bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear stress relaxation of carbon black‐filled rubber vulcanizates under various types of deformation
Authors: Tada Toshio , Urayama Kenji , Mabuchi Takahiro , Muraoka Kiyoshige , Takigawa Toshikazu 
Published: May 2010

AbstractNonlinear stress relaxation behavior of carbon black‐filled rubber vulcanizates under large strain is investigated for the three types of deformation (equibiaxial stretching, pure shear, and uniaxial stretching) with various sets of two principal ratio (λ1 and λ2). The stress relaxation curves in the wide time (t) region of t > 10−1 s at a reference temperature of 296 K are obtained by the time‐temperature superposition principle. We demonstrate that stress relaxation component Δσ(λ1, λ2, t) (≡ σ[λ1, λ2, t] − σ[λ1, λ2, ∞], where σ[λ1, λ2, ∞] is the equilibrium stress) is separable into the time (t)‐ and deformation (λ)‐dependent functions, that is, Δσ(λ1, λ2, t) = Δσtotal(λ1, λ2)ψ(t), where Δσtotal represents the total relaxation strength. We further show that the time‐dependent term ψ(t) of the filled rubbers is almost similar to that of the unfilled rubbers in the time region examined here, whereas Δσtotal for filled rubbers is considerably larger than that for unfilled ones. In addition, the reduced relaxation strength Δσtotal(λ1, λ2)/σ(λ1, λ2, ∞) is almost independent of the degree and type of deformation, and the value for the filled rubber is larger than that for the unfilled one. These results indicate that (1) the strain‐driven collapse of filler networks causes a large degree of stress relaxation, but it does not affect the relaxation dynamics in the time region investigated (∞ > t > 10−1 s), and (2) the relaxation dynamics in filled rubbers is governed by that in the rubber matrix. These findings considerably facilitate the full description of the finite deformation with time effect for filled rubbers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1380–1387, 2010
Scaling of the molecular weight‐dependent thermal volume transition of poly(N‐isopropylacrylamide)
Authors: Ye Xiaodong , Ding Yanwei , Li Junfang 
Published: May 2010

AbstractA series of narrowly distributed poly(N‐isopropylacrylamide) (PNIPAM) with molecular weight ranging from 8 × 104 to 2.3 × 107 g/mol were prepared by a combination of free radical polymerization and fractional precipitation. An ultrasensitive differential scanning calorimetry was used to study the effect of molecular weight on the thermal volume transition of these PNIPAM samples. The specific heat peak of the transition temperature (Tp,0) was obtained by extrapolation to zero heating rate (HR) because of the linear dependence of the transition temperature (Tp) on the HR. The relation between Tp,0 and the degree of polymerization (N) was investigated. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1388–1393, 2010
Molecular composites composed of castor oil‐modified poly(ε‐caprolactone) and self‐assembled hydroxystearic acid fibers
Authors: Shibata Mitsuhiro , Teramoto Naozumi , Kaneko Katsuyuki 
Published: May 2010

AbstractAfter (R)‐12‐hydroxystearic acid (HSA) was mixed at 100 °C with the castor oil‐modified poly(ε‐caprolactone) (CO‐PCL) prepared by the ring‐opening polymerization of ε‐caprolactone in the presence of castor oil, the mixture was gradually cooled to room temperature to give a solidified CO‐PCL/HSA composite. The CO‐PCL/HSA sample showed an exothermic peak at around 67–71 °C which was lower than the melting point of HSA (76.8 °C), indicating the formation of mesogenic HSA aggregates. The rheological measurement of the CO‐PCL/HSA revealed the formation of HSA organogel at around 67–55 °C during the cooling process from the melt. Furthermore, the polarized and normal optical microscopic analyses of CO‐PCL/HSA on the cooling stage revealed that anisotropic fibrous materials are formed at around 60 °C and then the fibrous network propagated over the matrix polymer. The flexural modulus and storage modulus of the CO‐PCL/HSA composite increased with increasing HSA content. The CO‐PCL/HSA composite annealed at 60 °C for 2 h on the cooling process had a higher flexural and storage modulus than the sample without annealing. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1281–1289, 2010
Nonisothermal crystallization kinetics of biodegradable poly(butylene succinate‐co‐propylene succinate)s
Authors: Lu Shih‐Fu , Chen Ming , Shih You‐Cheng , Chen Chi He 
Published: May 2010

AbstractPoly(butylene succinate) (PBSu) and two poly(butylene succinate‐co‐propylene succinate)s were synthesized via the direct polycondensation reaction. The copolyesters were characterized as having 7.0.and 11.5 mol % propylene succinate (PS) units, respectively, by 1H NMR. A differential scanning calorimeter (DSC) and a polarized light microscope (PLM) adopted to study the nonisothermal crystallization of these polyesters at a cooling rate of 1, 2, 3, 5, 6, and 10 °C/min. Morphology and the isothermal growth rates of spherulites under PLM experiments were monitored and obtained by curve‐fitting. These continuous rate data were analyzed with the Lauritzen−Hoffman equation. A transition of regime II → III was found at 95.6, 84.4, and 77.3 °C for PBSu, PBPSu 95/5, and PBPSu 90/10, respectively. DSC exothermic curves show that all of the nonisothermal crystallization occurred in regime III. DSC data were analyzed using modified Avrami, Ozawa, Mo, Friedman, and Vyazovkin equations. All the results of PLM and DSC measurements indicate that incorporation of minor PS units into PBSu markedly inhibits the crystallization of the resulting polymer. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1299–1308, 2010
Role of temperature during ageing under gamma irradiation of filled EPDM: consequences on mechanical properties
Authors: Planes Emilie , Chazeau Laurent , Vigier Gérard 
Published: May 2010

AbstractFilled EPDM materials have been processed and aged by gamma radiation at ambient temperature and at 80 °C to study the influence of the fillers presence in the material degradation. The acceleration of the polymer degradation by the ATH fillers, evidenced when irradiation is performed at 25 °C, is also effective at 80 °C. In addition, in the case of silica‐filled EPDM, the creation of strong filler‐matrix bonds, already reported for irradiation at 25 °C, is also thermally activated; this enables to this material to keep its integrity at high irradiation dose, whereas the irradiated ATH‐filled EPDM is so degraded that it flows. Thus, the introduction of fillers in the polymer has an impact on its resistance to irradiation, whatever the temperature at which the irradiation is performed. Moreover, the consequences of the degradation on the evolution of the mechanical properties of the composite are very dependent on the filler nature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1319–1328, 2010
Synthesis and characterization of polypyrrole/graphite oxide composite by in situ emulsion polymerization
Authors: Gu Zheming , Li Chunzhong , Wang Gengchao , Zhang Ling , Li Xiaohui , Wang Wendong , Jin Shilei 
Published: May 2010

AbstractThis work demonstrates a feasible route to synthesize the layered polypyrrole/graphite oxide (PPy/GO) composite by in situ emulsion polymerization in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) as emulsifier. AFM and XRD results reveal that the GO can be delaminated into nanosheets and well dispersed in aqueous solution in the presence of CTAB. The PPy nanowires are formed due to the presence of the lamellar mesostructured (CTA)2S2O8 as a template. The results of the PPy/GO composite indicate the PPy insert successfully into GO interlayers, and the nanofiber‐like PPy are deposited onto the GO surface. Owing to π–π electron stacking effect between the pyrrole ring of PPy and the unoxided domain of GO sheets, the electrical conductivity of PPy/GO composite (5 S/cm) significantly improves in comparison with pure PPy nanowires (0.94 S/cm) and pristine GO (1 × 10−6 S/cm). © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1329–1335, 2010
Linear viscoelastic characteristics of in situ compatiblized binary polymer blends with viscoelastic properties of components variable
Authors: Li Jingqing , Ma Guiqiu , Sheng Jing 
Published: May 2010

AbstractBy Friedel‐Crafts alkylation reaction, catalyzed by a Lewis acid of anhydrous aluminum chloride (AlCl3), binary polymer blends of polypropylene (PP)/polystyrene (PS) with volume proportion of 80/20 were in situ compatiblized and prepared in an XSS‐30 melt mixer at 210 °C. The linear viscoelastic characteristics of the blends were investigated by checking the variations of storage modulus, loss modulus, complex modulus, and complex viscosity of the in situ compatiblized blends, which were dependent on AlCl3 content. In addition, Han plots of the in situ compatiblized blends with different AlCl3 content were also used to characterize the linear viscoelastic properties of the blends. The results showed that both the dynamic rheological parameters and the Han plots were obviously influenced by the rheological properties of the matrix and slightly influenced by the rheological properties of the dispersed phase. Further investigations revealed that phase geometry contributions to the dynamic rheological parameters of the blends could be ignored in comparison with the contributions of the components and the interfacial modification, which were defined and obtained according to log‐linear‐additivity rule. The linear viscoelastic characteristics of the blends were mainly controlled by the combination of the effects of interfacial modification between phases and the rheological properties of the matrix. Storage modulus is the most sensitive dynamic rheological parameter to characterize the interfacial compatiblization effects in the in situ compatiblized binary polymer blends with rheological properties of components variable. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1349–1362, 2010
Evolutionary mechanism as a template for protein engineering
Authors: Eisenbeis Simone , Höcker Birte 
Published: May 2010

AbstractThe goal of a protein engineer is to adjust a protein to a specified new function. This is exactly what natural evolution has achieved many times. By studying evolutionary mechanisms, we can learn about ways to use the adaptability of proteins and to build new proteins. In fact, many techniques used in engineering are successfully mimicking evolutionary processes. We introduce the fundamental evolutionary mechanisms, take a closer look at duplication and fusion, recombination, and circular permutation and discuss their influence on protein engineering. Some important techniques are presented and illustrated with examples. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Phosphoramidate‐peptide synthesis by solution‐ and solid‐phase Staudinger‐phosphite reactions
Authors: Serwa Remigiusz A. , Swiecicki Jean‐Marie , Homann Denise , Hackenberger Christian P. R. 
Published: May 2010

AbstractThe chemoselective incorporation of phosphoramidate moieties into peptides by a Staudinger‐phosphite reaction of azides can be performed in many solvents, including water. In this report, we present two strategies for an efficient synthesis of phosphoramidate‐containing peptides, in which the Staudinger‐phosphite reaction is performed either on the solid support or in solution with aryl azido‐containing peptides. The corresponding Staudinger reactions proceed in high conversion rates and deliver phosphoramidate peptides, in which the modification site is located in the middle of the peptide sequence. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Structure–activity relationship of marinostatin, a serine protease inhibitor isolated from a marine organism
Authors: Taichi Misako , Yamazaki Tohimasa , Kawahara Kazuki , Motooka Daisuke , Nakamura Shota , Harada Shusaku , Teshima Tadashi , Ohkubo Tadayasu , Kobayashi Yuji , Nishiuchi Yuji 
Published: May 2010

AbstractA 12‐residue MST isolated from a marine organism is a potent serine protease inhibitor that has a double cyclic structure composed of two ester linkages formed between the β‐hydroxyl and β‐carboxyl groups, Thr3‐Asp9and Ser8‐Asp11. MST was synthesized by a regioselective esterification procedure employing two sets of orthogonally removable side‐chain protecting groups for the Asp and Ser/Thr residues. In the MST molecule, there were no significant changes observed in yield by changing the order of esterification. SAR study of MST revealed that the minimum required structure for expressing the inhibitory activity is the sequence (1–9) in a monocyclic structure where Pro7located in the ring plays a crucial role in keeping the structural rigidity. By applying the structural motif of MST, we rationally designed protease inhibitory specificities that differ from those of the natural product. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
The effect of heat treatment on the phase constitution and magnetic properties of Pr9Fe60Co13Zr1Ti3B14 alloy ribbons
Authors: Pawlik Piotr , Pawlik Katarzyna , Davies Hywel A. , Wysłocki Jerzy J. , Gębara Piotr 
Published: May 2010

AbstractFully amorphous ribbon samples of the alloy Pr9Fe60Co13Zr1Ti3B14 were produced by the melt‐spinning technique under an Ar atmosphere. In the as‐cast state, the samples were soft magnetic, with a coercivity JHc of ∼10 A/m and saturation magnetization Jr of ∼1 T. Subsequent annealing at various temperatures Ta (from 903 to 973 K for 10 min) resulted in an evolution of the phase constitution together with a significant change of their magnetic properties. X‐ray diffractometry (XRD) revealed the presence of the hard magnetic Pr2(Fe,Co)14B phase, precipitated during annealing. However, quantitative analysis of Mössbauer spectra for the alloy showed a multiphase constitution with a relatively low volume fraction of this crystalline phase. Furthermore, the temperature dependences of magnetization confirmed differences in the constitution of the samples annealed at various temperatures. The aim of present work was to investigate the correlation between the phase constitution and magnetic properties of the ribbon samples.
Anomalous capacitance–voltage characteristics of Pt–AlGaN/GaN Schottky diodes exposed to hydrogen
Authors: Irokawa Yoshihiro , Matsuki Nobuyuki , Sumiya Masatomo , Sakuma Yoshiki , Sekiguchi Takashi , Chikyo Toyohiro , Sumida Yasunobu , Nakano Yoshitaka 
Published: May 2010

AbstractWe have investigated the interaction of hydrogen with Pt‐AlGaN/GaN Schottky barrier diodes (SBDs) using a low‐frequency capacitance‐voltage (C‐V) technique. At a frequency of 1kHz, the C‐V curve in hydrogen shifts toward negative bias values as compared with that in nitrogen. As the frequency decreases from 1kHz to 1Hz, the capacitance in hydrogen significantly increases and the fluctuations of the capacitance are observed. These C‐V characteristics are quite anomalous and have not been reported yet, suggesting the formation of interfacial polarization which could be attributable to hydrogen‐related dipoles. The fluctuation of the capacitance may be related to the alignment of the dipoles. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of ITO spreading layer on performance of blue light‐emitting diodes
Authors: Bogdanov M. V. , Bulashevich K. A. , Khokhlev O. V. , Evstratov I. Yu. , Ramm M. S. , Karpov S. Yu. 
Published: May 2010

AbstractOperation of blue light emitting diodes with ITO spreading layers of various thicknesses deposited on top of the p‐contact layer is considered by simulations. Effects of the ITO layer on the current spreading in and the efficiency of light extraction from the LED dice are examined in detail. The electrical LED parameters, operation voltage and series resistance at a certain forward current, are found to be improved with the thickness of ITO films. In contrast, the optical parameters, external quantum efficiency and output power, become reduced with the thickness because of free‐carrier light absorption in the ITO films. These opposite trends make practically unrealistic simultaneous optimization of the electrical and optical parameters by varying the ITO layer properties only. An alternative way is suggested for improvement of the LED performance, based on optimization of light extraction from the LED due to a proper choice of the ITO parameters and of current spreading in the die due to an increase of doping level in the n‐contact layer. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Buffer‐trap and surface‐state effects on gate lag in AlGaN/GaN HEMTs
Authors: Horio Kazushige , Nakajima Atsushi 
Published: May 2010

AbstractTwo‐dimensional simulation of turn‐on characteristics of Al‐GaN/GaN HEMTs is performed in which both buffer traps and surface states are considered. It is studied how the so‐called gate lag is affected by these factors. It is shown that gate lag due to buffer traps can occur because in the off state where the gate voltage is negative, electrons are injected into the buffer layer and captured by the traps, leading to more negatively charged buffer layer. It is also shown that gate lag due to an electron‐trap‐type surface state can occur only when electron's gate tunneling is considered (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of unintentional arsenic incorporation into free‐standing zinc‐blende GaN and AlGaN layers grown by molecular beam epitaxy on GaAs substrates
Authors: Novikov S. V. , Zainal N. , Foxon C. T. , Kent A. J. , Luckert F. , Edwards P. R. , Martin R. W. 
Published: May 2010

AbstractIn this paper we have studied the unintentional incorporation of arsenic into thick (up to ∼75 μm) zinc‐blende (cubic) GaN and AlGaN layers grown by a plasma‐assisted molecular beam epitaxy (PA‐MBE) on (001) GaAs substrates. We present detailed studies of As incorporation into free‐standing zinc‐blende (Al)GaN by secondary ion mass spectroscopy (SIMS) and electron probe microanalysis (EPMA). We demonstrate that there is no significant arsenic contamination of zinc‐blende GaN layers and substrates due to diffusion of arsenic during the prolonged growths by PA‐MBE. Arsenic incorporation is limited to the first few hundred nanometers of the layer and it is due to initiation phase of the growth of zinc‐blende material, which involves use of arsenic as a surfactant to promote the growth of the cubic phase. These data have allowed us to determine the thickness of the unintentionally arsenic contaminated GaN region, which needs to be removed by polishing during production of free‐standing zinc‐blende GaN substrates. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation mechanism of Al‐depleted bands in MOVPE‐AlGaN layer on GaN template with trenches
Authors: Kuwano Noriyuki , Ezaki Tetsuya , Kurogi Takuya , Miyake Hideto , Hiramatsu Kazumasa 
Published: May 2010

AbstractA microstructure in an AlGaN/GaN layer was analyzed in detail by means of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) with special attention to the formation of steps on the surface. The AlGaN layer was grown by MOVPE on a GaN template with periodic trenches. It was revealed that there formed were Al‐depleted bands in the AlGaN layer. These bands were generated from rather lower regions in the AlGaN layer or those above the trenches, and run upwards. Some of them reached the top surface to connect a macro step. The formation mechanism of the Al‐depleted region is discussed in terms of thermodynamics. If the total bonding energy of atoms on the macro step of surface is assumed to be smaller than that of atoms on a flat surface, the Al‐depletion can be explained provided that the local equilibrium in concentration is conserved during the growth of AlGaN layer. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Plasma assisted LED wafer scribing and fabrication of Ag nanoparticle‐embedded LED
Authors: Lee Jong‐Moo , Bae Sung‐Bum , Youn Doo‐Hyub , Park Suntak , Ju Jung Jin , Jang Moon Sik , Jung Hyun Min , Kim Chang Tae 
Published: May 2010

AbstractTwo applications of plasma effects in fabrication of LEDs are introduced. One is scribing LED wafer by mechanical impacts of plasma, which is induced by laser ablation, to the bottom of LED wafer. The other one is the surface plasmon effect on light emission. Ag nano‐particles are formed on about 50‐nm thick p‐GaN epitaxial layer over multi‐quantum wells (MQWs) and an additional 150‐nm thick p‐GaN layer is grown again over the surface. As the result, the Ag nano‐particles are located within the overall p‐GaN epitaxial layer, very near to MQWs. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Semipolar GaInN/GaN light‐emitting diodes grown on honeycomb patterned substrates
Authors: Wunderer T. , Wang J. , Lipski F. , Schwaiger S. , Chuvilin A. , Kaiser U. , Metzner S. , Bertram F. , Christen J. , Shirokov S. S. , Yunovich A. E. , Scholz F. 
Published: May 2010

AbstractExcellent semipolar GaN material quality can be obtained by growing inverse GaN pyramids on full 2 inch c‐plane sapphire when combining the advantages of defect reduction via FACELO and selective area growth for faceted surfaces. The nearly defect free material is obtained by structuring the mask into a honeycomb pattern. When realizing full GaInN/GaN LED structures on those templates a relatively broad emission is observed during electroluminescence measurements.Furthermore, the dominant wavelength is found to be dependent on the applied current density. The pronounced shift is in good agreement with the wavelength shift along one single facet. Gas phase diffusion during the active area growth is believed to be the main reason for the varying indium content. The homogeneity could be influenced by changing the reactor pressure during the active area growth (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Highly defined and ordered top‐openings in TiO2 nanotube arrays
Authors: Albu Sergiu P. , Schmuki Patrik 
Published: May 2010

AbstractWe report a very simple and novel approach to produce anodic TiO2 nanotube arrays with highly defined and ordered tube openings. It is based on carrying out anodization through a slowly soluble photoresist coating. This eliminates the formation of undesired initiation layers on the tube tops and protects them to a certain extent from etching by the electrolyte.magnified image(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantification of monosaccharides through multiple‐reaction monitoring liquid chromatography/mass spectrometry using an aminopropyl column
Authors: Hammad Loubna A. , Derryberry Dakota Z. , Jmeian Yazen R. , Mechref Yehia 
Published: May 2010

AbstractA simple, sensitive, and reproducible quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was designed for the simultaneous quantification of monosaccharides derived from glycoprotein and blood serum using a multiple‐reaction monitoring (MRM) approach. Sialic acids and neutral monosaccharides were efficiently separated using an amino‐bonded silica phase column. Neutral monosaccharide molecules were detected as their aldol acetate anion adducts [M + CH3CO2]− using electrospray ionization in negative ion MRM mode, while sialic acids were detected as deprotonated ions [M–H]−. The new method did not require a reduction step, and exhibited very high sensitivity to carbohydrates with limits of detection of 1 pg for the sugars studied. The linearity of the described approach spanned over three orders of magnitude (pg to ng). The method was validated for monosaccharides originating from N‐linked glycans attached to glycoproteins and glycoproteins found in human blood serum. The method effectively quantified monosaccharides originating from as little as 1 µg of glycoprotein and 5 µL of blood serum. The method was robust, reproducible, and highly sensitive. It did not require reduction, derivatization or postcolumn addition of reagents. Copyright © 2010 John Wiley & Sons, Ltd.