bluuebunny/crossref_metadata_2025_split huggingface dataset:
Swelling kinetics of linseed oil‐based polymers
Authors: Sharma Vinay , Banait J. S. , Kundu P. P. 
Published: November 2008

AbstractKinetics of swelling and sorption behavior of copolymers (based on linseed oil, styrene, divinylbenzene, and acrylic acid via cationic and thermal polymerization) is studied in tetrahydrofuran (THF) at different temperatures. The values of n in the transport equation are found to be below 0.4, showing non‐Fickian or pseudo‐Fickian transport in the polymers. The dependence of diffusion coefficient on the composition and temperature has also been studied for the linseed oil‐based polymers. The diffusion coefficient in cationic samples decreases with an increase in the oil contents in the samples. In case of thermal samples, the diffusion coefficient first increases up to 30% oil contents and then decreases. The diffusion coefficient decreases with an increase in temperature for all of the linseed oil polymer samples. The sorption coefficient increases with an increase in the oil contents for all samples. The crosslink density (calculated from the THF swelling) ranges from 20.16 to 92.34 × 106 mol/cm3 for cationic samples and 20.62 to 86.01 × 106 mol/cm3 for thermal samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
TPA‐PPEs – New alternating donor copolymers for potential application in photovoltaic devices
Authors: Blankenburg Lars , Hager Martin D. , Sell Stephan , Sensfuss Steffi , Klemm Elisabeth 
Published: November 2008

AbstractA series of phenyleneethynylene copolymers with triphenylamine units as hole‐transporting moieties (TPA‐PPEs) were synthesized by the palladium‐catalyzed cross‐coupling polycondensation of diethynyltriphenylamines and selected dihalogen comonomers, for instance substituted benzene, thiophene, benzothiadiazole, or anthracene. Incorporation of the electron‐rich amino group into the PPE backbone does not interrupt the main chain conjugation. Furthermore, it has a decreasing effect on the oxidation potential, thus makes these polymers interesting as hole‐injection/hole‐transporting materials. The chemical structure of the new alternating copolymers was confirmed by 1H and 13C NMR spectroscopy and elemental analysis and gel‐permeation chromatography (GPC; THF, Mn ≈ 15,000–30,000 g/mol) was conducted. Furthermore, their optical properties were investigated by UV/vis spectroscopy. The TPA‐PPEs exhibit absorption maxima at around 400 nm (π‐π*), except anthracene containing copolymer 3f (λmax = 514 nm in THF) and benzothiadiazole containing one 3g (λmax = 503 nm in THF). The TPA copolymers have oxidation potentials about 1.1 V (Ag/AgCl). They are good photoconducting materials (3a: IPhoto = 4 × 10−10 A at 425 nm (400 V), 3g: IPhoto = 1.3 × 10−11 A at λmax = 500 nm (20 V)) and show emission after excitation at around 450 nm (560 nm 3f). Their application in nonoptimized polymer solar cells (bulk heterojunction) led to power conversion efficiencies of around 1–1.8% after illumination with 100 mW/cm2 of AM1.5. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Improved mechanical properties of NR/EPDM blends by controlling the migration of curative and filler via reactive processing technique
Authors: Sahakaro Kannika , Pongpaiboon Chararat , Nakason Charoen 
Published: November 2008

AbstractSimple blending of natural rubber/ethylene–propylene–diene rubber (NR/EPDM) generally results in inferior mechanical properties because of curative migration and their differences for filler affinity. In this work, the 70/30 and 50/50 NR/EPDM blends prepared by reactive processing techniques were investigated and compared with the simple, nonreactive blends. The reactive blend compounds were prepared by preheating EPDM, containing all curatives to a predetermined time related to their scorch time prior to blending with NR. For the 70/30 gum blends, four types of accelerators were studied: 2,2‐mercaptobenzothiazole (MBT), 2,2‐dithiobis‐ (benzothiazole) (MBTS), N‐cyclohexyl‐2‐benzothiazolesulfenamide (CBS), and N‐tert‐butyl‐2‐benzothiazolesulfenamide (TBBS). When compared with the simple blends, the reactive blends cured with CBS and MBTS showed a clearly improved tensile strength whereas the increase of tensile strength in the blends cured with TBBS and MBT was marginal. However, a dramatic improvement of ultimate tensile properties in the reactive 50/50 NR/EPDM blends cured with TBBS was observed when compared with the simple blend. For the N‐550‐filled blends at the blend ratios of 70/30 and 50/50, the reactive‐filled blends prepared under the optimized preheating times demonstrated superior tensile strength and elongation at break over the simple blends. The improved crosslink and/or filler distribution between the two rubber phases in the reactive blends accounts for such improvement in their mechanical properties. This is shown in the scanning electron micrographs of the tensile fractured surfaces of the reactive blends, which indicate a more homogeneous blend. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Mechanical and surface properties and hydrolytic stability of cycloaliphatic polyester‐based waterborne polyurethanes modified with fluoro oligomer
Authors: Hong Park Sang , Lee Su Kyoung , Choi Hee Young , Lee Eon Mi , Kim Eun Young , Lim Chung Hwan , Lee Dong Woon , Kim Byung Kyu 
Published: November 2008

AbstractPolyurethane dispersions (PUDs) have been designed and synthesized based on different types of soft segments, namely, poly(2,4‐diethyl‐1,5‐pentamethylene adipate) glycol (PDPAD; $\overline {M_n }$ = 1000) and poly(2,4‐diethyl‐1,5‐pentamethylene‐1,4‐cyclohexane dicarboxylate) glycol (PDPCD; $\overline {M_n }$ = 1000), and were subsequently modified with fluoro oligomer (BA‐N fluoroalcohol). It was found that the PDPCD segments improved the hydrolytic stability, whereas the contact angle with water drop was significantly increased with the addition and increasing amount of Zonyl for PDPAD‐based PU and it was marginally increased with PDPCD‐based PU. In addition, the PDPCD provided PUD with enhanced mechanical properties compared with the PDPAD. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Cellulose/polypropylene composites: Influence of the molecular weight and concentration of oxidatively degraded and maleated polypropylene compatibilizers on tensile behavior
Authors: Miyazaki Kensuke , Moriya Kyosuke , Okazaki Noriyasu , Terano Minoru , Nakatani Hisayuki 
Published: November 2008

AbstractTo improve interactions between fibrous cellulose (FC) and polypropylene (PP), oxidatively degraded polypropylene (DgPP) and maleated polypropylene (MAPP) were studied as compatibilizers. Both compatibilizers had the same mechanism, using esterification between the OH group in FC and the reactive (γ‐lactone, acid, and maleic anhydride) groups in the compatibilizers. However, the adhesion style with the ester bond was considerably different because of the arrangements of the reactive groups. DgPP had reactive groups at the polymer chain end, and the tensile behavior of the FC/PP/DgPP composite exhibited comparatively ductile behavior. However, MAPP had inner reactive groups, and the tensile behavior of the FC/PP/MAPP composite was quite brittle. Observation of these fracture surfaces suggested that the adhesion performance of the interface between FC and PP was strongly influenced by the arrangements of the reactive group. In addition, the performance was influenced by the molecular weight of DgPP and by the content of maleic anhydride groups in MAPP. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of comb‐type grafted hydrogels composed of polyacrylamide and chitosan and their use for DNA adsorption
Authors: Başer Burcu , Demirel Gökçen Birlik , Açık Leyla , Çaykara Tuncer 
Published: November 2008

AbstractComb‐type grafted hydrogels composed of polyacrylamide (PAAm) and chitosan (CT) were prepared and used for DNA adsorption. Instead of direct grafting of the acrylamide monomer onto the CT chain, semitelechelic PAAm with carboxylic acid end groups (PAAm–COOH) was synthesized by free‐radical polymerization with mercaptoacetic acid as the chain‐transfer agent, and it was grafted onto CT with amino groups. The synthesis of telechelic PAAm–COOH and the formation of comb‐type grafted hydrogels were confirmed by attenuated total reflectance/Fourier transform infrared spectroscopy and scanning electron microscopy measurements. The prepared comb‐type grafted hydrogels were used as sorbents in DNA adsorption experiments conducted at +4°C in a tris(hydroxymethyl)aminomethane/ethylenediaminetetraacetic acid solution of pH 7.4. DNA adsorption capacities as high as 2.0 × 103 μg of DNA/g of dry gel could be achieved by the comb‐type hydrogels with higher PAAm contents. This value was approximately 6 times higher than that of CT alone. In addition, the comb‐type hydrogels showed a high adsorption/desorption rate depending on the PAAm content in the hydrogel. As a result, these comb‐type hydrogels carrying higher amounts of DNA may be considered good candidates for achieving higher removal rates for anti‐DNA antibodies and for effective gene therapy systems. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Mixed stream channel morphologies: implications for fish community diversity
Authors: Cianfrani Christina M. , Sullivan S. Mažeika P. , Hession W. Cully , Watzin Mary C. 
Published: November 2008

Abstract
Stream classification systems are widely used in stream management and restoration. Whereas the principal morphological types of these classification systems are increasingly recognized for their ecological connections, the roles of intermediate and mixed morphologies are still poorly understood, yet may be biologically significant.
Twenty‐five stream reaches in north‐western Vermont were classified by channel morphology to determine whether fish community diversity differed among pool‐riffle, mixed (i.e. pool‐riffle/cascade, pool‐riffle/other) and forced pool‐riffle stream morphological groups. Stream reach surveys included cross‐sectional surveys, longitudinal profiles, bed substrate characterization, and fish surveys.
Three fish community diversity measures were calculated: (1) species richness (S); (2) Shannon–Weaver Index (H′); and (3) Simpson's Index (1/D). Multivariate analysis of covariance (MANCOVA) followed by analysis of variance (ANOVA) were used to explore potential differences in fish diversity among stream morphological groups. Fish diversity was significantly different for all three community diversity measures (P⩽0.05), with pool‐riffle/cascade morphology consistently exhibiting the greatest fish diversity and forced pool‐riffle the lowest.
These results suggest that fish community diversity is significantly associated with distinct channel morphologies. Generally, pool‐riffle/cascade and pool‐riffle/other stream morphological groups supported habitats that fostered greater species diversity than more homogeneous and uniform pool‐riffle reaches. The observed patterns of diversity are likely to be the result of habitat patches created by variations in flow and other physical characteristics in reaches of mixed morphologies.
These results support fish sampling schemes that incorporate morphological heterogeneity, such as proportional‐distance designation. Sampling strategies that focus on homogeneous reaches may underestimate diversity, and misrepresent stream condition when fish community data are used in indices of biological integrity (IBIs). Reaches of mixed stream morphologies should be recognized as areas of biological importance in stream and catchment management and in conservation efforts.
Copyright © 2008 John Wiley & Sons, Ltd.
Restoration effort, habitat mosaics, and macroinvertebrates — does channel form determine community composition?
Authors: Jähnig Sonja C. , Lorenz Armin W. , Hering Daniel 
Published: November 2008

Abstract
In certain lower mountainous regions of Germany multiple‐channel streams constitute the reference condition for stream restoration and conservation efforts. An increasing number of restoration projects re‐establish such stream sections, but their impact on macroinvertebrate communities remains vague and needs further elaboration.
Seven pairs of single‐ and multiple‐channel sections of mountain rivers were compared in terms of hydromorphology and macroinvertebrate communities. The stream sections were characterized by 16 hydromorphological metrics at various scales, e.g. shore length, channel feature or substrate diversity, flow variability and substrate coverage. Macroinvertebrate data were obtained from 140 substrate‐specific samples, which were combined to form representative communities for each section. Community data were subject to similarity and cluster analyses. Thirty‐five metrics were calculated with the taxa lists, including number of taxa, abundance, feeding type, habitat and current preferences.
Bray–Curtis similarity was very high (69–77%) between communities of single‐ and multiple‐channel sections. Biological metrics were correlated with hydromorphological parameters. Mean Spearman rank r was 0.59 (absolute values). The biological metrics percentage of the community preferring submerged vegetation, being grazers and scrapers or active filter feeders, percentage of epipotamal preference and the percentage of current preference (rheo‐ to limnophil and rheobiont) were significantly correlated with hydromorphological parameters.
Differences between stream sections can be attributed to single taxa occurring only in either the single‐ or multiple‐channel sections. These exclusive taxa were mainly found on organic substrates such as living parts of terrestrial plants, large wood, coarse particulate organic matter (CPOM) and mud. Reasons for high similarity of macroinvertebrate communities from single‐ or multiple‐channel sections are discussed, including the influence of large‐scale catchment pressures, length of restored sections and lack of potential re‐colonizers.
Copyright © 2008 John Wiley & Sons, Ltd.
Willow (Salix spp.) and aspen (Populus tremula) regrowth after felling by the Eurasian beaver (Castor fiber): implications for riparian woodland conservation in Scotland
Authors: Jones Kevin , Gilvear David , Willby Nigel , Gaywood Martin 
Published: November 2008

Abstract
A proposed trial reintroduction of the Eurasian beaver (Castor fiber L.) to Scotland has recently been approved (May 2008). A previous proposal was turned down by the licensing authority, partly over the perceived risks to woodland within a Special Area of Conservation.
This paper presents data on two years of willow (Salix spp.) and aspen (Populus tremula L.) regrowth following tree felling by captive beavers within two large semi‐natural enclosures in eastern Scotland. Both willow and aspen are highly preferred by beavers.
Regrowth of willow stems was quantified from cut stumps, felled logs and partially severed (‘incompletely felled’) trees, and compared with growth of stems in the canopies of untouched willows.
Maximum annual regrowth was observed in incompletely felled trees, followed by cut stumps and then unfelled control trees. Mean regrowth rates were ca 18 m regrowth per metre of measured tree section per year in incompletely felled trees. This was approximately 12 times more annual regrowth than that observed in unfelled trees, despite apparently selective browsing of the regrowth of incompletely felled trees by roe deer.
Although incompletely felled willows represent a relatively small component of felling activity (9% of all felled willow), they contribute disproportionately to the biomass of beaver‐engineered riparian woodlands, creating a more multi‐layered habitat structure.
Willow regrowth in inundated areas was avoided by deer, and harvesting of regrowth by beavers was rare.
Significant regrowth from 11 stumps of aspen in 2 years post‐felling occurred by suckering, with 85 suckers of mean height 2.1 m being recorded, all of which were subsequently avoided by browsing deer and beavers.
These data suggest that rapid regeneration of willow and aspen will occur in riparian woodlands in the event of major felling activity by Eurasian beaver, even in the presence of low to moderate levels of roe deer browsing, and that the conservation status of both these trees or the wider habitats that they form would not be threatened by a well planned and managed reintroduction of beavers to Scotland.
Copyright © 2008 John Wiley & Sons, Ltd.
Harbour seal movements and haul‐out patterns: implications for monitoring and management
Authors: Cunningham Louise , Baxter John M. , Boyd Ian L. , Duck Callan D. , Lonergan Mike , Moss Simon E. , McConnell Bernie 
Published: November 2008

Abstract
Compliance with conservation legislation requires knowledge on the behaviour, abundance and distribution of protected species. Seal life history is characterized by a combination of marine foraging and a requirement to haul out on a solid substrate for reproduction and moulting. Thus understanding the use of haul out sites, where seals are counted, as well as their at‐sea movements is crucial for designing effective monitoring and management plans.
This study used satellite transmitters deployed on 24 harbour seals in western Scotland to examine movements and haul‐out patterns.
The proportion of time harbour seals spent hauled out (daily means of between 11 and 27%) varied spatially, temporally and according to sex. The mean haul‐out duration was 5 h, with a maximum of over 24 h.
Patterns of movement were observed at two geographical scales; while some seals travelled over 100 km, 50% of trips were within 25 km of a haul‐out site. These patterns are important for the identification of a marine component to designated protected areas for the species.
On average seals returned to the haul‐out sites they last used during 40% of trips, indicating a degree of site fidelity, though there was wide variation between different haul‐out sites (range 0% to >75%).
Low fidelity haul‐out sites could form a network of land‐based protected areas, while high fidelity sites might form appropriate management units.
Copyright © 2008 John Wiley & Sons, Ltd.
Some comments on “A Proposal for a Dynamic h‐Type Index” by Rousseau and Ye
Authors: Burrell Quentin L. 
Published: November 2008

AbstractCaution is urged over the adoption of dynamic h‐type indexes as advocated by Rousseau and Ye (2008). It is shown that the dynamics are critically dependent upon model assumptions and that practical interpretation might therefore be problematic. However, interesting questions regarding the interrelations between various h‐type indexes are raised.
Simulating growth of the h‐index
Authors: Guns Raf , Rousseau Ronald 
Published: November 2008

AbstractTemporal growth of the h‐index in a diachronous cumulative time series is predicted to be linear by Hirsch (2005), whereas other models predict a concave increase. Actual data generally yield a linear growth or S‐shaped growth. We study the h‐index's growth in computer simulations of the publication‐citation process. In most simulations the h‐index grows linearly in time. Only occasionally does an S‐shape occur, while in our simulations a concave increase is very rare. The latter is often signalled by the occurrence of plateaus—periods of h‐index stagnation. Several parameters and their influence on the h‐index's growth are determined and discussed.
A method for extension of generative topographic mapping for fuzzy clustering
Authors: Bose Indranil , Chen Xi 
Published: November 2008

AbstractIn this paper, a new method for fuzzy clustering is proposed that combines generative topographic mapping (GTM) and Fuzzy c‐means (FCM) clustering. GTM is used to generate latent variables and their posterior probabilities. These two provide the distribution of the input data in the latent space. FCM determines the seeds of clusters, as well as the resultant clusters and the corresponding membership functions of the input data, based on the latent variables obtained from GTM. Experiments are conducted to compare the results obtained using FCM and the Gustafson‐Kessel (GK) algorithm with the proposed method in terms of four cluster‐validity indexes. Using simulated and benchmark data sets, it is observed that the hybrid method (GTMFCM) performs better than FCM and GK algorithms in terms of these indexes. It is also found that the superiority of GTMFCM over FCM and GK algorithms becomes more pronounced with the increase in the dimensionality of the input data set.
Birth Defects Cluster Study: A national approach to birth defects cluster investigations
Authors: Kucik James E. , Bitsko Rebecca H. , Williams Laura , Lazarus Carrie , Jarman Dwayne W. , Correa Adolfo 
Published: November 2008

AbstractBACKGROUND: Investigations of clusters of birth defects have been challenging endeavors that have had only modest success identifying causes or risk factors. Some of the challenges to individual cluster investigations have been small sample size and limited data collection. We describe a novel approach for investigating and analyzing pooled information from a series of birth defects cluster investigations. METHODS: The Birth Defects Cluster Study uses a case‐control study design with standardized methods, including a case definition, control selection, data collection methods, and data collected (e.g., maternal interviews, blood samples, and environmental samples). Analyses of pooled data from several clusters of the same defect are conducted for specific hypotheses once a sufficient sample size has been achieved. The feasibility of conducting individual birth defect investigations was evaluated on a cluster of gastroschisis. RESULTS: The pilot investigation of a cluster of gastroschisis demonstrated success in recruiting participants and in collecting data and specimens for eventual inclusion in a pooled analysis. CONCLUSIONS: The Birth Defects Cluster Study offers a unique and effective approach to cluster investigations that improves the likelihood of identifying genetic and environmental causes of birth defects and provides a model for cluster investigations of other noninfectious health outcomes. Birth Defects Research (Part A), 2008. Published 2008 Wiley‐Liss, Inc.