bluuebunny/crossref_metadata_2025_split huggingface dataset:
Imaging therapeutic response in human bone marrow using rapid whole‐body MRI
Authors: Ballon Douglas , Watts Richard , Dyke Jonathan P. , Lis Eric , Morris Michael J. , Scher Howard I. , Uluğ Aziz M. , Jakubowski Ann A. 
Published: November 2004

AbstractWhole‐body imaging of therapeutic response in human bone marrow was achieved without introduced contrast agents using diffusion‐weighted echo‐planar magnetic resonance imaging of physiologic water. Bone marrow disease was identified relative to the strong overlying signals from water and lipids in other anatomy through selective excitation of the water resonance and generation of image contrast that was dependent upon differential nuclear relaxation times and self‐diffusion coefficients. Three‐dimensional displays were generated to aid image interpretation. The geometric distortion inherent in echo‐planar imaging techniques was minimized through the acquisition of multiple axial slices at up to 12 anatomic stations over the entire body. Examples presented include the evaluation of therapeutic response in bone marrow during cytotoxic therapy for leukemia and metastatic prostate cancer and during cytokine administration for marrow mobilization prior to stem cell harvest. Magn Reson Med 52:1234–1238, 2004. © 2004 Wiley‐Liss, Inc.
MRI measurement of hepatic magnetic susceptibility—Phantom validation and normal subject studies
Authors: Chu Zili , Cohen Alan R. , Muthupillai Raja , Chung Taylor , Wang Zhiyue J. 
Published: November 2004

AbstractA magnetic resonance (MR) imaging method with the potential for assessing hepatic iron overload from measurements of hepatic magnetic susceptibility in vivo is described. Using the blood in the portal and hepatic veins as an internal reference, this technique uses the orientation dependence of signal phase to measure the susceptibility of the liver parenchyma. Computer simulations were done to investigate the requirements on spatial resolution and contrast ratio between the vessels and the background liver tissue for data acquisition. Validation studies were conducted using tube‐embedded gel phantoms doped with iron‐dextran from 0 to 10 mg Fe/mL to mimic healthy and iron‐overloaded livers. The phantom measurements were conducted without motion and flow, under respiration‐like oscillatory motion, and with flow. Studies on six normal human subjects demonstrated excellent reproducibility and precision. All images were collected at 1.5 T using a 3D T1‐weighted turbo field echo sequence for inflow MR angiographies with full flow compensation and capable of cardiac synchronization, navigator gating, and motion correction. Magn Reson Med 52:1318–1327, 2004. © 2004 Wiley‐Liss, Inc.
Zur Dynamik von stark nichtlinearen parametererregten Getriebesystemen
Authors: Hortel M. , Škuderová A. 
Published: November 2004

AbstractDie derzeitige Entwicklung von hochbeanspruchten hochtourigen und leicht ausgebauten Getriebesystemen von minimalen Dimensionen, wie sie z.B. im Flugzeug‐ und Automobilbau auf einer Seite und bei schweren Geländefahrzeugen mit begrenztem Antriebkonstruktionsraum auf der anderen Seite vorkommen, führt auf Getriebesysteme mit geteiltem Leistungsfluß in der Gestalt von Planetengetrieben. Maßgebend sind hierbei u.a. Stoßeffekte unter Last ‐ Vorspannung einzelner Planeten mit ihren Gegenrädern infolge der Existenz von Zahnflankenspielen. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of Damping of Vibrations in a System With Two‐Disc Inseparable Clutch
Authors: Andrzej Kosior 
Published: November 2004

AbstractThis paper presents the results of tests on free and forced harmonic torsional vibrations in a system with a two‐disc inseparable clutch, with structural friction taken into account. Nonlinear histeresis loop describing the frictional‐elastic properties of the system was introduced into the model. The mathematical model of the vibrating system containing two disks inseparable clutch was built. During free vibrations of the system, its damping characteristics were tested by a digital simulation method. The vibration damping decrement as a function of amplitude torsional displacement was determined. When vibrations were harmonically forced, the amplitude ‐ frequency characteristics of the system were determined numerically. The system was used as a nonlinear torsional vibration damper in a linear system with a harmonic force. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Verzweigungen in einem kontinuierlichen dynamischen System mit flächenhaftem, dissipativem Stoßkontakt
Authors: Müller I. , Schmieg H. , Vielsack P. 
Published: November 2004

AbstractZwangserregte Schwingungen kontinuierlicher Systeme mit flächenhaftem, dissipativem Stoßkontakt zeigen eine große Vielfalt möglicher Bewegungstypen. Neben nahezu harmonischen Systemantworten existieren weite Frequenzbereiche mit einperiodischen Antworten sowie verzweigten Bewegungsformen. Für die Kontaktbeschreibung bei der numerische Simulation erweist sich ein Projektionsverfahren als effiziente Alternative zur üblicherweise verwendeten Penalty‐Regularisierung. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On applying the Laplace transform method to an equation describing an axially moving string
Authors: Ponomareva S. , van Horssen W. T. 
Published: November 2004

AbstractIn this paper an initial‐boundary value problem for a linear, nonhomogeneous axially moving string equation will be considered. The velocity of the string is assumed to be constant, and the nonhomogeneous terms in the string equation are due to external forces acting on the string. The Laplace transform method will be used to construct the solution of the problem. It will turn out that the method has considerable, computational advantages compared to the usually applied method of modal analysis based on eigenfunction expansions. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibration Damping in a Power Transmission System Containing a Friction Clutch
Authors: Skup Zbigniew 
Published: November 2004

AbstractThis paper presents a theoretical study of the process of damping of non‐linear vibrations in a three‐mass model of power transmission system with a friction clutch. Both simultaneous structural friction phenomenon (passive damping) and piezoelectric effect (active damping) have been taken into account. The aim of the analysis is to assess the influence of geometric parameters of the system, its external load, unit pressure, viscotic damping coefficient and gain factor on the resonance curves of the steady‐state vibrations. The equations of motion of the examined system were solved by means of the Van der Pol method and digital simulation. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling and Flatness‐Based Control of a Carriage Actuated by Pneumatic Muscles
Authors: Aschemann Harald , Hofer Eberhard P. 
Published: November 2004

AbstractPneumatic muscles are innovative tension actuators consisting of textile‐fibre reinforced vulcanised rubber tubing and connection flanges at both ends. They offer several advantages as compared to pneumatic cylinders: significantly less weight, no moving parts within the muscle, and higher maximum force. The main drawback is given by their non‐linear characteristics demanding for sophisticated non‐linear feedback control schemes. This contribution presents a non‐linear control concept for a carriage driven by two pneumatic muscles in parallel connection. First, the modelling of the muscle driven carriage is described in detail. For the resulting non‐linear model the differential flatness property is proven and utilised for a decoupled position and pressure trajectory control. Experimental results from an implementation of this flatness‐based control scheme at a test rig demonstrate the high tracking performance and point out the potential of this new actuator. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entwurfsmethodik für einen approximativen Normalform‐Beobachter
Authors: Röbenack Klaus 
Published: November 2004

AbstractLäßt sich ein System in die Beobachter‐Normalform überführen, dann kann man unmittelbar einen Beobachter mit linearer Fehlerdynamik angeben. Die Berechnung der zugehörigen Transformation ist außerordentlich schwierig, da sie die Lösung eines Systems partieller Differentialgleichungen erfordert. Dieses Problem läßt sich mit dem erweiterten Luenberger‐Beobachter umgehen, der auf einer Linearisierung der Fehlerdynamik beruht. In diesem Beitrag wird eine Verallgemeinerung des erweiterten Luenberger‐Beobachters vorgestellt. Bei diesem neuen Zugang werden in der Fehlerdynamik auch Terme zweiter Ordnung kompensiert. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kinematische Verträglichkeit von Bindungen aufgrund der Benutzerinteraktion
Authors: Li Zhuo , Eberhard Peter , Kübler Lars 
Published: November 2004

AbstractDie Benutzermanipulationen in einer interaktiven VR‐Umgebung verletzt meistens die kinematischen Zwangsbedingungen einer Mehrkörpersystemsimulation. In diesem Beitrag werden zwei kinematische Ansätze zur Vermeidung oder Reduzierung dieser Verletzung der kinematischen Zwangsbedingungen diskutiert. Beide Ansätze wurden in einer VR‐Umgebung implementiert, getestet und verglichen. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the free‐edge effect in piezoelectric laminated plates
Authors: Artel Jens , Becker Wilfried 
Published: November 2004

AbstractThe present paper considers the effect of electromechanical coupling on the interlaminar stresses and the electric field strengths at free edges of laminated plates with piezoelectric material properties. The results of coupled and uncoupled piezoelectric analyses performed by use of the finite element method are compared. Exemplarily, a symmetric cross‐ply and a symmetric angle‐ply laminate are investigated under uniaxial tension and without any electrical loading. It is shown that the interlaminar stresses at the free edge are significantly higher in the coupled case for the symmetric cross‐ply laminate, whereas the coupling effect for the symmetric angle‐ply laminate is of minor significance. In addition, the occurrence of electric field strengths with singular character is revealed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anisotropic moisture depending viscoelastic material model for wood
Authors: Schmidt Jörg , Kaliske Michael 
Published: November 2004

AbstractA moisture depending anisotropic viscoelastic material model is presented in this paper. The necessity of consideration cylindrical anisotropy is caused by the growing process. Wood exhibits different creep characteristics depending on the state of stress. Therefore, the consideration of anisotropic viscoelasticity is required. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Konfigurationswechsel bei plastischen Stoffgesetzen mit dem Übertragungsoperator
Authors: Besdo D. , Ihlemann J. , Kirbach J. 
Published: November 2004

AbstractMit Hilfe des Übertragungsoperators in seiner ursprünglichen Form gelingt es in standardisierter Form, Formulierungen tensorieller Relationen in Eulerschen Größen und solcher in Lagrangeschen Größen ineinander zu überführen. Selbst bei enthaltenen tensorwertigen Funktionen tensorieller Argumente gelingt es, die Relation selbst identisch zu erhalten. Während der ursprüngliche Übertragungsoperator [1] auf dem vollständigen Deformationsgradienten $\underline \underline {F} = \underline {g}_i \circ \underline {\tilde g}^i$ basiert, wird das Konzept nun auf Betrachtungen mit einer Zwischenkonfiguration ausgedehnt. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stress mode dependent weighting functions for simulation of asymmetric creep effects
Authors: Mahnken Rolf 
Published: November 2004

AbstractThe paper presents a framework for creep modeling of materials, which experimentelly exhibit different behaviour in different loading scenarios such as tension, compression and shear, respectively. To this end the characterization of the stress modes is obtained in the octahedral plane of the deviatoric stress space in terms of the Lode angle, such that stress mode dependent scalar weighting functions can be constructed. These are exploited to formulate an additive decomposition of the flow rule into a sum of weighted stress mode related quantities. Verification of the approach is succeeded for a superalloy RENE95. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of particle filled polymer networks based on chain statistics under consideration of the Mullins effect
Authors: Böl Markus , Reese Stefanie 
Published: November 2004

AbstractIt is well‐known, that adding amounts of fine particular fillers, such as carbon black, to a polymer matrix can significantly influence the stiffness and the strength of the whole material. Many authors produced important contributions of trying to understand the mechanism of filled rubber. Maybe the most cited models is the Guth‐Gold model [2]. The above described phenomenon is investigated here using the tool of statistical mechanics. We propose in the present contribution a finite element approach which enables us to include for instance non‐affinity, (near‐)incompressibility, inelasticity, non‐Gaussian chain statistics as well as the material behaviour of filled polymers. Therefore special unit cells, consisting of one tetrahedron and six truss elements, have been used. Crucial point of this approach is the fact, that in the truss elements the micromechanical material behaviour of a single chain is implemented. The tetrahedron element provides for (near‐)incompressibility of the material, for more details see Böl & Reese [1]. Putting arbitrary configurations of such unit cells randomly together allows us to simulate complex structures of unfilled materials. To calculate systems consisting of filled materials, in the above described matrix material fine particular fillers in form of finite elements are included to take care for the increasing of the stiffness and the strength of the whole material. Rubber‐like materials and especially filled rubber‐like materials under cyclic loading are characterized through stress‐softening phenomenon, commonly known as the Mullins' effect. This effect is the consequence of chain breakage inside the material. Many models have been developed to simulate this material behaviour, e.g. the ones of Marckmann et al. [3] and Ogden & Roxburgh [5]. In the present proposal this softening effect is analyzed from the physical point of view. Direct comparisons with experimental data suggest that the new approach generates satisfying predictions, particularly for large strain deformations. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of hyperelastic 2‐D and 3‐D model foams at large deformations
Authors: Demiray S. , Becker W. , Hohe J. 
Published: November 2004

AbstractThe influence of the modeling dimension on the determination of effective properties for hyperelastic foams is investigated by means of regular 2‐D and 3‐D model foams. For calculating the effective stress‐strain relationships of both microstructures, a strain energy based homogenization procedure is employed. The results from numerical analyses show that with a 2‐D model foam the basic deformation mechanisms of the 3‐D model can be captured. Nevertheless, due to the distinct quantitative deviations found from the homogenization analyses, 3‐D modeling approaches should be used if quantitative predictions for the effective material properties are required. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Soft boundary layers in polymeric films
Authors: Diebels Stefan , Steeb Holger , Possart Wulff 
Published: November 2004

AbstractApplication of a polymer on a substrate, e. g. a metal sheet, generates a boundary layer in the polymer. In this boundary layer the properties of the polymer differ from the bulk properties. In the present contribution a mechanical theory based on a structural parameter is presented that allows for the existence of such interphases and, therefore, leads to effective material properties depending on the thickness of the layer. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A thermodynamic consistent model for an assumed transversely isotropic piezoceramic with nonlinear ferroelectric hysteresis
Authors: Romanowski H. , Schröder J. 
Published: November 2004

AbstractA characteristic feature of ferroelectric crystals is the appearance of a spontaneous polarisation, where its direction can be reversed by an applied electric field. This quantity, that has a maximum value at high electric‐fields, depends on the loading history of the material. In this paper we discuss a thermodynamic consistent phenomenological model for an assumed transversely isotropic ferroelectric crystal, where the history dependency is modelled by internal variables. The anisotropic behaviour is governed by isotropic tensor functions, depending on a finite set of invariants, that satisfy automatically the symmetry relationships of the considered body. The main goal of this investigation is to capture some characteristics of nonlinear ferroelectrica, such as the polarisation‐electric‐field and the strain‐electric‐field (butterfly) hysteresis loops. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the determination of crack initiation directions under mixed mode loading
Authors: Goswami S. , Müller A. , Hohe J. , Becker W. 
Published: November 2004

AbstractAn important issue in the mechanics of multilayered structures is the knowledge of local stress fields. Light‐weight heterogeneous structures with crack‐ or notch‐like discontinuities possess great danger of stress concentration and possible crack initiation leading to failure. In the present study, computational procedure, namely the finite element method, has been used to analyze bimaterial medium with various notch opening angles under arbitrary loading conditions. The prediction of the direction of crack initiation is important for wedge type constructions to gather a first hand knowledge of a potential damage zones which may undermine the integrity of the structure as a whole. The application of computational procedure to predict potential directions of crack initiation gives the flexibility required for different structural configurations, lamina orientations and incorporation of various boundary conditions. Superposition of various external loads to simulate pure mode I, mode II and mixed mode cases can also be carried out with excellent results in computational procedure. All the analysis results are based on the hypothesis of Erdogan and Sih. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design of a new fracture specimen by 3D singularity analyses
Authors: Kolk K. , Mishuris G. , Kuhn G. 
Published: November 2004

AbstractA new design of a fracture mechanics specimen is presented. It ensures a valid square‐root singularity along the whole threedimensional crack front under mode‐I conditions. Within the proposed concept it is possible to adjust the angle between the crack front and the free surface in advance. Therefore, the shape of the whole crack front can be influenced in a desired manner. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Material forces in continuum damage material
Authors: Näser Bastian , Kaliske Michael 
Published: November 2004

AbstractThe material force method is present state of the art in computational fracture mechanics. Material forces yield more information than standard approaches like the J‐integral in combination with a highly efficient evaluation in a separate post‐processing step. In this research, the material force method will be applied in tire durability simulations. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surgical management of pelvic sarcomas in children
Authors: Hosalkar Harish , Dormans John 
Published: November 2004

AbstractPelvic sarcomas are uncommon in childhood. Survival rates of children with pelvic sarcomas have shown significant improvements over the past few decades. Correspondingly, there has been an increase in limb‐sparing surgical procedures being performed in these children. This could be attributed in part to the newer generation imaging techniques, wider armamentarium of surgical techniques of reconstruction, and limb‐salvage and advances in neo‐adjuvant chemotherapy and radiotherapy. Reconstruction after resection of pelvic sarcomas while preserving function of the hip and limb can be extremely challenging especially in children where there are issues of growth potential and limb‐length discrepancies. This article focuses on the presentation and epidemiology of different types of pelvic sarcomas in children, the current state‐of‐art of imaging and surgical management of children with pelvic sarcomas. © 2004 Wiley‐Liss, Inc.
Immune reconstitution after childhood acute lymphoblastic leukemia is most severely affected in the high risk group
Authors: Ek Torben , Mellander Lotta , Andersson Bengt , Abrahamsson Jonas 
Published: November 2004

AbstractObjectiveThe aim was to examine the immune reconstitution after current chemotherapy for childhood ALL, with a special focus on finding immunologic variables that predict a poor immune response to vaccinations.ProcedureIn a cross‐sectional study of 31 children after treatment with the NOPHO ALL‐1992 protocol peripheral blood lymphocyte subsets, T‐ and B‐cell function in vitro and serum immunoglobulins (Ig) were measured. All patients were examined once, at 1 or at 6 months after cessation of chemotherapy, immediately before vaccination with DT and Hib.ResultsLymphocytes, T‐cells, and CD4+ T‐cells were low at 6 months after treatment. Naïve T‐cell subsets were more reduced than memory subsets. In the high risk (HR) ALL group, CD8+ T‐cells were reduced at 6 months. NK‐cells were low at 1 month, but normal at 6 months; however, the CD3+CD56+ (NKT) subset was reduced at both time points. Total B‐cell number was low at 1 month, but normal at 6 months. A relative increase of CD5+ B‐cells (B‐1 cells) was evident, particularly in the HR group. Antigen‐independent T‐ and B‐cell function in vitro were affected at 1 month, but virtually normalized at 6 months. Serum IgM level was decreased at 1 month and IgG3 level was increased at 1 and 6 months.ConclusionsThis study shows that immune reconstitution after childhood ALL is slower than previously reported and emphasizes the influence of treatment intensity. The most intensively treated patients still have persistent abnormalities in T‐, B‐, and NK‐cell subsets at 6 months post therapy and show a poor response to immunization with T‐cell dependent antigens. In the HR group, routine re‐immunizations before this time point are of limited benefit, and the effect of repeated vaccinations should be evaluated. © 2004 Wiley‐Liss, Inc.
Computational linear dependence in molecular electronic structure calculations using universal basis sets
Authors: Moncrieff D. , Wilson S. 
Published: November 2004

AbstractDistributed universal even‐tempered basis sets have been developed over recent years that are capable of supporting Hartree–Fock energies to an accuracy approaching the sub‐μHartree level. These basis sets have also been exploited in correlation studies, in applications to polyatomic molecules, and in the calculation of electric properties, such as multipole moments, polarizabilities, and hyperpolarizabilities. Jorge and coworkers have also developed universal basis sets and have recently reported applications to diatomic molecular systems. In this article, we compare the molecular calculations reported by Jorge and coworkers with our previous studies. Particular attention is given to the degree of computational linear dependence associated with the various basis sets employed and the consequential effects of the accuracy of the calculated energies. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005