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 - 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 - Vogt, Christian A1 - Iwanowski-Strahser, Katha A1 - Marquart, Gabriele A1 - Arnold, Juliane A1 - Mottaghy, Darius A1 - Pechnig, Renate A1 - Gnjezda, Daniel A1 - Clauser, Christoph T1 - Modeling contribution to risk assessment of thermal production power for geothermal reservoirs JF - Renewable Energy Y1 - 2013 U6 - https://doi.org/10.1016/j.renene.2012.11.026 SN - 0960-1481 VL - 53 SP - 230 EP - 241 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Voigt, Birgit A1 - Albrecht, Dirk A1 - Sievers, Susanne A1 - Becher, Dörte A1 - Bongaerts, Johannes A1 - Evers, Stefan A1 - Schweder, Thomas A1 - Maurer, Karl-Heinz A1 - Hecker, Michael T1 - High-resolution proteome maps of Bacillus licheniformis cells growing in minimal medium JF - Proteomics Y1 - 2015 U6 - https://doi.org/10.1002/pmic.201400504 SN - 1615-9861 VL - 15 IS - 15 SP - 2629 EP - 2633 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Voigt, Birgit A1 - Schroeter, Rebecca A1 - Jürgen, Britta A1 - Albrecht, Dirk A1 - Evers, Stefan A1 - Bongaerts, Johannes A1 - Maurer, Karl-Heinz A1 - Schweder, Thomas A1 - Hecker, Michael T1 - The response of Bacillus licheniformis to heat and ethanol stress and the role of the SigB regulon JF - Proteomics Y1 - 2013 SN - 1615-9861 (E-Journal); 1615-9853 (Print) VL - Vol. 13 IS - Iss. 14 SP - 2140 EP - 2146 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - von Häfen, Hajo A1 - Krautwald, Clemens A1 - Stolle, Jacob A1 - Bung, Daniel Bernhard A1 - Goseberg, Nils T1 - Overland flow of broken solitary waves over a two-dimensional coastal plane JF - Coastal Engineering N2 - Landslides, rock falls or related subaerial and subaqueous mass slides can generate devastating impulse waves in adjacent waterbodies. Such waves can occur in lakes and fjords, or due to glacier calving in bays or at steep ocean coastlines. Infrastructure and residential houses along coastlines of those waterbodies are often situated on low elevation terrain, and are potentially at risk from inundation. Impulse waves, running up a uniform slope and generating an overland flow over an initially dry adjacent horizontal plane, represent a frequently found scenario, which needs to be better understood for disaster planning and mitigation. This study presents a novel set of large-scale flume test focusing on solitary waves propagating over a 1:14.5 slope and breaking onto a horizontal section. Examining the characteristics of overland flow, this study gives, for the first time, insight into the fundamental process of overland flow of a broken solitary wave: its shape and celerity, as well as its momentum when wave breaking has taken place beforehand. KW - Landslide tsunamis KW - Hazard assessment KW - Large scale tests KW - Overland flow KW - Solitary waves Y1 - 2022 U6 - https://doi.org/10.1016/j.coastaleng.2022.104125 SN - 1872-7379 VL - 175 IS - August PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - von Knobelsdorf-Brenkenhoff, Florian A1 - Frauenrath, Tobias A1 - Prothmann, Marcel A1 - Dieringer, Matthias A. A1 - Hezel, Fabian A1 - Renz, Wolfgang A1 - Kretschel, Kerstin A1 - Niendorf, Thoralf A1 - Schulz-Menger, Jeanette T1 - Cardiac chamber quantification using magnetic resonance imaging at 7 Tesla—a pilot study N2 - Objectives Interest in cardiovascular magnetic resonance (CMR) at 7 T is motivated by the expected increase in spatial and temporal resolution, but the method is technically challenging. We examined the feasibility of cardiac chamber quantification at 7 T. Methods A stack of short axes covering the left ventricle was obtained in nine healthy male volunteers. At 1.5 T, steady-state free precession (SSFP) and fast gradient echo (FGRE) cine imaging with 7 mm slice thickness (STH) were used. At 7 T, FGRE with 7 mm and 4 mm STH were applied. End-diastolic volume, end-systolic volume, ejection fraction and mass were calculated. Results All 7 T examinations provided excellent blood/myocardium contrast for all slice directions. No significant difference was found regarding ejection fraction and cardiac volumes between SSFP at 1.5 T and FGRE at 7 T, while volumes obtained from FGRE at 1.5 T were underestimated. Cardiac mass derived from FGRE at 1.5 and 7 T was larger than obtained from SSFP at 1.5 T. Agreement of volumes and mass between SSFP at 1.5 T and FGRE improved for FGRE at 7 T when combined with an STH reduction to 4 mm. Conclusions This pilot study demonstrates that cardiac chamber quantification at 7 T using FGRE is feasible and agrees closely with SSFP at 1.5 T. Y1 - 2010 U6 - https://doi.org/10.1007/s00330-010-1888-2 SN - 0938-7994 VL - 20 SP - 2844 EP - 2852 PB - Springer CY - Berlin, Heidelberg ER - TY - JOUR A1 - Vorst, Phillip A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - AllemaniACs3D team description Y1 - 2006 SP - 1 EP - 6 ER - TY - JOUR A1 - Vos, E. K. A1 - Lagemaat, M. W. A1 - Barentsz, J. O. A1 - Fütterer, J. J. A1 - Zamecnik, P. A1 - Roozen, H. A1 - Orzada, S. A1 - Bitz, Andreas A1 - Maas, M. C. A1 - Scheenen, T. W. J. T1 - Image quality and cancer visibility of T2-weighted Magnetic Resonance Imaging of the prostate at 7 Tesla JF - European Radiology N2 - Objectives To assess the image quality of T2-weighted (T2w) magnetic resonance imaging of the prostate and the visibility of prostate cancer at 7 Tesla (T). Materials & methods Seventeen prostate cancer patients underwent T2w imaging at 7T with only an external transmit/receive array coil. Three radiologists independently scored images for image quality, visibility of anatomical structures, and presence of artefacts. Krippendorff’s alpha and weighted kappa statistics were used to assess inter-observer agreement. Visibility of prostate cancer lesions was assessed by directly linking the T2w images to the confirmed location of prostate cancer on histopathology. Results T2w imaging at 7T was achievable with ‘satisfactory’ (3/5) to ‘good’ (4/5) quality. Visibility of anatomical structures was predominantly scored as ‘satisfactory’ (3/5) and ‘good’ (4/5). If artefacts were present, they were mostly motion artefacts and, to a lesser extent, aliasing artefacts and noise. Krippendorff’s analysis revealed an α = 0.44 between three readers for the overall image quality scores. Clinically significant cancer lesions in both peripheral zone and transition zone were visible at 7T. Conclusion T2w imaging with satisfactory to good quality can be routinely acquired, and cancer lesions were visible in patients with prostate cancer at 7T using only an external transmit/receive body array coil. Y1 - 2014 U6 - https://doi.org/10.1007/s00330-014-3234-6 SN - 1432-1084 VL - 24 IS - 8 SP - 1950 EP - 1958 PB - Springer CY - Cham ER - TY - JOUR A1 - Vu, Duc Khoi A1 - Staat, Manfred T1 - Shakedown analysis of structures made of materials with temperature-dependent yield stress JF - International Journal of Solids and Structures. 44 (2007), H. 13 Y1 - 2007 SN - 0020-7683 SP - 4524 EP - 4540 ER -