bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photocurable transparent cycloaliphatic epoxy hybrid materials crosslinked by oxetane
Authors: Yang SeungCheol , Jin JungHo , Kwak Seung‐Yeon , Bae Byeong‐Soo 
Published: April 2012

AbstractOrganic/inorganic hybrid materials (hybrimers) were fabricated by the photocationic polymerization of sol–gel‐derived cycloaliphatic epoxy oligosiloxane (CAEO)/oxetane blends. The CAEO/oxetane blends showed faster photocationic polymerization rates compared to a CAEO resin. The CAEO/oxetane hybrimers showed a high crosslinking density and flexibility with the addition of oxetane monomer. The increased crosslinking density improved the insulation properties and lowered their dielectric constant. The CAEO/oxetane hybrimer with a substantial thickness of 2 mm showed high transparency (>90%) in the visible range. On the basis of these properties, the CAEO/oxetane hybrimers could be applied to various applications, including optics and display fields. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation of modified starch‐grafted poly(lactic acid) and a study on compatibilizing efficacy of the copolymers in poly(lactic acid)/thermoplastic starch blends
Authors: Wootthikanokkhan J. , Kasemwananimit P. , Sombatsompop N. , Kositchaiyong A. , Isarankura na Ayutthaya S. , Kaabbuathong N. 
Published: April 2012

AbstractThis study has concerned preparation of polylactic acid grafted with maleated thermoplastic starch (PLA‐g‐MTPS) and a study on compatibilizing efficacy of the above copolymers in PLA/thermoplastic starch (TPS) blends. The PLA‐g‐MTPS copolymers were prepared by two‐step reaction. First, maleated thermoplastic starch (MTPS) was prepared by reacting cassava starch with glycerol and maleic anhydride (MA). Second, the MTPS was grafted onto PLA molecules using peroxide as an initiator. Chemical structures of the products were characterized by using Fourier transform infrared spectroscopy and 1H‐NMR techniques, whereas the acid numbers of the copolymers were determined by titration. Thermal characteristic of the copolymer was also characterized by using dynamic mechanical thermal analysis. In total, 5 wt % of the graft copolymer was blended with PLA and TPS in a twin screw extruder. Mechanical, rheological, and morphological properties of the blends were evaluated via tensile test, melt flow index test, and scanning electron microscopy, respectively. It was found that mechanical properties of the blends depended on starch content and type of the PLA‐g‐MTPS. When the PLA‐g‐MTPS was prepared at low amount (0.25 pph) of peroxide, the mechanical properties of the blend was improved remarkably as compared to those of the normal blend and/or the blend containing different compatibilizers. Compatibilizing efficacy of the above copolymers became more obvious when the thermoplastic starch (TPS) blending ratio was increased. The above results were ascribed in the light of change in the viscosity and morphology of the blends. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Kinetics of thermal degradation of nanometer calcium carbonate/linear low‐density polyethylene nanocomposites
Authors: Cao Xinxin , Gao Jungang , Dai Xin , Liu Yufei , He Xiaofang 
Published: April 2012

AbstractTo improve the thermal properties of linear low‐density polyethylene (LLDPE), the CaCO3/LLDPE nanocomposites were prepared from nanometer calcium carbonate (nano‐CaCO3) and LLDPE by melt‐blending method. A series of testing methods such as thermogravimetry analysis (TGA), differential thermogravimetry analysis, Kim‐Park method, and Flynn‐Wall‐Ozawa method were used to characterize the thermal property of CaCO3/LLDPE nanocomposites. The results showed that the CaCO3/LLDPE nanocomposites have only one‐stage thermal degradation process. The initial thermal degradation temperature T0 increasing with nano‐CaDO3 content, and stability of LLDPE change better. The thermal degradation activation energy (Ea) is different for different nano‐CaCO3 content. When the mass fraction of nano‐CaCO3 in nanocomposites is up to 10 wt %, the nanocomposite has the highest thermal degradation Ea, which is higher (28 kJ/mol) than pure LLDPE. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Molecular simulation on relationship between composition and microstructure of PP/PC blend
Authors: Dai Shanshan , Ye Lin , Hu Guo‐Hua 
Published: April 2012

AbstractSimulations based on molecular dynamics and mesodyn theories were used to investigate the compatibility, morphology evolution of polypropylene/polycarbonate (PP/PC) blends, and the relationship between the composition and microstructure. Results of Flory–Huggins interaction parameters, integral structure factor, X‐ray intensity, free‐energy density, and order parameters all indicated that phase separations occurred in all PP/PC blend systems, and poor compatibility was exhibited for this polymer pair. The systems of PP/PC = 54/46, PP/PC = 31/69, and PP/PC = 18/82 showed stronger immiscibility and the faster separation process, while the systems of PP/PC = 82/18 and PP/PC = 5/95 showed less immiscibility and a slower separation process. Compared with the results of mechanical properties tests, the appearance of a cocontinuous structure obtained from simulation corresponds to the transition point of impact strength and tensile strength. After transition, the mechanical properties of the blends depended on the properties of the PC matrix, and the impact strength and tensile strength were both clearly enhanced. As the simulation steps increased, the morphology of PP/PC = 54/46 blend developed into a double‐lamellar structure by coarsening of PC phase from initial homogeneous configuration. In addition, the compatibilizing effect of SEBS was also investigated at the microscale, and varying the content of PS block in SEBS has little effect on the morphology of blend. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The Role of Pendant Amines in the Breaking and Forming of Molecular Hydrogen Catalyzed by Nickel Complexes
Authors: Raugei Simone , Chen Shentan , Ho Ming‐Hsun , Ginovska‐Pangovska Bojana , Rousseau Roger J. , Dupuis Michel , DuBois Daniel L. , Bullock R. Morris 
Published: April 2012

AbstractWe present the results of a comprehensive theoretical investigation of the role of pendant amine ligands in the oxidation of H2 and formation of H2 by [Ni(PR2NR′2)2]2+ electrocatalysts (PR2NR′2 is the 1,5‐R′‐3,7‐R derivative of 1,5‐diaza‐3,7‐diphosphacyclooctane, in which R and R′ are aryl or alkyl groups). We focus our analysis on the thermal steps of the catalytic cycle, as they are known to be rate‐determining for both H2 oxidation and production. We find that the presence of pendant amine functional groups greatly facilitates the heterolytic H2 bond cleavage, resulting in a protonated amine and a Ni hydride. Only one single positioned pendant amine is required to serve this function. The pendant amine can also effectively shuttle protons to the active site, making the redistribution of protons and the H2 evolution a very facile process. An important requirement for the overall catalytic process is the positioning of at least one amine in close proximity to the metal center. Indeed, only protonation of the pendant amines on the metal center side (endo position) leads to catalytically active intermediates, whereas protonation on the opposite side of the metal center (exo position) leads to a variety of isomers, which are detrimental to catalysis.
Iron Borohydride Pincer Complexes for the Efficient Hydrogenation of Ketones under Mild, Base‐Free Conditions: Synthesis and Mechanistic Insight
Authors: Langer Robert , Iron Mark A. , Konstantinovski Leonid , Diskin‐Posner Yael , Leitus Gregory , Ben‐David Yehoshoa , Milstein David 
Published: April 2012

AbstractThe new, structurally characterized hydrido carbonyl tetrahydridoborate iron pincer complex [(iPr‐PNP)Fe(H)(CO)(η1‐BH4)] (1) catalyzes the base‐free hydrogenation of ketones to their corresponding alcohols employing only 4.1 atm hydrogen pressure. Turnover numbers up to 1980 at complete conversion of ketone were reached with this system. Treatment of 1 with aniline (as a BH3 scavenger) resulted in a mixture of trans‐[(iPr‐PNP)Fe(H)2(CO)] (4 a) and cis‐[(iPr‐PNP)Fe(H)2(CO)] (4 b). The dihydrido complexes 4 a and 4 b do not react with acetophenone or benzaldehyde, indicating that these complexes are not intermediates in the catalytic reduction of ketones. NMR studies indicate that the tetrahydridoborate ligand in 1 dissociates prior to ketone reduction. DFT calculations show that the mechanism of the iron‐catalyzed hydrogenation of ketones involves alcohol‐assisted aromatization of the dearomatized complex [(iPr‐PNP*)Fe(H)(CO)] (7) to initially give the Fe0 complex [(iPr‐PNP)Fe(CO)] (21) and subsequently [(iPr‐PNP)Fe(CO)(EtOH)] (38). Concerted coordination of acetophenone and dual hydrogen‐atom transfer from the PNP arm and the coordinated ethanol to, respectively, the carbonyl carbon and oxygen atoms, leads to the dearomatized complex [(iPr‐PNP*)Fe(CO)(EtO)(MeCH(OH)Ph)] (32). The catalyst is regenerated by release of 1‐phenylethanol, followed by dihydrogen coordination and proton transfer to the coordinated ethoxide ligand.
Coordination Studies on Supramolecular Chiral Ligands and Application in Asymmetric Hydroformylation
Authors: Bellini Rosalba , Reek Joost N. H. 
Published: April 2012

AbstractIn this study we introduce a series of monodentate pyridine‐based ligands for which the phosphorus coordination mode to rhodium can be controlled by the binding of ZnII‐templates to the pyridyl group. A series of monodentate phosphoroamidite and phosphite ligands have been prepared and studied under hydroformylation conditions by in situ high‐pressure NMR and IR techniques. These studies reveal the exclusive formation of rhodium hydride complexes in which the phosphorus atom of the ligand resides in an axial position, trans to the hydride, but only after addition of ZnII‐template. In the absence of these templates the usual mono‐coordinated rhodium hydrido complexes are formed, with the phosphorus ligated in the equatorial plane, cis to the hydride. The catalytic performance of these complexes is evaluated in asymmetric hydroformylation of unfunctionalised internal alkenes in which the supramolecular change is reflected in higher activity and selectivity.
Ultrafine and Fine Particles in the Atmosphere – Sampling, Chemical Characterization and Sources
Authors: Müller Konrad , Spindler Gerald , van Pinxteren Dominik , Gnauk Thomas , Iinuma Yoshiteru , Brüggemann Erika , Herrmann Hartmut 
Published: April 2012

AbstractAtmospheric ultrafine particles (UFP) are high in number but low in mass. Because of the ability to reach deeply into the lungs UFP can influence human health. Chemical analysis of UFP is to some extent possible after sampling by means of low pressure impactors. Main component classes of compounds in UFP are organic and elemental carbon and the water soluble ions ammonium, sulfate and nitrate. Single organic compounds such as polycyclic aromatic compounds, alkanes or levoglucosan can also be measured. Primary emissions of traffic and stationary combustion processes are one and secondary formation in the atmosphere from gaseous precursors is another major source. Organic matter and elemental carbon contribute up to 75 % to the mass of UFP. Parallel sampling at three locations, influenced by different emissions, helped to identify sources of particles.
Efficient Engineering by Modularization into Package Units
Authors: Rottke Johannes , Grote Florian , Fröhlich Holger , Köster Dirk , Strube Jochen 
Published: April 2012

AbstractThe development of efficient engineering methods is an objective of many current research activities. One of the main areas of focus in this context is modularization and standardization in order to reduce project execution time. The intellectual key issue of this approach is the definition of modules that can be reused in a multitude of plant designs, thereby gaining efficiency in comparison to individually created designs. The paper describes an approach to configure any plant design for vendor offers based on customer requests concerning varying capacities, product specifications, plant locations and individual modifications. The novel idea is to assemble a set of tools that allows for a direct connection of 3D plant layouts and the corresponding cost calculations. Ultimately, it is aiming to be able to calculate the equipment size by using a process simulation tool in accordance with defined capacities and the local boundaries of the construction site. As a first proof of principle for the concept HPLC technical plants in a scale of 150 to 1000 mm ID are presented and discussed.
CuO/ZnO Nanocomposite Gas Sensors Developed by a Plasma‐Assisted Route
Authors: Simon Quentin , Barreca Davide , Gasparotto Alberto , Maccato Chiara , Tondello Eugenio , Sada Cinzia , Comini Elisabetta , Sberveglieri Giorgio , Banerjee Manish , Xu Ke , Devi Anjana , Fischer Roland A. 
Published: April 2012

AbstractCuO/ZnO nanocomposites were synthesized on Al2O3 substrates by a hybrid plasma‐assisted approach, combining the initial growth of ZnO columnar arrays by plasma‐enhanced chemical vapor deposition (PE‐CVD) and subsequent radio frequency (RF) sputtering of copper, followed by final annealing in air. Chemical, morphological, and structural analyses revealed the formation of high‐purity nanosystems, characterized by a controllable dispersion of CuO particles into ZnO matrices. The high surface‐to‐volume ratio of the obtained materials, along with intimate CuO/ZnO intermixing, resulted in the efficient detection of various oxidizing and reducing gases (such as O3, CH3CH2OH, and H2). The obtained data are critically discussed and interrelated with the chemical and physical properties of the nanocomposites.
Photoanodes Based on Nanostructured WO3 for Water Splitting
Authors: Tacca Alessandra , Meda Laura , Marra Gianluigi , Savoini Alberto , Caramori Stefano , Cristino Vito , Bignozzi Carlo Alberto , Pedro Victoria Gonzalez , Boix Pablo P. , Gimenez Sixto , Bisquert Juan 
Published: April 2012

AbstractAnodically grown WO3 photoelectrodes prepared in an N‐methylformamide (NMF) electrolyte have been investigated with the aim of exploring the effects induced by anodization time and water concentration in the electrochemical bath on the properties of the resulting photoanodes. An n‐type WO3 semiconductor is one of the most promising photoanodes for hydrogen production from water splitting and the electrochemical anodization of tungsten allows very good photoelectrodes, which are characterized by a low charge‐transfer resistance and an increased spectral response in the visible region, to be obtained. These photoanodes were investigated by a combination of steady state and transient photoelectrochemical techniques and a correlation between photocurrent produced, morphology, and charge transport has been evaluated.
The Yale‐Brown‐Cornell eating disorders scale self‐report questionnaire: A new, efficient tool for clinicians and researchers
Authors: Bellace Dara L. , Tesser Rebecca , Berthod Samantha , Wisotzke Kimberly , Crosby Ross D. , Crow Scott J. , Engel Scott G. , Le Grange Daniel , Mitchell James E. , Peterson Carol B. , Simonich Heather K. , Wonderlich Stephen A. , Halmi Katherine A. 
Published: April 2012

AbstractObjective:The YBC‐EDS is a semistructured interview assessing core preoccupations and rituals related to eating disorders.Method:We developed and conducted an examination of the reliability and validity of a self‐report questionnaire (SRQ) version of the YBC‐EDS. Convergent validity of YBC‐EDS‐SRQ with the YBC‐EDS was examined for 112 eating disordered patients.Results:All subscales and total scores were significantly intercorrelated. Thirty‐one additional patients completed YBC‐EDS‐SRQ at admission and again 1 week later. All correlations revealed significant test–retest reliability. Discriminant validity of the SRQ was evaluated for a smaller subset of participants who completed the Beck Depression Inventory (BDI) and State Trait Anxiety Inventory (STAI). There were no significant correlations between various symptom dimensions of the YBC‐EDS‐SRQ and the BDI and STAI.Discussion:Taken together, these findings indicate that the self‐report form of the YBC‐EDS is both valid and reliable. The SRQ can serve as a useful and efficient assessment of eating disorder patients for clinicians and researchers. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2012;45:856–860)
Binge eating during pregnancy and birth outcomes: A cohort study in a disadvantaged population in Brazil
Authors: Nunes Maria Angélica Antunes , Pinheiro Andrea Poyastro , Camey Suzi Alves , Schmidt Maria Ines 
Published: April 2012

AbstractObjective:To assess the impact of binge eating behavior (BE) during pregnancy on birth outcomes among 697 Brazilian women who attended primary care.Method:Pregnant women answered a questionnaire on sociodemographic data, obstetric history, and The Eating Disorder Examination Questionnaire (EDE‐Q). Perinatal outcomes were obtained from birth records. Birth weight, prematurity, caesarean delivery, being small or large for gestational age were compared among women reporting BE (N = 119) and those without BE (N = 578). Poisson regression was used to estimate the association between BE during pregnancy and birth outcomes.Results:BE during pregnancy was not significantly associated with the birth outcomes analyzed. Gestational weight gain was significantly higher among those who reported BE.Discussion:Binge eating behavior during pregnancy may not influence birth outcomes as binge eating disorder does but affects gestational weight gain. Women reporting binge eating during pregnancy should undergo a diagnostic assessment for eating disorders. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2012;45:827–831)
Cannabidiol‐induced apoptosis in murine microglial cells through lipid raft
Authors: Wu Hsin‐Ying , Goble Kathleen , Mecha Miriam , Wang Chia‐Chi , Huang Chung‐Hsiung , Guaza Carmen , Jan Tong‐Rong 
Published: April 2012

AbstractCannabidiol (CBD), the major nonpsychotropic phytocannabinoid, induces apoptosis in both immortalized and primary lymphocytes and monocytes. However, contrasting effects of CBD on the apoptosis between normal and immortalized glial cells have been reported. This study investigated the proapoptotic effect of CBD on primary microglial cells. Treatment of murine primary microglial cultures with CBD resulted in a time‐ and concentration‐dependent induction of apoptosis, as shown by increase in hypodiploid cells and DNA strand breaks, and marked activation of both caspase‐8 and −9. Mechanistic studies revealed that antioxidants, including N‐acetyl‐L‐cysteine and glutathione, the G protein‐coupled receptor 55 agonist abnormal‐CBD and specific antagonists for vanilloid, and CB1 and CB2 cannabinoid receptors did not counteract the apoptosis induced by CBD. In contrast, methyl‐β‐cyclodextrin (MCD), a lipid raft disruptor, potently attenuated CBD‐induced microglial apoptosis and caspase activation. Furthermore, CBD induced lipid raft coalescence and augmented the expression of GM1 ganglioside and caveolin‐1, all of which were attenuated by MCD. Taken together, these results suggest that CBD induces a marked proapoptotic effect in primary microglia through lipid raft coalescence and elevated expression of GM1 ganglioside and caveolin‐1. © 2012 Wiley Periodicals, Inc.
Association of Risk Factors with Musculoskeletal Disorders among Male Commercial Bus Drivers in Malaysia
Authors: Tamrin Shamsul Bahri M. , Yokoyama Kazuhito , Aziz Nasaruddin , Maeda Setsuo 
Published: April 2012

AbstractA national study in Malaysia was conducted with the main objective being to determine the prevalence of musculoskeletal disorders (MSDs) and the association between risk factors and MSDs among Malaysian bus drivers. Cross‐sectional data were collected from 1,181 male commercial bus drivers in Malaysia using questionnaires to determine demographic, working characteristics and a translated Nordic questionnaire to determine MSD complaints. A Human Vibration Meter was used to measure whole body vibration (WBV) exposure, and postural analysis was used to evaluate awkward working posture. To assess psychological factors, the validated Profile of Mood States (POMS) was used. The overall prevalence of MSD was 81.8% and, by body parts, low back pain was reported to be the highest complaint of lifetime MSD (58.5%) compared to other body parts. The levels of WBV acceleration magnitude A(8) exceed the European Union Directive (0.54 m/s2 root‐mean‐square [r.m.s.] acceleration), and only 1.2% of the bus drivers adopt more than 40% of awkward postures while driving. Logistic regression analysis, controlling for age, income, education level, and work activities, revealed that factors such as lack of seat adjustability, uncomfortable seat, seat's material, seat contour and design, WBV exposure, smoking, frequency of daily trips, duration of daily driving, prolonged sitting, working part time, and psychological factors (namely, feeling stress, feeling worried, feeling fatigued) were important risk factors of MSDs among Malaysian bus drivers. As a conclusion, bus drivers are exposed to a combination of risk factors that may lead to an increased risk of developing MSDs. © 2012 Wiley Periodicals, Inc.
Total waterborne carbon export and DOC composition from ten nested subarctic peatland catchments—importance of peatland cover, groundwater influence, and inter‐annual variability of precipitation patterns
Authors: Olefeldt David , Roulet Nigel , Giesler Reiner , Persson Andreas 
Published: April 2012

AbstractWaterborne carbon (C) export from terrestrial ecosystems is a potentially important flux for the net catchment C balance and links the biogeochemical C cycling of terrestrial ecosystems to their downstream aquatic ecosystems. We have monitored hydrology and stream chemistry over 3 years in ten nested catchments (0.6–15.1 km2) with variable peatland cover (0%–22%) and groundwater influence in subarctic Sweden. Total waterborne C export, including dissolved and particulate organic carbon (DOC and POC) and dissolved inorganic carbon (DIC), ranged between 2.8 and 7.3 g m–2 year–1, representing ~10%–30% of catchment net ecosystem exchange of CO2. Several characteristics of catchment waterborne C export were affected by interacting effects of peatland cover and groundwater influence, including magnitude and timing, partitioning into DOC, POC, and DIC and chemical composition of the exported DOC. Waterborne C export was greater during the wetter years, equivalent to an average change in export of ~2 g m–2 year–1 per 100 mm of precipitation. Wetter years led to a greater relative increase in DIC export than DOC export due to an inferred relative shift in dominance from shallow organic flow pathways to groundwater sources. Indices of DOC composition (SUVA254 and a250/a365) indicated that DOC aromaticity and average molecular weight increased with catchment peatland cover and decreased with increased groundwater influence. Our results provide examples on how waterborne C export and DOC composition might be affected by climate change. Copyright © 2012 John Wiley & Sons, Ltd.