bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitroxide‐Mediated Radical Polymerization in Microemulsion
Authors: Wakamatsu Junpei , Kawasaki Masahiro , Zetterlund Per B. , Okubo Masayoshi 
Published: October 2007

AbstractNitroxide‐mediated polymerizations of styrene in microemulsion have been carried out at 125 °C using the cationic surfactant tetradecyltrimethylammonium bromide and the nitroxides 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy (TEMPO) and N‐tert‐butyl‐N‐[1‐diethylphosphono‐(2,2‐dimethylpropyl)] nitroxide (SG1). TEMPO‐mediated polymerizations were extremely slow, with large particles (dn = 39–129 nm) and broad molecular weight distributions (MWDs). The origin of the broad MWDs was likely significant alkoxyamine decomposition and differing diffusion rates of monomer and low MW alkoxyamines (and nitroxide) between monomer‐swollen micelles and polymer particles. SG1‐mediated polymerizations proceeded at higher rates, resulting in nanoparticles (dn = 21–37 nm) and lower $\overline M _{\rm w} /\overline M _{\rm n}$ than for TEMPO.magnified image
Information retrieval in medicine: The electronic medical record as a new domain
Authors: Smith Catherine Arnott 
Published: November 2007

Abstract“The medical record is a material form of public memory,” Berg (1996) writes, “a structured distributing and collecting device, where all tasks concerning a patient's trajectory must begin and end…;” [Italics original; p. 510]. Structured distributing and collecting devices are the natural interest of information science. Unfortunately, of the 130 articles published about medicine in almost 36 years of JASIST, although 70 (54%) deal with information retrieval, communication and the work processes behind them, only 2 of these articles (1.5%) have focused on the medical record.The body of existing information retrieval work most relevant to the medical record as a base for experiment is the work called “passage retrieval” defined as “the task of identifying and extracting fragments from large, or short but heterogeneous full text documents” (Melucci, 1998, p. 44).This paper presents a document‐centered approach to the EHR as an information retrieval problem. It is clear that passage retrieval researchers working in the field of information science have seen similar values in document passages as have researchers in medical informatics. Without either literature acknowledging the other, workers in both camps have identified the same potential in document structure, labels, specificity and explicit hierarchies of knowledge for signaling relevance to the reader. The National Health Information Infrastructure Initiative (http://aspe.hhs.gov/sp/nhii/) identifies academics and researchers as natural stakeholders, like clinicians and caregivers, in enabling better healthcare through better information sharing (National Committee on Vital and Health Statistics, 2003). Information science has much to contribute to the health information technology arena and to electronic health records in particular: their development, their maintenance, and most importantly their improvement to serve the needs of diverse users.
On the integration schemes for Drucker–Prager's elastoplastic models based on exponential maps
Authors: Rezaiee‐Pajand M. , Nasirai Cyrus 
Published: October 2007

AbstractRate plasticity equations for the case of Drucker–Prager's model in small strain regime are considered. By defining an augmented stress vector, the formulations convert the original problem into a quasi‐linear differential equation system. Two new exponential mapping schemes for integrating model equations are proposed. In addition, two traditional schemes for solving the dynamical system in an explicit manner are discussed. The two semi‐implicit schemes developed pose higher accuracy and better convergency. Error contours are provided for all four methods to display the accuracy of each scheme. In order to compare the results, these contours for the classical one‐step backward Euler integration method are also displayed. Accuracy and efficiency along with the rate of convergency of the existing and the proposed methods are examined by numerical examples. Copyright © 2007 John Wiley & Sons, Ltd.
Computational fluid flow solution over endothelial cells inside the capillary vascular system
Authors: Arslan Nurullah , Erdogan Abdullah Said , Ashyralyev Allaberen 
Published: November 2007

AbstractComputational blood flow analysis through glycocalyx located over the endothelial cells in human capillary vascular system is performed. Stable numerical schemes are developed for obtaining approximate solutions to the mixed problem to the partial differential equation with variable space operator to model the blood flow. Numerical techniques are developed by applying a procedure of the solution to the linear difference equation with matrix coefficients. The flow equations inside the core flow region and porous region are established. Discretization is done and the flow velocities in both regions are calculated. The effect of the flow over the glycocalyx is investigated. The wall shear stresses and the drag force over the glycocalyx are calculated. Copyright © 2007 John Wiley & Sons, Ltd.
Reactive compatibilization of nylon copolymer/EPDM blends: experimental aspects and their comparison with theory
Authors: Komalan Cibi , George K.E , Jacob Sinto , Thomas S. 
Published: November 2007

AbstractIn situ reactive compatibilization was first time applied to a low melting nylon (nylon 6 and 66 copolymer) and EPDM blend system. The effects of in situ compatibilization and concentration of compatibilizer on the morphology and mechanical properties of nylon/EPDM blends have been investigated. The influence of EPM‐g‐MA on the phase morphology was examined by the scanning electron microscopy (SEM) after preferential extraction of the minor phase. The SEM micrographs were quantitatively analyzed for domain size measurements. The compatibilizer concentrations used were 0, 1, 2.5, 5, and 10 wt%. The graft copolymer (nylon‐g‐EPM) formed at the interface showed relatively high emulsifying activity. A maximum phase size reduction was observed when 2.5 wt% of compatibilizer was added to the blend system. This was followed by a leveling‐off at higher loadings indicating interfacial saturation. The conformation of the compatibilizer at the interface was deduced based on the area occupied by the compatibilizer at the blend interface. The experimental compatibilization results were compared with theoretical predictions of Noolandi and Hong. It was concluded that the molecular state of compatibilizer at interface changes with concentration. The in situ compatibilized blends showed considerable improvement in mechanical properties. Measurement of tensile properties shows increased elongation as well as enhanced modulus and strength up on compatibilization. At higher concentrations of compatibilizer, a leveling‐off of the tensile properties was observed. A good correlation has been observed between the mechanical properties and morphological parameters. Copyright © 2007 John Wiley & Sons, Ltd.
In‐plane anisotropic permeability characterization of deformed woven fabrics by unidirectional injection. Part I: Experimental results
Authors: Demaría C. , Ruiz Edu , Trochu F. 
Published: November 2007

AbstractBecause of the increasing use of polymer composites in a wide variety of industrial applications, the manufacturing of complex composite parts has become an important research topic. When a part is manufactured by liquid composite molding (LCM), the reinforcement undergoes a certain amount of deformation after closure and sealing of the mold. In the case of bidirectional woven fabrics, this deformation may significantly affect the resin flow and mold filling because of changes in the values of permeability. Among other considerations that govern the accuracy of numerical simulations of mold filling, it is important to predict the changes of permeability as a function of the local shearing angle of the preform. The resin flow through a fibrous reinforcement is governed by Darcy's law, which states that the fluid flow rate is proportional to the pressure gradient. The shape of the flow front in a point‐wise injection through an anisotropic preform is an ellipse. Part I of this article describes a new methodology based on the ellipse equation to derive the in‐plane permeability tensor from unidirectional injection experiments in deformed woven fabrics. Part II presents a mathematical model that predicts the principal permeabilities and their orientation for sheared fabrics from the permeability characterization of unsheared fabrics. Unidirectional flow experiments were conducted for a nonstitched, balanced, woven fabric for different shearing angles and fiber volume fractions. This article presents experimental results for deformed and undeformed fabrics obtained by unidirectional flow measurements. A comparison of the proposed characterization methodology with radial flow experiments is also included. POLYM. COMPOS. 28:797–811, 2007. © 2007 Society of Plastics Engineers.
In‐plane anisotropic permeability characterization of deformed woven fabrics by unidirectional injection. Part II: Prediction model and numerical simulations
Authors: Demaría C. , Ruiz Edu , Trochu F. 
Published: November 2007

AbstractThe production of polymer composites by resin injection has strongly increased in the recent years for a wide variety of industrial applications. Manufacturing techniques are continuously optimized for higher and faster production cycles and high performance composites are needed to meet industrial requirements. Actually, the reduction of cost and cycle time is the main motivation for liquid composite molding (LCM) process simulation. In this context, the characterization of preform permeability is a key issue in numerical flow analysis. This investigation concerns the experimental study and development of a predictive model for deformed fabric permeability. Such deformations occur when a fabric is draped on a complex surface. A local shear appears. In Part I, an experimental procedure has been described to measure the permeability of deformed fabrics, and a new methodology presented to characterize the in‐plane permeability tensor. In order to implement experimental results in numerical simulation, a permeability model for deformed fabrics is required. Part II develops a predictive model of the principal permeabilities of deformed fabrics and of the orientation of the permeability tensor. Based on unsheared fabric measurements, the model takes into account the unit cell deformation during shear and the initial elliptic flow pattern orientation and anisotropy ratio of undeformed fabrics. Model predictions are corroborated with sheared fabric measurements. Finally, numerical simulations for an automotive body part are carried out to illustrate the effects of fabric shearing on the filling of the composite part. POLYM. COMPOS. 28:812–827, 2007. © 2007 Society of Plastics Engineers.
Viscoelastic response of nanocomposite poly(vinyl acetate)‐hydroxyapatite with varying particle shape—Dynamic strain softening and modulus recovery
Authors: Kalfus J. , Jancar J. 
Published: November 2007

AbstractDynamic‐strain softening known as the Payne effect was investigated in the case of poly(vinyl acetate)‐hydroxyapatite (PVAc‐HA) model nanocomposites in which the nanoparticles served as reversible physical cross‐links. HA nanofillers with different particle shape and with size ranging from 5 to 60 nm were used. Filler concentration in PVAc nanocomposites was limited to maximum of 5 vol%. Dynamic‐mechanical spectra were recorded as a function of structural variables, strain amplitude, and test temperature using the dynamic‐mechanical thermal spectroscopy (DMTS). Additionally, amplitude sweep tests were supplemented by the modulus recovery experiments to provide relaxation time data. Observed phenomena were interpreted using polymer physics approach. POLYM. COMPOS., 28:743–747, 2007. © 2007 Society of Plastics Engineers
Comparison of the curing kinetic behavior for two epoxy resin systems containing EPIKOTE 828–EPIKURE 3090 and DURATEK KLM 606A–DURATEK KLM 606B
Authors: Tüzün F. Nihal , Gürü Metin , Akyüz Yüksel 
Published: November 2007

AbstractThe aim of the study is to determine the optimum cure temperatures and kinetics for two different epoxy resin systems without using solvent. Two resin systems consist of EPIKOTE 828® epoxy resin–EPIKURE® 3090 polyamidoamine curing agent and DURATEK® KLM 606A epoxy resin–DURATEK® KLM 606B polyamide curing agent. The ratio of resin to curing agent was kept as 1:1 for both the systems. Curing temperatures of both the systems were determined and kinetic parameters were calculated with respect to the experimental results following nth‐order kinetics. Then, a series of isothermal temperatures was applied to the resin systems in order to assess the cure process in terms of conversion, time, and temperature by using differential scanning calorimeter (DSC). The test results of both systems show that the rate of degree of cure for EPIKOTE 828® epoxy resin–EPIKURE® 3090 polyamidoamine curing agent system is approximately 10 times higher than that of DURATEK® KLM 606A epoxy resin–DURATEK® KLM 606B polyamide curing agent system at 230°C. POLYM. COMPOS., 28:762–770, 2007. © 2007 Society of Plastics Engineers
Copolymerization of propylene with 1,3‐butadiene using isospecific zirconocene catalysts
Authors: Ishihara Takeshi , Ban Hoang The , Hagihara Hideaki , Shiono Takeshi 
Published: October 2007

AbstractPoly(propylene‐ran‐1,3‐butadiene) was synthesized using isospecific zirconocene catalysts and converted to telechelic isotactic polypropylene by metathesis degradation with ethylene. The copolymers obtained with isospecific C2‐symmetric zirconocene catalysts activated with modified methylaluminoxane (MMAO) had 1,4‐inserted butadiene units (1,4‐BD) and 1,2‐inserted units (1,2‐BD) in the isotactic polypropylene chain. The selectivity of butadiene towards 1,4‐BD incorporation was high up to 95% using rac‐dimethylsilylbis(1‐indenyl)zirconium dichloride (Cat‐A)/MMAO. The molar ratio of propylene to butadiene in the feed regulated the number‐average molecular weight (Mn) and the butadiene contents of the polymer produced. Metathesis degradations of the copolymer with ethylene were conducted with a WCI6/SnMe4/propyl acetate catalyst system. The 1H NMR spectra before and after the degradation indicated that the polymers degraded by ethylene had vinyl groups at both chain ends in high selectivity. The analysis of the chain scission products clarified the chain end structures of the poly(propylene‐ran‐1,3‐butadiene). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5731–5740, 2007
Synthesis of core‐shell silver–polyaniline nanocomposites by gamma radiolysis method
Authors: Karim Mohammad Rezaul , Lim Kwon Taek , Lee Chul Jae , Bhuiyan Md Tauhidul Islam , Kim Hee Jin , Park Lee‐Soon , Lee Mu Sang 
Published: October 2007

AbstractCore‐shell silver (Ag)–polyaniline (PAni) nanocomposites have been synthesized by the in‐situ gamma radiation‐induced chemical polymerization method. Aqueous solution of aniline, a free‐radical oxidant, and/or silver metal salt were irradiated by γ‐rays. Reduction of the silver salt in aqueous aniline leads to the formation of silver nanoparticles which in turn catalyze oxidation of aniline to polyaniline. The resultant Ag‐PAni nanocomposites were characterized by using different spectroscopy analyses like X‐ray photoelectron, UV–visible, and infrared spectroscopy. The optical absorption bands revealed that the bands at about 400 nm are due to the presence of nanosilver and the blue‐shifted peak at ∼ 555 nm is due to the presence of metallic silver within the PAni matrix. X‐ray diffraction pattern clearly indicates the broad amorphous polymer and the sharp metal peaks. Scanning electron microscopy and transmission electron microscopy of the nanocomposite showed a uniform size distribution with spherical and granular morphology. Thermogravimetric analysis revealed that the composites have a higher degradation temperature than polyaniline alone. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5741–5747, 2007
Synthesis and properties of polymethacrylate bearing cyclic carbonate through urethane linkage
Authors: Ochiai Bungo , Ootani Yuuko , Maruyama Tetsushi , Endo Takeshi 
Published: October 2007

AbstractPolymethacrylates carrying cyclic carbonate through urethane linkage were prepared by radical (co)polymerizations of 2‐methacrylic acid 2‐(2‐oxo‐[1,3]dioxolan‐4‐ylmethoxycarbonylamino)ethyl ester (CUMA). Although brittleness of typical polymers bearing cyclic carbonate groups has been limited their practical applications, some copolymers from CUMA can be cast as films with good flexibility. The copolymers from CUMA and diethyleneglycol methyl ether methacrylate are miscible with lithium bis(trifluoromethanesulfone)imide. The coordination of the lithium cation to the carbonyl groups was confirmed by infrared spectrometry. © 2007 Wiley Periodicals, Inc. JPolym Sci Part A: Polym Chem 45: 5781–5789, 2007
Novel double hydrophilic block copolymers based on poly(p‐hydroxystyrene) derivatives and poly(ethylene oxide)
Authors: Mountrichas Grigoris , Pispas Stergios 
Published: October 2007

AbstractThe synthesis of three series of double hydrophilic block copolymers (DHBCs), consisting of poly(ethylene oxide) as the neutral water soluble block and a second polyelectrolyte block of variable chemistry, is described. The synthetic scheme involves the anionic polymerization of poly(p‐tert‐butoxystyrene‐b‐ethylene oxide) (PtBOS‐PEO) amphiphilic block copolymer precursors followed by the acidic hydrolysis of the hydrophobic poly(p‐tert‐butoxystyrene) (PtBOS) block to an annealed anionic polyelectrolyte poly(p‐hydroxystyrene) (PHOS) block. The PHOS block was subsequently transformed into a high charge density annealed cationic polyelectrolyte namely poly[3,5‐bis(dimethylaminomethylene) hydroxystyrene] (NPHOS), via aminomethylation. Finally, the NPHOS block was transformed into a quenched polyelectrolyte, namely quaternized poly[3,5‐bis(dimethylaminomethylene) hydroxystyrene] (QNPHOS) block by reaction with CH3I. The solution properties of the different series of the above block polyelectrolyte copolymers have been investigated using static, dynamic and electrophoretic light scattering, turbidimetry, and fluorescence spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5790–5799, 2007
Morphology of side chain liquid crystalline block copolymer thin films and effects of thermal annealing
Authors: Verploegen Eric , Boone Derrick , Hammond Paula T. 
Published: October 2007

AbstractThe self‐assembly behavior of siloxane based side chain liquid crystalline block copolymer thin films are investigated via grazing incidence small angle X‐ray scattering and atomic force microscopy. The as‐spun films displayed polystyrene cylinders perpendicular to the substrate and the cylinders reoriented parallel to the surface after thermal annealing. The morphology observed in the as‐spun films is resultant from the orientation of the smectic LC mesophase relative to the substrate. Annealing above both the polystyrene glass transition temperature and the smectic to isotropic transition temperature eliminates the influence of the LC phase, leading to a reorientation of the morphology that minimizes the interfacial energy of the system. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3263–3266, 2007
Electrical Discharges in Mixtures of Light and Heavy Water
Authors: Mededovic Selma , Finney Wright C. , Locke Bruce R. 
Published: October 2007

AbstractPulsed electrical discharges in pure solutions and mixtures of light and heavy water are examined. The concentration of H2O2 formed by electrical discharge in 100% H2O was found to be 1.4 times smaller than that of D2O2 produced by electrical discharge in 100% D2O. This difference in peroxide formation was due to the high reactivity of OH radicals with other species in the plasma channel, thereby reducing OH recombination to form H2O2, while the lower reactivity of OD radicals with other species allowed more OD recombination reactions to form D2O2. A new method based on Raman spectroscopy was also developed to quantify H2O2, D2O2, and HDO2 in mixtures containing all three species.magnified image
Molecular modeling of the second extracellular loop of G‐protein coupled receptors and its implication on structure‐based virtual screening
Authors: de Graaf Chris , Foata Nicolas , Engkvist Ola , Rognan Didier 
Published: October 2007

AbstractThe current study describes the validation of high‐throughput modeling procedures for the construction of the second extracellular loop (ecl2) of all nonolfactory human G Protein‐coupled receptors. Our modeling flowchart is based on the alignment of essential residues determining the particular ecl2 fold observed in the bovine rhodopsin (bRho) crystal structure. For a set of GPCR targets, the dopamine D2 receptor (DRD2), adenosine A3 receptor (AA3R), and the thromboxane A2 receptor (TA2R), the implications of including ecl2 atomic coordinates is evaluated in terms of structure‐based virtual screening accuracy: the suitability of the 3D models to distinguish between known antagonists and randomly chosen decoys using automated docking approaches. The virtual screening results of different models describing increasingly exhaustive receptor representations (seven helices only, seven helices and ecl2 loop, full model) have been compared. Explicit modeling of the ecl2 loop was found to be important in only one of three test cases whereas a loopless model was shown to be accurate enough in the two other receptors. An exhaustive comparison of ecl2 loops of 365 receptors to that of bRho suggests that explicit ecl2 loop modeling should be reserved to receptors where loop building can be guided by experimental restraints. Proteins 2008; 71:599–620. © 2007 Wiley‐Liss, Inc.
Cluster conservation as a novel tool for studying protein–protein interactions evolution
Authors: Rahat Ofer , Yitzhaky Assif , Schreiber Gideon 
Published: October 2007

AbstractProtein–protein interactions networks has come to be a buzzword associated with nets containing edges that represent a pair of interacting proteins (e.g. hormone‐receptor, enzyme‐inhibitor, antigen‐antibody, and a subset of multichain biological machines). Yet, each such interaction composes its own unique network, in which vertices represent amino acid residues, and edges represent atomic contacts. Recent studies have shown that analyses of the data encapsulated in these detailed networks may impact predictions of structure–function correlation. Here, we study homologous families of protein–protein interfaces, which share the same fold but vary in sequence. In this context, we address what properties of the network are shared among relatives with different sequences (and hence different atomic interactions) and which are not. Herein, we develop the general mathematical framework needed to compare the modularity of homologous networks. We then apply this analysis to the structural data of a few interface families, including hemoglobin α–β, growth hormone‐receptor, and Serine protease‐inhibitor. Our results suggest that interface modularity is an evolutionarily conserved property. Hence, protein–protein interfaces can be clustered down to a few modules, with the boundaries being evolutionarily conserved along homologous complexes. This suggests that protein engineering of protein–protein binding sites may be simplified by varying each module, but retaining the overall modularity of the interface. Proteins 2008. © 2007 Wiley‐Liss, Inc.