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 -