bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructure and mechanical properties of as-cast and solution-treated Mg-Zn-Gd-based alloys reinforced with quasicrystals
Authors: Huang Hua , Yuan Guangyin , Tong Jian , Ding Wenjiang 
Published: November 2012

Abstract
The microstructure and mechanical properties of as-cast and solution-treated Mg-xZn-yGd (x/y = 6, at.%) alloys reinforced with quasicrystals have been investigated. The results indicate that with the increase in the alloying elements contents, the dendritic microstructure is refined, the corresponding strength gradually increased, and the elongation gradually decreased as the increase in the second phase sizes leads to stress concentration under as-cast and solution-treated conditions. For as-cast alloys, micro-cracks originated in the α-Mg matrix and quasicrystals interface. The fracture mode exhibits intergranular fracture characteristics. After solution treatment, the yield strength decreased, and the ultimate tensile strength and elongation increased clearly due to the Mg2Zn3 phase dissolution and the second phase sizes decreasing. The fracture mode changes to transgranular fracture.
Isothermal transformation of β-phase in Cu-rich Cu-Al-Sn alloys
Authors: Chakrabarty A. K. , Jacob K. T. 
Published: November 2012

Abstract
Microstructural changes resulting from isothermal decomposition of the β-phase have been studied in Cu-rich binary Cu-Al and ternary Cu-Al-Sn alloys containing up to 3 at.% Sn at temperatures from 873 to 673 K. Results are presented as TTT diagrams. The decomposition occurs in several stages, each of which involves the establishment of metastable equilibrium between β and one or more of the product phases α β1 and γ2. Addition of Sn has been shown to increase the stability of the ordered β1-phase in relation to β. In alloys containing more than 2 at.% Sn, the β1 emerges as a stable phase. At low Sn concentrations β1 is metastable. An important new finding is the existence of three-phase equilibrium microstructure containing α β1 and γ2. Increasing addition of Sn alters the morphology of β1 from rosettes to dendrites and finally to Widmanstätten needles.
Grain refinement and mechanical properties of low-carbon steel by means of equal channel angular pressing and annealing
Authors: Mayer Galina G. , Astafurova Elena G. , Maier Hans J. , Naydenkin Eugene V. , Raab George I. , Odessky Pavel D. , Dobatkin Sergey V. 
Published: November 2012

Abstract
Equal channel angular pressing of low-carbon steel produces an ultrafine-grained microstructure with an average (sub-)grain size of 325 nm and both coarse and fine carbides, a microhardness of 330 HV and 0.2 % offset yield strength of σ0.2 = 815 MPa. The average (sub-)grain size and the mechanical properties of the steel after equal channel angular pressing were found to be stable up to 500 °C. The composition of the carbides, their sizes and their distribution in the microstructure were analyzed in order to understand their contribution to the mechanical properties and the thermal stability of the steel. Both the high strength and the thermal stability of the steel after equal channel angular pressing are associated with the grain refinement, the substructure strengthening, and precipitation hardening.
Biofilm formation and corrosion resistance of Ni/SiC nanocomposite layers
Authors: Benea Lidia , Ciubotariu Alina-Crina , Sand Wolfgang 
Published: November 2012

Abstract
Pure Ni and Ni/SiC nanocomposite layers were prepared by means of direct current electrodeposition in a sulfate–chloride nickel plating bath. The surface characteristics and properties of Ni/SiC nanocomposite layers and pure nickel coatings were comparatively investigated. The surface morphology, microstructure, topography, roughness and corrosion were characterized using scanning electron microscopy with energy dispersive X-ray spectroscopy, transmission electron microscopy, atomic force microscopy, epifluorescence microscopy and electrochemical methods. The results show that the electro-co-deposition of nano-SiC (20 nm) into a nickel matrix can significantly affect the morphology, microstructure and surface properties of Ni/SiC nanocomposite coatings. Ni/SiC nanocomposite coatings are of great interest for improving electrochemical corrosion resistance as well as resistance to bacteria attachment.
Kinetics of thermal dehydration of sol-gel derived MgO–ZrO2 composite hydrogel
Authors: Das Sudip , Mitra N. K. , Das Sukhen 
Published: November 2012

Abstract
The kinetics of thermal dehydration of mixed hydroxide hydrogels in MgO–ZrO2 system was studied as a function of composition by following the isothermal heat treatment route. Kinetic parameters were calculated through the application of the Guggenheim equation. The expulsion of both loosely bound water and constitutional OH groups were not continuous processes but proceeded in steps. The applicability of 1st order reaction kinetics for the major portion of the reaction for all compositions suggests that during the dehydroxylation process the dehydration is essentially controlled by the orientation of H2O molecules and the mutual interaction of hydroxyl groups. Due to a decrease in the concentration of the reacting species the activation energy was always higher at the final stage of dehydration.
Vertical static compression performance of honeycomb paperboard
Authors: Guo Yanfeng , Becker Wilfried , Xu Wencai 
Published: November 2012

Abstract
This paper evaluates the compression deformation behaviour and energy absorbing properties of honeycomb paperboards with different thicknesses under homogeneous vertical static compression loading. Each piece of the static compression stress and strain curves of the honeycomb paperboards is similar and comprises three parts of compression deformation (elastic region, plateau region, and densification region), which reflects the mechanical properties such as approximately linear elastic deformation, large plastic deformation with local collapse and densification. The unit volume deformation energy and strain curves and two kinds of static compression cushioning curves show that within the elastic region and plateau region of the stress and strain curves, the honeycomb paperboards hold better energy absorbing properties and the change of the cushioning factor with an increase in the thickness of honeycomb paperboards is very small.
Monitoring the Production of Polymer Nanocomposites by Melt Compounding with On-line Rheometry
Authors: Mould S. T. , Barbas J. M. , Machado A. V. , Nóbrega J. M. , Covas J. A. 
Published: November 2012

Abstract
Polymer nanocomposites are often prepared by melt compounding due to the suitability of the latter to industrial scale production. Even though monitoring the production process for quality control and/or optimization purposes is generally done off-line, the possibility of using on-line oscillatory rheometry has many inherent advantages. This work illustrates the use of a prototype rheometer to monitor the production of polymer nanocomposites by making measurements at specific locations along the extruder axis. The device is presented and its operation is explained. Examples of its use to characterize polypropylene and polyamide matrix nanocomposites with organoclays and carbon nanotubes are discussed, thus demonstrating the usefulness of the device.
Annular Extrudate Swell of a Fluoropolymer Melt
Authors: Mitsoulis E. , Hatzikiriakos S. G. 
Published: November 2012

Abstract
Annular extrudate swell is studied for a fluoropolymer (FEP) melt using a tubular die. The rheological data of the melt have been fitted using (i) a viscous model (Cross) and (ii) a viscoelastic one (the Kaye – Bernstein, Kearsley, Zapas/Papanastasiou, Scriven, Macosko or K-BKZ/PSM model). Numerical simulations have been undertaken to study the extrudate swell of the FEP melt in an annular die. Compressibility, thermal and pressure effects on viscosity, and slip at the wall were taken into account. In all cases, slip at the wall is the dominant contribution reducing the swelling when compared with corresponding no-slip simulations. The viscous (Cross) simulations show that the swell decreases with increasing apparent shear rate, which is opposite to what happens in the extrusion of viscoelastic melts. On the other hand, the viscoelastic (K-BKZ) simulations correctly obtain increasing swelling with increasing shear (flow) rates. It was found that due to the mild viscoelasticity of FEP and its severe slip at the wall the swelling of this melt is relatively small, reaching values of about 20% for a wide range of apparent shear rates, exceeding 5000 s−1. This is corroborated by experimental observations.
Processing of Polymer Nanocomposites Reinforced with Cellulose Nanocrystals: A Challenge
Authors: Dufresne A. 
Published: November 2012

Abstract
Aqueous suspensions of cellulose nanocrystals can be prepared by acid hydrolysis of the biomass. Due to their nanoscale dimensions and intrinsic physicochemical properties, these nanoparticles are promising renewable biomaterials. The high mechanical properties and reinforcing capability of these nanoparticles make them attractive for the processing of high performance nanocomposites. The main problem is related to the homogeneous dispersion of these nanoparticles within the polymeric matrix. Because cellulose nanocrystals are obtained as aqueous suspensions, water is the preferred processing medium. However, new strategies are envisaged to broaden the polymeric matrices that can be reinforced with these nanoparticles and avoid the liquid medium processing way. This paper reviews the different processing techniques of cellulose nanocrystals reinforced polymer nanocomposites focusing on the challenging melt processing technique.
Residual Wall Thickness Study of Variable Cross-section Tube in Water-assisted Injection Molding
Authors: Yang J. G. , Zhou X. H. , Niu Q. 
Published: November 2012

Abstract
Residual wall thickness is an important measure of the quality of water-assisted injection molding (WAIM) parts. Based on the traditional injection molding model, Reynolds stress was introduced into the WAIM model for the turbulent characteristics of high pressure water. In addition, residual wall thickness was computed by a computational fluid dynamics (CFD) method, and the results matched well with experimental data. The results show that the hollowed core ratio changes from small to large in the first half of water penetration, while in the latter half it is just the opposite. Difference of the residual wall thickness is larger at the large-diameter position of a part than other position. Residual wall thickness is mainly affected by water injection pressure, delay time, melt temperature, mold temperature and amount of short shot, in which the amount of short shot is the most obvious.
Structure, Mechanical and Barrier Properties of Uniaxially Stretched Multilayer Nylon/Clay Nanocomposite Films
Authors: Sadeghi F. , Ajji A. 
Published: November 2012

Abstract
Multilayer films consisting of a core layer of nylon 6 (PA6) sandwiched between two linear low density polyethylene (LLDPE) layers by using a tie layer were produced using a semi industrial cast film extrusion line. The core layer of the films was produced from neat PA6 and PA6/clay nanocomposite resins. The films were consequently uniaxially stretched in machine direction. The effect of stretching on crystalline structure, orientation as well as mechanical and barrier properties of the samples were investigated. Orientation of the films for both layers: polyethylene and nylon was assessed using FTIR (Fourier Transform Infrared Spectroscopy) and it was found that clay inclusion hindered orientation of the core nylon layer. Interaction of nylon molecules with clay influences the crystalline structure for nylon/clay nanocomposite film during the stretching as it hindered crystal transformation of γ to α phase. The effect of clay interaction on phase structure was also observed in DSC (Dynamic Scanning Calorimetry) results. Stretching improved barrier to oxygen for the samples. Oxygen transmission rate was reduced about 62.5% for the films having a nylon core and 50% for those with nylon/clay core when stretched to a draw ratio of 1.5 and remained nearly constant for higher draw ratios up to 3. Haze of the films was reduced with stretching; however the effect was more effective for the sample with neat nylon in the core layer when compared to the nylon/clay core one. Finally, it was observed that puncture resistance of the samples was improved significantly with stretching.
Comparison of the Clinical Expression of Patients with Ankylosing Spondylitis from Europe and Latin America
Authors: BENEGAS MARIANA , MUÑOZ-GOMARIZ ELISA , FONT PILAR , BURGOS-VARGAS RUBEN , CHAVES JOSÉ , PALLEIRO DANIEL , MALDONADO COCCO JOSÉ , GUTIÉRREZ MIGUEL , SÁENZ RICARDO , STECKMEN IVAN , RILLO OSCAR , MULERO JUAN , SAMPAIO-BARROS PERCIVAL , BARCELOS ANABELA , VANDER CRUYSSEN BERT , VAZQUEZ-MELLADO JANITZIA , COLLANTES ESTEVEZ EDUARDO 
Published: November 2012

Objective.To compare the clinical, demographic, and serologic characteristics and the treatment of patients diagnosed with ankylosing spondylitis (AS) from Europe (EU) and Latin America (LA).Methods.We included 3439 patients from national registries: the Spanish Registry of Spondyloarthritis (REGISPONSER), the Belgian registry (ASPECT), and the Latin American Registry of Spondyloarthropathies (RESPONDIA). We selected patients with diagnosis of AS who met the modified New York classification criteria. Demographic, clinical, disease activity, functional, and metrological measurement data were recorded. Current treatment was recorded. The population was classified into 2 groups: patients with disease duration < 10 years and those with disease duration ≥ 10 years. A descriptive and comparative analysis of variables of both groups was carried out.Results.There were 2356 patients in EU group and 1083 in LA group. Prevalence of HLA-B27 was 71% in LA group and 83% in EU group (p < 0.001). We found a greater frequency of peripheral arthritis and enthesitis (p < 0.001) in the LA population; prevalence of arthritis was 57% in LA and 42% in EU, and for enthesitis, 54% and 38%. Except for treatment with anti-tumor necrosis factor (anti-TNF), the use of nonsteroidal antiinflammatory drugs (NSAID), corticosteroids, and disease-modifying antirheumatic drugs (DMARD), and the association of anti-TNF and methotrexate use showed a significant difference (p < 0.001) in the 2 populations.Conclusion.The principal differences in the clinical manifestations of patients with AS from EU and LA were the greater frequency of peripheral arthritis and enthesitis in LA group, the higher percentage of HLA-B27 in EU group, and the form of treatment, with a greater use of NSAID, steroids, and DMARD in the LA group.
Les modifications de la technique
Authors: Lucarelli Daniela 
Published: November 2012

Résumé Autour des travaux de F. Richard et de A. M. Nicolò, l’auteur invite à un questionnement autour de la spécificité du travail analytique avec les adolescents et les éventuels aménagements du cadre – tant théorique que clinique – qu’il réclame.
De l'intérêt d'articuler les dimensions discursive et interactionnelle de la conversation. Le cas d'une profession en voie de légitimation
Authors: Laforest Marty 
Published: November 2012

Cet article est consacré à deux dimensions bien connues de la conversation (au sens large du terme) : les dimensions discursive et interactionnelle. L’objectif est de montrer que leur articulation dans l’analyse de tout ensemble de données enrichit notre compréhension de ses enjeux en ce qui a trait à la question des rapports entre l’échelle locale de l’événement singulier de parole et l’échelle globale des patterns sociaux. L’analyse s’appuie sur des consultations sage-femme/cliente au Québec. Sur le plan interactionnel, la consultation se distingue peu des interactions médecin/patient. Sur le plan discursif cependant, les sages-femmes construisent une identité distincte de celle des médecins. Seule l’articulation des deux dimensions de ce que l’on peut observer à l’échelle micro du langage permet de dresser un portrait précis de ce qui se passe à l’échelle sociale macro.
Geography of Multinational Corporations and Functional Specialization in Chinese Cities
Authors: He Canfei , Xiao Xiaojun 
Published: November 2012

There has been a transformation of urban structure from mainly sectoral to functional specialization. This transformation is inextricably interrelated with changes in firms’ organization. Some cities host upstream functions of the value chain while others attract production and assembly. This paper investigates the tendency toward functional specialization in Chinese cities by exploring divisions in multinational corporations’ (MNC) business operations in China. Based on data from Fortune Global 500 MNCs during 1979-2008, the study finds that MNCs have gradually expanded in China, both functionally and geographically. In that process, similar functions tend to agglomerate in certain cities while complementary functions co-agglomerate in others. The analysis indicates that Chinese cities may start to move toward functional specialization, with upstream functions clustering in the top tier cities of the political and economic urban hierarchy.
Shopping Centres and Intangible Consumption in Global Cities
Authors: Corniani Margherita 
Published: November 2012

In global markets, shopping centres are becoming important agents, defining the kind and quality of intangible features of supplies, not only establishing the assortments, but also affecting the consumption behaviour atmosphere that they determine in all its aspects. In this way, shopping malls are responsible for the quality of the intangible consumption process which has a profound impact on people and on the community that people live in. That is why shopping centres, both physical and virtual (i.e. e-commerce sites and other kinds of virtual marketplaces), are significant in big towns, where commercial density is high. By defining the intangible aspects of consumption, shopping centres determine the development of a particular geographical area (normally surrounding a big city) because they are able to concentrate demand, and they play an active role in establishing the choice alternatives, which means forging the consumption habits and expectations of populations and cities.
Ouverture de ‘Global Cities and Knowledge Management - 2’
Authors: Brondoni Silvio M. 
Published: November 2012

World cities are boosted by Nation-States to encourage and control the innovation processes, developing specific attractiveness factors for companies focused on knowledge production. The role of world cities as a knowledge hub is linked to the one of knowledge production-city, since in global cities there are high-knowledge producers, consumers and workers. It is possible to identify three models of global urban development, each one differing from the other for the degree of knowledge production and intangible consumption attracted and promoted within the city: the model of no-knowledge production; the model of low-knowledge production and the model of high-knowledge production.
Growth, Consumption and Knowledge Cities
Authors: Riccardo Cappellin  
Published: November 2012

Cities are important centres of service activities and hubs of new knowledge. The changing structure of production and consumption in post-industrial cities has been analysed by building on the recent economic literature in three related fields, such as: the ‘endogenous development’ of industrial clusters, the regional development of knowledge intensive business services and the regional factors of innovation and knowledge creation. The increasing interaction between users and producers for the development of new services within cities creates the internal aggregate demand, which is mainly concentrated within cities, and can be a powerful driver of national growth and the new motor or the drivers of the economy in a modern city.
Which Future? Strategic Visions For American Cities
Authors: Raffaella Nanetti  
Published: November 2012

The deep and widespread financial and economic crisis that started in 2007 has spawned powerful protest movements across the US. Some of the protest grass root movements are pushed forward by the crisis in giving up on that very notion by embracing a no growth and wealth redistribution approach. Other movements that are ideologically critical of public policies have been prompted by the crisis to return to an even more pronounced free market approach and to the anti-city posture . A distinctive lack of vision for the future of cities has become the common denominator of both movements. A constructive thinking for the future of American cities suggests a positive role with regard to cities so that they can continue to be the levers of knowledge production for a sustainable development.
Large Cities, Intangible Consumption and Knowledge Production
Authors: Lara Penco  
Published: November 2012

The purpose of this paper is to present the characteristics of the city in the knowledge era. In the knowledge era, we argue that a successful city assumes the role of: A) knowledge hub, because large cities host high tech industries, higher education and research institutions, knowledge intensive business services (KIBS); B) consumer hub, which generates consumption, especially of an intangible nature such as services, culture, entertainment, products which spread culture and knowledge (e.g. fashion and design products). This paper aims to provide a conceptual framework to understand the key-factors - implicit and explicit - useful to the development and success of the city.
Assessing Urban Environmental Management Practice with a Scalar Approach. The Shanghai Case
Authors: Wei Tu  
Published: November 2012

Shanghai’s urban environmental management in the past three decades has been focused primarily on the environmental problems at the intra-urban level. While this ‘end of pipe’ approach greatly mitigated domestic and industrial pollution, progresses were much slower in dealing with environmental impacts both at a smaller (i.e., those related to people’s daily activities) scale and at a larger (i.e., those related to inter-urban/regional or global issues) scale. Urban environmental management policies in Shanghai and China should prioritize and address urban environmental impacts at continuous geographic scales to achieve long-term ‘triple bottom line’ sustainability.