@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{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{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{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{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{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{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{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{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{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{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{SrivastavaLahiriMaitietal.2014, author = {Srivastava, A. and Lahiri, S. and Maiti, M. and Knolle, F. and Hoyler, Friedrich and Scherer, Ulrich W. and Schnug, E. W.}, title = {Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India}, series = {Journal of Radioanalytical and Nuclear Chemistry}, volume = {2014}, journal = {Journal of Radioanalytical and Nuclear Chemistry}, number = {302}, publisher = {Springer Nature}, address = {Basel}, issn = {1588-2780 (E-Journal); 0022-4081 (Print); 0134-0719 (Print); 0236-5731 (Print); 1417-2097 (Print)}, doi = {0.1007/s10967-014-3450-1}, pages = {1049 -- 1052}, year = {2014}, language = {en} } @article{MarxSchenkBehrensetal.2013, author = {Marx, Ulrich and Schenk, Friedrich and Behrens, Jan and Meyr, Ulrike and Wanek, Paul and Zang, Werner and Schmitt, Robert and Br{\"u}stle, Oliver and Zenke, Martin and Klocke, Fritz}, title = {Automatic production of induced pluripotent stem cells}, series = {Procedia CIRP : First CIRP Conference on BioManufacturing}, volume = {Vol. 5}, journal = {Procedia CIRP : First CIRP Conference on BioManufacturing}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8271}, pages = {2 -- 6}, year = {2013}, language = {en} } @article{EdipSesovButenwegetal.2018, author = {Edip, K. and Sesov, V. and Butenweg, Christoph and Bojadjieva, J.}, title = {Development of coupled numerical model for simulation of multiphase soil}, series = {Computers and Geotechnics}, volume = {96}, journal = {Computers and Geotechnics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0266-352X}, doi = {10.1016/j.compgeo.2017.08.016}, pages = {118 -- 131}, year = {2018}, abstract = {In this paper, a coupled multiphase model considering both non-linearities of water retention curves and solid state modeling is proposed. The solid displacements and the pressures of both water and air phases are unknowns of the proposed model. The finite element method is used to solve the governing differential equations. The proposed method is demonstrated through simulation of seepage test and partially consolidation problem. Then, implementation of the model is done by using hypoplasticity for the solid phase and analyzing the fully saturated triaxial experiments. In integration of the constitutive law error controlling is improved and comparisons done accordingly. In this work, the advantages and limitations of the numerical model are discussed.}, language = {en} } @article{MarinkovicButenweg2022, author = {Marinkovic, Marko and Butenweg, Christoph}, title = {Numerical analysis of the in-plane behaviour of decoupled masonry infilled RC frames}, series = {Engineering Structures}, volume = {272}, journal = {Engineering Structures}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0141-0296}, doi = {10.1016/j.engstruct.2022.114959}, pages = {18 Seiten}, year = {2022}, abstract = {Damage of reinforced concrete (RC) frames with masonry infill walls has been observed after many earthquakes. Brittle behaviour of the masonry infills in combination with the ductile behaviour of the RC frames makes infill walls prone to damage during earthquakes. Interstory deformations lead to an interaction between the infill and the RC frame, which affects the structural response. The result of this interaction is significant damage to the infill wall and sometimes to the surrounding structural system too. In most design codes, infill walls are considered as non-structural elements and neglected in the design process, because taking into account the infills and considering the interaction between frame and infill in software packages can be complicated and impractical. A good way to avoid negative aspects arising from this behavior is to ensure no or low-interaction of the frame and infill wall, for instance by decoupling the infill from the frame. This paper presents the numerical study performed to investigate new connection system called INODIS (Innovative Decoupled Infill System) for decoupling infill walls from surrounding frame with the aim to postpone infill activation to high interstory drifts thus reducing infill/frame interaction and minimizing damage to both infills and frames. The experimental results are first used for calibration and validation of the numerical model, which is then employed for investigating the influence of the material parameters as well as infill's and frame's geometry on the in-plane behaviour of the infilled frames with the INODIS system. For all the investigated situations, simulation results show significant improvements in behaviour for decoupled infilled RC frames in comparison to the traditionally infilled frames.}, language = {en} } @article{BaumgartnerFidlerWethetal.2008, author = {Baumgartner, Werner and Fidler, Florian and Weth, Agnes and Habbecke, Martin and Jakob, Peter and Butenweg, Christoph and B{\"o}hme, Wolfgang}, title = {Investigating the locomotion of the sandfish in desert sand using NMR-Imaging}, series = {PLOS ONE}, volume = {3}, journal = {PLOS ONE}, number = {10}, publisher = {Plos}, address = {San Francisco, California, US}, issn = {1932-6203}, doi = {10.1371/journal.pone.0003309}, pages = {e3309}, year = {2008}, abstract = {The sandfish (Scincus scincus) is a lizard having the remarkable ability to move through desert sand for significant distances. It is well adapted to living in loose sand by virtue of a combination of morphological and behavioural specializations. We investigated the bodyform of the sandfish using 3D-laserscanning and explored its locomotion in loose desert sand using fast nuclear magnetic resonance (NMR) imaging. The sandfish exhibits an in-plane meandering motion with a frequency of about 3 Hz and an amplitude of about half its body length accompanied by swimming-like (or trotting) movements of its limbs. No torsion of the body was observed, a movement required for a digging-behaviour. Simple calculations based on the Janssen model for granular material related to our findings on bodyform and locomotor behaviour render a local decompaction of the sand surrounding the moving sandfish very likely. Thus the sand locally behaves as a viscous fluid and not as a solid material. In this fluidised sand the sandfish is able to "swim" using its limbs.}, language = {en} } @article{AlexopoulosBreitbachHoffschmidtetal.2008, author = {Alexopoulos, Spiros and Breitbach, Gerd and Hoffschmidt, Bernhard and Stobbe, P.}, title = {Optimization of the geometry of porous SiC ceramic filtering modules using numerical methods}, series = {Developments in porous, biological and geopolymer ceramics : a collection of papers presented at the 31st International Conference on Advanced Ceramics and Composites, January 21 - 26, 2007, Daytona Beach, Florida ; [papers presented at the Symposium on Porous Ceramics: Novel Developments and Applications] / ed.: Manuel Brito ... Vol. ed.: Jonathan Salem ... The American Ceramics Society}, journal = {Developments in porous, biological and geopolymer ceramics : a collection of papers presented at the 31st International Conference on Advanced Ceramics and Composites, January 21 - 26, 2007, Daytona Beach, Florida ; [papers presented at the Symposium on Porous Ceramics: Novel Developments and Applications] / ed.: Manuel Brito ... Vol. ed.: Jonathan Salem ... The American Ceramics Society}, publisher = {Wiley}, address = {Hoboken, NJ}, isbn = {9780470196403}, pages = {95 -- 104}, year = {2008}, language = {en} } @article{GiresiniSassuButenwegetal.2017, author = {Giresini, Linda and Sassu, Mauro and Butenweg, Christoph and Alecci, Valerio and De Stefano, Mario}, title = {Vault macro-element with equivalent trusses in global seismic analyses}, series = {Earthquakes and Structures}, volume = {12}, journal = {Earthquakes and Structures}, number = {4}, publisher = {Techno-Press}, address = {Taejŏn}, issn = {2092-7614 (Print)}, doi = {10.12989/eas.2017.12.4.409}, pages = {409 -- 423}, year = {2017}, abstract = {This paper proposes a quick and simplified method to describe masonry vaults in global seismic analyses of buildings. An equivalent macro-element constituted by a set of six trusses, two for each transverse, longitudinal and diagonal direction, is introduced. The equivalent trusses, whose stiffness is calculated by fully modeled vaults of different geometry, mechanical properties and boundary conditions, simulate the vault in both global analysis and local analysis, such as kinematic or rocking approaches. A parametric study was carried out to investigate the influence of geometrical characteristics and mechanical features on the equivalent stiffness values. The method was numerically validated by performing modal and transient analysis on a three naves-church in the elastic range. Vibration modes and displacement time-histories were compared showing satisfying agreement between the complete and the simplified models. This procedure is particularly useful in engineering practice because it allows to assess, in a simplified way, the effectiveness of strengthening interventions for reducing horizontal relative displacements between vault supports.}, language = {en} } @article{ChudobaButenwegPeiffer2004, author = {Chudoba, Rostislav and Butenweg, Christoph and Peiffer, F.}, title = {Technical information system for collaborative material research}, series = {Advances in engineering software}, volume = {Volume 35}, journal = {Advances in engineering software}, number = {Issue 10-11}, issn = {1873-5339 (E-Journal); 0965-9978 (Print)}, doi = {10.1016/j.advengsoft.2004.03.021}, pages = {747 -- 756}, year = {2004}, language = {en} } @article{AlexopoulosHoffschmidt2010, author = {Alexopoulos, Spiros and Hoffschmidt, Bernhard}, title = {Solar tower power plant in Germany and future perspectives of the development of the technology in Greece and Cyprus}, series = {Renewable Energy . 35 (2010), H. 7}, journal = {Renewable Energy . 35 (2010), H. 7}, isbn = {0960-1481}, pages = {1352 -- 1356}, year = {2010}, language = {en} }