bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency-Domain Analysis for Motion of Floating Structures with Perforated Wall
Authors: Kim Jeongsoo , Jeong Youn Ju , Kim Young-Taek
Published: February 2024

As increasing demands for a floating structure expanded from offshore industry facilities to living facilities, it has emerged that necessity of techniques to reduce motions of a floating structure. This study present a floating structure with porosity on the outer surface of the floater. Under each regular and irregular wave, responses of the floater was investigated in frequency domain. The proposed structure is composed of inner and outer floaters, which are connected to each other and the outer wall is perforated, and the heave and the pitch of floaters with different perforation rates (0~30%) were compared with at both the center and the edge. The results showed that pitch responses can be decreased by increasing of perforation rate of the floater. Comparing with responses of the non-perforated floater, those of the proposed floating structure were reduced to above 10% and 2%, respectively for regular and irregular wave conditions.
Single‐Cell Analysis of Lipid Rafts in Lymphocytes and in T Cell–Containing Immunoconjugates
Authors: Lee William T. , Watson Andrew R. O.
Published: March 2006

Within the plasma membranes of many different cell types, certain membrane lipids, including cholesterol and sphingolipids, form lateral assemblies surrounded by unsaturated glycerophospholipids. The concentration of such membrane lipids and associated proteins results in the formation of microdomains termed lipid rafts” (or glycolipid‐enriched membranes or detergent‐insoluble glycosphingolipid‐enriched domains). Proteins that possess saturated acyl chains are generally associated with lipid rafts. Lipid rafts are believed to be involved in a number of cellular processes including cell activation. When material is limiting, raft‐associated proteins may be identified on single cells using microscopy. This unit describes the application of this technique in an immunological example, examining the location and movement of signal transduction complexes in single T lymphocytes and in interactive conjugates between T cells and antigen‐presenting cells (APCs).
Perspective‐taking vs. mental rotation transformations and how they predict spatial navigation performance
Authors: Kozhevnikov Maria , Motes Michael A. , Rasch Bjoern , Blajenkova Olessia
Published: March 2006

In Experiment 1, participants completed one of two versions of a computerized pointing direction task that used the same stimuli but different spatial transformation instructions. In the perspective‐taking version, participants were to imagine standing at one location facing a second location and then to imagine pointing to a third location. In the array‐rotation version, participants saw a vector pointing to one location, were to imagine the second vector with the same base as the first pointing to a second location, to mentally rotate the two vectors, and finally to indicate the direction of the imagined vector after the rotation. In Experiment 2, participants completed the perspective‐taking, mental rotation, and four large‐scale navigational tasks. The results showed that the perspective‐taking task required unique spatial transformation ability from the array rotation task, and the perspective‐taking task predicted unique variance over the mental rotation task in navigational tasks that required updating self‐to‐object representations. Copyright © 2006 John Wiley & Sons, Ltd.
Determination and quantification of the release of inorganic contaminants from municipal waste incineration ash
Authors: Lager Tanja , Delay Markus , Karius Volker , Hamer Kay , Frimmel Fritz H. , Schulz Horst D.
Published: March 2006

Various leaching experiments applied to municipal waste incineration ash were compared in order to find the best available procedure to measure the total mass flow caused by natural leaching (source strength) of the material. The results of various batch experiments and two different laboratory column experiments run under water‐saturated conditions were compared with water‐unsaturated field‐scale column experiments (lysimeter). The results of the batch experiments were not transferable to the column and field experiments. But, very good accordance could be observed between the breakthrough curves of the two column experiments conducted in the laboratory under water‐saturated conditions and the water‐unsaturated field‐scale columns, with few exceptions. The results show that batch experiments are not sufficient to predict the source strength and its changes over time. Instead, column experiments are essential for a realistic risk assessment. For most inorganic parameters, a laboratory column experiment lasting less than 5 days is sufficient for a risk assessment in the foreseeable future.
Matrix effects on the photocatalytical degradation of dichloroacetic acid and atrazine in water
Authors: Ziegmann Markus , Doll Tusnelda , Frimmel Fritz H.
Published: March 2006

The effect of different organic and inorganic aqueous matrices on the photocatalytical degradation of dissolved atrazine and dichloroacetic acid (DCA) with immobilized TiO2 was investigated. Two series of experiments were carried out at pH values around 7.1 for the degradation of atrazine and around 5.3 for the degradation of DCA. It is shown that the effects of the water constituents are completely different for the various substances and pH ranges. In pure deionized water 95% of the initial amount ρ = 1 mg/L of atrazine were degraded within 24 hours. Tap water as matrix led to a distinct lower degradation rate (factor 3). The single additives chloride, sulfate, phosphate, carbonate and DOC showed no decrease in the degradation rate. Especially in the case of phosphate and carbonate there was even a significant promoting effect. DEDIA, the doubly desalkylated and not dechlorinated product, occurred in higher concentrations than in the experiment without additives. In pure deionized water ρ0 (DCA) = 1 mg/L was completely degraded within 330 min. By addition of any tested substance, organic or inorganic, the degradation rate of DCA, which is strongly dependent on the adsorption on the TiO2 surface, decreased clearly. In the case of tap water the degradation rate decreased by a factor of 7.5. From the checked inorganic ions phosphate showed the strongest effect followed by sulfate, chloride and carbonate. Added DOC also had a significant influence on the degradation rate.
Making sound decisions: How to help your client evaluate settlement options
Authors: Barr Eleanor
Published: March 2006

Eleanor Barr, of Los Angeles, describes a path for analyzing decision‐making in evaluating settlement offers. She provides a method of charting out the risks and the dollar amounts for developing the best settlement choice
Psychological biases that become mediation impediments can be overcome with interventions that minimize blockages
Authors: Korobkin Russell
Published: March 2006

There often are deep‐seated reasons for mediation impasse. Russell Korobkin, of Los Angeles, discusses psychological biases that can impede mediation success. In the first of two parts, he covers negotiators' “overoptimistic overconfidence,” and attribution biases. He also provides interventions to deal with the problems
U.S. Supreme Court reaffirms separability rule
Authors: Pearson Scott M.
Published: March 2006

Scott M. Pearson, of Los Angeles, analyzes the February U.S. Supreme Court decision of Buckley Checking Inc. v. Cardegna, following up the preview article he co‐wrote last year.
Court's second '07‐'08 ADR case challenges arbitrator supremacy
Authors: Johnson Michael E. , Loone Piret
Published: March 2006

Can a California law requiring the state's labor commissioner to oversee contracts take priority over the Federal Arbitration Act's enforcement requirements? This preemption issue will be argued before the U.S. Supreme Court this month. Michael E. Johnson and Piret Loone, of New York, analyze the issues before the Court, discuss the key precedent likely to affect the outcome, and make a prediction. Also included is a sidebar summarizing the four amicus views.
Correlation between the morphology and dynamic mechanical properties of ethylene vinyl acetate/linear low‐density polyethylene blends: Effects of the blend ratio and compatibilization
Authors: Moly K. A. , Bhagawan S. S. , Groeninckx G. , Thomas S.
Published: March 2006

The effects of the blend composition and compatibilization on the morphology of linear low‐density polyethylene (LLDPE)/ethylene vinyl acetate (EVA) blends were studied. The blends showed dispersed/matrix and cocontinuous phase morphologies that depended on the composition. The blends had a cocontinuous morphology at an EVA concentration of 40–60%. The addition of the compatibilizer first decreased the domain size of the dispersed phase, which then leveled off. Two types of compatibilizers were added to the polymer/polymer interface: linear low‐density polyethylene‐g‐maleic anhydride and LLDPE‐g phenolic resin. Noolandi's theory was in agreement with the experimental data. The conformation of the compatibilizer at the blend interface could be predicted by the calculation of the area occupied by the compatibilizer molecule at the interface. The effects of the blend ratio and compatibilization on the dynamic mechanical properties of the blends were analyzed from −60°C to +35°C. The experiments were performed over a series of frequencies. The area under the curve of the loss modulus versus the temperature was higher than the values obtained by group contribution analysis. The loss tangent curve showed a peak corresponding to the glass transition of EVA, indicating the incompatibility of the blend system. The damping characteristics of the blends increased with increasing EVA content because of the decrease in the crystalline volume of the system. Attempts were made to correlate the observed viscoelastic properties of the blends with the morphology. Various composite models were used to model the dynamic mechanical data. Compatibilization increased the storage modulus of the system because of the fine dispersion of EVA domains in the LLDPE matrix, which provided increased interfacial interaction. Better compatibilization was effected at a 0.5–1% loading of the compatibilizer. This was in full agreement with the dynamic mechanical spectroscopy data. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4526–4538, 2006
Film formation from pigmented latex systems: Mechanical and surface properties of ground calcium carbonate/functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latex blend films
Authors: Ding Tianhua , Daniels Eric S. , El‐Aasser Mohamed S. , Klein Andrew
Published: March 2006

The mechanical and surface properties of films prepared from model latex/pigment blends were studied using tensile tests, surface gloss measurements, and atomic force microscopy. Functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) [P(BMA/BA)] and ground calcium carbonate (GCC) were used as latex and extender pigment particles, respectively. The critical pigment volume concentration of this pigment/latex blend system was found to be between 50 and 60 vol % as determined by surface gloss measurement and tensile testing of the blend films. As the pigment volume concentration increased in the blends, the Young's modulus of the films increased. Nielsen's equations were found to fit the experimental data very well. When the surface coverage of carboxyl groups on the latex particles was increased, the yield strength and Young's modulus of the films both increased, indicating better adhesion at the interfaces between the GCC and latex particles. When the carboxyl groups were neutralized during the film formation process, regions with reduced chain mobility were formed. These regions acted as a filler to improve the modulus of the copolymer matrix and the modulus of the resulting films. The carboxyl groups on the latex particle surfaces increased the surface smoothness of the films as determined by surface gloss measurement. When the initial stabilizer coverage of the latex particles was increased, the mechanical strength of the resulting films increased. At the same time, rougher film surfaces also were observed because of the migration of the stabilizer to the surface during film formation. With smaller‐sized latex particles, the pigment/latex blends had higher yield strength and Young's modulus. Higher film formation temperatures strengthen the resulting films and also influence their surface morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4550–4560, 2006
Structural modification of expandable polystyrene. III. Copolymerization with siloxane‐based macroinitiator
Authors: Taşkıran Isa
Published: March 2006

Conventional expandable polystyrene (EPS) was chemically modified by preparing copolymers containing 0.1%, 0.2%, and 0.5% siloxane‐based macroinitiator. This was used to enhance the surface and thermal properties of EPS particles. Copolymeric expandable polystyrene samples were characterized with various techniques including 1H‐NMR, gel permeation chromatography, differential scanning calorimetry, scanning electron microscopy, and contact angle measurement. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4826–4831, 2006
Effect of crosslinkers on the preparation and properties of ETFE‐based radiation‐grafted polymer electrolyte membranes
Authors: Chen Jinhua , Asano Masaharu , Yamaki Tetsuya , Yoshida Masaru
Published: March 2006

This study concerns a comparative study of three crosslinkers, divinylbenzene (DVB), 1,2‐bis(p,p‐vinylphenyl)ethane (BVPE), and triallyl cyanurate (TAC) crosslinked poly(ethylene‐co‐tetrafluoroethylene) (ETFE)‐based radiation‐grafted membranes, which were prepared by radiation grafting of p‐methylstyrene onto ETFE films and subsequent sulfonation. The effect of the different types and contents of the crosslinkers on the grafting and sulfonation, and the properties such as water uptake, proton conductivity, and thermal/chemical stability of the resulting polymer electrolyte membranes were investigated in detail. Introducing crosslink structure into the radiation‐grafted membranes leads to a decrease in proton conductivity due to the decrease in water uptake. The thermal stability of the crosslinked radiation‐grafted membranes is also somewhat lower than that of the noncrosslinked one. However, the crosslinked radiation‐grafted membranes show significantly higher chemical stability characterized in the 3% H2O2 at 50°C. Among the three crosslinkers, the DVB shows a most pronounced efficiency on the crosslinking of the radiation‐grafted membranes, while the TAC has no significant influence; the BVPE is a mild and effective crosslinker, showing the moderate influence between the DVB and TAC crosslinkers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4565–4574, 2006
In situ Fourier transform infrared spectroscopic study of the conformational changes of high‐density poly(ethylene) during the melting and crystallization processes
Authors: Xiao Yan , Yan Liangyu , Zhang Puming , Zhu Na , Chen Liang , He Peng , Wang Yanping , Shen Xinyuan , Zhu Xinyuan , Yan Deyue
Published: March 2006

The conformational analysis of high‐density poly(ethylene) (HDPE) during the melting and crystallization processes has been performed by the aid of the time‐reserved Fourier transform infrared spectroscopy and multivariate analysis technique. Upon heating, the conformational transition of HDPE takes place, gradually, due to the restraint of crystal lattice, and various conformational transformations can be discerned clearly. However, during the cooling process, HDPE crystallizes very quickly and only one major conformational transition occurs in the crystallization process. The comparison of conformational changes during the melting and crystallization processes exhibits that although the polymer crystallization is the reverse process of polymer melting, there still exist some obvious differences in the conformational transformation between them. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4835–4841, 2006
Determination of the degradation apparent activation energy of acrylonitrile/acrylic acid copolymers
Authors: Hou Chen , Liu Junshen , Ji Chunnuan , Wang Chengguo
Published: March 2006

Acrylonitrile/acrylic acid copolymers were prepared by H2O/dimethyl formamide suspension polymerization technique. Differential scanning calorimetry was used to investigate the degradation of acrylonitrile/acrylic acid copolymers in air. The apparent activation energy of degradation of the copolymer was calculated with the Kissinger method. Effects of copolymerization conditions on the apparent activation energy of copolymer were studied. It has been found that increasing the dimethyl formamide concentration in the solvent mixture led to a gradual increase (97.3–149.4 kJ mol−1) in the apparent activation energy of degradation of the acrylonitrile/acrylic acid copolymers. The apparent activation energy decreases with increase in acrylic acid concentration, and this change became less prominent as the acrylic acid/acrylonitrile weight ratio is more than 5/95. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4668–4671, 2006
Synthesis and characterization of polystyrene‐supported glucosamine resin and its adsorption behavior for Au(III)
Authors: Sun Changmei , Qu Rongjun , Wang Qun , Ji Chunnuan , Wang Chunhua , Xu Qiang , Fang Xiaofu , Cheng Guoxiang
Published: March 2006

A novel chelating resin, crosslinking polystyrene‐supported glucosamine (PS‐GA), was prepared and its structure was confirmed by FTIR, elemental analysis, and X‐ray photoelectron spectroscopy. The adsorption properties of PS‐GA for Au(III) were investigated. PS‐GA resin possessed excellent enriching property to Au(III) ions and adsorption proportion E% could reach to about 90 shortly after 3 h. The adsorption dynamics of Au(III) showed that the adsorption was controlled by liquid film diffusion and the apparent activation energy Ea was 12.91 kJ mol−1. Both Langmuir model and Freundlich model could describe the isothermal process of Au(III), and ΔG, ΔH, ΔS values were calculated. The mechanism of adsorption for Au(III) was confirmed by FTIR, SEM, and XPS. The results showed that redox reaction occurred and both coordination and ion‐exchange existed simultaneously in the adsorption. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4581–4586, 2006
Miscibility of dextran and poly(ethylene glycol) in dilute aqueous solutions. II. Effect of temperature and composition
Authors: Barsbay Murat , Güner Ali
Published: March 2006

The miscibility of dextran (Dx) with poly(ethylene glycol) (PEG) was investigated in dilute aqueous solutions by viscometry. Homopolymers of Dx and PEG and their blends with Dx/PEG ratios of 10/90, 25/75, 50/50, 75/25, and 90/10 were studied at 25, 30, 35, 40, and 45°C in bidistilled and deionized water. Starting with the classical Huggins equation, the results of the viscosity behavior of each parent polymer and their blends were interpreted in terms of miscibility parameters, Δk, Δb, α, β, ΔB, and μ. On the basis of the sign convention involved in these criteria, miscibility between Dx and PEG was found to increase with the weight fraction of PEG in the blend composition and temperature. The fourier transform infrared (FTIR) analysis is also used to investigate the miscibility of the polymer pairs. The existence of specific interactions between Dx and PEG was demonstrated by FTIR spectroscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4587–4594, 2006
Synthesis and characterization of 3,3′‐disulfonated‐4,4′‐dichlorodiphenyl sulfone (SDCDPS) monomer for proton exchange membranes (PEM) in fuel cell applications
Authors: Sankir M. , Bhanu V. A. , Harrison W. L. , Ghassemi H. , Wiles K. B. , Glass T. E. , Brink A. E. , Brink M. H. , McGrath J. E.
Published: March 2006

A systematic study of the synthesis and characterization of 3,3′‐disulfonated‐4,4′‐dichlorodiphenyl sulfone (SDCDPS) monomer was conducted by varying reactant stoichiometries (molar ratios of 4,4′‐dichlorodiphenyl sulfone (DCDPS) to SO3 1 : 2.2, 1 : 2.9, and 1 : 3.3), reaction temperature (90–120°C), and reaction time (4–6 h). The optimum synthesis batch process variables were 1 : 3.3 reactant molar ratio (DCDPS : SO3) at 110°C for 6 h. In earlier studies, recrystallization of the “crude” disulfonated monomer from alcohol–water mixture was necessary to remove the monosulfonated and DCDPS impurities that lowered yield. However, in the current research, SDCDPS was successfully synthesized at nearly 100% conversion, which effectively eliminated the need for recrystallization. Recrystallization of SDCDPS from several alcohol–water mixtures (methanol–, ethanol–, and isoproponal–water mixtures) was investigated to compare product purities. Several characterization methods including proton NMR, HPLC, UV–visible, and fast atom bombardment mass spectroscopy confirmed that the crude SDCDPS was completely disulfonated and identical to recrystallized SDCDPS, without having any monosulfonated or starting material DCDPS impurities. Hence, it was demonstrated that the crude SDCDPS monomer by the current one‐step process and the recrystallized SDCDPS monomer were identical. This optimized monomer synthesis has been used to scale up the SDCDPS and poly(arylene ether sulfone) random and statistical copolymers at controlled disulfonation (35 and 45 mol %) levels, which were then used to fabricate proton exchange membranes for fuel cell applications. The intrinsic viscosity data confirmed that high molecular weight film forming copolymers were synthesized. The calculated degree of disulfonations by proton NMR was in close agreement with target disulfonations. It may be concluded that this optimized SDCDPS synthesis eliminates the need for recrystallization, which would be expected to improve process economics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4595–4602, 2006
Kinetic study of copolymerization of acrylonitrile with ammonium acrylate
Authors: Hou Chen , Liu Junshen , Ying Liang
Published: March 2006

Ammonium acrylate was first used to successfully copolymerize with acrylonitrile. Kinetics of copolymerization of acrylonitrile with ammonium acrylate was investigated in a H2O/dimethylsulfoxide (DMSO) mixture. The rate of copolymerization and particle size were measured. Kinetic equation of the copolymerization was obtained. Effect of copolymerization systems on monomer apparent reactivity ratios for acrylonitrile/ammonium acrylate copolymers was studied in comparison. Values of monomer apparent reactivity ratios were calculated by Kelen‐Tudos method. It has been found that monomer apparent reactivity ratios in water‐rich reaction medium [H2O/DMSO>80/20] are approximately equivalent to those in aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H2O > 80/20), apparent reactivity ratios are similar to those in solution polymerization system. With an increase in polarity of solvent, values of apparent reaction ratios both decrease. The values of apparent reaction ratios gradually tend to 1 with increase in the copolymerization temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4679–4683, 2006
Polyelectrolyte complex beads composed of water‐soluble chitosan/alginate: Characterization and their protein release behavior
Authors: Shi Xiaowen , Du Yumin , Sun Liping , Zhang Baozhong , Dou Abo
Published: March 2006

Polyelectrolyte complex (PEC) beads were prepared from water‐soluble chitosan (WSC) and alginate complex solution with different ratios by dropping method, and all procedures used were performed in aqueous medium at neutral environment. The structure and morphology of the beads were characterized by IR spectroscopy and scanning electron microscopy (SEM). IR spectroscopy confirmed the electrostatic interactions between amino groups of WSC and carboxyl groups of alginate. SEM showed internal section of the PEC bead, which had porous structure compared with compact structure of alginate beads. The swelling behavior, encapsulation efficiency, and release behavior of bovine serum albumin (BSA) from the beads at different pHs were investigated. PEC beads demonstrated different responses to pH from alginate beads. The ratio of WSC to alginate influenced the encapsulation and release of BSA. At pH 1.2, small amount (< 15%) of BSA was released from the PEC beads except AC12. However, at pH 7.4, a large amount (> 80%) of BSA was released from AL in the first 3 h due to the rapid disintegration of the beads, whereas BSA release was retarded from complex beads due to the forming of PEC. The results suggested that the WSC/alginate beads could be a suitable polymeric carrier for site‐specific protein drug delivery in the intestine. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4614–4622, 2006
Preparation and mechanical properties of natural rubber powder modified by carbon nanotubes
Authors: Wang J. D. , Zhu Y. F. , Zhou X. W. , Sui G. , Liang J.
Published: March 2006

A suspension of carbon nanotubes in natural latex was obtained by liquid mixing and then was used to prepare powder natural rubber composites modified with carbon nanotubes by means of spray drying process. The composite powders were round‐like and fine, with an average diameter of less than about 5 μm. The dispersion of carbon nanotubes in the rubber matrix was improved remarkably compared with that obtained by the mechanical mixing method. By means of vulcanization tests, it was found that the addition of vulcanizing agent necessary for the powder rubber containing carbon nanotubes should be evidently greater than that in rubber prepared by mechanical mixing, there evidently existed vulcanization reversions for the natural rubber prepared by mechanical mixing, which disappeared in the powder rubber containing carbon nanotubes prepared by the spray drying process. The mechanical properties of the powder natural rubber containing carbon nanotubes were much improved because of the modification effect of carbon nanotubes in rubber. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4697–4702, 2006
Suppression of metallocene catalyst leaching by the removal of free trimethylaluminum from methylaluminoxane
Authors: Turunen Jani P. J. , Pakkanen Tuula T.
Published: March 2006

The leaching of the catalyst zirconocene dichloride (Cp2ZrCl2) from an SBA‐15 silica support during ethylene polymerization was studied; severe leaching was observed when commercial methylaluminoxane (MAO) was used as the cocatalyst. However, the removal of free trimethylaluminum (TMA) from an MAO solution with a sterically hindered phenol reduced the catalyst leaching by 97–100%. The results obtained from the leaching experiments with TMA‐free MAO suggested that the major reason for catalyst leaching was the free TMA in the commercial MAO solution, not the pure MAO itself. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4632–4635, 2006
Characteristics of poly(AAc5‐co‐HPMA3‐cl‐EGDMA15) hydrogel‐immobilized lipase of Pseudomonas aeruginosa MTCC‐4713
Authors: Kanwar S. S. , Pathak S. , Verma H. K. , Kumar S. , Gupta R. , Chimni S. S. , Chauhan G. S.
Published: March 2006

Four series of noble networks were synthesized with acrylic acid (AAc) copolymerized with varying amount of 2‐hydroxy propyl methacrylate or dodecyl methacrylate (AAc/HPMA or AAc/DMA; 5:1 to 5:5, w/w) in the presence of ethylene glycol dimethacrylate (EGDMA; 1, 5, 10, 15, and 20%, w/w) as a crosslinker and ammonium per sulfate (APS) as an initiator. Each of the networks was used to immobilize a purified lipase from Pseudomonas aeruginosa MTCC‐4713. The lipase was purified by successive salting out with (NH4)2SO4, dialysis, and DEAE anion exchange chromatography. Two of the matrices, E15a, i.e. [poly (AAc5‐co‐DMA1‐cl‐EGDMA15)] and I15c, i.e. [poly (AAc5‐co‐HPMA3‐cl‐EGDMA15)], that showed relatively higher binding efficiency for lipase were selected for further studies. I15c‐hydrogel retained 58.3% of its initial activity after 10th cycle of repetitive hydrolysis of p‐NPP, and I15c was thus catalytically more stable and efficient than the other matrix. The I15c‐hydrogel‐immobilized enzyme showed maximum activity at 65°C and pH 9.5. The hydrolytic activity of free and I15c‐hydrogel‐immobilized enzyme increased profoundly in the presence of 5 mM chloride salts of Hg2+, NH4+, Al3+, K+, and Fe3+. The immobilized lipase was preferentially active on medium chain length p‐nitrophenyl acyl ester (C:8, p‐nitrophenyl caprylate). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4636–4644, 2006
PPO–PC block‐copolymers used as compatibilizers in PS/PC blends
Authors: Sartore Luciana , Penco Maurizio , Della Sciucca Stefania , Mendichi Raniero , Di Landro Luca , D'Antone Salvatore
Published: March 2006

Block‐copolymers containing poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) and polycarbonate of bisphenol A (PC) segments were employed as compatibilizers in polystyrene (PS)/PC blends. Block‐copolymers were prepared starting from oligomeric diols‐terminated PPO and PC. The poly(phenylene ethers) was obtained by oxidative coupling of 2,6‐dimethyl‐phenol in presence of tetramethyl bisphenol A. The copolymers were obtained with a chain extension reaction between the starting oligomers using bischloroformate of bisphenol A or phosgene as coupling agent. PS/PC blends, cast from chloroform solutions or mixed by melt, were studied by differential scanning calorimeter (DSC), dynamic‐mechanical thermal analysis (DMTA), and optical microscopy (OP). The thermal and morphological analyses showed a clear compatibilization effect between PS and PC, if PPO–PC copolymer is added when blending is performed in the melt; in addition, also mechanical properties are increased when compared with blends without PPO–PC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4654–4660, 2006
Preparation of nanocomposites of thermosetting resin from benzoxazine and bisoxazoline with montmorillonite
Authors: Chen Qiao , Xu Riwei , Yu Dingsheng
Published: March 2006

The thermosetting resin from 2,2′‐(1,3‐phenylene)‐bis(4,5‐dihydro‐oxazoles) (PBO) and bis(3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazine)isopropane (BZ) was prepared, and it was found that the thermal property of the final resin was affected greatly by the content of PBO. The nanocomposite from the thermosetting resin from BZ and PBO (molar ratio of PBO to BZ, 0.8 : 1) (PBZ–PBO) and organically modified montmorillonite (OMMT) was prepared by melt method. Differential scanning calorimetry showed that on the introduction of OMMT, the onset curing temperature of the copolymerization of BZ and PBO decreased. The X‐ray diffractometer and transmission electron micrograph characterization of the dispersion of OMMT in the PBZ–PBO matrix suggested that exfoliation structure of OMMT was achieved. Dynamic mechanical analyses indicated that the nanocomposites exhibited much higher Tg values than the PBZ–PBO resin and pristine polybenzoxazine, and storage modulus of the nanocomposites was maintained up to higher temperature with the increasing OMMT content. Dynamic thermogravimetric analysis showed that the dispersion of clay nanolayers in the PBZ–PBO copolymer gave better thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4741–4747, 2006
Effect of some compatibilizing agents on clay dispersion of polypropylene‐clay nanocomposites
Authors: López‐Quintanilla M. L. , Sánchez‐Valdés S. , Ramos de Valle L. F. , Medellín‐Rodríguez F. J.
Published: March 2006

Polypropylene (PP)‐clay nanocomposites were obtained and studied by using three different coupling agents, glycidyl methacrylate (GMA), acrylic acid (AA), and maleic anhydride (MA). Three different clays, natural montmorillonite (Cloisite Na+) and chemically modified clays Cloisite 20A and Cloisite 30B, have also been used. Nanocomposites were prepared by melt‐blending in a twin‐screw extruder using two mixing methods: two‐step mixing and one‐step mixing. The relative influence of each factor was observed from structural analysis by WAXD, POM, TEM, and mechanical properties. The results were analyzed in terms of the effect of each compatibilizing agent and incorporation method in the clay dispersion and mechanical properties of the nanocomposite. Experimental results showed that clay dispersion and interfacial adhesion are greatly affected by the kind of matrix modification. The polarity and reactivity of polar groups give as a result better interfacial adhesion and subsequent mechanical performance. PP‐g‐GMA and PP‐g‐MA were better compatibilizing agents than PP‐g‐AA. Better dispersion and exfoliation for the nanoclays were obtained when using two‐step mixing than one‐step mixing conditions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4748–4756, 2006
Preparation and adsorption selectivity for Hg(II) and Ag(I) of chelating resin immobilizing benzothiazolyl group on crosslinked polystyrene via hydrophilic sulfur‐containing PEG spacer
Authors: Ji Chunnuan , Qu Rongjun , Sun Changmei , Wang Chunhua , Sun Yanzhi , Zhao Na , Xie Hongming
Published: March 2006

A new chelating resin incorporating 2‐mercaptobenzothiazole (MBZ) into macroporous chloromethylated polystyrene via hydrophilic spacer of polyethylene glycol containing sulfur was synthesized. The resin was characterized by elementary analysis and infrared spectra. The adsorption capacity of the resin for Ag+, Hg2+, Cu2+, Zn2+, and Pb2+ as a function of pH was determined. The effects of interference ions, such as Na+, Mg2+, Ca2+, Ba2+, Cu2+, Zn2+, and Pb2+, on percent recovery were also investigated. The results showed that the resin could effectively remove Hg2+ and Ag+ from solutions containing a large excess of Na+, Mg2+, Ca2+, Ba2+, Cu2+, Zn2+, and Pb2+. In column operation, it was observed that Hg2+ and Ag+ in trace quantities were effectively removed from binary metal ions. The percent recovery of the resin for Hg2+ and Ag+ was >98.6% and >97.5%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 5034–5038, 2006
Mechanical and thermal properties of waste silk fiber‐reinforced poly(butylene succinate) biocomposites
Authors: Ok Han Seong , Muk Lee Sang , Ho Park Won , Cho Donghwan
Published: March 2006

This article reports the mechanical and thermal properties of poly(butylene succinate) (PBS) biocomposites reinforced with industrially available waste silk fibers, fabricated with varying fiber contents and lengths. The result indicates that use of waste silk fibers may be a potential as reinforcement for effectively improving the static and dynamic mechanical properties of a biodegradable polymer matrix resin, depending on the waste silk fiber content and length in the present biocomposite system. The “as‐separated” waste silk/PBS biocomposites showed the maximum tensile and flexural properties at a fiber loading of 40 wt %, and the “chopped” waste silk/PBS biocomposites showed the optimal strength and modulus with waste silk fibers of 12.7 mm length. The chopped waste silk fibers play a more contributing role in improving the mechanical properties of waste silk/PBS biocomposites than the as‐separated waste silk fibers at a fixed fiber loading. Above the glass transition temperature, the storage modulus of waste silk/PBS biocomposites was significantly greater than that of PBS resin, especially in the higher temperature region. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4972–4980, 2006
Preparation of polysulfone hollow fiber affinity membrane modified with mercapto and its recovery properties. II. Preparation of PSF‐SH hollow fiber affinity membrane for recovery of Hg2+
Authors: Wang Bing , Cheng Bowen , Cui Yongfang
Published: March 2006

A high qualified polysulfone hollow fiber affinity membrane modified with mercapto as chelating groups was prepared by phase inversion technology using chlormethyl polysulfone (CMPSF) as membrane matrix materials, through the reaction between thiourea and CMPSF hollow fiber matrix membrane to afford the methyl isothiourium polysulfone and was then alkaline hydrolyzed. The adsorption isotherms of the hollow fiber affinity membrane chromatography for Hg2+ were determined, and the effects of mobile phase conditions and the operating parameters on removal performance of the hollow fiber affinity membrane chromatography for Hg2+ were also investigated. The experimental results showed that adsorption isotherms of Hg2+ could be described by the Langmuir isotherm. Addition of NaCl into feed solution for the increase of ionic strength was harmful for the removal of Hg2+. The recovery of Hg2+ decreased at low pH and the optimum range of pH was from 5.0 to 7.0. The feed concentration had a remote effect on recovery of Hg2+ at the specified loading amount of Hg2+, and the Hg2+ could be removed from different concentration feed solution by the hollow fiber affinity membrane chromatography. The increase of feed flow rate led to slight decrease of recovery of Hg2+ at the specified loading amount of Hg2+. The hollow fiber affinity membrane chromatography could be operated at height feed flow rate and a large scale removal of Hg2+ could be realized. With the increase of load amount, Hg2+ recovery decreased, but the saturation degree of hollow fiber affinity membrane chromatography increased. According to required recovery of Hg2+ and the saturation degree of membrane chromatography, the optimum loading amount of Hg2+ should be selected in the actual removal of Hg2+. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4795–4803, 2006
Reactions of trithiocyanuric acid with oxiranes. IV. Analysis of the initial stages of the synthesis of polyetherols
Authors: Chmiel‐Szukiewicz Elżbieta , Lubczak Jacek
Published: March 2006

The course of the reaction of trithiocyanuric acid (TTCA) with oxiranes, propylene oxide (PO), and epichlorohydrin in a dimethyl sulfoxide solution was monitored by the acid number and epoxy number. The involvement of one of the tautomers of TTCA was postulated on the basis of the studied reaction between TTCA and 3 equiv of oxirane. It was also evidenced that the use of a catalyst was necessary for the reaction between TTCA and an excess of PO. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4917–4920, 2006
Possibility for the light stabilization of polycaproamide for fiber production
Authors: Simeonov N. , Todorova S.
Published: March 2006

A considerable setback of polyamide fibers, especially polycaproamidefibers (PCAFs), is their low light resistance. This leads to changes in their appearance and their physicomechanical parameters under ambient atmosphere conditions and as a result of the effect of sunlight. This setback could be compensated to a certain extent by the introduction of suitable light stabilizers in the fiber mass. Depending on its efficiency, each light stabilizer is added at a concentration of 0.2–5% with respect to the mass of the polymer. We have investigated two possibilities for introducing the light stabilizer into the fiber mass. In the first one, the composition was finished immediately after the fiber spinning, and in the second one, polycaproamide granules were processed with a solution of light stabilizers before their melting. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4921–4924, 2006
Synthesis and characterization of sPS/montmorillonite nanocomposites
Authors: Torre L. , Lelli G. , Kenny J. M.
Published: March 2006

The present work analyzed the possibility of obtaining and producing syndiotactic polystyrene (sPS)–based nanocomposites. The work first focused on possible technology to use for intercalation from solution and melt intercalation. Using a blend of sPS with atactic polystyrene (aPS) as the matrix was also considered. Thermal analysis techniques, such as differential scanning calorimetry (DSC) and thermogravimetry (TGA), were used to study the thermal properties and stability of the nanocomposites obtained and to select the most appropriate nanocharges. The effect of the introduction of nanofillers on these properties also was evaluated. X–ray diffraction was used to investigate the degree of clay exfoliation. Finally, mechanical characterization of the nanocomposites obtained was performed and compared to that of the pure material. The tests demonstrated that nanodispersion of phyllosilicate layers improved the mechanical behavior of the polymers analyzed, especially the annealed sPS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4957–4963, 2006
Radiation effect on the thermal conductivity and diffusivity of ramie fibers in a range of low temperatures by γ rays
Authors: Yamanaka Atsuhiko , Izumi Yoshinobu , Terada Takaya , Ema Kimiko , Tsutsumi Masayuki , Nakamura Muneatsu , Oohazama Takeshi , Kitagawa Tooru , Fujishiro Hiroyuki , Abe Shunzo , Nishijima Shigehiro
Published: March 2006

To understand the influence on the thermal conductivity by the length of the molecular chain in the polymer fiber, the thermal conductivity and thermal diffusivity of ramie fibers and those irradiated by γ rays, which induced molecular chain scission of cellulose, were investigated in a range of low temperatures. The degrees of polymerization, crystallinities, and orientation angles of ramie fibers and those irradiated by γ rays (γ‐ray treatment) were measured by the solution viscosity method, solid‐state NMR, and X‐ray diffraction. Only the degree of polymerization decreased with the γ‐ray treatment, and the crystallinities and orientation angles were almost independent of the γ‐ray treatment. The thermal conductivities of the ramie fibers with and without γ‐ray treatments decreased with decreasing temperature. The thermal diffusivities of the ramie fibers and those irradiated by γ rays were almost constant from 250 to 100 K, increased slightly with the temperature decreasing from 100 to 50 K, and increased rapidly with the temperature decreasing below 50 K. The thermal conductivity and thermal diffusivity of the ramie fibers decreased with the γ‐ray treatment. The mean free path of the phonon in the ramie fibers was reduced by the γ‐ray treatment. This decrease of the thermal diffusivity and thermal conductivity was explained by the reduction of the mean free path of the phonon by molecular chain scission with γ rays. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 5007–5018, 2006
Relaxation time, activation energy, and reaction pathway determination of the poly(ethylene glycol dimethacrylate)–dopant (I2) interaction with the nuclear magnetic resonance technique
Authors: Ramelow Ulku S. , Braganza Samantha N. , Ramelow Gerald J. , Darbeau Ron W.
Published: March 2006

Conductive polymers were obtained with a new polymerization method in which UV light was used as a photochemical initiator. In a previous work, optimum irradiation times were determined to obtain high conversion percentages. The effect of dopants on the conductivity of the polymer poly(ethylene glycol dimethacrylate) (PEGDM) was studied with LiClO4 and I2 as a dopant. The most effective dopant concentration was determined by the measurement of conductivities. Through the tracing of the conductivity change at various temperatures during the reaction of PEGDM with the dopant, the activation energies of the interactions were calculated, and a method was developed to follow the kinetics of the polymerization reaction with a conductometric technique. This work presents a nuclear magnetic resonance (NMR) study of the same polymer prepared under the optimum conditions with the results obtained in a previous study. NMR spectroscopy was used to determine the relaxation time, rate constants, and activation energy of the polymer–dopant interactions. As a preliminary study, pyruvic acid was used, and for acid‐catalyzed pyruvic acid/water reactions, the relaxation time, activation energy, and enthalpy change values (ΔH) were determined. With the same NMR technique, the reaction mechanisms of the polymerization, relaxation times, and rate constants of the polymer–dopant interactions were determined. The polymerization pathway was determined with NMR spectra; the results were confirmed by the calculation of the activation energies and bond‐breaking energies. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:5087–5101, 2006
Development of bond strength model for FRP plates using back‐propagation algorithm
Authors: Park Do Kyong , Jang Hwasup , Ahn Namshik
Published: March 2006

For the flexural reinforcement of bridge and building structure, synthetic materials whose dynamic properties are superior and those containing the merit of corrosion‐proof are widely used as the substitute for a steel plate. Since FRP plate has improved bond strength owing to the fibers externally adhering to the plate, many researches regarding the bond strength improvement have been substantially performed. To search out such bond strength improvement, previous researchers had ever examined the bond strength of FRP plate through their experiment by setting up many variables. However, since the experiment for a research on the bond strength takes much of expenditure for setting up the equipment and is time‐consuming, also is difficult to be carried out, it is limitedly conducted. The purpose of this study was to develop the most suitable artificial neural network model by application of various neural network models and algorithm to the data of the bond strength experiment conducted by previous researchers. Many variables were used as input layers against bond strength: depth, width, modulus of elasticity, tensile strength of FRP plate and the compressive strength, tensile strength, and width of concrete. The developed artificial neural network model has been applied back‐propagation, and its error was learned to be converged within the range of 0.001. Besides, the process for the over‐fitting problem has been dissolved by Bayesian technique. The verification on the developed model was executed by comparison with the test results of bond strength made by other previous researchers, which was never been utilized to the learning as yet. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 5119–5127, 2006
Two‐dimensional and three‐dimensional resistivity imaging in archaeological site investigation
Authors: Papadopoulos N. G. , Tsourlos P. , Tsokas G. N. , Sarris A.
Published: March 2006

In this work, the application and the effectiveness of two‐ and three‐dimensional non‐linear inversion algorithms in processing and interpretation of electrical resistivity tomography (ERT) data collected from archaeological areas are investigated in the framework of a new field technique for gathering three‐dimensional pole–pole tomographic data in a relatively small amount of time using standard archaeological prospection equipment. The inversion routine, for both the two‐dimensional and the three‐dimensional case, is based on a smoothness constrained algorithm and the forward modelling calculations are carried out using two‐dimensional and three‐dimensional finite element solvers respectively. Results of combined two‐dimensional inversions (quasi‐three‐dimensional) are compared with the full three‐dimensional inversions. Comparisons are carried out in relation to the optimum survey direction of gathering the tomographic data using the pole–pole array for synthetic data arising from three‐dimensional structures commonly encountered in archaeological sites. The response of the algorithms in the presence of noisy data was also tested. The algorithms were also used in the processing of real data collected from the archaeological sites of Sikyon and Europos in Greece. The results from the synthetic and the real data indicate the superiority of the three‐dimensional inversion algorithms in processing tomographic data. The reconstructed three‐dimensional images do not suffer from the artefacts encountered in the quasi‐three‐dimensional approach, owing to the three‐dimensional nature of the archaeological features. Most importantly, both synthetic and real data results indicate that a single survey direction is adequate to produce a valid three‐dimensional subsurface image when full three‐dimensional inversion is used in contrast to the quasi‐three‐dimensional approach, which would require that two survey directions be used to obtain satisfactory results. Copyright © 2006 John Wiley & Sons, Ltd.