bluuebunny/crossref_metadata_2025_split huggingface dataset:
The surface radiation budget over North America: gridded data assessment and evaluation of regional climate models
Authors: Markovic Marko , Jones Colin G. , Winger Katja , Paquin Dominique 
Published: February 2009

AbstractWhile surface station observations of downwelling radiation offer accuracy at high temporal resolution, they do not easily allow an evaluation of model surface radiation budgets (SRB) over a wide geographical area. We evaluate three gridded SRB data sets against detailed observations from six surface radiation sites from the US surface radiation (SURFRAD) network. We subsequently use the most accurate surrogate observational data set for evaluation of model‐simulated SRB. The data sets assessed are: ERA40—reanalysis of European Centre for Medium‐Range Weather Forecasts (ECMWF), North American Regional Reanalysis (NARR)—regional reanalysis of National Centres for Environmental Prediction (NCEP) and the surface radiative budget (SRB) from the International Satellite Cloud Climatology Project (ISCCP). Due to varying constraints with respect to temporal coverage of each data set, the evaluation period used in this study is 1996–2001, inclusive.The ERA40 downwelling longwave radiation (DLR) appears the most accurate surrogate observation, while both ERA40 and ISCCP show accurate results when the incoming shortwave radiation (ISR) is considered across the annual cycle. Winter DLR is less accurate in ISCCP with a positive bias and lack of very low (<200 Wm−2) flux values. The NARR SRB shows a large positive bias in the ISR throughout the annual cycle, linked to a significant underestimate of cloud cover.The ERA40 data are subsequently used to evaluate the simulated SRB in three regional climate models across North America. With respect to solar radiation, cloud cover biases are seen to be crucial, while for longwave fluxes both cloud fraction and in‐cloud water content are important to simulate correctly. Inclusion of trace gases beyond H2O, CO2 and O3 appears necessary for an accurate calculation of clear‐sky longwave radiation. Error compensation frequently occurs between the various components contributing to a model total‐sky SRB. This is important to consider when trying to identify the underlying causes of errors in the simulated total SRB. Copyright © 2009 Royal Meteorological Society
Influence of ENSO on multi‐annual temperature variations at Hongyuan, NE Qinghai‐Tibet plateau: evidence from δ13C of spruce tree rings
Authors: Xu Hai , Hong Yetang , Hong Bing , Zhu Yongxuan , Wang Yu 
Published: February 2009

AbstractInfluence of ENSO on global temperature variations has aroused wide attention. However, little is known about this effect at regions where different monsoons prevail. In this study, we measured δ13C of spruce trees (picea likiangensis var. rubescens) and reconstructed temperature variations during the past 270 years at Hongyuan, the Zoige plateau where Indian summer monsoon (ISM) dominates. Temperature variation inferred from δ13Ctreering at the Zoige plateau shows anti‐teleconnection on multi‐annual timescales to the sea‐surface temperature (SST) anomaly in the Niño3 region (SSTANiño3 for short) which has been widely used as an indicator of the “El Niño–South Oscillation” (ENSO). We speculate that the ENSO may modulate the regional surface temperature by influencing the intensity of the ISM, which affects the influx of warm/moist air mass to the study region and subsequently changes the latent heating. On multi‐annual scales, when the SSTANiño3 is high (low), the ISM is weak (strong), monsoon precipitation decreases (increase), the latent heating is weakened (strengthened) and surface air temperature is lower (higher). Copyright © 2009 Royal Meteorological Society
Effects of vertical hedge interval of vetiver grass on erosion on steep agricultural lands
Authors: Donjadee S. , Clemente R. S. , Tingsanchali T. , Chinnarasri C. 
Published: February 2009

AbstractVetiver grass is widely used to reduce soil erosion and has been applied in many areas of the world. However, studies of the effect of vertical hedge intervals on runoff, soil loss and outflow sediment size distribution under a steep slope area are rare. The vetiver grass system (VGS) with three vertical hedge intervals (0·75, 1·5 and 3 m) and no hedgerow were tested at three land slopes (30, 40 and 50 per cent) under three simulated rainfall intensities (60, 85 and 110 mm h−1). It has been observed that vetiver grass (Vetiveria nemoralis) has great potential for reducing runoff and soil loss by about 38·7–68·6 and 56·2–87·9 per cent, respectively. The vetiver strips delayed incipient runoff and reduced peak runoff rate and steady erosion rate. The land slope affected soil loss but did not have a significant effect on runoff. A narrow vetiver hedge interval slightly reduced runoff and soil loss more than a wider one. The soil loss equation obtained in this study revealed that runoff has a higher effect on soil loss. The median sediment size that passed through the vetiver strip increased with rainfall intensity and was mostly dominated by very fine sand, silt and clay. Copyright © 2009 John Wiley & Sons, Ltd.
Combined peroneal and proximal tibial nerve palsies
Authors: Williams Eric H. , Williams Christopher G. , Rosson Gedge D. , Dellon A. Lee 
Published: February 2009

AbstractCombined compression of both the common peroneal nerve and the proximal tibial nerve at the level of the popliteal fossa is rare. Recently, an anatomic site of compression of the proximal tibial nerve at the soleal sling (originating arch for the soleus muscle) has been described in cadavers. The present report includes three patients who had a combined compression of the common peroneal nerve at the fibular neck (fibular tunnel syndrome) and compression of the proximal tibial nerve at the soleal sling (soleal sling syndrome). In each case, blunt trauma was the precipitating event. Neurolysis of both nerves resulted in restoration of motor and sensory function in each ofthese three patients. This is the first clinical report illustrating combined neurolysis of the common peroneal at the knee and the proximal tibial nerve in the soleal sling. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.
A new model updating method for damped structural systems
Authors: Jiang Jiashang , Yuan Yongxin 
Published: February 2009

AbstractIn this paper, the following two are considered:Problem IQEPGiven Ma∈SRn×n, Λ=diag{λ1, …, λp}∈Cp×p, X=[x1, …, xp]∈Cn×p, and both Λ and X are closed under complex conjugation in the sense that \documentclass{article}\footskip=0pc\pagestyle{empty}\begin{document}$\lambda_{2j} = \bar{\lambda}_{2j-1} \in {\mathbf{C}}$\end{document}, x2j=x̄2j−1∈Cn for j = 1,…,l, and λk∈R, xk∈Rn for k=2l+1,…,p, find real‐valued symmetric (2r+1)‐diagonal matrices D and K such that ∥MaXΛ2+DXΛ+KX∥=min.Problem IIGiven real‐valued symmetric (2r+1)‐diagonal matrices Da, Ka∈Rn×n, find
\documentclass{article}\footskip=0pc\usepackage{amssymb}\usepackage[mathscr]{euscript}\pagestyle{empty}\begin{document}$(\hat{D},\hat{K}) \in {\mathscr{S}}_{DK}$\end{document} such that \documentclass{article}\usepackage{amssymb}\usepackage[mathscr]{euscript}\footskip=0pc\pagestyle{empty}\begin{document}$\|\hat{D}-D_a \|^2+ \| \hat{K}-K_a \|^2=\rm{inf}_{(D,K) \in {\mathscr{S}}_{DK}}(\|D-D_a\|^2+\|K-K_a\|^2)$\end{document}, where 𝒮DK is the solution set of IQEP.By applying the Kronecker product and the stretching function of matrices, the general form of the solution of Problem IQEP is presented. The expression of the unique solution of Problem II is derived. A numerical algorithm for solving Problem II is provided. Copyright © 2009 John Wiley & Sons, Ltd.
The growth factor of a Hadamard matrix of order 16 is 16
Authors: Kravvaritis Christos , Mitrouli Marilena 
Published: February 2009

AbstractIn 1968 Cryer conjectured that the growth factor of an n × n Hadamard matrix is n. In 1988 Day and Peterson proved this only for the Hadamard–Sylvester class. In 1995 Edelman and Mascarenhas proved that the growth factor of a Hadamard matrix of order 12 is 12. In the present paper we demonstrate the pivot structures of a Hadamard matrix of order 16 and prove for the first time that its growth factor is 16. The study is divided in two parts: we calculate pivots from the beginning and pivots from the end of the pivot pattern. For the first part we develop counting techniques based on symbolic manipulation for specifying the existence or non‐existence of specific submatrices inside the first rows of a Hadamard matrix, and so we can calculate values of principal minors. For the second part we exploit sophisticated numerical techniques that facilitate the computations of all possible (n − j) × (n − j) minors of Hadamard matrices for various values of j. The pivot patterns are obtained by utilizing appropriately the fact that the pivots appearing after the application of Gaussian elimination on a completely pivoted matrix are given as quotients of principal minors of the matrix. Copyright © 2009 John Wiley & Sons, Ltd.
Friction induced flutter instability ‐ on modeling and simulation of brake‐squeal ‐
Authors: Hetzler Hartmut , Seemann Wolfgang 
Published: February 2009

AbstractThe issue of this contribution are self–excited vibrations due to sliding friction between moving elastic bodies. Starting from Hamiltons principle, the normal contact is implemented by two different approaches. Assuming discretizations in a spatial coordinate frame, the structure of the resulting equations of motions is outlined. For a simple model of a disc–brake, stability charts of the steady–state are presented, which show a considerable influence of the motion of the disc on the stability behavior. Finally, the influence of penalty approaches to the normal contact is addressed shortly. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Untersuchung von Schwingungen und Stößen an Systemen mit adhäsiven Kontakten
Authors: Kröger M. 
Published: February 2009

AbstractIn vielen technischen Anwendungen treten Kontakte auf, die sich bilden und wieder lösen, insbesondere bei Stößen zwischen Körpern. Besteht ein Kontaktpartner aus einem Elastomer, so ergibt sich durch das niedrige Elastizitätsmodul eine relativ große wahre Kontaktfläche, die dazu führt, dass intermolekulare Wechselwirkungen wie Van–der–Walls Bindungen zu großen adhäsiven Kräften führen können. Dadurch wird aus der einseitigen Bindung ein Kontakt, der auch Zugkräfte übertragen kann. Um diesen Vorgang sinnvoll zu beschreiben, muss die Dynamik des Gesamtsystems mit der adhäsiven Kontaktbeschreibung, inklusive der Beschreibung der Dynamik der Kontaktflächenbildung bzw. deren Abbau verknüpft werden. Die Grenze der Kontaktfläche kann als Rissspitze aufgefasst werden, wobei die Rissgeschwindigkeit von den viskoelastischen Materialeigenschaften abhängig ist. Sind die adhäsiven Effekte hinreichend groß, so wird der Kontakt nicht mehr gelöst und es kommt zu abklingenden Schwingungen. Hier werden experimentelle Untersuchungen an einem Adhäsionspendel und Ergebnissen aus der Simulation dargestellt. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Grundlagen zur Beschreibung der Wärmeleitung mit Zellulären Automaten
Authors: Müller Michael , Ostermeyer Georg‐Peter 
Published: February 2009

AbstractFür die Beschreibung der Temperaturleitung werden oftmals die für die Zeitintegration stabilen impliziten Lösungsverfahren (zum Beispiel in Form von Finite–Elemente–Modellen) verwendet, was für ein Zelluläre–Automaten–Modell jedoch aufgrund der dann extremen Zunahme der Rechenzeit nicht zweckmäßig ist. Stattdessen wird die Dynamik der Wärme im Sinne des Zellulären Automaten mit einem expliziten Algorithmus wiedergegeben, der auf dem lokalen Austausch von Energiemengen, also auf Bilanzgleichungen zwischen den Zellen basiert. Dieses Paper zeigt Aussagen zur numerischen Stabilität in Hinblick auf Zeit– wie Ortsdiskretisierung auf. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Existence and approximation for a 3D model of thermally‐induced phase transformations in shape‐memory alloys
Authors: Mielke Alexander , Paoli Laetitia , Petrov Adrien 
Published: February 2009

AbstractThis note deals with a three–dimensional model for thermal stress–induced transformations in shape–memory materials. Microstructure, like twined martensites, is described mesoscopically by a vector of internal variables containing the volume fractions of each phase. The problem is formulated mathematically within the energetic framework of rate–independent processes. An existence result is proved and we study space–time discretizations and establish convergence of these approximations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐Asymptotic Modelling of Medium Thickness Plates with Plane Periodic Structure
Authors: Baron Eugeniusz 
Published: February 2009

AbstractThe main aim of this contribution are presented a certain selected problems (aspects) of non–asymptotic modelling of medium thickness (or Reissner–type) rectangular plates with a plane periodic in–homogeneous structure. In course of non–asymptotic modeling, by using tolerance averaging technique (TAT), apart from the known separation for biperiodic and uniperiodic plates, it is necessary to introduce extra partitions. The four non–asymptotic models of plates with plane periodic structure can be led out independently	(© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling of a combined process of thermomechanical treatment of 304 stainless steel
Authors: Bontcheva Nikolina , Parashkevova Ludmila , Petzov Georgi 
Published: February 2009

AbstractGrain refinement due to phase transformation is an effective method for improving the mechanical properties of steel. An approach is proposed in the present work based on the FEM, for numerical simulation of the microstructure evolution. Grain refinement in 304 stainless steel is considered. Coupling of the thermoplastic deformation with microstructure evolution is realized. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the complexity and analysis of auxetic systems
Authors: Munteanu Ligia 
Published: February 2009

AbstractA challenge in creating a model for an auxetic system based on a formalism that is fully computable, is the aim of this paper. Two major levels of complexity are discussed in a way of understanding the structure and processes that define an auxetic system. The auxeticity and structural complexity are interpreted in the light of Cosserat elasticity which admits degrees of freedom not present in classical elasticity, i.e. the rotation of points in the material, and a couple per unit area or the couple stress. The Young'modulus computing for a laminated periodic system made up of alternating aluminum and an auxetic material is an example of computing complexity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Symmetric Cauchy stresses do not imply symmetric Biot strains in weak formulations of isotropic hyperelasticity with rotational degrees of freedom.
Authors: Fischle Andreas , Neff Patrizio , Münch Ingo 
Published: February 2009

AbstractWe show that symmetric Cauchy stresses do not imply symmetric Biot strains in relaxed weak formulations of finite isotropic hyperelasticity with exact rotational degrees of freedom. This is contrary to claims in the literature. It is noted that in the linear isotropic case with skew symmetric infinitesimal rotational degrees of freedom a similar discrepancy does not arise. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Towards Modeling the Curing Processes of Thermosets
Authors: Hossain Mokarram , Possart Gunnar , Steinmann Paul 
Published: February 2009

AbstractThis contribution presents a newly developed phenomenological model to describe the curing processes of thermosets undergoing small strain deformations [1]. The governing equations are derived from a number of physical and chemical assumptions. Some numerical examples demonstrate the model's capability to correctly represent the evolution of elastic and inelastic material properties as well as the volume shrinkage taking place during the curing process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Material Forces in elasto‐plastic Materials
Authors: Maatouki Ismail , Müller Ralf , Gross Dietmar 
Published: February 2009

AbstractIn this contribution the concept of configurational forces, also called material forces, is applied to rate–independent, elasto–plastic materials. The theory of configurational forces is briefly recast. Zones of plastic deformation can be interpreted as distributed inhomogeneities. With this background the theory of configurational forces can be applied in many situations, including plastic zones at crack tips, elastic inclusions in elasto–plastic materials and localized deformation. The numerical evaluation is done with the Finite Element Method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical analysis of the states of deformation and stress in the compact tension specimen (CT)
Authors: Malag Leszek , Kukielka Leon 
Published: February 2009

AbstractThis work presents a new method of determination of the states of stresses and strains in the compact tension specimen (CT). The numerical analysis was carried out in ANSYS/LS–DYNA programme. The Cowper–Symond's material model was applied in the computational analysis. Selected mechanical properties executed from the uniaxial tension test were used in the numerical calculations. The main aim of this paper is to determinate the influence of the dimensions and vertical notch angle of CT on the stresses and strains states. The present application allows a calculation of the states of stresses and strains in arbitrarily specimen place, and at any time of the duration of the tensile test process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature and Rate effects in Finite Viscoplasticity of Glassy Polymers at Different Deformation Modes: Experiments and Simulations
Authors: Méndez Diez Joel , Göktepe Serdar , Miehe Christian 
Published: February 2009

AbstractThe non–linear inelastic response of glassy polymers is highly influenced by the three–dimensional deformation state, the temperature and the strain rate at which they are deformed. The contribution presents new experiments for different deformation modes which are carried out at different temperatures and rates on commercial bis–phenol A polycarbonate. Emphasis is put not only on the experimental results by themselves but also on the setup and the technique employed in the obtention of the data. The effect of temperature on the velocity with which the neck propagates along the gaged section of a flat specimen under tension is studied means a facility based on photogrammetry. From the homogeneous compression experiments a single set of material parameters appearing in a constitutive model based on the distributed free volume theory under the frame work of additive kinematics will be identified. The inhomogeneous experimental results serve then as a validation for 3–D simulations since the non–uniform strain distribution on the surfaces of both, simulations and experiments, can be compared. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Homogenization of Unidirectional and Arbitrarily Oriented Fiber‐Reinforced Materials by the Method of Conditional Moments
Authors: Khoroshun Leonid , Nazarenko Lidija , Müller Wolfgang H. , Wille Ralf 
Published: February 2009

AbstractIn this paper the method of conditional moments is developed for the case of a two–component matrix composite with randomly distributed unidirectional and arbitrarily oriented ellipsoidal inclusions. The algorithm for determination of the effective elastic properties of composites from the given elastic constants of the components and geometrical parameters and orientation of inclusions is discussed. It is assumed that the components of the composite show orthotropic symmetry of thermoelastic properties. As a numerical example arbolite (straw particle inclusions in a cement matrix) is considered. The dependencies of Young's moduli, Poisson's ratios and shear moduli from the concentration of inclusions and for certain orientations of the inclusions are predicted and discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical treatment of a finite strain viscoplasticity model based on a double multiplicative split
Authors: Shutov A. V. , Kreißig R. 
Published: February 2009

AbstractA viscoplastic material model of overstress type is analyzed. The model is based on the kinematic assumption of a double multiplicative split in order to simulate a nonlinear kinematic hardening. We investigate theoretically and numerically two implicit time–stepping methods, which were used lately in engineering literature to integrate the evolution equations in the context of multiplicative plasticity/viscoplasticity. A common feature of both methods is that the plastic incompressibility constraint is exactly satisfied. Moreover, we show that both methods preserve the symmetry of internal variables, which is inherent to the problem. According to testing results, both methods are equivalent regarding robustness, accuracy, and computational efficiency. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modellierung und Simulation thermo‐mechanisch gekoppelter Umformprozesse
Authors: Bröcker C. , Matzenmiller A. 
Published: February 2009

AbstractDie thermomechanisch konsistente Materialmodellierung des viskoplastischen Werkstoffverhaltens der Metalle bei thermomechanischer Kopplung wird beschrieben. Dabei beinhaltet die Wärmeleitungsgleichung auf natürliche Weise die Wärmeproduktion aufgrund der dissipativen Vorgänge während der plastischen Deformation. Ein konkretes Materialmodell wird angegeben und anhand von Experimenten validiert. Abschließend wird ein Anwendungsbeispiel zur gleichzeitigen Warm–/ Kaltumformung einer Flanschwelle mit LS–DYNA thermo–mechanisch gekoppelt simuliert. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generalized EVI‐space‐time Galerkin method for dynamical modeling in porous media
Authors: Chen Z. , Steeb H. , Diebels S. 
Published: February 2009

AbstractWe investigate a generalized space–time discontinuous Galerkin formulation for modeling dynamical phenomena in porous media. The finite element approximation is based on a coupled space–time discretization. An advanced Embedded Velocity Integration (EVI) technique is applied to circumvent the direction solution of the displacement fields but to solve the rate term of the unknowns. Moverover, a stabilization factor α is introduced to modify the integration scheme of the velocities, which further contributes to the numerical stabilization of the overall solution. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Finite Element Analysis of General Magnetomechanical Coupling Phenomena
Authors: Kiefer Björn , Rosato Daniele , Miehe Christian 
Published: February 2009

AbstractIn this paper we consider the derivation of a finite element model for fully–coupled magneto–mechanical boundary value problems based on a vector–valued magnetic potential. The formulation allows for the incorporation of nonlinear, anisotropic and hysteretic constitutive response. A piezomagnetic inclusion problem is computed to test the implementation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical model for tsunami generation by subaerial landslides
Authors: Pasenow Frithjof , Zilian Andreas , Dinkler Dieter 
Published: February 2009

AbstractA discretization method based on stabilized space–time finite elements is presented for the numerical analysis of three–fluid flows of immiscible and incompressible fluids. Signed distance functions are used to assign the material properties to each spatial point in the domain. The motion and the change in topology of fluid–fluid interfaces are implicitly described by the level–set method. Strong and weak discontinuities in the fields of the physical state variables are captured by locally enriched approximations based on the partition–of–unity concept. An interior penalty method enforces interfacial conservation of mass and momentum. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)