bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactions of low molecular weight highly functionalized maleic anhydride grafted polyethylene with polyetherdiamines
Authors: Hameed Tayyab , Potter David K. , Takacs Elizabeth 
Published: January 2010

AbstractReaction between low molecular weight highly functionalized maleic anhydride grafted polyethylene and several diamines were carried out using xylene as a reaction media. The influence of varying the amine to maleic anhydride (NH2/MAH) molar ratio and chain length of diamine on reaction was investigated. It was shown that the reactions of these materials cannot be followed by FTIR measurements alone. In these examples, colorimetric titrations were used to assess residual acid/anhydride content that was not detected by FTIR. The reaction between anhydride and amine was observed to be fast. The degree of reaction and crosslinking in the reactor was observed to depend on the concentration of the reaction mixture and the NH2/MAH molar ratio. In some cases, a gelatinous insoluble mass was produced in the reactor and this material was not easily processed for further characterization. All soluble reaction products obtained were observed to be thermoplastic and could be melt processed at elevated temperatures. However, further reaction and crosslinking of these materials occurred during processing to produce thermosets, as demonstrated by rheological measurements and sintering experiments. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A study of critical processing technologies of liquid crystal polymer printed circuit board for high speed application
Authors: Yung K. C. , Liem H. , Choy H. , Yue T. M. 
Published: January 2010

AbstractRecent demand for high‐frequency and high‐speed signal transmission over GHz is driving the printed circuit board (PCB) industry towards a more advanced material‐based era. To meet this market demand, liquid crystal polymer (LCP) has been suggested for its predominant material characteristics, such as high temperature resistance, low moisture absorption and excellent dimensional stability. However, former experimental and theoretical studies on the fabrication technology for processing the LCP PCB at different treatment conditions are lacking. This article thus evaluates the recent development of LCP PCB process technology. Different process approaches involving in lamination, drilling, desmearing, and metallization are proposed and compared, and associated reliability testing is addressed. Experimental results are shown to demonstrate the efficacy of the proposed approach for developing the process technology of LCP PCB. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Measurement of the solubility and diffusivity of blowing agents in polystyrene
Authors: Perez‐Blanco Marcos , Hammons Jeffrey R. , Danner Ronald P. 
Published: January 2010

AbstractThe solubility and diffusivity of several gases in polystyrene (PS) and styrene acrylonitrile copolymer (SAN) were studied with the pressure decay method. Data were collected for carbon dioxide, isobutane, and 1,1,1,2‐tetrafluoroethane (R‐134a) in PS and for R‐134a in SAN. The temperature range was between 30 and 200°C, and the gas pressures ranged from approximately 0.2 to 8.2 MPa. To cover these ranges, both the absolute and differential pressure decay methods were required. Henry's law was found to adequately represent all the gas solubilities. Isobutane and R‐134a were found to have a plasticizing effect on PS and SAN; that is, the diffusivity increased significantly as the pressure (and mass uptake) increased. CO2 in PS had the highest diffusivity and lowest solubility and did not affect the diffusivity in PS over the pressure range studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of fluorine‐containing liquid crystalline polysiloxanes bearing cholesteryl cinnamate mesogens and trifluoromethyl‐substituted mesogens
Authors: Meng Fan‐Bao , Wang Zheng‐Yan , Chai Guo‐Wei , Wang Hong‐Guang , Chen Ying , Zhang Bao‐Yan 
Published: January 2010

AbstractSeveral novel side‐chain liquid crystalline (LC) polysiloxanes bearing cholesteryl cinnamate mesogens and trifluoromethyl‐substituted mesogens were synthesized by a one‐step hydrosilylation reaction with poly(methylhydrogeno)siloxane, a cholesteric LC monomer cholesteryl 3‐(4‐allyloxy‐phenyl)‐acryloate and a fluoro‐containing LC monomer 4‐[2‐(3‐trifluoromethyl‐phenoxy)‐acetoxy]‐phenyl 4‐allyloxy‐benzoate. The chemical structures and LC properties of the monomers and polymers were characterized by use of various experimental techniques, such as FTIR, 1H‐NMR, 13C‐NMR, TGA, DSC, POM, and XRD. The temperatures at which 5% weight loss occurred were greater than 300°C for all the polymers, and the residue weight near 600°C increased slightly with increase of the trifluoromethyl‐substituted mesogens in the fluorinated polymer systems. The samples containing mainly cholesteryl cinnamate mesogens showed chiral nematic phase when they were heated and cooled, but the samples containing more trifluoromethyl‐substituted mesogens exhibited chiral smectic A mesophase. The glass transition temperature of the series of polymers increased slightly with increase of trifluoromethyl‐substituted mesogens in the polymer systems, but mesophase–isotropic phase transition temperature did not change greatly. In XRD curves, the intensity of sharp reflections at low angle increased with increase of trifluoromethyl‐substituted mesogens in the fluorinated polymers systems, indicating that the smectic order derived from trifluoromethyl‐substituted mesogens should be strengthened. These results should be due to the fluorophobic effect between trifluoromethyl‐substituted mesogens and the polymer matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Structure and properties of polyethylene ionomer based nanocomposites
Authors: Santamaría Pablo , Eguiazábal Jose I. , Nazábal Jon 
Published: January 2010

AbstractLi and Zn ionomers of poly(ethylene‐co‐methacrylic acid) were modified by two organically modified montmorillonites by melt mixing. In the nanocomposites (NCs), the increase in the loss tangent main peak temperature indicated a reduction in the mobility of the long‐chain segments containing neutralized acid groups. The stack compaction observed by wide‐angle X‐ray scattering and transmission electron microscopy in the Cloisite 30B based NCs was attributed to the partial degradation of the surfactant and to the irreversible character of the ion‐exchange process of the ammonium cation of the surfactant with the Li cation. The considerable dispersion that occurred in the poly(ethylene‐co‐methacrylic acid) zinc salt (PEMA–Zn)/Cloisite 20A (20A) NCs was attributed to the high volume of the surfactant, which reduced undesired interactions between the inorganic clay surface and the ionomer. The ductile nature of the matrix remained in all of the NCs, and the increase in the modulus of elasticity of the PEMA–Zn/20A NCs reached a value five times greater than that of the PEMA–Zn matrix. The results suggest that this ionomer is suitable for use both as a matrix for 20A NCs and as a compatibilizer of polyolefin‐based NCs with 20A. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Macroscopic N‐halamine biocidal polymeric beads
Authors: Ahmed Abd El‐Shafey I. , Hay John N. , Bushell Michael E. , Wardell John N. , Cavalli Gabriel 
Published: January 2010

AbstractThe particle size of N‐halamine biocidal polymers was methodically modified forming beads of different sizes by blending water‐insoluble N‐halamine polyurethane with sodium alginate as the matrix and loading heterocyclic rings onto modified silica gels. The biological activity of the prepared beads and halogenated modified silica derivatives was evaluated against examples of Gram‐positive (Staphylococcus aureus) and Gram‐negative (Escherichia coli) bacteria. The recycling possibilities and the optimum preparation conditions of the blended beads were investigated; blending prehalogenated polyurethane (5%, w/v) with sodium alginate (3%, w/v) followed by crosslinking with CaCl2 (10%, w/v) at 40°C are the optimum preparation conditions for the alginate beads. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Fabrication of water‐stable electrospun polyacrylic acid‐based nanofibrous mats for removal of copper (II) ions in aqueous solution
Authors: Xiao Shili , Shen Mingwu , Ma Hui , Guo Rui , Zhu Meifang , Wang Shanyuan , Shi Xiangyang 
Published: January 2010

AbstractPolyacrylic acid (PAA) is an important polymer material for metal ion complexation and for nanocomposite materials syntheses. Generating ultrafine, uniform, and stable PAA nanofibers is of great scientific and technological interest for various applications. In this study, we systematically investigated the influence of processing parameters on the morphology and stability of the electrospun ultrafine PAA nanofibers. We show that a higher concentration (up to 25 wt %) favored the formation of uniform PAA nanofibers, whereas at the concentration of 10 wt %, only bead structures were produced. Increasing the applied voltage (up to 22.5 kV) resulted in more uniform PAA nanofibers. In addition, longer collection distance (20 cm) was beneficial for the evaporation of solvent and for decreasing the adhesion between nanofibers, thus leading to the nanofibrous mats with high porosity. Finally, the PAA nanofibers could be rendered water insoluble by heating the electrospun composite PAA/polyvinyl alcohol (PVA) nanofibers at 145°C for 30 min. The resulting nanofibrous mats exhibited excellent performance to remove Cu(II) ions in aqueous solution. The formed nanofibers may find various applications in ultrafiltration, separation, and environmental sciences. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Photoactive antimicrobial PVA hydrogel prepared by freeze‐thawing process for wound dressing
Authors: Hong Kyung Hwa , Sun Gang 
Published: January 2010

AbstractA freeze‐thawing process was employed to produce both rose bengal (RB)/polyvinyl alcohol (PVA) and benzophenone (BP)/PVA hydrogels, respectively. Results indicated that only RB incorporated PVA (RB/PVA) could form hydrogel after undergoing three cycles of freeze‐thawing process; One of the cycles should be conducted by freezing at −15°C ± 3°C for 18 h followed by thawing at 25°C for 6 h. The structural features and functional properties of the RB/PVA hydrogel were investigated by FTIR, XRD, SEM evaluations, and photo‐induced antimicrobial functions were examined as well. Release of RB from the RB/PVA hydrogel was examined by UV‐Vis spectroscopy. The freeze‐thawed RB/PVA hydrogel showed antimicrobial abilities against both E. coli and S. aureus under the exposure to fluorescence light as well as UVA (365 nm) light. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Formation and structure of poly(methyl methacrylate) gels containing triphenyl vinyl silane
Authors: Naghash Hamid Javaherian 
Published: January 2010

AbstractA series of Poly(methyl methacrylate) gels (PMMA) were prepared for making optical lenses by solution free radical crosslinking copolymerization of 2,2,2,‐trifluoroethyl methacrylate (TFEMA), methyl methacrylate (MMA), ethylene glycol dimethacrylate (EGDM), and triphenyl vinyl silane (TPVS) comonomer systems. They were then studied in toluene at a total monomer concentration of 5 molL−1and 70°C. The conversion of monomer, volume swelling ratio, weight fraction, and gel point were measured as a function of the TPVS concentration, temperature, and chain transfer agents up to the onset of macrogelation. Structural characteristics of the gels were examined by using equilibrium swelling in toluene, gel fraction, and Fourier‐transform infrared (FTIR) analysis. The morphology of the copolymers was also investigated by Scanning electron microscopy (SEM). The dilution of the monomer mixture resulted in an increase in the gel point and swelling degree and a decrease in the percentage of conversion and gel fraction. Finally, TPVS is a compatible vinyl type silicone comonomer for this system. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effects of acute or chronic exposure to dietary organic anions on secretion of methotrexate and salicylate by Malpighian tubules ofDrosophila melanogasterlarvae
Authors: Chahine Sarah , O'Donnell Michael J. 
Published: January 2010

AbstractThe effects of dietary exposure to organic anions on the physiology of isolated Malpighian tubules and on tubule gene expression were examined using larvae ofDrosophila melanogaster. Acute (24 h) or chronic (7 d) exposure to type I organic anions (fluorescein or salicylate) was associated with increased fluid secretion rates and increased fluxes of both salicylate and the type II organic anion methotrexate. By contrast, chronic exposure to dietary methotrexate was associated with increased fluid secretion rate and increased flux of methotrexate, but not salicylate. Exposure to methotrexate in the diet resulted in increases in the expression of a multidrug efflux transporter gene (MET; CG30344) in the Malpighian tubules. There were also increases in expression of genes for either aDrosophilamultidrug resistance–associated protein (dMRP; CG6214) or an organic anion transporting polypeptide (OATP; CG3380), depending on the concentration of methotrexate in the diet. Exposure to salicylate in the diet was associated with an increase in expression of dMRP and with decreases of MET and OATP. Exposure to dietary salicylate or methotrexate was also associated with different patterns of expression of heat shock protein genes. The results suggest that exposure to specific type I or type II organic anions has multiple effects and results not only in increased organic anion transport but also in increased rates of inorganic ion transport, which drives osmotically‐obliged fluid secretion. Increased fluid secretion may enhance secretion of organic anions by eliminating diffusive backflux from the tubule lumen to the hemolymph. © 2010 Wiley Periodicals, Inc.
Expression profiling of novel bacteria‐induced genes from the silkworm, Bombyx mori
Authors: Tanaka Hiromitsu , Suzuki Noriko , Nakajima Yoshiro , Sato Masaaki , Sagisaka Aki , Fujita Kosuke , Ishibashi Jun , Imanishi Shigeo , Mita Kazuei , Yamakawa Minoru 
Published: January 2010

AbstractIn this study, we have newly identified three bacteria‐induced genes from the silkworm Bombyx mori by quantitative reverse transcriptase‐polymerase chain reaction. One of these, eukaryotic initiation factor 4E‐1 (eIF4E‐1), is assumed to encode an eIF4E family, which plays a role in the initiation of translation as a mRNA cap‐binding protein. The second gene is BmFOXG1, belonging to a family of forkhead transcription factors, FOXG1. The third gene is MBF2‐related (MBF2‐R) whose product has high homology to a co‐activator protein MBF2 from B. mori. Although BmFOXG1 was up‐regulated in the fat body in response to three kinds of bacteria, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis, eIF4E‐1 and MBF2‐R were up‐regulated by E. coli and B. subtilis, but not S. aureus, suggesting that bacteria possessing meso‐diaminopimelic acid‐containing peptidoglycan but not lysine‐containing peptidoglycan activate eIF4E‐1 and MBF2‐R, probably through a conserved immune deficiency pathway. We further profiled the expression of three genes in different tissues and a silkworm cell line, NIAS‐Bm‐aff3, in response to bacteria, and at different times after bacterial challenge in the fat body. © 2010 Wiley Periodicals, Inc.
Synthesis of α‐ and β‐Pyran Naphthoquinones as a New Class of Antitubercular Agents
Authors: Ferreira Sabrina B. , de Carvalho da Silva Fernando , Bezerra Flávio A. F. M. , Lourenço Maria C. S. , Kaiser Carlos R. , Pinto Angelo C. , Ferreira Vitor F. 
Published: January 2010

AbstractA series of α‐ and β‐pyran naphthoquinones (lapachones) have been synthesized and evaluated for their in‐vitro antibacterial activity against Mycobacterium tuberculosis strain H37Rv (ATCC 27294) using the Alamar‐Blue susceptibility test; the activity was expressed as the minimum inhibitory concentration (MIC) in μg/mL. The synthetic methodology consisted of the formation of methylene and aryl o‐quinone methides (o‐QMs) generated by Knoevenagel condensation of 2‐hydroxy‐1,4‐naphthoquinone with formaldehyde and arylaldehydes. These o‐QMs then undergo facile hetero Diels–Alder reactions with dienophiles in aqueous ethanol media. Some naphthoquinones exhibited inhibition with MIC values of 1.25 μg/mL, similar to that of pharmaceutical concentrations currently used in tuberculosis treatment. These results justify further research into the value of these quinones as part of an original treatment for tuberculosis.
Post‐summer heavy rainfall events in Southeast Brazil associated with South Atlantic Convergence Zone
Authors: Lima Kellen Carla , Satyamurty Prakki 
Published: January 2010

AbstractHeavy rainfall events (HREs) in the post‐summer month of March in Southeast Brazil cause disasters such as floods, mudslides and landslides, mainly because the soil becomes saturated by February. Forty‐five years of rainfall data show that heavy rainfall frequency increases again in the month of March. The composite anomaly fields of the atmospheric circulation during and before HREs associated with the formation of South Atlantic Convergence Zone show some special characteristics that may be used as a guide for early warning. The convergence of moisture flux in the troposphere over the region grows 40% during the 48 h before the HRE in March. Copyright © 2010 Royal Meteorological Society
A developer's people mover education
Authors: Parker Jeffrey A. 
Published: January 2010

AbstractThe Three Rivers Corporate Center office complex proposed to the City of Pittsburgh initially included a half‐mile, automated people mover system as a link to downtown. After four years of effort and substantial investment, the project was dropped and the people mover was never built. What happened and what lessons were learned are described by the project's would‐be developer. Issues affecting the commercial application of people movers are examined from a developer's perspective and recommendations for improving the marketability of people movers to real estate decisionmakers are offered for consideration.
An evaluation of vehicle deceleration profiles
Authors: Wortman Robert H. , Fox Thomas C. 
Published: January 2010

AbstractVehicles stopping at signalized intersections were examined for the purpose of evaluating the validity of the common assumption of constant and uniform deceleration rates. The data set consisted of the first vehicles to stop upon the onset of the yellow signal interval with measurements of the initial approach speed, deceleration time, and deceleration distance.The deceleration rate may be computed using only two of the three measured values; thus the rate for each vehicle can be determined by three different equations. With nonuniform deceleration profiles, the equations will produce different values; and the degree of nonuniformity can be determined by comparing the differences in the computed deceleration rates.The analysis of the field observations indicated that 69 percent of the vehicles demonstrated deceleration profiles associated with nonuniform deceleration rates. Furthermore, the deceleration profile and the degree of nonuniformity were found to be a function of the initial approach speed.
Evaluation of forced flows on freeways with single‐loop detectors
Authors: Nihan Nancy L. 
Published: January 2010

AbstractThis paper documents the development of a simple method for identifying and/or predicting freeway congestion using single loop detection systems. The proposed algorithm is simple and easy to incorporate into most freeway management systems. The Washington State Department of Transportation's Traffic Systems Management Center (TSMC) sponsored the original study. The investigation also led to a recommendation to replace the original TSMC definition of congestion or forced flow conditions with a more reliable indicator. Although, the TSMC has recently implemented a more advanced prediction system based on fuzzy set theory and neural networks to further identify patterns and rules for ramp metering strategies, the findings presented here continue to be constructive to freeway managers looking for quick and easy analyses that rely solely on single‐loop detection systems.The Seattle Area freeway study section used for the original study was the portion of mainline 1–5 northbound starting at the downtown Seattle Station 108 and ending at the Mountlake Terrace Station 193. Several days' worth of volume and lane‐occupancy data were collected for the afternoon time period from 2:30 p.m. to 6:30 p.m. Time intervals of 20 seconds were chosen for each data collection period.Important products of this research include the following:
simple, and more reliable criterion for the definition of “bottleneck” or forced flow conditions than that originally used by the TSMC.
simple, and reliable criterion for predicting impending “bottlenecks” or forced flow conditions.
A proposed variable for improved selection of the appropriate metering rate. (Further analysis of the use of this variable for determining metering rates is recommended for future studies.
The proposed criteria are simple and easy to incorporate into current freeway management computer systems. Further investigation of freeway performance measurement using volume and occupancy data obtained from single‐loop systems is currently being performed.
Probabilistic reasoning in prediction and diagnosis: Effects of problem type, response mode, and individual differences
Authors: Wedell Douglas H. 
Published: January 2010

AbstractIn prediction, subset relations require that the probability of conjoined events is never higher than that of constituent events. However, people's judgments regularly violate this principle, producing conjunction errors. In diagnosis, the probability of a hypothesis normatively is often higher for conjoined cues. An online survey used a within‐subjects design to explore the degree to which participants (n = 347) differentiated diagnosis and prediction using matched scenarios and both choice and estimation responses. Conjunctions were judged more probable than a constituent in diagnosis (76%) more often than prediction (64%) and in choice (84%) more often than direct estimation (57%), with no interaction of type of task and response mode. Correlation, regression, and path analyses were used to determine the relationships among individual difference variables and the diagnosis and prediction tasks. Among the correlation findings was that time spent on the task predicted higher conjunction probabilities in diagnosis but not prediction and that class inclusion errors predicted increased conjunction errors in choice but not estimation. Need for cognition and numeracy were only minimally related to reasoning about conjunctions. Results are consistent with the idea that people may misapply diagnostic reasoning to the prediction task and consequently commit the conjunction error. Copyright © 2010 John Wiley & Sons, Ltd.
An overview of developmental and reproductive toxicity risk assessment in China
Authors: Wang Haixue , Wang Qingli , Liao Mingyang 
Published: January 2010

AbstractDevelopment and reproductive toxicology (DART) studies in animals are integral parts of nonclinical safety evaluation of drugs. The State Food and Drug Administration (SFDA) of the People's Republic of China developed a new guideline on DART studies in 2006. This guideline is in broad agreement with ICH guideline S5A (1994), “Detection of Toxicity to Reproduction for Medical Products,” and M3, “Nonclinical Safety Studies for the Conduct of Human Clinical Trials for Pharmaceuticals.” However, the new guideline on DART testing differs from ICH in some detailed requirements. This overview reviews some main specifications in China's guidelines on DART testing, and also briefly introduces the recommendations for conducting human clinical trials and marketing authorization in China. Birth Defects Res (Part B) 89:2–8, 2010. © 2010 Wiley‐Liss, Inc.