bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stable Model Inversion for Underactuated Multibody Systems
Authors: Seifried Robert , Eberhard Peter 
Published: February 2009

AbstractInverse models for underactuated multibody systems are presented. The derivation of the inverse model is based on the transformation of the equation of motion into a nonlinear input–output normal–form. These inverse models often include a internal dynamics, for which different methods of solution are presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some Methods of Analysis of the Dynamic Systems with the Various Dissipation in Dynamics of a Rigid Body
Authors: Shamolin Maxim V. 
Published: February 2009

AbstractIn is well–known due to its complexity, the problem of the motion of a rigid body in an unbounded medium requires the introduction of certain simplifying restrictions. The main aim in this connection is to introduce hypotheses that would make it possible to study the motion of the rigid body separately from the motion of the medium in which the body is embedded. On the one hand, a similar approach was realized in the classical Kirchhoff problem on the motion of a body in an unbounded ideal incompressible fluid that undergoes an irrotational motion and is at rest at infinity. On the other hand, it is obvious that the above–mentioned Kirchhoff problem does not exhaust the possibilities of this kind of simulation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pathplanning and control of an autonomous robot vehicle with a manipulator
Authors: Stadlbauer Klaus , Bremer Hartmut 
Published: February 2009

AbstractAn autonomous mobile robot is presented. It consists of two parts: a mobile vehicle underneath a robotarm with DOF 5. These two are a nonholomic (the mobile vehicle) and a holonomic subsystem (the robotarm).To give the robot orders or tasks to accomplish this can be done from an external controlsoftware via TCP–IP to the controlsoftware of the robot. An embedded system involves chart creation, pathplanning (global, local), evaluation of sensorsignals, object– and/or marker–detection and a controlled movement. Futhermore it communicates over FIFOs with an nonrealtime–task which allows a communication via TCP–IP.Several sensors are implemented, e.g. infrared–/ ultrasonic–range sensors connected via CAN to the embedded board, as well as the control boards for each engine. A Laserscanner is installed in front of the robot to detect edges and obstacles. For marker–tracking and object recognition an USB–Webcam is added on the robotarm.For avoidance of collisions between the robotarm and the mobile robot a repeller is introduced. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Control of long cable crane systems
Authors: Vogelsang Jan , Büskens Christof 
Published: February 2009

AbstractCrane systems like overhead cranes used in high–rack warehouses are usually modeled as a multi body system with the cable modeled as a pendulum whose cable is regarded as linear. With cables around 40–50 meters long, it is possible that the description of the cable by a straight line is not sufficient anymore, because the cable is bended slightly. The shape of the cable is more like a curve than a straight line.A more suitable description could be achieved by a chain of piecewise linear links, which is again a multi body system and leads to a differential–algebraic system. Each of these links can be modeled again by a pendulum. Using the example of an overhead crane system used in high–rack warehouses, the conventional model with linearly connected trolley and load is compared to the new model with a piecewise linear connection between trolley and load.The optimal trajectories and controls for both models with respect to the same objective function are analyzed for different cable lengths, loads, transport distances and objective functions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A microstructurally motivated anisotropic viscoelastic model for soft tissues
Authors: Ehret Alexander E. , Itskov Mikhail , Weinhold Georg 
Published: February 2009

AbstractIn this paper, a microstructurally motivated approach to take into account the anisotropic viscoelastic behaviour of soft biological tissues is proposed. The constitutive model is based on the assumption that this behaviour results from an interaction between collagen fibres and surrounding matrix constituents. Accordingly, a non–linear viscoelastic one–dimensional model for fibres and the nearby ground substance is developed. This model is then generalised to the anisotropic three–dimensional case. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of non‐Newtonian blood flow in bypass models
Authors: Jonášová Alena , Vimmr Jan 
Published: February 2009

AbstractThe article presents the numerical investigation of non–Newtonian effects of steady blood flow in complete idealized 3–D bypass models, whose native artery is either coronary or femoral with average physiological parameters. Considering the blood to be a generalized Newtonian fluid, the shear–dependent viscosity is described by two well–known macroscopic non–Newtonian models (the Carreau–Yasuda model and the modified Cross model). The results were obtained by own developed computational software based on the pseudo–compressibility approach and on the cell–centred finite volume method defined on unstructured hexahedral grids. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability study of the human body‐seat system into an autovehicle
Authors: Simona Rodean , Paul Rodean Claudiu , Geamilia Solea , Arghir Mariana 
Published: February 2009

AbstractThe paper presents the study of the human body, as a mechanical system, seated inside an autovehicle and exposed under the vertical harmonic vibration action during the auto vehicle motion time. The human body may be roughly approximated by a linear lumped parameter at low frequencies and low vibration levels. Therefore, the model has 5 DOFs in translation, where 4 DOFs represents the human body and 1 DOF is for the seat cushion The mechanical model of the human body, in sitting position on the seat cushion of a vehicle seat, consists of four parts: pelvis, upper torso, viscera and head.. The eigenvalues for the human body – seat system and the damping ratio for the system was been calculate. The system stability analysis is given by the existence of a Lyapunov function for the system. The stability of a system can also be characterized by the eigenvalues of the system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On Numerical Simulation of Interlaminar Failure of Composites
Authors: Kula Krzysztof , Schlebusch Rainer , Zastrau Bernd W. , Kuczma Mieczysław 
Published: February 2009

AbstractThis paper deals with one of the most dangerous failure modes in fiber reinforced composites, namely delamination. The laminated structure is modeled by a solid–shell finite element. The mechanical modeling of delamination onset and propagation is based upon a cohesive zone model implemented into a cohesive element located between laminae of a composite structure. The numerical simulations are accomplished within the commercial software package ABAQUS by the implementation of a user–written finite element. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fracture Analysis of Functionally Graded Piezoelectric Materials
Authors: Rao B. N. , Kuna M. 
Published: February 2009

AbstractThis paper presents domain form of interaction integrals based on three independent formulations for computation of stress intensity factors and electric displacement intensity factor for cracks in functionally graded piezoelectric materials. Each of the formulation differs in the way auxiliary fields are imposed in the evaluation of interaction integral and each of them results in a consistent form of interaction integral in the sense that extra terms naturally appears in their derivation to compensate for the difference in the chosen crack tip asymptotic fields of homogeneous and functionally graded piezoelectric medium. The additional terms play an important role of ensuring domain independence of the presented interaction integrals. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Material force method: theoretical and numerical aspects in nonlinear electro‐elastostatics
Authors: Vu Duc Khoi , Steinmann Paul 
Published: February 2009

AbstractFormulations of the spatial and material motion problem in nonlinear electroelastostatics are considered in this work by a virtual work approach. Based on these formulations, a finite element discretization is realized and a numerical example is presented to demonstrate possible uses of the material force method in studying the closing process of cracks. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of Rosenbrock‐type methods to a finite element formulation based on large strain viscoelasticity
Authors: Hamkar Ahmad‐Wahadj , Hartmann Stefan 
Published: February 2009

AbstractThe present paper is focused on the solution of differential–algebraic equation systems (DAE), which arise in large viscoelastic deformations within the quasi–static finite element context. For this purpose linearly implicit methods of Rosenbrock–type are used, which avoid completely the solution of non–linear equations. This article investigates a possible treatment of the new global approach with respect to expense and achievable accuracy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A finite element framework for the numerical implementation of boundary potentials
Authors: Javili Ali , Steinmann Paul 
Published: February 2009

AbstractThis contribution deals with the implications of boundary potential energies on deformational mechanics in the framework of the finite element method at finite strains. The common material models in continuum mechanics are taking the bulk into account, nevertheless, neglecting the boundary. However, boundary effects sometimes play a dominant role in the material behavior, e.g. surface tension in fluids. The boundary potentials, in general, are allowed to depend not only on the boundary deformation gradient but also on the spatial surface–normal / curve–tangent, as well. For the finite element implementation, a suitable curvilinear coordinate system attached to the boundary is defined and corresponding geometrical and kinematical derivations are carried out. Afterwards, the discretization of the generalized weak formulation, including boundary potentials, is carried out and finally numerical examples are presented to demonstrate the boundary effects due to the different proposed material behavior. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Goal‐oriented r‐adaptivity based on the evaluation of the physical and material residual
Authors: Materna Daniel , Barthold Franz‐Joseph 
Published: February 2009

AbstractThis contribution is concerned with goal–oriented r‐adaptivity based on energy minimization principles for the primal and the dual problem. We obtain a material residual of the primal and of the dual problem, which are indicators for non–optimal finite element meshes. For goal–oriented r‐adaptivity we have to optimize the mesh with respect to the dual solution, because the error of a local quantity of interest depends on the error in the corresponding dual solution. We use the material residual of the primal and dual problem in order to obtain a procedure for mesh optimization with respect to a local quantity of interest. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aspects Regarding the Conception, Modeling and Implementation of an Articulated Robot in Space with Noises and Vibrations
Authors: Ispas Virgil , Petrişor Silviu Mihai , Arghir Mariana , Ispas Viorel 
Published: February 2009

AbstractThe authors want to conceive and to model a structure of a 6R serial modular industrial robot with six freedom degrees. Some specific points are followed: the direct geometric modelling of the robot using the matrix of rotation method, the given in 3D modelling of the robot, the presentation of its components having some possible applications in the processes of production in the spaces with noises and vibrations. The direct geometrical modelling will be determinate the relative orientation matrices, which express the position of each system Ti, (i=1‐6), according to the system Ti–1, also expressing the vectors of relative position of origin Oi of the systems Ti. They will be expressed the orientation of each system Ti in account to the fixed system To attached to the robot base, the set of independent parameters of orientation then are obtained the final equation of the column vector of the generalized coordinates, which express the position and the orientation of the clamping device. The paper presents the two possible applications of the studied robot implementation in a flexible manufacturing cel for the manipulation operations of parts. The robot will be used on the other side for the execution of weld in a points applied to the car carcases. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The relationship of the level of circulating antiangiogenic factors to the clinical manifestations of preeclampsia
Authors: Kim Young Nam , Lee Dae Shim , Jeong Dae Hoon , Sung Moon Su , Kim Ki Tae 
Published: February 2009

AbstractObjectiveThis study investigated whether the antiangiogenic factors' concentrations differ according to the clinical manifestations of preeclampsia.MethodsThis study included 62 preeclampsia and compared the soluble fms‐like tyrosine kinase‐1 (sFlt‐1), soluble endoglin (sEng), and placental growth factor (PlGF) concentrations among patients with different clinical manifestations of preeclampsia. We also compared the patients with preeclampsia to 62 controls matched by age, gestational age, and parity after 20 weeks of gestation.ResultsThe sEng concentrations were significantly elevated in early‐onset than in late‐onset preeclampsia (105.4 ± 37.9 vs 66.3 ± 36.0 ng/mL, p = 0.0008). Moreover, the sEng levels were also higher in severe preeclampsia compared to mild (42.5 ± 31.0 vs 79.2 ± 38.6 ng/mL, p = 0.0013) and in the small for gestational age (SGA) group compared to the group without SGA (68.3 ± 39.3 vs 85.7 ± 38.2 ng/mL, p = 0.0273). The sFlt‐1 levels, however, did not reveal significant difference according to the onset‐time, severity, and presence of SGA. The antiangiogenic factors' concentrations were not related with the degree of hypertension or proteinuria.ConclusionAltered antiangiogenic factors might be involved in the pathogenesis of preeclampsia with synergistic, but different roles. Especially, sEng may be more related with early and severe preeclampsia. Copyright © 2009 John Wiley & Sons, Ltd.
Study of fluorescent nanoparticle comprising iron DMAc complex embedded within polyimide matrix
Authors: Kundnani Chitra , Gupta Anand Kumar , Arya Madhulica , Shrivastava Deepali , Aseri Priyanka , Keller Jagmohan , Bajpai Rakesh 
Published: February 2009

AbstractIron complexed with dimethylacetamide (DMAc) was incorporated in variable ultra low concentration in polyimide (PI) at it precursor stage to obtain nanoscopically manipulated metallopolyimide films. The in situ generation of these nanophase structures, their stability within PI matrix, and interaction with its chains was studied using UV–vis spectroscopy. AFM topographic image shows the presence of rock‐shaped nano particles, which is produced by the formation of polyamic acid salt of Fe‐DMAc complex. Unique fluorescence and improved hydrolytic stability of these metallopolyimide films were due to the formation of nanophase structures. Different photo‐physical properties of developed films are attributed to size quantization effect. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Gamma‐irradiation effects on polypropylene‐based composites with and without an internal lubricant
Authors: Brostow Witold , Deshpande Sameer , Fan Kimberly , Mahendrakar Sridhar , Pietkiewicz Dorota , Wisner Steve R. 
Published: February 2009

AbstractPolypropylene (PP) based materials for nonreusable syringe applications have been investigated, some of them containing an internal liquid lubricant. Hardness, tensile properties, and friction measured by two distinct procedures have been determined. We report three series of results: for nonirradiated samples; for samples directly after stopping the irradiation; and also for samples after accelerated aging equivalent to 2 years of shelf life. We find that effects of irradiation and aging on Shore A and Shore D hardness are small. Tensile strength at break, elongation at yield, and elongation at break all decrease after irradiation and then decrease still more after aging; these results are quantified but expected. By contrast, results from pin‐on‐disk tribometry are quite varied. In some cases γ irradiation and aging both increase friction, in other cases both decrease friction. We also have a case when irradiation increases friction while aging decreases it—as well as vice versa. Possible mechanisms of all these types of behavior are advanced. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Fracture analysis of rubber‐like materials using global and local approaches: Initiation and propagation direction of a crack
Authors: Aït Hocine N. , Naït Abdelaziz M. 
Published: February 2009

AbstractIn this work, fracture of elastomers is analyzed using global and local approaches, combining experiments, analytical developments, and finite element calculations. The J‐integral is chosen as a global parameter characterizing crack initiation in such materials. Particular attention is paid to single specimen methods for measuring the fracture surface energy. More precisely, models developed in the literature are summarized and, because of the lack of accuracy of these models, an original pertinent expression of J is proposed by analogy with linear elastic fracture mechanics frameworks. However, the J‐integral is not able to predict the kinetic or the propagation direction of a crack. Thus, some local parameters are examined: principal strains, principal stresses, and the strain energy density (SED) factor. Results revealed that all these parameters represent reasonable indicators of the crack propagation direction in elastomers. Moreover, unlike maximal principal stress and SED factor, maximal principal strain seems to govern the crack initiation in this kind of materials. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Viscoelasticity and mechanical properties of reactive PVC plastisols
Authors: Boudhani Hassane , Lainé Carole , Fulchiron René , Bounor‐Legaré Véronique , Cassagnau Philippe 
Published: February 2009

AbstractReactive poly(vinyl chloride) (PVC) plastisols have been developed to substitute the hydrocarbon diluents generally used in low viscosity PVC plastisols. For this purpose, methacrylate monomers (5–15%) were added in the PVC suspension (based on diisononyl phtalate plasticizer) to reduce the viscosity at room temperature and to polymerize (by radical polymerization initiated by an organic peroxide) during the gelation process. Both the reactive processing and the gelation process were carried out between the plates of a rheometer cell in the linear viscoelasticity domain (small deformation) and under increasing temperature from room temperature up to 160°C (ω = 6.283 rad s−1,
$ \dot {\rm T} $
= 5°C min−1). A temperature criterion was proposed to define the right balance between the polymerization and the gelation to get the best mechanical properties (i.e., elongation and stress at break). The polymerization process must be slower than the gelation process as the polymerization must take place when PVC grains have fused together to form a homogeneous medium at least at the microscale. Actually, the polymerization kinetics can be controlled by the decomposition kinetics of the organic peroxide. Finally, triethylene glycol dimethacrylate and lauryl methacrylate monomers and dicumyl peroxide as initiator turned out to be the best reactive system for some potential industrial applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Rural breast cancer survivors: exercise preferences and their determinants
Authors: Rogers Laura Q. , Markwell Stephen J. , Verhulst Steven , McAuley Edward , Courneya Kerry S. 
Published: February 2009

AbstractObjective: As a first step in planning interventions to promote exercise in rural breast cancer survivors (BCS), we sought to determine the exercise preferences of rural BCS and to identify the major determinants of these preferences.Methods: Self‐administered mail survey to a population‐based sample from a state cancer registry.Results: Among the 483 respondents, 96% were White with mean education of 13±2.5 years and mean months since diagnosis of 39.0±21.5. Only 19% reported ⩾150 min of moderate to vigorous physical activity per week. Although up to half were open to various counseling options, the most popular options were counseling after treatment (36%), face‐to‐face (47%), and from an exercise specialist (40%). Rural BCS preferred home‐based (63%), unsupervised (47%), moderate intensity exercise (65%) that was primarily walking. The strongest preference correlates include higher education with exercise specialist, higher environment score with outdoors, more comorbidities with low intensity and counseling after cancer treatment, higher social support with exercising with friends or family, sedentary or insufficient physical activity with low intensity, and lower household income with preferring supervised exercise.Conclusions: Interventions designed to promote exercise among rural BCS are needed. Such interventions should consider the environmental aspects of this population and include multiple options based on the preferences of targeted subgroups. Copyright © 2009 John Wiley & Sons, Ltd.
Correlates of physical activity among lung cancer survivors
Authors: Coups Elliot J. , Park Bernard J. , Feinstein Marc B. , Steingart Richard M. , Egleston Brian L. , Wilson Donna J. , Ostroff Jamie S. 
Published: February 2009

AbstractObjective: Lung cancer survivors commonly experience impairments in quality of life, which may be improved through regular physical activity. However, little is known regarding correlates of physical activity in this survivor population. The current study addressed this research gap.Methods: The participants were 175 survivors of early‐stage non‐small cell lung cancer who completed surgical treatment from 1 to 6 years previously. Information regarding medical factors was obtained from chart records and from participant self‐report. Participants also answered questions about demographic and social cognitive factors that may be associated with physical activity, which was assessed as reported engagement in moderate/strenuous activities and leisurely walking.Results: Participants reported an average of 77.7 min of moderate/strenuous weekly activity and 64.6% reported engaging in leisurely walking at least three times per week. Less leisurely walking was reported by older individuals (p=0.001) and those with a lower education level (p<0.001), who also reported less engagement in moderate/strenuous activities (p=0.004). Individuals with poorer pre‐operative pulmonary function reported less moderate/strenuous physical activity (p=0.014) and the number of surgical complications was inversely associated with leisurely walking (p=0.003). Multiple social cognitive constructs were associated with moderate/strenuous activity and leisurely walking.Conclusions: The study identified several lung cancer survivor subgroups who may be most in need of physical activity interventions. Identification of social cognitive correlates of physical activity provides valuable information regarding theory‐guided constructs that should be targeted in future physical activity interventions for lung cancer survivors. Copyright © 2009 John Wiley & Sons, Ltd.