additional, Koenen, T., additional, Weber, T., additional, Zachoval, R., additional, Mayerle, J., additional, Raziorrouh, B., additional, Angeli, W., additional, Beckebaum, S., additional, Doberauer, C., additional, Durmashkina, E., additional, Hackelsberger, A., additional, Erhardt, A., additional, Garrido-Lüneburg, A., additional, Gattringer, H., additional, Genné, D., additional, Gschwantler, M., additional, Gundling, F., additional, Hametner, S., additional, Schöfl, R., additional, Hartmann, C., additional, Heyer, T., additional, Hirschi, C., additional, Jussios, A., additional, Kanzler, S., additional, Kordecki, N., additional, Kraus, M., additional, Kullig, U., additional, Wollschläger, S., additional, Magenta, L., additional, Beretta-Piccoli, B. Terziroli, additional, Menges, M., additional, Mohr, L., additional, Muehlenberg, K., additional, Niederau, C., additional, Paulweber, B., additional, Petrides, A., additional, Pinkernell, M., additional, Piso, R., additional, Rambach, W., additional, Reiser, M., additional, Riecken, B., additional, Rieke, A., additional, Roth, J., additional, Schelling, M., additional, Schlee, P., additional, Schneider, A., additional, Scholz, D., additional, Schott, E., additional, Schuchmann, M., additional, Schulten-Baumer, U., additional, Seelhoff, A., additional, Stich, A., additional, Stickel, F., additional, Ungemach, J., additional, Walter, E., additional, Weber, A., additional, Winzer, T., additional, Abels, W., additional, Adler, M., additional, Audebert, F., additional, Baermann, C., additional, Bästlein, E., additional, Barth, R., additional, Barthel, K., additional, Becker, W., additional, Behrends, J., additional, Benninger, J., additional, Berger, F., additional, Berzow, D., additional, Beyer, T., additional, Bierbaum, M., additional, Blaukat, O., additional, Bodtländer, A., additional, Böhm, G., additional, Börner, N., additional, Bohr, U., additional, Bokemeyer, B., additional, Bruch, H.R., additional, Bucholz, D., additional, Burkhard, O., additional, Busch, N., additional, Chirca, C., additional, Delker, R., additional, Diedrich, J., additional, Frank, M., additional, Diehl, M., additional, Dienethal, A., additional, Dietel, P., additional, Dikopoulos, N., additional, Dreck, M., additional, Dreher, F., additional, Drude, L., additional, Ende, K., additional, Ehrle, U., additional, Baumgartl, K., additional, Emke, F., additional, Glosemeyer, R., additional, Felten, G., additional, Hüppe, D., additional, Fischer, U., additional, Frederking, D., additional, Frick, B., additional, Friese, G., additional, Gantke, B., additional, Geyer, P., additional, Schwind, H.R., additional, Glas, M., additional, Glaunsinger, T., additional, Goebel, F., additional, Göbel, U., additional, Görlitz, B., additional, Graf, R., additional, Gruber, H., additional, Härter, G., additional, Herder, M., additional, Heuchel, T., additional, Heuer, S., additional, Höffl, K.-H., additional, Hörster, H., additional, Sonne, J.-U., additional, Hofmann, W.P., additional, Holst, F., additional, Hunstiger, M., additional, Hurst, A., additional, Jägel-Guedes, E., additional, John, C., additional, Jung, M., additional, Kallinowski, B., additional, Kapzan, B., additional, Kerzel, W., additional, Khaykin, P., additional, Klarhof, M., additional, Klüppelberg, U., additional, Klugewitz, K., additional, Knapp, B., additional, Knevels, U., additional, Kochsiek, T., additional, Körfer, A., additional, Köster, A., additional, Kuhn, M., additional, Langekamp, A., additional, Künzig, B., additional, Link, R., additional, Littman, M., additional, Löhr, H., additional, Lutz, T., additional, Knecht, G., additional, Lutz, U., additional, Mainz, D., additional, Mahle, I., additional, Maurer, P., additional, Mayer, C., additional, Meister, V., additional, Möller, H., additional, Heyne, R., additional, Moritzen, D., additional, Mroß, M., additional, Mundlos, M., additional, Naumann, U., additional, Nehls, O., additional, Ningel, K.&R., additional, Oelmann, A., additional, Olejnik, H., additional, Gadow, K., additional, Pascher, E., additional, Petersen, J., additional, Philipp, A., additional, Pichler, M., additional, Polzien, F., additional, Raddant, R., additional, Riedel, M., additional, Rietzler, S., additional, Rössle, M., additional, Rufle, W., additional, Rump, A., additional, Schewe, C., additional, Hoffmann, C., additional, Schleehauf, D., additional, Schmidt, K.J., additional, Schmidt, W., additional, Schmidt-Heinevetter, G., additional, Schmidtler-von Fabris, J., additional, Schnaitmann, E., additional, Schneider, L., additional, Schober, A., additional, Niehaus-Hahn, S., additional, Schwenzer, J., additional, Seidel, T., additional, Seitel, G., additional, Sick, C., additional, Simon, K.G., additional, Stähler, D., additional, Stenschke, F., additional, Steffens, H., additional, Stein, K., additional, Steinmüller, M., additional, Sternfeld, T., additional, Svensson, K., additional, Tacke, W., additional, Teuber, G., additional, Teubner, K., additional, Thieringer, J., additional, Tomesch, A., additional, Trappe, U., additional, Ullrich, J., additional, Urban, G., additional, Usadel, S., additional, von Lucadou, A., additional, Weinberger, F., additional, Werheid-Dobers, M., additional, Werner, P., additional, Winter, T., additional, Zehnter, E., additional, and Zipf, A., additional

Published
2021
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45. Thermal Characterization of Pockmarks Across Vestnesa and Svyatogor Ridges, Offshore Svalbard

Author

Riedel, M., Villinger, H., Freudenthal, T., Pape, T., Bünz, Stefan, Bohrmann, G., Villinger, H., 2 Department of Geosciences University of Bremen Bremen Germany, Freudenthal, T., 3 MARUM‐Center for Marine Environmental Sciences University of Bremen Bremen Germany, Pape, T., Bünz, S., 4 Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geology UiT The Arctic University of Norway Tromsø Norway, and Bohrmann, G.

Subjects
622.15, VDP::Mathematics and natural science: 400::Geosciences: 450::Marine geology: 466, pockmark, VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Marin geologi: 466, gas hydrate, heat flow, Svalbard margin, MeBo drilling
Abstract

The Svalbard margin represents one of the northernmost gas hydrate provinces worldwide. Vestnesa Ridge (VR) and Svyatogor Ridge (SR) west of Svalbard are two prominent sediment drifts showing abundant pockmarks and sites of seismic chimney structures. Some of these sites at VR are associated with active gas venting and were the focus of drilling and coring with the seafloor‐deployed MARUM‐MeBo70 rig. Understanding the nature of fluid migration and gas hydrate distribution requires (among other parameters) knowledge of the thermal regime and in situ gas and pore fluid composition. In situ temperature data were obtained downhole at a reference site at VR defining a geothermal gradient of ~78 mK m−1 (heat flow ~95 mW m−2). Additional heat probe data were obtained to describe the thermal regime of the pockmarks. The highest heat flow values were systematically seen within pockmark depressions and were uncorrelated to gas venting occurrences. Heat flow within pockmarks is typically ~20 mW m−2 higher than outside pockmarks. Using the downhole temperature data and gas compositions from drilling we model the regional base of the gas hydrate stability zone (BGHSZ). Thermal modeling including topographic effects suggest a BGHSZ up to 40 m deeper than estimated from seismic data. Uncertainties in sediment properties (velocity and thermal conductivity) are only partially explaining the mismatch. Capillary effects due to small sediment grain sizes may shift the free gas occurrence above the equilibrium BGHSZ. Changes in gas composition or pore fluid salinity at greater depth may also explain the discrepancy in observed and modeled BGHSZ., Key Points: Heat flow variations across the Vestnesa and Svyatogor Ridges off Svalbard are correlated with seismic data showing gas hydrate BSRs. In situ temperatures were measured with the MARUM MeBo70 rig up to ~60 mbsf indicating a background thermal gradient of ~78°C/km. Heat flow is significantly higher within the pockmarks but is not correlated to the occurrence of gas venting., Statoil http://dx.doi.org/10.13039/501100004342, CAGE, German Research Foundation (DFG)

Published
2020

46. Pressurized operation of solid oxide electrolysis stacks: An experimental comparison of the performance of 10-layer stacks with fuel electrode and electrolyte supported cell concepts

Author

Riedel, M., Heddrich, M. P., Ansar, A., Fang, Q., Blum, Ludger, and Friedrich, K. A.

Subjects
ddc:620
Abstract

The electrochemical behavior of two different types of planar 10-layer solid oxide cell (SOC) stacks with having either fuel electrode supported cells or electrolyte supported cells, are examined under steam, co- and CO2 electrolysis at elevated pressures of up to 8 bar. Experiments with steady-state and dynamically recorded U(i)-characteristics are performed in order to evaluate the performances over a wide temperature range and for different operating conditions. Furthermore, the influence of the operating pressure is quantified via the temperature and pressure dependency of the related ASR values of each stack. Impedance analysis is conducted in order to investigate the major differences and the pressure effect on the specific process resistances during steam and CO2 electrolysis.In case of the stack with fuel electrode supported cells, the ASR is found to decrease significantly at elevated pressure leading to an overall performance gain, whereas the stack with electrolyte supported cells shows a minor pressure effect. An impedance study shows that the diffusion and activation resistances are significantly affected when conducting CO2 instead of H2O electrolysis for both stack concepts. Furthermore, the pressure sensitivity is found to be more dominant during CO2 electrolysis than during pure steam electrolysis operation.

Published
2020
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