bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and properties of acrylonitrile–EPDM–N‐vinylcarbazole graft terpolymer
Authors: Seo Beom‐Doo , Park Duck‐Jei , Ha Chang‐Sik , Cho Won‐Jei 
Published: April 2003

AbstractA graft terpolymer of acrylonitrile (AN) and N‐vinylcarbazole (NVC) onto ethylene–propylene–diene terpolymer (EPDM) was synthesized in toluene using benzoyl peroxide. The effects of EPDM content, mole ratio of NVC to AN, reaction time, reaction temperature, and initiator concentration in the graft copolymerization were examined. The synthesized AN–EPDM–NVC graft terpolymers (AEVC) were identified by infrared (IR) and 1H‐NMR (nuclear magnetic resonance) spectra. The thermal stability, tensile strength, and light resistance of AEVC were investigated by using a Fade‐o‐Meter, thermogravimetric analyzer, and tensile tester. It was found that the heat resistance of AEVC is considerably better than that of acrylonitrile–butadiene–styrene (ABS) copolymer. © 1995 John Wiley & Sons, Inc.
Preparation and characterization of cellulose acetate organic/inorganic hybrid films
Authors: Shojaie Saeed S. , Rials Timothy G. , Kelley Stephen S. 
Published: April 2003

AbstractA series of organic/inorganic hybrid (OIH) films were prepared using cellulose acetate (CA) as the organic component and tetraethyl orthosilicate (TEOS) as the inorganic component. The chemical, morphological, and mechanical properties of these films were evaluated with a variety of analytical techniques. The results of these evaluations showed that crosslinked CA OIH films were formed during the sol‐gel reactions. The structure of OIH films was very sensitive to the CA/TEOS ratio and film formation conditions. All of the films with added TEOS were two phase on a molecular level, i.e., inorganic TEOS domains surrounded by a CA matrix. Under some film formation conditions the presence of TEOS, a nonsolvent for CA, led to solvent/nonsolvent phase separation on the micron scale. © 1995 John Wiley & Sons, Inc.
Influence of pentaerythritol triacrylate acrylic carrier swelling on immobilization of enzymes
Authors: Kolarz B. N. , Wojaczyńska M. , Bryjak J. , Łobarzewski J. , Pawłów B. 
Published: April 2003

AbstractSuspension copolymerization and modification of pentaerythritol triacrylate (PENTA)–butyl acrylate (BA) matrices with ethylenediamine (EtDA) are discussed. It is shown that aminolysis in water solution offers gel structure carriers with small pore radii (about 3 nm). These carriers are characterized by the high swelling and sharp correlation between the pH value and the specific volume. The enzymes (acylase, glucoamylase, and peroxydase) are immobilized by means of the glutaraldehyde method. The best matrix seems to be copolymers modified in a 95% solution of ethylenediamine in water. Preparations do not lose activity after 1 month storage at 4°C. © 1995 John Wiley & Sons, Inc.
Application of syndiotacticity‐rich PVA hydrogels to drug delivery system
Authors: Horiike S. , Matsuzawa S. 
Published: April 2003

AbstractThe preparation of stable syndiotacticity‐rich poly(vinyl alcohol) (s‐PVA) hydrogels is easier in comparison with that of the atactic poly(vinyl alcohol) (a‐PVA) hydrogels. The drug release with use of s‐PVA hydrogels containing indomethacin of 1.5 mg/mL buffer, solution was studied under several conditions: at the gelation temperatures of 20–30°C, the release temperatures of 27–47°C, and pHs of phosphate buffer solutions of 6.6–7.4, for the gels with the concentrations of PVA of 3–8% using the degree of polymerization of 2170–4380. Indomethacin has been released spending 14 h. The diffusion exponents were 0.45–0.50, corresponding to Fickian diffusion. © 1995 John Wiley & Sons, Inc.
Morphology of microporous neosepta ion‐exchange membranes and its effect on separation of biological mixtures
Authors: Tishchenko Galina , Bleha Miroslav , S̆kvor Jir̆í , Bures̆ Ladislav , Mizutani Yukio , Ohmura Nobuhiko 
Published: April 2003

AbstractSpecially prepared microporous Neosepta ion‐exchange membranes were investigated to establish a correlation between their structural characteristics (pore‐size distribution, porosity) and permeability to components of immunoglobulin (Ig) fractions of mouse ascitic fluids. The solutions to be separated contained IgG1 with specificity to horseradish peroxidase or to the heavy chain of human IgM, some other proteins, and a large amount of ammonium sulfate (0.22–0.35M). Analysis of the membrane morphology carried out by scanning electron microscopy and mercury porosimetry showed that the membranes possess a polymodal pore‐size distribution. There are large open pores (400–600 and 200–300 nm in diameter) on the membrane surfaces, but the void volume of the membranes is a system of connected pores of smaller diameters (from 60–100 to 7–10 nm). The main part of the pores in the membranes displaying the best separation ability was 8–17 nm in diameter. It was found that highly porous charged membranes (relative porosity 58–60%) with low ion‐exchange capacity (0.02–0.1 meq/g) made it possible to achieve the desired desalination degree of protein mixture (80–83%) within 5–7 h instead of 5 days needed in the traditional dialysis. Moreover, the amount of separated accompanying proteins reached 25–30% depending on membrane porosity and the quality of specific IgG1 was considerably improved. © 1995 John Wiley & Sons, Inc.
Rheological measurements: Some basic yet vital considerations
Authors: Bafna Sudhir S. 
Published: April 2003

AbstractThis article addresses a seemingly trivial question—“Based on rheological measurements, when are two samples different beyond experimental error?”—and proceeds to give a nontrivial answer. The preferred answer requires the application of t statistics to multiple measurements on each sample. The larger the number of multiple measurements made, the lower is the uncertainty in conclusively discriminating between two samples. However, such multiple measurements on every sample are seldom feasible in real life and then it becomes necessary to resort to the use of Z statistics. A stepwise procedure for the application of both, t and Z statistics is given. Knowledge of the measurement precision is a prerequisite for scientifically answering this seemingly trivial question. Hence, the precision of capillary rheometry measurements (apparent viscosity, extrudate swell ratio, and entrance pressure loss) is discussed in detail. The precision of these capillary rheometry measurements improves as the magnitude of the variable measured (force/pressure or swell) increases. This implies that the precision of capillary rheometry measurements can be improved by lowering the experimental temperature. Extensive numerical data on various high‐density polyethylenes generated using two different capillary rehometers are given and are compared with the ASTM round‐robin data. © 1995 John Wiley & Sons, Inc.
Grafting of acrylonitrile onto styrene‐maleic acid copolymer by tetravalent cerium ion
Authors: Vora R. A. , Trivedi H. C. , Patel C. P. , Trivedi M. C. 
Published: April 2003

AbstractThe graft copolymerization of acrylonitrile (AN) onto a styrene‐maleic acid copolymer (SY‐MAc) with ceric ammonium nitrate (CAN) as a redox initiator in an aqueous medium has been studied. The effects of various reaction parameters, including reaction time and temperature, concentrations of initiator, nitric acid, and monomer, on the grafting yields and the rates of polymerization (Rp), graft copolymerization (Rg), and homopolymerization (Rh) were studied systematically. The results are discussed. The kinetic scheme of free‐radical graft copolymerization has been proposed and the equations relating the values of Rp, Rg, and Rh are also suggested. The experimental results are found to be in good agreement with the proposed kinetic scheme. The activation energies of graft copolymerization and total polymerization are calculated. © 1995 John Wiley & Sons, Inc.
Oxygen barrier properties of polypropylene/polyamide 6 blends
Authors: Holsti‐Miettinen R. M. , Perttilä K. P. , Seppälä J. V. , Heino M. T. 
Published: April 2003

AbstractEffects of composition, compatibilization, and blending procedure on oxygen barrier properties of injection‐molded polypropylene/polyamide 6 blends were investigated. The main attention was paid to the relationships between oxygen permeability, mechanical properties, and blend morphology. The effect of the polypropylene/polyamide 6 ratio was evident in blends with a homogeneous dispersion type of morphology. After the phase inversion, when polyamide became the continuous phase, the barrier properties of the blends were significantly improved and approached those of polyamide 6. Increasing the amount of the compatibilizer, maleic anhydride grafted polypropylene, was found to increase the permeability of the blend. The blending procedure had a significant effect on the permeability of the blends. The injection‐molded blend exhibited a laminar type of morphology when polyamide 6 and the compatibilizer were preblended in a twin‐screw extruder, and polypropylene was added later as a dry‐blend before injection molding. The dispersed polyamide phase formed thin elongated platelets in the polypropylene matrix. This laminar morphology resulted in significant improvement of oxygen barrier properties approaching the level of the theoretical values calculated for corresponding coextruded structures. Moreover, both the tensile and impact properties of this particular blend were exceptionally good. © 1995 John Wiley & Sons, Inc.
An advanced computer algorithm for determining morphology development in latex particles
Authors: Durant Yvon G. , Sundberg Donald C. 
Published: April 2003

AbstractA new algorithm is presented for the prediction of equilibrium morphology in latex particles. Thermodynamic equilibrium calculations of the interfacial free energies associated with a large array of possible morphologies serve to create a continuous free‐energy surface upon which the preferred morphology is located. When the computations are performed on a 486DX33 PC, the calculations are essentially instantaneous. The graphical output can be refreshed on the monitor screen in less than 2 s. The algorithm is applied to simulate the conversion‐dependent morphology for several latex systems composed of polystyrene and poly(methyl methacrylate) and two very different surfactants. © 1995 John Wiley & Sons, Inc.
Gelation of poly(vinyl alcohol)/phenol/water solutions and gel spinning
Authors: Yamaura Kazuo , Suzuki Masayoshi , Yamamoto Minako , Shimada Rumi , Tanigami Tetsuya 
Published: April 2003

AbstractThe light transmittance of the gels of poly(vinyl alcohol) (PVA)/phenol/water solutions was examined for the entire range of phenol/water content. Excellent transparency was found for the gels with phenol contents of 70–95 vol %. In full consideration of the results for the transparency and melting temperature of the gels and the viscosity and gelation ability of solutions, the PVA solutions of 75 vol % phenol content were selected for the gel spinning. The maximum dynamic moduli of drawn filaments at 25°C (room temperature) were 42 GPa (15x) for atactic PVA and 45 GPa (14x) for syndiotacticity‐rich PVA. © 1995 John Wiley & Sons, Inc.
Stability of aqueous solutions of poly[(maleic acid)‐alt‐styrene] sodium salts in the presence of divalent cations
Authors: Jarm V. , SertiĆ S. , Ŝegudović N. 
Published: April 2003

AbstractThe influence of divalent salts (MgCl2, CaCl2, BaCl2) on precipitation of polyelectrolyte, poly[(maleic acid)‐alt‐styrene]sodium salts, NaMA/St, having two degrees of neutralization (100 mass %, 100NaMA/St and 50 mass % 50NaMA/St) from their aqueous solutions, has been investigated. The experiments were performed by variation of the copolymer concentration, cp = 0.005‐0.04M/L, salt concentration, cs = 0.002‐0.4M/L, and temperature, T 298‐333 K. The critical concentrations of salts, csc, used as a measure of solution stability, were determined from turbidimetric measurements, while viscosity and refractive index measurements were used to indicate the changes in dimensions and hydration of polyions, respectively. © 1995 John Wiley & Sons, Inc.
Preparation of ultrahigh molecular weight polyacrylonitrile and its terpolymers
Authors: Zhang C. , Gilbert R. D. , Fornes R. E. 
Published: April 2003

AbstractThe synthesis of high molecular weight (in excess of 106 million Daltons) poly(acrylonitrile) and poly(acrylonitrile‐co‐methylacrylate‐co‐itaconic acid) is described. An inverse emulsion polymerization formulation with AIBN as the initiator was used. However, polymer precipitation occurred early in the polymerization. In each case, the molecular weight distribution was surprisingly narrow (M̄w/M̄n ∼ 1.5). Conversion vs. time plots with monomers containing the inhibitor had the “S” shape typical of emulsion polymerizations. The terpolymer composition and molecular weight were quite uniform throughout the polymerization. With inhibitor‐free monomers, the initial molecular weights were very high (∼ 3 × 106 Daltons), but gelation occurred at ca. 50% conversion. There was an inverse relationship between the monomer inhibitor content and the polymer molecular weight. It is suggested that the growing polymer radicals are occluded in the precipitated polymer particles and are terminated by inhibitor diffusing into the particles, accounting for the narrow molecular weight distribution. © 1995 John Wiley & Sons, Inc.
Sulfur vulcanization of polyisoprene accelerated by benzothiazole derivatives. II. Reaction of 2‐mercaptobenzothiazole and its zinc salt with sulfur and ZnO in polyisoprene
Authors: Gradwell M. H. S. , Mcgill W. J. 
Published: April 2003

AbstractCompounds of polyisoprene with sulfur and bis(2‐mercaptobenzothiazole)zinc(II) (Zn(mbt)2) or ZnO and 2‐mercaptobenzothiazole (MBT) were vulcanized by heating in a differential scanning calorimeter. The reaction was stopped at points along the thermogram and the product analyzed. ZnO and MBT readily react, the reaction going to completion during compounding. The presence of Zn(mbt)2 delays the onset of crosslinking compared to compounds without zinc. It is suggested that the induction period prior to crosslinking is occasioned by the inactivity of Zn(mbt)2, which must breakdown to MBT before it can participate in the vulcanization process. Such decomposition results from attack by anions generated when polysulfidic crosslinks, formed in the unaccelerated sulfur that occurs in the early stages of crosslinking, undergo scission. The effect of MBT, not bound to zinc, on the mechanism of the reaction is discussed. © 1995 John Wiley & Sons, Inc.
Adsorption behavior of Cu2+ and UO ions on crosslinked poly[2,2‐bis(acrylamido)acetic acid]
Authors: Rivas B. L. , Maturana H. A. , Ocampo X. , Peric I. M. 
Published: April 2003

AbstractThe synthesis of a water‐insoluble metal ion complexing resin was carried out by radical polymerization of 2,2‐bis(acrylamido) acetic acid. The resin was characterized by elemental analyses, FTIR spectroscopy, and thermal analyses. The ability to bind copper(II), iron(II), iron(III), and uranium(VI) as well as the elution of the metal ions from the loaded resins were studied. For uranyl ions, pH 5 was the optimum sorption pH value. Sorption selectivity from the binary mixture Cu(II) + U(VI) was studied at pH 2. The thermal stability is increased by adsorption of UO. According to these results a coordination mechanism is suggested for sorption of copper and uranium. © 1995 John Wiley & Sons, Inc.
Development of poly(vinyl alcohol) hydrogel for waste water cleaning. I. Study of poly(vinyl alcohol) gel as a carrier for immobilizing microorganisms
Authors: Okazaki Masaki , Hamada Tosihiro , Fujii Hiroaki , Mizobe Akio , Matsuzawa Shuji 
Published: April 2003

AbstractThe structures and properties of poly(viny1 alcohol) (PVA) hydrogel prepared by the freezing and thawing method and poly(ethy1ene glycol) and polyacrylamide hydrogels prepared by polymerization were compared in view of immobilizing microorganisms. Observation in a scanning electron microscope and measurement of the physicochemical properties revealed that the frozen PVA gel is superior in water content and oxygen permeability than the other gels. The PVA hydrogel has a high tensile and folding strength and good handleability and processability. The durability against abrasion and chemical resistance of PVA gel were also studied. Activated sludge was immobilized and fixed on PVA gel particles and incubated. This gel had a treating capacity for synthetic sewage of about two to three times that with the standard activated sludge process. © 1995 John Wiley & Sons, Inc.
Multiobjective optimization of an industrial semibatch nylon 6 reactor
Authors: Sareen Rajiv , Gupta Santosh K. 
Published: April 2003

AbstractMultiobjective Pareto optimal solutions have been generated for three grades of nylon 6 being produced in an industrial semibatch reactor. The optimal operating conditions (called preferred solutions) for these three batches are easy to implement and lead to substantial improvements over current practice. The technique used is quite general and can easily be applied to improve the operation of other industrial polymerization reactors or design better (new) reactors. Good mathematical models, which account for the important physicochemical aspects actually operative in a reactor and which have been tested on industrial data, are a prerequisite for such optimization studies. © 1995 John Wiley & Sons, Inc.
Phagocytosis and peroxidase release by seabream (Sparus aurata L.) leucocytes in response to yeast cells
Authors: Rodríguez Alejandro , Esteban M. Ángeles , Meseguer José 
Published: April 2003

AbstractA flow cytometric method was adapted to evaluate phagocytosis by gilthead seabream leucocytes after incubation with yeast cells (Saccharomyces cerevisiae). Head‐kidney leucocytes were incubated in vitro for different times in different proportions with heat‐killed fluorescein isothiocyanate (FITC)‐labeled yeast cells to study the kinetics of phagocytosis. Attached and internalized yeast cells were differentiated by quenching FITC‐labeled S. cerevisiae with trypan blue dye. Only internalized cells kept their FITC fluorescence after quenching. Monocyte‐macrophages and acidophilic granulocytes showed phagocytic activity, as demonstrated by transmission electron microscopy (TEM). From the ultrastructural features of the phagocytic process, it was observed that cytoplasmic granule membranes fused with the phagocyte membrane at the point where the yeast cell was attached to the phagocyte surface. This observation led us to adapt a colorimetric method to study peroxidase (myeloperoxidase and eosinophil peroxidase) release, since both are considered to be markers of the degranulation that occurs in seabream head‐kidney leucocytes in response to yeast cells. Head‐kidney leucocytes were incubated with calcium ionophore (CaI), phorbol myristate acetate (PMA), or yeast cells for different periods of time (0–30 min) to study the kinetics of peroxidase release. The results obtained indicate that CaI and yeast cells, but not PMA, stimulate the degranulation (by about 44.51% and 21.04%, respectively, at 30 min) of seabream head‐kidney leucocytes. Anat Rec Part A 272A:415–423, 2003. © 2003 Wiley‐Liss, Inc.
A proposal of monitoring and testing for distributed object oriented systems
Authors: Terashima Yoshiaki , Imai Isao , Shimotsuma Yoshiki , Sato Fumiaki , Mizuno Tadanori 
Published: April 2003

AbstractRecently, the development of systems consisting of objects developed with different installation methods has been expanding rapidly. In such development, systems become more complicated and reliability is decreased. Hence, it is important as the final stage of testing to verify the behavior of each object during the behavior of the entire system. In this paper, a system functionality test is proposed that evaluates object behavior during an operation without dependence on the installation architecture by using the IDL (Interface Definition Language) for interoperability. First, the weight reduction in the test and the treatment of the object behavior are explained. A test configuration for resolving these and a method of analyzing the trace of the effect and cause of object behavior by message tracing are explained. Also, the practicality of the test is described. It is shown that the individual installation architecture can be concealed in the development flow of the testing environment from the IDL specification. Finally, a quantitative evaluation and discussions are presented and effectiveness of the proposed method is verified. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(10): 33–44, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10059
Efficient representation of short‐time phase based on time‐domain smoothed group delay
Authors: Banno Hideki , Lu Jinlin , Nakamura Satoshi , Shikano Kiyohiro , Kawahara Hideki 
Published: April 2003

AbstractA method for representing the short‐time phase of speech efficiently is proposed. In this paper, we attempt to represent the short‐time phase using a time‐domain smoothed group delay (TSGD) obtained by scaling the inverse Fourier transformed speech group delay by an appropriate order. The results of tests using segmental SNRs show that information regarding the shapes of waveforms is concentrated at TSGDs of orders less than 100. In addition, subjective evaluation tests show that high‐quality speech almost indistinguishable from the original speech is synthesized when the order of the TSGD is about 30 and the short‐time phase can be represented efficiently by the proposed scheme. In addition, since the proposed scheme also suppresses degradation due to errors associated with speech–no speech decisions, which has been a problem in past analysis‐synthesis schemes, it is considered to be useful in applications such as speech coding and speech quality transformation. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(10): 56–64, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10120
Driver model based on reinforced learning with multiple‐step state estimation
Authors: Koike Yasuharu , Doya Kenji 
Published: April 2003

AbstractIn this study the authors proposed a method for reinforced learning using multistep state estimation based on internal model of control object. It offers a discussion of learning results obtained by application of this model to a vehicle running on a road including various curvatures, for evaluating whether the vehicle would wander off the road. The vehicle's dynamic model acquired by learning was used for estimating rewards and determining the control outputs, based on the estimated states at multiple time intervals. Results of simulation confirmed that safe driving was possible even with road shapes containing nonlearned curvatures and speeds. Since in this control method external information varies depending on the employed control patterns and environmental conditions, it is possible to consider a model with changing view in order to obtain necessary information for driving control. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(10): 85–95, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10123