bluuebunny/crossref_metadata_2025_split huggingface dataset:
Particle simulation of spontaneous crack generation problems in large‐scale quasi‐static systems
Authors: Zhao Chongbin , Hobbs B. E. , Ord A. , Hornby P. , Peng Shenglin , Liu Liangming 
Published: August 2006

AbstractTo extend the application range of the distinct element method from a laboratory scale into a large scale such as a geological scale, we need to deal with an upscale issue associated with simulating spontaneous crack generation problems in large‐scale quasi‐static systems. Toward this direction, three important simulation issues, which may affect the quality of the particle simulation results of a quasi‐static system, have been addressed in details in this paper. The first simulation issue is how to determine the particle‐scale mechanical properties of a particle from the measured macroscopic mechanical properties of rocks. The second simulation issue is that the fictitious time, rather than the physical time, is used in the particle simulation of a quasi‐static problem. The third simulation issue is that the conventional loading procedure used in the distinct element method is conceptually inaccurate, at least from the force propagation point of view. A new loading procedure is proposed to solve the conceptual problem resulting from the third simulation issue. The proposed loading procedure is comprised of two main types of periods, a loading period and a frozen period. Using the proposed loading procedure, the parameter selection problem stemming from the first issue can be somewhat solved. Since the second issue is an inherent one, it is strongly recommended that a particle‐size sensitivity analysis of at least two different models, which have the same geometry but different smallest particle sizes, be carried out to confirm the particle simulation result of a large‐scale quasi‐static system. The related simulation results have demonstrated the usefulness and correctness of the proposed loading procedure for dealing with spontaneous crack generation problems in large‐scale quasi‐static geological systems. Copyright © 2006 John Wiley & Sons, Ltd.
A boundary condition in Padé series for frequency‐domain solution of wave propagation in unbounded domains
Authors: Song Chongmin , Bazyar Mohammad Hossein 
Published: August 2006

AbstractA boundary condition satisfying the radiation condition at infinity is frequently required in the numerical simulation of wave propagation in an unbounded domain. In a frequency domain analysis using finite elements, this boundary condition can be represented by the dynamic stiffness matrix of the unbounded domain defined on its boundary. A method for determining a Padé series of the dynamic stiffness matrix is proposed in this paper. This method starts from the scaled boundary finite‐element equation, which is a system of ordinary differential equations obtained by discretizing the boundary only. The coefficients of the Padé series are obtained directly from the ordinary differential equations, which are not actually solved for the dynamic stiffness matrix. The high rate of convergence of the Padé series with increasing order is demonstrated numerically. This technique is applicable to scalar waves and elastic vector waves propagating in anisotropic unbounded domains of irregular geometry. It can be combined seamlessly with standard finite elements. Copyright © 2006 John Wiley & Sons, Ltd.
A case for Sherlock Holmes: forensic investigation of a gunshot wound to the head dating from Victorian London
Authors: Bailey J. , Mitchell P. D. 
Published: August 2006

AbstractThis is an investigation of a fatal gunshot wound that occurred over a century ago, in Victorian England. Records dating from 1900 show that it was regarded as suicide by officials of the time. Forensic, palaeopathological, and historical techniques are applied in order to determine whether the manner of death was suicide, murder, or accident. Comparison of the projectile trajectory with modern forensic series suggests that this case is statistically more likely to have been a murder than a suicide. This raises the possibility that a killer successfully staged events to appear as if a suicide had taken place. A summary is given of the important points to consider when interpreting gunshot trauma to the head in skeletal remains. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of time aids on independence and autonomy in adults with developmental disabilities
Authors: Arvidsson Gunnel , Jonsson Hans 
Published: August 2006

AbstractThe aim of this study was to describe how people with developmental disabilities experienced the use of time aids one year after their introduction by an occupational therapist. Data were obtained through semi‐structured interviews. The analysis was performed using a phenomenographic qualitative approach. The results showed that independence and autonomy should be considered as two separate phenomena. Increased independence did not always lead to increased autonomy or vice versa. Four different relationships between these two phenomena were found. They all illustrate the different priorities of the participants and different levels of independence and autonomy. Concerning the usability of time aids, the occupational therapist has to recognize the importance of having frequent communication with the client to understand the phenomena that may affect the use of the aids. The occupational therapist should always try to involve both the client and significant support persons while introducing time aids. Future research in time aids with clients with developmental disabilities could involve multiple interviews with participants combined with participant observations and interviews. Copyright © 2006 John Wiley & Sons, Ltd.
Cultural influences on occupational therapy practice in Singapore: a pilot study
Authors: Yang SuYi , Shek Mei Poh , Tsunaka Megumi , Lim Hua Beng 
Published: August 2006

AbstractOver the past decades, numerous occupational therapy frameworks have been published and adopted in the West but there is little discussion of their applicability to Singapore. The purpose of this study was to examine the relevance and applicability of occupational therapy frameworks in Singapore. Data were gathered from nine highly experienced occupational therapists. Audio‐taped semi‐structured interviews were used to collect data. Qualitative methods were used in identifying five themes – independence, applicability of client‐centred practice, concepts of occupation/activity, client's areas of concern, and application of occupational therapy models to practice. The themes were discussed in the context of three broad areas: (1) the potential discrepancy between occupational therapy's philosophical base and clients' values, (2) mismatch between the occupational therapists' prescription of activity and the meaning of activities to clients, and (3) the potential conflict between the occupational therapy approach and the corporate culture in Singapore. One of the important results from the study was that in Singapore culture, clients generally did not believe that achieving independence was important and they expected to be taken care of by their families. Further research with a larger sample is necessary to explore how culture and societal values impact on occupational therapy practice in Singapore. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of 2,2′‐biphenol‐ and 1,1′bi(2‐napthol)‐based poly(ether sulfones) and copolymers by classical step‐growth polymerization and by entropically‐driven ring‐opening polymerization of macrocyclic oligomers
Authors: Ben‐Haida Abderrazak , Hodge Philip , Nisar Mohammed , Helliwell Madeleine 
Published: August 2006

Abstract2,2′‐Biphenol‐ and (R/S)‐ and (R)‐1,1′‐bi(2‐naphthol)‐based polysulfones were synthesized by classical step‐growth polymerizations and by entropically‐driven ring‐opening polymerizations (ED‐ROPs) of the corresponding macrocyclic oligomers (MCOs). To facilitate comparisons, the polysulfone derived from 4,4′‐cyclohexylidenebisphenol was synthesized similarly. ED‐ROP was also used to prepare copolymers. The molecular weights obtained using ED‐ROP were generally higher than those obtained using the classical step growth method. The MCOs required as the starting materials for ED‐ROPs were prepared by classical high dilution syntheses using the biphenols and bis(4‐chlorophenyl)sulfone in the presence of base. The cyclic dimer from a high dilution synthesis using (R)‐1,1′‐bi‐2‐naphthol and the cyclic dimer from a similar synthesis using 4,4′‐cyclohexylidenebisphenol were isolated as pure compounds by column chromatography and the molecular structures determined by single crystal X‐ray diffraction. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and properties of magnetite/poly (aniline‐co‐8‐amino‐2‐naphthalenesulfonic acid) (SPAN) nanocomposites
Authors: Reddy Kakarla Raghava , Lee Kwang‐Pill , Gopalan Anantha Iyengar , Showkat Ali Md 
Published: August 2006

AbstractComposites were prepared by incorporating magnetite (Fe3O4) nanoparticles into the matrix of a sulfonated polyaniline (SPAN) [poly(aniline‐co‐8‐amino‐2‐naphthalenesulfonic acid) PANSA] through chemical oxidative polymerization of a mixture of aniline and 8‐amino‐2‐naphthalenesulfonic acid in the presence of magnetite nanoparticles. The composite, magnetite/SPAN(PANSA) was characterized by means of transmission electron microscopy (TEM), X‐ray diffraction (XRD), elemental analysis (EA), Fourier transform infrared (FT‐IR) spectra, UV‐vis spectroscopy, thermogravimetric analysis (TGA), conductivity and magnetic properties measurements. TEM image shows that magnetite nanoparticles were finely distributed into the SPAN matrix. XRD pattern of the nanocomposite reveals the presence of additional crystalline order through the appearance of a sharp peak at ∼43° and 71°. Conductivity of the nanocomposite (0.23 S/cm) is much higher than pristine copolymer (1.97 × 10−2 S/cm). The results of FT‐IR and UV‐visible spectroscopy reveal the presence of molecular level interactions between SO groups in SPAN and magnetite nanoparticles in the composite. Copyright © 2006 John Wiley & Sons, Ltd.
New composite polymer electrolytes based on room temperature ionic liquids and polyether
Authors: Jiang Hui , Fang Shibi 
Published: August 2006

AbstractComposite polymer electrolytes based on room temperature ionic liquids and polyether have been designed and synthesized. All room temperature ionic liquids which contain short poly(ethylene oxide) chains have good compatibility with the prepolymer, polyether based on polysiloxane. An ultraviolet polymerization method was utilized for the curing of the composite polymer electrolytes. The composite polymer electrolytes which are composed of the room temperature ionic liquids and polyether based on polysiloxane showed high ionic conductivity and high thermal stability. The ionic conductivity of the composite polymer electrolytes is nearly two magnitudes higher than those electrolytes with pure polyether based on polysiloxane. A maximum conductivity of 1.05 × 10−3 S/cm−1 is achieved at 30°C. Thermogravimetic analysis revealed scarcely any thermal weight loss at 80°C and thermal decomposition of the composite polymer electrolytes had not been observed up to 250°C. It retains electrochemical stable till 4.2 V which is acceptable. Copyright © 2006 John Wiley & Sons, Ltd.
Preparation and characterization of poly(ethylene terephthalate)/clay nanocomposites by melt blending using thermally stable surfactants
Authors: Costache Marius C. , Heidecker M. J. , Manias E. , Wilkie Charles A. 
Published: August 2006

AbstractPoly(ethylene terephthalate) (PET)/clay nanocomposites were prepared by melt blending and their morphologies and properties were investigated through X‐ray diffraction, bright field transmission electron microscopy, thermogravimetric analysis and cone calorimetry. Three clays were comparatively studied—montmorillonite, hectorite and magadiite—all organically modified with thermally stable surfactants developed in this laboratory. Two such organic modifications were investigated, alkyl‐quinolinium surfactants and vinylbenzyl‐ammonium containing copolymers; both organic modifications combine high enough degradation temperature to allow for melt processing with PET, and also favorable thermodynamics for nanocomposite formation with PET. All nanocomposites showed about the same value for the peak heat release rate (PHRR). The amount of char increases after nanocomposite formation and this could account for the PHRRs. Copyright © 2006 John Wiley & Sons, Ltd.
The mechanism of cumene peroxidation catalyzed by cobalt(II)‐chelated copolymer
Authors: Wang Cheng‐Chien , Chen Hui‐Chun , Chen Chuh‐Yean 
Published: August 2006

AbstractCumene peroxide is an important oxidant in the chemistry industry; however, the conversion and selectivity of cumene peroxide are still not desirable in the practical preparation process because there are some side reactions occurring in the high conversion. Hence, the reaction mechanism is investigated by many researchers. Fortunately, the high catalysis performance polymeric catalyst for cumene peroxidation was successfully synthesized in a previous study, thus, the reaction mechanism is to be investigated in this study. Except for cumene peroxide, three by‐products, including acetophenone, 2‐phenyl‐2‐propanol, 1‐methylethenyl benzene of cumene peroxidation are identified from the results of high performance liquid chromatography (HPLC), gas chromatography mass spectroscopy (GC‐MS), H1‐NMR analysis. Furthermore, the mechanism of cumene peroxidation catalyzed by cobalt(II)‐chelated copolymer is also proposed herein. The initiation rate equation represents ri = k[cumene]1.0[polymer‐Co(II) complex]0.5 according to the kinetic study of cumene peroxidation catalyzed by metal‐chelated copolymer. Meanwhile, the activation energy of cumene peroxidation by metal‐chelated copolymer catalyst is 10.7 kcal/mol, which is located in the range of radical reactions. Copyright © 2006 John Wiley & Sons, Ltd.
Poly(propylene)/montmorillonite/polypyrrole composites: structure and conductivity
Authors: Mravčáková Miroslava , Omastová Mária , Pötschke Petra , Pozsgay András , Pukánszky Béla , Pionteck Jürgen 
Published: August 2006

AbstractPoly(propylene)/montmorillonite/polypyrrole (PP/MMT/PPy) composites were prepared by oxidative polymerization of pyrrole in the presence of dispersed poly(propylene) (PP) and montmorillonite (MMT) particles in aqueous solution of an anionic surfactant, dodecylbenzenesulfonic acid (DBSA), or in water/methanol solution. During the oxidative polymerization of pyrrole the exfoliated MMT rearranges to multilayered MMT intercalated with polypyrrole (PPy). The degree of intercalation depends on the charge compensation of the negatively charged MMT‐layers. Favored interlayer distances have been detected by wide angle X‐ray scattering, which are independent of the amount of PPy formed in the system. Excess PPy is located at the surface of the multilayered structures of MMT as well as at the surface of the PP particles present. The composites were processed to flat sheets. Morphology and, therefore, electrical conductivity strongly depend on the type of processing, but also on the amount of conducting PPy present in the composite and on the reaction medium used for PPy synthesis. Higher conductivities and improved stability against shear are observed when MMT is present in the composite samples compared to samples devoid of MMT. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of sulfonic group on solubility parameters and solubility behavior of poly(2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Gong Chunli , Guan Rong , Shu Yao‐Chi , Chuang Fu‐Sheng , Tsen Wen‐Chin 
Published: August 2006

AbstractAn investigation on the effect of sulfonic group on solubility parameters and solubility behavior of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) is presented. Sulfonated PPO (SPPO) was prepared using chlorosulfonic acid as a sulfonating agent. The structure of SPPO was confirmed by FT‐IR, and the ion exchange capacity (IEC) of SPPO was accurately determined by conductometric titration and 1H‐NMR. The three‐dimensional solubility parameters of SPPO defined by Hansen were estimated by group contribution, and this approach was used to obtain the three coordinates of a solubility parameter in terms of: a dispersion part δd, a polar part δp and a hydrogen bonding part δh. The theoretical predications of solubility behavior were characterized using “soluble sphere” in three‐dimensional space. The estimated results were in accordance with the solubility experiments in different solvents. Copyright © 2006 John Wiley & Sons, Ltd.
The influence of ionic liquid's nature on free radical polymerization of vinyl monomers and ionic conductivity of the obtained polymeric materials
Authors: Vygodskii Yakov S. , Mel'nik Olga A. , Lozinskaya Elena I. , Shaplov Alexander S. , Malyshkina Inna A. , Gavrilova Nadejda D. , Lyssenko Konstantin A. , Antipin Mikhail Yu. , Golovanov Denis G. , Korlyukov Alexander A. , Ignat'ev Nikolai , Welz‐Biermann Urs 
Published: August 2006

AbstractVarious 1,3‐dialkylimidazolium and tetraalkylphosphonium ionic liquids (ILs), including novel ones, have been studied as reaction media for free radical polymerization of methyl methacrylate (MMA), acrylonitrile (AN) and 1‐vinyl‐3‐ethylimidazolium salts (ViEtIm+)Y−. The influence of IL's nature upon the polymer formulation was investigated. The use of different ionic liquids allows not only to obtain the polymers with high molecular weight (PMMA, ${\bar M}_w$ up to 5,770,000 g/mol; PAN, ${\bar M}_v$ up to 735,000 g/mol and poly[(ViEtIm+)Y−], $\bar M_z$ up to 1,130,000 g/mol) in high yields, but also to control the polymerization rate and molecular mass. The physicochemical characteristics, including mechanical properties, thermal stability and heat‐resistance of the obtained polymers were studied in order to compare with those of polymers prepared in a traditional media. It was found that elongation, tensile modulus and strength of PAN, which was synthesized in ionic liquid, are reliatively higher. The influence of IL's nature upon their ionic conductivity and the formation of conductive polymers from molten‐salt‐type vinyl monomers was investigated. Molecular design of the polymers simultaneously with the influence of IL's nature in order to achieve higher ionic conductivity is discussed. Flexible, transparent polymer films, obtained in different ways, show relatively high ionic conductivity (of about 10−5 S cm−1 at 20°C). Copyright © 2006 John Wiley & Sons, Ltd.
Assembled cation‐exchange/anion‐exchange polypyrrole layers as new simplified artificial muscles
Authors: Ochoteco Estibalitz , Pomposo Jose A. , Bengoechea Miguel , Grande Hans , Rodriguez Javier 
Published: August 2006

AbstractA simplified artificial muscle has been constructed by assembling different polypyrrole structures in the same synthesis process. This produces not only “all‐polymeric” but rather a new generation of “all‐conducting‐polymer” artificial muscles, capable of moving in electrolytic media by an electrical current application with no evidence of delamination after several cycles. Suitable devices can be constructed for biomedical applications, based on this conducting polymer film. Copyright © 2006 John Wiley & Sons, Ltd.
Switch to an invasive growth phase in melanoma is associated with tenascin‐C, fibronectin, and procollagen‐I forming specific channel structures for invasion
Authors: Kääriäinen E , Nummela P , Soikkeli J , Yin M , Lukk M , Jahkola T , Virolainen S , Ora A , Ukkonen E , Saksela O , Hölttä E 
Published: August 2006

AbstractMalignant melanomas are characterized by their high propensity to invade and metastasize, but the molecular mechanisms of these traits have remained elusive. Our DNA microarray analyses of benign nevi and melanoma tissue specimens revealed that the genes encoding extracellular matrix proteins tenascin‐C (TN‐C), fibronectin (FN), and procollagen‐I (PCOL‐I) are highly upregulated in invasive and metastatic melanomas. The expression and distribution of these proteins were further studied by immunohistochemistry in benign nevi, radially and vertically growing melanomas, sentinel node micrometastases, and macrometastases. TN‐C was increased in all invasive tumours and metastases, especially at invasion fronts, but not in benign nevi or non‐invasive melanomas. Significantly, the intensity of TN‐C staining correlated with metastasis to sentinel lymph nodes, better than tumour thickness (Breslow). Moreover, TN‐C, FN, and PCOL‐I appeared to co‐localize in the tumours and form tubular meshworks and channels ensheathing the melanoma cells. Our data suggest that melanoma invasion is associated with the formation of special channel‐like structures, providing a new concept, structured tumour cell spreading. Altogether, these data provide potential new prognostic markers and therapeutic targets/strategies for preventing melanoma dissemination. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Factors influencing laboratory workers' decisions to accept or decline anthrax vaccine adsorbed (AVA): results of a decision‐making study in CDC's anthrax vaccination program
Authors: Fowler Gabrielle L. , Baggs James M. , Weintraub Eric S. , Martin Stacey W. , McNeil Michael M. , Gust Deborah A. 
Published: August 2006

AbstractBackgroundLaboratory technicians, laboratory supervisors, decontamination/remediation workers, and environmental investigators are at increased risk for repeated occupational exposure to Bacillus anthracis. In 2002, the Advisory Committee on Immunization Practices (ACIP) recommended pre‐exposure vaccination for these occupational groups.ObjectivesTo determine (1) the factors that influenced an individual's decision to either accept or decline Anthrax Vaccine Adsorbed (AVA), and (2) if laboratory workers' concern about AVA safety was related to their information needs and trust in the information provided.MethodsWe conducted a decision‐making survey of 404 participants at 44 Laboratory Response Network laboratories located throughout the United States. All participants were enrolled between October 2002 and December 2004, and all were eligible to receive AVA according to the 2002 ACIP recommendations. Chi‐square tests and multivariate logistic regression were used in the analyses.ResultsThe response rate of eligible individuals at participating laboratories was 94% (404/430). Sixty‐six percent of respondents accepted and 34% declined AVA. Laboratory workers who declined AVA were more likely to rate their risk of exposure to inhalation anthrax as low (OR = 6.9; 95%CI 1.7, 28.3), report being very concerned (OR = 4.1; 95%CI 1.8, 9.3) or concerned (OR = 2.0; 95%CI 1.3, 3.1) about the safety of the vaccine, report that they did not trust the information provided in the Vaccine Information Statement (VIS) (OR = 2.3; 95%CI 1.1, 4.5), and to be enrolled in the study during 2002 (OR = 24.7; 95%CI 6.4, 95.3) or 2003 (OR = 5.0; 95%CI 2.5, 9.8), the first 2 years of the study. Furthermore, we found a significant association between a participant's level of concern about the safety of AVA and their perception that they received enough information and/or trusted the information in the VIS.ConclusionsLow perceived necessity, concern about the safety of the vaccine, and a lack of trust in the VIS were associated with the decision of laboratory workers to decline AVA. Results of this decision‐making study may be used to try to improve acceptance rates of AVA among persons considered at high risk, and may inform educational efforts for other adult vaccines. Copyright © 2006 John Wiley & Sons, Ltd.