Navegando por Palavras-chave "Nanostructures"

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    Electrochemical degradation of benzene in natural water using silver nanoparticle-decorated carbon nanotubes
    (Elsevier B.V., 2013-08-15) Cesarino, Ivana; Cesarino, Vivian; Moraes, Fernando C.; Ferreira, Tanare C. R.; Lanza, Marcos R. V.; Mascaro, Lucia H. [UNIFESP]; Machado, Sergio A. S.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    In this study, a novel methodology for the electrochemical degradation of benzene in natural water using silver nanoparticle-decorated carbon nanotubes has been investigated. the morphology, the structure, and the electrochemical performance of the multi-walled carbon nanotubes-silver (MWCNT-Ag) nano-composite film were characterised by transmission electron microscopy (TEM), X-ray diffraction (XRD), and cyclic voltammetry (CV), respectively. Electrocatalytic oxidation of benzene in an aqueous solution was studied to evaluate potential applications of the MWCNT-Ag modified glassy carbon (GC) electrode in environmental science. the benzene removal efficiency in natural water containing 10 mg L-1 benzene yielded 77.9% at an applied potential of +2.0 V for 2 h using the MWCNT-Ag-GC electrode. in comparison, the removal efficiency reached only 8.0% with the bare GC electrode, showing the suitability of the MWCNT-Ag nanocomposite modified GC electrode for electro-oxidation of benzene in natural water. (c) 2013 Elsevier B.V. All rights reserved.
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    Room and high temperature ECAP processing of Al-10%Si alloy
    (Elsevier B.V., 2013-12-10) Regina Cardoso, K. [UNIFESP]; Munoz-Morris, M. A.; Valdes Leon, K.; Morris, D. G.; Universidade Federal de São Paulo (UNIFESP); CSIC
    An Al-10%Si metal matrix composite has been processed by severe plastic deformation over a range of temperatures in order to refine microstructure and improve mechanical behaviour. Material in the as-cast state is too brittle to process significantly at room temperature and requires higher temperatures for processing, while material given a previous globularising heat treatment or previously hot extruded is more ductile and can be processed at relatively low temperatures. All processing treatments lead to refinements of matrix grain and Si particles, with corresponding improvements in both strength and ductility. Microstructures are not refined as much as expected, based on previous studies of Al-7%Si, which is explained by the inability to accumulate high densities of geometrically-necessary dislocations and construct the refining grain boundaries. the strengthening found is due to a combination of grain boundary hardening, matrix and particle hardening, and dislocation hardening, with this latter term being the most important for low processing temperatures but negligible when processing at high temperatures. (C) 2013 Elsevier B.V. All rights reserved.