TY - JOUR A1 - Fiedler, Thomas M. A1 - Orzada, Stephan A1 - Flöser, Martina A1 - Rietsch, Stefan H. G. A1 - Quick, Harald H. A1 - Ladd, Mark E. A1 - Bitz, Andreas T1 - Performance analysis of integrated RF microstrip transmit antenna arrays with high channel count for body imaging at 7 T JF - NMR in Biomedicine N2 - The aim of the current study was to investigate the performance of integrated RF transmit arrays with high channel count consisting of meander microstrip antennas for body imaging at 7 T and to optimize the position and number of transmit ele- ments. RF simulations using multiring antenna arrays placed behind the bore liner were performed for realistic exposure conditions for body imaging. Simulations were performed for arrays with as few as eight elements and for arrays with high channel counts of up to 48 elements. The B1+ field was evaluated regarding the degrees of freedom for RF shimming in the abdomen. Worst-case specific absorption rate (SARwc ), SAR overestimation in the matrix compression, the number of virtual obser- vation points (VOPs) and SAR efficiency were evaluated. Constrained RF shimming was performed in differently oriented regions of interest in the body, and the devia- tion from a target B1+ field was evaluated. Results show that integrated multiring arrays are able to generate homogeneous B1+ field distributions for large FOVs, espe- cially for coronal/sagittal slices, and thus enable body imaging at 7 T with a clinical workflow; however, a low duty cycle or a high SAR is required to achieve homoge- neous B1+ distributions and to exploit the full potential. In conclusion, integrated arrays allow for high element counts that have high degrees of freedom for the pulse optimization but also produce high SARwc , which reduces the SAR accuracy in the VOP compression for low-SAR protocols, leading to a potential reduction in array performance. Smaller SAR overestimations can increase SAR accuracy, but lead to a high number of VOPs, which increases the computational cost for VOP evaluation and makes online SAR monitoring or pulse optimization challenging. Arrays with interleaved rings showed the best results in the study. KW - body imaging at UHF MRI KW - integrated transmit coil arrays KW - VOP compression Y1 - 2021 U6 - https://doi.org/10.1002/nbm.4515 SN - 0952-3480 (ISSN) SN - 1099-1492 (eISSN) VL - 34 IS - 7 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Kurulgan demirci, Eylem A1 - Fırat, Ipek Seda A1 - Oflaz, Hakan A1 - Artmann, Gerhard T1 - Recombinant activated protein C (rhAPC) affects lipopolysaccharide-induced mechanical compliance changes and beat frequency of mESC-derived cardiomyocyte monolayers JF - SHOCK KW - Septic cardiomyopathy KW - LPS KW - cardiomyocyte biomechanics KW - CellDrum KW - actin cytoskeleton Y1 - 2021 U6 - https://doi.org/10.1097/SHK.0000000000001845 SN - 1540-0514 PB - Wolters Kluwer CY - Köln ER - TY - JOUR A1 - Dickhoff, Jens A1 - Horikawa, Atsushi A1 - Funke, Harald T1 - Hydrogen Combustion - new DLE Combustor Addresses NOx Emissions and Flashback JF - Turbomachinery international : the global journal of energy equipment Y1 - 2021 SN - 2767-2328 SN - 0149-4147 VL - 62 IS - 4 SP - 26 EP - 27 PB - MJH Life Sciences CY - Cranbury ER - TY - JOUR A1 - Butenweg, Christoph A1 - Kubalski, Thomas A1 - El-Deib, Khaled A1 - Gellert, Christoph ED - Jesse, Dirk T1 - Erdbebennachweis von Mauerwerksbauten nach DIN EN 1998-1/NA-2021 JF - Bautechnik : Zeitschrift für den gesamten Ingenieurbau N2 - Mauerwerksbauten in Deutschland sind mit Einführung des nationalen Anwendungsdokuments DIN EN 1998-1/NA auf Grundlage einer neuen probabilistischen Erdbebenkarte nachzuweisen. Für erfolgreiche Erdbebennachweise üblicher Grundrissformen von Mauerwerksbauten stehen in dem zukünftigen Anwendungsdokument neue rechnerische Nachweismöglichkeiten zur Verfügung, mit denen die Tragfähigkeitsreserven von Mauerwerksbauten in der Baupraxis mit einem überschaubaren Aufwand besser in Ansatz gebracht werden können. Das Standardrechenverfahren ist weiterhin der kraftbasierte Nachweis, der nun mit höheren Verhaltensbeiwerten im Vergleich zur DIN 4149 durchgeführt werden kann. Die höheren Verhaltensbeiwerte basieren auf der besseren Ausnutzung der gebäudespezifischen Verformungsfähigkeit und Energiedissipation sowie der Lastumverteilung der Schubkräfte im Grundriss mit Ansatz von Rahmentragwirkung durch Wand-Deckeninteraktionen. Alternativ dazu kann ein nichtlinearer Nachweis auf Grundlage von Pushover-Analysen zur Anwendung kommen. Vervollständigt werden die Regelungen für Mauerwerksbauten durch neue Regelungen für nichttragende Innenwände und Außenmauerschalen. Der vorliegende Beitrag stellt die Grundlagen und Hintergründe der neuen rechnerischen Nachweise in DIN EN 1998-1/NA vor und demonstriert deren Anwendung an einem Beispiel aus der Praxis. Y1 - 2021 U6 - https://doi.org/10.1002/bate.202100064 SN - 1437-0999 SN - 0005-6820, 0932-8351 VL - 98 IS - 11 SP - 852 EP - 863 PB - Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Oertel, Mario A1 - Bung, Daniel Bernhard T1 - Hochwasserschutz - eine Aufgabe für eine nachhaltige Wasserwirtschaft JF - Wasserwirtschaft KW - Wasserbau KW - Architektur KW - Wasserwirtschaft KW - Deutschland Y1 - 2021 SN - 0043-0978 VL - 111 IS - 9-10 SP - 3 EP - 19 PB - Springer Vieweg CY - Wiesbaden ER - TY - JOUR A1 - Seefeldt, Patric A1 - Dachwald, Bernd T1 - Temperature increase on folded solar sail membranes JF - Advances in Space Research Y1 - 2021 U6 - https://doi.org/10.1016/j.asr.2020.09.026 SN - 0273-1177 VL - 67 IS - 9 SP - 2688 EP - 2695 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Valero, Daniel A1 - Schalko, Isabella A1 - Friedrich, Heide A1 - Abad, Jorge D. A1 - Bung, Daniel Bernhard A1 - Donchyts, Gennadii A1 - Felder, Stefan A1 - Ferreira, Rui M. L. A1 - Hohermuth, Benjamin A1 - Kramer, Matthias A1 - Li, Danxun A1 - Mendes, Luis A1 - Moreno-Rodenas, Antonio A1 - Nones, Michael A1 - Paron, Paolo A1 - Ruiz-Villanueva, Virginia A1 - Wang, Ruo-Qian A1 - Franca, Mario J. T1 - Pathways towards democratization of hydro-environment observations and data JF - Iahr White Paper Series Y1 - 2021 IS - 1 SP - 1 EP - 9 PB - International Association for Hydro-Environment Engineering and Research (IAHR) ER - TY - JOUR A1 - German, Laura A1 - Mikucki, Jill A. A1 - Welch, Susan A. A1 - Welch, Kathleen A. A1 - Lutton, Anthony A1 - Dachwald, Bernd A1 - Kowalski, Julia A1 - Heinen, Dirk A1 - Feldmann, Marco A1 - Francke, Gero A1 - Espe, Clemens A1 - Lyons, W. Berry T1 - Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry JF - International Journal of Environmental Analytical Chemistry N2 - Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe’s sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2−+NO3− from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica. Y1 - 2021 U6 - https://doi.org/10.1080/03067319.2019.1704750 SN - 0306-7319 VL - 101 IS - 15 SP - 2654 EP - 2667 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Köhler, Klemens A1 - Röpke, René A1 - Wolf, Martin R. T1 - Through a mirror darkly – On the obscurity of teaching goals in game-based learning in IT security JF - ISAGA 2019: Simulation Gaming Through Times and Disciplines N2 - Teachers and instructors use very specific language communicating teaching goals. The most widely used frameworks of common reference are the Bloom’s Taxonomy and the Revised Bloom’s Taxonomy. The latter provides distinction of 209 different teaching goals which are connected to methods. In Competence Developing Games (CDGs - serious games to convey knowledge) and in IT security education, a two- or three level typology exists, reducing possible learning outcomes to awareness, training, and education. This study explores whether this much simpler framework succeeds in achieving the same range of learning outcomes. Method wise a keyword analysis was conducted. The results were threefold: 1. The words used to describe teaching goals in CDGs on IT security education do not reflect the whole range of learning outcomes. 2. The word choice is nevertheless different from common language, indicating an intentional use of language. 3. IT security CDGs use different sets of terms to describe learning outcomes, depending on whether they are awareness, training, or education games. The interpretation of the findings is that the reduction to just three types of CDGs reduces the capacity to communicate and think about learning outcomes and consequently reduces the outcomes that are intentionally achieved. KW - IT security education KW - Competence Developing Games KW - Game-based learning KW - Keyword analysis KW - Bloom’s Taxonomy Y1 - 2021 U6 - https://doi.org/10.1007/978-3-030-72132-9_6 N1 - ISAGA 2019 - International Simulation and Gaming Association Conference. 26-30 August 2019. Warsaw, Poland. Part of the Lecture Notes in Computer Science book series (LNCS, volume 11988) SP - 61 EP - 73 PB - Springer CY - Cham ER - TY - JOUR A1 - El-Deib, Khaled A1 - Butenweg, Christoph A1 - Klinkel, Sven ED - Jesse, Dirk T1 - Erdbebennachweis von Mauerwerksbauten mit realistischen Modellen und erhöhten Verhaltensbeiwerten JF - Mauerwerk N2 - Die Anwendung des linearen Nachweiskonzepts auf Mauerwerksbauten führt dazu, dass bereits heute Standsicherheitsnachweise für Gebäude mit üblichen Grundrissen in Gebieten mit moderaten Erdbebeneinwirkungen nicht mehr geführt werden können. Diese Problematik wird sich in Deutschland mit der Einführung kontinuierlicher probabilistischer Erdbebenkarten weiter verschärfen. Aufgrund der Erhöhung der seismischen Einwirkungen, die sich vielerorts ergibt, ist es erforderlich, die vorhandenen, bislang nicht berücksichtigten Tragfähigkeitsreserven in nachvollziehbaren Nachweiskonzepten in der Baupraxis verfügbar zu machen. Der vorliegende Beitrag stellt ein Konzept für die gebäudespezifische Ermittlung von erhöhten Verhaltensbeiwerten vor. Die Verhaltensbeiwerte setzen sich aus drei Anteilen zusammen, mit denen die Lastumverteilung im Grundriss, die Verformungsfähigkeit und Energiedissipation sowie die Überfestigkeiten berücksichtigt werden. Für die rechnerische Ermittlung dieser drei Anteile wird ein nichtlineares Nachweiskonzept auf Grundlage von Pushover-Analysen vorgeschlagen, in denen die Interaktionen von Wänden und Geschossdecken durch einen Einspanngrad beschrieben werden. Für die Bestimmung der Einspanngrade wird ein nichtlinearer Modellierungsansatz eingeführt, mit dem die Interaktion von Wänden und Decken abgebildet werden kann. Die Anwendung des Konzepts mit erhöhten gebäudespezifischen Verhaltensbeiwerten wird am Beispiel eines Mehrfamilienhauses aus Kalksandsteinen demonstriert. Die Ergebnisse der linearen Nachweise mit erhöhten Verhaltensbeiwerten für dieses Gebäude liegen deutlich näher an den Ergebnissen nichtlinearer Nachweise und somit bleiben übliche Grundrisse in Erdbebengebieten mit den traditionellen linearen Rechenansätzen nachweisbar. N2 - Seismic verification of masonry buildings based on realistic calculation models and increased behavior factorsWith the application of the traditional linear verification con­cept to masonry structures it is already no longer possible to carry out structural safety verifications even for buildings with standard ground plan configurations in areas with moderate seismicity. This problem will be exacerbated in Germany with the introduction of continuous probabilistic earthquake maps. Due to the increased seismic actions, it is necessary to make the existing load­bearing capacity reserves that have not yet been taken into account available in comprehensible verifica­tion concepts in construction practice. This article presents a concept for the building­specific determination of increased behavior factors. The behavior factors are composed of three components, which take into account the load redistribution in ground plans, the deformation capability and energy dissipation and all kinds of overstrength effects. For the calculation of these three components, a non­linear verification concept based on pushover analyses is applied, in which the interac­tions of walls and floor slabs are described by a level of re­straint. A non­linear modeling approach of the overall building is introduced for the determination of the restraint levels, with which the interaction of walls and floor slabs can be simulated. The results of the linear verifications with increased behavior factors for this building are significantly closer to the results of non­linear verifications and thus the standard ground plan con­figurations in areas with moderate seismicity can still be veri­fied with the traditional linear calculation approaches. KW - Mauerwerksbauten KW - Erdbebeneinwirkung KW - Bemessung KW - Verhaltensbeiwerte KW - Pushover­Analysen Y1 - 2021 U6 - https://doi.org/10.1002/dama.202110014 SN - 1437-1022 SN - 1432-3427 VL - 2021 IS - 3 SP - 110 EP - 119 PB - Wiley CY - Weinheim ER -