TY - JOUR A1 - Alebouyeh Samami, Behzad A1 - Pieper, Martin A1 - Breitbach, Gerd A1 - Hodapp, Josef T1 - Heat production in the windings of the stators of electric machines under stationary condition JF - Heat and mass transfer N2 - In electric machines due to high currents and resistive losses (joule heating) heat is produced. To avoid damages by overheating the design of effective cooling systems is required. Therefore the knowledge of heat sources and heat transfer processes is necessary. The purpose of this paper is to illustrate a good and effective calculation method for the temperature analysis based on homogenization techniques. These methods have been applied for the stator windings in a slot of an electric machine consisting of copper wires and resin. The key quantity here is an effective thermal conductivity, which characterizes the heterogeneous wire resin-arrangement inside the stator slot. To illustrate the applicability of the method, the analysis of a simplified, homogenized model is compared with the detailed analysis of temperature behavior inside a slot of an electric machine according to the heat generation. We considered here only the stationary situation. The achieved numerical results are accurate and show that the applied homogenization technique works in practice. Finally the results of simulations for the two cases, the original model of the slot and the homogenized model chosen for the slot (unit cell), are compared to experimental results. Y1 - 2014 U6 - http://dx.doi.org/10.1007/s00231-014-1371-8 SN - 0947-7411 (Print) ; 1432-1181 (E-Journal) VL - 50 SP - 1707 EP - 1716 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Alexopoulos, Spiros A1 - Breitbach, Gerd A1 - Hoffschmidt, Bernhard A1 - Stobbe, P. T1 - Computational fluid flow of porous resic ceramic filtering modules and optimization of the channel edge form geometry JF - Proceedings : April 14 - 18, 2008, Leipzig, Germany / hosted by VDI, Society for Chemical and Process Engineering . Vol 2 Y1 - 2008 N1 - Verein Deutscher Ingenieure ; World Filtration Congress ; (10 : ; 2008.04.14-18 : ; Leipzig) ; WFC ; (10 : ; 2008.04.14-18 : ; Leipzig) SP - 300 EP - 304 PB - Filtech Exhibitions CY - Meerbusch ER - TY - JOUR A1 - Alexopoulos, Spiros A1 - Breitbach, Gerd A1 - Hoffschmidt, Bernhard A1 - Stobbe, P. T1 - Optimization of the geometry of porous SiC ceramic filtering modules using numerical methods JF - 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 Y1 - 2008 SN - 9780470196403 N1 - Ceramic engineering and science proceedings ; 28,9 SP - 95 EP - 104 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard T1 - Solar tower power plant in Germany and future perspectives of the development of the technology in Greece and Cyprus JF - Renewable Energy . 35 (2010), H. 7 Y1 - 2010 SN - 0960-1481 SP - 1352 EP - 1356 ER - TY - JOUR A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard T1 - Advances in solar tower technology JF - Wiley interdisciplinary reviews : Energy and Environment : WIREs Y1 - 2017 U6 - http://dx.doi.org/10.1002/wene.217 SN - 2041-840X VL - 6 IS - 1 SP - 1 EP - 19 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Arpshofen, Ingo A1 - Pool, M. J. A1 - Sommer, Ferdinand A1 - Gerling, Ulrich A1 - Predel, Bruno A1 - Schultheiss, Emil T1 - Determination of the integral mixing enthalpies in the Cu-Pd-Si liquid ternary alloy system at 1600 K JF - Zeitschrift für Metallkunde : international journal of materials research and advanced techniques. Bd. 74, H. 1 Y1 - 1983 SN - 0044-3093 ; 0179-4841 SP - 25 EP - 32 ER - TY - JOUR A1 - Balewski, J. A1 - Brauksiepe, S. A1 - Hardt, Arno T1 - Threshold measurements at the internal experimental facility COSY-11 / J. Balewski [u.a.] JF - Nuclear physics A. Vol. 626, iss. 1-2 Y1 - 1997 SN - 1873-1554 (E-Journal) ; 0375-9474 (Print) SP - 85 EP - 92 ER - TY - JOUR A1 - Bansal, N. K. A1 - Müller, C. A1 - Vieira, M. E. A1 - Faber, Christian A1 - Schwarzer, Klemens T1 - Thermal performance of a rock bed storage system JF - Proceedings : University of Stuttgart, Germany, August 28th until September 1st, 2000 / Terrastock 2000, 8th International Conference on Thermal Energy Storage. Ed.: M. Benner ... - Vol. 1 Y1 - 2000 SN - 3-9805274-1-7 N1 - Terrastock <2000, Stuttgart> ; Institut für Thermodynamik und Wärmetechnik SP - 433 EP - 439 PB - Inst. für Thermodynamik und Wärmetechnik CY - Stuttgart ER - TY - JOUR A1 - Barsov, S. A1 - Bechstedt, U. A1 - Hardt, Arno T1 - ANKE, a new facility for medium energy hadron physics at COSY-Jülich / S. Barsov [u.a.] JF - Nuclear instruments and methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Vol. 462, iss. 3 Y1 - 2001 SN - 0167-5087 (Print) ; 0168-9002 (E-journal) SP - 364 EP - 381 ER - TY - JOUR A1 - Baumgartner, Werner A1 - Fidler, Florian A1 - Weth, Agnes A1 - Habbecke, Martin A1 - Jakob, Peter A1 - Butenweg, Christoph A1 - Böhme, Wolfgang T1 - Investigating the locomotion of the sandfish in desert sand using NMR-Imaging JF - PLOS ONE N2 - 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. KW - magnetic resonance imaging KW - body limbs KW - swimming KW - lizards KW - deserts Y1 - 2008 U6 - http://dx.doi.org/10.1371/journal.pone.0003309 SN - 1932-6203 VL - 3 IS - 10 PB - Plos CY - San Francisco, California, US ER - TY - JOUR A1 - Bechstedt, U. A1 - Haas, H. A1 - Hacker, U. A1 - Hardt, Arno A1 - Henn, K. A1 - Martin, S. A1 - Wimmer, J. T1 - Magnets for the German Spallation Source SNQ JF - IEEE transactions on nuclear science. Vol. 32, iss. 5 Y1 - 1985 SN - 1558-1578 (E-Journal); 0018-9499 (Print) SP - 3631 EP - 3633 ER - TY - JOUR A1 - Becker, Meike A1 - Frauenrath, Tobias A1 - Hezel, Fabian A1 - Krombach, Gabriele A. A1 - Kremer, Ute A1 - Koppers, Benedikt A1 - Butenweg, Christoph A1 - Goemmel, Andreas A1 - Utting, Jane F. A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf T1 - Comparison of left ventricular function assessment using phonocardiogram- and electrocardiogram-triggered 2D SSFP CINE MR imaging at 1.5 T and 3.0 T JF - European Radiology N2 - Objective: As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to interference from electromagnetic fields (EMF) and to magneto-hydrodynamic (MHD) effects increases and with it the motivation for a CMR triggering alternative. This study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects (n=14). Methods: Quantitative analysis of 2D CINE steady-state free precession (SSFP) images was conducted to compare ACT’s performance with vector ECG (VCG). Endocardial border sharpness (EBS) was examined paralleled by quantitative LV function assessment. Results: Unlike VCG, ACT provided signal traces free of interference from EMF or MHD effects. In the case of correct Rwave recognition, VCG-triggered 2D CINE SSFP was immune to cardiac motion effects—even at 3.0 T. However, VCG-triggered 2D SSFP CINE imaging was prone to cardiac motion and EBS degradation if R-wave misregistration occurred. ACT-triggered acquisitions yielded LV parameters (end-diastolic volume (EDV), endsystolic volume (ESV), stroke volume (SV), ejection fraction (EF) and left ventricular mass (LVM)) comparable with those derived fromVCG-triggered acquisitions (1.5 T: ESVVCG=(56± 17) ml, EDVVCG=(151±32)ml, LVMVCG=(97±27) g, SVVCG=(94± 19)ml, EFVCG=(63±5)% cf. ESVACT= (56±18) ml, EDVACT=(147±36) ml, LVMACT=(102±29) g, SVACT=(91± 22) ml, EFACT=(62±6)%; 3.0 T: ESVVCG=(55±21) ml, EDVVCG=(151±32) ml, LVMVCG=(101±27) g, SVVCG=(96±15) ml, EFVCG=(65±7)% cf. ESVACT=(54±20) ml, EDVACT=(146±35) ml, LVMACT= (101±30) g, SVACT=(92±17) ml, EFACT=(64±6)%). Conclusions: ACT’s intrinsic insensitivity to interference from electromagnetic fields renders KW - Magnetic resonance imaging (MRI) KW - MR-stethoscope KW - Magnetic field strength KW - Left ventriular function KW - Cardiovascular MRI Y1 - 2010 U6 - http://dx.doi.org/10.1007/s00330-009-1676-z SN - 1432-1084 (Onlineausgabe) SN - 0938-7994 (Druckausgabe) VL - 20 SP - 1344 EP - 1355 PB - Springer CY - Berlin ER - TY - JOUR A1 - Berg-Postweiler, Julia A1 - Steuer-Dankert, Linda A1 - Leicht-Scholten, Carmen T1 - One size does not fit all: Applying antibias trainings in academia JF - The International Journal of Organizational Diversity N2 - Antibias training is increasingly demanded and practiced in academia and industry to increase employees’ sensitivity to discrimination, racism, and diversity. Under the heading of “Diversity Management,” antibias trainings are mainly offered as one-off workshops intending to raise awareness of unconscious biases, create a diversity-affirming corporate culture, promote awareness of the potential of diversity, and ultimately enable the reflection of diversity in development processes. However, coming from childhood education, research and scientific articles on the sustainable effectiveness of antibias in adulthood, especially in academia, are very scarce. In order to fill this research gap, the article aims to explore how sustainable the effects of individual antibias trainings on participants’ behavior are. In order to investigate this, participant observation in a qualitative pre–post setting was conducted, analyzing antibias training in an academic context. Two observers actively participated in the training sessions and documented the activities and reflection processes of the participants. Overall, the results question the effectiveness of single antibias trainings and show that a target-group adaptive approach is mandatory owing to the background of the approach in early childhood education. Therefore, antibias work needs to be adapted to the target group’s needs and realities of life. Furthermore, the study reveals that single antibias trainings must be embedded in a holistic diversity management approach to stimulate sustainable reflection processes among the target group. This article is one of the first to scientifically evaluate antibias training effectiveness, especially in engineering sciences and the university context. KW - Antibias KW - Diversity Management KW - Organizational Culture KW - Engineering Habitus Y1 - 2023 U6 - http://dx.doi.org/10.18848/2328-6261/CGP/v24i01/1-23 SN - 2328-6261 (Print) SN - 2328-6229 (Online) VL - 24 IS - 1 SP - 1 EP - 23 PB - Common Ground Research Networks ER - TY - JOUR A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Reger, Vitali A1 - Kuhnhenne, Markus T1 - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates JF - Geothermal Energy N2 - Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar fow and 60% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the fow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics. Y1 - 2021 U6 - http://dx.doi.org/10.1186/s40517-021-00201-3 SN - 2195-9706 N1 - Corresponding author: Tobias Blanke VL - 9 IS - Article number: 19 PB - Springer CY - Berlin ER - TY - JOUR A1 - Bouquegneau, Christian A1 - Kern, Alexander A1 - Rousseau, Alain T1 - Lightning safety guidelines Y1 - 2010 N1 - Ground´2010 International Conference on Grounding and Earthing ; 4th International Conference ond Lightning Physics and Effects, Nov. 2010 Salvador - Brazil SP - 1 EP - 6 ER - TY - JOUR A1 - Breitbach, Gerd A1 - Deschka, S. A1 - Akiba, M. T1 - High heat flux tests on brazed divertor components in electron and ion beam test facilities / S. Deschka ; M. Akiba ; G. Breitbach ... JF - International journal of refractory metals and hard materials. 11 (1992), H. 6 Y1 - 1992 SN - 0263-4368 N1 - 2. ISSN (Druck-Ausg.): 0263-4368 SP - 367 EP - 375 ER - TY - JOUR A1 - Breitbach, Gerd A1 - Schmidt-Plutka, A. A1 - Schubert, F. A1 - Nickel, H. T1 - Deformation behaviour of structures exposed at very high temperatures to cyclic thermal and mechanical loadings JF - Structural mechanics in reactor technology : transactions of the 12th International Conference on Structural Mechanics in Reactor Technology, Stuttgart, Germany, 15-20 August 1993 / ed. Karl F. Kussmaul. - Bd. L : Inelastic behaviour of solids and structures Y1 - 1993 SN - 0-444-81515-5 N1 - SMiRT <12, 1993, Stuttgart> ; L08/3 SP - 203 EP - 208 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Breitbach, Gerd A1 - Schubert, F. T1 - A contribution to stress prediction in coatings for gas turbine blades JF - Archive of applied mechanics. 73 (2004), H. 9-10 Y1 - 2004 SN - 0939-1533 N1 - 2. ISSN (Druck-Ausg.): 1432-0681 SP - 682 EP - 689 ER - TY - JOUR A1 - Breitbach, Gerd A1 - Wolf, U. A1 - Deschka, S. A1 - Nickel, H. T1 - Thermomechanical analysis of an actively cooled divertor mock up JF - Tagungsbericht : Jahrestagung Kerntechnik : Stadthalle Karlsruhe, 5.-7. Mai 1992, Karlsruhe = Proceedings / Kerntechnische Gesellschaft ... [Red.: Karl G. Bauer]. - 1. Aufl., als Ms. gedr.. Y1 - 1992 N1 - Jahrestagung Kerntechnik <1992, Karlsruhe> SP - 457 EP - 461 PB - INFOFORUM CY - Bonn ER - TY - JOUR A1 - Brüssermann, Klaus T1 - H3 and C14 air monitoring according to KTA 1503.1 JF - 2. Karlsruhe international conference on analytical chemistry in nuclear technology, Karlsruhe (Germany), 5-9 Jun 1989 Y1 - 1989 ER -