@article{OlaruKowalskiSethietal.2012, author = {Olaru, Alexandra Maria and Kowalski, Julia and Sethi, Vaishali and Bl{\"u}mich, Bernhard}, title = {Exchange relaxometry of flow at small P{\´e}clet numbers in a glass bead pack}, series = {Journal of Magnetic Resonance (JMR)}, volume = {220}, journal = {Journal of Magnetic Resonance (JMR)}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1096-0856}, doi = {10.1016/j.jmr.2012.04.015}, pages = {32 -- 44}, year = {2012}, abstract = {In this paper we consider low P{\´e}clet 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.}, language = {en} } @article{FischerKowalskiPudasaini2012, author = {Fischer, Jan-Thomas and Kowalski, Julia and Pudasaini, Shiva P.}, title = {Topographic curvature effects in applied avalanche modelling}, series = {Cold Regions Science and Technology}, volume = {74-75}, journal = {Cold Regions Science and Technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7441}, doi = {10.1016/j.coldregions.2012.01.005}, pages = {21 -- 30}, year = {2012}, abstract = {This paper describes the implementation of topographic curvature effects within the RApid Mass MovementS (RAMMS) snow avalanche simulation toolbox. RAMMS is based on a model similar to shallow water equations with a Coulomb friction relation and the velocity dependent Voellmy drag. It is used for snow avalanche risk assessment in Switzerland. The snow avalanche simulation relies on back calculation of observed avalanches. The calibration of the friction parameters depends on characteristics of the avalanche track. The topographic curvature terms are not yet included in the above mentioned classical model. Here, we fundamentally improve this model by mathematically and physically including the topographic curvature effects. By decomposing the velocity dependent friction into a topography dependent term that accounts for a curvature enhancement in the Coulomb friction, and a topography independent contribution similar to the classical Voellmy drag, we construct a general curvature dependent frictional resistance, and thus propose new extended model equations. With three site-specific examples, we compare the apparent frictional resistance of the new approach, which includes topographic curvature effects, to the classical one. Our simulation results demonstrate substantial effects of the curvature on the flow dynamics e.g., the dynamic pressure distribution along the slope. The comparison of resistance coefficients between the two models demonstrates that the physically based extension presents an improvement to the classical approach. Furthermore a practical example highlights its influence on the pressure outline in the run out zone of the avalanche. Snow avalanche dynamics modeling natural terrain curvature centrifugal force friction coefficients.}, language = {en} } @article{BuehlerChristenKowalskietal.2011, author = {B{\"u}hler, Yves and Christen, Marc and Kowalski, Julia and Bartelt, Perry}, title = {Sensitivity of snow avalanche simulations to digital elevation model quality and resolution}, series = {Annals of Glaciology}, volume = {52}, journal = {Annals of Glaciology}, number = {58}, publisher = {Cambridge University Press}, address = {Cambridge}, isbn = {1727-5644}, pages = {72 -- 80}, year = {2011}, abstract = {Digital elevation models (DEMs), represent the three-dimensional terrain and are the basic input for numerical snow avalanche dynamics simulations. DEMs can be acquired using topographic maps or remote-sensing technologies, such as photogrammetry or lidar. Depending on the acquisition technique, different spatial resolutions and qualities are achieved. However, there is a lack of studies that investigate the sensitivity of snow avalanche simulation algorithms to the quality and resolution of DEMs. Here, we perform calculations using the numerical avalance dynamics model RAMMS, varying the quality and spatial resolution of the underlying DEMs, while holding the simulation parameters constant. We study both channelized and open-terrain avalanche tracks with variable roughness. To quantify the variance of these simulations, we use well-documented large-scale avalanche events from Davos, Switzerland (winter 2007/08), and from our large-scale avalanche test site, Valĺee de la Sionne (winter 2005/06). We find that the DEM resolution and quality is critical for modeled flow paths, run-out distances, deposits, velocities and impact pressures. Although a spatial resolution of ~25 m is sufficient for large-scale avalanche modeling, the DEM datasets must be checked carefully for anomalies and artifacts before using them for dynamics calculations.}, language = {en} } @article{DachwaldSchmidtSeboldtetal.2003, author = {Dachwald, Bernd and Schmidt, Tanja D. and Seboldt, Wolfgang and Auweter-Kurtz,}, title = {Flight Opportunities from Mars to Earth for Piloted Missions Using Continuous Thrust Propulsion / Schmidt, Tanja D. ; Dachwald, Bernd ; Seboldt, Wolfgang ; Auweter-Kurtz, Monika}, publisher = {-}, pages = {1 -- 9}, year = {2003}, language = {en} } @article{Kowalski2008, author = {Kowalski, Julia}, title = {Mathematische Murgangmodellierung}, series = {Newsletter Naturgefahren}, volume = {2008}, journal = {Newsletter Naturgefahren}, number = {2}, organization = {Eidgen{\"o}ssisches Institut f{\"u}r Schnee-und Lawinenforschung SLF}, pages = {4 -- 5}, year = {2008}, language = {de} } @article{SaffeLodewiksHaasetal.1989, author = {Saffe, P. and Lodewiks, J. and Haas, H.-J. and Feigel, H.-J. and Ulrich, H. and Mauer, J. and Ortwig, H. and Dahmann, Peter and Rotth{\"a}user, S. and Tao, J. and Ohlischl{\"a}ger, O. and Scholz, D. and Bergmann, M. and Anders, P.}, title = {Neues von ASB Antreiben - Steuern - Bewegen}, series = {{\"O}lhydraulik und Pneumatik. Vol. 33 (1989), H. 7}, journal = {{\"O}lhydraulik und Pneumatik. Vol. 33 (1989), H. 7}, issn = {0341-2660}, pages = {550 -- 572}, year = {1989}, language = {de} } @article{HennPolaczek2007, author = {Henn, Gudrun and Polaczek, Christa}, title = {Studienerfolg in den Ingenieurwissenschaften}, series = {Das Hochschulwesen : HSW ; Forum f{\"u}r Hochschulforschung, -praxis und -politik}, volume = {55}, journal = {Das Hochschulwesen : HSW ; Forum f{\"u}r Hochschulforschung, -praxis und -politik}, number = {5}, issn = {0018-2974}, pages = {144 -- 147}, year = {2007}, language = {de} } @article{PolaczekHenn2008, author = {Polaczek, Christa and Henn, Gudrun}, title = {Gute Vorkenntnisse verk{\"u}rzen die Studienzeit}, series = {Mathematikinformation : eine Zeitschrift von Begabtenf{\"o}rderung Mathematik e.V.}, volume = {2008}, journal = {Mathematikinformation : eine Zeitschrift von Begabtenf{\"o}rderung Mathematik e.V.}, number = {49}, publisher = {Begabtenf{\"o}rderung Mathematik}, address = {Neubiberg}, issn = {1612-9156}, pages = {46 -- 50}, year = {2008}, language = {de} } @article{GenzKingWahle1992, author = {Genz, M. and King, H. and Wahle, Michael}, title = {Mikrozellige Polyurethan-Elastomere als Federelement in Automobilanwendungen}, series = {Automobiltechnische Zeitschrift ; ATZ}, volume = {94}, journal = {Automobiltechnische Zeitschrift ; ATZ}, number = {10}, issn = {0001-2785}, pages = {512 -- 520}, year = {1992}, language = {de} } @article{KraemerDaabMuelleretal.2013, author = {Kr{\"a}mer, Stefan and Daab, Dominique Jonas and M{\"u}ller, Brigitte and Wagner, Tobias and Baader, Fabian and Hessel, Joana and Gdalewitsch, Georg and Plescher, Engelbert and Dachwald, Bernd and Wahle, Michael and Gierse, Andreas and Vetter, Rudolf and Pf{\"u}tzenreuter, Lysan}, title = {Development and flight-testing of a system to isolate vibrations for microgravity experiments on sounding rockets}, series = {21st ESA Symposium on Rocket and Balloon Research}, journal = {21st ESA Symposium on Rocket and Balloon Research}, pages = {1 -- 8}, year = {2013}, language = {en} }