TY - JOUR A1 - Staat, Manfred A1 - Heitzer, M. T1 - Limit and Shakedown Analysis with Uncertain Data JF - Stochastic optimization techniques : numerical methods and technical applications / Marti, K. [ed] Y1 - 2002 SN - 3-540-42889-5 SP - 241 EP - 254 PB - Springer CY - Heidelberg 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 - JOUR A1 - Staat, Manfred T1 - LISA - a European project for FEM-based limit and shakedown analysis N2 - The load-carrying capacity or the safety against plastic limit states are the central questions in the design of structures and passive components in the apparatus engineering. A precise answer is most simply given by limit and shakedown analysis. These methods can be based on static and kinematic theorems for lower and upper bound analysis. Both may be formulated as optimization problems for finite element discretizations of structures. The problems of large-scale analysis and the extension towards realistic material modelling will be solved in a European research project. Limit and shakedown analyses are briefly demonstrated with illustrative examples. KW - Einspielen KW - Traglast KW - Finite-Elemente-Methode KW - Traglastanalyse KW - Einspielanalyse KW - FEM KW - limit analysis KW - shakedown analysis Y1 - 2001 ER - TY - JOUR A1 - Staat, Manfred A1 - Heitzer, M. A1 - Hicken, E.F. T1 - LISA, ein europäisches Projekt zur direkten Berechnung der Tragfähigkeit duktiler Strukturen. Y1 - 1998 N1 - PERMAS–Benutzertagung, 8.–9.10.1998, Stuttgart (1998) ER - TY - JOUR A1 - Staat, Manfred A1 - Tran, Thanh Ngoc A1 - Kreißig, R. T1 - Load bearing capacity of thin shell structures made of elastoplastic material by direct methods JF - Technische Mechanik. 28 (2008), H. 3-4 Y1 - 2008 SP - 299 EP - 309 ER - TY - JOUR A1 - Staat, Manfred T1 - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels JF - International Journal of Pressure Vessels and Piping. 82 (2005), H. 3 Y1 - 2005 SN - 0308-0161 SP - 217 EP - 225 ER - TY - JOUR A1 - Staat, Manfred T1 - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels N2 - Limit loads can be calculated with the finite element method (FEM) for any component, defect geometry, and loading. FEM suggests that published long crack limit formulae for axial defects under-estimate the burst pressure for internal surface defects in thick pipes while limit loads are not conservative for deep cracks and for pressure loaded crack-faces. Very deep cracks have a residual strength, which is modelled by a global collapse load. These observations are combined to derive new analytical local and global collapse loads. The global collapse loads are close to FEM limit analyses for all crack dimensions. KW - Finite-Elemente-Methode KW - Grenzwertberechnung KW - Axialbelastung KW - FEM KW - Grenzwertberechnung KW - Axialbelastung KW - Traglastanalyse KW - Limit analysis KW - Global and local collapse KW - Axially cracked pipe KW - Pressure loaded crack-face Y1 - 2005 ER - TY - JOUR A1 - Akimbekov, Nuraly S. A1 - Digel, Ilya A1 - Tastambek, Kuanysh T. A1 - Sherelkhan, Dinara K. A1 - Jussupova, Dariya B. A1 - Altynbay, Nazym P. T1 - Low-rank coal as a source of humic substances for soil amendment and fertility management JF - Agriculture N2 - Humic substances (HS), as important environmental components, are essential to soil health and agricultural sustainability. The usage of low-rank coal (LRC) for energy generation has declined considerably due to the growing popularity of renewable energy sources and gas. However, their potential as soil amendment aimed to maintain soil quality and productivity deserves more recognition. LRC, a highly heterogeneous material in nature, contains large quantities of HS and may effectively help to restore the physicochemical, biological, and ecological functionality of soil. Multiple emerging studies support the view that LRC and its derivatives can positively impact the soil microclimate, nutrient status, and organic matter turnover. Moreover, the phytotoxic effects of some pollutants can be reduced by subsequent LRC application. Broad geographical availability, relatively low cost, and good technical applicability of LRC offer the advantage of easy fulfilling soil amendment and conditioner requirements worldwide. This review analyzes and emphasizes the potential of LRC and its numerous forms/combinations for soil amelioration and crop production. A great benefit would be a systematic investment strategy implicating safe utilization and long-term application of LRC for sustainable agricultural production. KW - soil remediation KW - crop yield KW - soil health KW - soil amendment KW - low-rank coal Y1 - 2021 U6 - http://dx.doi.org/10.3390/agriculture11121261 SN - 2077-0472 N1 - This article belongs to the Special Issue "From Waste to Fertilizer in Sustainable Agriculture" VL - 11 IS - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Dachwald, Bernd A1 - Carnelli, I. A1 - Vasile, M. T1 - Low-Thrust Gravity Assist Trajectory Optimization Using Evolutionary Neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile ... JF - Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3) Y1 - 2006 SN - 0-87703-527-X N1 - Astrodynamics Conference <2005, South Lake Tahoe, Calif.> ; American Astronautical Society ; Number: AAS-05-374 SP - 1911 EP - 1928 PB - Univelt CY - San Diego, Calif. ER - TY - JOUR A1 - Dachwald, Bernd T1 - Low-Thrust Trajectory Optimization and Interplanetary Mission Analysis Using Evolutionary Neurocontrol JF - Deutscher Luft- und Raumfahrtkongress 2004 : Dresden, 20. bis 23. September 2004, Motto: Luft- und Raumfahrt - Brücke für eine wissensbasierte Gesellschaft / Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 2. - (Jahrbuch ... der Deutschen Gesellschaft für Luft- und Raumfahrt) Y1 - 2004 N1 - Deutscher Luft- und Raumfahrt-Kongress <2004, Dresden> ; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth ; DGLR-2004-116 SP - 917 EP - 926 CY - Bonn ER - TY - JOUR A1 - Karamanidis, Kiros A1 - Albracht, Kirsten A1 - Braunstein, Bjoern A1 - Catala, Maria Moreno A1 - Goldmann, Jan-Peter A1 - Brüggemann, Gert-Peter T1 - Lower leg musculoskeletal geometry and sprint performance JF - Gait and Posture N2 - The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components. Y1 - 2011 U6 - http://dx.doi.org/10.1016/j.gaitpost.2011.03.009 SN - 0966-6362 VL - 34 IS - 1 SP - 138 EP - 141 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Eijck, Lambert van A1 - Demmel, Franz A1 - Artmann, Gerhard A1 - Stadtler, Andreas Maximilian T1 - Macromolecular dynamics in red blood cells investigated using neutron spectroscopy JF - Journal of the Royal Society Interface Y1 - 2011 SN - 1742-5689 VL - 8 IS - 57 SP - 590 EP - 600 PB - The Royal Society CY - London ER - TY - JOUR A1 - Dachwald, Bernd A1 - Seboldt, W. A1 - Loeb, H. W A1 - Schartner, K.-H. T1 - Main Belt Asteroid Sample Return Mission Using Solar Electric Propulsion JF - Acta Astronautica. 63 (2008), H. 1-4 Y1 - 2008 SN - 0094-5765 N1 - International Astronautical Federation Congress <58, 2007, Hyderabad> ; International Astronautical Congress <58, 2007, Hyderabad> ; IAC-07-A3.5.07 SP - 91 EP - 101 ER - TY - JOUR A1 - Seifarth, Volker A1 - Grosse, Joachim O. A1 - Grossmann, Matthias A1 - Janke, Heinz Peter A1 - Arndt, Patrick A1 - Koch, Sabine A1 - Epple, Matthias A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Mechanical induction of bi-directional orientation of primary porcine bladder smooth muscle cells in tubular fibrin-poly(vinylidene fluoride) scaffolds for ureteral and urethral repair using cyclic and focal balloon catheter stimulation JF - Journal of Biomaterials Applications Y1 - 2017 U6 - http://dx.doi.org/10.1177/0885328217723178 SN - 1530-8022 VL - 32 IS - 3 SP - 321 EP - 330 PB - Sage CY - London ER - TY - JOUR A1 - Chloé, Radermacher A1 - Malyaran, Hanna A1 - Craveiro, Rogerio Bastos A1 - Peglow, Sarah A1 - Behbahani, Mehdi A1 - Pufe, Thomas A1 - Wolf, Michael A1 - Neuss, Sabine T1 - Mechanical loading on cementoblasts: a mini review JF - Osteologie N2 - Orthodontic treatments are concomitant with mechanical forces and thereby cause teeth movements. The applied forces are transmitted to the tooth root and the periodontal ligaments which is compressed on one side and tensed up on the other side. Indeed, strong forces can lead to tooth root resorption and the crown-to-tooth ratio is reduced with the potential for significant clinical impact. The cementum, which covers the tooth root, is a thin mineralized tissue of the periodontium that connects the periodontal ligament with the tooth and is build up by cementoblasts. The impact of tension and compression on these cells is investigated in several in vivo and in vitro studies demonstrating differences in protein expression and signaling pathways. In summary, osteogenic marker changes indicate that cyclic tensile forces support whereas static tension inhibits cementogenesis. Furthermore, cementogenesis experiences the same protein expression changes in static conditions as static tension, but cyclic compression leads to the exact opposite of cyclic tension. Consistent with marker expression changes, the singaling pathways of Wnt/ß-catenin and RANKL/OPG show that tissue compression leads to cementum degradation and tension forces to cementogenesis. However, the cementum, and in particular its cementoblasts, remain a research area which should be explored in more detail to understand the underlying mechanism of bone resorption and remodeling after orthodontic treatments. KW - Cementoblast KW - Compression KW - Tension KW - Mechanotransduction KW - Forces Y1 - 2022 U6 - http://dx.doi.org/10.1055/a-1826-0777 SN - 1019-1291 VL - 31 IS - 2 SP - 111 EP - 118 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Demirci, T. A1 - Trzewik, J. A1 - Linder, Peter A1 - Digel, Ilya A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Mechanical Stimulation of 3T3 Fibroblasts Activates Genes: ITGB5 and p53 Responses as Quantified on the mRNA Level JF - Biomedizinische Technik . 49 (2004), H. Erg.-Bd. 2 Y1 - 2004 SN - 0932-4666 SP - 1030 EP - 1031 ER - TY - JOUR A1 - Demirci, T. A1 - Trzewik, J. A1 - Linder, Peter A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Mechanical Stimulation of 3T3 Fibroblasts Activates Genes: Real Time PCR Products and Suppliers by Comparison JF - Biomedizinische Technik . 49 (2004), H. Erg.-Bd. 2 Y1 - 2004 SN - 0932-4666 SP - 1046 EP - 1047 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Digel, Ilya A1 - Linder, Peter A1 - Porst, Dariusz T1 - Mechanism of haemoglobin sensing body temperature JF - Tissue Engineering Part A. 14 (2008), H. 5 Y1 - 2008 SN - 1937-3341 N1 - TERMIS EU 2008 Porto Meeting June 22–26, 2008 Porto Congress Center–Alfândega Portugal SP - 754 EP - 754 ER - TY - JOUR A1 - Goßmann, Matthias A1 - Frotscher, Ralf A1 - Linder, Peter A1 - Bayer, Robin A1 - Epple, U. A1 - Staat, Manfred A1 - Temiz Artmann, Aysegül A1 - Artmann, Gerhard T1 - Mechano-pharmacological characterization of cardiomyocytes derived from human induced pluripotent stem cells JF - Cellular physiology and biochemistry N2 - Background/Aims: Common systems for the quantification of cellular contraction rely on animal-based models, complex experimental setups or indirect approaches. The herein presented CellDrum technology for testing mechanical tension of cellular monolayers and thin tissue constructs has the potential to scale-up mechanical testing towards medium-throughput analyses. Using hiPS-Cardiac Myocytes (hiPS-CMs) it represents a new perspective of drug testing and brings us closer to personalized drug medication. Methods: In the present study, monolayers of self-beating hiPS-CMs were grown on ultra-thin circular silicone membranes and deflect under the weight of the culture medium. Rhythmic contractions of the hiPS-CMs induced variations of the membrane deflection. The recorded contraction-relaxation-cycles were analyzed with respect to their amplitudes, durations, time integrals and frequencies. Besides unstimulated force and tensile stress, we investigated the effects of agonists and antagonists acting on Ca²⁺ channels (S-Bay K8644/verapamil) and Na⁺ channels (veratridine/lidocaine). Results: The measured data and simulations for pharmacologically unstimulated contraction resembled findings in native human heart tissue, while the pharmacological dose-response curves were highly accurate and consistent with reference data. Conclusion: We conclude that the combination of the CellDrum with hiPS-CMs offers a fast, facile and precise system for pharmacological, toxicological studies and offers new preclinical basic research potential. KW - Inotropic compounds KW - Pharmacology KW - Ion channels KW - CellDrum KW - Heart tissue culture KW - Induced pluripotent stem cells KW - Cardiac myocytes Y1 - 2016 U6 - http://dx.doi.org/10.1159/000443124 SN - 1421-9778 (Online) SN - 1015-8987 (Print) VL - 38 IS - 3 SP - 1182 EP - 1198 PB - Karger CY - Basel ER - TY - JOUR A1 - Bayer, Robin A1 - Temiz Artmann, Aysegül A1 - Digel, Ilya A1 - Falkenstein, Julia A1 - Artmann, Gerhard A1 - Creutz, Till A1 - Hescheler, Jürgen T1 - Mechano-pharmacological testing of L-Type Ca²⁺ channel modulators via human vascular celldrum model JF - Cellular Physiology and Biochemistry N2 - Background/Aims: This study aimed to establish a precise and well-defined working model, assessing pharmaceutical effects on vascular smooth muscle cell monolayer in-vitro. It describes various analysis techniques to determine the most suitable to measure the biomechanical impact of vasoactive agents by using CellDrum technology. Methods: The so-called CellDrum technology was applied to analyse the biomechanical properties of confluent human aorta muscle cells (haSMC) in monolayer. The cell generated tensions deviations in the range of a few N/m² are evaluated by the CellDrum technology. This study focuses on the dilative and contractive effects of L-type Ca²⁺ channel agonists and antagonists, respectively. We analyzed the effects of Bay K8644, nifedipine and verapamil. Three different measurement modes were developed and applied to determine the most appropriate analysis technique for the study purpose. These three operation modes are called, particular time mode" (PTM), "long term mode" (LTM) and "real-time mode" (RTM). Results: It was possible to quantify the biomechanical response of haSMCs to the addition of vasoactive agents using CellDrum technology. Due to the supplementation of 100nM Bay K8644, the tension increased approximately 10.6% from initial tension maximum, whereas, the treatment with nifedipine and verapamil caused a significant decrease in cellular tension: 10nM nifedipine decreased the biomechanical stress around 6,5% and 50nM verapamil by 2,8%, compared to the initial tension maximum. Additionally, all tested measurement modes provide similar results while focusing on different analysis parameters. Conclusion: The CellDrum technology allows highly sensitive biomechanical stress measurements of cultured haSMC monolayers. The mechanical stress responses evoked by the application of vasoactive calcium channel modulators were quantified functionally (N/m²). All tested operation modes resulted in equal findings, whereas each mode features operation-related data analysis. Y1 - 2020 U6 - http://dx.doi.org/10.33594/000000225 SN - 1421-9778 VL - 54 SP - 371 EP - 383 PB - Cell Physiol Biochem Press CY - Düsseldorf ER -