TY - JOUR A1 - Hoffstadt, Kevin A1 - Cheenakula, Dheeraja A1 - Nikolausz, Marcell A1 - Krafft, Simone A1 - Harms, Hauke A1 - Kuperjans, Isabel T1 - Design and construction of a new reactor for flexible biomethanation of hydrogen JF - Fermentation N2 - The increasing share of renewable electricity in the grid drives the need for sufficient storage capacity. Especially for seasonal storage, power-to-gas can be a promising approach. Biologically produced methane from hydrogen produced from surplus electricity can be used to substitute natural gas in the existing infrastructure. Current reactor types are not or are poorly optimized for flexible methanation. Therefore, this work proposes a new reactor type with a plug flow reactor (PFR) design. Simulations in COMSOL Multiphysics ® showed promising properties for operation in laminar flow. An experiment was conducted to support the simulation results and to determine the gas fraction of the novel reactor, which was measured to be 29%. Based on these simulations and experimental results, the reactor was constructed as a 14 m long, 50 mm diameter tube with a meandering orientation. Data processing was established, and a step experiment was performed. In addition, a kLa of 1 h−1 was determined. The results revealed that the experimental outcomes of the type of flow and gas fractions are in line with the theoretical simulation. The new design shows promising properties for flexible methanation and will be tested. KW - methanation KW - plug flow reactor KW - bubble column KW - bio-methane KW - power-to-gas Y1 - 2023 U6 - https://doi.org/10.3390/fermentation9080774 SN - 2311-5637 N1 - The article belongs to the Special Issue Fermentation Processes: Modeling, Optimization and Control VL - 9 IS - 8 SP - 1 EP - 16 PB - MDPI CY - Basel ER - TY - CHAP A1 - Niederwestberg, Stefan A1 - Schneider, Falko A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Introduction to a direct irradiated transparent tube particle receiver T2 - SOLARPACES 2020 N2 - New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work. KW - Solar irradiance KW - Ceramics Y1 - 2022 SN - 978-0-7354-4195-8 U6 - https://doi.org/10.1063/5.0086735 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - SOLARPACES 2020: 26th International Conference on Concentrating Solar Power and Chemical Energy Systems, 28 September–2 October 2020, Freiburg, Germany IS - 2445 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY ER - TY - JOUR A1 - Götten, Falk A1 - Finger, Felix A1 - Havermann, Marc A1 - Braun, Carsten A1 - Marino, M. A1 - Bil, C. T1 - Full configuration drag estimation of short-to-medium range fixed-wing UAVs and its impact on initial sizing optimization JF - CEAS Aeronautical Journal N2 - The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used for surveillance, reconnaissance, and search and rescue missions. The aircraft is simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV’s parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft’s total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft. KW - Parasitic drag KW - UAV KW - CFD KW - Aircraft sizing Y1 - 2021 U6 - https://doi.org/10.1007/s13272-021-00522-w SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Falk Götten VL - 12 SP - 589 EP - 603 PB - Springer CY - Berlin ER - TY - CHAP A1 - Bagheri, Mohsen A1 - Schleupen, Josef A1 - Dahmann, Peter A1 - Kallweit, Stephan T1 - A multi-functional device applying for the safe maintenance at high-altitude on wind turbines T2 - 20th International Conference on Composite Materials : Copenhagen, 19 - 24th July 2015 Y1 - 2015 SP - 1 EP - 6 ER - TY - CHAP A1 - Abbas, Karim A1 - Thurn, Laura A1 - Kessler, Julia A1 - Eichler, Fabian T1 - Basic research of the consideration of additive manufactured lattice structures under thermoand fluid dynamic loads T2 - Modern technologies in manufacturing (MTeM 2019) Y1 - 2019 U6 - https://doi.org/10.1051/matecconf/201929901009 N1 - MATEC Web of Conferences 299; MTeM 2019 VL - 299 IS - Article 01009 ER - TY - JOUR A1 - Bhattarai, Aroj A1 - Staat, Manfred T1 - A computational study of organ relocation after laparoscopic pectopexy to repair posthysterectomy vaginal vault prolapse JF - Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization Y1 - 2019 U6 - https://doi.org/10.1080/21681163.2019.1670095 SN - 2168-1171 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Capitain, Charlotte A1 - Ross-Jones, Jesse A1 - Möhring, Sophie A1 - Tippkötter, Nils T1 - Differential scanning calorimetry for quantification of polymer biodegradability in compost JF - International Biodeterioration & Biodegradation N2 - The objective of this study is the establishment of a differential scanning calorimetry (DSC) based method for online analysis of the biodegradation of polymers in complex environments. Structural changes during biodegradation, such as an increase in brittleness or crystallinity, can be detected by carefully observing characteristic changes in DSC profiles. Until now, DSC profiles have not been used to draw quantitative conclusions about biodegradation. A new method is presented for quantifying the biodegradation using DSC data, whereby the results were validated using two reference methods. The proposed method is applied to evaluate the biodegradation of three polymeric biomaterials: polyhydroxybutyrate (PHB), cellulose acetate (CA) and Organosolv lignin. The method is suitable for the precise quantification of the biodegradability of PHB. For CA and lignin, conclusions regarding their biodegradation can be drawn with lower resolutions. The proposed method is also able to quantify the biodegradation of blends or composite materials, which differentiates it from commonly used degradation detection methods. Y1 - 2020 U6 - https://doi.org/10.1016/j.ibiod.2020.104914 SN - 0964-8305 VL - 149 SP - In Press, Article number 104914 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Stresses produced by different textile mesh implants in a tissue equivalent JF - BioNanoMaterials N2 - Two single-incision mini-slings used for treating urinary incontinence in women are compared with respect to the stresses they produce in their surrounding tissue. In an earlier paper we experimentally observed that these implants produce considerably different stress distributions in a muscle tissue equivalent. Here we perform 2D finite element analyses to compare the shear stresses and normal stresses in the tissue equivalent for the two meshes and to investigate their failure behavior. The results clearly show that the Gynecare TVT fails for increasing loads in a zipper-like manner because it gradually debonds from the surrounding tissue. Contrary to that, the tissue at the ends of the DynaMesh-SIS direct may rupture but only at higher loads. The simulation results are in good agreement with the experimental observations thus the computational model helps to interpret the experimental results and provides a tool for qualitative evaluation of mesh implants. Y1 - 2014 U6 - https://doi.org/10.1515/bnm-2014-0003 SN - 2191-4672 (E-Journal); 2193-066X (E-Journal); 0011-8656 (Print); 1616-0177 (Print); 2193-0651 (Print) VL - 15 IS - 1-2 SP - 25 EP - 30 PB - De Gruyter CY - Berlin ER - TY - CHAP A1 - Kerpen, Nils B. A1 - Bung, Daniel Bernhard A1 - Valero, Daniel A1 - Schlurmann, Torsten T1 - Energy dissipation within the wave run-up at stepped revetments T2 - 8th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering, Qingdao, China KW - energy disspation KW - wave run-up KW - friction Y1 - 2016 ER - TY - JOUR A1 - Vu, Duc Khoi A1 - Staat, Manfred A1 - Tran, Ich Thinh T1 - Analysis of pressure equipment by application of the primal-dual theory of shakedown JF - Communications in Numerical Methods in Engineering. 23 (2007), H. 3 Y1 - 2007 SN - 1069-8299 SP - 213 EP - 225 ER - TY - JOUR A1 - Staat, Manfred A1 - Vu, Khoi Duc T1 - Limit loads of circumferentially flawed pipes and cylindrical vessels under internal pressure JF - International Journal of Pressure Vessels and Piping. 83 (2006), H. 3 Y1 - 2006 SN - 0308-0161 SP - 188 EP - 196 ER - TY - CHAP A1 - Breitbach, Gerd A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard T1 - Fluid flow in porous ceramic multichannel crossflower filter modules Y1 - 2007 PB - COMSOL Inc. CY - Burlington, Mass. ER - TY - CHAP A1 - Götten, Falk A1 - Finger, Felix A1 - Havermann, Marc A1 - Braun, Carsten A1 - Marino, Matthew A1 - Bil, Cees T1 - Full Configuration Drag Estimation of Small-to-Medium Range UAVs and its Impact on Initial Sizing Optimization T2 - CEAS Aeronautical Journal N2 - The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used on surveillance, reconnaissance, and search and rescue missions. The aircraft are simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV's parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft's total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft. Y1 - 2020 U6 - https://doi.org/10.1007/s13272-021-00522-w SN - 1869-5590 N1 - 69. Deutscher Luft- und Raumfahrtkongress 2020, 1. September 2020 - 3. September 2020, online VL - 12 SP - 589 EP - 603 PB - Springer CY - Wien ER - TY - JOUR A1 - Ferrein, Alexander A1 - Rens, Gavin A1 - Poel, Etienne van der T1 - A BDI agent architecture for a POMDP planner / Rens, Gavin ; Ferrein, Alexander ; Poel, Etienne van der Y1 - 2009 N1 - 9th International Symposium on Logical Formalization of Commonsense Reasoning: Commonsense 2009, Toronto, Canada, 1-3 June, 2009 SP - 1 EP - 6 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - Calibration of network analyser measurements with leakage errors JF - Electronics letters. 30 (1994), H. 1 Y1 - 1994 SN - 0013-5194 SP - 52 EP - 53 ER - TY - JOUR A1 - Weigand, Christoph T1 - Optimal Production Schedule for a K Products Single Machine Problem JF - Economic Quality Control. 9 (1994) Y1 - 1994 SN - 0940-5151 SP - 91 EP - 101 ER - TY - JOUR A1 - Engel, Mareike A1 - Holtmann, Dirk A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - Increased Biobutanol Production by Mediator‐Less Electro‐Fermentation JF - Biotechnology Journal N2 - A future bio-economy should not only be based on renewable raw materials but also in the raise of carbon yields of existing production routes. Microbial electrochemical technologies are gaining increased attention for this purpose. In this study, the electro-fermentative production of biobutanol with C. acetobutylicum without the use of exogenous mediators is investigated regarding the medium composition and the reactor design. It is shown that the use of an optimized synthetic culture medium allows higher product concentrations, increased biofilm formation, and higher conductivities compared to a synthetic medium supplemented with yeast extract. Moreover, the optimization of the reactor system results in a doubling of the maximum product concentrations for fermentation products. When a working electrode is polarized at −600 mV vs. Ag/AgCl, a shift from butyrate to acetone and butanol production is induced. This leads to an increased final solvent yield of Yᴀᴃᴇ = 0.202 gg⁻¹ (control 0.103 gg⁻¹), which is also reflected in a higher carbon efficiency of 37.6% compared to 23.3% (control) as well as a fourfold decrease in simplified E-factor to 0.43. The results are promising for further development of biobutanol production in bioelectrochemical systems in order to fulfil the principles of Green Chemistry. Y1 - 2018 U6 - https://doi.org/10.1002/biot.201800514 SN - 1860-7314 VL - 14 IS - 4 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Riga, Evi A1 - Pitilakis, Kyriazis A1 - Butenweg, Christoph A1 - Apostolaki, Stefania A1 - Karatzetzou, Anna ED - Arion, Cristian ED - Scupin, Alexandra ED - Ţigănescu, Alexandru T1 - Investigating the impact of the new European Seismic Hazard Model ESHM20 on the seismic design and safety control of industrial facilities T2 - The Third European Conference on Earthquake Engineering and Seismology N2 - The seismic performance and safety of major European industrial facilities has a global interest for Europe, its citizens and economy. A potential major disaster at an industrial site could affect several countries, probably far beyond the country where it is located. However, the seismic design and safety assessment of these facilities is practically based on national, often outdated seismic hazard assessment studies, due to many reasons, including the absence of a reliable, commonly developed seismic hazard model for whole Europe. This important gap is no more existing, as the 2020 European Seismic Hazard Model ESHM20 was released in December 2021. In this paper we investigate the expected impact of the adoption of ESHM20 on the seismic demand for industrial facilities, through the comparison of the ESHM20 probabilistic hazard at the sites where industrial facilities are located with the respective national and European regulations. The goal of this preliminary work in the framework of Working Group 13 of the European Association for Earthquake Engineering (EAEE), is to identify potential inadequacies in the design and safety control of existing industrial facilities and to highlight the expected impact of the adoption of the new European Seismic Hazard Model on the design of new industrial facilities and the safety assessment of existing ones. KW - ESHM20, industrial facilities KW - seismic hazard KW - seismic design KW - safety control Y1 - 2022 SN - 978-973-100-533-1 N1 - 3ECEES - Third European Conference on Earthquake Engineering and Seismology, September 4 – September 9, 2022, Bucharest SP - 3261 EP - 3270 ER - TY - JOUR A1 - Engel, Mareike A1 - Gemünde, Andre A1 - Holtmann, Dirk A1 - Müller-Renno, Christine A1 - Ziegler, Christiane A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Clostridium acetobutylicum’s connecting world: cell appendage formation in bioelectrochemical systems JF - ChemElectroChem N2 - Bacterial cell appendix formation supports cell-cell interaction, cell adhesion and cell movement. Additionally, in bioelectrochemical systems (BES), cell appendages have been shown to participate in extracellular electron transfer. In this work, the cell appendix formation of Clostridium acetobutylicum in biofilms of a BES are imaged and compared with conventional biofilms. Under all observed conditions, the cells possess filamentous appendages with a higher number and density in the BES. Differences in the amount of extracellular polymeric substance in the biofilms of the electrodes lead to the conclusion that the cathode can be used as electron donor and the anode as electron acceptor by C. acetobutylicum. When using conductive atomic force microscopy, a current response of about 15 nA is found for the cell appendages from the BES. This is the first report of conductivity for clostridial cell appendices and represents the basis for further studies on their role for biofilm formation and electron transfer. Y1 - 2019 U6 - https://doi.org/10.1002/celc.201901656 SN - 2196-0216 VL - 7 IS - 2 SP - 414 EP - 420 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Tran, N. T. A1 - Tran, Thanh Ngoc A1 - Matthies, M. G. A1 - Stavroulakis, G. E. A1 - Staat, Manfred T1 - Shakedown Analysis Under Stochastic Uncertainty by Chance Constrained Programming T2 - Advances in Direct Methods for Materials and Structures N2 - In this paper we propose a stochastic programming method to analyse limit and shakedown of structures under uncertainty condition of strength. Based on the duality theory, the shakedown load multiplier formulated by the kinematic theorem is proved actually to be the dual form of the shakedown load multiplier formulated by static theorem. In this investigation a dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit and the shakedown limit. The edge-based smoothed finite element method (ES-FEM) with three-node linear triangular elements is used for structural analysis. Y1 - 2017 SN - 978-3-319-59810-9 U6 - https://doi.org/10.1007/978-3-319-59810-9_6 SP - 85 EP - 103 PB - Springer CY - Cham ER - TY - JOUR A1 - Jung, Alexander A1 - Staat, Manfred T1 - Erratum to "Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue" [GAMM-Mitteilungen, (2019), 42, 4, 10.1002/gamm.201900002] JF - GAMM-Mitteilungen Y1 - 2020 U6 - https://doi.org/10.1002/gamm.202000011 SN - 1522-2608 N1 - Refers to: Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue. Alexander Jung, Manfred Staat. Volume 42, Issue 4. GAMM-Mitteilungen, 2019. https://doi.org/10.1002/gamm.201900002 VL - 43 IS - 4 PB - Wiley-VCH GmbH CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Roikaew, Wipa A1 - Ulber, Roland A1 - Hoffmann, Alexander A1 - Denzler, Hans-Jörg A1 - Buchholz, Heinrich T1 - Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food JF - Biotechnology Progress N2 - Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L-1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed. Y1 - 2010 U6 - https://doi.org/10.1002/btpr.384 SN - 8756-7938 VL - 26 IS - 3 SP - 756 EP - 762 PB - Wiley CY - Hoboken, NJ ER - TY - CHAP A1 - Bhattarai, Aroj A1 - Staat, Manfred ED - Fernandes, P.R. ED - Tavares, J. M. T1 - Pectopexy to repair vaginal vault prolapse: a finite element approach T2 - Proceedings CMBBE 2018 N2 - The vaginal prolapse after hysterectomy (removal of the uterus) is often associated with the prolapse of the vaginal vault, rectum, bladder, urethra or small bowel. Minimally invasive surgery such as laparoscopic sacrocolpopexy and pectopexy are widely performed for the treatment of the vaginal prolapse with weakly supported vaginal vault after hysterectomy using prosthetic mesh implants to support (or strengthen) lax apical ligaments. Implants of different shape, size and polymers are selected depending on the patient’s anatomy and the surgeon’s preference. In this computational study on pectopexy, DynaMesh®-PRP soft, GYNECARE GYNEMESH® PS Nonabsorbable PROLENE® soft and Ultrapro® are tested in a 3D finite element model of the female pelvic floor. The mesh model is implanted into the extraperitoneal space and sutured to the vaginal stump with a bilateral fixation to the iliopectineal ligament at both sides. Numerical simulations are conducted at rest, after surgery and during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues and prosthetic meshes are modeled as incompressible, isotropic hyperelastic materials. The positions of the organs are calculated with respect to the pubococcygeal line (PCL) for female pelvic floor at rest, after repair and during Valsalva maneuver using the three meshes. Y1 - 2018 N1 - 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization. CMBBE 2018. 26-29 March 2018, Lisbon, Portugal ER - TY - CHAP A1 - Dowidat, Linda A1 - König, Johannes Alexander A1 - Wolf, Martin R. T1 - The motivational competence developing game framework T2 - Mensch und Computer 2017 - Tagungsband N2 - Competence Developing Games (CDGs) are a new concept of how to think about games with serious intentions. In order to emphasize on this topic, a new framework has been developed. It basically relies on learning and motivation theories. This ‘motivational Competence Developing Game Framework’ demonstrates how it is possible to use these theories in a CDG development process. The theoretical derivation and use of the framework is explained in this paper. KW - Competence Developing Games KW - Serious Games KW - Gamification KW - motivation theories KW - learning theories Y1 - 2017 U6 - https://doi.org/10.18420/muc2017-mci-0130 SP - 15 EP - 26 PB - Gesellschaft für Informatik e.V. CY - Regensburg ER - TY - JOUR A1 - Limpert, Nicolas A1 - Wiesen, Patrick A1 - Ferrein, Alexander A1 - Kallweit, Stephan A1 - Schiffer, Stefan T1 - The ROSIN Project and its Outreach to South Africa JF - R&D Journal Y1 - 2019 VL - 35 SP - 1 EP - 6 ER - TY - JOUR A1 - Voigt, Birgit A1 - Albrecht, Dirk A1 - Sievers, Susanne A1 - Becher, Dörte A1 - Bongaerts, Johannes A1 - Evers, Stefan A1 - Schweder, Thomas A1 - Maurer, Karl-Heinz A1 - Hecker, Michael T1 - High-resolution proteome maps of Bacillus licheniformis cells growing in minimal medium JF - Proteomics Y1 - 2015 U6 - https://doi.org/10.1002/pmic.201400504 SN - 1615-9861 VL - 15 IS - 15 SP - 2629 EP - 2633 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Jung, Alexander A1 - Staat, Manfred ED - Erni, Daniel T1 - Computing olympic gold: Ski jumping as an example T2 - 1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen Y1 - 2016 SN - 978-3-940402-06-6 U6 - https://doi.org/10.17185/duepublico/40821 SP - 54 EP - 55 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - JOUR A1 - Finger, Felix A1 - Bil, Cees A1 - Braun, Carsten T1 - Initial Sizing Methodology for Hybrid-Electric General Aviation Aircraft JF - Journal of Aircraft Y1 - 2019 U6 - https://doi.org/10.2514/1.C035428 SN - 1533-3868 VL - 57 IS - 2 SP - 245 EP - 255 ER - TY - CHAP A1 - Spurmann, Jörn A1 - Ohndorf, Andreas A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Löb, Horst A1 - Schartner, Karl-Heinz T1 - Interplanetary trajectory optimization for a sep mission to Saturn T2 - 60th International Astronautical Congress 2009 N2 - The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general. KW - Spacecraft KW - Reusable Rocket Engines KW - Hybrid Propellants Y1 - 2009 SN - 9781615679089 N1 - 60th International Astronautical Congress 2009 (IAC 2009) Held 12-16 October 2009, Daejeon, Republic of Korea. SP - 5234 EP - 5248 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Schiffer, Stefan A1 - Booysen, T. A1 - Stopforth, R. T1 - Why it is harder to run RoboCup in South Africa: Experiences from German South African collaborations JF - International Journal of Advanced Robotic Systems N2 - Robots are widely used as a vehicle to spark interest in science and technology in learners. A number of initiatives focus on this issue, for instance, the Roberta Initiative, the FIRST Lego League, the World Robot Olympiad and RoboCup Junior. Robotic competitions are valuable not only for school learners but also for university students, as the RoboCup initiative shows. Besides technical skills, the students get some project exposure and experience what it means to finish their tasks on time. But qualifying students for future high-tech areas should not only be for students from developed countries. In this article, we present our experiences with research and education in robotics within the RoboCup initiative, in Germany and South Africa; we report on our experiences with trying to get the RoboCup initiative in South Africa going. RoboCup has a huge support base of academic institutions in Germany; this is not the case in South Africa. We present our ‘north–south’ collaboration initiatives in RoboCup between Germany and South Africa and discuss some of the reasons why we think it is harder to run RoboCup in South Africa. Y1 - 2016 U6 - https://doi.org/10.1177/1729881416662789 SN - 1729-8806 VL - 13 IS - 5 SP - 1 EP - 13 ER - TY - CHAP A1 - Alhwarin, Faraj A1 - Schiffer, Stefan A1 - Ferrein, Alexander A1 - Scholl, Ingrid T1 - An Optimized Method for 3D Body Scanning Applications Based on KinectFusion T2 - Communications in Computer and Information Science Y1 - 2019 U6 - https://doi.org/10.1007/978-3-030-29196-9_6 SN - 1865-0929 N1 - 11th International Joint Conference on Biomedical Engineering Systems and Technologies, BIOSTEC 2018; Funchal; Portugal; 19 January 2018 through 21 January 2018 VL - 1024 SP - 100 EP - 113 PB - Springer ER - TY - CHAP A1 - Pütz, Sebastian A1 - Baier, Ralph A1 - Brauner, Philipp A1 - Brillowski, Florian A1 - Dammers, Hannah A1 - Liehner, Luca A1 - Mertens, Alexander A1 - Rodemann, Niklas A1 - Schneider, Sebastian A1 - Schollemann, Alexander A1 - Steuer-Dankert, Linda A1 - Vervier, Luisa A1 - Gries, Thomas A1 - Leicht-Scholten, Carmen A1 - Nagel, Saskia K. A1 - Piller, Frank T. A1 - Schuh, Günther A1 - Ziefle, Martina A1 - Nitsch, Verena T1 - An interdisciplinary view on humane interfaces for digital shadows in the internet of production T2 - 2022 15th International Conference on Human System Interaction (HSI) N2 - Digital shadows play a central role for the next generation industrial internet, also known as Internet of Production (IoP). However, prior research has not considered systematically how human actors interact with digital shadows, shaping their potential for success. To address this research gap, we assembled an interdisciplinary team of authors from diverse areas of human-centered research to propose and discuss design and research recommendations for the implementation of industrial user interfaces for digital shadows, as they are currently conceptualized for the IoP. Based on the four use cases of decision support systems, knowledge sharing in global production networks, human-robot collaboration, and monitoring employee workload, we derive recommendations for interface design and enhancing workers’ capabilities. This analysis is extended by introducing requirements from the higher-level perspectives of governance and organization. KW - digital twin KW - digital shadow KW - cyber-physical production system KW - human-machine interface Y1 - 2022 SN - 978-1-6654-6823-7 (Print) SN - 978-1-6654-6822-0 (Online) U6 - https://doi.org/10.1109/HSI55341.2022.9869467 SN - 2158-2246 (Print) SN - 2158-2254 (Online) N1 - 15th International Conference on Human System Interaction (HSI), 28-31 July 2022, Melbourne, Australia. PB - IEEE ER - TY - CHAP A1 - Steuer-Dankert, Linda A1 - Leicht-Scholten, Carmen ED - Tipurić, Darko ED - Hruška, Domagoj T1 - Diversity- and innovation management in complex engineering organizations T2 - 7th International OFEL Conference on Governance, Management and Entrepreneurship: Embracing Diversity in Organisations. April 5th - 6th, 2019, Dubrovnik, Croatia N2 - Diversity is increasingly being addressed as an innovation-promoting factor. For this reason, companies and institutions tackle the integration of a diversity management approach that enables a heterogenic perspective on innovation development. However, system-theoretical frameworks state that the implementation of diversity measures that are not tailored to the needs of the organization often leads to a rejection or reactivity with regard to the management approach. In this context, especially organizations, which are characterized by a specific hierarchical structure, a dominant habitus or specialist culture, must face the challenge of realizing a sustainable change of the corporate culture that sets the basis for implementing diversity management approaches. The presented research project focuses on analyzing the situation in a huge scientific collaborative project - so called Cluster of Excellence (CoE) - with the aim to implement a diversity - and innovation management strategy. Considering the influencing determinants, the CoE is characterized by its embeddedness in the scientific system, a complex organizational structure, and a high fluctuation rate. The paper presents a systemic approach of reflecting these factors in order to develop a diversity- and innovation management strategy. In this frame, the results of a quantitative survey of CoE employees and derived mindset-types are presented. The results show a need for taking different mindset-types into account, to be able to develop a tailored management strategy. The aim of the project is to give recommendations for developing a sustainable management concept that promotes both diversity and innovation by drawing on the persisting mindsets of organization members while reflecting top down as well as bottom up factors of implementation processes as well as the psychology of change. This paper addresses all who are concerned with the management of human resources in innovation processes and are striving for a cultural change within the framework of complex organizations. KW - Change Management KW - Corporate Culture KW - Diversity Management KW - Engineering KW - Innovation Management Y1 - 2019 SP - 136 EP - 157 PB - Governance Research and Development Centre (CIRU) CY - Zagreb ER - TY - JOUR A1 - Rausch, Valentin A1 - Kahmann, Stephanie Lucina A1 - Baltschun, Christoph A1 - Staat, Manfred A1 - Müller, Lars P. A1 - Wegmann, Kilian T1 - Pressure distribution to the distal biceps tendon at the radial tuberosity: a biomechanical study JF - The Journal of Hand Surgery N2 - Purpose Mechanical impingement at the narrow radioulnar space of the tuberosity is believed to be an etiological factor in the injury of the distal biceps tendon. The aim of the study was to compare the pressure distribution at the proximal radioulnar space between 2 fixation techniques and the intact state. Methods Six right arms and 6 left arms from 5 female and 6 male frozen specimens were used for this study. A pressure transducer was introduced at the height of the radial tuberosity with the intact distal biceps tendon and after 2 fixation methods: the suture-anchor and the cortical button technique. The force (N), maximum pressure (kPa) applied to the radial tuberosity, and the contact area (mm²) of the radial tuberosity with the ulna were measured and differences from the intact tendon were detected from 60° supination to 60° pronation in 15° increments with the elbow in full extension and in 45° and 90° flexion of the elbow. Results With the distal biceps tendon intact, the pressures during pronation were similar regardless of extension and flexion and were the highest at 60° pronation with 90° elbow flexion (23.3 ± 53.5 kPa). After repair of the tendon, the mean peak pressure, contact area, and total force showed an increase regardless of the fixation technique. Highest peak pressures were found using the cortical button technique at 45° flexion of the elbow and 60° pronation. These differences were significantly different from the intact tendon. The contact area was significantly larger in full extension and 15°, 30°, and 60° pronation using the cortical button technique. Conclusions Pressures on the distal biceps tendon at the radial tuberosity increase during pronation, especially after repair of the tendon. Clinical relevance Mechanical impingement could play a role in both the etiology of primary distal biceps tendon ruptures and the complications occurring after fixation of the tendon using certain techniques. Y1 - 2020 U6 - https://doi.org/10.1016/j.jhsa.2020.01.006 SN - 0363-5023 VL - 45 IS - 8 SP - 776.e1 EP - 776.e9 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Duwe, A. A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Lignocellulose-Biorefinery: Ethanol-Focused T2 - Biorefineries N2 - The development prospects of the world markets for petroleum and other liquid fuels are diverse and partly contradictory. However, comprehensive changes for the energy supply of the future are essential. Notwithstanding the fact that there are still very large deposits of energy resources from a geological point of view, the finite nature of conventional oil reserves is indisputable. To reduce our dependence on oil, the EU, the USA, and other major economic zones rely on energy diversification. For this purpose, alternative materials and technologies are being sought, and is most obvious in the transport sector. The objective is to progressively replace fossil fuels with renewable and more sustainable fuels. In this respect, biofuels have a pre-eminent position in terms of their capability of blending with fossil fuels and being usable in existing cars without substantial modification. Ethanol can be considered as the primary renewable liquid fuel. In this chapter enzymes, micro-organisms, and processes for ethanol production based on renewable resources are described. KW - Bioethanol KW - Biorefinery KW - Lignocellulose feedstook Y1 - 2018 U6 - https://doi.org/10.1007/10_2016_72 N1 - Part of the Advances in Biochemical Engineering/Biotechnology book series (ABE,volume 166) SP - 177 EP - 215 PB - Springer CY - Cham ER - TY - JOUR A1 - Lehnertz, Klaus A1 - Bialonski, Stephan A1 - Horstmann, Marie-Therese A1 - Krug, Dieter A1 - Rothkegel, Alexander A1 - Staniek, Matthäus A1 - Wagner, Tobias T1 - Synchronization phenomena in human epileptic brain networks JF - Journal of neuroscience methods Y1 - 2009 U6 - https://doi.org/10.1016/j.jneumeth.2009.05.015 SN - 0165-0270 VL - 183 IS - 1 SP - 42 EP - 48 ER - TY - CHAP A1 - Mataré, Victor A1 - Schiffer, Stefan A1 - Ferrein, Alexander ED - Steinbauer, Gerald ED - Ferrein, Alexander T1 - golog++ : An integrative system design T2 - CogRob 2018. Cognitive Robotics Workshop : Proceedings of the 11th Cognitive Robotics Workshop 2018 co-located with 16th International Conference on Principles of Knowledge Representation and Reasoning (KR 2018) Tempe, AZ, USA, October 27th, 2018 Y1 - 2019 SN - 1613-0073 SP - 29 EP - 35 ER - TY - JOUR A1 - Staat, Manfred T1 - Shakedown and ratchetting under tension-torsion loadings: analysis and experiments N2 - Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis. KW - Einspielen KW - Einspielen KW - Ratchetting KW - Zug-Druck Belastung KW - shakedown KW - ratchetting KW - tension–torsion loading Y1 - 2003 ER - TY - CHAP A1 - Feldhusen, Jörg A1 - Brezing, Alexander Nikolaus A1 - Pütz, Claus A1 - Wählisch, Georg T1 - Multi-system CAD-teaching in large classes T2 - When design education and design research meet : proceedings of the 12th International Conference on Engineering and Product Design Education, Norwegian University of Science and Technology (NTNU) Trondheim, Norway, 2nd - 3rd September 2010 ; [E&PDE] Y1 - 2010 SN - 978-1-904670-19-3 SP - 204 EP - 209 PB - Design Society CY - Glasgow ER - TY - JOUR A1 - Hoffstadt, Kevin A1 - Nikolausz, Marcell A1 - Krafft, Simone A1 - Bonatelli, Maria A1 - Kumar, Vivekanantha A1 - Harms, Hauke A1 - Kuperjans, Isabel T1 - Optimization of the ex situ biomethanation of hydrogen and carbon dioxide in a novel meandering plug flow reactor: start-up phase and flexible operation JF - Bioengineering KW - methanation KW - plug flow reactor KW - bubble column KW - biomethane KW - P2G Y1 - 2024 U6 - https://doi.org/10.3390/bioengineering11020165 SN - 2306-5354 VL - 11 IS - 2 PB - MDPI CY - Basel ER - TY - CHAP A1 - Warerkar, S. A1 - Schmitz, S. A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Tamme, R. T1 - Performance analysis of an air-sand heat exchanger prototype for high-temperature storage T2 - EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings ; 7th - 10th October 2008, Lisbon, Portugal : key lectures / ISES, International Solar Energy Society. Vol. 1 Y1 - 2008 SN - 978-1-61782-228-5 SP - 2215 EP - 2222 PB - Sociedade Portuguesa De Energia Solar (SPES) CY - Lissabon ER - TY - JOUR A1 - Staat, Manfred A1 - Vu, Duc-Khoi T1 - Limit analysis of flaws in pressurized pipes and cylindrical vessels. Part I: Axial defects JF - Engineering Fracture Mechanics. 74 (2007), H. 3 Y1 - 2007 SN - 0013-7944 SP - 431 EP - 450 ER - TY - JOUR A1 - Cheenakula, Dheeraja A1 - Hoffstadt, Kevin A1 - Krafft, Simone A1 - Reinecke, Diana A1 - Klose, Holger A1 - Kuperjans, Isabel A1 - Grömping, Markus T1 - Anaerobic digestion of algal–bacterial biomass of an Algal Turf Scrubber system JF - Biomass Conversion and Biorefinery N2 - This study investigated the anaerobic digestion of an algal–bacterial biofilm grown in artificial wastewater in an Algal Turf Scrubber (ATS). The ATS system was located in a greenhouse (50°54′19ʺN, 6°24′55ʺE, Germany) and was exposed to seasonal conditions during the experiment period. The methane (CH4) potential of untreated algal–bacterial biofilm (UAB) and thermally pretreated biofilm (PAB) using different microbial inocula was determined by anaerobic batch fermentation. Methane productivity of UAB differed significantly between microbial inocula of digested wastepaper, a mixture of manure and maize silage, anaerobic sewage sludge, and percolated green waste. UAB using sewage sludge as inoculum showed the highest methane productivity. The share of methane in biogas was dependent on inoculum. Using PAB, a strong positive impact on methane productivity was identified for the digested wastepaper (116.4%) and a mixture of manure and maize silage (107.4%) inocula. By contrast, the methane yield was significantly reduced for the digested anaerobic sewage sludge (50.6%) and percolated green waste (43.5%) inocula. To further evaluate the potential of algal–bacterial biofilm for biogas production in wastewater treatment and biogas plants in a circular bioeconomy, scale-up calculations were conducted. It was found that a 0.116 km2 ATS would be required in an average municipal wastewater treatment plant which can be viewed as problematic in terms of space consumption. However, a substantial amount of energy surplus (4.7–12.5 MWh a−1) can be gained through the addition of algal–bacterial biomass to the anaerobic digester of a municipal wastewater treatment plant. Wastewater treatment and subsequent energy production through algae show dominancy over conventional technologies. KW - Biogas KW - Methane KW - Algal Turf Scrubber KW - Algal–bacterial bioflm KW - Circular bioeconomy Y1 - 2022 U6 - https://doi.org/10.1007/s13399-022-03236-z SN - 2190-6823 N1 - Corresponding author: Dheeraja Cheenakula VL - 13 SP - 15 Seiten PB - Springer CY - Berlin ER - TY - JOUR A1 - Bornheim, Tobias A1 - Grieger, Niklas A1 - Blaneck, Patrick Gustav A1 - Bialonski, Stephan T1 - Speaker Attribution in German Parliamentary Debates with QLoRA-adapted Large Language Models JF - Journal for language technology and computational linguistics : JLCL N2 - The growing body of political texts opens up new opportunities for rich insights into political dynamics and ideologies but also increases the workload for manual analysis. Automated speaker attribution, which detects who said what to whom in a speech event and is closely related to semantic role labeling, is an important processing step for computational text analysis. We study the potential of the large language model family Llama 2 to automate speaker attribution in German parliamentary debates from 2017-2021. We fine-tune Llama 2 with QLoRA, an efficient training strategy, and observe our approach to achieve competitive performance in the GermEval 2023 Shared Task On Speaker Attribution in German News Articles and Parliamentary Debates. Our results shed light on the capabilities of large language models in automating speaker attribution, revealing a promising avenue for computational analysis of political discourse and the development of semantic role labeling systems. KW - large language models KW - German KW - speaker attribution KW - semantic role labeling Y1 - 2024 U6 - https://doi.org/10.21248/jlcl.37.2024.244 SN - 2190-6858 VL - 37 IS - 1 PB - Gesellschaft für Sprachtechnologie und Computerlinguistik CY - Regensburg ER - TY - CHAP A1 - Sattler, Johannes Christoph A1 - Atti, Vikrama A1 - Alexopoulos, Spiros A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf A1 - Dutta, Siddharth A1 - Kioutsioukis, Ioannis T1 - DNI forecast tool for the smart operation of a parabolic trough collector system with concrete thermal energy storage: Theory, results and outlook T2 - SolarPACES 2022 conference proceedings N2 - This work presents a basic forecast tool for predicting direct normal irradiance (DNI) in hourly resolution, which the Solar-Institut Jülich (SIJ) is developing within a research project. The DNI forecast data shall be used for a parabolic trough collector (PTC) system with a concrete thermal energy storage (C-TES) located at the company KEAN Soft Drinks Ltd in Limassol, Cyprus. On a daily basis, 24-hour DNI prediction data in hourly resolution shall be automatically produced using free or very low-cost weather forecast data as input. The purpose of the DNI forecast tool is to automatically transfer the DNI forecast data on a daily basis to a main control unit (MCU). The MCU automatically makes a smart decision on the operation mode of the PTC system such as steam production mode and/or C-TES charging mode. The DNI forecast tool was evaluated using historical data of measured DNI from an on-site weather station, which was compared to the DNI forecast data. The DNI forecast tool was tested using data from 56 days between January and March 2022, which included days with a strong variation in DNI due to cloud passages. For the evaluation of the DNI forecast reliability, three categories were created and the forecast data was sorted accordingly. The result was that the DNI forecast tool has a reliability of 71.4 % based on the tested days. The result fulfils SIJ’s aim to achieve a reliability of around 70 %, but SIJ aims to still improve the DNI forecast quality. KW - Direct normal irradiance forecast KW - DNI forecast KW - Parabolic trough collector KW - PTC KW - Thermal Energy Storage Y1 - 2024 U6 - https://doi.org/10.52825/solarpaces.v1i.731 SN - 2751-9899 (online) N1 - SolarPACES 2022, 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - 1 PB - TIB Open Publishing CY - Hannover ER - TY - CHAP A1 - Sattler, Johannes Christoph A1 - Schneider, Iesse Peer A1 - Angele, Florian A1 - Atti, Vikrama A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Development of heliostat field calibration methods: Theory and experimental test results T2 - SolarPACES 2022 conference proceedings N2 - In this work, three patent pending calibration methods for heliostat fields of central receiver systems (CRS) developed by the Solar-Institut Jülich (SIJ) of the FH Aachen University of Applied Sciences are presented. The calibration methods can either operate in a combined mode or in stand-alone mode. The first calibration method, method A, foresees that a camera matrix is placed into the receiver plane where it is subjected to concentrated solar irradiance during a measurement process. The second calibration method, method B, uses an unmanned aerial vehicle (UAV) such as a quadrocopter to automatically fly into the reflected solar irradiance cross-section of one or more heliostats (two variants of method B were tested). The third calibration method, method C, foresees a stereo central camera or multiple stereo cameras installed e.g. on the solar tower whereby the orientations of the heliostats are calculated from the location detection of spherical red markers attached to the heliostats. The most accurate method is method A which has a mean accuracy of 0.17 mrad. The mean accuracy of method B variant 1 is 1.36 mrad and of variant 2 is 1.73 mrad. Method C has a mean accuracy of 15.07 mrad. For method B there is great potential regarding improving the measurement accuracy. For method C the collected data was not sufficient for determining whether or not there is potential for improving the accuracy. KW - Heliostat Field Calibration KW - Unmanned aerial vehicle KW - UAV KW - Quadrocopter KW - Camera system Y1 - 2024 U6 - https://doi.org/10.52825/solarpaces.v1i.678 SN - 2751-9899 (online) N1 - SolarPACES 2022: 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - 1 PB - TIB Open Publishing CY - Hannover ER - TY - CHAP A1 - Gömmel, A. A1 - Butenweg, Christoph A1 - Kob, M. T1 - A fluid-structure interaction model of vocal fold oscillation T2 - 5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007 N2 - Since fluid-structure interaction within the finite-element method is state of the art in many engineering fields, this method is used in voice analysis. A quasi two-dimensional model of the vocal folds including the ventricular folds is presented. First results of self-sustained vocal fold oscillation are presented and possibilities as well as limitations are discussed. KW - finite element method KW - fluid structure interaction KW - vocal fold oscillation Y1 - 2007 SN - 978-888453674-7 N1 - 5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007; Florence; Italy; 13 December 2007 through 15 December 2007 SP - 127 EP - 128 ER - TY - JOUR A1 - Vant, Christianne A1 - Staat, Manfred A1 - Baroud, Gamal T1 - Percutaneous Vertebroplasty: A Review of Two Intraoperative Complications JF - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.) Y1 - 2008 SN - 978-3-540-75408-4 SP - 527 EP - 539 PB - Springer CY - Berlin ER - TY - CHAP A1 - Krüger, Dirk A1 - Anthrakidis, Anette A1 - Fischer, Stephan A1 - Lokurlu, Ahmet A1 - Walder, Markus A1 - Croy, Reiner A1 - Quaschning, Volker T1 - Experiences with solar steam supply for an industrial steam network in the P3 Project T2 - SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings Y1 - 2009 SN - 9783000287558 PB - Deutsches Zentrum f. Luft- u. Raumfahrt CY - Stuttgart ER - TY - JOUR A1 - Vu, Duc Khoi A1 - Staat, Manfred T1 - Shakedown analysis of structures made of materials with temperature-dependent yield stress JF - International Journal of Solids and Structures. 44 (2007), H. 13 Y1 - 2007 SN - 0020-7683 SP - 4524 EP - 4540 ER -