TY - JOUR A1 - Mottaghy, Darius A1 - Vosteen, Hans-Dieter A1 - Schellschmidt, Rüdiger T1 - Temperature dependence of the relationship of thermal diffusivity versus thermal conductivity for crystalline rocks JF - International Journal of Earth Sciences Y1 - 2008 U6 - https://doi.org/10.1007/s00531-007-0238-3 SN - 1437-3262 VL - 97 IS - 2 SP - 435 EP - 442 ER - TY - JOUR A1 - Rath, V. A1 - Mottaghy, Darius T1 - Smooth inversion for ground surface temperature histories: estimating the optimum regularization parameter by generalized cross-validation JF - Geophysical Journal International Y1 - 2007 U6 - https://doi.org/10.1111/j.1365-246X.2007.03587.x SN - 1365-246X VL - 171 IS - 3 SP - 1440 EP - 1448 ER - TY - JOUR A1 - Vogt, C. A1 - Mottaghy, Darius A1 - Wolf, A. A1 - Rath, V. A1 - Pechnig, R. A1 - Clauser, C. T1 - Reducing temperature uncertainties by stochastic geothermal reservoir modelling JF - Geophysical Journal International N2 - 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. Y1 - 2010 U6 - https://doi.org/10.1111/j.1365-246X.2009.04498.x SN - 1365-246X VL - 181 IS - 1 SP - 321 EP - 333 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Mottaghy, Darius A1 - Rath, Volker T1 - Latent heat effects in subsurface heat transport modelling and their impact on palaeotemperature reconstructions JF - Geophysical Journal International Y1 - 2006 U6 - https://doi.org/10.1111/j.1365-246X.2005.02843.x SN - 1365-246X VL - 164 IS - 1 SP - 236 EP - 245 ER - TY - JOUR A1 - Mottaghy, Darius A1 - Schellschmidt, R. A1 - Popov, Y. A. A1 - Clauser, C. A1 - Kukkonen, I. T. A1 - Nover, G. A1 - Milanovsky, S. A1 - Romushkevich, R. A. T1 - New heat flow data from the immediate vicinity of the Kola super-deep borehole: Vertical variation in heat flow density confirmed and attributed to advection JF - Tectonophysics Y1 - 2005 U6 - https://doi.org/10.1016/j.tecto.2005.03.005 SN - 1879-3266 VL - 401 IS - 1-2 SP - 119 EP - 142 ER - TY - JOUR A1 - Jildeh, Zaid B. A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Pieper, Martin T1 - Simulating the electromagnetic‐thermal treatment of thin aluminium layers for adhesion improvement JF - Physica status solidi (a) N2 - A composite layer material used in packaging industry is made from joining layers of different materials using an adhesive. An important processing step in the production of aluminium-containing composites is the surface treatment and consequent coating of adhesive material on the aluminium surface. To increase adhesion strength between aluminium layer and the adhesive material, the foil is heat treated. For efficient heating, induction heating was considered as state-of-the-art treatment process. Due to the complexity of the heating process and the unpredictable nature of the heating source, the control of the process is not yet optimised. In this work, a finite element analysis of the process was established and various process parameters were studied. The process was simplified and modelled in 3D. The numerical model contains an air domain, an aluminium layer and a copper coil fitted with a magnetic field concentrating material. The effect of changing the speed of the aluminium foil (or rolling speed) was studied with the change of the coil current. Statistical analysis was used for generating a general control equation of coil current with changing rolling speed. Y1 - 2015 U6 - https://doi.org/10.1002/pssa.201431893 SN - 1862-6319 VL - Vol. 212 IS - 6 SP - 1234 EP - 1241 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Kern, Alexander A1 - Braun, Christian T1 - Risk management according to IEC 62305-2 edition 2: 2010–12 assessment of structures with a risk of explosion T2 - 2014 International Conference on Lightning Protection (ICLP), Shanghai, China N2 - Risk management for structures with a risk of explosion should be considered very carefully when performing a risk analysis according to IEC 62305-2. In contrast to the 2006 edition of the standard, the 2010 edition describes the topic “Structures with a risk of explosion” in more detail. Moreover, in Germany separate procedures and parameters are defined for the risk analysis of structures with a risk of explosion (Supplement 3 of the German DIN EN 62305-2 standard). This paper describes the contents and the relevant calculations of this Supplement 3, together with a numerical example. Y1 - 2014 SP - 1237 EP - 1242 ER - TY - CHAP A1 - Rousseau, Alain A1 - Kern, Alexander T1 - How to deal with environmental risk in IEC 62305-2 T2 - 2014 International Conference on Lightning Protection (ICLP), Shanghai, China N2 - The 2nd edition of the lightning risk management standard (IEC 62305-2) considers structures, which may endanger environment. In these cases, the loss is not limited to the structure itself, which is valid for usual structures. In the past (Edition 1) this danger was simply taken into account by a special hazard factor, multiplying the existing risk for the structure with a number. Now, in the edition 2, we add to the risk for the structure itself a “second risk” due to the losses outside the structure. The losses outside can be treated independently from what occurs inside. This is a major advantage to analyze the risk for sensitive structures, like chemical plants, nuclear plants, or structures containing explosives, etc. In this paper, the existing procedure given by the European version EN 62305-2 Ed.2 is further developed and applied to a few structures. Y1 - 2014 SP - 521 EP - 527 ER - TY - THES A1 - Reyes Ochoa, Leonel T1 - Engineering aspects of a parabolic trough collector field with direct steam generation and an organic rankine cycle Y1 - 2014 N1 - Aachen, Fachhochsch., Masterarbeit, 2014 PB - Fachhochschule Aachen CY - Aachen ER - TY - CHAP A1 - Lo Piparo, G. B. A1 - Kern, Alexander A1 - Mazzetti, C. T1 - Some masterpoints about risk due to lightning T2 - International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna Y1 - 2012 SN - 978-1-4673-1896-9 (E-Book) ; 978-1-4673-1898-3 (Print) SP - 1 EP - 6 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Kern, Alexander A1 - Schelthoff, Christof A1 - Mathieu, Moritz T1 - Calculation of interception efficiencies for mesh-type air-terminations according to IEC 62305-3 using a dynamic electro-geometrical model T2 - International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna Y1 - 2012 SN - 978-1-4673-1896-9 (E-Book) ; 978-1-4673-1898-3 (Print) SP - 1 EP - 6 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Wetter, Martin A1 - Kern, Alexander T1 - Number of lightning strikes to tall structures - comparison of calculations and measurements using a modern lightning monitoring system T2 - 2014 International Conference on Lightning Protection (ICLP), Shanghai, China Y1 - 2014 SP - 1 EP - 7 ER - TY - CHAP A1 - Pieper, Martin A1 - Schulz, Silvia T1 - Teaching Simulation Methods with COMSOL Multiphysics N2 - This paper describes two courses on simulation methods for graduate students: “Simulation Methods” and “Simulation and Optimization in Virtual Engineering” The courses were planned to teach young engineers how to work with simulation software as well as to understand the necessary mathematical background. As simulation software COMSOL is used. The main philosophy was to combine theory and praxis in a way that motivates the students. In addition “soft skills” should be improved. This was achieved by project work as final examination. As underlying didactical principle the ideas of Bloom’s revised taxonomy were followed. The paper basically focusses on educational aspects, e.g. how to structure the course, plan the exercises, organize the project work and include practical COMSOL examples. KW - COMSOL Multiphysics KW - Optimization module KW - LiveLink for MATLAB KW - Bloom Taxonomy KW - education Y1 - 2014 ER - TY - JOUR A1 - Marx, Ulrich A1 - Schenk, Friedrich A1 - Behrens, Jan A1 - Meyr, Ulrike A1 - Wanek, Paul A1 - Zang, Werner A1 - Schmitt, Robert A1 - Brüstle, Oliver A1 - Zenke, Martin A1 - Klocke, Fritz T1 - Automatic production of induced pluripotent stem cells JF - Procedia CIRP : First CIRP Conference on BioManufacturing Y1 - 2013 SN - 2212-8271 VL - Vol. 5 SP - 2 EP - 6 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Srivastava, A. A1 - Lahiri, S. A1 - Maiti, M. A1 - Knolle, F. A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, E. W. T1 - Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India JF - Journal of Radioanalytical and Nuclear Chemistry Y1 - 2014 U6 - https://doi.org/0.1007/s10967-014-3450-1 SN - 1588-2780 (E-Journal); 0022-4081 (Print); 0134-0719 (Print); 0236-5731 (Print); 1417-2097 (Print) VL - 2014 IS - 302 SP - 1049 EP - 1052 PB - Springer Nature CY - Basel ER - TY - JOUR A1 - Alebouyeh Samami, Behzad A1 - Pieper, Martin A1 - Breitbach, Gerd A1 - Hodapp, Josef T1 - Heat production in the windings of the stators of electric machines under stationary condition JF - Heat and mass transfer N2 - In electric machines due to high currents and resistive losses (joule heating) heat is produced. To avoid damages by overheating the design of effective cooling systems is required. Therefore the knowledge of heat sources and heat transfer processes is necessary. The purpose of this paper is to illustrate a good and effective calculation method for the temperature analysis based on homogenization techniques. These methods have been applied for the stator windings in a slot of an electric machine consisting of copper wires and resin. The key quantity here is an effective thermal conductivity, which characterizes the heterogeneous wire resin-arrangement inside the stator slot. To illustrate the applicability of the method, the analysis of a simplified, homogenized model is compared with the detailed analysis of temperature behavior inside a slot of an electric machine according to the heat generation. We considered here only the stationary situation. The achieved numerical results are accurate and show that the applied homogenization technique works in practice. Finally the results of simulations for the two cases, the original model of the slot and the homogenized model chosen for the slot (unit cell), are compared to experimental results. Y1 - 2014 U6 - https://doi.org/10.1007/s00231-014-1371-8 SN - 0947-7411 (Print) ; 1432-1181 (E-Journal) VL - 50 SP - 1707 EP - 1716 PB - Springer CY - Heidelberg ER - TY - CHAP A1 - Augenstein, Eckardt A1 - Herbergs, S. A1 - Kuperjans, Isabel A1 - Lucas, K. ED - Kjelstrup, Signe T1 - Simulation of industrial energy supply systems with integrated cost optimization T2 - Proceedings of ECOS 2005, the 18th International Conference on Efficiency, Cost, Optimization, Simulation, and Environmental Impact of Energy Systems : Trondheim, Norway, June 20 - 22, 2005. - Vol. 2 Y1 - 2005 SN - 82-519-2041-8 N1 - CD-ROM-Ausg. u.d.T.: Shaping our future energy systems SP - 627 EP - 634 PB - Tapir Academic Press CY - Trondheim ER - TY - CHAP A1 - Augenstein, Eckardt A1 - Kuperjans, Isabel A1 - Lucas, K. ED - Tsatsaronis,, Georgios T1 - EUSEBIA - Decision-Support-System for Technical, Economical and Ecological Design and Evaluation of Industrial Energy Systems T2 - ECOS 2002 : proceedings of the 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, Berlin, Germany July 3 - 5, 2002. - Vol. 1 Y1 - 2002 SN - 3-00-009533-0 SP - 446 EP - 453 PB - Techn. Univ., Inst. for Energy Engineering CY - Berlin ER - TY - CHAP A1 - Kumaran, P. A1 - Gopinathan, M. A1 - Razali, N. M. A1 - Kuperjans, Isabel A1 - Hariffin, B. A1 - Hamdan, H. T1 - Preliminary evaluation of atomization characteristics of improved biodiesel for gas turbine application T2 - IOP Conference Series: Earth and Environmental Science (EES) Y1 - 2013 U6 - https://doi.org/10.1088/1755-1315/16/1/012014 SN - 1755-1315 VL - 16 IS - 1 SP - 012014/1 EP - 012014/4 PB - Institute of Physics Publishing (IOP) CY - London [u.a.] ER - TY - CHAP A1 - Rens, Gavin A1 - Ferrein, Alexander A1 - Poel, Etienne van der T1 - Extending DTGolog to deal with POMD-Ps T2 - Proceedings of the Nineteenth Annual Symposium of the Pattern Recognition Association of South Africa (PRASA 2008) Y1 - 2008 SP - 49 EP - 54 ER -