TY - JOUR A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Combined amperometric/field-effect sensor for the detection of dissolved hydrogen JF - Sensors and actuators B: Chemical N2 - Real-time and reliable monitoring of the biogas process is crucial for a stable and efficient operation of biogas production in order to avoid digester breakdowns. The concentration of dissolved hydrogen (H₂) represents one of the key parameters for biogas process control. In this work, a one-chip integrated combined amperometric/field-effect sensor for monitoring the dissolved H₂ concentration has been developed for biogas applications. The combination of two different transducer principles might allow a more accurate and reliable measurement of dissolved H₂ as an early warning indicator of digester failures. The feasibility of the approach has been demonstrated by simultaneous amperometric/field-effect measurements of dissolved H₂ concentrations in electrolyte solutions. Both, the amperometric and the field-effect transducer show a linear response behaviour in the H₂ concentration range from 0.1 to 3% (v/v) with a slope of 198.4 ± 13.7 nA/% (v/v) and 14.9 ± 0.5 mV/% (v/v), respectively. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.snb.2012.10.050 SN - 0925-4005 N1 - Part of special issue "Selected Papers from the 14th International Meeting on Chemical Sensors" VL - 187 SP - 168 EP - 173 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Weigand, Christoph T1 - Statistical Tests Based on Reliability and Precision JF - Economic Quality Control : EQC ; international journal for quality and reliability N2 - The construction of a statistical test is investigated which is based only on “reliability” and “precision” as quality criteria. The reliability of a statistical test is quantifiedin a straightforward way by the probability that the decision of the test is correct. However, the quantification of the precision of a statistical test is not at all evident. Thereforethe paper presents and discusses several approaches. Moreover the distinction of “nullhypothesis” and “alternative hypothesis” is not necessary any longer. Y1 - 2012 U6 - http://dx.doi.org/10.1515/eqc-2012-0002 SN - 1869-6147 VL - 27 IS - 1 SP - 43 EP - 64 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Fateri, Miranda A1 - Hötter, Jan-Steffen A1 - Gebhardt, Andreas T1 - Experimental and Theoretical Investigation of Buckling Deformation of Fabricated Objects by Selective Laser Melting JF - Physics Procedia N2 - Although Selective Laser Melting (SLM) process is an innovative manufacturing method, there are challenges such as inferior mechanical properties of fabricated objects. Regarding this, buckling deformation which is caused by thermal stress is one of the undesired mechanical properties which must be alleviated. As buckling deformation is more observable in hard to process materials, silver is selected to be studied theoretically and experimentally for this paper. Different scanning strategies are utilized and a Finite Element Method (FEM) is applied to calculate the temperature gradient in order to determine its effect on the buckling deformation of the objects from experiments. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.phpro.2012.10.062 SN - 1875-3892 N1 - Part of special issue "Laser Assisted Net shape Engineering 7 (LANE 2012)" VL - 39 SP - 464 EP - 470 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hasan, Istabrak A1 - Keil, Ludger A1 - Staat, Manfred A1 - Wahl, Gerhard A1 - Bourauel, Christoph T1 - Determination of the frictional coefficient of the implant-antler interface : experimental approach JF - Biomedical Engineering / Biomedizinische Technik N2 - The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5–0.7 and 0.3–0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens. Y1 - 2012 SN - 1862-278X VL - 57 IS - 5 SP - 359 EP - 363 PB - De Gruyter CY - Berlin ER - TY - BOOK A1 - Wosnitza, Franz A1 - Hilgers, Hans Gerd T1 - Energieeffizienz und Energiemanagement : ein Überblick heutiger Möglichkeiten und Notwendigkeiten Y1 - 2012 SN - 978-3-8348-1941-3 N1 - eISBN 978-3-8348-8671-2 PB - Springer Spektrum CY - Wiesbaden ER - TY - BOOK A1 - Janser, Frank A1 - Havermann, Marc T1 - Inkompressible Strömungen Y1 - 2012 SN - 978-3-86130-446-3 N1 - Strömungslehre und Aerodynamik PB - Mainz CY - Aachen ER - TY - CHAP A1 - Schopp, Christoph A1 - Nachtrodt, Frederik A1 - Heuermann, Holger A1 - Scherer, Ulrich W. A1 - Mostacci, Domiziano A1 - Finger, Torsten A1 - Tietsch, Wolfgang T1 - A novel 2.45 GHz/200 W Microwave Plasma Jet for High Temperature Applications above 3600 K T2 - Journal of Physics : Conference Series Y1 - 2012 SN - 1742-6596 VL - 406 IS - 012029 ER - TY - CHAP A1 - Nix, Yvonne A1 - Frotscher, Ralf A1 - Staat, Manfred ED - Eberhardsteiner, J. T1 - Implementation of the edge-based smoothed extended finite element method T2 - Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 Y1 - 2012 ER - TY - CHAP A1 - Frotscher, Ralf A1 - Raatschen, Hans-Jürgen A1 - Staat, Manfred ED - Eberhardsteiner, J. T1 - Application of an edge-based smoothed finite element method on geometrically non-linear plates of non-linear material T2 - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Y1 - 2012 N1 - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 ER - TY - CHAP A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Huynh A1 - Staat, Manfred ED - Eberhardsteiner, J. T1 - Numerical stability enhancement of modeling hyperelastic materials T2 - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Y1 - 2012 N1 - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 ER - TY - CHAP A1 - Tran, Thanh Ngoc A1 - Staat, Manfred ED - Eberhardsteiner, J. T1 - A primal-dual shakedown analysis of 3D structures using the face-based smoothed finite element method T2 - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Y1 - 2012 N1 - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 ER - TY - CHAP A1 - Pham, Phu Tinh A1 - Nguyen, Thanh Ngoc A1 - Staat, Manfred T1 - FEM based shakedown analysis of hardening structures T2 - Proceedings International Conference on Advances in Computational Mechanics (ACOME) Y1 - 2012 N1 - International Conference on Advances in Computational Mechanics (ACOME), August 14-16, 2012, Ho Chi Minh City, Vietnam SP - 870 EP - 882 ER - TY - CHAP A1 - Funke, Harald A1 - Börner, Sebastian A1 - Keinz, Jan A1 - Kusterer, K. A1 - Kroninger, D. A1 - Kitajima, J. A1 - Kazari, M. A1 - Horikama, A. T1 - Numerical and experimental characterization of low NOx Micromix combustion principle for industrial hydrogen gas turbine applications T2 - Proceedings of ASME Turbo Expo 2012 Y1 - 2013 N1 - ASME Turbo Expo 2012, GT2012, June 11-15, 2012, Copenhagen, Denmark ER - TY - CHAP A1 - Funke, Harald A1 - Börner, Sebastian A1 - Keinz, Jan A1 - Hendrick, P. A1 - Recker, E. T1 - Low NOx Hydrogen combustion chamber for industrial gas turbine applications“, 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery T2 - ISROMAC-14 : the Forteenth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 27 - March 02nd, 2012 Y1 - 2012 N1 - International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; (14 ; 2012.02.27-03.02 ; Honolulu, Hawaii) ER - TY - JOUR A1 - Nomdedeu, Mar Monsonis A1 - Willen, Christine A1 - Schieffer, Andre A1 - Arndt, Hartmut T1 - Temperature-dependent ranges of coexistence in a model of a two-prey-one-predator microbial food web JF - Marine Biology N2 - The objective of our study was to analyze the effects of temperature on the population dynamics of a three-species food web consisting of two prey bacteria (Pedobacter sp. and Acinetobacter johnsonii) and a protozoan predator (Tetrahymena pyriformis) as model organisms. We assessed the effects of temperature on the growth rates of all three species with the objective of developing a model with four differential equations based on the experimental data. The following hypotheses were tested at a theoretical level: Firstly, temperature changes can affect the dynamic behavior of a system by temperature-dependent parameters and interactions and secondly, food web response to temperature cannot be derived from the single species temperature response. The main outcome of the study is that temperature changes affect the parameter range where coexistence is possible within all three species. This has significant consequences on our ideas regarding the evaluation of effects of global warming. Y1 - 2012 U6 - http://dx.doi.org/10.1007/s00227-012-1966-x SN - 1432-1793 VL - 159 IS - 11 SP - 2423 EP - 2430 PB - Springer CY - Berlin ER - TY - THES A1 - Schieffer, Andre T1 - Studies on diversity and coexistence in an experimental microbial community N2 - Biodiversity and the coexistence of species have puzzled and fascinated biologists since decades and is a hotspot in todays’ natural sciences. Preserving this biodiversity is a great challenge as habitats and environments underlying tremendous changes like climate change and the loss of natural habitats, which are mainly due to anthropogenic influences. The coexistence of numerous species even in homogeneous environments is a stunning feature of natural communities and has been summarized under the term ‘paradox of plankton’. Up to now, there are several mechanisms discussed, which may contribute to local and global diversity of organisms. Several interspecific trade offs have been identified maintaining the coexistence of species like their abilities regarding competition and predator avoidance, their capability to disperse in space and time, and their ability to exploit variable resources. Further, micro-evolutionary dynamics supporting the coexistence of species have been added to our knowledge, and deriving from theoretical deterministic models, non-linear dynamics which describe the temporal fluctuation of abundances of organisms. Whereas competition and predation seem to be clue structural elements within interacting organisms, the intrinsic dynamic behavior – by means of temporal changes in abundance - plays an important role regarding coexistence within a community. The present work sheds light on different factors affecting the coexistence of species using experimental microbial model systems consisting of a bacterivorous ciliate as the predator and two bacteria strains as prey organism. Additionally, another experimental setup consisting of two up to five bacteria species competing for one limiting resource was investigated. Highly controllable chemostat systems were established to exclude extrinsic disturbances. According to theoretical analyses I was able to show - experimentally and theoretically - that phenotypic plasticity of one species within a microbial one-predator-two-prey food web enlarges the range of possible coexistence of all species under different dynamic conditions, compared to a food web without phenotypic plasticity. This was accompanied by non-linear (chaotic) population dynamics within all experimental systems showing phenotypic plasticity. The experiments on the interplay of competition, predation and invasion showed that all aspects have an influence on species coexistence. Under undisturbed controlled conditions all aspects were analyzed in detail and in combination. Populations showed oscillations which were shown by quasi-chaotic attractors in phase space diagrams. Competition experiments with two up to five bacteria species competing for one limiting resource showed that all organisms were able to coexist which was mediated by species oscillations entering a regime of chaos. Besides that fact it was found, that the productivity (biomass) as well as the total cell numbers – under the same nutrition supply – increased by an increasing number of species in the experimental systems. Up to now, the occurrence of non-linear dynamics in well controlled experimental studies has been recognized several times and this phenomenon seemed to be more common in natural systems than generally assumed. N2 - Biodiversität und die Koexistenz von Arten fasziniert und verblüfft Biologen seit Jahr-zehnten und stellen einen Schwerpunkt in der heutigen Umweltforschung dar. Der Schutz und die Konservierung dieser Mannigfaltigkeit stellen eine große Herausfor-derung dar, da die natürlichen Lebensräume sowie die Umwelt enormen Verände-rungen unterworfen sind, welche meist in einem anthropogenen Ursprung wurzeln. Die Koexistenz vieler Arten, auch in relativ homogenen Habitaten ist ein faszinieren-des Charakteristikum natürlicher Lebensgemeinschaften und wird als ‚Paradox des Planktons‘ bezeichnet. Gegenwärtig werden diverse Ursachen diskutiert, welche vermutlich zur lokalen und globalen Diversität von Organismen beitragen. Einige die-ser möglichen Ursachen, die zur Aufrechterhaltung der Koexistenz der Arten beitra-gen, wurden identifiziert: Das Vermögen der Konkurrenz- und Prädationsvermeidung, die Fähigkeit räumlicher sowie zeitlicher Verteilung, sowie das Vermögen variable Ressourcen zu nutzen. Des Weiteren wurden mikro-evolutionäre Phänomene und Dynamiken identifiziert, sowie, von theoretischen deterministischen Modellen ausge-hend, nichtlineare Dynamiken, welche die zeitlichen Schwankungen der Abundanzen von Organismen beschreiben. Diese Aspekte stellen die Schlüsselkomponenten zwi-schen interagierenden Organismen dar, wobei das intrinsiche, nicht lineare dynami-sche Verhalten in Form von zeitlichen Veränderungen in Abundanzen eine zusätzli-che entscheidende Rolle bezüglich der Koexistenz von Arten spielen kann. Einige dieser Aspekte wurden in der vorliegenden Arbeit untersucht. In Anlehnung an theoretische Analysen konnte experimentell sowie theoretisch gezeigt werden, dass phänotypische Plastizität in einer Bakterienart in einem mikrobiellen Ein-Räuber-zwei-Beute-Nahrungsgewebe den Bereich der möglichen Koexistenz unter sich än-dernden experimentellen Bedingungen (Änderungen der Durchflussraten der Chemostate) – im direkten Vergleich zu einem experimentellen Nahrungsgewebe ohne phänotypische Plastizität – erweitern kann. Dies wurde begleitet durch nicht lineare Abundanzschwankungen in den Populationen aller untersuchten Versuchs-ansätze. In weiteren Untersuchungen wurde das Zusammenspiel von Konkurrenz, Prädation und Invasion in einer experimentellen mikrobiellen Gemeinschaft untersucht. Unter kontrollierten Bedingungen konnten diese Aspekte detailliert untersucht werden und es konnten Aufschlüsse darüber gewonnen werden, welche Reaktionen (Interaktionen) innerhalb der untersuchten Gemeinschaften stattfinden. Im Versuchsverlauf wurden Veränderungen in den Abundanzen sowie chaotische Schwankungen der Zellzahlen festgestellt. In Konkurrenzexperimenten von zwei bis zu fünf um eine limitierende Ressource konkurrierende Bakterienarten konnte gezeigt werden, dass alle Arten – vermittelt durch chaotische Abundanzschwankungen – nebeneinander koexistieren konnten. Begleitend dazu wurde herausgefunden, dass die Produktivität (Biomasse) sowie die Gesamtzellzahl bei gleicher Nahrungsverfügbarkeit der experimentellen Systeme mit steigender Artenzahl zunehmen. Gegenwärtig ist das Auftreten von Chaos in gut kontrollierten experimentellen Studien vereinzelt beobachtet worden, wobei dieses Phänomen jedoch häufiger in der Natur aufzutreten scheint als generell vermutet. Y1 - 2012 N1 - Köln, Univ., Diss., 2012 ER - TY - JOUR A1 - Alexopoulos, Spiros T1 - Biogas systems: basics, biogas multifunction, principle of fermentation and hybrid application with a solar tower for the treatment of waste animal manure JF - Journal of Engineering Science and Technology Review N2 - Two of the main environmental problems of today’s society are the continuously increasing production of organic wastes as well as the increase of carbon dioxide in the atmosphere and the related green house effect. A way to solve these problems is the production of biogas. Biogas is a combustible gas consisting of methane, carbon dioxide and small amounts of other gases and trace elements. Production of biogas through anaerobic digestion of animal manure and slurries as well as of a wide range of digestible organic wastes and agricultural residues, converts these substrates into electricity and heat and offers a natural fertiliser for agriculture. The microbiological process of decomposition of organic matter, in the absence of oxygen takes place in reactors, called digesters. Biogas can be used as a fuel in a gas turbine or burner and can be used in a hybrid solar tower system offering a solution for waste treatment of agricultural and animal residues. A solar tower system consists of a heliostat field, which concentrates direct solar irradiation on an open volumetric central receiver. The receiver heats up ambient air to temperatures of around 700°C. The hot air’s heat energy is transferred to a steam Rankine cycle in a heat recovery steam generator (HRSG). The steam drives a steam turbine, which in turn drives a generator for producing electricity. In order to increase the operational hours of a solar tower power plant, a heat storage system and/ or hybridization may be considered. The advantage of solar-fossil hybrid power plants, compared to solar-only systems, lies in low additional investment costs due to an adaptable solar share and reduced technical and economical risks. On sunny days the hybrid system operates in a solar-only mode with the central receiver and on cloudy days and at night with the gas turbine only. As an alternative to methane gas, environmentally neutral biogas can be used for operating the gas turbine. Hence, the hybrid system is operated to 100% from renewable energy sources Y1 - 2012 SN - 1791-2377 N1 - Special Issue on Renewable Energy Systems VL - 5 IS - 4 SP - 48 EP - 55 ER - TY - CHAP A1 - Streun, M. A1 - Al-Kaddoum, R. A1 - Parl, C. A1 - Pietrzyk, U. A1 - Ziemons, Karl A1 - Waasen, S. van T1 - Simulation studies of optical photons in monolithic block scintillators T2 - 2011 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - The interest in PET detectors with monolithic block scintillators is growing. In order to obtain high spatial resolutions dedicated positioning algorithms are required. But even an ideal algorithm can only deliver information which is provided by the detector. In this simulation study we investigated the light distribution on one surface of cuboid LSO scintillators of different size. Scintillators with a large aspect ratio (small footprint and large height) showed significant position information only for a minimum interaction depth of the gamma particle. The results allow a quantitative estimate for a useful aspect ratio. Y1 - 2012 SN - 978-1-4673-0120-6 (electronic ISBN) SN - 978-1-4673-0118-3 (print ISBN) U6 - http://dx.doi.org/10.1109/NSSMIC.2011.6154621 SP - 1380 EP - 1382 PB - IEEE CY - New York ER - TY - CHAP A1 - Frotscher, Ralf A1 - Raatschen, Hans-Jürgen A1 - Staat, Manfred ED - Holzapfel, Gerhard A. T1 - Effectiveness of the edge-based smoothed finite element method applied to soft biological tissues T2 - ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012 Y1 - 2012 SN - 978-3-85125-223-1 PB - Verlag d. Technischen Universität Graz CY - Graz ER - TY - CHAP A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Hunyh A1 - Staat, Manfred T1 - Finite Element Implementation of a 3D Fung-type Model T2 - ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012 Y1 - 2012 SN - 978-3-85125-223-1 PB - Verlag d. Technischen Universität Graz CY - Graz ER - TY - CHAP A1 - Engels, Elmar A1 - Schnabel, Holger T1 - Rapid-control-prototyping of industrial drives for the sercos automation bus T2 - 13th International Workshop on Mechatronics (MECATRONICS), 2012 9th France-Japan & 7th Europe-Asia Congress on and Research and Education in Mechatronics (REM) N2 - This article describes the functionality of a MATLAB® library that can be used to develop motion-logic applications in MATLAB programming language for industrial drive and control systems using the well known sercos automation bus. Therewith MATLAB's functionality is extended to designing automation applications from single axis machines up to multi-kinematic robots. KW - MATLAB , MLPI , Motion control , Open Core , industrial drives , rapid control prototypin , sercos automation bus Y1 - 2012 UR - http://dx.doi.org/10.1109/MECATRONICS.2012.6451005 SN - 978-1-4673-4771-6 SP - 177 EP - 181 ER - TY - JOUR A1 - Kirstein, Simon A1 - Müller, Karsten A1 - Walecki-Mingers, Mark A1 - Deserno, Thomas M. T1 - Robust adaptive flow line detection in sewer pipes JF - Automation in construction N2 - As part of a novel approach to automatic sewer inspection, this paper presents a robust algorithm for automatic flow line detection. A large image repository is obtained from about 50,000 m sewers to represent the high variability of real world sewer systems. Automatic image processing combines Canny edge detection, Hough transform for straight lines and cost minimization using Dijkstra's shortest path algorithm. Assuming that flow lines are mostly smoothly connected horizontal structures, piecewise flow line delineation is reduced to a process of selecting adjacent line candidates. Costs are derived from the gap between adjacent candidates and their reliability. A single parameter α enables simple control of the algorithm. The detected flow line may precisely follow the segmented edges (α = 0.0) or minimize gaps at joints (α = 1.0). Both, manual and ground truth-based analysis indicate that α = 0.8 is optimal and independent of the sewer's material. The algorithm forms an essential step to further automation of sewer inspection. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.autcon.2011.05.009 SN - 1872-7891 (E-Journal) ; 0926-5805 (Print) IS - 21 SP - 24 EP - 31 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Ganegedara, H. A1 - Alahakoon, D. A1 - Mashford, J. A1 - Paplinski, A. A1 - Müller, Karsten A1 - Deserno, T. M. T1 - Self organising map based region of interest labelling for automated defect identification in large sewer pipe image collections T2 - The 2012 International Joint Conference on Neural Networks (IJCNN) : 10 - 15 June 2012, Brisbane, Australia ; [part of the] 2012 IEEE World Congress on Computational Intelligence (IEEE-WCCI 2012) Y1 - 2012 SN - 978-1-4673-1490-9 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Alexopoulos, Spiros A1 - Kluczka, Sven A1 - Vaeßen, Christiane A1 - Roeb, M. A1 - Neises, M. T1 - Scenario development for efficient methanol production using CO2 and solar energy T2 - Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012 Y1 - 2012 SP - ID 99 CY - Rijeka ER - TY - CHAP A1 - Sauerborn, Markus A1 - Klimek, J. A1 - Hoffschmidt, Bernhard A1 - Essen, H. A1 - Sieger, S. A1 - Biegel, G. A1 - Göttsche, Joachim A1 - Hilger, Patrick T1 - Eurosun 2012 : radar technology for heliostat posititon control T2 - Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012 Y1 - 2012 SP - ID 80 CY - Rijeka ER - TY - JOUR A1 - Ferrein, Alexander A1 - Meyer, Thomas T1 - A Brief Overview of Artificial Intelligence in South Africa JF - AI Magazine N2 - South Africa in recent years is the establishment of a number of research hubs involved in AI activities ranging from mobile robotics and computational intelligence, to knowledge representation and reasoning, and human language technologies. In this survey we take the reader through a quick tour of the research being conducted at these hubs, and touch on an initiative to maintain and extend the current level of interest in AI research in the country. Y1 - 2012 U6 - http://dx.doi.org/10.1609/aimag.v33i1.2357 SN - 0738-4602 VL - 33 IS - 1 SP - 99 EP - 101 PB - AAAI CY - Menlo Park ER - TY - CHAP A1 - Ferrein, Alexander A1 - Kallweit, Stephan A1 - Lautermann, Mark T1 - Towards an autonomous pilot system for a tunnel boring machine T2 - 5th Robotics and Mechatronics Conference of South Africa (ROBMECH) : 26 - 27 November 2012 ; CSIR International Conference Centre Gauteng South Africa Y1 - 2012 SN - 978-1-4673-5183-6 N1 - Robotics and Mechatronics Conference of South Africa <5, 2012, Johannesburg> ; ROBOMECH <5, 2012, Johannesburg> PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Göttsche, Joachim A1 - Sauerborn, Markus T1 - High concentration solar collectors T2 - Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications N2 - Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this chapter, different criteria for the choice of technology are analyzed in detail. KW - Central receiver system KW - Concentrated solar collector KW - Fresnel collector KW - Optical and thermal analysis KW - Solar concentration Y1 - 2012 SN - 978-0-08-087873-7 U6 - http://dx.doi.org/10.1016/B978-0-08-087872-0.00306-1 VL - 3 SP - 165 EP - 209 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Sattler, Johannes, Christoph A1 - Anthrakidis, Anette A1 - Teixeira Boura, Cristiano José A1 - O'Connor, P. A1 - Hilger, Patrick T1 - Concentrating solar power T2 - Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications Y1 - 2012 SN - 978-0-08-087872-0 U6 - http://dx.doi.org/10.1016/B978-0-08-087872-0.00319-X VL - 3 SP - 595 EP - 636 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Baumann, Torsten A1 - Teixeira Boura, Cristiano José A1 - Eckstein, Julian A1 - Dabrowski, Jan A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Schmitz, Stefan A1 - Zunft, Stefan T1 - Properties of bulk materials for high-temperature air-sand heat exchangers T2 - 30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 2 Y1 - 2012 SN - 978-1-61839-364-7 SP - 1270 EP - 1278 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Sauerborn, Markus A1 - Hoffschmidt, Bernhard A1 - Telle, R. A1 - Wagner, M. T1 - Heatable optical analyse system for high temperature absorbers T2 - 30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5 Y1 - 2012 SN - 978-1-61839-364-7 SP - 3852 EP - 3860 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Fricke, Barbara A1 - Ziolko, C. A1 - Anthrakidis, Anette A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard A1 - Giese, F. A1 - Dillig, M. T1 - InnoSol - environmental aspects of the open volumetric receiver technology T2 - 30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5 Y1 - 2012 SP - 3895 EP - 3900 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard A1 - Rau, Christoph A1 - Sattler, Johannes, Christoph T1 - Simulation of hybrid solar tower power plants T2 - 30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5 Y1 - 2012 SP - 4044 EP - 4050 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Hoffschmidt, Bernhard A1 - Breitbach, Gerd A1 - Latzke, Markus T1 - Modelling and validation of a transient heat recovery steam generator of the solar tower power plant Juelich T2 - Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012 Y1 - 2012 SP - ID 97 CY - Rijeka ER - TY - CHAP A1 - Sauerborn, Markus A1 - Arshadi, S. A1 - Rohrmoser, R. T1 - Influence of clouds and aerosols to the haze of the sunshape T2 - 30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5 Y1 - 2012 SP - 3887 EP - 3894 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Schoene, Jens A1 - Hegger, Josef A1 - Gallwoszus, Jörg A1 - Feldmann, Markus A1 - Kopp, Maik A1 - Gündel, Max ED - Cairns, John W. T1 - Investigation on bond mechanisms of innovative small-scale shear connectors between steel and concrete T2 - Bond in concrete 2012. Vol. 2. Bond in new materials and under severe conditions Y1 - 2012 SN - 978-88-907078-3-4 SP - 893 EP - 898 PB - Publisher creations CY - Manerbio, Brescia ER - TY - JOUR A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Mokrov, Oleg A1 - Ahmed, Essam T1 - Statistical modeling of laser welding of DP/TRIP steel sheets JF - Optics and laser technology N2 - In this research work, a statistical analysis of the CO2 laser beam welding of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets was done using response surface methodology. The analysis considered the effect of laser power (2–2.2 kW), welding speed (40–50 mm/s) and focus position (−1 to 0 mm) on the heat input, the weld bead geometry, uniaxial tensile strength, formability limited dome height and welding operation cost. The experimental design was based on Box–Behnken design using linear and quadratic polynomial equations for predicting the mathematical models. The results indicate that the proposed models predict the responses adequately within the limits of welding parameters being used and the welding speed is the most significant parameter during the welding process. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.optlastec.2011.05.025 SN - 1879-2545 (E-Journal); 0030-3992 (Print); 0308-4280 (Print) VL - 44 IS - 1 SP - 92 EP - 101 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Mokrov, Oleg A1 - Ahmed, Essam T1 - Optimization of laser welding of DP/TRIP steel sheets using statistical approach JF - Optics and laser technology N2 - Generally, the quality of a weld joint is directly influenced by the welding input parameter settings. Selection of proper process parameters is important to obtain the desired weld bead profile and quality. In this research work, numerical and graphical optimization techniques of the CO2 laser beam welding of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets were carried out using response surface methodology (RSM) based on Box–Behnken design. The procedure was established to improve the weld quality, increase the productivity and minimize the total operation cost by considering the welding parameters range of laser power (2–2.2 kW), welding speed (40–50 mm/s) and focus position (−1 to 0 mm). It was found that, RSM can be considered as a powerful tool in experimental welding optimization, even when the experimenter does not have a model for the process. Strong, efficient and low cost weld joints could be achieved using the optimum welding conditions. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.optlastec.2011.06.028 SN - 1879-2545 (E-Journal); 0030-3992 (Print); 0308-4280 (Print) VL - 44 IS - 1 SP - 255 EP - 262 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Reisgen, Uwe A1 - Olschok, Simon A1 - Jakobs, Stefan A1 - Schleser, Markus A1 - Mokrov, Oleg A1 - Rossiter, Eduardo T1 - Laser beam submerged arc hybrid welding JF - Physics procedia N2 - The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.phpro.2012.10.016 SN - 1875-3892 N1 - Part of special issue "Laser assisted net shape engineering 7 (LANE 2012)" VL - 39 SP - 75 EP - 83 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Abdurakhmanov, Aydemir A1 - Turichin, Gleb A1 - Valdaitseva, Elena A1 - Bach, Friedrich-Wilhelm A1 - Hassel, Thomas A1 - Beniyashi, Alexander T1 - Investigation of factors influencing the formation of weld defects in non-vacuum electron beam welding JF - The Paton welding journal N2 - The influence of welding condition parameters and properties of material on formation of defects, such as humping and undercuts, in non-vacuum electron beam welding was investigated. The influence of separate welding parameters on the quality of welds was determined. Y1 - 2012 SN - 0957-798X VL - 2012 IS - 2 SP - 11 EP - 18 PB - Paton Publishing House CY - Kiev ER - TY - JOUR A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Abdurakhmanov, Aydemir A1 - Gumenyuk, Andrey T1 - Measuring of plasma properties induced by non-vacuum electron beam welding JF - Physics of plasma N2 - Electron beam plasma measurement was realised by means of DIABEAM system invented by ISF RWTH Aachen. The Langmuir probe method is used for measurement. The relative simplicity of the method and the possibility of dispersion of high power on the probe allow its application for the investigation of high-power electron beams. The key element of the method is a rotating thin tungsten wire, which intersects the beam transversely on its axis and collects part of the current by itself. The signals, which are registered in the DIABEAM as a voltage, were taken in the form of amplitude. The conversion of the probe current into the distribution along the beam radius was realised using the Abel’s method. A voltage-current characteristic was built for the beam current. The local electron density as well as the electron temperature, the floating potential and the plasma potential were measured and calculated by means of this characteristic. Y1 - 2012 U6 - http://dx.doi.org/10.1063/1.3675874 SN - 1089-7674 (E-Journal); 1070-664X (Print) VL - 19 IS - 1 SP - 1 EP - 7 PB - AIP Publishing CY - Melville, NY ER - TY - CHAP A1 - Hartmann, Axel A1 - Kallweit, Stephan A1 - Feldusen, Antje A1 - Schröder, Wolfgang T1 - Detection of upstream propagating sound waves at buffet flow using high-speed PIV BT - 16th International Symposium on Applications of Laser Techniques to Fluid Mechanics ; 9th to 12th July 2012 Lisbon, Portugal Y1 - 2012 N1 - Aerodynamisches Institut ; International Symposium on Applications of Laser Techniques to Fluid Mechanics <16, 2012, Lissabon> ER - TY - CHAP A1 - Quadflieg, Till A1 - Schoene, Jens A1 - Schleser, Markus A1 - Jockenhövel, Stefan A1 - Reisgen, Uwe A1 - Gries, Thomas ED - Heslehurst, Rikard Benton T1 - Shear connectors for hybrid joints of metal and FRP T2 - Diversity in composites : conference proceedings : Composites Australia and CRC-ACS 2012 conference Y1 - 2012 SN - 978-0-9873285-0-2 SP - [152] EP - [160] PB - Composites Australia CY - Hawthorne ER - TY - JOUR A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Mokrov, Oleg A1 - Zabirov, Alexander A1 - Füssel, Uwe A1 - Schnick, Michael A1 - Hertel, Martin A1 - Jaeckel, Sebastian T1 - Modelling and visualisation of the GMA process JF - Welding and Cutting Y1 - 2012 SN - 1612-3433 VL - 11 IS - 4 SP - 242 EP - 249 PB - DVS Verlag CY - Düsseldorf ER - TY - CHAP A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Abdurakhmanov, Aydemir A1 - Gumenyuk, Andrej T1 - Application of electron beam welding to fabrication of steel-aluminium dissimilar joint T2 - Beam technologies & laser application : proceedings of the VII international conference, Saint Petersburg, Sept. 18-21, 2012 Y1 - 2012 SP - 265 EP - 279 PB - Publ. House CY - Saint Petersburg ER - TY - JOUR A1 - Borgmeier, Claudia A1 - Bongaerts, Johannes A1 - Meinhardt, Friedhelm T1 - Genetic analysis of the Bacillus licheniformis degSU operon and the impact of regulatory mutations on protease production JF - Journal of biotechnology N2 - Disruption experiments targeted at the Bacillus licheniformis degSU operon and GFP-reporter analysis provided evidence for promoter activity immediately upstream of degU. pMutin mediated concomitant introduction of the degU32 allele – known to cause hypersecretion in Bacillus subtilis – resulted in a marked increase in protease activity. Application of 5-fluorouracil based counterselection through establishment of a phosphoribosyltransferase deficient Δupp strain eventually facilitated the marker-free introduction of degU32 leading to further protease enhancement achieving levels as for hypersecreting wild strains in which degU was overexpressed. Surprisingly, deletion of rapG – known to interfere with DegU DNA-binding in B. subtilis – did not enhance protease production neither in the wild type nor in the degU32 strain. The combination of degU32 and Δupp counterselection in the type strain is not only equally effective as in hypersecreting wild strains with respect to protease production but furthermore facilitates genetic strain improvement aiming at biological containment and effectiveness of biotechnological processes. KW - Marker-free mutagenesis KW - Extracellular enzymes KW - Uracil-phosphoribosyltransferase KW - Hypersecretion Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.jbiotec.2012.02.011 SN - 1873-4863 (E-Journal); 0168-1656 (Print) VL - 159 IS - 1-2 SP - 12 EP - 20 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Boettcher, Martin A1 - Haselhuhn, Angelika A1 - Jakse, Gerhard A1 - Brehmer, Bernhard A1 - Kirschner-Hermanns, Ruth T1 - Overactive bladder syndrome: an underestimated long-term problem after treatment of patients with localized prostate cancer? JF - BJU international N2 - In this study we observed courses of micturition symptoms and differentiated degrees of symptoms for each point in time while also considering the impact of bothersomeness. Our data show that not only significantly more patients who have undergone BT suffer from OAB than those who have undergone RP, but also that those affected show significantly higher values for severity of OAB symptoms throughout the whole observation period of 36 months. Our data analysis further shows that variability of OAB symptoms as well as fluctuation of severity of OAB symptoms vary to a significantly higher degree after BT than after RP. Looking only at mean figures at a given point in time clearly underestimates the underlying problem. This fact is not reflected in the literature. KW - quality of life KW - prostate cancer KW - prostatectomy KW - incontinence KW - brachytherapy Y1 - 2012 U6 - http://dx.doi.org/10.1111/j.1464-410X.2011.10623.x SN - 1365-2176 (E-Journal); 1464-410X (E-Journal); 0007-1331 (Print); 1464-4096 (Print) VL - 109 IS - 12 SP - 1824 EP - 1830 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Oertel, Mario A1 - Bung, Daniel B. T1 - Initial stage of two-dimensional dam-break waves: laboratory versus VOF JF - Journal of hydraulic research N2 - Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found. KW - VOF KW - PIV KW - physical model KW - numerical model KW - drag force KW - dam-break Y1 - 2012 U6 - http://dx.doi.org/10.1080/00221686.2011.639981 SN - 1814-2079 (E-Journal); 0022-1686 (Print) VL - 50 IS - 1 SP - 89 EP - 97 PB - Taylor & Francis CY - London ER - TY - CHAP A1 - Feldmann, Markus A1 - Pyschny, D. A1 - Döring, Bernd A1 - Kuhnhenne, Markus T1 - Life cycle assessment of steel constructions T2 - Life-cycle and sustainability of civil infrastructure systems : proceedings of the Third International Symposium on Life-Cycle Civil Engineering (IALCCE'12) : Vienna, Austria, October 3-6, 2012 Y1 - 2012 SN - 978-0-203-10336-4 SP - 321 PB - Taylor and Francis CY - Hoboken ER - TY - CHAP A1 - Kuhnhenne, Markus A1 - Döring, Bernd A1 - Pyschny, Dominik A1 - Feldmann, Markus T1 - Energy efficient sandwich construction T2 - Proceedings of the VI International Congress on Architectural Envelopes : 20.6. - 22.6.2012, San Sebastian, Spain Y1 - 2012 SP - 277 EP - 285 PB - ICAE ER - TY - CHAP A1 - Achenbach, Timm A1 - Geimer, Konstantin A1 - Lynen, Arthur A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard T1 - Simulation of thermo-mechanical processes in open volumetric absorber modules T2 - SolarPaces 2012 : concentrating solar power and chemical energy systems : Sept. 11 - 14 2012, Marrakech, Marokko Y1 - 2012 SP - 1 EP - 8 ER - TY - JOUR A1 - Hötter, Jan-Steffen A1 - Fateri, Miranda A1 - Gebhardt, Andreas T1 - Selective laser melting of metals: desktop machines open up new chances even for small companies JF - Advanced materials research N2 - Additive manufacturing (AM) of metal parts by using Selective Laser Melting (SLM) has become a powerful tool mostly in the area of automotive, aerospace engineering and others. Especially in the field of dentistry, jewelry and related branches that require individualized or even one-of-a-kind products, the direct digital manufacturing process opens up new ways of design and manufacturing. In these fields, mostly small and medium sized businesses (SME) are operating which do not have sufficient human and economic resources to invest in this technology. But to stay competitive, the application of AM can be regarded as a necessity. In this situation a new desktop machine (Realizer SLM 50) was introduced that cost about 1/3 of a shop floor SLM machine and promises small quality parts. To find out whether the machine really is an alternative for SMEs the University of Applied Science, Aachen, Germany, designed, build and optimized typical parts from the dentistry and the jewelry branches using CoCr and silver material, the latter being new with this application. The paper describes the SLM procedure and how to find and optimize the most important parameters. The test is accompanied by digital simulation in order to verify the build parameters and to plan future builds. The procedure is shown as well as the resulting parts made from CoCr and silver material. Y1 - 2012 U6 - http://dx.doi.org/10.4028/www.scientific.net/AMR.622-623.461 SN - 1662-8985 (E-Journal); 1022-6680 (Print) VL - 622-623 SP - 461 EP - 465 PB - Trans Tech Publ. CY - Baech ER - TY - CHAP A1 - Bung, Daniel B. A1 - Sun, Q. A1 - Meireles, I. A1 - Matos, J. A1 - Viseu, T. T1 - USBR type III stilling basin performance for steep stepped spillways T2 - Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto Y1 - 2012 SN - 978-989-8509-01-7 ER - TY - CHAP A1 - Oertel, Mario A1 - Bung, Daniel B. T1 - Characteristics of cross-bar block ramp flows T2 - Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto Y1 - 2012 SN - 978-989-8509-01-7 ER - TY - CHAP A1 - Bung, Daniel B. T1 - Sensitivity of phase detection techniques in aerated chute flows to hydraulic design parameters T2 - 2nd European IAHR congress : 27. - 29. June 2012, München Y1 - 2012 SN - 978-3-943683-03-5 SP - Artikelkennnummer: B15 PB - Lehrstuhl u. Versuchsanst. für Wasserbau u. Wasserwirtschaft d. TU München CY - München ER - TY - CHAP A1 - Schlurmann, Torsten A1 - Bung, Daniel B. T1 - Experimental investigation of flow-induced radial gate vibrations at Lower Subansiri dam T2 - Sixth Chinese-German Joint Symposium on Hydraulic and Ocean Engineering : JOINT 2012 : 23.-29.9.2012, Keelung Y1 - 2012 SP - 7 EP - 14 ER - TY - JOUR A1 - Ribitsch, D. A1 - Heumann, S. A1 - Karl, W. A1 - Gerlach, J. A1 - Leber, R. A1 - Birner-Gruenberger, R. A1 - Gruber, K. A1 - Eiteljoerg, I. A1 - Remler, P. A1 - Siegert, Petra A1 - Lange, J. A1 - Maurer, Karl-Heinz A1 - Berg, G. A1 - Guebitz, G. M. A1 - Schwab, H. T1 - Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli JF - Journal of biotechnology N2 - A large strain collection comprising antagonistic bacteria was screened for novel detergent proteases. Several strains displayed protease activity on agar plates containing skim milk but were inactive in liquid media. Encapsulation of cells in alginate beads induced protease production. Stenotrophomonas maltophilia emerged as best performer under washing conditions. For identification of wash-active proteases, four extracellular serine proteases called StmPr1, StmPr2, StmPr3 and StmPr4 were cloned. StmPr2 and StmPr4 were sufficiently overexpressed in E. coli. Expression of StmPr1 and StmPr3 resulted in unprocessed, insoluble protein. Truncation of most of the C-terminal domain which has been identified by enzyme modeling succeeded in expression of soluble, active StmPr1 but failed in case of StmPr3. From laundry application tests StmPr2 turned out to be a highly wash-active protease at 45 °C. Specific activity of StmPr2 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 17 ± 2 U/mg. In addition we determined the kinetic parameters and cleavage preferences of protease StmPr2. KW - Alginate beads KW - Stenotrophomonas maltophilia KW - Detergent protease Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.jbiotec.2011.09.025 SN - 1873-4863 (E-Journal); 0168-1656 (Print) VL - 157 IS - 1 SP - 140 EP - 147 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Dachwald, Bernd A1 - Feldmann, Marco A1 - Espe, Clemens A1 - Plescher, Engelbert A1 - Konstantinidis, K. A1 - Forstner, R. T1 - Enceladus explorer - A maneuverable subsurface probe for autonomous navigation through deep ice T2 - 63rd International Astronautical Congress 2012, IAC 2012; Naples; Italy; 1 October 2012 through 5 October 2012. (Proceedings of the International Astronautical Congress, IAC ; 3) Y1 - 2012 SN - 978-1-62276-979-7 SP - 1756 EP - 1766 PB - Curran CY - Red Hook, NY ER - TY - JOUR A1 - Schmitz, Philipp A1 - Weber, Martin T1 - Buying and selling behavior of individual investors in option-like securities JF - Die Betriebswirtschaft : DBW N2 - We analyze the trading behavior of individual investors in option-like securities, namely bankissued warrants, and thus expand the growing literature of investors behavior to a new kind of securities. A unique data set from a large German discount broker gives us the opportunity to analyze the trading behavior of 1,454 investors, making 89,958 transactions in 6,724 warrants on 397 underlyings. In different logit regression, we make use of the facts that investors can speculate on rising and falling prices of the underlying with call and put warrants and that we also have information about the stock portfolios of the investors. We report several facts about the trading behavior of individual investors in warrants that are consistent with the literature on the behavior of individual investors in the stock market. The warrant investors buy calls and sell puts if the price of the underlying has decreased over the past trading days and they sell calls and buy puts if the price of the underlying has increased. That means, the investors follow negative feedback trading strategies in all four trading categories observed. In addition, we find strong evidence for the disposition effect for call as well as put warrants, which is reversed in December. The trading behavior is also influenced if the underlying reaches some exceptionally prices, e.g. highs, lows or the strike price. We show that hedging, as one natural candidate to buy puts, does not play an important role in the market for bank-issued warrants. KW - Bank-issued Warrants KW - Disposition Effect KW - Negative Feedback Trading KW - Trading Behavior KW - Individual Investors Y1 - 2012 U6 - http://dx.doi.org/10.2139/ssrn.2055088 SN - 0342-7064 VL - 72 IS - 5 SP - 409 EP - 426 PB - Schäffer-Poeschel CY - Stuttgart ER - TY - CHAP A1 - Kern, Alexander A1 - Schelthoff, Christof A1 - Mathieu, Moritz T1 - Calculation of interception efficiencies for mesh-type air-terminations according to IEC 62305-3 using a dynamic electro-geometrical model T2 - International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna Y1 - 2012 SN - 978-1-4673-1896-9 (E-Book) ; 978-1-4673-1898-3 (Print) SP - 1 EP - 6 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Eilmann, Britta A1 - Rigling, Andreas ED - Abrams, Marc T1 - Tree-growth analyses to estimate tree species' drought tolerance JF - Tree Physiology N2 - Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species. Y1 - 2012 U6 - http://dx.doi.org/10.1093/treephys/tps004 SN - 0829-318X (Print) SN - 1758-4469 (Online) VL - 32 IS - 2 SP - 178 EP - 187 PB - Oxford University Press CY - Oxford ER - TY - CHAP A1 - Lo Piparo, G. B. A1 - Kern, Alexander A1 - Mazzetti, C. T1 - Some masterpoints about risk due to lightning T2 - International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna Y1 - 2012 SN - 978-1-4673-1896-9 (E-Book) ; 978-1-4673-1898-3 (Print) SP - 1 EP - 6 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Bragard, Michael A1 - van Hoek, H. A1 - De Doncker, R. W. T1 - A major design step in IETO concept realization that allows overcurrent protection and pushes limits of switching performance JF - IEEE transactions on power electronics N2 - This paper presents the latest prototype of the integrated emitter turn-off thyristor concept, which potentially ranks among thyristor high-power devices like the gate turn-off thyristor and the integrated gate-commutated thyristor (IGCT). Due to modifications of the external driver stage and mechanical press-pack design optimization, this prototype allows for full device characterization. The turn-off capability was increased to 1600 A with an active silicon area of 823mm2 . This leads to a transient peak power of 672.1kW/cm² . Within this paper, measurements and concept assessment are presented and a comparison to state-of-the-art IGCT devices is provided. Y1 - 2012 U6 - http://dx.doi.org/10.1109/TPEL.2012.2189136 SN - 0885-8993 VL - 27 IS - 9 SP - 4163 EP - 4171 PB - IEEE CY - New York ER - TY - THES A1 - Bragard, Michael T1 - The integrated emitter turn-off thyristor : an innovative MOS-gated high-power device. - (Aachener Beiträge des ISEA ; 62) N2 - This thesis introduces the Integrated Emitter Turn-Off (IETO) Thyristor as a new high-power device. Known state-of-the-art research activities like the Dual GCT, the ETO thyristor and the ICT were presented and critically reviewed. A comparison with commercialized solutions identifies the pros and cons of each type of device family. Based on this analysis, the IETO structure is proposed, covering most benefits of each device class. In particular the combination of a MOS-assisted turn-off with a thyristor-based device allows a voltage-controlled MOS switching and the low on-state voltage of the thyristors. The following synthesis of an IETO device stands on a three-dimensional field of optimization spanned by electric, mechanical and thermal aspects. From an electric point of view, the lowest possible parasitic inductance and resistance within the commutation path are optimization criteria. The mechanical construction has to withstand the required contact pressure of multiple kilo Newtons. Finally, thermal borders limit the maximum average current of the device. FEM simulations covering these three aspects are performed for several design proposals. An IETO prototype is constructed and measurements on various test benches attest thermal, mechanical and electric performance. A local decoupling of the external driver stage and the presspack housing is presented by a cable connection. This separation enables a thermal and mechanical independence, which is advantageous in terms of vibrations and thermal cycles including increased reliability. The electric pulse performance of the prototype device is a factor of 3.1 above today''s solutions. In single-pulse measurements, a current up to 1600 A was successfully turned off at 115°C with an active silicon area of 823 mm². One reason for this increased turn-off capability is the extremely low-inductive construction. Additional functionality of the IETO thyristor like over-current self-protection and defined short-circuit failure state are successfully verified. Y1 - 2012 SN - 978-3-8440-1152-4 N1 - Zugl.: Aachen, Techn. Hochsch., Diss., 2012 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Nötzold, K. A1 - Uphues, A. A1 - Wegener, R. A1 - Soter, S. A1 - Fink, K. A1 - Bragard, Michael A1 - Griessel, R. T1 - Inverter based test setup for LVRT verification of a full-scale 2 MW wind power converter T2 - EPE Joint Wind Energy and T&D Chapters Seminar : 28th and 29th of June 2012, in the Utzon Centre, Aalborg, Denmark ; papers, posters, presentations. - Session 2: Grid connection, compliance Y1 - 2012 PB - EPE Association CY - Brussels ER - TY - JOUR A1 - Rigling, Andreas A1 - Bigler, Christof A1 - Eilmann, Britta A1 - Feldmeyer-Christe, Elisabeth A1 - Gimmi, Urs A1 - Ginzler, Christian A1 - Graf, Ulrich A1 - Mayer, Phillip A1 - Vacchiano, Giorgio A1 - Weber, Pascal A1 - Wohlgemuth, Thomas A1 - zweifel, Roman A1 - Dobbertin, Matthias T1 - Driving factors of a vegetation shift from Scots pine to pubescent oak in dry Alpine forests JF - Global Change Biology N2 - An increasing number of studies have reported on forest declines and vegetation shifts triggered by drought. In the Swiss Rhone valley (Valais), one of the driest inner-Alpine regions, the species composition in low elevation forests is changing: The sub-boreal Scots pine (Pinus sylvestris L.) dominating the dry forests is showing high mortality rates. Concurrently the sub-Mediterranean pubescent oak (Quercus pubescens Willd.) has locally increased in abundance. However, it remains unclear whether this local change in species composition is part of a larger-scale vegetation shift. To study variability in mortality and regeneration in these dry forests we analysed data from the Swiss national forest inventory (NFI) on a regular grid between 1983 and 2003, and combined it with annual mortality data from a monitoring site. Pine mortality was found to be highest at low elevation (below 1000 m a.s.l.). Annual variation in pine mortality was correlated with a drought index computed for the summer months prior to observed tree death. A generalized linear mixed-effects model indicated for the NFI data increased pine mortality on dryer sites with high stand competition, particularly for small-diameter trees. Pine regeneration was low in comparison to its occurrence in the overstorey, whereas oak regeneration was comparably abundant. Although both species regenerated well at dry sites, pine regeneration was favoured at cooler sites at higher altitude and oak regeneration was more frequent at warmer sites, indicating a higher adaptation potential of oaks under future warming. Our results thus suggest that an extended shift in species composition is actually occurring in the pine forests in the Valais. The main driving factors are found to be climatic variability, particularly drought, and variability in stand structure and topography. Thus, pine forests at low elevations are developing into oak forests with unknown consequences for these ecosystems and their goods and services. Y1 - 2012 U6 - http://dx.doi.org/10.1111/gcb.12038 SN - 1354-1013 (Print) SN - 1365-2486 (Online) VL - 19 IS - 1 SP - 229 EP - 240 PB - Wiley-Blackwell CY - Oxford ER - TY - CHAP A1 - Weil, M. A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Cherstvy, A. T1 - Electrical monitoring of layer-by-layer adsorption of oppositely charged macromolecules by means of capacitive field-effect devices Y1 - 2012 SN - 978-3-9813484-2-2 U6 - http://dx.doi.org/10.5162/IMCS2012/P2.5.2 SP - 1575 EP - 1578 ER - TY - CHAP A1 - Bohrn, Ulrich A1 - Mucha, Andreas A1 - Werner, Frederik A1 - Stütz, Evamaria A1 - Bäcker, Matthias A1 - Krumbe, Christoph A1 - Schienle, Meinrad A1 - Fleischer, Maximilian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Detection of toxic chromium species in water using cellbased sensor systems Y1 - 2012 SN - 978-3-9813484-2-2 U6 - http://dx.doi.org/10.5162/IMCS2012/P2.1.14 SP - 1364 EP - 1367 ER - TY - CHAP A1 - Bohrn, Ulrich A1 - Stütz, Evamaria A1 - Fleischer, Maximilian A1 - Schöning, Michael Josef A1 - Wagner, Patrick T1 - Living cell-based gas sensor system for the detection of acetone in air Y1 - 2012 SN - 978-3-9813484-2-2 U6 - http://dx.doi.org/10.5162/IMCS2012/3.2.3 SP - 269 EP - 272 ER - TY - CHAP A1 - Takenaga, Shoko A1 - Werner, Frederik A1 - Sawada, Kazuaki A1 - Schöning, Michael Josef T1 - Comparison of label-free ACh image sensors based on CCD and LAPS Y1 - 2012 SN - 978-3-9813484-2-2 U6 - http://dx.doi.org/10.5162/IMCS2012/4.2.6 SP - 356 EP - 359 ER - TY - CHAP A1 - Fuchs, Britta A1 - Ritz, Thomas A1 - Strauch, Jakob ED - Obaidat, Mohammad S. T1 - Usability of mobile applications : dissemination of usability engineering in small and medium enterprises T2 - Proceedings of the International Conference on Data Communication Networking, e-Business and Optical Communication Systems : Rome, Italy, 24 - 27 July, 2012 ; [integrated in the ICETE (International Conference on e-Business and Telecommunications)] Y1 - 2012 SN - 978-989-8565-23-5 N1 - Nebentitel: DCNET; ICE-B; OPTICS SP - 272 EP - 277 PB - SciTePress CY - [Lissabon] ER - TY - JOUR A1 - Leidinger, Rafael A1 - Noisten, Thomas A1 - Wollert, Jörg T1 - Realtime automation networks in moVing industrial environments JF - Journal of systemics, cybernetics and informatics N2 - The radio-based wireless data communication has made the realization of new technical solutions possible in many fields of the automation technology (AT). For about ten years, a constant disproportionate growth of wireless technologies can be observed in the automation technology. However, it shows that especially for the AT, conventional technologies of office automation are unsuitable and/or not manageable. The employment of mobile services in the industrial automation technology has the potential of significant cost and time savings. This leads to an increased productivity in various fields of the AT, for example in the factory and process automation or in production logistics. In this paper technologies and solutions for an automation-suited supply of mobile wireless services will be introduced under the criteria of real time suitability, IT-security and service orientation. Emphasis will be put on the investigation and development of wireless convergence layers for different radio technologies, on the central provision of support services for an easy-to-use, central, backup enabled management of combined wired / wireless networks and on the study on integrability in a Profinet real-time Ethernet network. KW - PROFINET KW - Distributed Control Systems, KW - Industrial Automation Technology, KW - 802.15.4 KW - Bluetooth KW - Wireless Networks Y1 - 2012 SN - 1690-4532 VL - Vol. 10 IS - Iss. 2 SP - 52 EP - 56 PB - IIIC CY - Orlando ER - TY - CHAP A1 - Wollert, Jörg T1 - The performance of UWB-communication in an industrial environment T2 - IEEE 1st International Symposium on Wireless Systems : (IDAACS-SWS) : Offenburg, 20-21 Sept. 2012 Y1 - 2012 SN - 978-1-4673-4678-8 U6 - http://dx.doi.org/10.1109/IDAACS-SWS.2012.6377639 SP - 85 EP - 90 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Kötter, Jens A1 - Decker, Stefan A1 - Detzler, Raphael A1 - Schäfer, Jochen A1 - Schmitz, Mark A1 - Herrmann, Ulf T1 - Cost Reduction of Solar Fields with HelioTrough Collector Y1 - 2012 N1 - Concentration Solar Power and Chemical Energy Systemes : SolarPaces 2012, September 11 14 2002, Marrakesh, Morroco PB - FLAGSOL CY - Köln ER - TY - JOUR A1 - Mottaghy, Darius A1 - Dijkshoorn, Lydia T1 - Implementing an effective finite difference formulation for borehole heat exchangers into a heat and mass transport code JF - Renewable Energy N2 - We present an effective finite difference formulation for implementing and modeling multiple borehole heat exchangers (BHE) in the general 3-D coupled heat and flow transport code SHEMAT. The BHE with arbitrary length can be either coaxial or double U-shaped. It is particularly suitable for modeling deep BHEs which contain varying pipe diameters and materials. Usually, in numerical simulations, a fine discretization of the BHE assemblage is required, due to the large geometric aspect ratios involved. This yields large models and long simulation times. The approach avoids this problem by considering heat transport between fluid and the soil through pipes and grout via thermal resistances. Therefore, the simulation time can be significantly reduced. The coupling with SHEMAT is realized by introducing an effective heat generation. Due to this connection, it is possible to consider heterogeneous geological models, as well as the influence of groundwater flow. This is particularly interesting when studying the long term behavior of a single BHE or a BHE field. Heating and cooling loads can enter the model with an arbitrary interval, e.g. from hourly to monthly values. When dealing with large BHE fields, computing times can be further significantly reduced by focusing on the temperature field around the BHEs, without explicitly modeling inlet and outlet temperatures. This allows to determine the possible migration of cold and warm plumes due to groundwater flow, which is of particular importance in urban areas with a high BHE installation density. The model is validated against the existing BHE modeling codes EWS and EED. A comparison with monitoring data from a deep BHE in Switzerland shows a good agreement. Synthetic examples demonstrate the field of application of this model. KW - Borehole heat exchanger KW - Finite differences KW - Heat transport Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.renene.2012.02.013 SN - 0960-1481 VL - 45 SP - 59 EP - 71 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Henken, F. E. A1 - Oosterhuis, K. A1 - Öhlschläger, Peter A1 - Bosch, L. A1 - Hooijberg, E. A1 - Haanen, J. B. A. G. A1 - Steenbergen, R. D. M. T1 - Preclinical safety evaluation of DNA vaccines encoding modified HPV16 E6 and E7 JF - Vaccine N2 - Persistent infection with high-risk human papillomaviruses (hrHPV) can result in the formation of anogenital cancers. As hrHPV proteins E6 and E7 are required for cancer initiation and maintenance, they are ideal targets for immunotherapeutic interventions. Previously, we have described the development of DNA vaccines for the induction of HPV16 E6 and E7 specific T cell immunity. These vaccines consist of ‘gene-shuffled’ (SH) versions of HPV16 E6 and E7 that were fused to Tetanus Toxin Fragment C domain 1 (TTFC) and were named TTFC-E6SH and TTFC-E7SH. Gene-shuffling was performed to avoid the risk of inducing malignant transformation at the vaccination site. Here, we describe the preclinical safety evaluation of these candidate vaccines by analysis of their transforming capacity in vitro using established murine fibroblasts (NIH 3T3 cells) and primary human foreskin keratinocytes (HFKs). We demonstrate that neither ectopic expression of TTFC-E6SH and TTFC-E7SH alone or in combination enabled NIH 3T3 cells to form colonies in soft agar. In contrast, expression of HPV16 E6WT and E7WT alone or in combination resulted in effective transformation. Similarly, retroviral transduction of HFKs from three independent donors with both TTFC-E6SH and TTFC-E7SH alone or in combination did not show any signs of immortalization. In contrast, the combined expression of E6WT and E7WT induced immortalization in HFKs from all donors. Based on these results we consider it justified to proceed to clinical evaluation of DNA vaccines encoding TTFC-E6SH and TTFC-E7SH in patients with HPV16 associated (pre)malignancies. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.vaccine.2012.04.013 SN - 0264-410X VL - 30 IS - 28 SP - 4259 EP - 4266 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Immel, Timo A1 - Grützke, Martin A1 - Späte, Anne-Katrin A1 - Groth, Ulrich A1 - Öhlschläger, Peter A1 - Huhn, Thomas T1 - Synthesis and X-ray structure analysis of a heptacoordinate titanium(IV)-bis-chelate with enhanced in vivo antitumor efficacy JF - Chemical Communications N2 - Chelate stabilization of a titanium(IV)–salan alkoxide by ligand exchange with 2,6-pyridinedicarboxylic acid (dipic) resulted in heptacoordinate complex 3 which is not redox-active, stable on silica gel and has increased aqueous stability. 3 is highly toxic in HeLa S3 and Hep G2 and has enhanced antitumor efficacy in a mouse cervical-cancer model. Y1 - 2012 U6 - http://dx.doi.org/10.1039/C2CC31624B SN - 1364-548X VL - 48 IS - 46 SP - 5790 EP - 5792 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty JF - Tap chi Khoa hoc & ung dung - Dai hoc Ton Duc Thang Y1 - 2012 N1 - = Journal of Applied Sciences - Ton Duc Thang University VL - 19 SP - 45 EP - 47 ER - TY - JOUR A1 - Orzada, S. A1 - Maderwald, S. A1 - Poser, B. A. A1 - Johst, S. A1 - Kannengiesser, S. A1 - Ladd, M. E. A1 - Bitz, Andreas T1 - Time-interleaved acquisition of modes: an analysis of SAR and image contrast implications JF - Magnetic Resonance in Medicine N2 - s the magnetic field strength and therefore the operational frequency in MRI are increased, the radiofrequency wavelength approaches the size of the human head/body, resulting in wave effects which cause signal decreases and dropouts. Especially, whole-body imaging at 7 T and higher is therefore challenging. Recently, an acquisition scheme called time-interleaved acquisition of modes has been proposed to tackle the inhomogeneity problems in high-field MRI. The basic premise is to excite two (or more) different Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-1 modes using static radiofrequency shimming in an interleaved acquisition, where the complementary radiofrequency patterns of the two modes can be exploited to improve overall signal homogeneity. In this work, the impact of time-interleaved acquisition of mode on image contrast as well as on time-averaged specific absorption rate is addressed in detail. Time-interleaved acquisition of mode is superior in Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-2 homogeneity compared with conventional radiofrequency shimming while being highly specific absorption rate efficient. Time-interleaved acquisition of modes can enable almost homogeneous high-field imaging throughout the entire field of view in PD, T2, and T2*-weighted imaging and, if a specified homogeneity criterion is met, in T1-weighted imaging as well. Y1 - 2012 U6 - http://dx.doi.org/10.1002/mrm.23081 SN - 1522-2594 VL - 67 IS - 4 SP - 1033 EP - 1041 PB - Wiley-Liss CY - New York ER - TY - JOUR A1 - Kobus, Thiele A1 - Bitz, Andreas A1 - Uden, Mark J. van A1 - Lagemaat, Miram W. A1 - Rothgang, Eva A1 - Orzada, Stephan A1 - Heerschap, Arend A1 - Scheenen, Tom W. J. T1 - In vivo 31P MR spectroscopic imaging of the human prostate at 7 T: safety and feasibility JF - Magnetic Resonance in Medicine N2 - 31P MR spectroscopic imaging of the human prostate provides information about phosphorylated metabolites that could be used for prostate cancer characterization. The sensitivity of a magnetic field strength of 7 T might enable 3D 31P MR spectroscopic imaging with relevant spatial resolution in a clinically acceptable measurement time. To this end, a 31P endorectal coil was developed and combined with an eight-channel 1H body-array coil to relate metabolic information to anatomical location. An extensive safety validation was performed to evaluate the specific absorption rate, the radiofrequency field distribution, and the temperature distribution of both coils. This validation consisted of detailed Finite Integration Technique simulations, confirmed by MR thermometry and Burn:x-wiley:07403194:media:MRM24175:tex2gif-stack-1 measurements in a phantom and in vivo temperature measurements. The safety studies demonstrated that the presence of the 31P endorectal coil had no influence on the specific absorption rate levels and temperature distribution of the external eight-channel 1H array coil. To stay within a 10 g averaged local specific absorption rate of 10 W/kg, a maximum time-averaged input power of 33 W for the 1H array coil was allowed. For transmitting with the 31P endorectal coil, our safety limit of less than 1°C temperature increase in vivo during a 15-min MR spectroscopic imaging experiment was reached at a time-averaged input power of 1.9 W. With this power setting, a second in vivo measurement was performed on a healthy volunteer. Using adiabatic excitation, 3D 31P MR spectroscopic imaging produced spectra from the entire prostate in 18 min with a spatial resolution of 4 cm3. The spectral resolution enabled the separate detection of phosphocholine, phosphoethanolamine, inorganic phosphate, and other metabolites that could play an important role in the characterization of prostate cancer. Y1 - 2012 U6 - http://dx.doi.org/10.1002/mrm.24175 SN - 1522-2594 VL - 68 IS - 6 SP - 1683 EP - 1695 PB - Wiley-Liss CY - New York ER - TY - JOUR A1 - Yazdanbakhsh, Pedram A1 - Solbach, Klaus A1 - Bitz, Andreas T1 - Variable power combiner for RF mode shimming in 7-T MR imaging JF - IEEE Transaction on Biomedical Engineering N2 - This contribution discusses the utilization of RF power in an MRI system with RF mode shimming which enables the superposition of circularly polarized modes of a transmit RF coil array driven by a Butler matrix. Since the required power for the individual modes can vary widely, mode-shimming can result in a significant underutilization of the total available RF power. A variable power combiner (VPC) is proposed to improve the power utilization: it can be realized as a reconfiguration of the MRI transmit system by the inclusion of one additional matrix network which receives the power from all transmit amplifiers at its input ports and provides any desired (combined) power distribution at its output ports by controlling the phase and amplitude of the amplifiers’ input signals. The power distribution at the output ports of the VPC is then fed into the “mode” ports of the coil array Butler matrix in order to superimpose the spatial modes at the highest achievable power utilization. The VPC configuration is compared to the standard configuration of the transmit chain of our MRI system with 8 transmit channels and 16 coils. In realistic scenarios, improved power utilization was achieved from 17% to 60% and from 14% to 55% for an elliptical phantom and a region of interest in the abdomen, respectively, and an increase of the power utilization of 1 dB for a region of interest in the upper leg. In general, it is found that the VPC allows significant improvement in power utilization when the shimming solution demands only a few modes to be energized, while the technique can yield loss in power utilization in cases with many modes required at high power level. Y1 - 2012 U6 - http://dx.doi.org/10.1109/TBME.2012.2205926 SN - 1558-2531 VL - 59 IS - 9 SP - 2549 EP - 2557 PB - IEEE CY - New York ER - TY - CHAP A1 - Bitz, Andreas A1 - Kraff, O. A1 - Orzada, S. A1 - Maderwald, S. A1 - Brote, I. A1 - Johst, S. A1 - Ladd, E. T1 - Assessment of RF Safety of Transmit Coils at 7 Tesla by Experimental and Numerical Procedures (490.) T2 - 19th annual ISMRM scientific meeting and exhibition 2011 : Montreal, Quebec, Canada, 7 - 13 May 2011 Y1 - 2012 SN - 978-1-61839-284-8 IS - Volume 1 SP - 475 PB - Curran CY - Red Hook, NY ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Kong, Shushu A1 - Arciszewski, Pawel A1 - Wielbalck, Swantje A1 - Abram, Ulrich T1 - Aryl and NHC Compounds of Technetium and Rhenium JF - Journal of the American Chemical Society N2 - Air- and water-stable phenyl complexes with nitridotechnetium(V) cores can be prepared by straightforward procedures. [TcNPh2(PPh3)2] is formed by the reaction of [TcNCl2(PPh3)2] with PhLi. The analogous N-heterocyclic carbene (NHC) compound [TcNPh2(HLPh)2], where HLPh is 1,3,4-triphenyl-1,2,4-triazol-5-ylidene, is available from (NBu4)[TcNCl4] and HLPh or its methoxo-protected form. The latter compound allows the comparison of different Tc–C bonds within one compound. Surprisingly, the Tc chemistry with such NHCs does not resemble that of corresponding Re complexes, where CH activation and orthometalation dominate. Y1 - 2012 U6 - http://dx.doi.org/10.1021/ja3033718 SN - 1520-5126 VL - 134 IS - 22 SP - 9118 EP - 9121 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Ngyugen, Hung Huy A1 - Kahlcke, Nils A1 - Deflon, Victor M. A1 - Abram, Ulrich T1 - Tricarbonyltechnetium(I) and -rhenium(I) complexes with N′-thiocarbamoylpicolylbenzamidines JF - Polyhedron N2 - N,N-Dialkylamino(thiocarbonyl)-N′-picolylbenzamidines react with (NEt4)2[M(CO)3X3] (M = Re, X = Br; M = Tc, X = Cl) under formation of neutral [M(CO)3L] complexes in high yields. The monoanionic NNS ligands bind in a facial coordination mode and can readily be modified at the (CS)NR1R2 moiety. The complexes [99Tc(CO)3(LPyMor)] and [Re(CO)3(L)] (L = LPyMor, LPyEt) were characterized by X-ray diffraction. Reactions of [99mTc(CO)3(H2O)3]+ with the N′-thiocarbamoylpicolylbenzamidines give the corresponding 99mTc complexes. The ester group in HLPyCOOEt allows linkage between biomolecules and the metal core. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.poly.2012.04.008 SN - 0277-5387 VL - 40 IS - 1 SP - 153 EP - 158 PB - Elsevier CY - Amsterdam ER - TY - BOOK A1 - Bialonski, Stephan T1 - Inferring complex networks from time series of dynamical systems: Pitfalls, misinterpretations, and possible solutions Y1 - 2012 N1 - Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Diss., 2012 PB - Universitäts- und Landesbibliothek Bonn CY - Bonn ER - TY - JOUR A1 - Becker, Jörg A1 - Delfmann, Patrick A1 - Eggert, Mathias A1 - Schwittay, Sebastian T1 - Generalizability and Applicability of Model-Based Business Process Compliance-Checking Approaches — A State-of-the-Art Analysis and Research Roadmap JF - Business Research : BuR N2 - With a steady increase of regulatory requirements for business processes, automation support of compliance management is a field garnering increasing attention in Information Systems research. Several approaches have been developed to support compliance checking of process models. One major challenge for such approaches is their ability to handle different modeling techniques and compliance rules in order to enable widespread adoption and application. Applying a structured literature search strategy, we reflect and discuss compliance-checking approaches in order to provide an insight into their generalizability and evaluation. The results imply that current approaches mainly focus on special modeling techniques and/or a restricted set of types of compliance rules. Most approaches abstain from real-world evaluation which raises the question of their practical applicability. Referring to the search results, we propose a roadmap for further research in model-based business process compliance checking. Y1 - 2012 U6 - http://dx.doi.org/10.1007/BF03342739 SN - 1866-8658 VL - 5 IS - 2 SP - 221 EP - 247 PB - Springer CY - Heidelberg ER - TY - CHAP A1 - Becker, Jörg A1 - Eggert, Mathias A1 - Heddier, Marcel A1 - Knackstedt, Ralf T1 - Merging Conceptual Modeling and Law for Legally Compliant Information Systems Design - A Framework-Based Research Agenda T2 - 45th Hawaii International Conference on System Sciences 2012 Y1 - 2012 SN - 978-0-7695-4525-7 U6 - http://dx.doi.org/10.1109/HICSS.2012.428 SP - 5241 EP - 5248 ER - TY - CHAP A1 - Becker, Jörg A1 - Eggert, Mathias A1 - Schwittay, Sebastian ED - Mattfeld, Dirk Christian T1 - How to Evaluate the Practical Relevance of Business Process Compliance Checking Approaches? T2 - Multikonferenz Wirtschaftsinformatik 2012 - Tagungsband der MKWI 2012 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:084-13011115376 SP - 849 EP - 862 PB - Institut für Wirtschaftsinformatik CY - Braunschweig ER - TY - CHAP A1 - Knackstedt, Ralf A1 - Eggert, Mathias A1 - Fleischer, Stefan T1 - The Legal Perspective on Business to Government Reporting - A Conceptual Modeling Approach and Its Application in the Financial Sector T2 - 45th Hawaii International Conference on System Sciences 2012 Y1 - 2012 SN - 978-0-7695-4525-7 U6 - http://dx.doi.org/10.1109/HICSS.2012.576 SP - 2309 EP - 2318 ER - TY - CHAP A1 - Rosemann, Michael A1 - Eggert, Mathias A1 - Voigt, Matthias A1 - Beverungen, Daniel T1 - Leveraging Social Network Data for Analytical CRM Strategies - The Introduction of Social BI. T2 - ECIS 2012 Proceedings Y1 - 2012 N1 - European Conference on Information Systems (ECIS), 2012 ER - TY - JOUR A1 - Scheer, Nico A1 - Balimane, Praveen A1 - Hayward, Michael D. A1 - Buechel, Sandra A1 - Kauselmann, Gunther A1 - Wolf, C. Roland T1 - Generation and Characterization of a Novel Multidrug Resistance Protein 2 Humanized Mouse Line JF - Drug Metabolism and Disposition N2 - The multidrug resistance protein (MRP) 2 is predominantly expressed in liver, intestine, and kidney, where it plays an important role in the excretion of a range of drugs and their metabolites or endogenous compounds into bile, feces, and urine. Mrp knockout [Mrp2(−/−)] mice have been used recently to study the role of MRP2 in drug disposition. Here, we describe the first generation and initial characterization of a mouse line humanized for MRP2 (huMRP2), which is nulled for the mouse Mrp2 gene and expresses the human transporter in the organs and cell types where MRP2 is normally expressed. Analysis of the mRNA expression for selected cytochrome P450 and transporter genes revealed no major changes in huMRP2 mice compared with wild-type controls. We show that human MRP2 is able to compensate functionally for the loss of the mouse transporter as demonstrated by comparable bilirubin levels in the humanized mice and wild-type controls, in contrast to the hyperbilirubinemia phenotype that is observed in MRP2(−/−) mice. The huMRP2 mouse provides a model to study the role of the human transporter in drug disposition and in assessing the in vivo consequences of inhibiting this transporter by compounds interacting with human MRP2. Y1 - 2012 U6 - http://dx.doi.org/10.1124/dmd.112.047605 SN - 1521-0111 VL - 40 IS - 11 SP - 2212 EP - 2218 PB - ASPET CY - Bethesda, Md. ER - TY - JOUR A1 - Scheer, Nico A1 - Kapelyukh, Yury A1 - Rode, Anja A1 - Buechel, Sandra A1 - Wolf, C. Roland T1 - Generation and characterization of novel cytochrome P450 Cyp2c gene cluster knockout and CYP2C9 humanized mouse lines JF - Molecular Pharmacology N2 - Compared with rodents and many other animal species, the human cytochrome P450 (P450) Cyp2c gene cluster varies significantly in the multiplicity of functional genes and in the substrate specificity of its enzymes. As a consequence, the use of wild-type animal models to predict the role of human CYP2C enzymes in drug metabolism and drug-drug interactions is limited. Within the human CYP2C cluster CYP2C9 is of particular importance, because it is one of the most abundant P450 enzymes in human liver, and it is involved in the metabolism of a wide variety of important drugs and environmental chemicals. To investigate the in vivo functions of cytochrome P450 Cyp2c genes and to establish a model for studying the functions of CYP2C9 in vivo, we have generated a mouse model with a deletion of the murine Cyp2c gene cluster and a corresponding humanized model expressing CYP2C9 specifically in the liver. Despite the high number of functional genes in the mouse Cyp2c cluster and the reported roles of some of these proteins in different biological processes, mice deleted for Cyp2c genes were viable and fertile but showed certain phenotypic alterations in the liver. The expression of CYP2C9 in the liver also resulted in viable animals active in the metabolism and disposition of a number of CYP2C9 substrates. These mouse lines provide a powerful tool for studying the role of Cyp2c genes and of CYP2C9 in particular in drug disposition and as a factor in drug-drug interaction. Y1 - 2012 U6 - http://dx.doi.org/10.1124/mol.112.080036 SN - 1521-0111 VL - 82 IS - 6 SP - 1022 EP - 1029 PB - ASPET CY - Bethesda, Md. ER - TY - JOUR A1 - Lempiäinen, Harri A1 - Couttet, Philippe A1 - Bolognani, Federico A1 - Müller, Arne A1 - Dubost, Valérie A1 - Luisier, Raphaëlle A1 - Rio-Espinola, Alberto del A1 - Vitry, Veronique A1 - Unterberger, Elif B. A1 - Thomson, John P. A1 - Treindl, Fridolin A1 - Metzger, Ute A1 - Wrzodek, Clemens A1 - Hahne, Florian A1 - Zollinger, Tulipan A1 - Brasa, Sarah A1 - Kalteis, Magdalena A1 - Marcellin, Magali A1 - Giudicelli, Fanny A1 - Braeuning, Albert A1 - Morawiec, Laurent A1 - Zamurovic, Natasa A1 - Längle, Ulrich A1 - Scheer, Nico A1 - Schübeler, Dirk A1 - Goodman, Jay A1 - Chibout, Salah-Dine A1 - Marlowe, Jennifer A1 - Theil, Dietlinde A1 - Heard, David J. A1 - Grenet, Olivier A1 - Zell, Andreas A1 - Templin, Markus F. A1 - Meehan, Richard R. A1 - Wolf, Roland C. A1 - Elcombe, Clifford R. A1 - Schwarz, Michael A1 - Moulin, Pierre A1 - Terranova, Rémi A1 - Moggs, Jonathan G. T1 - Identification of Dlk1-Dio3 imprinted gene cluster non-coding RNAs as novel candidate biomarkers for liver tumor promotion JF - Toxicological Sciences N2 - The molecular events during nongenotoxic carcinogenesis and their temporal order are poorly understood but thought to include long-lasting perturbations of gene expression. Here, we have investigated the temporal sequence of molecular and pathological perturbations at early stages of phenobarbital (PB) mediated liver tumor promotion in vivo. Molecular profiling (mRNA, microRNA [miRNA], DNA methylation, and proteins) of mouse liver during 13 weeks of PB treatment revealed progressive increases in hepatic expression of long noncoding RNAs and miRNAs originating from the Dlk1-Dio3 imprinted gene cluster, a locus that has recently been associated with stem cell pluripotency in mice and various neoplasms in humans. PB induction of the Dlk1-Dio3 cluster noncoding RNA (ncRNA) Meg3 was localized to glutamine synthetase-positive hypertrophic perivenous hepatocytes, sug- gesting a role for β-catenin signaling in the dysregulation of Dlk1-Dio3 ncRNAs. The carcinogenic relevance of Dlk1-Dio3 locus ncRNA induction was further supported by in vivo genetic dependence on constitutive androstane receptor and β-catenin pathways. Our data identify Dlk1-Dio3 ncRNAs as novel candidate early biomarkers for mouse liver tumor promotion and provide new opportunities for assessing the carcinogenic potential of novel compounds. Y1 - 2012 U6 - http://dx.doi.org/10.1093/toxsci/kfs303 SN - 1094-2025 VL - 131 IS - 2 SP - 375 EP - 386 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Mansurov, Z. A1 - Digel, Ilya A1 - Biisenbaev, M. A1 - Savistkaya, I. A1 - Kistaubaeva, A. A1 - Akimbekov, N. A1 - Zhubanova, A. T1 - Bio-composite material on the basis of carbonized rice husk in biomedicine and environmental applications JF - Eurasian Chemico-Technological Journal Y1 - 2012 U6 - http://dx.doi.org/10.18321/ectj105 SN - 2522-4867 VL - 14 IS - 2 SP - 115 EP - 131 PB - Institute of Combustion Problems CY - Almaty ER - TY - JOUR A1 - Scheer, Nico A1 - Kapelyukh, Yury A1 - McEwan, Jillian A1 - Beuger, Vincent A1 - Stanley, Lesley A. A1 - Rode, Anja A1 - Wolf, C. Roland T1 - Modeling Human Cytochrome P450 2D6 Metabolism and Drug-drug Interaction by a Novel Panel of Knockout and Humanized Mouse Lines JF - Molecular Pharmacology N2 - The highly polymorphic human cytochrome P450 2D6 enzyme is involved in the metabolism of up to 25% of all marketed drugs and accounts for significant individual differences in response to CYP2D6 substrates. Because of the differences in the multiplicity and substrate specificity of CYP2D family members among species, it is difficult to predict pathways of human CYP2D6-dependent drug metabolism on the basis of animal studies. To create animal models that reflect the human situation more closely and that allow an in vivo assessment of the consequences of differential CYP2D6 drug metabolism, we have developed a novel straightforward approach to delete the entire murine Cyp2d gene cluster and replace it with allelic variants of human CYP2D6. By using this approach, we have generated mouse lines expressing the two frequent human protein isoforms CYP2D6.1 and CYP2D6.2 and an as yet undescribed variant of this enzyme, as well as a Cyp2d cluster knockout mouse. We demonstrate that the various transgenic mouse lines cover a wide spectrum of different human CYP2D6 metabolizer phenotypes. The novel humanization strategy described here provides a robust approach for the expression of different CYP2D6 allelic variants in transgenic mice and thus can help to evaluate potential CYP2D6-dependent interindividual differences in drug response in the context of personalized medicine. Y1 - 2012 U6 - http://dx.doi.org/10.1124/mol.111.075192 SN - 1521-0111 VL - 81 IS - 1 SP - 63 EP - 72 PB - ASPET CY - Bethesda, Md. ER - TY - THES A1 - Oflaz, Hakan T1 - Entwicklung eines Prototypen zur Prognose von Frühgeburten : ein biomedizintechnischer Ansatz Y1 - 2012 U6 - http://dx.doi.org/10.4126/38m-004639208 N1 - Köln, Univ., Diss., 2012 PB - Deutsche Zentralbibliothek für Medizin CY - Köln ER - TY - THES A1 - Kurulgan Demirci, Eylem T1 - The effect of rhAPC on contractile tension : an in-vitro sepsis model of cardiomyocytes and endothelial cells T1 - Der Effekt von rhAPC auf die zelluläre Kontraktionskraft : ein In-vitro-Sepsismodell für Kardiomyozyten und Endothelzellen Y1 - 2012 N1 - Aachen, Techn. Hochsch., Diss., 2012 ER - TY - BOOK A1 - Gell, Sebastian T1 - Determinants of earnings forecast error, earnings forecast revision and earnings forecast accuracy N2 - ​Earnings forecasts are ubiquitous in today’s financial markets. They are essential indicators of future firm performance and a starting point for firm valuation. Extremely inaccurate and overoptimistic forecasts during the most recent financial crisis have raised serious doubts regarding the reliability of such forecasts. This thesis therefore investigates new determinants of forecast errors and accuracy. In addition, new determinants of forecast revisions are examined. More specifically, the thesis answers the following questions: 1) How do analyst incentives lead to forecast errors? 2) How do changes in analyst incentives lead to forecast revisions?, and 3) What factors drive differences in forecast accuracy? Y1 - 2012 SN - 978-3-8349-3936-4 SN - 978-3-8349-3937-1 U6 - http://dx.doi.org/10.1007/978-3-8349-3937-1 N1 - Titel in der Buchreihe: Quantitatives Controlling PB - Springer Gabler CY - Wiesbaden ER - TY - CHAP A1 - Borggrafe, Andreas A1 - Ohndorf, Andreas A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang T1 - Analysis of interplanetary solar sail trajectories with attitude dynamics T2 - Dynamics and Control of Space Systems 2012 N2 - We present a new approach to the problem of optimal control of solar sails for low-thrust trajectory optimization. The objective was to find the required control torque magnitudes in order to steer a solar sail in interplanetary space. A new steering strategy, controlling the solar sail with generic torques applied about the spacecraft body axes, is integrated into the existing low-thrust trajectory optimization software InTrance. This software combines artificial neural networks and evolutionary algorithms to find steering strategies close to the global optimum without an initial guess. Furthermore, we implement a three rotational degree-of-freedom rigid-body attitude dynamics model to represent the solar sail in space. Two interplanetary transfers to Mars and Neptune are chosen to represent typical future solar sail mission scenarios. The results found with the new steering strategy are compared to the existing reference trajectories without attitude dynamics. The resulting control torques required to accomplish the missions are investigated, as they pose the primary requirements to a real on-board attitude control system. Y1 - 2012 SN - 978-0-87703-587-9 SP - 1553 EP - 1569 PB - Univelt Inc CY - San Diego ER - TY - JOUR A1 - Czarnecki, Christian A1 - Spiliopoulou, Myra T1 - A holistic framework for the implementation of a next generation network JF - International Journal of Business Information Systems N2 - As the potential of a next generation network (NGN) is recognised, telecommunication companies consider switching to it. Although the implementation of an NGN seems to be merely a modification of the network infrastructure, it may trigger or require changes in the whole company, because it builds upon the separation between service and transport, a flexible bundling of services to products and the streamlining of the IT infrastructure. We propose a holistic framework, structured into the layers ‘strategy’, ‘processes’ and ‘information systems’ and incorporate into each layer all concepts necessary for the implementation of an NGN, as well as the alignment of these concepts. As a first proof-of-concept for our framework we have performed a case study on the introduction of NGN in a large telecommunication company; we show that our framework captures all topics that are affected by an NGN implementation. KW - next generation network KW - telecommunication KW - NGN KW - IP-based networks KW - product bundling Y1 - 2012 U6 - http://dx.doi.org/10.1504/IJBIS.2012.046291 SN - 1746-0972 VL - 9 IS - 4 SP - 385 EP - 401 PB - Inderscience Enterprises CY - Olney, Bucks ER -