bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intersections in steel shell structures
Authors: Teng J G 
Published: August 2002

AbstractCylinders, cones, spheres and tori are some of the common basic shell elements. Steel shell structures such as silos, tanks, pressure vessels, offshore platforms, chimneys and tubular towers generally consist of two or more of these basic shell elements. Axisymmetric intersections featuring meridional slope mismatches between the connected elements are common features in steel shell structures. High bending and circumferential membrane stresses are developed in these intersections, and their buckling and collapse strengths are a key design consideration. This paper presents a summary of recent research on the stress, stability and strength of axisymmetric steel shell intersections. Particular attention is paid to intersections formed from cylindrical and conical segments as these are more common and have been more extensively researched. A simple approximate method for extrapolating the knowledge gained on these intersections to those containing curved shell segments is also suggested.
Modulatory influence of Andrographis paniculata on mouse hepatic and extrahepatic carcinogen metabolizing enzymes and antioxidant status
Authors: Singh Rana P. , Banerjee S. , Rao A. Ramesha 
Published: August 2002

AbstractThe effects of two doses (50 and 100 mg/kg body wt/day for 14 days) of an 80% hydroalcohol extract of Andrographis paniculata and butylated hydroxyanisole (BHA) were examined on drug metabolizing enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase (LDH) and lipid peroxidation in the liver of Swiss albino mice (6–8 weeks old). The effect of the extract and BHA were also examined on lung, kidney and forestomach for the activities of glutathione S‐transferase (GST), DT‐diaphorase (DTD), superoxide dismutase (SOD) and catalase. A significant increase in the levels of acid soluble sulphydryl (‐SH) content, cytochrome P450, cytochrome P450 reductase, cytochrome b5 reductase, GST, DTD and SOD were observed at both dose levels of extract treatment while catalase, glutathione peroxidase and glutathione reductase (GR) showed significant increases only at the higher dose in the liver. Both Andrographis treated groups showed a significant decrease in activity of LDH and malondialdehyde (MDA) formation. BHA treated mice showed a significant increase in the levels of cytochrome b5, GST, DTD, ‐SH content, GR and catalase in liver; while LDH and MDA levels were reduced significantly compared with their control values. In the lung, SOD, catalase and DTD, in the kidney catalase, DTD and GST, and in the forestomach SOD and DTD showed a significant increase at both dose levels of treatment. In BHA treated mice GST, DTD and catalase were significantly induced in the lung and along with these enzymes SOD was also induced in the kidney. In the case of the forestomach of BHA treated mice GST, DTD and SOD were enhanced significantly. These findings indicate the chemopreventive potential of Andrographis paniculata against chemotoxicity including carcinogenicity. Copyright © 2001 John Wiley & Sons, Ltd.
Adaptogenic activity of a novel, withanolide‐free aqueous fraction from the roots of Withania somnifera Dun.
Authors: Singh B. , Saxena A. K. , Chandan B. K. , Gupta D. K. , Bhutani K. K. , Anand K. K. 
Published: August 2002

AbstractThe practitioners of the traditional Indian system of medicine regard Withania somnifera Dun. as the ‘Indian ginseng’. A new withanolide‐free aqueous fraction was isolated from the roots of this plant and was evaluated for putative antistress activity against a battery of tests such as hypoxia time, antifatigue effect, swimming performance time, swimming induced gastric ulceration and hypothermia, immobilization induced gastric ulceration, autoanalgesia and biochemical changes in the adrenal glands. This bioactive fraction exhibited significant antistress activity in a dose‐related manner in all the parameters studied. The extract of Withania somnifera root (a commercial preparation available locally) was used to compare the results. A preliminary acute toxicity study in mice showed a good margin of safety. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of plastic packages for guava refrigerated preservation
Authors: Jacomino Angelo Pedro , Kluge Ricardo Alfredo , Sarantópoulos Claire Isabel Grígoli de Luca , Sigrist José Maria Monteiro 
Published: August 2002

AbstractGuavas cv. ‘Kumagai’ were packed in several plastic materials and stored at 10°C and 85–90% relative humidity (RH) for 7, 14, 21 and 28 days (+3 days at 25°C). The plastic materials studied were: multilayer co‐extruded polyolephine film with selective permeability (PSP), low‐density polyethylene film (LDPE), LDPE film with mineral incorporation (LDPEm) and heat‐shrinkable polyolephine film (SHR). Guavas not packed were taken as control samples. The physicochemical characteristics of the fruits, O2 and CO2 transmission rates of the packaging materials and gas composition at the package headspace were evaluated. The LDPE film, 69 µm in thickness, with the lowest permeability to both O2 and CO2, led to anaerobiosis and high CO2 concentration inside the packages and promoted physiological disturbances and changes in fruit flavour. The SHR film, 15 µm in thickness, was the most permeable to CO2 and had quite high O2 transmission, which modified the inner atmosphere of the packages slightly. The fruits packed in this film showed a poorer quality than the controls, possibly due to the heat produced during the shrinking of the film. The LDPEm film, 24 µm in thickness, was almost as permeable to CO2 but had reduced O2 transmission, promoting an atmosphere of equilibrium of 3% O2 and 4.5% CO2. Fruits packed in this film kept their skin colour and pulp firmness, suitable for consumption up to 14 days. The PSP film, 35 µm in thickness, had the greatest O2 transmission but just over half of the CO2 transmission of LDPEm, promoting an atmosphere of equilibrium of 0.5% O2 and 4.5% CO2 inside the packages. Fruits packed in such packages kept their physicochemical characteristics up to 21 days. Copyright © 2001 John Wiley & Sons, Ltd.
Note on the theory of bifurcation of chemical reactions
Authors: Palmeiro Raul , Frutos Luis Manuel , Castaño Obis 
Published: August 2002

AbstractIn the present communication two existing definitions of valley ridge inflection, (VRI), point, one attributed to Valtazanos and Ruedenberg and the other one to Basilevsky are discussed. From our study we conclude that both definitions are not equivalent, and we demonstrate in which cases it occurs. However, they are used without any distinction in the bibliography. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Bound states of oscillators in infinite and finite domains: A semiclassical study
Authors: Mukhopadhyay S. , Bhattacharyya K. 
Published: August 2002

AbstractBy involving the uncertainty product along with a semiclassical requirement for observables, a simple variational scheme is employed to extract major features of bound states of systems in (−∞,∞) and the same of systems confined in (−L,L). Special attention is paid to perturbative studies on the asymptotic behavior of energies for oscillators in infinite domains and dependence of energy spectra of oscillators in finite domains on various system parameters. A corrected form of the virial theorem is obtained in the latter case. The governing equations for quantum isothermal and adiabatic processes, derived recently, are also shown to be modified for general confined oscillator systems and closed‐form expressions are found. These results are useful in dealing with the quantum Carnot cycles. Advantages of the present route over other semiclassical strategies are stressed. Pilot calculations demonstrate nicely the efficacy of the endeavor under various situations. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
A novel approach for calculating correlation energy based on the two‐electron density matrix formalism
Authors: Bálint Imre , Dezső Gergely , Gyémánt Iván 
Published: August 2002

AbstractThe two‐particle density matrix contains all information which is “readable” by one‐ and two‐particle operators. This work discusses the building of a two‐electron density matrix, which is perfectly N‐representable by construction. The 2‐matrix of a pure quantum state is obtained without the intermediate determination of the wave function. The procedure is illustrated by computations on atomic and small molecular systems. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 84: 32–38, 2001
A fresh look at the computation of spherically averaged electron momentum densities for wave functions built from Gaussian‐type functions
Authors: Thakkar Ajit J. , Sharma Bhawani S. 
Published: August 2002

AbstractA new method for deriving the spherical average of the product of the Fourier transforms of two Gaussians is described. The method generates the result in terms of a few spherical Bessel functions leading to expressions that are much more compact than those in the literature. These integrals are required in the computation of spherically averaged electron momentum densities, and rotationally averaged X‐ray and high‐energy electron scattering crossections. All integrals needed for spherically averaged momentum densities are tabulated for s, p, d, and f‐type Gaussians. As an illustration of the method, we apply it to calculate spherically averaged electron momentum densities and their moments for H2O. The calculations are performed at the Hartree–Fock and 2nd‐ and 4th‐order Møller–Plesset perturbation theory levels with the aug‐cc‐pVDZ and aug‐cc‐pVTZ basis sets. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Electronic density‐matrix algorithm for nonadiabatic couplings in molecular dynamics simulations
Authors: Tommasini M. , Chernyak V. , Mukamel S. 
Published: August 2002

AbstractClosed expressions for nonadiabatic couplings are derived using the collective electronic oscillators (CEO) algorithm based on the time‐dependent Hartree–Fock equations. Analytic derivatives allow the calculation of transition density matrices and potential surfaces at arbitrary nuclear geometries using a molecular dynamics trajectory that only requires a CEO calculation at a single configuration. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Can an independent‐electron model be exact for an N‐electron system?
Authors: Nesbet R. K. 
Published: August 2002

AbstractDensity functional theory (DFT) is commonly understood to provide an exact independent‐electron model of N‐electron ground states, using only local potential functions. It has recently been shown that restriction to local potentials leads to inconsistencies in the Thomas–Fermi theory, in the Hartree–Fock model of DFT (local exchange potential), and in linear response theory (the exchange response kernel differs from the exact linear exchange operator derived in 1930 by Dirac). It is shown here that by extending the theory to a more general orbital functional theory (OFT) these inconsistencies or paradoxes can be resolved. An orbital‐functional representation of correlation energy leads to a formally exact theory of stationary states and of linear response. The theory is free of self‐interaction and implies physically meaningful one‐electron energies, consistent with Landau quasiparticles in many‐body theory. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Principal component analysis of mass spectra of peptides generated from the tryptic digestion of protein mixtures
Authors: Bryant Duncan K. , Monté Soraya , Man Wai J. , Kramer Kerstin , Bugelski Peter , Neville William , White Ian R. , Camilleri Patrick 
Published: August 2002

AbstractPrincipal component analysis (PCA) has been used to analyse mass spectral peptide profiles obtained from the enzymatic digestion of standard protein mixtures. Scores and loadings plots clearly revealed peptide fragments that differentiated one protein mixture from another. Peptide map search results identified with a high degree of certainty any additional proteins in these mixtures. As a proof‐of‐concept this methodology was applied to hepatic protein mixtures obtained from rats treated with two hepatotoxic compounds: methapyriline and SB‐219994. Liver proteins were extracted, pre‐separated by one‐dimensional polyacrylamide gel electrophoresis, subjected to tryptic digestion and analysed by mass spectrometry. Two up‐regulated proteins, glutathione S‐transferase with methapyrilene and peroxisomal bifunctional enzyme with SB‐219994, were identified in this manner. Copyright © 2001 John Wiley & Sons, Ltd.
Characterizing the fragmentation of 2,5‐bis (4‐amidinophenyl)furan‐bis‐O‐methylamidoxime and selected metabolites using ion trap mass spectrometry
Authors: Zhou Lian , Voyksner Robert D. , Thakker Dhiren R. , Stephens Chad E. , Anbazhagan Mariappan , Boykin David W. , Hall James E. , Tidwell Richard R. 
Published: August 2002

AbstractA novel prodrug [2,5‐bis(4‐amidinophenyl)furan‐bis‐O‐methylamidoxime (DB289)] of the promising antimicrobial agent, 2,5‐bis(4‐amidinophenyl)furan (DB75), has excellent oral activity. It is currently undergoing phase II clinical evaluation as an orally administered drug candidate against African trypanosomiasis and Pneumocystis carinii pneumonia. The sequential product ion (MSn) fragmentations of DB289 and selected metabolites were characterized using ion trap mass spectrometry with electrospray ionization. An unusual homolytic bond cleavage, formation of an odd‐electron ion from an even‐electron ion with the loss of a radical, was commonly seen in the fragmentation patterns of DB289 and its metabolites. Both O‐ethyl and N‐methyl homologues of DB289 were utilized to confirm this fragmentation pathway. The labile hydrogen atoms in DB289 are readily exchanged with deuterium atoms in the solvent containing deuterium oxide (D2O) instead of water. The mass shift patterns displayed in the product ion spectra of DB289 in D2O proved useful in verifying the fragmentation pathway. Octadeuterated DB289 and DB75 (d‐labeling on the diphenyl rings) showed unequivocally that the diphenylfuran moiety is not involved in the fragmentation. The fragmentation pathways uncovered in this work will facilitate structural characterization of all the metabolites produced in the metabolic activation of DB289. Copyright © 2002 John Wiley & Sons, Ltd.
Cost Evaluation for Selected Remediation Technologies
Authors: Kingscott John , Weisman Richard J. 
Published: August 2002

AbstractRelatively little data are available to document the historical cost for using common remediation
technologies, and site managers often must rely on information from technology vendors and predictive models,
which may not accurately reflect the experiences of previous technology users. To help address these concerns,
the U.S. Environmental Protection Agency (EPA) conducted an evaluation of data on historical costs of
common remediation technologies. Cost curves were developed for four technologies, showing the relationship
between cost for remediation and quantity of material treated. Although costs are known to be highly
site‐specific and affected by many factors, the curves are useful in illustrating the variability of
historical costs and the economies of scale for treating relatively large quantities of material. © 2002
Wiley Periodicals, Inc.
Primate hepatitis B viruses – genetic diversity, geography and evolution
Authors: Robertson Betty H. , Margolis Harold S. 
Published: August 2002

AbstractThere are six well characterised genotypes (A–F) of human hepatitis B virus that have distinct geographic ranges which generally relate to chronic HBV infection. A seventh human genotype (G) has recently been described, but there is limited information on ethnic and geographic distribution. Despite the fact that early studies indicated that HBV antigens were present in other primates, the prevailing dogma that HBV was a human disease precluded alternative explanations. Within the past 5 years, hepatitis B viruses have been characterised from all the Old World great apes (orangutan, gibbons, gorillas and chimpanzees) and from a New World woolly monkey. Each group of non‐human primates appears to have a distinct strain of hepatitis B virus that can be distinguished from human sequences based upon the nucleotide sequence and selected amino acid changes in the viral proteins. The woolly monkey HBV is most divergent from other primate and human sequences, while the great ape HBV sequences cluster together with separate branches for each group. Published in 2002 by John Wiley & Sons, Ltd.
Potential of combined spaceborne infrared and microwave radiometry for near real‐time rainfall attenuation monitoring along earth‐satellite links
Authors: Marzano Frank S. , Turk Joseph F. , Ciotti Piero , Michele Sabatino Di , Pierdicca Nazzareno 
Published: August 2002

AbstractThe objective of this paper is to investigate how spaceborne remote sensors, and their derived products, can be exploited to optimize the performances of a satellite communication system in the presence of precipitating clouds along the path. The complementarity between sun‐synchronous microwave (MW) and geo‐stationary infrared (IR) radiometry for monitoring the earth's atmosphere is discussed and their potential as a rain detection system within near real‐time countermeasure techniques for earth‐satellite microwave links is analysed. A general approach, consisting in estimating rainfall intensity and attenuation by polar‐orbiting microwave radiometers and temporally tracking the rainfall areas by geo‐stationary infrared radiometers, is delineated. Multiple regression algorithms for predicting rainfall attenuation from spaceborne brightness temperatures and from surface rainrate, trained by radiative transfer and cloud models, are illustrated. A maximum likelihood technique is delineated to discriminate stratiform and convective rainfall from spaceborne brightness temperatures. The differences among attenuation estimates derived from layered raining‐cloud structures with respect to those obtained from simple rain slabs, as recommended by ITU‐R, are also quantified. A test of the proposed attenuation prediction methods is performed using raingage and Italsat data acquired in Spino d'Adda (Italy) during 1994. A description of the statistical method, based on the probability matching technique, adopted to combine MW and IR data for retrieving and tracking precipitating cloud systems in terms of path attenuation and accumulated rain at ground is finally provided together with its application to a case study over the Mediterranean area during October 1998. Copyright © 2001 John Wiley & Sons, Ltd.
Comparing expectations to actual events: the post mortem of a Y2K analysis
Authors: Backus George , Schwein Michael T. , Johnson Scott T. , Walker Robert J. 
Published: August 2002

AbstractThis article reviews an analysis performed for a “high‐tech” company in mid‐1998 to evaluate the potential impacts of Y2K on the company's performance. The authors are no longer directly associated with the company and the results have been restated to protect the company's identity. The model performed better than existing in‐house tools, but inconsistency tests uncovered “insider” information that needed to be included in the model. The final scenarios and associated recommendations indicated response requirements incompatible with the time constants of information flows within the company. Like the Titanic moving toward the iceberg, it was already too late for the company to do much more than hope that fate would be kind. The causal dynamics left little to fate. A “validated” model often becomes part of the problem and the feedback (decision‐making) system it is attempting to influence. To have a successful impact, consultants may need to give up their supposed objective position and personally engage themselves in the risk‐ridden, internal, political processes of the client organization. Copyright © 2001 John Wiley & Sons, Ltd.
Comparison of the Tougaard, ARXPS, RBS and ellipsometry methods to determine the thickness of thin SiO2 layers
Authors: Semak B. S. , van der Marel C. , Tougaard S. 
Published: August 2002

AbstractThe Tougaard and angle‐resolved x‐ray photoelectron spectroscopy (ARXPS) methods were compared with ellipsometry and Rutherford backscattering (RBS) for their ability to determine the amount of SiO2 on an Si substrate. The Tougaard and ARXPS methods give generally consistent results (root‐mean‐square deviation ∼12%), whereas the deviation between the other techniques is significantly larger (∼30–40%). The Tougaard method gives consistent results for all angles of emission θ ≤ 60°. It is found also that the amount of SiO2 determined by the two methods depends approximately linearly on the inelastic mean free path. The ARXPS method also depends on the accuracy with which one can separate the peak area of the bulk and the oxide part of the peaks. The correction for elastic scattering in the ARXPS method gives a reduction of only 5–7% in the determined amount of SiO2. Copyright © 2002 John Wiley & Sons, Ltd.
Interlaboratory study on the degradation of poly(vinyl chloride), nitrocellulose and poly(tetrafluoroethylene) by x‐rays in XPS
Authors: Yoshihara K. , Tanaka A. 
Published: August 2002

AbstractIn XPS, it is often observed that the x‐ray flux causes changes in the surface structure and chemistry in the surface region of organic materials. However, at present, there is no standard guide to estimate the relationship between the degradation rate and x‐ray source flux. To investigate this relationship, we conducted an interlaboratory study on the degradation of three kinds of polymers—poly(vinyl chloride) (PVC), nitrocellulose + cellulose acetate (NC + CA) and poly(tetrafluoroethylene) (PTFE)—by x‐ray irradiation as Project A5 of the VAMAS Technical Working Area 2 on Surface Analysis; 40 laboratories participated in this study.From this interlaboratory study, it was concluded that the rate constant of the degradation for PVC and NC+CA could be obtained from the peak intensity changes of Cl 2p and N 1s photoelectrons, respectively, assuming first‐order reaction with photons. There is a fairly good correlation between the rate constants of the degradation for PVC and that of NC + CA, and, if the analysis was carried out using achromatic x‐ray sources only, a better correlation was obtained than that by a monochromatic source. Therefore, PVC and NC + CA will be good specimens for the indicators of x‐ray source flux. The degradation behaviour of PTFE is more complicated and does not follow a first‐order reaction. The rate constant of the degradation for PTFE obtained at the initial stage of the irradiation was compared with that of NC + CA. However, there is a poor correlation between them. Copyright © 2002 John Wiley & Sons, Ltd.