bluuebunny/crossref_metadata_2025_split huggingface dataset:
An empirical approach to study the occurrence of ion exchange in the ionic micellar‐mediated semi‐ionic reactions: Kinetics of the rate of reaction of piperidine with ionized phenyl salicylate in the presence of cationic micelles
Authors: Khan M. Niyaz , Ismail Emaran 
Published: September 2002

AbstractPseudo‐first‐order rate constants (kobs)—obtained for the cleavage of ionized phenyl salicylate (PS−) at constant [NaOH], [MeCN], [CTAZ]T (total concentration of cetyltrimethylammonium chloride and bromide), [Pip]T (total concentration of piperidine), and varying concentrations of sodium cinnamate, acetate, and butanoate ([NaX])—follow the relationship: kobs = (k0 + θ K[NaX])/(1 + K[NaX]), where θ and K are empirical parameters. The values of θ are almost independent of [CTAZ]T, while K values decrease with the increase in [CTAZ]T within its range 0.006–0.020 M. The values of θ and K are explained in terms of pseudophase model of micelle coupled with an empirical relationship: KS = KS0/(1 + ΨX/S [NaX]), where KS is the CTAZ micellar binding constant of PS− in the presence of NaX. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 288–294, 2001
Laboratory studies of the ·OH‐initiated photooxidation of ethyl‐n‐butyl ether and di‐n‐butyl ether
Authors: Johnson D. , Andino J. M. 
Published: September 2002

AbstractOxygenated compounds such as ethers and alcohols are used as gasoline additives and industrial solvents. However, despite their widespread use, the atmospheric reaction mechanisms of some of these compounds are unknown. This study examines the ·OH‐initiated gas‐phase removal mechanisms of ethyl‐n‐butyl ether (ENBE) and di‐n‐butyl ether (DNBE) utilizing gas chromatography–mass spectrometry techniques. The primary products and molar yields from the hydroxyl‐radical–initiated photooxidation of ENBE in the presence of nitric oxide were acetaldehyde (0.173 ± 0.012), ethyl formate (0.219 ± 0.033), butyraldehyde (0.076 ± 0.004), butyl formate (0.241 ± 0.009), butyl acetate (0.032 ± 0.001), and ethyl butyrate (0.0044 ± 0.0006). From the calculated molar yields, approximately 45.5% of the reacted carbon were recovered. The primary products and molar yields from the DNBE and hydroxyl radical reaction in the presence of nitric oxide were propionaldehyde (0.379 ± 0.022), butyraldehyde (0.119 ± 0.003), butyl formate (0.410 ± 0.009), and butyl butyrate (0.019 ± 0.001). Approximately 47.7% of the reacted DNBE were recovered. The chemical mechanisms are presented to explain the formation of these products. In addition, the importance of the isomerization and nitrate/nitrite formation pathways in the reactions of large ethers are discussed. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 328–341, 2001
Pressure effects on cation migration in 2,5‐di‐tert‐butyl‐1,4‐benzoquinone radical anion
Authors: Kasahara Masamichi , Sueishi Yoshimi , Yamamoto Shunzo 
Published: September 2002

AbstractPressure effects on the two‐site jumping of sodium and potassium cations in a 2,5‐di‐tert‐butyl‐1,4‐benzoquinone ion pair have been studied using a high‐pressure EPR technique. The rate constants of the intramolecular and intermolecular migrations for Na+ and K+ were determined from an EPR spectral simulation. The migration rates were found to be accelerated by increasing the external pressure. Using the pressure dependence of the migration rates, we estimated the activation volumes of the intramolecular (ΔV1‡) and intermolecular (ΔV2‡) processes for the Na+ and K+ migrations: ΔV1‡ = −5.3 cm3 mol−1 and ΔV2‡ = −29 cm3 mol−1 for Na+, and ΔV1‡ = −8.3 cm3 mol−1 and ΔV2‡ = −0.85 cm3 mol−1 for K+. Based on the results, the mechanisms for the two‐site jumping of Na+ and K+ are discussed in terms of volume. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 397–401, 2001
Kinetics and mechanism of alkaline hydrolysis of 4‐nitrophthalimide in the absence and presence of cationic micelles
Authors: Niyaz Khan M. , Abdullah Zunoliza 
Published: September 2002

AbstractPseudo‐first‐order rate constants (kobs) for alkaline hydrolysis of 4‐nitrophthalimide (NPTH) decreased by nearly 8‐ and 6‐fold with the increase in the total concentration of cetyltrimethyl‐ammonium bromide ([CTABr]T) from 0 to 0.02 M at 0.01 and 0.05 M NaOH, respectively. These observations are explained in terms of the pseudophase model and pseudophase ion‐exchange model of micelle. The increase in the contents of CH3CN from 1 to 70% v/v and CH3OH from 0 to 80% v/v in mixed aqueous solvents decreases kobs by nearly 12‐ and 11‐fold, respectively. The values of kobs increase by nearly 27% with the increase in the ionic strength from 0.03 to 3.0 M. The mechanism of alkaline hydrolysis of NPTH involves the reactions between HO− and nonionized NPTH as well as between HO− and ionized NPTH. The micellar inhibition of the rate of alkaline hydrolysis of NPTH is attributed to medium polarity effect. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 407–414, 2001
Oxidation of ethanolamines by sodium N‐bromobenzenesulfonamide in alkaline buffer medium: A kinetic and mechanistic study
Authors: Puttaswamy  , Vaz Nirmala , Made Gowda N. M. 
Published: September 2002

AbstractThe kinetics of oxidation of ethanolamines, monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA), by sodium N‐bromobenzenesulfonamide or bromamine‐B (BAB) in alkaline buffer medium (pH 8.7–12.2) has been studied at 40°C. The three reactions follow identical kinetics with first‐order in [oxidant] and fractional‐order each in [substrate] and [OH−]. Under comparable experimental conditions, the rate of oxidation increases in the order: DEA > TEA > MEA. The added reaction product, benzenesulfonamide, retards the reaction rate. The addition of halide ions and the variation of ionic strength of the medium have no significant effect on the rate. The dielectric effect is negative. The solvent isotope effect k′(H2O)/k′(D2O) ≈ 0.92. Activation parameters for the composite reaction and for the rate‐limiting step were computed from the Eyring plots. Michaelis‐Menten type of kinetics is observed. The formation and decomposition constants of ethanolamine‐BAB complexes are evaluated. An isokinetic relationship is observed with β = 430 K indicating that enthalpy factors control the rate. For each substrate, a mechanism consistent with the kinetic data has been proposed. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 480–490, 2001
Multi‐factorial causes of land‐use change: land‐use dynamics in the agropastoral village of Im Mial, northwestern Syria
Authors: Nielsen T. L. , Zöbisch M. A. 
Published: September 2002

AbstractLand‐use dynamics in drylands are complex processes. In the context of a typical agropastoral village in northwestern Syria Im Mial, the effects of demographic and social changes, reduced soil productivity, changes in agricultural technologies and historical events on land use and land productivity are examined. Decreasing yields, mainly the result of reduced fallow periods and low investments in the land, and the deterioration of the grazing resources are the two main signs of the loss of land productivity in the area. The growing population forces the villagers to practise continuous rainfed barley cultivation with no or only occasional fallow, and without any application of plant nutrients. Also, technological changes, from the use of donkey ploughs and hand harvesting to less labour‐intensive and time‐consuming cultivation practices with tractors and combine harvesters, and the increased importance of stubble in the livestock diet have contributed to the reduction of the fallow periods. The villagers attribute the yield decreases mainly to the low rainfall in the area. The high rainfall variability discourages the fallowing of fields because continuous cultivation maximizes the chances for good harvests in years with high rainfall. There is also an expansion of cultivation into the less fertile and sloping traditional grazing areas. Population growth, increased numbers of livestock and the expansion of cultivated land into grazing areas has also put pressure on the grazing resources of the village. The possession of livestock is seen as a sign of wealth and the villagers aim to have large flocks of animals. For them, livestock is also an important means for investment of cash earned from off‐farm work, which is the main source of income for most of the households in the village. There is a recent trend of increasing levels of crop‐livestock integration with less free grazing that produces higher return to the land users. This may also have a positive effect on the restoration and conservation of the degraded natural traditional grazing grounds. The stabilization and productive use of the land resources in this dry environment requires the combined and interdisciplinary effort from both the land‐users and the policy‐makers. Copyright © 2001 John Wiley & Sons, Ltd.
Consumer vulnerability to scams, swindles, and fraud: A new theory of visceral influences on persuasion
Authors: Langenderfer Jeff , Shimp Terence A. 
Published: September 2002

AbstractScams exact a huge toll on consumers and society at large, with annual costs in the United States alone exceeding $100 billion. The global proliferation of the Internet has enabled con artists to export their craft to a rapidly expanding market and reach previously untapped consumers. In spite of the prevalence of scams around the world, there has been virtually no academic attention devoted to understanding the factors that might account for why individuals differ in their scamming vulnerability. Building on the background of elder consumer disadvantage and informed by the authors' own survey of expert opinion, this article presents a tentative theory of scamming vulnerability. The proposed theory incorporates the effects of visceral influences on consumer response to scam offers and hypothesizes a role for various moderating factors such as self‐control, gullibility, susceptibility to interpersonal influence, and scam knowledge. Theoretical propositions are provided for future empirical investigation. © 2001 John Wiley & Sons, Inc.
Gotcha! Findings from an exploratory investigation on the dangers of using deceptive practices in the mail‐order business
Authors: Vanhamme Joëlle , Lindgreen Adam 
Published: September 2002

AbstractThis exploratory investigation examines the impact of some Belgian mail‐order companies' deceptive practices—specifically, the use of gifts—on long‐term relationships with their customers. The results support the premise that the use of deceptive gifts first elicits negative surprise and, subsequently, disappointment or even outrage. Deceptive gifts also seem to have a negative impact on the company's brand image and on the trust customers place in the company and its products. The results also suggest that the use of deceptive gifts hinders customer retention and customer loyalty. Moreover, deceptive gifts deprive the company of valuable advantages, such as preference for its products and positive perceptions of the company and its products, which could result from using non‐deceptive gifts. © 2001 John Wiley & Sons, Inc.
Biopolymer mechanics: stability, dynamics, and statistics
Authors: Wiggins Chris H. 
Published: September 2002

AbstractMotivated by the dynamics of twisted biopolymers such as DNA and filaments ofBacillus subtilis, we formulate the over‐damped dynamics of a twisted elastic rod. The development exploits the ‘natural’ frame, in which curve dynamics are described by a pair of non‐linear partial differential equations, partitioning bending from twisting motions and highlighting their geometric interplay. A number of open problems are highlighted, along with connections with questions about cellular structure and statistical dynamics. Copyright © 2001 John Wiley & Sons, Ltd.
The LGL (Lighthill–Gueron–Liron) Theorem—historical perspective and critique
Authors: Liron Nadav 
Published: September 2002

AbstractThe 1970s saw a series of works on the modelling of slender bodies moving in slow flow (Re=0), instigated by the interest to understand the principles underlying the swimming of ciliates and flagellates. It was Lighthill in 1975, who wrote down the first theorem connecting slender body motion and singularities distributions along the centre line. This paper will describe the historical development from the early results through Lighthill's theorem to the Gueron–Liron Theorem, which enables discrete‐cilia modelling, i.e., modelling of a multitude of slender bodies attached to a surface. Copyright © 2001 John Wiley & Sons, Ltd.
Smectic A liquid crystal configurations with interface defects
Authors: Calderer M. Carme , Liu Chun , Voss Karl 
Published: September 2002

AbstractWe study planar energy minimizing configurations of smectic A liquid crystal materials and classify the corresponding defect structures. We investigate focal conic configurations in wedge, non‐parallel plates, funnel‐shaped domains, and non‐concentric annuli. The application of the stability condition for focal conics is relevant to the specification of the location of the interfacial defects. Self‐similar structures are discussed for a class of solutions with the same bulk energy. We propose surface energies terms to serve as selection mechanisms of particular self‐similar configurations. We also show how the modelling of chevron texture naturally arises in the present framework. Copyright © 2001 John Wiley & Sons, Ltd.
Eigen‐frequencies in thin elastic 3‐D domains and Reissner–Mindlin plate models
Authors: Dauge Monique , Yosibash Zohar 
Published: September 2002

AbstractThe eigen‐frequencies of elastic three‐dimensional thin plates are addressed and compared to the eigen‐frequencies of two‐dimensional Reissner–Mindlin plate models obtained by dimension reduction. The qualitative mathematical analysis is supported by quantitative numerical data obtained by the p‐version finite element method.The mathematical analysis establishes an asymptotic expansion for the eigen‐frequencies in power series of the thickness parameter. Such results are new for orthotropic materials and for the Reissner–Mindlin model. The 3‐D and R–M asymptotics have a common first term but differ in their second terms.Numerical experiments for clamped plates show that for isotropic materials and relatively thin plates the Reissner–Mindlin eigen‐frequencies provide a good approximation to the three‐dimensional eigen‐frequencies. However, for some anisotropic materials this is no longer the case, and relative errors of the order of 30 per cent are obtained even for relatively thin plates. Moreover, we showed that no shear correction factor is known to be optimal in the sense that it provides the best approximation of the R–M eigen‐frequencies to their 3‐D counterparts uniformly (for all relevant thicknesses range). Copyright © 2002 John Wiley & Sons, Ltd.
Effective circle‐construction algorithms for minimizing the wavelength requirement in WDM rings
Authors: Zhu Guangyu , Yuan Fei , Ghafouri‐Shiraz H. 
Published: September 2002

AbstractCircle constructions can find many applications in the system design phase of WDM ring networks to optimize system performance, while still efficiently utilizing the network resources under consideration (e.g., total number of wavelengths or transceivers). In this letter, we present a series of matrix‐based circle‐construction algorithms to minimize the number of required wavelengths in both unidirectional and bidirectional rings under an arbitrary traffic pattern. A Matlab implementation of the algorithms can effectively generate the optimum design solution in terms of the total cost on wavelengths. Thus, it ensures that the channel bandwidth and I/O capacity in the WDM rings are utilized most efficiently. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 221–225, 2001.
Small printed‐wing antenna suitable for wireless handset terminals
Authors: Kan H. K. , Waterhouse R. B. 
Published: September 2002

AbstractA novel, small winged microstrip patch antenna incorporating a single shorting post is introduced. The proposed antenna is significantly smaller than a conventional shorted patch antenna, and is therefore very suited to wireless communication handsets where limited antenna size is a premium. Importantly, the antenna is easy to develop. An integrated version of the proposed antenna on a standard communication handset chassisep is also presented, and its performance is compliant with most cordless systems requirements. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 226–229, 2001.
A double‐folded, capacitive‐fed, cavity‐backed microstrip antenna
Authors: Ooi B. L. 
Published: September 2002

AbstractA novel, folded, capacitive‐fed microstrip antenna with a length of λ/3 and placed over a cavity backing is proposed. Compared to the small rectangular patch antenna of Luk, our proposed antenna has a large impedance bandwidth of 20.1%. The cross‐polarization level is ∼−17 dB. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 240–241, 2001.
FDTD design of bifilar and quadrifilar truncated spherical helical antennas
Authors: Yang Shiwen , Tan Soon Hie , Xia Jun 
Published: September 2002

AbstractThe radiation characteristics of bifilar and quadrifilar truncated spherical helix antennas are analyzed using the FDTD method. Special attention is paid to the generation of a circularly polarized wave over a wide region above the antenna. By introducing the multiarm structure and changing the feeding geometry, the proposed antennas are capable of providing a symmetric, circularly polarized, broad‐beam radiation pattern, as well as a conical radiation pattern. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 246–249, 2001.
A small‐signal equivalent‐circuit model of quantum‐well lasers based on three‐level rate equations
Authors: Jianjun Gao , Baoxin Gao , Chunguang Liang 
Published: September 2002

AbstractAn intrinsic equivalent‐circuit model for quantum‐well lasers is presented. The model is based on the three‐level rate equations, and includes the carrier transport effects and the role of the gateway state at the quantum well. The simulation results of the frequency response are compared with experimentally obtained data, and agreement is obtained consistently on separate confinement heterostructures (SCHs) of different sizes. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 270–271, 2001.
Quick derivation of high‐power thermal resistance values of HBTs using an existing measurement technique and a theoretical formula
Authors: Tan C. L. , Hui P. , Yan Beiping , Wang Hong , Zheng Haiqun , Yang Hong , Radhakrishnan K. 
Published: September 2002

AbstractA method is presented for the quick derivation of high‐power thermal resistance values using an existing measurement technique and a theoretical formula. It first derives the low‐power thermal resistance value, and then substitutes this value into the general form for the dependence of thermal resistance derived using the Kirchhoff transformation. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 287–289, 2001.
Comment on “On the Matching Conditions of Different PML Schemes Applied to Multilayer Isotropic Dielectric Media”
Authors: Gedney Stephen D. 
Published: September 2002

AbstractThe focus of this comment is to correct potential misconceptions regarding the application of perfectly matched layer (PML) absorbing media to terminating inhomogeneous media within the finite‐difference time‐domain (FDTD) method. Initially, it is demonstrated that the PML is material independent by nature. That is, by specifying the constitutive parameters to be independent of the host material medium, both the split‐field form and the anisotropic form (or unsplit form) of the PML are materially independent. It is then demonstrated that the split‐field and nonsplit‐field forms of the “materially independent PML” (MIPML) proposed earlier are identical to Berenger's split‐field PML and the anisotropic PML formulations, respectively, after a simple scaling of the conductivity by a constant. While this validates the MIPML, it also illustrates that the MIPML is a subset of previously proven PML methods. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 289–291, 2001.
Conformal proton radiation treatment for retroperitoneal neuroblastoma: Introduction of a novel technique
Authors: Hug Eugen B. , Nevinny‐Stickel Meinhard , Fuss Martin , Miller Daniel W. , Schaefer Rosemary A. , Slater Jerry D. 
Published: September 2002

AbstractBackgroundPostoperative irradiation for locoregionally advanced neuroblastoma requires coverage of the paraspinal retroperitoneum. The proximity of both kidneys and the liver, and a more complex target configuration, can pose a dosimetric challenge for conventional X‐ray treatment and intraoperative irradiation. We utilized proton radiation therapy (PRT) to reduce dose to uninvolved kidneys, liver, intestine, and spinal cord.ProcedureA 4‐year‐old male underwent PRT for neuroblastoma of the right adrenal gland, following chemotherapy and delayed surgical resection. Clinical target volume (CTV), boost volume, and normal structures were outlined on the 3D treatment planning CT scan. The patient received 25.2 CGE (cobalt Gray equivalent) to the CTV and 34.2 CGE to the boost region, using 1.8 CGE per fraction, five treatments per week. Dose‐volume histograms (DVHs) were obtained for target and nontarget structures.ResultsThe 95% isodose volume enclosed CTV and boost volumes. The dose to 50% of the ipsilateral kidney, with tumor involvement of the medial renal surface, was ≤ 16 CGE (47% of prescribed total dose). Doses to 50% and 20% of the contralateral kidney in close proximity to deep left‐side, paraspinal soft tissue involvement were restricted to 1 CGE and 10 CGE, respectively. Eighty percent of the liver received 27 CGE (80% of prescribed dose). Using a patch technique, unique to charged particle therapy, the spinal cord was almost completely spared during boost volume irradiation.ConclusionsPRT can achieve excellent dose conformity for advanced retroperitoneal, paraspinal lesions, while respecting normal tissue tolerance levels. Med. Pediatr. Oncol. 37:36–41, 2001. © 2001 Wiley‐Liss, Inc.
Assignment of the 1H and 13C NMR spectra, sequence and conformation of the synthetic pentasaccharide SanOrg34006 and its precursors
Authors: Bootsma Judica , Wagenaars Gerard , Dreef Erik , Hout Floris , Kellenbach Edwin 
Published: September 2002

AbstractProton and carbon chemical shift data and proton–proton coupling constants of the synthetic antithrombotic pentasaccharide SanOrg34006 and its synthetic precursors are reported. Long‐range heteronuclear correlation experiments allow the determination of the substitution pattern of the protecting groups in the precursor molecules. Also, the sequence of the oligosaccharide was confirmed this way. The conformation of the α‐L‐iduronic acid moiety was studied by the analysis of the 3J(1H,1H) coupling constants. Copyright © 2001 John Wiley & Sons, Ltd.