bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistent tracking and identification of regime‐switching systems with structural uncertainties: unmodeled dynamics, observation bias, and nonlinear model mismatch
Authors: Kan Shaobai , Yin George , Wang Le Yi 
Published: April 2012

SUMMARYThis work focuses on tracking and system identification of systems with regime‐switching parameters, which are modeled by a Markov process. It introduces a framework for persistent identification problems that encompass many typical system uncertainties, including parameter switching, stochastic observation disturbances, deterministic unmodeled dynamics, sensor observation bias, and nonlinear model mismatch. In accordance with the ‘frequency’ of the parameter switching process, we divide the problems into two classes. For fast‐switching systems, the switching parameters are stochastic processes modeled by irreducible and aperiodic Markov chains. Because accurately tracking real‐time parameters in such systems is not possible because of the uncertainty principles, the effect of parameter switching is evaluated on their average by the stationary distribution of the Markovian chain and estimated by the least squares algorithms. We derive upper and lower bounds on identification errors, which characterize how identification accuracy depends on the earlier uncertainty terms. When the system parameters switch their values infrequently in a probabilistic sense, their values can be tracked based on input/output observations. Stochastic approximation algorithms with adaptive step sizes are used for such systems. Simulation studies are carried out to demonstrate that slowly varying parameters could be tracked with reasonable accuracy.Copyright © 2012 John Wiley & Sons, Ltd.
Effect of Reaction Conditions on the Particle Morphology of Aqueous Dispersion of Poly(acrylamide‐acrylatedimethylaminoethyl methacrylate methyl chloride)
Authors: Hu Zunfu , Zhang Jun , Liu Juan , Wang Chuanxing , Wu Yumin 
Published: April 2012

AbstractAmphoteric polyacrylamide was prepared by dispersion polymerization with acrylamide, dimethylaminoethyl methacrylate methyl chloride, and acrylate acid as monomers, ammonium sulfate (AS) aqueous solution as a reaction medium, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as a stabilizer, and 2,2′‐azobis(2‐amidinopropane) dihydrochloride as an initiator. The influence of particle morphology on AmPAM dispersion and other factors and polymerization were investigated. Three crucial factors responsible for particle morphology are the dispersant concentration, sodium chloride concentration, and ionic degree of terpolymer. The ammonium sulfate concentration had relatively less of an effect on particle morphology, but a suitable concentration was necessary to obtain a stable dispersion system. A higher concentration of PDMC could yield more uniform and spherical particles during dispersion polymerization. A small amount of sodium chloride can decrease particle size and dispersion viscosity. These four factors heavily influenced the viscosity of polymer dispersion, and they had a large effect on the intrinsic viscosity of AmPAM except for the AS and NaCl concentration. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E212–E220, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21264
Polymers in industry: From guncotton to CO2 glass
Authors: Mascia Leno , Acierno Domenico 
Published: April 2012

AbstractThe origins of the commercial exploitation of synthetic polymers and the subsequent industrial developments are reviewed, and the main landmarks are highlighted, starting from the pioneering work on the nitration of cellulose in the 19th century and progressing through various advancements to the latest innovations. This includes the contribution made by many authorities, starting from Staudinger, as the founder of polymer science, to the most recent Nobel laureates in the field. The increased awareness for the need to capture CO2 from combustion gases has stimulated interests in the possibility of using polymerization methods as a route to produce useful solid products. The available theoretical arguments and experimental evidence are presented in relation to the feasibility of producing linear polymers, both as homopolymer and copolymers, placing emphasis on stability aspects and possible uses of the products. The various claims on the possibility of opening both double bonds of molecular CO2 to produce stable networks are also analyzed. Arguments in support of the possibilities of producing mixed CO2–SiO2 glasses are provided, and the expected properties of the resulting solids are discussed. Suggestions are made for the possible utilization of such products. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 31: 179–192, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21275
Multi‐Length‐Scale Morphologies in PCPDTBT/PCBM Bulk‐Heterojunction Solar Cells
Authors: Gu Yu , Wang Cheng , Russell Thomas P. 
Published: April 2012

AbstractAdditives are known to improve the performance of organic photovoltaic devices based on mixtures of a low bandgap polymer, poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]‐dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadiazole)] (PCPDTBT) and [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM). The evolution of the morphology during the evaporation of the mixed solvent, which comprises additive and chlorobenzene (CB), is investigated by in‐situ grazing incidence X‐ray scattering, providing insight into the key role the additive plays in developing a multi‐length‐scale morphology. Provided the additive has a higher vapor pressure and a selective solubility for PCBM, as the host solvent (CB) evaporates, the mixture of the primary solvent and additive becomes less favorable for the PCPDTBT, while completely solubilizing the PCBM. During this process, the PCPDTBT first crystallizes into fibrils and then the PCBM, along with the remaining PCPDTBT, is deposited, forming a phase‐separated morphology comprising domains of pure, crystalline PCPDTBT fibrils and another domain that is a PCBM‐rich mixture with amorphous PCPDTBT. X‐ray/neutron scattering and diffraction methods, in combination with UV–vis absorption spectroscopy and transmission electron microscopy, are used to determine the crystallinity and phase separation of the resultant PCPDTBT/PCBM thin films processed with or without additives. Additional thermal annealing is carried out and found to change the packing of the PCPDTBT. The two factors, degree of crystallinity and degree of phase separation, control the multi‐length‐scale morphology of the thin films and significantly influence device performance.
Association between perceived union connection and upper body musculoskeletal pains among unionized construction apprentices
Authors: Kim Seung‐Sup , Perry Melissa J. , Okechukwu Cassandra A. 
Published: April 2012

AbstractBackgroundSeveral studies show varying associations between unionization and workers' health and well‐being. This study investigated the association between individual worker's perceived union connection and musculoskeletal pains (MSPs).MethodsWe conducted a cross‐sectional survey of 1,757 unionized construction apprentices. Perceived union connection is a psychosocial scale measured by six questions that assessed individual worker's connection to their union (range 10–24) at unionized workplaces. We measured the prevalence of four MSPs (neck, shoulder, arm, and back pain) and difficulty in daily home activities, job activities, and sleeping caused by each of the four MSPs.ResultsWe found that a one score increase in perceived union connection was associated with 5% decreased odds of reporting neck pain (OR: 0.95, 95% CI: 0.91–1.00) and back pain (OR: 0.95, 95% CI: 0.91–0.99) after adjusting for confounders including self‐reported ergonomic strain. We also found significant associations between perceived union connection and MSPs causing difficulty in daily activities. For a one score increase in perceived union connection, the odds of reporting back pain causing difficulty in home activities, job activities, and sleeping was 9% (95% CI: 0.87–0.96), 8% (95% CI: 0.88–0.96), and 7% (95% CI: 0.89–0.98) lower, respectively.ConclusionsAlthough our findings are limited by the cross‐sectional nature of the data, these results suggest that workers' perceived union connection can vary even within unionized workplaces, and it may be associated with the prevalence of MSPs and MSPs causing difficulty in daily activities. Am. J. Ind. Med. 56:189–196, 2013. © 2011 Wiley Periodicals, Inc.
The association between nonstandard work and occupational injury in Korea
Authors: Im Hyoung‐June , Oh Dae‐gyu , Ju Young‐Su , Kwon Young‐Jun , Jang Tae‐Won , Yim Jun 
Published: April 2012

AbstractBackgroundThe number of workers who died due to occupational injury in Korea as of 2007 was 1,383. The aim of this study was to identify whether there were any differences in the risk of occupational injury between nonstandard workers (temporary workers and/or subcontract workers) and regular workers.Methods1,576 injured workers, selected from National Health Insurance and National Workers' Compensation Insurance, were interviewed via telephone survey using standardized questionnaires in 2007. The control group was 1,500 workers matched for age, gender, and severity of injury. A multivariate logistic regression model was used to analyze the association between the type of nonstandard work and occupational injury.ResultsNonstandard temporary workers were more likely to be injured than regular workers even if other related factors of occupational injury were statistically adjusted (adjusted odds ratio, OR 2.87, 95% confidence interval 2.37–3.49).ConclusionsThe reason why the risks of nonstandard workers are higher than those of regular workers is that nonstandard workers are placed in poor working conditions. Am. J. Ind. Med. 55:876–883, 2012. © 2012 Wiley Periodicals, Inc.
Work safety climate and safety practices among immigrant Latino residential construction workers
Authors: Arcury Thomas A. , Mills Thomas , Marín Antonio J. , Summers Phillip , Quandt Sara A. , Rushing Julia , Lang Wei , Grzywacz Joseph G. 
Published: April 2012

AbstractBackgroundLatino residential construction workers experience high rates of occupational fatality and injury. Work safety climate is an especially important consideration for improving the safety of these immigrant workers. This analysis describes work safety climate among Latino residential construction workers, delineates differences in work safety climate by personal and employment characteristics, and determines associations of work safety climate with specific work safety behaviors.MethodsData are from a cross‐sectional survey of 119 Latino residential framers, roofers, and general construction workers in western North Carolina; 90 of these participants also provided longitudinal daily diary data for up to 21 days using an Interactive Voice Response (IVR) system. Measures included the Perceived Safety Climate Scale, and daily reports of five individual and five collective safety practices.ResultsWork safety climate was mixed among workers, with roofers (19.9) having lower levels than framers (24.3) or general construction workers (24.3). Days reported for several individual (glove‐related risks, not doing something known to be unsafe) and collective safety practices (attended daily safety meeting, not needing to use damaged equipment, not seeing coworker create an unsafe situation) were positively associated with work safety climate.ConclusionsWork safety climate predicts subsequent safety behaviors among Latino residential construction workers, with differences by trade being particularly important. Interventions are needed to improve safety training for employers as well as workers. Further research should expand the number of workers and trades involved in analyses of work safety climate. Am. J. Ind. Med. 55:736–745, 2012. © 2012 Wiley Periodicals, Inc.
Variations in peak expiratory flow measurements associated to air pollution and allergic sensitization in children in Sao Paulo, Brazil
Authors: Correia‐Deur Joya Emilie de M. , Claudio Luz , Imazawa Alice Takimoto , Eluf‐Neto Jose 
Published: April 2012

AbstractBackgroundIn the last 20 years, there has been an increase in the incidence of allergic respiratory diseases worldwide and exposure to air pollution has been discussed as one of the factors associated with this increase. The objective of this study was to investigate the effects of air pollution on peak expiratory flow (PEF) and FEV1 in children with and without allergic sensitization.MethodsNinety‐six children were followed from April to July, 2004 with spirometry measurements. They were tested for allergic sensitization (IgE, skin prick test, eosinophilia) and asked about allergic symptoms. Air pollution, temperature, and relative humidity data were available.ResultsDecrements in PEF were observed with previous 24‐hr average exposure to air pollution, as well as with 3–10‐day average exposure and were associated mainly with PM10, NO2, and O3 in all three categories of allergic sensitization. Even though allergic sensitized children tended to present larger decrements in the PEF measurements they were not statistically different from the non‐allergic sensitized. Decrements in FEV1 were observed mainly with previous 24‐hr average exposure and 3‐day moving average.ConclusionsDecrements in PEF associated with air pollution were observed in children independent from their allergic sensitization status. Their daily exposure to air pollution can be responsible for a chronic inflammatory process that might impair their lung growth and later their lung function in adulthood. Am. J. Ind. Med. 55:1087–1098, 2012. © 2012 Wiley Periodicals, Inc.
A decade of malignant mesothelioma surveillance in Korea
Authors: Jung Soon‐Hee , Kim Hyoung‐Ryoul , Koh Sang‐Baek , Yong Suk‐Joong , Chung Myoung Ja , Lee Chang‐Hun , Han Joungho , Eom Min‐Seob , Oh Sung‐Soo 
Published: April 2012

AbstractBackgroundThe objectives of this study were to examine trends in mesothelioma incidence over a decade and to identify histories of asbestos exposure among cases in Korea.MethodsIn 2001, The Korea Occupational Safety and Health Agency organized a nationwide cardiopulmonary pathology group and established a malignant mesothelioma surveillance system covering all general hospitals in Korea. Mesothelioma cases were reported to this surveillance system with information about age, gender, location, occupational history, asbestos exposure environment, date of diagnosis, diagnostic method, histopathologic subtype, occurrence site, and other clinical information. Additionally, an epidemiological survey was conducted using a structured verbal questionnaire to allow further evaluation of asbestos exposures.ResultsA total of 399 cases of malignant mesothelioma were reported in the last decade, translating to approximately 40 annual cases, and an annual average incidence rate of 0.83 cases per million. Of the 152 patients interviewed by occupational physicians, 56 had occupational asbestos exposure histories (36.8%). Their occupations and industries included construction (19.7%), automobile repair (5.9%), asbestos textile, shipbuilding and repair, refinery work, boiler making, and asbestos cement work. Another 31 patients had environmental asbestos exposure histories.ConclusionsSurveillance data indicate that malignant mesothelioma incidence in Korea is, thus far, lower than that of other developed countries, and that construction and environmental asbestos exposure were the main identifiable causes of malignant mesothelioma. Am. J. Ind. Med. 55:869–875, 2012. © 2012 Wiley Periodicals, Inc.
Women's knowledge, attitudes, and beliefs about Down syndrome: A qualitative research study
Authors: Levis Denise M. , Harris Shelly , Whitehead Nedra , Moultrie Rebecca , Duwe Kara , Rasmussen Sonja A. 
Published: April 2012

AbstractWomen who are or may become pregnant need up‐to‐date information about Down syndrome (DS). Asking women about their knowledge, opinions, resources, and information needs on the topic of DS is an important precursor to develop effective strategies for education. We conducted 24 focus groups (N = 111) in two US cities with women who were recently pregnant (who had a child ≤3 years old without DS) and women who planned to have a child in the next year. Groups were further segmented by age and race‐ethnicity. Questions explored women's knowledge, attitudes, and beliefs about DS; resources used to obtain information about health and DS; and information needs on the topic of DS. All participants reported having some knowledge of DS: facial features, chromosomal condition, and maternal age as a risk factor. Many participants had misconceptions, including the life expectancy for persons with DS, other maternal and paternal risk factors, and the idea that having a child with DS would disrupt their lives. Participants requested stories to help illustrate what life is like for families with DS. Many Hispanic and African American participants said they only saw or knew of Caucasian persons with DS and requested culturally diverse educational materials about DS. Participants said they would seek information on DS from the Internet and from their health care providers. Results suggest that women need tailored materials that contain clinical information about DS as well as information about living with a child with DS. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Candidate locus analysis for PHACE syndrome
Authors: Mitchell Sheri , Siegel Dawn H. , Shieh Joseph T.C. , Stevenson David A. , Grimmer J. Fredrik , Lewis Tracey , Metry Denise , Frieden Ilona , Blei Francine , Kayserili Hulya , Drolet Beth A. , Bayrak‐Toydemir Pinar 
Published: April 2012

AbstractPHACE syndrome (OMIM #606519) is a neurocutaneous syndrome of unknown etiology and pathogenesis. We report on an individual with PHACE syndrome with a complete deletion of SLC35B4 on 7q33. In order to further analyze this region, SLC35B4 was sequenced for 33 individuals with PHACE syndrome and one parental set. Common polymorphisms with a possible haplotype but no disease causing mutation were identified. Sixteen of 33 samples of the PHACE syndrome patients were also analyzed for copy number variations using high‐resolution oligo‐comparative genomic hybridization (CGH) microarray. A second individual in this cohort had a 26.5 kb deletion approximately 80 kb upstream of SLC35B4 with partial deletion of the AKR1B1 on 7q33. The deletions observed on 7q33 are not likely the singular cause of PHACE syndrome; however, it is possible that this region provides a genetic susceptibility to phenotypic expression with other confounding genetic or environmental factors. © 2012 Wiley Periodicals, Inc.
Effect of non‐rubber substances on vulcanization kinetics of natural rubber
Authors: Ping‐Yue Wang , Yong‐Zhou Wang , Bei‐Long Zhang , Hong‐Hai Huang 
Published: April 2012

AbstractEffect of non‐rubber components on vulcanization kinetics of natural rubber was studied with the use of a Rheometer MDR‐2000. The results show that the rate constants of induction period and curing period of natural rubber (NR) are greater than that of natural rubber extracted with acetone (NRE), and the activation energies of induction period and curing period of NR are lower than that of NRE. The activation energy of induction period of NR is reduced by16.9% and the activation energy of curing period of NR is reduced by 3.2% compared to the activation energies of NRE. The time tdis of NR is shorter than that of NRE at the same temperature. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Toughening of polylactide by melt blending with methyl methacrylate–butadiene–styrene copolymer
Authors: Zhang Huiliang , Liu Nanan , Ran Xianghai , Han Changyu , Han Lijing , Zhuang Yugang , Dong Lisong 
Published: April 2012

AbstractBrittle polylactide (PLA) was toughened by introducing 5–25 wt % of methyl methacrylate–butadiene–styrene (MBS) copolymer. PLA/MBS blends were characterized by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), dynamic rheometer, mechanical testing, scanning electron microscopy, and transmission electron microscope. From the result of DSC, MBS could act as an effective heterogeneous nucleation agent for PLA and significantly improved the degree of crystallinity of PLA. DMA results showed a single high temperature peak of Tg between that of pure PLA and that of the shell composition of the MBS, which suggested that PLA and the shell of MBS were compatible. With an increase of MBS content, the tensile strength of the blends decreased; however, the elongation at break and impact strength increased significantly which indicated the toughening effects of the MBS on PLA. It was found that the PLA matrix showed large plastic deformation (shear yielding) in the blend subjected the impact tests, which was an important energy‐dissipation process and led to a toughened polymer blend. MBS could act as impact modifier of PLA. Rheological investigation demonstrated that there was a significantly dependence of viscosity on composition. When the MBS content increased, the viscosity began to increase. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Hydrophilic modification of poly(vinylidene fluoride) membrane with poly(vinyl pyrrolidone) via a cross‐linking reaction
Authors: Bi Qiuyan , Li Qian , Tian Ye , Lin Yakai , Wang Xiaolin 
Published: April 2012

AbstractA highly hydrophilic hollow fiber poly(vinylidene fluoride) (PVDF) membrane [PVDF‐cl‐poly(vinyl pyrrolidone) (PVP) membrane] was prepared by a cross‐linking reaction with the hydrophilic PVP, which was immobilized firmly on the outer surface and cross‐section of the PVDF hollow fiber membrane via a simple immersion process. The cross‐linking between PVDF and PVP was firstly verified via nuclear magnetic resonance measurement on PVP solution after cross‐linking. The hydrophilic stability of the modified PVDF membrane was evaluated by measuring the pure water flux after different times of immersion and drying. The anti‐fouling properties were estimated by cyclic filtration of protein solution. When the cross‐linking time was as long as 6 hr and the PVP content reached 5 wt %, the pure water flux (Jv) was constant as ∼ 600 L m−2 hr−1. The hydrophilicity of the PVDF‐cl‐PVP membrane was significantly enhanced and exhibited a good stability. The PVDF‐cl‐PVP membrane showed an excellent anti‐protein‐fouling performance during the cyclic filtration of bovine serum albumin solution. Therefore, a highly hydrophilic and anti‐protein‐fouling PVDF hollow fiber membrane with a long‐term stability can be prepared by a simple and economical cross‐linking process with PVP. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of isotactic polypropylene/fibrous cellulose composite oxo‐biodegradation induced by poly(ethylene oxide)/TiO2 initiator and accelerator system
Authors: Miyazaki Kensuke , Shibata Kazuto , Nakatani Hisayuki 
Published: April 2012

AbstractIn this work, a novel isotactic polypropylene (PP)/fibrous cellulose (FC) composite containing a poly(ethylene oxide) (PEO)/TiO2 was prepared, and its oxo‐biodegradation behavior was studied. FC loading of 5 and 1% resulted in an opaque film and relatively good transparence, respectively. Fourier transform infrared (FTIR) spectra of the nonphotodegraded composite samples revealed little PP auto‐oxidation under the melt‐mixing condition. Ultraviolet irradiation enhanced the auto‐oxidation of the composite. FTIR analyses of the composite indicated that TiO2 and PEO functioned as the initiator and accelerator of PP auto‐oxidation, respectively. In addition, even with 1% PEO, the accelerator effect was enhanced by the spreading of the degraded PEO component from other areas when the film thickness was increased. All PP/PEO/TiO2/FC composites with a PEO content varying from 0.3 to 5% showed a Young's modulus value of ∼ 180% higher than that of pristine PP. Biodegradability of the photodegraded composite was confirmed by a soil burial test. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013