@article{FateriGebhardt2015, author = {Fateri, Miranda and Gebhardt, Andreas}, title = {Additive manufactured mechanical disentanglement lock}, series = {RTejournal - Forum f{\"u}r Rapid Technologie}, volume = {12}, journal = {RTejournal - Forum f{\"u}r Rapid Technologie}, publisher = {Fachhochschule Aachen}, address = {Aachen}, issn = {1614-0923}, url = {http://nbn-resolving.de/urn:nbn:de:0009-2-42147}, year = {2015}, language = {en} } @article{CehreliAkpinarTemizArtmannetal.2015, author = {Cehreli, Ruksan and Akpinar, Hale and Temiz Artmann, Ayseg{\"u}l and Sagol, Ozgul}, title = {Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis}, series = {Gastroenterology Research}, volume = {8}, journal = {Gastroenterology Research}, number = {5}, issn = {1918-2813}, doi = {10.14740/gr683w}, pages = {265 -- 273}, year = {2015}, language = {en} } @article{DoeringRegerKuhnhenneetal.2015, author = {D{\"o}ring, Bernd and Reger, Vitali and Kuhnhenne, Markus and Feldmann, Markus and Kesti, Jyrki and Lawson, Mark and Botti, Andrea}, title = {Steel solutions for enabling zero-energy buildings}, series = {Steel Construction - Design and Research}, volume = {8}, journal = {Steel Construction - Design and Research}, number = {3}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1867-0539}, doi = {10.1002/stco.201510029}, pages = {194 -- 200}, year = {2015}, language = {en} } @article{BronderPoghossianSchejaetal.2015, author = {Bronder, Thomas and Poghossian, Arshak and Scheja, Sabrina and Wu, Chunsheng and Keusgen, Michael and Mewes, Dieter and Sch{\"o}ning, Michael Josef}, title = {DNA Immobilization and Hybridization Detection by the Intrinsic Molecular Charge Using Capacitive Field-Effect Sensors Modified with a Charged Weak Polyelectrolyte Layer}, series = {Applied Materials \& Interfaces}, volume = {36}, journal = {Applied Materials \& Interfaces}, number = {7}, publisher = {American Chemical Society}, address = {Washington, DC}, doi = {10.1021/acsami.5b05146}, pages = {20068 -- 20075}, year = {2015}, abstract = {Miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge favor the semiconductor field-effect platform as one of the most attractive approaches for the development of label-free DNA chips. In this work, a capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensor covered with a layer-by-layer prepared, positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was used for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization. The negatively charged probe single-stranded DNA (ssDNA) molecules were electrostatically adsorbed onto the positively charged PAH layer, resulting in a preferentially flat orientation of the ssDNA molecules within the Debye length, thus yielding a reduced charge-screening effect and a higher sensor signal. Each sensor-surface modification step (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), reducing an unspecific adsorption by a blocking agent, incubation with noncomplementary DNA (ncDNA) solution) was monitored by means of capacitance-voltage and constant-capacitance measurements. In addition, the surface morphology of the PAH layer was studied by atomic force microscopy and contact-angle measurements. High hybridization signals of 34 and 43 mV were recorded in low-ionic strength solutions of 10 and 1 mM, respectively. In contrast, a small signal of 4 mV was recorded in the case of unspecific adsorption of fully mismatched ncDNA. The density of probe ssDNA and dsDNA molecules as well as the hybridization efficiency was estimated using the experimentally measured DNA immobilization and hybridization signals and a simplified double-layer capacitor model. The results of field-effect experiments were supported by fluorescence measurements, verifying the DNA-immobilization and hybridization event.}, language = {en} } @article{KuertenMottaghyZiegler2015, author = {K{\"u}rten, Sylvia and Mottaghy, Darius and Ziegler, Martin}, title = {Design of plane energy geostructures based on laboratory tests and numerical modelling}, series = {Energy and Buildings}, volume = {107}, journal = {Energy and Buildings}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0378-7788}, doi = {10.1016/j.enbuild.2015.08.039}, pages = {434 -- 444}, year = {2015}, language = {en} } @article{KuertenMottaghyZiegler2015, author = {K{\"u}rten, Sylvia and Mottaghy, Darius and Ziegler, Martin}, title = {A new model for the description of the heat transfer for plane thermo-active geotechnical systems based on thermal resistances}, series = {Acta Geotechnica}, volume = {10}, journal = {Acta Geotechnica}, number = {2}, publisher = {Springer}, address = {Berlin}, issn = {1861-1133}, doi = {10.1007/s11440-014-0311-6}, pages = {219 -- 229}, year = {2015}, language = {en} } @article{ChenClauserMarquartetal.2015, author = {Chen, Tao and Clauser, Christoph and Marquart, Gabriele and Willbrand, Karen and Mottaghy, Darius}, title = {A new upscaling method for fractured porous media}, series = {Advances in Water Resources}, volume = {80}, journal = {Advances in Water Resources}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0309-1708}, doi = {10.1016/j.advwatres.2015.03.009}, pages = {60 -- 68}, year = {2015}, language = {en} } @article{VogtMottaghyRathetal.2014, author = {Vogt, C. and Mottaghy, Darius and Rath, V. and Marquart, G. and Dijkshoorn, L. and Wolf, A. and Clauser, C.}, title = {Vertical variation in heat flow on the Kola Peninsula: palaeoclimate or fluid flow?}, series = {Geophysical Journal International}, volume = {199}, journal = {Geophysical Journal International}, number = {2}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1365-246X}, doi = {10.1093/gji/ggu282}, pages = {829 -- 843}, year = {2014}, abstract = {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.}, language = {en} } @article{VogtIwanowskiStrahserMarquartetal.2013, author = {Vogt, Christian and Iwanowski-Strahser, Katha and Marquart, Gabriele and Arnold, Juliane and Mottaghy, Darius and Pechnig, Renate and Gnjezda, Daniel and Clauser, Christoph}, title = {Modeling contribution to risk assessment of thermal production power for geothermal reservoirs}, series = {Renewable Energy}, volume = {53}, journal = {Renewable Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {10.1016/j.renene.2012.11.026}, pages = {230 -- 241}, year = {2013}, language = {en} } @article{MottaghySchwambornRath2013, author = {Mottaghy, Darius and Schwamborn, G. and Rath, V.}, title = {Past climate changes and permafrost depth at the Lake El'gygytgyn site: implications from data and thermal modeling}, series = {Climate of the Past}, volume = {9}, journal = {Climate of the Past}, number = {1}, publisher = {Copernicus}, address = {Katlenburg-Lindau}, issn = {1814-9332}, doi = {10.5194/cp-9-119-2013}, pages = {119 -- 133}, year = {2013}, language = {en} } @article{MottaghyDijkshoorn2012, author = {Mottaghy, Darius and Dijkshoorn, Lydia}, title = {Implementing an effective finite difference formulation for borehole heat exchangers into a heat and mass transport code}, series = {Renewable Energy}, volume = {45}, journal = {Renewable Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {10.1016/j.renene.2012.02.013}, pages = {59 -- 71}, year = {2012}, abstract = {We present an effective finite difference formulation for implementing and modeling multiple borehole heat exchangers (BHE) in the general 3-D coupled heat and flow transport code SHEMAT. The BHE with arbitrary length can be either coaxial or double U-shaped. It is particularly suitable for modeling deep BHEs which contain varying pipe diameters and materials. Usually, in numerical simulations, a fine discretization of the BHE assemblage is required, due to the large geometric aspect ratios involved. This yields large models and long simulation times. The approach avoids this problem by considering heat transport between fluid and the soil through pipes and grout via thermal resistances. Therefore, the simulation time can be significantly reduced. The coupling with SHEMAT is realized by introducing an effective heat generation. Due to this connection, it is possible to consider heterogeneous geological models, as well as the influence of groundwater flow. This is particularly interesting when studying the long term behavior of a single BHE or a BHE field. Heating and cooling loads can enter the model with an arbitrary interval, e.g. from hourly to monthly values. When dealing with large BHE fields, computing times can be further significantly reduced by focusing on the temperature field around the BHEs, without explicitly modeling inlet and outlet temperatures. This allows to determine the possible migration of cold and warm plumes due to groundwater flow, which is of particular importance in urban areas with a high BHE installation density. The model is validated against the existing BHE modeling codes EWS and EED. A comparison with monitoring data from a deep BHE in Switzerland shows a good agreement. Synthetic examples demonstrate the field of application of this model.}, language = {en} } @article{MottaghyPechnigVogt2011, author = {Mottaghy, Darius and Pechnig, Renate and Vogt, Christian}, title = {The geothermal project Den Haag: 3D numerical models for temperature prediction and reservoir simulation}, series = {Geothermics}, volume = {40}, journal = {Geothermics}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0375-6505}, doi = {10.1016/j.geothermics.2011.07.001}, pages = {199 -- 210}, year = {2011}, abstract = {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.}, language = {en} } @article{MottaghyVosteenSchellschmidt2008, author = {Mottaghy, Darius and Vosteen, Hans-Dieter and Schellschmidt, R{\"u}diger}, title = {Temperature dependence of the relationship of thermal diffusivity versus thermal conductivity for crystalline rocks}, series = {International Journal of Earth Sciences}, volume = {97}, journal = {International Journal of Earth Sciences}, number = {2}, issn = {1437-3262}, doi = {10.1007/s00531-007-0238-3}, pages = {435 -- 442}, year = {2008}, language = {en} } @article{KrebsbachSchillerBrunneretal.2006, author = {Krebsbach, M. and Schiller, C. and Brunner, D. and G{\"u}nther, G. and Hegglin, M. I. and Mottaghy, Darius and Riese, M. and Spelten, N. and Wernli, H.}, title = {Seasonal cycles and variability of O_3 and H_2O in the UT/LMS during SPURT}, series = {Atmospheric Chemistry and Physics}, volume = {6}, journal = {Atmospheric Chemistry and Physics}, number = {1}, doi = {10.5194/acp-6-109-2006}, pages = {109 -- 125}, year = {2006}, language = {en} } @article{RathMottaghy2007, author = {Rath, V. and Mottaghy, Darius}, title = {Smooth inversion for ground surface temperature histories: estimating the optimum regularization parameter by generalized cross-validation}, series = {Geophysical Journal International}, volume = {171}, journal = {Geophysical Journal International}, number = {3}, issn = {1365-246X}, doi = {10.1111/j.1365-246X.2007.03587.x}, pages = {1440 -- 1448}, year = {2007}, language = {en} } @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{MottaghyRath2006, author = {Mottaghy, Darius and Rath, Volker}, title = {Latent heat effects in subsurface heat transport modelling and their impact on palaeotemperature reconstructions}, series = {Geophysical Journal International}, volume = {164}, journal = {Geophysical Journal International}, number = {1}, issn = {1365-246X}, doi = {10.1111/j.1365-246X.2005.02843.x}, pages = {236 -- 245}, year = {2006}, language = {en} } @article{MottaghySchellschmidtPopovetal.2005, author = {Mottaghy, Darius and Schellschmidt, R. and Popov, Y. A. and Clauser, C. and Kukkonen, I. T. and Nover, G. and Milanovsky, S. and Romushkevich, R. A.}, title = {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}, series = {Tectonophysics}, volume = {401}, journal = {Tectonophysics}, number = {1-2}, issn = {1879-3266}, doi = {10.1016/j.tecto.2005.03.005}, pages = {119 -- 142}, year = {2005}, language = {en} } @article{BronderPoghossianSchejaetal.2015, author = {Bronder, Thomas and Poghossian, Arshak and Scheja, S. and Wu, Chunsheng and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Electrostatic Detection of Unlabelled Single- and Double-stranded DNA Using Capacitive Field-effect Devices Functionalized with a Positively Charged Polyelectrolyte Layer}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.710}, pages = {544 -- 547}, year = {2015}, abstract = {Capacitive field-effect electrolyte-insulator-semiconductor sensors consisting of an Al-p-Si-SiO2 structure have been used for the electrical detection of unlabelled single- and double-stranded DNA (dsDNA) molecules by their intrinsic charge. A simple functionalization protocol based on the layer-by-layer (LbL) technique was used to prepare a weak polyelectrolyte/probe-DNA bilayer, followed by the hybridization with complementary target DNA molecules. Due to the flat orientation of the LbL-adsorbed DNA molecules, a high sensor signal has been achieved. In addition, direct label-free detection of in-solution hybridized dsDNA molecules has been studied.}, language = {en} } @article{MiyamotoBingWagneretal.2015, author = {Miyamoto, Ko-ichiro and Bing, Yu and Wagner, Torsten and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, title = {Visualization of Defects on a Cultured Cell Layer by Utilizing Chemical Imaging Sensor}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.806}, pages = {936 -- 939}, year = {2015}, abstract = {The chemical imaging sensor is a field-effect sensor which is able to visualize both the distribution of ions (in LAPS mode) and the distribution of impedance (in SPIM mode) inthe sample. In this study, a novel wound-healing assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the defect of a cell layer brought into proximity of the sensing surface.A reduced impedance inside the defect, which was artificially formed ina cell layer, was successfully visualized in a photocurrent image.}, language = {en} }