TY - CHAP A1 - Dachwald, Bernd A1 - Xu, Changsheng A1 - Feldmann, Marco A1 - Plescher, Engelbert T1 - IceMole : Development of a novel subsurface ice probe and testing of the first prototype on the Morteratsch Glacier T2 - EGU General Assembly 2011 Vienna | Austria | 03 – 08 April 2011 N2 - 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). Y1 - 2011 ER - TY - CHAP A1 - Loeb, Horst W. A1 - Schartner, Karl-Heinz A1 - Dachwald, Bernd A1 - Ohndorf, Andreas A1 - Seboldt, Wolfgang T1 - An Interstellar – Heliopause mission using a combination of solar/radioisotope electric propulsion T2 - Presented at the 32nd International Electric Propulsion Conference N2 - 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. Y1 - 2011 N1 - 32nd International Electric Propulsion Conference, 11-15 September. Wiesbaden, Germany SP - 1 EP - 7 ER - TY - CHAP A1 - Ohndorf, Andreas A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Schartner, Karl-Heinz T1 - Flight times to the heliopause using a combination of solar and radioisotope electric propulsion T2 - 32nd International Electric Propulsion Conference N2 - 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". KW - low-thrust trajectory optimization KW - heliosphere KW - ion propulsion Y1 - 2011 N1 - IEPC-2011-051 32nd International Electric Propulsion Conference,September 11–15, 2011 Wiesbaden, Germany SP - 1 EP - 12 ER - TY - RPRT A1 - Artmann, Gerhard T1 - Plant mutant scanner : Hochdurchsatzscanner zur Charakterisierung von Pflanzenmutanten. Abschlussbericht ; FHprofUnd ; PhytoScan ; Laufzeit des Vorhabens: 01.07.2008 - 30.06.2011 Y1 - 2011 U6 - http://dx.doi.org/10.2314/GBV:747569150 N1 - Förderkennzeichen BMBF 1736X08 PB - Technische Informationsbibliothek u. Universitätsbibliothek CY - Aachen ER - TY - RPRT A1 - Artmann, Gerhard T1 - FhprofUnd EasyBioforce Abschlussbericht : Miniaturisierte, integrierte und automatisierte Screening Plattform eines 36-Well-Hochdurchsatz-Testsystems zur funktionellen Kraftmessung an Zell- und Gewebeschichten für die Arzneimittelforschung : Laufzeit des Vorhabens: 01.03.2007 - 31.12.2010 Y1 - 2011 U6 - http://dx.doi.org/10.2314/GBV:782964621 N1 - Förderkennzeichen BMBF 1760X07 PB - Technische Informationsbibliothek u. Universitätsbibliothek CY - Aachen ER - TY - RPRT A1 - Artmann, Gerhard T1 - HPBioforce: Integrierte und automatisierte Screening Plattform eines 96-Well-Hochdurchsatz-Testsystems zur funktionellen Kraftmessung an einige um dicken Zell- und Gewebeschichten für die Arzneimittelforschung : gemeinsamer Abschlussbericht der FH Aachen, Hitec Zang GmbH, IKFE Mainz, IKFE Berlin und der Dr. Gerhard Schmidt GmbH zum InnoNet-Projekt ... ; Programm "Förderung von innovativen Netzwerken" (InnoNet) des Bundesministerium für Wirtschaft und Technologie (BMWi) ; Laufzeit: 01.05.2007 bis 31.12.2010 Y1 - 2011 U6 - http://dx.doi.org/10.2314/GBV:68757076X N1 - Förderkennzeichen BMWi 16IN0536. - Verbund-Nr. 01056220 PB - Technische Informationsbibliothek u. Universitätsbibliothek CY - Aachen [u.a.] ER - TY - JOUR A1 - Nguyen-Xuan, H. A1 - Rabczuk, T. A1 - Nguyen-Thoi, T. A1 - Tran, Thanh Ngoc A1 - Nguyen-Thanh, N. T1 - Computation of limit and shakedown loads using a node-based smoothed finite element method JF - International Journal for Numerical Methods in Engineering N2 - This paper presents a novel numerical procedure for computing limit and shakedown loads of structures using a node-based smoothed FEM in combination with a primal–dual algorithm. An associated primal–dual form based on the von Mises yield criterion is adopted. The primal-dual algorithm together with a Newton-like iteration are then used to solve this associated primal–dual form to determine simultaneously both approximate upper and quasi-lower bounds of the plastic collapse limit and the shakedown limit. The present formulation uses only linear approximations and its implementation into finite element programs is quite simple. Several numerical examples are given to show the reliability, accuracy, and generality of the present formulation compared with other available methods. Y1 - 2011 U6 - http://dx.doi.org/10.1002/nme.3317 SN - 1097-0207 VL - 90 IS - 3 SP - 287 EP - 310 PB - Wiley CY - Weinheim ER - TY - THES A1 - Behbahani, Mehdi T1 - Modeling and Simulation of Shear-Dependent Platelet Reactions in Blood Vessels and Blood-Contacting Medical Devices Y1 - 2011 SN - 978-3-8439-0134-5 PB - Verlag Dr. Hut CY - München ER - TY - THES A1 - Pham, Phu Tinh T1 - Upper bound limit and shakedown analysis of elastic-plastic bounded linearly kinematic hardening structures Y1 - 2011 N1 - Aachen, Techn. Hochsch., Diss., 2011 PB - RWTH Aachen University CY - Aachen ER - TY - JOUR A1 - Karamanidis, Kiros A1 - Albracht, Kirsten A1 - Braunstein, Bjoern A1 - Catala, Maria Moreno A1 - Goldmann, Jan-Peter A1 - Brüggemann, Gert-Peter T1 - Lower leg musculoskeletal geometry and sprint performance JF - Gait and Posture N2 - 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. Y1 - 2011 U6 - http://dx.doi.org/10.1016/j.gaitpost.2011.03.009 SN - 0966-6362 VL - 34 IS - 1 SP - 138 EP - 141 PB - Elsevier CY - Amsterdam ER -