bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distributed finite element structural analysis using the client–server model
Authors: Hudli Anand V. , Pidaparti R. M. V. 
Published: August 2005

AbstractThe paper presents a distributed computing approach for concurrent finite element analysis of truss structures. The client‐server model of distributed computation is applied to the plane frame finite element algorithm and implemented on SUN workstations. The remote procedure call combined with the ability to create threads of computation allows one to efficiently implement distributed and concurrent programs. The present approach is demonstrated through a typical truss structure to illustrate the details of the implementation. This approach can be used for very large finite element systems.
Selecting upwind parameters for improved iterative performance
Authors: Abbasian Reza O. , Carey Graham F. 
Published: August 2005

AbstractThe effect of upwinding on iterative performance of convection–diffusion problems is investigated. An analysis of the iterative method considered here leads to a criterion for selecting the optimal upwinding parameter to improve iterative performance for a class of two‐dimensional convection–diffusion problems. Supporting numerical experiments are presented.
The h‐, p‐ and hp‐versions of the BEM in elasticity: Numerical results
Authors: Holzer Stefan M. 
Published: August 2005

AbstractThe paper investigates the convergence of the h‐, p‐ and hp‐versions of a variational symmetric boundary element method (BEM) in plane elasticity by numerical experiments. The study discusses mixed boundary value problems on polygonal domains, i.e. problems for which the exact solution is analytic except in a finite number of points. The convergence of the error in energy norm is displayed for all versions of the BEM. All results are also compared with those obtained by the corresponding finite element methods. The theoretically predicted asymptotic convergence rates for all versions of the method can be observed in the numerical experiments. A comparison of computer times is given as well.
Comparison of symbolic and numerical integration methods for an assumed‐stress hybrid shell element
Authors: Rengarajan Govind , Knight Norman F. , Aminpour Mohammad A. 
Published: August 2005

AbstractHybrid shell elements have long been regarded with reserve by the commercial finite element developers despite the high degree of reliability and accuracy associated with such formulations. The fundamental reason is the inherent higher computational cost of the hybrid approach as compared to the displacement‐based formulations. However, a noteworthy factor in favour of hybrid elements is that numerical integration to generate element matrices can entirely be avoided by the use of symbolic integration. In this paper, the use of the symbolic computational approach is presented for an assumed‐stress hybrid shell element with drilling degrees of freedom, and the significant time saving achieved is demonstrated through an example.
On the evaluation of nearly singular kernel integrals in boundary element analysis
Authors: Wu Shukai 
Published: August 2005

AbstractThe paper concentrates on the numerical evaluation of nearly singular kernel integrals commonly encountered in boundary element analysis. Limitations of the method developed recently by Huang and Cruse (1993) for the direct evaluation of nearly singular kernel integrals are analysed and pointed out. A general method is developed that extends the idea for all practical cases. Example results are presented, demonstrating the effectiveness of the method.
New stress recovery formula for B‐bar methods
Authors: Jirásek Milan 
Published: August 2005

AbstractAn alternative justification of the B‐bar procedure using the Hu–Washizu variational principle is presented. In contrast to previous work, the derivation starts from the three groups of algebraic equations (strain‐displacement equations, stress‐strain equations and equations of equilibrium) obtained by discretization of the Hu–Washizu functional. Based on an appropriate assumption, these equations can be manipulated to yield the element stiffness matrix in the form typical of the B‐bar procedure. This approach directly leads to a stress‐recovery formula different from the one suggested before. The theory is illustrated by application to a family of quadrilateral plane elements.
Modal reaction method for modal participation factors in support motion problems
Authors: Chen J. T. , Hong H.‐K. , Yeh C. S. 
Published: August 2005

AbstractAn efficient method, called the modal reaction method, for calculating the modal participation factors for support motion problems is proposed. It is found that modal reactions at supports proportionally describe the magnitudes of the modal participation factors. Thus, the modal participation factor for support motion problems can be calculated very efficiently, saving more than 99 per cent, for the given example with 640 degreees of freedom, of the CPU time compared with using the popular quasistatic decomposition method.
Evaluation of some error estimators for the four‐noded lagrangian quadrilateral
Authors: Ramsay A. C. A. , Sbresny H. 
Published: August 2005

AbstractA comparative study of error estimators using a patch recovery scheme with those using simple nodal averaging is made for the four‐noded Lagrangian quadrilateral element through two plane stress elasticity problems. It is demonstrated that error estimators using a patch recovery scheme are generally more effective and have an estimated stress field that is closer to the exact one than those using simple nodal averaging.
Parallel computation of integral equation methods for three‐dimensional transient wave propagation
Authors: Walker S. P. , Yeung C. Y. 
Published: August 2005

AbstractElectromagnetic and acoustic scattering from bodies many wavelengths long presents some of the largest computational problems, with costs scaling with the fourth to sixth power of incident frequency. Parallel processing offers one contributory route to the increase in computational power required for such analyses. The paper presents a parallel implementation of the integral formulation of the transient wave equation. It is demonstrated that it is the repeated evaluation of far field effects which is the dominant cost, and that with appropriate domain partitioning this process can be parallelised very effectively. Results for scattering problems comprising up to 1658 nodes are presented, evaluated on 64‐ and 128‐processor systems.
Finite hyperelements: A 4D geometrical framework using covariant bases and metric tensors
Authors: Perrochet P. 
Published: August 2005

AbstractA method is presented to evaluate space‐time finite element matrices in a general 4D context. Unlike the classical Jacobian‐based ‘textbook’ approach, the method described herein uses curvilinear gradient operators to properly handle finite elements having fewer local dimensions (i.e. two or three) than the global embedding domain. This unconventional, but powerful, method is described in details and is illustrated by an application simulating 4D pure convection in a curved diverging‐converging flow field.
Calculation of fully developed flows of complex fluids in pipes of arbitrary shape, using a mapped circular domain
Authors: Ahmeda M. , Normandin M. , Clermont J.‐R. 
Published: August 2005

AbstractThe problem of determination of fully developed duct flows of arbitrary shape is considered for fluids obeying various constitutive equations. A numerical method based on the transformation of the physical flow (simply connected) domain into a mapped circular domain is set up. The numerical determination of the unknown transformation between the two domains leads to knowledge of the velocities and stresses in the duct, starting from circular contour values of the velocity in the mapped computational domain. Different constitutive equations are investigated for several flow geometries. The comparisons with existing analytical solutions are found to be consistent for all the geometries tested. The method may provide a useful tool for determination, in steady flow conditions, of the flow characteristics for various types of ducts and constitutive equations.
The use of conjugate gradients methods with a segregated finite volume procedure for solving transient, incompressible Navier–Stokes equations
Authors: Nieplocha J. , Schreiber W. C. 
Published: August 2005

AbstractPISO (pressure‐implicit with splitting of operators) is an algorithm devised to solve the transient incompressible Navier–Stokes and energy equations. In that it uses separate equations for each of two pressure corrections, velocity components and transported scalars, PISO is known as a segregated solution procedure. Preconditioned, generalized conjugate gradient (GCG) methods in combination with schemes for vectorization and storage minimization are described in the paper for the purpose of solving both the symmetric and non‐symmetric algebraic equation systems that result from the PISO algorithm. Of particular interest in the paper is a comparison of the present procedure with a procedure described by Chin et al. (1992) in which preconditioned conjugate gradient methods are used to solve the Jacobian matrix used in the Newton iteration of the fully coupled non‐linear equations. The two methods are similar in that both techniques are based on a discretization using staggered control volumes with the power‐law method for modelling advection‐diffusion transport.
Theoretical formulations for adaptive finite element computations
Authors: Li L.‐Y. , Bettess P. , Bull J. W. , Bond T. , Applegarth I. 
Published: August 2005

AbstractA new mesh refinement formulation for h‐adaptive solutions of linear elliptic problems is presented. The reliability of the methods employed for estimating errors and the convergence rate of the errors during an adaptive process are investigated by means of an asymptotic analysis method. The present adaptive mesh refinement strategy significantly improves adaptivity performance and has higher error convergence rates than those usually used. Numerical examples are shown to illustrate the efficiency of the method shown.
Computation of the turbulent flow field around an aerofoil by k‐ϵ‐γ model in a non‐staggered, C‐type single‐grid system
Authors: Kim Ki Sup , Chung Myung Kyoon 
Published: August 2005

AbstractThe whole turbulent flow field around a two‐dimensional aerofoil is solved with a consistent numerical method on a single‐grid system and with an intermittency implemented two‐equation model, namely the k‐ϵ‐γ turbulence model in elliptic form. In order to solve the numerical instability problem arising from the branch‐cut in C‐type grids using the non‐staggered finite‐volume method, a new numerical technique is proposed to guarantee the correct velocity‐pressure coupling along the branch‐cut. The computational results are compared with those by the standard k‐ϵ model and experimental data. This study demonstrates the relative simplicity of the present C‐type single grid system, and the capability is assessed of the k‐ϵ‐γ equations for predicting turbulent flows consisting of both wall‐free and wall‐bounded regions.
Numerical simulation of viscoelastic complex flows using the stream‐tube method and optimization algorithms
Authors: Bereaux Y. , Clermont J. R. , Yassine A. 
Published: August 2005

AbstractNumerical simulation of complex flows of viscoelastic fluids requires us to use efficient algorithms for solving the non‐linear governing equations. The stream‐tube analysis permits calculation of such flows by considering elementary subdomains in a mapped computational domain where the transformed streamlines are parallel and straight. The consideration of subregions leads us to use optimization procedures. The paper concerns the application of such algorithms to compute main flows in axisymmetric converging geometries, for fluids obeying memory‐integral constitutive equations.
Finite element nodal ordering algorithms
Authors: Kaveh A. , Behfar S. M. R. 
Published: August 2005

AbstractGraph theoretical algorithms are presented for finite element nodal ordering to reduce the bandwidth of their stiffness matrices. Five different graphs are defined for representing the connectivity of FE models, and the problem of finite element nodal ordering is transformed into that of a graph nodal ordering. The efficiencies of these methods are compared through examples of two‐ and three‐dimensional finite element models.
Infinite boundary element for elastodynamic problems of anti‐plane motion in an elastic half‐space
Authors: Fu T. M. , Cheung Y. K. 
Published: August 2005

AbstractFor elastodynamic problems in an elastic half‐space, the idea of describing the displacement variation on the free ground surface outside the region being studied with the fundamental solution in a full space is presented in the paper. Then a corresponding mapped infinite boundary element is constructed for the problems of anti‐plane motion. The computed results show that such an element can be applied effectively to obtain high‐precision solutions.
A finite difference algorithm for plotting electric force surface in three‐dimensional field computation
Authors: Slimani D. , Djellal K. , Chemali H. , Kolli K. , Mesli R. 
Published: August 2005

AbstractA finite difference algorithm for plotting the electric force surface is presented in three‐dimensional electrostatic field computation. Based on the flux concept, the nodal electric flux is calculated numerically through the curve integral of the electric displacement vector which was obtained by a numerical differentiation of the nodal electric potential. This latter is calculated by a finite difference method. The electric force surface may also be plotted.
Rapid growth of KDP crystal from aqueous solutions with additives and its optical studies
Authors: Li Guohui , Xue Liping , Su Genbo , Li Zhengdong , Zhuang Xinxin , He Youping 
Published: August 2005

AbstractPotassium Chloride (KCl) and Ethylene diamine tetraacetie acid (EDTA) as new additives were added into the KDP solutions in a small amount (5M% and 0.01M% respectively). The solubility curve and metastable zone width of KDP solution with 5M%KCl was determined and we explained the mechanism of rapid growth of KDP crystal with KCl additve. The clear transparent crystal of KDP with a dimension of 54 × 54 × 42 mm have been grown rapidly by cooling solution method in 2 days. The crystal grown from additives added solution was subjected to optical transmission and laser damage threshold studies as compared with the crystal grown by traditional growing method. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A novel metal‐organic coordination complex crystal: tri‐allylthiourea zinc chloride (ATZC)
Authors: Sun H. Q. , Yuan D. R. , Wang X. Q. , Cheng X. F. , Gong C. R. , Zhou M. , Xu H. Y. , Wei X. C. , Luan C. N. , Pan D. Y. , Li Z. F. , Shi X. Z. 
Published: August 2005

AbstractA new metal‐organic coordination nonlinear optical crystal, tri‐allylthiourea zinc chloride (ZnCl2(AT)3, where AT is CH2=CHCH2NHCSNH2, abbreviated as ATZC), is reported. It was synthesized in water and recrystallized in ethanol. For the crystal structure, optical and thermal characterization were determined by elemental analyses, X‐ray diffraction, infrared spectroscopy, differential scanning calorimeter, thermogravimetric analysis, and powder SHG efficiency meansurement. It belongs to the trigonal system, space group R3, with a = 11.0498(4) Å, c = 16.0416(11) Å, z = 3 and V = 1696.24(15) Å3. It exhibits powder SHG efficiency the same order as Urea crystal. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High pressure electrical resistivity study on nonlinear bis thiourea cadmium chloride (BTCC) single crystal
Authors: Ariponnammal S. , Selva Vennila R. , Radhika S. , Arumugam S. 
Published: August 2005

AbstractThe Bis Thiourea Cadmium Chloride (BTCC) crystals have been crystallized by slow evaporation technique. The lattice parameters of the grown crystals have been determined by the Energy dispersive x‐ray diffraction technique (EDXRD) and the structure has been confirmed. The high pressure electrical resistivity study have been carried out on this crystal and the results have been reported here. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conduction mechanisms in TlSbSe2 chalcogenides
Authors: Ulutas K. , Kalkan N. , Yildirim S. , Deger D. 
Published: August 2005

AbstractTlSbSe2 samples used for electrical measurements were cleaved from larger crystals grown by using the Bridgman ‐ Stockbarger method. Electrical properties of the samples are investigated with a view of determining the dominant conduction mechanism. DC conduction studies reveal that Poole – Frenkel conduction is predominant. The DC conduction studies revealed the non‐ohmic type conduction. The activation energies are also calculated. It is seen that the activation energy decreases with increase of applied voltage. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric properties of thallium gallium diselenide layered crystal in the incommensurate phase
Authors: Şentürk E. , Tümbek L. , Mikailov F. A. 
Published: August 2005

AbstractThe dielectric measurements of the layered crystal were studied in temperature range of successive phase transitions. The measurements revealed that the phase transition occurred in 242 K is an incommensurate phase transition. When the sample is annealed at a stabilized temperature in the incommensurate phase, a remarkable memory effect has been observed on cooling run. The mechanism of the memory effect in the incommensurate phase of the semiconducting ferroelectric TlGaSe2 can be interpreted in the frame of the theory of defect density waves. This theory claims that the memory effect is the result of pinning of the incommensurate structure by the lattice inhomogeneities. With decreasing the annealing temperature the phase transition temperature shifts to lower temperatures gradually. Moreover, the peak intensities also increase gradually. In addition to these effects, the phase transition temperature shifts to lower temperatures with increasing annealing time. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microstructure of a genuine Damascus sabre
Authors: Levin A. A. , Meyer D. C. , Reibold M. , Kochmann W. , Pätzke N. , Paufler P. 
Published: August 2005

AbstractThe surface and cross‐section of a genuine Damascus sword was characterised by means of wide‐angle X‐ray scattering techniques complemented by optical and transmisssion electron microscopy. Position‐resolved X‐ray phase analysis revealed that, unlike ferrite and martensite, the distribution of cementite is inhomogeneous in different spatial zones parallel to the cutting edge of the blade. For the first time a quantitative X‐ray phase and texture analysis was made possible by averaging all spatial zones of the surface and the cross‐section of the sword and applying the Rietveld method with code TOPAS. Differences concerning texture and structure characteristics of ferrite, martensite and cementite are discussed. More evidence for the structure of cementite nanowires is supplied. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bacterial growth studied by flow cytometry
Authors: Steen Harald B. , Boye Erik 
Published: August 2005

AbstractThe feasibility of flow cytometry for measurements on bacteria has been demonstrated by measurements of DNA‐associated fluorescence of Escherichia coli K‐12 in various phases of cell growth. Bacteria were stained with a combination of ethidium bromide and mithramycin after fixation in 70% ethanol. Cultures grown to stationary phase accumulated in two peaks representing cells with two and four chromosomes. Qualitatively similar histograms were obtained with cells grown in the presence of chloramphenicol, whereas cells of the temperature sensitive strain E 177 (dnaA) ended up with only one chromosome per cell at the restrictive temperature. The fluorescence intensity of cells with one chromosome was about 103 times smaller than that of human diploid cells. Instrumental resolution at this level of intensity was CV = 5%, whereas peak widths corresponded to CV = 7–8%. Dyes bound to RNA did not appear to contribute significantly to the fluorescence.
SV40‐Infected muntjac cells: Cell cycle kinetics, cell ploidy and T antigen concentration
Authors: Gershey Edward L. 
Published: August 2005

AbstractMuntjac cells in which the SV40 virus neither readily causes transformation nor replicates were used to study the effect of SV40 infection on cell ploidy and the influence of ploidy on the concentration of T antigen, which is required for the initiation of viral DNA synthesis. Both the DNA content, as measured by flow microfluorometry of propidium iodide‐DNA fluorescence, and the average number of chromosomes per cell indicated that infection with SV40 did not alter the ploidy of the host cell. SV40 infection had no effect on the ploidy distribution of muntjac cells. After immunofluoresceinlabeled anti‐γG, infected and uninfected cultures were compared. In uninfected cells incubated with a 1:20 dilution of anti‐T serum no fluorescence could be observed by fluorescence microscopy, but when examined by flow microfluorometry, fluorescence was detected after standing with as little as 1000‐fold diluted antiserum. Determination of the amount of T antigen and DNA content in the same cell by simultaneous measurement of fluorescein isothiocyanate‐conjugate and propidium iodide fluorescence, indicated that the cellular concentration of T antigen did not vary with the ploidy of the genome or the number of nuclei per cell. These results suggest that gene dosage is not a factor which determines the permissive environment for SV40 replication.
Correlation of the growth of chinese hamster V279‐171b multicellular spheroids with cytokinetic parameters
Authors: Johnson T. S. , Bain E. , Raju M. R. , Martin J. C. 
Published: August 2005

AbstractThe volumes of Chinese hamster V279‐171b multicellular spheroids grown in spinner culture were measured and correlated to DNA distribution and cell volume distribution information. Spheroid growth curves were obtained over a 21‐day period using both electronic cell volume measurements and microscope micrometer sizing. The spheroids were collected from the aperture tube after electronic sizing, and single cell suspensions were prepared via trypsinization. Saline‐washed cells were then stained with mithramycin and analyzed as unfixed or ethanol‐fixed cells for both cell volume and DNA fluorescence measurements. Spheroid growth was determined to have an initial 8‐ to 9‐day rapid growth phase, and a slow phase from 10 to 21 days. The single cell volume distributions of cells obtained from spheroids were dependent on spheroid volume and the relative proportions of small volume noncycling cells to large volume cycling cells comprising the spheroids were also dependent on spheroid volume. DNA distribution data and dual parameter DNA distribution cell volume contour patterns obtained for single cells dissociated from spheroids were closely related to the measured spheroid volume and revealed that the fraction of small, hypoxic G0‐like cells was greatest in old, large spheroids.
Characterization of the cell cycle and synchrony in a CV‐1 cell line
Authors: D'Alisa Rose M. , Gershey Edward L. 
Published: August 2005

AbstractSynchronous populations of CV‐1 cells have been prepared by the selective detachment of mitotic cells. An approach, using a combination of standard techniques, has allowed evaluation of the degree of synchrony throughout the cell cycle. CV‐1 cells have a cycle of ∼19‐hr duration, throughout which synchronous populations progress with a dispersion of 3 hr, i.e., ≥90% of the cells enter S phase and subsequently divide within a 3‐hr period. A major cause of this dispersion is the differential attachment times of individual cells within the population when a synchronous culture is initiated.