bluuebunny/crossref_metadata_2025_split huggingface dataset:
A component decomposition preconditioning for 3D stress analysis problems
Authors: Mihajlović M. D. , Mijalković S. 
Published: October 2002

AbstractA preconditioning methodology for an iterative solution of discrete stress analysis problems based on a space decomposition and subspace correction framework is analysed in this paper. The principle idea of our approach is a decomposition of a global discrete system into the series of subproblems each of which correspond to the different Cartesian co‐ordinates of the solution (displacement) vector. This enables us to treat the matrix subproblems in a segregated way. A host of well‐established scalar solvers can be employed for the solution of subproblems. In this paper we constrain ourselves to an approximate solution using the scalar algebraic multigrid (AMG) solver, while the subspace correction is performed either in block diagonal (Jacobi) or block lower triangular (Gauss–Seidel) fashion. The preconditioning methodology is justified theoretically for the case of the block‐diagonal preconditioner using Korn's inequality for estimating the ratio between the extremal eigenvalues of a preconditioned matrix. The effectiveness of the AMG‐based preconditioner is tested on stress analysis 3D model problems that arise in microfabrication technology. The numerical results, which are in accordance with theoretical predictions, clearly demonstrate the superiority of a component decomposition AMG preconditioner over the standard ILU preconditioner, even for the problems with a relatively small number of degrees of freedom. Copyright © 2002 John Wiley & Sons, Ltd.
An investigation of historical and archaeological evidence for age‐related bone loss and osteoporosis
Authors: Brickley Megan 
Published: October 2002

AbstractA growing awareness of the problems caused by osteoporosis‐related fractures has led to increased investigation of the condition in past populations. The present study seeks to examine the ways in which osteoporosis‐related fractures may be explored through different approaches; modern clinical information, historical records of fractures and analysis of archaeological bone may provide fuller information on the condition. The three types of fractures upon which this study focuses are fractures of the femoral neck, Colles' fractures and vertebral compression fractures. The results of the investigation clearly demonstrate the way in which the various sources produce a slightly different picture of the condition. The archaeological significance of the different types of fractures was found to be the reverse of that which would be suspected in the light of information derived from historical sources and the clinical literature. To date vertebral crush fractures have been the most commonly found osteoporosis‐related fracture in archaeological material, but their significance to people in the past is likely to have been minimal. In contrast hip fractures have rarely been reported from archaeological bone material, but historical information makes it clear they were well known, and knowledge derived from clinical sources emphasizes the serious consequences of such a fracture for the affected individuals. The results indicate the value of undertaking a multi‐disciplinary approach where possible. Copyright © 2002 John Wiley & Sons, Ltd.
Public management and organizational performance: The effect of managerial quality
Authors: Meier Kenneth J. , O'Toole Laurence J. 
Published: October 2002

AbstractThis paper presents the first large study of public management quality and its effect on program performance.
Using 5 years of data from more than 1000 Texas school districts, the authors measure quality as the additional
salary paid to school superintendents over and above the normal determinants of salary. This measure of managerial
quality is positively correlated with 10 of 11 performance indicators covering organizational goals ranging from
standardized tests to school attendance. These relationships hold even in the presence of controls for other
determinants of program success. The measure has the potential to be used in tests of existing management theories,
thus moving the literature beyond case studies to more systematic research involving many subjects. © 2002 by
the Association for Public Policy and Analysis and Management.
Use of calcium channel blockers as antihypertensives in relation to mortality and cancer incidence: a population‐based observational study
Authors: Lindberg Gunnar , Lindblad Ulf , Löw‐Larsen Bent , Merlo Juan , Melander Arne , Råstam Lennart 
Published: October 2002

AbstractPurposeTreatment with blood pressure lowering drugs may reduce morbidity and mortality. However, the efficacy and effectiveness may differ between antihypertensive agents. The current investigation aimed to compare mortality and cancer incidence in hypertensive patients treated with calcium channel blockers (CCB) or with other antihypertensive drugs (AHD).MethodsAll patients in two outpatient clinics treated with AHD who underwent an annual check‐up during 1989 or 1990 were selected. Fatal events were identified through 1997 and incident cancers through 1998.ResultsTwo hundred and fourteen patients on CCB and 1029 on other AHD were identified. Overall mortality and the combined mortality from myocardial infarction and stroke were higher in CCB users; hazard ratios adjusted for sex, age, co‐morbidity and other and risk factors were 1.84 (95% CI 1.25–2.72) and 2.37 (95% CI 1.27–4.44), respectively. The risk estimates for cancer mortality and for cancer incidence did not differ significantly.ConclusionsResults from clinical trials as well as observational studies, including the present one, indicate a higher mortality risk and a higher cardiovascular morbidity risk associated with use of CCB. Accordingly, CCB should not be regarded as first line drugs in hypertension. Copyright © 2002 John Wiley & Sons, Ltd.
Calcium channel blockers and myocardial infarction: a case–control study in a Japanese hospital
Authors: Ohyama Yoshiharu , Funao Kazuhiro , Kawabe Eri , Hayashi Doubun , Yamazaki Tsutomu , Iga Tatsuji , Koide Daisuke , Ohe Kazuhiko , Kubota Kiyoshi 
Published: October 2002

AbstractPurposeTo examine the relationship of the use of calcium channel blockers (CCBs) in hypertensive patients to myocardial infarction in Japan, where CCBs are prescribed much more frequently than in Europe and America.DesignWe conducted a nested case–control study using a hospital information system in Japan.SubjectsCases were hypertensive patients who were repeat visitors to Tokyo University Hospital as of April 1996 and had an incidence of fatal or non‐fatal myocardial infarction between 1996 and 1999. Controls were hypertensive patients individually matched to cases by sex, age and history of angina pectoris.ResultsThe study consisted of 16 cases, who were matched to 80 controls. Of the 80 control patients, 54 (68%) received CCBs. On the other hand, all but one of 16 cases received CCBs and the crude odds ratio of myocardial infarction associated with the use of calcium channel blockers was as high as 7.0 (0.9–55.3). The odds ratio was reduced to 4.9 (0.6–42.4) when adjusted by diabetes and diastolic blood pressure.ConclusionsAlthough the crude odds ratio of myocardial infarction associated with CCBs was high, the ratio was reduced when adjusted by known confounding factors, suggesting a mechanism of confounding by indication. In addition, the results obtained in this study using records from a single hospital should not be generalized. Copyright © 2002 John Wiley & Sons, Ltd.
Precipitation polymerization of aniline in the presence of water‐soluble organic acids
Authors: Laska Jadwiga , Widlarz Joanna , Woźny Ewa 
Published: October 2002

AbstractThe precipitation polymerization of aniline in the presence of organic acids, including toluene‐4‐sulfonic acid, phenylphosphonic acid, 4‐aminophenylphosphonic acid, and acetophosphonic acid, led in one step to conductive polyaniline. The polyaniline showed very good affinity for water and was easily modified to be water‐soluble. In comparison with the widely studied postpolymerization of doped polyaniline, this reaction allowed reasonably good conductivity to be achieved at a lower acid/polyaniline ratio. Moreover, the easy in situ incorporation of the dopant into the polymer structure caused high stability of the created salt; that is, no dedoping was observed after it was washed with water, methanol, or other solvents. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3562–3569, 2002
Penultimate unit effects in the free‐radical copolymerization of styrene with acrylonitrile according to theoretical thermochemistry
Authors: Cieplak Piotr , Megiel Elżbieta , Kaim Andrzej 
Published: October 2002

AbstractPenultimate unit effects in the free‐radical copolymerization of styrene with acrylonitrile were investigated by the consideration of the theoretical thermochemistry of three subsequent propagation steps in the copolymerization process at 298 K and the electronic properties of the relevant reactants. The total energies, zero‐point energies incorporating a 0.96 scale factor, and thermal enthalpy corrections for all optimized structures were computed with the B3LYP density functional theory and the 6‐311G(d,p) basis set. The penultimate unit effect on the enthalpy of reaction for elementary propagation reactions ranged from −1.2 to 2.7 kcal/mol. The enthalpies of elementary copolymerization propagation reactions showed that penultimate unit effects depended not only on the γ substituent itself but also on the terminal unit of the growing radical and the monomer being attached. The exothermicity of the addition of radicals, varying in the penultimate unit for a given monomer, was lower for more polar radicals and smaller Mulliken charges at the radical atom, except for radicals with a CN substituent placed in the γ position when they reacted with acrylonitrile. For the latter system, the repulsive interactions between the CN substituent and nitrile group of the monomer being added contributed to the reaction enthalpy. Almost no penultimate unit effect was detected upon spin distribution at the radical atom, and this probably indicated the absence of the independent implicit penultimate model. The results obtained strengthen the concept of the inseparability of implicit and explicit penultimate unit effects in radical copolymerization. However, it appears that for the styrene–acrylonitrile copolymerization system, the explicit penultimate model prevails over the implicit penultimate model. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3592–3603, 2002
Influence of jacket tightness and pressure on raised lung volume forced expiratory maneuvers in infants
Authors: Lum Sooky , Hoo Ah‐Fong , Stocks Janet 
Published: October 2002

AbstractWhile the use of the raised volume rapid thoraco‐abdominal compression (RVRTC) technique has been shown to provide new insights into airway and pulmonary pathophysiology in infants, and appears to resemble the spirometric techniques used in older subjects, there is as yet no consensus regarding measurement procedures, which are known to vary considerably between laboratories (Gappa [1999] Pediatr Pulmonol 28:391–393). The aims of this study were to assess the effects of tightness of jacket fit, the efficiency with which pressure is transmitted from the jacket to the intrathoracic airways, and the effect of jacket pressure on parameters derived from the RVRTC technique. Paired forced expiratory maneuvers were performed in 20 infants with the jacket snugly or loosely wrapped around the infant's torso, and in a further 21 infants using “optimal” or a higher jacket pressure (Pj) (1–2 kPa above “optimal” Pj).When either a loosened jacket or a higher than “optimal” Pj was used, forced expired flow at low lung volumes (FEF75) was significantly reduced by, on average, 8% and 7%, respectively. There were, however, minimal changes in forced vital capacity (FVC) or forced expired volume in 0.4 sec (FEV0.4). The observed changes may have been due to the increased pressure transmitted to the intrathoracic structures under these experimental conditions, and emphasize the need to assess optimal jacket pressure within each infant when using the RVRTC technique. In addition, when using a loosened jacket or a higher than “optimal” Pj, chest wall and upper airway reflexes such as glottic closure, peripheral airway closure, and negative flow dependence were more evident. Pediatr Pulmonol. 2002; 34:361–368. © 2002 Wiley‐Liss, Inc.
Hemoptysis following blunt trauma: Case report
Authors: Norrashidah A.W. , Henry R.L. , Hartman S. 
Published: October 2002

AbstractA 9‐year‐old boy developed significant hemoptysis and pulmonary parenchymal injury following blunt trauma. There was delayed development of hemoptysis following chest injury, and the trauma did not produce any evidence of external body injury. Pediatr Pulmonol. 2002; 34:395–397. © 2002 Wiley‐Liss, Inc.
Pulmonary alveolar microlithiasis in childhood: Clinical and radiological follow‐up
Authors: Jankovic Stipan , Pavlov Neven , Ivkosic Ante , Erceg Ivana , Glavina‐Durdov Meri , Tocilj Jadranka , Dragisic‐Ivulic Slavica , Primorac Dragan 
Published: October 2002

AbstractThis report describes a case of pulmonary alveolar microlithiasis that was diagnosed in an 8.5‐year‐old girl by high‐resolution computed tomography (CT) and open lung biopsy. Presence of symptoms (productive cough, fever), their periodic occurrence (lasting up to 1 week), and comparatively long asymptomatic periods should be emphasized. Despite extensive X‐ray abnormalities, tests of pulmonary interstitium involvement and exercise tests revealed normal results. A therapeutic regimen, including disodium etidronate, was administered for 18 months with no significant clinical or radiological improvement. Pediatr Pulmonol. 2002; 34:384–387. © 2002 Wiley‐Liss, Inc.
Photocatalytic degradation of pesticides and bio‐molecules in water
Authors: Muszkat Lea , Feigelson Leonid , Bir Lena , Muszkat Karol A 
Published: October 2002

AbstractTwo approaches are suggested for the acceleration of the photocatalytic oxidation of organic contaminants of water: acceleration by oxidants and photo‐enhancement by dyes. These processes were examined with several substances: two widely applied herbicides, bromacil (a uracil) and metribuzin (a triazine), and three proteins, studied as models of biocontaminated waters. The effects of oxygen and hydrogen peroxide indicated two different reaction patterns of photo‐oxidation of the herbicides. With metribuzin, oxygen had a pronounced effect on the rate of photo‐oxidation, while the influence of hydrogen peroxide was quite moderate; with bromacil, oxygen had a limited effect on the rate of photo‐oxidation, which however was considerably enhanced by hydrogen peroxide. Acceleration of the photo‐catalytic oxidation of colourless refractory contaminants by photo‐excited dye was observed. Both UV and visible light were required for the enhanced decomposition. The mechanism of the reaction seems to involve a combination of oxidation by hydroxyl radicals, via the hole‐electron semiconductor route, with subsequent oxidation of photo‐intermediates by singlet oxygen formed by dye sensitization. The TiO2‐photocatalyzed oxidation of proteins (albumin, ovalbumin and gamma‐globulin) showed the susceptibility of proteins to photocleavage and of the amino acids to photocatalytic degradation. Tyrosine was the most sensitive, while the degradation of the aliphatic amino acids Gly and Asp was slow.© 2002 Society of Chemical Industry
Generalized non‐stationary preventive maintenance model for deteriorating repairable systems
Authors: Kobbacy K. A. H. , Jeon J. 
Published: October 2002

AbstractThis paper deals with a practical approach for the analysis and modelling of preventive maintenance (PM) data for repairable systems which have an increasing failure frequency and/or increasing severity. The concept and testing for the trend of severity of corrective work (CO) and PM are discussed. A framework for statistical analysis of interarrival times and downtimes due to CO/PM is proposed. A generalized non‐stationary model for scheduling PM to maximize availability is suggested. The effect of severity on scheduling PM activities is shown through sensitivity analysis. Copyright © 2002 John Wiley & Sons, Ltd.
Structure and electronic properties of cyanothiophene derivatives: A theoretical ab initio and DFT study*
Authors: De Oliveira Marcos A. , Dos Santos Hélio F. , De Almeida Wagner B. 
Published: October 2002

AbstractOligotiophenes derivatives present potential applicability for the construction of electronic devices. In this work we analyzed the structure–property relationship for a class of cyanothiophene compounds using ab initio [Hartree–Fock (HF) and second‐order Møller–Plesset (MP2)] and density functional theory (DFT) theoretical approaches. The energy gap between the valence and conduction bands was evaluated using distinct methodologies, being the results compared with experimental data. At the DFT level using the HF optimized geometries (DFT//HF) the average deviation was 0.22 eV (SVWN//HF) and 0.23 eV (BLYP//HF). The results from the configuration interaction implemented in the semiempirical ZINDO/S‐CI program were also in good agreement with experiment, being the average deviation found to be 0.20 eV when the HF optimized geometries were used. In general, the energy gap for the cyanothiophene derivatives was lower than the values for the unsubstituted parent compounds, showing that these molecules should be considered as a good prototype to develop new organic conductor polymers. We believe this study may be useful to predict electronic properties that are related with the conductivity of organic materials. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Harmonic oscillator basis functions and Gaussian model potentials for the analysis of anharmonic vibrations*
Authors: Schmidt P. P. 
Published: October 2002

AbstractPotential energy surfaces are mapped onto expansions in Gaussian basis functions in order to examine vibrational anharmonicity in molecules; the Gaussian expansions are constructed to take many‐body effects into account. Subsequent quantum mechanical analyses using harmonic oscillator basis sets are carried out. The appropriate matrix elements needed for the analyses follow using Talmi transformations and several standard integrals involving harmonic oscillator basis functions. Local anharmonicity can be explored with relatively modest expansions of the potential energy surfaces. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Energy levels of the 4s24p2 states of germanium and germaniumlike ions
Authors: Ishikawa Yasuyuki , Vilkas Marius J. 
Published: October 2002

AbstractRelativistic multireference Møller–Plesset second‐order perturbation theory calculations have been performed for the ground and low‐lying excited states of the 4s24p2 configuration in germanium and germaniumlike ions, As1+, Se2+, Br3+, and Kr4+. The method is efficient and good agreement with experiment is obtained. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Two‐center exchange interactions in rare earth doped materials
Authors: Smentek Lidia 
Published: October 2002

AbstractTwo‐center exchange interactions between rare earth ion and ligands are taken into account as a source of new contributions to the energy transfer resulting in sensitized luminescence. The consequences of the exchange of two electrons are described in an algebraic form by the so‐called Dirac's identity after prior transformation of the radial functions localized on ligand to the coordinate frame of the central ion. This procedure enables one to use for the description of electrostatic interactions a simple multipole one‐center expansion. The energy transfer amplitude is defined within the free ionic system approximation adopted for the rare earth ion, and its value is modified in a perturbative way by the contributions caused by the influence of crystal field potential produced by the surrounding ligands. The general expressions are defined in the terms of double tensor operators that determine isotropic and anisotropic parts, symmetric and antisymmetric ones. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Relations between Pariser–Parr–Pople and Heisenberg models
Authors: Karwowski Jacek , Flocke Norbert 
Published: October 2002

AbstractNecessary conditions under which the lowest‐energy states obtained as exact (full configuration interation) solutions of the Pariser–Parr–Pople (PPP) model may be interpreted in terms of the Heisenberg model are analyzed. In particular, for a set of model lattices the range of empirical parameters in which the lowest part of the PPP spectrum corresponds to the covalent states has been determined. It has been demonstrated that the energy gap between the lowest ionic and the highest covalent states of the PPP model, as a function of empirical parameters and of the geometric structure of the lattice, behaves in a specific and regular way. The results may be useful for determining limits of applicability of the Heisenberg model and for further studies aimed at a construction of an effective, Heisenberg‐type Hamiltonian that could reproduce the lowest part of the PPP spectrum. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Fast convergent approach for computing atomic resonances
Authors: Bednarz Eugeniusz , Bylicki Mirosław 
Published: October 2002

AbstractThe complex eigenvalue Schrödinger equation (CESE) method, involving complex rotation of coordinates, and expansions correlated by explicit dependence on interelectronic distances, both proven separately to be efficient tools for, respectively, resonance and many‐electron state computations, are combined. Test computations performed for the well known 2s2 1S helium resonance show that this explicitly correlated complex eigenvalue Schrödinger equation (ECCESE) approach is more efficient than CESE within an orbital‐based expansion and the complex coordinate rotation with an explicitly correlated basis. The results of ECCESE converge very fast with respect to the size of expansion and are very stable with respect to the complex rotation parameter. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
N‐H· · ·F improper blue‐shifting H‐bond
Authors: Hobza Pavel 
Published: October 2002

AbstractThe MP2/6‐31G** calculations reveal a different pattern of H‐bonding in F2NH· · ·Y (Y = FH, OH2, NH2) complexes. Whereas the blue‐shifted H‐bonding was found for F2NH· · ·FH complex (the first known case of NH· · ·Y improper blue‐shifting H‐bonding), standard H‐bonding exists for F2NH· · ·OH2and F2NH· · ·NH3complexes. A different character of H‐bonding is explained by natural bond orbital analysis showing a systematic increase of electron density in the σ* antibonding orbital of the NH bond as well as in the lone‐electron pairs of fluorine atoms of proton the acceptor. Whereas the former effect leads to elongation of the NH bond and a red shift of NH stretch frequency, the latter effect gives the opposite, that is, contraction of the NH bond and a blue shift of NH stretch frequency. Existence of a red‐ or blue‐shifted H‐bonding is explained by the dominance of the former or latter effect. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Four‐ and 8‐reference state‐specific Brillouin–Wigner coupled‐cluster method: Study of the singlet oxygen
Authors: Pittner Jiří , Čársky Petr , Hubač Ivan 
Published: October 2002

AbstractWe developed and implemented the state‐specific Brillouin–Wigner coupled‐cluster theory restricted to single and double excitations (BWCCSD) method for a general number of closed‐ and open‐shell reference configurations. The method (together with the previously suggested a posteriori size‐extensivity correction) is applied to the calculation of oxygen molecule in the X3Σ, a1Δg, and b1Σ states, and results of this multireference treatment are compared with those obtained by the DIP STEOMCCSD and multireference (MR)‐CISD methods and with experimental spectroscopic data. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002