@article{VogtMottaghyWolfetal.2010, author = {Vogt, C. and Mottaghy, Darius and Wolf, A. and Rath, V. and Pechnig, R. and Clauser, C.}, title = {Reducing temperature uncertainties by stochastic geothermal reservoir modelling}, series = {Geophysical Journal International}, volume = {181}, journal = {Geophysical Journal International}, number = {1}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1365-246X}, doi = {10.1111/j.1365-246X.2009.04498.x}, pages = {321 -- 333}, year = {2010}, abstract = {Quantifying and minimizing uncertainty is vital for simulating technically and economically successful geothermal reservoirs. To this end, we apply a stochastic modelling sequence, a Monte Carlo study, based on (i) creating an ensemble of possible realizations of a reservoir model, (ii) forward simulation of fluid flow and heat transport, and (iii) constraining post-processing using observed state variables. To generate the ensemble, we use the stochastic algorithm of Sequential Gaussian Simulation and test its potential fitting rock properties, such as thermal conductivity and permeability, of a synthetic reference model and—performing a corresponding forward simulation—state variables such as temperature. The ensemble yields probability distributions of rock properties and state variables at any location inside the reservoir. In addition, we perform a constraining post-processing in order to minimize the uncertainty of the obtained distributions by conditioning the ensemble to observed state variables, in this case temperature. This constraining post-processing works particularly well on systems dominated by fluid flow. The stochastic modelling sequence is applied to a large, steady-state 3-D heat flow model of a reservoir in The Hague, Netherlands. The spatial thermal conductivity distribution is simulated stochastically based on available logging data. Errors of bottom-hole temperatures provide thresholds for the constraining technique performed afterwards. This reduce the temperature uncertainty for the proposed target location significantly from 25 to 12 K (full distribution width) in a depth of 2300 m. Assuming a Gaussian shape of the temperature distribution, the standard deviation is 1.8 K. To allow a more comprehensive approach to quantify uncertainty, we also implement the stochastic simulation of boundary conditions and demonstrate this for the basal specific heat flow in the reservoir of The Hague. As expected, this results in a larger distribution width and hence, a larger, but more realistic uncertainty estimate. However, applying the constraining post-processing the uncertainty is again reduced to the level of the post-processing without stochastic boundary simulation. Thus, constraining post-processing is a suitable tool for reducing uncertainty estimates by observed state variables.}, language = {en} } @article{KernSchelthoffMathieu2010, author = {Kern, Alexander and Schelthoff, Christof and Mathieu, Moritz}, title = {Probability of lightning strikes to air-terminations of structures using the electro-geometrical model theory and the statistics of lightning current parameters}, pages = {750-1 -- 750-8}, year = {2010}, language = {en} } @article{FleischhakerEversDey2010, author = {Fleischhaker, Robert and Evers, J{\"o}rg and Dey, Tarak N.}, title = {Phase modulation induced by cooperative effects in electromagnetically induced transparency}, series = {Physical Review A - Atomic, molecular, and optical physics}, volume = {82}, journal = {Physical Review A - Atomic, molecular, and optical physics}, number = {1}, publisher = {AIP Publishing}, address = {Melville, NY}, issn = {1050-2947}, doi = {10.1103/PhysRevA.82.013815}, pages = {013815}, year = {2010}, abstract = {We analyze the influence of dipole-dipole interactions in an electromagnetically induced transparency set up for a density at the onset of cooperative effects. To this end, we include mean-field models for the influence of local-field corrections and radiation trapping into our calculation. We show both analytically and numerically that the polarization contribution to the local field strongly modulates the phase of a weak pulse. We give an intuitive explanation for this local-field-induced phase modulation and demonstrate that it distinctively differs from the nonlinear self-phase-modulation that a strong pulse experiences in a Kerr medium.}, language = {en} } @article{KernKloetersPferdemenges2010, author = {Kern, Alexander and Kl{\"o}ters, Georg and Pferdemenges, J{\"o}rg}, title = {Optimised protection against lightning for the signalling and safety systems of level crossings on non-electrified railway lines}, series = {RTR : European Rail Technology Review}, volume = {50}, journal = {RTR : European Rail Technology Review}, number = {2}, isbn = {0079-9548}, year = {2010}, language = {en} } @article{PieperKlein2010, author = {Pieper, Martin and Klein, Peter}, title = {Numerical solution of the heat equation with non-linear, time derivative-dependent source term}, series = {International Journal for Numerical Methods in Engineering}, volume = {84}, journal = {International Journal for Numerical Methods in Engineering}, number = {10}, publisher = {Wiley}, address = {Chichester}, issn = {0029-5981}, doi = {10.1002/nme.2937}, pages = {1205 -- 1221}, year = {2010}, abstract = {The mathematical modeling of heat conduction with adsorption effects in coated metal structures yields the heat equation with piecewise smooth coefficients and a new kind of source term. This term is special, because it is non-linear and furthermore depends on a time derivative. In our approach we reformulated this as a new problem for the usual heat equation, without source term but with a new non-linear coefficient. We gave an existence and uniqueness proof for the weak solution of the reformulated problem. To obtain a numerical solution, we developed a semi-implicit and a fully implicit finite volume method. We compared these two methods theoretically as well as numerically. Finally, as practical application, we simulated the heat conduction in coated aluminum fibers with adsorption in the zeolite coating. Copyright © 2010 John Wiley \& Sons, Ltd.}, language = {en} } @article{ButenwegGellertSchlundt2010, author = {Butenweg, Christoph and Gellert, Christoph and Schlundt, Andreas}, title = {Nichtlinearer Erdbebennachweis von Geb{\"a}uden aus Kalksandsteinmauerwerk nach DIN EN 1998}, series = {Mauerwerk : European journal of masonry}, volume = {14}, journal = {Mauerwerk : European journal of masonry}, number = {3}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1432-3427}, doi = {10.1002/dama.201000463}, pages = {120 -- 125}, year = {2010}, abstract = {Die Erdbebensicherheit von Geb{\"a}uden aus Kalksandsteinmauerwerk ist aktuell nach DIN 4149 mit linearen Verfahren nachzuweisen. Dies f{\"u}hrt in der praktischen Anwendung zu großen Problemen, da selbst traditionell {\"u}bliche Grundrisse teilweise nicht mehr ohne zus{\"a}tzliche Maßnahmen nachweisbar sind. Zur L{\"o}sung dieser Problematik wurden von der deutschen Mauerwerksindustrie auf nationaler und europ{\"a}ischer Ebene Forschungsprojekte initiiert, deren Ergebnisse in Form von statisch nichtlinearen Verfahren Eingang in den Nationalen Anhang zur DIN EN 1998-1 [12] gefunden haben. Mit den Verfahren wird die Nachweissituation zuk{\"u}nftig grundlegend verbessert, da mit diesen die Tragwerksreserven wesentlich besser ausgenutzt werden k{\"o}nnen. Im Folgenden wird die Anwendung der Verfahren am Beispiel einer Reihenhauszeile aus Kalksandsteinmauerwerk demonstriert. Der Nachweis der Reihenh{\"a}user wurde im Rahmen einer Zustimmung im Einzelfall, die vom Bundesverband Kalksandsteinindustrie eV in Hannover koordiniert wurde, durch unabh{\"a}ngige Gutachter und die Bauaufsicht eingehend gepr{\"u}ft und f{\"u}r richtig befunden. Die Durchf{\"u}hrung des Nachweises erfolgte auf Grundlage eines an der RWTH Aachen entwickelten neuen Nachweiskonzeptes. Die baupraktische Anwendbarkeit und einfache Nachvollziehbarkeit dieses Konzepts ist durch eine softwaretechnische Umsetzung sichergestellt.}, language = {de} } @incollection{MeskourisGellertButenweg2010, author = {Meskouris, Konstantin and Gellert, Christoph and Butenweg, Christoph}, title = {Neuer Ansatz f{\"u}r die Bemessung von Mauerwerksbauten}, series = {Innovationen im konstruktiven Ingenieurbau : Methoden - Materialien - Bauwerke ; Festschrift Professor Hirschfeld / hrsg. von Karl Beucke}, booktitle = {Innovationen im konstruktiven Ingenieurbau : Methoden - Materialien - Bauwerke ; Festschrift Professor Hirschfeld / hrsg. von Karl Beucke}, publisher = {Bauhaus-Univ. Weimar}, address = {Weimar}, pages = {217 -- 224}, year = {2010}, language = {de} } @inproceedings{FeldhusenBrezingPuetzetal.2010, author = {Feldhusen, J{\"o}rg and Brezing, Alexander Nikolaus and P{\"u}tz, Claus and W{\"a}hlisch, Georg}, title = {Multi-system CAD-teaching in large classes}, series = {When design education and design research meet : proceedings of the 12th International Conference on Engineering and Product Design Education, Norwegian University of Science and Technology (NTNU) Trondheim, Norway, 2nd - 3rd September 2010 ; [E\&PDE]}, booktitle = {When design education and design research meet : proceedings of the 12th International Conference on Engineering and Product Design Education, Norwegian University of Science and Technology (NTNU) Trondheim, Norway, 2nd - 3rd September 2010 ; [E\&PDE]}, publisher = {Design Society}, address = {Glasgow}, organization = {International Conference on Engineering and Product Design Education <12, 2010, Trondheim>}, isbn = {978-1-904670-19-3}, pages = {204 -- 209}, year = {2010}, language = {en} } @inproceedings{Goldbach2010, author = {Goldbach, Daniel}, title = {Management der funktionalen Sicherheit einer Entwicklung eines sicherheitskritischen Systems im Bereich Nutzfahrzeuge}, series = {Commercial vehicle technology 2010 : proceedings of the 1st Commercial Vehicle Technology Symposium (CVT 2010), March 16 - 18, 2010, Kaiserslautern / K. Berns ... (ed.)}, booktitle = {Commercial vehicle technology 2010 : proceedings of the 1st Commercial Vehicle Technology Symposium (CVT 2010), March 16 - 18, 2010, Kaiserslautern / K. Berns ... (ed.)}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8322-9040-5}, pages = {487 -- 495}, year = {2010}, language = {de} } @article{BouquegneauKernRousseau2010, author = {Bouquegneau, Christian and Kern, Alexander and Rousseau, Alain}, title = {Lightning safety guidelines}, pages = {1 -- 6}, year = {2010}, language = {en} }