bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study of γ‐radiation‐crosslinked HDPE/EPDM composites as flame retardants
Authors: Jia Shaojin , Zhang Zhicheng , Wang Zhengzhou , Zhang Xianfeng , Du Zhiwen 
Published: December 2004

AbstractThe dynamic flammability of flame‐retardant composites that consist of high‐density polyethylene (HDPE) and ethylene–propylene–diene rubber (EPDM) and other additives, and can be used as wire‐ and cable‐insulation materials, was studied before and after irradiation. The data for the heat‐release rate (HRR), the time to ignition, the specific extinction area and the concentrations of CO and CO2 from the burning process of cone colorimeter tests were assessed. By blending HDPE with EPDM, the HRR of HDPE was reduced and the residue char of the composite increased. The HRR of HDPE/EPDM was further reduced and the residue char of HDPE/EPDM was further increased after irradiation. The oxygen index, mechanical properties, and thermal stability of the composites, and the morphology of the char formed in the cone calorimeter test, were also investigated. Copyright © 2004 Society of Chemical Industry
Non‐isothermal crystallization kinetics of poly(ε‐caprolactone) in hydrogen‐bond‐coupled polymeric‐inorganic hybrid materials
Authors: Nie Kangming , Pang Wenmin , Zheng Sixun , Wang Yusong , Lu Fei , Zhu Qingren 
Published: December 2004

AbstractSome hydrogen‐bonding‐interactions‐mediated poly(ε‐caprolactone) (PCL)/silica (SiO2) polymeric‐inorganic hybrids were prepared by the sol–gel process. The non‐isothermal crystallization kinetics of PCL in the hybrids was investigated by means of differential scanning calorimetry. The results show that the Jeziorny method, together with the combination of the Avrami and Ozawa equations, is applicable to describe the non‐isothermal crystallization kinetics of the PCL in the hybrid system, while the Ozawa theoretical method can be used just for the pure PCL and the 70/30 TEOS/PCL hybrids. Depending on the composition of the PCL/silica, the hybrids displayed microphase separation at various scales, which in turn affect the crystallization behavior and mechanism of PCL in the hybrids. On the one hand, the inorganic component (viz SiO2) could act as the nucleating agent to facilitate the crystallization of PCL in the hybrids. On the other hand, the SiO2 networks also confine the crystallization of PCL. Copyright © 2004 Society of Chemical Industry
Study of polypropylene/montmorillonite nanocomposites prepared by solid‐state shear compounding (S3C) using pan‐mill equipment: the morphology of montmorillonite and thermal properties of the nanocomposites
Authors: Shao Weiguo , Wang Qi , Ma Hong 
Published: December 2004

AbstractIn this paper, polypropylene (PP)/organophilic montmorillonite (OMMT) nanocomposites were successfully prepared without any compatibilizers by solid‐state shear compounding (S3C) using pan‐mill equipment. X‐ray diffraction (XRD) patterns show that the OMMT characteristic (001) peak at 2θ equal to 4.59 degrees disappeared for the milled OMMT and corresponding composites. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) photographs show that the thickness of pan‐milled OMMT decreased from ca 100–200 nm to ca 30–50 nm, and OMMT was partly exfoliated in the PP matrix because the pan‐type mill can exert fairly strong squeezing force in the normal direction and shearing force in both radial and tangential directions on milled materials. PP/OMMT nanocomposites at low OMMT loading have higher melting point, crystallization temperature, thermal degradation temperature and heat distortion temperature than those of neat PP. Moreover, addition of OMMT accelerates crystallization of PP significantly. S3C is a novel approach to prepare polymer/layered silicate nanocomposites with high performances at low filler loading. Copyright © 2004 Society of Chemical Industry
Grafting studies onto cellulose by atom‐transfer radical polymerization
Authors: Coskun Mehmet , Temüz Mehmet Mürşit 
Published: December 2004

AbstractStyrene (Sty), methyl methacrylate (MMA), methacrylamide (MAm) and acrylomorpholine (AcM) were grafted onto powder cellulose by atom‐transfer radical polymerization. Cellulose chloroacetate (Cell‐ClAc), as a macro‐initiator, was first prepared by the reaction of chloroacetyl chloride with primary alcoholic OH groups on powder cellulose. CuBr and 1,2‐dipiperidinoethane were used as a transition‐metal compound and as a ligand, respectively. These reactions were monitored by FT‐IR and weight increase in Cell‐ClAc. In case of styrene, although some weight increase occurred, no evidence of grafting could be observed in the FT‐IR spectrum, while there were strong evidence of grafting with MMA, MAm and AcM. Cell‐graft‐MAm, Cell‐graft‐AcM and Cell‐graft‐MMA showed new carbonyl bands at 1665, 1640 and 1735 cm−1, respectively. Dye‐uptake and dye‐absorption properties of cellulose, for alizarin yellow (basic dye) and bromocresol green (acidic dye), and its moisture‐ and water‐uptake capacities improved with the grafting, but some decrease was observed in thermal stability. Copyright © 2004 Society of Chemical Industry
More on the poly(L‐lactide) prepared using ferrous acetate as catalyst
Authors: Stolt Mikael , Krasowska Katarzyna , Rutkowska Maria , Janik Helena , Rosling Ari , Södergård Anders 
Published: December 2004

AbstractPolylactides were prepared by ring‐opening polymerization (ROP) in bulk using as catalyst either stannous 2‐ethylhexanoate at a monomer to catalyst ratio of 2000, or ferrous acetate (Fe(OAc)2) at monomer to catalyst ratios of 500, 1000, 2000 and 3000. The crystallization behaviour was studied for the prepared polymers as well as the degradation behaviour both in laboratory and natural compost environments by using differential scanning calorimetry, size exclusion chromatography, X‐ray diffractiometry and microscopy. No differences were apparent due to the choice or amount of catalyst used, except for those which could be related to the increased racemization when the Fe(OAc)2 was used. Copyright © 2004 Society of Chemical Industry
Facile modifications of polyimide via chloromethylation: II. Synthesis and characterization of thermocurable transparent polyimide having methylene acrylate side groups
Authors: Li Xiang‐Dan , Zhong Zhen‐Xin , Han Sang‐Hoon , Lee Seung Hee , Lee Myong‐Hoon 
Published: December 2004

AbstractFrom chloromethylated polyimide, a useful starting material for modification of aromatic polyimides, a thermocurable transparent polyimide having acrylate side groups was prepared. In the presence of 1,8‐diazabicyclo[5,4,0]undec‐7‐ene, chloromethylated polyimide was esterified with acrylic acid to synthesize poly(imide methylene acrylate). The polymer was soluble in organic solvent, which makes it possible to prepare a planar film by spin coating. The polymer film became insoluble after thermal treatment at 230 °C for 30 min. Optical transparency of the film at 400 nm (for 1 µm thickness) was higher than 98 % and not affected by further heating at 230 °C for 250 min. Adhesion properties measured by the ASTM D3359‐B method ranged from 4B to 5B. Preliminary results of planarization testing showed a high degree of planarization (DOP) value (>0.53). These properties demonstrate that poly(imide methylene acrylate) could be utilized as a thermocurable transparent material in fabricating display devices such as TFT‐LCD. Copyright © 2004 Society of Chemical Industry
Spectroscopic analysis of Nd3+(4f3) absorption intensities in a plastic host (HEMA)
Authors: Sardar Dhiraj K , Yow Raylon M , Coeckelenbergh Cody H , Sayka Anthony , Gruber John B 
Published: December 2004

AbstractSpectroscopic and laser properties of Nd3+ embedded in a 2‐hydroxyethyl methacrylate (HEMA) solid plastic host are characterized. The Judd–Ofelt model has been applied to the room temperature absorption intensities of Nd3+(4f3) transitions in HEMA to determine the three phenomenological intensity parameters: Ω2, Ω4 and Ω6. The intensity parameters are then utilized to determine the radiative decay rates (emission probabilities of transitions) and branching ratios of the Nd3+(4f3) transitions from the upper manifold state 4F3/2 to the lower‐lying multiplet manifolds 4IJ′. The predicted decay rates and branching ratios of the Nd3+(4f3) inter‐manifold transitions in HEMA are compared with those in other laser host media. From the radiative decay rates, the radiative lifetime of the Nd3+4F3/2 excited state is determined. Copyright © 2004 Society of Chemical Industry
Synthesis of acrylamide end‐functionalised poly(1‐hexene) using an α‐diimine nickel catalyst
Authors: Fernandes Susete , Ascenso José R , Gomes Pedro T , Costa Sandra I , Silva Leonel C , Chien James CW , Marques Maria M 
Published: December 2004

AbstractThe nickel precursor [bis(N,N′‐dimesitylimino)acenaphthene]dibromonickel and methylaluminoxane were used to catalyse the functionalisation of 1‐hexene with acrylamide by passivation of acrylamide with tri‐isobutylaluminium. The polymer obtained was characterised by GPC/SEC and NMR. The NMR experiments performed, COSY, DEPT, long‐range selective INEPT, HSQC and TOCSY 1D, showed that a 2,1 insertion of a single molecule of acrylamide per macromolecule had occurred at the end of the polyhexene chain. Copyright © 2004 Society of Chemical Industry
Space charge distribution and crystalline structure in low density polyethylene (LDPE) blended with high density polyethylene (HDPE)
Authors: Lin Yijian , Du Weichuan , Tu Demin , Zhong Wei , Du Qiangguo 
Published: December 2004

AbstractThe space charge distribution in polyethylene blends under direct current electrical field was measured by a pulsed electro‐acoustic method. It was found that blending LDPE with 0.5 wt% HDPE decreased the amount of accumulated space charges and improved their distribution. Small‐angle light scattering and differential scanning calorimetry showed that crystallization of LDPE/HDPE started at higher temperature than virgin LDPE, and the sizes of LDPE/HDPE spherulites were smaller than that of LDPE. HDPE plays a role on nucleation during the crystallization process. Crystalline form was investigated by wide‐angle X‐ray diffraction and the results indicate that the crystal form did not change after blending. The reduction of space charges in the blended sample can be explained as the result of the dissipation of charges through boundary regions of smaller spherulites. Copyright © 2004 Society of Chemical Industry
Direct synthesis of poly(4′‐oxy‐4‐biphenylcarbonyl) and poly(2‐oxy‐6‐naphthoyl) under nonstoichiometric conditions
Authors: Kohama Shin‐ichiro , Kimura Kunio , Uchida Tetsuya , Umehara Shin‐ichi , Ikemoto Yume , Yamashita Yuhiko 
Published: December 2004

AbstractDirect synthesis of poly(4′‐oxy‐4‐biphenylcarbonyl) (POBP) and poly(2‐oxy‐6‐naphthoyl) (PON) was examined by polycondensation of 4′‐hydroxy‐4‐biphenylcarboxylic acid (HBPA) and 2‐hydroxy‐6‐naphthoic acid (HNA) in the presence of 4‐ethoxybenzoic anhydride or 2‐naphthoic anhydride as condensation reagents. Polymerizations were carried out at 320 °C in aromatic solvents and liquid paraffin. POBP, having a number‐average degree of polymerization (DPn) of 38, was obtained as plate‐like crystals at the molar ratio of HBPA and anhydride of 50 mol%. PON was also obtained as plate‐like crystals but the DPn was only 13. HBPA and HNA were first converted to reactive acyloxyaromatic acid intermediates. Then the DPn was increased by means of reaction‐induced crystallization of oligomers and subsequent solid‐state polymerization via an acid–ester exchange under nonstoichiometric conditions caused by the monocarboxylic acid by‐product. Even though the DPn of PON was not as high, direct polycondensation of HBPA and HNA proceeded successfully with aromatic anhydrides. Copyright © 2004 Society of Chemical Industry
Synthesis and characterization of new thermally stable aromatic copoly(ester–amide)s from diester‐dicarboxylic acids
Authors: Banihashemi Ahmad , Toiserkani Hojjat 
Published: December 2004

AbstractTwo new aromatic diester‐dicarboxylic acids containing furan rings, namely, benzofuro[2,3‐b]benzofuran‐2,9‐dicarboxyl‐bis‐pyridyl ester‐4,4′‐dicarboxylic acid and benzofuro[2,3‐b]benzofuran‐2,9‐dicarboxyl‐bis‐phenyl ester‐4,4′‐dicarboxylic acid were synthesized by the reaction of benzofuro[2,3‐b]benzofuran‐2,9‐dicarbonyl chloride with 6‐hydroxynicotinic acid and 4‐hydroxybenzoic acid, respectively. These monomers were converted to aromatic copoly(ester–amide)s by reaction with various aromatic diamines via direct polycondensation. Polymers were characterized by FTIR and 1H NMR spectroscopy, thermogravimetry, viscosity and solubility tests. The inherent viscosity of the polymers was in the range 0.23–0.46 dl g−1 in dimethyl sulfoxide at 30 °C. They dissolved readily in polar solvents at room temperature. They possess a glass‐transition temperature in the range 210–260 °C and exhibit excellent thermal stability. Copyright © 2004 Society of Chemical Industry
Normal and shear forces between a polyelectrolyte brush and a solid surface
Authors: Kampf Nir , Gohy Jean‐François , Jérôme Robert , Klein Jacob 
Published: December 2004

AbstractThe diblock copolymer poly(methyl methacrylate)‐b‐poly(sodium sulfonated glycidyl methacrylate) (PMMA‐b‐PSGMA) was end‐attached by its hydrophobic block (PMMA) onto mica hydrophobized by a stearic trimethylammonium iodide (STAI) layer, to form a polyelectrolyte brush immersed in water. With a surface force balance (SFB), we extended earlier measurements between two such brush layers for the case of normal and shear forces at different shear rates, surface separation, and compressions between one mica surface coated with STAI or a STAI‐diblock layer against a bare mica surface. After coating one of the surfaces with STAI, a long range attraction that results in a jump into an adhesive flat contact between the hydrophobic and hydrophilic surfaces was observed. A very different behavior was seen after forming the polyelectrolyte brush on the STAI‐coated surface. The long range attraction was replaced by repulsion, accompanied by very low friction during shear (ca. three orders of magnitude lower than with adsorbed polyelectrolytes). On further compression, a weak attraction to the adhesive contact was observed. From the final surface–surface contact separation, we deduce that most of the polyelectrolyte diblock brush layer was squeezed out from the gap, leaving the STAI layer and a small amount of the polymer attached to the surface. Stick‐sliding behavior was seen while applying shear, suggesting a dissipation mechanism caused by the trapped polyelectrolyte. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 193–204, 2005
CuInS2 films using repeated chemical spray pyrolysis
Authors: John Teny Theresa , Wilson K. C. , Ratheesh Kumar P. M. , Sudha Kartha C. , Vijayakumar K. P. , Kashiwaba Y. , Abe T. , Yasuhiro Y. 
Published: December 2004

AbstractCuInS2 films of thickness 1.17 µm were deposited onto glass substrates using repeated spraying technique without any pinholes on the samples. It has been shown that the structure, optical and electrical properties depend on the [Cu]/[In] ratio taken in the solution. Studies using X‐ray Diffraction, X‐ray Photoelectron Spectroscopy (XPS), Energy Dispersive X‐ray Analysis (EDX), optical absorption, photosensitivity and conductivity measurements proved this. Moreover, XPS depth‐profiling revealed that there is no oxygen present in the bulk of the film; even though it was prepared using repeated spraying. Oxygen was present only in few atomic layers at the surface of the film and near the substrate–film interface. Use of Cu‐rich initial solution resulted in better crystallinity as well as conductivity. EDX measurements showed that [Cu]/[In] ratio in the film is slightly less than that taken in the solution. Photosensitivity of the samples decreased with increase in [Cu]/[In] ratio. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Iterative solution of algebraic matrix Riccati equations in open loop Nash games
Authors: Azevedo‐Perdicoúlis Teresa Paula , Jank Gerhard 
Published: December 2004

AbstractIn this note we study a fixed point iteration approach to solve algebraic Riccati equations as they appear in general two player Nash differential games on an infinite time horizon, where the information structure is of open loop type. We obtain conditions for existence and uniqueness of non‐negative solutions. The performance of the numerical algorithm is shown in an example. Copyright © 2005 John Wiley & Sons, Ltd.
Robust output regulation of minimum phase nonlinear systems using conditional servocompensators
Authors: Seshagiri Sridhar , Khalil Hassan K. 
Published: December 2004

AbstractWe consider the design of a robust continuous sliding mode controller for the output regulation of a class of minimum‐phase nonlinear systems. Previous work has shown how to do this by incorporating a linear servocompensator in the sliding mode design, but the transient performance is degraded when compared to ideal sliding mode control. Extending previous ideas from the design of ‘conditional integrators’ for the case of asymptotically constant references and disturbances, we design the servocompensator as a conditional one that provides servocompensation only inside the boundary layer; achieving asymptotic output regulation, but with improved transient performance. We give both regional as well as semi‐global results for error convergence, and show that the controller can be tuned to recover the performance of an ideal sliding mode control. Copyright © 2005 John Wiley & Sons, Ltd.
Sequential tests for gene–environment interactions in matched case–control studies
Authors: Tweel Ingeborg van der , Schipper Maria 
Published: December 2004

AbstractThe sample size necessary to detect a significant gene × environment interaction in an observational study can be large. For reasons of cost‐effectiveness and efficient use of available biological samples we investigated the properties of sequential designs in matched case–control studies to test for both non‐hierarchical and hierarchical interactions. We derived the test statistics Z and V and their characteristics when applied in a two‐sided triangular test. Results of simulations show good agreement with theoretical values for V and the type I error. Power values were larger than their theoretical values for very large sample sizes. Median gain in efficiency was about 27 per cent. For a ‘rare’ phenotype gain in efficiency was larger when the alternative hypothesis was true than under the null hypothesis. Sequential designs lead to substantial efficiency gains in tests for interaction in matched case–control studies. Copyright © 2004 John Wiley & Sons, Ltd.
Efficiency of the cross‐over design: an empirical estimation
Authors: Garcia Raquel , Benet Marta , Arnau Catalina , Cobo Erik 
Published: December 2004

AbstractThe aim of the present study is to estimate the relative efficiency of cross‐over clinical trials as compared to the corresponding parallel designs. A MEDLINE ‘full text’ search covering years 2000–2003 over the word ‘cross‐over’ identified 40 true cross‐over studies with the parametric approach published in leading medical journals.A parallel design is expected to need, in order to achieve the same power, between 4 and 10 times more subjects than the corresponding cross‐over design, meaning that cost of a parallel design can be between 2 and 5 times higher.There is a high proportion of cross‐over studies recently published in leading medical journals that, disregarding the CONSORT recommendations, does not provide estimates for the effect size and its standard error, hence, not allowing for the posterior use of the data in a meta‐analysis. Copyright © 2004 John Wiley & Sons, Ltd.
Perceived changes in food intake in response to stress: the role of conscientiousness
Authors: O'Connor Daryl B. , O'Connor Rory C. 
Published: December 2004

AbstractThe role of conscientiousness in understanding the effects of stress on eating behavior remains unknown. In this study, the interactive effects of conscientiousness and established individual differences variables (e.g. restraint, perfectionism) on perceived changes in food intake during a 2‐week stressful and non‐stressful period were examined. One hundred and fifty‐five female participants completed measures of conscientiousness, self‐oriented perfectionism, socially prescribed perfectionism and eating style (i.e. external eating, emotional eating and dietary restraint) at the beginning of the study. Perceived changes in food intake (i.e. between‐meal snacking), stress and emotional distress were also assessed. The results found that low conscientious individuals who were currently trying to lose weight or were high on self‐oriented perfectionism reported eating more between‐meal snacks than usual during the stressful period compared to the non‐stressful period. This study demonstrates, for the first time, that conscientiousness in conjunction with established individual differences variables is associated with perceived increases in food intake. These results suggest that when faced with a stressful encounter, low conscientious individuals (who are dieters or self‐oriented perfectionists) may be less well equipped to cope and as a result shift their preference to more palatable and high energy dense snacks foods. Copyright © 2004 John Wiley & Sons, Ltd.
Sliding wigner solid on liquid4He
Authors: Shirahama Keiya , Kono Kimitoshi 
Published: December 2004

AbstractWe report a systematic experimental study of the anomalous nonlinear magnetotransport in the Wigner solid (WS) trapped on a liquid4He surface. The ac Corbino conductivity σxx exhibits an abrupt jump at a certain driving voltage. The threshold input voltage Vth for the σxx jump varies as Vth ∝ B−0.8 ω−1 n1.5sE⊥, where B, ω, ns, and E⊥ are magnetic field, frequency, electron density and pressing electric field, respectively. We interpret the σxx jump as the transition between the WS accompanied with the periodic 4He surface deformation and the WS which decouples from the surface, due to the large driving force. A simple model is presented: The rigid-potential sliding model qualitatively explains the above mentioned behaviors of Vth. We have found that the dependences of σxx on B and E⊥ are different from those of the liquid phase. The anomalous behaviors of σxx play a crucial role on the sliding model.
Penicillium frequentans isolated from Picea glehnii seedling roots as a possible biological control agent against damping‐off
Authors: Yamaji Keiko , Fukushi Yukiharu , Hashidoko Yasuyuki , Tahara Satoshi 
Published: December 2004

AbstractPicea glehnii seedlings are affected by damping‐off fungi in nurseries. The aims of this study were (1) to isolate fungi grown in the seedling rhizosphere in forest soil of P. glehnii, (2) to select fungi that produce antifungal compounds against Pythium vexans, and (3) to examine whether or not selected fungi can protect seedlings from P. vexans. Penicillium frequentans from Picea glehnii seedling roots produced antibiotic penicillic acid. Penicillic acid did not cause significant phytotoxicity to the seedlings. Penicillium frequentans increased the average percentage of surviving seedlings when inoculated together with Pythium vexans, but the increase was not significant. Vigorous mycelial growth of P. frequentans around seedling roots seems to be one of the mechanisms for protection, but the amount of penicillic acid was too low to show antifungal activity in the seedling rhizosphere.