bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of carbon black on electrical property of graphite nanoplatelets/epoxy resin composites
Authors: Fan Zhuangjun , Zheng Chao , Wei Tong , Zhang Yicheng , Luo Guilian 
Published: July 2009

AbstractEpoxy/graphite nanoplatelets (GNPs)/carbon black (CB) composites were prepared by liquid mixing method. The morphologies and microstructures of the composites were examined by scanning electron microscope and X‐ray diffraction. The results indicated that CB can improve effectively the dispersion of GNPs and form excellent conductive network in the matrix. When the weight ratio of GNPs to CB was 9:1 (total filler content was 1 wt%), the conductivity of the composite was three orders of magnitude higher than that of composites with GNPs alone (1 wt%). The percolation threshold of GNPs0.9CB0.1/epoxy resin composites was 0.5 wt. %, which was lower than that of composites with GNPs alone (1 wt%). The mechanism for the effect of CB on electrical property of GNPs/epoxy resin composites was also investigated. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers.
Reinforcing and toughening on poly(ether imide) by a novel thermo tropic liquid crystalline poly(ester‐imide‐ketone) with low content
Authors: Xu Bing , Zhang Yi , Liu Siwei , Chi Zhenguo , Peng Xiangfang , Lin Yongqiang , Xu Jiarui 
Published: July 2009

AbstractReinforcing and toughening effects on the thermoplastic poly(ether imide) (PEI) by a novel thermo tropic liquid crystalline poly(ester‐imide‐ketone) (TLCPEIK) with low content were studied in this work. The novel TLCPEIK with kink naphthalene structure in the backbone was synthesized in our laboratory. A series of in‐situ composites (TLCPEIK/PEI) with a low concentration of TLCPEIK(≤5 wt%) were prepared by direct extrusion. Tensile strength, flexural strength, and flexural modulus of the composites increased with increasing TLCPEIK content. Impact strength and elongation at break of the composites were enhanced greatly when compared with that of pure PEI. To explain the simultaneously reinforcing and toughening effects on PEI by TLCPEIK, miscibility and morphology of the composites were studied by differential scanning calorimetry (DSC) and scanning electron microscopy. The experimental results suggest that good compatibility of the components is beneficial to improve the ultimate properties of TLCPEIK/PEI in‐situ composites. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers.
A novel miniature mixing device for polymeric blends and nanocomposites
Authors: Sentmanat Martin , Stamboulides Christos , Hatzikiriakos Savvas G. 
Published: July 2009

AbstractA new miniature mixer has been developed to monitor and optimize the preparation protocol of various polymeric compounds and blend systems. The effect of mixing time and other basic processing parameters on the shear and extensional rheological properties of said compounds and blends is examined to understand the effect of undermixed and/or overmixed conditions on the rheological properties and thus the quality of the final products. Results from the new miniature mixer are compared with the results from other conventional mixing techniques to assess the scalability of the new mixing protocol. Two examples are used, those of polymer blending and nanocomposite formation. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers.
Monitoring epoxy and unsaturated polyester reactions under pressure—Reaction rates and mechanical properties
Authors: Cruz Javier C. , Osswald Tim A. 
Published: July 2009

AbstractThe effects of pressure on reaction rates and final mechanical properties were studied for an unsaturated polyester (UP) and epoxy resin. A pressure chamber where reactions can be monitored by use of Raman spectroscopy has been built for these purposes. The chamber allows for pressures up to 13.8 MPa at 200°C. An advanced temperature control system has been adapted to the vessel to precisely control and monitor sample temperature variations and overshoots. It is described how for an accelerated UP reaction increasing pressure will result in a competing effect on the reaction rate where the rate will initially lower, but with increased pressures it may accelerate due to acceleration of the reaction rate constants. The final mechanical properties exhibit a similar behavior slightly increasing with pressure but lowering as pressure is raised further. For epoxy, it was shown that the reaction kinetics were accelerated by pressure although no mechanical property differences could be noted for the pressure ranges tested. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers.
Graduate students' administration and scoring errors on the Woodcock‐Johnson III Tests of Cognitive Abilities
Authors: Ramos Erica , Alfonso Vincent C. , Schermerhorn Susan M. 
Published: July 2009

AbstractThe interpretation of cognitive test scores often leads to decisions concerning the diagnosis, educational placement, and types of interventions used for children. Therefore, it is important that practitioners administer and score cognitive tests without error. This study assesses the frequency and types of examiner errors that occur during the administration and scoring of the Woodcock‐Johnson III Tests of Cognitive Abilities (WJ III COG). Data from 36 graduate students across 108 test records revealed a total of 500 errors across all records. Further analyses indicated three frequently occurring errors, including the use of incorrect ceilings, failure to record errors, and failure to encircle the correct row for the total number correct. The results of this study may be used to inform training programs so that appropriate steps can be taken to decrease the number of examiner errors on the WJ III COG and similar cognitive test batteries. © 2009 Wiley Periodicals, Inc.
Evolution of Atmospheric‐Pressure RF Plasmas as the Excitation Frequency Increases
Authors: Liu Da Wei , Iza Felipe , Kong Michael G. 
Published: July 2009

AbstractExperimental results confirm the previously reported computational finding that increasing the excitation frequency of an atmospheric‐pressure plasma leads to an extension of the glow‐like operation mode. Furthermore, it is shown that more intense plasmas are attainable at higher frequencies due to the ability to couple more power into the plasma without inducing the transition into the γ mode. If the frequency is increased at a constant power, however, the plasmas become noticeably less intense even though more power is coupled into the electrons. This paradox is explained by the different evolution of the power coupled to electrons in the sheaths and in the bulk as frequency increases.magnified image
Or0404—Effect of a Tribochemical Reacted Film on Friction and Wear Properties of DLC Coatings
Authors: Yoshida Kentaro , Horiuchi Takahiro , Kano Makoto , Kumagai Masao 
Published: July 2009

AbstractDiamond‐like carbon (DLC) coatings provide low friction properties without lubricants and, with lubricants, should provide super low friction. In this study, the friction and wear properties of DLC coatings with lubrication in the sliding contact area were evaluated to find an environmentally friendly material combination that can provide super low friction (i.e., a coefficient of friction lower than 0.01). The friction and wear properties of a steel pin on a DLC coated disk with lubrication were evaluated by using environmentally friendly fluids (organic acid or alcohol) as lubricants. In a sliding test of tetrahedral amorphous carbon (ta‐C) lubricated with DL (a mixture of dextrorotatory and levorotatory molecules)‐lactic acid, a super low coefficient of friction (0.01) was obtained at the end of the test and was much lower than that of an uncoated disk and an amorphous hydrogenated carbon (a‐C:H) disk. The coefficient of friction obtained with DL‐lactic acid was lower than that seen for acetic acid or glycerol. The ta‐C disk lubricated with DL‐lactic acid showed a small wear scar width. The main reason for the reduced friction and wear is probably attributable to the formation of a tribochemical reacted film in a tribochemical reaction with the acid. An oxidation film (white colored layer) of FeO also formed on the mating pin under DL‐lactic acid lubrication in the sliding contact area. These results showed not only the difference in the adsorbed lubricants due to the chemical structure of DLC, but also that the oxidized condition of the steel pin influenced the coefficient of friction.
“Magnetically enhanced hollow cathode—a new plasma source for high‐rate deposition processes”
Authors: Fietzke Fred , Morgner Henry , Günther Steffen 
Published: July 2009

AbstractHollow cathode arc discharges have been studied for some decades in basic research and different fields of practical application. Especially in the field of physical vapor deposition (PVD) they are often used for metal evaporation and the generation of plasma. Problematical aspects were found in the high throughput of working gas necessary for stable operation and in the inhomogeneous, locally concentrated ionization efficiency. A promising way out of this dilemma was found in a special arrangement of hollow cathode and annular anode in an axial magnetic field. This configuration allows a drastic reduction of working gas flow without loss of discharge stability. Moreover, with reduction of gas flow a strong increase in ion current density was observed together with a highly expanded volume of plasma plume.
Plasma Sheath Dynamics in Dielectric Barrier‐Free Atmospheric Pressure Radio‐Frequency Glow Discharges
Authors: Laimer Johann , Puchhammer Alexander , Störi Herbert 
Published: July 2009

AbstractThe atmospheric pressure plasma jet (APPJ) makes use of a dielectric barrier‐free atmospheric pressure radio‐frequency (RF) glow discharge. In its usual operation mode it produces a uniform glow discharge, filling the gap. This alpha mode of the RF discharge is sustained by bulk ionization by oscillating electrons, as long as the gap spacing is sufficient. At higher RF powers the alpha sheath breaks down and the gamma mode, sustained by secondary electron emission occurs. Present experiments test the above model by taking images with nanosecond time resolution. The experiments clearly showed the differences in the development of the discharge over the RF cycle in correlation with gap spacing and α or γ mode, corroborating the model.
Surface Modification of Natural Vulcanized Rubbers by Atmospheric Dielectric Barrier Discharges Plasma Treatments
Authors: Moreno‐Couranjou Maryline , Choquet Patrick , Guillot Jerôme , Migeon Henri‐Noël 
Published: July 2009

AbstractA natural vulcanized rubber was treated by atmospheric dielectric barrier discharges to improve its adhesion to silicone adhesive. The different operating conditions were: (i) the nature of the plasma gas associated or not with organic precursors such as acetic acid or allyl alcohol, (ii) the concentration of the precursors in the gas phase, (iii) the power discharge (between 500 and 1 000 W) and (iv) the treatment time (between 18 and 30 s). The surface modifications induced by the plasma treatments were characterized by water contact angle measurements and XPS analyses. T‐peel tests were carried out to evaluate the influence of the surface modifications on the adhesion properties of the treated rubber. The efficiency of plasma treatments with the use of allyl alcohol has been proved for the adhesion improvement of natural vulcanized rubbers to a silicone adhesive (increase by a factor of 10). XPS analysis revealed that this treatment induced an increase of the total oxygen amount in the sample with the preferential formation of CO bonds, which might explain the adhesion improvement observed.
New‐build gentrification in Central Shanghai: demographic changes and socioeconomic implications
Authors: He Shenjing 
Published: July 2009

AbstractIn Shanghai, globalised urban images and a well‐functioning accumulation regime are enthusiastically sought after by urban policy, and explicitly promoted as a blueprint for a civilised city life. The city is celebrating its thriving neo‐liberal urbanism by implementing enormous new‐build gentrification, mostly in the form of demolition–rebuild development involving direct displacement of residents and landscapes. This study aims to understand demographic changes and the socioeconomic consequences of new‐build gentrification in central Shanghai. The paper first examines demographic changes between 1990 and 2000 in central Shanghai, i.e. the changing distribution of potential gentrifiers and displacees. It then looks into two cases of new‐build gentrification projects in central Shanghai, to compare residents' socioeconomic profiles in old neighbourhoods and new‐build areas. This study also examines the impacts of gentrification on displacees' quality of life and socioeconomic prospects. Because the enlarging middle class and the pursuit of wealth‐induced growth by the municipal government are turning the central city into a hotspot of gentrification, inequalities in housing and socioeconomic prospects are being produced and intensified in the metropolitan area. This study thus emphasises that critical perspectives in gentrification research are valuable and indispensable. Copyright © 2009 John Wiley & Sons, Ltd.
Excitonic absorption spectra and ultrafast dephasing dynamics in arbitrary carbon nanotubes
Authors: Malic Ermin , Hirtschulz Matthias , Reich Stephanie , Knorr Andreas 
Published: July 2009

AbstractWe illustrate the potential of the density matrix theory for investigation of optical properties of arbitrary single‐walled carbon nanotubes (CNTs). We have performed microscopic calculations of excitonic absorption spectra for CNTs of different chiral angles and diameters. The obtained results are in good agreement with experiments, in particular the excitonic binding energies match well both experiments and ab initio calculations. Furthermore, we show the strength of our approach by presenting calculations of the ultrafast Coulomb driven non‐equilibrium dynamics in CNTs. We find excitation induced dephasing on the picosecond time scale depending on the excitation strength. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oxidation of bovine serum albumin: identification of oxidation products and structural modifications
Authors: Guedes Sofia , Vitorino Rui , Domingues Rosário , Amado Francisco , Domingues Pedro 
Published: July 2009

AbstractAlbumin is an important plasma antioxidant protein, contributing to protecting mechanisms of cellular and regulatory long‐lived proteins. The metal‐catalyzed oxidation (MCO) of proteins plays an important role during oxidative stress. In this study, we examine the oxidative modification of albumin using an MCO in vitro system. Mass spectrometry, combined with off‐line nano‐liquid chromatography, was used to identify modifications in amino acid residues. We have found 106 different residues oxidatively damaged, being the main oxidized residues lysines, cysteines, arginines, prolines, histidines and tyrosines. Besides protein hydroxyl derivatives and oxygen additions, we detected other modifications such as deamidations, carbamylations and specific amino acid oxidative modifications. The oxidative damage preferentially affects particular subdomains of the protein at different time‐points. Results suggest the oxidative damage occurs first in exposed regions near cysteine disulfide bridges with residues like methionine, tryptophan, lysine, arginine, tyrosine and proline appearing as oxidatively modified. The damage extended afterwards with further oxidation of cysteine residues involved in disulfide bridges and other residues like histidine, phenylalanine and aspartic acid. The time‐course evaluation also shows the number of oxidized residues does not increase linearly, suggesting that oxidative unfolding of albumin occurs through a step‐ladder mechanism. Copyright © 2009 John Wiley & Sons, Ltd.
Electron ionization mass spectrometry of the ryanodine receptor‐based Ca2+‐channel stabilizer S‐107 and its implementation into routine doping control
Authors: Thevis Mario , Beuck Simon , Thomas Andreas , Fußhöller Gregor , Sigmund Gerg , Schlörer Nils , Rodchenkov Grigory , Schäfer Mathias , Schänzer Wilhelm 
Published: July 2009

AbstractNew insights into the biochemistry of cardiac arrhythmia and skeletal muscle fatigue have yielded new drug candidates to counteract these phenomena. Major biological targets have become ryanodine receptor (RyR)‐based Ca2+‐release channels, which tend to ‘leak’ under various circumstances including strenuous exercise and, thus, cause aberrant calcium sparks that entail impaired muscle function. Therapeutics, which are referred to as rycals, are currently being developed to treat cardiac arrhythmia via enhancement of calstabin‐ryanodine affinities that causes a stabilization of the RyR. These therapeutics possess potential for misuse in sports, and an early implementation of target analytes such as the benzothiazepine derivatives S‐107 and JTV‐519 or putative metabolites into doping control screening procedures is recommended. Reference compounds, deuterated analogues, and a putative metabolic product were synthesized, and electron ionization mass spectra of these products were studied and dissociation pathways elucidated by means of tandem mass spectrometry (MS/MS) and accurate mass measurements. The characterized analytes were incorporated into existing sports drug testing assays based on liquid‐liquid extraction and subsequent gas chromatography/mass spectrometry (GC/MS) analysis, and specificity, lower limit of detection (4–6 ng/mL), intraday and interday precision (1.5–17.2%), as well as recovery (63–66%) were determined. The established procedure proved suitable for routine doping control analysis to detect a potential misuse of the drug candidate S‐107 in elite sport. Copyright © 2009 John Wiley & Sons, Ltd.
Secure prophet address allocation for MANETs
Authors: Zhou Hongbo , Mutka Matt W. , Ni Lionel M. 
Published: July 2009

AbstractA mobile node in a MANET must be assigned a free IP address before it may participate in unicast communications. This is a fundamental and difficult problem in the practical application of any MANET. There have been several solutions proposed, among which prophet address allocation outperforms others in terms of communication overhead, latency, and scalability. However, none of the approaches can survive attacks in an insecure environment. Although there are a few secure autoconfiguration schemes proposed, they all have some disadvantages. Based on studies of insecure scenarios, attack schemes, and our previous work, a secure autoconfiguration algorithm, namely secure prophet address allocation, is proposed in the paper. The proposed approach is able to maintain uniqueness of address assignment in the presence of IP spoofing attacks, [state pollution] attacks, and Sybil attacks. The invulnerability of the scheme is supported by both theoretical analysis and simulation results. Copyright © 2009 John Wiley & Sons, Ltd.
What really is alliance management capability and how does it impact alliance outcomes and success?
Authors: Schreiner Melanie , Kale Prashant , Corsten Daniel 
Published: July 2009

AbstractStrategy scholars have asserted that a firm's alliance capability provides competitive advantage. As interest in alliance capability has grown, we see two streams of research emerge that address different, but equally important, issues related to this subject: one stream that focuses on how alliance capability develops in firms, and a second stream that investigates what elements specifically constitute a firm's alliance capability. In recent literature, the question of how firms develop alliance capability has received greater attention than the question of what elements actually comprise it; therefore, in this study we address the latter issue in great depth. We do this by building on prior research and on our fieldwork, to conceptualize alliance management capability as a multidimensional construct that comprises three distinct but related aspects or skills to address the following aspects in managing a given individual alliance after it is up and running: coordination, communication, and bonding. We then test our conceptualization in a framework that also links this capability to relevant outcomes at the alliance and firm level. We use survey and secondary data from a large sample of interfirm relationships between software service providers and three major global software vendors. We find general empirical support for our conceptualization of alliance management capability and for its predictive validity in impacting certain alliance outcomes. Copyright © 2009 John Wiley & Sons, Ltd.
Contingencies within dynamic managerial capabilities: interdependent effects of resource investment and deployment on firm performance
Authors: Sirmon David G. , Hitt Michael A. 
Published: July 2009

AbstractDynamic managerial capabilities focus on managers' resource‐related decisions. Asset orchestration, a central component of dynamic managerial capabilities and of resource management, highlights the importance of integrating (matching) resource investment and deployment decisions. Building on these recent theoretical advances, we examine the contingent nature of resource investment and deployment decisions. The results, based on a sample of banking firms, indicate that firm performance suffers when managers' investment decisions deviate from the norms of rivals for both human and physical capital. However, when deployment decisions support investment decisions, greater investment deviation, both high and low, generally enhances performance. Specifically, firm performance is optimized by making congruent resource investment and deployment decisions as opposed to maximizing or economizing either decision independently. Therefore, resource management via asset orchestration is vital for superior performance. Copyright © 2009 John Wiley & Sons, Ltd.
Learning progressions: Aligning curriculum, instruction, and assessment
Authors: Duncan Ravit Golan , Hmelo‐Silver Cindy E. 
Published: July 2009

AbstractScholarship on learning progressions (LPs) in science has emerged over the past 5 years, with the first comprehensive descriptions of LPs, on the nature of matter and evolution, published as commissioned reports (Catley, Lehrer, & Reiser, 2005; Smith, Wiser, Anderson, & Krajcik, 2006). Several recent policy reports have advocated for the use of LPs as a means of aligning standards, curriculum, and assessment (National Research Council [NRC], 2005, 2007). In some ways, LPs are not a new idea; developmental psychologists have long been examining the development of childrens' ideas over time in several scientific domains. However, the emerging research offers renewed interest, a new perspective, and potentially new applications for this construct. For these reasons, this special issue of theJournal for Research in Science Teachingis timely. Our goal in this introduction is to explain the motivation for developing LPs, propose a consensual definition of LPs, describe the ways in which these constructs are being developed and validated, and finally, discuss some of the unresolved questions regarding this emerging scholarship. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 606–609, 2009