TY - JOUR A1 - Maiwald, Volker A1 - Dachwald, Bernd T1 - Mission Design for a Multiple-Rendezvous Mission to Jupiter's Trojans Y1 - 2010 N1 - COSPAR 2010 ; 38th COSPAR Scientific Assembly. Held 18-25 July 2010 in Bremen, Germany [Abstract] SP - 3 ER - TY - CHAP A1 - Carzana, Livio A1 - Dachwald, Bernd A1 - Noomen, Ron T1 - Model and trajectory optimization for an ideal laser-enhanced solar sail T2 - 68th International Astronautical Congress N2 - A laser-enhanced solar sail is a solar sail that is not solely propelled by solar radiation but additionally by a laser beam that illuminates the sail. This way, the propulsive acceleration of the sail results from the combined action of the solar and the laser radiation pressure onto the sail. The potential source of the laser beam is a laser satellite that coverts solar power (in the inner solar system) or nuclear power (in the outer solar system) into laser power. Such a laser satellite (or many of them) can orbit anywhere in the solar system and its optimal orbit (or their optimal orbits) for a given mission is a subject for future research. This contribution provides the model for an ideal laser-enhanced solar sail and investigates how a laser can enhance the thrusting capability of such a sail. The term ”ideal” means that the solar sail is assumed to be perfectly reflecting and that the laser beam is assumed to have a constant areal power density over the whole sail area. Since a laser beam has a limited divergence, it can provide radiation pressure at much larger solar distances and increase the radiation pressure force into the desired direction. Therefore, laser-enhanced solar sails may make missions feasible, that would otherwise have prohibitively long flight times, e.g. rendezvous missions in the outer solar system. This contribution will also analyze exemplary mission scenarios and present optimial trajectories without laying too much emphasis on the design and operations of the laser satellites. If the mission studies conclude that laser-enhanced solar sails would have advantages with respect to ”traditional” solar sails, a detailed study of the laser satellites and the whole system architecture would be the second next step Y1 - 2017 N1 - 68th International Astronautical Congress: Unlocking Imagination, Fostering Innovation and Strengthening Security, IAC 2017, 2017-09-25 → 2017-09-29, Adelaide, Australia ER - TY - JOUR A1 - Dachwald, Bernd A1 - Tsinas, L. T1 - A combined neural and genetic learning algorithm / Tsinas, L. ; Dachwald, B. JF - Proceedings of the First IEEE Conference on Evolutionary Computation, 1994. IEEE World Congress on Computational Intelligence. Y1 - 1994 SN - 0-7803-1899-4 SP - 770 EP - 774 CY - Orlando, Fl ER - TY - JOUR A1 - Baader, Fabian A1 - Boxberg, Marc S. A1 - Chen, Qian A1 - Förstner, Roger A1 - Kowalski, Julia A1 - Dachwald, Bernd T1 - Field-test performance of an ice-melting probe in a terrestrial analogue environment JF - Icarus N2 - Melting probes are a proven tool for the exploration of thick ice layers and clean sampling of subglacial water on Earth. Their compact size and ease of operation also make them a key technology for the future exploration of icy moons in our Solar System, most prominently Europa and Enceladus. For both mission planning and hardware engineering, metrics such as efficiency and expected performance in terms of achievable speed, power requirements, and necessary heating power have to be known. Theoretical studies aim at describing thermal losses on the one hand, while laboratory experiments and field tests allow an empirical investigation of the true performance on the other hand. To investigate the practical value of a performance model for the operational performance in extraterrestrial environments, we first contrast measured data from terrestrial field tests on temperate and polythermal glaciers with results from basic heat loss models and a melt trajectory model. For this purpose, we propose conventions for the determination of two different efficiencies that can be applied to both measured data and models. One definition of efficiency is related to the melting head only, while the other definition considers the melting probe as a whole. We also present methods to combine several sources of heat loss for probes with a circular cross-section, and to translate the geometry of probes with a non-circular cross-section to analyse them in the same way. The models were selected in a way that minimizes the need to make assumptions about unknown parameters of the probe or the ice environment. The results indicate that currently used models do not yet reliably reproduce the performance of a probe under realistic conditions. Melting velocities and efficiencies are constantly overestimated by 15 to 50 % in the models, but qualitatively agree with the field test data. Hence, losses are observed, that are not yet covered and quantified by the available loss models. We find that the deviation increases with decreasing ice temperature. We suspect that this mismatch is mainly due to the too restrictive idealization of the probe model and the fact that the probe was not operated in an efficiency-optimized manner during the field tests. With respect to space mission engineering, we find that performance and efficiency models must be used with caution in unknown ice environments, as various ice parameters have a significant effect on the melting process. Some of these are difficult to estimate from afar. Y1 - 2023 U6 - https://doi.org/10.1016/j.icarus.2023.115852 N1 - Forschungsdaten hierzu: "Performance data of an ice-melting probe from field tests in two different ice environments" (https://opus.bibliothek.fh-aachen.de/opus4/frontdoor/index/index/docId/10890) IS - 409 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Artmann, Gerhard A1 - Kelemen, Christina A1 - Porst, Dariusz A1 - Büldt, G. [u.a.] T1 - Temperature transitions of protein properties in human red blood cells. Artmann, Gerhard Michael, Kelemen, Christina; Porst, D.; Büldt, G.; Chien, S. JF - Biophysical Journal. 75 (1998), H. 6 Y1 - 1998 SN - 1542-0086 N1 - http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1299989&blobtype=pdf SP - 3179 EP - 3183 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Shi, Young de A1 - Agosti, R. A1 - Longhini, E. T1 - A modified casson equation to characterize blood rheology for hypertension. Shi, Young de; Artmann, Gerhard Michael; Agosti, R.; Longhini, E. JF - Clinical Hemorheology Microcirculation. 19 (1998), H. 2 Y1 - 1998 SN - 1386-0291 SP - 115 EP - 127 ER - TY - JOUR A1 - Li, Anlan A1 - Shi, Young de A1 - Landsmann, B. A1 - Schankowski-Bouvier, P. A1 - Dikta, Gerhard A1 - Bauer, U. A1 - Artmann, Gerhard T1 - Hemorheology and walking distance of Peripheral Arterial Occlusive Disease patients during treatment with Ginkgo-biloba extract JF - Acta Pharmacologica Sinica = ZHONGUO YAOLI XUEBAO. 19 (1998), H. 5 Y1 - 1998 SN - 1745-7254 N1 - ISSN der parallelen Ausgabe 1671-4083; China-Zs.-Code: CN31-1347 abstract frei unter SP - 417 EP - 421 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Sung, K.-L. Paul A1 - Horn, Thomas A1 - Whittemore, Darren [u.a.] T1 - Micropipette aspiration of human erythrocytes induces echinocytes via membrane phospholipid translocation. Artmann, Gerhard Michael; Sung, K.-L. Paul; Horn, Thomas; Whittemore, Darren; Norwich, Gerald; Chien, Shu JF - Biophysical journal. 72 (1997), H. 3 Y1 - 1997 SN - 1542-0086 SP - 1434 EP - 1441 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, Jürgen A1 - Ates, M. T1 - A novel method to quantify mechanical tension in cell monolayers. Trzewik, Jürgen; Ates, M., Artmann, Gerhard Michael JF - Biomedizinische Technik. 47 (2002), H. Suppl. 1. Pt. 1 Y1 - 2002 SN - 0013-5585 N1 - Druckausgabe unter 63 Z 47 vorhanden SP - 379 EP - 381 ER - TY - JOUR A1 - Maggakis-Kelemen, Christina A1 - Biselli, Manfred A1 - Artmann, Gerhard T1 - Determination of the elastic shear modulus of cultured human red blood cells JF - Biomedizinische Technik. 47 (2002), H. Suppl. 1 Pt. 1 Y1 - 2002 SN - 0013-5585 N1 - Druckausgabe unter 63 Z 471 vorhanden SP - 106 EP - 109 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Zhou-Stache, J. A1 - Buettner, R. A1 - Mittermayer, C. [u.a.] T1 - Inhibition of TNF-alpha induced cell death in HUVEC and Jurkat cells by protocatechuic acid. Zhou-Stache, J.; Buettner, R.; Artmann, Gerhard Michael; Mittermayer, C.; Bosserhoff, A. K. JF - Medical and Biological Engineering and Computing. 40 (2002), H. 6 Y1 - 2002 SN - 0140-0118 SP - 698 EP - 703 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, Jürgen A1 - Mallipattu, S. K. A1 - Delano, F. A. [u.a.] T1 - Evidence for a second valve system in Lymphatics: Endothelial Microvalves. Trzewik, Jürgen; Mallipattu, S. K.; Artmann, Gerhard Michael; Delano, F. A.; Schmid-Schonbein, G. W JF - The FASEB Journal. 15 (2001) Y1 - 2001 SN - 1530-6860 SP - 1711 EP - 1717 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Bäumler, H. A1 - Voigt, A. A1 - Mitlöhner, R. [u.a.] T1 - Plastic behaviour of polyelectrolyte microcapsules derived from colloid templates. Bäumler, H., Artmann, Gerhard Michael; Voigt, A., Mitlöhner, R., Neu, B., Kiesewetter, H. JF - Journal of Microencapsulation. 17 (2000), H. 5 Y1 - 2000 SN - 1464-5246 SP - 651 EP - 655 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Gorbatenkova, E. A. A1 - Panasenko, O. M. T1 - Hypochlorous acid and human blood low density lipoproteins modified by hypochlorous acid increase erythrocyte adhesion to endothelial cells. Gorbatenkova, E. A.; Artmann, Gerhard Michael; Panasenko, O. M. JF - Membrane and cell biology. 13 (2000), H. 4 Y1 - 2000 SN - 1023-6597 SP - 537 EP - 546 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Kelemen, C. A1 - Chien, S. T1 - Temperature transition of human hemoglobin at body temperature: effects of calcium. Kelemen, C.; Chien, S.; Artmann, Gerhard Michael JF - Biophysical journal. 80 (2001), H. 6 Y1 - 2001 SN - 1542-0086 SP - 2622 EP - 2630 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Hueck, I. S. A1 - Hollweg, H. G. A1 - Schmid-Schönbein, G. W. T1 - Chlorpromazine modulates the Morphological Macro- and Microstructure of Endothelial Cells. Hueck, I. S.; Hollweg, H. G.; Schmid-Schönbein, G. W.; Artmann, Gerhard Michael JF - American Journal of Physiology. Cell Physiology. 278 (2000), H. 5 Y1 - 2000 SN - 1522-1563 N1 - Zählung: C873- C878 SP - 873 EP - 878 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Li, Anlan A1 - Seipelt, H. A1 - Müller, C. [u.a.] T1 - Effects of salicylic acid derivatives on red blood cell membranes. Li, Anlan; Seipelt, H.; Müller, C.;Shi, Yong de; Artmann, Gerhard Michael JF - Pharmacology and Toxicology. 85 (1999) Y1 - 1999 SN - 0902-9938 SP - 206 EP - 211 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Hovav, T. A1 - Goldfarb, A. A1 - Yedgar, S. [u.a.] T1 - Enhanced adherence of beta-thalassaemic erythrocytes to endothelial cells. Hovav, T., Goldfarb, A.; Artmann, Gerhard Michael, Yedgar, S.; Barstein, G. JF - British Journal of Haematology. 106 (1999), H. 1 Y1 - 1999 SN - 1365-2141 SP - 178 EP - 181 ER - TY - JOUR A1 - Artmann, Gerhard T1 - A microscopic photometric method for measuring erythrocyte deformability. Artmann, Gerhard Michael JF - Clinical Hemorheology. 6 (1986) Y1 - 1986 SN - 0271-5198 SP - 617 EP - 627 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Schmid-Schönbein, H. A1 - Grebe, R. A1 - Teitel, P. [u.a.] T1 - Restoration of Microsieve Filterability of Human Red Cells After Exposure to Hyperosmolarity and Lactazidosis: Effect of Vinpocetine. Schmid-Schönbein, H.; Grebe, R.; Teitel, P.; Artmann, Gerhard Michael, Eschweiler, H.; Schröder, Susanne JF - Drug Development Research. 14 (1988), H. 3-4 Y1 - 1988 SN - 1098-2299 N1 - Abstracts frei unter: SP - 205 EP - 211 ER -