TY - JOUR AU - Bocchini, Adriana AU - Eigner, Christof AU - Silberhorn, Christine AU - Schmidt, Wolf Gero AU - Gerstmann, Uwe ID - 20682 JF - Phys. Rev. Materials TI - Understanding gray track formation in KTP: Ti^3+ centers studied from first principles VL - 4 ER - TY - CONF AU - Müller, Inez ID - 44159 SN - 978-3-86205-600-2 TI - Generationelle und gesellschaftliche Differenzen im wiedervereinigten Deutschland - "Der neunzigste Geburtstag. Ein ländliches Idyll" von Günter de Bruyn in postkolonialer Lesart. VL - 11 ER - TY - JOUR AU - Müller, Inez ID - 44160 JF - Peter Weiss Jahrbuch SN - 978-3-86110-748-4 TI - Transmediale und transkulturelle Schreibweisen im Exil der Gegenwart - Prosa und Lyrik syrischer Autoren in Europa VL - 28 ER - TY - CHAP AU - Moritzer, Elmar AU - Hüttner, M. AU - Henning, Bernd AU - Webersen, Manuel ID - 24479 T2 - Advances in Polymer Processing 2020 TI - The Influence of Hydrothermal Aging on the Material Properties of Continuous Fiber-Reinforced Thermoplastics and its Non-Destructive Characterization ER - TY - JOUR AU - Grabo, Matti AU - Staggenborg, Christoph AU - Philippi, Kai Alexander AU - Kenig, Eugeny ID - 22266 JF - Frontiers in Energy Research SN - 2296-598X TI - Modeling and Optimization of Rectangular Latent Heat Storage Elements in an Air-Guided Heat Storage System VL - 8 ER - TY - JOUR AB - The influence of latent heat storage elements on the cooling performance and the temperature rise time of household refrigerating appliances is studied experimentally in the context of the “new global refriger- ator standard”IEC 62552:2015. In addition to the daily energy consumption, this international standard- ization introduced performance tests for cooling capacity and temperature rise time. While the cooling capacity has long been anchored in various test procedures of consumer organizations, the temperature rise time, which has only been tested on freezers so far, will be a decisive factor in the future. Moreover, the need for so-called "smart appliances" that may balance power consumption is increasing since such devices may compensate the volatility of renewable energies and thus stabilize the power grid. Against this background, eight commercial household refrigerators and refrigerator-freezers are equipped with polymer-bound phase change materials (PCM) and their performance is determined under the new stan- dard test conditions. The results show that the introduction of PCM increases the cooling capacity by up to 33 % and also increases the temperature rise time by up to 145 %, without affecting power consump- tion, as compared to the unmodified refrigeration appliances. AU - Sonnenrein, Gerrit AU - Baumhögger, Elmar AU - Elsner, Andreas AU - Morbach, A. AU - Neukötter, Moritz AU - Paul, Andreas AU - Vrabec, J. ID - 21514 JF - International Journal of Refrigeration SN - 0140-7007 TI - Improving the performance of household refrigerating appliances through the integration of phase change materials in the context of the new global refrigerator standard IEC 62552:2015 VL - 119 ER - TY - JOUR AB - Despite the omnipresence of household refrigeration appliances, there is still a lack of knowledge about their agerelated efficiency loss over time. Past studies provide basic evidence for increasing electricity consumption of cooling appliances with ageing but fail to investigate the associated technical wear. Concentrating on the degradation of the thermal insulation, we first determined the ageing process of sealed samples of polyurethane rigid foam by investigating changes in cell gas composition and thermal conductivity over time. Simultaneously, the main challenge was to develop an approach that investigates the age-related efficiency loss of the insulation without its destruction. This testing procedure is referred to as the Bonn method. The non-destructive Bonn method was applied to varying refrigerator models in a series of successive experiments to evaluate the insulation degradation over time. Subsequently, the physical relationship between the test value of the Bonn method and the heat transfer through the multi-layered compartment walls of domestic refrigeration appliances was established, ultimately characterising the degrading insulation in terms of increasing heat transfer. Our results give substantiated evidence that the efficiency loss of cooling appliances is greatly influenced by insulation degradation over time. The ageing of sealed samples of polyurethane rigid foam indicates a large initial increase of thermal conductivity by 15% within the first year, corresponding to a change in cell gas composition. These results are in line with those of the Bonn method, emphasising an increasing heat flow through the multi-layered compartment walls of domestic refrigerators with ageing. Therewith, the present study is of significance to a wide range of stakeholders and forms the basis for future research. AU - Hueppe, Christian AU - Geppert, Jasmin AU - Stamminger, Rainer AU - Wagner, Hendrik AU - Hoelscher, Heike AU - Vrabec, Jadran AU - Paul, Andreas AU - Elsner, Andreas AU - Becker, Wolfgang AU - Gries, Ulrich AU - Freiberger, Alfred ID - 21512 JF - Applied Thermal Engineering SN - 1359-4311 TI - Age-related efficiency loss of household refrigeration appliances: Development of an approach to measure the degradation of insulation properties VL - 173 ER - TY - GEN AB - Due to the trend towards lightweight design in car body development mechanical joining technologies become increasingly important. These techniques allow for the joining of dissimilar materials and thus enable multi-material design, while thermic joining methods reach their limits. Semi-tubular self-piercing riveting is an important mechanical joining technology. The rivet production, however, is costly and time-consuming, as the process consists of several process steps including the heat treatment and coating of the rivets in order to achieve an adequate strength and corrosion resistance. The use of high nitrogen steel as rivet material leads to the possibility of reducing process steps and hence increasing the efficiency of the process. However, the high tool loads being expected due to the high strain hardening of the material are a major challenge during the rivet production. Thus, there is a need for appropriate forming strategies, such as the manufacturing of the rivets at elevated temperatures. Prior investigations led to the conclusion that forming already at 200 °C results in a distinct reduction of the yield strength. To create a deeper understanding of the forming behaviour of high nitrogen steel at elevated temperatures, compression tests were conducted in a temperature range between room temperature and 200 °C. The determined true stress – true strain curves are the basis for the further process and tool design of the rivet production. Another key factor for the rivet manufacturing at elevated temperatures is the influence of the process temperature on the tribological conditions. For this reason, ring compression tests at room temperature and 200 °C are carried out. The friction factors are determined on the basis of calibration curves resulting from the numerical analysis of the ring compression process. The investigations indicate that the friction factor at 200 °C is significantly higher compared to room temperature. This essential fact has to be taken into account for the process and tool design for the rivet production using high nitrogen steel. ED - Kuball, Clara-Maria ED - Jung, R ED - Uhe, Benedikt ED - Meschut, Gerson ED - Merklein, Marion ID - 19974 KW - High nitrogen steel KW - Self-piercing riveting KW - Joining by forming KW - Bulk forming KW - Strain hardening TI - Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel VL - 1 ER - TY - JOUR AB - As a result of lightweight design, increased use is being made of high-strength steel and aluminium in car bodies. Self-piercing riveting is an established technique for joining these materials. The dissimilar properties of the two materials have led to a number of different rivet geometries in the past. Each rivet geometry fulfils the requirements of the materials within a limited range. In the present investigation, an improved rivet geometry is developed, which permits the reliable joining of two material combinations that could only be joined by two different rivet geometries up until now. Material combination 1 consists of high-strength steel on both sides, while material combination 2 comprises aluminium on the punch side and high-strength steel on the die side. The material flow and the stress and strain conditions prevailing during the joining process are analysed by means of numerical simulation. The rivet geometry is then improved step-by-step on the basis of this analysis. Finally, the improved rivet geometry is manufactured and the findings of the investigation are verified in experimental joining tests. AU - Uhe, Benedikt AU - Kuball, Clara-Maria AU - Merklein, Marion AU - Meschut, Gerson ID - 19973 JF - Production Engineering KW - Self-piercing riveting KW - Joining technology KW - Rivet geometry KW - Multi-material design KW - High-strength steel KW - Aluminium TI - Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints VL - 14 ER - TY - JOUR AU - Tinkloh, Steffen Rainer AU - Wu, Tao AU - Tröster, Thomas AU - Niendorf, Thomas ID - 15945 JF - Composite Structures SN - 0263-8223 TI - A micromechanical-based finite element simulation of process-induced residual stresses in metal-CFRP-hybrid structures VL - 238 ER - TY - JOUR AU - Martin, Sven AU - Camberg, Alan A. AU - Tröster, Thomas ID - 16859 JF - Procedia Manufacturing SN - 2351-9789 TI - Probability Distribution of Joint Point Loadings in Car Body Structures under Global Bending and Torsion ER - TY - CONF AU - Bertling, René AU - Hack, Mathias AU - Ausner, Ilja AU - Kenig, Eugeny ID - 23409 TI - CFD Simulation of Film and Rivulet Flows on Microstructured Surfaces ER - TY - CONF AU - Rozo Vasquez, Julian AU - Arian, Bahman AU - Riepold, Markus AU - Homberg, Werner AU - Trächtler, Ansgar AU - Walther, Frank ID - 22965 T2 - 54. Metallographie-Tagung TI - Microstructural investigation on phase transformation during flow forming of the metastable austenite AISI 304 ER - TY - JOUR AU - Ma, Xuekai AU - Berger, B AU - Aßmann, M AU - Driben, R AU - Meier, Torsten AU - Schneider, C AU - Höfling, S AU - Schumacher, Stefan ID - 20580 IS - 1 JF - Nature Communications SN - 2041-1723 TI - Realization of all-optical vortex switching in exciton-polariton condensates VL - 11 ER - TY - JOUR AU - Ahrens, Stephan ID - 44371 IS - Nr. 1 JF - Journal of Italian Cinema & Media Studies 9, Nr. 1 TI - Federico Fellini’s Sanctifying Effect. ER - TY - BOOK AU - Ahrens, Stephan ID - 44365 TI - Vom Klang bewegt. Das Kino und Ludwig van Beethoven. ER - TY - JOUR AU - Ahrens, Stephan ID - 44393 JF - Dschungel (jungle World) TI - Offensive Sensation. Ein Porträt von Melina Mercouri ER - TY - GEN AU - Ahrens, Stephan ID - 44395 T2 - in die tageszeitung TI - Glücklich ohne Happy End ER - TY - GEN AU - Ahrens, Stephan ID - 44396 T2 - Dschungel (Jungle World) TI - Das Stadtgespräch ER - TY - GEN AU - Ahrens, Stephan ID - 44394 TI - In memoriam Sarah Maldoror ER - TY - GEN AU - Ahrens, Stephan ID - 44402 TI - Eine andere Welt, Porträt Stéphane Brizé ER - TY - JOUR AU - Schultz, Andreas Maximilian AU - Lamers, Christoph AU - Koch, Rainer AU - Lüke, Richard AU - Sauerland, Torben ID - 22898 JF - vfdb-Zeitschrift TI - IRiS – Intelligente Rettung im SmartHome VL - 4 ER - TY - CHAP AU - Eckel, Julia ED - Beyer, Marcel ID - 44470 T2 - Exzess und Entzug: Ferres vor Gursky, Ferres vor Immendorff TI - Ferres vor/neben/mit/am … – Instagrammatikalische Präpositionen ER - TY - CHAP AU - Eckel, Julia ED - Althoff, Sebastian ED - Linseisen, Elisa ED - Müller, Maja-Lisa ED - Winter, Franziska ID - 44471 T2 - Re-/Dissolving Mimesis TI - Re/Dis-Solved Selves: (Re)Searching Selfies, (Inter)Facing the Face ER - TY - CHAP AU - Spiegel, Anna ED - Poferl, Angelika ED - Winkel, Heidemarie ID - 36726 T2 - Multiple Gender Cultures, Sociology and Plural Modernities. Re-reading Social Constructions of Gender across the Globe in a De-Colonial Perspective. TI - The Work of Entanglement. Translating Women's Rights in Malaysia ER - TY - BOOK ED - Köngeter, Stefan ED - Engel, Nicolas ED - Spiegel, Anna ED - Klemm, Matthias ED - Struve, Karen ED - Klein-Zimmer, Kathrin ED - Duscha, Annemarie ED - Chmelar, Kristina ED - Bretting, Johannes ID - 44480 SN - 3837643808 TI - Wissen in der Transnationalisierung. Zur Ubiquität und Krise der Übersetzung ER - TY - CONF AB - This paper presents the results of static short-term and long-term tensile tests for beta-nucleated joined polypropylene samples by the hot plate welding process. In the present study different dimensionless joining displacements are accounted for. The results show that high short-term tensile strength does not directly transfer to high long-term tensile strength. The morphology of the weld seam in the joined samples is examined by means of transmitted and reflected light microscopy. For the dimensionless joining displacements of 0.75 and 0.95, stretched spherulites are obtained. X-Ray diffraction can be used as a tool for qualitative and quantitative analysis and eventually for differentiation of samples of various joining displacements. AU - Wübbeke, Andrea AU - Schöppner, Volker AU - Paul, André AU - Tiemann, Michael AU - Austermeier, Laura AU - Fitze, Marcus AU - Chen, Mingie AU - Jakob, Fabian AU - Heim, Hans-Peter AU - Wu, Tao AU - Niendorf, Thomas AU - Röhricht, Marie-Luise AU - Schmidt, Michael ID - 42892 T2 - SPE ANTEC 2020: The Virtual Edition 5 TI - Long- and Short-Term Tensile Strength and Morphology of Joined Beta-Nucleated Polypropylene Parts ER - TY - CONF AU - Schöppner, Volker AU - Wübbeke, Andrea AU - Geißler, B. AU - Schmidt, M. AU - Maginer, A. AU - Wu, T. AU - Niendorf, T. AU - Jakob, F. AU - Heim, H. ID - 24245 T2 - 73rd Annual Assembly of the International Institute of Welding (IIW) TI - Investigation of residual stresses of hot plate welding ER - TY - JOUR AB - In diesem Artikel werden das Scherzugverhalten und der morphologische Zustand von konturgeschweißtem Polypropylen (PP) mit einem Massenanteil von 0,2% Ruß untersucht. Dabei zeigen die Ergebnisse ... AU - Schöppner, Volker AU - Wübbeke, Andrea AU - Schriegel, Fabian AU - Paul, Andrej AU - Tiemann, Michael AU - Geißler, Bastian AU - Schmidt, Michael AU - Magnier, Arnaud AU - Niendorf, Thomas ID - 24236 JF - Joining Plastics TI - Selected Aspects for the Assessment of Laser Transmission Welding ER - TY - CONF AU - Schöppner, Volker AU - Wübbeke, Andrea AU - Paul, A. AU - Tiemann, M. AU - Austermeier, Laura AU - Fitze, M. AU - Chen, M. AU - Jakob, F. AU - Heim, H.-P- AU - Wu, T. AU - Niendorf, T. AU - Röhricht, M.-L. AU - Schmidt, M. ID - 24472 T2 - ANTEC20 TI - LONG- AND SHORT-TERM TENSILE STRENGTH AND MORPHOLOGY OF JOINED BETA-NUCLEATED POLYPROPYLENE PARTS ER - TY - JOUR AU - Rostek, Tim AU - Wiens, Eugen AU - Homberg, Werner ID - 30713 JF - Procedia Manufacturing TI - Joining with Versatile Friction-Spun Joint Connectors VL - 47 ER - TY - CONF AB - Even though the spectrum of parts is expected to shift over the long term as a result of increasing e-mobility, there is still an extremely high demand for complex components made of high-strength materials which can only be produced by hydroforming technologies. The innovative combination of hydroforming processes with other forming processes, as well as the improvement of the processes themselves, offers considerable potential for improvement. A number of promising ways of improving the hydroforming process chain are therefore the subject of this contribution. The focus of the article is on possible approaches for combining (incremental) pre- and post-forming operations, which can permit considerable improvements in both quality and features at a reduced cost. Furthermore, a novel combination of quasi-static and high-speed forming processes is presented, leading to an improved overall forming process (with a high application potential) for the production of complex parts. AU - Wiens, Eugen AU - Djakow, Eugen AU - Homberg, Werner ID - 21447 KW - Hydroforming KW - Incremental Forming KW - Internal Flow-turning KW - High-speed Forming T2 - Nebu/Nehy 2020 TI - Some ideas for the further development of hydroforming process chains ER - TY - JOUR AB - In this paper, we study properties of the algebras of planar quasi-invariants. These algebras are Cohen–Macaulay and Gorenstein in codimension one. Using the technique of matrix problems, we classify all Cohen–Macaulay modules of rank one over them and determine their Picard groups. In terms of this classification, we describe the spectral modules of the planar rational Calogero–Moser systems. Finally, we elaborate the theory of the algebraic inverse scattering method, providing explicit computations of some ‘isospectral deformations’ of the planar rational Calogero–Moser system in the case of the split rational potential. AU - Burban, Igor AU - Zheglov, A. ID - 44331 IS - 4 JF - Proceedings of the London Mathematical Society TI - Cohen-Macaulay modules over the algebra of planar quasi-invariants and Calogero-Moser systems VL - 121 ER - TY - CHAP AU - van Ackeren, Isabell AU - Buhl, Heike M. AU - Eickelmann, Birgit AU - Heinrich, Martin AU - Wolfswinkler, Günther ED - Kaspar, Kai ED - Becker-Mrotzek, Michael ED - Hofhues, Sandra ED - König, Johannes ED - Schmeinck, Daniela ID - 28883 T2 - Bildung, Schule und Digitalisierung TI - Digitalisierung in der Lehrerbildung durch Communities of Practice. Konzeption, Governance und Qualitätsmanagement des ComeIn-Verbundvorhabens in Nordrhein-Westfalen ER - TY - CHAP AU - Labusch, Amelie AU - Eickelmann, Birgit AU - Drossel, Kerstin AU - Vennemann, Mario ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27838 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Digitalisierungsbezogene Berufswahlneigung und Sichtweisen von Mädchen und Jungen auf die Relevanz digitaler Medien für die Gesellschaft ER - TY - JOUR AU - Eickelmann, Birgit AU - Drossel, Kerstin ID - 28882 JF - SchulVerwaltung BW TI - Schulschließungen und Perspektiven für die Pandemie-Zeit –– Ergebnisse der Studie ‚Schule auf Distanz‘ VL - 12 ER - TY - JOUR AU - Eickelmann, Birgit AU - Kummer Wyss, Annemarie ID - 28908 IS - 4 JF - Journal für Schulentwicklung TI - Fortbildung im digitalen Zeitalter. Editorial VL - 24 ER - TY - BOOK AU - Labusch, Amelie AU - Eickelmann, Birgit AU - Conze, Daniela ID - 28905 TI - ICILS 2018 #Transfer. Gestaltung digitaler Schulentwicklung in Deutschland ER - TY - CHAP AU - Eickelmann, Birgit AU - Drossel, Kerstin AU - Labusch, Amelie AU - Heldt, Melanie ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27839 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Wünsche zur schulischen Nutzung digitaler Medien, digitalisierungsbezogene Berufswahlneigung und Sichtweisen von Schülerinnen und Schülern auf die Relevanz digitaler Medien für die Gesellschaft ER - TY - CHAP AU - Drossel, Kerstin AU - Lorenz, Ramona AU - Labusch, Amelie AU - Eickelmann, Birgit ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27853 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Selbsteingeschätzte Kompetenzen von Lehrkräften zum schulischen Einsatz digitaler Medien ER - TY - CHAP AU - Labusch, Amelie AU - Eickelmann, Birgit AU - Gerick, Julia AU - Drossel, Kerstin ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27842 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Kompetenzen im Bereich ‚Computational Thinking‘ von Mädchen und Jungen ER - TY - CHAP AU - Drossel, Kerstin AU - Eickelmann, Birgit ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27849 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Lehrkräftekooperation im Kontext des Lernens und Lehrens mit digitalen Medien ER - TY - CHAP AU - Eickelmann, Birgit AU - Drossel, Kerstin AU - Labusch, Amelie ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27855 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Schulischer IT-Support: Sichtweisen und Zuständigkeiten ER - TY - CHAP AU - Labusch, Amelie AU - Eickelmann, Birgit AU - Drossel, Kerstin ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27856 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Schulische IT-Ausstattung und Wahrnehmung der IT-Ausstattungsqualität ER - TY - CHAP AU - Conze, Daniela AU - Drossel, Kerstin AU - Eickelmann, Birgit ED - Kaspar, Kai ED - Becker-Mrotzek, Michael ED - Hofhues, Sandra ED - König, Johannes ED - Schmeinck, Daniela ID - 27862 T2 - Bildung, Schule und Digitalisierung TI - Lehrer*innenbildung in virtuellen Lernnetzwerken – Warum engagieren sich Lehrkräfte im #twitterlehrerzimmer? ER - TY - CHAP AU - Eickelmann, Birgit AU - Labusch, Amelie AU - Drossel, Kerstin AU - Vennemann, Mario ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27857 T2 - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich TI - Anlage der Studie ICILS 2018-NRW ER - TY - JOUR AU - Eickelmann, Birgit AU - Drossel, Kerstin ID - 27861 JF - SchulVerwaltung NRW TI - Schulschließungen und Perspektiven für die Pandemie-Zeit - Ergebnisse der Studie ‚Schule auf Distanz‘ VL - 9 ER - TY - BOOK ED - Eickelmann, Birgit ED - Labusch, Amelie ED - Drossel, Kerstin ED - Vennemann, Mario ID - 27858 TI - ICILS 2018 #NRW. Vertiefende Analysen und Befunde für Nordrhein-Westfalen im internationalen Vergleich ER - TY - JOUR AU - Rezat, Sara AU - Rezat, Sebastian ID - 33594 JF - Die Grundschulzeitschrift 320 TI - Schulbücher. Werkzeuge zum Üben in den Fächern Deutsch und Mathematik ER - TY - CHAP AU - Rezat, Sebastian ED - Meister, Dorothee ED - Ilka, Mindt ID - 44688 SN - 2512-112X T2 - Mobile Medien im Schulkontext TI - Mathematiklernen mit digitalen Schulbüchern im Spannungsfeld zwischen Individualisierung und Kooperation ER -