bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced kinetic mechanism for high‐temperature propane ignition
Authors: Prince J. C. , Treviño C. , Williams F. A.
Published: September 2008

The high‐temperature ignition (above 1100 K) of propane and air mixtures is studied in this work. The initial detailed mechanism consists of 177 elementary reactions with 40 species, which reproduces the ignition time of propane under a wide range in the parametric space (initial temperature, equivalence ratio, pressure). Through a systematic reduction strategy, using the classical normalized sensitivity analysis, the minimal set of elementary chemical reactions can be reduced to 43 with 27 species, reproducing the ignition conditions. Basically, the ignition delay time corresponds to the depletion time of the propane fuel, attacked by radicals, which produces secondary fuels such as ethylene (C2H4), ethane (C2H6), and acetylene (C2H2), among others, which are consumed in times much shorter than the consumption time of the primary fuel. Thus, the radical concentrations must be properly deduced to describe correctly the ignition delay time. A 15‐step global reaction mechanism is proposed and tested successfully. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 721–729, 2008
Supramolecular Structure and Properties of High Strength Regenerated Cellulose Films
Authors: Liu Shilin , Zhang Lina , Sun Yunxia , Lin Yi , Zhang Xianzheng , Nishiyama Yoshiharu
Published: September 2008

Water‐swollen cellulose films prepared from LiOH/urea solution were uniaxially drawn to investigate the effect of orientation on their supramolecular structure and properties. Their structures and properties were investigated with X‐ray diffraction, atomic force microscopy and tensile testing. The results revealed that the drawing process led to substantial reorientation of the cellulose molecular chains, resulting in a significant improvement of their mechanical properties and water‐resistance. With an increase of the drawn ratios from 1 to 1.22, the tensile strength of the films at dry and wet states increased from 89 to 213 MPa and 2.9 to 33.9 MPa, respectively. Furthermore, the drawn cellulose films also exhibited good biocompatibility with the capability of supporting cell adhesion and proliferation.

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Electrochemical and mechanical behaviour of Sn‐2.5Ag‐0.5Cu and Sn‐48Bi‐2Zn solders
Authors: Montesperelli G. , Rapone M. , Nanni F. , Travaglia P. , Riani P. , Marazza R. , Gusmano G.
Published: September 2008

In this paper, two tin‐based alloys (Sn‐2.5Ag‐0.5Cu and Sn‐48Bi‐2Zn) are proposed as new lead‐free solders. Alloys have been developed by melting pure elements. Samples have been evaluated in terms of microstructure, corrosion resistance and mechanical features. Corrosion tests have been performed in 3% NaCl solution by polarization curves and electrochemical impedance spectroscopy (EIS). SEM observations and EDS analysis were carried out on samples before and after corrosion tests. Static monotonic tensile tests have been performed on three specimens for each alloy. SEM and EDS analysis revealed the presence of Sn‐Ag and Sn‐Cu intermetallic compounds within the Sn‐Ag‐Cu alloy. As a result of corrosion test, the Sn‐Ag‐Cu alloy showed a better corrosion resistance with respect to Sn‐Bi‐Zn. Both alloys evidenced good mechanical properties higher than the traditional Sn‐Pb system. Sn‐Ag‐Cu seems to be a suitable soldering material.
Uniform corrosion and intergranular corrosion behavior of nickel‐free and manganese alloyed high nitrogen stainless steels
Authors: Wu X. Q. , Xu S. , Huang J. B. , Han E. H. , Ke W. , Yang K. , Jiang Z. H.
Published: September 2008

The uniform and intergranular corrosion behavior of two kinds of nickel‐free and manganese alloyed high nitrogen stainless steels (HNSSs) were investigated. A type of 316L stainless steel (316L SS) was also included for comparison purpose. Both solution annealed (SA) and sensitization treated (ST) steels were examined. It was found that the SA HNSSs had much weaker resistance to uniform corrosion compared to the SA 316L SS. The addition of molybdenum, to some extent, improved the uniform corrosion resistance of the HNSSs. The sensitization treatment had little influence on the uniform corrosion resistance of all the steels. The HNSSs showed an obvious susceptibility to intergranular corrosion, in particular the ST HNSSs. The intergranular corrosion rates of the sensitized HNSSs were much higher than that of the sensitized 316L SS. The degree of interganular attack for the ST HNSSs was much more serious than that for the 316L SS. The addition of molybdenum obviously improved the resistance of the ST HNSSs to intergranular corrosion. The double loop electrochemical potentiokinetic reactivation tests also proved that the HNSSs were rather susceptible to the sensitization treatment compared to the 316L SS. The relatively weak resistance of the HNSSs to uniform and intergranular corrosion may be due to high manganese promoted anodic dissolution. The improvement of uniform and intergranular corrosion resistance caused by the addition of molybdenum could be attributed to the synergistic effects of molybdenum and nitrogen in the HNSSs on the formation and stability of passive film.
Experimental and theoretical structural analysis of Zn(II)‐1‐hydroxyethane‐1,1‐diphosphonic acid corrosion inhibitor films in chloride ions solution
Authors: Reznik L. Y. , Sathler L. , Cardoso M. J. B. , Albuquerque M. G.
Published: September 2008

This work aims to analyze, through weight loss and X‐ray photoelectron spectroscopy (XPS) methods, the inhibitive films of 1‐hydroxyethane‐1,1‐diphosphonic acid (1‐hydroxyethylidene‐1,1‐diphosphonic acid, HEDP) and zinc(II) ions formed on AISI 1020 carbon steel when immersed in solutions containing 30 ppm of chloride ions, 50 ppm of HEDP, and three different concentrations of zinc(II) ions (14, 20, and 30 ppm). Moreover, the results of the experimental surface analyses were compared to molecular modeling studies of the proposed HEDP–Fe(III)/Zn(OH)2/HEDP–Zn(II) protective film. The film presented dissimilar structures responsible for the different levels of metallic protection for each particular zinc(II) concentration. In general, the increase in Zn(II) concentration leads to more compact and adherent film formation, with decreased corrosion rates of carbon steel.
The influence of copper content on intergranular corrosion of model AlMgSi(Cu) alloys
Authors: Zhan H. , Mol J. M. C. , Hannour F. , Zhuang L. , Terryn H. , de Wit J. H. W.
Published: September 2008

Application prospects in automotive and aerospace industry have led to extensive studies on AA6xxx alloys in recent years. Varying amounts of Mg, Si and Cu and heat treatments are used to achieve the desired mechanical properties in these alloys. In this investigation, a series of tests have been designed and carried out on model AlMgSi(Cu) alloys to investigate the effects of Cu, Mg and Si composition and heat treatments on the corrosion properties for a range of Cu content levels (0.03, 0.15 and 0.80 wt%, respectively). The results indicate that the localized corrosion susceptibility of the model alloys primarily increased with Cu content. The Si and Mg content and ratio do not appear to have a significant effect on the local corrosion behaviour. Heat treatment can improve the corrosion resistance. However, this effect is small compared to that of the Cu content for the range of model alloys investigated. Intergranular corrosion will occur by micro‐galvanic coupling between the cathodic AlMgSi(Cu) (Q) phase precipitates and the aluminum matrix adjacent to the particles. The increasing susceptibility to intergranular corrosion with Cu content can be attributed to an increased formation of Q phase particles.
Improvement of pitting corrosion resistance of AISI 444 stainless steel to make it a possible substitute for AISI 304L and 316L in hot natural waters
Authors: Bellezze T. , Roventi G. , Quaranta A. , Fratesi R.
Published: September 2008

The pitting corrosion resistance of AISI 444, 304L and 316L stainless steels in two tap waters with different chloride concentrations at 80 °C was studied. Cyclic potentiodynamic polarization (CPP) tests were carried out starting from Ecorr − 30 mV until the current density reached 0.1 mA/cm2 (scan rate 0.166 mV/s); the scan was then reversed and continued until new passivity conditions were achieved. The corrosion potential was measured before the polarization experiments. From the E‐log i plots, the values of pitting and protection potential were obtained; from these potentials, the perfect and the imperfect passivity regions were defined to compare the corrosion resistance of the studied steels. CPP tests were performed both on as received stainless steel samples and on samples submitted to different cleaning–passivation treatments to improve their corrosion resistance. The results indicate that, for industrial production, AISI 444 stainless steel can substitute the more expensive AISI 304L or 316L after a cleaning–passivation treatment that reduces the presence of inclusions.

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The electrochemical behaviour of Ti‐13Nb‐13Zr alloy in various solutions
Authors: Assis S. L. , Wolynec S. , Costa I.
Published: September 2008

The electrochemical behaviour of a near‐β Ti‐13Nb‐13Zr alloy for the application as implants was investigated in various solutions. The electrolytes used were 0.9 wt% NaCl solution, Hanks' solution and a culture medium known as minimum essential medium (MEM) composed of salts, vitamins and amino acids, all at 37 °C. The electrochemical behaviour was investigated by the following electrochemical techniques: open circuit potential measurements as a function of time, electrochemical impedance spectroscopy (EIS) and determination of polarisation curves. The obtained results showed that the Ti alloy was passive in all electrolytes. The EIS results were analysed using an equivalent electrical circuit representing a duplex structure oxide layer, composed of an inner barrier layer, mainly responsible for the alloy corrosion resistance, and an outer and porous layer that has been associated to osteointegration ability. The properties of both layers were dependent on the electrolyte used. The results suggested that the thickest porous layer is formed in the MEM solution whereas the impedance of the barrier layer formed in this solution was the lowest among the electrolytes used. The polarisation curves showed a current increase at potentials around 1300 mV versus saturated calomel electrode (SCE), and this increase was also dependent on the electrolyte used. The highest increase in current density was also associated to the MEM solution suggesting that this is the most aggressive electrolyte to the Ti alloy among the three tested solutions.
Mechanic treatment of fastener holes: The influence of compressive residual stress on the corrosion behaviour of aluminium alloys
Authors: Schneider J. , Haindl H.
Published: September 2008

Corrosion has a significant impact on the life cycle cost of military aircraft. Fleet experiences show that structural areas around joining elements (rivets, bolts) and faying surfaces are particularly sensitive to corrosion. During the repair currently performed the corrosion usually is blended out, the surface protection applied, the fastener inserted and a new top coat applied. Blending out corrosion often results in a reduction of fatigue life. To restore fatigue life the induction of compressive stress in the area affected is common practice. It is generally accepted that the induction of compressive residual stress extends fatigue life but its impact on the overall corrosion behaviour of alloys is discussed controversially in the literature. For this reason the influence of compressive residual stress on the corrosion behaviour was investigated in a joint experimental project. The compressive residual stress was introduced in different ways on laboratory scale and the specimens artificially weathered to simulate the effect of corrosion.
A study of electrical chloride extraction of iron artifacts
Authors: Lin Yantao , Liu Jianguo
Published: September 2008

The chloride extraction rule of iron artifacts was studied by electrical methods. The effect of the current and potential value on the desalination result of simulated iron artifacts was studied through the galvanostatic and potentiostatic experiments; the ingredients of the rust before and after treatments were also analyzed by the X‐ray diffraction (XRD). It has been found that the optimal current density was between −0.50 and −0.75 mA/cm2 and the optimal potential was between −1.175 and −1.200 V. The phase of the samples rusts transformed after treatment, as well as the anti‐corrosion performance improved.
Modification and Grafting of Multi‐Walled Carbon Nanotubes with Bisphenol‐A‐polycarbonate
Authors: Mormann Werner , Lu Yong , Zou Xuena , Berger Ralf
Published: September 2008

Multi‐walled carbon nanotubes (MWNT) were oxidized with nitric acid and resulting carboxy groups were transformed to amino groups with a diamine under microwave irradiation. Grafting of bisphenol‐A‐polycarbonate onto carboxy‐ and amino‐functional MWNT through transesterification or aminolysis resulted in weight increase up to 300%. The morphology of functionalized and grafted MWNTs was investigated with scanning force microscopy (SFM) and transmission electron microscopy (TEM). Depending on the type of functionalisation and the extent of grafting different morphologies were observed. Aminofunctional MWNT‐g‐PCs showed more “ball‐like” or irregular protrusions of grafted PC. Carboxyfunctional MWNT‐g‐PCs were more smoothly covered with PC.

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Investigation of Chain Dynamics in Poly(n‐alkyl methacrylate)s by Solid‐State NMR: Comparison with Poly(n‐alkyl acrylate)s
Authors: Gaborieau Marianne , Graf Robert , Spiess Hans Wolfgang
Published: September 2008

PnAMAs exhibit a local nanophase separation associated with intriguing chain dynamics (Macromol. Chem. Phys. 2005, 206, 142). PnAMAs of high molar mass, as determined by SEC and MHKS parameters, were investigated in the melt with a recently‐developed solid‐state NMR method (NOE with dipolar filter; Solid State Nucl. Magn. Res. 2005, 28, 160). The correlation times are assigned to the relaxation of the alkyl nanodomains, as coupled motions of the main chain and hindered local modes in the side chain. Comparison with poly(n‐alkyl acrylates) shows a higher anisotropy of the main chain motions and a better organized local nanophase separation in PnAMAs.

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Comparison of Three Different Click Reaction Methods for the Synthesis of Fluorene‐Based Polymers and Performance in Quasi‐Solid‐State DSSCs
Authors: Karim Md. Anwarul , Cho Young‐Rae , Park Jin Su , Ryu Tae In , Lee Myung Jin , Song Myungkwan , Jin Sung‐Ho , Lee Jae Wook , Gal Yeong‐Soon
Published: September 2008

The three different methods of click reaction has been used to synthesize fluorene‐based click polymers and compared its effect on polymer electro‐optical properties as well as photovoltaic performances in DSSCs. The DSSCs devices with configuration of SnO2:F/TiO2/N719 dye/quasi‐solid‐state electrolyte/Pt devices were fabricated using these click polymers as a quasi‐solid‐state electrolyte components. Among the devices, the catalyzed click polymer composed DSSCs device exhibited high power conversion efficiency (PCE) of 4.62% under AM 1.5G illumination. These click polymers are promising materials for device application and the CuI‐catalyst 1,3‐dipolar cycloaddition click reaction is an efficient synthetic methodology.

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Biotin‐, Pyrene‐, and GRGDS‐Functionalized Polymers and Nanogels via ATRP and End Group Modification
Authors: Siegwart Daniel J. , Oh Jung Kwon , Gao Haifeng , Bencherif Sidi A. , Perineau Fabien , Bohaty Andrew K. , Hollinger Jeffrey O. , Matyjaszewski Krzysztof
Published: September 2008

Functionality, one of the key attributes of atom transfer radical polymerization (ATRP), was utilized for the synthesis of well‐controlled polymers functionalized with biotin, pyrene, and peptides. Hydroxy‐functionalized poly(oligo(ethylene oxide) monomethyl ether methacrylate) (HO‐POEOMA) was prepared by AGET ATRP of OEOMA initiated by 2‐hydroxyethyl 2‐bromoisobutyrate in water or in inverse miniemulsion of water/cyclohexane at ambient temperature. HO‐POEOMA was then further functionalized with biotin, pyrene, and GRGDS peptide. In addition, ATRP and click chemistry offered an efficient route for the synthesis of telechelic di‐biotin polymers. These general methods can be applied to the formation of different functional materials conjugated with proteins, dyes, nucleic acids, and drugs.

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Additive Processing of Polymers
Authors: Wendel Bettina , Rietzel Dominik , Kühnlein Florian , Feulner Robert , Hülder Gerrit , Schmachtenberg Ernst
Published: September 2008

Additive processing technologies are rapidly growing in all fields of application. A large number of scientific publications were investigated in order to provide a comprehensive overview of rapid prototyping methods for polymers and their applications, of currently available materials and research concerning additive processes. The current problems of additive processes are described, together with their potential solutions. Furthermore, this article delivers an insight into possible future trends of additive technologies.

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Sigmoidal Chemorheological Models of Chip‐Underfill Materials Offer Alternative Predictions of Combined Cure and Flow
Authors: Love Brian J. , Teyssandier Fabien , Sun Yang Y. , Wong Ching P.
Published: September 2008

Prior rheology results on chip‐underfill epoxy resins have been re‐analyzed by a sigmoidal model that contains three variable physical parameters, including the terminal cured viscosity of the gel, an induction or dwell time and a time factor associated with the speed of conversion as viscosity undergoes large dynamic changes during rapid crosslinking. The analyses were conducted with resins that were originally cured between 150 and 180 °C and show obvious non‐linearity, even on a semi‐log plot of dynamic viscosity. The sigmoidal models more accurately represent a wider range of dynamic viscosity than power‐law‐based rheological models, which are both more common and more generally accepted for practical application. If total flow is the critical design parameter in terms of chip underfill, perhaps these alternative sigmoidal models need to be more thoroughly evaluated to gauge their practical use and validity.

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Electrospun Silica—Polybenzimidazole Nanocomposite Fibers
Authors: von Graberg Till , Thomas Arne , Greiner Andreas , Antonietti Markus , Weber Jens
Published: September 2008

A new route for the manufacturing of silica/poly(benzimidazole) (PBI) nanocomposites fibers is described. PBI was synthesized via melt polycondensation and polycondensation in poly(phosphoric acid). Solutions of PBI and silica nanoparticles in N,N‐dimethylacetamide (DMAc) were electrospun to fibers and non‐wovens. The resulting materials were analyzed by ATR‐IR spectroscopy, small‐angle X‐ray scattering (SAXS) and nitrogen sorption measurements. The non‐wovens could be processed towards dense, cross‐linked membranes by hot pressing and treatment with p‐xylylene dichloride.

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Highly Fluorescent Conjugated Copolymers Containing Dithieno[3,2‐b:2′,3′‐d]pyrrole
Authors: Zhang Wei , Li Jun , Zhang Bao , Qin Jingui
Published: September 2008

Three copolymers that incorporate dithieno[3,2‐b:2′,3′‐d]pyrrole with fluorene, carbazole, or pyridine have been prepared by Suzuki reaction and characterized by NMR spectroscopy and GPC. A new homopolymer of dithieno[3,2‐b:2′,3′‐d]pyrrole was also synthesized for the comparison of their structure–property relationships. Their thermal, optical, and electrochemical properties have been investigated. All the polymers exhibit good thermal stability with decomposition temperatures around 400 °C. The fluorescence quantum efficiencies of all these polymers in solution are in the range of 33.5–55.5%. The copolymers also show high film fluorescence quantum efficiencies of about 20% while the fluorescence of the homopolymer film is almost quenched.

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Acyclic Triene Metathesis Polymerization with Chain‐Stoppers: Molecular Weight Control in the Synthesis of Branched Polymers
Authors: Fokou Patrice A. , Meier Michael A. R.
Published: September 2008

The synthesis of branched macromolecules from renewable resources via olefin metathesis is described. We observed that it is possible to control the molecular weight during the acyclic triene metathesis (ATMET) of a triglyceride by the application of methyl acrylate as a chain stopper for this straightforward one step one pot polymerization. The resulting branched materials were characterized by GPC, NMR as well as ESI‐MS and the combination of these techniques provided valuable insights into the polymer structure as well as occurring side reactions during this olefin metathesis polymerization reaction.

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Synthesis of Seven‐Arm Poly(vinyl pyrrolidone) Star Polymers with Lysozyme Core Prepared by MADIX/RAFT Polymerization
Authors: McDowall Lyndall , Chen Gaojian , Stenzel Martina H.
Published: September 2008

A poly(vinyl pyrrolidone) (PVP) seven‐arms star polymer with lysozyme core was synthesized by conjugating linear N‐succinimidyl ester terminated PVP polymer to lysozyme. Reactive PVP polymers were synthesized using a MADIX/RAFT agent functionalized with N‐succinimidyl ester. The polymerization of N‐vinyl pyrrolidone proceeded in a living fashion up to more than 90% conversion reaching molecular weight of up to 33 000 g · mol−1 with narrow molecular weight distributions. The PVP polymer was conjugated to lysozyme resulting in the attachment of seven PVP polymers to one lysozyme core. While the reaction was found to be complete when using low‐molecular weight PVP, some by‐products with less than seven arms were observed when using PVP with a molecular weight of 33 000 g · mol−1.

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Controlling Fusion and Aggregation in Polymersome Dispersions
Authors: Smart Thomas P. , Fernyhough Christine , Ryan Anthony J. , Battaglia Giuseppe
Published: September 2008

The effects of addition of poly(ethylene oxide) (PEO) to poly(ethylene oxide)16‐block‐poly(butylene oxide)22 (EB1) polymersome dispersions has been studied. Aggregation and membrane fusion between polymersomes were observed with great control of the outcome by varying PEO molecular weight. Small‐scale fusion of 2 to 3 polymersomes was seen with low‐molecular‐weight PEO, whilst large‐scale aggregation occurred above a critical PEO molecular weight of 4 000 Da. The resulting highly porous EB1‐PEO aggregate shows great promise for applications in cell entrapment for transport and delivery, and as a three‐dimensional scaffold for use in tissue engineering.

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Macromol. Rapid Commun. 18/2008
Authors: Luxenhofer Robert , Bezen Manuela , Jordan Rainer
Published: September 2008

Cover: Kinetic investigations on the polymerization of 2‐methyl‐2‐oxazoline with pluritriflate initiators showed that defined star‐like poly(2‐oxazoline)s with evenly propagating arms can be obtained. Further details can be found in the article by R. Luxenhofer, M. Bezen, and R. Jordan* on page 1509.
Mechanical Characterization of Motor Proteins: A Molecular Dynamics Approach
Authors: Aprodu Iuliana , Soncini Monica , Redaelli Alberto
Published: September 2008

A new approach, based on molecular dynamics, is presented to measure the mechanical properties of motor proteins, which are important for accomplishing their intracellular functions. Two different set‐ups were designed to mimic the optical tweezers and surface force apparatus experiments. The results obtained show that the stiffness and elastic modulus of kinesin motor domain are 377 pN · nm−1 and 0.17 GPa, respectively, while the myosin motor domain is characterized by a stiffness of 271 pN · nm−1 and an elastic modulus of 0.26 GPa. These results suggest that the source of the very low stiffness detected for full‐length molecules is located outside of the globular part of the proteins.

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A differential constraint approach to obtain global stability for radiation‐induced double‐diffusive convection in a porous medium
Authors: Hill Antony A.
Published: September 2008

The stability of double‐diffusive porous convection with a concentration‐based internal heat source is studied. Owing to the significant sensitivity of standard energy method, a highly desirable reduction in the number of required coupling parameters is achieved through the novel energy method of van Duijn et al. (Environmental Mechanics: Water, Mass and Energy Transfer in the Biosphere. American Geophysical Union: Washington, DC, 2002; 155–169). This approach incorporates the Darcy equation as a differential constraint, and has been shown by van Duijn et al. to generally yield sharper nonlinear results. Owing to the widespread use of coupling parameters in analysing porous media stability, this result strongly advocates the differential constraint approach for obtaining optimal nonlinear stability thresholds. Copyright © 2008 John Wiley & Sons, Ltd.
Generation of viscous grids at ridges and corners
Authors: Aubry Romain , Löhner Rainald
Published: September 2008

An extension of Löhner (AIAA‐93‐3348‐CP, 1993) for the generation of high aspect ratio volume grids on surfaces with ridges and corners is presented for Reynolds‐averaged Navier–Stokes computations. Multiple point normals are introduced along ridges and corners. The original technique generates a semi‐structured boundary layer of prismatic elements growing along point normals. Therefore, extra degenerated faces must be introduced to take into account the multiple growth curves at ridges and corners and produce a valid topological surface triangulation. The major task of the algorithm consists in recovering conformity in the surface mesh triangulation, which has been lost due to the introduction of the virtual faces. The procedure relies on a topological taxonomy of an arbitrary combination of concave and convex ridges. Each case is highlighted in detail. Special boundary conditions such as symmetry planes and periodic boundary conditions are also handled. Several complex geometries have been chosen to illustrate the proposed procedure, and timings are given, showing that the new module does not place any extra burden on the previous semi‐structured approach. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis, photocrosslinking characteristics, and biocompatibility evaluation of N‐vinyl pyrrolidone/polycaprolactone fumarate biomaterials using a new proton scavenger
Authors: Sharifi Shahriar , Mirzadeh Hamid , Imani Mohammad , Ziaee Farshid , Tajabadi Maryam , Jamshidi Ahmad , Atai Mohammad
Published: September 2008

Photocrosslinkable and biodegradable polymeric networks were formulated based on N‐vinyl pyrrolidone‐poly(ε‐caprolactone fumarate) (NVP/PCLF) compositions for hard tissue engineering applications using a new proton scavenger, propylene oxide (PO). The synthesized macromers were obtained as a white clear paste with no colorization. The obtained macromers were thoroughly characterized using spectroscopic (NMR and FT‐IR) and chromatographic (gel permeation chromatography (GPC)) techniques. Photocrosslinking of the PCLF/NVP compositions was achieved using camphorquinone and dimethyl toluidine (DMT) as a photoinitiator system. The cytocompatibility of the macromers and their corresponding networks were evaluated via MTT assay. Characterization of the networks indicated the importance of NVP content on the network properties. Sol fraction studies indicated that more than 90% of the PCLFs were crosslinked over the studied range of PCLF/NVP compositions; however most of the NVP above a stoichiometric ratio of one NVP to fumerate unit remained unreacted. It was also found that in the concentrations more than 10% NVP, the unreacted NVP monomer neither participated in the crosslinking reaction nor homopolymerized to poly(vinyl pyrrolidone) (PVP). The elastic modulus (G′) and estimated molecular weight between crosslinks also confirmed that at the higher NVP content the PCLF photocrosslinking was hindered. Copyright © 2008 John Wiley & Sons, Ltd.
The Human Protein Atlas—a tool for pathology
Authors: Pontén F , Jirström K , Uhlen M
Published: September 2008

Tissue‐based diagnostics and research is incessantly evolving with the development of new molecular tools. It has long been realized that immunohistochemistry can add an important new level of information on top of morphology and that protein expression patterns in a cancer may yield crucial diagnostic and prognostic information. We have generated an immunohistochemistry‐based map of protein expression profiles in normal tissues, cancer and cell lines. For each antibody, altogether 708 spots of tissues and cells are analysed and the resulting images and data are presented as freely available in the Human Protein Atlas (www.proteinatlas.org). The new version 4 of the atlas, including more than 5 million images of immunohistochemically stained tissues and cells, is based on 6122 antibodies, representing 5011 human proteins encoded by approximately 25% of the human genome. The gene‐centric database includes a putative classification of proteins in various protein classes, both functional classes, such as kinases or transcription factors and project‐related classes, such as candidate genes for cancer or cardiovascular diseases. For each of the internally generated antibodies, the exact antigen sequence is presented, together with a visualization of application‐specific validation data, including a protein array assay, western blot analysis, immunohistochemistry and, in most cases, immunofluorescent‐based confocal microscopy. The updated version also includes new search algorithms to allow complex queries regarding expression profiles, protein classes and chromosome location. Thus, the presented Human Protein Atlas provides a resource for pathology‐based biomedical research, including protein science and biomarker discovery. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of fumed silica nanoparticles on glass fiber filled thermotropic liquid crystalline polymer composites
Authors: Park Sang Ki , Kim Seong Hun , Hwang Jin Taek
Published: September 2008

Glass fiber filled thermotropic liquid crystalline polymer (gLCP)/silica composites were prepared by melt compounding. The total torque of the gLCP/silica composites decreased and the melt flow index increased with increasing silica content, which indicates that the fumed silica nanoparticles act as good processing aids and enhance the processing behavior of gLCP/silica composites. The rheological properties of the gLCP/silica composites were significantly dependent on the silica content. The complex viscosity and storage modulus (G′) of the gLCP/silica composites decreased with increasing silica content. This was attributed to the ability of the silica nanoparticles to break the glass fiber–glass fiber interactions in the gLCPs. The storage modulus and loss modulus (G″) of the gLCP/silica composites increased with increasing frequency, and the increment was more significant at low frequency. Incorporation of a small quantity of silica nanoparticles improved the thermal stability and mechanical properties of gLCP/silica composites. However, at high silica nanoparticle content the mechanical properties of gLCP/silica composites decreased because of the aggregation of silica nanoparticles. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Structure and conditioning effect on mechanical behavior of poly(vinyl alcohol)/calcium lactate biocomposites
Authors: Sedlarik Vladimír , Galya Tsermaa , Emri Igor , Saha Petr
Published: September 2008

The structural and mechanical characteristics of polymeric biocomposites based on calcium lactate (CL) and either partially (88 mol%) or fully (98 mol%) hydrolyzed poly(vinyl alcohol) (PVA) were studied using optical microscopy, Fourier transform infrared spectroscopy equipped with attenuated total reflectance accessory, water content determination, and differential scanning calorimetry. In addition, the moisture absorption effect on the mechanical properties of the biocomposites was tested in this work. The results reveal that CL is a suitable modifier for both types of PVA. However, a more efficient enhancement of uniform shape and size distribution of CL particles within the PVA matrix was noticed in fully hydrolyzed matrix at low water contents. It is in agreement with glass transition temperature's observations. The samples conditioned at 50% of relative humidity (RH) showed decrease in E modulus and tensile strength in comparison with the material stored below 20% RH. Nevertheless, the enhancement of tensile properties, because of the modification with CL, was still noticeable especially for the partially hydrolyzed PVA‐based biocomposites. The optimum concentration of the modifier was estimated on the basis of the obtained results. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
The school neuropsychology of ADHD: Theory, assessment, and intervention
Authors: Goldstein Sam , Naglieri Jack A.
Published: September 2008

Although the five‐part diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision (DSM‐IV‐TR) for attention‐deficit/hyperactivity disorder (ADHD) are behavioral and descriptive in nature, this condition has increasingly been defined as a disorder resulting from impaired behavioral inhibition leading to executive function deficits. Recent research, particularly involving the Planning, Attention, Simultaneous, Successive (PASS) theory offers an understanding of the intellectual and neuropsychological processes implicated in ADHD. We provide an overview of ADHD as a neuropsychological condition; reviews of research on the PASS theory, which provide a process‐based understanding of ADHD; and recommendations for assessment and intervention. The research base summarized here provides support that ADHD have a distinctive profile of PASS processes that is consistent with the cognitive nature of their disorder and that researchers have shown increased academic performance when children are taught to better use planning processes when completing academic tasks. © 2008 Wiley Periodicals, Inc.
Identification of N‐linked glycoproteins in human milk by hydrophilic interaction liquid chromatography and mass spectrometry
Authors: Picariello Gianluca , Ferranti Pasquale , Mamone Gianfranco , Roepstorff Peter , Addeo Francesco
Published: September 2008

Breastfeeding is now generally recognized as a critical factor in protecting newborns against infections. An important mechanism responsible for the antibacterial and antiviral effects of breast milk is the prevention of pathogen adhesion to host cell membranes mediated by a number of glycoconjugates, also including glycoproteins. A number of approaches to describe the complexity of human milk proteome have provided only a partial characterization of restricted classes of N‐linked glycoproteins. To achieve this objective, profiling N‐linked glycoproteins of human milk was performed by Hydrophilic Interaction LC (HILIC) and MS analysis. Glycopeptides were selectively enriched from the protein tryptic digest of human milk samples. Oligosaccharide‐free peptides obtained by peptide N‐glycosidase F (PNGase F) treatment were characterized by a shotgun MS‐based approach, allowing the identification of N‐glycosylated sites localized on proteins. Using this strategy, 32 different glycoproteins were identified and 63 N‐glycosylated sites encrypted in them were located. The glycoproteins include immunocompetent factors, membrane fat globule‐associated proteins, enzymes involved in lipid degradation and cell differentiation, specific receptors, and other gene products with still unknown functions.
Improvements of TArgeted multiplex mass spectrometry IMaging
Authors: Thiery Gwendoline , Anselmi Elsa , Audebourg Anne , Darii Ekaterina , Abarbri Mohamed , Terris Benoît , Tabet Jean‐Claude , Gut Ivo G.
Published: September 2008

MALDI mass spectrometers have become popular tools for imaging histological sections. Currently this technology is primarily used for imaging naturally occurring molecules. Here we report on the improvement of TArgeted multiplex MS IMaging (TAMSIM) technology. For TAMSIM we attach photocleavable mass tags to antibodies. Staining histological sections is done analogously to standard immunohistochemical procedures with chemiluminescent or fluorescent detection with the sole difference that multiple antibodies each with a distinct mass tag are used in a single reaction. Mass tags are released from their respective antibodies by a laser pulse at 355 nm without added matrix. After scanning, MS images are created for each tag mass. The enhancements of TAMSIM presented here relate to four elements, the use of an improved generation of tags, their conjugation directly to primary antibodies, the comparison of fresh frozen sections with paraffin embedded ones for the TAMSIM imaging technology and finally, the increase of multiplex detection. Sections of healthy human pancreatic tissue were imaged to visualize different specific biomarkers (synaptophysin, chromogranin, insulin, calcitonin, somatostatin) in neuroendocrine cells of Langerhans islets. The aim was to localize these biomarkers on the tissue sections simultaneously.
Methods for the analysis of the composition of bone tissue, with a focus on imaging mass spectrometry (TOF‐SIMS)
Authors: Malmberg Per , Nygren Håkan
Published: September 2008

The review describes methods available for analyzing mineralization of bone tissue in healing of fractures and implants in bone. The recent development of imaging MS, TOF‐secondary ion MS (SIMS), enabling localization of hydroxyapatite (HA) in tissue samples will be presented in some detail. We strongly believe that imaging MS has the potential of becoming an important method for the studies of bone mineralization. Formation and mineralization of bone tissue with HA is a process controlled by cells, the osteoblasts, osteocytes, and osteoclasts. Formation, de novo, of bone in embryonic tissue takes place in extracellular areas within cell clusters that regulate the environment of the mineralization zone. The process of de novo formation of bone as in embryonic tissue is reactivated in adults for example during fracture healing, with or without the presence of bone implants. Thus, bone healing is one of few examples of scar‐free healing of a differentiated tissue. Much of the interest of researchers in bone mineralization stems from a desire to influence the process of bone formation towards fast and endurable bone healing. There is also a wish to understand the pathogenesis of bone diseases, for example osteogenesis imperfecta, Turner's syndrome and osteoporosis.
Project Portfolio Control and Portfolio Management Performance in Different Contexts
Authors: Müller Ralf , Martinsuo Miia , Blomquist Tomas
Published: September 2008

This article investigates the nature and relationship of project portfolio control techniques and portfolio management performance, and how this relationship is moderated by situational idiosyncrasies of internal and external dynamics, industries, governance types, and geographic location. A worldwide questionnaire with 242 responses was used, of which 136 high-performing responses were filtered out for quantitative analysis of best practices. Three portfolio control factors were identified: portfolio selection, portfolio reporting, and decision-making style. Two measures for portfolio management performance were identified: achievement of desired portfolio results and achievement of project and program purpose. The results indicate that different portfolio control mechanisms are associated with different performance measures. A contingency model was developed, including moderating effects by contextual variables.
Does Our Literature Support Sectors Newer to Project Management? The Search for Quality Publications Relevant to Nontraditional Industries
Authors: Carden Lila , Egan Toby
Published: September 2008

Despite the broadening use of systematic approaches to project management, the majority of related literature is focused on a handful of industries–construction, engineering, government, information technology, and utilities– that have, until recently, been the traditional areas for project management. Currently, the nontraditional project management areas include banking, pharmaceuticals, consulting, advertising, legal, health care, safety, and non-traditional manufacturing and industrial sectors (Kerzner, 2001). In recognition of growth, scholars and practitioners have begun to include viewpoints generalized across the field as well as perspectives from specific industries. We report on the findings from a systematic review of project management literature.
The Pathogen Construct in Risk Analysis
Authors: Busby Jerry S. , Zhang Hongliang
Published: September 2008

Project risk analysis has traditionally emphasized the analysis of external threats. Here we argue that internal decisions and structures are more fundamental, because they determine which external events pose risks to project management. A “pathogen” metaphor is used to understand these internal sources of risk, in an analysis of failure in two sets of projects that lie on the border between the private and public sectors. This analysis goes beyond earlier work on organizational pathogens by treating them as subjective interpretations, not objective conditions. The study suggests that the more insidious risks to which a project is exposed involve different project members holding contradictory beliefs about what is pathogenic and what is protective
Theoretical investigation of an unusual substituent effect on the dienophilicity of >CP functionality present in 2‐phosphaindolizines
Authors: Bansal Raj K. , Gupta Neelima , Dixit Govind , Kumawat Surendra K.
Published: September 2008

Effect of the number and positions of the methoxycarbonyl substituents in 2‐phosphaindolizine on the feasibility of its Diels–Alder (DA) reaction with 1,3‐butadiene has been investigated theoretically at the density functional theory (DFT) level. Among the series of four differently substituted 2‐phosphaindolizines, 3‐methoxycarbonyl‐2‐phosphaindolizine does not undergo the DA reaction due to the highest activation barrier (29.49 kcal mol−1) and endothermicity, whereas the activation barrier of the corresponding reaction of 1,3‐bis(methoxycarbonyl)‐2‐phosphaindolizine is lowest (22.43 kcal mol−1) with exothermicity making it possible to occur. This reactivity trend is corroborated by FMO energy gaps as well as by global electrophilicity powers of the reactants. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of polyaniline/multiwall carbon nanotube composite via inverse emulsion polymerization
Authors: Kim Duk Ki , Wha Oh Kyung , Kim Seong Hun
Published: September 2008

The composite of polyaniline (PANI) and multiwall carbon nanotube carboxylated through acid treatment (c‐MWCNT) was synthesized by chemical oxidative polymerization in an inverse emulsion system. The resultant composites were compared with products from aqueous emulsion polymerization to observe the improvements in electrical conductivity, structural properties, and thermal stability obtained by this synthetic method. Prior to the inverse emulsion polymerization, MWCNT was treated with a strong acid mixture to be functionalized with carboxylic acid groups. Carboxylic acid groups on surfaces induced selective dispersibility between polar and nonpolar solvents because of the increase of hydrophilicity. As the content of c‐MWCNT was increased, the electrical conductivity was increased by a charge transport function from the intrinsic electrical conductivity of MWCNT and the formation of a highly ordered dense structure of PANI molecules on the surface of c‐MWCNT. The images observed with electron spectroscopy showed the capping of c‐MWCNT with PANI. The growth of additional ordered structures of PANI/c‐MWCNT composite, which was observed through wide‐angle X‐ray diffraction patterns, supported the capping by PANI. It was observed that the doping of the composite had a significant relationship with the concentration of dodecylbenzenesulfonic acid (DBSA). The thermal stability of PANI composite was improved by the addition of c‐MWCNT; this was thought to be related with structure ordering by inverse emulsion polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2255–2266, 2008
Different Ways to Plasma‐Polymerize HMDSO in DBD Configuration at Atmospheric Pressure for Corrosion Protection
Authors: Bour Jérôme , Bardon Julien , Aubriet Hugues , Del Frari Doriane , Verheyde Bert , Dams Roel , Vangeneugden Dirk , Ruch David
Published: September 2008

Organosilicon layers were deposited on galvanized steel to give a protective coating against corrosion. HMDSO was atomized and injected into a DBD plasma at atmospheric pressure. Plasma‐polymerized HMDSO layers were different when HMDSO nanodroplets reacted directly in the plasma area or when such droplets reacted with the plasma once deposited on the surface. Addition of a plasma curing step was also studied. Influence of the deposition method on the properties of ppHMDSO layers was also studied. Layer structure was measured by SEM and interferometry, and its chemical structure was analyzed by FTIR and XPS. Corrosion resistance, which was measured by electrochemistry, was significantly increased when a plasma curing step was performed.

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Methylaminosilane fed Inductively Coupled Plasmas for Silicon Nitride Deposition
Authors: Di Mundo Rosa , Palumbo Fabio , Fracassi Francesco , d'Agostino Riccardo
Published: September 2008

Silicon nitride‐like films can be deposited by inductively coupled discharges fed with dimethylaminosilanes without addition of reactive gases. At high input power fairly inorganic films can be obtained. In the present work in situ diagnostics of plasma phase, i.e. Fourier transform infrared spectroscopy (FT‐IRAS) and optical emission spectroscopy (OES), have been utilized to investigate the deposition mechanism of bis(dimethylamino)dimethylsilane (BDMADMS) fed discharges. Results indicate that the monomer undergoes a pronounced depletion even at low input power and that fragmentation increases with increasing this parameter. The main fragmentation steps seem to involve the cleavage of the SiN bond and the conversion of the –NMe2 group.

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Annual assessment spirometry, plethysmography, and gas transfer in cystic fibrosis: Do they predict death or transplantation
Authors: Rosenthal Mark
Published: September 2008

Aim

The long‐ and short‐term prognostic value of pediatric spirometry, plethysmography, and gas transfer measurements in cystic fibrosis (CF) were assessed.

Methods

Two hundred ninety‐eight children with CF and ≥4 annual assessment lung function measurements at a single institution were analyzed in mid childhood. Long‐term outcome was death or lung transplantation (D/T) before 2007. Short‐term outcome was forced expired volume in one second (FEV1) z‐score 1 year after the previous lung function measurements.

Results

26/298 had a D/T outcome at median 19.5 years. A zFEV1 < −2 aged 8 years had a positive predictive value of 67% (sensitivity 67%) for D/T in those homozygous for ΔF508 but zFEV1 at older ages and all genotypes was unhelpful. The ratio of residual volume to total lung capacity z‐score could also predict a few D/T individuals when zFEV1 was normal in mid childhood. Most other lung function measurements were not helpful. Matching D/T with alive groups for year of birth left prognostic utility unchanged. Only current zFEV1 could significantly predict zFEV1 1 year hence (56% variability explained, P < 0.00001); no other lung function, gender, age or nutrition factor was significant.

Conclusion

The value of routine plethysmography and gas transfer measurements in CF is questionable in CF management. Detecting abnormal spirometry even at age 8 years may be too late to affect long‐term outcome. Pediatr Pulmonol. 2008; 43:945–952. © 2008 Wiley‐Liss, Inc.