TY - GEN A1 - Maiwald, Volker A1 - Dachwald, Bernd T1 - Mission design for a multiple-rendezvous mission to Jupiter's trojans N2 - In this paper, we will provide a feasible mission design for a multiple-rendezvous mission to Jupiter's Trojans. It is based on solar electric propulsion, as being currently used on the DAWN spacecraft, and other flight-proven technology. First, we have selected a set of mission objectives, the prime objective being the detection of water -especially subsurface water -to provide evidence for the Trojans' formation at large solar distances. Based on DAWN and other comparable missions, we have determined suitable payload instruments to achieve these objectives. Afterwards, we have designed a spacecraft that is able to carry the selected payload to the Trojan region and rendezvous successively with three target bodies within a maximum mission duration of 15 years. Accurate low-thrust trajectories have been obtained with a global low-thrust trajectory optimization program (InTrance). During the transfer from Earth to the first target, the spacecraft is propelled by two RIT-22 ion engines from EADS Astrium, whereas a single RIT-15 is used for transfers within the Trojan region to reduce the required power. For power generation, the spacecraft uses a multi-junction solar array that is supported by concentrators. To achieve moderate mission costs, we have restricted the launch mass to a maximum of 1600 kg, the maximum interplanetary injection capability of a Soyuz/Fregat launcher. Our final layout has a mass of 1400 kg, yielding a margin of about 14%. Nestor (a member of the L4-population) was determined as the first mission target. It can be reached within 4.6 years from launch. The fuel mass ratio for this transfer is about 35%. The stay time at Nestor is 1.2 years. Eurymedon was selected as the second target (transfer time 3.5 years, stay time 3.0 years) and Irus as the third target (transfer time 2.2 years). The transfers within the Trojan L4-population can be accomplished with fuel mass ratios of about 3% for each trajectory leg. Including the stay times in orbit around the targets, the mission can be accomplished within a total duration of about 14.5 years. According to our mission analysis, it is also feasible to fly to the L5-population with similar flight times. It has to be noted that -for a first analysis -we have taken only the named targets into account. Allowing also rendezvous with unnamed objects will very likely decrease the mission duration. Based on a scaling of DAWN's mission costs (due to comparable scientific instruments and mission objectives), and taking into account the longer mission duration and the potential re-use of already developed technology, we have estimated that these three rendezvous can be accomplished with a budget of about 250 Million Euros, i.e. about 25% of ROSETTA's budget. Y1 - 2010 N1 - 38th COSPAR Scientific Assembly. Held 18-15 July 2010,Bremen, Germany SP - 3 ER - TY - CHAP A1 - Geimer, Konstantin A1 - Sauerborn, Markus A1 - Hoffschmidt, Bernhard A1 - Schmitz, Mark A1 - Göttsche, Joachim T1 - Test facility for absorber specimens of solar tower power plants T2 - Advances in Science and Technology N2 - The Solar-Institute Jülich (SIJ) has initiated the construction of the first and only German solar tower power plant and is now involved in the accompanying research. The power plant for experimental and demonstration purposes in the town of Jülich started supplying electric energy in the beginning of 2008. The central receiver plant features as central innovation an open volumetric receiver, consisting of porous ceramic elements that simultaneously absorb the concentrated sunlight and transfer the heat to ambient air passing through the pores so that an average temperature of 680°C is reached. The subsequent steam cycle generates up to 1.5 MWe. A main field of research at the SIJ is the optimization of the absorber structures. To analyze the capability of new absorber specimens a special test facility was developed and set up in the laboratory. A high-performance near-infrared radiator offers for single test samples a variable and repeatable beam with a power of up to 320 kW/m² peak. The temperatures achieved on the absorber surface can reach more than 1000°C. To suck ambient air through the open absorber - like on the tower - it is mounted on a special blower system. An overview about the test facility and some recent results will be presented. Y1 - 2010 U6 - https://doi.org/10.4028/www.scientific.net/AST.74.266 N1 - 5th Forum on New Materials : CIMTEC 2010, Montecatini Terme, Italy 13-18 June 2010. Part C VL - 74 SP - 266 EP - 271 PB - Trans Tech Publications CY - Baech ER - TY - CHAP A1 - Gerhards, Michael A1 - Belloum, Adam A1 - Berretz, Frank A1 - Sander, Volker A1 - Skorupa, Sascha T1 - A history-tracing XML-based provenance framework for workflows T2 - The 5th Workshop on Workflows in Support of Large-Scale Science N2 - The importance of validating and reproducing the outcome of computational processes is fundamental to many application domains. Assuring the provenance of workflows will likely become even more important with respect to the incorporation of human tasks to standard workflows by emerging standards such as WS-HumanTask. This paper addresses this trend by an actor-based workflow approach that actively support provenance. It proposes a framework to track and store provenance information automatically that applies for various workflow management systems. In particular, the introduced provenance framework supports the documentation of workflows in a legally binding way. The authors therefore use the concept of layered XML documents, i.e. history-tracing XML. Furthermore, the proposed provenance framework enables the executors (actors) of a particular workflow task to attest their operations and the associated results by integrating digital XML signatures. KW - workflow KW - provenance KW - framework KW - containers KW - humans KW - synchronization KW - libraries KW - history KW - concrete KW - XML Y1 - 2010 SN - 978-1-4244-8989-3 U6 - https://doi.org/10.1109/WORKS.2010.5671873 N1 - The 5th Workshop on Workflows in Support of Large-Scale Science, 14 Nov. 2010, New Orleans, USA PB - IEEE CY - New York ER - TY - CHAP A1 - Bouquegneau, Christian A1 - Kern, Alexander A1 - Rousseau, Alain T1 - Lightning safety guidelines N2 - This paper introduces lightning to the layman, noting the right behaviour in front of thunderstorms as well as protective measures against lightning. It also contributes to the prevention of lightning injuries and damages. This report was prepared by the authors inside the AHG1 Group for IEC TC81 (Lightning Protection). Y1 - 2010 N1 - Ground´2010 & 4th LPE, International Conference on Grounding and Earthing & 4th International Conference on Lightning Physics and Effects, Salvador - Brazil, November, 2010 ER - TY - GEN A1 - Jansen, Sebastian A1 - Behbahani, Mehdi A1 - Laumen, Marco A1 - Kaufmann, Tim A1 - Hormes, Marcus A1 - Schmitz-Rode, Thomas A1 - Behr, Marek A1 - Steinseifer, Ulrich T1 - 3D stereo-PIV validation for CFD-simulation of steady flow through the human aorta using rapid-prototyping techniques Y1 - 2010 N1 - MPF2010, IV International Symposium on Modelling of Physiological Flows, Sardinia, Italy, June 02-05, 2010 ER - TY - CHAP A1 - Börner, Sebastian A1 - Funke, Harald A1 - Hendrick, P. A1 - Recker, E. T1 - Control system modifications for a hydrogen fuelled gas-turbine T2 - Proceedings of ISROMAC 13 Y1 - 2010 SN - 978-1-617-38848-4 N1 - 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13), Honolulu, Hawaii, USA, April 4-7, 2010 SP - 665 EP - 670 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Kern, Alexander A1 - Frentzel, Ralf A1 - Behrens, Jörg T1 - Simulation of the transient voltages in the auxiliary power network of a large power plant in case of a direct lightning strike to the high-voltage overhead transmission line N2 - Large power plants can be endangered by lightning strikes with possible consequences regarding their safety and availability. A special scenario is a lightning strike to the HV overhead transmission line close to the power plant's connection to the power grid. If then additionally a so-called shielding failure of the overhead ground wire on top of the overhead transmission line is assumed, i.e. the lightning strikes directly into a phase conductor, this is an extreme electromagnetic disturbance. The paper deals with the numerical simulation of such a lightning strike and the consequences on the components of the power plant's auxiliary power network connected to different voltage levels. KW - power generation KW - surges KW - conductors KW - arresters KW - power transmission lines KW - lightning Y1 - 2010 SN - 978-88-905519-0-1 U6 - https://doi.org/10.1109/ICLP.2010.7845756 N1 - 2010 30th International Conference on Lightning Protection (ICLP), 13-17 Sept. 2010, Cagliari, Italy SP - 749-1 EP - 749-7 PB - IEEE CY - New York ER - TY - CHAP A1 - Kern, Alexander A1 - Schelthoff, Christof A1 - Mathieu, Moritz T1 - Probability of lightning strikes to air-terminations of structures using the electro-geometrical model theory and the statistics of lightning current parameters N2 - Planning the air-terminations for a structure to be protected the use of the rolling-sphere method (electro-geometrical model) is the best way from the physics of lightning point-of-view. Therefore, international standards prefer this method. However, using the rolling-sphere method only results in possible point-of-strikes on a structure without giving information about the probability of strikes at the individual points compared to others. KW - atmospheric modeling KW - probability distribution KW - lightning protection KW - standards KW - planning Y1 - 2010 SN - 978-88-905519-0-1 U6 - https://doi.org/10.1109/ICLP.2010.7845757 N1 - 2010 30th International Conference on Lightning Protection (ICLP), 13-17 Sept. 2010, Cagliari, Italy SP - 750-1 EP - 750-8 PB - IEEE CY - New York ER - TY - CHAP A1 - Berretz, Frank A1 - Skorupa, Sascha A1 - Sander, Volker A1 - Belloum, Adam T1 - Towards an actor-driven workflow management system for grids T2 - Proceedings of 2010 International Symposium on Collaborative Technologies and Systems N2 - Currently, most workflow management systems in Grid environments provide push-oriented job distribution strategies, where jobs are explicitly delegated to resources. In those scenarios the dedicated resources execute submitted jobs according to the request of a workflow engine or Grid wide scheduler. This approach has various limitations, particularly if human interactions should be integrated in workflow execution. To support human interactions with the benefit of enabling inter organizational computation and community approaches, this poster paper proposes the idea of a pull-based task distribution strategy. Here, heterogeneous resources, including human interaction, should actively select tasks for execution from a central repository. This leads to special demands regarding security issues like access control. In the established push-based job execution the resources are responsible for granting access to workflows and job initiators. In general this is done by access control lists, where users are explicitly mapped to local accounts according to their policies. In the pull-based approach the resources actively apply for job executions by sending requests to a central task repository. This means that every resource has to be able to authenticate against the repository to be authorized for task execution. In other words the authorization is relocated from the resources to the repository. The poster paper introduces current work regarding to the mentioned security aspects in the pull-based approach within the scope of the project “HiX4AGWS”. KW - scheduling KW - engines KW - resource management KW - grid computing KW - access control KW - distribution strategy KW - authorization KW - security KW - humans KW - workflow management software Y1 - 2010 SN - 978-1-4244-6619-1 U6 - https://doi.org/10.1109/CTS.2010.5478458 N1 - 2010 International Symposium on Collaborative Technologies and Systems, 17-21 May 2010, Chicago, IL, USA SP - 611 EP - 616 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Schmitt, Robert A1 - Scholl, Ingrid A1 - Cai, Yu A1 - Xia, Ji A1 - Dziwoki, Paul A1 - Harding, Martin A1 - Pavim, Alberto T1 - Machine vision system for inline inspection in carbide insert production T2 - Proceedings of the 36th International MATADOR Conference N2 - In steps of the production chain of carbide inserts, such as unloading or packaging, the conformity test of the insert type is done manually, which causes a statistic increase of errors due to monotony and fatigue of the worker and the wide variety of the insert types. A machine vision system is introduced that captures digital frames of the inserts in the production line, analyses inspects automatically and measures four quality features: coating colour, edge radius, plate shape and chip-former geometry. This new method has been tested on several inserts of different types and has shown that the prevalent insert types can be inspected and robustly classified in real production environment and therefore improves the manufacturing automation. Y1 - 2010 SN - 978-1-84996-431-9 U6 - https://doi.org/10.1007/978-1-84996-432-6_77 N1 - 36th MATADOR Conference, University of Manchester, July 2010 SP - 339 EP - 342 PB - Springer CY - Berlin ER -