bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tailoring Electrode/Electrolyte Interfacial Properties in Flexible Supercapacitors by Applying Pressure
Authors: Masarapu Charan , Wang Lian‐Ping , Li Xin , Wei Bingqing 
Published: April 2012

AbstractElectrode/electrolyte interfacial properties of flexible supercapacitors assembled with nanostructured activated carbon fabric (ACF) electrodes can be tailored by applying a pressure and tuning electrolyte ion size relative to electrode pore size. Experimental results reveal that increasing pressure between the supercapacitor electrodes can significantly improve capacitive performance. The ratio of solvated ion size in the electrolyte to the pore size on the electrodes determines the minimum pressure necessary to achieve an optimum performance. For a specific electrode material, this minimum pressure for optimum performance is primarily governed by the size of the larger solvated ions (either the anions or cations), and is lower (∼689 KPa) when the ratio of the solvated ion size to the pore size is higher than 0.6, and is higher (at least 1379 KPa) when the ratio is lower than 0.6. An analytical model capable of predicting the experimental performance data has been developed. These results together provide a fundamental understanding of pressure dependence of electrode/electrolyte interfacial properties and pave the way for practical applications of flexible supercapacitors.
Are Large and Complex Agricultural Cooperatives Losing Their Social Capital?
Authors: Nilsson Jerker , Svendsen Gunnar L.H. , Svendsen Gert Tinggaard 
Published: April 2012

ABSTRACTDuring the last 20 years many traditionally organized agricultural cooperatives have been forced to abandon their business form. Explanations have been put forward, comprising a variety of economic and sociological theories. The present study suggests that the social capital paradigm may add explanatory power when analyzing this development. It is claimed that the problems are due to the members having increasingly little trust in the cooperatives and in each other. The cooperatives’ decision makers have no instruments for estimating how much social capital is lost when they pursue strategies of vertical and horizontal integration. Therefore, they do not consider this loss in their calculations. Thus, the problems caused by the cooperatives’ vaguely defined property rights are becoming increasingly serious. This reasoning is summarized into a model, which is influenced by the consumer choice model.[EconLit Classification; A130; P130; Q130].
Vertical Relationships in the Ready‐to‐Eat Breakfast Cereal Industry in Boston
Authors: Chidmi Benaissa 
Published: April 2012

ABSTRACTThis study examines the vertical relationship between manufacturers and retailers in the ready‐to‐eat cereal (RTEC) industry in Boston. More precisely, the questions to be answered are, “What kind of vertical relationship exists between the manufacturers and the retailers?” “Does this relationship support the high price‐cost margins in the RTEC industry?” The results indicate that the RTEC manufacturers have the pricing decisions and that the retailers do not intervene in setting the retail prices for breakfast cereal brands. This is consistent with the vertical restraints theory that helps the manufacturers eliminate the externality created by the double marginalization scenario and an excessive demand contraction. [JEL Codes: L11, L13, L66].
Effect of styrene butadiene latex polymer contents on the bond properties of macro polypropylene fiber in polymer‐modified cement‐based composites
Authors: Park Chan‐Gi , Lee Jin‐Hyung 
Published: April 2012

AbstractBecause of its hydrophobicity, macro polypropylene (PP) fiber does not bond well in cement‐based composites and can reduce the mechanical properties. This study evaluated the influence of styrene–butadiene latex polymer (0–25 wt %) on the bonding of macro PP fiber in these composites. Bond strength was determined using dog‐bone test specimens compliant with JCI SF‐8. The bond strength of macro PP fiber improved with increasing styrene–butadiene latex polymer (latex) content up to 15%. The elastic behavior of the precrack zone increased, and interface toughness increased because the debonded zone was strong after crack formation. For latex content above 20%, the latex retarded the hydration reaction due to the absorption of latex into cement particles. This resulted in bond strengths that were lower than those for composites prepared with up to 15% latex content. Microstructural analysis of the macro PP fiber revealed that the amount of scratches also increased with increasing latex content up to 15%. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of solvent interactions on the structure and properties of prepared PAni nanofibers
Authors: Pramanik Sujata , Karak Niranjan , Banerjee Somik , Kumar Ashok 
Published: April 2012

AbstractThe changes of structure and properties of nanofibers were studied as a function of solubility parameters of the organic solvents that are used in interfacial polymerization of polyaniline (PAni) nanofibers. The presence of UV–visible absorbance at 340, 440, and 800 nm confirmed the formation of emeraldine salt structure of the prepared PAni nanofibers. Fourier transform infrared spectral results indicate an increasing trend of benzenoid to quinoid ratio with the decrease of interaction of the solvents with aniline. This can be correlated to the increase in the degree of conjugation of the polymer chain. Photoluminescence study revealed an increase in the density of defect state with the decrease of interaction. Single‐line approximation technique was used to analyze the broadening of the most intense X‐ray reflection peak corresponding to (110) plane of the nanofibers. The greater the solvent–monomer interaction, the lesser was the domain length and π‐stacking of the PAni chains. The study of this interaction is instrumental to precisely control the internal conformation of the PAni nanofibers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of annealing treatment on the structure and properties of polyurethane/multiwalled carbon nanotube nanocomposites
Authors: Jiang Fengdan , Zhang Liqun , Jiang Yi , Lu Yonglai , Wang Wencai 
Published: April 2012

AbstractThe thermoplastic polyurethane/multiwalled carbon nanotube (TPU/CNT) nanocomposites with high conductivity and low percolation threshold value were prepared by melting blending and annealing treatment. The effect of annealing process on the microphase structure and the properties of TPU/CNT nanocomposites was studied. It has been shown that CNT flocculation can occur in TPU/CNT nanocomposites during the annealing process. At a critical CNT content, which defined the percolation threshold, CNTs could form conductivity network. The conductive percolation threshold value of TPU/CNT nanocomposites was decreased from 10 to 4% after annealing process, and the conductivity of TPU/CNT nanocomposites with 10 vol % of CNT could reach 1.1 S/m after an annealing time of 1 h. The significant enhancement of electrical conductivity was influenced by the annealing time and the content of CNTs. The formation of CNT networks was also verified by dynamic viscoelastic characterization. The results of X‐ray diffraction and differential scanning calorimetry indicated that annealing process reinforced the microphase separation of the nanocomposites. Mechanical properties test showed that the annealing treatment was in favor of improving the mechanical properties; however, further increase in the annealing time has negative effect on the mechanical properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Study on short glass fiber‐reinforced poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) composites
Authors: Yu Zhifang , Yang Yaya , Zhang Linlin , Ding Yongchao , Chen Xiangming , Xu Kaitian 
Published: April 2012

AbstractBiobased non‐fossil polyester poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P3/4HB) containing 4.0 mol % 4‐hydroxybutyrate (4HB) was melt‐mixed with short glass fibers (SGF) via a co‐rotating twin‐screw extruder. The compositing conditions, average glass fiber length and distribution, thermal, crystallization, and mechanical properties of the P3/4HB/SGF composites were investigated. Calcium stearate, two kinds of paraffin wax and modified ethylene bis‐stearamide (TAF) were investigated as lubricants for the P3/4HB/SGF composites. It revealed that TAF is the most efficient lubricant of the P3/4HB/SGF composites. Coupling agents 2,2′‐(1,3‐phenylene)bis‐2‐oxazoline (1,3‐PBO) and pyromellitic dianhydride (PMDA) were used as end‐group crosslinkers to reduce the degradation of P3/4HB and increase the mechanical properties of the P3/4HB/SGF composites. It showed that 1,3‐PBO is the efficient coupling agent. The optimum condition of the P3/4HB/SGF composites is 1.5 phr TAF, 1.0 phr 1,3‐PBO, and 30 wt % glass fiber content. And the maximum of tensile strength, tensile modulus, and impact strength of the composites is 3.7, 6.6, 1.8 times of the neat P3/4HB polymer, respectively. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Sugarcane bagasse composites from vegetable oils
Authors: Quirino Rafael L. , Larock Richard C. 
Published: April 2012

AbstractSugarcane bagasse composites have been prepared by the free radical polymerization of regular or modified vegetable oils with divinylbenzene and n‐butyl methacrylate in the presence of dried, ground sugarcane bagasse. Various cure times and temperatures have been investigated to determine the optimum cure sequence for the new materials. The postcure time has also been varied, and an ideal postcure treatment of 1 h at 180°C at ambient pressure has given the best overall properties. The effect of varying the filler load and resin composition has been assessed by means of tensile tests, dynamic mechanical analysis, thermogravimetric analysis, Soxhlet extraction, followed by proton nuclear magnetic resonance spectroscopic analysis of the extracts, and scanning electron microscopy. It has been observed that the initial washing and drying of the filler influence the filler–resin interaction and impact the final properties of the composites. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Role of compatibilizers on the physicomechanical performance of tea dust polypropylene composites
Authors: Hassan M. Masudul , Mueller Marco , Tartakowska Diana J. , Wagner Manfred H. 
Published: April 2012

AbstractTea dust (TD) polypropylene (PP) biocomposites and glycidyl methacrylate (GMA)‐grafted PP (GMA‐g‐PP) were manufactured using Brabender (PL‐2000, Plasti‐Corder, Germany) and hot press machine. The effects of fiber loading and the role of compatibilizer like maleic anhydride‐grafted PP (MAH‐g‐PP) and GMA‐g‐PP on morphology and physicomechanical properties of the TD‐reinforced PP biocomposites were investigated. On preliminary observation, it is found that the tensile strength of the biocomposites increased with increasing fiber content and presence of the compatibilizer at a certain limit. Scanning electron microscopic studies revealed that the dispersion of fiber in the matrix became worse with increasing fiber content but improved with addition of compatibilizer. The improved mechanical properties of the biocomposites correspond to the presence of the compatibilizer, which is attributed to interactions between hydroxyl groups in the filler and epoxy groups in GMA‐g‐PP and carboxylic group in MAH‐g‐PP. Swelling properties and biodegradable behavior test of the composites have also been performed. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
New petroleum absorbers based on lignin‐CNSL‐formol magnetic nanocomposites
Authors: Grance E. G. O. , Souza F. G. , Varela A. , Pereira E. D. , Oliveira G. E. , Rodrigues C. H. M. 
Published: April 2012

AbstractA magnetic resin based on lignin produced using the Kraft process was prepared and characterized. The material, because of its aromatic/aliphatic balance, can be used in oil‐spill clean‐up processes. The resin was prepared through bulk polycondensation of lignin, cashew nutshell liquid, and formaldehyde in the presence of maghemite nanoparticles. The obtained magnetic composites were studied by Fourier transform infrared spectroscopy, X‐ray diffraction, and Small‐angle X‐ray scattering. Cure degree, magnetic force, and oil removal capability tests were also performed. The results show that the composites possess an elevated cure degree, besides a considerable magnetic force. The materials exhibit a good oil removal capability—the composite containing 3.3 vol % of maghemite can remove 11 parts of oil from water. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Quantification of human hepatocyte cytochrome P450 enzymes and transporters induced by HIV protease inhibitors using newly validated LC‐MS/MS cocktail assays and RT‐PCR
Authors: Liu Li , Mugundu Ganesh M. , Kirby Brian J. , Samineni Divya , Desai Pankaj B. , Unadkat Jashvant D. 
Published: April 2012

ABSTRACTHuman immunodeficiency virus (HIV) protease inhibitors (PIs) produce profound and unpredictable drug–drug interactions (DDIs) that cannot be explained fully by their inhibition/inactivation of CYP3A enzymes. Delineating and quantifying the CYPs and transporters inducible by PIs are crucial in developing an integrative mechanistic understanding and prediction of PI‐based DDIs. To do so, two LC‐MS/MS cocktail assays were modified and validated simultaneously to quantify the CYP activity of CYP3A, 2B6, 2C8, 2C9, 2C19, 1A, 2E1, 2A6 and 2D6 enzymes. These new assays were applied to evaluate the induction potential of eight PIs in microsomes isolated from PI‐treated human hepatocytes. The mRNA expression of these CYPs and transporters (OATP1B1, OATP1B3, OATP1A2, MDR1, MRP2 and MRP4) was also evaluated using relative RT‐PCR. The majority of PIs were net inducers of CYP3As and 2B6 at both the mRNA and activity level (> 2‐fold), while ritonavir, saquinavir, nelfinavir or lopinavir did not induce CYP3A activity (< 2‐fold), presumably due to CYP3A inactivation. OATP1B1 and MDR1 were the only two hepatic transporters induced (> 2‐fold) by the PIs. Amprenavir was the most potent net inducer. In conclusion, our validated cocktail assays can be implemented to comprehensively quantify CYP activities in human liver microsomes and hepatocyte studies. The results also provide the much needed data on the net induction potential of the PIs for hepatic CYPs and transporters. A qualitative agreement was observed between our results and published PI‐based DDIs, suggesting that human hepatocytes are a useful platform for more extensive and quantitative in vitro–in vivo prediction of PI‐based DDIs. Copyright © 2012 John Wiley & Sons, Ltd.
Vanadium Catalyzed Synthesis of Cyclic Organic Carbonates
Authors: Coletti Alessia , Whiteoak Christopher J. , Conte Valeria , Kleij Arjan W. 
Published: April 2012

AbstractVanadium complexes bearing easily synthesized, differently functionalized salen and salphen ligands were prepared and tested for their ability to catalyze the cycloaddition of carbon dioxide to epoxides resulting in cyclic organic carbonates. The reactivity of the prepared catalysts dramatically increases when a coordinating hydroxyl group is present as a substituent in the organic epoxide. The commercially available [VO(acac)2] complex was used as reference compound, and, in this case, we found that V10O26⋅(NBu4)4 was formed during the catalytic reactions. This compound, characterized by X‐ray diffraction analysis, is likely the active catalyst, and it results in significantly better yields of cyclic carbonates compared to those obtained with Schiff base containing vanadyl complexes. The high activity of the mixed polyoxo vanadyl‐vanadate complex marks it as a powerful catalyst within the context of CO2 fixation chemistry.
Electrochemistry of Nanocrystalline 3C Silicon Carbide Films
Authors: Yang Nianjun , Zhuang Hao , Hoffmann René , Smirnov Waldemar , Hees Jakob , Jiang Xin , Nebel Christoph E. 
Published: April 2012

AbstractSilicon carbide (SiC) films have been used frequently for high‐frequency and powder devices but have seldom been applied as the electrode material. In this paper, we have investigated the electrochemical properties of the nanocrystalline 3C‐SiC film in detail. A film with grain sizes of 5 to 20 nm shows a surface roughness of about 30 nm. The resistivity of the film is in the range of 3.5–6.2 kΩ cm. In 0.1 M H2SO4 solution, the film has a double‐layer capacitance of 30–35 μF cm−2 and a potential window of 3.0 V if an absolute current density of 0.1 mA cm−2 is defined as the threshold. Its electrochemical activity was examined by using redox probes of [Ru(NH3)6]2+/3+ and [Fe(CN)6]3−/4− in aqueous solutions and by using redox probes of quinone and ferrocene in nonaqueous solutions. Diffusion‐controlled, quasi‐reversible electrode processes were achieved in four cases. The surface chemistry of the nanocrystalline 3C‐SiC film was studied by electrochemical grafting with 4‐nitrobenzenediazonium salts. The grafting was confirmed by time‐of‐flight secondary ion mass spectroscopy. All these results confirm that the nanocrystalline 3C‐SiC film is promising for use as an electrode material.
Continuous‐Flow Reactor‐Based Enzymatic Synthesis of Phosphorylated Compounds on a Large Scale
Authors: Babich Lara , Hartog Aloysius F. , van der Horst Michael A. , Wever Ron 
Published: April 2012

AbstractAcid phosphatase, an enzyme that is able to catalyze the transfer of a phosphate group from cheap pyrophosphate to alcoholic substrates, was covalently immobilized on polymethacrylate beads with an epoxy linker (Immobeads‐150 or Sepabeads EC‐EP). After immobilization 70 % of the activity was retained and the immobilized enzyme was stable for many months. With the immobilized enzyme we were able to produce and prepare D‐glucose‐6‐phosphate, N‐acetyl‐D‐glucosamine‐6‐phosphate, allyl phosphate, dihydroxyacetone phosphate, glycerol‐1‐phosphate, and inosine‐5′‐monophosphate from the corresponding primary alcohol on gram scale using either a fed‐batch reactor or a continuous‐flow packed‐bed reactor.
Composition‐Tunable Pt–Co Alloy Nanoparticle Networks: Facile Room‐Temperature Synthesis and Supportless Electrocatalytic Applications
Authors: Xu You , Yuan Yongqiang , Ma Aijing , Wu Xuan , Liu Yang , Zhang Bin 
Published: April 2012

AbstractPt–Co alloy nanoparticle networks (NNs) with adjustable composition are synthesized by co‐reduction of H2PtCl6 and CoCl2 with NaBH4 in an ethylene glycol assisted cetyltrimethylammonium bromide/water/chloroform system at room temperature. Electrochemical measurements indicate that the as‐prepared spongelike Pt–Co NNs exhibit composition‐dependent electrocatalytic activities and CO tolerance with better durability toward methanol and formic acid oxidation than commercially available Pt/C catalyst. In particular, Pt3Co NNs show the highest specific activity, while Pt2Co NNs exhibit optimal mass activity among Pt–Co alloy NNs with different composition. These Pt–Co alloy NNs may be promising supportless anode catalysts for the direct methanol and direct formic acid fuel cells.
Bonding of Gold with Unsaturated Species
Authors: Nava Paola , Hagebaum‐Reignier Denis , Humbel Stéphane 
Published: April 2012

AbstractInteractions of gold(I) catalysts with alkenes and alkynes are analyzed. Neutral chlorido, and cationic phosphine and N‐heterocyclic carbene complexes are studied. High‐level ab initio calculations are performed to benchmark the accuracy of popular DFT methods. Donation and backdonation contributions in the bond between the gold fragment and the alkene/alkyne substrate are discussed. These contributions depend on the nature of the gold fragment, but also on the substituents on the alkene/alkyne.
Regeneration of Silica‐Supported Silicotungstic Acid as a Catalyst for the Dehydration of Glycerol
Authors: Katryniok Benjamin , Paul Sébastien , Capron Mickaël , Bellière‐Baca Virginie , Rey Patrick , Dumeignil Franck 
Published: April 2012

AbstractThe dehydration reaction of glycerol to acrolein is catalyzed by acid catalysts. These catalysts tend to suffer from the formation of carbonaceous species on their surface (coking), which leads to substantial degradation of their performances (deactivation). To regenerate the as‐deactivated catalysts, various techniques have been proposed so far, such as the co‐feeding of oxygen, continuous regeneration by using a moving catalytic bed, or alternating between reaction and regeneration. Herein, we study the regeneration of supported heteropolyacid catalysts. We show that the support has a strong impact on the thermal stability of the active phase. In particular, zirconia has been found to stabilize silicotungstic acid, thus enabling the nondestructive regeneration of the catalyst. Furthermore, the addition of steam to the regeneration feed has a positive impact by hindering the degradation reaction by equilibrium displacement. The catalysts are further used in a periodic reaction/regeneration process, whereby the possibility of maintaining long‐term catalytic performances is evidenced.
Evidence of environmental niche differentiation in the striped mouse (Rhabdomyssp.): inference from its current distribution in southern Africa
Authors: Meynard Christine N. , Pillay Neville , Perrigault Manon , Caminade Pierre , Ganem Guila 
Published: April 2012

AbstractThe aim of this study was to characterize environmental differentiation of lineages withinRhabdomysand provide hypotheses regarding potential areas of contact between them in the Southern African subregion, including the Republic of South Africa, Lesotho, and Namibia. Records ofRhabdomystaxa across the study region were compiled and georeferenced from the literature, museum records, and field expeditions. Presence records were summarized within a 10 × 10 km grid covering the study area. Environmental information regarding climate, topography, land use, and vegetation productivity was gathered at the same resolution. Multivariate statistics were used to characterize the current environmental niche and distribution of the whole genus as well as of three mitochondrial lineages known to occur in southern Africa. Distribution modeling was carried out using MAXENT in order to generate hypotheses regarding current distribution of each taxa and their potential contact zones. Results indicate that the two species withinRhabdomysappear to have differentiated across the precipitation/temperature gradient present in the region from east to west.R. dilectusoccupies the wettest areas in eastern southern Africa, whileR. pumiliooccupies the warmer and drier regions in the west, but also penetrates in the more mesic central part of the region. We provide further evidence of environmental differentiation within two lineages ofR. dilectus. Contact zones between lineages appear to occur in areas of strong environmental gradients and topographic complexity, such as the transition zones between major biomes and the escarpment area where a sharp altitudinal gradient separates coastal and plateau areas, but also within more homogeneous areas such as within grassland and savannah biomes. Our results indicate thatRhabdomysmay be more specialized than previously thought when considering current knowledge regarding mitochondrial lineages. The genus appears to have differentiated along two major environmental axes in the study region, but results also suggest dispersal limitations and biological interactions having a role in limiting current distribution boundaries. Furthermore, the projection of the potential geographic distribution of the different lineages suggests several contact zones that may be interesting study fields for understanding the interplay between ecological and evolutionary processes during speciation.