bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlled/living RAFT polymerization of N‐phenyl maleimide and synthesis of its block copolymers
Authors: Li Anlong , Lu Jiang 
Published: July 2009

AbstractThe controlled/living radical polymerization of N‐phenyl maleimide (NPMI) was achieved using 2,2′‐azobisisobutyronitrile as the initiator and 2‐cyanopropyl‐2‐yl dithiobenzoate as the reversible addition‐fragmentation chain transfer agent at 75°C in dichloroethane/ethylene carbonate (60/40, w/w) mixed solvent. The block copolymers of polystyrene‐b‐polyNPMI and poly(n‐butyl methacrylate)‐b‐polyNPMI were successfully prepared by chain extension from dithiobenzoate‐terminated polystyrene and poly (n‐butyl methacrylate) to NPMI, respectively. The obtained NPMI‐based (co)polymers were characterized by gel permeation chromatography and 1H‐NMR spectroscopy. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of high pressure carbon dioxide on the solubility and diffusivity of dichloromethane in polyetherimide
Authors: Law Yuk Yu , Balashova Ida M. , Danner Ronald P. 
Published: July 2009

AbstractThe high pressure inverse gas chromatography technique was used to study the effect of carbon dioxide on the solubility and diffusivity of dichloromethane in polyetherimide. CO2 was used as the carrier gas with pressures from 0.7 to 3.5 MPa and temperatures between 100 and 175°C. Similar data were obtained for the dichloromethane‐polyetherimide system using helium as the inert carrier gas. As a result of less favorable thermodynamic interactions between the polymer and solvent, the solubility of the dichloromethane was found to be decreased appreciably in the presence of CO2. The increased free volume in the polymer provided by the dissolved CO2 significantly increased the diffusion coefficient. When the temperature was increased the solubility was decreased while the diffusivity was increased. These behaviors have the potential to considerably improve devolatilization processes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of thermoset composites from natural fibres and acrylate modified soybean oil resins
Authors: Åkesson Dan , Skrifvars Mikael , Walkenström Pernilla 
Published: July 2009

AbstractStructural composites with a high content of renewable material were produced from natural fibres and an acrylated epoxidized soybean oil resin. Composites were prepared by spray impregnation followed by compression moulding at elevated temperature. The resulting composites had good mechanical properties in terms of tensile strength and flexural strength. Tensile testing as well as dynamical mechanical thermal analysis showed that increasing the fibre content, increased the mechanical properties. The resin can be reinforced with up to 70 wt % fibre without sacrifice in processability. The tensile modulus ranged between 5.8 and 9.7 GPa depending on the type of fibre mat. The study of the adhesion by low vacuum scanning electron microscopy shows that the fibres are well impregnated in the matrix. The aging properties were finally evaluated. This study shows that composites with a very high content of renewable constituents can be produced from soy bean oil resins and natural fibres. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The synthesis of poly(butylene terephthalate) from terephthalic acid, part II: Assessment of the first stage of the polymerization process
Authors: Devroede Jan , Duchateau Robbert , Koning Cor E. 
Published: July 2009

AbstractThe production of poly(butylene terephthalate) (PBT) struggles with the formation of substantial amounts of tetrahydrofuran (THF). When PBT is synthesized from terephthalic acid (TPA) instead of dimethyl terephthalate (DMT), even more THF is formed, mainly during the first stage of the melt polymerization process. Although a lot of literature reports on the existence of this side reaction in both processes, to the best of our knowledge, a comparison, which reveals the importance of the acidity and insolubility of TPA on the THF formation, was never described. Finally, an interesting study was performed on the THF formation during the synthesis of PBT from mixtures of DMT and TPA as well as from the completely soluble monomethyl terephthalate (MMT). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Kinetic and mechanistic modeling of acid‐catalyzed degradation of polymers with various cracking catalysts
Authors: Lin Yeuh‐Hui , Yang Mu‐Hoe 
Published: July 2009

AbstractA new approach is presented that combines kinetic and mechanistic considerations which take into account chemical reactions and catalyst deactivation in the modeling of the catalytic degradation of polymers. Though acid‐catalyzed hydrocarbon cracking reactions involve a large number of compounds, reactions and catalyst deactivation and are very complex, the model gives a good representation of experimental results from the degradation of polyethylene and polypropylene over fluidized acidic catalysts. This model provides the benefits of product selectivity for the chemical composition such as alkanes, alkenes, aromatics, and coke in relation to the effect of structurally different polymer feeds, the performance of the catalyst and the selection of their particle sizes, and the influence of different reaction temperatures. It is an improvement of the currently available empirical “lumping” techniques which usually are severely restricted in terms of product definitions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Melt spinning and metal chloride vapor curing process on polymethylsilsesquioxane as SiOC fiber precursor
Authors: Narisawa Masaki , Sumimoto Ryu‐Ichi , Kita Ken‐Ichiro , Kado Hiroyuki , Mabuchi Hiroshi , Kim Young‐Wook 
Published: July 2009

AbstractMelt spinning process of polymethylsilsesquioxane (PMSQ) at 403–453 K was investigated as a SiOC fiber precursor in terms of averages and distributions of spun fiber diameters. Because of fusible character of PMSQ at low temperature, the spun fibers were exposed to vapors of various metal chlorides (SiCl4, Si(CH3)Cl3, TiCl4, and BCl3) to promote the fiber curing. Cured fibers were investigated by FTIR and TG analyses. In a case of the fiber synthesized with SiCl4 curing, tensile tests on the pyrolyzed fibers were performed. Exposure of the synthesized fiber at high temperature with a flame of an oxygen‐gas burner was examined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Atom transfer radical homo‐ and copolymerization of styrene and methyl acrylate initiated with trichloromethyl‐ terminated poly(vinyl acetate) macroinitiator: A kinetic study
Authors: Semsarzadeh Mohammad Ali , Abdollahi Mahdi 
Published: July 2009

AbstractAtom transfer radical bulk copolymerization of styrene (St) and methyl acrylate (MA) initiated with trichloromethyl‐terminated poly(vinyl acetate) macroinitiator was performed in the presence of CuCl/PMDETA as a catalyst system at 90°C. Linear dependence of ln[M]0/[M] versus time data along with narrow polydispersity of molecular weight distribution revealed that all the homo‐ and copolymerization reactions proceed according to the controlled/living characteristic. To obtain more reliable monomer reactivity ratios, the cumulative average copolymer composition at moderate to high conversion was determined by 1H‐NMR spectroscopy. Reactivity ratios of St and MA were calculated by the extended Kelen‐Tudos (KT) and Mao‐Huglin (MH) methods to be rSt = 1.018 ± 0.060, rMA = 0.177 ± 0.025 and rSt = 1.016 ± 0.053, rMA = 0.179 ± 0.023, respectively, which are in a good agreement with those reported for the conventional free‐radical copolymerization of St and MA. Good agreement between the theoretical and experimental composition drifts in the comonomer mixture and copolymer as a function of the overall monomer conversion were observed, indicating that the reactivity ratios calculated by copolymer composition at the moderate to high conversion are accurate. Instantaneous copolymer composition curve and number‐average sequence length of comonomers in the copolymer indicated that the copolymerization system tends to produce a random copolymer. However, MA‐centered triad distribution results indicate that the spontaneous gradient copolymers can also be obtained when the mole fraction of MA in the initial comonomer mixture is high enough. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Dynamic mechanical properties of cotton/polypropylene commingled composite systems
Authors: Elappunkal Tomlal Jose , Mathew Rani , Thomas P.C. , Thomas Sabu , Joseph Kuruvilla 
Published: July 2009

AbstractThe dynamic mechanical properties of cotton/polypropylene (PP) commingled composite system was studied with reference to the fiber content, chemical treatments with potassium permanganate and maleic anhydride modified PP, processing conditions and applied frequency. Side by side commingling of matrix and reinforcing fibers was adopted for the fabrication of composite laminates as they provide the shortest melt flow distance during the melting of matrix fibers. This method can also be used for the recycling of textile wastes. The storage modulus was found to increase with the fiber content across a range of temperatures. The loss factor was found to decrease with the increase in fiber content while the glass transition temperature increases. The chemical treatments increase the value of storage modulus. A master curve was constructed and also made a comparison between the experimental results and the theoretically predicted values. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Metal–π Interactions Dominate in the Solid‐State Structures of Molecular Heterobimetallic Alkali‐Metal–Europium(II) Aryloxo Complexes
Authors: Deacon Glen B. , Junk Peter C. , Moxey Graeme J. 
Published: July 2009

AbstractTreatment of Eu metal, 2,6‐diphenylphenol (HOdpp), and MOdpp (M=Na, K) at elevated temperature in the presence of mercury afforded heterobimetallic complexes which were structurally characterized after crystallization from toluene. The structures of [MEu(Odpp)3]⋅nPhMe (M=Na, n=1, 1; K, n=2.5, 2) consist solely of bridging aryloxide ligands and feature extensive π‐Ph–metal interactions. Rather than a heterobimetallic species, treatment of Eu metal and HOdpp with LiOdpp under similar conditions afforded a number of products, including a mixed‐valent europium complex, [Eu2(Odpp)3][Eu(Odpp)4]⋅4 PhMe (3). The structural framework of the [Eu2(Odpp)3]+ cation of 3 is similar to that of the molecular heterobimetallics 1 and 2, including the presence of π‐Ph–Eu interactions. The reluctance of the reaction to provide a Eu/Li heterobimetallic complex was exemplified by the simultaneous crystallization of [Eu2(Odpp)4]⋅PhMe (6) and the homoleptic cubane [Li4(Odpp)4]⋅2 C6H14 (5) from toluene/hexane.
Bioencapsulation of apomyoglobin in nanoporous organosilica sol–gel glasses: Influence of the siloxane network on the conformation and stability of a model protein
Authors: Menaa Bouzid , Miyagawa Yuya , Takahashi Masahide , Herrero Mar , Rives Vicente , Menaa Farid , Eggers Daryl K. 
Published: July 2009

AbstractNanoporous sol–gel glasses were used as host materials for the encapsulation of apomyoglobin, a model protein employed to probe in a rational manner the important factors that influence the protein conformation and stability in silica‐based materials. The transparent glasses were prepared from tetramethoxysilane (TMOS) and modified with a series of mono‐, di‐ and tri‐substituted alkoxysilanes, RnSi(OCH3)4−n (R = methyl‐, n = 1; 2; 3) of different molar content (5, 10, 15%) to obtain the decrease of the siloxane linkage (SiOSi). The conformation and thermal stability of apomyoglobin characterized by circular dichroism spectroscopy (CD) was related to the structure of the silica host matrix characterized by 29Si MAS NMR and N2 adsorption. We observed that the protein transits from an unfolded state in unmodified glass (TMOS) to a native‐like helical state in the organically modified glasses, but also that the secondary structure of the protein was enhanced by the decrease of the siloxane network with the methyl modification (n = 0 < n = 1 < n = 2 < n = 3; 0 < 5 < 10 < 15 mol %). In 15% trimethyl‐modified glass, the protein even reached a maximum molar helicity (−24,000 deg. cm2 mol−1) comparable to the stable folded heme‐bound holoprotein in solution. The protein conformation and stability induced by the change of its microlocal environment (surface hydration, crowding effects, microstructure of the host matrix) were discussed owing to this trend dependency. These results can have an important impact for the design of new efficient biomaterials (sensors or implanted devices) in which properly folded protein is necessary. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 895–906, 2009.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Bridging the theory‐and‐practice gap: Mediator power in practice
Authors: Gerami Arghavan 
Published: July 2009

AbstractAlthough mediators are assumed to be neutral third parties, effective fulfillment of their role involves exercising a significant amount of authority and power. Mediators employ a range of approaches, orientations, and strategies. This article reviews some of the scholarship in this area. It then examines the various dimensions of mediator power, looking specifically at (1) the nature of mediator power and (2) its exercise of power through knowledge and expertise, through designing and controlling the process through reframing, and through imposing pressure to settle. Finally, the article discusses “ethical mediation” in light of mediator power.
Practice note: Community mediation as social intervention
Authors: Neves Tiago 
Published: July 2009

AbstractRather than understanding mediation solely as an attempt at problem solving between two individuals, this article examines the possibility of mediation as a social intervention designed to bring systemic change. If the mediation process is to have broader societal impact, one must address the questions this raises related to the mediator's role and neutrality. This article uses the case study of mediation in Brazil as a basis to launch the discussion.
Partial discharge pattern recognition based on optimal uncorrelated discriminant vectors in GIS
Authors: Zhang Xiaoxing , Yao Yao , Tang Ju 
Published: July 2009

AbstractWhile partial discharge (PD) pattern recognition is widely considered as an important method to evaluate insulation state, the major problem encountered in recognition is to extract PD pattern features. This paper designed four typical physical models of defects in GIS, and PD three‐dimensional patterns were constructed based on mass sample gathered by the very high frequency (VHF) and high‐speeds systems. A principal component analysis (PCA)–statistically uncorrelated optimal discriminant vectors (SUODV) method is put forward based on 3D patterns images. Firstly, the PCA is employed to condense the dimension of PD images, then uncorrelated discriminate features are extracted by improved SUODV algorithm, and the minimum distance classifier was constructed as classifier. The recognition results showed that this method can effectively classify four kinds of defects in GIS. Copyright © 2008 John Wiley & Sons, Ltd.
Tuning‐in to the beat: Aesthetic appreciation of musical rhythms correlates with a premotor activity boost
Authors: Kornysheva Katja , von Cramon D.Yves , Jacobsen Thomas , Schubotz Ricarda I. 
Published: July 2009

AbstractListening to music can induce us to tune in to its beat. Previous neuroimaging studies have shown that the motor system becomes involved in perceptual rhythm and timing tasks in general, as well as during preference‐related responses to music. However, the role of preferred rhythm and, in particular, of preferred beat frequency (tempo) in driving activity in the motor system remains unknown. The goals of the present functional magnetic resonance imaging (fMRI) study were to determine whether the musical rhythms that are subjectively judged as beautiful boost activity in motor‐related areas and if so, whether this effect is driven by preferred tempo, the underlying pulse people tune in to. On the basis of the subjects' judgments, individual preferences were determined for the different systematically varied constituents of the musical rhythms. Results demonstrate the involvement of premotor and cerebellar areas during preferred compared to not preferred musical rhythms and indicate that activity in the ventral premotor cortex (PMv) is enhanced by preferred tempo. Our findings support the assumption that the premotor activity increase during preferred tempo is the result of enhanced sensorimotor simulation of the beat frequency. This may serve as a mechanism that facilitates the tuning‐in to the beat of appealing music. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Focusing effects ofL‐dopa in Parkinson's disease
Authors: Ng Bernard , Palmer Samantha , Abugharbieh Rafeef , McKeown Martin J. 
Published: July 2009

AbstractPrevious fMRI motor studies in Parkinson's disease (PD) have suggested thatL‐dopa may “normalize” areas of hypo‐ and hyperactivity. However, results from these studies, which were largely based on analyzing BOLD signal amplitude, have been conflicting. Examining only amplitude changes at distinct loci may thus be inadequate in fully capturing the activation changes induced byL‐dopa. In this article, we extended prior analyses on the effects ofL‐dopa by investigating both amplitude and spatial changes of brain activation before and afterL‐dopa. Ten subjects with PD, both on and off medication, and ten healthy, age‐matched controls performed a visuo‐motor tracking task in which they sinusoidally squeezed a bulb at 0.25, 0.5, and 0.75 Hz. This task was contrasted with static squeezing to generate fMRI activation maps. To investigate the effects ofL‐dopa, we examined the amplitude and spatial variance of the BOLD response within anatomically‐defined regions of interest (ROIs).L‐dopa had significant main effects on the amplitude of BOLD signal in bilateral primary motor cortex and left SMA. In contrast,L‐dopa‐mediated spatial changes were apparent in bilateral cerebellar hemispheres, M1, SMA, and right prefrontal cortex. Moreover,L‐dopa appeared to normalize the spatial distribution of ROI activation in PD to that of the controls. Specifically,L‐dopa had a “focusing” effect on activity—an effect more pronounced than the typically‐measured fMRI amplitude changes. This observation is consistent with modeling studies, which demonstrated that dopamine increases the signal‐to‐noise ratio at the neuronal level with a resultant focusing of representations at the macroscopic level. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Nuclear factor erythroid 2–related factor 2 is a positive regulator of human bile salt export pump expression # †
Authors: Weerachayaphorn Jittima , Cai Shi-Ying , Soroka Carol J. , Boyer James L. 
Published: July 2009

Abstract
The bile salt export pump (BSEP) is the major determinant of bile salt–dependent bile secretion, and its deficiency leads to cholestatic liver injury. BSEP/Bsep gene expression is regulated by the nuclear farnesoid X receptor. However, BSEP expression, though reduced, is retained in the livers of Fxr
−/− mice, indicating that additional transcriptional factors may regulate its expression. Nuclear factor erythroid 2–related factor 2 (Nrf2) plays a major role in response to oxidative stress by binding to antioxidant-responsive elements that regulate many hepatic phase I and II enzymes as well as hepatic efflux transporters. Computer software analysis of human BSEP reveals two musculo-aponeurotic fibrosacroma (Maf) recognition elements (MAREs) from the sequence in the proximal promoter region where Nrf2 may bind. In this study, we assessed whether Nrf2 plays a role in human BSEP expression and if this might be mediated by MAREs. Oltipraz, a potent activator of Nrf2, increased BSEP messenger RNA expression by approximately seven-fold in HepG2 cells and protein by approximately 70% in human hepatocytes. Small interfering RNAs lowered NRF2 expression in HepG2 cells and prevented the up-regulation of BSEP by oltipraz. Human BSEP promoter activity was stimulated by Nrf2 in a dose-dependent manner in luciferase reporter assays. Mutations of the predicted MARE1, but not MARE2, abolished this Nrf2 transcriptional activation. Chromatin immunoprecipitation assays also demonstrated that Nrf2 specifically bound to MARE1, but not MARE2 regions in the BSEP promoter in HepG2 cells. Electrophoretic mobility shift assays further demonstrated direct binding of MARE1 in the BSEP promoter. Conclusion: Nrf2 is a positive transcriptional regulator of human BSEP expression. Pharmacological activation of Nrf2 may be beneficial for cholestatic liver injury. (Hepatology 2009.)
The employability of older workers as teleworkers: An appraisal of issues and an empirical study
Authors: Sharit Joseph , Czaja Sara J. , Hernandez Mario A. , Nair Sankaran N. 
Published: July 2009

AbstractThe aging of the population and, concomitantly, of the workforce has a number of important implications for governments, businesses, and workers. In this article, we examine the prospects for the employability of older workers as home‐based teleworkers. This alternative work could accommodate many of the needs and preferences of older workers and at the same time benefit organizations. However, before telework can be considered a viable work option for many older workers there are a number of issues to consider, including the ability of older workers to adapt to the technological demands that are typically associated with telework jobs and managerial attitudes about older workers and about telework. Through an integrated examination of these and other issues, our goal is to provide a comprehensive understanding of the challenges associated with employing older workers as teleworkers. We also present findings from a questionnaire study that assessed managers' perceptions of worker attributes desirable for telework and how older workers compare to younger workers on these attributes. The sample included 314 managers with varying degrees of managerial experience from a large variety of companies in the United States. The results presented a mixed picture with respect to the employability of older workers as teleworkers, and strongly suggested that less experienced managers would be more resistant to hiring older people as teleworkers. We conclude with a number of recommendations for improving the prospects for employment of older workers for this type of work arrangement. © 2009 Wiley Periodicals, Inc.