bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthethic Properties of 4‐Sulfamide Derivatives of 2,5‐Dimethyl‐1‐N‐pyrrole‐3‐carboxylic Acid
Authors: Skorenko A. V. , Kobylinskii D. B. , Kravchenko D. V. , Dorogov M. V. , Balakin K. V. , Blyumina M. V. 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 3‐Alkenyl‐2‐arylchromones and 2,3‐Dialkenylchromones via Acid‐Catalyzed Retro‐Michael Ring Opening of 3‐Acylchroman‐4‐ones.
Authors: Clarke David S. , Gabbutt Christopher D. , Hepworth John D. , Heron B. Mark 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Allylation of Meldrum′s Acids by Allylic Alcohols Using Tetrakis[triphenylphosphine]palladium(0) Catalysts.
Authors: Hou Rei‐Sheu , Wang Huey‐Min , Huang Hsin‐Yu , Chen Ling‐Ching 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Pyrrolo[2,3‐d]pyrimidine‐2,4‐diones by Sunlight Photolysis of N‐(5‐Vinyluracil‐6‐yl)sulfilimines.
Authors: Matsumoto Nobuaki , Takahashi Masahiko 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Microwave Induced Cyclization of α‐Phenylsulfonyl‐enaminoacrylates for the Preparation of 4‐Aryl‐4H‐1,4‐benzothiazine 1,1‐Dioxide Derivatives.
Authors: Lopez Simon E. , Salazar Jose , Rebollo Oscar , Restrepo Jelem 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 1,2,4‐Triazolo[1,5‐d]‐1,2,4‐triazine‐5‐thiones.
Authors: Heravi Majid M. , Montazeri Naser , Rahimizadeh Mohammad , Bakavoli Mehdi , Ghassemzadeh Mitra 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 2‐H‐1,2‐Oxaphosphorin 2‐Oxides via Ag2CO3‐Catalyzed Cyclization of (Z)‐2‐Alken‐4‐ynylphosphonic Monoesters.
Authors: Peng Ai‐Yun , Ding Yi‐Xiang 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Direct, Facile Aldehyde and Ketone α‐Selenenylation Reactions Promoted by L‐Prolinamide and Pyrrolidine Sulfonamide Organocatalysts.
Authors: Wang Jian , Li Hao , Mei Yujiang , Lou Bihshow , Xu Dingguo , Xie Daiqian , Guo Hua , Wang Wei 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Enantioselective Synthesis of (2S)‐α‐(Hydroxymethyl)‐glutamic Acid by the Catalytic Michael Addition of 2‐Naphthalen‐1‐yl‐2‐oxazoline‐4‐carboxylic Acid tert‐Butyl Ester.
Authors: Lee Yeon‐Ju , Lee Jihye , Kim Mi‐Jeong , Jeong Byeong‐Seon , Lee Jeong‐Hee , Kim Taek‐Soo , Lee Jihoon , Ku Jin‐Mo , Jew Sang‐sup , Park Hyeung‐geun 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Structure and Absolute Stereochemistry of Novel C15‐Halogenated Acetogenins from the Anaspidean Mollusc Aplysia dactylomela.
Authors: Manzo Emiliano , Ciavatta M. Letizia , Gavagnin Margherita , Puliti Raffaella , Mollo Ernesto , Guo Yue‐Wei , Mattia Carlo Andrea , Mazzarella Lelio , Cimino Guido 
Published: November 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Palladium‐Catalysed Amination Reactions Using Cobalt‐Containing Bulky Phosphane Ligands
Authors: Lee Jian‐Cheng , Wang Ming‐Gin , Hong Fung‐E. 
Published: November 2005

AbstractAminations of aryl bromides by morpholine have been investigated using palladium complexes as catalyst precursors modified by the cobalt‐containing phosphane ligand [(μ‐PPh2CH2PPh2)Co2(CO)4][μ,η‐PhC≡CP(tBu)2] (1). Reactions were carried out under various conditions with satisfactory results. The components of the optimised reaction conditions consist of 1.0 mmol of aryl bromide, 1.2 equiv. of morpholine, 1.4 equiv. of NaOtBu, 1 mL of toluene and 1 mol‐% of a 1:1 mixture of 1 and Pd(OAc)2. In contrast, related aminations using [(μ‐PPh2CH2PPh2)Co2(CO)4][μ,η‐pyC≡CP(tBu)2] (2), [(μ‐PPh2CH2PPh2)Co2(CO)4][{μ,η‐PhC≡CP(cy)2}] (3) and [(μ‐PPh2CH2PPh2)Co2(CO)4][μ,η‐PhC≡CP(iPr)2] (4) as phosphane ligands do not exhibit comparable efficiency. A novel palladium complex 5, i.e. Pd(OAc) chelated by deprotonated 1 was obtained from the reaction of 1 with Pd(OAc)2. As revealed by the crystal structure, an orthometallation process occurs between the phenyl ring of 1 and the palladium ion. Presumably, the process is accompanied by release of one equivalent of acetic acid. The coordinated acetate ligand binds to the palladium ion in a bidentate chelating mode. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Oxo‐Entity‐Controlled Diastereomer Peculiarity of Rhenium(V) Complexes ReOX2(P~O)py [X = Cl, Br, I; P~O = (OCMe2CMe2O)POCMe2CMe2O(1–); py = pyridine]: Synthesis and Molecular and Crystal Structural Characterization
Authors: Rybak Witold K. , Skarżyńska Anna , Szterenberg Ludmiła , Ciunik Zbigniew , Głowiak Tadeusz 
Published: November 2005

AbstractThe stability of diastereomers of ReOX2(P~O)py complexes determined by the arrangement of the oxo‐entity O=Re(–O~P) is manifested in molecular recognition and crystallization behavior [X = Cl, Br, I; P~O = (OCMe2CMe2O)POCMe2CMe2O(1–); py = pyridine]. With X = Cl and Br both chiral cis [OC‐6–52] and achiral trans [OC‐6–15] complexes can be obtained concomitantly, while for X = I only a trans complex can be afforded. Molecular structures were characterized using NMR IR and UV/Vis spectroscopic methods with the aid of DFT computational analysis and were ultimately corroborated by the single‐crystal X‐ray diffraction method. These analyses revealed that the most stable diastereomers involve an O=Re(–O~P) oxo arrangement in an axial disposition reinforced with a phosphorus ligating atom mutually cis due to extensive π‐bonding both for chiral cis and achiral trans complexes, regardless of whether X = Cl, Br, or I. However, the disparate intramolecular geometry either cis or trans in the solid state results in enantiomorphic crystals related to space group P212121 (X = Cl, Br) or crystals pertinent to the centrosymmetric framework P21/c (X = Cl, Br, I), respectively. Thoughtful analysis of crystal structures reveals a supramolecular architecture due to intermolecular forces involving hydrogen bonding and electric dipole–dipole interactions (among other contact interactions). Thus, chiral cis complexes (X = Cl, Br) show helical crystal packing that succeeds in spontaneous resolution, while trans stereoisomers (X = Cl, Br, I) do not and rather exhibit a zig‐zag supramolecular framework. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Self‐Assembly of an Alkali Metal Cluster Stabilized by a New Flexidentate Metalloligand: Formation and Structure of Heterobimetallic Na–Mo and Cs–Mo 2D Networks
Authors: Khatua Snehadrinarayan , Dasgupta Sohaham , Biradha Kumar , Bhattacharjee Manish 
Published: November 2005

AbstractA new tridentate ligand, {(3,5‐di‐tert‐butyl‐2‐hydroxybenzyl)amino}acetic acid, has been synthesized. This ligand forms [{Na4(H2O)4(μ‐H2O)2}(Mo2O5L2)2] (1), which contains an Na44+ cluster cation stabilized by [LMoO2(μ‐O)MoO2L]2–, upon reaction with Na2MoO4 in aqueous methanol. This compound has been characterized by various spectroscopic techniques and crystallizes in the triclinic space group P$\bar {1}$. Furthermore, compound 1 undergoes smooth exchange of Na+ for Cs+ to give [Cs2(Mo2O5L2)·H2O]n (2) upon treatment with CsCl in aqueous methanol. Similarly, 2 reacts with an excess of NaCl to produce 1. Complex 2 crystallizes in the monoclinic space group C2/c. The crystal structure of this compound reveals that the geometry of the [LMoO2(μ‐O)MoO2L]2– unit stays almost intact but that it stabilizes a polymeric chain of Cs+ cations, unlike in 1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Syntheses, Structure and Intercalation Properties of Low‐Dimensional Phenylphosphonates, A(HO3PC6H5)(H2O3PC6H5) (A = Alkali Metal, NH4 and Tl)
Authors: Rao Koya Prabhakara , Vidyasagar Kanamaluru 
Published: November 2005

AbstractSeven new low‐dimensional phenylphosphonates, A(HO3PC6H5)(H2O3PC6H5) [A = Li (1), Na (2), K (3), Rb (4), Cs (5), NH4 (6) and Tl (7)], have been synthesized and characterized by X‐ray diffraction, spectroscopic and thermal studies. They crystallize in triclinic unit cells with two formula units and have approximately planar arrangement of A+ ions, coordinated to oxygen atoms of phenylphosphonates, on both sides. Compounds 1 and 6 are one‐dimensional, whereas others are two‐dimensional. All of them undergo room‐temperature intercalation reactions with primary n‐alkylamines and ammonia. Single crystal X‐ray structures of compounds 1, 2 and 6 have been determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Access to Tri‐ and Tetracyclic Structures by Thermally Promoted and High‐Pressure‐Promoted [4+2] Cycloadditions of 2‐, 3‐ or 4‐Vinyl‐Substituted Binuclear Heterocycles
Authors: Le Strat Frédéric , Vallette Hélène , Toupet Loïc , Maddaluno Jacques 
Published: November 2005

AbstractA set of 3‐(2‐alkoxyvinyl)benzofurans, ‐furopyridines and‐indoles 5–8 have been tested in [4+2] cycloaddition reactions. The results indicate that they all behave as good dienes, even with only moderately activated dienophiles such as acrylates or MVK. The endo/exo selectivity observed in the adducts depends on the activation conditions: in general, thermal conditions tend to favour the exo isomers, while high pressures preferentially provide the endo isomers. Only the (E) isomers of these dienes proved reactive, the (Z) isomers generally being recovered unaltered. The [4.4.0] binuclear heterocycles such as the isochromene compound 13 and the isoquinolinones 14–16 tested here proved to be significantly less reactive. Finally, the resulting tricyclic adducts 19 were engaged in ene reactions with NPM. Additions involving solely the endo isomers of these adducts took place, stereoselectively affording the succinimide derivatives 29, although in low yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Free surface flow during the filling of a cylinder
Authors: Abdullah Z. , Salcudean M. 
Published: November 2005

AbstractA technique is proposed to model flows with free surfaces using the control volume method. The free surface is tracked by determining the locations of the ambient pressure in the domain. Special conditions are imposed on the nodes in the vicinity of the free surface. Flow visualization experiments are carried out to determine the free surface shapes and velocity distributions during the filling of a cylindrical container with water. Computations are carried out to model the flow in the experimental test case using a mesh transformation and the free surface treatment. The proposed free surface treatment yields results of better accuracy as compared with the results using the free slip condition. The predicted locations and heights of the spout are reasonable.
The effect of using non‐orthogonal boundary‐fitted grids for solving the shallow water equations
Authors: Nielsen Per , Skovgaard Ove 
Published: November 2005

AbstractThe purpose of this paper is to examine the effects of using non‐orthogonal boundary‐fitted grids for the numerical solution of the shallow water equations. Two geometries with well known analytical solutions are introduced in order to investigate the accuracy of the numerical solutions. The results verify that a reasonable departure from orthogonality can be allowed when the rate of change of cell areas is kept sufficiently small (i.e. it is not necessary to create a strictly orthogonal grid when the grid is sufficiently smooth).
Simple test calculations concerning finite element applications to numerical weather prediction
Authors: Steppeler J. 
Published: November 2005

AbstractDifferent finite element schemes are investigated with respect to their application in numerical weather prediction. Different methods of staggering of variables are considered. The tests concern the accuracy of a Rossby wave prediction and the generation of noise in a geostrophic adjustment process. Theoretical results concerning the noise level of different schemes are confirmed by computations with a one‐dimensional model. Favourable results were obtained by hybrid schemes, using different Galerkin treatments for different terms of the dynamic equations.
A comprehensive analysis of the viscous incompressible flow in quasi‐three‐dimensional aerofoil cascades
Authors: Baskharone E. A. , McArthur D. R. 
Published: November 2005

AbstractA rigorous model of the fully elliptic flow over the blade‐to‐blade stream surface in an annular aerofoil cascade is developed. The model accuracy stems from its precise simulation of the meridional hub‐to‐casing flow effects, including those of the shear stress components that are created by the spanwise velocity gradients. These stresses are unprecedentedly introduced in the flow‐governing equations in the form of source terms and are modelled as such. The final set of flow‐governing equations are solved using the Galerkin weighted residual method coupled with a biquadratic finite element of the Lagrangian type. The flow solution is verified against the numerical results of a fully three‐dimensional flow model and a set of experimental data, both concerning a low‐aspect‐ratio stator of an axial flow turbine under a low Reynolds number and subsonic flow operation mode. The numerical results in this case show well predicted aerofoil loading and pitch‐averaged exit flow conditions. Also evident is a substantial capability of the analysis in modelling such critical regions as the wake subdomain. It is further proven that the new terms in the governing equations enhance the quality of the numerical predictions in this class of flow problems.
On the theory of semi‐implicit projection methods for viscous incompressible flow and its implementation via a finite element method that also introduces a nearly consistent mass matrix. Part 1: Theory
Authors: Gresho Philip M. 
Published: November 2005

AbstractEver since the time of Chorin's classic 1968 paper on projection methods, there have been lingering and poorly understood issues related to the best—or even proper or appropriate—boundary conditions (BCs) that should be (or could be) applied to the ‘intermediate’ velocity when the viscous terms in the incompressible Navier–Stokes equations are treated with an implicit time integration method and a Poisson equation is solved as part of a ‘time step’. These issues also pervade all related methods that uncouple the equations by ‘splitting’ the pressure computation from that of the velocity—at least in the presence of solid boundaries and (again) when implicit treatment of the viscous terms is employed. This paper is intended to clarify these issues by showing which intermediate BCs are ‘best’ and why some that are not work well anyway. In particular we show that all intermediate BCs must cause problems related to the regularity of the solution near boundaries, but that a near‐miraculous recovery occurs such that accurate results are nevertheless achieved beyond the spurious boundary layer introduced by such methods. The mechanism for this ‘miracle’ is related to the existence of a higher‐order equation that is actually satisfied by the pressure. All that is required then for projection (splitting, fractional step, etc.) methods to work well is that the spurious boundary layer be thin—as has been largely observed in practice.
Finite element analysis of confined turbulent swirling flows
Authors: Benim A. C. 
Published: November 2005

AbstractThe finite element method is applied to incompressible and statistically steady confined turbulent swirling flows. A velocity–pressure formulation is employed. The momentum and continuity equations are solved using a segregated algorithm. Two turbulence models, namely the standard κ–ε model and the algebraic stress model, are considered. It is shown that the algebraic stress model leads to significantly more accurate results in swirling flows compared to the κ–ε model. A novel way of implementing the algebraic stress model is presented in which the stresses are coupled to the Navier–Stokes equations in such a way that they ‘correct’ the effective viscosity hypothesis. This formulation seems to provide a convenient approach for finite elements. In deriving the discretization equations, a streamline‐upwind/Petrov–Galerkin method is employed. Comparisons performed between various upwind schemes show that the numerical solution may be substantially affected by the particular upwind procedure used. The analysis is extended to the prediction of particle motion in turbulent swirling flow fields. Here the fluid turbulence is modelled adopting a stochastic approach. The influence of turbulence modelling on particle movement is investigated.
Uncoupled finite element solution of biharmonic problems for vector potentials
Authors: Ruas V. , Quartapelle L. 
Published: November 2005

AbstractA method for the uncoupled solution of three‐dimensional biharmonic problems for the vector potential in viscous incompressible flow is presented. The strategy applied in a previous work on vector Poisson equations is employed to reduce the vector fourth‐order problem to a sequence of scalar biharmonic problems. A finite element aimed at the implementation of the method in a discrete version is considered. A conjugate gradient algorithm which is particularly efficient for the uncoupled solution method is also described.
Discretization of incompressible vorticity–velocity equations on triangular meshes
Authors: Choudhury Shenaz , Nicolaides R. A. 
Published: November 2005

AbstractThis paper describes a new approach to discretizing first‐ and second‐order partial differential equations. It combines the advantages of finite elements and finite differences in having both unstructured (triangular/tetrahedral) meshes and low‐order physically intuitive schemes. In this ‘co‐volume’ framework, the discretized gradient, divergence, curl, (scalar) Laplacian, and vector Laplacian operators satisfy relationships found in standard vector field theory, such as a Helmholtz decomposition. This article focuses on the vorticity–velocity formulation for planar incompressible flows. The algorithm is described and some supporting numerical evidence is provided.
Open boundary condition symposium benchmark solution: Stratified flow over a backward‐facing step
Authors: Leone John M. 
Published: November 2005

AbstractThis paper presents a detailed numerical solution to a simplified version of two‐dimensional stratified flow over a backward‐facing step with a Froude number of 16/9, a Reynolds number of 800 and a Prandtl number of 1—one of the Open Boundary Condition Symposium test problems. The steady state solution was derived by integrating the time‐dependent Boussinesq equations forward in time using a semi‐implicit finite‐element‐based model on a 38400‐element mesh. In addition to presenting the results derived on this grid, the paper also presents the results of a Richardson extrapolation calculation for a set of ‘key’ parameters. It is hoped that this solution can be used as a baseline to compare the performance of the various techniques discussed at the Open Boundary Condition Symposium.
An efficient algorithm for strain history tracking in finite element computations of non‐Newtonian fluids with integral constitutive equations
Authors: Luo X.‐L. , Mitsoulis E. 
Published: November 2005

AbstractA new finite element technique has been developed for employing integral‐type constitutive equations in non‐Newtonian flow simulations. The present method uses conventional quadrilateral elements for the interpolation of velocity components, so that it can conveniently handle viscoelastic flows with both open and closed streamlines (recirculating regions). A Picard iteration scheme with either flow rate or elasticity increment is used to treat the non‐Newtonian stresses as pseudo‐body forces, and an efficient and consistent predictor‐corrector scheme is adopted for both the particle‐tracking and strain tensor calculations. The new method has been used to simulate entry flows of polymer melts in circular abrupt contractions using the K‐BKZ integral constitutive model. Results are in very good agreement with existing numerical data. The important question of mesh refinement and convergence for integral models in complex flow at high flow rate has also been addressed, and satisfactory convergence and mesh‐independent results are obtained. In addition, the present method is relatively inexpensive and in the meantime can reach higher elasticity levels without numerical instability, compared with the best available similar calculations in the literature.
An upwind scheme for the three‐dimensional boundary layer equations
Authors: Johnston L. J. 
Published: November 2005

AbstractThe development of a calculation method to solve the compressible, three‐dimensional, turbulent boundary layer equations is described. An implicit finite difference solution procedure is adopted involving local upwinding of convective transport terms. A consistent approach to discretization and linearization is taken by casting all equations in a similar form. The implementation of algebraic, one‐equation and two‐equation turbulence models is described. An initial validation of the method is made by comparing prediction with measurements in two quasi‐three‐dimensional boundary layer flows. Some of the more obvious deficiencies in current turbulence‐modelling standards for three‐dimensional flows are discussed.
Three‐dimensional adaptive finite element computations and applications to non‐Newtonian fluids
Authors: Dannelongue H. H. , Tanguy P. A. 
Published: November 2005

AbstractAn adaptive strategy for the finite element solution of three‐dimensional viscous flow problems is defined and implemented. The solution strategy is based on an advancing front mesh generator making use of binary data structures for fast geometrical data handling. The error is estimated a posteriori with a residual‐type bound. The error estimate is shown to exhibit proper convergence for tetrahedral elements. Its combination with the mesh generator and an interpolation scheme for unstructured meshes is shown to generate adaptive meshes and to reduce the solution cost for a given error level, as illustrated by the isothermal flow of a shear‐thinning fluid.
Transonic viscous‐inviscid interaction by a finite element method
Authors: Hafez M. M. , Habashi W. G. , Przybytkowski S. M. 
Published: November 2005

AbstractA method is outlined for solving two‐dimensional transonic viscous flow problems, in which the velocity vector is split into the gradient of a potential and a rotational component. The approach takes advantage of the fact that for high‐Reynolds‐number flows the viscous terms of the Navier‐Stokes equations are important only in a thin shear layer and therefore solution of the full equations may not be needed everywhere. Most of the flow can be considered inviscid and, neglecting the entropy and vorticity effects, a potential model is a good approximation in the flow core. The rotational part of the flow can then be calculated by solution of the potential, streamfunction and vorticity transport equations. Implementation of the no‐slip and no‐penetration boundary conditions at the walls provides a simple mechanism for the interaction between the viscous and inviscid solutions and no extra coupling procedures are needed. Results are presented for turbulent transonic internal choked flows.