4 resultados para Variações de densidade

em Repositório Institucional da Universidade Estadual de São Paulo - UNESP


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Nowadays, we live in a time of rapid research for technological advances, in a way that this pursuit of new technologies is deeply connected to the diversity of new materials that have been developed by mankind. It deals with issues such as materials with enhanced properties which offer better quality, less cost and high performance, while they are accessible both in their production and moment of operation. In this context, it was required to develop electrodes that were easy to prepare as well as which present high electric conductivity and good mechanic proprieties by using carbonaceous material as basis. For this reason, the best parameters of the furfuryl resin cures were established with different pH variations through viscosimetric measurements and differential scanning calorimetry. By scanning electron microscopy (SEM) was possible to identify an increased porosity in the samples with pH 7 and pH 8, as compared to samples with lower pH content. After carbonization of the material, the characterization of monolithic glassy carbon was held by means of FT-IR techniques, Raman spectroscopy, X-ray diffraction and cyclic voltammetry. The spectra showed that the change in pH does not have significant influence on the crystallographic ordering of the material and its structural characteristics. As for the electrochemical character, the CVM electrodes showed excellent response, with good reversibility and wide potential window. Some voltammetric curve deviations were only observed for the sample with pH 4, which may be related to processing parameters adopted

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In this work, we address the informational Density Index (IDI) a methodological Option How To be used on the Research Procedures Analysis of Commerce Geography. The IDI and an indicator of Technological Complexity level of economic activities and a review and made a database from CNEFE / NCEA, where the first signifies the National Register of Establishments for statistical purposes and the second means a National Classification Economic Activities. Elaborated with emphasis on discussion of between center and centrality relations, wish to present a constitution of a data base on level sampling with an analysis elaboration do IDI from the criteria: home-page and e - commerce. This methodology helps us understand how polycentric structures, locational enterprise well as a reflection on the middle cities using a through the analysis on city of São Carlos/SP. Where we see the establishments with greater and lesser content as well as its geographical distribution, noting of according to the criteria listed number of establishments with IDI 0 very relevant. Our analysis as well as such divisions that meet greater index, so, IDI 2 like to financial activities. Also present at methodological level the city of São José do Rio Preto/SP paragraph seizure of care when working there in database