bluuebunny/crossref_metadata_2025_split huggingface dataset:
A modified extraction and clean‐up procedure for the detection and determination of parathion‐methyl and chlorpyrifos residues in tea
Authors: Shanker Adarsh , Sood Chitra , Kumar Vipin , Ravindranath Srigripuram Desikachar 
Published: September 2002

AbstractRecent advances in methodology and instrumentation have made possible the detection and determination of pesticides at µg kg−1 (ppb) levels. The sensitivity of a method of analysis depends greatly on the efficient extraction of the pesticide and the subsequent clean‐up of the extract. The extract from green tea leaves is a mixture of aroma components, polyphenols and caffeine. The preparation of made tea from green tea leaves adds to this complexity by concentrating these co‐extractives. Conventional clean‐up techniques provide poor recoveries for parathion‐methyl and chlorpyrifos from both green tea leaves and made tea. This arises from interference by caffeine during gas chromatography, as it has a similar retention time to the two pesticides and peaks overlap. A modification to the protocol based on a solvent partitioning process using dichloromethane and subsequent washing of the extracts with warm water removed the caffeine, and pigments were removed by column chromatography. Recoveries ranging from 80 to 90% were then obtained for both pesticides.© 2001 Society of Chemical Industry
On the practical use of weld improvement methods
Authors: Nussbaumer A , Imhof D 
Published: September 2002

AbstractMany laboratory studies have shown the beneficial effects of weld improvement methods on the fatigue strength of welded details. However, no structural codes systematically include weld improvement methods in detail classification. The purpose of this paper is to discuss the possibilities of using these methods in practice on either new or existing structures. This paper provides the reader with practical rules for designing and computing the fatigue strength of improved welded joints. A computation method based on the concept of effective stress range is introduced to model the effects of peening improvement methods on fatigue strength. For the most popular improvement methods, the fatigue strength of improved details can be deduced from the extensive existing database of full‐scale test results. However, for non‐classified details, or when fabrication and improvement processes require validation, testing of the improved details is the only method available to guarantee the fatigue strength of a particular detail. In this paper a recent application of validation through testing in the case of longitudinal attachments is described.
Prediction of bending strength of long corrugated boxes
Authors: Panyarjun Oranis , Burgess Gary 
Published: September 2002

AbstractLong corrugated boxes were supported at both ends and bent by a concentrated force applied at the middle. Boxes with different lengths, cross‐sectional shapes, flute directions and board strengths were tested, using a standard compression tester with a fixed platen in accordance with ASTM D‐642. An equation was developed to relate compression strength to the various properties of the box. The correlation coefficient R2 for the fit to actual data was about 0.4. Boxes having the flutes run around the box had a 20% higher compression strength than with horizontal flutes. The most significant factor was found to be the board edge crush strength. The results suggest that failure of boxes in bending is due to localized crushing at the point of application of the load, rather than whole‐box collapse. Copyright © 2001 John Wiley & Sons, Ltd.
Stability of fruit juice drinks in aseptic packages
Authors: Alves Rosa M. Vercelino , Sarantópoulos Claire I. G. L. , Saron Elisabete Segantini , Bordin Maurício R. 
Published: September 2002

AbstractCashew and passion fruit juice drinks were aseptically filled in cartons and in three types of plastic packages (with oxygen transmission rate‐OTR of 1,40; 2,96 and 13,74 cm3 (STP)/m2/day at 25 °C, 75% RH and 1 atm), with nitrogen gas flushing. No adverse effect on product sterility was found, neither were any significant changes in pH and acidity detected during storage at 25 ± 2°C. A decrease of the oxygen concentration in the headspace of the cashew juice drink plastic packs was observed, which appears to be caused by consumption of that gas in oxidation reactions. The shelf‐life of the cashew juice drink was limited to 45–70 days, after which period sensory changes attained objectionable levels (development of dark colours and deterioration of the typical fruit flavour). Passion fruit juice drink proved to be less sensitive to oxygen than cashew, since an increase of the oxygen concentration was detected in the headspace of the three plastic packs. The shelf‐life of passion fruit juice drink was limited to 70–90 days, due to deterioration of the typical passion fruit flavour and colour. Copyright © 2001 John Wiley & Sons, Ltd.
Ab initio study of reactions of hydroxyl radicals with chloro‐ and fluoro‐substituted methanes
Authors: El‐Taher S. 
Published: September 2002

AbstractAb initio calculations at the unrestricted Hartree–Fock (UHF) level have been performed to investigate the hydrogen abstraction reactions of ⋅OH radicals with methane and nine halogen‐substituted methanes (F, Cl). Geometry optimization and vibrational frequency calculations have been performed on all reactants, adducts, products, and transition states at the UHF/6‐31G* level. Single‐point energy calculations at the MP2/6‐31++G* level using the UHF/6‐31G* optimized geometries have also been carried out on all species. Pre‐ and postreaction adducts have been detected on the UHF/6‐31G* potential energy surfaces of the studied reactions. Energy barriers, ΔE‡, reaction energies, ΔEr, reaction enthalpies, ΔHr, and activation energies, Ea, have been determined for all reactions and corrected for zero‐point energy effects. Both Ea and ΔHr come into reasonable agreement with the experiment when correlation energy is taken into account and when more polarized and diffuse basis sets are used. The Ea values, estimated at the PMP2/6‐31++G* level, are found to be in good agreement with the experimental ones and correctly reproduce the experimentally observed trends in fluorine and chlorine substitution effects. A linear correlation between Ea and ΔHr is obtained, suggesting the presence of an Evans–Polanyi type of relationship. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem 84: 426–440, 2001
Accurate mass measurement of synthetic analogues of prazosine by matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry
Authors: Andalò Christian , Bocchini Paola , Pozzi Romina , Galletti Guido C. 
Published: September 2002

AbstractMatrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOFMS) has been investigated as a tool for accurate determination of the molecular mass of synthetic analogues of prazosine, a molecule used for the treatment of hypertension. Samples were dissolved in methanol, mixed with mass calibration standards, and crystallised on the target with α‐cyano‐4‐hydroxycinnamic acid as matrix. Acquisition of spectra was rapidly completed in reflectron mode, allowing high resolution (6000–10000) and sensitive (about 1–10 pmol of sample on target) determination of the synthetic products. The results show the effectiveness of MALDI‐TOFMS for accurate mass determination of these fairly large molecules, which are otherwise difficult to analyse by other high‐resolution mass spectrometric techniques. Copyright © 2001 John Wiley & Sons, Ltd.
An experimental comparison of electrospray ion‐trap and matrix‐assisted laser desorption/ionization post‐source decay mass spectra for the characterization of small drug molecules
Authors: LeRiche Tammy , Osterodt Jens , Volmer Dietrich A. 
Published: September 2002

AbstractAn experimental comparison of product ion spectra produced by matrix‐assisted laser desorption/ionization (MALDI) and electrospray ion‐trap MS
n for a group of small drug molecules is presented in this paper. The goal of the study was to demonstrate the usefulness of MALDI‐MS with post‐source decay (PSD) and collision‐induced dissociation (CID) for the structural analysis of small drug molecules in the drug discovery process, where traditionally electrospray LC/MS methods are used. PSD and PSD/CID gave diverse product ions that were highly indicative of the structure of the drugs investigated (a group of 4‐quinolone antibiotics and oleandomycin). In addition, the number of different product ions generated with MALDI‐MS was always higher than with electrospray ion‐trap MS
n (with n ≤4) for the drug molecules studied. This investigation also showed that the choice of a suitable MALDI matrix for the analysis of low molecular weight compounds is quite important. It was found that of the three matrices examined, α‐cyano‐4‐hydroxycinnamic acid (α‐CHCA) produced the most intense fragmentation levels while TiO2, with its advantage of virtually no low mass background signals, did not generate quite the same amount of information. Copyright © 2001 John Wiley & Sons, Ltd.
The generalized Rice lognormal channel model—first and second order statistical characterization and simulation
Authors: Vatalaro F. , Mazzenga F. , De Maio G. , Forcella A. 
Published: September 2002

AbstractThe Rice‐lognormal (RLN) channel model was recently generalized to include an additive scattering component having constant average power. The generalized Rice‐lognormal (GRLN) model includes as limiting cases many well‐known narrowband models such as, e.g. Rice, lognormal (and combinations), and Loo's. The paper provides the GRLN first‐order statistical description of envelope and phase, and the second‐order statistics in terms of level crossing rate. The paper then provides a fitting procedure to extract model parameters from experimental data. Finally, it presents a new simulation procedure and validates it through comparison with theoretical results. Copyright © 2002 John Wiley & Sons, Ltd.
Structuring financial empowerment for localized development within Joint Forest Management (JFM): examples from Madhya Pradesh, India1
Authors: Sethi Pia , Khan Hilaluddin 
Published: September 2002

AbstractJoint Forest Management (JFM) in India provides local communities with forest usufructs such as fuelwood, fodder, non‐timber forest produce and a share in the final timber harvest in lieu of their forest protection and regeneration activities. Such usufructs, alone, are unlikely to sustain interest in the JFM programme. Instead, village resource development activities may provide a potent mechanism for reducing dependence on forests, for enhancing participation in the JFM programme and for leading to improvements in people's livelihood status. Through case studies on the experiences with village development in the Indian state of Madhya Pradesh, this paper attempts to make a case for using JFM as a medium for localized development and for diversifying and encouraging fund sources for this purpose, particularly village common funds. Copyright © 2001 John Wiley & Sons, Ltd and ERP Environment.
Direct visualization of telomeric DNA loops in cells by AFM
Authors: Chen Ai , Cao En‐Hua , Sun Xue‐Guang , Qin Jing‐Fen , Liu Dage , Wang Chen , Bai Chun‐li 
Published: September 2002

AbstractTelomeres are an essential nucleoprotein structure at the ends of all eukaryotic chromosomes. Studies on the structure and function of telomeres have received particular attention owing to their possible significance to ageing and cancer. In this work, human telomere from HeLa cells were isolated and purification by bio‐gel P‐2 column. Large duplex loops with a tail were first observed directly in the purified telomeric DNA species by atomic force microscopy (AFM). The lengths of the loop and tail are ∼2.5 ± 0.5 and 2.0 ± 1.5 kb, respectively. The AFM images also showed that the circular portion of loops is assumed to be a double‐stranded structure according to its apparent height, but to be a triplex or tetraplex structure for the loop–tail junction. These results indicate that telomeres in human cells may end in large loops, which is an advantage in further studies on the structure and function of telomeres in cells and provides a new procedure for the study of telomere structure. Copyright © 2001 John Wiley & Sons, Ltd.
Room‐temperature surface structure of 4‐aminobenzoic acid on Cu(110) surfaces
Authors: Chen Q. , Frankel D. J. , Richardson N. V. 
Published: September 2002

AbstractThe room‐temperature adsorption of 4‐aminobenzoic acid on a Cu(110) surface is studied with high‐resolution electron energy‐loss spectroscopy (HREELS), low‐energy electron diffraction (LEED), temperature‐programmed desorption and scanning tunnelling microscopy. Initially, the molecule adsorbs in a flat‐lying geometry and forms domains with a periodicity of (3 × 4)g. Increasing the coverage, the surface is saturated with this flat‐lying structure at a coverage of 0.167 ML. Further increasing the surface coverage, the HREEL spectrum shows some additional upright species without any change in LEED pattern. Scanning tunnelling microscopy shows that this upright species is present along domain boundaries that are preferentially aligned along the (3, ±4) directions. Copyright © 2001 John Wiley & Sons, Ltd.
In situ STM studies on underpotential deposition of Sn on Au(100)
Authors: Yan J. W. , Tang J. , Yang Y. Y. , Wu J. M. , Xie Z. X. , Sun S. G. , Mao B. W. 
Published: September 2002

AbstractWe present in situ STM studies on Sn electrodeposition on Au(100) surfaces at underpotentials. The Sn under potential deposition (UPD) on Au(100) proceeds in three stages: the reversible submonolayer UPD; surface alloying; and alloying that extends to the bulk. The formation of the reversible submonolayer UPD proceeds in the form of clusters of ∼2 nm at potentials as early as 0.04 V. The surface alloying takes place at −0.04 V, which is evidenced by sudden immersion of the Sn clusters as well as significant changes of steps on the surface. The bulk alloying sets in at −0.3 V, which leads to rapid change of the surface morphology. The earlier set in of the surface and bulk alloying process is considered the result of enhanced interdiffusion of Sn and Au atoms upon decreasing the potential. It has been shown that Sn UPD on Au(100) is much more complex than that of other metal UPD systems studied previously by electrochemical scanning tunnelling microscopy, but it serves as a good system for all‐sided studies of the UPD processes. Copyright © 2001 John Wiley & Sons, Ltd.
Characteristics of Au/Ti/p‐diamond ohmic contacts prepared by r.f. sputtering
Authors: Zhen Congmian , Liu Xueqin , Yan Zhijun , Gong Hengxiang , Wang Yinyue 
Published: September 2002

AbstractLow‐resistance ohmic contacts were fabricated on diamond films by boron ion implantation and subsequent Ti/Au bilayer metallization. The I–V measurements showed that the as‐deposited contacts were ohmic. After annealing at 500 °C for 10 min in a vacuum of 10−4Pa, the I–V characteristics were improved significantly. As a result of annealing, the specific contact resistance (ρC) value, measured by the circular transmission line model (CTLM), decreased from 6.2 × 10−3 to 1.2 × 10−6 Ω·cm2. Compared with the value calculated by the transmission line model (TLM), the ρC value was reduced by more than two orders of magnitude for the annealed contacts. The CTLM should be more accurate in measurement than the TLM. The changes of the ρC value with the operating temperature indicated that the ρC value decreased with increasing operating temperature at low temperatures. Tunnelling was suggested to be the dominant transport mechanism at the metal/diamond interface. The band model was quantified. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of sulphonation on polymer and polymer blend surfaces studied by atomic force microscopy
Authors: Berlinger A. , Gliemann H. , Barczewski M. , Durigon P. E. R. , Siqueira Petri D. F. , Schimmel Th. 
Published: September 2002

AbstractFilms of immiscible blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) on silicon wafers were prepared by spin‐coating and subsequently modified by sulphonation with sulfuric acid. The weight ratios of the polymer blends were 1 : 3 and 3 : 1. The increase of the PS fraction combined with chemical treatment of the blends with sulfuric acid results in an increase in surface wettability by water. This correlation can be understood by investigating the influence of these parameters on the surface of the polymer blends by atomic force microscopy. To determine the distribution of PS and PMMA within the polymer blends we used cyclohexane and acetic acid as selective solvents for PS and PMMA, respectively, and compared the coating topography before and after treatment with the solvents. Copyright © 2001 John Wiley & Sons, Ltd.
Plasma modification of PTFE surfaces. Part II: Plasma‐treated surfaces following storage in air or PBS
Authors: Wilson D. J. , Williams R. L. , Pond R. C. 
Published: September 2002

AbstractThe mechanisms and kinetics of the ageing process of polytetrafluoroethylene (PTFE) samples stored in either phosphate‐buffered saline (PBS) or air for periods of up to 1 month have been investigated. Changes of surface chemistry and wettability were studied as a function of ageing time using the complementary techniques of x‐ray photoelectron spectroscopy, static secondary ion mass spectroscopy and dynamic contact angle measurements. Specimens were aged either in the as‐received condition or after treatment by O2, Ar, N2 and NH3 plasma as described in Part I. Evidence was obtained for two ageing mechanisms, namely chemical reaction with the storage medium and relaxation in the surface region of the polymer. The extent of these mechanisms depended on the initial plasma treatment and the nature of the storage medium. These issues are discussed in a framework that correlates wettability with surface chemistry in a semiquantitative manner. This analysis facilitates comparison of the changes induced on virgin material by plasma treatment and ageing in storage environments relevant to the biomedical application of PTFE. Copyright © 2001 John Wiley & Sons, Ltd.
ToF‐SIMS and XPS study of photoactivatable reagents designed for surface glycoengineering. Part III. 5‐Carboxamidopentyl‐N‐[m‐[3‐(trifluoromethyl)diazirin‐3‐yl]phenyl‐β‐D‐galactopyranosyl]‐(1‐>4)‐1‐thio‐β‐D‐glucopyranoside (lactose aryl diazirine) on diamond
Authors: Léonard D. , Chevolot Y. , Heger F. , Martins J. , Crout D. H. G. , Sigrist H. , Mathieu H. J. 
Published: September 2002

AbstractTime‐of‐flight Secondary Ion Mass Spectrometry (ToF‐SIMS) and x‐ray photoelectron spectroscopy (XPS) are used to characterize a newly synthesized glycosylated photoactivatable reagent designed for surface glycoengineering. The immobilization on diamond surfaces of the glycoaryldiazirine reagent lactose aryl diazirine (5‐carboxamidopentyl‐N‐[m‐[3‐(trifluoromethyl)diazirin‐3‐yl]phenyl‐β‐D‐galactopyranosyl]‐(1‐>4)‐1‐thio‐β‐D‐glucopyranoside) is compared to a previously studied monoglycosylated photoactivatable reagent (MAD‐Gal). The XPS atomic constituents and chemical shifts, as well as ToF‐SIMS specific characteristic fragments and molecular peaks of the new photoimmobilized molecule are recorded. Spectral differences are identified in XPS C 1s spectra and in the high mass range of positive ion ToF‐SIMS spectra for the surface immobilized disaccharide. The ToF‐SIMS characteristic high‐mass ions involve both cationization with Na+ and loss of the diazirine function. The results can be related to differences observed in biological assays with each of the surface immobilized saccharides. Copyright © 2001 John Wiley & Sons, Ltd.
Surface‐related investigations to characterize different preparation techniques of Sb‐doped SnO2 powders
Authors: Szczuko D. , Werner J. , Behr G. , Oswald S. , Wetzig K. 
Published: September 2002

AbstractAntimony‐doped tin oxide powders were prepared using different routes and annealing conditions. The influence of preparation on the distribution of antimony in the powders was studied and correlated with the electrical properties of the powders. A model of doped SnO2 powder that allows the bulk concentration of the doping element to be calculated from the XPS results is proposed. The doping after crystallization of SnO2 leads to a very strong surface segregation that is proved by x‐ray photoelectron spectroscopy. Antimony is incorporated at the largest concentration in the tin oxide lattice when it is added during the formation of stannic acid. The annealing temperature plays an important role in the antimony distribution. The lower the temperature, the smaller the crystallite size and the lower the incorporation of antimony in the lattice of SnO2. A strong correlation between bulk concentration and electrical and morphological properties was found. Copyright © 2001 John Wiley & Sons, Ltd.
Comment on ‘AES and SAM microanalysis of structure ceramics by thinning and coating the backside. Yu and Jin’
Authors: Paparazzo E. 
Published: September 2002

AbstractA paper by Yu and Jin (Surf. Interface Anal. 2001; 31: 338) describing Auger microanalysis of ceramic insulating materials is commented upon. The major criticism regards the authors' claim that reliable scanning Auger microscopy (SAM) analysis can be performed on the (Y,La)‐doped α‐Si3N4 sample when this is made thinner by dimpling and Ar+ ion etching, two procedures that prevent surface charging phenomena. In fact, this comment shows that: Ar+ ion bombardment produces insurgence of Si–Si bonding states as a result of chemical reduction of surface SixNyOz species, so that no chemical‐state information actually can be derived from the Si LVV and Si KLL spectra of this sample because the layers probed by Auger analysis are not very reminiscent of the genuine chemical composition of this material; and SAM imaging results obtained from the same material are heavily affected by topographical artefacts and no reliable information thus can be derived from its true microchemical surface lateral heterogeneity.It is suggested that the use of reflected electron energy‐loss microscopy, i.e. a technique that is in itself immune to surface charging phenomena, would have been likely to assist better than SAM in the microchemical characterization of insulating materials. Copyright © 2001 John Wiley & Sons, Ltd.
Reply to “Comment on ‘AES and SAM microanalysis of structure ceramics by thinning and coating the backside. Yu and Jin’”
Authors: Yu Ling , Jin Deling 
Published: September 2002

AbstractThe comments by Paparazzo1 on our paper2 raise some interesting points that certainly deserve further comment. In the discussion below we address the two substantive points raised by Paparazzo and show that, in our opinion, our methodology is a valid approach to the type of analysis in question. Copyright © 2001 John Wiley & Sons, Ltd.
Reproducibility in r.f.‐GDOES depth profiling analysis of thin films
Authors: Shimizu K. , Habazaki H. , Skeldon P. , Thompson G. E. 
Published: September 2002

AbstractThe reproducibility in radiofrequency glow discharge optical emission spectroscopy (r.f.‐GDOES) depth profiling has been examined using a 360 nm thick anodic alumina film with a chromium‐containing delta‐function layer. The time required to sputter through the film was constant, to within 1%, whereas the signal intensities of film species agreed to within 3%. This level of reproducibility together with high depth resolution makes the technique ideal for on‐site quality control of various surface‐enhanced industrial products, embracing electronics and protective surface treatments. Copyright © 2001 John Wiley & Sons, Ltd.