bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Linear and Cross-Linked Acrylate Polymers Bearing O-Cyanoethylated (Glycosyloxy)ethyl Side Chain with High Dielectric Properties over Wide Temperature Range
Authors: Nishida Ryosuke , Ishikawa Teruhiko , Saito Seiki 
Published: January 2003

Abstract
UV-irradiation (365 nm) on a spreaded mixture of 2-[tetra-O-(cyanoethyl)glucopyranosyloxy]ethyl acrylate and ethylene glycol dimethacrylate onto a copper plate gave a cross-linked copolymer which exhibited extremely stable and high dielectric permittivity (ε′) of 23 to 30 (−100 to −10 °C) and as high as 49 even at 20 °C.
Submicroscopic Morphology of the Laser Induced Surface Structure of Partially Renatured Gelatin Films
Authors: Sugiura Masaru , Tsunoda Katsunori , Yajima Hirofumi , Ishii Tadahiro , Itoh Hiroshi , Nagai Yutaka 
Published: January 2003

Abstract
The formation of nap-type structures induced by UV-laser irradiation of renatured gelatin films with various triple helix contents was observed by an atomic force microscope. Surface topography was found to be dependent on degree of helix content (DHC), fluence, and number of applied pulses (PN). The surface roughness (Ra) increased with PN following a hyperbolic curve for the renatured gelatin films with DHC of more than ca. 7%. The increment of Ra tended to be depressed with increasing DHC.
Steric and Conformational Effects on the Photophysical and DNA Binding Properties of Novel Viologen Linked Tolylacridines
Authors: Eldho Nadukkudy V , Joseph Joshy , Ramaiah Danaboyina 
Published: January 2003

Abstract
Two novel water soluble tolylacridines having viologen at the para and ortho to the acridine chromophore have been synthesized. Photophysical and DNA binding studies have revealed that the para-isomer exists in the extended conformation and binds to DNA by partial intercalation whereas the ortho-isomer exists both in folded and extended conformations and fails to interact with DNA.
Selective Hydrogenation of Benzene to Cyclohexadiene and Cyclohexene by Lanthanide Precipitates Obtained from Eu or Yb Metal Solutions in Liquid Ammonia
Authors: Imamura Hayao , Nishimura Kouzi , Sumioki Kenji , Fujimoto Mitoshi , Sakata Yoshihisa 
Published: January 2003

Abstract
Lanthanide precipitates obtained by decomposition of Eu or Yb metal solutions in liquid ammonia were active at 393 K for the partial liquid-phase hydrogenation of benzene to cyclohexene with high selectivity (≥90%). When the reaction temperature decreased to 323 K, cyclohexadienes were preferentially formed. The reducing behavior was markedly enhanced by the addition of ammonia to the reaction system.
The Preparation of Solid Superacid of Sulfated Tin Oxide with Acidity Higher Than Sulfated Zirconia
Authors: Matsuhashi Hiromi , Miyazaki Hidenori , Arata Kazushi 
Published: January 2003

Abstract
A highly active solid superacid of sulfated tin oxide was prepared from tin oxide gel which was precipitated from SnCl4 solution and washed with aqueous ammonium acetate solution. The sulfated tin oxide showed activity much higher than the sulfated zirconia, a well known solid superacid, for the skeletal isomerization of n-pentane, and its acid strength estimated by temperature-programmed desorption using argon was also higher than that of the latter.
Synthesis and Properties of Perfluoroalkylalkoxy Substituted Benzoic Acid Derivatives II: Forming Liquid Crystalline Cubic Phases
Authors: Nishikawa Etsushi , Yamamoto Jun , Yokoyama Hiroshi 
Published: January 2003

Abstract
A benzoic acid derivative having a long flexible fluorinated chain is synthesized. The material dimerizing through hydrogen bonding shows a smectic C phase at room temperature. The acid/base complex with 4,4′-dipyridyl exhibits a thermotropic liquid crystalline cubic phase. Flexibility of the fluorinated substituent and incompatibility with the hard aromatic cores are crucial factors to form a cubic phase.
A New Nonlinear Optical Borate Crystal Na3La2(BO3)3
Authors: Zhang Guochun , Wu Yicheng , Fu Peizhen , Wang Guofu , Pan Shilie , Chen Chuangtian 
Published: January 2003

Abstract
A new nonlinear optical (NLO) borate crystal Na3La2(BO3)3 (sodium lanthanum borate, NLBO) has been discovered. The bar-shaped crystal with sizes up to 8 × 3 × 2 mm3 was grown by the Top-Seeded Solution Growth (TSSG) method using Na2CO3–H3BO3–NaF as fluxes. The measurement of the infrared spectrum indicated that the basic anionic group is the BO3 group. Furthermore, NLBO crystal exhibits an optical second harmonic generation effect about twice as large as that of KDP(KH2PO4).
Synthesis and Characterization of the Dicobalt Bisporphyrin Complex Linked by 1,2-Phenylene Bridge
Authors: Shimazaki Yuichi , Takesue Hironori , Chishiro Takefumi , Tani Fumito , Naruta Yoshinori 
Published: January 2003

Abstract
The structure of a 1,2-phenylene linked dicobalt tetraarylporphyrin dimer was determined by X-ray crystallography and its dioxygen adduct was characterized by absorption and ESR spectroscopies. Since the porphyrin dimer has a long metal–metal distance and a rigid framework against inward bending, the cobalt centers were not bridged by the coordinated dioxygen.
Control of Ion Binding by Cooperative Ion-Pair Recognition Using a Flexible Heterotopic Receptor
Authors: Nabeshima Tatsuya , Hanami Takeshi , Akine Shigehisa , Saiki Toshiyuki 
Published: January 2003

Abstract
Complex of the host, which bears four amide groups and two crown ethers, and Cs+, recognizes chloride and bromide anions much more strongly than the free host, because the host captures one Cs+ ion with the two crown rings in a face-to-face fashion to cyclize the host, and the preorganization of the amide protons forms the good binding site for the anions.
Highly Syndiospecific Living Polymerization of Propylene Using a Titanium Complex Having Two Phenoxy-Imine Chelate Ligands
Authors: Saito Junji , Mitani Makoto , Mohri Jun-ichi , Ishii Sei-ichi , Yoshida Yasunori , Matsugi Tomoaki , Kojoh Shin-ichi , Kashiwa Norio , Fujita Terunori 
Published: January 2003

Abstract
A titanium complex having fluorine-containing phenoxy-imine chelate ligands, when activated with methylalumoxane (MAO), promotes a highly stereospecific living polymerization of propylene at room temperature to produce syndiotactic polypropylene (rr = 87%, Tm = 137 °C) having extremely narrow polydispersity (Mw/Mn = 1.11).
Is the Gulf Stream responsible for Europe's mild winters?
Authors: Seager R. , Battisti D. S. , Yin J. , Gordon N. , Naik N. , Clement A. C. , Cane M. A. 
Published: January 2003

AbstractIs the transport of heat northward by the Gulf Stream and North Atlantic Drift, and its subsequent release into the midlatitude westerlies, the reason why Europe's winters are so much milder than those of eastern North America and other places at the same latitude? Here, it is shown that the principal cause of this temperature difference is advection by the mean winds. South‐westerlies bring warm maritime air into Europe and north‐westerlies bring frigid continental air into north‐eastern North America. Further, analysis of the ocean surface heat budget shows that the majority of the heat released during winter from the ocean to the atmosphere is accounted for by the seasonal release of heat previously absorbed and not by ocean heat‐flux convergence. Therefore, the existence of the winter temperature contrast between western Europe and eastern North America does not require a dynamical ocean. Two experiments with an atmospheric general‐circulation model coupled to an ocean mixed layer confirm this conclusion. The difference in winter temperatures across the North Atlantic, and the difference between western Europe and western North America, is essentially the same in these models whether or not the movement of heat by the ocean is accounted for. In an additional experiment with no mountains, the flow across the ocean is more zonal, western Europe is cooled, the trough east of the Rockies is weakened and the cold of north‐eastern North America is ameliorated. In all experiments the west coast of Europe is warmer than the west coast of North America at the same latitude whether or not ocean heat transport is accounted for. In summary the deviations from zonal symmetry of winter temperatures in the northern hemisphere are fundamentally caused by the atmospheric circulation interacting with the oceanic mixed layer. Copyright © 2002 Royal Meteorological Society.
Entrainment in stratocumulus‐topped mixed layers
Authors: Stevens Bjorn 
Published: January 2003

AbstractMixed‐layer theory is used to synthesize and evaluate recently proposed entrainment parametrizations (rules) for the stratocumulus‐topped boundary layer. The results illustrate that recently proposed entrainment rules exhibit marked differences. Significant differences are found between rules derived from a single set of simulations and rules derived from different sets of simulations. Such differences imply steady‐state boundary layers that can differ by as much as a factor of two in climatologically important properties such as vertically integrated liquid water and boundary‐layer depth. In addition, surface fluxes depend significantly on entrainment, as do different measures for the limits of applicability of the mixed‐layer theory. Moreover, differences among proposed entrainment rules yield steady states with different equilibrium sensitivities; models closed with some rules are more sensitive to divergence while others are more sensitive to variations in the sea surface temperature. Overall we expect that these differences should be evident in the climatology and climate sensitivity of stratocumulus derived from models which use these rules. This degree of sensitivity encourages attempts to bound entrainment rules observationally, by requiring consistency with the observed stratocumulus climatology. The analysis also encourages the use of somewhat simpler strategies for the parametrization of the stratocumulus‐topped boundary layer in large‐scale models. Copyright © 2002 Royal Meteorological Society.
Comparison between observed and modelled radiative properties of stratocumulus clouds
Authors: Sun Zhian , Pethick David 
Published: January 2003

AbstractMeasurements of radiative and microphysical characteristics of stratocumulus clouds in a coastal region of South Australia are reported. The measurements were taken on 14 April 1999 using two aircraft from Airborne Research Australia based at the Flinders University of South Australia during the Kangaroo Island Radiation and Cloud Experiments (KIRCE). The measurements include radiation, cloud liquid‐water content, ambient temperature and humidity. A new method to process the measurements is described. Cloud albedo and absorption were determined using the observed solar irradiances at the cloud top and base and the results were compared with theoretical calculations. Five water‐cloud optical parametrization schemes were tested against the observations. In addition, some observational data from the Joint Air–Sea Interaction (JASIN) experiment were used in the comparisons. It has been found that measured cloud properties from the KIRCE experiment are very similar to those of the JASIN experiment. The modelled results from most schemes are compatible and generally in good agreement with the measurements. Copyright © 2002 Royal Meteorological Society.
Surface oxidation of styrene butadiene copolymers: Study by laser ablation and secondary ion mass spectrometry
Authors: Ruch D. , Boes C. , Zimmer R. , Migeon H.‐N. , Muller J. F. 
Published: January 2003

AbstractThe capabilities of ion bombardment and laser ablation coupled to mass spectrometry as independent techniques to investigate the surface thermooxidative stability of polystyrene, polybutadiene polymers, and styrene butadiene rubber (SBR) copolymers were investigated. Surface chemical modifications were detected according to the polymeric structure. The degradation products detected by static secondary ion mass spectrometry appeared at m/z 29, 43, and 55. Their compositions were related to the general formulae CnHmO+ with n = 1–3 and m = 1–3 for polybutadiene and styrene butadiene copolymers, whereas polystyrene was not affected by the aging treatment. The CnHmO+ ions result from butadiene unit degradation. The laser ablation ionization Fourier transform ion cyclotron resonance mass‐spectrometry results confirmed the detection of CnHmO+ ions. Finally, it may be considered that the surface thermooxidative process of SBR copolymers begins with butadiene unit degradation. The development of butadiene unit oxidation showed a dynamic oxidation phase, which coincided with a loss of unsaturation. The influence of the polymer conformation (blocked, branched, and random) on the surface oxidation for 30% styrene SBR compounds was also studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1910–1917, 2003
Molecular weight development in emulsion copolymerization of n‐butyl acrylate and styrene
Authors: Zoco Nuria , de Arbina Lourdes López , Leiza José R. , Asua José M. , Arzamendi Gurutze 
Published: January 2003

AbstractThe seeded emulsion copolymerization of n‐butyl acrylate and styrene in a weight ratio of 50/50 was investigated. The effect of the type of process (batch vs. semicontinuous) and the amounts of initiator and emulsifier charged into the reactor on the time evolution of the fractional conversion, number of polymer particles, and weight‐average molecular weight (Mw) was analyzed. It was found that the Mw depends to a slight extent on the type of process and the emulsifier concentration and to a larger extent on the initiator concentration. The molecular weight distributions (MWDs) and the gel content of the final latexes were also analyzed. In the absence of chain transfer agents (CTAs), the fraction of gel was higher in the semicontinuous processes. It was also found that the gel content increased with increasing initiator concentration in the recipe. The addition of 1 wt % CTA avoided gel formation and led to an important reduction of the Mw. Nevertheless, the MWDs presented a shoulder or even a second peak at high molecular weights that was due to reactions of chain transfer to the polymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1918–1926, 2003
Effect of diluents on the curing behavior of vinyl ester resin
Authors: Agrawal S. , Mishra A. , Rai J.S.P. 
Published: January 2003

AbstractAn acidic vinyl ester resin (∼6 mg KOH per gram of solid) was prepared by reacting a bisphenol‐A‐based epoxy resin with acrylic acid in the presence of tributyl amine. The acrylated epoxy resin thus obtained was characterized by Fourier transform infrared spectroscopy. Five samples of vinyl ester resin containing styrene and methyl methacrylate (MMA) in the weight ratios 40:0, 30:10, 20:20, 10:30, and 0:40 were prepared at 30°C, and their curing behavior was studied by differential scanning calorimetry in the presence of benzoyl peroxide (2 phr). Curing behavior was dependent on the ratio of the two monomers used as reactive diluents. The kinetic parameters were determined by Ozawa's method. The energy of activation and frequency factor varied from 17 to 23 kcal mol−1 and 8.47 × 109 to 5.21 × 1012 min−1, respectively and were lowest for the samples containing 30:10 and 10:30 styrene/MMA weight ratios. The curing reactions followed first‐order kinetics and obeyed the Arrhenius rate expression. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1948–1951, 2003
Preparation and characterization of poly(dimethyldiallyl ammonium)chloride and antiglobulin tests for antibody detection
Authors: Yang Xujie , Wang Xin , Wang Hengzhi , Zhu Junwu , Lu Lude , Zhou Tongbin , Lian Jianfeng 
Published: January 2003

AbstractPoly(dimethyldiallyl ammonium)chloride [poly(DMDAAC)] was prepared in our laboratory and monomer‐to‐polymer structures were characterized by infrared (IR), proton, and carbon‐13 nuclear magnetic resonance (NMR) as well as DEPT techniques. The polyelectrolytes were used to detect the antibodies of red blood cells (RBCs) in human sera and the results were compared with hexadimethrine bromide (polybrene), bromeline, and other methods. This article presents data supporting the use of the manual poly(DMDAAC) test; the 1‐min procedure at room temperature provided a rapid and sensitive test. The states of agglutination of RBCs were investigated by transmission electron microscopy (TEM). The results of the morphology were in agreement with the manual poly(DMDAAC) test. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1957–1961, 2003
Electrical properties and EMI shielding characteristics of polypyrrole–nylon 6 composite fabrics
Authors: Kim Seong Hun , Jang Soon Ho , Byun Sung Weon , Lee Jun Young , Joo Jin Soo , Jeong Sung Hoon , Park Myung‐Ja 
Published: January 2003

AbstractPolypyrrole (PPy) was polymerized both chemically and electrochemically in sequence on nylon 6 woven fabrics, giving rise to polypyrrole–nylon 6 composite fabrics (PPy–N) with a high electric conductivity. The stability of the composite prepared by electrochemical polymerization (ECP) on chemical oxidative polymerization (COP) fabric was better than that of the composite prepared solely by the COP process, since the AQSA dopant was able to strongly interact with the PPy main chain and had a large molecular structure. The temperature dependence of the conductivity of the composites was verified over four heating and cooling cycles. The change in conductivity over these four repeated heating and cooling cycles was affected by the interaction between the thermal stability of the dopant and the rearrangement of the PPy main chain. The electromagnetic interference shielding efficiency (EMI SE) values were in the range 5–40 dB and depended on the conductivity and the layer array sequence of the conductive fabric. The composites with a high conductivity represented reflection‐dominant EMI shielding characteristics, which are typical of the EMI shielding characteristics of metals. However, composites with low conductivity showed absorption‐dominant EMI shielding characteristics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1969–1974, 2003
Effect of the crystallization conditions on the phase behavior of syndiotactic polystyrene/poly(phenylene oxide) blends
Authors: Dutt G. , Kit K. M. 
Published: January 2003

AbstractSyndiotactic polystyrene (sPS) and poly(phenylene oxide) (PPO) blends, miscible in the melt state, were crystallized from the melt and the quenched state at different temperatures. The effect of the crystallization temperature on the phase behavior of the blends and the polymorphic changes in sPS was investigated by dynamic mechanical analysis (DMA), wide‐angle X‐ray diffraction (WAXD), and density measurements. In most blends, the crystallization of sPS induced segregation into two homogeneous amorphous phases of different compositions. The temperatures of the DMA relaxations of the neat homopolymers and crystallized blends were fit by the Gordon–Taylor relation to calculate the compositions of these phases. In melt‐crystallized blends, with slower crystallization, the major amorphous phase became sPS‐rich, whereas the minor phase became PPO‐rich. These major and minor amorphous phases could be tentatively assigned to interfibrillar and interlamellar regions, respectively. In cold‐crystallized blends, slower crystallization decreased the sPS concentration in both phases, and the scale of segregation was much smaller. WAXD studies and density measurements indicated a complex polymorphic behavior of sPS after it was blended with PPO. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1975–1983, 2003
Effect of time/temperature treatment parameters on depolymerization of chitosan
Authors: No Hong Kyoon , Nah Jae Woon , Meyers Samuel P. 
Published: January 2003

AbstractDepolymerization of the biopolymer chitosan by an autoclaving process at 121°C and 15 psi was investigated using various treatments. Acetic acid was found to be the most effective solvent in decreasing chitosan viscosity among the six organic acids tested. The rate of viscosity decrease increased with increasing chitosan concentration. The viscosity of 1% chitosan in 1% acetic acid decreased rapidly to 91% of the initial viscosity following the initial 15 min of autoclaving. This decreased gradually to 93% and 94% in 30 and 60 min, respectively, without being adversely affected by the chitosan solution volume. The degree of deacetylation was comparable before and after autoclaving for 60 min. Chitosan at three molecular weights (Mr = 1597, 1110, and 789 kDa) decreased in molecular weight by 46%–51% in the 15‐min treatment, 55%–60% in the 30‐min treatment, and 60%–62% in the 60‐min treatment. The addition of 0.1%–1.0% (v/v) concentrations of hydrogen peroxide to the chitosan solution autoclaved for 15 min decreased viscosity by 94%–98% and molecular weight by 69%–83%. This process is a simple, timesaving, homogeneous depolymerization procedure, and it is possible to prepare partially hydrolyzed chitosan with specified molecular weights by regulating the time of treatment. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1890–1894, 2003
Study of glycolysis of poly(ethylene terephthalate) recycled from postconsumer soft‐drink bottles. III. Further investigation
Authors: Chen Cheng‐Ho 
Published: January 2003

AbstractA modified glycolysis reaction of recycled poly(ethylene terephthalate) (PET) bottles by ethylene glycol (EG) was investigated. Influences of the glycolysis temperature, the glycolysis time, and the amount of catalysts (per kg of recycled PET) were illustrated in this study. The manganese acetate was used as a glycolysis catalyst in this study. Bis‐2‐hydroxyethyl terephthalate (BHET) and its dimer were predominately glycolysis products. It was found the optimum glycolysis temperature is 190°C. And the best glycolysis condition is 190°C of glycolysis temperature, 1.5 h of glycolysis time, and 0.025 moles of manganese acetate based on per kg of recycled PET. If the best glycolysis condition is conducted, the glycolysis conversion may be as high as 100%. For a given reaction time (1.0 h), the ln(% glycolysis conversion) is linear to 1/T (K−1) and the activation energy (E) of glycolysis reaction is around 92.175 kJ/(g mole). The glycolysis conversion rate increases significantly with increasing the glycolysis temperature, the glycolysis time, or the amount of manganese acetate (glycolysis catalyst). Thermal analyses of glycolysis products were examined by a differential scanning calorimetry (DSC) and a thermogravimetric analysis (TGA). According to the definition of a 23 factorial experimental design, the sequence of the main effects on the glycolysis conversion of the recycled PET, in ascending order, is the glycolysis time (0.18) < the amount of catalyst per kg of the recycled PET (0.34) < the glycolysis temperature (0.40). Meanwhile, the prediction equation of glycolysis conversion from the result of a 23 factorial experimental design is Ŷ = 0.259+0.20X1+0.09X2+0.17X3+0.06X1
X2+0.145X1X3+0.05X2X3+0.035X1X2X3. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2004–2010, 2003
Influence of maleated polypropylene on mechanical properties of composite made of viscose fiber and polypropylene
Authors: Paunikallio Teemu , Kasanen Jossi , Suvanto Mika , Pakkanen Tuula T. 
Published: January 2003

AbstractThe purpose of this work was to study how viscose fiber behaves in polypropylene (PP) matrix when maleated polypropylene (MAPP) is used as a coupling agent. The influences of processing conditions on composite properties was of interest. Composites were characterized by FTIR and mechanical testing. The most notable result was the effect of the MAPP concentration on the tensile strength of the composites; the tensile strength increased from 40 to 69 MPa when MAPP was added in amounts up to 6 wt % of the fiber weight. The interaction between MAPP and fiber was confirmed with FTIR. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1895–1900, 2003