bluuebunny/crossref_metadata_2025 huggingface dataset:
An investigation of historical and archaeological evidence for age‐related bone loss and osteoporosis
Authors: Brickley Megan
Published: October 2002

A 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

This 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.
Electronically conductive polymers
Authors: Jagur‐Grodzinski Joseph
Published: October 2002

A concise review of papers published during the last 3 years about the synthesis, blends, processing, and applications of electronically conductive polymers, is presented in this article. Copyright © 2002 John Wiley & Sons, Ltd.
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

Purpose

Treatment 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).

Methods

All 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.

Results

Two 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.

Conclusions

Results 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

Purpose

To 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.

Design

We conducted a nested case–control study using a hospital information system in Japan.

Subjects

Cases 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.

Results

The 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.

Conclusions

Although 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

The 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

Penultimate 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

While 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

A 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

This 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

Two 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

This 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

Oligotiophenes 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

Potential 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

Relativistic 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

Two‐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

Necessary 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

The 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

The 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

We 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
Evaluation of quantum mechanical perturbative sums in terms of quadratic surds and their use in the approximation of ζ(3)/π3
Authors: Bracken Paul , Čížek Jiri
Published: October 2002

The first correction to the energy using Rayleigh–Schrödinger perturbation theory is calculated for the ground state of the one‐dimensional Hubbard model. An algebraic technique is developed which can be used to evaluate these perturbative sums such that the final result is expressed as a finite linear combination of the elements which occur in the individual terms of the sum. The first nontrivial correction to the energy for the ground state of the one‐dimensional Hubbard model in closed form is evaluated. A number theoretic application of this calculation will be given, which is related to the Euclidean construction of regular polygons inside the circle. It is shown that ζ(3) can be approximated by a product of nested radicals and rational constants, multiplied by π3, much in the same way that ζ(2) was expressed by Euler as a product of rational numbers and π2. It is discussed how this analysis can be continued to higher orders in perturbation theory such that ζ(2m+1) is obtained as a multiple of π2m+1 and nested radicals. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Structure and self‐energy of the electron
Authors: Blinder S. M.
Published: October 2002

The region very close to an electron (r≲r0=e2/mc2≈2.8×10−13 cm) is, according to quantum electrodynamics, a seething maelstrom of virtual electron–positron pairs flashing in and out of existence. To take account of this well‐established physical reality, a phenomenological representation for vacuum polarization is introduced into the framework of classical electrodynamics. Such a model enables a consistent picture of classical point charges with finite electromagnetic self‐energy. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Polarization potential for e‐argon scattering by differential scattering minimization at intermediate energies
Authors: Paikeday Joseph M. , Alexander Jason
Published: October 2002

The differential scattering cross section (DCS) for electrons scattered elastically by argon atoms is studied using a model potential. In the present study the long range polarization potential is represented by an energy‐dependent function in the form Vp(E,r)=αd/[r+ξ(a,b,E)]4 and the short range part is constructed from the nonrelativistic Hartree–Fock wave function of the target atom in the form Vs(r)=(2Z/r)∑nCnexp {−nC0r}. Accurate phase shifts have been computed for angular momentum in the range 0<ℓ<13 from the Schrödinger equation and the Born approximation for higher values of ℓ<1000. The computed differential cross section obtained using the approximate effective interaction potential for electrons scattered by the target atoms in their ground state is compared with available published results. In the present study the parameters contained in the energy‐dependent polarization potential are determined by the minimization of the DCS with respect to angle θ and the incident energy of E. The critical values of angle and energy (θc,Ec) are found to be (117.3°, 120.0 eV), (64.1°, 41.3 eV), and (140.1°, 37.3 eV). The resulting DCS in the angular range 2°<θ<178° is found to be an improvement over earlier results and in better agreement with the available experimental data in the intermediate energy range. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Recurrent generation of approximate functionals in density functional theory*
Authors: Liu Shubin
Published: October 2002

The idea of recurrent generation of approximate exchange–correlation energy density functionals in density functional theory is investigated and evaluated in this article through the so‐called Levy transformation, which enables one to obtain the exact exchange correlation energy without knowing the details of its kinetic energy component. Although in principle the transformation is valid only for exact functionals, it is argued that approximate functionals may also be applied and then recurrently used. As a demonstration of the idea, a generalized form of the Wigner‐type functional is introduced and transformed into polylogarithm functionals. Numerical illustrations of examples show that for local functionals, better results may be yielded after the transformation, whereas for nonlocal functionals, identical results have been obtained for n≥2 transformations. In addition, two nonlocal approximate functionals beyond the generalized gradient approximation (GGA) are proposed which show better performance in energetics over GGA functionals. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
QR–SCMEH–MO calculations on NdO and UO
Authors: Boudreaux Edward A. , Baxter Eric
Published: October 2002

Electronic structures and chemical bonding within the NdO and UO molecules have been studied computationally via the QR–SCMEH–MO (quasirelativistic–self‐consistent modified extended Hückel–molecular orbital) method. This is a non‐ab initio, self‐consistent, nonempirical routine that accounts for correlation in an approximate way. It also incorporates other features so as to account for all electron interactions. Both molecules were found to be bonding [contrary to a report based on ab initio density functional theory (DFT)–SCF relativistic calculations on UO]. The covalency in UO is somewhat greater than that of NdO, which for all practical purposes is mostly electrostatic. Good agreement between calculated and observed bond dissociation energies and ionization potentials have been obtained. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Intermolecular perturbation theory applied to an exactly solvable model
Authors: Adams William H.
Published: October 2002

It is remarkable that application of intermolecular perturbation theory to a simple, exactly solvable model of diatomic molecules reproduces the basic problems encountered when that theory is applied to real systems. For real systems it took over 50 years to recognize fully the consequences of choosing products of atomic/molecular functions as unperturbed wave functions. The primary consequence is that the physical ground state energy is generally buried in a continuum of unphysical state energies, i.e., energies of states which violate the Pauli Exclusion Principle. This makes the simplest perturbation theory incapable of predicting even the ground state energy of most systems when summed to infinite order. The model reveals clearly why and how unphysical solutions arise in intermolecular perturbation theory. The model neglects the interaction between electrons, reducing the N‐electron problem to that of the one‐electron molecular ion. Because the model can be solved exactly, it is suggested that it could be useful in testing new perturbation theories for the calculation of intermolecular potential surfaces. The traditional test systems, H2+ and H2, provide no real test because they have no unphysical solutions. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Calculation of nuclear‐attraction and modified overlap integrals using Gegenbauer coefficients*
Authors: Öztekin E. , Özcan S. , Orbay M. , Yavuz M.
Published: October 2002

The modified overlap and nuclear‐attraction integrals over Slater‐type orbitals are calculated for extremely large quantum numbers using Gegenbauer coefficients and basic overlap integrals. The accuracy of the results is quite high for the principal quantum numbers of Slater functions and for arbitrary values of internuclear distances and screening constants of atomic orbitals. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Rapid method for determination of chlormequat residues in tomato products by ion‐exchange liquid chromatography/electrospray tandem mass spectrometry
Authors: Careri M. , Elviri L. , Mangia A. , Zagnoni I.
Published: October 2002

A rapid method has been devised for the direct determination of chlormequat in tomato samples. No clean‐up is required, and analysis uses ion‐exchange liquid chromatography/tandem mass spectrometry interfaced with electrospray ionization (LC/ESI‐MS/MS). A cation‐exchange column was used with an aqueous ammonium acetate/acetonitrile mixture as the mobile phase under isocratic conditions. The method was validated in terms of detection limits (LOD), quantitation limits (LOQ), linearity, recovery, precision and accuracy. Good results in the low µg kg−1 level were obtained for the LOD and LOQ of chlormequat in tomato samples. Comparison of solvent and matrix‐matched calibration curves demonstrated the absence of significant matrix effects and the feasibility of using external calibration. Linearity was established over two orders of magnitude by performing homoscedasticity and Mandel fitting statistical tests. The absence of both constant and proportional systematic errors was verified by evaluating the recovery function, demonstrating good method accuracy. Excellent precision in terms of intra‐day repeatability was calculated (RSD% <3.4). Extraction recoveries from tomato products were calculated, by using a labelled internal standard (d4‐chlormequat), to be in the 93 ± 5–99 ± 7% range. The applicability of the method to the determination of chlormequat residues in tomato products was demonstrated. Copyright © 2002 John Wiley & Sons, Ltd.
Easy amino acid sequencing of sulfonated peptides using post‐source decay on a matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometer equipped with a variable voltage reflector
Authors: Hellman Ulf , Bhikhabhai Rama
Published: October 2002

Tryptic peptides were labeled with sulfonic acid groups at the N‐termini using an improved chemistry. The derivatization was performed in common aqueous buffers on peptides adsorbed onto a ZipTip™ C18, thus allowing simultaneous desalting/concentration of the sample. When only Arg‐terminating peptides were considered, the procedure from adsorption onto the ZipTip until analysis by MALDI‐PSD took about 10 min and several samples could be worked on in parallel. The resulting improved post‐source decay (PSD) fragmentation produced spectra containing only y‐ions. PSD amino acid sequencing of underivatized and derivatized synthetic peptides was compared. From the sequence information obtained from derivatized peptides isolated by ion selection from tryptic in‐gel digests, a protein was correctly identified which was difficult to analyze from an unclear peptide mass fingerprint analysis. The method was also applied to the identification and localization of phosphorylated Ser and Tyr residues in native and synthetic peptides. Copyright© 2002 John Wiley & Sons, Ltd.
Liquid chromatography/tandem mass spectrometric bioanalysis using normal‐phase columns with aqueous/organic mobile phases – a novel approach of eliminating evaporation and reconstitution steps in 96‐well SPE
Authors: Naidong Weng , Shou Wilson Z. , Addison Thomas , Maleki Saber , Jiang Xiangyu
Published: October 2002

Bioanalytical methods using automated 96‐well solid‐phase extraction (SPE) and liquid chromatography with electrospray tandem mass spectrometry (LC/MS/MS) are widely used in the pharmaceutical industry. SPE methods typically require manual steps of drying of the eluates and reconstituting of the analytes with a suitable injection solvent possessing elution strength weaker than the mobile phase. In this study, we demonstrated a novel approach of eliminating these two steps in 96‐well SPE by using normal‐phase LC/MS/MS methods with low aqueous/high organic mobile phases, which consisted of 70–95% organic solvent, 5–30% water, and small amount of volatile acid or buffer. While the commonly used SPE elution solvents (i.e. acetonitrile and methanol) have stronger elution strength than a mobile phase on reversed‐phase chromatography, they are weaker elution solvents than a mobile phase for normal‐phase LC/MS/MS and therefore can be injected directly. Analytical methods for a range of polar pharmaceutical compounds, namely, omeprazole, metoprolol, fexofenadine, pseudoephedrine as well as rifampin and its metabolite 25‐desacetyl‐rifampin, in biological fluids, were developed and optimized based on the foregoing principles. As a result of the time saving, a batch of 96 samples could be processed in one hour. These bioanalytical LC/MS/MS methods were validated according to “Guidance for Industry — Bioanalytical Method Validation” recommended by the Food and Drug Administration (FDA) of the United States.1 Copyright © 2002 John Wiley & Sons, Ltd.
Carbon isotope ratio analysis of organic moieties from fossil mummified wood: establishing optimum conditions for off‐line pyrolysis extraction using gas chromatography/mass spectrometry
Authors: Poole Imogen , van Bergen Pim F.
Published: October 2002

Mummified fossil wood was studied using off‐line pyrolysis‐gas chromatography/mass spectrometry to reveal detailed insights into the pyrolysis conditions that are needed to obtain simultaneously sufficient amounts of both cellulose and lignin markers for stable carbon isotope analyses. The off‐line pyrolysis was applied at a range of temperatures (200, 250 and 300 °C) and times (1 and 2 h) to determine the optimum temperature and time that yielded the highest quantity of true markers for lignin and cellulose. Increasing the time from 1 to 2 h had no effect whereas increasing the temperature led to large differences. The products released during the low‐temperature pyrolysis were mostly related to thermally labile moieties. Only at 300 °C were sufficient amounts of products released that represent true cellulose and lignin building blocks and which could be studied using gas chromatography/combustion isotope ratio mass spectrometry. Copyright © 2002 John Wiley & Sons, Ltd.
Generalization capabilities of co‐evolution in learning robot behavior
Authors: Berlanga A. , Sanchis A. , Isasi P. , Molina J.M.
Published: October 2002

In this article, a co‐evolutive method is used to evolve neural controllers for general

obstacle‐avoidance of a Braitenberg vehicle. During a first evolutionary process, Evolution Strategies

were applied to generate neural controllers; the generality of the obtained behaviors was quite poor.

During a second evolutionary process, a new co‐evolutive method, called Uniform Co‐evolution, is

introduced to co‐evolve both the controllers and the environment. A comparison of both methods shows that

the co‐evolutive approach improves the generality of controllers. © 2002 Wiley Periodicals, Inc.
A cross‐coupling controller using anH∞scheme and its application to a two‐axis direct‐drive robot
Authors: Fang Ren‐Wu , Chen Jian‐Shiang
Published: October 2002

A cross‐coupling controller (CCC) using anH∞control scheme has been proposed to reduce the contouring error for a two‐axis, direct‐drive robot in tracking linear and circular contours effectively. Under the consideration that contour‐tracking performance is a primary target over point‐to‐point tracking performance in a trajectory‐tracking task, a CCC has been associated with joint controllers to reduce the contouring error by coordinating the motion of a two‐axis robot arm. Contouring performance can thus be improved significantly. Furthermore, the proposed CCC design, which is a typical Multi‐Input Multi‐Output (MIMO) system with linear time varying (LTV) characteristics, has been verified as being internally stable. A USM (ultrasonic motor)‐driven, two‐axis, direct‐drive robot is utilized to demonstrate the feasibility of the proposed scheme. Several experiments under various operating conditions are performed to validate its efficacy, and the results showed that the proposed scheme can reduce the contouring error significantly. © 2002 Wiley Periodicals, Inc.
Performance evaluation of decision making strategies for an embedded lane departure warning system
Authors: Kwon Woong , Lee Sukhan
Published: October 2002

An on‐board lane departure warning system embedded in a vehicle is composed of a localization module and a decision making module. The decision making module detects unintended lane departure so as to warn the driver of the danger. The performance of a decision making module is crucial to the performance of the total embedded system. This article proposes two heuristic decision making strategies: a lateral offset (LO) based strategy and a time‐to‐lane crossing (TLC) based strategy. The performance criteria of decision making strategies are proposed as: (1) false alarm rate, and (2) alarm triggering time (ATT). Numerical parameters of both strategies are optimized through numerical simulation, taking the performance criteria into consideration. The proposed strategies are incorporated into the prototype system and evaluated in real expressway experiments. The comparative study of both methods with experimental results shows the applicability of the on‐board lane departure warning system. © 2002 Wiley Periodicals, Inc.
Characterization of cell cultures with ToF‐SIMS and laser‐SNMS
Authors: Fartmann M. , Dambach S. , Kriegeskotte C. , Wiesmann H. P. , Wittig A. , Sauerwein W. , Lipinsky D. , Arlinghaus H. F.
Published: October 2002

We have applied time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) and non‐resonant laser secondary neutral mass spectrometry (NR‐laser‐SNMS) for examining freeze‐fractured, freeze‐dried primary osteoblast and cancer cells. Both techniques can simultaneously detect all masses with very high sensitivity and subcellular resolution. Because most of the sputtered particles are neutrals, laser‐SNMS has the additional advantage of being more quantitative. With both techniques, high‐resolution elemental and molecular images were obtained from cell cultures. Ion‐induced electron images were used to identify individual cells. Measurement of the Na/K ratio clearly demonstrated that the preparation techniques used are appropriate for preserving the chemical and structural integrity of living cells. Presputtering the samples with different primary ion dose densities makes it possible to take three‐dimensional images and to monitor the elemental distributions inside the cells. From the efficiency achieved, it can be concluded that ToF‐SIMS and laser‐SNMS are well suited for imaging trace element and molecule concentrations in biological samples. Copyright © 2002 John Wiley & Sons, Ltd.
Pd on Cu(110): growth mode monitored by LEIS
Authors: Delichère P. , Bertolini J. C.
Published: October 2002

Metal on metal deposits can have very different, and interesting, physical and chemical properties compared with those of the pure metal. In this framework we investigated the behaviour of low amounts of palladium deposited at 300 K on the (110) face of copper, but copper is known to have a lower surface energy than palladium and therefore will tend to segregate at the surface, a process that depends on the temperature.

The absolute calibration of the Pd deposit was made on a polycrystalline Cu sample with the combined use of XPS and Rutherford backscattering spectroscopy: for 6 × 1015 Pd atoms cm−2, the intensity ratio of Pd3d5/2/Cu3s is 7.2.

For Pd deposited at room temperature on Cu(110), the presence of a large amount of copper at the surface is clearly evidenced by low‐energy ion scattering. The Pd atomic concentration at the surface does not exceed 15% for one monolayer (ML) of Pd deposited (1 ML = 1.1 × 1015 Pd atoms cm−2). This indicates either that Pd does not spray uniformly at the surface or that Cu diffusion and alloying effects do exist.

These results are discussed in relation with some catalytic properties of the Pd on Cu(110) adlayers. Copyright © 2002 John Wiley & Sons, Ltd.
Transport of copper over paper in high‐voltage electrical insulation
Authors: Whitfield T. B. , Castle J. E. , Saracco C. , Ali M.
Published: October 2002

Copper windings in the transformers used on national distribution networks are often insulated with layers of paper. In large current transformers the whole paper‐insulated assembly is immersed in an insulating mineral oil within a de‐aerated tank. Such transformers have a normal life span in excess of 30 years. However, from time to time, insulation problems arise and this is then associated with significant darkening of the paper. Analysis of the damaged paper by XPS shows that the darkening arises from the deposition, within the paper winding, of copper compounds, usually Cu2O or CuO.

Laboratory studies in support of work designed to eliminate the problem have shown that copper diffusion occurs in mineral oil if it contains a trace of oxygen. In this paper we will show that the transport of copper through up to 20 layers of paper can be measured by XPS and that the concentration from one paper winding to the next declines in accord with Fick's law for non‐steady‐state diffusion.

Measurements of surface concentrations by XPS have allowed determination of the diffusion coefficients and activation energy for the transport process and thus provide a basis for interpretation of the diffusion profiles found in the transformer in terms of time and temperature of operation. Copyright © 2002 John Wiley & Sons, Ltd.
Non‐destructive surface analysis applied to atmospheric corrosion of tin
Authors: Jouen S. , Hannoyer B. , Piana O.
Published: October 2002

Tin samples have been exposed in industrial, rural and urban outdoor atmospheres. Corroded surfaces were studied with Fourier transform infrared reflection absorption spectroscopy (FTIRAS), x‐ray diffraction (XRD), SEM, energy‐dispersive spectroscopy (EDS) analysis and Mössbauer spectroscopy. Corrosion is continuous and heterogeneous during the first 10 months of exposure, and the corrosion products seem mainly insoluble and non‐protective. Corrosion rate differs between each site of exposure, increasing from urban to rural area. Analyses performed reveal that the corrosion layers are mainly composed of poorly crystallized and hydrated stannic oxide SnO2·xH2O. Lower proportions of Sn(II) and Sn(IV) corrosion products are also identified as carbonates, sulphates and chlorides compounds. The FTIRAS and Mössbauer spectroscopy analyses remain the most adaptable to perform the characterization of tin corrosion products. They give reliable information about the chemical species, the valence state of tin nuclei and the evolution of the corrosion layer with time. Copyright © 2002 John Wiley & Sons, Ltd.
Is XPS combined with argon ion sputtering pertinent for depth profiling molybdenum‐implanted stainless‐steel layers?
Authors: Mottu N. , Vayer M. , Benoit R. , Erre R.
Published: October 2002

This paper discusses and compares depth profiles obtained on Mo‐implanted stainless steel by XPS and argon ion bombardment with those obtained by TRIM calculations and Rutherford backs scattering spectroscopy (RBS) analyses. The XPS profiles were highly dependent on the layer structure. When the structure remained highly crystallized, contamination carbon did not diffuse in the implanted layer and corrected Mo profiles were in agreement with RBS analyses. With a slight degradation of the implanted layer, corrected Mo profiles were still in agreement with RBS analyses but the carbon diffusion into the implanted layer was clearly visible (up to 10 at.%). When the implanted layer was completely amorphous, XPS profiles translated this amorphization and were highly dispersed. Copyright © 2002 John Wiley & Sons, Ltd.
Chemical effects in Auger electron spectra of aluminium
Authors: Timmermans B. , Vaeck N. , Hubin A. , Reniers F.
Published: October 2002

The bonding and electronic structure of surface atoms is most often studied by XPS, where the energy shift of a photoelectron peak can be ascribed to a change in the chemical environment. Because three atomic levels are involved in the Auger emission process, the use of Auger spectroscopy to obtain this information from peak positions and lineshape is more difficult. However, new progress in signal analysis techniques makes the extraction of chemical information intrinsically present in the Auger spectra possible. The advantage of AES over XPS is its higher lateral resolution, allowing study of the surface distribution of the elements (Auger mapping). This, combined with modern computational methods, opens up new opportunities in surface analysis.

In order to try to correlate the changes in the Auger peak energies with the changes in the chemical environment, we performed a full experimental and theoretical study of the Auger KLL lines of aluminium in several compounds (Al2O3, AlN, AlB2 and AlF3) by AES and x‐ray‐induced AES, the peak position for AlB2 being reported for the first time. The inner‐shell KLL peaks of Al show large energy shifts, depending on the chemical environment. The experimental results are compared to ab initio calculations based on a new cluster model including chemical, structural and relaxation effects. Copyright © 2002 John Wiley & Sons, Ltd.
How to measure accurately mass transport in thin films by AES
Authors: Girardeaux C. , Clugnet G. , Erdélyi Z. , Nyéki J. , Bernardini J. , Beke D. , Rolland A.
Published: October 2002

In this paper, we show that AES is a powerful technique to determine mass transport in thin films with model metal/metal thin‐layer structures (for systems without any compound formation). We show the conditions where grain boundary and/or bulk diffusion coefficients can be determined accurately at unusually low temperatures by monitoring the surface segregation kinetics of an impurity through a nanocrystalline film using the Hwang–Balluffi approach (systems with total solubility), and the dissolution of ultrathin deposits in a matrix using a model based on Martin's kinetic deterministic equations (systems with total solubility). Copyright © 2002 John Wiley & Sons, Ltd.