TY - JOUR A1 - Steffens, Oliver A1 - Wensauer, Andreas A1 - Suhrke, Michael T1 - Collective excitations in quantum dots: Calculated Raman spectra JF - physica status solidi (b) N2 - Electronic Raman scattering provides information on excited states, whose collective character as being related to the charge or spin density can be distinguished by using different polarization configurations. We employ time-dependent spin-density functional theory to calculate Raman spectra for circular semiconductor quantum dots with up to 10 electrons for the polarized and depolarized configuration and in dependence on an external magnetic field and the momentum transfer. Our results demonstrate an increase of the collective (or many-particle) character of the excitations with increasing momentum transfer and a mixing of spin- and charge-density modes for excitations from ground states with finite spin density. These results have predictive character, because corresponding experiments on few-electron dots have not yet been performed. Y1 - 1999 U6 - https://doi.org/10.1002/(SICI)1521-3951(199909)215:1<365::AID-PSSB365>3.0.CO;2-C VL - 215 SP - 365 EP - 371 PB - Wiley ER - TY - JOUR A1 - Suhrke, Michael A1 - Steffens, Oliver A1 - Rotter, Peter A1 - Rössler, Ulrich T1 - Quantum chaos and magnetotransport in lateral superlattices: The transition from weak to strong modulation potential JF - Physica E: Low-dimensional Systems and Nanostructures N2 - Magnetotransport in lateral superlattices covers a variety of apparently different physics dependent on the amplitude of the modulation potential relative to the Fermi energy ranging from the weakly modulated 2DEG to the antidot lattice. Here we investigate the transition between weak modulation and antidots within the quantum-mechanical theory by studying (i) the single-particle spectrum with respect to quantum signatures of classical chaos and (ii) the change of characteristic features in the magnetoresistance starting from the Kubo formula. KW - Lateral superlattices KW - Quantum chaos KW - Level statistics KW - Magnetotransport KW - Commensurability oscillations Y1 - 1997 U6 - https://doi.org/10.1016/S1386-9477(97)00060-X SN - 1386-9477 VL - 1 IS - 1-4 SP - 281 EP - 287 ER - TY - RPRT A1 - Steffens, Oliver A1 - Rössler, Ulrich A1 - Suhrke, Michael T1 - Comment on "Shell Filling and Spin Effects in a Few Electron Quantum Dot" T2 - Physical Review Letters N2 - We briefly report on calculated addition spectra for electrons in a circular quantum dot with perpendicular magnetic field. We compare our current density functional theory calculations with recent experiments by Tarucha et al. [PRL 77, 3613 (1996)]. We find a very good qualitative agreement of the structures and find an additional effect caused by Hund's first rule in magnetic field, which gives rise to new substructures not discussed in the paper by Tarucha. Y1 - 1996 UR - http://arxiv.org/abs/cond-mat/9711077 VL - 77 SP - 3613 ER - TY - JOUR A1 - Steffens, Oliver T1 - Energetische Modernisierung und Restaurierung historisch wertvoller Stadtquartiere. Regenerative Energieversorgung als Schwerpunkt einer nachhaltigen Modernisierung historisch wertvoller Stadtquartiere (RENARHIS) JF - Zukunft bauen. Forschungsinitiative Zukunft Bau 2016 Y1 - 2016 IS - 5 SP - 62 EP - 65 PB - Bundesministerium für Umwelt, Naturschutz, Bau und Reaktorsicherheit (BMUB) ER - TY - GEN A1 - Steffens, Oliver A1 - Saller, Tobias T1 - Modernisierungskonzepte für das denkmalgeschützte Ensemble am Jahn-Stadion Regensburg Prüfeninger Straße 47–52 BT - Studiengang Gebäudeklimatik. Studienarbeiten Y1 - 2014 ER - TY - CHAP A1 - Höller, Christoph A1 - Steffens, Oliver T1 - Bauphysikalische Grundlagenausbildung an der OTH Regensburg während der COVID-19-Pandemie T2 - Tagungsband DAGA 2021: 47. Jahrestagung für Akustik, 15.-18. August 2021, Wien und Online Y1 - 2021 UR - https://www.dega-akustik.de/publikationen/online-proceedings SN - 978-3-939296-18-8 PB - Deutsche Gesellschaft für Akustik e.V. ER - TY - INPR A1 - Steffens, Oliver T1 - Binomial Distribution Nomogram after Larson N2 - Following an idea of Larson (1966) we construct a nomogram for cumulative binomial distribution that can be used to perform hypothesis testing, quality management (e.g. test design) and other statistical tasks. The nomogram can be printed and directly used with a simple ruler to read the results. It is instructive and as an analog computing device continuous changes are easily visible. Y1 - 2024 UR - https://www.researchgate.net/publication/383270775_Binomial_Distribution_Nomogram_after_Larson ER - TY - INPR A1 - Malz, Sebastian A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. A1 - Steffens, Oliver A1 - Kusterle, Wolfgang T1 - Determination of the Water Content within Tunnel Linings to Assess Fire Safety T2 - SSRN Electronic Journal N2 - Fires in tunnels are known to lead to explosive spalling of the tunnel linings, mainly due to rapid expansion of water as a result of vaporization in the concrete. In order to determine water content and assess fire safety within tunnel linings a novel measurement system has been developed. The development process includes the calibration of the sensor system via both direct and indirect approaches. This work compares both calibration methods and shows the differences that can occur due to measurement uncertainty. This work presents the measured water content within the Inntal tunnel, Austria as a representative tunnel from a total of four investigated tunnels. The obtained water content is compared to that found in the literature, and recommendations for practical work in terms of fire safety is given. KW - tunnel inner lining KW - water content KW - moisture sensor KW - moisture measurement KW - Fire safety KW - concrete spalling Y1 - 2023 U6 - https://doi.org/10.2139/ssrn.4390700 ER - TY - CHAP A1 - Mühlberger, Thomas A1 - Schoplocher, Paul Dragos A1 - Steffens, Oliver ED - Fouad, Nabil A. T1 - Thermische Gebäudesimulation: aktuelle Anwendungen und Erweiterungen mittels der Finite‐Elemente‐Methode T2 - Bauphysik-Kalender 2025: Simulationen, BIM und KI N2 - Nach einem kurzen historischen Abriss der Entwicklung der Gebäudesimulation wird die aktuell übliche gleichungsbasierte Kompaktmodell-Simulation beschrieben und deren praktische Anwendung aufgezeigt. Dabei wird auf die Bedeutung der Validierung von Simulationstools und auf etablierte Validierungsstandards eingegangen. Gebäudesimulation dient der Optimierung des Bauens in allen Planungsphasen. Mit Praxisbeispielen vom sommerlichen Wärmeschutz bis hin zur Modellierung innovativer Konstruktionen werden unterschiedliche Einsatzbereiche demonstriert. Im zweiten Teil wird die Verwendung der Finite-Elemente-Methode (FEM) für die bauphysikalische Modellierung vorgestellt. Anhand von Beispielen zeigen wir, dass die (rechenzeitintensive) FEM aufgrund einer detaillierteren Modellierung von Geometrie, Strahlung und Konvektion präzisere Simulationsergebnisse liefert. Zum Abschluss werden Wege vorgeschlagen, wie dies zur Erweiterung der schnelleren Kompaktmodell-Simulation eingesetzt werden kann. KW - Energieeffizienz KW - Finite-Elemente-Methode KW - Gebäudesimulation KW - Kompaktmodelle KW - thermische Bauphysik Y1 - 2025 SN - 9783433034514 U6 - https://doi.org/10.1002/9783433612095.ch12 SP - 435 EP - 468 PB - Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Beimler, Josef A1 - Leißl, Caroline A1 - Ebner, Lena A1 - Elsner, Michael A1 - Mühlbauer, Gerhard A1 - Kohlert, Dieter A1 - Schubert, Martin J. W. A1 - Weiß, Andreas P. A1 - Sterner, Michael A1 - Raith, Thomas A1 - Afranseder, Martin A1 - Krapf, Tobias A1 - Mottok, Jürgen A1 - Siemers, Christian A1 - Großmann, Benjamin A1 - Höcherl, Johannes A1 - Schlegl, Thomas A1 - Schneider, Ralph A1 - Milaev, Johannes A1 - Rampelt, Christina A1 - Roduner, Christian A1 - Glowa, Christoph A1 - Bachl, Christoph A1 - Schliekmann, Claus A1 - Gnan, Alfons A1 - Grill, Martin A1 - Ruhland, Karl A1 - Piehler, Thomas A1 - Friers, Daniel A1 - Wels, Harald A1 - Pflug, Kenny A1 - Kucera, Markus A1 - Waas, Thomas A1 - Schlachetzki, Felix A1 - Boy, Sandra A1 - Pemmerl, Josef A1 - Leis, Alexander A1 - Welsch, Andreas F.X. A1 - Graf, Franz A1 - Zenger, Gerhard A1 - Volbert, Klaus A1 - Waas, Thomas A1 - Scherzinger, Stefanie A1 - Klettke, Meike A1 - Störl, Uta A1 - Heyl, C. A1 - Boldenko, A. A1 - Monkman, Gareth J. A1 - Kujat, Richard A1 - Briem, Ulrich A1 - Hierl, Stefan A1 - Talbot, Sebastian A1 - Schmailzl, Anton A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Valentino, Piergiorgio A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Furgiuele, Franco A1 - Gebbeken, Norbert A1 - Eisenried, Michael A1 - Jungbauer, Bastian A1 - Hutterer, Albert A1 - Bauhuber, Michael A1 - Mikrievskij, Andreas A1 - Argauer, Monika A1 - Hummel, Helmut A1 - Lechner, Alfred A1 - Liebetruth, Thomas A1 - Schumm, Michael A1 - Joseph, Saskia A1 - Reschke, Michael A1 - Soska, Alexander A1 - Schroll-Decker, Irmgard A1 - Putzer, Michael A1 - Rasmussen, John A1 - Dendorfer, Sebastian A1 - Weber, Tim A1 - Al-Munajjed, Amir Andreas A1 - Verkerke, Gijsbertus Jacob A1 - Renkawitz, Tobias A1 - Haug, Sonja A1 - Rudolph, Clarissa A1 - Zeitler, Annika A1 - Schaubeck, Simon A1 - Steffens, Oliver A1 - Rechenauer, Christian A1 - Schulz-Brize, Thekla A1 - Fleischmann, Florian A1 - Kusterle, Wolfgang A1 - Beer, Anne A1 - Wagner, Bernd A1 - Neidhart, Thomas ED - Baier, Wolfgang T1 - Forschungsbericht 2013 T3 - Forschungsberichte der OTH Regensburg - 2013 Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7990 CY - Regensburg ER - TY - JOUR A1 - Mauerer, Wolfgang A1 - Rexhepaj, Tanja A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Diermeier, Andreas A1 - Neidhart, Thomas A1 - Wolfrum, Dominik A1 - Sterner, Michael A1 - Heberl, Michael A1 - Nusko, Robert A1 - Maier, Georg A1 - Nagl, Klaus A1 - Reuter, Monika A1 - Hofrichter, Andreas A1 - Lex, Thomas A1 - Lesch, Florian A1 - Kieninger, Bärbel A1 - Szalo, Alexander Eduard A1 - Zehner, Alexander A1 - Palm, Christoph A1 - Joblin, Mitchell A1 - Apel, Sven A1 - Ramsauer, Ralf A1 - Lohmann, Daniel A1 - Westner, Markus A1 - Strasser, Artur A1 - Munndi, Maximilian A1 - Ebner, Lena A1 - Elsner, Michael A1 - Weiß, Nils A1 - Segerer, Matthias A1 - Hackenberg, Rudolf A1 - Steger, Sebastian A1 - Schmailzl, Anton A1 - Dostalek, Michael A1 - Armbruster, Dominik A1 - Koch, Fabian A1 - Hierl, Stefan A1 - Thumann, Philipp A1 - Swidergal, Krzysztof A1 - Wagner, Marcus A1 - Briem, Ulrich A1 - Diermeier, Andreas A1 - Spreitzer, Stefan A1 - Beiderbeck, Sabrina A1 - Hook, Christian A1 - Zobel, Martin A1 - Weber, Tim A1 - Groß, Simon A1 - Penzkofer, Rainer A1 - Dendorfer, Sebastian A1 - Schillitz, Ingo A1 - Bauer, Thomas A1 - Rudolph, Clarissa A1 - Schmidt, Katja A1 - Liebetruth, Thomas A1 - Hamer, Markus A1 - Haug, Sonja A1 - Vernim, Matthias A1 - Weber, Karsten A1 - Saßmannshausen, Sean Patrick A1 - Books, Sebastian A1 - Neuleitner, Nikolaus A1 - Rechenauer, Christian A1 - Steffens, Oliver A1 - Kusterle, Wolfgang A1 - Gömmel, Roland A1 - Wellnitz, Felix A1 - Stierstorfer, Johannes A1 - Stadler, Dominik A1 - Hofmann, Matthias J. A1 - Motschmann, Hubert A1 - Shamonin (Chamonine), Mikhail A1 - Bleicher, Veronika A1 - Fischer, Sebastian A1 - Hackenberg, Rudolf A1 - Horn, Anton A1 - Kawasch, Raphael A1 - Petzenhauser, Michael A1 - Probst, Tobias A1 - Udalzow, Anton A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian ED - Baier, Wolfgang T1 - Forschungsbericht 2016 T3 - Forschungsberichte der OTH Regensburg - 2016 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13840 CY - Regensburg ER -