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 - JOUR A1 - Hötter, Jan-Steffen A1 - Fateri, Miranda A1 - Gebhardt, Andreas T1 - Prozessoptimierung des SLM-Prozesses mit hoch-reflektiven und thermisch sehr gut leitenden Materialien durch systematische Parameterfindung und begleitende Simulationen am Beispiel von Silber JF - RTejournal - Forum für Rapid Technologie N2 - Additive Manufacturing durch Aufschmelzen von Metallpulvern hat sich auf breiter Front als Herstellverfahren, auch für Endprodukte, etabliert. Besonders für die Variante des Selective Laser Melting (SLM) sind Anwendungen in der Zahntechnik bereits weit verbreitet und der Einsatz in sensitiven Branchen wie der Luftfahrt ist in greifbare Nähe gerückt. Deshalb werden auch vermehrt Anstrengungen unternommen, um bisher nicht verarbeitete Materialien zu qualifizieren. Dies sind vorzugsweise Nicht-Eisen- und Edelmetalle, die sowohl eine sehr hohe Reflektivität als auch eine sehr gute Wärmeleitfähigkeit aufweisen – beides Eigenschaften, die die Beherrschung des Laser-Schmelzprozesses erschweren und nur kleine Prozessfenster zulassen. Die Arbeitsgruppe SLM des Lehr- und Forschungsgebietes Hochleistungsverfahren der Fertigungstechnik hat sich unter der Randbedingung einer kleinen und mit geringer Laserleistung ausgestatteten SLM Maschine der Aufgabe gewidmet und am Beispiel von Silber die Parameterfelder für Einzelspuren und wenig komplexe Geometrien systematisch untersucht. Die Arbeiten wurden von FEM Simulationen begleitet und durch metallographische Untersuchungen verifiziert. Die Ergebnisse bilden die Grundlage zur schnellen Parameterfindung bei komplexen Geometrien und bei Veränderungen der Zusammensetzung, wie sie bei zukünftigen Legierungen zu erwarten sind. Die Ergebnisse werden exemplarisch auf unterschiedliche Geometrien angewandt und entsprechende Bauteile gezeigt. N2 - Additive manufacturing by melting of metal powders is a method that has been established even for the manufacturing of final products. In particular, Selective Laser Melting (SLM) is currently applied for prosthetic dentistry. In the near future, this technology will access sensitive industries like aerospace engineering. This leads to the need to process new materials. Therefore, especially non-ferrous metals and noble metals must be determined and qualified. These materials have in common a very high reflectivity and an excellent thermal conductivity. In general, these two properties counteract the control of the melt pool and contribute to very narrow process windows. The “SLM” research team of the Aachen University of Applied Science, AcUAS (FH Aachen) systematically investigated process parameter fields for silver. The work focused on a small SLM desktop machine with comparably low laser power. The results are verified using FEA and metallographic inspections and will support future set-ups for complex geometries. Furthermore, the obtained parameter fields are applied to make different geometric objects and to manufactured parts, which are presented. KW - SLM KW - Selektives Laser Schmelzen KW - Silber Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0009-2-33639 SN - 1614-0923 VL - 9 IS - 1 SP - 1 EP - 14 PB - Fachhoschule Aachen CY - Aachen ER - TY - CHAP A1 - Fabo, Sabine T1 - Einführung T2 - Vielen Dank für Ihren Einkauf : Konsumkultur aus Sicht von Design, Kunst und Medien Y1 - 2012 SN - 978-3-8376-2170-9 SP - 9 EP - 13 PB - Transcript Verlag CY - Bielefeld ER - TY - CHAP A1 - Fabo, Sabine T1 - Die Kunst der Irritation und ihr Mehrwert T2 - Vielen Dank für Ihren Einkauf : Konsumkultur aus Sicht von Design, Kunst und Medien Y1 - 2012 SN - 978-3-8376-2170-9 SP - 112 EP - 145 PB - Transcript Verlag CY - Bielefeld ER - TY - CHAP A1 - Kurz, Melanie T1 - Prizing & Pricing : Design zwischen Rang und Regal T2 - Vielen Dank für Ihren Einkauf : Konsumkultur aus Sicht von Design, Kunst und Medien Y1 - 2012 SN - 978-3-8376-2170-9 U6 - http://dx.doi.org/10.1515/transcript.9783839421703.26 SP - 26 EP - 39 PB - Transcript Verlag CY - Bielefeld ER - TY - CHAP A1 - Jakobs, Helmut T1 - Vorwort T2 - Vielen Dank für Ihren Einkauf : Konsumkultur aus Sicht von Design, Kunst und Medien Y1 - 2012 SN - 978-3-8376-2170-9 SP - 7 PB - Transcript Verlag CY - Bielefeld ER - TY - BOOK A1 - Uibel, Thomas T1 - Spaltverhalten von Holz beim Eindrehen von selbstbohrenden Holzschrauben Y1 - 2012 SN - 978-3-86644-835-3 N1 - Karlsruhe, Univ., Diss. 2012 - Karlsruher Berichte zum Ingenieurholzbau ; 20 PB - KIT Scientific Publishing CY - Karlsruhe ER - TY - BOOK A1 - Blaß, Hans Joachim A1 - Uibel, Thomas T1 - Spaltversagen von Holz in mehrreihigen Verbindungen : Erweiterung des Rechen-modells für die Rissbildung beim Eindrehen von Holzschrauben Y1 - 2012 SN - 978-3-86644-852-0 N1 - Karlsruher Berichte zum Ingenieurholzbau ; Band 21 PB - KIT Scientific Publishing CY - Karlsruhe 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 - Wolf, Martin T1 - Von Security Awareness zum Secure Behaviour JF - Hakin9 Extra – IT-Forensik N2 - Security Awareness ist derzeit ein viel diskutiertes Thema. Es reicht nicht, einfach nur ein paar technische Systeme (z.B. Firewalls) zu installieren, um ein angemessenes Schutzniveau zu erzielen. Neben einer guten Organisation von IT Security ist es auch notwendig, den Mitarbeiter einzubinden. Der vielzitierte "Faktor Mensch" ist derjenige, der die Technik korrekt anwenden muss und der durch falsches Verhalten technische und organisatorische Schutzmaßnahmen aushebeln kann. Deshalb reicht es nicht aus, wenn sich der Mitarbeiter der Gefahren bewusst ("aware") ist, er muss auch dementsprechend "sicher" handeln. Y1 - 2012 SN - 1733-7186 VL - 2012 IS - 5 SP - 18 EP - 19 PB - Software Wydawnictwo CY - Warszawa ER - TY - CHAP A1 - Klocke, Martina T1 - Projektmodul im Bachelorstudiengang Maschinenbau und Mechatronik T2 - VDI-Workshop Projektorientiertes und problem-basiertes Lernen (PBL) in der Ingenieurausbildung Y1 - 2012 N1 - 25 Folien zum eingeladenen Vortrag beim VDI-Workshop. Darmstadt, 22./23.11.2012 SP - 1 EP - 25 ER - TY - PAT A1 - Gollewski, Torsten A1 - Lange, Robert A1 - Ringbeck, Thorsten A1 - Hess, Holger A1 - Buxbaum, Bernd T1 - Verfahren und Vorrichtung zur Laufzeitsensitiven Messung eines Signals [Offenlegungsschrift / Europäische Patentschrift] T1 - Apparatus for delay-sensitive measurement of a signal T1 - Dispositif pour le mesurage sensitif au temps de transit d'un signal Y1 - 2006 PB - Deutsches Patent- und Markenamt / Europäisches Patentamt CY - München / Den Hague ER - TY - BOOK A1 - Klein, Hartmut Heinz A1 - Müller, Thomas A1 - Lieber, Bettina T1 - Änderung der Unternehmensform : Handbuch zum Umwandlungs- und Umwandlungssteuerrecht Y1 - 2012 SN - 978-3-482-42259-1 PB - Verl. Neue Wirtschafts-Briefe CY - Herne ET - 9. Aufl. ER - TY - CHAP A1 - Oertel, Mario A1 - Bung, Daniel B. A1 - Schlenkhoff, Andreas ED - Carstensen, Dirk T1 - Blocksteinrampen in Riegelbauweise : Neue Bemessungsansätze T2 - Staubauwerke : planen, bauen, betreiben; 35. Dresdner Wasserbaukolloquium 2012, 08. - 09. März 2012 Y1 - 2012 SN - 978-3-86780-261-1 SP - 317 EP - 326 PB - Selbstverl. der Techn. Univ. CY - Dresden ER - TY - BOOK A1 - Dören, Horst-Peter T1 - Fügetechnik, Schweißtechnik. Horst-Peter Dören (Hrsg.).- 8., aktualis. und erw. Aufl. Y1 - 2012 SN - 978-3-87155-999-0 PB - DVS Media CY - Düsseldorf 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 - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros T1 - Perspektiven für Solarthermische Kraftwerke im Sonnengürtel T2 - Energiewende : Aspekte, Optionen, Herausforderungen : Vorträge auf der DPG-Frühjahrstagung Arbeitskreis Energie in der Deutschen Physikalischen Gesellschaft Berlin, 26. bis 28. März 2012 / hrsg. von Hardo Bruhns Y1 - 2012 SP - 81 EP - 93 PB - DPG CY - Baf Honnef 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 - BOOK A1 - Armgardt, Jan T1 - Ich mache (m)ein Ding : Möbel-Unikate Y1 - 2012 SN - 978-3-00-039169-9 PB - [Selbstverl.] CY - [s.l.] 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 - Anthrakidis, Anette T1 - Prüfeinrichtung zur Bestimmung der Leistungsfähigkeit von solarthermischen Kollektoren bis 200 Grad C T2 - 22. Symposium Thermische Solarenergie : 09. bis 11. Mai 2012, Kloster Banz, Bad Staffelstein Y1 - 2012 SN - 978-3-941785-89-2 SP - 134 EP - 135 PB - OTTI CY - Regensburg 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 - CHAP A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Mokrov, Oleg A1 - Ufer, Sebastian A1 - Guenel, Ismet A1 - Gach, Stefan T1 - Voruntersuchungen mit Ansys CFX zu einer Druckstufe von einem Druckstufensystem für das Elektronenstrahlschweißen T2 - DVS Congress 2012 : Große Schweißtechnische Tagung, DVS-Studentenkongress ; Vorträge der Veranstaltungen in Saarbrücken am 17. und 18. September 2012. (DVS-Berichte ; 286) Y1 - 2012 SN - 978-3-87155-593-0 SP - 33 EP - 35 PB - DVS Media CY - Düsseldorf 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 - CHAP A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Thiele, Regina T1 - Schweißverbindungen in Lithium-Ionen-Batterien T2 - DVS Congress 2012 : Große Schweißtechnische Tagung, DVS-Studentenkongress ; Vorträge der Veranstaltungen in Saarbrücken am 17. und 18. September 2012. (DVS-Berichte ; 286) Y1 - 2012 SN - 978-3-87155-593-0 SP - 157 EP - 161 PB - DVS-Media CY - Düsseldorf ER - TY - CHAP A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Essers, Marc A1 - Thiele, Regina A1 - Schiebahn, Alexander T1 - Klebstofffixiertes Rührreibschweißen von dünnen Aluminiumblechen T2 - DVS Congress 2012 : Große Schweißtechnische Tagung, DVS-Studentenkongress ; Vorträge der Veranstaltungen in Saarbrücken am 17. und 18. September 2012. (DVS-Berichte ; 286) Y1 - 2012 SN - 978-3-87155-593-0 SP - 20 EP - 25 PB - DVS-Media CY - Düsseldorf 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 - 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 - Modellierung und Visualisierung der MSG-Lichtbogenprozesse JF - Schweissen und Schneiden : Fachzeitschrift für Schweißen und verwandte Verfahren Y1 - 2012 SN - 0036-7184 VL - 64 IS - 4 SP - 166 EP - 174 PB - DVS Verlag CY - Düsseldorf ER - TY - CHAP A1 - Naujokat, Anke ED - Heynen, Hilde ED - Gosseye, Janina T1 - Leon Battista Alberti and the consonance of old and new T2 - Proceedings of the 2nd International conference of the European Architectural History Network, Brussels 31 May - 2 June 2012 Y1 - 2012 SN - 978-90-6569-102-6 SP - 182 EP - 184 PB - KVAB CY - Brüssel ER - TY - BOOK A1 - Esch, Thomas T1 - Experimentelle Untersuchungen an Antriebssystemen von Kraft-, Luft- und Raumfahrzeugen : Vorlesungsumdruck. 2. Aufl. Bd. 2 Y1 - 2012 PB - Fachhochschule Aachen, Lehr- und Forschungsgebiet Thermodynamik und Verbrennungstechnik CY - Aachen ER - TY - JOUR A1 - Martius, Alexander A1 - Mischke, Winfried T1 - Die Vernehmung des Wohnungseigentümers : wann ist der Wohnungseigentümer als Partei, wann als Zeuge zu vernehmen? JF - Zeitschrift für die Anwaltspraxis : ZAP Y1 - 2012 SN - 0936-7292 IS - Fach 7 SP - 431 EP - 434 PB - ZAP Verlag CY - Bonn ER -