TY - JOUR A1 - Bayon, Arnau A1 - Valero, Daniel A1 - Garcia-Bartual, Rafael A1 - Vallés-Morán, Francisco José A1 - López-Jiménez, P. Amparo T1 - Performance assessment of OpenFOAM and FLOW-3D in the numerical modeling of a low Reynolds number hydraulic jump JF - Environmental Modelling & Software N2 - A comparative performance analysis of the CFD platforms OpenFOAM and FLOW-3D is presented, focusing on a 3D swirling turbulent flow: a steady hydraulic jump at low Reynolds number. Turbulence is treated using RANS approach RNG k-ε. A Volume Of Fluid (VOF) method is used to track the air–water interface, consequently aeration is modeled using an Eulerian–Eulerian approach. Structured meshes of cubic elements are used to discretize the channel geometry. The numerical model accuracy is assessed comparing representative hydraulic jump variables (sequent depth ratio, roller length, mean velocity profiles, velocity decay or free surface profile) to experimental data. The model results are also compared to previous studies to broaden the result validation. Both codes reproduced the phenomenon under study concurring with experimental data, although special care must be taken when swirling flows occur. Both models can be used to reproduce the hydraulic performance of energy dissipation structures at low Reynolds numbers. Y1 - 2016 SN - 1364-8152 U6 - https://doi.org/10.1016/j.envsoft.2016.02.018 VL - 80 SP - 322 EP - 335 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Orzada, Stephan A1 - Flöser, Martina A1 - Rietsch, Stefan H. G. A1 - Schmidt, Simon A1 - Stelter, Jonathan K. A1 - Wittrich, Marco A1 - Quick, Harald H. A1 - Bitz, Andreas A1 - Ladd, Mark E. T1 - Performance and safety assessment of an integrated transmit array for body imaging at 7 T under consideration of specificabsorption rate, tissue temperature, and thermal dose JF - NMR in Biomedicine N2 - In this study, the performance of an integrated body-imaging array for 7 T with 32 radiofrequency (RF) channels under consideration of local specific absorption rate (SAR), tissue temperature, and thermal dose limits was evaluated and the imaging performance was compared with a clinical 3 T body coil. Thirty-two transmit elements were placed in three rings between the bore liner and RF shield of the gradient coil. Slice-selective RF pulse optimizations for B1 shimming and spokes were performed for differently oriented slices in the body under consideration of realistic constraints for power and local SAR. To improve the B1+ homogeneity, safety assessments based on temperature and thermal dose were performed to possibly allow for higher input power for the pulse optimization than permissible with SAR limits. The results showed that using two spokes, the 7 T array outperformed the 3 T birdcage in all the considered regions of interest. However, a significantly higher SAR or lower duty cycle at 7 T is necessary in some cases to achieve similar B1+ homogeneity as at 3 T. The homogeneity in up to 50 cm-long coronal slices can particularly benefit from the high RF shim performance provided by the 32 RF channels. The thermal dose approach increases the allowable input power and the corresponding local SAR, in one example up to 100 W/kg, without limiting the exposure time necessary for an MR examination. In conclusion, the integrated antenna array at 7 T enables a clinical workflow for body imaging and comparable imaging performance to a conventional 3 T clinical body coil. KW - body imaging at 7 T MRI KW - thermal dose KW - tissue temperature KW - transmit antenna arrays Y1 - 2022 U6 - https://doi.org/10.1002/nbm.4656 SN - 0952-3480 (Print) SN - 1099-1492 (Online) VL - 35 IS - 5 SP - 1 EP - 17 PB - Wiley ER - TY - JOUR A1 - Havermann, Marc A1 - Beylich, A. E. T1 - Performance and Limitations of the Laser-Induced Fluorescence Measurement Technique and the Established Experimental Methods for the Study of Supersonic Mixing / Havermann, M. ; Beylich, A. E. JF - International Journal of heat and technology. 15 (1997), H. 2 Y1 - 1997 SP - 3 EP - 10 PB - - ER - TY - JOUR A1 - Schuba, Marko T1 - Performance Analysis of Reliable Multicast Mechanisms for Widely Spread Distributed Applications in the Internet JF - International Conference on Parallel and Distributed Processing Techniques and Applications : PDPTA '99 ; June 28 - July 1, 1999, Las Vegas, Nevada, USA / ed.: Hamid R. Arabnia Y1 - 1999 SN - 1892512157 SP - 1 EP - 7 ER - TY - JOUR A1 - Gutheil, Inge A1 - Berg, Tommy A1 - Grotendorst, Johannes T1 - Performance Analysis of Parallel Eigensolvers of two Libraries on BlueGene/P JF - Journal of Mathematics and Systems Science N2 - Many applications in computational science and engineering require the computation of eigenvalues and vectors of dense symmetric or Hermitian matrices. For example, in DFT (density functional theory) calculations on modern supercomputers 10% to 30% of the eigenvalues and eigenvectors of huge dense matrices have to be calculated. Therefore, performance and parallel scaling of the used eigensolvers is of upmost interest. In this article different routines of the linear algebra packages ScaLAPACK and Elemental for parallel solution of the symmetric eigenvalue problem are compared concerning their performance on the BlueGene/P supercomputer. Parameters for performance optimization are adjusted for the different data distribution methods used in the two libraries. It is found that for all test cases the new library Elemental which uses a two-dimensional element by element distribution of the matrices to the processors shows better performance than the old ScaLAPACK library which uses a block-cyclic distribution. KW - performance analysis KW - Elemental KW - ScaLAPACK KW - eigensolvers KW - Numerical linear algebra Y1 - 2012 U6 - https://doi.org/10.17265/2159-5291/2012.04.003 SN - 2159-5291 VL - 2 IS - 4 SP - 231 EP - 236 PB - David Publishing CY - Libertyville ER - 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 - Scholz, Christina A1 - Romagnoli, Daniele A1 - Dachwald, Bernd A1 - Theil, Stephan T1 - Performance analysis of an attitude control system for solar sails using sliding masses JF - Advances in Space Research Y1 - 2011 SN - 0273-1177 VL - 48 IS - 11 SP - 1822 EP - 1835 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Beckenbach, Isabel A1 - Scheidweiler, Robert T1 - Perfect ƒ-Matchings and ƒ-Factors in Hypergraphs - A Combinatorial Approach JF - Discrete Mathematics N2 - We prove characterizations of the existence of perfect ƒ-matchings in uniform mengerian and perfect hypergraphs. Moreover, we investigate the ƒ-factor problem in balanced hypergraphs. For uniform balanced hypergraphs we prove two existence theorems with purely combinatorial arguments, whereas for non-uniform balanced hypergraphs we show that the ƒ-factor problem is NP-hard. Y1 - 2016 U6 - https://doi.org/10.1016/j.disc.2017.05.005 SN - 2192-7782 N1 - Als Volltext auch bei ZIB (Zuse Institute Berlin) VL - 240 IS - 10 SP - 2499 EP - 2506 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Vant, Christianne A1 - Staat, Manfred A1 - Baroud, Gamal T1 - Percutaneous Vertebroplasty: A Review of Two Intraoperative Complications JF - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.) Y1 - 2008 SN - 978-3-540-75408-4 SP - 527 EP - 539 PB - Springer CY - Berlin ER - TY - JOUR A1 - Berndt, Heinz A1 - Zahn, Helmut T1 - Peptide, 99 : Monomere cyclische Cystinpeptidderivate, III ; Synthese der Schafinsulin-A-Kettensequenzen A2–21 und A1–21 als monomere cyclische Dicystinpeptidderivate JF - Justus Liebigs Annalen der Chemie N2 - Die Synthese der Sequenzen A2—21 (13) und A1—21 (15) der Schafinsulin-A-Kette als monomere cyclische Dicystinpeptidderivate wird beschrieben. Die intrachenaren Cystinbrücken A6—7 und A 11 —20 vermitteln die Löslichkeit dieser Derivate in Dimethylformamid und ermöglichen erstmalig die Reindarstellung vollgeschützter Insulin-A-Kettenderivate. Die während der Synthese eingesetzten Schutzgruppen lassen sich mittels Trifluoressigsäure und 2-Mercaptoäthanol quantitativ entfernen. Y1 - 1975 U6 - https://doi.org/10.1002/jlac.197519750908 SN - 1099-0690 VL - 1975 IS - 9 SP - 1601 EP - 1612 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schwertner, Eberhard A1 - Berndt, Heinz A1 - Gielen, Hans-Günter A1 - Zahn, Helmut T1 - Peptide 96 : Synthese einiger [2-(p-Biphenylyl)isopropyloxycarbonyl]-Aminosäurederivate JF - Justus Liebigs Annalen der Chemie N2 - Die Darstellung der N-[2-(p-Biphenylyl)isopropyloxycarbonyl]-Derivate (Bpoc-Derivate) des Cysteins unter Verwendung der Thiolschutzgruppen Tetrahydropyranyl (Thp) für 1, Diphenylmethyl (Dpm) für 2, Trityl (Trt) für 3 und S-tert.-Butyl (SBut) für 4 sowie die Synthese von aktivierten Estern der Bpoc-Derivate des Glycins (5), Isoleucins (6) und Prolins (7) werden beschrieben. An einem Beispiel wird die Möglichkeit aufgezeigt, die Bpoc-Gruppe über das Bpoc-Azid nachträglich in den Peptidverband einzuführen. Y1 - 1975 U6 - https://doi.org/10.1002/jlac.197519750318 SN - 1099-0690 VL - 75 IS - 3 SP - 581 EP - 585 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Fabo, Sabine ED - Mohr, Klaus T1 - Pepräsentatives Dösen JF - Idiopendent Lyfestile (Boxhorn ; 27) Y1 - 2013 SN - 1864-2535 SP - 134 EP - 139 PB - FH CY - Aachen ER - TY - JOUR A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Razavi, Arash A1 - Besmehn, Astrid A1 - Bijnens, Nathalie A1 - Williams, Oliver A. A1 - Haenen, Ken A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Penicillin detection with nanocrystalline-diamond field-effect sensor JF - physica status solidi (a). 205 (2008), H. 9 Y1 - 2008 SN - 1862-6319 N1 - Special Issue: Hasselt Diamond Workshop 2008 - SBDD XIII SP - 2141 EP - 2145 ER - TY - JOUR A1 - Koch, Claudia A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Wege, Christian T1 - Penicillin Detection by Tobacco Mosaic Virus-Assisted Colorimetric Biosensors JF - Nanotheranostics N2 - The presentation of enzymes on viral scaffolds has beneficial effects such as an increased enzyme loading and a prolonged reusability in comparison to conventional immobilization platforms. Here, we used modified tobacco mosaic virus (TMV) nanorods as enzyme carriers in penicillin G detection for the first time. Penicillinase enzymes were conjugated with streptavidin and coupled to TMV rods by use of a bifunctional biotin-linker. Penicillinase-decorated TMV particles were characterized extensively in halochromic dye-based biosensing. Acidometric analyte detection was performed with bromcresol purple as pH indicator and spectrophotometry. The TMV-assisted sensors exhibited increased enzyme loading and strongly improved reusability, and higher analysis rates compared to layouts without viral adapters. They extended the half-life of the sensors from 4 - 6 days to 5 weeks and thus allowed an at least 8-fold longer use of the sensors. Using a commercial budget-priced penicillinase preparation, a detection limit of 100 µM penicillin was obtained. Initial experiments also indicate that the system may be transferred to label-free detection layouts. Y1 - 2018 U6 - https://doi.org/10.7150/ntno.22114 SN - 2206-7418 VL - 2 IS - 2 SP - 184 EP - 196 PB - Ivyspring CY - Sydney ER - TY - JOUR A1 - Poghossian, Arshak A1 - Thust, M. A1 - Schroth, P. A1 - Steffen, A. A1 - Lüth, H. A1 - Schöning, Michael Josef T1 - Penicillin detection by means of silicon-based field-effect structures JF - Sensors and Materials. 13 (2001), H. 4 Y1 - 2001 SN - 0392-2510 SP - 207 EP - 223 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Yoshinobu, T. A1 - Simonis, A. A1 - Ecken, H. A1 - Lüth, H. A1 - Schöning, Michael Josef T1 - Penicillin detection by means of field-effect based sensors: EnFET, capacitive EIS sensor or LAPS? JF - Proceedings : Copenhagen, Denmark, 27 - 30 August 2000 / [ed.: R. de Reus ...] Y1 - 2000 SN - 87-89935-50-0 N1 - Eurosensors ; (14, 2000, København) ; Eurosensors ; (14 : ; 2000.08.27-30 : ; Copenhagen) ; European Conference on Solid-State Transducers ; (14 : ; 2000.08.27-30 : ; Copenhagen) SP - 27 EP - 30 PB - MIC, Mikroelektronik Centret CY - Lyngby, Denmark ER - TY - JOUR A1 - Poghossian, Arshak A1 - Yoshinobu, Tatsuo A1 - Simonis, A. A1 - Ecken, H. A1 - Lüth, Hans A1 - Schöning, Michael Josef T1 - Penicillin detection by means of field-effect based sensors: EnFET, capacitive EIS sensor or LAPS? JF - Sensors and Actuators B. 78 (2001), H. 1-3 Y1 - 2001 SN - 0925-4005 SP - 237 EP - 242 ER - TY - JOUR A1 - Siqueira, José R. Jr. A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Zucolotto, Valtencir A1 - Oliveira, Osvaldo N. Jr. A1 - Schöning, Michael Josef T1 - Penicillin biosensor based on a capacitive field-effect structure functionalized with a dendrimer/carbon nanotube multilayer JF - Biosensors and Bioelectronics. 25 (2009), H. 2 Y1 - 2009 SN - 0956-5663 SP - 497 EP - 501 ER - TY - JOUR A1 - Mühl, Thomas A1 - Schwarz, Michael T1 - Pegel- und Dämpfungsmessung an Wellenlängenmultiplex-Systemen und -Komponenten JF - Nachrichtentechnische Zeitschrift. 46 (1993), H. 1 Y1 - 1993 SN - 0027-707X SP - 36 EP - 38 ER - TY - JOUR A1 - Förster, Arnold A1 - Schmidt, T. A1 - Tewordt, M. A1 - Haug, R. J. T1 - Peak-to-valley ratio of small resonant-tunneling diodes with various barrier-thickness asymmetries / T. Schmidt ; M. Tewordt ; R. J. Haug ... A. Förster ... JF - Applied physics letters. 68 (1996), H. 6 Y1 - 1996 SN - 0003-6951 N1 - ISSN der E-Ausg.: 1077-3118 SP - 838 EP - 840 ER -