bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flame‐Synthesized Ceria‐Supported Copper Dimers for Preferential Oxidation of CO
Authors: Kydd Richard , Teoh Wey Yang , Wong Kenneth , Wang Yong , Scott Jason , Zeng Qing‐Hua , Yu Ai‐Bing , Zou Jin , Amal Rose 
Published: December 2008

AbstractRapid synthesis of CuCeO2 catalysts by flame spray pyrolysis produces highly active Cu dimer morphologies without the need for additional catalyst pretreatment. The active Cu component is enriched onto the CeO2 surface at concentrations higher than the nominal loading with no evidence of amorphous or crystalline CuO phase. Increasing the Cu content results in a morphological transition from isolated Cu monomers to oxygen‐bridged dimers and an associated increase in oxygen vacancy concentration. Dimer‐containing CuCeO2 catalysts display high levels of activity and selectivity in the low‐temperature preferential oxidation of CO. Experimental measurements and simulations suggest that the geometry of the dimer presents a comparatively ionic CuO bond at the catalyst surface. Further studies indicate that these ionic dimer species promote preferential CO oxidation at lower temperatures than observed for monomeric Cu species. This is the first report to explicitly propose and demonstrate that the structural distortion associated with the formation of Cu dimers directly induces increased bond ionicity at the catalyst surface and that these changes are responsible for improved catalytic activity.
The relationship between chronic rhinosinusitis and occupation: The 1998, 2001, and 2005 Korea National health and nutrition examination survey (KNHANES)
Authors: Koh Dong‐Hee , Kim Hyoung‐Ryoul , Han Soon‐Sil 
Published: December 2008

AbstractObjectivesWe examined the relationship between chronic rhinosinusitis and occupation.MethodsWe analyzed data from the 1998, 2001, and 2005 Korea National Health and Nutrition Examination Survey (KNHANES). Men and women aged 20–59 who participated in the three KNHANES were included to analyze the relationship between chronic rhinosinusitis and occupation. Trained interviewers visited subjects' homes and administered a standardized questionnaire on diagnosed diseases. Subjects were asked if they had experienced chronic rhinosinusitis during the previous year or had had rhinosinusitis for three or more consecutive months. Occupational classification followed the major groups of the Korean Standard Classification of Occupations (KSCO). We calculated the prevalence ratios (PRs) of chronic rhinosinusitis by major groups compared with clerical workers in the three KNHANES. Poisson regression with robust standard error was conducted, adjusting for age in 10‐year strata.ResultsThere were significantly increased PRs of chronic rhinosinusitis in plant and machinery operators and assemblers, elementary occupations, crafts and related trade workers, and the unemployed.ConclusionsThese results support the relationship between chronic rhinosinusitis and occupational exposure at the macro level. Am. J. Ind. Med. 52:179–184, 2009. © 2008 Wiley‐Liss, Inc.
Coat condition of ringtailed lemurs,Lemur cattaat Berenty Reserve, Madagascar: I. differences by age, sex, density and tourism, 1996–2006
Authors: Jolly Alison 
Published: December 2008

AbstractAn index of coat condition can be a non‐invasive tool for tracking health and stress at population level. Coat condition in ringtailed lemurs,Lemur catta,was recorded during September–November birth seasons of 1996, 1997, 1999, and 2001–2006 at Berenty Reserve, Madagascar. Condition was scored on a scale from 0: full, fluffy coat with guard hairs present, to 5: half or more of body hairless. Adult males did not differ overall from adult females. Coats were worse in adults than in 2‐year‐old subadults; 1‐year‐old juveniles were intermediate. Mothers and adult males lost coat condition as the season progressed: non‐mother females maintained condition. Years 1999–2002 scored better coats than either 1996–1997 or 2003–2006. Lemurs in high population density areas had worse coats than in natural forest, but tourist presence had less effect than density. Monitoring coat condition in an apparently healthy population reveals differences between population segments, and in a forest fragment with limited immigration or emigration it can track progressive changes, correcting impressions of progressive improvement or degradation over time. Above all it gives a baseline for response to climate changes or eventual pathology. Am. J. Primatol. 71:191–198, 2009. © 2008 Wiley‐Liss, Inc.
High assimilation of the sacrum in a sample of American skeletons: Prevalence, pelvic size, and obstetrical and evolutionary implications
Authors: Tague Robert G. 
Published: December 2008

AbstractHigh assimilation sacrum is fusion of the caudal‐most lumbar vertebra to the first sacral vertebra. Previous studies have shown that high assimilation is associated with clinical problems, including obstetrical difficulty. This study used adult American males (n = 1,048) and females (n = 1,038) of the Hamann–Todd and Terry skeletal collections to determine the prevalence of high assimilation and its effect on pelvic size, and to consider the obstetrical and evolutionary implications of high assimilation. The prevalence of high assimilation in this sample is 6.3%, with males and females not differing significantly from one another in their prevalence. This prevalence is near the median for that reported in 41 other samples. In both males and females, individuals with high assimilation have significantly longer anteroposterior and posterior sagittal diameters of the inlet, and shorter sacrum compared to those with a nonassimilated sacrum. Females with high assimilation have a significantly narrower sacral angulation (i.e., reduced inclination of ventral axis of sacrum), and shorter posterior sagittal diameter of the outlet compared to those with a nonassimilated sacrum. A short posterior sagittal diameter of the outlet is associated with childbirth difficulty. As high assimilation is partial homeotic transformation of a lumbar vertebra, this study supports previous research that homeotic transformation of vertebrae is selectively disadvantageous. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Investigating cultural heterogeneity in San Pedro de Atacama, northern Chile, through biogeochemistry and bioarchaeology
Authors: Knudson Kelly J. , Torres‐Rouff Christina 
Published: December 2008

AbstractIndividuals living in the San Pedro de Atacama oases and the neighboring upper Loa River Valley of northern Chile experienced the collapse of an influential foreign polity, environmental decline, and the appearance of a culturally distinct group during the Late Intermediate Period (ca. AD 1,100–1,400). We investigate cultural heterogeneity at the Loa site of Caspana through analyses of strontium and oxygen isotopes, cranial modification styles, and mortuary behavior, integrating biological aspects of identity, particularly geographic origins, with cultural aspects of identity manifested in body modification and mortuary behavior. We test the hypothesis that the Caspana population (n = 66) represents a migrant group, as supported by archeological and ethnographic evidence, rather than a culturally distinct local group. For Caspana archeological human tooth enamel, mean 87Sr/86Sr = 0.70771 ± 0.00038 (1σ, n = 30) and mean δ18Oc(V‐PDB) = −3.9 ± 0.6‰ (1σ, n = 16); these isotopic data suggest that only one individual lived outside the region. Material culture suggests that the individuals buried at Caspana shared some cultural affinity with the San Pedro oases while maintaining distinct cultural traditions. Finally, cranial modification data show high frequencies of head shaping [92.4% (n = 61/65)] and an overwhelming preference for annular modification [75.4% (n = 46/61)], contrasting sharply with practices in the San Pedro area. Based on multiple lines of evidence, we argue that, rather than representing a group of altiplano migrants, the Caspana population existed in the region for some time. However, cranial modification styles and mortuary behavior that are markedly distinct from patterns in surrounding areas raise the possibility of cultural heterogeneity and cultural fissioning. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Masticatory loading and bone adaptation in the supraorbital torus of developing macaques
Authors: Kupczik K. , Dobson C.A. , Crompton R.H. , Phillips R. , Oxnard C.E. , Fagan M.J. , O'Higgins P. 
Published: December 2008

AbstractResearch on the evolution and adaptive significance of primate craniofacial morphologies has focused on adult, fully developed individuals. Here, we investigate the possible relationship between the local stress environment arising from masticatory loadings and the emergence of the supraorbital torus in the developing face of the crab‐eating macaque Macaca fascicularis. By using finite element analysis (FEA), we are able to evaluate the hypothesis that strain energy density (SED) magnitudes are high in subadult individuals with resulting bone growth in the supraorbital torus. We developed three micro‐CT‐based FEA models of M. fascicularis skulls ranging in dental age from deciduous to permanent dentitions and validated them against published experimental data. Applied masticatory muscle forces were estimated from physiological cross‐sectional areas of macaque cadaveric specimens. The models were sequentially constrained at each working side tooth to simulate the variation of the bite point applied during masticatory function. Custom FEA software was used to solve the voxel‐based models and SED and principal strains were computed. A physiological superposition SED map throughout the face was created by allocating to each element the maximum SED value from each of the load cases. SED values were found to be low in the supraorbital torus region throughout ontogeny, while they were consistently high in the zygomatic arch and infraorbital region. Thus, if the supraorbital torus arises to resist masticatory loads, it is either already adapted in each of our subadult models so that we do not observe high SED or a lower site‐specific bone deposition threshold must apply. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Formkontrolle bei der Synthese von Metallnanokristallen: einfache Chemie, komplexe Physik?
Authors: Xia Younan , Xiong Yujie , Lim Byungkwon , Skrabalak Sara E. 
Published: December 2008

AbstractNanokristalle sind von grundlegender Bedeutung in der modernen Wissenschaft und Technologie. Die Eigenschaften eines Nanokristalls lassen sich über seine Form beeinflussen und auf eine bestimmte Anwendung hin zuschneiden. Ziel dieses Aufsatzes ist es, einen umfassenden Überblick über den aktuellen Stand der Forschung auf dem Gebiet der formkontrollierten Synthese von Metallnanokristallen zu geben. Nach einer kurzen Einleitung über die Prinzipien von Kristallkeimbildung und ‐wachstum diskutieren wir einzelne Arten von Nanokristallformen und betrachten verschiedene experimentelle Parameter, über die die Keimbildung und das Wachstum von Metallnanokristallen in der Lösungssynthese gezielt manipuliert werden kann. Wir erläutern diese Methoden anhand von Beispielen, wo zumindest ein Grundverständnis für die beobachtete Formkontrolle vorhanden ist. Schließlich stellen wir Anwendungen vor, bei denen die Formkontrolle von Metallnanokristallen ein entscheidender Faktor ist, und beenden den Aufsatz mit einem persönlichen Ausblick auf künftig zu erwartende Entwicklungen auf diesem Gebiet.
Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?
Authors: Xia Younan , Xiong Yujie , Lim Byungkwon , Skrabalak Sara E. 
Published: December 2008

AbstractNanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape‐controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution‐phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape‐controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.
Prediction and experimental verification of bubble and processing characteristics in blown‐film extrusion
Authors: Majumder Khokan Kanti , Ding Yan , Hobbs Graham , Bhattacharya Sati N 
Published: December 2008

AbstractBlown‐film modeling is useful to the flexible packaging industry for predicting process and bubble characteristics, such as freeze line height (FLH), bubble diameter, and film thickness. The use of a suitable rheological equation to describe material properties is critical in simulating the blown‐film process. In this article, we present an improved rheological constitutive equation, which incorporates more realistic parameters of stress and deformation properties of the materials by combining the Hookean model with the Phan‐Thien Tanner (PTT) model. The proposed PTT–Hookean model is aimed at enhancing the viscoelastic behavior of the melt during biaxial stretching in the blown‐film extrusion. Predictions of the blown‐film bubble characteristics and FLH obtained with the PTT–Hookean model agreed well with the experimental data of this study and previous studies with different materials and different die geometries. The justification for combining the Hookean model with the PTT model in the blown‐film process is also reported here. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Influence of impact load‐temperature conformity on toughening of poly(vinyl chloride) by core‐shell rubber particles
Authors: Javadi A. , Mohammadi N. , Garmabi H. , Pourrahimi A. M. , Mashayekhi J. 
Published: December 2008

AbstractThe work focused on the elucidation of several key parameters in toughening poly(vinyl chloride) (PVC) by the methyl methacrylate–butadiene–styrene (MBS) core‐shell particles. Accordingly, blends containing various weight percent of the MBS particles were prepared and characterized by dilute solution viscometry, dynamic light scattering, dynamic mechanical thermal analysis, transmission electron microscopy, and temperature variable impact test. The results showed PVC/MBS solution miscibility in almost all compositions with their maximum thermodynamic affinities at about 17 and 67 wt % of MBS in tetrahydrofurane (THF). In addition, MBS weight percent increase in its blend with the PVC above 10 led to severe impact energy raise with eventual leveling at about 17 wt %. Furthermore, blend toughness and its components miscibility in solution increased in parallel up to 20 wt % of MBS particles. On the other hand, blend toughness declined with test temperature decrease toward impact modifier core Tg at about −30°C even for the sample with 20 wt % of the MBS particles. Finally, the brittle‐ductile transition of the blend containing 20 wt % of the MBS particles comparison with its matrix tan δ‐temperature correlation implied 2500 J/m impact energy equivalence with 90°C sample temperature rise in secondary relaxation activation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation, characterization, and salicylic acid release behavior of chitosan/poly(vinyl alcohol) blend microspheres
Authors: Şanlı Oya , Karaca İlker , Işıklan Nuran 
Published: December 2008

AbstractBlend microspheres of chitosan (CS) with poly(vinyl alcohol) (PVA) were prepared as candidates for oral delivery system. CS/PVA microspheres containing salicylic acid (SA), as a model drug, were obtained using the coacervation‐phase separation method, induced by addition of a nonsolvent (sodium hydroxide solution) and then crosslinked with glutaraldehyde (GA) as a crosslinking agent. The microspheres were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy. Percentage entrapment efficiency, particle size, and equilibrium swelling degree of the microsphere formulations were determined. The results indicated that these parameters were changed by preparation conditions of the microspheres. Effects of variables such as CS/PVA ratio, pH, crosslinker concentration, and drug/polymer (d/p) ratio on the release of SA were studied at three different pH values (1.2, 6.8, and 7.4) at 37°C. It was observed that SA release from the microspheres increased with decreasing CS/PVA ratio and d/p ratio whereas it decreased with the increase in the extent of crosslinking. It may also be noted that drug release was much higher at pH 1.2 than that of at pH 6.8 and 7.4. The highest SA release percentage was obtained as 100% for the microspheres prepared with PVA/CS ratio of 1/2, d/p ratio of 1/2, exposure time to GA of 5 min, and concentration of GA 1.5% at the end of 6 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Functionalization of polymethylhydrosiloxane gels with an allyl ureido benzocrown ether derivative: Complexation properties
Authors: Nasr Gihane , Bestal Hanan , Barboiu Mihail , Bresson Bruno , Thami Thierry 
Published: December 2008

AbstractCrosslinked polymethylhydrosiloxane (PMHS) thin films prepared by sol–gel polycondensation have been functionalized by Pt‐catalyzed hydrosilylation of SiH groups with an allyl ureido crown ether precursor. To this purpose, both 4′‐allylurea‐benzo‐15‐crown‐5 (1) and 1‐allyl‐3‐propyl‐urea (2) were synthesized and characterized. We have shown that competitive side‐reactions occurred following hydrosilylation due to the hydrolysis of part of the SiH groups resulting in the formation of new crosslinks Si(CH3)O3/2 as shown by solid‐state 29Si‐NMR. This is explained by the deactivation of the Pt catalyst toward hydrosilylation by amide groups. For thin films (∼ 1 μm) prepared on silicon wafers, a quantitative method based on FT‐IR transmission spectroscopy was used to measure the crosslinking density of the network, and the percentage of functionalization (SiC %) following hydrosilylation. The results are discussed in relation to the mesh size of the network, and the diffusion of alkenes and water molecules within lightly crosslinked PMHS gels obtained by varying the amount of triethoxysilane crosslinker (mol %) from 15 to 1%. The self‐organization properties of ureido groups by H‐bonding were studied by FT‐IR for the functionalized thin films. The complexation properties of the crown ether 1‐functionalized thin films were evidenced by using FT‐IR following diffusion‐reactions of NaSCN and KSCN salts in CHCl3 : MeOH solvent mixtures within thin films. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Separation of gold(III) ions from copper(II) and zinc(II) ions using thiourea–formaldehyde or urea–formaldehyde chelating resins
Authors: Ertan Elif , Gülfen Mustafa 
Published: December 2008

AbstractThiourea–formaldehyde (TF) and urea–formaldehyde (UF) chelating resins were synthesized and these resins were used in the separation of gold(III) ions from copper(II) and zinc(II) base metal ions. In the experimental studies, the effect of acidity on gold(III) uptake and gold(III) adsorption capacities by batch method, and loading and elution profiles of gold(III) ions, gold(III), copper(II), and zinc(II), dynamic adsorption capacities and the stability tests of TF and UF resins by column method were examined. By batch method, the optimum acidities were found as pH 2 and 0.5M HCl, and gold(III) adsorption capacities in the solutions including copper(II) and zinc(II) ions were obtained as 0.088 and 0.151 meq Au(III)/g for UF and TF resins, respectively. On the other hand, by column method, the dynamic adsorption capacities were calculated as 0.109 meq Au(III)/g with TF, 0.023 meq Au(III)/g with UF, 0.015 meq Cu(II)/g with TF, 0.0057 meq Cu(II)/g with UF, and under 6.1 × 10−5 meq Zn(II)/g with TF or UF. TF resin was more effective in the separation and the concentration of gold(III) ions from copper(II) and zinc(II) ions than UF resin. It was seen that sulfur atoms contributed the gold(III) adsorption comparing with oxygen atoms. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and physical properties of wood/polypropylene/clay nanocomposites
Authors: Lee Hongkwan , Kim Dae Su 
Published: December 2008

AbstractWood plastic composites (WPCs) are attracting a lot of interests because they are economic, environmentally friendly, and show fairly good performance. To improve the performance of a wood/polypropylene (PP) composite, an organoclay was incorporated as a nanosize filler in this work. WPCs were prepared by melt blending followed by compression molding, and their performance was investigated by universal testing machine, izod impact tester, dynamic mechanical analyzer, thermal mechanical analyzer, differential scanning calorimetry, and TGA. Maleic anhydride polypropylene copolymer (MAPP) was used to increase compatibility between the PP matrix and wood particles and also improve the dispersion and exfoliation of the organoclay in the PP matrix. XRD analysis showed that the matrix of the WPCs with organoclay had intercalated structure. The SEM images of the WPCs with MAPP showed improved interfacial adhesion between the matrix and wood particles. The degree of water absorption increased with immersion time, but it could be restrained by incorporating MAPP. The performance of the WPCs was improved by the incorporation of the organoclay. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Piezoresistive behavior of epoxy matrix‐carbon fiber composites with different reinforcement arrangements
Authors: Boschetti‐de‐Fierro A. , Pardey R. , Savino V. , Müller A. J. 
Published: December 2008

AbstractIn this work, the self‐monitoring capability of epoxy matrix‐carbon fiber composites has been studied. Different concentrations and arrangements of reinforcements were used, including random chopped, unidirectional and bi‐directional continuous carbon fibers, weaved and nonweaved. Mechanical properties were determined by uniaxial tensile tests. The composite electric to mechanical behavior was established by determining its electrical resistivity variation as a function of the stress‐strain curve. It was observed that the composites electrical resistance increased during tensile tests, a trend that indicates piezoresistive behavior. The increase was linear for the chopped reinforced composites, while it exhibits different slopes in the continuous reinforced composites. The initial smaller slope corresponds mainly to separation of the 90° oriented fibers and/or transversal cracking of the matrix, whereas the latter higher slope is caused by fiber fracture. The results demonstrated how each reinforcement configuration exhibited a unique and typical electrical response depending on the specific reinforcement, which might be appropriate either for strain‐monitoring or damage‐monitoring. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009