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 - 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 - 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 - 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 - Vogt, C. A1 - Mottaghy, Darius A1 - Rath, V. A1 - Marquart, G. A1 - Dijkshoorn, L. A1 - Wolf, A. A1 - Clauser, C. T1 - Vertical variation in heat flow on the Kola Peninsula: palaeoclimate or fluid flow? JF - Geophysical Journal International N2 - Following earlier studies, we present forward and inverse simulations of heat and fluid transport of the upper crust using a local 3-D model of the Kola area. We provide best estimates for palaeotemperatures and permeabilities, their errors and their dependencies. Our results allow discriminating between the two mentioned processes to a certain extent, partly resolving the non-uniqueness of the problem. We find clear indications for a significant contribution of advective heat transport, which, in turn, imply only slightly lower ground surface temperatures during the last glacial maximum relative to the present value. These findings are consistent with the general background knowledge of (i) the fracture zones and the corresponding fluid movements in the bedrock and (ii) the glacial history of the Kola area. Y1 - 2014 U6 - https://doi.org/10.1093/gji/ggu282 SN - 1365-246X VL - 199 IS - 2 SP - 829 EP - 843 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Chen, Tao A1 - Clauser, Christoph A1 - Marquart, Gabriele A1 - Willbrand, Karen A1 - Mottaghy, Darius T1 - A new upscaling method for fractured porous media JF - Advances in Water Resources Y1 - 2015 U6 - https://doi.org/10.1016/j.advwatres.2015.03.009 SN - 0309-1708 N1 - Corrigendum 2019: https://doi.org/10.1016/j.advwatres.2019.01.004 VL - 80 SP - 60 EP - 68 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kürten, Sylvia A1 - Mottaghy, Darius A1 - Ziegler, Martin T1 - A new model for the description of the heat transfer for plane thermo-active geotechnical systems based on thermal resistances JF - Acta Geotechnica Y1 - 2015 U6 - https://doi.org/10.1007/s11440-014-0311-6 SN - 1861-1133 VL - 10 IS - 2 SP - 219 EP - 229 PB - Springer CY - Berlin ER - TY - JOUR A1 - Kürten, Sylvia A1 - Mottaghy, Darius A1 - Ziegler, Martin T1 - Design of plane energy geostructures based on laboratory tests and numerical modelling JF - Energy and Buildings Y1 - 2015 U6 - https://doi.org/10.1016/j.enbuild.2015.08.039 SN - 0378-7788 VL - 107 SP - 434 EP - 444 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Tewari, Udit A1 - Neshvad, Surena A1 - Goldbach, Daniel A1 - Sachau, Jürgen T1 - Verification and Implementation of Pseudo-Random-Binary-Sequences for Online Determination of Grid Impedance Spectrum T2 - International Conference on Renewable Energies and Power Quality (ICREPQ´15), La Conuna, Spain, 25th to 27th March, 2015 Y1 - 2015 ER - TY - CHAP A1 - Srivastava, Alok A1 - Knolle, Friedhart A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, Ewald T1 - Uranium Toxicity in the State of Punjab in North-Western India T2 - Management of Natural Resources in a Changing Environment N2 - Lately there has been an increasing concern about uranium toxicity in some districts of Punjab State located in the North Western part of India after the publication of a report (Blaurock-Busch et al. 2010) which showed that the concentration of uranium in hair and urine of children suffering from physical deformities, neurological and mental disorder from Malwa region (Fig. 1) of Punjab State was manifold higher than the reference ranges. A train which connects the affected region with the nearby city of Bikaner which has a Cancer Hospital has been nicknamed as Cancer Express due to the frenzy generated on account of uranium related toxicity. Y1 - 2015 SN - 978-3-319-12559-6 U6 - https://doi.org/10.1007/978-3-319-12559-6_21 SP - 271 EP - 275 PB - Springer CY - Cham ER - TY - CHAP A1 - Sirazitdinova, Y. A1 - Dulzon, A. A1 - Müller, Burghard T1 - Project management practices in engineering university T2 - 21st International Conference for Students and Young Scientists: Modern Technique and Technologies, MTT 2015; National Research Tomsk Polytechnic UniversityTomsk; Russian Federation; 5 October 2015 through 9 October 2015 Y1 - 2015 U6 - https://doi.org/10.1088/1757-899X/93/1/012080 N1 - IOP Conference Series: Materials Science and Engineering Vol. 93, Issue 1 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 -