TY - CHAP A1 - Höckner, Benny A1 - Hofstedt, Petra A1 - Vörtler, Thilo A1 - Sauer, Peter A1 - Hinze, Thomas ED - Hanus, Michael ED - Rocha, Ricardo T1 - Constraint-based Approach for an Early Inspection of the Feasibility of Cyber Physical Systems T2 - 20th International Conference on Applications of Declarative Programming and Knowledge Management (INAP). 2013 Y1 - 2013 UR - http://www.informatik.uni-kiel.de/uploads/tx_publication/tr-1306-bericht.pdf SP - 183 EP - 197 PB - Institut für Informatik, Christian-Albrechts-Universität CY - Kiel ER - TY - GEN A1 - Giersch, Thomas A1 - Hönisch, Peter A1 - Beirow, Bernd A1 - Kühhorn, Arnold T1 - Forced Response Analyses of Mistuned Radial Inflow Turbines T2 - Journal of Turbomachinery N2 - Radial turbine wheels designed as blade integrated disks (blisk) are widely used in various industrial applications. However, related to the introduction of exhaust gas turbochargers in the field of small and medium sized engines, a sustainable demand for radial turbine wheels has come along. Despite those blisks being state of the art, a number of fundamental problems, mainly referring to fluid-structure-interaction and, therefore, to the vibration behavior, have been reported. Aiming to achieve an enhanced understanding of fluid-structure-interaction in radial turbine wheels, a numerical method, able to predict forced responses of mistuned blisks due to aerodynamic excitation, is presented. In a first step, the unsteady aerodynamic forcing is determined by modeling the spiral casing, the stator vanes, and the rotor blades of the entire turbine stage. In a second step, the aerodynamic damping induced by blade vibration is computed using a harmonic balance technique. The structure itself is represented by a reduced order model being extended by aerodynamic damping effects and aerodynamic forcings. Mistuning is introduced by adjusting the modal stiffness matrix based on results of blade by blade measurements that have been performed at rest. In order to verify the numerical method, the results are compared with strain-gauge data obtained during rig-tests. As a result, a measured low engine order excitation was found by modeling the spiral casing. Furthermore, a localization phenomenon due to frequency mistuning could be proven. The predicted amplitudes are close to the measured data. Y1 - 2013 UR - http://turbomachinery.asmedigitalcollection.asme.org/article.aspx?articleid=1672771 U6 - https://doi.org/10.1115/1.4007512 SN - 1528-8900 VL - 135 IS - 3 SP - 031034-1 EP - 031034-9 ER - TY - GEN A1 - Zöllner, Marvin Hartwig A1 - Niu, Gang A1 - Jhang, Jin-Hao A1 - Schäfer, Andreas A1 - Zaumseil, Peter A1 - Bäumer, Marcus A1 - Schröder, Thomas T1 - Temperature dependent reduction of epitaxial Ce1-xPrxO2-δ (x = 0-1) thin films on Si(111): A combined TPD, XRD, XPS and Raman study T2 - Journal of Physical Chemistry : C Y1 - 2013 U6 - https://doi.org/10.1021/jp4082867 SN - 1932-7455 VL - 117 IS - 47 SP - 24851 EP - 24857 ER - TY - GEN A1 - Zaumseil, Peter A1 - Kozłowski, Grzegorz A1 - Yamamoto, Yuji A1 - Schubert, Markus Andreas A1 - Schroeder, Thomas T1 - X-ray Characterization of Ge Dots Epitaxially Grown on Nano-structured Si Islands on SOI Substrates T2 - Journal of Applied Crystallography Y1 - 2013 SN - 0021-8898 VL - 46 IS - 4 SP - 868 EP - 873 ER - TY - GEN A1 - Niu, Gang A1 - Zaumseil, Peter A1 - Schubert, Markus Andreas A1 - Zöllner, Marvin Hartwig A1 - Dabrowski, Jarek Marek A1 - Schroeder, Thomas T1 - Lattice-matched single crystalline ternary PrxY2-xO3 films on SrO-passivated Si (001): interface engineering and crystallography tailoring T2 - Applied Physics Letters Y1 - 2013 VL - 102 SP - 011906-1 EP - 011906-5 ER - TY - GEN A1 - Niu, Gang A1 - Zöllner, Marvin Hartwig A1 - Zaumseil, Peter A1 - Pouliopoulos, A. A1 - d'Acapito, F. A1 - Schröder, Thomas A1 - Boscherini, F. T1 - X-ray diffraction and extended X-ray absorption fine structure study of epitaxial mixed ternary bixbyite PrxY2-xO3 (x=0-2) films on Si (111) T2 - Journal of Applied Physics Y1 - 2013 SN - 0021-8979 VL - 113 IS - 4 SP - 043504 EP - 043506 ER - TY - GEN A1 - Tarnawska, Lidia Lupina A1 - Dabrowski, Jarek Marek A1 - Grzela, Tomasz A1 - Niermann, T. A1 - Lehmann, M. A1 - Storck, Peter A1 - Schröder, Thomas T1 - Interface science of virtual GaN substrates on Si(111) via Sc2O3/Y2O3 buffers: Experiment and Theory T2 - Journal of Applied Physics Y1 - 2013 SN - 0021-8979 VL - 113 IS - 21 SP - 213507 EP - 213507 ER - TY - GEN A1 - Niermann, T. A1 - Zengler, D. A1 - Tarnawska, Lidia Lupina A1 - Storck, Peter A1 - Schroeder, Thomas T1 - Virtual GaN substrates via Sc2O3/Y2O3 buffers on Si(111): TEM Characterization of growth defects T2 - Journal of Applied Physics Y1 - 2013 SN - 0021-8979 VL - 113 IS - 22 SP - 223501 EP - 223501-8 ER - TY - CHAP A1 - Giersch, Thomas A1 - Figaschewsky, Felix A1 - Hönisch, Peter A1 - Kühhorn, Arnold A1 - Schrape, Sven T1 - Numerical Analysis and Validation of the Rotor Blade Vibration Response Induced by High Pressure Compressor Deep Surge T2 - ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics Düsseldorf, Germany, June 16–20, 2014, Paper GT2014-26295 N2 - The following paper presents a numerical analysis of a deep surge cycle of a 4.5 stage research compressor. The resulting unsteady loads are used to determine the response of two particular rotor blade rows that are then compared to strain gauge data from measurements. Within a deep surge cycle the compressor experiences a rapid change of the flow field from forward to reversed flow. This rapid breakdown is linked to a new mean blade load. Hence, the rapid change in blade loads are able to excite fundamental blade modes similar to an impulse load. The resulting vibration magnitudes might reach critical levels. This paper demonstrates two different approaches to evaluate the unsteady flow during a surge cycle. The first uses a three dimensional, time accurate finite volume solver for viscid compressible flows to calculate the transient surge cycle of the compressor. The compressor itself is represented by a multi-blade-row sector model. The second approach makes use of the same solver and compressor domain to determine steady state characteristics of the HPC in forward, stalled and reversed flow. Based on these characteristics an one dimensional finite volume solver for inviscid compressible flows was developed to determine the transient compressor behavior. The one dimensional solver represents the compressor by source terms that are linked to the previously determined steady state characteristics. Copyright © 2014 by Rolls-Royce Deutschland Ltd & Co KG KW - Compressors KW - High pressure (Physics) KW - Numerical analysis Y1 - 2014 SN - 978-0-7918-4577-6 U6 - https://doi.org/10.1115/GT2014-26295 PB - ASME CY - New York, NY ER - TY - GEN A1 - Limberg, Wolfgang A1 - Ebel, Thomas A1 - Pyczak, Florian A1 - Oehring, Michael A1 - Schimansky, Frank-Peter T1 - Influence of the sintering atmosphere on the mechanical properties of MIM-processed Ti 45Al 5Nb 0.2B 0.2C T2 - Materials Science and Engineering A Y1 - 2012 IS - 552 SP - 323 EP - 329 ER - TY - GEN A1 - Schloffer, Martin A1 - Iqbal, Farasat A1 - Gabrisch, Heike A1 - Schwaighofer, Emanuel A1 - Schimansky, Frank-Peter A1 - Mayer, Svea A1 - Stark, Andreas A1 - Lippmann, Thomas A1 - Göken, Mathias A1 - Pyczak, Florian A1 - Clemens, Helmut T1 - Microstructure development and hardness of a powder metallurgical multi phase gamma-TiAl based alloy T2 - Intermetallics Y1 - 2012 U6 - https://doi.org/10.1016/j.intermet.2011.11.015 SN - 0966-9795 IS - 22 SP - 231 EP - 240 ER - TY - GEN A1 - Ebel, Thomas A1 - Ferri, Orley Milagres A1 - Limberg, Wolfgang A1 - Oehring, Michael A1 - Pyczak, Florian A1 - Schimansky, Frank-Peter T1 - Metal injection moulding of titanium and titanium-aluminides T2 - Key Engineering Materials Y1 - 2012 SN - 1662-9795 IS - 520 SP - 153 EP - 160 ER - TY - GEN A1 - Kainer, Karl Ulrich A1 - Ebel, Thomas A1 - Ferri, Orley Milagres A1 - Limberg, Wolfgang A1 - Pyczak, Florian A1 - Schimansky, Frank-Peter T1 - From titanium to magnesium: processing by advanced metal injection moulding T2 - Powder Metallurgy Y1 - 2012 VL - 55 IS - 4 SP - 315 EP - 321 ER - TY - GEN A1 - Schloffer, Martin A1 - Schmoelzer, Thomas A1 - Mayer, Svea A1 - Schwaighofer, Emanuel A1 - Hawranek, G. A1 - Schimansky, Frank-Peter A1 - Pyczak, Florian A1 - Clemens, Helmut T1 - The Characterisation of a Powder Metallurgically Manufactured TNM™ Titanium Aluminide Alloy Using Complimentary Quantitative Methods T2 - Practical Metallography - Praktische Metallkunde Y1 - 2011 U6 - https://doi.org/10.3139/147.110138 SN - 0032-678x VL - 48 IS - 11 SP - 594 EP - 604 ER - TY - GEN A1 - Kaysser, Wolfgang A1 - Esslinger, Jörg A1 - Abetz, Volker A1 - Huber, Norbert A1 - Kainer, Karl Ulrich A1 - Klassen, Thomas A1 - Pyczak, Florian A1 - Schreyer, Andreas A1 - Staron, Peter T1 - Research with Neutron and Synchrotron Radiation on Aerospace and Automotive Materials and Components T2 - Advanced Engineering Materials Y1 - 2011 U6 - https://doi.org/10.1002/adem.201100150 SN - 1527-2648 VL - 13 IS - 8 SP - 637 EP - 657 ER - TY - GEN A1 - Staron, Peter A1 - Beckmann, Felix A1 - Lippmann, Thomas A1 - Stark, Andreas A1 - Oehring, Michael A1 - Pyczak, Florian A1 - Salgado, Mario A1 - Hort, Norbert A1 - Eckerlebe, Horst A1 - Kainer, Karl Ulrich A1 - Müller, Martin A1 - Schreyer, Andreas T1 - In situ studies of light metals with synchrotron radiation and neutrons T2 - Materials Science Forum Y1 - 2011 SN - 1662-9752 IS - 690 SP - 192 EP - 197 ER - TY - GEN A1 - Jabbar, Houria A1 - Monchoux, Jean-Philippe A1 - Houdellier, Florent A1 - Dollé, Mickaël A1 - Schimansky, Frank-Peter A1 - Pyczak, Florian A1 - Thomas, Marc A1 - Couret, Alain T1 - Microstructure and mechanical properties of high niobium containing TiAl alloys elaborated by Spark Plasma Sintering T2 - Intermetallics Y1 - 2010 SN - 0966-9795 VL - 18 IS - 12 SP - 2312 EP - 2321 ER - TY - CHAP A1 - Klimczak, Peter A1 - Wolff, Matthias A1 - Lindemann, Jens A1 - Petersen, Christer A1 - Römer, Ronald A1 - Zoglauer, Thomas ED - Hoffmann, Rüdiger T1 - Die kognitive Heizung T2 - Elektronische Sprachsignalverarbeitung 2014, Tagungsband der 25. Konferenz Dresden, 26. – 28. März 2014 Y1 - 2014 SN - 978-3-944331-51-5 SP - 89 EP - 96 PB - TUD press CY - Dresden ER - TY - GEN A1 - Garner, Jennifer A1 - Cheben, Michael A1 - Demant, Daniel A1 - Enke, Uwe A1 - Herd, Rainer A1 - Labuda, Jozef A1 - Modarressi-Tehrani, Diana A1 - Stöllner, Thomas A1 - Tóth, Peter T1 - Neue montanarchäologische Untersuchungen im Slowakischen Erzgebirge T2 - Der Anschnitt : Zeitschrift für Kunst und Kultur im Bergbau KW - Slowakisches Erzgebirge Y1 - 2014 SN - 0003-5238 VL - 66 IS - 2-3 SP - 66 EP - 77 ER - TY - CHAP A1 - Seifarth, Olaf A1 - Walczyk, Christian A1 - Lupina, Grzegorz A1 - Zaumseil, Peter A1 - Schmeißer, Dieter A1 - Müssig, Hans-Joachim A1 - Schroeder, Thomas T1 - The electronic band diagram of thin PrO2(111) / Pr-silicate buffers on Si(111) and its relevance to dielectric properties T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44 N2 - Thin dielectric buffers of cubic PrO2(111) on Si(111) are ideally suited to integrate Ge onto Si by moderating the lattice mismatch between the materials. The leakage current across this dielectric buffer is strongly influenced by the electronic band diagram and defects inside the band gap. Therefore, we measured the band offsets, band gaps and defect positions by means of synchrotron radiation based photoemission spectroscopy techniques (XPS and XAS) with special emphasis on the Pr-silicate interface. In a next step we compare the spectroscopic data with information from dielectric studies, based on temperature dependent leakage current studies. We observe a close relation between dielectric properties and the electronic structure. Y1 - 2009 UR - http://www.dpg-verhandlungen.de/year/2009/conference/dresden/part/df/session/6/contribution/5 SN - 0420-0195 SP - S. 136 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Dudek, Peter A1 - Lupina, Grzegorz A1 - Kozłowski, Grzegorz A1 - Dabrowski, Jarek Marek A1 - Lippert, Gunther A1 - Müssig, Hans-Joachim A1 - Schmeißer, Dieter A1 - Schroeder, Thomas T1 - Band structure and electrical properties of MBE grown HfO2 - based alkaline earth perovskites T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - Ultra thin dielectric films (<20 nm) deposited on TiN electrodes are interesting for MIM capacitor application. High capacitance density and dielectric permittivity must be accompanied by extremely low leakage currents (10−8 A/cm2) at bias 0.5 V. To achieve such low leakage currents, high band gap and proper band alignment is required. Occupied electronic states can be probed with standard laboratory photoemission methods. Probing of unoccupied states is more challenging. Synchrotron based PES in combination with XAS forms a powerful method to study the band alignment. ASAM end station located at the U 49/2 PGM 2 beamline of BESSY II (Berlin) offers excellent conditions for performing such measurements. We investigated HfO2 - based alkaline earth perovskite - BaHfO3 with subsequent admixture of TiO2, resulting in formation of BaHf0.5Ti0.5O3 compound. The analysis of data indicates that band gap for HfO2 is similar to BaHfO3 and amounts 5.8 eV; for BaHf0.5Ti0.5O3 it decreases to 3.8 eV. We conclude that the addition of TiO2 to BaHfO3 increases significantly the dielectric permittivity but also impacts the band gap alignment. The conduction band offset shrinks, influencing the leakage current behavior. Y1 - 2010 UR - http://www.dpg-verhandlungen.de/year/2010/conference/regensburg/part/ds/session/24/contribution/4 SN - 0420-0195 SP - S. 232 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER -