bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dental topography and diets of four old world monkey species
Authors: Bunn Jonathan M. , Ungar Peter S. 
Published: April 2009

AbstractDental topographic analysis allows comparisons of variably worn teeth within and between species to infer relationships between dental form and diet in living primates, with implications for reconstructing feeding adaptations of fossil forms. Although analyses to date have been limited mainly to the M2s of a few primate taxa, these suggest that dental topographic analysis holds considerable promise. Still, larger samples including a greater range of species and different tooth types are needed to determine the potential of this approach. Here we examine dental topography of molar teeth of Cercocebus torquatus (n=48), Cercopithecus campbelli (n=50), Colobus polykomos (n=50), and Procolobus badius (n=50). This is the first such study of large samples of Old World monkeys, and the first to include analyses of both M1s and M2s. Average slope, relief, and surface angularity were computed and compared among tooth types, wear stages, and species. Results suggest that (1) data for M1s and M2s cannot be compared directly; (2) slope and relief decline with wear on M2s of all taxa, and M1s of the colobines, whereas angularity does not generally change except in the most worn specimens; and (3) folivorous colobines tend to have more sloping surfaces and more relief than do frugivorous cercopithecines, though angularity does not clearly separate taxa by diet. Am. J. Primatol. 71:466–477, 2009. © 2009 Wiley‐Liss, Inc.
Effects of high‐ and low‐fiber diets on fecal fermentation and fecal microbial populations of captive chimpanzees
Authors: Kišidayová Svetlana , Váradyová Zora , Pristaš Peter , Piknová Mária , Nigutová Katarína , Petrželková Klára J. , Profousová Ilona , Schovancová Kateřina , Kamler Jiří , Modrý David 
Published: April 2009

AbstractWe examined fiber fermentation capacity of captive chimpanzee fecal microflora from animals (n=2) eating low‐fiber diets (LFDs; 14% neutral detergent fiber (NDF) and 5% of cellulose) and high‐fiber diets (HFDs; 26% NDF and 15% of cellulose), using barley grain, meadow hay, wheat straw, and amorphous cellulose as substrates for in vitro gas production of feces. We also examined the effects of LFD or HFD on populations of eubacteria and archaea in chimpanzee feces. Fecal inoculum fermentation from the LFD animals resulted in a higher in vitro dry matter digestibility (IVDMD) and gas production than from the HFD animals. However, there was an interaction between different inocula and substrates on IVDMD, gas and methane production, and hydrogen recovery (P<0.001). On the other hand, HFD inoculum increased the production of total short‐chain fatty acids (SCFAs), acetate, and propionate with all tested substrates. The effect of the interaction between the inoculum and substrate on total SCFAs was not observed. Changes in fermentation activities were associated with changes in bacterial populations. DGGE of bacterial DNA revealed shift in population of both archaeal and eubacterial communities. However, a much more complex eubacterial population structure represented by many bands was observed compared with the less variable archaeal population in both diets. Some archaeal bands were related to the uncultured archaea from gastrointestinal tracts of homeothermic animals. Genomic DNA in the dominant eubacterial band in the HFD inoculum was confirmed to be closely related to DNA from Eubacterium biforme. Interestingly, the predominant band in the LFD inoculum represented DNA of probably new or yet‐to‐be‐sequenced species belonging to mycoplasms. Collectively, our results indicated that fecal microbial populations of the captive chimpanzees are not capable of extensive fiber fermentation; however, there was a positive effect of fiber content on SCFA production. Am. J. Primatol. 71:548–557, 2009. © 2009 Wiley‐Liss, Inc.
Reproductive parameters of wild Trachypithecus leucocephalus: seasonality, infant mortality and interbirth interval
Authors: Jin Tong , Wang De‐Zhi , Zhao Qing , Yin Li‐Jie , Qin Da‐Gong , Ran Wen‐Zhong , Pan Wen‐Shi 
Published: April 2009

AbstractUnderstanding the reproductive parameters of endangered primate species is vital for evaluating the status of populations and developing adequate conservation measures. This study provides the first detailed analysis of the reproductive parameters of wild white‐headed langurs (Trachypithecus leucocephalus), based on demographic data collected over an 8‐year period in the Nongguan Karst Hills in Chongzuo County, Guangxi, China. From 1998 to 2002, a total of 133 live births were recorded in the population based on systematic censuses. Births occurred throughout the year, but the temporal pattern was highly correlated with seasonal variation in temperature and rainfall, with the birth peak coinciding with the dry and cold months of November–March. The average birthrate was 0.47±0.13 births per female per year and mortality for infants younger than 20 months was 15.8%. From 1998 to 2006, 14 females gave birth to 41 infants in four focal groups. The average age at first birth for female langurs was 5–6 years (n=5) and the interbirth interval (IBI) was 23.2±5.2 months (median=24.5 months, n=27). Infants are weaned at 19–21 months of age. The IBI for females with infant loss before weaning was significantly shorter than those for females whose infants survived. It appears that birth seasonality in the white‐headed langurs is influenced by seasonal changes in food availability. The timing of conceptions was found to coincide with peak food availability. The reproductive parameters for white‐headed langurs reported here are quite similar to those reported for other colobine species. One major difference is our observation of lower infant mortality in Trachypithecus. Am. J. Primatol. 71:558–566, 2009. © 2009 Wiley‐Liss, Inc.
On the flow‐phase diagram for nematic liquid crystalline polymer under magnetic field
Authors: Fu Shufang , Bai Jing 
Published: April 2009

AbstractThe effect of magnetic fields on molecular configuration of liquid crystalline polymers under shear flows are numerically analyzed using the extended Doi theory in which a molecular shape parameter is admitted. The evolution equation for the probability density function of the LCP molecules is directly solved without any closure approximations. One case is considered that the magnetic field makes 45° with respect to the flow direction. We can find that the magnetic fields strongly affect on the transition among flow‐orientation modes, such as tumbling, wagging, and aligning modes. And a new aligning flow‐orientation mode emerges at low shear rate, which is macroscopically same as the ordinary aligning mode, but is microscopically quite different from the ordinary one. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and properties of fluorinated biphenyl‐type epoxy resin
Authors: Ding J. P. , Tao Z. Q. , Fan L. , Yang S. Y. 
Published: April 2009

AbstractA novel fluorinated biphenyl‐type epoxy resin (FBE) was synthesized by epoxidation of a fluorinated biphenyl‐type phenolic resin, which was prepared by the condensation of 3‐trifluoromethylphenol and 4,4′‐bismethoxymethylbiphenyl catalyzed in the presence of strong Lewis acid. Resin blends mixed by FBE with phenolic resin as curing agent showed low melt viscosity (1.3–2.5 Pa s) at 120–122°C. Experimental results indicated that the cured fluorinated epoxy resins possess good thermal stability with 5% weight loss under 409–415°C, high glass‐transition temperature of 139–151°C (determined by dynamic mechanical analysis), and outstanding mechanical properties with flexural strength of 117–121 MPa as well as tensile strength of 71–72 MPa. The thermally cured fluorinated biphenyl‐type epoxy resin also showed good electrical insulation properties with volume resistivity of 0.5–0.8 × 1017 Ω cm and surface resistivity of 0.8–4.6 × 1016 Ω. The measured dielectric constants at 1 MHz were in the range of 3.8–4.1 and the measured dielectric dissipation factors (tan δ) were in the range of 3.6–3.8 × 10−3. It was found that the fluorinated epoxy resins have improved dielectric properties, lower moisture adsorption, as well as better flame‐retardant properties compared with the corresponding commercial biphenyl‐type epoxy resins. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Nanomechanical characterization of single micron‐sized polymer particles
Authors: He J. Y. , Zhang Z. L. , Kristiansen H. 
Published: April 2009

AbstractThe mechanical characterization of single micron‐sized polymer particles is very important for understanding the anisotropic conductive adhesives interconnection. In this article, a nanoindentation‐based flat punch method was employed to investigate the mechanical properties of single polymer particles. A diamond flat tip, instead of a commonly used sharp tip for indentation, was specially designed to deform single polymer particles. The maximum applied load is 10 mN and the linear loading/unloading rate is 2 mN/s. Two types of amorphous polymer particles were examined. The polymer particles display significantly different stress–strain behaviors. The material responses at different strain levels were analyzed and compared. A particle size effect, the smaller the diameter, the harder the particle, on the compression stress–strain behavior, was observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and properties of new poly(ether imides) based on pyridine‐containing aromatic dianhydride and diamine monomers
Authors: Wang Xiaolong , Li Yanfeng , Gong Chenliang , Ma Tao , Zhang Shujiang 
Published: April 2009

AbstractA series of novel aromatic poly(ether imides) with inherent viscosities of 0.48–0.70 dL/g and weight‐average molecular weights of 18,800–40,500 g/mol were successfully prepared from two dianhydride and two diamine monomers containing pyridine moiety via both two‐step method and one‐step method. Comparison of the one‐step and the two‐step methods for the preparation of poly(ether imides) was carried out and shown that poly (ether imides) obtained via one‐step method exhibited higher molecular weights than the similar polymers prepared through two‐step process. Poly(ether imide) resins obtained via both one‐step and two‐step methods with subsequent chemical dehydration showed good solubility not only in high boiling point solvents but also in low boiling point solvents. High‐quality poly(ether imide) films could be obtained via the two‐step method with subsequent thermal imidization, which exhibited excellent thermal properties with glass transition temperatures of 239–278°C, initial decomposition temperatures of 540–574°C, residual weight percent at 800°C of 64.5–69.3% under nitrogen, good thermo‐oxidative stability with initial decomposition temperatures of 521–544°C, residual weight percent at 800°C of 33.6–51.1% under air atmosphere, outstanding mechanical properties with tensile strengths in the range of 104.6–109.4 MPa, tensile modulus in the range of 1.92–2.58 GPa, and elongation at break from 6.9 to 8.0%, as well as good transparency with cutoff wavelengths of 386–392 nm and low dielectric constants of 2.80–2.92 at 1 MHz. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of polyimide oligomer attached with hemicyanine dye
Authors: Qin Chuanxiang , Wang Jianjun , Li Yi , Xie Hongde , Wang Xinbo , Dai Lixing , Wang Xiaomei , Chen Guoqiang 
Published: April 2009

AbstractTwo hemicyanine dyes, trans‐4‐[p‐(N,N‐di(2‐hydroxyethyl)) amino‐styryl]‐N‐methylpyridinium tetraphenylborate (dye‐C1) and trans‐4‐[p‐(N,N‐di(2‐hydroxyethyl)) amino‐styryl]‐N‐octylpyridinium tetraphenylborate (dye‐C8) were synthesized, and characterized by infrared, 1H‐NMR, thermoanalysis, respectively. Then polyimide (PI) oligomers (referred to as P‐C1 and P‐C8) with these hemicyanine dyes attached to the polymer side chain were prepared through Mitsunobu condensation. When the linear optical properties of the two dyes and the two PI oligomers were studied in dimethylformamide solvent, there were obvious blue shifts in the spectra of the oligomers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Evaluation of biodegradability of epoxy‐guar gum composites
Authors: D'Melo D. J. , Shenoy M. A. 
Published: April 2009

AbstractEpoxy composites incorporating natural components have been mainly limited to the use of natural fibers. However, there have been a few instances where polysaccharides have been used as particulate fillers in thermoset compositions. The present study investigated the effect of guar gum/hydroxypropyl guar gum as a filler on the degradative properties of epoxy composites at various filler concentrations, with reference to fungal degradation and soil burial tests. It was found that at higher filler concentrations, the degradation increased. Composites based on hydroxypropyl guar gum showed increased degradation initially but on prolonged exposure to the fungal environment, the difference between guar gum and the hydroxypropyl guar gum‐based composites was found to be marginal. Microscopic evaluation of the composites showed that the degradation occurred at both the composite surface and in the bulk. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Lignin in jute fabric–polypropylene composites
Authors: Acha B. A. , Marcovich N. E. , Reboredo M. M. 
Published: April 2009

AbstractIn this work, the feasibility of using lignin as a compatibilizer for composites made from jute fiber fabric and polypropylene (PP) was studied. Since lignin contains polar (hydroxyl) groups and nonpolar hydrocarbon, it was expected to be able to improve the compatibility between the two components of the composite. It was found that lignin acted as β nucleation, fire retardant, and toughening agent for PP matrix. Jute composites exhibit higher stiffness, tensile strength, and impact behavior in respect to those of neat PP. Although scanning electron micrographic observations indicate that PP‐jute adhesion was slightly improved by lignin addition, additional benefits were only obtained from impact behavior. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Temperature dependence of the conductivity behavior of graphite nanoplatelet‐filled epoxy resin composites
Authors: Zheng Chao , Fan Zhuangjun , Wei Tong , Luo Guilian 
Published: April 2009

AbstractIn this article, epoxy/graphite nanoplatelet (GNP) conductive composites with the low percolation threshold of ∼ 0.5 vol % were prepared. The effect of microstructure, particularly the spatial distribution of fillers in the matrix on the resistivity and its dependence on temperature, also was investigated. It is suggested that the high aspect ratio and good distribution of GNPs in the matrix contribute to the low threshold of the composite. The thermal–electrical behavior of the composite is also significantly influenced by the GNP content and microstructure of the composite. When the GNP content is greater than percolation threshold, a noticeable positive temperature coefficient of resistivity disappears. It is explained by the unique conductive network formed by plane contact between GNPs, which is hardly affected by the expansion of matrix during heating. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Graft copolymerization of maleic anhydride onto low‐molecular‐weight polyisobutylene through solvothermal method
Authors: Gong Wenjuan , Qi Rongrong 
Published: April 2009

AbstractThe free‐radical graft copolymerization of maleic anhydride (MAH) onto highly reactive low molecular weight polyisobutylene was conducted by the use of benzoyl peroxide as an initiator through the solvothermal method. Fourier transform infrared spectra and 1H‐NMR spectra confirmed that maleic anhydride was successfully grafted onto highly reactive low molecular weight polyisobutylene backbone, and the grafting mechanism also was proposed. The effect of benzoyl peroxide content, MAH concentration, total reactant amount in the reaction vessels, reaction temperature and time, and different kinds and volumes of solvents on MAH's degree of grafting was investigated in detail. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of interfacial interaction on the crystallization and mechanical properties of PP/nano‐CaCO3 composites modified by compatibilizers
Authors: Wang Yuhai , Shen Hao , Li Gu , Mai Kancheng 
Published: April 2009

AbstractTo investigate the effect of interfacial interaction on the crystallization and mechanical properties of polypropylene (PP)/nano‐CaCO3 composites, three kinds of compatibilizers [PP grafted with maleic anhydride (PP‐g‐MA), ethylene–octene copolymer grafted with MA (POE‐g‐MA), and ethylene–vinyl acetate copolymer grafted with MA (EVA‐g‐MA)] with the same polar groups (MA) but different backbones were used as compatibilizers to obtain various interfacial interactions among nano‐CaCO3, compatibilizer, and PP. The results indicated that compatibilizers encapsulated nano‐CaCO3 particles, forming a core–shell structure, and two interfaces were obtained in the compatibilized composites: interface between PP and compatibilizer and interface between compatibilizer and nano‐CaCO3 particles. The crystallization and mechanical properties of PP/nano‐CaCO3 composites were dependent on the interfacial interactions of these two interfaces, especially the interfacial interaction between PP and compatibilizer. The good compatibility between PP chain in PP‐g‐MA and PP matrix improved the dispersion of nano‐CaCO3 particles, favored the nucleation effect of nano‐CaCO3, increased the tensile strength and modulus, but reduced the ductility and impact strength of composites. The partial compatibility between POE in POE‐g‐MA and PP matrix had little effect on crystallization and mechanical properties of PP/nano‐CaCO3 composites. The poor compatibility between EVA in EVA‐g‐MA and PP matrix retarded the nucleation effect of nano‐CaCO3, and reduced the tensile strength, modulus, and impact strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Semi‐interpenetrating networks based on poly(N‐isopropyl acrylamide) and poly(N‐vinylpyrrolidone)
Authors: Žugić Dragana , Spasojević Pavle , Petrović Zoran , Djonlagić Jasna 
Published: April 2009

AbstractThree series of novel semi‐interpenetrating polymer networks, based on crosslinked poly(N‐isopropylacrylamide), PNIPA, and different amounts of the linear poly(N‐vinylpyrrolidone), PVP, were synthesized to improve the mechanical properties and thermal response of PNIPA gels. The effect of the incorporation of the linear PVP into the temperature responsive networks on the temperature‐induced transition, swelling/deswelling behavior, and mechanical properties was studied. Polymer networks with four different crosslinking densities were prepared with varying molar ratios (25/1 to 100/1) of the monomer (N‐isopropylacrylamide) to the crosslinker (N,N′‐methylenebisacrylamide). The hydrogels were characterized by determination of the equilibrium degree of swelling, the dynamic shear modulus and the effective crosslinking density, as well as tensile strength and elongation at break. Furthermore, the deswelling kinetics of the hydrogels was studied by measuring their water retention capacity. The inclusion of the linear hydrophilic PVP in the PNIPA networks increased the equilibrium degree of swelling. The tensile strength of the semi‐interpenetrating networks (SIPNs) reinforced with linear PVP was higher than that of the PNIPA networks. The elongation at break of these SIPNs varied between 22% and 55%, which are 22 – 41% larger than those for pure PNIPA networks. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Investigation on fluorescence properties of ultrafine PVA fiber mats‐contained polyoxometalate with different molecular structure
Authors: Sun Yongling , Shan Yuping , Cui Xiujun , Li Bin , Gong Jian , Su Zhongmin , Qu Lunyu 
Published: April 2009

AbstractNovel luminescence ultrafine fiber mats containing K11[Eu(PW11O39)2] [EuPW11] and Na9[EuW10O36] [EuW10] entrapped in polyvinyl alcohol (PVA) have been successfully prepared by electrospinning method. By comparing the luminescence emission spectra of EuPW11/PVA and EuW10/PVA ultrafine fiber mats, we conclude lower site symmetry of Eu3+ in the EuPW11/PVA ultrafine fiber mats. We further investigate the different configurations of EuPW11 and EuW10, which lead to the different site symmetry of Eu3+ in the ultrafine fiber mats of EuPW11/PVA and EuW10/PVA. Fluorescence property shows EuPW11/PVA ultrafine fiber mats display pure red emission. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Physical, structural, and mechanical characterization of calcium–shellac microspheres as a carrier of carbamide peroxide
Authors: Xue Jing , Zhang Zhibing 
Published: April 2009

AbstractCalcium–shellac microspheres with encapsulated carbamide peroxide (CP) were made by emulsification to generate an emulsion including shellac ammonium salt aqueous solution with soluble CP dispersed in sunflower oil with calcium chloride powders, followed by gelation between shellac and calcium. The effects of formulation and processing conditions on the encapsulation efficiency of CP, the physical, structural, and mechanical properties of calcium–shellac microspheres, including size, inner structure, and mechanical strength, were investigated. The sizes of the prepared microspheres were in the range of 10–100 μm, depending on the agitation speed used in the emulsification process. The morphology of calcium–shellac microspheres was characterized using scanning electron microscopy and image analysis. Their inner structure was evaluated using X‐ray microcomputed tomography, and their mechanical strength was determined by a micromanipulation technique. The structure and mechanical strength of the microspheres were compared with those bigger calcium–shellac beads (1–3 mm in diameter) made by extrusion followed by gelation (Xue and Zhang, J Microencapsul 2008, 25, 523), and clear contrast in the properties between the two preparation methods has been found. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Predictability of apparent viscosity in a vibratory shearing flow field
Authors: Qu Jin‐Ping , Wei Bao‐Hua , Yang Zhi‐Tao , Cai Yong‐Hong 
Published: April 2009

AbstractA self‐developed experimental facility by the National Engineering Research Center of Novel Equipment for Polymer Processing, called a coaxial barrel dynamic rheometer, was used to test the predictability of the apparent viscosity equations of polymer melts in flat vibrating shear flows. The testing principle of the rheometer is to transform the shear power of a motor and extrusion pressure in a shear field to melt viscosity. The shear field can simulate an orthogonal superposed vibratory flow, boundary vibrating pressure flow, and their combined flow. By comparing equation predictions with experimental results, we show a qualitatively satisfactory and quantitatively reasonable predictive ability, which verifies the work of our mathematical derivations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009