bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alcohol Crossover Behavior in Direct Alcohol Fuel Cells (DAFCs) System
Authors: Chu Y. H. , Shul Y. G. 
Published: January 2012

AbstractThe alcohols (methanol, ethanol, and 1‐propanol) crossover behavior of through fuel cell membrane electrode assembly (MEA) in direct alcohol fuel cell (DAFC) system was studied. We divided five different factors which affect alcohol crossover behavior through MEA to analyze alcohol crossover behavior. Those are membrane effect, physical blocking effect of anode, alcohol oxidation effect of anode electrocatalysts, physical blocking effect of cathode, and alcohol oxidation effect of cathode. Among these five factors, the four factors caused by two different electrodes (anode and cathode) were evaluated by fabricating various types of MEA. In the case of alcohols through membrane without any electrode was increased when the cell temperature was raised from room temperature to 100 °C, but it was decreased above the cell temperature of 100 °C. Among the electrode effects on alcohol crossover rate, physical blocking effect of electrodes played dominant role below 100 °C. However alcohol oxidation effects of electrodes was predominant above the 100 °C.
Characterization and Comparison of Different Cathode Materials for SC‐SOFC: LSM, BSCF, SSC, and LSCF
Authors: Rembelski D. , Viricelle J. P. , Combemale L. , Rieu M. 
Published: January 2012

AbstractFour cathode materials for single chamber solid oxide fuel cell (SC‐SOFC) [La0.8Sr0.2MnO3–δ (LSM), Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF), Sm0.5Sr0.5CoO3–δ (SSC), and La0.6Sr0.4Co0.2Fe0.8O3–δ (LSCF)] were investigated regarding their chemical stability, electrical conductivity, catalytic activity, and polarization resistance under air and methane/air atmosphere. Electrolyte‐supported fuel cells, with Ce0.9Gd0.1O2–δ (CGO) electrolyte and a Ni‐CGO anode, were tested in several methane/air mixtures with each cathode materials between 625 and 725 °C. These single cells were not optimized but only designed to compare the four studied cathodes. The decrease of methane‐to‐oxygen ratio from 2 to 0.67 strongly increased the performance of fuel cells for all cathode materials but the effect of temperature was not always significant. Cells with SSC, BSCF, and LSCF have shown a maximum power density about 20 mW cm–2 while the cell with LSM has given only 5 mW cm–2.
Design and Optimization of Composite Electrodes in Solid Oxide Cells
Authors: Ge X.‐M. , Fang Y.‐N. , Chan S.‐H. 
Published: January 2012

AbstractThe performance of solid oxide cells (SOCs) heavily relies on the population of three‐phase boundaries (TPBs) in the composite electrodes. In this study, SOC composite electrodes are described by percolating binary particle aggregates that are constructed from random loose packing models and classical sintering theories. Summed perimeters of the sintering necks represent the total TPB lengths. A case study has been carried out on lanthanum strontium manganite (LSM)–yttria‐stabilized zirconia (YSZ) composite electrodes. By employing three‐dimensional data that are converted from relevant two‐dimensional data, the TPB length of baseline LSM–YSZ electrodes investigated in this study is 35.4 μm μm–3. The parametric and sensitivity analyses show the changes of TPB lengths in functions of the weight fraction of powders, particle size and particle size ratio of powders, void fraction of electrodes, and density of materials. In the case of baseline LSM–YSZ electrodes, proper electrode design and optimization would result in 2–3 times of the enlargement of TPBs. Technical guidelines on the design and optimization of SOC composite electrodes are proposed.
Characterization of La0.6Sr0.4Co0.2Fe0.8O3–δ + La2NiO4+δ Composite Cathode Materials for Solid Oxide Fuel Cells
Authors: Chen M. , Moon B. H. , Kim S. H. , Kim B. H. , Xu Q. , Ahn B.‐G. 
Published: January 2012

AbstractThe structure, electrical conduction, thermal expansion and electrochemical properties of the La0.6Sr0.4Co0.2Fe0.8O3–δ + La2NiO4+δ (LSCF‐LNO) composite cathodes were investigated with regard to the volume fraction of the LNO composition. No chemical reaction product between the two constituent phases was found for the composite cathodes sintered at 1,400 °C for 10 h within the sensitivity of the XRD. Compared to the performance of the LSCF cathode, the LNO composition in the composite cathode plays a role in deteriorating both electrical conductivity and electrochemical properties, however, improving the thermal expansion properties. The trade‐off between electrical conducting and thermal expansion classifies the composite cathode containing 30 volume percent (vol.%) LNO as the optimum composition. For characterizing cathode performance in a single cell, a slurry spin coating technique was employed to prepare a porous cathode layer as well as a YSZ/Ce0.8Sm0.2O3–δ (SDC) electrolyte. The optimum conditions for fabricating the YSZ/SDC electrolyte were investigated. The resulting single cell with 70 vol.% LSCF‐30 vol.%LNO (LSCF‐LNO30) cathode shows a power density of 497 mW cm–2 at 800 °C, which is lower than that of the cell with a LSCF cathode, but still within the limits acceptable for practical applications.
Durable Transition‐Metal‐Carbide‐Supported Pt–Ru Anodes for Direct Methanol Fuel Cells
Authors: Nishanth K. G. , Sridhar P. , Pitchumani S. , Shukla A. K. 
Published: January 2012

AbstractMolybdenum carbide (MoC) and tungsten carbide (WC) are synthesized by direct carbonization method. Pt–Ru catalysts supported on MoC, WC, and Vulcan XC‐72R are prepared, and characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, and transmission electron microscopy in conjunction with electrochemistry. Electrochemical activities for the catalysts towards methanol electro‐oxidation are studied by cyclic voltammetry. All the electro‐catalysts are subjected to accelerated durability test (ADT). The electrochemical activity of carbide‐supported electro‐catalysts towards methanol electro‐oxidation is found to be higher than carbon‐supported catalysts before and after ADT. The study suggests that Pt–Ru/MoC and Pt–Ru/WC catalysts are more durable than Pt–Ru/C. Direct methanol fuel cells (DMFCs) with Pt–Ru/MoC and Pt–Ru/WC anodes also exhibit higher performance than the DMFC with Pt–Ru/C anode.
Enhanced Performance of Solid Oxide Fuel Cell by Manipulating the Orientation of Cylindrical Pores in Anode Substrate
Authors: Pan W.‐P. , Lü Z. , Chen K.‐F. , Zhang Y.‐H. , Wei B. , Wang Z.‐H. , Su W.‐H. 
Published: January 2012

AbstractEffect of the orientation of cylindrical pores within an anode has been studied on the performance of anode‐supported solid oxide fuel cell (SOFC). Paper‐fibers are used as pore‐former and highly oriented cylindrical pores are formed within the anode prepared by uniaxial compaction. A thick anode brick is fabricated followed by cutting in different directions to obtain anode substrates with desirable orientation of pores. When the orientation of cylindrical pores is perpendicular to the anode surface, the gas transport is significantly improved so that the reduction rate of the NiO/YSZ anode is considerably accelerated and the cell concentration polarization is minimized. The corresponding single cell exhibits a maximum power density as high as 1.54 W cm–2 in hydrogen and 0.90 W cm–2 in nitrogen diluted methane at 800 °C. The result indicates that the output performance of anode‐supported cells could be significantly improved by manipulating the orientation of pores.
Electrochemical Impedance Analysis of SOFC Cathode Reaction Using Evolutionary Programming
Authors: Hershkovitz S. , Baltianski S. , Tsur Y. 
Published: January 2012

AbstractInvestigation of the cathode reaction in solid oxide fuel cells (SOFC) by impedance spectroscopy (IS) measurements using evolutionary‐based programming analysis is demonstrated. In contrast to the conventional analysis methods used for impedance spectroscopy measurements, e.g., equivalent circuits, the impedance spectroscopy genetic programming (ISGP) program seeks for a distribution of relaxation times that has the form of a peak or a sum of several peaks, assuming the Debye kernel. Using this method one finds a functional (parametric) form of the distribution of relaxation times. A symmetric cell configuration of Pt|LSCF|GDC|LSCF|Pt was examined using IS measurements combined with I–V measurements. Different samples at different temperatures and different oxygen partial pressures were examined in order to investigate their influence on the oxygen reduction reaction. The resulting IS data was analyzed using the ISGP program and the resulting peaks constructing the distribution of relaxation times were assigned for the different processes that occur at the cathode side. The activation energies as well as the dependence of the processes on the oxygen partial pressure were also evaluated.
Preoperative prediction of papillary thyroid carcinoma prognosis with the assistance of computerized morphometry of cytology samples obtained by fine‐needle aspiration: Preliminary report
Authors: Shih Shyang–Rong , Chang Yi–Cheng , Li Hung–Yuan , Liau Jau–Yu , Lee Chia–Yen , Chen Chung–Ming , Chang Tien–Chun 
Published: January 2012

AbstractBackgroundThe purpose of this study was to analyze the relationship between cytologic features, clinical features, and recurrence of papillary thyroid cancer (PTC). We hoped to predict prognosis preoperatively.MethodsWe retrospectively studied cytologic features by using computerized morphometry and clinical data of 118 patients with usual‐type PTC without initial metastasis, including 34 patients with cancer recurrence in 10 years after surgery and 84 patients who did not have recurrence for more than 10 years after surgery. Another 24 patients were recruited for validation.ResultsMultivariate logistic analysis indicated that nucleus‐to‐cell ratio, variation of nuclear area, tumor size, and patient age were significantly related to recurrence. Cox regression analysis showed that hazard ratios were 3.34, 1.53, 1.77, and 2.6, respectively.ConclusionCytologic features of PTC analyzed with computerized morphometry significantly correlated with recurrence. It helped to predict prognosis preoperatively and may be helpful for planning further treatment. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Cyclooxygenase‐2 expression and clinical parameters in laryngeal squamous cell carcinoma, vocal fold nodule, and laryngeal atypical hyperplasia
Authors: Sayar Cağdaş , Sayar Hamide , Özdemir Süleyman , Selçuk Tahsin , Görgülü Orhan , Akbaş Yücel , Kemal Olgun Mustafa 
Published: January 2012

AbstractBackgroundThe diagnostic role of cyclooxygenase‐2 (COX‐2) expression in laryngeal atypical hyperplasia, vocal fold nodule, and laryngeal squamous cell carcinoma was examined.MethodsSpecimens obtained from patients diagnosed with vocal fold nodule (n = 35), atypical hyperplasia (n = 35), laryngeal squamous cell carcinoma (n = 35), and clinical parameters were evaluated retrospectively.ResultsAlthough no staining was observed in patients with vocal fold nodules, staining was noted in laryngeal atypical hyperplasia and squamous cell carcinoma. The percentage of COX‐2 staining was the highest in the carcinoma group.ConclusionIt was determined that COX‐2 staining was significantly associated with laryngeal squamous cell carcinoma. It should be noted that overexpression of COX‐2, a potentially important factor in the evolution of carcinogenesis in precancerous lesions, might be an indicator of the development of carcinoma. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Mechanism of FGF23 processing in fibrous dysplasia
Authors: Bhattacharyya Nisan , Wiench Malgorzata , Dumitrescu Claudia , Connolly Brian M , Bugge Thomas H , Patel Himatkumar V , Gafni Rachel I , Cherman Natasha , Cho Monique , Hager Gordon L , Collins Michael T 
Published: January 2012

Abstract
Fibroblast growth factor-23 (FGF23) is a phosphate- and vitamin D-regulating hormone derived from osteoblasts/osteocytes that circulates in both active (intact, iFGF23) and inactive (C-terminal, cFGF23) forms. O-glycosylation by O-glycosyl transferase N-acetylgalactosaminyltransferase 3 (ppGalNAcT3) and differential cleavage by furin have been shown to be involved in regulating the ratio of active to inactive FGF23. Elevated iFGF23 levels are observed in a number of hypophosphatemic disorders, such as X-linked, autosomal recessive, and autosomal dominant hypophosphatemic rickets, whereas low iFGF23 levels are found in the hyperphosphatemic disorder familial tumoral calcinosis/hyperphosphatemic hyperostosis syndrome. Fibrous dysplasia of bone (FD) is associated with increased total FGF23 levels (cFGF23 + iFGF23); however, classic hypophosphatemic rickets is uncommon. Our results suggest that it can be explained by increased FGF23 cleavage leading to an increase in inactive cFGF23 relative to active iFGF23. Given the fact that FD is caused by activating mutations in the small G-protein Gsα that results in increased cyclic adenosine monophosphate (cAMP) levels, we postulated that there may be altered FGF23 cleavage in FD and that the mechanism may involve alterations in cAMP levels and ppGalNacT3 and furin activities. Analysis of blood specimens from patients with FD confirmed that the elevated total FGF23 levels are the result of proportionally increased cFGF23 levels, consistent with less glycosylation and enhanced cleavage by furin. Analysis of primary cell lines of normal and mutation-harboring bone marrow stromal cells (BMSCs) from patients with FD demonstrated that BMSCs harboring the causative Gsα mutation had higher cAMP levels, lower ppGalNAcT3, and higher furin activity. These data support the model wherein glycosylation by ppGalNAcT3 inhibits FGF23 cleavage by furin and suggest that FGF23 processing is a regulated process that controls overall FGF23 activity in FD patients. © 2012 American Society for Bone and Mineral Research.
Density functional study of SN2 substitution reactions for CH3Cl + CX1X2•− (X1X2 = HH, HF, HCl, HBr, HI, FF, ClCl, BrBr, and II)
Authors: Liang Jun‐Xi , Geng Zhi‐Yuan , Wang Yong‐Cheng 
Published: January 2012

AbstractA systematic investigation on the SN2 displacement reactions of nine carbene radical anions toward the substrate CH3Cl has been theoretically carried out using the popular density functional theory functional BHandHLYP level with different basis sets 6‐31+G (d, p)/relativistic effective core potential (RECP), 6‐311++G (d, p)/RECP, and aug‐cc‐pVTZ/RECP. The studied models are CX1X2•− + CH3Cl → X2X1CH3C• + Cl−, with CX1X2•− = CH2•−, CHF•−, CHCl•−, CHBr•−, CHI•−, CF2•−, CCl2•−, CBr2•−, and CI2•−. The main results are proposed as follows: (a) Based on natural bond orbital (NBO), proton affinity (PA), and ionization energy (IE) analysis, reactant CH2•− should be a strongest base among the anion‐containing species (CX1X2•−) and so more favorable nucleophile. (b) Regardless of frontside attacking pathway or backside one, the SN2 reaction starts at an identical precomplex whose formation with no barrier. (c) The back‐SN2 pathway is much more preferred than the front‐SN2 one in terms of the energy gaps [ΔE(front)−ΔE(back)], steric demand, NBO population analysis. Thus, the back‐SN2 reaction was discussed in detail. On the one hand, based on the energy barriers (ΔE and ΔE) analysis, we have strongly affirmed that the stabilization of back attacking transition states (b‐TSs) presents increase in the order: b‐TS‐CI2 < b‐TS‐CBr2 < b‐TS‐CCl2 < b‐TS‐CHI < b‐TS‐CHBr < b‐TS‐CHCl < b‐TS‐CF2 < b‐TS‐CHF < b‐TS‐CH2. On the other hand, depended on discussions of the correlations of ΔE with influence factors (PA, IE, bond order, and ΔE), we have explored how and to what extent they affect the reactions. Moreover, we have predicted that the less size of substitution (α‐atom) required for the gas‐phase reaction with α‐nucleophile is related to the α‐effect and estimated that the reaction with the stronger PA nucleophile, holding the lighter substituted atom, corresponds to the greater exothermicity given out from reactants to products. © 2012 Wiley Periodicals, Inc. J Comput Chem, 2012
Theoretical investigation on the transportation behavior of molecular wires with redox reaction
Authors: Li Jinliang , Zhao Zhenzhen , Yu Cui , Wang Hongbo , Zhao Jianwei 
Published: January 2012

AbstractA series of model molecules [sequential quinone (Q) or hydroquinone (HQ) rings connected by triple bonds] as molecular wires have been investigated by using density functional theory combined with nonequilibrium Green's function method. The results show that the system has two discrete conductance states: a low‐conductance state with Q form, and a high‐conductance state with HQ form. The systematic investigations have suggested that more Q/HQ pairs in the system may improve the on/off ratio, though long molecule reduces the conductance of the molecular junction. The switch mechanism has been explained via molecular electronic structure as well as transmission spectra. © 2012 Wiley Periodicals, Inc. J Comput Chem, 2012
The addition of ethanol as defoamer in fermentation of rhamnolipids
Authors: Sha Ruyi , Meng Qin , Jiang Lifang 
Published: January 2012

AbstractBACKGROUND: Rhamnolipids biosurfactants mainly produced by Pseudomonas aeruginosa have a wide range of potential applications. However, production of rhamnolipids on a large scale is constrained by severe foaming in fermentation. This study addressed the applicability of organic solvents as both defoamer and carbon substrate in rhamnolipids fermentation.RESULTS: In this work, although isopropanol and n‐butanol performed better defoaming activities against rhamnolipid‐induced foams, ethanol was focused on as a potential defoamer due to its high bioavailability and low toxicity in a shaking culture of P. aeruginosa ZJU. The most appropriate dose of ethanol addition was determined to be 1% (v/v) and the best time for addition was after 48 h of culture in shaking flasks. The capability of ethanol to control foaming was further illustrated during rhamnolipids fermentation in 2 L and 50 L bioreactors. In both fermentations, the addition of ethanol not only suppressed severe foaming but also supported cell growth.CONCLUSIONS: The use of ethanol as a defoamer is a potential strategy to avoid undesirable foam in fermentation of biosurfactant. Copyright © 2012 Society of Chemical Industry
A techno‐economic comparison of various process options for the production of 1,1‐diethoxy butane
Authors: Agirre Ion , Güemez María Belén , Motelica Anatolie , van Veen Henk M. , Vente Jaap F. , Arias Pedro L. 
Published: January 2012

AbstractBACKGROUND: Acetals can be considered important bio‐based diesel additives. The production of most of these compounds, from an alcohol and an aldehyde, suffers from low conversion due to thermodynamic limitations. These limitations can be overcome through the removal of the by‐product water. Previous studies showed that the in situ dehydration options of reactive distillation and pervaporation membrane reactor integration offer little advantage or at least not at reasonable unit dimensions. The aim of the present work is the development of a membrane based process and comparison with other alternatives (based on experimental data).RESULTS: Three different membrane processes were developed. The one in which the reaction mixture is recycled over a first dehydration membrane module and subsequently through a simple distillation column, was found to give the highest overall conversion (100%) at low recycle rates and reasonable membrane area. This process was techno‐economically compared with other possible alternatives: (1) a process based on a conventional tubular reactor and several distillation columns; and (2) a process based on reactive distillation.CONCLUSIONS: Efficient water removal by membranes avoids possible azeotropes in downstream distillation units making them much simpler, reducing considerably the unit sizes and the energy demand (40% lower). Copyright © 2012 Society of Chemical Industry
Embryonic development of a whirligig beetle, Dineutus mellyi, with special reference to external morphology (insecta: Coleoptera, Gyrinidae)
Authors: Komatsu Shintaro , Kobayashi Yukimasa 
Published: January 2012

AbstractThe egg morphology and successive changes of developing embryos of the whirligig beetle, Dineutus mellyi (Adephaga: Gyrinidae) are described from observations based on light and scanning electron microscopy. The egg surface is characterized by minute conical projections covering the entire egg surface, a stalk‐like micropylar projection at the anterior pole of the egg, and a longitudinal split line along which the chorion is cleaved during the middle embryonic stages. The germ band or embryo is formed on the ventral egg surface, and develops on the surface throughout the egg period; thus, the egg is a superficial type, as is the case in most coleopteran species. A pair of lateral tracheal gills (LTGs) of the first abdominal segment originates from appendage‐like projections arising at the lateral side of pleuropodia, and the LTGs of the second to ninth abdominal segments are arranged in a row with that of the first segment. Therefore, LTGs are structures with serial homology. The paired dorsal tracheal gills (DTGs) of the ninth abdominal segment are formed on the regions just latero‐dorsal to the LTGs of this segment. Regarding the pleuropodia as the structures being homologous with thoracic legs, neither the LTGs nor DTGs are homologous with thoracic legs, but originate in the more lateral region corresponding to the future pleura of the thoracic segments. The last (10th) abdominal segment in the larva is formed by the fusion of the embryonic 10th and 11th abdominal segments. Four terminal hooks at the end of the last abdominal segment originate from two pairs of swellings on the posterior end of the embryonic 11th abdominal segment. It is proposed that the terminal hooks possibly correspond to the claws of medially fused cerci of the embryonic 11th abdominal segment. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.
Water‐silicone separated volumetric MR acquisition for rapid assessment of breast implants
Authors: Madhuranthakam Ananth J. , Smith Martin P. , Yu Huanzhou , Shimakawa Ann , Reeder Scott B. , Rofsky Neil M. , McKenzie Charles A. , Brittain Jean H. 
Published: January 2012

AbstractPurpose:To develop a robust T2‐weighted volumetric imaging technique with uniform water‐silicone separation and simultaneous fat suppression for rapid assessment of breast implants in a single acquisition.Materials and Methods:A three‐dimensional (3D) fast spin echo sequence that uses variable refocusing flip angles was combined with a three‐point chemical‐shift technique (IDEAL) and short tau inversion recovery (STIR). Phase shifts of −π/6, +π/2, and +7π/6 between water and silicone were used for IDEAL processing. For comparison, two‐dimensional images using 2D‐FSE‐IDEAL with STIR were also acquired in axial, coronal, and sagittal orientations.Results:Near‐isotropic (true spatial resolution—0.9 × 1.3 × 2.0 mm3) volumetric breast images with uniform water‐silicone separation and simultaneous fat suppression were acquired successfully in clinically feasible scan times (7:00–10:00 min). The 2D images were acquired with the same in‐plane resolution (0.9 × 1.3 mm2), but the slice thickness was increased to 6 mm with a slice gap of 1 mm for complete coverage of the implants in a reasonable scan time, which varied between 18:00 and 22:30 min.Conclusion:The single volumetric acquisition with uniform water and silicone separation enables images to be reformatted into any orientation. This allows comprehensive assessment of breast implant integrity in less than 10 min of total examination time. J. Magn. Reson. Imaging 2012;35:1216‐1221. © 2012 Wiley Periodicals, Inc.