bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of alkyl chain length on inhibition performance of imidazoline derivatives investigated by molecular dynamics simulation
Authors: Yu L. J. , Zhang J. , Qiao G. M. , Yan Y. G. , Ti Y. , Zhang Y. 
Published: August 2011

AbstractIn this article, the inhibition efficiency of imidazoline derivatives with different alkyl chain was investigated from aspect of diffusion using molecular dynamics method. The diffusion coefficient of three corrosive ions in the inhibitor membrane was proposed to evaluate the inhibition efficiency, and three related parameters, fractional free volume of membrane, interaction energy between membrane and particle, mobility of inhibitor membrane, were also discussed to illuminate the diffusion performance of corrosive particles in inhibitor membrane at length. These researches provide one more reasonable theoretical method to evaluate the inhibition efficiency, and may have important significance for the filtration of inhibitor.
Effect of surface treatments based on self‐assembling molecules and cerium coatings on the AA3003 alloy corrosion resistance
Authors: Banczek E. P. , Moraes S. R. , Assis S. L. , Costa I. , Motheo A. J. 
Published: August 2011

AbstractThis work presents the effects of a cerium conversion coating, self‐assembling molecules (SAM) treatment, and a combination of these two treatments on the corrosion resistance of the AA3003 alloy. The results were compared to that of a conversion coating treatment with hexavalent chromium (Cr VI). The corrosion resistance of the surface‐treated AA3003 alloy samples was investigated by electrochemical impedance spectroscopy and anodic polarization curves in 0.5 mol/L sodium sulfate solution with pH adjusted to 4.0. The results showed that the SAM treatment offered better corrosion protection for the AA3003 alloy than that provided by cerium conversion coating. The combination of cerium conversion and SAM treatments improved the corrosion resistance of the AA3003 alloy due to SAM adsorption on the alloy substrate exposed at the defects in the cerium conversion layer.
Corrosion of high‐velocity oxy‐fuel (HVOF) sprayed iron‐based amorphous metallic coatings for marine pump in sodium chloride solutions
Authors: Wang Y. , Zheng Y. G. , Ke W. , Sun W. H. , Wang J. Q. 
Published: August 2011

AbstractFeCrMoMnWBCSi amorphous metallic coatings (AMCs) were deposited onto the 304 stainless steel (base material of pump impeller operated in sand‐containing seawater) by high‐velocity oxygen‐fuel (HVOF) thermal spray. The preparation, microstructural characteristics, and static corrosion behavior of the AMCs were presented. The microstructure and corrosion behavior of the AMCs were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and electrochemical methods. Melt‐spun ribbon and 304 stainless steel were also used for comparison purposes. The results indicated that the AMCs can spontaneously passivate with a wide passive region, and much higher ability to withstand pitting corrosion than that of the 304 stainless steel for the high pitting resistance equivalent value. The passive current density of the AMCs was at least two orders of magnitude higher than the counterpart ribbon, which showed a slightly decreased uniform corrosion resistance of the AMCs due to the incompact structure and porosity. The corrosion resistance of the AMCs increased with the coating thickness and decreased with the concentration of NaCl solution. A stable passivation ability held in the AMCs endowed them suitably used in marine environments.
A new theory for the negative difference effect in magnesium corrosion
Authors: Bender S. , Goellner J. , Heyn A. , Schmigalla S. 
Published: August 2011

AbstractAn unusual feature known as the negative difference effect (NDE) can be observed in magnesium when recording corrosion current density–potential curves. More hydrogen is evolved at a more positive potential which does not occur in conventional metals. Several models have been proposed in the literature in order to explain the phenomenon of NDE. They succeed in explaining some effects, and fail to deal with others. A new model, which explains the NDE by two electron consuming processes, is presented in this paper. By potentiostatic investigations of magnesium in a chloride electrolyte, measurements of hydrogen evolution and chemical analysis of the electrolyte the new model was experimentally verified.
Influence of dual‐RRA temper on the exfoliation corrosion and electrochemical behavior of Al–Zn–Mg–Cu alloy
Authors: Peng G.‐S. , Chen K.‐H. , Chen S.‐Y. , Fang H.‐C. 
Published: August 2011

AbstractInfluence of dual‐retrogression and reaging (dual‐RRA) temper on the exfoliation corrosion (EC) and electrochemical behavior of Al–Zn–Mg–Cu alloy has been investigated by means of transmission electron microscope, energy dispersive X‐ray spectroscopy, tensile test, polarization curve, and EIS. Dual‐RRA temper not only kept the strength similar to retrogression and reaging temper, but also improved EC resistance compared to T76 temper, being attributed to coarser and sparser grain boundary precipitates as well as higher Cu and lower Zn content. Obtained polarization curves and EIS are in good agreement with EC rating sequence.
On a class of singular Trudinger‐Moser type inequalities and its applications
Authors: Marcos do Ó João , de Souza Manassés 
Published: August 2011

AbstractThis paper deals with an improvement of a class of the Trudinger‐Moser inequality with a singular weight associated to the embedding of the standard Sobolev space H10(Ω) into Orlicz spaces for any smooth domain \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\Omega \subset \mathbb {R}^2$\end{document}, in particular for \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\Omega = \mathbb {R}^2$\end{document}. As an application of this result, using the Ekeland variational principle and the mountain‐pass theorem we establish sufficient conditions for the existence and multiplicity of weak solutions for the following class of problems

where a ∈ [0, 2), V(x) is a continuous positive potential bounded away from zero and which can be “large” at the infinity, the nonlinearity f(s) behaves like \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$e^{\alpha s^2}$\end{document} when |s| → +∞ and \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$h \in (H^1(\mathbb {R}^2))^*$\end{document} is a small perturbation. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Obsessive‐compulsive symptoms in primary focal dystonia: A controlled study
Authors: Barahona‐Corrêa Bernardo , Bugalho Paulo , Guimarães João , Xavier Miguel 
Published: August 2011

AbstractPrimary focal dystonia is an idiopathic neurological disorder causing involuntary muscle contraction. Its pathophysiology probably involves the basal ganglia and cortical‐basal pathways. Primary dystonia appears to be associated with significant obsessive‐compulsive symptoms, but evidence remains scarce and contradictory. We addressed the following research questions: (1) Do primary dystonia patients have high obsessive‐compulsive symptom scores? (2) Are these symptoms more severe in dystonia than in controls with equivalent peripheral neurological disorders? and (3) Is psychopathology different in botulinum toxin‐treated and ‐untreated dystonia patients? This work was a cross‐sectional, descriptive, controlled study comprising 45 consecutive patients with primary focal dystonia (i.e., blepharospasm, spasmodic torticollis, or writer's cramp) 46 consecutive patients with hemifacial spasm, cervical spondylarthropathy, or carpal tunnel syndrome, and 30 healthy volunteers. Assessment included the DSM‐IV based psychiatric interview, Symptom Checklist 90R, Yale‐Brown Obsessive‐Compulsive Scale and Checklist, and the Unified Dystonia Rating Scale. Dystonia patients had higher Yale‐Brown Obsessive‐Compulsive Symptom scores than both control groups. Dystonia patients with obsessive‐compulsive symptom scores above cut‐off for clinical significance predominantly developed hygiene‐related symptoms. Major depression and generalized anxiety disorder were the most frequent psychiatric diagnoses in primary focal dystonia. Obsessive‐compulsive disorder frequency was 6.7%. Primary focal dystonia patients have higher obsessive‐compulsive symptom scores than individuals with similar functional disabilities resulting from other neurological disorders, suggesting that obsessive‐compulsive symptoms in dystonia are not reactive to chronic disability. Dystonic muscle contractions and obsessive‐compulsive symptoms may share a common neurobiological basis related to cortical‐basal dysfunction. Psychopathology, especially obsessive‐compulsive symptoms, should be actively explored and treated in primary focal dystonia. © 2011 Movement Disorder Society
Modeling the Microstructure of Acrylic‐Polyurethane Hybrid Polymers Synthesized by Miniemulsion Polymerization
Authors: Reyes Yuri , Lopez Aitziber , Asua José M. 
Published: August 2011

AbstractA computer simulation is presented for the prediction of the detailed microstructure of acrylic‐polyurethane hybrid polymers synthesized by miniemulsion polymerization. The simulation considers the polymerization of a mixture of acrylic monomers, one of them having a hydroxyl group, in the presence of a diisocyanate terminated prepolymer and a diol. The simulation approach is able to reproduce the experimental tendency (gel content, sol molecular weight and swelling capability) and provide additional information that is not attainable otherwise, as the distribution of pendant PU chains and dangling acrylic chains and the loop size distribution of the hybrid network. The analysis of such complex structures opens the possibility of tuning the performance of crosslinked emulsion polymers by adjusting their microstructure.magnified image
A Polymerization Kinetics Comparison between a Metallocene Catalyst Activated by Tetrakis(pentafluorophenyl) Borate and MAO for the Polymerization of Ethylene in a Semi‐batch Solution Reactor
Authors: Mehdiabadi Saeid , Soares Joaõ B. P. , Bilbao Daniel , Brinen Jeffrey L. 
Published: August 2011

AbstractThis work investigates the effects of activator species on catalyst reactivity in the semi‐batch, solution polymerization of ethylene using rac‐dimethylsilyl‐bis(indenyl)hafnium dimethyl catalyst. The two activators compared are methylalumoxane and tetrakis(pentafluorophenyl) borate dimethylanilinium salt ([B(C6F5)4]–[Me2NHPh]+). For each of the catalyst/activator systems, monomer and activator concentrations were varied to gain a basic understanding of polymerization kinetics, allowing for direct comparison of each system. Copolymerization experiments involving 1‐octene were also carried out to further investigate the influence of activator type on copolymerization kinetics and products. magnified image
Unimodal Particle Size Distribution Latexes: Effect of Reaction Conditions on Viscosity and Stability at High Solids Content
Authors: Mariz Inês de F. A. , de la Cal José C. , Leiza Jose R. 
Published: August 2011

AbstractThe effect of process variables on the stability and viscosity of high solids content (HSC) latexes (60 wt%) with unimodal particle size distribution (PSD) (centered in 300 nm) synthesized by conventional seeded semibatch emulsion polymerization was investigated. The effect of the use of carboxylic monomers and its type, the concentration and type of surfactants and the pH of the polymerization were considered. It was found that the more stable latexes were produced under basic pH and using carboxylic monomers in the formulation. When carboxylic monomers were not used stable latexes could also be obtained, but using slightly larger concentrations of the anionic surfactant. The use of non‐ionic surfactants in combinations with anionic ones during the synthesis of the latexes was deleterious in all the cases. The viscosity of the latexes was shear thinning and latexes synthesized at basic pH and with higher concentration of surfactant presented relatively higher viscosities. magnified image
Application of Parameter Selection and Estimation Techniques in a Thermal Styrene Polymerization Model
Authors: Woloszyn John D. , McAuley Kimberley B. 
Published: August 2011

AbstractA model is developed to describe thermally‐initiated polymerization of styrene between 100 and 170 °C. The model accounts for generation and consumption of styrene adduct. Chain transfer to adduct is the only transfer reaction used. Autoacceleration is modeled using the break‐point method of Hui and Hamielec. Using formal ranking and parameter selection techniques that account for parameter sensitivity, correlation and uncertainty, 4 of the 40 model parameters are selected for estimation to improve fit between model predictions and data. After estimation, the model predicts conversion data with a standard error of 5%, and provides excellent fit to a MWD curve obtained at 100 °C. Simulation results confirm that high‐temperature degradation reactions are not important in the temperature range of interest.magnified image
Kinetics and Modeling of Solution ARGET ATRP of Styrene, Butyl Acrylate, and Methyl Methacrylate
Authors: Li Xiaohui , Wang Wen‐Jun , Li Bo‐Geng , Zhu Shiping 
Published: August 2011

AbstractThis work reports a kinetic model for the activator‐regenerated‐by‐electron‐transfer atom‐transfer radical polymerization (ARGET ATRP) and its verification by the experimental data of solution ARGET ATRP of styrene, methyl methacrylate, and butyl arylate from literatures. The effects of ATRP equilibrium constant K and apparent reducing rate coefficient kr on the ARGET ATRP kinetics are investigated. A highly active initiation/catalyst system with a large K results in a poor control of the polymerization while an increased kr promotes the polymerization rate but the formation of dead polymer chains. Reducing agent with a moderate kr gives good control over ARGET ATRP. It is not feasible to use a moderate catalyst system for the ARGET ATRP of highly active monomers. magnified image
Degenerative Joint Disease and Social Status in the Terminal Late Archaic Period (1000–500 b.c.) of Ohio
Authors: Woo Eun Jin , Sciulli Paul W. 
Published: August 2011

ABSTRACTThis research presents an analysis of the inferred Late Archaic social structure in Ohio based on degenerative joint disease (DJD, also known as osteoarthritis) and mortuary practices. We tested the hypothesis that mechanical loading involving physical activities is differentially distributed in a population along levels or types of social stratification. This hypothesis was investigated via statistical treatment of DJD as a skeletal stress marker of activity, its occurrence by age and sex, an association with grave goods, and spatial distribution in terminal Late Archaic cemeteries. The skeletal samples used in this study came from three cemeteries, the Boose, Kirian‐Treglia (KT), and Duff sites, dating to the Ohio terminal Late Archaic period.In general, the high overall prevalence of DJD in these people indicates that this population led a rigorous life. This study hypothesized that the burials in the Late Archaic period in Ohio might be socially patterned as evidenced from the unequal distribution of grave goods and skeletal variability in DJD. Nevertheless, the analyses suggest that there is no statistical association between DJD and mortuary practices including grave goods and burial location in a cemetery. As observed in numerous hunter–gatherer populations, the societies in our sample were also characterized by the absence of a marked social stratification. The results suggest that there were only ‘natural inequalities’ in Late Archaic societies due to biological factors, such as age and sex. Copyright © 2011 John Wiley & Sons, Ltd.
Managing dopamine agonist withdrawal syndrome in Parkinson's disease
Authors: Lindahl Andrea J , MacMahon Douglas G 
Published: August 2011

AbstractDopamine agonist withdrawal syndrome (DAWS) has recently been named in the Archives of Neurology. It describes a cluster of symptoms occurring in Parkinson's disease patients with impulse control disorders on tapering down or withdrawal of their dopamine agonist. Drs Lindahl and MacMahon discuss the risk factors for the development of DAWS and some approaches to its management. Copyright © 2011 Wiley Interface Ltd
Psychiatric diagnosis needs a more scientific approach
Authors: Titmarsh Steve , Goodyer Ian 
Published: August 2011

AbstractA more rigorous and scientific approach to characterisation and diagnosis of mental illness, particularly among children, could help reduce the number of patients who do not respond to treatment. That was the view put forward by Professor Ian Goodyer, Professor of Child and Adolescent Psychiatry at Cambridge University in his Keynote Lecture at the 10th Latest Advances in Psychiatry Symposium held in London in March. Steve Titmarsh reports. Copyright © 2011 Wiley Interface Ltd
Comparison of a memory service database with primary care dementia registers
Authors: O'Kelly Allison , Richards Giles 
Published: August 2011

AbstractUnder the Quality Outcome Framework (QOF), points are awarded to GP practices that keep a dementia register and record patient reviews. The aim of this audit was to compare the East Cornwall Memory Service's database of diagnosed patients against the QOF registers for dementia held by nine GP practices in East Cornwall. Copyright © 2011 Wiley Interface Ltd
A novel protocol for the preparation of uniform polymer microspheres with high yields through step polymerization of isophorone diisocyanate
Authors: Jiang Xubao , Kong Xiang Zheng , Zhu Xiaoli 
Published: August 2011

AbstractUniform polymer microspheres with neat surface are of high interests. Precipitation polymerization of vinylic monomers remains a very limited process owing to very low monomer concentration allowed. Here, a fully novel protocol for the production of uniform polymeric microspheres is presented. Using one single monomer, isophorone diisocyanate, highly monodisperse polyurea microspheres were achieved with very high yield in a very short time period via precipitation polymerization in water–acetone mixed solvent. Results demonstrated that the ratio of water–acetone and polymerization temperature played important roles in the process. The size of the microspheres was readily adjustable by varying monomer concentration, water/acetone ratio or polymerization temperature. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Poly(allyl glycidyl ether)‐A versatile and functional polyether platform
Authors: Lee Bongjae F. , Kade Matthew J. , Chute Jerred A. , Gupta Nalini , Campos Luis M. , Fredrickson Glenn H. , Kramer Edward J. , Lynd Nathaniel A. , Hawker Craig J. 
Published: August 2011

AbstractAllyl glycidyl ether, polymerized from potassium alkoxide/naphthalenide initiators under both neat and solution conditions was shown to be a highly controlled process. In both cases, molar masses (10–100 kg/mol) were determined by the reaction stoichiometry, and low polydispersity indices (1.05–1.33) could be obtained with a full understanding of the dominant side reaction, isomerization of the allyl side chain, being developed. The degree of isomerization of allyl to cis‐prop‐1‐enyl ether groups (0–10% mol) was not correlated to the molar mass or polydispersity of the polymer but was dictated by the polymerization temperature. This allows the extent of isomerization to be reduced to essentially zero under either melt or solution conditions at polymerization temperatures of less than 40 °C. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Controlled epoxidation of poly(styrene‐b‐isoprene‐b‐styrene) block copolymer for the development of nanostructured epoxy thermosets
Authors: Garate Hernan , Mondragon Iñaki , Goyanes Silvia , D'Accorso Norma B. 
Published: August 2011

AbstractTo be used as templates for nanostructured thermosets, a commercial poly(styrene‐b‐isoprene‐b‐styrene) (SIS) block copolymer (BCP) was epoxidized by three different epoxidation procedures. An exhaustive analysis of methodologies using metal catalyzed/hydrogen peroxide, dimethyldioxirane (DMDO), and meta‐chloroperbenzoic acid (m‐CPBA) was performed to obtain reactive BCPs. The DMDO approach was the best strategy to obtain highly epoxidized SIS BCP (85 mol %) without formation of side products. Careful control in BCP epoxidation by metal catalyzed/hydrogen peroxide and m‐CPBA approaches led to a maximum epoxidation degree (ED) of approximately 60 mol % without the formation of side products. The ED by metal catalyzed/hydrogen peroxide strategy could be further increased to 69 mol %, but a significant amount of crosslinking, ring opening, and polymer chain scission reactions were detected by spectroscopic and chromatographic techniques. The miscibility of epoxidized BCPs with diglycidyl ether of bisphenol‐A epoxy system before and after curing was analyzed to develop nanostructured epoxy thermosets. For ED higher than 69 mol %, BCPs were miscible, while those with lower ED presented macrophase separation. Highly epoxidized BCPs obtained by the DMDO methodology were successfully used to obtain ordered nanodomains inside the epoxy matrix, as determined by atomic force microscopy. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Modulating catalytic activity of polymer‐based cuAAC “click” reactions
Authors: Bell Craig A. , Jia Zhongfan , Perrier Sébastien , Monteiro Michael J. 
Published: August 2011

AbstractThe copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) reaction is used to synthesize complex polymer architectures. In this work, we demonstrate the control of this reaction at 25 °C between polystyrene (PSTY) chains through modulating the catalytic activity by varying the combinations of copper source (i.e., Cu(I)Br or copper wire), ligand (PMDETA and/or triazole ligand), and solvent (toluene or DMF). The fastest rate of CuAAC was found using Cu(I)Br/PMDETA ligand in toluene, reaching near full conversion after 15 min at 25 °C. For the same catalysts system, DMF also gave fast rates of “click” (95% conversion in 25 min). Cu(0) wire in toluene gave a conversion of 98% after 600 min, a much higher rate than that observed for the same catalyst system used in DMF. When the PSTY had a chemically bound triazole ring close to the site of reaction, the rate of CuAAC in toluene increased significantly, 97% in 180 min at 25 °C, in agreement with our previously published results. This suggests that rapid rates can be obtained using copper wire and will have direct applications to the synthesis of compound where air, removal of copper, and reuse of the copper catalyst are required. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Homogeneous radical polymerization of 2‐hydroxyethyl methacrylate mediated by cyclometalated cationic Ruthenium(II) complexes with PF6− and Cl− in protic media
Authors: Diaz Maria Ortencia Gonzalez , Morales Salvador Lopez , Lagadec Ronan Le , Alexandrova Larissa 
Published: August 2011

AbstractCationic coordinatively saturated complexes of ruthenium(II), [Ru(o‐C6H4‐2‐py)(phen)(MeCN)2]+, bearing different counterions of PF6− and Cl− have been used in the radical polymerization of 2‐hydroxyethyl methacrylate in protic media and acetone under homogeneous conditions. Exchange of PF6− by Cl− increases the solubility of the complex in water. Both complexes led to the fast polymerization under mild conditions, but control was achieved only in methanol and acetone and was better for the complex with Cl−. The polymerization accelerated in aqueous media and proceeded to a high conversion even with a monomer/catalyst = 2000/1, but without control. Polymerization mediated by complex bearing Cl− was slower in protic solvents but faster in acetone and always resulted in lower molecular weight polymers. Thus, the nature of the anion strongly affected the catalytic activity of the complexes and may serve as way of fine‐tuning the catalytic properties. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011