bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer Membranes for Fuel Cells
Authors: Wycisk Ryszard , Ballengee Jason , Pintauro Peter N. 
Published: April 2013

Abstract
Polymeric membranes are a key component of hydrogen/air and direct methanol fuel cells. The desired properties of fuel cell membranes are (i) high proton conductivity, (ii) high mechanical strength, (iii) good oxidative and thermal stability, (iv) low fuel and oxidant permeability, and (v) low cost. The most important and most widely studied membrane polymers include perfluorosulfonic acids (PFSAs), poly(arylene ether)s, polyimides, polyphosphazenes, and polybenzimidazole. Membranes are fabricated via melt extrusion and, most frequently, by solution casting. Composite membranes offer improved mechanical strength and higher temperature stability. Typically, composite membranes are obtained by pore filling, layer‐by‐layer assembly, and electrospinning. The list of current fuel cell membrane manufacturers is relatively short. Most notable is E.I. DuPont de Nemours and Co., which sells PFSA membranes under the trade name Nafion®. Other manufacturers are Solvay Solexis, FuMA‐Tech, BASF, Tokuyama, and Asahi Kasei Chemical Corporation.
CO2Capture
Authors: He Xuezhong , Yu Qiang , Hägg May‐Britt 
Published: April 2013

AbstractGlobal warming is becoming a world‐challenging issue related to the emission of greenhouse gases, mainly from CO2. A lot of effort has been put on reduction of CO2emission from large CO2point sources such as fossil fuel power plants and other industries. Membrane technology has already been used in selected gas separation processes such as air separation, natural gas sweetening, biogas upgrading, and hydrogen production during the last two decades, and can be potentially used for CO2capture due to its energy‐efficient and low cost. In this article, a brief review of membrane materials (organic and inorganic) and their properties (physical, chemical, thermal, mechanical stability, and gas separation performance) is provided, and then the main directions of industrial applications of CO2capture using membrane systems are also surveyed. The challenges of membrane systems used for CO2capture are discussed to document that process design and pretreatment are very important for membrane unit operations. Moreover, the process feasibility for CO2capture using different membranes was evaluated by process simulation, economic cost estimation and comparison with traditional amine‐based absorption method in some specific applications.
Natural Gas Purification
Authors: Lin Haiqing , White Lloyd S. , Lokhandwala Kaaeid , Baker Richard W. 
Published: April 2013

AbstractSince the installation of the first membrane system for CO2removal in the early 1980s, membrane separation has become a proven technology for natural gas purification, such as the removal of carbon dioxide, hydrogen sulfide, heavy hydrocarbons, and nitrogen. Membrane systems can perform the bulk removal of impurities or produce pipeline natural gas. Today, large membrane plants can process up to 1 billion standard cubic feet of natural gas per day (scfd) for CO2removal. This article outlines the advantages of and challenges to membrane processes for natural gas purification, and provides an overview of the advancement in membrane materials, membrane structure, membrane separation performance, module configuration, and process designs for natural gas purification. Furthermore, this article reviews the current commercial membrane systems installed in natural gas processing plants, providing theory and literature references relevant to commercially practiced technology, as well as case design studies derived from actual industrial installations.
Membrane Contactors
Authors: Criscuoli Alessandra 
Published: April 2013

AbstractThis article gives a general outline on membrane contactors, providing basic information on how these systems work, the unit operations that they can cover, the membranes used, the main advantages and disadvantages with respect to conventional devices, as well as the most studied applications. The aspects of these membrane operations that still need to be improved for enlarging and consolidating their areas of application are also reported. The goal is to furnish a general knowledge on the subject, underlining potentialities, problems, and research trends in the field.
Application of Membranes in Biotechnology
Authors: Ghosh Raja 
Published: April 2013

AbstractMembranes are widely used in biotechnology with the main applications being focused around bioproduct purification. Membranes are also used for laboratory filtration and analysis as components of membrane bioreactors, for biomedical applications such as dialysis and blood oxygenation, and for drug delivery. This article reviews the application of membranes in biological separation processes. The membranes techniques commonly used in these applications are microfiltration, ultrafiltration, and membrane chromatography. This article first reviews the common features and then discusses them individually, highlighting working principles and specific applications.
Membrane‐Based Treatment of Textile Industry Wastewaters
Authors: Koyuncu Ismail , Güney Kenan 
Published: April 2013

AbstractTextile industry is distinguished from other industries by using a great variety of chemicals and large water consumption. As the cost of freshwater increases and the regulations become stringent, the need for reuse of textile effluents is growing enormously. In this article, membrane‐based treatments of textile industry wastewater is discussed. First, characteristics of textile industry wastewater are given. Then, treatment scenarios at different points of the industry are explained. Nanofiltration (NF) and reverse osmosis (RO) separation processes with/without ultrafiltration (UF) pretreatment are investigated in detail for segregated streams. It is observed that segregated water reuse concept has more advantages than the end‐of‐pipe treatment by means of water volume reused and chemicals recycled.
Individual and National Level Associations Between Economic Deprivation and Partner Violence Among College Students in 31 National Settings
Authors: Sabina Chiara 
Published: April 2013

AbstractThis study expands previous work by examining individual and national level effects of economic deprivation on partner violence among college students. Three main hypotheses were tested: (1) individual level economic deprivation (i.e., ability to meet daily needs and family income) is associated with partner violence, (2) gross national income is associated with the mean rates of partner violence across nations, and (3) the association between individual level economic deprivation and partner violence varies according to the economic national context as measured by gross national income. Data for 14,090 participants from 31 nations came from the International Dating Violence Study that queried university students about violence in their relationships and relevant risk factors. A series of overdispersed Poisson hierarchical linear regression models were specified to test the hypotheses. Ability to meet daily needs, but not family income, was associated with rates of partner violence. Gross national income was also associated with mean rates of partner violence across nations as well as the relationships between ability to meet daily and partner violence and between family income and partner violence. The findings show the importance of context, as indicated by national economic standing, on rates of partner violence. Not only do economically deprived individuals experience more partner violence, but those living in poorer nations experience more partner violence, regardless of individual economic deprivation. Limitations of the study include a non‐random sample and substantial variation in the study sites beyond economic standing. Nonetheless, findings indicate efforts to confront partner violence must also call for cross‐national economic development. Aggr. Behav. 39:247–256, 2013. © 2013 Wiley Periodicals, Inc.
Preparation and characterization of surface modified silicon carbide/polystyrene nanocomposites
Authors: Cao Jian‐Ping , Zhao Jun , Zhao Xiaodong , Hu Guo‐Hua , Dang Zhi‐Min 
Published: April 2013

AbstractA simple method is reported to coat silicon carbide (SiC) nanoparticles with polystyrene (PS) to improve the interfacial adhesion between polymer matrix and SiC nanoparticles. The morphology of untreated SiC nanoparticles, PS coated SiC (p‐SiC) nanoparticles, SiC/PS nanocomposites, and p‐SiC/PS nanocomposites are observed. The HRTEM image of p‐SiC shows that the thickness of PS on the surface of SiC is about 1.5–2.0 nm, which is consistent with the TGA results. With 24.7 vol % untreated SiC nanoparticles dispersed into PS matrix, the thermal conductivity (λ) of the SiC/PS composites increases by about 192%. However, when the same volume fraction of p‐SiC nanoparticles is used, the increase is about 353%. This big difference could be attributed to the promoted dispersion of the p‐SiC in the PS matrix. The measurements of glass transition (Tg), dielectric constant (ε), and tensile strength at break (σb) also support this explanation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Influence of the mixing time on the phase structure and glass‐transition behavior of poly(ethylene terephthalate)/poly(ethylene‐2,6‐naphthalate) blends
Authors: Tao Wang , Wei Wu , Yu Chen , Ren Wu , Qiaoling Luo 
Published: April 2013

AbstractBlends of poly(ethylene terephthalate) and poly(ethylene‐2,6‐naphthalate) (70 : 30 w/w) were prepared via a melt‐mixing process at 280°C with various mixing times. The melt‐mixed blends were analyzed by magnetic resonance spectroscopy, differential scanning calorimetry, dynamic mechanical measurements, transmission electron microscopy, and tensile tests. The results indicate that the blends mixed for short times had lower extents of transesterification and were miscible to a limited extent. The blends initially show two glass transitions, which approached more closely and merged gradually with increasing mixing time. A mechanical model was used to help understand the glass‐transition behavior. With increasing mixing time, the phase structure of the blends improved, and this led to an increase in the tensile strength. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of UV reactive montmorillonite and characterization of its nanocomposites with poly(vinyl alcohol)
Authors: Schauberger Jörg Guido , Riess Gisbert , Kern Wolfgang 
Published: April 2013

AbstractA cation‐exchanged montmorillonite clay is prepared as filler material with high dispersibility, that should act as Fe3+‐donor for photochemical crosslinking of PVA/Fe3+‐MMT materials with filler contents of up to 50 wt % with regard to the polymer matrix. Hence, no organic photoinitiators and hazardous compounds are utilized. This material may be considered environmentally benign and could be applied in the field of food packaging or for biomedical applications. Upon UV exposure of liquid PVA/Fe3+‐MMT dispersion samples, a significant change of the refractive index is determined and the absorption at 360 nm decreased. This indicates the transition of Fe3+ to Fe2+, which initiates a radical crosslinking mechanism. A homogenous distribution and parallel orientation of the modified clay particles is revealed by SEM measurements. The solubility behavior of the PVA/Fe3+‐MMT composite materials in deionized water, changes considerably due to the high filler content and UV‐induced crosslinking, resulting in gel contents exceeding 90 wt %. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Periconceptional paternal smoking and the risk of congenital heart defects: A case‐control study
Authors: Deng Kui , Liu Zhen , Lin Yuan , Mu Dezhi , Chen Xinlin , Li Jun , Li Nana , Deng Ying , Li Xiaohong , Wang Yanping , Li Shengli , Zhu Jun 
Published: April 2013

BackgroundMaternal smoking during pregnancy has been consistently associated with an increased risk of congenital heart defects (CHDs). However, few studies have reported the association between paternal smoking during pregnancy and CHDs among offspring. This report presents the first case‐control study to investigate the possible association between periconceptional paternal smoking and CHDs in China.MethodsFrom February 2010 through October 2011, 284 case fetuses with nonsyndromic CHDs and 422 control fetuses with no birth defects were recruited. The mothers of cases and controls were interviewed regarding whether the fathers of fetuses smoked and avoided the mothers while smoking during the periconceptional period. An unconditional logistic regression was used to calculate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) while controlling for potential confounders.RESULTSLight paternal smoking increased the risk of isolated conotruncal heart defects (AOR, 2.23; 95% CI, 1.05, 4.73). Medium paternal smoking seemed to be associated with septal defects (AOR, 2.04; 95% CI, 1.05, 3.98) and left ventricular outflow tract obstructions (AOR, 2.48; 95% CI, 1.04, 5.95). Heavy paternal smoking was also associated with isolated conotruncal heart defects (AOR, 8.16; 95% CI, 1.13, 58.84) and left ventricular outflow tract obstructions (AOR, 13.12; 95% CI, 2.55, 67.39). Paternal smoking with no avoidance behavior was associated with an increased risk of these CHDs subtypes.CONCLUSIONSPericonceptional paternal smoking increased the risk of isolated conotruncal heart defects, septal defects and left ventricular outflow tract obstructions. The avoidance behavior of paternal smokers may decrease the risk of selected CHDs.Birth Defects Research (Part A) 97:210–216, 2013. © 2013 Wiley Periodicals, Inc.
Commonality in Down and fetal alcohol syndromes
Authors: Solzak Jeffrey P. , Liang Yun , Zhou Feng C. , Roper Randall J. 
Published: April 2013

BACKGROUNDDown syndrome (DS) and Fetal Alcohol Syndrome (FAS) are two leading causes of birth defects with phenotypes ranging from craniofacial abnormalities to cognitive impairment. Despite different origins, we report that in addition to sharing many phenotypes, DS and FAS may have common underlying mechanisms of development.METHODSLiterature was surveyed for DS and FAS as well as mouse models. Gene expression and apoptosis were compared in embryonic mouse models of DS and FAS by qPCR, immunohistochemical and immunoflurorescence analyses. The craniometry was examined using MicroCT at postnatal day 21.RESULTSA literature survey revealed over 20 comparable craniofacial and structural deficits in both humans with DS and FAS and corresponding mouse models. Similar phenotypes were experimentally found in pre‐ and postnatal craniofacial and neurological tissues of DS and FAS mice. Dysregulation of two genes, Dyrk1a and Rcan1, key to craniofacial and neurological precursors of DS, was shared in craniofacial precursors of DS and FAS embryos. Increased cleaved caspase 3 expression was also discovered in comparable regions of the craniofacial and brain precursors of DS and FAS embryos. Further mechanistic studies suggested overexpression of trisomic Ttc3 in DS embyros may influence nuclear pAkt localization and cell survival.CONCLUSIONSThis first and initial study indicates that DS and FAS share common dysmorphologies in humans and animal models. This work also suggests common mechanisms at cellular and molecular levels that are disrupted by trisomy or alcohol consumption during pregnancy and lead to craniofacial and neurological phenotypes associated with DS or FAS. Birth Defects Research (Part A) 97:187–197, 2013. © 2013 Wiley Periodicals, Inc.
Combination therapy with gefitinib and doxorubicin inhibits tumor growth in transgenic mice with adrenal neuroblastoma
Authors: Kawano Kumi , Hattori Yoshiyuki , Iwakura Hiroshi , Akamizu Takashi , Maitani Yoshie 
Published: April 2013

AbstractHighly relevant mouse models of human neuroblastoma (NB) are needed to evaluate new therapeutic strategies against NB. In this study, we characterized transgenic mice with bilateral adrenal tumors. On the basis of information from the tumoral gene expression profiles, we examined the antitumor effects of unencapsulated and liposomal doxorubicin (DXR), alone and in combination with gefitinib, on adrenal NB. We showed that intravenous injection of unencapsulated or liposomal DXR alone inhibited tumor growth in a dose‐dependent manner, as assessed by magnetic resonance imaging (MRI). However, liposomal DXR did not exhibit greater antitumor effect than unencapsulated DXR. Immunohistochemical analysis revealed that the adrenal tumor vasculature with abundant pericyte coverage was a less leaky structure for liposomes. Combination therapy with unencapsulated or liposomal DXR plus gefitinib strongly suppressed tumor growth and delayed tumor regrowth than treatment with unencapsulated or liposomal DXR alone, even at a lower dose of DXR. Dynamic contrast‐enhanced MRI analysis revealed that gefitinib treatment increased blood flow in the tumor, indicating that gefitinib treatment changes the tumor vascular environment in a manner that may increase the antitumor effect of DXR. In conclusion, the combination of gefitinib and DXR induces growth inhibition of adrenal NBs in transgenic mice. These findings will provide helpful insights into new treatments for NB.
Simultaneous Production of Biodiesel and Free Lutein from Chlorella vulgaris
Authors: Prommuak C. , Pavasant P. , Quitain A. T. , Goto M. , Shotipruk A. 
Published: April 2013

AbstractBiodiesel and valuable free lutein were demonstrated to be simultaneously produced from Chlorella vulgaris lipid extracts. The alkali catalyst used in the transesterification of triglycerides acted as a reactant in converting lutein fatty acid esters to free lutein. A maximum biodiesel yield of 33.6 % by weight of the algal lipids was obtained after a 4‐h reaction with MeOH at the MeOH/biomass ratio of 16:1 using 6 % alkali catalyst. The excess of alkali and MeOH employed in the production of biodiesel ensured the complete saponification of all lutein fatty acid esters to free lutein, giving a maximum yield of 2.3 % by weight of the algal lipids. In addition, a process for the separation of the biodiesel and free lutein products from the reaction mixture is proposed. Finally, a preliminary economic assessment was conducted, the results of which suggest that the process for the simultaneous production of biodiesel and lutein from C. vulgaris may be economically feasible.
A Practical Modular Course of Combinatorial and High‐Throughput Methods for Use in Academic Teaching Laboratories
Authors: Stöwe Klaus , Ausfelder Florian 
Published: April 2013

AbstractCombinatorial and high‐throughput methods are increasingly common in industrial research. Academic institutions are often unable to afford the equipment necessary and to provide the maintenance required for permanent operation. Teaching is often more constrained by budget than by research topics. This article describes a modular course that has been designed to allow an affordable implementation of combinatorial and high‐throughput experiments in academic teaching laboratories. Currently, the course consists of five experimental modules and has already been successfully taught on two occasions.
Molecular Hydrogels with Esterase‐like Activity
Authors: Yang Chengbiao , Wang Huaimin , Li Dongxia , Wang Ling 
Published: April 2013

AbstractThe development of molecular hydrogels that can be applied for mimicking bioactive molecules attracts extensive interests of researchers in fields of self‐assembly. In this study, we reported on several molecular hydrogels based on naphthylacetic acid‐peptides containing L‐histidine formed by the heating‐cooling process. All hydrogels exhibited higher activity to hydrolyze 4‐nitrophenyl acetate (4‐NPA) than the free L‐histidine probably due the high density of L‐histidine residue at the surface of self‐assembled nanofibers. To calculate the 4‐NPA hydrolysis rates, the Michaelis‐Menten enzyme kinetics model was made. Among these gels, the gel of Nap‐GFFYGHY possesses the highest enzyme activity of making the ester bond cleavage, which is approximately 25 times higher than that of the control (free L‐histidine and Nap‐GFFYGYY). These results indicate that molecular hydrogels with self‐assembled nanofibers have great potential for the generation of self‐assembled multivalent materials.
Interpretations arising from Wrightian and Malthusian fitness under strong frequency dependent selection
Authors: Wu Bin , Gokhale Chaitanya S. , van Veelen Matthijs , Wang Long , Traulsen Arne 
Published: April 2013

AbstractFitness is the central concept in evolutionary theory. It measures a phenotype's ability to survive and reproduce. There are different ways to represent this measure: Malthusian fitness and Wrightian fitness. One can go back and forth between the two, but when we characterize model properties or interpret data, it can be important to distinguish between them. Here, we discuss a recent experiment to show how the interpretation changes if an alternative definition is used.
Food stoichiometry affects the outcome of Daphnia–parasite interaction
Authors: Aalto Sanni L. , Pulkkinen Katja 
Published: April 2013

AbstractPhosphorus (P) is an essential nutrient for growth in consumers. P‐limitation and parasite infection comprise one of the most common stressor pairs consumers confront in nature. We conducted a life‐table study using a Daphnia–microsporidian parasite model, feeding uninfected or infected Daphnia with either P‐sufficient or P‐limited algae, and assessed the impact of the two stressors on life‐history traits of the host. Both infection and P‐limitation negatively affected some life‐history traits tested. However, under P‐limitation, infected animals had higher juvenile growth rate as compared with uninfected animals. All P‐limited individuals died before maturation, regardless of infection. The numbers of spore clusters of the microsporidian parasite did not differ in P‐limited or P‐sufficient hosts. P‐limitation, but not infection, decreased body phosphorus content and ingestion rates of Daphnia tested in separate experiments. As parasite spore production did not suffer even under extreme P‐limitation, our results suggest that parasite was less limited by P than the host. We discuss possible interpretations concerning the stoichiometrical demands of parasite and suggest that our results are explained by parasite‐driven changes in carbon (C) allocation of the hosts. We conclude that the impact of nutrient starvation and parasite infection on consumers depends not only on the stoichiometric demands of host but also those of the parasite.
Ring‐Opening Reactions of Cyclopropenedicarboxylates with Organolithiums and Organozincs
Authors: Liu Yu , Yu Qiong , Ma Shengming 
Published: April 2013

AbstractRing‐opening reactions of cyclopropenedicarboxylates with organolithiums and organozincs have been studied. Organolithiums and dialkyl‐ or diphenylzincs afforded a series of 1‐alkenyl malonates with attack occurring by the organic group from the organometallic reagent at the less substituted sp2‐hybridized carbon of the cyclopropene moiety. Mechanistic studies proved both anion and dianion intermediates are involved in the reactions with organolithiums. Phenylcyclopropenedicarboxylate and phenylzinc bromide underwent a ring‐opening dimerization to afford a 1,4‐enyne product.