bluuebunny/crossref_metadata_2025 huggingface dataset:
Projection‐Based Model Reduction for Time‐Varying Descriptor Systems Using Recycled Krylov Subspaces
Authors: Hossain Mohammad‐Sahadet , Benner Peter
Published: February 2009

We will present a projection approach for model reduction of linear time–varying descriptor systems based on earlier ideas in the work of Philips and others. The idea behind the proposed procedure is based on a multipoint rational approximation of the monodromy matrix of the corresponding differential–algebraic equation. This is realized by orthogonal projection onto a rational Krylov subspace. The algorithmic realization of the method employs recycling techniques for shifted Krylov subspaces and their invariance properties. The proposed method works efficiently for macromodels, such as time varying circuit systems and models arising in network interconnection, on limited frequency ranges. Bode plots and step response are used to illustrate the performance of the reduced order models. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Horizontale Positionierung des Plasmagefäßes des Fusionsexperimentes Wendelstein 7‐X
Authors: Bartkowiak René , Woernle Christoph , Schauer Felix , Tereshchenko Andrey , Missal Bernd
Published: February 2009

Am Institut für Plasmaphysik (IPP) in Greifswald soll in den nächsten Jahren das Fusionsexperiment Wendelstein 7‐X (W7‐X) durchgeführt werden, welches als Ziel hat, einen Nachweis über die Eignung des Stellarators als Herzstück eines Fusionskraftwerkes zu erbringen. Das Plasmagefäß des W7‐X muss vertikal abgestützt sowie horizontal zentriert und justiert werden, um u.a. Kollisionen des Plasmagefäßes mit dem Plasma oder umgebenden Komponenten zu verhindern. Das Designkonzept für die horizontale Abstützung und Zentrierung sieht ein System von einstellbaren Pendelstützen und Stellschrauben vor. Auf Grundlage eines elastokinematischen FE‐Modells wird für die Stellgrößen ein Optimierungsalgorithmus entwickelt, der es ermöglicht, in Abhängigkeit von einer zu wählenden Gewichtung die Lageabweichung sowie den Verspannungszustand zu minimieren. Unter Ausnutzung der geometrischen Symmetrieeigenschaften des Systems kann die Anzahl der Messungen zur Identifikation der benötigten Systemparameter stark verringert werden. Die Ergebnisse werden mittels des FE‐Modells validiert. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Matrix formulation of the motion equations of a rigid body and identification of the ten inertia characteristics
Authors: Atchonouglo K. , Dumitriu D. , Monnet T. , Vallée C.
Published: February 2009

The motion equations of a rigid body involve ten inertial characteristics: the mass, the mass center position and the inertia matrix. In order to identify these ten inertia characteristics, we propose an approach unifying them in a 4 × 4 positive definite symmetric matrix. The translation vector and the rotation matrix of the rigid body are also gathered in a 4 × 4 matrix. Therefore the motion equations are formulated as an equality between 4 × 4 skew–symmetric matrices: one representing the sum of external forces and torques, the second representing the dynamic force and torque. The identification is performed by a projected conjugate gradient algorithm developped in the 10–dimensional linear space of 4 × 4 symmetric matrices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An approach for optimization of robot‐generated rigid‐body interpolation using dynamic criteria
Authors: Geu Flores Francisco , Kecskeméthy Andrés
Published: February 2009

The present paper describes an approach for generating spatial trajectories in multibody systems including rigid–body rotations such that dynamic criteria such as forces, accelerations, velocities, etc. as well as limiting restrictions for the motion–generating mechanical device, e.g., a robot, can be considered. The task is to find a rigid–body interpolation that fulfills optimality criteria at the target trajectory as well as in the mechanical system. Application of general optimization methods fails due to the difficulty of finding feasible initial guesses that will converge. The present approach proposes to decouple the general problem into two stages, a first stage in which a pure trajectory optimization is carried out without regard of the mechanical system, and a second stage in which the carrying mechanical system is incorporated. The trajectory planning involves the use of splines of 5–th order as well as an SQP optimization for determining the spline support points as design variables. The approach is illustrated for the example of the generalized waiter problem. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Dynamic Model for a Hybrid Articulated Robot
Authors: Höbarth Wolfgang , Gattringer Hubert , Bremer Hartmut
Published: February 2009

The dynamic modeling of hybrid systems, consisting of flexible and rigid parts results in large partial differential equation systems (PDE). With the assumption of small deflections and the Ritz expansion the PDE can be approximated by an ordinary differential equation system (ODE) but the number of degrees of freedom is generally high.

In this paper a hybrid articulated robot with 2 flexible links and 6 joints is under consideration. The joints are equipped with Harmonic Drive gears with high gear ratio but relative low stiffness. Therefore additionally degrees of freedom are introduced for the elastic deflection of the gears. The links are modeled with flexibility in two bending directions and in torsional sense.

To be able to achieve structured equations the projection equation in subsystem representation is used. The projection equation is based on the momentum and the angular momentum equations of each single finite or infinitesimal body which are projected into the space of minimal coordinates and subsequently are summed up. Groups of bodies are collected to the so called subsystems with separated describing velocities. These subsystems are linked together with the kinematical chain. Because the robot is tree structured it is possible to obtain an explicit expression for the second derivatives of the minimal coordinates with a recursive scheme (O(n) efficiency).

The robot is controlled with a feed forward controller and a linear PD joint controller. Simulation results and measured data are presented and compared. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of Force Transmission in Vehicle Steering Systems
Authors: Tobias Christoph , Eberhard Peter
Published: February 2009

This contribution proposes an approach, how the problem of a moving load on an elastic, beam–like body in an elastic MBS can be solved. Thereby a so–called moving interface marker is used. This marker can move along the bending line of the elastic, beam–like body and locates the point where the moving load is applied. With its help, the moving load can be transformed to forces and torques that have to be applied at the adjoining body–fixed interface markers. These calculated forces and torques lead to an identical deformation of the beam. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the performance of ground vehicles under the influence of stochastic wind loads
Authors: Wetzel Christian , Proppe Carsten
Published: February 2009

The influence of aerodynamic loads on the performance of ground vehicles is an important economical, safety and comfort issue. For the safety and comfort matters, especially the crosswind behavior of the ground vehicles is of great interest, as strong lateral winds can cause major accidents or at least make the driver and the passengers feel very uncomfortable and insecure.

Two different failure scenarios dominate the safety aspect. The most important one is the risk of overturning, which happens not very often but if it occurs it leads in most cases to serious personal damages and the second one is the sudden lane change of road vehicles and the associated driving instabilities because of unforeseen gusts.

As most of the design and excitation parameters of the system are uncertain, they are recognized as stochastic variables. Taking the mentioned failure scenarios into account the probability of failure of a freight vehicle has been computed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computer system for kinematic and dynamic analysis synthesis of rigid and flexible multibody systems
Authors: Zahariev E.
Published: February 2009

In the paper an overview of a general numerical algorithm and program system library for deriving the kinematic constraint equations and dynamic equations of motion, as well as, computation of their first and second order partial derivatives with respect to kinematic parameters of motion, design parameters and mass and inertia characteristics for rigid and flexible multibody systems is presented. These are the main basic computational modules for implementation of kinematic and dynamic synthesis, optimization and design. The main theoretical basis consists in matrix methods for deriving the kinematic constraints and dynamic equations, as well as, the generalized Newton – Euler dynamic equations for rigid and flexible bodies, and finite element discretization in relative coordinates. Block–scheme of the computational procedures and problem oriented program compilation is presented. An example of kinematic synthesis of six–link path generating mechanism with singular points is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An efficient quantitative ultrasonic elastography based on variational h‐refinement
Authors: Arnold Alexander , Mosler Jörn , Reichling Stefan , Khaled Walaa , Bruhns Otto Timme
Published: February 2009

Quantitative elastography is a method to visualise a stiffness distribution. It is motivated by the observation that changes in mechanical properties of soft tissue mostly include important diagnostic information. With an ultrasound–elastography system, the displacement field can be calculated from the pre– and post–deformation image. Using the assumption that the material is elastic, isotropic and nearly incompressible, the distribution of shear modulus is determined by solving an inverse problem. While common approaches use a constant mesh, a variational h–refinement is in the focus of this work. In doing so, the efficiency and accuracy of the determination can be increased. The presented results are generated by using numerical simulations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure induced phase transitions in edible fats
Authors: Gillig Sebastian , Ferstl Peter , Eder Cornelia , Wierschem Andreas , Ruß Winfried
Published: February 2009

Phase change reactions of food ingredients are essential for food technology. We present an optical in situ–technique to examine high pressure induced freezing processes in edible fats up to 450 MPa. The results indicate that the thermodynamic parameters not only influence the solidification kinetics, but also influence the structure of the resulting solid fat. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of different plasticity criteria for trabecular bone failure modelling
Authors: Jirousek Ondrej
Published: February 2009

Different plasticity criteria applied to failure analysis of trabecular bone are compared. A cylindrical sample of bovine trabecular bone is mechanically tested in uniaxial compression/tension with 2% applied strain. Obtained response in compared to responses obtained using finite element model of trabecular bone inner structure subjected to the same loading conditions. FE model is reconstructed from micro–CT images. Elastic material properties at the level of trabecula are determined using nanoindentation. Compared plasticity criteria are based on these elastic material properties, i.e. on Young's modulus of elasticity from nanoindentation. The objective of the paper is to demonstrate the importance to reflect the anisotropic plasticity and to evaluate variation in obtained response when the anisotropy is neglected. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a variational, free‐discontinuity formulation of brittle fracture: mean‐field relaxation and numerical solution
Authors: Dimitrov Slav , Bhlke Thomas
Published: February 2009

In this paper we address the resolution of two important issues arising in the context of the relaxed variational formulation of the incremental free–boundary value problem of brittle fracture. First issue, is how by recasting the formulation into a discrete, minimum–maximum problem one can avoid the undesirable scale effects expressed in terms of the characteristic size and domain–shape dependence of the calculated minimum; second, how by a remeshing procedure in combination with a domain–shape update for tracking the propagating 0–th level set one can reconstruct the crack surface. We finally illustrate our approach by a geometrically linear 2–dimensional example for crack propagation in an initially isotropic brittle solid. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of primary and secondary creep for a wide stress range
Authors: Gorash Yevgen , Altenbach Holm , Naumenko Konstantin
Published: February 2009

Many materials exhibit a stress range dependent creep behavior. The power–law creep observed for a certain stress range changes to the viscous type creep if the stress value decreases. Recently published experimental data for advanced heat resistant steels indicate that the high creep exponent (in the range 5–12 for power–law behaviour) may decrease to the low value of approximately 1 within the stress range relevant for engineering structures. The aim of this paper is to confirm the necessity of the assumption of the stress range dependent power–law–viscous creep transition for the solution of stress relaxation problems affected by creep behavior at elevated temperatures. A constitutive model for the minimum creep rate is introduced to describe both the linear and the power law creep depending upon the stress level. The proposed constitutive model includes a strain hardening function to describe the primary creep stage. To demonstrate the existence of the linear creep behaviour in the low stress range of application area and the influence of the primary creep behaviour on relaxation, several solutions of a uniaxial stress relaxation problem are presented for the loading values relevant to engineering applications. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fracture analysis of cladded components considering residual stresses
Authors: Hohe Jörg , Brand Marcus , Siegele Dieter
Published: February 2009

The present study is concerned with an experimental and numerical investigation of the behavior of sub–clad and surface cracks in cladded components considering the residual stress field due to the welding and heat treatment processes. For this purpose, two large–scale tests on cladded cracked specimens have been performed and analyzed numerically. It is observed that the fracture process is initiated in the heat affected zone of the base metal underneath the cladding whereas the cladding remains intact even in case of a brittle crack extension and arrest in the base material. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Periodic set of the interface cracks with contact zones
Authors: Kozinov S.
Published: February 2009

A closed form solution to the plane problem of the theory of elasticity for an infinite isotropic bimaterial space (plane) with a periodic set of the interface cracks with frictionless contact zones near its tips is obtained. By means of the complex function presentation the problem is reduced to the combined Dirichlet–Riemann boundary value problem for a sectionally–holomorphic function and solved exactly. The equations for the determination of the contact zone length as well as the closed form expressions for the stress intensity factors are carried out. The variation of the mentioned values with respect to the distance between the cracks is illustrated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A phase field model for fracture
Authors: Kuhn C. , Müller R.
Published: February 2009

The variational formulation of brittle fracture as formulated for example by Francfort and Marigo in [1], where the total energy is minimized with respect to any admissible crack set and displacement field, allows the identification of crack paths, branching of preexisting cracks and even crack initiation without additional criteria. For its numerical treatment a continuous approximation of the model in the sense of Γ‐convergence has been presented by Bourdin in [2]. In the regularized Francfort–Marigo model cracks are represented by an additional field variable (secondary variable) s∈[0,1] which is 0 if the material is cracked and 1 if it is undamaged.

In this work, we reinterpret the crack variable as a phase field order parameter and address cracking as a phase transition problem. The crack growth is governed by the evolution equation of the order parameter which resembles the Ginzburg–Landau equation. The numerical treatment is done by finite elements combined with an implicit Euler scheme for the time integration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fracture Mechanics of Rubber Material
Authors: Morgner Christiane , Kaliske Michael
Published: February 2009

This contribution presents an approach based on the material force method which allows to evaluate the fracture sensitivity of rubber material. In order to account for the rate–independent dissipation of filled elastomers subjected to low rates, an endochronic plasticity formulation is introduced. It is shown how configurational forces under consideration of material body forces correspond with the elastic and dissipative energy and how they can be related to energy release rates measured in test configurations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of Cracks with Bridged Zone of Large Scale
Authors: Perelmuter Mikhail
Published: February 2009

ABSTRACT. The direct boundary element method is used to analyze of the stress–strain state and fracture parameters of fiber–reinforced and layered composites with bridged interface cracks under transient thermal and mechanical loadings. It is supposed that unbroken fibers make up a bridged zone along of whole or part of a delamination region between layers of composite materials. For modelling purposes a bridged zone is considered as a part of a crack between joined materials and supposed that distributed spring–like bonds with given nonlinear deformation law link and constrain crack surfaces. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a numerical scheme for curved crack propagation based on configurational forces and maximum dissipation
Authors: Schütte Henning , Molla‐Abbasi Kianoush
Published: February 2009

A numerical scheme is presented to predict crack trajectories in two dimensional components. First a relation between the curvature in mixed–mode crack propagation and the corresponding configurational forces is derived, based on the principle of maximum dissipation. With the help of this, a numerical scheme is presented which is based on a predictor–corrector method using the configurational forces acting on the crack together with their derivatives along real and test paths. With the help of this scheme it is possible to take bigger than usual propagation steps, represented by splines. Essential for this approach is the correct numerical determination of the configurational forces acting on the crack tip. The methods used by other authors are shortly reviewed and an approach valid for arbitrary non–homogenous and non–linear materials with mixed–mode cracks is presented. Numerical examples show, that the method is a able to predict the crack paths in components with holes, stiffeners etc. with good accuracy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fatigue crack initiation in naval welded joints: experimental and numerical approaches
Authors: Thevenet D. , Lautrou N. , Cognard J.Y.
Published: February 2009

This work deals with the fatigue behavior of welded joints. The proposed strategy can be split into two stages: the structure shakedown study and the fatigue crack initiation study. Firstly, stabilized elastic stress–strain cycles are obtained in any point of the welded joint by a finite element analysis, taking constant or variable amplitude loadings into account. The second part of this work is the calculation of the fatigue crack initiation period. Under the assumption of a fast elastic shakedown, a recent approach, proposed by Lemaitre et al., based on damage mechanics, can be used to predict the fatigue crack initiation life in a structure subjected to variable and complex loadings. This strategy is used as a post–treatment of the shakedown finite element calculation for the studied welded specimen. As a validation, four–point bending fatigue tests under constant amplitude loading were carried out on welded specimens provided by DCNS group. Good correlations between experimental and calculated fatigue crack initiation lives have been established. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive finite elements methods for virtual engineering design
Authors: Barthel Corinna , Gabbert Ulrich
Published: February 2009

The focus of this paper is the utilization of improved stresses on the surface of a construction for error estimation. The improved stresses are derived by using stress boundary conditions. They are applied for the calculation of recovered stresses required by the Zienkiewicz–Zhu error indicator. This approach leads to an enhancement of the error estimation on the boundary. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigations of the influence of geometrical irregularities and roughness on the normal contact stiffness of joints
Authors: Goerke Daniel , Willner Kai
Published: February 2009

Conducting experiments is necessary to determine the normal contact stiffness of rough surfaces. In compression tests the interface of specimen pairs is loaded in normal direction and the deflection is measured by extensometers with strain gages. The results can be used for example to describe the contact behaviour of joints in finite element analyses. It is shown that geometrical irregularities which are superposed by the surface roughness have a large influence on the elastic deformation of a joint and on the determination of the contact stiffness. They can be characterized by a skewed and a waved form of the surface with wavelengths which are larger than the surface roughness. In the experimental setup several different surfaces are compressed. In addition, the influence of the size of the contact area on the deformation of a joint is analysed. The results of the normal contact tests are compared with numerical simulations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combined unstructured and hanging‐node‐based remeshing with boundary control for metal forming simulations
Authors: Gu X. , Hortig C. , Svendsen B.
Published: February 2009

During finite element simulation of metal forming process, the mesh which represents the workpiece undergoes extreme large deformation, which could result in highly distorted mesh and numerical failure in simulation. To overcome the problem and improve computation efficiency, advancing front quad meshing technique and non–conforming mesh refinement approach are combined to generate new mesh according to desired mesh size distribution. Application of the combined remeshing strategy to rolling simulation will be presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessment of Historic Masonry by Cutting and Fracture Tests
Authors: Gutermann Marc , Schröder Carsten
Published: February 2009

The existing stress and strain conditions of historic masonry structures are unknown due to several influences (e.g. damages, settlements, permanent loads). Their actual load carrying safety can only be assessed analytically by a conservative estimation of all imponderables. The result is often insufficient and may lead to a reduction of the allowed live load. By assessing experimentally the existing strain conditions using a slightly destructive method, the allowed live load may be increased. Thus some masonry structures can be prevented from demolition or be admitted to higher live load. The new developed method is based on the well known “Flat–Jack–Procedure” and shall improve the applications as well as the accuracy. It involves attaching measurement devices to the masonry surface, cutting longitudinally and horizontally and measuring the relief of strain. A mobile load device is used to collect information of the inhomogeneous specimen (consisting of brick and mortar). Thus Young's Modulus of Elasticity as well as the ultimate strain ϵ[u] are assessed. In this paper the theoretical background and the experimental set–up is described and examples show the achieved results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability analysis of a liquid filled barrelled horizontal tank
Authors: Jasion P.
Published: February 2009

The present work is devoted to the stability of liquid filled horizontal tanks. The possibility of substitution of a cylindrical tank with a barrelled one is investigated. A family of barrelled shells was created and subjected to the numerical analysis. The model of the shell was simply supported at both ends and subjected to the hydrostatic pressure. The values of the critical load and the buckling shapes were determined. The advantages of barrelled shells and their behaviour under hydrostatic load are described. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Material models in principal stretches for elastodynamics
Authors: Müller Melanie , Groß Michael , Betsch Peter
Published: February 2009

In the present work we deal with the conserving integration of elastic bodies undergoing finite deformations. In particular, we make use of constitutive laws formulated in terms of principal stretches.

Most material models for hyperelastic isotropic materials are described in terms of principal stretches (Simo and Taylor [1]), like the Neo–Hooke material which is a special case of the Ogden material, or in invariants. The main advantage of principal stretches is the fact that they can be measured directly, which means that the numerical results can be compared easily with experimental ones, see for example, Ogden [2]. Moreover, it is advantageous to describe viscoelastic material behaviour (e.g. rubberlike materials) in terms of principal stretches.

Concerning the discretization in space we apply the enhanced assumed strain (EAS) method, see Simo and Armero [3]. For the discretization in time we aim at numerical integrators which inherit fundamental conservation laws from the underlying continuous system. In particular, we propose an energy and momentum conserving time–stepping scheme which relies on the notion of a discrete gradient (or derivative) in the sense of Gonzalez [4]. The proposed approach starts from our previous developments in [5]. Numerical examples demonstrate the advantageous properties of the present formulation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elactic buckling of thin‐walled beams with sandwich and double bends flanges
Authors: Paczos P. , Zawodny P.
Published: February 2009

This of the paper are two thin–walled beams with sandwich and double bends flanges. Cross section of these beams is of C type. The beams are simply supported and subjected to a couple of moment – the pure bending. Geometric propeties (warping functions and inertia moments) of two sections with sandwich and double bendsflanges are separately described by dimensionless parameters. Values of critical loads for family of thin–walled beams are numerically determined on the ground of analytical solution. A comparative analysis for selected beams with the use of FEM is performed. Morover the values of critical loads for a family of thin–walled beams are experimentally researched in the Material Strength Laboratoey of the Poznan University of Technology. Finally, the results of the investigation for thin–walled beams are compared in paper. Results of the calculation are presented in tables and figures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cornelia de Lange syndrome (CdLS): prenatal and autopsy findings
Authors: Chong Karen , Keating Sarah , Hurst Stephanie , Summers Anne , Berger Howard , Seaward Gareth , Martin Nicole , Friedberg Tami , Chitayat David
Published: February 2009

Cornelia de Lange Syndrome (CdLS) is a multisystem disorder characterized by somatic defects and mental retardation. Prenatal diagnosis of this severe condition is difficult in view of the non‐specific ultrasound abnormalities. We report three cases with prenatally suspected CdLS based on the ultrasound findings as well as low PAPP‐A detected on first trimester screening in one case, and the results of the autopsy and the NIPBL gene mutation analysis. Copyright © 2009 John Wiley & Sons, Ltd.
An evaluation of the decision‐making process regarding amniocentesis following a screen‐positive maternal serum screen result
Authors: Kobelka Christine , Mattman André , Langlois Sylvie
Published: February 2009

Objectives

To identify the decision‐making factors and personal characteristics of women who opt for and against amniocentesis following a screen‐positive maternal serum screen (MSS) result.

Methods

A questionnaire was mailed to 597 women who were randomly selected among women in the province of British Columbia (BC) who screened positive for Down syndrome (DS) on the MSS between January and June 2005. Subjects were evenly distributed across two main parameters: screen‐positive women who opted for, and declined, amniocentesis (Groups 1 and 2, respectively).

Results

Significant differences (P < 0.05) between Groups 1 and 2 include; reasons for wanting the MSS, post‐positive MSS anxiety level, risk of miscarriage associated with amniocentesis, MSS risk estimate, reasons for wanting, or not wanting amniocentesis, normal fetal ultrasound, attitudes towards termination and religious beliefs. About half of all women across both groups did not find the MSS helpful in their pregnancy, primarily stating that it caused unnecessary increased anxiety.

Conclusions

To help avoid, or at least prepare women for the likelihood of increased anxiety following a screen‐positive MSS result, and help prepare them for decision making, it is important to target MSS counselling to the individuality of the patient, and address these factors before MSS is undertaken. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of solvent, film thickness, and hydrogen bonding on surface‐relief gratings
Authors: Jung Woo‐Hyuk , Lee Ki‐Tae , Lee Dong‐Han , Han Sang‐Cheol , Kim Yang , Lee Jang‐Oo
Published: February 2009

This work focuses on the development of a new type of surface‐relief grating (SRG) using more effective materials than a typical epoxy‐based azopolymer for the recording layer of optical data storage. Thus, aniline‐based azopolymers were synthesized by reaction of N,N‐diglycidylaniline with aniline (An) followed by diazocoupling with 4‐aminobenzonitrile or 4‐nitroaniline. Such azopolymers when spin‐cast from THF/dioxane showed better diffraction efficiency than those cast from THF alone due to residual dioxane creating a large free volume in the solid state. A second diazocoupling reaction of the diazopolymers initially obtained produced polymers with bis(diazobenzene) substituents which exhibited a higher saturation level of the diffraction efficiency for a thicker than for a thinner film. Azopolymers in which the diazo substituents incorporated hydroxyl groups ortho to the diazo unit were obtained via the reaction of the diglycidyl ether of bisphenol‐A with aniline or 3‐hydroxyaniline followed by coupling with diazotised hydroxynitroaminobenzene. These hydroxy groups, presumably as a result of their H‐bonding to the diazo‐N, effectively prevented the photoisomerization of the chromophores, so that the polymers showed no SRG at a normal laser intensity of 100 mW/cm2. Polyurethane‐based azopolymers, synthesized with toluene‐2,4‐diisocyanate and disperse orange 17 containing no hydroxyl groups in the main chains, showed better diffraction efficiency than the other azopolymers with nitro group substituents. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Studies on fluorescent PVA + PVP + MPDMAPP composite films
Authors: Bhajantri R.F. , Ravindrachary V. , Poojary Boja , Ismayil  , Harisha A. , Crasta Vincent
Published: February 2009

Polymer blends along with 1‐(4‐methylphenyl)‐3‐(4‐N,N, dimethyl amino phenyl)‐2‐propen‐1‐one (MPDMAPP) NLO‐chromophore‐doped composite films were prepared by solvent casting method using DMF. The optical properties were studied using UV–visible, refractive index, steady state fluorescence, and fluorescence microscopic imaging techniques. The UV–vis absorption spectra showed three absorption bands and were assigned to localized n → π*, n → π* inter band, and π → π* transition of charge transfer groups. The observed changes in the absorption peak, edges, and intensity with dopant concentration are understood based on charge transfer complex (CTC) formation. The refractive indices of the composite films varied from 1.4937–1.5398 for red and 1.5165–1.5516 for green light respectively. The steady state fluorescence data showed both emission peak wavelengths and intensity changes with MPDMAPP doping level in blend. The fluorescence anisotropy (r) variations in the composite films indicate the suppressed molecular motion of MPDMAPP in the solid composite film. The fluorescence microscopic image of these composite films showed that the films are photochromatic in nature. These modified properties are thought to be due to the charge transfer upon excitation from the donor to the acceptor connected through benzene ring and CTC formation. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Quantitative identification of protein nitration sites
Authors: Chiappetta Giovanni , Corbo Claudia , Palmese Angelo , Marino Gennaro , Amoresano Angela
Published: February 2009

Several labelling strategies have been developed targeting specific amino acid residues and/or PTMs. Methods specifically tailored for the qualitative and sometimes quantitative determination of PTMs have emerged. Many research groups have focused their attention towards o‐nitrotyrosine residues, developing various methodologies for their identification, while direct quantification has remained elusive. So far the iTRAQ chemistry has been limited to primary amines. Here, we report a new strategy based on the use of iTRAQ reagents coupled to MS analysis for the selective labelling of o‐nitrotyrosine residues. This method was proved to lead to the simultaneous localisation and quantification of nitration sites both in model proteins and in biological systems.
Proteomic analysis of multidrug‐resistance mechanisms in adriamycin‐resistant variants of DLKP, a squamous lung cancer cell line
Authors: Keenan Joanne , Murphy Lisa , Henry Michael , Meleady Paula , Clynes Martin
Published: February 2009

Alterations in protein expression associated with adriamycin resistance in a panel of variants derived from the poorly differentiated squamous cell lung carcinoma DLKP were investigated using 2‐D DIGE. Of the 80 proteins identified as being differentially expressed, 32 correlated to adriamycin resistance. Twenty‐four proteins showed positive correlations with drug resistance, 11 correlated directly with increase in the resistance (including NDPK, RPA2, CCT2, HSP70 and Annexin A1) while 13 proteins (including HNRP K and H1, aldehyde dehydrogenase (ALDH), stomatin and CCT3) increased to a similar level in all drug‐resistant variants. Fewer proteins showed an inverse correlation with resistance; two (protein disulphide isomerase (PDI) and HSP70 variant 1) displayed a similar decrease in all variants and six (including prohibitin (PHB) and EIF5A) correlated inversely with resistance. Three proteins (EEF1D, Actin G1 and Annexin 1) correlated with the invasive status of these variants. Some expected targets of adriamycin action showed correlation with resistance including RPA2 (critical for DNA damage repair), while others proteins involved in protection from ROS production (such as GST, peroxiredoxins and thioredoxins) did not. The proteomic analysis revealed a large number of changes in protein expression that may contribute to a more apoptosis‐resistant state. Many of these changes could provide novel targets for overcoming resistance.
Building Value through Sustainable Project Management Offices
Authors: Hurt Mimi , Thomas Janice L.
Published: February 2009

Organizations’ attempts to implement and gain value from investments in project management have resulted in the rapid growth and, in some cases, demise of project management offices (PMOs). The recent research literature on PMOs provides an ambiguous picture of the value case for PMOs and suggests the tenuous nature of their current position in many organizations. In studying project management implementations for the Value of Project Management project, we chose to use three detailed cases and comparisons with the remaining 62 organizations in the value project to study how PMOs are connected to value realization for organizations investing in project management. Specifically, we sought to understand how PMOs deliver sustained value to organizations. Using the theories of Jim Collins (Collins, 2001; Collins & Porras, 1994) as an interpretive framework, we explore these cases to understand how to create and sustain project management value through investment in PMOs.
Project Management Improvement Efforts—Creating Project Management Value by Uniqueness or Mainstream Thinking?
Authors: Andersen Erling S. , Vaagaasar Anne Live
Published: February 2009

This paper presents a research study that is part of the large international Project Management Institute (PMI)-sponsored research project the “Value of Project Management.” Three case studies have been conducted on Norwegian enterprises. This article focuses on how enterprises improve project management and presents the improvement efforts and the stated reasons behind them. There are striking similarities as to the prioritized ways the enterprises have chosen to make improvements: use of a rather standardized model for project work and internal schooling activities. The enterprises all explain their efforts as internally driven, even if some consultancy assistance was used. This article discusses three drivers behind the improvement efforts: an economic perspective, a new institutionalism perspective, and an innovation perspective. This article identifies indicators pointing to all drivers and helps us understand why and how enterprises are improving project management. The importance of research on the practice of the most capable enterprises within the project management field is acknowledged.
Project Management Models as Value Creators
Authors: Eskerod Pernille , Riis Eva
Published: February 2009

Based on findings from five case studies, we discuss benefits obtained by using a common project management model. The case studies are part of an international research project aimed at determining the value of project management. All five companies applied a customized project management model. The five models are presented, and their characteristics, similarities, and differences are discussed. Based on interviews and comparisons with literature, the values obtained are identified. The values relate to efficiency, legitimacy, power and control, and stakeholder satisfaction. Further, the article points to necessary preconditions (both technical and human factors) in order to harvest the values.
Exploring the Dynamics of Value and Fit: Insights from Project Management
Authors: Mullaly Mark , Thomas Janice L.
Published: February 2009

The strategic management literature has struggled with how to recognize, measure, and even understand the concept of “fit” between strategy, structure, and environment. Nevertheless, the concept of fit was fundamentally important from the beginning of the Value of Project Management project. In this article, we compare the “fit” construct defined by Miles and Snow (1984) with our concerns with value direction (Thomas & Mullaly, 2008). A comparative analysis of these two constructs provides insights into how both dimensions improve overall organizational understanding. We demonstrate that while each of these dimensions independently provides useful information, it is their intersection that provides a means of interpreting not just current realities but appropriate future actions.
Government and Governance: The Value of Project Management in the Public Sector
Authors: Crawford Lynn H. , Helm Jane
Published: February 2009

Governance is an emerging theme that has been associated in the public sector with a real political need to satisfy stakeholders by demonstrating accountability and transparency while effectively implementing policy. Many initiatives relating to governance are generated by a need for improvement of organizational performance and ability to implement and adapt to change. These generally take the form of projects and programs encouraging a variety of project management implementations in the public sector. This article reports on examination of the expectations and realization of value from investment in project management in four Australian public-sector organizations with particular reference to the government context, the perspective of public value management (PVM), and the support that project management provides in meeting the demands of public-sector governance.
Home‐based exercise among cancer survivors: adherence and its predictors
Authors: Pinto Bernardine M. , Rabin Carolyn , Dunsiger Shira
Published: February 2009

Objective: Evidence of the benefits of exercise for those treated for cancer has led to exercise interventions for this population. Some have questioned whether cancer patients offered a home‐based intervention adhere to the exercise prescribed.

Method: We examined exercise adherence in a randomized controlled trial of a 12‐week, home‐based exercise trial for breast cancer patients. Three adherence outcomes were examined: minutes of exercise participation/week, number of steps taken during planned exercise/week, and whether the participant met her weekly exercise goal. Predictors of adherence (e.g. demographic and medical variables, Transtheoretical Model variables, history of exercise) were examined.

Results: Findings indicate that participants significantly increased their minutes of exercise and steps taken during planned exercise from Week 1 to 12. The percentage of participants achieving exercise goals was highest in the first few weeks. Exercise self‐efficacy significantly predicted each adherence outcome. Baseline PA predicted mean exercise session steps over the 12 weeks.

Conclusion: Adherence to a home‐based exercise intervention for breast cancer patients changes over time and may be related to baseline levels of exercise self‐efficacy. Copyright © 2009 John Wiley & Sons, Ltd.
Development, feasibility and efficacy of a community‐based exercise training program in pediatric cancer survivors
Authors: Takken Tim , van der Torre Patrick , Zwerink Marlies , Hulzebos Erik H. , Bierings Marc , Helders Paul J. M. , van der Net Janjaap
Published: February 2009

Objective: The aim of this study was to develop a 12‐week exercise training program (comprising aerobic and strength exercises), and to study the feasibility and efficacy of this exercise program in children who survived acute lymphoblastic leukemia.

Sample and methods: A 12‐week exercise program was developed and tested for feasibility in nine children who survived cancer.

Results: From the 16 eligible children for the intervention, 9 participated, while 4 were able to complete the entire program. Feasibility of the program was scored by five children, two of them reported the program as being too demanding. The participating physiotherapists were satisfied with training methodology and training progress. The efficacy of the program on muscle strength, exercise capacity, functional mobility and fatigue showed no significant differences between pre and post training.

Conclusion: In designing a community‐based exercise training program, not only the stage of the disease needs to be considered, but more so the age of the children, the variety of exercises, the location of implementation and even more importantly the views and motivation of the parents concerning the execution of an exercise training program. A careful balance between these parameters could lead to a greater adherence and by that, to a better outcome of these programs. Copyright © 2009 John Wiley & Sons, Ltd.
Restorative yoga for women with breast cancer: findings from a randomized pilot study
Authors: Danhauer Suzanne C. , Mihalko Shannon L. , Russell Gregory B. , Campbell Cassie R. , Felder Lynn , Daley Kristin , Levine Edward A.
Published: February 2009

Objectives: Restorative yoga (RY) is a gentle type of yoga that may be beneficial for cancer patients and post‐treatment survivors. Study goals were: to determine the feasibility of implementing a RY intervention for women with breast cancer; and to examine group differences in self‐reported emotional, health‐related quality of life, and symptom outcomes.

Methods: Women with breast cancer (n=44; mean age 55.8 years) enrolled in this study; 34% were actively undergoing cancer treatment. Study participants were randomized to the intervention (10 weekly 75‐minute RY classes) or a waitlist control group. Participants completed questionnaires at Week 0 (baseline) and Week 10 (immediately post‐intervention for the yoga group).

Results: Group differences favoring the yoga group were seen for mental health, depression, positive affect, and spirituality (peace/meaning). Significant baseline*group interactions were observed for negative affect and emotional well‐being. Women with higher negative affect and lower emotional well‐being at baseline derived greater benefit from the yoga intervention compared to those with similar values at baseline in the control group. The yoga group demonstrated a significant within‐group improvement in fatigue; no significant difference was noted for the control group.

Conclusions: Although limited by sample size, these pilot data suggest potential benefit of RY on emotional outcomes and fatigue in cancer patients. This study demonstrates that a RY intervention is feasible for women with breast cancer; implications for study design and implementation are noted with an emphasis on program adoption and participant adherence. Copyright © 2009 John Wiley & Sons, Ltd.