bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Synthetic Approaches to Functionally Substituted 4,5‐Dihydro‐1,2,3‐oxadiazole 2‐Oxides
Authors: Tartakovskii V. A. , Ermakov A. S. , Strelenko Yu. A. , Vinogradov D. B. , Petrov E. Yu. 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Antimicrobial Activity of New Linearly Fused 6‐Substituted‐3,8‐diacetyl‐4,7‐dimethyl‐2H‐pyrano[6,5‐f]indoles, Their Chemoselective Bromination and Synthesis of 3‐Thiazolylpyranoindoles.
Authors: Gadaginamath Guru S. , Pujar Shashikant R. , Donawade Dundappa S. , Kavali Rajesh R. 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Potassium Exchanged Layered Zirconium Phosphate as Catalyst in the Preparation of 4H‐Chromenes.
Authors: Curini Massimo , Epifano Francesco , Chimichi Stefano , Montanari Francesca , Nocchetti Morena , Rosati Ornelio 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient and Fast Heck Vinylation of 2‐Bromo‐6‐methylpyridines with Methyl Acrylate. Application to the Synthesis of 6‐Methylcyclopenta[b]pyridinone.
Authors: Robert Nicolas , Hoarau Christophe , Celanire Sylvain , Ribereau Pierre , Godard Alain , Queguiner Guy , Marsais Francis 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Some Novel Azido‐ and Tetrazoloquinoline‐3‐carbonitriles and Their Conversion into 2,4‐Diaminoquinoline‐3‐carbonitriles.
Authors: Mekheimer Ramadan Ahmed , Elgemeie Galal Hamza , Kappe Thomas 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
On the Synthesis of Some 2‐Arylhydrazono‐3‐oxothieno[2,3‐b]pyridines by Reaction of Nitrilimines with 2‐Mercaptonicotinic Acid.
Authors: Zahra Jalal A. , Thaher Bassam Abu , El‐Abadelah Mustafa M. , Otto Hans‐Hartwig 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis, Biological Studies and Molecular Modeling Investigation of 1,3‐Dimethyl‐2,4‐dioxo‐6‐methyl‐8‐(substituted) 1,2,3,4‐Tetrahydro‐[1,2,4]‐triazolo‐[3,4‐f]‐purines as Potential Adenosine Receptor Antagonists.
Authors: Pastorin Giorgia , Bolcato Chiara , Cacciari Barbara , Kachler Sonja , Klotz Karl‐Norbert , Montopoli Christian , Moro Stefano , Spalluto Giampiero 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Methods for the Synthesis of 2‐Hydroxyphenazine Based on the Pd‐Catalyzed N‐Arylation of Aryl Bromides.
Authors: Tietze Mario , Iglesias Alberto , Merisor Elena , Conrad Juergen , Klaiber Iris , Beifuss Uwe 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Catalysis of the Reaction of Cholesteryl Acetate with 4‐Phenyl‐1,2,4‐triazoline‐3,5‐dione by Lithium Perchlorate.
Authors: Kinart Wojciech J. , Nazarski Ryszard B. , Kinart Cezary M. , Thuong Quang T. , Oszczeda Rafal 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Simple, Concise, Stereocontrolled Synthesis of (8E,10Z)‐Pentadecadien‐1‐ol Acetate.
Authors: Chavan Subhash P. , Kharul Rajendra K. , Kamat Subhash K. , Kalkote Uttam R. , Kale Ramesh R. 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Local Dynamics in Polypeptides Studied by Solid State 2H NMR: Side Chain Dynamics of Poly(γ‐benzyl L‐glutamate) and Racemic Poly(γ‐benzyl Glutamate)
Authors: Hiraoki T. , Kitazawa S. , Tsutsumi A. 
Published: August 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Colorectal carcinoma screening procedure use among primary care patients
Authors: Lafata Jennifer Elston , Williams L. Keoki , Ben‐Menachem Tamir , Moon Christina , Divine George 
Published: August 2005

AbstractBACKGROUNDDespite evidence‐based recommendations for colorectal carcinoma screening, population‐based surveys report low screening rates. To the authors' knowledge, the extent to which screening procedures are used by patients seen in primary care is not as clear. The authors estimated the annual and 5‐year colorectal carcinoma screening procedure use among a cohort of primary care patients and evaluated the correlation between patient characteristics and the use of screening procedures.METHODSThe authors identified a cohort of patients (n = 21,833 patients) ages 55–70 years who had a primary care visit in 2003 and who were enrolled in a health plan for the 5‐year period ending December 31, 2003. Using automated data for the 5‐year period ending December 31, 2003, information on patient sociodemographic characteristics, primary care and health maintenance examination (HME) visits, comorbid diagnoses, income, and screening receipt was compiled. The latter included barium enema, colonoscopy, fecal occult blood testing (FOBT), and flexible sigmoidoscopy use.RESULTSApproximately one‐half of insured, primary care patients (54%) received recommended colorectal carcinoma screening procedures over the 5‐year observation period. Among individuals who received screening, colonoscopy was used most frequently (39.9%), followed by flexible sigmoidoscopy testing alone (28.3%) or in combination with FOBT (4.3%). Annual screening rates increased by 3.1% between 1999 and 2003. Among individuals who did not receive recommended colorectal carcinoma screening, 64% had at least 3 HME visits, and 41% received at least 1 FOBT. Increasing HME visits and other primary care visit frequency, along with increasing age, income, male gender, and African‐American race, were associated with screening receipt.CONCLUSIONSSignificant opportunities exist to increase colorectal carcinoma screening among primary care patients. Cancer 2005. © 2005 American Cancer Society.
A partitioned solution procedure for geothermal reservoir analysis
Authors: Schrefler B. A. 
Published: August 2005

AbstractThe monolithic augmentation approach, when applied to the analysis of geothermal reservoirs, results in an unsymmetric coefficient matrix of the combined equations. The computational difficulties experienced with this approach suggest the use of a partitioned solution procedure. For this purpose, the fully coupled first‐order three‐field system of equations is integrated in the time domain by a two‐point recurrence scheme. The resulting time‐discrete algebraic system is then partitioned in such a way that the coefficient matrix remains symmetric. A stability analysis of the partitioned system is also carried out.
The condensation of the boundary element stiffness matrix in FEBEM analysis
Authors: Sharma K. G. , Varadarajan A. , Singh R. B. 
Published: August 2005

AbstractTwo alternatives are discussed to take into consideration symmetry due to shape and loading in the development of the boundary element stiffness matrix. The resulting boundary element stiffness matrix is coupled with the finite element stiffness matrix and the displacements are computed for a circular tunnel. There is a considerable saving in computation time when symmetry is considered by either of the alternatives, but one appears to be preferable to the other.
A note on the imposition of traction boundary conditions when using the FEM for solving incompressible flow problems
Authors: Taylor C. , Rance J. , Medwell J. O. 
Published: August 2005

AbstractA traction boundary condition is particularly useful when analysing flow governed by the Navier–Stokes equation. For a large range of flow situations, such as fully developed laminar flow in a pipe or far field flow, the values of boundary traction can be evaluated explicitly. The former can be readily determined from the local values of the primitive variables, while the latter corresponds to zero traction. A general approach is advocated where traction boundary conditions can be evaluated as part of the solution procedure and its value is not required, a priori, before the solution can proceed. An iterative procedure for the evaluation and imposition of non‐zero tractions on boundaries, where advection is appreciable, is demonstrated by utilizing the finite element method (FEM) to simulate laminar flow, both steady state and transient, rearward of a downstream‐facing step within a bounded domain.
Exact expression for a two‐dimensional finite‐part integral appearing during the numerical solution of crack problems in three‐dimensional elasticity
Authors: Ioakimidis N. I. 
Published: August 2005

AbstractAn exact expression is derived for the finite‐part integral over a triangular domain S, where r denotes the distance of the points of the triangle from one of its vertices and f is a linear function of the Cartesian co‐ordinates. The more general case where r denotes the distance of the points of the triangle from another constant point inside (or outside) the triangle is also studied and numerical results are presented. These integrals appear during the numerical solution of plane crack problems (under constant or variable pressure distribution) in three‐dimensional elasticity. The availability of exact expressions for these integrals will increase the accuracy of the numerical results and, simultaneously, it will permit us not to use cubature formulae over triangular domains for the numerical solution of the previous class of problems.
Shape effect on Morley's element
Authors: Abdalla Hamed , Hassan Kamal 
Published: August 2005

AbstractA quantitative study of shape effect on the constant‐moment plate‐bending element of Morley is presented. The so‐called eccentricity coefficients were used to express in a very simple form the shape functions and the stiffness matrix of this triangular finite element. Eigenvalues of different shapes of triangles were calculated and the results of this study reaffirm the influence of smallest angle of triangle on the numerical deterioration of its properties.
A singly‐iterative second‐order method of characteristics for unsteady compressible one‐dimensional flows
Authors: Flatt R. 
Published: August 2005

AbstractUnsteady compressible and frictional pipe flows in the high subsonic range, especially near the choking condition, are delicate to handle with numerical methods. Even the well‐established first‐order characteristics method may not be accurate enough. This communication describes a procedure based on second‐order interpolations using curved characteristics within each numerical space–time mesh. As only one level of iteration is needed, a considerable amount of computing time can be saved.
Finding polynomial roots: A fast algorithm convergent on the complex plane
Authors: Ivanisov Andrey V. , Polishchuk Vadim K. 
Published: August 2005

AbstractAn algorithm is suggested which performs fast calculations of all the roots of a polynomial with maximal computer accuracy using, as the only primary information, the coefficients and the degree of the polynomial. The algorithm combines global as well as local convergences, i.e. it ensures a rapid hit into a small neighbourhood of a root for 2–3 iterations from any random initial approximation and cubic convergence within the neighbourhood. A modification of the method is given which allows the roots of entire functions to be found. A numerical comparison of the method with commonly used methods (Newton–Raphson, Bairstow–Newton, steepest descent) shows its advantages in speed, accuracy and stability both for real and complex polynomials.
A finite element approximation of the Benard problem
Authors: Krishnan R. 
Published: August 2005

AbstractThe finite element method is used to approximate a solution to the Benard problem. Non‐dimensional heat transfer rates are computed over a range of Rayleigh numbers in three cases: when the upper and lower boundaries are rigid, the upper boundary is free while the lower is rigid, and both upper and lower boundaries are free. In the first case, these values are compared with previously reported numerical work using the finite difference method and with experiments.
The design of shock‐free supercritical airfoils including viscous effects
Authors: Hassan A. A. 
Published: August 2005

AbstractA numerical procedure has been developed for the design of shock‐free supercritical airfoil sections with an allowance for viscous effects, provided the boundary layer is fully attached over the airfoil. The method described combines, in an interative process, an inviscid hodograph‐based inverse‐design algorithm (IDA) developed by the author and the inverse‐boundary layer algorithm (LTBLCEQL) by Miner, Anderson and Lewis. Here, the subcritical portion of the inviscid solution is obtained by solving the full stream function equation in a computational plane which is a conformal map of the two‐sheeted hodograph plane. For the supercritical portion, a characteristics calculation is carried out in the hodograph plane. Viscous effects are then incorporated via the displacement surface concept. A Crank–Nicolson type implicit finite difference scheme is utilized to solve the laminar and turbulent boundary layer equation which are expressed in Levy–Lees variables. A transition model allowing for gradual, rather than instantaneous, transition to turbulent flow is also incorporated. The numerical coupling procedure is applied to the design of two airfoil sections for a range of supercritical Mach numbers.
The application of inverse boundary layer methods to the three‐dimensional viscous design problem
Authors: Lekoudis S. G. , Sankar N. L. , Malone J. B. 
Published: August 2005

AbstractThe problem of designing three‐dimensional configurations with specified skin friction is addressed. For wall flows that are boundary layers, the following procedure is described. The input skin friction is used as a target for an inverse boundary layer calculation. The resulting pressure distribution is used as input to an inviscid configuration design procedure. This procedure computes the body geometry. The procedure is demonstrated by modifying the lift of a wing section, in compressible flow.
A quasi three‐dimensional inverse design method using source and vortex integral equations
Authors: Ribaut M. , Martin D. 
Published: August 2005

AbstractAn integral equation method is presented for the quasi three‐dimensional inverse aerofoil and cascade design. Fluid compressibility and vorticity diffusion are introduced by means of sources resp. distribution functions for the boundary vortices. Application of a Taylor development to the kinematical condition, enlarged by an additional source term, leads to a linear equation system for the profile shape and the channel height. Thus, both the velocity distribution and the profile thickness can be prescribed. Several calculations of aerofoil sections and cascades are presented, which illustrate the accuracy and possibilities of the method.
Temperature fields in simulation of butt‐welding of large plates
Authors: Lindgren Lars‐Erik 
Published: August 2005

AbstractThe simulation of butt‐welding of plates has been performed. Temperature fields were calculated by the use of analytical solutions instead of using the finite element method as was done in Reference 1. The analytical solutions were studied in order to find possible simplifications in the thermal analysis. The thermal material properties were assumed to be independent of temperature in the analytical solutions. The heat flow in the welding direction was neglected in one of these solutions. Three different analytical solutions were studied in the five simulations performed. The mechanical analysis was performed by the finite element method. A thermo‐elastoplastic formulation, considering temperature‐dependent mechanical material properties, was adopted. Volume changes due to phase transformations were also accounted for. Change in gap width in front of the moving arc and residual stresses were calculated in the mechanical analysis. It was found that the temperatures could be calculated from analytical solutions if the residual stresses are of interest. The finite element method should be used to calculate temperatures if the change in gap width is of interest. It was also found that the heat flow along the weld could be neglected even for low welding speeds.
Explicit integration and the isoparametric arch and shell elements
Authors: Crisfield M. A. 
Published: August 2005

AbstractThe paper demonstrates that the standard technique for explicitly integrating the isoparametric degenerate–continuum arch element destroys the strain‐free rigid‐body rotation. It is also shown that this difficulty can be overcome with the aid of Irons's ‘isoparametric shell theory’. Although the developments involve an arch, they are also related to isoparametric shells.
The finite element analysis of homogeneous and laminated composite plates using a simple higher order theory
Authors: Ren J. G. , Hinton E. 
Published: August 2005

AbstractThe higher order shear deformation plate‐bending theory introduced by Reddy and others is used as a basis for the development of two new finite elements. This higher order theory allows a parabolic distribution of transverse shear strains through the plate thickness. Solutions obtained using the new elements are compared with exact closed‐form solutions based on three‐dimensional, first and higher order shear deformation plate bending theories.
Numerical algorithms on the crystal multicomputer
Authors: Meyer R. R. 
Published: August 2005

AbstractThe Crystal multicomputer at the Computer Sciences Department of the University of Wisconsin‐Madison allows the exploration of parallel numerical algorithms by providing a collection of loosely‐coupled minicomputers of substantial computing power (currently, twenty VAX 11/750's) that can exchange data in an efficient manner via messages. Very promising results have already been obtained through through the use of Crystal on nonlinear traffic assignment problems. Additional applications of Crystal are in progress for generalized network flow problems. SOR methods for linear programming, and multigrid methods.
Overhead considerations for parallelizing conjugate gradient
Authors: Seager Mark K. 
Published: August 2005

AbstractA standard preconditioned conjugate gradient (PCG) algorithm for the solution of symmetric linear systems is studied in the context of multi‐processing. It has been observed that the overheads associated with parallel processing can be expensive. Several alternative approaches are taken in order to try to minimize this cost. Examples are given for Cray X‐MP class machines using CRI's standard multitasking library and a new micro‐tasking compiler preprocessor. These approaches to utilizing multiple CPU's are discussed and overhead measurements given. The quite different PCG implementations under multitasking and micro‐tasking are discussed and compared.
Parallelism in finite element modelling
Authors: Carey Graham F. 
Published: August 2005

AbstractParallel processes can be identified at several different levels in the computational simulation of physical processes and problems. We first briefly sketch the main steps involved in modelling physical processes and give examples where inherent parallelism is evident. We then proceed more specifically to describe both inherent and induced parallelism that occur when finite element methods are applied to the solution of boundary and evolution problems, and indicate several opportunitites for parallel processing in finite element analysis.
Element stiffness computation on CDC CYBER 205 computer
Authors: Noor Ahmed K. , Peters Jeanne M. 
Published: August 2005

AbstractAn algorithm is presented for the evaluation of the linear stiffness matrices on the CDC CYBER 205 computer. Discussion is focused on the organization of the computation and the mode of storage of the different arrays to take advantage of CYBER 205 pipeline (streaming) capability. The algorithm is based on partitioning the element stiffness matrix by rows and columns into nodal submatrices and generating simultaneously the coefficients in all the nodal partitions for a group of distinct elements. An assessment is made of the performance of the proposed algorithm for generating the stiffness matrices of shear‐flexible shallow shell elements having 5 degrees of freedom per node. The nomenclature used is given in Appendix II.
Acceleration of vector sequences by multi‐dimensional Δ2 methods
Authors: Macleod Allan J. 
Published: August 2005

AbstractNine different algorithms for the acceleration of vector sequences are considered. All have the property that, in one dimension, they reduce to the standard Aitken Δ2 process. Different rules for deciding when to accelerate are also discussed. Theoretical and practical results show a wide range of performance, but it is shown that certain methods can be recommended for use.
A viscous–inviscid coupling method for the design of low Reynolds number aerofoil sections
Authors: Hassan Ahmed A. 
Published: August 2005

AbstractAn interactive numerical coupling procedure has been developed for the design of aerofoil sections with an allowance for viscous effects, provided that the boundary layer is fully attached over the aerofoil. Special emphasis is given to the design of natural laminar flow (NLF) aerofoils. The method described combines, in an iterative process, an inviscid hodograph‐based inverse‐design algorithm (IDA) developed by the author, the inviscid‐analysis algorithm (FLO6) by Jameson, and the boundary layer algorithm (LTBLCEQL) by Miner, Anderson and Lewis. In the physical plane, the inviscid computational results define an aerofoil configuration (or displacement surface) having a preset trailing edge gap. Viscous effects are then incorporated in the design procedure via the displacement surface concept. As expected, the numerical results suggest that aerofoils having long runs of NLF are easily obtained, provided that the proper choice of the gradients of the prescribed input pressure distribution is made.
High order difference group explicit (HODGE) methods
Authors: Yousif W. S. , Evans D. J. 
Published: August 2005

AbstractPoint iterative methods at which, at any one time, only a single equation of the linear system is treated are well known. However, in recent times block (or line) iterative methods, in which a group of equations (or points on the grid mesh) are treated implicity and solved directly by a specialized algorithm, have become the standard techniques for solving the sparse linear systems derived from the finite difference/element discretization of a self‐adjoint elliptic partial differential equation on a two‐dimensional grid. The main concern of this paper is to construct new groupings of the mesh points of the network into four and nine points using the high order accurate nine‐point finite difference equations and to investigate their advantages when used explicity in the standard iterative methods4,5,6.
On computing eigenvalues of two‐point boundary value problems
Authors: Usmani Riaz A. 
Published: August 2005

AbstractThis paper presents some new finite difference methods for computing eigenvalues of two‐point boundary value problems of the form y″ + λq(x)y = 0, y(a) = y(b) = 0. The approximations Λ for λ are computed from a generalized seven‐band symmetric matrix eigenvalue problem resulting from a suitable discretization of this boundary value problem. The numerical approximations are 0(h4)‐convergent. It is shown that the accuracy of the numerical results can be pushed to 0(h5) and 0(h6), provided that the function q(x) vanishes at x = a and b. Some numerical evidence is included to demonstrate the practical usefulness of the algorithms.
On the numerical solution of the Riccati algebraic matrix equation
Authors: El‐Gindy T. M. , Salim M. S. , Farghaly M. S. 
Published: August 2005

AbstractThe Riccati equation arises in various problems, particularly in practical engineering problems. It is required to solve the resulting Riccati algebraic matrix equation instead of solving the time‐invariant optimal control problem in one of its standard forms. In this paper an unconstrained minimization technique referred to as the Davidon–Fletcher–Powell (DFP) method is used in solving such an equation by minimizing its norm. The positive‐definite solution of the equation is also obtained, which is desirable in most engineering problems.