bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linear viscoelastic and morphological description of multiphase systems affected by processing parameters
Authors: Kuthanová Vanda , Hausnerová Berenika , Kitano Takeshi , Lapčíková Monika , Sáha Petr 
Published: October 2010

AbstractInfluence of processing methods, in terms of comparing compression and injection moldings, on the rheological behavior of polycarbonate (PC)/acrylonitrile‐butadiene‐styrene (ABS) blends and PC/ABS/glass fibers composites is presented. Blend compositions and fiber content are considered as material variables. For blends, the effect of the processing route on the viscoelastic functions is evident only for low shearing frequencies. Injection molding created morphology with cocontinuous character, while compression molded blends have “relaxed” structure, where dispersed phase domains are several times larger than in injection molded ones. The glass fiber reinforcement led to the significant differences in viscoelastic properties of composites processed by injection and compression molding. Injected composites have both moduli always higher than compression molded. Also, fiber lengths are reduced more for compressing molding. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Poly(acrylonitrile‐co‐methyl acrylate) copolymers: Correlation between copolymer composition, morphology and positron annihilation lifetime parameters
Authors: Zengeni E. , Hartmann P. C. , Sanderson R. D. , Mallon P. E. 
Published: October 2010

AbstractA series of poly(acrylonitrile‐co‐methyl acrylate) copolymers of differing copolymer compositions are synthesized through free radical emulsion copolymerisation of methyl acrylate (MA) and acrylonitrile (AN) and by variation of the monomer feed ratios. The copolymers are characterized by NMR, SEC, WAXD, DMA, and positron annihilation lifetime spectroscopy. Results show that, there is a linear decrease in the glass transition temperature (Tg) of the copolymers and the MA content. There is also a progressive decrease in the crystallinity of the copolymers with increasing MA content. Positron results show a sigmoidal variation in the ortho positronium lifetime with an increasing MA content. The low MA content, semi‐crystalline copolymers show a positive deviation from the linear additive relationship between the o‐Ps lifetime and MA content, whereas the higher MA content amorphous copolymers show a negative deviation from the linear additive behavior. The o‐PS intensity shows a linear behavior with MA content with a slight deviation from the additive linear behavior for the very high‐content MA copolymer. These variations in the measured positron lifetime parameters are interpreted in terms of the copolymer morphology. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of hydrocarbon resin on the morphology and mechanical properties of isotactic polypropylene/clay composites
Authors: Cimmino Sossio , Silvestre Clara , Duraccio Donatella , Pezzuto Marilena 
Published: October 2010

AbstractThe article reports an investigation of the effect of a hydrocarbon resin, Necirés TR100, on the structure, morphology, and properties of two isotactic polypropylene/clay composites. The clays are Dellite HPS, a purified montmorillonite, and Dellite 67G, a purified and modified montmorillonite with a high content of quaternary ammonium salt. Necirés TR100 contains hydroxyl and acid groups, which were expected to interact during the melt mixing with the polar surface of the clays to have intercalation with Dellite HPS and/or exfoliation of Dellite 67G, which is already intercalated by the quaternary ammonium salt. The morphological results indicate that the composite isotactic polypropylene/Dellite HPS presents large and coarse clay domains, whereas the composite isotactic polypropylene/Dellite 67G presents a better distribution of the clay clusters, although the presence of some clay domains of a few μm are also detected. Although results from Wide Angle X‐ray Diffraction have indicated that Necirés TR100 has no effect on the layers distance of Dellite HPS and Dellite 67G its addition produces composites with clay particles homogenously distributed in the polyolefin matrix, better tensile properties (higher values of Young's modululs and elongation to break) and decrease of permeability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation, characterization, and application of NR/SBR/Organoclay nanocomposites in the tire industry
Authors: Shan Chunpeng , Gu Zheng , Wang Li , Li Peiyao , Song Guojun , Gao Zhenbin , Yang Xiaoyu 
Published: October 2010

AbstractThe natural rubber/styrene butadiene rubber/organoclay (NR/SBR/organoclay) nanocomposites were successfully prepared with different types of organoclay by direct compounding. The optimal type of organoclay was selected by the mechanical properties characterization of the NR/SBR/organoclay composites. The series of NR/SBR/organoclay (the optimal organoclay) nanocomposites were prepared with various organoclay contents loading from 1.0 to 7.0 parts per hundreds of rubber (phr). The nearly completely exfoliated organoclay nanocomposites with uniform dispersion were confirmed by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The results of mechanical properties measurement showed that the tensile strength, tensile modulus, and tear strength were improved significantly when the organoclay content was less than 5.0 phr. The tensile strength and the tear strength of the nanocomposite with only 3.0 phr organoclay were improved by 92.8% and 63.4%, respectively. It showed organoclay has excellent reinforcement effect with low content. The reduction of the score and cure times of the composites indicated that the organoclay acted as accelerator in the process of vulcanization. The incorporation of a small amount of organoclay greatly improved the swelling behavior and thermal stability, which was attributed to the good barrier properties of the dispersed organoclay layers. The outstanding performance of co‐reinforcement system with organoclay in the tire formulation showed that the organoclay had a good application prospect in the tire industry, especially for the improvement of abrasion resistance and the reduction of production cost. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Single polymeric bubble for the preparation of multiple micro/nano fibers
Authors: Ren Zhong‐Fu , He Ji‐Huan 
Published: October 2010

AbstractBubble‐electrospinning is suggested to produce micro/nano fibers. Contrary to classical electrospinning where a high voltage is applied to overcome the surface tension of the Taylor's cone, in bubble‐electrospinning, the voltage is applied to overcome the bubble's surface tension, which mainly depends upon the size of the bubble. Instead of single jet, millions of charged jets are observed simultaneously. In this article, we design a single bubble‐electrospinning to primarily study the effect of concentration on the spinning procedure. Polyvinylpyrrolidone (PVP) is used in the experiment. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Surface modification of linear low‐density polyethylene film by amphiphilic graft copolymers based on poly(higher α‐olefin)‐graft‐poly(ethylene glycol)
Authors: Fu Zhisheng , Liu Min , Xu Junting , Wang Qi , Fan Zhiqiang 
Published: October 2010

AbstractIn this article, a series of amphiphilic graft copolymers, namely poly(higher α‐olefin‐co‐para‐methylstyrene)‐graft‐poly(ethylene glycol), and poly(higher α‐olefin‐co‐acrylic acid)‐graft‐poly(ethylene glycol) was used as modifying agent to increase the wettability of the surface of linear low‐density polyethylene (LLDPE) film. The wettability of the surface of LLDPE film could be increased effectively by spin coating of the amphiphilic graft copolymers onto the surface of LLDPE film. The higher the content of poly(ethylene glycol) (PEG) segments, the lower the water contact angle was. The water contact angle of modified LLDPE films was reduced as low as 25°. However, the adhesion between the amphiphilic graft copolymer and LLDPE film was poor. To solve this problem, the modified LLDPE films coated by the amphiphilic graft copolymers were annealed at 110° for 12 h. During the period of annealing, heating made polymer chain move and rearrange quickly. When the film was cooled down, the alkyl group of higher α‐olefin units and LLDPE began to entangle and crystallize. Driven by crystallization, the PEG segments rearranged and enriched in the interface between the amphiphilic graft copolymer and air. By this surface modification method, the amphiphilic graft copolymer was fixed on the surface of LLDPE film. And the water contact angle was further reduced as low as 14.8°. The experimental results of this article demonstrate the potential pathway to provide an effective and durable anti‐fog LLDPE film. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of recrystallization on the molecular mobility of a copolymer of vinylidene fluoride and hexafluoropropylene
Authors: Kochervinskij Valentin V. , Malyshkina Inna A. , Bessonova Natalia P. , Suljanov Sergey N. , Dembo Kirill A. 
Published: October 2010

AbstractRelaxation processes in copolymers of vinylidene fluoride with hexafluoropropylene (93/7) were studied by means of a dielectric method. The initial extruded film was recrystallized by free heating to temperatures above the melting point and by subsequent cooling. This increased both the perfection of the crystal phase and the degree of crystallinity. The impact of recrystallization on both the relaxation times (τ's) and the activation parameters of the local mobility (β process) and micro‐Brownian cooperative mobility in amorphous phase (αa process) was almost negligible, whereas the τ's of the αc relaxation were an order of magnitude higher after recrystallization. Qualitatively, it was predicted by the soliton model for the αc relaxation. The recrystallization affected characteristics of the transition at the highest temperature (α) registered in the region of the melting of the crystals even more. The process is related to the relaxation of the space charge formed by ionogenic impurities, which migrate through the amorphous phase with high free volume. It was shown that the dynamics in the amorphous phase controlled the drift mobility of free charge carriers and, by that, determined the τ of the space charge relaxation process. The structuring processes during the recrystallization also affected the parameters of the order–disorder transition in the low‐perfect ferroelectric (antiferroelectric) phase. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Structure, properties, and phase transitions of melt‐spun poly(vinylidene fluoride) fibers
Authors: Steinmann W. , Walter S. , Seide G. , Gries T. , Roth G. , Schubnell M. 
Published: October 2010

AbstractThree different experimental techniques were used to study structural phase transitions in melt‐spun poly(vinylidene fluoride) fibers, which were produced with different process parameters and processed in the draw‐winding process at different temperatures and draw ratios. The fibers are examined with the help of wide‐angle X‐ray diffraction at elevated temperatures, differential scanning calorimetry with stochastic temperature modulation, and dynamic mechanical analysis. An oriented mesophase and deformed crystal structures can be observed in all fibers and assigned to the mechanical stress occurring in the processes. Furthermore, several phase transitions during melting and two mechanical relaxation processes could be detected. The observed transitions affect the crystal geometry, the orientation distribution, anisotropic thermal expansion, and the mechanic response of the fiber samples. The relaxation processes can be related with an increasing amount of crystalline β‐phase in fibers drawn at different temperatures. The detailed information about phase transitions and the related temperatures are used to produce fibers with an extended amount of β‐phase crystallites, which are responsible for piezoelectric properties of the material. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co‐citation analysis, bibliographic coupling, and direct citation: Which citation approach represents the research front most accurately?
Authors: Boyack Kevin W. , Klavans Richard 
Published: October 2010

AbstractIn the past several years studies have started to appear comparing the accuracies of various science mapping approaches. These studies primarily compare the cluster solutions resulting from different similarity approaches, and give varying results. In this study we compare the accuracies of cluster solutions of a large corpus of 2,153,769 recent articles from the biomedical literature (2004–2008) using four similarity approaches: co‐citation analysis, bibliographic coupling, direct citation, and a bibliographic coupling‐based citation‐text hybrid approach. Each of the four approaches can be considered a way to represent the research front in biomedicine, and each is able to successfully cluster over 92% of the corpus. Accuracies are compared using two metrics—within‐cluster textual coherence as defined by the Jensen‐Shannon divergence, and a concentration measure based on the grant‐to‐article linkages indexed in MEDLINE. Of the three pure citation‐based approaches, bibliographic coupling slightly outperforms co‐citation analysis using both accuracy measures; direct citation is the least accurate mapping approach by far. The hybrid approach improves upon the bibliographic coupling results in all respects. We consider the results of this study to be robust given the very large size of the corpus, and the specificity of the accuracy measures used.
Apolipoprotein A‐IMilano anion exchange chromatography: Mass transfer and adsorption kinetics
Authors: Bankston Theresa E. , Carta Giorgio 
Published: October 2010

AbstractThe mass transfer and adsorption kinetics of self‐associating apolipoprotein A‐IMilano (apoA‐IM) was investigated for the two anion exchangers Q‐Sepharose‐HP and Macro‐Prep‐HQ. At high salt where no protein binding occurs and without urea, mass transfer was controlled by hindered pore diffusion of multiple associated forms for both materials. Adding urea suppressed self‐association, but resulted in higher viscosity and caused unfolding. As a consequence, the effective diffusivity decreased as urea was added and was greater for the larger pore Macro‐Prep‐HQ resin. At low salt, under strong binding conditions, the adsorption kinetics followed a more complex mechanism. In this case, the kinetics was very slow for both stationary phases up to 2 M urea. However, at higher urea concentrations, the adsorption kinetics for the smaller pore Q‐Sepharose‐HP matrix became much faster, suggesting a transition from pore‐ to surface‐dominated diffusion. Microscopic observations confirmed that different transport mechanisms were in play below and above 2 M urea, which marked the approximate boundary above which self‐association was suppressed and unfolding occurred. The net result was enhanced uptake kinetics at high urea concentrations (e.g., 4 M) where protein unfolding is thought to lead to a more flexible structure that can reptate along the pore surface. Although the observed enhancement was dependent on the pore size and, thus, the surface area of the resin, it was not limited to apoA‐IM. BSA showed a similar trend as a function of urea when its disulfide bonds were reduced.
Internal pudendal artery stenoses and erectile dysfunction: Correlation with angiographic coronary artery disease
Authors: Rogers Jason H. , Karimi Houshang , Kao John , Link Daniel , Javidan Javid , Yamasaki Dwayne S. , Dolan Mark , Laird John R. , Low Reginald I. 
Published: October 2010

AbstractObjectives: To describe the angiographic characteristics of pelvic arterial disease in patients with erectile dysfunction (ED) nonresponsive to phosphodiesterase‐5 inhibitors (PDE5i) and suspected coronary artery disease (CAD). Background: ED and CAD share common risk factors which can result in endothelial dysfunction, atherosclerosis and flow‐limiting stenoses in the coronary and internal pudendal arteries. Methods: Ten patients undergoing cardiac catheterization with ED and a history of unsatisfactory response to a PDE5i were studied. ED severity was quantified using the International Index of ED scoring system. We performed angiography and quantitative vessel analysis of the coronary arteries, bilateral common and internal iliac arteries, and internal pudendal arteries (IPAs). Results: In this pilot observational study, we found a high correlation between the presence of angiographic CAD and IPA disease. The reference IPA diameters at the point of maximal stenosis were 2.7 ± 0.4 mm (right IPA) and 2.7 ± 0.5 mm (left IPA). In the nine patients with IPA disease, the average stenosis severity was 55 ± 31% (right) and 66% ± 25% (left), and average lesion length was 12.4 ± 5.2 mm (right) and 10.0 ± 3.5 mm (left). Four patients had unilateral IPA total occlusions, three of whom had moderate contralateral disease. The majority of IPA stenoses occurred in the mid to distal IPA and appears amenable to percutaneous revascularization. Conclusions: This represents the first angiographic report of CAD correlated with IPA disease in patients with ED. Further investigation is required to determine whether the development of macrovascular disease in the IPA causes ED and whether endovascular treatment is safe and effective in this population. © 2010 Wiley‐Liss, Inc.
Conformational studies on chiral rhodium complexes by ECD and VCD spectroscopy
Authors: Szilvágyi Gábor , Majer Zsuzsa , Vass Elemér , Hollósi Miklós 
Published: October 2010

AbstractThis article reports vibrational circular dichroism (VCD) and electronic circular dichroism (ECD) spectroscopic studies in acetonitrile on the chiral Rh2(O‐Phe‐Cbz)1(OAc)3 and Rh2(O‐Phe‐Ac)1(OAc)3 complexes (abbreviated Rh2Z1 and Rh2Ac1, respectively; Phe, L‐phenylalanine; Cbz, benzyloxycarbonyl; Ac, acetyl) supported by theoretical calculations. The ECD spectra of the complexes depend on temperature that indicates the conformational mobility of the chiral ligands. Calculations of the VCD spectra were performed at ab initio (DFT) level of theory using Gaussian 03 [B3LYP functional combined with the LANL2DZ basis set for the dirhodium core and the 6‐31G(d) basis set for other atoms]. The population‐weighted sums of the computed VCD spectra of the conformers are in excellent agreement with the experimental VCD spectra. The combination of the VCD and ECD spectroscopic methods led us to the structural characterization of the complexes. Chirality, 2011. © 2010 Wiley‐Liss, Inc.
Katalysatoren für die Sonnenenergie
Authors: Harrer Roswitha 
Published: October 2010

AbstractDie Entwicklung der künstlichen Photosynthese und somit die mehr oder minder direkte Nutzung der Sonnenenergie ist seit Jahren ein zentrales Thema. Wie kann man Sonnenenergie billiger und besser zugänglich machen? Konkrete Empfehlungen für die zukünftige Forschung sprechen Wissenschaftler nach dem ersten Chemical Sciences and Society Symposium (CS3) zur Nutzung von Sonnenlicht aus.
Bakterien im Zahnbelag atmen Nitrat
Authors: Feil Sylvia 
Published: October 2010

AbstractIm Meer wird jede Oberfläche besiedelt. So entstehen auf Schiffsrümpfen Biofilme und auch jedes Sandkorn im Meeressediment ist mit Bakterien besiedelt. Aber wie sieht es im menschlichen Körper aus? Die Mundhöhle zum Beispiel bietet Wärme und Feuchtigkeit, sodass viele Arten von Bakterien darin siedeln. Bremer Meeresbiologen haben nun Stickoxide im Zahnbelag gemessen und nachgewiesen, das diese durch aerobe denitrifizierende Bakterien gebildet werden.
Iris color and texture: A comparative analysis of real irises, ocular prostheses, and colored contact lenses
Authors: Herrera Jorge A. , Vilaseca Meritxell , Düll Jochen , Arjona Montserrat , Torrecilla Elena , Pujol Jaume 
Published: October 2010

AbstractIn this work, we analyzed the color and texture of irises, ocular prostheses, and cosmetic colored contact lenses measured by means of a multispectral system, which provides the CIE L*a*b* colorimetric coordinates of a high resolution image pixel by pixel. The same subject, who has dark brown irises, participated in the measurement of all the contact lenses. The CIE L*a*b* colorimetric coordinates were analyzed to classify the samples into three major groups (brown, blue and green) using a new algorithm developed for this purpose. This classification allowed us to carry out a comparison of the color associated with each set of samples, using the corresponding color gamuts in the CIE L*a*b* color space. Furthermore, we analyzed the iris color reproduction achieved by prostheses and contact lenses in terms of CIEDE2000 color differences, and obtained closer results with prostheses. In addition, we performed an analysis of texture by means of the color spatial distribution of all samples. This was achieved by means of two statistical approaches: first order statistics of image histograms and second order statistics using co‐occurrence matrices. The results suggest that the texture associated with real irises, ocular prostheses and colored contact lenses is very different. This study provides useful information about the color and texture of irises that may help to establish a strategy for improving the techniques used in the manufacturing process of prostheses and colored contact lenses to obtain a better and more realistic appearance. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2011
P‐GRADE portal family for grid infrastructures
Authors: Kacsuk Peter 
Published: October 2010

AbstractP‐GRADE portal is one of the most widely used general‐purpose grid portal in Europe. The paper summarizes the most advanced features of P‐GRADE, such as parameter sweep workflow execution, multi‐grid workflow execution and integration with the DSpace workflow repository. It also shows the NGS P‐GRADE portal that extends P‐GRADE with the GEMLCA legacy code execution support in Grid systems, as well as with coarse‐grain workflow interoperability services. Next, the paper introduces the second generation P‐GRADE portal called WS‐PGRADE that merges the advanced features of the first generation P‐GRADE portals and extends them with new workflow and architecture concepts. Finally, the application‐specific science gateway of the CancerGrid project is briefly described to demonstrate that application‐specific portals can easily be developed on top of the general‐purpose WS‐PGRADE portal. Copyright © 2010 John Wiley & Sons, Ltd.
Diffusiophoresis of an Elongated Cylindrical Nanoparticle along the Axis of a Nanopore
Authors: Joo Sang W. , Lee Sang Yoon , Liu Jing , Qian Shizhi 
Published: October 2010

AbstractThe translation of a charged, elongated cylindrical nanoparticle along the axis of a nanopore driven by an imposed axial salt concentration gradient is investigated using a continuum theory, which consists of the ionic mass conservation equations for the ionic concentrations, the Poisson equation for the electric potential in the solution, and the modified Stokes equations for the hydrodynamic field. The diffusiophoretic motion is driven by the induced electrophoresis and chemiphoresis. The former is driven by the generated overall electric field arising from the difference in the ionic diffusivities and the double layer polarization, while the latter is generated by the induced osmotic pressure gradient around the charged particle. The induced diffusiophoretic motion is investigated as functions of the imposed salt concentration gradient, the ratio of the particle’s radius to the double layer thickness, the cylinder’s aspect ratio (length/radius), the ratio of the nanopore size to the particle size, the surface charge densities of the nanoparticle and the nanopore, and the type of the salt used. The induced diffusiophoretic motion of a nanorod in an uncharged nanopore is mainly governed by the induced electrophoresis, driven by the induced electric field arising from the double layer polarization. The induced particle motion is driven by the induced electroosmotic flow, if the charges of the nanorod and nanopore wall have the same sign.