@incollection{BorggrafeOhndorfDachwaldetal.2012, author = {Borggrafe, Andreas and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang}, title = {Analysis of interplanetary solar sail trajectories with attitude dynamics}, series = {Dynamics and Control of Space Systems 2012}, booktitle = {Dynamics and Control of Space Systems 2012}, publisher = {Univelt Inc}, address = {San Diego}, isbn = {978-0-87703-587-9}, pages = {1553 -- 1569}, year = {2012}, abstract = {We present a new approach to the problem of optimal control of solar sails for low-thrust trajectory optimization. The objective was to find the required control torque magnitudes in order to steer a solar sail in interplanetary space. A new steering strategy, controlling the solar sail with generic torques applied about the spacecraft body axes, is integrated into the existing low-thrust trajectory optimization software InTrance. This software combines artificial neural networks and evolutionary algorithms to find steering strategies close to the global optimum without an initial guess. Furthermore, we implement a three rotational degree-of-freedom rigid-body attitude dynamics model to represent the solar sail in space. Two interplanetary transfers to Mars and Neptune are chosen to represent typical future solar sail mission scenarios. The results found with the new steering strategy are compared to the existing reference trajectories without attitude dynamics. The resulting control torques required to accomplish the missions are investigated, as they pose the primary requirements to a real on-board attitude control system.}, language = {en} } @article{LoebSchartnerDachwaldetal.2012, author = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Ohndorf, Andreas and Seboldt, Wolfgang}, title = {Interstellar heliopause probe}, series = {Труды МАИ}, journal = {Труды МАИ}, number = {60}, publisher = {Moskauer Staatliches Luftfahrtinstitut (МАИ)}, address = {Moskau}, pages = {2 -- 2}, year = {2012}, abstract = {There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft traveling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by European Space Agency (ESA). Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope-electric propulsion (REP). As a further alternative, we here investigate a combination of solar-electric propulsion (SEP) and REP. The SEP stage consists of six 22-cms diameter RIT-22 ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW at begin of mission (BOM) is provided by a lightweight solar array.}, language = {en} } @inproceedings{DuongNguyenStaat2012, author = {Duong, Minh Tuan and Nguyen, Nhu Huynh and Staat, Manfred}, title = {Numerical stability enhancement of modeling hyperelastic materials}, series = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)}, booktitle = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)}, editor = {Eberhardsteiner, J.}, year = {2012}, language = {en} } @article{HasanKeilStaatetal.2012, author = {Hasan, Istabrak and Keil, Ludger and Staat, Manfred and Wahl, Gerhard and Bourauel, Christoph}, title = {Determination of the frictional coefficient of the implant-antler interface : experimental approach}, series = {Biomedical Engineering / Biomedizinische Technik}, volume = {57}, journal = {Biomedical Engineering / Biomedizinische Technik}, number = {5}, publisher = {De Gruyter}, address = {Berlin}, issn = {1862-278X}, pages = {359 -- 363}, year = {2012}, abstract = {The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5-0.7 and 0.3-0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens.}, language = {en} } @inproceedings{TranStaat2012, author = {Tran, Thanh Ngoc and Staat, Manfred}, title = {A primal-dual shakedown analysis of 3D structures using the face-based smoothed finite element method}, series = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)}, booktitle = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)}, editor = {Eberhardsteiner, J.}, year = {2012}, language = {en} } @inproceedings{FrotscherRaatschenStaat2012, author = {Frotscher, Ralf and Raatschen, Hans-J{\"u}rgen and Staat, Manfred}, title = {Effectiveness of the edge-based smoothed finite element method applied to soft biological tissues}, series = {ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012}, booktitle = {ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012}, editor = {Holzapfel, Gerhard A.}, publisher = {Verlag d. Technischen Universit{\"a}t Graz}, address = {Graz}, isbn = {978-3-85125-223-1}, year = {2012}, language = {en} } @inproceedings{NixFrotscherStaat2012, author = {Nix, Yvonne and Frotscher, Ralf and Staat, Manfred}, title = {Implementation of the edge-based smoothed extended finite element method}, series = {Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012}, booktitle = {Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012}, editor = {Eberhardsteiner, J.}, year = {2012}, language = {en} } @inproceedings{PhamNguyenStaat2012, author = {Pham, Phu Tinh and Nguyen, Thanh Ngoc and Staat, Manfred}, title = {FEM based shakedown analysis of hardening structures}, series = {Proceedings International Conference on Advances in Computational Mechanics (ACOME)}, booktitle = {Proceedings International Conference on Advances in Computational Mechanics (ACOME)}, pages = {870 -- 882}, year = {2012}, language = {en} } @article{Staat2012, author = {Staat, Manfred}, title = {Limit and shakedown analysis under uncertainty}, series = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, volume = {19}, journal = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, pages = {45 -- 47}, year = {2012}, language = {en} } @book{DigelZhubanovaAkimbekov2012, author = {Digel, Ilya and Zhubanova, Azhar Ahmetovna and Akimbekov, Nuraly S.}, title = {Visual Virology}, address = {Almaty}, isbn = {978-601-247-298-1}, pages = {144 S. : zahlr. Ill.}, year = {2012}, language = {en} } @inproceedings{FrotscherRaatschenStaat2012, author = {Frotscher, Ralf and Raatschen, Hans-J{\"u}rgen and Staat, Manfred}, title = {Application of an edge-based smoothed finite element method on geometrically non-linear plates of non-linear material}, series = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)}, booktitle = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)}, editor = {Eberhardsteiner, J.}, year = {2012}, language = {en} } @article{StaatVu2012, author = {Staat, Manfred and Vu, Duc Khoi}, title = {Limit analysis of flaws in pressurized pipes and cylindrical vessels Part II: Circumferential defects}, series = {Engineering Fracture Mechanics ; 97(2013), H. 1}, volume = {97}, journal = {Engineering Fracture Mechanics ; 97(2013), H. 1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-7944}, doi = {10.1016/j.engfracmech.2012.05.017}, pages = {314 -- 333}, year = {2012}, abstract = {Upper and lower bound theorems of limit analyses have been presented in part I of the paper. Part II starts with the finite element discretization of these theorems and demonstrates how both can be combined in a primal-dual optimization problem. This recently proposed numerical method is used to guide the development of a new class of closed-form limit loads for circumferential defects, which show that only large defects contribute to plastic collapse with a rapid loss of strength with increasing crack sizes. The formulae are compared with primal-dual FEM limit analyses and with burst tests. Even closer predictions are obtained with iterative limit load solutions for the von Mises yield function and for the Tresca yield function. Pressure loading of the faces of interior cracks in thick pipes reduces the collapse load of circumferential defects more than for axial flaws. Axial defects have been treated in part I of the paper.}, language = {en} } @book{Artmann2011, author = {Artmann, Gerhard}, title = {Stem cell engineering : principles and applications / Gerhard M. Artmann ... eds.}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-642-11864-7}, pages = {XLI, 541 S. : Ill., graph. Darst.}, year = {2011}, language = {en} } @article{EijckDemmelArtmannetal.2011, author = {Eijck, Lambert van and Demmel, Franz and Artmann, Gerhard and Stadtler, Andreas Maximilian}, title = {Macromolecular dynamics in red blood cells investigated using neutron spectroscopy}, series = {Journal of the Royal Society Interface}, volume = {8}, journal = {Journal of the Royal Society Interface}, number = {57}, publisher = {The Royal Society}, address = {London}, isbn = {1742-5689}, pages = {590 -- 600}, year = {2011}, language = {en} } @article{BehbahaniTranJockenhoeveletal.2011, author = {Behbahani, Mehdi and Tran, L. and Jockenh{\"o}vel, S. and Behr, M. and Mottaghy, K.}, title = {Numerical prediction of thrombocyte reactions for application to a vascular flow model}, series = {British Journal of Surgery}, volume = {98}, journal = {British Journal of Surgery}, number = {S5}, publisher = {Oxford University Press}, address = {Oxford}, isbn = {1365-2168}, pages = {S17}, year = {2011}, language = {en} } @article{KotliarLanzl2011, author = {Kotliar, Konstantin and Lanzl, Ines M.}, title = {Can vascular function be assessed by the interpretation of retinal vascular diameter changes?}, series = {Investigative Ophthalmology \& Visual Science, IOVS. 52 (2011), H. 1}, journal = {Investigative Ophthalmology \& Visual Science, IOVS. 52 (2011), H. 1}, publisher = {ARVO}, address = {Rockville, Md.}, isbn = {0146-0404}, pages = {635 -- 636}, year = {2011}, language = {en} } @article{LanzlSeidovaMaieretal.2011, author = {Lanzl, Ines M. and Seidova, Seid-Fatima and Maier, Mathias and Schmidt-Trucks{\"a}ss, Arno and Halle, Martin and Kotliar, Konstantin}, title = {Dynamic retinal vessel response to flicker in age-related macular degeneration patients before and after vascular endothelial growth factor inhibitor injection}, series = {Acta Ophthalmologica}, volume = {89}, journal = {Acta Ophthalmologica}, number = {5}, publisher = {Wiley}, address = {Weinheim}, isbn = {1755-3768}, pages = {472 -- 479}, year = {2011}, language = {en} } @article{MikielewiczKotliarBarraqueretal.2011, author = {Mikielewicz, Marek and Kotliar, Konstantin and Barraquer, Rafael I. and Michael, Ralph}, title = {Air-pulse corneal applanation signal curve parameters for the characterisation of keratoconus}, series = {British Journal of Ophthalmology (eBJO)}, volume = {95}, journal = {British Journal of Ophthalmology (eBJO)}, number = {6}, publisher = {BMJ Publ. Group}, address = {London}, issn = {1468-2079}, pages = {793 -- 798}, year = {2011}, language = {en} } @article{KotliarBaumannVilseretal.2011, author = {Kotliar, Konstantin and Baumann, Marcus and Vilser, Walthard and Lanzl, Ines M.}, title = {Pulse wave velocity in retinal arteries of healthy volunteers}, series = {British Journal of Ophthalmology (eBJO)}, volume = {95}, journal = {British Journal of Ophthalmology (eBJO)}, number = {11}, publisher = {BMJ Publ. Group}, address = {London}, isbn = {1468-2079}, pages = {675 -- 679}, year = {2011}, language = {en} } @article{KotliarLanzlSchmidtTrucksaessetal.2011, author = {Kotliar, Konstantin and Lanzl, Ines M. and Schmidt-Trucks{\"a}ss, A. and Sitnikova, Diana and Ali, Mohammad and Blume, Katharina and Halle, Martin and Hansser, Henner}, title = {Dynamic retinal vessel response to flicker in obesity: A methodological approach}, series = {Microvascular Research}, volume = {81}, journal = {Microvascular Research}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0026-2862}, pages = {123 -- 128}, year = {2011}, language = {en} } @article{DashevskyLanzlKotliar2011, author = {Dashevsky, Alexey V. and Lanzl, Ines M. and Kotliar, Konstantin}, title = {Non-penetrating intracanalicular partial trabeculectomy via the ostia of Schlemm's canal}, series = {Graefe's Archive for Clinical and Experimental Ophthalmology}, volume = {249}, journal = {Graefe's Archive for Clinical and Experimental Ophthalmology}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {0721-832x}, pages = {565 -- 573}, year = {2011}, language = {en} } @article{HanssenNickelDrexeletal.2011, author = {Hanssen, H. and Nickel, T. and Drexel, V. and Hertel, G. and Emslander, I. and Sisic, Z. and Lorang, D. and Schuster, T. and Kotliar, Konstantin and Pressler, A. and Schmidt-Trucks{\"a}ss, A. and Weis, M. and Halle, M.}, title = {Exercise-induced alterations of retinal vessel diameters and cardiovascular risk reduction in obesity}, series = {Atherosclerosis}, volume = {216}, journal = {Atherosclerosis}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0021-9150}, pages = {433 -- 439}, year = {2011}, language = {en} } @article{DoorschodtSchreinemachersBehbahanietal.2011, author = {Doorschodt, B. M. and Schreinemachers, M. C. J. M. and Behbahani, Mehdi and Florquin, S. and Weis, J. and Staat, Manfred and Tolba, R. H.}, title = {Hypothermic machine perfusion of kidney grafts: which pressure is preferred}, series = {Annals of Biomedical Engineering. 39 (2011), H. 3}, journal = {Annals of Biomedical Engineering. 39 (2011), H. 3}, publisher = {Springer}, address = {Berlin}, isbn = {1573-9686}, pages = {1051 -- 1059}, year = {2011}, language = {en} } @inproceedings{OhndorfDachwaldSeboldtetal.2011, author = {Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and Schartner, Karl-Heinz}, title = {Flight times to the heliopause using a combination of solar and radioisotope electric propulsion}, series = {32nd International Electric Propulsion Conference}, booktitle = {32nd International Electric Propulsion Conference}, pages = {1 -- 12}, year = {2011}, abstract = {We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks' parameter set. Based on a parameter space study, in which the number of thrust units, the unit's specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the escape direction is restricted to the heliosphere's "nose".}, language = {en} } @article{ScholzRomagnoliDachwaldetal.2011, author = {Scholz, Christina and Romagnoli, Daniele and Dachwald, Bernd and Theil, Stephan}, title = {Performance analysis of an attitude control system for solar sails using sliding masses}, series = {Advances in Space Research}, volume = {48}, journal = {Advances in Space Research}, number = {11}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, pages = {1822 -- 1835}, year = {2011}, language = {en} } @inproceedings{LoebSchartnerDachwaldetal.2011, author = {Loeb, Horst W. and Schartner, Karl-Heinz and Dachwald, Bernd and Ohndorf, Andreas and Seboldt, Wolfgang}, title = {An Interstellar - Heliopause mission using a combination of solar/radioisotope electric propulsion}, series = {Presented at the 32nd International Electric Propulsion Conference}, booktitle = {Presented at the 32nd International Electric Propulsion Conference}, pages = {1 -- 7}, year = {2011}, abstract = {There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft travelling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by ESA.Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope electric propulsion. As a further alternative, we here investigate a combination of solar-electric propulsion and radioisotope-electric propulsion. The solar-electric propulsion stage consists of six 22 cm diameter "RIT-22"ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW BOM is provided by a light-weight solar array. The REP-stage consists of four space-proven 10 cm diameter "RIT-10" ion thrusters that will be operating one after the other for 9 yrs in total. Four advanced radioisotope generators provide 648 W at BOM. The scientific instrument package is oriented at earlier studies. For its mass and electric power requirement 35 kg and 35 W are assessed, respectively. Optimized trajectory calculations, treated in a separate contribution, are based on our "InTrance" method.The program yields a burn out of the REP stage in a distance of 79.6 AU for a usage of 154 kg of Xe propellant. With a C3 = 45,1 (km/s)2 a heliocentric probe velocity of 10 AU/yr is reached at this distance, provided a close Jupiter gravity assist adds a velocity increment of 2.7 AU/yr. A transfer time of 23.8 yrs results for this scenario requiring about 450 kg Xe for the SEP stage, jettisoned at 3 AU. We interpret the SEP/REP propulsion as a competing alternative to solar sail and ballistic/REP propulsion. Omiting a Jupiter fly-by even allows more launch flexibility, leaving the mission duration in the range of the ESA specification.}, language = {en} } @article{KaramanidisAlbrachtBraunsteinetal.2011, author = {Karamanidis, Kiros and Albracht, Kirsten and Braunstein, Bjoern and Catala, Maria Moreno and Goldmann, Jan-Peter and Br{\"u}ggemann, Gert-Peter}, title = {Lower leg musculoskeletal geometry and sprint performance}, series = {Gait and Posture}, volume = {34}, journal = {Gait and Posture}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2011.03.009}, pages = {138 -- 141}, year = {2011}, abstract = {The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components.}, language = {en} } @phdthesis{Behbahani2011, author = {Behbahani, Mehdi}, title = {Modeling and Simulation of Shear-Dependent Platelet Reactions in Blood Vessels and Blood-Contacting Medical Devices}, publisher = {Verlag Dr. Hut}, address = {M{\"u}nchen}, isbn = {978-3-8439-0134-5}, year = {2011}, language = {en} } @inproceedings{DachwaldXuFeldmannetal.2011, author = {Dachwald, Bernd and Xu, Changsheng and Feldmann, Marco and Plescher, Engelbert}, title = {IceMole : Development of a novel subsurface ice probe and testing of the first prototype on the Morteratsch Glacier}, series = {EGU General Assembly 2011 Vienna | Austria | 03 - 08 April 2011}, booktitle = {EGU General Assembly 2011 Vienna | Austria | 03 - 08 April 2011}, year = {2011}, abstract = {We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named "IceMole", is currently developed, built, and tested at the FH Aachen University of Applied Sciences' Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).}, language = {en} } @article{Digel2011, author = {Digel, Ilya}, title = {Primary thermosensory events in cells}, series = {Transient receptor potential channels / Md. Shahidul Islam, ed.}, journal = {Transient receptor potential channels / Md. Shahidul Islam, ed.}, publisher = {Springer}, address = {Dordrecht [u.a.]}, isbn = {978-94-007-0264-6}, pages = {451 -- 468}, year = {2011}, language = {en} } @article{KurulganDemirciDemirciTrzewiketal.2011, author = {Kurulgan Demirci, Eylem and Demirci, T. and Trzewik, J{\"u}rgen and Linder, Peter and Karakulah, G. and Artmann, Gerhard and Sakizli, M. and Temiz Artmann, Ayseg{\"u}l}, title = {Genome-Wide Gene Expression Analysis of NIH 3T3 Cell Line Under Mechanical Stimulation}, series = {Cellular and molecular bioengineering. 4 (2011), H. 1}, journal = {Cellular and molecular bioengineering. 4 (2011), H. 1}, publisher = {Springer}, address = {Berlin}, isbn = {1865-5025}, pages = {46 -- 55}, year = {2011}, language = {en} } @article{DachwaldWurm2011, author = {Dachwald, Bernd and Wurm, Patrick}, title = {Mission analysis and performance comparison for an Advanced Solar Photon Thruster}, series = {Advances in Space Research}, volume = {48}, journal = {Advances in Space Research}, number = {11}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, pages = {1858 -- 1868}, year = {2011}, language = {en} } @article{DigelTemizArtmann2011, author = {Digel, Ilya and Temiz Artmann, Ayseg{\"u}l}, title = {The emperor's new body : seeking for a blueprint of limb regeneration in humans}, series = {Stem cell engineering : principles and applications / Gerhard M. Artmann ... eds.}, journal = {Stem cell engineering : principles and applications / Gerhard M. Artmann ... eds.}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-642-11864-7}, pages = {3 -- 37}, year = {2011}, language = {en} } @article{BehbahaniProbstMaietal.2010, author = {Behbahani, Mehdi and Probst, M. and Mai, A. and Tran, L. and Vonderstein, K. and Keschenau, P. and Linde, T. and Steinseifer, U. and Behr, M. and Mottaghy, K.}, title = {The influence of high shear on thrombosis and hemolysis in artificial organs}, series = {Artificial Organs}, volume = {33}, journal = {Artificial Organs}, number = {7}, isbn = {0391-3988}, pages = {426 -- 426}, year = {2010}, language = {en} } @article{JansenBehbahaniLaumenetal.2010, author = {Jansen, Sebastian and Behbahani, Mehdi and Laumen, Marco and Kaufmann, Tim and Hormes, Marcus and Schmitz-Rode, Thomas and Behr, Marek and Steinseifer, Ulrich}, title = {3D Stereo-PIV Validation for CFD-Simulation of Steady Flow through the Human Aorta using Rapid-Prototyping techniques}, year = {2010}, language = {en} } @article{BehbahaniNamWalugaetal.2010, author = {Behbahani, Mehdi and Nam, J. and Waluga, C. and Behr, M. and Pasquali, M. and Mottaghy, K.}, title = {Modeling and Numerical Analysis of Platelet Activation, Adhesion and Aggregation in Artificial Organs}, doi = {10.1097/01.mat.0000369377.65122.a3}, year = {2010}, language = {en} } @article{JansenBehbahaniLaumenetal.2010, author = {Jansen, S. V. and Behbahani, Mehdi and Laumen, M. and Kaufmann, T. and Hormes, M. and Behr, M. and Schmitz-Rode, T. and Steinseifer, U.}, title = {Investigation of Steady Flow Through a Realistic Model of the Thoracic Human Aorta Using 3D Stereo PIV and CFD-Simulation}, year = {2010}, language = {en} } @article{NamAroraBehbahanietal.2010, author = {Nam, J. and Arora, D. and Behbahani, Mehdi and Probst, M. and Benkowski, R. and Behr, M. and Pasquali, M.}, title = {New computational method in hemolysis analysis for artificial heart pump}, year = {2010}, language = {en} } @article{BehbahaniProbstMaietal.2010, author = {Behbahani, Mehdi and Probst, M. and Mai, A. and Behr, M. and Tran, L. and Vonderstein, K. and Mottaghy, K.}, title = {Numerical Prediction of Blood Damage in Biomedical Devices}, year = {2010}, language = {en} } @article{ProbstBehbahaniBorrmannetal.2010, author = {Probst, M. and Behbahani, Mehdi and Borrmann, E. and Elgeti, S. and Nicolai, M. and Behr, M.}, title = {Hemodynamic Modeling for Numerical Analysis and Design of Medical Devices}, year = {2010}, language = {en} } @article{BehbahaniMaiBergmannetal.2010, author = {Behbahani, Mehdi and Mai, A. and Bergmann, B. and Waluga, C. and Behr, M. and Tran, L. and Vonderstein, K. and Mottaghy, K.}, title = {Modeling and Numerical Simulation of Blood Damage}, year = {2010}, language = {en} } @article{BehbahaniMaiWalugaetal.2010, author = {Behbahani, Mehdi and Mai, A. and Waluga, C. and Bergmann, B. and Tran, L. and Vonderstein, K. and Behr, M. and Mottaghy, K.}, title = {Numerical Modeling of Flow-Related Thrombus Formation under Physiological and Non-Physiological Flow Conditions}, series = {Acta Physiologica}, volume = {198}, journal = {Acta Physiologica}, number = {Supplement 677}, isbn = {1748-1716}, pages = {185}, year = {2010}, language = {en} } @article{KotliarNagelVilseretal.2010, author = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Seidova, Seid-Fatima and Lanzl, Ines}, title = {Microstructural alterations of retinal arterial blood column along the vessel axis in systemic hypertension}, series = {Investigative Ophthalmology \& Visual Science, IOVS}, volume = {51}, journal = {Investigative Ophthalmology \& Visual Science, IOVS}, number = {4}, publisher = {ARVO}, address = {Rockville, Md.}, issn = {0146-0404}, doi = {10.1167/iovs.09-3649}, pages = {2165 -- 2172}, year = {2010}, abstract = {Purpose: Image analysis by the retinal vessel analyzer (RVA) observes retinal vessels in their dynamic state online noninvasively along a chosen vessel segment. It has been found that high-frequency diameter changes in the retinal artery blood column along the vessel increase significantly in anamnestically healthy volunteers with increasing age and in patients with glaucoma during vascular dilation. This study was undertaken to investigate whether longitudinal sections of the retinal artery blood column are altered in systemic hypertension. Methods: Retinal arteries of 15 untreated patients with essential arterial hypertension (age, 50.9 ± 11.9 years) and of 15 age-matched anamnestically healthy volunteers were examined by RVA. After baseline assessment, a monochromatic luminance flicker (530-600 nm; 12.5 Hz; 20 s) was applied to evoke retinal vasodilation. Differences in amplitude and frequency of spatial artery blood column diameter change along segments (longitudinal arterial profiles) of 1 mm in length were measured and analyzed using Fourier transformation. Results: In the control group, average reduced power spectra (ARPS) of longitudinal arterial profiles did not differ when arteries changed from constriction to dilation. In the systemic hypertension group, ARPS during constriction, baseline, and restoration were identical and differed from ARPS during dilation (P < 0.05). Longitudinal arterial profiles in both groups showed significant dissimilitude at baseline and restoration (P < 0.05). Conclusions: The retinal artery blood column demonstrates microstructural alterations in systemic hypertension and is less irregular along the vessel axis during vessel dilation. These microstructural changes may be an indication of alterations in vessel wall rigidity, vascular endothelial function, and smooth muscle cells in this disease, leading to impaired perfusion and regulation.}, language = {en} } @article{PresslerEsefeldScherretal.2010, author = {Pressler, Axel and Esefeld, Katrin and Scherr, Johannes and Ali, Mohammad and Hanssen, Henner and Kotliar, Konstantin and Lanzl, Ines and Halle, Martin and Kaemmerer, Harald and Schmidt-Trucks{\"a}ss, Arno and Hager, Alfred}, title = {Structural alterations of retinal arterioles in adults late after repair of aortic isthmic coarctation}, series = {The American Journal of Cardiology}, volume = {105}, journal = {The American Journal of Cardiology}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0002-9149}, doi = {10.1016/j.amjcard.2009.10.070}, pages = {740 -- 744}, year = {2010}, abstract = {Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5\%, first to third quartile 2.1\% to 4.5\% vs 3.6\%, first to third quartile 2.2\% to 4.3\%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients.}, language = {en} } @article{GarhoferBekBoehmetal.2010, author = {Garhofer, Gerhard and Bek, Toke and Boehm, Andreas G. and Gherghel, Doina and Grundwald, Juan and Jeppesen, Peter and Kergoat, H{\´e}l{\`e}ne and Kotliar, Konstantin and Lanzl, Ines and Lovasik, John V. and Nagel, Edgar and Vilser, Walthard and Orgul, Selim and Schmetterer, Leopold}, title = {Use of the retinal vessel analyzer in ocular blood flow research}, series = {Acta Ophthalmol}, volume = {88}, journal = {Acta Ophthalmol}, number = {7}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1755-3768}, doi = {10.1111/j.1755-3768.2009.01587.x}, pages = {717 -- 722}, year = {2010}, abstract = {The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed.}, language = {en} } @article{KozhalakovaZhubanovaMansurovetal.2010, author = {Kozhalakova, A. A. and Zhubanova, Azhar A. and Mansurov, Z. A. and Digel, Ilya and Tazhibayeva, S. M. and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Adsorption of bacterial lipopolysaccharides on carbonized rice shell}, series = {Science of Central Asia (2010)}, journal = {Science of Central Asia (2010)}, pages = {50 -- 54}, year = {2010}, language = {en} } @article{KurzLinderTrzewiketal.2010, author = {Kurz, R. and Linder, Peter and Trzewik, J{\"u}rgen and R{\"u}ffer, M. and Artmann, Gerhard and Digel, Ilya and Rothermel, A. and Robitzki, A. and Temiz Artmann, Ayseg{\"u}l}, title = {Contractile tension and beating rates of self-exciting monolayers and 3D-tissue constructs of neonatal rat cardiomyocytes}, series = {Medical and Biological Engineering and Computing}, volume = {48}, journal = {Medical and Biological Engineering and Computing}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {1741-0444}, doi = {10.1007/s11517-009-0552-y}, pages = {59 -- 65}, year = {2010}, abstract = {The CellDrum technology (The term 'CellDrum technology' includes a couple of slightly different technological setups for measuring lateral mechanical tension in various types of cell monolayers or 3D-tissue constructs) was designed to quantify the contraction rate and mechanical tension of self-exciting cardiac myocytes. Cells were grown either within flexible, circular collagen gels or as monolayer on top of respective 1-mum thin silicone membranes. Membrane and cells were bulged outwards by air pressure. This biaxial strain distribution is rather similar the beating, blood-filled heart. The setup allowed presetting the mechanical residual stress level externally by adjusting the centre deflection, thus, mimicking hypertension in vitro. Tension was measured as oscillating differential pressure change between chamber and environment. A 0.5-mm thick collagen-cardiac myocyte tissue construct induced after 2 days of culturing (initial cell density 2 x 10(4) cells/ml), a mechanical tension of 1.62 +/- 0.17 microN/mm(2). Mechanical load is an important growth regulator in the developing heart, and the orientation and alignment of cardiomyocytes is stress sensitive. Therefore, it was necessary to develop the CellDrum technology with its biaxial stress-strain distribution and defined mechanical boundary conditions. Cells were exposed to strain in two directions, radially and circumferentially, which is similar to biaxial loading in real heart tissues. Thus, from a biomechanical point of view, the system is preferable to previous setups based on uniaxial stretching.}, language = {en} } @article{PhamVuTranetal.2010, author = {Pham, Phu Tinh and Vu, Khoi Duc and Tran, Thanh Ngoc and Staat, Manfred}, title = {A primal-dual algorithm for shakedown analysis of elastic-plastic bounded linearly kinematic hardening bodies}, pages = {1 -- 7}, year = {2010}, language = {en} } @article{NguyenRaatschenStaat2010, author = {Nguyen, N.-H. and Raatschen, Hans-J{\"u}rgen and Staat, Manfred}, title = {A hyperelastic model of biological tissue materials in tubular organs}, pages = {1 -- 12}, year = {2010}, language = {en} } @inproceedings{BorggraefeDachwald2010, author = {Borggr{\"a}fe, Andreas and Dachwald, Bernd}, title = {Mission performance evaluation for solar sails using a refined SRP force model with variable optical coefficients}, series = {2nd International Symposium on Solar Sailing}, booktitle = {2nd International Symposium on Solar Sailing}, pages = {1 -- 6}, year = {2010}, abstract = {Solar sails provide ignificant advantages over other low-thrust propulsion systems because they produce thrust by the momentum exchange from solar radiation pressure (SRP) and thus do not consume any propellant.The force exerted on a very thin sail foil basically depends on the light incidence angle. Several analytical SRP force models that describe the SRP force acting on the sail have been established since the 1970s. All the widely used models use constant optical force coefficients of the reflecting sail material. In 2006,MENGALI et al. proposed a refined SRP force model that takes into account the dependancy of the force coefficients on the light incident angle,the sail's distance from the sun (and thus the sail emperature) and the surface roughness of the sail material [1]. In this paper, the refined SRP force model is compared to the previous ones in order to identify the potential impact of the new model on the predicted capabilities of solar sails in performing low-cost interplanetary space missions. All force models have been implemented within InTrance, a global low-thrust trajectory optimization software utilizing evolutionary neurocontrol [2]. Two interplanetary rendezvous missions, to Mercury and the near-Earth asteroid 1996FG3, are investigated. Two solar sail performances in terms of characteristic acceleration are examined for both scenarios, 0.2 mm/s2 and 0.5 mm/s2, termed "low" and "medium" sail performance. In case of the refined SRP model, three different values of surface roughness are chosen, h = 0 nm, 10 nm and 25 nm. The results show that the refined SRP force model yields shorter transfer times than the standard model.}, language = {en} }