bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological variation in adult chimpanzees (Pan troglodytes verus) of the Taï National Park, Côte d'Ivoire
Authors: Zihlman Adrienne L. , Stahl Daniel , Boesch Christophe 
Published: September 2007

AbstractTwenty five adult chimpanzee skeletons (Pan troglodytes verus) of known age and sex (15 females, 10 males) from a long‐term study site in Taï National Park, Cote d'Ivoire present new data on variation. These skeletons provide a rare opportunity to measure the cranium and postcranium from the same individuals. We compare measurements and indices of the Taï sample with those of relatively complete Pan troglodytes schweinfurthii skeletons from Gombe National Park, Tanzania. Measurements of Pan paniscus are included as an outside comparison. The Taï and Gombe samples are analyzed by sex; combined sex samples are compared between the two groups, and the two sexes to each other. Taï females and males do not differ in most long bone lengths or in pelvic dimensions, but do differ significantly in cranial capacity, facial measurements, clavicle length, scapular breadth, and femur length. Gombe females and males differ significantly in some facial measurements and in scapular breadth. In combined sex samples, Taï individuals have lower cranial capacity, longer palate and mandible, and greater dimensions in the trunk and limb lengths. Taï females account for most of the variation; males differ from each other only in greater length of humerus and femur. The Taï skeletons provide new data for assessing individual variation and sexual dimorphism within and between populations and species. The combination of cranial and postcranial data provides a clearer picture of chimpanzee intraspecific and interspecific variation than can be gained from either data set alone. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Prey foraging of red titi monkeys,Callicebus cupreus, in comparison to sympatric tamarins,Saguinus mystaxandSaguinus fuscicollis
Authors: Nadjafzadeh Mirjam N. , Heymann Eckhard W. 
Published: September 2007

AbstractWe compared the prey capture strategies of red titi monkeys,Callicebus cupreus, with those of sympatric mustached,Saguinus mystax, and saddleback tamarins,Saguinus fuscicollis,to examine whether animal prey is important in niche differentiation between these Neotropical primates. We collected data on strata and substrate use during foraging, on prey searching and capturing, and on prey type of twoC. cupreusgroups and one group each ofS. mystaxandS. fuscicollisduring a 5‐month field study in northeastern Peruvian Amazonia. Our results showed thatC. cupreusdiffered both fromS. mystaxandS. fuscicollisin prey capture strategies: (1)C. cupreusused lower forest strata for prey search and capture thanS. mystaxand higher forest strata thanS. fuscicollis.(2)C. cupreuscaptured prey on a higher variety of substrates thanS. mystaxand more often on open microhabitats compared toS. fuscicollis. (3)C. cupreuscaptured prey more often directly thanS. mystaxand rarely by manual search, in contrast toS. fuscicollis. (4)C. cupreusfed exclusively on arthropods and focused on Hymenoptera, in contrast to both tamarin species that focused on Orthoptera and included vertebrates in their diet. These findings indicate that animal prey plays a role in niche differentiation betweenC. cupreusandS. fuscicollis/S. mystaxand might facilitate the coexistence of these three sympatric species. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Shell thickness and chemical structure of polyurea microcapsules prepared with haxamethylene diisocyanate uretidione and isocyanurate
Authors: Takahashi Tadatsugu , Taguchi Yoshinari , Tanaka Masato 
Published: September 2007

AbstractTo investigate the dependence of the shell thickness on both the microcapsule size and the concentration of hexamethylene diisocyanate (HMDI) and to analyze the chemical structure of the polyurea shell, polyurea microcapsules were prepared by using the reaction between HMDI uretidione/isocyanurate and ethylene diamine (EDA) in an oil‐in‐water emulsion. In the experiment, the concentrations of hexamethylane diisocyanate and EDA were changed. The shell thickness was correlated well with the mean size and the concentration of HMDI on the surface area per unit volume of microcapsule. From the solid‐state 13C NMR spectroscopy analysis, the uretidione and isocyanurate ring structures were found to be not changed before and after the reaction. From the wide‐angle X‐ray diffraction analysis, it was suggested that the chemical structure of the polyurea shell was amorphous. From the FTIR spectra analysis, it could be concluded that polyurea microcapsules were prepared by the reaction between HMDI uretidione/isocyanate and EDA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Surface characteristics of ionically crosslinked chitosan membranes
Authors: Karakeçili Ayşe Gönen , Satriano Cristina , Gümüşderelioğlu Menemşe , Marletta Giovanni 
Published: September 2007

AbstractIn this study, homogenous dense chitosan membranes were prepared by solution‐casting procedure. Then the membranes were ionically crosslinked by sulfuric acid. The surfaces of chitosan membranes before and after crosslinking were characterized by using FTIR‐ATR, X‐ray photoelectron spectroscopy (XPS), and atomic‐force microscopy (AFM) techniques. The XPS data suggest that the surface composition of crosslinked membrane does not change significantly with respect to uncrosslinked membrane and the most important evidence is a certain amount of sulfur, coming from the crosslinker. The result from FTIR‐ATR data shows the effectiveness of the crosslinking procedure by the shift in amide I and amide II bands. The investigation of membrane surfaces by AFM indicates that the crosslinking procedure modifies the surface morphology of chitosan. After crosslinking, the surface topography becomes more homogenous and relatively flat. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Trichloroacetic acid‐imprinted polypyrrole film and its property in piezoelectric quartz crystal microbalance and electrochemical sensors to application for determination of haloacetic acids disinfection by‐product in drinking water
Authors: Suedee Roongnapa , Intakong Wimon , Lieberzeit Peter A. , Wanichapichart Pikul , Chooto Pipat , Dickert Franz L. 
Published: September 2007

AbstractA molecularly trichloroacetic acid (TCAA) imprinted non‐crosslinked polypyrole (TCAA‐MIPpy) has been successfully prepared and evaluated in its properties for both piezoelectric quartz crystal microbalance (QCM) and electrochemical means of detection, and application of such sensors for determination of haloacetic acid concentrations in water. Haloacetic acid selectivity was demonstrated in gravimetric or in electrochemical sensors via either cyclic voltammetric or inter‐digitated conductometric (IDC) analyses studies upon comparison with nonimprinted polypyrrole and TCAA‐imprinted polypyrrole. The measurement results with all these systems revealed that the prepared molecularly imprinted polymer can recognize TCAA well from structurally similar compounds. The TCAA‐MIPpy incorporated with only the IDC transduction system produced the specific signal for TCAA detection in aqueous environment, which is useful for the quantifying TCAA disinfection by‐product in water. The analytical application for determination of TCAA in real‐life samples was readily achieved with the incorporation of TCAA‐MIPpy in the IDC analysis system, the results revealing the high sensitivity and selectivity of the method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
The factors of speeds and loads on the tribological properties of PVA‐H/HA composites
Authors: Wu Gang , Wang Chengtao , Zhang Wenguang 
Published: September 2007

AbstractPoly (vinyl alcohol) (PVA)/Hydroxy apatite (HA) composite prepared from aqueous solution of the polymer and dimethylsulfoxide (DMSO) by freezing and thawing method are developing to repair or replace articular cartilage. In the present study, the tribological behaviors of this composite were investigated in a three‐factor, three‐level designed experiment using an improved four‐ball tester. Factors include sliding velocity, applied load, and HA content of composite. Friction coefficient of the PVA‐H/HA was found to depend significantly on load and sliding velocity, while HA content had small effects on the friction coefficient of PVA‐HA composite. We also found that wear loss of PVA‐H/HA increased sharply with the increasing loads and HA content of specimen. Increased HA content from 0.5% to 1.5% resulted in an increasing of 355% in wear loss, while increasing sliding velocity slightly decreases wear loss of specimen. We also found some correlation between friction coefficient and wear loss of specimen under the given condition. These results may be useful in the tribological design of PVA‐H/HA composite for both low wear and low friction using as artificial cartilage substitutes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Polypeptide/layered silicate nanocomposites using fish‐based collagen peptide: Effect of crosslinking and chain extension of the collagen peptide
Authors: Teramoto Naozumi , Uchiumi Daisuke , Niikura Ayako , Someya Yoshihiro , Shibata Mitsuhiro 
Published: September 2007

AbstractCollagen peptide (ColP), which was extracted from fish scale with hot water was mixed with glutaraldehyde (GA) in water in the presence of sodium montmorillonite (MMT), and subsequent heat treatment gave the ColP crosslinked by GA (GA‐ColP)/MMT composite films. Also, the ColP was chain extended by the use of a water‐soluble carbodiimide and 1‐hydroxybenzotriazole to give a chain‐extended collagen peptide (CE‐ColP). The composite films based on the CE‐ColP and MMT were prepared by solution‐casting method. The XRD and TEM analyses of their composites revealed that the exfoliated nanocomposites whose silicate layers are finely dispersed are formed for CE‐ColP/MMT, and that the degree of exfoliation decreases with the increasing feed amount of GA for GA‐ColP/MMT. Although GA‐ColP/MMT films were very brittle, CE‐ColP/MMT films were relatively tough. Storage moduli of the CE‐ColP/MMT films were higher than that of CE‐ColP film, and increased with increasing inorganic content. The 10% weight loss temperature of GA‐ColP (325°C) was higher than that of CE‐ColP (302°C), and the addition of MMT to GA‐ColP and CE‐ColP resulted in a slight rise of the degradation temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Influence of nanoclay on properties of HDPE/wood composites
Authors: Lei Yong , Wu Qinglin , Clemons Craig M. , Yao Fei , Xu Yanjun 
Published: September 2007

AbstractComposites based on high density polyethylene (HDPE), pine flour, and organic clay were made by melt compounding and then injection molding. The influence of clay on crystallization behavior, mechanical properties, water absorption, and thermal stability of HDPE/pine composites was investigated. The HDPE/pine composites containing exfoliated clay were made by a two‐step melt compounding procedure with the aid of a maleated polyethylene (MAPE). The use of 2% clay decreased the crystallization temperature (Tc), crystallization rate, and the crystallinity level of the HDPE/pine composites, but did not change the crystalline thickness. When 2% MAPE was added, the crystallization rate increased, but the crystallinity level was further lowered. The flexural and tensile strength of HDPE/pine composites increased about 20 and 24%, respectively, with addition of 1% clay, but then decreased slightly as the clay content increased to 3%. The tensile modulus and tensile elongation were also increased with the addition of 1% clay. The impact strength was lowered about 7% by 1% clay, but did not decrease further as more clay was added. The MAPE improved the state of dispersion in the composites. Moisture content and thickness swelling of the HDPE/pine composites was reduced by the clay, but the clay did not improve the composite thermal stability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Morphological, thermal, and mechanical studies of film elaborated with the blend low‐density polyethylene and chemical‐modified banana starch
Authors: Torres Apolonio Vargas , Zamudio‐Flores Paul Baruk , Salgado‐Delgado René , Bello‐Pérez Luis Arturo 
Published: September 2007

AbstractFilms were prepared by extrusion acetylated and oxidized banana starches at different concentration mixed with low‐density polyethylene. Morphological, mechanical, and thermal characteristics of the films were tested. Irregularities in the films prepared with native and oxidized banana starches were observed by scanning electron microscopy. This pattern is maybe due to the incompatibility between both polymers. However, films elaborated with acetylated banana starch showed a smooth surface. The tensile strength and elongation at break decreased when starch level in the blend increased. An inverse pattern was showed for elastic module. The effect on mechanical properties was more notorious in those films elaborated with the acetylated and oxidized banana starches. Two thermal transitions were observed by differential scanning calorimetry, the principal transition at ∼ 111°C was due to disorganization of the low‐density polyethylene. Enthalpy value associated to that principal transition was higher in the films elaborated with acetylated banana starch, showing higher compatibility between both polymers. The use of biodegradable polymers such as chemically modified banana starch might be feasible for elaboration of films with adequate mechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation and characterization of biaxially oriented polypropylene film with high molecular orientation in the machine direction by sequential biaxial stretching
Authors: Masuda Jun'ichi , Ohkura Masatoshi 
Published: September 2007

AbstractNovel approach of applying the ternary polymer blend of long‐chain branched polypropylene (LCB‐PP), conventional polypropylene (PP), and hydrogenated polydicyclopentadiene (hDCPD) has been employed to tensilize biaxially oriented polypropylene (BOPP) film in the machine direction (MD) by successive sequential biaxial stretching method. It is found that the addition of LCB‐PP improves the MD stretchability of the BOPP film of PP/hDCPD blend. Depending on the content of LCB‐PP, LCB‐PP/PP/hDCPD ternary blend could be biaxially stretched up to the MD stretching ratio (MDX) of 12 without film breakage whereas that of PP (conventional BOPP film) resulted in the MDX up to 6. This excellent MD stretchability enabled to tensilize the BOPP film in the MD, where Young's modulus in the MD could be increased up to 4.9 GPa, twice higher than that of conventional BOPP film. The orientation of total molecular chains and that of crystalline molecular chains were evaluated by in‐plane distribution of refractive indices and wide‐angle X‐ray diffraction, respectively. The results are discussed from the viewpoint of deformation behavior during stretching process. Moreover, the resultant film had a dimensional stability substantially equivalent to that of conventional one, in spite of the higher stretching ratio, and an improved moisture barrier property. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Impacts of coating with various varnishes after impregnation with boron compounds on the combustion properties of Uludag fir
Authors: Atar Musa , Keskin Hakan 
Published: September 2007

AbstractThis study was performed to determine the effects of varnishing after impregnation with boron compounds on combustion properties of Uludag Fir. For this purpose, the test samples prepared from Uludag fir (Abies Bornmülleriana Mattf.) wood were impregnated according to ASTM D 1413‐99 with boric acid (Ba) and borax (Bx) by vacuum technique. After impregnation, surfaces were coated by cellulosic (Cv), synthetic (Sn), polyurethane (Pu), waterborne (Wb), acrylic (Ac), and acid hardening (Ah) varnishes in accordance to ASTM D 3023. Combustion properties of samples after varnishing process were determined according to ASTM E 160‐50. According to material and process type, combustion temperature was highest in without flame source combustion (WFSC), Bx, and Wb but the lowest in flame source combustion (FSC), Ba, and Pu. For the combination of combustion type, impregnation material and varnish type, combustion temperature was the highest in WFSC + Ba + Wb combination but the lowest in WFSC + Ba + Cv combination. Consequently, the tested varnishes showed an increasing impact but boron compounds (Ba and Bx) showed a decreasing impact on combustion properties of Uludag fir wood. In consequence, for usage areas having a high risk of fire, impregnation of wood material with boron compounds before varnishing will decrease combustion temperature and provide security. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Structure and properties of blend fibers prepared from alginate and konjac glucomannan
Authors: Fan Lihong , Zhu Huibin , Zheng Hua , Xu Yongmei , Zhang Chaocan 
Published: September 2007

AbstractAlginate/konjac glucomannan (KGM) blend fibers, prepared by spinning their mixture solution through a viscose‐type spinneret into a coagulating bath containing aqueous CaCl2 and ethanol, were studied for structure and properties with the aid of infrared spectroscopy and scanning electron micrography. The analyses indicated a good miscibility between alginate and KGM because of the strong interaction. The dry tensile strength of the blend fiber increased with increase in KGM content. The wet tensile strength of fibers decreased with increase in KGM content. The optimal breaking elongations in dry and wet state were obtained when the KGM contents were 30 and 10 wt %, respectively. The most obvious change is that the introduction of KGM in the blend fiber can dramatically improve water‐retention properties of blend fiber compared with pure alginate fiber. The fibers treated with aqueous solution of silver nitrate have good antibacterial activity to Staphylococcus aureus. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Electrical conductivity and mechanical properties of polyaniline/natural rubber composite fibers
Authors: Sukitpaneenit Panu , Thanpitcha Tuspon , Sirivat Anuvat , Weder Christoph , Rujiravanit Ratana 
Published: September 2007

AbstractElectrically conducting elastomer fibers based on natural rubber (NR) and up to 10% w/w polyaniline (PANI) in its emeraldine base (EB) form were fabricated by a wet spinning process. The resulting fibers at various PANI contents were doped by immersion in aqueous HCl solution, which converted the PANI to the electrically conductive emeraldine salt (ES) form. The morphology of the composite fibers was studied by scanning electron microscopy (SEM). PANI particles were inhomogeneously distributed in the NR matrix. The electrical conductivity of the fibers increased with the increasing PANI‐ES content and leveled off at a value of around 10−3 S/cm at PANI‐ES concentration of 5% w/w. The fibers retained most of their elasticity upon doping, while the tenacity was somewhat reduced. Gratifyingly, the electrical conductivity of the new elastomer fibers was preserved upon elongational deformation, even if strains as large as 600% were applied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Egghe's construction of Lorenz curves resolved
Authors: Burrell Quentin L. 
Published: September 2007

AbstractIn a recent article (Burrell, 2006), the author pointed out that the version of Lorenz concentration theory presented by Egghe (2005a, 2005b) does not conform to the classical statistical/econometric approach. Rousseau (2007) asserts confusion on our part and a failure to grasp Egghe's construction, even though we simply reported what Egghe stated. Here the author shows that Egghe's construction rather than “including the standard case,” as claimed by Rousseau, actually leads to the Leimkuhler curve of the dual function, in the sense of Egghe. (Note that here we distinguish between the Lorenz curve, a convex form arising from ranking from smallest to largest, and the Leimkuhler curve, a concave form arising from ranking from largest to smallest. The two presentations are equivalent. See Burrell, 1991, 2005; Rousseau, 2007.)
Adaptive technology for e‐learning: principles and case studies of an emerging field
Authors: Scalise Kathleen , Bernbaum Diana J. , Timms Mike , Harrell S. Veeragoudar , Burmester Kristen , Kennedy Cathleen A. , Wilson Mark 
Published: September 2007

AbstractThis article discusses the rapidly emerging field of computer‐based assessment for adaptive content in e‐learning (National Research Council, 2001), which we call differentiated e‐learning. In e‐learning products, a variety of assessment approaches are being used for such diverse purposes as adaptive delivery of content, individualizing learning materials, dynamic feedback, cognitive diagnosis, score reporting, and course placement (Gifford, 2001). A recent paper at the General Teaching Council Conference in London, England, on teaching, learning, and accountability described assessment for personalized learning through e‐learning products as a “quiet revolution” taking place in education (Hopkins, 2004). In our study, we examine approaches for the use of assessment evidence in e‐learning in four case studies. The products in the case studies were selected for exhibiting at least one exemplary aspect regarding assessment and measurement. The principles of the Berkeley Evaluation & Assessment Research Center Assessment System (Wilson & Sloane, 2000) are used as a framework of analysis for these products with respect to key measurement principles.
Extended Architectures Constructed from Sandwich Tetra‐Metal‐Substituted Polyoxotungstates and Transition‐Metal Complexes
Authors: Zheng Shou‐Tian , Wang Ming‐Hui , Yang Guo‐Yu 
Published: September 2007

AbstractThree unprecedented 2D architectures made up of sandwich‐type tetra‐metal‐substituted polyoxotungstates and transition‐metal complexes, [Cu(dien)(H2O)]2{[Cu(dien)(H2O)]2‐[Cu(dien)(H2O)2]2[Cu4(SiW9O34)2]}⋅ 5H2O (1; dien=diethylenetriamine), [Zn(enMe)2(H2O)]2{[Zn(enMe)2]2[Zn4‐ (HenMe)2(PW9O34)2]}⋅8H2O (2; enMe =1,2‐diaminopropane), and [Zn(enMe)2‐(H2O)]4[Zn(enMe)2]2{(enMe)2{[Zn‐ (enMe)2]2[Zn4(HSiW9O34)2]}{[Zn‐ (enMe)2(H2O)]2[Zn4(HSiW9O34)2]}}⋅ 13H2O (3) were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single‐crystal X‐ray diffraction. Compound 1 consists of anions [Cu4(SiW9O34)2]12− linked by copper complexes into a 2D structure, whereas 2 is constructed from novel inorganic–organic hybrid anions [Zn4(HenMe)2(PW9O34)2]8− linked by zinc complexes into a 2D structure. The most interesting is the unique 2D network 3, which consists of anions [Zn4(PW9O34)2]10− with two types of bridging groups: zinc complexes and enMe ligands.
Spectrum–Structure Relationship in Carbohydrate Vibrational Circular Dichroism and Its Application to Glycoconjugates
Authors: Taniguchi Tohru , Monde Kenji 
Published: September 2007

AbstractPreliminary reports of the nature of the vibrational circular dichroism (VCD) peak at around 1145 cm−1, which is characteristic of axial glycosidic sugars and is called the glycoside band (J. Am. Chem. Soc. 2004, 126, 9496), have been throughly examined. Through systematic carbohydrate measurements, it was found that the sign of the glycoside band reflects not only the anomeric configuration but also the pyranose conformation. Isotope and theoretical studies characterized its vibrational mode as C1–H1 deformation coupled with C1–O1 stretching, which indicates its applicability to more‐complicated glycoconjugates. In this study, for the first time, carbohydrate VCD spectra were reliably predicted by means of density functional theory (DFT) calculations. The VCD technique was applied to glycopeptides, and simultaneous analysis of both the carbohydrate and aglycan parts was carried out.