TY - JOUR A1 - Probst, M. A1 - Behbahani, Mehdi A1 - Borrmann, E. A1 - Elgeti, S. A1 - Nicolai, M. A1 - Behr, Marek T1 - Hemodynamic Modeling for Numerical Analysis and Design of Medical Devices Y1 - 2010 N1 - Posterpresentation ; NIC Symposium 2010 ; 24 - 25 February 2010 Jülich, Germany ER - TY - JOUR A1 - Esch, Thomas A1 - Salber, Wolfgang A1 - Wolters, Peter A1 - Geiger, José A1 - Dilthey, Jochen T1 - Synergies of variable valve actuation and direct injection JF - Direct injection SI engine technology 2002 : [SAE 2002 world congress, Detroit, Michigan, USA, March 4 - 7, 2002]. Y1 - 2002 SN - 0-7680-0961-8 N1 - Konferenz-Einzelbericht SP - 45 EP - 53 PB - Society of Automotive Engineers CY - Warrendale, Pa ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Mai, A. A1 - Bergmann, B. A1 - Waluga, C. A1 - Behr, Marek A1 - Tran, L. A1 - Vonderstein, K. A1 - Mottaghy, K. T1 - Modeling and Numerical Simulation of Blood Damage Y1 - 2010 N1 - Posterpresentation ; Umbrella Symposium "Modelling and Simulation in Medicine, Engineering and Sciences", Forschungszentrum Jülich, January 18-20, 2010 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Probst, M. A1 - Mai, A. A1 - Behr, Marek A1 - Tran, L. A1 - Vonderstein, K. A1 - Mottaghy, K. T1 - Numerical Prediction of Blood Damage in Biomedical Devices Y1 - 2010 N1 - Posterpresentation ; Biomedica Congress, Aachen, March 17-18, 2010 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Waluga, C. A1 - Stock, S. A1 - Mai, A. A1 - Bergmann, B. A1 - Behr, Marek A1 - Tran, L. A1 - Vonderstein, K. A1 - Scheidt, H. A1 - Oedekoven, B. A1 - Mottaghy, K. T1 - Modelling and Numerical Analysis of Platelet Reactions and Surface Thrombus Growth Y1 - 2009 N1 - Posterpresentation ; European Society of Biomaterials (ESB), Lausanne, Switzerland, September 7-10, 2009 ER - TY - JOUR A1 - Martín-Vaquero, J. A1 - Kleefeld, Andreas T1 - Solving nonlinear parabolic PDEs in several dimensions: Parallelized ESERK codes JF - Journal of Computational Physics N2 - There is a very large number of very important situations which can be modeled with nonlinear parabolic partial differential equations (PDEs) in several dimensions. In general, these PDEs can be solved by discretizing in the spatial variables and transforming them into huge systems of ordinary differential equations (ODEs), which are very stiff. Therefore, standard explicit methods require a large number of iterations to solve stiff problems. But implicit schemes are computationally very expensive when solving huge systems of nonlinear ODEs. Several families of Extrapolated Stabilized Explicit Runge-Kutta schemes (ESERK) with different order of accuracy (3 to 6) are derived and analyzed in this work. They are explicit methods, with stability regions extended, along the negative real semi-axis, quadratically with respect to the number of stages s, hence they can be considered to solve stiff problems much faster than traditional explicit schemes. Additionally, they allow the adaptation of the step length easily with a very small cost. Two new families of ESERK schemes (ESERK3 and ESERK6) are derived, and analyzed, in this work. Each family has more than 50 new schemes, with up to 84.000 stages in the case of ESERK6. For the first time, we also parallelized all these new variable step length and variable number of stages algorithms (ESERK3, ESERK4, ESERK5, and ESERK6). These parallelized strategies allow to decrease times significantly, as it is discussed and also shown numerically in two problems. Thus, the new codes provide very good results compared to other well-known ODE solvers. Finally, a new strategy is proposed to increase the efficiency of these schemes, and it is discussed the idea of combining ESERK families in one code, because typically, stiff problems have different zones and according to them and the requested tolerance the optimum order of convergence is different. KW - Multi-dimensional partial differential equations KW - Higher-order codes KW - Nonlinear PDEs Y1 - 2020 U6 - https://doi.org/10.1016/j.jcp.2020.109771 SN - 0021-9991 IS - 423 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Uysal, Karya A1 - Firat, Ipek Serat A1 - Creutz, Till A1 - Aydin, Inci Cansu A1 - Artmann, Gerhard A1 - Teusch, Nicole A1 - Temiz Artmann, Aysegül T1 - A novel in vitro wound healing assay using free-standing, ultra-thin PDMS membranes JF - membranes N2 - Advances in polymer science have significantly increased polymer applications in life sciences. We report the use of free-standing, ultra-thin polydimethylsiloxane (PDMS) membranes, called CellDrum, as cell culture substrates for an in vitro wound model. Dermal fibroblast monolayers from 28- and 88-year-old donors were cultured on CellDrums. By using stainless steel balls, circular cell-free areas were created in the cell layer (wounding). Sinusoidal strain of 1 Hz, 5% strain, was applied to membranes for 30 min in 4 sessions. The gap circumference and closure rate of un-stretched samples (controls) and stretched samples were monitored over 4 days to investigate the effects of donor age and mechanical strain on wound closure. A significant decrease in gap circumference and an increase in gap closure rate were observed in trained samples from younger donors and control samples from older donors. In contrast, a significant decrease in gap closure rate and an increase in wound circumference were observed in the trained samples from older donors. Through these results, we propose the model of a cell monolayer on stretchable CellDrums as a practical tool for wound healing research. The combination of biomechanical cell loading in conjunction with analyses such as gene/protein expression seems promising beyond the scope published here. Y1 - 2022 U6 - https://doi.org/10.3390/membranes13010022 N1 - This article belongs to the Special Issue "Latest Scientific Discoveries in Polymer Membranes" VL - 2023 IS - 13(1) PB - MDPI CY - Basel ER - TY - GEN A1 - Dieringer, Matthias A. A1 - Renz, Wolfgang A1 - Lindel, Tomasz Dawid A1 - Seifert, Frank A1 - Frauenrath, Tobias A1 - Waiczies, Helmar A1 - von Knobelsdorff-Brenkhoff, Florian A1 - Santoro, Davide A1 - Hoffmann, Werner A1 - Ittermann, Bernd A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf T1 - 4CH TX/RX Surface Coil for 7T: Design, Optimization and Application for Cardiac Function Imaging T2 - 2010 ISMRM-ESMRMB joint annual meeting N2 - Practical impediments of ultra high field cardiovascular MR (CVMR) can be catalogued in exacerbated magnetic field and radio frequency (RF) inhomogeneities, susceptibility and off-resonance effects, conductive and dielectric effects in tissue, and RF power deposition constraints, which all bear the potential to spoil the benefit of CVMR at 7T. Therefore, a four element cardiac transceive surface coil array was developed. Cardiac imaging provided clinically acceptable signal homogeneity with an excellent blood myocardium contrast. Subtle anatomic structures, such as pericardium, mitral and tricuspid valves and their apparatus, papillary muscles, and trabecles were accurately delineated. Y1 - 2010 SN - 1545-4428 N1 - ISMRM-ESMRMB joint annual meeting, 1 - 7 May 2010, Stockholm, Sweden ER - TY - CHAP A1 - Schmitz, Annika A1 - Apandi, Shah Eiman Amzar Shah A1 - Spillner, Jan A1 - Hima, Flutura A1 - Behbahani, Mehdi ED - Digel, Ilya ED - Staat, Manfred ED - Trzewik, Jürgen ED - Sielemann, Stefanie ED - Erni, Daniel ED - Zylka, Waldemar T1 - Effect of different cannula positions in the pulmonary artery on blood flow and gas exchange using computational fluid dynamics analysis T2 - YRA MedTech Symposium (2024) N2 - Pulmonary arterial cannulation is a common and effective method for percutaneous mechanical circulatory support for concurrent right heart and respiratory failure [1]. However, limited data exists to what effect the positioning of the cannula has on the oxygen perfusion throughout the pulmonary artery (PA). This study aims to evaluate, using computational fluid dynamics (CFD), the effect of different cannula positions in the PA with respect to the oxygenation of the different branching vessels in order for an optimal cannula position to be determined. The four chosen different positions (see Fig. 1) of the cannulas are, in the lower part of the main pulmonary artery (MPA), in the MPA at the junction between the right pulmonary artery (RPA) and the left pulmonary artery (LPA), in the RPA at the first branch of the RPA and in the LPA at the first branch of the LPA. Y1 - 2024 SN - 978-3-940402-65-3 U6 - https://doi.org/10.17185/duepublico/81475 N1 - 4th YRA MedTech Symposium, February 1, 2024. FH Aachen, Campus Jülich SP - 29 EP - 30 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Kleefeld, Andreas ED - Constanda, Christian T1 - Numerical calculation of interior transmission eigenvalues with mixed boundary conditions T2 - Computational and Analytic Methods in Science and Engineering N2 - Interior transmission eigenvalue problems for the Helmholtz equation play an important role in inverse wave scattering. Some distribution properties of those eigenvalues in the complex plane are reviewed. Further, a new scattering model for the interior transmission eigenvalue problem with mixed boundary conditions is described and an efficient algorithm for computing the interior transmission eigenvalues is proposed. Finally, extensive numerical results for a variety of two-dimensional scatterers are presented to show the validity of the proposed scheme. Y1 - 2020 SN - 978-3-030-48185-8 (Hardcover) U6 - https://doi.org/10.1007/978-3-030-48186-5_9 SP - 173 EP - 195 PB - Birkhäuser CY - Cham ER -