@misc{Kowalski2010, type = {Master Thesis}, author = {Kowalski, Julia}, title = {Streamline estimation from sparsely sampled q-space Magnetic Resonance data}, year = {2010}, language = {de} } @article{ChristenKowalskiBartelt2010, author = {Christen, Marc and Kowalski, Julia and Bartelt, Perry}, title = {RAMMS: Numerical simulation of dense snow avalanches in three-dimensional terrain}, series = {Cold Regions Science and Technology}, volume = {63}, journal = {Cold Regions Science and Technology}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7441}, doi = {10.1016/j.coldregions.2010.04.005}, pages = {1 -- 14}, year = {2010}, abstract = {Numerical avalanche dynamics models have become an essential part of snow engineering. Coupled with field observations and historical records, they are especially helpful in understanding avalanche flow in complex terrain. However, their application poses several new challenges to avalanche engineers. A detailed understanding of the avalanche phenomena is required to construct hazard scenarios which involve the careful specification of initial conditions (release zone location and dimensions) and definition of appropriate friction parameters. The interpretation of simulation results requires an understanding of the numerical solution schemes and easy to use visualization tools. We discuss these problems by presenting the computer model RAMMS, which was specially designed by the SLF as a practical tool for avalanche engineers. RAMMS solves the depth-averaged equations governing avalanche flow with accurate second-order numerical solution schemes. The model allows the specification of multiple release zones in three-dimensional terrain. Snow cover entrainment is considered. Furthermore, two different flow rheologies can be applied: the standard Voellmy-Salm (VS) approach or a random kinetic energy (RKE) model, which accounts for the random motion and inelastic interaction between snow granules. We present the governing differential equations, highlight some of the input and output features of RAMMS and then apply the models with entrainment to simulate two well-documented avalanche events recorded at the Vall{\´e}e de la Sionne test site.}, language = {en} } @article{ChristenBarteltKowalski2010, author = {Christen, Marc and Bartelt, Perry and Kowalski, Julia}, title = {Back calculation of the In den Arelen avalanche with RAMMS: Interpretation of model results}, series = {Annals of Glaciology}, volume = {51}, journal = {Annals of Glaciology}, number = {54}, publisher = {Cambridge University Press}, address = {Cambridge}, isbn = {1727-5644}, doi = {10.3189/172756410791386553}, pages = {161 -- 168}, year = {2010}, abstract = {Two- and three-dimensional avalanche dynamics models are being increasingly used in hazard-mitigation studies. These models can provide improved and more accurate results for hazard mapping than the simple one-dimensional models presently used in practice. However, two- and three-dimensional models generate an extensive amount of output data, making the interpretation of simulation results more difficult. To perform a simulation in three-dimensional terrain, numerical models require a digital elevation model, specification of avalanche release areas (spatial extent and volume), selection of solution methods, finding an adequate calculation resolution and, finally, the choice of friction parameters. In this paper, the importance and difficulty of correctly setting up and analysing the results of a numerical avalanche dynamics simulation is discussed. We apply the two-dimensional simulation program RAMMS to the 1968 extreme avalanche event In den Arelen. We show the effect of model input variations on simulation results and the dangers and complexities in their interpretation.}, language = {en} } @article{Fabo2010, author = {Fabo, Sabine}, title = {Sisyphus wird Steiff}, series = {Pr{\"a}dikat spießig (Boxhorn ; 21)}, volume = {2010}, journal = {Pr{\"a}dikat spießig (Boxhorn ; 21)}, editor = {Mohr, Klaus}, publisher = {FH Aachen, Fachbereich Gestaltung}, address = {Aachen}, issn = {1864-2535}, pages = {58 -- 61}, year = {2010}, abstract = {Eine Reise durch die fremde Welt eines Kaufhaus-Schaufensters. Pl{\"u}schtiere mit eingebauter Bewegungstechnik - knuffig oder nur eine Ausformulierung des Ernst des Lebens?}, language = {de} } @article{PieperKlein2010, author = {Pieper, Martin and Klein, Peter}, title = {Numerical solution of the heat equation with non-linear, time derivative-dependent source term}, series = {International Journal for Numerical Methods in Engineering}, volume = {84}, journal = {International Journal for Numerical Methods in Engineering}, number = {10}, publisher = {Wiley}, address = {Chichester}, issn = {0029-5981}, doi = {10.1002/nme.2937}, pages = {1205 -- 1221}, year = {2010}, abstract = {The mathematical modeling of heat conduction with adsorption effects in coated metal structures yields the heat equation with piecewise smooth coefficients and a new kind of source term. This term is special, because it is non-linear and furthermore depends on a time derivative. In our approach we reformulated this as a new problem for the usual heat equation, without source term but with a new non-linear coefficient. We gave an existence and uniqueness proof for the weak solution of the reformulated problem. To obtain a numerical solution, we developed a semi-implicit and a fully implicit finite volume method. We compared these two methods theoretically as well as numerically. Finally, as practical application, we simulated the heat conduction in coated aluminum fibers with adsorption in the zeolite coating. Copyright © 2010 John Wiley \& Sons, Ltd.}, language = {en} } @misc{Digel2010, author = {Digel, Ilya}, title = {In-situ biological decontamination of an ice melting probe}, year = {2010}, language = {en} } @article{KozhalakovaZhubanovaMansurovetal.2010, author = {Kozhalakova, A. A. and Zhubanova, Azhar A. and Mansurov, Z. A. and Digel, Ilya and Tazhibayeva, S. M. and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Adsorption of bacterial lipopolysaccharides on carbonized rice shell}, series = {Science of Central Asia}, journal = {Science of Central Asia}, pages = {50 -- 54}, year = {2010}, language = {en} } @article{KurzLinderTrzewiketal.2010, author = {Kurz, R. and Linder, Peter and Trzewik, J{\"u}rgen and R{\"u}ffer, M. and Artmann, Gerhard and Digel, Ilya and Rothermel, A. and Robitzki, A. and Temiz Artmann, Ayseg{\"u}l}, title = {Contractile tension and beating rates of self-exciting monolayers and 3D-tissue constructs of neonatal rat cardiomyocytes}, series = {Medical and Biological Engineering and Computing}, volume = {48}, journal = {Medical and Biological Engineering and Computing}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {1741-0444}, doi = {10.1007/s11517-009-0552-y}, pages = {59 -- 65}, year = {2010}, abstract = {The CellDrum technology (The term 'CellDrum technology' includes a couple of slightly different technological setups for measuring lateral mechanical tension in various types of cell monolayers or 3D-tissue constructs) was designed to quantify the contraction rate and mechanical tension of self-exciting cardiac myocytes. Cells were grown either within flexible, circular collagen gels or as monolayer on top of respective 1-mum thin silicone membranes. Membrane and cells were bulged outwards by air pressure. This biaxial strain distribution is rather similar the beating, blood-filled heart. The setup allowed presetting the mechanical residual stress level externally by adjusting the centre deflection, thus, mimicking hypertension in vitro. Tension was measured as oscillating differential pressure change between chamber and environment. A 0.5-mm thick collagen-cardiac myocyte tissue construct induced after 2 days of culturing (initial cell density 2 x 10(4) cells/ml), a mechanical tension of 1.62 +/- 0.17 microN/mm(2). Mechanical load is an important growth regulator in the developing heart, and the orientation and alignment of cardiomyocytes is stress sensitive. Therefore, it was necessary to develop the CellDrum technology with its biaxial stress-strain distribution and defined mechanical boundary conditions. Cells were exposed to strain in two directions, radially and circumferentially, which is similar to biaxial loading in real heart tissues. Thus, from a biomechanical point of view, the system is preferable to previous setups based on uniaxial stretching.}, language = {en} } @article{GarhoferBekBoehmetal.2010, author = {Garhofer, Gerhard and Bek, Toke and Boehm, Andreas G. and Gherghel, Doina and Grundwald, Juan and Jeppesen, Peter and Kergoat, H{\´e}l{\`e}ne and Kotliar, Konstantin and Lanzl, Ines and Lovasik, John V. and Nagel, Edgar and Vilser, Walthard and Orgul, Selim and Schmetterer, Leopold}, title = {Use of the retinal vessel analyzer in ocular blood flow research}, series = {Acta Ophthalmol}, volume = {88}, journal = {Acta Ophthalmol}, number = {7}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1755-3768}, doi = {10.1111/j.1755-3768.2009.01587.x}, pages = {717 -- 722}, year = {2010}, abstract = {The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed.}, language = {en} } @article{PresslerEsefeldScherretal.2010, author = {Pressler, Axel and Esefeld, Katrin and Scherr, Johannes and Ali, Mohammad and Hanssen, Henner and Kotliar, Konstantin and Lanzl, Ines and Halle, Martin and Kaemmerer, Harald and Schmidt-Trucks{\"a}ss, Arno and Hager, Alfred}, title = {Structural alterations of retinal arterioles in adults late after repair of aortic isthmic coarctation}, series = {The American Journal of Cardiology}, volume = {105}, journal = {The American Journal of Cardiology}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0002-9149}, doi = {10.1016/j.amjcard.2009.10.070}, pages = {740 -- 744}, year = {2010}, abstract = {Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5\%, first to third quartile 2.1\% to 4.5\% vs 3.6\%, first to third quartile 2.2\% to 4.3\%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients.}, language = {en} } @article{WiescherKotliarNeuhannetal.2010, author = {Wiescher, A. and Kotliar, Konstantin and Neuhann, T. and Lanzl, Ines M.}, title = {Rasch progrediente Visusminderung beider Augen bei einem jungen Patienten}, series = {Der Ophthalmologe}, volume = {105}, journal = {Der Ophthalmologe}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1433-0423}, doi = {10.1007/s00347-007-1586-x}, pages = {389 -- 392}, year = {2010}, abstract = {Ein 34-j{\"a}hriger m{\"a}nnlicher Patient stellte sich zur Abkl{\"a}rung einer seit dem 9. Lebensjahr bestehenden und im letzten Jahr rasch progredienten Visusminderung beider Augen bei uns vor. Er beschrieb eine subjektiv zunehmende, im Spiegel f{\"u}r ihn selbst sichtbare, weißliche Tr{\"u}bung in der Pupille beidseits und eine starke Blendempfindlichkeit. Nebenbefundlich gab er rezidivierende Konjunktivitiden und morgens verklebte Lider an. Eine Allergie auf Gr{\"a}serpollen und eine Unvertr{\"a}glichkeit auf Alkohol sowie mehrere Lebensmittel seien ebenfalls bekannt. Zus{\"a}tzlich leidet der Patient an stark ausgepr{\"a}gtem atopischem Ekzem. Dieses wurde nie systemisch, sondern nur bei Bedarf mit kortisonhaltiger Salbe therapiert.}, language = {de} } @article{LanzlSeidovaErbenetal.2010, author = {Lanzl, Ines M. and Seidova, Seid-Fatima and Erben, A. and Th{\"u}rmel, K. and Kotliar, Konstantin}, title = {Diffuse stromale Hornhauttr{\"u}bungen und Ver{\"a}nderungen der H{\"a}nde}, series = {Der Ophthalmologe}, volume = {107}, journal = {Der Ophthalmologe}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1433-0423}, doi = {10.1007/s00347-009-2066-2}, pages = {363 -- 365}, year = {2010}, abstract = {Bilaterale stromale Hornhauttr{\"u}bungen sind f{\"u}r den Augenarzt eine differenzialdiagnostische Herausforderung. Im folgenden Beitrag werden 2 Patieninnen (30 und 36 Jahre) mit unterschiedlich stark ausgepr{\"a}gter stromaler diffuser Hornhauttr{\"u}bung vorgestellt. Patientin 1 war kleinw{\"u}chsig (114 cm) und Patientin 2 normal groß (172 cm). Beide Patientinnen wiesen ver{\"a}nderte Gelenkstrukturen an Hand und Fußgelenken sowie diffuse stromale Hornhauttr{\"u}bungen auf. Des Weiteren lagen eine Mitral- und Aorteninsuffizienz (Patientin 1) bzw. eine Aorteninsuffizienz (Patientin 2) vor. Die stromalen diffusen Hornhauttr{\"u}bungen ließen im Zusammenhang mit den Gelenkver{\"a}nderungen ein Scheie-Syndrom vermuten. Therapeutisch ist bei Patienten mit Visusminderung eine (lamell{\"a}re) Keratoplastik sinnvoll.}, language = {de} } @article{KotliarNagelVilseretal.2010, author = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Seidova, Seid-Fatima and Lanzl, Ines}, title = {Microstructural alterations of retinal arterial blood column along the vessel axis in systemic hypertension}, series = {Investigative Ophthalmology \& Visual Science, IOVS}, volume = {51}, journal = {Investigative Ophthalmology \& Visual Science, IOVS}, number = {4}, publisher = {ARVO}, address = {Rockville, Md.}, issn = {0146-0404}, doi = {10.1167/iovs.09-3649}, pages = {2165 -- 2172}, year = {2010}, abstract = {Purpose: Image analysis by the retinal vessel analyzer (RVA) observes retinal vessels in their dynamic state online noninvasively along a chosen vessel segment. It has been found that high-frequency diameter changes in the retinal artery blood column along the vessel increase significantly in anamnestically healthy volunteers with increasing age and in patients with glaucoma during vascular dilation. This study was undertaken to investigate whether longitudinal sections of the retinal artery blood column are altered in systemic hypertension. Methods: Retinal arteries of 15 untreated patients with essential arterial hypertension (age, 50.9 ± 11.9 years) and of 15 age-matched anamnestically healthy volunteers were examined by RVA. After baseline assessment, a monochromatic luminance flicker (530-600 nm; 12.5 Hz; 20 s) was applied to evoke retinal vasodilation. Differences in amplitude and frequency of spatial artery blood column diameter change along segments (longitudinal arterial profiles) of 1 mm in length were measured and analyzed using Fourier transformation. Results: In the control group, average reduced power spectra (ARPS) of longitudinal arterial profiles did not differ when arteries changed from constriction to dilation. In the systemic hypertension group, ARPS during constriction, baseline, and restoration were identical and differed from ARPS during dilation (P < 0.05). Longitudinal arterial profiles in both groups showed significant dissimilitude at baseline and restoration (P < 0.05). Conclusions: The retinal artery blood column demonstrates microstructural alterations in systemic hypertension and is less irregular along the vessel axis during vessel dilation. These microstructural changes may be an indication of alterations in vessel wall rigidity, vascular endothelial function, and smooth muscle cells in this disease, leading to impaired perfusion and regulation.}, language = {en} } @book{Tuennemann2010, author = {T{\"u}nnemann, Thomas}, title = {formine 2010 ... ein Haus ... : Workshop ; Fachbereich Architektur / T{\"u}nnemann, Thomas [Red.]}, publisher = {Fachhochschule Aachen, Fachbereich Architektur}, address = {Aachen}, isbn = {978-3-9811003-3-4}, publisher = {Fachhochschule Aachen}, pages = {65 S. : zahlr. Ill.}, year = {2010}, language = {de} } @article{HaselgruberMautnerThiele2010, author = {Haselgruber, Nikolaus and Mautner, Karin and Thiele, Jan}, title = {Usage Space Analysis for Reliability Testing}, series = {Quality and Reliability Engineering International}, volume = {26}, journal = {Quality and Reliability Engineering International}, number = {8}, publisher = {Wiley}, address = {New York}, issn = {1099-1638}, doi = {10.1002/qre.1155}, pages = {877 -- 885}, year = {2010}, abstract = {During the development process of a complex technical product, one widely used and important technique is accelerated testing where the applied stress on a component is chosen to exceed the reference stress, i.e. the stress encountered in field operation, in order to reduce the time to failure. For that, the reference stress has to be known. Since a complex technical product may fail regarding numerous failure modes, stress in general is highly dimensional rather than scalar. In addition, customers use their products individually, i.e. field operation should be described by a distribution rather than by one scalar stress value. In this paper, a way to span the customer usage space is shown. It allows the identification of worst case reference stress profiles in significantly reduced dimensions with minimal loss of information. The application example shows that even for a complex product like a combustion engine, stress information can be compressed significantly. With low measurement effort it turned out that only three reference stress cycles were sufficient to cover a broad range of customer stress variety.}, language = {en} } @article{FornaciariGuidettiHavermannetal.2010, author = {Fornaciari, Andrea and Guidetti, Marco and Havermann, Marc and Lettini, Antonio}, title = {Maccine mobili pi{\`u} efficienti}, series = {Fluidotecnica}, journal = {Fluidotecnica}, number = {345}, publisher = {Quine Business Publisher}, address = {Milano}, pages = {11 -- 14}, year = {2010}, abstract = {Secondo le attuali normative tutte le macchine mobili, entro il 2012, dovranno essere soggette a un incremento di efficienza energetica. Un'evoluzione del sistema idraulico potr{\`a} contribuire in maniera significativa al miglioramento richiesto. Elettronica e idraulica sempre pi{\`u} protagoniste.}, language = {it} } @inproceedings{HavermannSeilerHenning2010, author = {Havermann, Marc and Seiler, F. and Henning, P.}, title = {Shock Tunnel Experiments and CFD Simulation of Lateral Jet Interaction in Hypersonic Flows}, series = {New Results in Numerical and Experimental Fluid Mechanics VII; Contributions to the 16th STAB/DGLR Symposium Aachen, Germany 2008}, booktitle = {New Results in Numerical and Experimental Fluid Mechanics VII; Contributions to the 16th STAB/DGLR Symposium Aachen, Germany 2008}, editor = {Dillmann, Andreas and Heller, Gerd and Klaas, Michael and Kreplin, Hans-Peter and Nitsche, Wolfgang and Schr{\"o}der, Wolfgang}, publisher = {Springer}, address = {Berlin}, isbn = {9783642142437}, doi = {10.1007/978-3-642-14243-7_45}, pages = {365 -- 372}, year = {2010}, language = {en} } @inproceedings{LettiniHavermannGuidettietal.2010, author = {Lettini, Antonio and Havermann, Marc and Guidetti, Marco and Fornaciari, Andrea}, title = {Improved functionalities and energy saving potential on mobile machines combining electronics with flow sharing valve and variable displacement pump}, series = {7th International Fluid Power Conference - Vol. 3 - Aachen Efficiency through Fluid Power Workshop Proceedings}, booktitle = {7th International Fluid Power Conference - Vol. 3 - Aachen Efficiency through Fluid Power Workshop Proceedings}, publisher = {Apprimus Verlag}, address = {Aachen}, isbn = {978-3-940565-92-1}, pages = {103 -- 114}, year = {2010}, language = {en} } @book{LemaitreBlome2010, author = {Lemaitre, George and Blome, Hans-Joachim}, title = {Von der klassischen Kosmologie zum Quantenkosmos}, editor = {Blome, Hans-Joachim}, publisher = {Deutsch}, address = {Frankfurt am Main}, isbn = {978-3-8171-3304-8}, pages = {240 S.}, year = {2010}, language = {de} } @book{HoffschmidtLanFrickeetal.2010, author = {Hoffschmidt, Bernhard and Lan, Marco and Fricke, Barbara and Anthrakidis, Anette and Peter, Stefan}, title = {Struktur und Dynamik einer Stromversorgung mit einem hohen Anteil erneuerbarer Energieerzeuger. Kurzbezeichnung: Energiestudie. Schlussbericht}, publisher = {Solar-Institut, FH Aachen}, address = {J{\"u}lich}, pages = {134 S. Ill., graph. Darst.}, year = {2010}, language = {de} } @article{SchneiderSchneider2010, author = {Schneider, Bettina and Schneider, Wilhelm}, title = {Die Fallstudie: Konzernrechnungslegung}, series = {Das Wirtschaftsstudium : WISU ; Zeitschrift f{\"u}r Ausbildung, Examen und Weiterbildung}, volume = {39}, journal = {Das Wirtschaftsstudium : WISU ; Zeitschrift f{\"u}r Ausbildung, Examen und Weiterbildung}, number = {11}, publisher = {Lange}, address = {D{\"u}sseldorf}, issn = {0340-3084}, pages = {1495 -- 1498}, year = {2010}, language = {de} } @inproceedings{ReckerBosschaertsWagemakersetal.2010, author = {Recker, Elmar and Bosschaerts, Walter and Wagemakers, Rolf and Hendrick, Patrick and Funke, Harald and B{\"o}rner, Sebastian}, title = {Experimental study of a round jet in cross-flow at low momentum ratio}, pages = {13 Seiten}, year = {2010}, abstract = {With the final objective of optimizing the "Micromix" hydrogen combustion principle, a round jet in a laminar cross-flow prior to its combustion is investigated experimentally using Stereoscopic Particle Image Velocimetry. Measurements are performed at a jet to cross-stream momentum ratio of 1 and a Reynolds number, based on the jet diameter and jet velocity, of 1600. The suitability to combine side, top and end views is analyzed statistically. The statistical theory of testing hypotheses, pertaining to the joint distribution of the averaged velocity along intersecting observation planes, is employed. Overall, the averaged velocity fields of the varying observation planes feature homogeneity at a 0.05 significance level. Minor discrepancies are related to the given experimental conditions. By use of image maps, averaged and instantaneous velocity fields, an attempt is made to elucidate the flow physics and a kinematically consistent vortex model is proposed. In the time-averaged flow field, the principal vortical systems were identified and the associated mixing visualized. The jet trajectory and physical dimensions scale with the momentum ratio times the jet diameter. The jet/cross-flow mixture converging upon the span-wise centre-line, the lifting action of the Counter Rotating Vortex Pair and the reversed flow region contribute to the high entrainment and mixedness. It is shown that the jet width is larger on the downstream side as compared to the upstream side of the centre-streamline. The deepest penetration of the particles on the outer boundary occurs in the centre-plane. Meanwhile, with increasing off-centre position, the boundaries all lay further from the centre-line position than does the boundary in the centre-plane, corresponding to a kidney-like shape of the flow cross-section. The generation of the Counter Rotating Vortex Pair and the instability mechanism is documented by instantaneous image maps and vector fields. The necessary circulation for the Counter Rotating Vortex Pair originates from a combined effect of steady in-hole, hanging and wake vortices. The strong cross-flow and jet interaction induces a three-dimensional waving, the stream-wise Counter Rotating Vortex Pair pair, leading to the formation of Ring Like Vortices. A secondary Counter Rotating Vortex Pair forms on top of the primary Counter Rotating Vortex Pair, resulting in mixing by "puffs". Overall, Stereoscopic Particle Image Velocimetry proofed capable of elucidating the Jet in Cross-Flow complex flow field. The gained insight in the mixing process will definitely contribute to the "Micromix" hydrogen combustion optimization.}, language = {en} } @inproceedings{FunkeBoernerRobinsonetal.2010, author = {Funke, Harald and B{\"o}rner, Sebastian and Robinson, A. and Hendrick, P. and Recker, E.}, title = {Low NOx H2 combustion for industrial gas turbines of various power ranges}, year = {2010}, language = {en} } @inproceedings{FunkeRobinsonHendricketal.2010, author = {Funke, Harald and Robinson, A. E. and Hendrick, P. and Wagemakers, R.}, title = {Design and Testing of a Micromix Combustor With Recuperative Wall Cooling for a Hydrogen Fuelled µ-Scale Gas Turbine}, series = {Conference Proceedings ASME Turbo Expo 2010: Power for Land, Sea, and Air. Volume 5: Industrial and Cogeneration; Microturbines and Small Turbomachinery; Oil and Gas Applications; Wind Turbine Technology}, booktitle = {Conference Proceedings ASME Turbo Expo 2010: Power for Land, Sea, and Air. Volume 5: Industrial and Cogeneration; Microturbines and Small Turbomachinery; Oil and Gas Applications; Wind Turbine Technology}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4400-7}, doi = {10.1115/GT2010-23453}, pages = {587 -- 596}, year = {2010}, abstract = {For more than a decade up to now there is an ongoing interest in small gas turbines downsized to micro-scale. With their high energy density they offer a great potential as a substitute for today's unwieldy accumulators, found in a variety of applications like laptops, small tools etc. But micro-scale gas turbines could not only be used for generating electricity, they could also produce thrust for powering small unmanned aerial vehicles (UAVs) or similar devices. Beneath all the great design challenges with the rotating parts of the turbomachinery at this small scale, another crucial item is in fact the combustion chamber needed for a safe and reliable operation. With the so called regular micromix burning principle for hydrogen successfully downscaled in an initial combustion chamber prototype of 10 kW energy output, this paper describes a new design attempt aimed at the integration possibilities in a μ-scale gas turbine. For manufacturing the combustion chamber completely out of stainless steel components, a recuperative wall cooling was introduced to keep the temperatures in an acceptable range. Also a new way of an integrated ignition was developed. The detailed description of the prototype's design is followed by an in depth report about the test results. The experimental investigations comprise a set of mass flow variations, coupled with a variation of the equivalence ratio for each mass flow at different inlet temperatures and pressures. With the data obtained by an exhaust gas analysis, a full characterisation concerning combustion efficiency and stability of the prototype chamber is possible. Furthermore the data show a full compliance with the expected operating requirements of the designated μ-scale gas turbine.}, language = {en} } @inproceedings{Ferrein2010, author = {Ferrein, Alexander}, title = {golog.lua: Towards a non-prolog implementation of Golog for embedded systems}, series = {Dagstuhl Seminar Proceedings, Volume 10081}, booktitle = {Dagstuhl Seminar Proceedings, Volume 10081}, doi = {10.4230/DagSemProc.10081.9}, pages = {1 -- 15}, year = {2010}, abstract = {Among many approaches to address the high-level decision making problem for autonomous robots and agents, the robot program¬ming and plan language Golog follows a logic-based deliberative approach, and its successors were successfully deployed in a number of robotics applications over the past ten years. Usually, Golog interpreter are implemented in Prolog, which is not available for our target plat¬form, the bi-ped robot platform Nao. In this paper we sketch our first approach towards a prototype implementation of a Golog interpreter in the scripting language Lua. With the example of the elevator domain we discuss how the basic action theory is specified and how we implemented fluent regression in Lua. One possible advantage of the availability of a Non-Prolog implementation of Golog could be that Golog becomes avail¬able on a larger number of platforms, and also becomes more attractive for roboticists outside the Cognitive Robotics community.}, language = {en} } @article{Ferrein2010, author = {Ferrein, Alexander}, title = {golog.lua: Towards a Non-Prolog Implementation of Golog for Embedded Systems}, publisher = {AAAI}, address = {Menlo Park}, pages = {20 -- 28}, year = {2010}, language = {en} } @inproceedings{FerreinSteinbauer2010, author = {Ferrein, Alexander and Steinbauer, Gerald}, title = {On the Way to High-Level Programming for Resource-Limited Embedded Systems with Golog}, series = {Simulation, Modeling, and Programming for Autonomous Robots}, booktitle = {Simulation, Modeling, and Programming for Autonomous Robots}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-17319-6_23}, pages = {229 -- 240}, year = {2010}, abstract = {In order to allow an autonomous robot to perform non-trivial tasks like to explore a foreign planet the robot has to have deliberative capabilities like reasoning or planning. Logic-based approaches like the programming and planing language Golog and it successors has been successfully used for such decision-making problems. A drawback of this particular programing language is that their interpreter usually are written in Prolog and run on a Prolog back-end. Such back-ends are usually not available or feasible on resource-limited robot systems. In this paper we present our ideas and first results of a re-implementation of the interpreter based on the Lua scripting language which is available on a wide range of systems including small embedded systems.}, language = {en} } @inproceedings{RensVarzinczakMeyeretal.2010, author = {Rens, Gavin and Varzinczak, Ivan and Meyer, Thomas and Ferrein, Alexander}, title = {A Logic for Reasoning about Actions and Explicit Observations}, series = {AI 2010: Advances in Artificial Intelligence}, booktitle = {AI 2010: Advances in Artificial Intelligence}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-17432-2_40}, pages = {395 -- 404}, year = {2010}, abstract = {We propose a formalism for reasoning about actions based on multi-modal logic which allows for expressing observations as first-class objects. We introduce a new modal operator, namely [o |α], which allows us to capture the notion of perceiving an observation given that an action has taken place. Formulae of the type [o |α]ϕ mean 'after perceiving observation o, given α was performed, necessarily ϕ'. In this paper, we focus on the challenges concerning sensing with explicit observations, and acting with nondeterministic effects. We present the syntax and semantics, and a correct and decidable tableau calculus for the logic}, language = {en} } @article{Ferrein2010, author = {Ferrein, Alexander}, title = {Robot controllers for highly dynamic environments with real-time constraints}, series = {K{\"u}nstliche Intelligenz : KI}, volume = {24}, journal = {K{\"u}nstliche Intelligenz : KI}, number = {2}, publisher = {Springer}, address = {Heidelberg}, issn = {1610-1987}, doi = {10.1007/s13218-010-0041-3}, pages = {175 -- 178}, year = {2010}, abstract = {In this extended abstract we describe the robot programming and planning language READYLOG, a GOLOG dialect which was developed to support the decision making of robots acting in dynamic real-time domains like robotic soccer. The formal framework of READYLOG, which is based on the situation calculus, features imperative control structures like loops and procedures, allows for decision-theoretic planning, and accounts for a continuously changing world. We developed high-level controllers in READYLOG for our soccer robots in RoboCup's Middle-size league, but also for service robots and for autonomous agents in interactive computer games.}, language = {en} } @inproceedings{NiemuellerFerreinBecketal.2010, author = {Niem{\"u}ller, Tim and Ferrein, Alexander and Beck, Daniel and Lakemeyer, Gerhard}, title = {Design principles of the component-based robot software framework Fawkes}, series = {Simulation, Modeling, and Programming for Autonomous Robots}, booktitle = {Simulation, Modeling, and Programming for Autonomous Robots}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-17319-6_29}, pages = {300 -- 311}, year = {2010}, abstract = {The idea of component-based software engineering was proposed more that 40 years ago, yet only few robotics software frameworks follow these ideas. The main problem with robotics software usually is that it runs on a particular platform and transferring source code to another platform is crucial. In this paper, we present our software framework Fawkes which follows the component-based software design paradigm by featuring a clear component concept with well-defined communication interfaces. We deployed Fawkes on several different robot platforms ranging from service robots to biped soccer robots. Following the component concept with clearly defined communication interfaces shows great benefit when porting robot software from one robot to the other. Fawkes comes with a number of useful plugins for tasks like timing, logging, data visualization, software configuration, and even high-level decision making. These make it particularly easy to create and to debug productive code, shortening the typical development cycle for robot software.}, language = {en} } @inproceedings{NiemuellerFerreinLakemeyer2010, author = {Niem{\"u}ller, Tim and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {A Lua-based behavior engine for controlling the humanoid robot Nao}, series = {RoboCup 2009: Robot Soccer World Cup XIII}, booktitle = {RoboCup 2009: Robot Soccer World Cup XIII}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-642-11876-0_21}, pages = {240 -- 251}, year = {2010}, abstract = {The high-level decision making process of an autonomous robot can be seen as an hierarchically organised entity, where strategical decisions are made on the topmost layer, while the bottom layer serves as driver for the hardware. In between is a layer with monitoring and reporting functionality. In this paper we propose a behaviour engine for this middle layer which, based on formalism of hybrid state machines (HSMs), bridges the gap between high-level strategic decision making and low-level actuator control. The behaviour engine has to execute and monitor behaviours and reports status information back to the higher level. To be able to call the behaviours or skills hierarchically, we extend the model of HSMs with dependencies and sub-skills. These Skill-HSMs are implemented in the lightweight but expressive Lua scripting language which is well-suited to implement the behaviour engine on our target platform, the humanoid robot Nao.}, language = {en} } @article{FerreinSiebelSteinbauer2010, author = {Ferrein, Alexander and Siebel, Nils T. and Steinbauer, Gerald}, title = {Hybrid control for autonomous systems — Integrating learning, deliberation and reactive control}, series = {Robotics and Autonomous Systems}, volume = {58}, journal = {Robotics and Autonomous Systems}, number = {9}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0921-8890}, doi = {10.1016/j.robot.2010.06.003}, pages = {1037 -- 1038}, year = {2010}, language = {en} } @article{LeimenaArtmannDachwaldetal.2010, author = {Leimena, W. and Artmann, Gerhard and Dachwald, Bernd and Temiz Artmann, Ayseg{\"u}l and Gossmann, Matthias and Digel, Ilya}, title = {Feasibility of an in-situ microbial decontamination of an ice-melting probe}, series = {Eurasian Chemico-Technological Journal}, volume = {12}, journal = {Eurasian Chemico-Technological Journal}, number = {2}, publisher = {Institute of Combustion Problems}, address = {Almaty}, isbn = {1562-3920}, doi = {10.18321/ectj37}, pages = {145 -- 150}, year = {2010}, abstract = {Autonomous robotic systems for penetrating thick ice shells with simultaneous collecting of scientific data are very promising devices in both terrestrial (glacier, climate research) and extra-terrestrial applications. Technical challenges in development of such systems are numerous and include 3D-navigation, an appropriate energy source, motion control, etc. Not less important is the problem of forward contamination of the pristine glacial environments with microorganisms and biomolecules from the surface of the probe. This study was devoted to establishing a laboratory model for microbial contamination of a newly constructed ice-melting probe called IceMole and to analyse the viability and amount of the contaminating microorganisms as a function of distance. The used bacterial strains were Bacillus subtilis (ATCC 6051) and Escherichia coli (ATCC 11775). The main objective was development of an efficient and reliable in-situ decontamination method of the melting probe. Therefore, several chemical substances were tested in respect of their efficacy to eliminate bacteria on the surface of the melting probe at low temperature (0 - 5 °C) and at continuous dilution by melted water. Our study has shown that at least 99.9\% decontamination of the IceMole can be successfully achieved by the injection of 30\% (v/v) hydrogen peroxide and 3\% (v/v) sodium hypochlorite into the drilling site. We were able to reproduce this result in both time-dependent and depth-dependent experiments. The sufficient amount of 30\% (v/v) H₂O₂ or 3\% (v/v) NaClO has been found to be approximately 18 L per cm² of the probe's surface.}, language = {en} } @misc{BehbahaniMaiWalugaetal.2010, author = {Behbahani, Mehdi and Mai, A. and Waluga, C. and Bergmann, B. and Tran, L. and Vonderstein, K. and Behr, Marek and Mottaghy, K.}, title = {Numerical Modeling of Flow-Related Thrombus Formation under Physiological and Non-Physiological Flow Conditions}, series = {Acta Physiologica}, volume = {198}, journal = {Acta Physiologica}, number = {Supplement 677}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1748-1716}, pages = {185}, year = {2010}, abstract = {Aims: Thrombotic complications due to activation of platelets and plasmatic clotting factors belong still to the most investigated topics in the field of study of patho-physiological mechanisms. Mathematical modeling of thrombotic reactions is established and validated in test cases. Aim of this study is to experimentally evaluate and computationally simulate platelets under the influence of well-defined shear flow conditions. Platelet behaviour and reactions are experimentally reproduced, measured and used for validation of the numerical simulation. Methods: A mathematical model of platelet activation, adhesion and aggregation has been implemented into a finite element CFD (Computational Fluid Dynamics) code. The approach is based on the advective and diffusive transport equations for resting platelets, activated platelets and platelet released agonists. Adhesion rates for the reactive surfaces depend on the hemocompatibility properties of the surface and the local shear rate. Experiments with citrate-anticoagulated freshly-drawn whole blood are performed in a perfusion flow chamber as well as in a system of rotating cylinders for Couette and Taylor-vortex flow. Different biomaterials are used. The activation, drop of platelet concentration, adhesion and aggregation are quantified using scanning electron microscopy (SEM) and flow cytometry. Results: Regions and flow conditions with a high potential for thrombus growth could be identified. The experiments clearly show the influence of the blood contacting material and flow properties. By means of SEM diverse platelet adhesion patterns are observed. Numerical analysis can explain the patterns and the degree of thrombus formation. Conclusion: The numerical method shows good agreement with experimental data indicating a possible prediction of initiation of activation and detection of the local adhesion areas in connection with the role of Von-Willebrand-Factor.}, language = {en} } @article{BehbahaniMaiBergmannetal.2010, author = {Behbahani, Mehdi and Mai, A. and Bergmann, B. and Waluga, C. and Behr, Marek and Tran, L. and Vonderstein, K. and Mottaghy, K.}, title = {Modeling and Numerical Simulation of Blood Damage}, year = {2010}, language = {en} } @article{ProbstBehbahaniBorrmannetal.2010, author = {Probst, M. and Behbahani, Mehdi and Borrmann, E. and Elgeti, S. and Nicolai, M. and Behr, Marek}, title = {Hemodynamic Modeling for Numerical Analysis and Design of Medical Devices}, year = {2010}, language = {en} } @article{BehbahaniProbstMaietal.2010, author = {Behbahani, Mehdi and Probst, M. and Mai, A. and Behr, Marek and Tran, L. and Vonderstein, K. and Mottaghy, K.}, title = {Numerical Prediction of Blood Damage in Biomedical Devices}, year = {2010}, language = {en} } @misc{BehbahaniNamWalugaetal.2010, author = {Behbahani, Mehdi and Nam, J. and Waluga, C. and Behr, Marek and Pasquali, M. and Mottaghy, K.}, title = {Modeling and Numerical Analysis of Platelet Activation, Adhesion and Aggregation in Artificial Organs}, series = {ASAIO Journal}, volume = {56}, journal = {ASAIO Journal}, number = {2}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1538-943X}, doi = {10.1097/01.mat.0000369377.65122.a3}, pages = {85}, year = {2010}, abstract = {Purpose of Study: Thrombosis-related complications are among the leading causes for morbidity and mortality in patients who depend on artificial organs. For the prediction of platelet behavior both the flow conditions inside the device and the thrombogenic properties of the blood-contacting surfaces must be considered. Platelet reactions under the influence of well-defined shear rates are experimentally evaluated and numerically simulated. The approach is intended for the analysis of VAD and oxygenator design. Methods Used: A mathematical model of platelet activation, adhesion and aggregation has been implemented into a finite element CFD (Computational Fluid Dynamics) code. The approach is based on the advective and diffusive transport equations for resting and activated platelets and platelet released agonists. Experiments with citrate-anticoagulated freshly-drawn whole blood are performed in a perfusion flow chamber as well as in a system of rotating cylinders for Couette and Taylor-vortex flow. Different biomaterials are used. The activation, adhesion and aggregation are quantified using scanning electron microscopy and flow cytometry. Summary of Results: Regions and flow conditions with a high potential for thrombus growth could be identified. The experiments clearly show the influence of the blood contacting material and governing shear rates. Numerical analysis can explain observed adhesion patterns and the degree of thrombus formation}, language = {en} } @article{JansenBehbahaniLaumenetal.2010, author = {Jansen, S. V. and Behbahani, Mehdi and Laumen, M. and Kaufmann, T. and Hormes, M. and Behr, Marek and Schmitz-Rode, T. and Steinseifer, U.}, title = {Investigation of Steady Flow Through a Realistic Model of the Thoracic Human Aorta Using 3D Stereo PIV and CFD-Simulation}, series = {ASAIO Journal}, volume = {56}, journal = {ASAIO Journal}, number = {2}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, doi = {10.1097/01.mat.0000369377.65122.a3}, pages = {98}, year = {2010}, language = {en} } @article{NamAroraBehbahanietal.2010, author = {Nam, J. and Arora, D. and Behbahani, Mehdi and Probst, M. and Benkowski, R. and Behr, Marek and Pasquali, M.}, title = {New computational method in hemolysis analysis for artificial heart pump}, year = {2010}, language = {en} } @article{GoettscheHoffschmidtSchmitzetal.2010, author = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Sauerborn, Markus}, title = {Solar Concentrating Systems Using Small Mirror Arrays}, series = {Journal of solar energy engineering}, volume = {132}, journal = {Journal of solar energy engineering}, number = {1}, publisher = {ASME}, address = {New York}, issn = {0199-6231}, doi = {10.1115/1.4000332}, pages = {4 Seiten}, year = {2010}, abstract = {The cost of solar tower power plants is dominated by the heliostat field making up roughly 50\% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ~ 20 kg/m² steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m² caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10x10 cm²) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0,5x0,5 m² demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun's path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad.}, language = {en} } @article{Hillgaertner2010, author = {Hillg{\"a}rtner, Michael}, title = {Normative Regulations}, series = {ECPE Cluster Seminar EMC in Hybrid and Electric Vehicles : 18 May 2010, Fraunhofer Institute Erlangen}, journal = {ECPE Cluster Seminar EMC in Hybrid and Electric Vehicles : 18 May 2010, Fraunhofer Institute Erlangen}, publisher = {European Center for Power Electronics}, address = {N{\"u}rnberg}, pages = {1 CD-ROM}, year = {2010}, language = {en} } @inproceedings{BoernerFunkeHendricketal.2010, author = {B{\"o}rner, Sebastian and Funke, Harald and Hendrick, P. and Recker, E.}, title = {Control system modifications for a hydrogen fuelled gas-turbine}, series = {Proceedings of ISROMAC 13}, booktitle = {Proceedings of ISROMAC 13}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {978-1-617-38848-4}, pages = {665 -- 670}, year = {2010}, language = {en} } @misc{JansenBehbahaniLaumenetal.2010, author = {Jansen, Sebastian and Behbahani, Mehdi and Laumen, Marco and Kaufmann, Tim and Hormes, Marcus and Schmitz-Rode, Thomas and Behr, Marek and Steinseifer, Ulrich}, title = {3D stereo-PIV validation for CFD-simulation of steady flow through the human aorta using rapid-prototyping techniques}, year = {2010}, language = {en} } @article{BehbahaniProbstMaietal.2010, author = {Behbahani, Mehdi and Probst, M. and Mai, A. and Tran, L. and Vonderstein, K. and Keschenau, P. and Linde, T. and Steinseifer, U. and Behr, Marek and Mottaghy, K.}, title = {The influence of high shear on thrombosis and hemolysis in artificial organs}, series = {The International Journal of Artificial Organs}, volume = {33}, journal = {The International Journal of Artificial Organs}, number = {7}, publisher = {Sage}, address = {Thousand Oaks}, issn = {0391-3988}, pages = {426 -- 426}, year = {2010}, language = {en} } @misc{MaiwaldDachwald2010, author = {Maiwald, Volker and Dachwald, Bernd}, title = {Mission design for a multiple-rendezvous mission to Jupiter's trojans}, pages = {3}, year = {2010}, abstract = {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.}, language = {en} } @misc{AlexopoulosHoffschmidt2010, author = {Alexopoulos, Spiros and Hoffschmidt, Bernhard}, title = {Solarthermische Kraftwerke mit thermischen Speichern}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {1522-2640}, doi = {10.1002/cite.201050678}, pages = {1606}, year = {2010}, abstract = {Solarthermische Kraftwerke stellen eine bedeutende Technologieoption f{\"u}r einen nachhaltigen Energiemix der Zukunft dar. Sie konzentrieren die Strahlung der Sonne, erzeugen W{\"a}rme und wandeln diese mit konventioneller Kraftwerkstechnik in Strom um. Die W{\"a}rme kann auch gespeichert werden, so dass der Betrieb w{\"a}hrend des Durchzugs von Wolken m{\"o}glich ist und bis in die Abendstunden hinein verl{\"a}ngert werden kann. Zu den solarthermischen Kraftwerken geh{\"o}ren neben der Parabolrinne und dem Solarturm der Fresnel-Kollektor und die Dish-Stirling-Systeme. Im Zuge einer sp{\"a}teren Vergr{\"o}ßerung des Solarfeldes von Solarkraftwerken kann mithilfe von thermischen Energiespeichern die solare Energieerzeugung bei gleichbleibender Kraftwerksleistung sukzessiv bis um den Faktor 3 erweitert werden. Es besteht so die M{\"o}glichkeit einer massiven Substitution von fossilen Brennstoffen.Bei den ersten solarthermischen Speichern f{\"u}r die SEGS-Parabolrinnekraftwerke wurde {\"O}l als Speichermedium eingesetzt. Ein weiteres Speichermedium ist Salzschmelze, die im Andasol-1-Projekt in Spanien sowie bei Solarturmkraftwerken eingesetzt wird. Beton ist ein weiteres m{\"o}gliches Speichermaterial f{\"u}r Parabolrinnensysteme. Eine weitere Alternative bei einem Solarturmkraftwerk mit Luft als W{\"a}rmetr{\"a}germedium ist die Verwendung von keramischen Feuerfestmaterialien in Form von Sch{\"u}ttungen oder stapelbaren, por{\"o}sen Elementen. In J{\"u}lich wurde das weltweit erste solarthermische Turmkraftwerk mit einer Leistung von 1,5 MWe, das Luft als W{\"a}rmetr{\"a}germedium einsetzt und einen solchen Speicher verwendet, gebaut.}, language = {de} } @inproceedings{GeimerSauerbornHoffschmidtetal.2010, author = {Geimer, Konstantin and Sauerborn, Markus and Hoffschmidt, Bernhard and Schmitz, Mark and G{\"o}ttsche, Joachim}, title = {Test facility for absorber specimens of solar tower power plants}, series = {Advances in Science and Technology}, volume = {74}, booktitle = {Advances in Science and Technology}, publisher = {Trans Tech Publications}, address = {Baech}, doi = {10.4028/www.scientific.net/AST.74.266}, pages = {266 -- 271}, year = {2010}, abstract = {The Solar-Institute J{\"u}lich (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 J{\"u}lich 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.}, language = {en} } @article{GebhardtSchmidtHoetteretal.2010, author = {Gebhardt, Andreas and Schmidt, Frank-Michael and H{\"o}tter, Jan-Steffen and Sokalla, Wolfgang and Sokalla, Patrick}, title = {Additive manufacturing by selective laser melting the realizer desktop machine and its application for the dental industry}, series = {Physics Procedia}, volume = {5 B}, journal = {Physics Procedia}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1875-3892}, doi = {10.1016/j.phpro.2010.08.082}, pages = {543 -- 549}, year = {2010}, abstract = {Additive Manufacturing of metal parts by Selective Laser Melting has become a powerful tool for the direct manufacturing of complex parts mainly for the aerospace and medical industry. With the introduction of its desktop machine, Realizer targeted the dental market. The contribution describes the special features of the machine, discusses details of the process and shows manufacturing results focused on metal dental devices.}, language = {en} } @article{SrivastavaSinghAggarwaletal.2010, author = {Srivastava, Alok and Singh, Virendra and Aggarwal, Pranav and Schneeweiss, F. and Scherer, Ulrich W. and Friedrich, W.}, title = {Optical studies of insulating polymers for radiation dose monitoring}, series = {Indian Journal of Pure and Applied Physics}, volume = {48}, journal = {Indian Journal of Pure and Applied Physics}, number = {11}, publisher = {Council Of Scientific And Industrial Research (CSIR), National Institute Of Science Communication and Policy Research (NIScPR)}, address = {New Delhi}, isbn = {0019-5596}, pages = {782 -- 786}, year = {2010}, abstract = {The optical study carried out on insulating polymers namely polyethyleneterephthalate (PET) and polyvinylchloride (PVC) has been described. The polymers are exposed to different radiation doses by exposing them to swift heavy ions of carbon (90 MeV), silicon (120 MeV) and nickel (100 MeV) which influence on their optical properties. The studies show that amongst the investigated polymers, PVC and PET have potential for application as dosimeter beyond a threshold dose which is strongly dependent on the nature of the material and the radiation type. The optical micrographs show a distinct change in colour of the sample with increase in radiation dose.}, language = {en} }