TY - CHAP A1 - Nix, Yvonne A1 - Frotscher, Ralf A1 - Staat, Manfred ED - Eberhardsteiner, J. T1 - Implementation of the edge-based smoothed extended finite element method T2 - Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 Y1 - 2012 ER - TY - JOUR A1 - Nomdedeu, Mar Monsonis A1 - Willen, Christine A1 - Schieffer, Andre A1 - Arndt, Hartmut T1 - Temperature-dependent ranges of coexistence in a model of a two-prey-one-predator microbial food web JF - Marine Biology N2 - The objective of our study was to analyze the effects of temperature on the population dynamics of a three-species food web consisting of two prey bacteria (Pedobacter sp. and Acinetobacter johnsonii) and a protozoan predator (Tetrahymena pyriformis) as model organisms. We assessed the effects of temperature on the growth rates of all three species with the objective of developing a model with four differential equations based on the experimental data. The following hypotheses were tested at a theoretical level: Firstly, temperature changes can affect the dynamic behavior of a system by temperature-dependent parameters and interactions and secondly, food web response to temperature cannot be derived from the single species temperature response. The main outcome of the study is that temperature changes affect the parameter range where coexistence is possible within all three species. This has significant consequences on our ideas regarding the evaluation of effects of global warming. Y1 - 2012 U6 - http://dx.doi.org/10.1007/s00227-012-1966-x SN - 1432-1793 VL - 159 IS - 11 SP - 2423 EP - 2430 PB - Springer CY - Berlin ER - TY - JOUR A1 - Novacek, V. A1 - Tran, Thanh Ngoc A1 - Klinge, U. A1 - Tolba, R. H. A1 - Staat, Manfred A1 - Bronson, D. G. A1 - Miesse, A. M. A1 - Whiffen, J. A1 - Turquier, F. T1 - Finite element modelling of stapled colorectal end-to-end anastomosis : Advantages of variable height stapler design JF - Journal of Biomechanics N2 - The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge. KW - Variable height stapler design KW - Anastomotic leakage KW - Finite element modelling KW - End-to-end colorectal anastomosis KW - Surgical staplers Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.jbiomech.2012.07.021 SN - 1873-2380 VL - 45 IS - 115 SP - 2693 EP - 2697 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Nötzold, K. A1 - Uphues, A. A1 - Wegener, R. A1 - Soter, S. A1 - Fink, K. A1 - Bragard, Michael A1 - Griessel, R. T1 - Inverter based test setup for LVRT verification of a full-scale 2 MW wind power converter T2 - EPE Joint Wind Energy and T&D Chapters Seminar : 28th and 29th of June 2012, in the Utzon Centre, Aalborg, Denmark ; papers, posters, presentations. - Session 2: Grid connection, compliance Y1 - 2012 PB - EPE Association CY - Brussels ER - TY - JOUR A1 - Oertel, Mario A1 - Bung, Daniel B. T1 - Initial stage of two-dimensional dam-break waves: laboratory versus VOF JF - Journal of hydraulic research N2 - Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found. KW - VOF KW - PIV KW - physical model KW - numerical model KW - drag force KW - dam-break Y1 - 2012 U6 - http://dx.doi.org/10.1080/00221686.2011.639981 SN - 1814-2079 (E-Journal); 0022-1686 (Print) VL - 50 IS - 1 SP - 89 EP - 97 PB - Taylor & Francis CY - London ER - TY - CHAP A1 - Oertel, Mario A1 - Bung, Daniel B. T1 - Characteristics of cross-bar block ramp flows T2 - Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto Y1 - 2012 SN - 978-989-8509-01-7 ER - TY - CHAP A1 - Oertel, Mario A1 - Bung, Daniel B. A1 - Schlenkhoff, Andreas ED - Carstensen, Dirk T1 - Blocksteinrampen in Riegelbauweise : Neue Bemessungsansätze T2 - Staubauwerke : planen, bauen, betreiben; 35. Dresdner Wasserbaukolloquium 2012, 08. - 09. März 2012 Y1 - 2012 SN - 978-3-86780-261-1 SP - 317 EP - 326 PB - Selbstverl. der Techn. Univ. CY - Dresden ER - TY - THES A1 - Oflaz, Hakan T1 - Entwicklung eines Prototypen zur Prognose von Frühgeburten : ein biomedizintechnischer Ansatz Y1 - 2012 U6 - http://dx.doi.org/10.4126/38m-004639208 N1 - Köln, Univ., Diss., 2012 PB - Deutsche Zentralbibliothek für Medizin CY - Köln ER - TY - JOUR A1 - Olaru, Alexandra Maria A1 - Kowalski, Julia A1 - Sethi, Vaishali A1 - Blümich, Bernhard T1 - Exchange relaxometry of flow at small Péclet numbers in a glass bead pack JF - Journal of Magnetic Resonance (JMR) N2 - In this paper we consider low Péclet number flow in bead packs. A series of relaxation exchange experiments has been conducted and evaluated by ILT analysis. In the resulting correlation maps, we observed a collapse of the signal and a translation towards smaller relaxation times with increasing flow rates, as well as a signal tilt with respect to the diagonal. In the discussion of the phenomena we present a mathematical theory for relaxation exchange experiments that considers both diffusive and advective transport. We perform simulations based on this theory and discuss them with respect to the conducted experiments. KW - NMR exchange relaxometry KW - Low-field NMR Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.jmr.2012.04.015 SN - 1096-0856 VL - 220 SP - 32 EP - 44 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Olbertz, Klaus T1 - Übergang von Leiharbeitnehmern bei Übertragung des Entleiherbetriebs - Entscheidung des EuGH zum Recht des Betriebsübergangs JF - NWB - Steuer- und Wirtschaftsrecht N2 - Wieder einmal hat eine Entscheidung des Europäischen Gerichtshofs (EuGH) das bisherige nationale Verständnis zu einer Frage des Rechts des Betriebsübergangs erheblich ins Wanken gebracht. Bisher entsprach es allgemeiner Auffassung, dass die Arbeitsverhältnisse von Zeit- bzw. Leiharbeitnehmern bei einem Betriebs(teil)übergang des die Leiharbeitnehmer entleihenden Betriebs nicht auf den Betriebserwerber übergehen. Der EuGH hat in der Rechtssache Albron Catering mit Urteil vom 21.10.2010 jedoch entschieden, dass auch Leiharbeitnehmer von einem Betriebs(teil)übergang erfasst sein können. Folglich kann der Erwerber eines Betriebs oder Betriebsteils gem. § 613a BGB zukünftig verpflichtet sein, auch die an den Betriebsveräußerer verliehenen Leiharbeitnehmer zu übernehmen. Die Entscheidung des EuGH hat somit zur Konsequenz, dass der Übergang von Leiharbeitsverhältnissen auf den Erwerber eines Betriebs jedenfalls nicht mehr pauschal ausgeschlossen werden kann. Dies gilt es bei künftigen Betriebs(teil)übertragungen zu berücksichtigen, um unliebsame Überraschungen zu vermeiden. Y1 - 2018 SN - 1860-9449 IS - 5 SP - 398 EP - 403 PB - NWB-Verlag CY - Herne ER -