TY - JOUR A1 - Mottaghy, Darius A1 - Schwamborn, G. A1 - Rath, V. T1 - Past climate changes and permafrost depth at the Lake El'gygytgyn site: implications from data and thermal modeling JF - Climate of the Past Y1 - 2013 U6 - http://dx.doi.org/10.5194/cp-9-119-2013 SN - 1814-9332 VL - 9 IS - 1 SP - 119 EP - 133 PB - Copernicus CY - Katlenburg-Lindau ER - TY - JOUR A1 - Kürten, Sylvia A1 - Mottaghy, Darius A1 - Ziegler, Martin T1 - Wärmeübergangswiderstand bei flächigen thermo-aktiven Bauteilen am Beispiel thermo-aktiver Abdichtungselemente JF - Bautechnik Y1 - 2013 U6 - http://dx.doi.org/10.1002/bate.201300035 SN - 1437-0999 VL - 90 IS - 7 SP - 387 EP - 394 PB - Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Mottaghy, Darius A1 - Pechnig, Renate A1 - Vogt, Christian T1 - The geothermal project Den Haag: 3D numerical models for temperature prediction and reservoir simulation JF - Geothermics N2 - The proposed Den Haag Zuidwest district heating system of the city of The Hague consists of a deep doublet in a Jurassic sandstone layer that is designed for a production temperature of 75 °C and a reinjection temperature of 40 °C at a flow rate of 150 m3 h−1. The prediction of reservoir temperature and production behavior is crucial for success of the proposed geothermal doublet. This work presents the results of a study of the important geothermal and geohydrological issues for the doublet design. In the first phase of the study, the influences of the three-dimensional (3D) structures of anticlines and synclines on the temperature field were examined. A comprehensive petrophysical investigation was performed to build a large scale 3D-model of the reservoir. Several bottomhole temperatures (BHTs), as well as petrophysical logs were used to calibrate the model using thermal conductivity measurements on 50 samples from boreholes in different lithological units in the study area. Profiles and cross sections extracted from the calculated temperature field were used to study the temperature in the surrounding areas of the planned doublet. In the second phase of the project, a detailed 3D numerical reservoir model was set up, with the aim of predicting the evolution of the producer and injector temperatures, and the extent of the cooled area around the injector. The temperature model from the first phase provided the boundary conditions for the reservoir model. Hydraulic parameters for the target horizons, such as porosity and permeability, were taken from data available from the nearby exploration wells. The simulation results are encouraging as no significant thermal breakthrough is predicted. For the originally planned location of the producer, the extracted water temperature is predicted to be around 79 °C, with an almost negligible cooling in the first 50 years of production. When the producer is located shallower parts of the reservoir, the yield water temperatures is lower, starting at ≈76 °C and decreasing to ≈74 °C after 50 years of operation. This comparatively larger decrease in temperature with time is caused by the structural feature of the reservoir, namely a higher dip causes the cooler water to easily move downward. In view of the poor reservoir data, the reservoir simulation model is constructed to allow iterative updates using data assimilation during planned drilling, testing, and production phases. Measurements during an 8 h pumping test carried out in late 2010 suggest that a flow rate of 150 m3 h−1 is achievable. Fluid temperatures of 76.5 °C were measured, which is very close to the predicted value. Y1 - 2011 U6 - http://dx.doi.org/10.1016/j.geothermics.2011.07.001 SN - 0375-6505 VL - 40 IS - 3 SP - 199 EP - 210 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Berg, Milena A1 - Angerer, Anita A1 - Martinelli, Walter A1 - Hammer, Stephan A1 - Mottaghy, Darius T1 - Erkundung des geothermischen Potenzials eines ehemaligen Untertagebergbaus JF - BBR - Fachmagazin für Brunnen- und Leitungsbau Y1 - 2013 VL - 64 IS - 6 SP - 46 EP - 52 ER - TY - JOUR A1 - Mottaghy, Darius A1 - Pechnig, Renate A1 - Taugs, Renate A1 - Kröger, Jens A1 - Thomsen, Claudia A1 - Hesse, Fabian A1 - Liebsch-Doerschner, Thomas T1 - Erstellung eines geothermischen Modells für Teile Hamburgs und anliegende Gebiete JF - BBR - Fachmagazin für Brunnen- und Leitungsbau Y1 - 2010 SN - 1611-1478 VL - 61 IS - 12 SP - 52 EP - 59 PB - WVGW Wirtschafts- u. Verl.Ges. Gas und Wasser CY - Bonn ER - TY - JOUR A1 - Mottaghy, Darius A1 - Pechnig, Renate T1 - Numerische 3D Modelle zur Temperaturvorhersage und Reservoirsimulationen JF - BBR - Fachmagazin für Brunnen- und Leitungsbau Y1 - 2009 VL - 60 IS - 10 SP - 44 EP - 51 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 - http://dx.doi.org/10.1007/s00531-007-0238-3 SN - 1437-3262 VL - 97 IS - 2 SP - 435 EP - 442 ER - TY - JOUR A1 - Baier, C. A1 - Mottaghy, Darius A1 - Ziegler, M. A1 - Rath, V. T1 - Numerische Simulation des Gefrierprozesses bei der Baugrundvereisung im durchströmten Untergrund JF - Bauingenieur Y1 - 2008 SN - 0005-6650 VL - 83 IS - 2 SP - 49 EP - 60 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 - http://dx.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 - http://dx.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 - http://dx.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 - http://dx.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 - Walter, G. A1 - Borchert, Jörg T1 - Der Einsatz von Realoptionen in der Elektrizitätswirtschaft JF - M & A Review Y1 - 2002 SN - 1616-0878 IS - 4 SP - 198 ER - TY - JOUR A1 - Jungbluth, Christian A1 - Borchert, Jörg T1 - Möglichkeiten der Strompreisbeeinflussung im oligopolistischen Markt JF - ZNER Zeitschrift für Neues Energierecht Y1 - 2008 IS - 4 SP - 314 EP - 323 ER - TY - JOUR A1 - Borchert, Jörg A1 - Schemm, R. T1 - Einsatz der Portfoliotheorie im Asset Allokations-Prozess am Beispiel eines fiktiven Anlageraumes von Windkraftstandorten JF - Zeitschrift für Energiewirtschaft Y1 - 2007 SN - 0343-5377 VL - 31 IS - 4 SP - 311 ER - TY - JOUR A1 - Borchert, Jörg A1 - Hasenbeck, Marc T1 - Bewertung und Steuerung von Kraftwerksscheiben JF - Zeitschrift für Energiewirtschaft Y1 - 2009 U6 - http://dx.doi.org/10.1007/s12398-009-0014-0 SN - 1866-2765 VL - 33 IS - 2 SP - 115 EP - 126 PB - Vieweg CY - Wiesbaden ER - TY - JOUR A1 - Borchert, Jörg A1 - Hasenbeck, Marc A1 - Jungbluth, Christian A1 - Schemm, Ralf T1 - Bewertung und Steuerung von Gasspeichern bzw. Gasspeicherscheiben JF - Zeitschrift für Energiewirtschaft N2 - In diesem Artikel werden zunächst einleitend der Gasmarkt Deutschland und der sich daraus ergebende Speicherbedarf skizziert. Folgend wird auf verschiedene Speichernutzen aus betriebswirtschaftlicher Perspektive eingegangen und die in diesem Artikel vorgestellten Bewertungsverfahren einleitend beschrieben. In diesem Artikel werden stochastische Optimierungsmethoden aufgegriffen, die sowohl eine Bewertung der Speicher gegenüber einem Spotpreis, als auch gegenüber einer gesamten Forwardcurve ermöglichen. Hierzu werden zunächst Modelle zur Beschreibung der Marktpreise vorgestellt und anhand empirischer Daten kalibriert. Dann wird eine beispielhafte Speicherscheibe zunächst auf Basis der LeastSquareMonteCarloTechnik gegenüber dem stochastischen mehrfaktoriellen Spotpreismodell bewertet. Hieran schließt sich die Vorstellung der Bewertung sowie des Hedgings gegenüber der Forwardcurve an. Abschließend erfolgt eine vergleichende Gegenüberstellung beider Verfahren. Y1 - 2009 U6 - http://dx.doi.org/10.1007/s12398-009-0033-x SN - 1866-2765 VL - 33 IS - 4 SP - 279 EP - 293 PB - Springer CY - Berlin 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 - http://dx.doi.org/10.1002/pssa.201431893 SN - 1862-6319 VL - Vol. 212 IS - 6 SP - 1234 EP - 1241 PB - Wiley CY - Weinheim 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 - http://dx.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 -