978 resultados para Revestimento básico


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This article deals with the Park School, a proposal prepared by AnísioTeixeira to organize basic education in Brazil. This is a bibliographic study, anchored in texts produced by the author himself and researchers who are dedicated to their legacy. Records show that the proposed Park School was an experiment, bold and innovative, to arrange a policy for primary education in Brazil. Was expertly planned and stood out in the architectural and pedagogical aspects. Park School has shown that it is possible to provide a quality public education; political commitment and solid educational training are therefore fundamental.

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Nanotechnology, the science of minuscule, has developed products which are able t o manipulate atoms and molecules that could be applied in the sterilization process of dental instruments. Objetives: The objective of the present study was to evaluate the self-cleaning action of TiO2 and Ag nanoparticles coating on dental instruments by the photocataliys process under UV and visible light irradiation. Material and method: Microbiologic tests were done using dental cement spatulas coated with TiO2 and Ag nanoparticles (one or three layers), and contaminated with 10 mcrl of Pseudomonas aeruginosa and Enterococcus faecalis, respectively. After contamination, they were exposed to ultraviolet light and visible light for 120 minutes. Next, they were transferred to and stored in test tubes with BHI (Brain Heart Infusion) and incubated in 35 to 37 °C. Checking times for bacterial growth and for control and retrieval tests were done at: 24, 48, 72 and 96 hours. Result: The Pseudomonas aeruginosa was inactive after 120 minutes of ultraviolet light irradiation, thus confirming the heterogeneous photocatalytic activity of TiO2 and Ag. The Pseudomonas aeruginosa was not inactivated under visible light irradiation and the Enterococcus faecalis was not inactivated under UV and visible light irradiation of the dental cement spatulas coated with TiO2 and Ag nanoparticles in the readings to 96 hours, showing bacterial growth. Conclusion: There were no influence of one or three layers of TiO2 and Ag nanoparticles coating of the spatulas in the results. The heterogeneous photocatalysis activity of TiO2 and Ag under UV light irradiation was confirmed for Pseudomonas aeruginosa but not under visible light. Enterococcus faecalis did not confirmed the photocatalytics activity of TiO2 and Ag under UV light irradiation and visible lights irradiation.

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Pós-graduação em Matemática em Rede Nacional - IBILCE

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Pós-graduação em Engenharia Mecânica - FEG

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The study is intended to portray the experiment of mechanical engineering course academicians’ that work on health and labor security field, at the project “Primary Training of Operation and Operational Security of Agricultural Machines”, by practical and theoretical content for workers of a rural community, aiming operational security orientation on their work activities.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fuel cells powered directly with ethanol (Direct Ethanol Fuel Cell-DEFC) are very attractive for the possibility of using a renewable fuel in the generation of clean energy. However, it is still necessary to deepen the understanding of catalytic processes and their dependence on the catalytic properties. This work proposes to study the catalytic activity of ethanol oxidation in an alkaline medium of Pd nanoparticles supported in carbon oxide hybrids using various transition metal oxides (MoO3, TiO2, WO3 and ZrO2). The materials prepared were characterized by techniques such as X-ray diffraction, transmission electron microscopy (TEM) and X-ray dispersive spectroscopy (EDX) to verify the structure, the distribution of particles in the supports and the presence of Pd on particles oxide. Experiments of X-rays absorption spectroscopy were carried out using soft X-rays (SXS) to evaluate the changes in the electronic properties of the Pd particles caused by interactions with different oxides. Measurements of cyclic voltammetry and potential sweeps of adsorbed CO oxidation allowed evaluating general aspects of the catalysts' electrochemical behavior and determining the electrochemically active area thereof. The catalytic performances of ethanol oxidation in alkaline medium were evaluated by electrochemical techniques (potential scan and chronoamperometry), and showed an improvement in activity with the addition of oxides in material containing only carbon, which was most pronounced for the catalyst containing TiO2. This improvement was predominantly associated with the electronic effects caused by the interaction of Pd on the support, causing a vacancy in the 4d band of Pd which, in turn, produces variations in adsorption energies of the species...

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Fuel cells powered directly with ethanol (Direct Ethanol Fuel Cell-DEFC) are very attractive for the possibility of using a renewable fuel in the generation of clean energy. However, it is still necessary to deepen the understanding of catalytic processes and their dependence on the catalytic properties. This work proposes to study the catalytic activity of ethanol oxidation in an alkaline medium of Pd nanoparticles supported in carbon oxide hybrids using various transition metal oxides (MoO3, TiO2, WO3 and ZrO2). The materials prepared were characterized by techniques such as X-ray diffraction, transmission electron microscopy (TEM) and X-ray dispersive spectroscopy (EDX) to verify the structure, the distribution of particles in the supports and the presence of Pd on particles oxide. Experiments of X-rays absorption spectroscopy were carried out using soft X-rays (SXS) to evaluate the changes in the electronic properties of the Pd particles caused by interactions with different oxides. Measurements of cyclic voltammetry and potential sweeps of adsorbed CO oxidation allowed evaluating general aspects of the catalysts' electrochemical behavior and determining the electrochemically active area thereof. The catalytic performances of ethanol oxidation in alkaline medium were evaluated by electrochemical techniques (potential scan and chronoamperometry), and showed an improvement in activity with the addition of oxides in material containing only carbon, which was most pronounced for the catalyst containing TiO2. This improvement was predominantly associated with the electronic effects caused by the interaction of Pd on the support, causing a vacancy in the 4d band of Pd which, in turn, produces variations in adsorption energies of the species...

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O presente artigo realiza uma análise que compara o desempenho dos provedores públicos e privados de serviços de saneamento básico no Brasil. As diferenças de desempenho entre os provedores que, de acordo com a literatura, estão submetidos a diferentes incentivos foram avaliadas com base nos dados do Sistema Nacional de Informações sobre Saneamento (Snis) de 2010 a partir de uma estimativa em cross-section para uma amostra de 4.930 municípios brasileiros. Os resultados não fornecem evidências fortes de que um grupo seja superior a outro na maior parte dos indicadores. Dado que os grupos revelaram superioridade em indicadores específicos, a contribuição deste estudo é propor o desenho de uma política que considere diversas modalidades de gestão e provisão como possível solução para o desafio de universalizar os serviços no país.

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[ES] Esta investigación tiene como objeto la defensa de la traducción de las letras de las canciones para el aprendizaje de lenguas extranjeras, entre otras razones. Nuestra hipótesis se sustenta en la definición del texto musical pop como poesía cantada enmarcada, a su vez, dentro del concepto de discurso poético. A este respecto, nos inclinamos por una descripción motivada del género musical pop en su vinculación con la recepción y sus receptores. A partir de la concepción de género como enfoque lingüístico de los diferentes tipos de discurso, llegamos a la conclusión de que existe una confusión entre el pop como categoría supraordinada y los estilos de él derivados. No obstante, también debemos trabajar categorías estéticas, dado que en el texto musical conviven, a su vez, dos textos interrelacionados: la música y la letra. Nuestro estudio contempla las traducciones dentro de las subordinaciones del medio escrito y las limitaciones impuestas por el lenguaje poético.