bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of Strain Distribution and Material Flow in Bulk Deformation by the Screw Method
Authors: Zhang J. , Yuan S. J. , He Z. B. 
Published: July 2007

Abstract
A new method for the observation of material flow and measurement of plastic strain in deformed parts is proposed. First, a specimen with machined threaded holes containing threaded bolts was deformed and then sectioned along the mid-section of the bolts. The deformed screw interfaces at the section were observed and measured by a microscope. The plastic strain on the screw interfaces was calculated by the change of screw pitch. The experimental results and numerical simulation show good agreement. In contrast to other physical modeling methods, this method utilizes the actual metal for sensor and workpiece, rather than using substitute materials. Furthermore, the proposed method can be used to observe and measure material flow and plastic strain inside the specimen without splitting it before deformation. It can be used to study material flow and predict strain distribution in general bulk metal forming processes such as upsetting, extrusion, die forging, etc.
Improved Grazing Management Increases Terrestrial Invertebrate Inputs that Feed Trout in Wyoming Rangeland Streams
Authors: Saunders W. Carl , Fausch Kurt D. 
Published: July 2007

AbstractResearch in forest and grassland ecosystems worldwide indicates that terrestrial invertebrates can be a significant source of prey for fish, providing about 50% of their annual energy. We examined whether input of terrestrial invertebrates to rangeland streams in western Wyoming provides an important prey resource for brown trout Salmo trutta and brook trout Salvelinus fontinalis and how it is modified by livestock grazing. During summers of 2004 and 2005 we sampled falling invertebrate input and trout diets in five pairs of streams that had riparian zones under two different grazing systems: High‐density, short‐duration (HDSD) grazing versus season‐long (SL) grazing. The biomass of riparian vegetation and the input of terrestrial invertebrates were two to three times greater in reaches with riparian zones under HDSD than under SL grazing management. Likewise, the afternoon diets of individual trout in HDSD reaches had, on average, about twice as much terrestrial invertebrate biomass during summer than those of trout in SL reaches, but this was statistically significant only during late summer due to high variability. Overall, 57% of the afternoon diets of trout in reaches under both grazing systems consisted of terrestrial prey. Diel diet sampling during August 2005 showed that fish in HDSD reaches also had consumed more aquatic invertebrate prey, primarily at night. Total trout biomass in HDSD reaches was more than twice that in SL reaches. These results suggest that in rangeland streams of the western United States, both terrestrial and aquatic invertebrates are important prey resources for trout and that improved grazing management has the potential to influence fish populations through multiple food web pathways.
Three‐phase oil–water–gas horizontal co‐current flow part II. Holdup measurement and prediction
Authors: Spedding P. L. , Donnelly G. F. , Benard E. 
Published: July 2007

AbstractHoldup data are presented for three‐phase co‐current oil‐water‐air in a horizontal 0.0259 m i.d. pipe. Detailed two‐phase studies confirmed the validity of the experimental technique employed. A model is presented for the prediction of oil‐air two‐phase holdup. The three‐phase holdup values were shown to be flow regime dependent and could be qualitatively explained on the basis of the fine structure of the liquid phases. A model is presented for the prediction of three‐phase liquid holdup. This work extends the regime study by Spedding et al. (Trans. Inst. Chem. Eng, Part A, Chem. Eng. Res. Des. 2005, 83A: 401–411) to holdup measurement and prediction for three‐phase flow. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
Re‐entrainment of wall deposits from a laboratory‐scale spray dryer
Authors: Hanus M. J. , Langrish T. A. G. 
Published: July 2007

AbstractThis work has determined the magnitude of re‐entrainment and established the operational parameters that may be manipulated to influence re‐entrainment of salt particles for a small‐scale spray dryer (Buchi B‐290). The wetness of the spray dryer wall deposits was found to significantly influence the magnitude of re‐entrainment. It was shown both experimentally and numerically that wet deposits form at low nozzle air‐to‐liquid ratios (<2000), which form large droplets that dry slowly, while the initial droplet velocity did not have a large influence on wet deposition. Wet deposits form strong liquid and solid bridges, and thus deposits formed from wet particles were difficult to re‐entrain. Less than 2% of deposits formed at nozzle air‐to‐liquid ratios less than 2000 were re‐entrained, while 15.4 to 21.2% of dry deposited particles (formed at nozzle air‐to‐liquid ratios ranging from 2308 to 3409) were re‐entrained. The threshold re‐entrainment velocity of sodium chloride particles in the Buchi B‐290 spray dryer was found to be between 4 and 7.7 ms−1, which is consistent with the lower‐end threshold velocities presented in the literature. No significant trend relating relative humidity to the magnitude of re‐entrainment was found in the 0.2–7.4% average relative humidity range, suggesting that the adhesive forces in spray dryer wall deposits are fairly constant across this relative humidity range. Decreasing wall deposit wetness through use of high (>2000) nozzle air‐to‐liquid ratios and use of high main gas velocities increased the re‐entrainment of wall deposits in this spray dryer. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
Time–temperature dependence of the electrical resistivity of high‐density polyethylene/carbon black composites
Authors: Traina Matteo , Pegoretti Alessandro , Penati Amabile 
Published: July 2007

AbstractSeveral carbon blacks with surface areas from 105 to 1353 m2/g were used to produce composites through melt compounding with a high‐density polyethylene matrix. The electrical behavior of the obtained composites was investigated by the measurement of their resistivity as a function of the carbon black content and type at various temperatures and times during isothermal annealing treatments. The percolation threshold markedly decreased as the carbon black surface area increased, reaching a minimum value of 1.8 vol % for the carbon black with a surface area of 1353 m2/g. The resistivity passed through a maximum as the test temperature increased. Moreover, the analysis of the experimental data evidenced that the host high‐density polyethylene matrix and the conductive carbon black network rearranged during the isothermal thermal treatments, causing a resistivity decrease. This rearrangement became less and less important as the carbon black surface area increased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Curing behavior of a novel polytriazole resin
Authors: Wan Liqiang , Tian Jianjun , Huang Jianzhi , Hu Yanhong , Huang Farong , Du Lei 
Published: July 2007

AbstractThe curing behavior of a novel low temperature curing polytriazole resin, prepared from p‐xylylene diazide and N,N,N′,N′‐tetrapropargyl‐p,p′‐diaminodiphenylmethane, was investigated by DSC and rheological analyses. The kinetics of the curing of the resin was studied by nonisothermal and isothermal DSC measurements and the kinetics parameters were obtained. The values of apparent activation energy Ea of the curing reaction obtained by nonisothermal and isothermal DSC are 80.7 and 75.3 kJ/mol, respectively. The curing of the resin was traced by the isothermal rheological analysis. The gelation times of the resin at 70, 75, 80, and 85°C are about 200, 150, 110, and 75 min, respectively. The viscosity equation for the resin was found as follows:
$ \ln \eta= -107 + {{33.5 \times 10^3} \over T} + t \exp \left(26.3 + {{9.87 \times 10^3} \over T}\right). $
© 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Recycled PET‐organoclay nanocomposites with enhanced processing properties and thermal stability
Authors: Kráčalík Milan , Studenovský Martin , Mikešová Jana , Kovářová Jana , Sikora Antonín , Thomann Ralf , Friedrich Christian 
Published: July 2007

AbstractPreparation of thermally stable recycled PET‐organoclay nanocomposites with improved processing and mechanical properties is a challenging task from the environmental as well as industrial and commercial point of view. In this work, both modification of sodium‐type montmorillonite with 1,2‐dimethyl‐3‐octadecyl‐1H‐imidazol‐3‐ium chloride and additional treatment with [3‐(glycidyloxy)propyl]trimethoxysilane was performed. Thermal stability of the organoclays and nanocomposites prepared by melt compounding was tested by thermogravimetric analysis, differential scanning calorimetry, and melt rheology. In comparison with the organoclays modified with quaternary ammonium compounds, the prepared clays showed substantial suppression of matrix degradation during melt mixing. The increase in interlayer distance of silicate platelets and homogeneity of dispersions in the recycled and virgin PET matrices have been evaluated by transmission electron microscopy and wide‐angle X‐ray scattering. The higher degree of delamination in the nanocomposites filled with imidazole organoclays was in a good agreement with improved rheological characteristics and led to significant enhancement in mechanical properties and thermal stability. A difference in structure (besides the level of delamination and homogeneity of silicate platelets) of recycled versus virgin PET nanocomposites was detected by X‐ray diffraction patterns. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation of novel ZSM‐5 zeolite‐filled chitosan membranes for pervaporation separation of dimethyl carbonate/methanol mixtures
Authors: Liu Bingbing , Cao Yiming , Wang Tonghua , Yuan Quan 
Published: July 2007

AbstractNovel mixed matrix membranes were prepared by incorporating ZSM‐5 zeolite into chitosan polymer for the pervaporative separation of dimethyl carbonate (DMC) from methanol. These membranes were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) to assess their morphology, intermolecular interactions, and crystallinity. Sorption studies indicated that the degree of swelling for zeolite‐filled membranes increased with zeolite content in the membrane increasing and the separation selectivity of DMC/methanol was dominated by solubility selectivity rather than diffusivity selectivity. The characteristics of these membranes for separating DMC/methanol mixtures were investigated by varying zeolite content, feed composition, and operating temperature. The pervaporation separation index (PSI) showed that 5 wt % of ZSM‐5 zeolite‐filled membrane gave the optimum performance in the PV process. From the temperature‐dependent permeation values, the Arrhenius activation parameters were estimated. The resulting lower activation energy values obtained for zeolite‐filled membranes contribute to the framework of the zeolite. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Fluorocarbon‐containing hydrophobically modified poly(acrylic acid) gels as drug release system
Authors: Zhao Xian , Tian Qin , Tang Xiaozhen 
Published: July 2007

AbstractHydrophobically modified acrylic acid (AA) hydrogels containing fluorocarbon hydrophobic group and hydrocarbon‐modified gels using 2‐(N‐ethylperfluorooctanesulfoamido) ethyl methacrylate (FMA), and lauryl acrylate (LA) respectively, 2‐(N‐ethylperfluorooctanesulfoamido) ethyl methacrylate (FMA), were synthesized. Acetaminophen, with analgesic and antipyretic property, acted as the model drug. Swelling, rheological, and mechanical properties of the gels were investigated. Fluorocarbon‐modified gels show the stronger hydrophobicity than do the hydrocarbon‐modified gels, which affected the gel's drug‐releasing behavior. The drug release behavior depends on pH of the solution medium, the type of hydrophobic modification and the amount of hydrophobes. Hydrophobically modified PAA gels have higher storage modulus E′ than the unmodified PAA gels. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of percolation on electrical and dielectric properties of acrylonitrile butadiene styrene/graphite composite
Authors: Dahiya H. S. , Kishore Nawal , Mehra R. M. 
Published: July 2007

AbstractPrelocalized Acrylonitrile Butadiene Styrene/graphite composites were prepared by hot compression molding technique. The increased conductivity with increase of graphite content exhibits percolation phenomenon. The current–voltage characteristics are found to change from nonlinear to linear above the percolation threshold. A positive temperature coefficient of resistance is observed in these composites, and this effect is more pronounced in samples having graphite concentration near percolation threshold. The dielectric constant was found to increase slowly up to the percolation concentration and beyond it a sudden increase in its value is observed. The dissipation factor exhibits maxima in the vicinity of percolation threshold. The dielectric properties are discussed in terms of the interfacial Maxwell‐Wagner effects. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
E‐beam‐cured layered‐silicate and spherical silica epoxy nanocomposites
Authors: Chen Chenggang , Anderson David P. 
Published: July 2007

AbstractThis research demonstrates that an epoxy nanocomposite can be made through electron beam (e‐beam) curing. The nanofillers can be two‐dimensional (layered‐silicate) and zero‐dimensional (spherical silica). Both the spherical silica epoxy nanocomposite and the layered‐silicate epoxy nanocomposite can be cured to a high degree of curing. The transmission electron microscopy (TEM) and small‐angle X‐ray scattering of the e‐beam‐cured layered‐silicate epoxy nanocomposites demonstrate the intercalated nanostructure or combination of exfoliated and intercalated nanostructure. The TEM images show that the spherical silica epoxy nanocomposite has the morphology of homogeneous dispersion of aggregates of silica nanoparticles. The aggregate size is ∼ 100 nm. The dynamic mechanical analysis shows that the storage modulus of the spherical silica nanocomposite has been improved, and the glass transition temperature can be very high (∼ 175°C). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis of Novel 1‐Pyrazolylpyridin‐2‐ones as Potential Anti‐Inflammatory and Analgesic Agents
Authors: Ismail Magda M. F. , Ammar Yousry A. , El‐Zahaby Heba S. A. , Eisa Sally I. , El‐Sayed Barakat Saber 
Published: July 2007

AbstractA new series of 4‐alkyl/aryl‐2‐oxo‐1‐pyrazolyl‐1,2‐dihydropyridine‐3‐carbonitriles, pyrazolo[3,4‐b]pyridine‐5‐carbonitriles and pyrido[2,3‐d]pyrimidine‐6‐carbonitriles have been synthesized and tested for their anti‐inflammatory and analgesic activities. Among the tested compounds, 3e and 8b exhibited comparable anti‐inflammatory activity to the standard (indomethacin). Compounds 5, 7a, and 8b displayed potent analgesic activity. Detailed syntheses, spectroscopic and biological data are reported.
Introduction to the special topic section on mining Web resources for enhancing information retrieval
Authors: Lam Wai , Yang Christopher C. , Menczer Filippo 
Published: July 2007

AbstractThe amount of information on the Web has been expanding at an enormous pace. There are a variety of Web documents in different genres, such as news, reports, reviews. Traditionally, the information displayed on Web sites has been static. Recently, there are many Web sites offering content that is dynamically generated and frequently updated. It is also common for Web sites to contain information in different languages since many countries adopt more than one language. Moreover, content may exist in multimedia formats including text, images, video, and audio.
On the critical Richardson number in stably stratified turbulence
Authors: Galperin Boris , Sukoriansky Semion , Anderson Philip S. 
Published: July 2007

AbstractThe critical Richardson number, Ric, is used in studies of stably stratified turbulence as a measure of flow laminarization. The accepted range of Ric is between 0.2 and 1. A growing body of experimental and observational data indicates, however, that turbulence survives for Ri ≫ 1. This result is supported by a new spectral theory of turbulence that accounts for strong anisotropy and waves. The anisotropization results in the enhanced horizontal mixing of both momentum and scalar. Internal wave contribution preserves vertical momentum mixing above its molecular level. In the absence of laminarization, Ric becomes devoid of its conventional meaning. Copyright © 2007 Royal Meteorological Society
Molecular changes associated with teratogen‐induced cyclopia
Authors: Loucks Evyn J. , Schwend Tyler , Ahlgren Sara C. 
Published: July 2007

AbstractBACKGROUND: Exposure of zebrafish embryos to a number of teratogens results in cyclopia, but little is known about the underlying molecular changes. METHODS: Using zebrafish embryos, we compare the effects cyclopamine, forskolin, and ethanol delivered starting just before gastrulation, on gene expression in early axial tissues and forebrain development. RESULTS: Although all three teratogens suppress gli1 expression, they do so with variable kinetics, suggesting that while suppression of Shh signaling is a common outcome of these three teratogens, it is not a common cause of the cyclopia. Instead, all teratogens studied produce a series of changes in the expression of gsc and six3b present in early axial development, as well as a later suppression of neural crest cell marker dlx3b. Ethanol and forskolin, but not cyclopamine, exposure reduced anterior markers, which most likely contributes to the cyclopic phenotype. CONCLUSIONS: These data suggest that each teratogen exposure leads to a unique set of molecular changes that underlie the single phenotype of cyclopia. Birth Defects Research (Part A), 2007. © 2007 Wiley‐Liss, Inc.
Studies in solid‐phase peptide synthesis: A personal perspective
Authors: Mitchell Alexander R. 
Published: July 2007

AbstractBy the early 1970s it had became apparent that the solid‐phase synthesis of ribonuclease A could not be generalized. Consequently, virtually every aspect of solid‐phase peptide synthesis (SPPS) was reexamined and improved during the decade of the 1970s. The sensitive detection and elimination of possible side reactions (amino acid insertion, Nα‐trifluoroacetylation, Nαϵ‐alkylation) were examined. The quantitation of coupling efficiency in SPPS as a function of chain length was studied. A new and improved support for SPPS, the “PAM‐resin,” was prepared and evaluated. These and many other studies from the Merrifield laboratory and elsewhere increased the general acceptance of SPPS leading to the 1984 Nobel Prize in Chemistry for Bruce Merrifield. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90:215–233, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprintversion. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Prediction of the 3D Structure of FMRF‐amide Neuropeptides Bound to the Mouse MrgC11 GPCR and Experimental Validation
Authors: Heo Jiyoung , Han Sang‐Kyou , Vaidehi Nagarajan , Wendel John , Kekenes‐Huskey Peter , Goddard William A. 
Published: July 2007

AbstractWe report the 3D structure predicted for the mouse MrgC11 (mMrgC11) receptor by using the MembStruk computational protocol, and the predicted binding site for the F‐M‐R‐F‐NH2 neuropeptide together with four singly chirally modified ligands. We predicted that the R‐F‐NH2 part of the tetrapeptide sticks down into the protein between the transmembrane (TM) domains 3, 4, 5, and 6. The Phe (F‐NH2) interacted favorably with Tyr110 (TM3), while the Arg makes salt bridges to Asp161 (TM4) and Asp179 (TM5). We predicted that the Met extends from the binding site, but the terminal Phe residue sticks back into an aromatic/hydrophobic site flanked by Tyr237, Leu238, Leu240, and Tyr256 (TM6), and Trp162 (TM4). We carried out subsequent mutagenesis experiments followed by intracellular calcium‐release assays that demonstrated the dramatic decrease in activity for the Tyr110Ala, Asp161Ala, and Asp179Ala substitutions, which was predicted by our model. These experiments provide strong evidence that our predicted G protein‐coupled receptor (GPCR) structure is sufficiently accurate to identify binding sites for selective ligands. Similar studies were made with the mMrgA1 receptor, which did not bind the R‐F‐NH2 dipeptide; we explain this to be due to the increased hydrophobic character of the binding pocket in mMrgA1.
Two‐dimensional display for multivariate data using all principle components embedding chemical information by regular polygon approach (RPA)
Authors: Barakat Nasser A. Mohamed 
Published: July 2007

AbstractRegular polygon approach (RPA) is a new methodology proposed in this study to visualize the multivariate data points in two‐dimensional space. The proposed approach is excerpted from the phase diagram which is widely utilized in various fields of science. The proposed approach is considered as a modification of the principal component analysis (PCA) display method. However, in RPA all principal components carrying chemically meaningful information might be fully utilized in the visualization process. The data are displayed in an (n + 1)‐side regular polygon where n is the number of principal components embedding chemical information. The proposed method has been applied on 11 real chemical data sets and some of them could not be visualized successfully by the conventional PCA method. The obtained results have indicated that RPA might be exploited in a case of failure of the conventional PCA technique in displaying the data successfully. Copyright © 2007 John Wiley & Sons, Ltd.
Predictive weighting for cluster ensembles
Authors: Smyth Christine , Coomans Danny 
Published: July 2007

AbstractAn ensemble of regression models predicts by taking a weighted average of the predictions made by individual models. Calculating the weights such that they reflect the accuracy of individual models (post processing the ensemble) has been shown to increase the ensemble's accuracy. However, post processing cluster ensembles has not received as much attention because of the inherent difficulty in assessing the accuracy of an individual cluster model. By enforcing the notion that clusters must be ‘predictable’, this paper suggests a means of implicitly post processing cluster ensembles by drawing analogies with regression post processing techniques. The product of the post processing procedure is an intelligently weighted co‐occurrence matrix. A new technique, similarity‐basedk‐means (SBK), is developed to split this matrix into clusters. The results using three real life datasets underpinned by chemical and biological phenomena show that splitting an intelligently weighted co‐occurrence matrix gives accuracy that approaches supervised classification methods. Copyright © 2007 John Wiley & Sons, Ltd.