bluuebunny/crossref_metadata_2025_split huggingface dataset:
Psychosocial work environment and medical symptoms among Swedish commercial airline cabin crew
Authors: Wahlstedt Kurt , Lindgren Torsten , Norbäck Dan , Wieslander Gunilla , Runeson Roma 
Published: March 2010

AbstractBackgroundAssociations between stress measured by the demands‐control model, iso‐strain model, and stress‐related symptoms among cabin crew were studied.MethodsA questionnaire about psychosocial work environment and symptoms was answered by 918 (82%) flight attendants, stewards, and pursers at one airline company in 2005. Adjustment was made for age, gender, smoking, job category, and flight length using multiple logistic regression.ResultsWeekly headaches, concentration difficulties, fatigue, and gastrointestinal symptoms were reported at rates of 18%, 10%, 56%, and 13%, respectively. Pursers scored higher on control than the others and they had lower associations between the strain measured by the demands‐control model and symptoms than stewards and flight attendants. All symptoms were more common in the high strain situation than in the low strain (reference). An active situation was related to an excess of symptoms. Low social support in the iso‐strain model increased risk of symptoms.ConclusionsDemands‐control and iso‐strain models are useful in studying stress‐related symptoms in cabin crews. The dimension of social support adds explanatory value. Am. J. Ind. Med. 53:716–723, 2010. © 2010 Wiley‐Liss, Inc.
Local attitudes and perceptions toward crop‐raiding by orangutans (Pongo abelii) and other nonhuman primates in northern Sumatra, Indonesia
Authors: Campbell‐Smith Gail , Simanjorang Hubert V.P. , Leader‐Williams Nigel , Linkie Matthew 
Published: March 2010

AbstractHuman–wildlife conflicts, such as crop‐raiding, increase as people expand their agricultural activities into wildlife habitats. Crop‐raiding can reduce tolerance toward species that are already threatened, whereas potential dangers posed by conflicts with large‐bodied species may also negatively influence local attitudes. Across Asia, wild pigs and primates, such as macaques, tend to be the most commonly reported crop raiders. To date, reports of crop‐raiding incidents involving great apes have been less common, but incidents involving orangutans are increasingly emerging in Indonesia. To investigate the interplay of factors that might explain attitudes toward crop‐raiding by orangutans (Pongo abelii), focal group discussions and semi‐structured interviews were conducted among 822 farmers from 2 contrasting study areas in North Sumatra. The first study area of Batang Serangan is an agroforest system containing isolated orangutans that crop‐raid. In contrast, the second area of Sidikalang comprises farmlands bordering extensive primary forest where orangutans are present but not reported to crop‐raid. Farmers living in Batang Serangan thought that orangutans were dangerous, irrespective of earlier experience of crop‐raiding. Farmers placed orangutans as the third most frequent and fourth most destructive crop pest, after Thomas' leaf monkey (Presbytis thomasi), wild boar (Sus scrofa), and long‐tailed macaque (Macaca fascicularis). Although most (57%) farmers across both study areas were not scared of wildlife species, more than a quarter (28%) of the farmers' feared orangutans. Farmers in Batang Serangan were generally more tolerant toward crop‐raiding orangutans, if they did not perceive them to present a physical threat. Most (67%) Batang Serangan farmers said that the local Forestry Department staff should handle crop‐raiding orangutans, and most (81%) said that these officials did not care about such problems. Our results suggest that efforts to mitigate human–orangutan conflict may not, per se, change negative perceptions of those who live with the species, because these perceptions are often driven by fear. Am. J. Primatol. 72:866–876, 2010. © 2010 Wiley‐Liss, Inc.
Time course of vocal modulation during isolation in common marmosets (Callithrix jacchus)
Authors: Yamaguchi Chieko , Izumi Akihiro , Nakamura Katsuki 
Published: March 2010

AbstractCommon marmosets vocalize phee calls as isolation calls, which seem to facilitate their reunion with family groups. To identify multiple acoustic properties with different time courses, we examined acoustic modulations of phees during different social contexts of isolation. Subject marmosets were totally isolated in one condition, were visually isolated and could exchange vocalizations in another condition, and were visually isolated and subsequently totally isolated in a third condition. We recorded 6,035 phees of 10 male–female marmoset pairs and conducted acoustic analysis. The marmosets frequently vocalized phees that were temporally elongated and louder during isolation, with varying time courses of these changes in acoustic parameters. The vocal rates and sound levels of the phees increased as soon as the marmosets saw their pair mates being taken away, and then gradually calmed down. The phee duration was longer in conditions during which there were no vocal responses from their pair mates. Louder vocalizations are conspicuous and seem to be effective for long‐distance transmission, whereas shorter call duration during vocal exchanges might avoid possible vocal overlap between mates. Am. J. Primatol. 72:681–688, 2010. © 2010 Wiley‐Liss, Inc.
Kinetics of reaction of benzyl chloride with H2S‐rich aqueous monoethanolamine: selective synthesis of dibenzyl sulfide under liquid–liquid phase‐transfer catalysis
Authors: Sen Sujit , Pradhan Narayan C. , Patwardhan Anand V. 
Published: March 2010

AbstractThe development of viable alternative processes for the conversion of hydrogen sulfide (H2S) to produce commercially important chemicals is important in process industries, particularly in refineries handling large quantity of sour crude. This work was undertaken to synthesize value‐added chemicals such as dibenzyl sulfide (DBS) and benzyl mercaptan (BM) utilizing H2S from various by‐product gas streams. This process is a viable alternative to the expensive Claus process, which produces only the less valuable elemental sulfur product from H2S. The reaction between benzyl chloride (BC) and H2S‐rich aqueous monoethanolamine (MEA) was carried out in an organic solvent, toluene, using tetra‐n‐butylammonium bromide as phase‐transfer catalyst. Two products, DBS and BM, were identified in the reaction mixture and both chemicals have many industrial uses. The conversion of BC and the selectivity of DBS, were maximized by considering the effect of various parameters such as stirring speed, catalyst loading, concentration of BC, concentration of MEA, concentration of sulfide, and temperature. The highest selectivity of DBS obtained was about 99% after 480 min of reaction with excess BC at 60 °C. The apparent activation energy for the kinetically controlled reaction was found to be 51.3 kJ/mol. The MEA/H2S mole ratio was found to have a significant effect on the selectivity of DBS and BM. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Parameter estimation protocol for secondary clarifier models based on sludge volume index and operational parameters
Authors: Zhen Zhou , Zhichao Wu , Guowei Gu , Zhiwei Wang 
Published: March 2010

AbstractThe development of an accurate biological process model of activated sludge systems is important for the control, management, and optimization of a wastewater treatment plant (WWTP). The performance of the secondary clarifier is closely related to successful operation of the WWTP, and the most suitable secondary clarifier model for activated sludge process modeling is the one‐dimensional layered model. The one‐dimensional layered model combined with a double‐exponential settling velocity model has been extensively used for secondary clarifier modeling, but the complexity in parameter estimation has limited its application and extension to a full‐scale WWTP. A parameter estimation protocol of the secondary clarifier model was developed by empirical formula estimation in combination with sensitivity analysis based on sludge volume index and routine operational parameters and employed in the secondary clarifier modeling with data from a pilot‐scale test and a full‐scale WWTP. Based on the sensitivity analysis results, the importance of each model parameter is assessed. The one‐dimensional layered clarifier model after parameter estimation provides good predictions for the suspended solids (SS) profile, and overflow and underflow SS concentrations, in both the pilot‐scale clarifier test and the full‐scale WWTP. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Catalytic resolution of racemic ethyl lactate to produce D‐lactic acid by immobilized cells of Rhizopus sp. WS0128
Authors: Shen Xueliang , Wang Zhao 
Published: March 2010

AbstractD‐Lactic acid can be produced by either chemical or biochemical methods and is an important raw material or intermediate used in many fields including pesticides and herbicides production, and as polymers with promising applications in medical areas. Esterase produced by Rhizopus sp. WS0128 was effective in the catalytic resolution of racemic ethyl lactate to produce optically pure D‐lactic acid. The cells of Rhizopus sp. WS0128 were immobilized by entrapping them into calcium alginate gels, and the fermentation of the immobilized cells was carried out in an external‐loop airlift bioreactor (ELAB) (11.5 l). Optimal growth conditions for the microorganism were determined such that the maximum esterase activity of the immobilized cells reached 57.9 U/g cells after 48 h of fermentation. The immobilized cells of Rhizopus sp. WS0128 containing abundant esterase could be used directly as a biocatalyst in the enantioselective hydrolysis of ethyl lactate. The optimal hydrolysis reaction conditions were initial substrate concentration 160 g/l, temperature 40 °C, pH value 7.5 and reaction time 3.5 h. Under these conditions, the hydrolysis yield of ethyl lactate was 43.4% and the optical purity of D‐lactic acid was 96.3%. The immobilized cells were quite stable and could be utilized repeatedly in the biocatalytic process for at least six batches, where the average hydrolysis yield of ethyl lactate and the average optical purity of D‐lactic acid were 43.1% and 95.9%, respectively. This research work showed a promising process of D‐lactic acid preparation by biotransformation. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Combined method of complex coacervation and electrospray for encapsulate preparation
Authors: Omidi Javad , Khorram Mohammad , Samimi Abdolreza 
Published: March 2010

AbstractEncapsulate beads composed of alginate and chitosan as shell and bovine serum albumin (BSA) as core were prepared by combined method of complex coacervation and electrospray. The main objective of this work was to produce mono‐sized and spherical capsule of chitosan‐alginate with controlled sizes of capsules and shell. However, the effects of applied voltage, flow rate, and molecular weight of chitosan were investigated on the size, size distribution, membrane thickness of the prepared capsules, as well as the release rate of BSA. The results revealed that by the method developed in this study, it was possible to produce spherical capsules with controlled size and narrow size distribution. Increasing the voltage and decreasing the flow rate reduced the radius of capsule and its shell thickness from 2.09 mm to 750 μm and from 1.31 mm to 490 μm, respectively. Furthermore, the molecular weight of chitosan had no significant effect on the capsules' size and the release rate of BSA, whereas the rate of BSA release was increased with increase of the voltage. The later effect would be due to the increase of shell porosity at the higher voltages. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of resin IV: Salicylic acid, diaminonaphthalein, and formaldehyde terpolymer and its ion exchange
Authors: Masram Dhanraj T. , Bhave Narayan S. , Kariya Kiran P. 
Published: March 2010

AbstractThis article reports the synthesis, characterization, and ion exchange properties of a terpolymer. The terpolymer resin salicylic acid‐diaminonaphthalein‐formaldehyde (SDNF) was synthesized by the condensation of salicylic acid and diaminonaphthalein with formaldehyde in the presence of a hydrochloric acid catalyst. Terpolymer resin was characterized by elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance spectroscopy, and UV–Visible spectral studies. The number average molecular weight of the resin was determined by nonaqueous conductometric titration. Chelation ion exchange properties have also been studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+, Pb2+ ions employing a batch equilibrium method. It was employed to study the selectivity of metal ion uptake involving the measurements of distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over wide pH range and in a media of various ionic strengths. The terpolymer showed higher selectivity for Fe3+, Cu2+, and Ni2+ions than for Co2+, Zn2+, Cd2+, and Pb2+ ions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Slow release polymer–iodine tablets for disinfection of untreated surface water
Authors: Mazumdar Nasreen , Chikindas M. L. , Uhrich Kathryn 
Published: March 2010

AbstractSimple water treatment devices are designed to treat small amounts of drinking water for home use. This study was undertaken to develop an iodine‐releasing polymeric formulation and examine its potential as a domestic water purifier for untreated surface water. The antimicrobial tablet formulation was made from gum arabic (GA), poly(vinylalcohol) (PVA), ethyl cellulose (EC), and poly(vinylpyrrolidone)‐iodine (PVP‐I). The formulation consisted of a dispersible core tablet surrounded by a hydrophilic coating of EC and poly(ethylene glycol) mixture. These stable, non‐vaporizing, and water‐insoluble tablets slowly release iodine through diffusion over 48 h when suspended in water. The swelling behavior and release were observed to be the functions of excipient composition, iodine loading, and coating materials. Iodine release was determined by UV–VIS spectroscopy and volumetric titrations. The tablets were also assessed for antimicrobial activity against Escherichia coli, Staphylococcus aureus, Listeria monocytogenes Scott A, and Salmonella typhimurium. The disinfection efficiency of the developed tablets was compared with a commercial formulation (Potable Aqua®) as both contain iodine‐releasing active compounds and work on the antimicrobial property of released iodine. The difference between the two formulations is that water‐dispersible Potable Aqua® has a higher amount of free iodine quickly available in water thereby making it a fast‐action emergency water purifier, whereas the developed water‐insoluble polymer–iodine tablets act slowly and require 24 h to show the same disinfection efficacy with lower content of iodine in water. Overnight release of iodine in water from polymer–iodine tablets was effective in 99.9% reduction of an initial cell count of ∼ 107 colony forming units (cfu)/mL. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Novel starch based copolymers (DiHydroxyl Starch) as ocular lubricants: Synthesis and characterizations
Authors: Liu Weipeng , Townsend Wendy M. , Steffe James , Narayan Ramani 
Published: March 2010

AbstractDry eye syndrome is an ocular tear deficiency disorder that affects millions of people in the United States. It has been recognized as a significant lifestyle issue and is among the most frequently established diagnoses in ophthalmology. Tear substitutes (or artificial tear formulations) are the mainstay of dry eye therapy. While many commercial products are available, their efficacy is limited because of their short retention time in the eye, and/or low patient acceptance. In this study, our objectives were to obtain water soluble products with opened glucose rings along the starch backbone, and tear substitute formulations based on these products with strengthened mucoadhesion, shear thinning behavior, improved tear film stability, and no irritancy to the eye. To this end we have synthesized a series of starch based copolymers, DiHydroxyl Starches (DHS). This modification of starch is not a new science, but the application of these polymers to tear substitutes is novel. These polymers were characterized as ocular lubricants utilizing both in vitro and in vivo testing. Specifically, mucoadhesion and rheological behavior were examined. Their performance as ocular lubricants was evaluated utilizing the tear‐film break up times of rabbits before and after application of the copolymers. In addition, the effect of autoclaving and ocular toxicity were tested. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of the crosslink functionality on the mechanical properties of crosslinked 1,2,3‐triazole polymers as potential binders for rocket propellants
Authors: Song Yuming , Wang Ling , Gyanda Reena , Sakhuja Rajeev , Cavallaro Mayra , Jackson David Carnaby , Meher Nabin K. , Ciaramitaro David A. , Bedford Clifford D. , Katritzky Alan R. , Duran Randolph S. 
Published: March 2010

AbstractThe mechanical properties of crosslinked polymers depend on their structural features, one of which is the functionality of the crosslinks in a polymer network. To study the effect of crosslink functionality (ϕ) on the mechanical properties of 1,2,3‐triazole polymers for potential application as rocket propellant binders, crosslinkers with different ϕ's (3, 4, 6, 16, 32, and 64) were used in the polymerization. As the percentage of acetylenic groups provided by crosslinker was kept constant and the functionality of the crosslinker increased, the resulting polymer showed a higher modulus but a lower strain. Compared to traditional polyurethane binders, 1,2,3‐triazole polymers showed comparable mechanical properties, although the stress and modulus tended to be lower and the strain capability tended to be greater for the triazole‐linked rubbers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effects of solution processing on the photovoltaic response of poly(n‐vinyl carbazole) films
Authors: Chung P. S. , Holloway P. H. 
Published: March 2010

AbstractThe effects of solution processing on the photovoltaic response of poly(n‐vinyl carbazole) (PVK) films were investigated. PVK films were formed by spincasting onto glass coated with indium tin oxide (ITO) and poly(3,4‐ethylenedioxythiophene) (PEDOT)–polystyrenesulfonate (PSS). Some of the PVK films were redissolved in chlorobenzene and redried in the absence or presence of an electric field. Illuminated current–voltage characteristics were measured for an ITO/PEDOT:PSS/PVK/Ca:Al device. Films spincast from a 50 mg/mL solution, redissolved, and dried in the absence of the electric field exhibited a 26% higher charge collection efficiency than films dried in the presence of the electric field. The increased charge collection efficiency was attributed to changes in the molecular configuration of the PVK films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Investigation of the interphase effects on the mechanical behavior of carbon nanotube polymer composites by multiscale modeling
Authors: Montazeri A. , Naghdabadi R. 
Published: March 2010

AbstractIn this article, a multiscale modeling procedure is implemented to study the effect of interphase on the Young's modulus of CNT/polymer composites. For this purpose, a three‐phase RVE is introduced which consists of three components, i.e., a carbon nanotube, an interphase layer, and an outer polymer matrix. The nanotube is modeled at the atomistic scale using molecular structural mechanics. Moreover, three‐dimensional elements are employed to model the interphase layer and polymer matrix. The nanotube and polymer matrix are assumed to be bonded by van der Waals interactions based on the Lennard‐Jones potential at the interface. Using this Molecular Structural Mechanics/Finite Element multiscale model, we investigate the macroscopic material properties of nanocomposite with and without considering the interphase and compare the results with molecular dynamics (MD) simulations. It is shown that there is a noticeable deviation from MD results with two‐phase model. Meanwhile, the three‐phase modeling shows that by considering the effect of the interphase, the elastic constants of these nanocomposites could be calculated the same as the MD results with maximum deviation of 1.8% and negligible computational cost in comparison with the MD simulation. Hence, considering the interphase layer in modeling the CNT‐based nanocomposites is necessary and cannot be ignored. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Study of plastic compounds containing polypropylene and wood derived fillers from waste of different origin
Authors: Viksne Armanda , Berzina Rita , Andersone Inga , Belkova Lubova 
Published: March 2010

AbstractThe scope of the article was to study the perspectives of the using of wood derived fillers (WDF) from waste of different origin as fillers of polypropylene. The WDF used in this study was hard wood flour (HW), birch veneer polishing dust (VD) and tetra‐pack carton cellulose fiber (TC). Some mechanical strength parameters, water uptake in the static and cyclic test and resistance to fungal decay of polypropylene (PP) composites containing these three types of WDF were studied and compared with similar loading (40 wt %) talc‐filled PP. Composites containing TC and VD fibers as filler showed the highest flexural strength at three test temperatures (−40, +20, and +40°C) and flexural modulus and tensile strength at plus temperatures. On the other hand talc‐filled PP exhibited greatest flexural modulus at minus temperature, greatest impact strength at room temperature and best flow ability. Significant difference was observed between PP composites with HW and VD fillers regarding water uptake in cyclic tests, however flexural strength and modulus change of composites were reversible after drying. No weight loss of WDF/PP composites was observed after 6 week exposure to brown‐ and white‐rot fungi, however, degradation of the surface of samples was detected by SEM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, characterization, and thermal behaviors of tannin stearates prepared from quebracho and pine bark extracts
Authors: Luo Chunhua , Grigsby Warren , Edmonds Neil , Easteal Allan , Al‐Hakkak Jafar 
Published: March 2010

AbstractReported is the preparation of various condensed tannin stearates and the associated chemical characterization and thermal properties of these products. Stearate esters of condensed tannins from both quebracho and pine bark extracts were prepared in generally high, isolated yields from reaction with stearic acid chloride. Tannin esterification was confirmed by both Fourier transform infrared and nuclear magnetic resonance (NMR), and the average degree of stearate substitution was calculated from 1H‐NMR analysis. Product degree of substitution (DS) was observed to proportionately increase with higher stearic acid chloride ratio with maximum DS values of 4.0 and 5.1 achieved for quebracho and pine tannins, respectively. Thermal analysis revealed that tannin stearate products have increased thermal stability with a degradation onset at significantly higher temperature for those samples possessing relatively greater DS. Analysis using differential scanning calorimetry revealed isolated products to consist of multiple components which exhibit interesting melt behaviors, a likely result from their work up on isolation. However, multiple melt features of the individual components in products were lost on heating to give single, broad melt endotherms due to coalescence of sample components. Furthermore, tannin stearate samples with high DS show relatively greater endothermic melting at higher temperature than those samples with lower DS. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010