bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conductive Materials for Proton Exchange Membrane Fuel Cell Bipolar Plates Made from PVDF, PET and Co‐continuous PVDF/PET Filled with Carbon Additives
Authors: Nguyen L. , Mighri F. , Deyrail Y. , Elkoun S. 
Published: August 2010

AbstractThe aim of this work was to develop and characterise electrically conductive materials for proton exchange membrane fuel cells and bipolar plates (BPPs). These BPPs were made from highly conductive blends of polyethylene terephthalate (PET) and polyvinylidene fluoride (PVDF), as matrix phase. The conductive materials were developed from carefully formulated blends composed of conductive carbon black (CB) powder and, in some cases, graphite synthetic flakes mixed with pure PET, PVDF or with PVDF/PET systems. They were first developed by twin‐screw extrusion process then compression‐molded to give BPP final shape. As the developed blends have to meet properties suitable for BPP applications, they were characterised for their rheological properties, electrical through‐plane resistivity (the inverse of conductivity), oxygen permeability, flexural and impact properties. Results showed that lower resistivity was obtained with PVDF/CB blends due to the higher interfacial energy between the PVDF matrix and CB and also the higher density and crystallinity of PVDF, compared to those of PET. It was also observed that the lowest resistivity values were obtained with mixing PVDF and PET at controlled compositions to ensure PVDF/PET co‐continuous morphology. Also, slow cooling rates helped to attain the lowest values of through‐plane resistivity for all studied blends. This behaviour was related to the higher crystallinity obtained with low cooling rates leading to smaller amorphous regions in which carbon particles are much more concentrated.
Electrochemical Performance of La2NiO4‐based Cathode for Solid Oxide Fuel Cells. Single Cell Test
Authors: Pérez‐Coll D. , Aguadero A. 
Published: August 2010

AbstractThe electrochemical performance of La2NiO4‐Ce0.8Sm0.2O1.9 composite cathode material with Ce0.8Sm0.2O1.9 electrolyte and Ni‐Ce0.8Sm0.2O1.9 anode has been studied. Powders of La2NiO4 were prepared by a nitrate‐citrate route whereas commercial Ce0.8Sm0.2O1.9 was used to prepare the electrolyte and composites/cermets of cathode and anode, respectively. Fuel cell tests were performed with stationary air as oxidant and humidified hydrogen as fuel using single cells with 450 μm‐thick electrolytes. Values of maximum power density higher than 130, 200 and 275 mW cm–2 were obtained for temperatures of 750, 800 and 850 °C, respectively. Impedance spectroscopy under open cell voltage (OCV) conditions and with different current loads was used as a complementary tool to study the different contributions to the voltage loss of the system. The ohmic loss was revealed as the main important contribution to the internal voltage loss of the single cell even at lower temperatures due to the use of a 450 μm‐thick electrolyte. Decreasing the electrolyte thickness to values in the order of 150 μm is expected to produce a decrease higher than 45% in the total cell resistance under OCV conditions, improving the maximum power density to 190 mW cm–2 at 750 °C. The performance of the cell was affected by the hydrogen flux as was made evident by changing the flow rate of the fuel in the range 8–66 ml min–1. An increase higher than 20% in the maximum power density was directly obtained by simply increasing the hydrogen flux from 8 to 66 ml min–1. However, the increase in the hydrogen flow rate produced a decrease in the fuel utilisation. Very good stability of the single cell was also obtained after operation times higher than 40 h with the cell producing the maximum power density.
Electrochemical Properties of PSFC–BCYb Composites as Cathodes for Proton Conducting Solid Oxide Fuel Cells
Authors: Vert V. B. , Solís C. , Serra J. M. 
Published: August 2010

AbstractThe electrochemical properties of mixed conducing ceramic–ceramic composites for proton conducting fuel cells have been investigated. Different ratios of Pr0.58Sr0.4Fe0.8Co0.2O3–δ–BaCe0.9Yb0.1O3–δ composites have been tested as cathodes in symmetrical cells based on BaCe0.9Y0.1O3–δ dense electrolytes. Impedance measurements have been carried out in the temperature range of 600–800 °C under wet (2.5%) air. Different dilutions on both oxygen partial pressure and water content have been performed as a function of the temperature in order to characterise the processes (surface reaction and charge transport) occurring at the composite electrode under oxidising conditions. The variation of the impedance spectra after replacing protonated water by heavy water has been studied in order to understand the role of the proton transport in the overall composite cathode operation. Additional four‐point DC‐conductivity measurements have been done under different atmospheres comprising different oxygen partial pressures and H2O/D2O saturation for composites and single materials.
Quality control and quality assurance in genotypic data for genome‐wide association studies
Authors: Laurie Cathy C. , Doheny Kimberly F. , Mirel Daniel B. , Pugh Elizabeth W. , Bierut Laura J. , Bhangale Tushar , Boehm Frederick , Caporaso Neil E. , Cornelis Marilyn C. , Edenberg Howard J. , Gabriel Stacy B. , Harris Emily L. , Hu Frank B. , Jacobs Kevin B. , Kraft Peter , Landi Maria Teresa , Lumley Thomas , Manolio Teri A. , McHugh Caitlin , Painter Ian , Paschall Justin , Rice John P. , Rice Kenneth M. , Zheng Xiuwen , Weir Bruce S. ,   for the GENEVA Investigators
Published: August 2010

AbstractGenome‐wide scans of nucleotide variation in human subjects are providing an increasing number of replicated associations with complex disease traits. Most of the variants detected have small effects and, collectively, they account for a small fraction of the total genetic variance. Very large sample sizes are required to identify and validate findings. In this situation, even small sources of systematic or random error can cause spurious results or obscure real effects. The need for careful attention to data quality has been appreciated for some time in this field, and a number of strategies for quality control and quality assurance (QC/QA) have been developed. Here we extend these methods and describe a system of QC/QA for genotypic data in genome‐wide association studies (GWAS). This system includes some new approaches that (1) combine analysis of allelic probe intensities and called genotypes to distinguish gender misidentification from sex chromosome aberrations, (2) detect autosomal chromosome aberrations that may affect genotype calling accuracy, (3) infer DNA sample quality from relatedness and allelic intensities, (4) use duplicate concordance to infer SNP quality, (5) detect genotyping artifacts from dependence of Hardy‐Weinberg equilibrium test P‐values on allelic frequency, and (6) demonstrate sensitivity of principal components analysis to SNP selection. The methods are illustrated with examples from the “Gene Environment Association Studies” (GENEVA) program. The results suggest several recommendations for QC/QA in the design and execution of GWAS. Genet. Epidemiol. 34: 591–602, 2010. © 2010 Wiley‐Liss, Inc.
Genome‐wide association studies using haplotype clustering with a new haplotype similarity
Authors: Jin Lina , Zhu Wensheng , Guo Jianhua 
Published: August 2010

AbstractAssociation analysis, with the aim of investigating genetic variations, is designed to detect genetic associations with observable traits, which has played an increasing part in understanding the genetic basis of diseases. Among these methods, haplotype‐based association studies are believed to possess prominent advantages, especially for the rare diseases in case‐control studies. However, when modeling these haplotypes, they are subjected to statistical problems caused by rare haplotypes. Fortunately, haplotype clustering offers an appealing solution. In this research, we have developed a new befitting haplotype similarity for “affinity propagation” clustering algorithm, which can account for the rare haplotypes primely, so as to control for the issue on degrees of freedom. The new similarity can incorporate haplotype structure information, which is believed to enhance the power and provide high resolution for identifying associations between genetic variants and disease. Our simulation studies show that the proposed approach offers merits in detecting disease‐marker associations in comparison with the cladistic haplotype clustering method CLADHC. We also illustrate an application of our method to cystic fibrosis, which shows quite accurate estimates during fine mapping. Genet. Epidemiol. 34: 633–641, 2010. © 2010 Wiley‐Liss, Inc.
Quantile regression analysis of the rational addiction model: investigating heterogeneity in forward‐looking behavior
Authors: Laporte Audrey , Karimova Alfia , Ferguson Brian 
Published: August 2010

AbstractThe time path of consumption from a rational addiction (RA) model contains information about an individual's tendency to be forward looking. In this paper, we use quantile regression (QR) techniques to investigate whether the tendency to be forward looking varies systematically with the level of consumption of cigarettes. Using panel data, we find that the forward‐looking effect is strongest relative to the addiction effect in the lower quantiles of cigarette consumption, and that the forward‐looking effect declines and the addiction effect increases as we move toward the upper quantiles. The results indicate that QR can be used to illuminate the heterogeneity in individuals' tendency to be forward looking even after controlling for factors such as education. QR also gives useful information about the differential impact of policy variables, most notably workplace smoking restrictions, on light and heavy smokers. Copyright © 2010 John Wiley & Sons, Ltd.
A New Cardenolide and Two New Pregnane Glycosides from the Root Barks of Periploca sepium
Authors: Deng Yan‐Ru , Wei Yin‐Pan , Yin Fei , Yang Hong , Wang Ying 
Published: August 2010

AbstractA new cardenolide and two new pregnane glycosides, periplogenin 3‐[O‐β‐glucopyranosyl‐(1→4)‐β‐sarmentopyranoside] (1), (3β,20S)‐pregn‐5‐ene‐3,17,20‐triol 20‐[O‐β‐glucopyranosyl‐(1→6)‐O‐glucopyranosyl‐(1→4)‐β‐canaropyranoside] (2), and (3β,14β,17α)‐3,14,17‐trihydroxy‐21‐methoxypregn‐5‐en‐20‐one 3‐[O‐β‐oleandropyranosyl‐(1→4)‐O‐β‐cymaropyranosyl‐(1→4)‐β‐cymaropyranoside] (3), were isolated from the root barks of Periploca sepium Bge, together with seven related known compounds, periplogenin, xysmalogenin, (3β,20S)‐pregn‐5‐ene‐3,17,20‐triol, (3β,14β,17α)‐3,14,17‐trihydroxy‐21‐methoxypregn‐5‐en‐20‐one, (3β,20S)‐pregn‐5‐ene‐3,20‐diol 3‐β‐glucopyranoside 20‐β‐glucopyranoside, (3β,20S)‐pregn‐5‐ene‐3,20‐diol 3‐[O‐2‐O‐acetyl‐β‐digitalopyranosyl‐(1→4)‐β‐cymaropyranoside] 20‐[O‐β‐glucopyranosyl‐(1→6)‐O‐β‐glucopyranosyl‐(1→2)‐β‐digitalopyranoside], and (3β,20S)‐ pregn‐5‐ene‐3,20‐diol 20‐[O‐β‐glucopyranosyl‐(1→6)‐β‐glucopyranoside]. Their structures were elucidated on the basis of spectroscopic analyses.
The Adverse Effect of Benzannelation on the Aromaticity of Oxocinyl Anion: A Combined Experimental and Theoretical Study
Authors: Kasmai Hamid S. , Wang Xiaodong , Doan Hanh‐Nhon , Femia Josef F. , Yablonsky Thad M. , Read Mary E. , Dutton David T. 
Published: August 2010

AbstractA synthesis of 2H‐1‐benzoxocin from readily available compounds was accomplished. The potentially ‘aromatic’ π‐excessive systems 2H‐1‐benzoxocinyl and 6H‐dibenz[b,f]oxocinyl anions were generated from their corresponding conjugate acid precursors 7c and 8, respectively. It was found that 2H‐1‐benzoxocinide 3d lacks the type of π‐frame stability associated with the parent 2H‐oxocinide 1d and that the dibenzo analog 5b is more unstable than 3d. Both 3d and 5b undergo rapid structural reorganization to form their corresponding stable isomeric anions. We were able to characterize the proton‐quenched products of these anions as the ring‐opened structures 15 and 18, respectively. 1H‐NMR and an ab initio calculation at the 6‐31g* level indicated that, unlike the ‘aromatic’ parent 2H‐oxocinide 1d and the aza analog 3c, 3d incorporates a non‐planar oxocinyl ring in which the negative charge is primarily localized on the pentadienyl moiety of the ring, but also partial delocalization of π‐electron density onto the benzene ring occurs.
A New Dimeric Alkaloid from the Leaf of Psychotria calocarpa
Authors: Zhou Hua , He Hong‐Ping , Wang Yue‐Hu , Hao Xiao‐Jiang 
Published: August 2010

AbstractPsychotriasine was isolated from the leaves of Psychotria calocarpa (Rubiaceae). The structure was established by spectroscopic methods including 2D‐NMR analysis. To the best of our knowledge, psychotriasine is the first example of a dimeric tryptamine‐related alkaloid that contains a free Nα‐methyltryptamine unit in the molecule.
Hydroformylation of Oct‐1‐ene in Novel Ionic Liquid Crystals
Authors: Yang Jing , Li Fei‐Fei , Zhang Juan , Li Ji , Wang Wen‐Xin 
Published: August 2010

AbstractHydroformylation of oct‐1‐ene leading to nonanal (denoted by n) and 2‐methyloctanal (denoted by iso), in a novel series of caprolactam‐based and common imidazolium‐based ionic liquid crystals (ILCs; see Fig. 1) carried out for the first time (caprolactam=hexahydro‐2H‐azepin‐2‐one) (Scheme). Variation of the chain length (n) of the alkyl substituent (Cn) at the caprolactam cation (CP+) from n=12 to 18 caused the n/iso ratios to vary from 1.7 to 2.9. Meanwhile, the TOF (turnover frequency) decreased from 148 to 122 mol mol−1 h−1. Hydroformylation in the imidazolium‐based ILCs revealed that [C16MIm]⋅BF4 (n/iso 5.2, TOF 969 mol mol−1 h−1) was more favorable than [C16MIm]⋅MsO (n/iso 3.7, TOF 969 mol mol−1 h−1) for the formation of the unbranched aldehyde. Although the n/iso ratio in caprolactam‐based ILCs was lower than that in imidazolium‐based ILCs, the conversions are higher in the former ILCs on the whole. It should be noted that the lamellar mesophase has a strong effect on the regioselectivity and TOF of the hydroformylation. Also, it is evident that the influences of different ILCs on the hydroformylation under the various reaction conditions are greatly different. The identification of the reaction products was established by GC and GC/MS analyses.
Stereoselective Synthesis of [5‐[4,4,4,4′,4′,4′‐Hexafluoro‐N‐(2‐hydroxyethoxy)‐D‐valine]]‐ and [5‐[4,4,4,4′,4′,4′‐Hexafluoro‐N‐(2‐hydroxyethoxy)‐L‐valine]cyclosporin A
Authors: Eberle Marcel K. , Keese Reinhart 
Published: August 2010

AbstractAddition of various amines to the 3,3‐bis(trifluoromethyl)acrylamides 10a and 10b gave the tripeptides 11a–11f, mostly as mixtures of epimers (Scheme 3). The crystalline tripeptide 11f2 was found to be the N‐terminal (2‐hydroxyethoxy)‐substituted (R,S,S)‐ester HOCH2CH2O‐D‐Val(F6)‐MeLeu‐Ala‐OtBu by X‐ray crystallography. The C‐terminal‐protected tripeptide 11f2 was condensed with the N‐terminus octapeptide 2b to the depsipeptide 12a which was thermally rearranged to the undecapeptide 13a (Scheme 4). The condensation of the epimeric tripeptide 11f1 with the octapeptide 2b gave the undecapeptide 13b directly. The undecapeptides 13a and 13b were fully deprotected and cyclized to the [5‐[4,4,4,4′,4′,4′‐hexafluoro‐N‐(2‐hydroxyethoxy)‐D‐valine]]‐ and [5‐[4,4,4,4′,4′,4′‐hexafluoro‐N‐(2‐hydroxyethoxy)‐L‐valine]]cyclosporins 14a and 14b, respectively (Scheme 5). Rate differences observed for the thermal rearrangements of 12a to 13a and of 12b to 13b are discussed.
Perceptual denoising of color images
Authors: Netravali Ilka A. , Holt Robert J. , Webb Charles 
Published: August 2010

AbstractDenoising of color images is a trade‐off between sharpness of an image and perceived noise. We formulate a novel optimization problem that can maximize sharpness of an image while limiting the perceived noise under a model of visibility of additive random noise. We derive a closed‐form expression for an optimal two‐dimensional finite impulse response filter, show its uniqueness and existence, and present simulation results for black and white as well as color images. Simulation results show remarkable reduction in perceptibility of noise, while preserving sharpness. The computational burden required for the optimal filter is reduced by a new adhoc filter which is simple but has near optimal performance. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 215–222, 2010.
Shadow removal from image of stained glass windows
Authors: Suganthan Shanmugalingam , MacDonald Lindsay 
Published: August 2010

AbstractShadows may be formed on stained glass windows by structural bars supporting the leaded panels, or by external protective wire grilles, or by masonry, such as mullions or buttresses, or external objects, such as trees. The eye tends to “discount” such shadow formations when viewing the actual windows even though in the photographic images they are very clearly visible. This article introduces a method to remove shadow effects on stained‐glass windows; the observed image, as captured by the camera, may be modeled mathematically as a combination of a “true stained glass image” and a “grille/bar image.” A mixture model is derived, based on a theoretical model of image formation, leading to a conjectured relationship between “shadow” pixels and the neighboring “nonshadow” pixels. The resulting mixture model assumes a multiplicative relationship. If this mixture can be separated into its original components, then it should be possible to remove the unwanted shadow component from the captured image to produce the desired image of the stained glass without the shadows. The digital modeling techniques enable the shadows to be characterized and removed with a reasonable degree of success. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 223–226, 2010.
Lie group method: A new approach to image matching with arbitrary orientations
Authors: Ying Shihui , Qiao Hong 
Published: August 2010

AbstractIn this article, we develop a new method for image matching of any two images with arbitrary orientations. The idea comes from the workpiece localization in machining industry. We first describe an image as a 3D point set other than the common 2D function f(x, y), then, making the sets corresponding to the compared images form solid surfaces, we equivalently translate the matching problem into an optimization problem on the Lie group SE(3). Through developing a kind of steepest descent algorithms on a general Lie group, we present an practical algorithm for matching problem. Simulations of eye detection and face detection are presented to show the feasibility and efficiency of the proposed algorithm. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 245–252, 2010.
Automatic facial expression recognition based on pixel‐pattern‐based texture feature
Authors: Lu Hu‐Chuan , Huang Ying‐Jie , Chen Yen‐Wei 
Published: August 2010

AbstractPCA, ICA, and Gabor wavelet are considered as the important and powerful face representation methods. In this article, we propose a new approach for face representation, which is called a pixel‐pattern‐based texture feature (PPBTF) and apply it to the real‐time facial expression recognition. A gray scale image is transformed into a pattern map where edges and lines are used for characterizing the facial texture information. Based on the pattern map, a feature vector is comprised of the numbers of the pixels belonging to each pattern. We use the image basis functions obtained by principal component analysis as the templates for pattern matching. Adaboost and Support Vector Machine are adopted to classify facial expression. Extensive experiments on the Cohn‐Kanade Database, PIE Database, and DUT Database illustrate that the PPBTF is quite effective and insensitive to illumination. The comparison with Gabor show the PPBTF is speedy. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 253–260, 2010
Estimation of a dense velocity field based on the statistics of dynamic speckle
Authors: Aoudi Walid , Vray Didier 
Published: August 2010

AbstractThis article presents a new technique for flow velocity estimation from ultrasound image sequences. The method is based on the analysis of the temporal statistics of the speckle pattern in motion. We demonstrate that the biased local temporal variance (LTV) of a single pixel within an image of dynamic speckle is related to velocity. This allows us to estimate the total velocity magnitude without the requirement of neither block matching nor autocovariance estimation. A new estimator, asymptotically without bias, called LTV is presented. Results conducted on experimental B mode sequences (40 MHz) of blood mimicking fluid with calibrated velocities are presented. Performances of the estimator are studied and results show good agreement with the statistical model. Magnitude of the 3D velocity vector in the range of 0.1–2 mm/s have been estimated with a standard deviation error of less than 12%. The validity of the method and its limitations are then discussed. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 268‐276, 2010
Selective and adaptive signal hiding technique for security of JPEG2000
Authors: Seo Young‐Ho , Choi Hyun‐Jun , Yoo Ji‐Sang , Kim Dong‐Wook 
Published: August 2010

AbstractIn this article, we proposed a selective partial image encryption scheme of Secure JPEG2000 (JPSEC) for digital cinema or any other JPEG2000‐based applications. It makes a scalable encryption scheme possible on the basis of a trade‐off relationship between the encryption effect and the encryption cost. The encryption scheme was designed to activate during the image compression process, which is between quantization and entropy coding. Three data selection schemes were involved to select the parts of data to be encrypted: subband selection, data bit selection, and random selection of coefficients. The experimental results with over 3000 test images revealed that the PSNRs were between about 9.5 to 7.5 dB when the portion of the encrypted data by this scheme was between 1/4096 and 1/256. As the encryption effect is reasonably high with very low cost, the proposed scheme has high potential to provide secure communications in a variety of wired/wireless scenarios. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 277‐284, 2010
c‐Cbl regulates glioma invasion through matrix metalloproteinase 2
Authors: Lee Hojin , Tsygankov Alexander Y. 
Published: August 2010

Abstractc‐Cbl, a multifunctional adaptor and an E3 ubiquitin ligase, plays a role in such cytoskeleton‐mediated events as cell adhesion and migration. Invasiveness of human glioma is dependent on cell adhesion, migration, and degradation of extracellular matrix (ECM). However, the function of c‐Cbl in glioma invasion has never been investigated. We report here, for the first time, that c‐Cbl plays a positive role in the invasion of ECM by SNB19 glioma cells. RNAi‐mediated depletion of c‐Cbl decreases SNB19 cell invasion and expression of matrix metalloproteinase 2 (MMP2). Consistent with these findings, SNB19 cells expressing wild‐type, but not mutant c‐Cbl show increased invasion and MMP2 expression. We demonstrate that the observed role of c‐Cbl in invasion of SNB19 cells is not mediated by the previously shown effects of c‐Cbl on cell adhesion and migration or on EGFR signaling. Together, our results suggest that c‐Cbl promotes glioma invasion through up‐regulation of MMP2. J. Cell. Biochem. 111: 1169–1178, 2010. © 2010 Wiley‐Liss, Inc.