bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microscopic charcoal in sediments: Quaternary fire history of the grassland and savanna regions in South Africa
Authors: Scott L. 
Published: August 2002

AbstractThe microscopic charcoal content of several Quaternary pollen sequences is used to investigate fire history in South Africa both during the Holocene and the Late Pleistocene. Although fluctuations in charcoal composition are recorded, it is difficult to link them directly to either human‐made or natural fires. Strong long‐term variations in microscopic charcoal of Middle and Upper Pleistocene layers are independent of pollen indications of past temperature and moisture conditions. Holocene charcoal sequences from different areas show no correlation, so no phases of regional burning are found. Some fluctuations in charcoal probably are the result of local burning in the various regions. The arrival of Iron Age people some 2000 yr ago apparently did not coincide with widespread wild fires, as these events do not consistently appear in regional microscopic charcoal records. The only exception appears to be the Wonderkrater spring deposit. Relatively open savanna environments, which are implied by pollen analysis at some sites during this period and the generally low microscopic charcoal contents, were either caused by climate change or controlled burning by Iron Age people. Copyright © 2002 John Wiley & Sons, Ltd.
Application of the wavelet transform method in quantitative analysis of Raman spectra
Authors: Cai Wensheng , Wang Liya , Pan Zhongxiao , Zuo Jian , Xu Cunyi , Shao Xueguang 
Published: August 2002

AbstractThe Raman spectra of ethanolic solutions of CCl4 of different concentrations were measured and de‐noised by the wavelet transform method. The results show that noise can be filtered efficiently without changing the peak positions and the linear relationships between the peak intensity and the concentration can be maintained. It was demonstrated that the wavelet transform method can be used efficiently in quantitative analysis of Raman spectra with high noise levels. Copyright © 2001 John Wiley & Sons, Ltd.
Surface‐enhanced resonance Raman spectroscopy of water‐insoluble Ni(II) porphine adsorbed on aqueous silver sol: suppression of antisymmetric scattering, antiresonance effect and higher order scattering
Authors: Li Xiao‐Yuan , Petrov Vladimir I. , Chen Dongming , Yu Nai‐Teng 
Published: August 2002

AbstractWith the intention of examining how adsorption on a SERS‐active surface affects the electronic resonance enhancement in surface‐enhanced resonance Raman scattering (SERRS) from Ni(II) porphine (NiP), we acquired high‐quality SERR spectra from very low concentrations of NiP (∼10−8 M) in aqueous Ag sol from 50 to 3500 cm−1 with excitations across both the Soret and Q absorption bands. Water‐insoluble NiP was transferred to aqueous silver sol surface by using pyridine as carrying solvent, taking advantage of the fact that it both dissolves NiP and is partially miscible with water at the same time. It was found that SERS boosts the overall sensitivity of resonance Raman scattering by providing extra enhancement (the surface enhancement) to a1g, b1g and b2g modes, but not to a2g modes. As a consequence, a relative ‘suppression’ effect of antisymmetric scattering by a2g modes was observed when excitation was tuned into the Q absorption band region in SERR spectra. With excitations in the valley between the Soret and Q absorption bands, an antiresonance effect was observed in the SERR spectra for the totally symmetric ν6 mode at 995 cm−1 which was attributed to the destructive interference between Franck–Condon and Herzberg–Teller mechanisms. Strong second‐order and weak third‐order Raman scattering were observed in the SERR spectra of NiP when excitation was tuned close to and across the Q1 absorption band. A vibronic theory based on the extension of Albrecht's formalism was developed to account for the activation of high‐order Raman scattering and for the antiresonance effect of the ν6 band. More than 100 Raman wavenumbers, including both fundamentals and overtones/combinations, both in‐plane and out‐of‐plane modes, were observed for NiP in its SERRS spectra. The wavenumbers from the SERR spectra agree very well with those obtained from RR spectra from a homogeneous NiP solution and FTIR data from KBr (CsI) pellets, suggesting that adsorption of NiP on a SERS‐active surface is physisorption in nature, and that such adsorption has a negligibly small effect to the vibrational wavenumbers. The observed Raman wavenumbers from SERR spectra are also in excellent agreement with those predicted from ab initio/DFT calculations for both in‐plane and out‐of‐plane modes. Many out‐of‐plane modes and IR‐active in‐plane modes were observed in the SERR spectra of NiP, suggesting that the effective symmetry of the adsorbed NiP is lower than the ideal planar D4h. Copyright © 2001 John Wiley & Sons, Ltd.
Temperature‐dependent structural characterization of sol–gel deposited strontium titanate (SrTiO3) thin films using Raman spectroscopy
Authors: Gupta S. , Katiyar R. S. 
Published: August 2002

AbstractAn Erratum has been published for this article in Journal of Raman Spectroscopy 33 (2) 2002, 131.
The dynamics of the lattice optical phonons in strontium titanate (SrTiO3) thin films deposited on M‐plane sapphire [Al2O3(1010)] substrate using the sol–gel route were investigated. A detailed study of the temperature dependence of first‐order zone‐center optical phonons in the 70–300 K temperature range was carried out by means of Raman spectroscopy. The transverse optical phonons (denoted by TO1,2,3,4 in order of increasing wavenumber), which are symmetry forbidden in single crystals at room temperature, become Raman active in thin films. The lowering of symmetry is attributed either to the micro‐stress/strain or the presence of defects (such as oxygen vacancies V0), intrinsic defects in oxidic perovskites. The temperature dependence of the lowest wavenumber mode (TO1) is discussed and its Raman cross‐section was utilized to demonstrate the first‐order nature of Raman spectra. The Fano line profile and the associated asymmetric factor denoted by q of the TO2 phonon is interpreted as evidence of micro‐ or nanopolar regions (also known as ferroelectric microregions) in thin films, possibly arising due to highly polarized oxygen ions, likely to exist because of incomplete oxygenation during the film deposition. These optical phonon lines and the asymmetry of TO2 persist up to room temperature, another implication of the violation of the k conservation rule by breaking either the inversion or/and translation symmetry. The significant utility of micro‐Raman scattering in contrast to x‐ray diffraction as an important structural probe is also demonstrated. Copyright © 2001 John Wiley & Sons, Ltd.
Observation of phase decomposition of Sr2FeMoO6 by Raman spectroscopy
Authors: Son Le Hoang , Phuc Nguyen Xuan , Phuc Phan Vinh , Hong Nguyen Minh , Hong Le Van 
Published: August 2002

AbstractSamples of Sr2FeMoO6 were prepared by a solid‐state reaction method in an ambient gas of strictly controlled oxygen content. These materials show a room temperature magnetoresistance of 2% in a magnetic field of 1.5 T. The double perovskite phase Sr2FeMoO6 is stable at low oxygen partial pressure. In air at temperatures higher than 400 °C it is unstable and quickly decomposes into SrMoO4 and SrFeO3−x. By means of different techniques such as x‐ray diffraction, thermogravimetric analysis (TGA), thermomagnetization (TM) and Raman spectroscopy, we observed phase decomposition of the double perovskite Sr2FeMoO6. The temperature on the sample at the laser spot was estimated based on the ratio of the Stokes and anti‐Stokes intensity in the Raman scattering spectra, which were excited by an He–Ne laser beam with power densities ranging from 103 to 104 W cm−2. The estimated temperatures show that the decomposition is greatest around 550 °C. This is in agreement with results obtained from x‐ray diffraction, TGA and TM. Copyright © 2001 John Wiley & Sons, Ltd.
Study of structural defects in γ‐MnO2 by Raman spectroscopy
Authors: Julien C. , Massot M. , Rangan S. , Lemal M. , Guyomard D. 
Published: August 2002

AbstractThe structural arrangement of γ‐MnO2 is currently explained by a random intergrowth of pyrolusite layers in a ramsdellite matrix. The structures of a large variety of γ‐MnO2 samples with various structural parameters Pr were studied by x‐ray powder diffraction and Raman scattering spectroscopy. We show that elucidation of the quantitative determination of the structural disorder present in γ‐MnO2 is accurate by Raman scattering spectroscopy. The Raman data for manganese dioxides with the γ‐type structure are treated by a local environment model, which allows one to consider the relationship between the band wavenumber and the pyrolusite intergrowth that corresponds to the structural De Wolff defects. Copyright © 2002 John Wiley & Sons, Ltd.
Genes affecting starch biosynthesis exert pleiotropic effects on the protein content and composition of pea seeds
Authors: Hughes Richard K , Desforges Neil , Selwood Christopher , Smith Roger , Speirs Charles I , Sinnaeve Georges , Gorton Peter G , Wiseman Julian , Jumel Kornelia , Harding Stephen E , Hill Sandra E , Street Val , Wang Trevor L , Hedley Cliff L 
Published: August 2002

AbstractWe have used a series of near‐isogenic mutant pea lines defective in starch biosynthesis to identify genes that exert pleiotropic effects on the protein content and composition of the pea seed. The total protein contents of the flours obtained from the dry seed of these lines, determined using a new method based on amino acid analysis and validated by near‐infrared reflectance spectroscopy, ranged from 19 to 28% of dry matter. Modifications in the legumin (11S)/vicilin (7S) ratios were confirmed by analytical ultracentrifugation and accompanied by compensatory increases in the albumin (2S–4S) content. Improving the albumin fraction of plant protein can be used to improve its nutritional value. There is additional variability in the solubility profiles for the protein in these lines. This variability has implications for the functional properties, processing behaviour, potential industrial applications, digestibility and nutritional value of the different pea meal and the protein fractions derived therefrom. Digestibility of the protein in meal and in air‐classified and extruded products from selected lines will be compared in nutritional evaluation trials with poultry to assess the suitability of these products for incorporation into animal diets.© 2001 Society of Chemical Industry
Phenolic compounds and related enzymes as determinants of quality in fruits and vegetables
Authors: Tomás‐Barberán Francisco A , Espín Juan Carlos 
Published: August 2002

AbstractPhenolic secondary metabolites play an important role in plant‐derived food quality, as they affect quality characteristics such as appearance, flavour and health‐promoting properties. Their content in foods is affected by many factors that influence phenolic stability, biosynthesis and degradation. In terms of their biosynthesis the key enzyme phenylalanine ammonia‐lyase (PAL) is especially relevant, as it can be induced by different stress (environmental) conditions. In addition, polyphenol oxidases (PPO) and peroxidases (POD) are the main enzymes responsible for quality loss due to phenolic degradation. The different factors affecting phenolic‐related food quality are reviewed. These include internal (genetic) and environmental (agronomic) factors, technological treatments applied during postharvest storage of fruits and vegetables, as well as processing and storage of the processed products. The different strategies that are required to either maintain or enhance the phenolic‐related quality of foods are critically reviewed. Genetic modification designed to decrease polyphenol oxidases or peroxidases is not always a feasible method, owing to side problems related to the growth and defence of the plant. Agronomic treatments can be used to enhance the phenolic content and pigmentation of fruits and vegetables, although the information available on this topic is very scarce and even contradictory. Some postharvest treatments (cold storage, controlled or modified atmospheres, etc) can also improve phenolic‐related quality, as well as new processing methods such as irradiation (gamma, UV), high‐field electric pulses, high hydrostatic pressures and microwaves.© 2001 Society of Chemical Industry
Flaxseed as a functional food source
Authors: Oomah B Dave 
Published: August 2002

AbstractFlaxseed is emerging as one of the key sources of phytochemicals in the functional food arena. In addition to being one of the richest sources of α‐linolenic acid oil and lignans, flaxseed is an essential source of high‐quality protein and soluble fibre and has considerable potential as a source of phenolic compounds. The implications of diets containing flaxseed or its components for human nutrition and disease prevention are analysed in this paper. Results of the first meta‐analysis examining the relationship between intake of flaxseed or its components and risk reduction of disease in humans is presented. Some areas of potential opportunities and impact of using flaxseed or its components in the diet are highlighted.For the Department of Agriculture and Agri‐Food, Government of Canada. © Minister of Public Works and Government Services Canada 2001. Published for SCI by John Wiley & Sons, Ltd.
Mechanism of the pyrolysis of 1,2‐dichloroethane in the absence and presence of added chlorine
Authors: Huybrechts G. , Wouters G. 
Published: August 2002

AbstractA detailed radical reaction model, both homogeneous and heterogeneous, is shown to describe quantitatively published initial rates of the pyrolysis of 1,2‐dichloroethane in the gas phase. These data were obtained in conditioned static reactors with different surface‐to‐volume ratios, in the absence (at 703 K) and presence (at 572 K) of chlorine. The pressures of 1,2‐dichloroethane and chlorine vary from 20 to 500 torr and from 0 to 16 torr, respectively. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 316–321, 2002
Direct measurements of the reaction H + CH2O → H2+ HCO behind shock waves by means of Vis–UV detection of formaldehyde
Authors: Friedrichs Gernot , Davidson David F. , Hanson Ronald K. 
Published: August 2002

AbstractThe combination of sensitive detection of formaldehyde by 174 nm absorption and use of ethyl iodide as a hydrogen atom source allowed direct measurements of the reaction H + CH2O → H2+ HCO behind shock waves. The rate constant was determined for temperatures from 1510 to 1960 K to bek2= 6.6 × 1014exp(−40.6 kJ mol−1/RT) cm3mol−1s−1(Δ logk2= ± 0.22)Considering the low uncertainty ink2, which accounts both for experimental and mechanism‐induced contributions, this result supports the upper range of previously reported, largely scattered high temperature rate constants. Vis–UV light of 174 nm was generated by a microwave N2discharge lamp. At typical reflected shock wave conditions of 1750 K and 1.3 atm, as low as 33 ppm formaldehyde could be detected. High temperature absorption cross sections of CH2O and other selected species have been determined. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 374–386, 2002
Rate constants for H + CH4, CH3 + H2, and CH4 dissociation at high temperature
Authors: Sutherland J. W. , Su M.‐C. , Michael J. V. 
Published: August 2002

AbstractThe Laser Photolysis‐Shock Tube technique coupled with H‐atom atomic resonance absorption spectrometry has been used to study the reaction, H + CH4 → CH3 + H2, over the temperature range, 928–1697 K. Shock‐tube studies on the reverse of this reaction, CH3 + H2 → H + CH4, using CH3I dissociation in the presence of H2 yielded H‐atom formation rates and rate constants for the reverse process over the temperature range, 1269–1806 K. These results were transformed (using well‐established equilibrium constants) to the forward direction. The combined results for H + CH4 can be represented by an experimental three parameter expression, k = 6.78 × 10−21 T3.156 exp(−4406 K/T) cm3 molecule−1 s−1 (348–1950 K) that was evaluated from the present work and seven previous studies. Using this evaluation, disagreements between previously reported values for the dissociation of CH4 could be reconciled. The thermal decomposition of CH4 was then studied in Kr bath gas. The dissociation results agreed with the earlier studies and were theoretically modeled with the Troe formalism. The energy transfer parameter necessary to explain both the present results and those of Kiefer and Kumaran (J Phys Chem 1993, 97, 414) is, −〈ΔE〉all/cm−1 = 0.3323 T0.7. The low temperature data on the reverse reaction, H + CH3 (in He) from Brouard et al. (J Phys Chem 1989, 93, 4047) were also modeled with the Troe formalism. Lastly, the rate constant for H + CH4 was theoretically calculated using conventional transition state theory with Eckart tunneling corrections. The potential energy surface used was from Kraka et al. (J Chem Phys 1993, 99, 5306) and the derived T‐dependence with this method agreed almost perfectly with the experimental evaluation. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 669–684, 2001
Total value management — a knowledge management concept for integrating TQM into concurrent product and process development
Authors: Prasad Biren 
Published: August 2002

AbstractMost industrial implementations of total quality management (TQM) are based on dimensions, which are ‘quality‐oriented’, goals are ‘quality‐focused’ or efforts are ‘quality‐driven’. Today manufacturing sectors are much more fiercely competitive and global than before. Consumers are more demanding, competition is more contentious and ruthless, and technology is advancing (and changing) rapidly. The quality‐based philosophy inherent in a TQM implementation does not exploit the concurrencies present in today's complex product design, development and delivery (PD3) environment. The competitors are always finding better and faster ways of designing and developing products. With the TQM process alone, it is difficult to accomplish all aspects of Total Value Management (TVM) such as X‐ability, cost, leanness, responsiveness, agility, tools and technology, and organization issues. A new concurrent Knowledge Management process for Total Value Management is proposed here, which accounts for concurrency — paralleling of value characteristics — along with an integrated methodology for their systematic deployment. Copyright © 2001 John Wiley & Sons, Ltd.
Towards an integrated approach to knowledge management: ‘hard’, ‘soft’ and ‘abstract’ issues
Authors: Hlupic Vlatka , Pouloudi Athanasia , Rzevski George 
Published: August 2002

AbstractCompanies are often unaware of the potential value of corporate information and extent of data held in their systems. It is increasingly argued that analysis of such data and information can be transformed into knowledge that in turn can be used to gain business benefits such as a competitive advantage, minimization of costs, improved quality, responsiveness, or improved service to customers. This paper investigates the benefits of a systematic and interdisciplinary approach to research in knowledge management, particularly in investigating technical (‘hard’), organizational (‘soft’), as well as philosophical (‘abstract’) aspects of the concept. It describes in detail the framework used in research undertaken by the Centre for Knowledge and Business Process Management at Brunel University. We argue that this framework is useful to researchers and practitioners alike as it contributes to a systematic and more effective knowledge management approach. Copyright © 2002 John Wiley & Sons, Ltd.
Evaluating enterprise resource planning (ERP) systems using an interpretive approach
Authors: Skok Walter , Legge Michael 
Published: August 2002

AbstractEnterprise Resource Planning (ERP) systems may be defined as the implementation of standard software modules for core business processes, usually combined with customization for competitive differentiation. The aim is to provide breadth of integration and depth of functionality across multi‐functional and often multi‐national organizations. However, current research has shown that there has been a notable decrease in the satisfaction levels of ERP implementations over the period 1998–2000. The environment in which such software is selected, implemented andused may be viewed as a social activity system, which consists of a variety ofstakeholders e.g.users, developers, managers, suppliers and consultants. In such a context, an interpretive research approach is appropriate in order to understand the influences at work. This paper reports on an interpretive study that attempts to understand the reasons for this apparent lack ofsuccess by analyzing issues raised by representatives of key stakeholder groups. Conclusions are drawn on a wide range of organizational, management, cultural and political issues that provide guidance in managing such large‐scale, complex business projects. These conclusions have led theauthors to review the area of critical success factors (CSFs) for IS projects and to identify those peculiar to ERP projects. Copyright © 2002 John Wiley & Sons, Ltd.
The hydrological impacts and sustainability of wetland drainage cultivation in Illubabor, Ethiopia
Authors: Dixon A. B. 
Published: August 2002

AbstractWetlands are critical resources in the highlands of southwest Ethiopia, where they perform numerous environmental functions and provide a range of benefits for local communities. In recent years, however, an increase in the drainage and cultivation of these areas and reports of wetland degradation have raised concerns over the sustainability of wetland agriculture. This paper presents the results of a study in which groundwater levels were monitored in a series of wetlands undergoing different stages of drainage and cultivation, to establish the hydrological changes taking place as a consequence. The results suggest that drainage and cultivation induce extreme spatial and temporal variations in the wetland watertable. This is linked in part to structural and chemical changes in the wetland soil which affect hydraulic conductivity. Statistical analysis of this variability revealed the existence of wetland subunits, exhibiting specific hydrological behaviour, which may reflect the influence of current and past land use. Although degradation of these wetlands does occur, many wetland users are aware of their impacts and have developed practices which, in most cases, prevent overdrainage to the extent that the wetlands cannot support agriculture. In this respect, it is argued that wetland use remains hydrologically sustainable, although this ultimately rests upon the ability of communities to continue to develop and apply their indigenous wetland management practices under rapidly changing environmental, socio‐economic and political conditions. Copyright © 2002 John Wiley & Sons, Ltd.
Voluntary simplicity and the ethics of consumption
Authors: Shaw Deirdre , Newholm Terry 
Published: August 2002

AbstractThe increased levels of consumption that have accompanied our consumer‐oriented culture have also given rise to some consumers questioning their individual consumption choices, with many opting for greater consumption simplicity. This link between consideration of actual consumption levels and consumer choices is evident among a group of consumers known as ethical consumers. Ethical consumers consider a range of ethical issues in their consumer behavioral choices. Particularly prevalent is voluntary simplification due to concerns for the extent and nature of consumption. Through the presentation of findings from two qualitative studies exploring known ethical consumers, the relationship of consumer attitudes to consumption levels, and how these attitudes impact approaches to consumer behavior, are discussed. © 2002 John Wiley & Sons, Inc.