TY - JOUR A1 - Artmann, Gerhard A1 - Zerlin, Kay A1 - Digel, Ilya A1 - Stadler, Andreas M. T1 - Physical discontinuities at body temperature in human red blood cells / Artmann, GM ; Zerlin, K ; Digel, I ; Stadler, A ; Zaccai, G ; Temiz, AA JF - Tissue Engineering. 13 (2007), H. 7 Y1 - 2007 SN - 1076-3279 N1 - TERMIS-EU Meeting Abstracts London, UK September 4–7, 2007 SP - 1778 EP - 1778 ER - TY - JOUR A1 - Turlybekuly, Amanzhol A1 - Pogrebnjak, Alexander A1 - Sukhodub, L. F. A1 - Sukhodub, Liudmyla B. A1 - Kistaubayeva, A. S. A1 - Savitskaya, Irina A1 - Shokatayeva, D. H. A1 - Bondar, Oleksandr V. A1 - Shaimardanov, Z. K. A1 - Plotnikov, Sergey V. A1 - Shaimardanova, B. H. A1 - Digel, Ilya T1 - Synthesis, characterization, in vitro biocompatibility and antibacterial properties study of nanocomposite materials based on hydroxyapatite-biphasic ZnO micro- and nanoparticles embedded in Alginate matrix JF - Materials Science and Engineering C Y1 - 2019 U6 - https://doi.org/10.1016/j.msec.2019.109965 VL - 104 IS - Article number 109965 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - O\'Heras, Carlos A1 - Digel, Ilya A1 - Temiz Artmann, Aysegül T1 - Nanostructured carbon-based column for LPS/protein adsorption : [abstract] N2 - The absence of a general method for endotoxin removal from liquid interfaces gives an opportunity to find new methods and materials to overcome this gap. Activated nanostructured carbon is a promising material that showed good adsorption properties due to its vast pore network and high surface area. The aim of this study is to find the adsorption rates for a carboneous material produced at different temperatures, as well as to reveal possible differences between the performance of the material for each of the adsorbates used during the study (hemoglobin, serum albumin and lipopolysaccharide, LPS). KW - Kohlenstofffaser KW - Adsorption KW - Lipopolysaccharide KW - aktivierte nanostrukturierte Kohlenstofffaser KW - lipopolysaccharides KW - activated nanostructured carbon Y1 - 2009 ER - TY - CHAP A1 - ElBashir, Rasha A1 - Digel, Ilya T1 - Effect of nitric oxide gas on hydrogels : [abstract] N2 - The results support our theory that the NO gas has an influence in increasing the translational diffusion of hydrogels and it accelerates the melting process of the gels. KW - Stickstoffmonoxid KW - Hydrogel KW - nitric oxide gas KW - hydrogel Y1 - 2009 ER - TY - JOUR A1 - Karnatak, Rajat A1 - Kantz, Holger A1 - Bialonski, Stephan T1 - Early warning signal for interior crises in excitable systems JF - Physical Review E Y1 - 2017 U6 - https://doi.org/10.1103/PhysRevE.96.042211 SN - 2470-0053 VL - 96 IS - 4 SP - 042211 ER - TY - CHAP A1 - Bassam, Rasha A1 - Digel, Ilya A1 - Artmann, Gerhard T1 - Effect of nitric oxide on protein thermal stability : [abstract] N2 - As a deduction from these results, we can conclude that proteins mainly in vitro, denaturate totally at a temperature between 57°C -62°C, and they also affected by NO and different ions types. In which mainly, NO cause earlier protein denaturation, which means that, NO has a destabilizing effect on proteins, and also different ions will alter the protein denaturation in which, some ions will cause earlier protein denaturation while others not. KW - Stickstoffmonoxid KW - Proteine KW - Hämoglobin KW - nitric oxide gas KW - protein KW - hemoglobin Y1 - 2009 ER - TY - JOUR A1 - Leimena, W. A1 - Artmann, Gerhard A1 - Dachwald, Bernd A1 - Temiz Artmann, Aysegül A1 - Gossmann, Matthias A1 - Digel, Ilya T1 - Feasibility of an in-situ microbial decontamination of an ice-melting probe JF - Eurasian Chemico-Technological Journal. 12 (2010), H. 2 Y1 - 2010 SN - 1562-3920 SP - 145 EP - 150 ER - TY - JOUR A1 - Bassam, Rasha A1 - Digel, Ilya A1 - Hescheler, Jürgen A1 - Temiz Artmann, Aysegül A1 - Artmann, Gerhard T1 - Effects of spermine NONOate and ATP on protein aggregation: light scattering evidences JF - BMC Biophysics Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?10.1186/2046-1682-6-1 SN - 2046-1682 SP - 1 EP - 14 PB - BioMed Central CY - London ER - TY - JOUR A1 - Turaliyeva, M. A1 - Yeshibaev, A. A1 - Saparbekova, A. A1 - Akynova, L. A1 - Abildayeva, R. A1 - Sadenova, M. A1 - Sartayeva, K. A1 - Schieffer, Andre A1 - Digel, Ilya T1 - Species composition and injuriousness of stranger xylophilous fauna affecting indigenous urban dendroflora of Central Asia JF - Asian journal of microbiology, biotechnology & environmental sciences : AJMBES N2 - At the present time, one of the most serious environmental problems of Central Asia and South Kazakhstan is the ongoing large-scale deterioration of principal urban tree populations. Several major centers of massive spread of invasive plant pests have been found in urban dendroflora of this region. The degree of damage of seven most wide-spread aboriginal tree species was found to range from 21.4±1.1 to 85.4±1.8%. In particular, the integrity of the native communities of sycamore (Platanus spp.), willow (Salix spp.), poplar (Populus spp.) and elm (Ulmus spp.) is highly endangered. Our taxonomic analysis of the most dangerous tree pests of the region has revealed them as neobiontic xylophilous insects such as Cossus cossus L. (Order: Lepidoptera L.) Monochamus urussovi Fisch., Monochamus sutor L., Acanthocinus aedelis L. and Ñetonia aureate L. (Order: Coleoptera L.). We relate the origin of this threatening trend with the import of industrial wood in the mid 90’s of the last century that was associated with high degree of the constructional work in the region. Because of the absence of efficient natural predators of the pest species, the application of microbiological methods of the pest control and limitation is suggested. Y1 - 2016 SN - 0972-3005 VL - 18 IS - 2 SP - 359 EP - 366 PB - EM International ER - TY - CHAP A1 - Pham, Phu Tinh A1 - Staat, Manfred T1 - A simplification for shakedown analysis of hardening structures T2 - Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 20.07.2015 - 23.07.2015 / ed.: Stefanie Elgeti ; Jaan-Willem Simon Y1 - 2015 SP - 1 EP - 4 PB - RWTH Aachen University CY - Aachen ER - TY - JOUR A1 - Vu, Duc-Khoi A1 - Staat, Manfred T1 - An algorithm for shakedown analysis of structure with temperature dependent yield stress N2 - This work is an attempt to answer the question: How to use convex programming in shakedown analysis of structures made of materials with temperature-dependent properties. Based on recently established shakedown theorems and formulations, a dual relationship between upper and lower bounds of the shakedown limit load is found, an algorithmfor shakedown analysis is proposed. While the original problem is neither convex nor concave, the algorithm presented here has the advantage of employing convex programming tools. KW - Einspielen KW - Temperaturabhängigkeit KW - Fließgrenze KW - Shakedown KW - shakedown analysis KW - yield stress Y1 - 2004 ER - TY - JOUR A1 - Ciritsis, Alexander A1 - Horbach, Andreas A1 - Staat, Manfred A1 - Kuhl, Christiane K. A1 - Kraemer, Nils Andreas T1 - Porosity and tissue integration of elastic mesh implants evaluated in vitro and in vivo JF - Journal of Biomedical Materials Research: Part B: Applied Biomaterials N2 - Purpose In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model. Material and Methods Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro. A group of three pigs each were treated with magnetic resonance imaging (MRI) visible conventional stiff polyvinylidene fluoride meshes (PVDF) or with soft thermoplastic polyurethane meshes (TPU) (FEG Textiltechnik mbH, Aachen, Germany), respectively. MRI was performed with a pneumoperitoneum at a pressure of 0 and 15 mmHg, which resulted in bulging of the abdomen. The mesh-induced signal voids were semiautomatically segmented and the mesh areas were determined. With the deformations assessed in both mesh types at both pressure conditions, the porosity change of the meshes after 8 weeks of ingrowth was calculated as an indicator of preserved elastic properties. The explanted specimens were examined histologically for the maturity of the scar (collagen I/III ratio). Results In TPU, the in vitro porosity increased constantly, in PVDF, a loss of porosity was observed under mild stresses. In vivo, the mean mesh areas of TPU were 206.8 cm2 (± 5.7 cm2) at 0 mmHg pneumoperitoneum and 274.6 cm2 (± 5.2 cm2) at 15 mmHg; for PVDF the mean areas were 205.5 cm2 (± 8.8 cm2) and 221.5 cm2 (± 11.8 cm2), respectively. The pneumoperitoneum-induced pressure increase resulted in a calculated porosity increase of 8.4% for TPU and of 1.2% for PVDF. The mean collagen I/III ratio was 8.7 (± 0.5) for TPU and 4.7 (± 0.7) for PVDF. Conclusion The elastic properties of TPU mesh implants result in improved tissue integration compared to conventional PVDF meshes, and they adapt more efficiently to the abdominal wall. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 827–833, 2018. Y1 - 2018 U6 - https://doi.org/10.1002/jbm.b.33877 SN - 1552-4981 VL - 106 IS - 2 SP - 827 EP - 833 PB - Wiley CY - New York, NY ER - TY - GEN A1 - Hackl, Michael A1 - Wegmann, Kilian A1 - Kahmann, Stephanie Lucina A1 - Heinze, Nicolai A1 - Staat, Manfred A1 - Neiss, Wolfram F. A1 - Scaal, Martin A1 - Müller, Lars P. T1 - Reply to the letter to the editor: shortening osteotomy of the proximal radius T2 - Knee Surgery, Sports Traumatology, Arthroscopy Y1 - 2017 U6 - https://doi.org/10.1007/s00167-017-4666-8 VL - 25 IS - 10 SP - 3328 EP - 3329 ER - TY - JOUR A1 - Staat, Manfred A1 - Ballmann, J. T1 - Computation of impacts on elastic solids by methods of bicharacteristics JF - Computational Mechanics '88 : theory and applications ; proceedings of the International Conference on Computational Engineering Science April 10-14, 1988, Atlanta, GA, USA ; vol. 2 N2 - Shock waves, explosions, impacts or cavitation bubble collapses may generate stress waves in solids causing cracks or unexpected dammage due to focussing, physical nonlinearity or interaction with existing cracks. There is a growing interest in wave propagation, which poses many novel problems to experimentalists and theorists. KW - Bicharakteristikenverfahren KW - Elastizität KW - elastic solids KW - bicharacteristics Y1 - 1988 SP - 1719 EP - 1722 ER - TY - JOUR A1 - Staat, Manfred T1 - Basis Reduction for the Shakedown Problem for Bounded Kinematic Hardening Material N2 - Limit and shakedown analysis are effective methods for assessing the load carrying capacity of a given structure. The elasto–plastic behavior of the structure subjected to loads varying in a given load domain is characterized by the shakedown load factor, defined as the maximum factor which satisfies the sufficient conditions stated in the corresponding static shakedown theorem. The finite element dicretization of the problem may lead to very large convex optimization. For the effective solution a basis reduction method has been developed that makes use of the special problem structure for perfectly plastic material. The paper proposes a modified basis reduction method for direct application to the two-surface plasticity model of bounded kinematic hardening material. The considered numerical examples show an enlargement of the load carrying capacity due to bounded hardening. KW - Finite-Elemente-Methode KW - Einspielen KW - Basis Reduktion KW - konvexe Optimierung KW - FEM KW - Druckgeräte KW - Basis reduction KW - Convex optimization KW - FEM KW - Shakedown analysis Y1 - 2000 ER - TY - CHAP A1 - Staat, Manfred A1 - Ballmann, J. T1 - Fundamental aspects of numerical methods for the propagation of multi-dimensional nonlinear waves in solids T2 - Nonlinear hyperbolic equations : theory, computations methods, and applications ; proceedings of the 2nd International Conference on Nonlinear Hyperbolic Problems, Aachen N2 - The nonlinear scalar constitutive equations of gases lead to a change in sound speed from point to point as would be found in linear inhomogeneous (and time dependent) media. The nonlinear tensor constitutive equations of solids introduce the additional local effect of solution dependent anisotropy. The speed of a wave passing through a point changes with propagation direction and its rays are inclined to the front. It is an open question whether the widely used operator splitting techniques achieve a dimensional splitting with physically reasonable results for these multi-dimensional problems. May be this is the main reason why the theoretical and numerical investigations of multi-dimensional wave propagation in nonlinear solids are so far behind gas dynamics. We hope to promote the subject a little by a discussion of some fundamental aspects of the solution of the equations of nonlinear elastodynamics. We use methods of characteristics because they only integrate mathematically exact equations which have a direct physical interpretation. KW - Nichtlineare Welle KW - Nichtlineare Gleichung KW - Festkörper KW - Elastodynamik KW - Multi-dimensional wave propagation KW - nonlinear solids KW - nonlinear tensor constitutive equation Y1 - 1989 SP - 574 EP - 588 ER - TY - CHAP A1 - Tran, Ngoc Trinh A1 - Matthies, Hermann G. A1 - Stavroulakis, Georgios Eleftherios A1 - Staat, Manfred T1 - Direct plastic structural design by chance constrained programming T2 - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK N2 - We propose a stochastic programming method to analyse limit and shakedown of structures under random strength with lognormal distribution. In this investigation a dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit or the shakedown limit. The edge-based smoothed finite element method (ES-FEM) using three-node linear triangular elements is used. Y1 - 2018 ER - TY - JOUR A1 - Staat, Manfred A1 - Heitzer, M. A1 - Lang, H. A1 - Wirtz, K. T1 - Direct Finite Element Route for Design-by-Analysis of Pressure Components JF - International Journal of Pressure Vessels and Piping. 82 (2005), H. 1 Y1 - 2005 SN - 0308-0161 SP - 61 EP - 67 ER - TY - CHAP A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty T2 - Proceedings International Conference on Advances in Computational Mechanics (ACOME) Y1 - 2012 N1 - International Conference on Advances in Computational Mechanics (ACOME), August 14-16, 2012, Ho Chi Minh City, Vietnam SP - 837 EP - 861 ER - TY - CHAP A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Huynh A1 - Staat, Manfred ED - Eberhardsteiner, J. T1 - Numerical stability enhancement of modeling hyperelastic materials T2 - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Y1 - 2012 N1 - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 ER - TY - JOUR A1 - Staat, Manfred A1 - Ballmann, J. T1 - Anisotrope Ausbreitung und Fokussierung von Beschleunigungswellen in vorgespannten nichtlinearelastischen Scheiben JF - Wellenfokussierung, Kolloquium des SFB 27, RWTH Aachen Y1 - 1985 SP - 140 EP - 158 CY - Aachen ER - TY - JOUR A1 - Pogorelova, Natalia A1 - Rogachev, Evgeniy A1 - Digel, Ilya A1 - Chernigova, Svetlana A1 - Nardin, Dmitry T1 - Bacterial Cellulose Nanocomposites: Morphology and Mechanical Properties JF - Materials N2 - Bacterial cellulose (BC) is a promising material for biomedical applications due to its unique properties such as high mechanical strength and biocompatibility. This article describes the microbiological synthesis, modification, and characterization of the obtained BC-nanocomposites originating from symbiotic consortium Medusomyces gisevii. Two BC-modifications have been obtained: BC-Ag and BC-calcium phosphate (BC-Ca3(PO4)2). Structure and physicochemical properties of the BC and its modifications were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and infrared Fourier spectroscopy as well as by measurements of mechanical and water holding/absorbing capacities. Topographic analysis of the surface revealed multicomponent thick fibrils (150–160 nm in diameter and about 15 µm in length) constituted by 50–60 nm nanofibrils weaved into a left-hand helix. Distinctive features of Ca-phosphate-modified BC samples were (a) the presence of 500–700 nm entanglements and (b) inclusions of Ca3(PO4)2 crystals. The samples impregnated with Ag nanoparticles exhibited numerous roundish inclusions, about 110 nm in diameter. The boundaries between the organic and inorganic phases were very distinct in both cases. The Ag-modified samples also showed a prominent waving pattern in the packing of nanofibrils. The obtained BC gel films possessed water-holding capacity of about 62.35 g/g. However, the dried (to a constant mass) BC-films later exhibited a low water absorption capacity (3.82 g/g). It was found that decellularized BC samples had 2.4 times larger Young’s modulus and 2.2 times greater tensile strength as compared to dehydrated native BC films. We presume that this was caused by molecular compaction of the BC structure. Y1 - 2020 SN - 1996-1944 U6 - https://doi.org/10.3390/ma13122849 VL - 13 IS - 12 SP - 1 EP - 16 PB - MDPI CY - Basel ER - TY - JOUR A1 - Kohler, Annette A1 - Kirschner-Hermanns, Ruth A1 - Staat, Manfred A1 - Brehmer, Bernhard T1 - Pathogenese, funktionelle und anatomische Aspekte der weiblichen Belastungsinkontinenz T1 - Female stress incontinence: aspects of pathogenesis and functional anatomy JF - Aktuelle Urologie N2 - Der vorliegende Artikel fokussiert sich auf die weibliche Belastungsinkontinenz als Insuffizienz der Speicherfunktion der Blase, auch wenn im klinischen Alltag die Harninkontinenz der Frau häufig verschiedene Ursachen hat und insbesondere eine Belastungsinkontinenz im Alter und bei neurologischer Komorbidität nur selten isoliert vorkommt. Das kleine Becken der Frau ist sowohl als Funktions- als auch als strukturelle Einheit zu betrachten. Dabei unterliegen bei der Frau Blase, Harnröhre, Gebärmutter und Enddarm sowie die muskulären und ligamentösen Strukturen des kleinen Beckens durch Fertilitätsphase, mögliche Schwangerschaften, Geburten und Menopausen-Phase, über das „normale Altern“ hinaus, gravierenden Veränderungen. This article focuses on female stress incontinence in the form of pelvic floor dysfunction and urethral sphincter deficiency, although isolated stress incontinence accounts for less than half of all incontinence cases. Especially in women of old age and those with neurological comorbidities, the causes of incontinence are mostly multifactorial. Also it has to be considered that the female bladder, urethra, uterus and rectum as well as the muscular and ligamentous structures of the female pelvis minor are affected by phases of fertility, possible pregnancies, births and menopause in addition to the normal ageing process. Y1 - 2018 U6 - https://doi.org/10.1055/s-0043-120616 SN - 1438-8820 VL - 49 IS - 1 SP - 47 EP - 51 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Hackl, M. A1 - Andermahr, J. A1 - Staat, Manfred A1 - Bremer, I. A1 - Borggrefe, J. A1 - Prescher, A. A1 - Müller, L. P. A1 - Wegmann, K. T1 - Suture button reconstruction of the central band of the interosseous membrane in Essex-Lopresti lesions: a comparative biomechanical investigation JF - The Journal of Hand Surgery (European Volume) Y1 - 2017 U6 - https://doi.org/10.1177/1753193416665943 SN - 2043-6289 (Online) SN - 1753-1934 (Print) VL - 42 IS - 4 SP - 370 EP - 376 PB - Sage CY - London ER - TY - JOUR A1 - Göddeke, Dominik A1 - Strzodka, Robert A1 - Mohd-Yusof, Jamaludin A1 - McCormick, Patrick A1 - Buijssen, Sven H.M. A1 - Grajewski, Matthias A1 - Turek, Stefan T1 - Exploring weak scalability for FEM calculations on a GPU-enhanced cluster JF - Parallel Computing Y1 - 2007 U6 - https://doi.org/10.1016/j.parco.2007.09.002 SN - 0167-8191 VL - 33 IS - 10-11 SP - 685 EP - 699 ER - TY - JOUR A1 - Stulpe, Werner A1 - Hellwig, K.-E. T1 - A Classical Reformulation of Finite-Dimensional Quantum Mechanics. Hellwig, K.-E.; Stulpe, W. JF - Quantum measurement, irreversibility and the physics of information / Symposium on the Foundations of Modern Physics 1993, Cologne, Germany 1 - 5 June 1993. Ed. Paul Busch Y1 - 1993 SN - 981021507X N1 - Symposium on the Foundations of Modern Physics ; <1993, Köln> SP - 209 EP - 214 PB - World Scientific CY - Singapore [u.a.] 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 - Topçu, Murat A1 - Madabhushi, Gopal S.P. A1 - Staat, Manfred T1 - A generalized shear-lag theory for elastic stress transfer between matrix and fibres having a variable radius JF - International Journal of Solids and Structures N2 - A generalized shear-lag theory for fibres with variable radius is developed to analyse elastic fibre/matrix stress transfer. The theory accounts for the reinforcement of biological composites, such as soft tissue and bone tissue, as well as for the reinforcement of technical composite materials, such as fibre-reinforced polymers (FRP). The original shear-lag theory proposed by Cox in 1952 is generalized for fibres with variable radius and with symmetric and asymmetric ends. Analytical solutions are derived for the distribution of axial and interfacial shear stress in cylindrical and elliptical fibres, as well as conical and paraboloidal fibres with asymmetric ends. Additionally, the distribution of axial and interfacial shear stress for conical and paraboloidal fibres with symmetric ends are numerically predicted. The results are compared with solutions from axisymmetric finite element models. A parameter study is performed, to investigate the suitability of alternative fibre geometries for use in FRP. KW - Natural fibres KW - Polymer-matrix composites KW - Biocomposites KW - Stress concentrations KW - Finite element analysis Y1 - 2022 U6 - https://doi.org/10.1016/j.ijsolstr.2022.111464 SN - 0020-7683 VL - 239–240 IS - Art. No. 111464 PB - Elsevier CY - New York, NY ER - TY - BOOK A1 - Stulpe, Werner T1 - Classical Representations of Quantum Mechanics Related to Statistically Complete Observables Y1 - 1997 SN - 3-89685-438-0 N1 - Zugl. Berlin, Techn. Univ., Habil.-Schr. 1997 PB - Wissenschaft und Technik Verl. CY - Berlin ER - TY - JOUR A1 - Bhattarai, Aroj A1 - Horbach, Andreas A1 - Staat, Manfred A1 - Kowalczyk, Wojciech A1 - Tran, Thanh Ngoc T1 - Virgin passive colon biomechanics and a literature review of active contraction constitutive models JF - Biomechanics N2 - The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel–Gasser–Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill’s three-element model, Murphy’s four-state cross-bridge chemical kinetic model and Huxley’s sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine. KW - virgin passive KW - strain energy function KW - smooth muscle contraction KW - viscoelasticity KW - damage Y1 - 2022 U6 - https://doi.org/10.3390/biomechanics2020013 SN - 2673-7078 VL - 2 IS - 2 SP - 138 EP - 157 PB - MDPI CY - Basel ER - TY - JOUR A1 - Abel, Alexander A1 - Kahmann, Stephanie Lucina A1 - Mellon, Stephen A1 - Staat, Manfred A1 - Jung, Alexander T1 - An open-source tool for the validation of finite element models using three-dimensional full-field measurements JF - Medical Engineering & Physics N2 - Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed. Y1 - 2020 U6 - https://doi.org/10.1016/j.medengphy.2019.10.015 SN - 1350-4533 VL - 77 SP - 125 EP - 129 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Jung, Alexander A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts T2 - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK N2 - The CellDrum provides an experimental setup to study the mechanical effects of fibroblasts co-cultured with hiPSC-derived ventricular cardiomyocytes. Multi-scale computational models based on the Finite Element Method are developed. Coupled electrical cardiomyocyte-fibroblast models (cell level) are embedded into reaction-diffusion equations (tissue level) which compute the propagation of the action potential in the cardiac tissue. Electromechanical coupling is realised by an excitation-contraction model (cell level) and the active stress arising during contraction is added to the passive stress in the force balance, which determines the tissue displacement (tissue level). Tissue parameters in the model can be identified experimentally to the specific sample. Y1 - 2018 ER - TY - JOUR A1 - Vögele, Stefan A1 - Grajewski, Matthias A1 - Govorukha, Kristina A1 - Rübbelke, Dirk T1 - Challenges for the European steel industry: Analysis, possible consequences and impacts on sustainable development JF - Applied Energy N2 - The steel industry in the European Union (EU), important for the economy as a whole, faces various challenges. These are inter alia volatile prices for relevant input factors, uncertainties concerning the regulation of CO₂-emissions and market shocks caused by the recently introduced additional import duties in the US, which is an important sales market. We examine primary and secondary effects of these challenges on the steel industry in the EU and their impacts on European and global level. Developing and using a suitable meta-model, we analyze the competitiveness of key steel producing countries with respect to floor prices depending on selected cost factors and draw conclusions on the impacts in the trade of steel on emissions, energy demand, on the involvement of developing countries in the value chain as well on the need for innovations to avoid relocations of production. Hence, our study contributes to the assessment of sustainable industrial development, which is aimed by the Sustainability Development Goal “Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation countries”. By applying information on country-specific Human Development Indexes (reflecting aspects of life expectancy, education, and per capita income), we show that relocating energy-intensive industries from the EU may not only increase global energy demand and CO₂-emissions, but may also be to the disadvantage of developing countries. Y1 - 2020 U6 - https://doi.org/10.1016/j.apenergy.2020.114633 SN - 0306-2619 VL - 264 IS - Article number: 114633 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Kahmann, Stephanie Lucina A1 - Uschok, Stephan A1 - Wegmann, Kilian A1 - Müller, Lars-P. A1 - Staat, Manfred T1 - Biomechanical multibody model with refined kinematics of the elbow T2 - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK N2 - The overall objective of this study is to develop a new external fixator, which closely maps the native kinematics of the elbow to decrease the joint force resulting in reduced rehabilitation time and pain. An experimental setup was designed to determine the native kinematics of the elbow during flexion of cadaveric arms. As a preliminary study, data from literature was used to modify a published biomechanical model for the calculation of the joint and muscle forces. They were compared to the original model and the effect of the kinematic refinement was evaluated. Furthermore, the obtained muscle forces were determined in order to apply them in the experimental setup. The joint forces in the modified model differed slightly from the forces in the original model. The muscle force curves changed particularly for small flexion angles but their magnitude for larger angles was consistent. Y1 - 2018 ER - TY - JOUR A1 - Anding, Ralf A1 - Tabaza, Ruth A1 - Staat, Manfred A1 - Trenz, Eva A1 - Lohmann, Philipp A1 - Klinge, Uwe A1 - Kirschner-Hermanns, Ruth T1 - Introducing a method of in vitro testing of different anchoring systems used for female incontinence and prolapse surgery JF - BioMed research international Y1 - 2013 SN - 1110-7251 (E-Journal); 2314-6141 (E-Journal); 1110-7243 (Print); 2314-6133 (Print) VL - Vol. 2013 SP - Article ID 401417 ER - TY - GEN A1 - Staat, Manfred A1 - Barry, Steve T1 - Continuum Mechanics with an Introduction to the Finite Element Method / Steve Barry; Manfred Staat. With extensions by Manfred Staat. N2 - Contents: 1 Introduction 2 One Dimensional Continuum Mechanics 3 Tensors 4 Three Dimensional Stress and Strain 5 Conservation Laws 6 Contiunuum Modelling 7 Plain Problems 8 Questions 9 Reference Information KW - Technische Mechanik KW - Finite-Elemente-Methode Y1 - 2006 ER - TY - JOUR A1 - Hackl, Michael A1 - Leschinger, T. A1 - Staat, Manfred A1 - Müller, Lars-Peter A1 - Wegmann, Kilian T1 - Reconstruction of the interosseous membrane in the Essex Lopresti lesion — a biomechanical evaluation JF - Knee surgery, sports traumatology, arthroscopy N2 - Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique. Y1 - 2016 U6 - https://doi.org/10.1007/s00167-016-4080-7 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 130 EP - 131 PB - Springer CY - Berlin ER - TY - CHAP A1 - Bhattarai, Aroj A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Biomechanical study of the female pelvic floor dysfunction using the finite element method T2 - Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 20.07.2015 - 23.07.2015 / ed.: Stefanie Elgeti ; Jaan-Willem Simon Y1 - 2015 SP - 1 EP - 4 PB - RWTH Aachen University CY - Aachen ER - TY - GEN A1 - Jung, Alexander A1 - Müller, Wolfram A1 - Staat, Manfred T1 - Corrigendum to “Wind and fairness in ski jumping: A computer modelling analysis” [J. Biomech. 75 (2018) 147–153] T2 - Journal of Biomechanics Y1 - 2021 U6 - https://doi.org/10.1016/j.jbiomech.2021.110690 SN - 0021-9290 N1 - Refers to: Alexander Jung, Wolfram Müller, Manfred Staat: Wind and fairness in ski jumping: A computer modelling analysis. Journal of Biomechanics, Volume 75. 25 June 2018. Pages 147-153. https://doi.org/10.1016/j.jbiomech.2018.05.001 VL - 128 IS - Article number: 110690 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Akimbekov, Nuraly S. A1 - Qiao, Xiaohui A1 - Digel, Ilya A1 - Abdieva, Gulzhamal A1 - Ualieva, Perizat A1 - Zhubanova, Azhar T1 - The effect of leonardite-derived amendments on soil microbiome structure and potato yield JF - Agriculture N2 - Humic substances originating from various organic matters can ameliorate soil properties, stimulate plant growth, and improve nutrient uptake. Due to the low calorific heating value, leonardite is rather unsuitable as fuel. However, it may serve as a potential source of humic substances. This study was aimed at characterizing the leonardite-based soil amendments and examining the effect of their application on the soil microbial community, as well as on potato growth and tuber yield. A high yield (71.1%) of humic acid (LHA) from leonardite has been demonstrated. Parental leonardite (PL) and LHA were applied to soil prior to potato cultivation. The 16S rRNA sequencing of soil samples revealed distinct relationships between microbial community composition and the application of leonardite-based soil amendments. Potato tubers were planted in pots in greenhouse conditions. The tubers were harvested at the mature stage for the determination of growth and yield parameters. The results demonstrated that the LHA treatments had a significant effect on increasing potato growth (54.9%) and tuber yield (66.4%) when compared to the control. The findings highlight the importance of amending leonardite-based humic products for maintaining the biogeochemical stability of soils, for keeping their healthy microbial community structure, and for increasing the agronomic productivity of potato plants. Y1 - 2020 U6 - https://doi.org/10.3390/agriculture10050147 VL - 10 IS - Art. 147 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - CHAP A1 - Frotscher, Ralf A1 - Goßmann, Matthias A1 - Raatschen, Hans-Jürgen A1 - Temiz Artmann, Aysegül A1 - Staat, Manfred T1 - Simulation of cardiac cell-seeded membranes using the edge-based smoothed FEM T2 - Shell and membrane theories in mechanics and biology. (Advanced structured materials ; 45) N2 - We present an electromechanically coupled Finite Element model for cardiac tissue. It bases on the mechanical model for cardiac tissue of Hunter et al. that we couple to the McAllister-Noble-Tsien electrophysiological model of purkinje fibre cells. The corresponding system of ordinary differential equations is implemented on the level of the constitutive equations in a geometrically and physically nonlinear version of the so-called edge-based smoothed FEM for plates. Mechanical material parameters are determined from our own pressure-deflection experimental setup. The main purpose of the model is to further examine the experimental results not only on mechanical but also on electrophysiological level down to ion channel gates. Moreover, we present first drug treatment simulations and validate the model with respect to the experiments. Y1 - 2015 SN - 978-3-319-02534-6 ; 978-3-319-02535-3 SP - 187 EP - 212 PB - Springer CY - Heidelberg ER - TY - CHAP A1 - Bhattarai, Aroj A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Computational Analysis of Pelvic Floor Dysfunction T2 - Women's Health and Biomechanics N2 - Pelvic floor dysfunction (PFD) is characterized by the failure of the levator ani (LA) muscle to maintain the pelvic hiatus, resulting in the descent of the pelvic organs below the pubococcygeal line. This chapter adopts the modified Humphrey material model to consider the effect of the muscle fiber on passive stretching of the LA muscle. The deformation of the LA muscle subjected to intra-abdominal pressure during Valsalva maneuver is compared with the magnetic resonance imaging (MRI) examination of a nulliparous female. Numerical result shows that the fiber-based Humphrey model simulates the muscle behavior better than isotropic constitutive models. Greater posterior movement of the LA muscle widens the levator hiatus due to lack of support from the anococcygeal ligament and the perineal structure as a consequence of birth-related injury and aging. Old and multiparous females with uncontrolled urogenital and rectal hiatus tend to develop PFDs such as prolapse and incontinence. KW - Pelvic muscle KW - Muscle fibers KW - Passive stretching KW - Pelvic floor dysfunction Y1 - 2018 SN - 978-3-319-71574-2 U6 - https://doi.org/10.1007/978-3-319-71574-2_17 N1 - Lecture Notes in Computational Vision and Biomechanics, vol 29 SP - 217 EP - 230 PB - Springer CY - Cham ER - TY - JOUR A1 - Staat, Manfred T1 - Anisotrope Wellenausbreitung in isotropen hyperelastischen Scheiben JF - Zeitschrift für angewandte Mathematik und Mechanik : ZAMM. 67 (1987), H. 4 Y1 - 1987 SN - 0946-8463 SP - T241 EP - T243 ER - TY - JOUR A1 - Kühn, Raoul-Roman A1 - Haugner, Werner A1 - Staat, Manfred A1 - Sponagel, Stefan T1 - A Two Phase Mixture Model based on Bone Observation N2 - An optimization method is developed to describe the mechanical behaviour of the human cancellous bone. The method is based on a mixture theory. A careful observation of the behaviour of the bone material leads to the hypothesis that the bone density is controlled by the principal stress trajectories (Wolff’s law). The basic idea of the developed method is the coupling of a scalar value via an eigenvalue problem to the principal stress trajectories. On the one hand this theory will permit a prediction of the reaction of the biological bone structure after the implantation of a prosthesis, on the other hand it may be useful in engineering optimization problems. An analytical example shows its efficiency. KW - Knochen KW - Knochenbildung KW - Knochenchirugie KW - Strukturanalyse KW - Schwammknochen KW - Knochendichte KW - Wolffsches Gesetz KW - bone structure KW - bone density KW - Wolff's Law KW - cancellous bone Y1 - 2004 ER - TY - JOUR A1 - Wegmann, Kilian A1 - Hackl, Michael A1 - Staat, Manfred A1 - Mayer, Katharina A1 - Müller, Lars-Peter T1 - Double plate osteosynthesis of proximal ulna fractures: biomechanical and clinical results JF - Knee surgery, sports traumatology, arthroscopy N2 - While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates. Y1 - 2016 U6 - https://doi.org/10.1007/s00167-016-4079-0 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 58 EP - 59 PB - Springer CY - Berlin ER - TY - JOUR A1 - Jung, Alexander A1 - Staat, Manfred A1 - Müller, Wolfram T1 - Flight style optimization in ski jumping on normal, large, and ski flying hills JF - Journal of biomechanics Y1 - 2013 SN - 1873-2380 (E-Journal); 0021-9290 (Print) N1 - Corrigendum to “Flight style optimization in ski jumping on normal, large, and ski flying hills” [J. Biomech 47 (2014) 716-722] Journal of Biomechanics, 2018;71:313. VL - Vol. 47 IS - Iss. 3 SP - 716 EP - 722 PB - Elsevier CY - Amsterdam 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 - CHAP A1 - Bäcker, Matthias A1 - Koch, C. A1 - Geiger, F. A1 - Eber, F. A1 - Gliemann, H. A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - A New Class of Biosensors Based on Tobacco Mosaic Virus and Coat Proteins as Enzyme Nanocarrier T2 - Procedia Engineering Y1 - 2016 U6 - https://doi.org/10.1016/j.proeng.2016.11.228 SN - 1877-7058 N1 - Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, Hungary VL - Vol. 168 SP - 618 EP - 621 ER - TY - CHAP A1 - Wu, Chunsheng A1 - Poghossian, Arshak A1 - Werner, Frederik A1 - Bronder, Thomas A1 - Bäcker, Matthias A1 - Wang, Ping A1 - Schöning, Michael Josef T1 - An application of a scanning light-addressable potentiometric sensor for label-free DNA detection T2 - 11. Dresdner Sensor-Symposium : 9.-11.12.2013 Y1 - 2013 SN - 978-3-9813484-5-3 SP - 164 EP - 168 ER - TY - JOUR A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Scheja, S. A1 - Wu, Chunsheng A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Electrostatic Detection of Unlabelled Single- and Double-stranded DNA Using Capacitive Field-effect Devices Functionalized with a Positively Charged Polyelectrolyte Layer JF - Procedia Engineering N2 - Capacitive field-effect electrolyte-insulator-semiconductor sensors consisting of an Al-p-Si-SiO2 structure have been used for the electrical detection of unlabelled single- and double-stranded DNA (dsDNA) molecules by their intrinsic charge. A simple functionalization protocol based on the layer-by-layer (LbL) technique was used to prepare a weak polyelectrolyte/probe-DNA bilayer, followed by the hybridization with complementary target DNA molecules. Due to the flat orientation of the LbL-adsorbed DNA molecules, a high sensor signal has been achieved. In addition, direct label-free detection of in-solution hybridized dsDNA molecules has been studied. Y1 - 2015 U6 - https://doi.org/10.1016/j.proeng.2015.08.710 SN - 1877-7058 N1 - Eurosensors 2015 VL - 120 SP - 544 EP - 547 PB - Elsevier CY - Amsterdam ER -