bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permeation resistance of poly(ether ether ketone) to hydrogen, nitrogen, and oxygen gases
Authors: Monson Loxie , Moon Sung In , Extrand C. W. 
Published: May 2012

AbstractWe studied the gas permeation properties of poly(ether ether ketone) (PEEK) and compared it with two other polymers commonly used in the construction of semiconductor microenvironments, polycarbonate (PC), and poly(ether imide) (PEI). The PEEK specimens consisted of extruded films as well as compression‐ and injection‐molded specimens. The compression‐molded specimens were prepared to achieve the highest crystallinity. Injection‐molded disks, representing products, were milled to a prescribed thickness. Permeation, diffusion, and solubility coefficients were measured on these various PEEK specimens for hydrogen, nitrogen, and oxygen gases. It was found that PEEK generally has better permeation resistance than PC or PEI; showing up to five times lower permeation rates than PC or PEI, depending on grade, crystallinity, and gas. The superior permeation resistance of injection‐molded or extruded PEEK, when compared with similarly processed PC or PEI, comes from its crystallinity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Properties of rigid polyurethane foams prepared from recycled aircraft deicing agent with hexamethylene diisocyanate
Authors: Wang Bao , Cheng Yan‐Ling , Liu Yuhuan , Chen Paul , Li Dong , Ruan Roger 
Published: May 2012

AbstractPolyurethane (PUR) rigid foams were prepared from recycled aircraft deicing agent (aircraft deicing fluid) with reaction of hexamethylene diisocyanate at temperature of 55°C. The effect of [NCO]/[OH] ratio on properties of microscopic structure, cell size distribution, compressive strength, apparent density, as well as thermal conductivity (k) was studied. Higher [NCO]/[OH] ratio helped achieve better micromorphology, higher apparent density, and compressive strength of the PUR foams. With the [NCO]/[OH] ratio of 0.75 and 0.8, some shrinking happened during foam rising, causing a decrease in total volume of the PUR foam, and leading to higher apparent density as well as sharply increased compressive strength. All PUR foams displayed good thermal insulation properties in this study. With [NCO]/[OH] ratio increased from 0.7 to 0.8, the k value increased significantly from 34.3 to 42.2 mW m−1 K−1. The k value here was chiefly governed by the apparent density of the foams, which was in turn a function of the ratio of [NCO]/[OH]. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Molecularly imprinted “bulk” copolymers as selective sorbents for gallic acid
Authors: Nicolescu Tanta‐Verona , Sarbu Andrei , Ovidiu Dima Stefan , Nicolae Cristian , Donescu Dan 
Published: May 2012

AbstractWe report the synthesis of molecularly imprinted sorbents, selective for gallic acid. The particles were prepared by using acrylic acid, acrylonitrile, and hydroxyethyl methacrylate as functional monomers, whereas ethyleneglycol dimethacrylate and 1,4‐buthanediol dimethacrylate were used as crosslinkers. Preparation and manipulation protocols were adjusted considering template's nature. To highlight the influence of monomer/crosslinker nature upon imprinted particles, the adsorption capacity, the imprinting factor, and the distribution and selectivity coefficients were calculated. An imprinting factor of 3.53 and a selectivity coefficient of 6.86 were found for hydroxyethyl methacrylate/ethylene glycol methacrylate system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci. 2013
Prediction of mechanical properties of compatibilized styrene/natural‐rubber blend by using reaction conditions: Central composite design vs. artificial neural networks
Authors: Sresungsuwan Natsupa , Hansupalak Nanthiya 
Published: May 2012

AbstractA polystyrene (PS)/rubber blend compatibilized with PS‐g‐rubber copolymer, prepared via emulsion polymerization using redox initiator system, is used to investigate the utilization of central composite design (CCD) and artificial neural network (ANN) approaches in correlating polymerization conditions to mechanical properties (tensile strength and abrasion loss) of unfilled compound vulcanizates. The conditions were manipulated by changing four factors: reaction temperature and time, percentage of deproteinized rubber in the mixture containing natural rubber, and amount of chain transfer agent. The results show that the relationships between the conditions and the mechanical properties for compatibilized PS/rubber blend are too complex to be explained by polynomials, but are well described by the ANN models, developed for each response. In addition, simulation results for the tensile strength response as a function of those factors using the obtained ANN are in agreement with literature, whereas those results for the abrasion loss do not quite agree with literature due to the interference of the large measurement error. This suggests that only experimental data with high precision should be used to train an ANN to achieve a model with not only best performance but also high reliability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci. 2013
Cationic fluorinated polyacrylate core‐shell latex with pendant long chain alkyl: Synthesis, film morphology, and its performance on cotton substrates
Authors: An Qiufeng , Xu Wei , Hao Lifen , Huang Liangxian 
Published: May 2012

AbstractWe synthesized a novel cationic fluorinated polyacrylate latex (FLDH) with pendant long chain alkyl by copolymerization of perfluoroalkyl ethyl acrylate, lauryl methacrylate, dimethylaminoethyl methacrylate, and 2‐hydroxypropyl acrylate. FTIR, 1H‐NMR, TEM, DSC, and TGA were used to characterize the as‐prepared FLDH. Then fine morphology, components, and hydrophobicity of films on silicon wafer and cotton substrates were investigated by scanning electron microscope, field emission scanning electronic microscope, atomic force microscope, X‐ray photoelectron spectroscopy (XPS), contact angle meter, etc. Results showed that the FLDH particles had quasi‐spherical core‐shell structure with an average diameter of 144 nm. The core‐shell FLDH film thus had two Tg and its thermal property was improved compared to fluorine‐free acrylate latex. FLDH could form a film on both the cotton fiber and silicon wafer substrate. At an amplification of <60,000 (of the original fiber) and the observation rule (working distance) of >100 nm, FLDH showed a smooth resin film on the treated fabric/fiber surface. However, as the observation rule decreased to 2 nm‐almost a molecular lever‐the FLDH film mostly exhibited an inhomogeneous structure and uneven morphology in its atomic force microscope images. There were many low or high peaks in FLDH topography. Consequently, in 5 μm2 scanning field, the root mean square roughness of FLDH film reached to 0.506 nm. XPS analysis indicated the perfluoroalkyl groups had the tendency to enrich at the surface. In addition, water contact angle of the treated fabric could attain 146.2°. FLDH do not influence whiteness of the treated fabric but will make it slightly stiff at high doses. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Review of climate change impacts on marine fish and shellfish around the UK and Ireland
Authors: Heath Michael R. , Neat Francis C. , Pinnegar John K. , Reid David G. , Sims David W. , Wright Peter J. 
Published: May 2012

ABSTRACT

Recent and projected future changes in the temperature and chemistry of marine waters around the UK and Ireland are having, and will in the future have, effects on the phenology, productivity and distribution of marine fish and shellfish. However, the overall consequences are still hard to predict because behaviour, genetic adaptation, habitat dependency and the impacts of fishing on species, result in complex species' responses that may be only partially explained by simple climate envelope predictions.
There is a broad body of evidence that climatic fluctuations are playing an important role in changing fish distributions and abundances, which is discernible against the background of trends in abundance due to fishing. During warm periods, southern species have tended to become more prominent and northern species less abundant. However, the changes in distribution are often more complicated than might be expected from a simple climate envelope approach, partly due to ocean circulation patterns which create invasion routes for southern water species into the North Sea from the south and from the north via the continental shelf west of Britain and Ireland.
The eventual population‐scale impacts of ocean acidification on fish and shellfish are currently very difficult to predict. However, the scant evidence suggests that indirect food web effects arising from the enhanced sensitivity of calcifying planktonic organisms may be important, and the direct effect on fish sensory systems leading to subtle influences on behaviour with possible population‐level implications are possible.
In British waters, the lesser sandeel (Ammodytes marinus) is identified as being at particular risk from climate change. Owing to its strict association with coarse sandy sediments it is unable to adapt its distribution to compensate for warming sea temperatures. Sandeels are a key link in the food web, linking primary and zooplankton production to top predators. Copyright © 2012 John Wiley & Sons, Ltd.
Review of climate change impacts on marine fisheries in the UK and Ireland
Authors: Cheung William W. L. , Pinnegar John , Merino Gorka , Jones Miranda C. , Barange Manuel 
Published: May 2012

ABSTRACT

Commercial fishing is an important socio‐economic activity in coastal regions of the UK and Ireland. Ocean–atmospheric changes caused by greenhouse gas emissions are likely to affect future fish and shellfish production, and lead to increasing challenges in ensuring long‐term sustainable fisheries management.
The paper reviews existing knowledge and understanding of the exposure of marine ecosystems to ocean‐atmospheric changes, the consequences of these changes for marine fisheries in the UK and Ireland, and the adaptability of the UK and Irish fisheries sector.
Ocean warming is resulting in shifts in the distribution of exploited species and is affecting the productivity of fish stocks and underlying marine ecosystems. In addition, some studies suggest that ocean acidification may have large potential impacts on fisheries resources, in particular shell‐forming invertebrates.
These changes may lead to loss of productivity, but also the opening of new fishing opportunities, depending on the interactions between climate impacts, fishing grounds and fleet types. They will also affect fishing regulations, the price of fish products and operating costs, which in turn will affect the economic performance of the UK and Irish fleets.
Key knowledge gaps exist in our understanding of the implications of climate and ocean chemistry changes for marine fisheries in the UK and Ireland, particularly on the social and economic responses of the fishing sectors to climate change. However, these gaps should not delay climate change mitigation and adaptation policy actions, particularly those measures that clearly have other ‘co‐benefits’. Copyright © 2012 John Wiley & Sons, Ltd.
Rates of hospitalized bacterial infection associated with juvenile idiopathic arthritis and its treatment
Authors: Beukelman Timothy , Xie Fenglong , Chen Lang , Baddley John W. , Delzell Elizabeth , Grijalva Carlos G. , Lewis James D. , Ouellet‐Hellstrom Rita , Patkar Nivedita M. , Saag Kenneth G. , Winthrop Kevin L. , Curtis Jeffrey R. ,   on behalf of the SABER Collaboration
Published: May 2012

AbstractObjectiveTo compare the incidence of hospitalized bacterial infections among children with and children without juvenile idiopathic arthritis (JIA) and to examine the effects of selected medications.MethodsUsing national Medicaid data from 2000 through 2005, we identified a cohort of children with JIA and a comparator cohort of children with attention deficit hyperactivity disorder (ADHD). Exposures to methotrexate (MTX), TNF inhibitors, and oral glucocorticoids (GCs) were determined using pharmacy claims. Patients hospitalized with bacterial infections were identified using coded discharge diagnoses. We calculated adjusted hazard ratios (HRadj) to compare infection incidence rates while adjusting for relevant covariates.ResultsWe identified 8,479 JIA patients with 13,003 person‐years of followup; 36% took MTX and 16% took TNF inhibitors. Compared with ADHD patients, JIA patients who were not currently taking MTX or TNF inhibitors had an increased rate of infection (HRadj 2.0 [95% confidence interval (95% CI) 1.5, 2.5]). Among JIA patients not receiving TNF inhibitor therapy, MTX users had a similar rate of infection as those not currently taking MTX (HRadj 1.2 [95% CI 0.9, 1.7]). TNF inhibitor use (irrespective of MTX) resulted in a similar rate of infection as use of MTX without a TNF inhibitor (HRadj 1.2 [95% CI 0.8, 1.8]). Use of high‐dose GCs (≥10 mg/day of prednisone or equivalent) increased the rate of infection as compared with no GC use, after adjustment for MTX and TNF inhibitor use (HRadj 3.1 [95% CI 2.0, 4.7]).ConclusionChildren with JIA had an increased rate of infection compared to children with ADHD. Among children with JIA, the rate of infection was not increased with MTX or TNF inhibitor use, but was significantly increased with high‐dose GC use.
Adaptive Harmonic Steady‐State Disturbance Rejection with Frequency Tracking
Authors: Pigg S. , Bodson M. 
Published: May 2012

AbstractThis paper is concerned with the rejection of sinusoidal disturbances of unknown frequency acting at the output of unknown plants. Disturbance rejection is based on an adaptive harmonic steady‐state (ADHSS) algorithm combined with a magnitude/phase locked‐loop (MPLL) frequency estimator. The harmonic steady‐state method assumes that the plant can be approximated by its steady‐state frequency response. For high‐order plants such as those encountered in active noise and vibration control (ANVC), this assumption greatly reduces the number of parameters and enables online estimation of the plant response using simple algorithms. The paper shows that when the MPLL is integrated with the ADHSS algorithm, the two components work together in such a way that the control input does not prevent frequency tracking by the MPLL, and so that the order of the ADHSS can be reduced. Thus, the addition of the MPLL allows disturbances of unknown frequency to be considered without significantly increasing the complexity of the original ADHSS. After analyzing the reduced‐order ADHSS in the ideal case, the equations describing the complete system are considered. The theory of averaging is used to gain insight into the steady‐state behavior of the algorithm. It is found that the system has a two‐dimensional equilibrium surface such that the disturbance is cancelled exactly. A subset of the surface is proved to be locally stable. Extensive active noise control experiments demonstrate the performance of the algorithm, even when disturbance and plant parameters are changing.
Optimization of mixed cycle length traffic signals
Authors: Kesur Khewal Bhupendra 
Published: May 2012

SUMMARYMixed cycle length operation has been recommended for networks where individual intersections process considerably different traffic volumes. The signals to operate at lower or higher cycle lengths are determined heuristically. This paper demonstrates that the use of mixed cycle lengths as given by the heuristic is inferior to operation under a common cycle length. This contradicts findings in earlier studies, and the difference in conclusion is due to the use of updated optimization methodology. A procedure for incorporating the allocation of mixed cycle lengths into the global optimization of all signal timing variables by a genetic algorithm is proposed. The mixed cycle length timing plans obtained from this procedure are an improvement over those determined heuristically. Mixed cycle length operation is found to be of a more limited application than indicated in previous studies. Copyright © 2012 John Wiley & Sons, Ltd.
Inducing mechanism of biological phosphorus removal driven by the aerobic/extended‐idle regime
Authors: Wang Dongbo , Yang Guojing , Li Xiaoming , Zheng Wei , Wu Yan , Yang Qi , Zeng Guangming 
Published: May 2012

AbstractRecently, it was found that excess phosphorus (Pi) removal could be achieved in activated sludge with an aerobic/extended‐idle (AEI) process. In this study, batch tests were performed to further reveal the inducing mechanism of Pi removal involved in the AEI process. Unlike the classical anaerobic/aerobic process where an anaerobic Pi release along with a significant polyhydroxyalkanoate (PHA) accumulation drives polyphosphate (poly‐P) accumulating organisms (PAOs) to over‐store Pi as poly‐P, an idle Pi release accompanied by a low‐idle PHA production, which is usually considered to be detrimental for biological Pi removal, was observed to induce some cells to effectively uptake Pi in excess of metabolic requirement in the AEI process. With the increase of idle Pi release, Pi removal efficiency linearly increased. The results also showed that a long idle period with a low level of intracellular glycogen could significantly increase Pi release contents, thus remarkably enhancing Pi removal performances. Fluorescence in situ hybridization analysis further revealed that activated sludge in the AEI process contained 37.6% of Accumulibacter (PAOs) and 28.2% of Competibacter and Defluviicoccus‐related organisms (glycogen accumulating organisms). This study revealed an actually existent, yet previously unrecognized, inducing mechanism of poly‐P accumulation, and this mechanism behind the AEI regime may provide a scientific basis for the development of an alternative strategy for Pi removal from wastewaters. Biotechnol. Bioeng. 2012; 109: 2798–2807. © 2012 Wiley Periodicals, Inc.
Production of miltiradiene by metabolically engineered Saccharomyces cerevisiae
Authors: Dai Zhubo , Liu Yi , Huang Luqi , Zhang Xueli 
Published: May 2012

AbstractMetabolic engineering of microorganisms is an alternative and attractive route for production of valuable terpenoids that are usually extracted from plant sources. Tanshinones are the bioactive components of Salvia miltiorrhizha Bunge, which is a well‐known traditional Chinese medicine widely used for treatment of many cardiovascular diseases. As a step toward microbial production of tanshinones, copalyl diphosphate (CPP) synthase, and normal CPP kaurene synthase‐like genes, which convert the universal diterpenoid precursor geranylgeranyl diphosphate (GGPP) to miltiradiene (an important intermediate of the tanshinones synthetic pathway), was introduced into Saccharomyces cerevisiae, resulting in production of 4.2 mg/L miltiradiene. Improving supplies of isoprenoid precursors was then investigated for increasing miltiradiene production. Although over‐expression of a truncated 3‐hydroxyl‐3‐methylglutaryl‐CoA reductase (tHMGR) and a mutated global regulatory factor (upc2.1) gene did improve supply of farnesyl diphosphate (FPP), production of miltiradiene was not increased while large amounts of squalene (78 mg/L) were accumulated. In contrast, miltiradiene production increased to 8.8 mg/L by improving supply of GGPP through over‐expression of a fusion gene of FPP synthase (ERG20) and endogenous GGPP synthase (BTS1) together with a heterologous GGPP synthase from Sulfolobus acidocaldarius (SaGGPS). Auxotrophic markers in the episomal plasmids were then replaced by antibiotic markers, so that engineered yeast strains could use rich medium to obtain better cell growth while keeping plasmid stabilities. Over‐expressing ERG20‐BTS1 and SaGGPS genes increased miltiradiene production from 5.4 to 28.2 mg/L. Combinatorial over‐expression of tHMGR‐upc2.1 and ERG20‐BTS1‐SaGGPS genes had a synergetic effects on miltiradiene production, increasing titer to 61.8 mg/L. Finally, fed‐batch fermentation was performed, and 488 mg/L miltiradiene was produced. The yeast strains engineered in this work provide a basis for creating an alternative way for production of tanshinones in place of extraction from plant sources. Biotechnol. Bioeng. 2012; 109: 2845–2853. © 2012 Wiley Periodicals, Inc.
Physiological response of Clostridium carboxidivorans during conversion of synthesis gas to solvents in a gas‐fed bioreactor
Authors: Ukpong Michael N. , Atiyeh Hasan K. , De Lorme Marthah J.M. , Liu Kan , Zhu Xiaoguang , Tanner Ralph S. , Wilkins Mark R. , Stevenson Bradley S. 
Published: May 2012

AbstractClostridium carboxidivorans P7 is one of three microbial catalysts capable of fermenting synthesis gas (mainly CO, CO2, and H2) to produce the liquid biofuels ethanol and butanol. Gasification of feedstocks to produce synthesis gas (syngas), followed by microbial conversion to solvents, greatly expands the diversity of suitable feedstocks that can be used for biofuel production beyond commonly used food and energy crops to include agricultural, industrial, and municipal waste streams. C. carboxidivorans P7 uses a variation of the classic Wood–Ljungdahl pathway, identified through genome sequence‐enabled approaches but only limited direct metabolic analyses. As a result, little is known about gene expression and enzyme activities during solvent production. In this study, we measured cell growth, gene expression, enzyme activity, and product formation in autotrophic batch cultures continuously fed a synthetic syngas mixture. These cultures exhibited an initial phase of growth, followed by acidogenesis that resulted in a reduction in pH. After cessation of growth, solventogenesis occurred, pH increased and maximum concentrations of acetate (41 mM), butyrate (1.4 mM), ethanol (61 mM), and butanol (7.1 mM) were achieved. Enzyme activities were highest during the growth phase, but expression of carbon monoxide dehydrogenase (CODH), Fe‐only hydrogenases and two tandem bi‐functional acetaldehyde/alcohol dehydrogenases were highest during specific stages of solventogenesis. Several amino acid substitutions between the tandem acetaldehyde/alcohol dehydrogenases and the differential expression of their genes suggest that they may have different roles during solvent formation. The data presented here provide a link between the expression of key enzymes, their measured activities and solvent production by C. carboxidivorans P7. This research also identifies potential targets for metabolic engineering efforts designed to produce higher amounts of ethanol or butanol from syngas. Biotechnol. Bioeng. 2012; 109: 2720–2728. © 2012 Wiley Periodicals, Inc.