998 resultados para Nitrogenio - Análise
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The application of microwave radiation on the sample preparation has been expanding increasingly in areas involving decomposition by wet and dry roads, fusion, extraction, acceleration of chemical reactions, for example. Currently, the use of microwave ovens for analytical purposes are recognized for having excellent performance for organic and inorganic samples. In the international market there are several kinds of microwaves oven which adapt the varied purposes, however yet with elevated prices which incapacitate your use as routine equipment in laboratory. Thus, many researchers have been choosing for developing own projects of microwaves oven production or to use domestic oven for the laboratory, with or without adaptations. For the evaluation of the proposed method was used in the Kjeldahl methodology for determining total nitrogen in samples of crude protein, using a domestic microwave oven and a digester pot made up in TeflonTM and distillation by steam. Were made to adapt and characterization of a domestic microwave oven, the confeccion vessel digester and the metal support for the vessel. The accuracy of the proposed method was confirmed by comparison of two methods, the standard method for conventional heating and by the proposed method, with heating by microwave radiation through the calculated values of relative standard deviation analysis
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Pós-graduação em Engenharia Civil e Ambiental - FEB
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The sol-gel process is a method for obtaining vitreous or vitro-ceramic materials which, are prepared a sol and by drying the liquid phase. This technique has been used extensively for the preparation of glassy gels, films, fibers and particles from the hydrolysis and polycondensation reactions of metal alkoxides. The usual methods for drying are: evaporation drying (xerogels), freeze drying (criogéis) and via supercritical CO2 extraction (aerogels). In the present work, we studied the preparation of silica gels by the sol-gel process from the hydrolysis of alkoxides tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTS). The hydrolysis was promoted from GPTS and TEOS in proportion (4: 1) under acidic conditions. The hydrolysis reaction was promoted inside a Becker at room temperature. After hydrolyses the prepared sol had pH 2, and kept under mechanical agitation for a period of 1 hour. In order to accelerate the polycondensation reaction, the pH was corrected to a value near 5 by slowly adding NH4OH. Then the sols were leaked in sealed polycarbonate containers and maintained for 20 days at 40°C for gelation. Silica aerogels were prepared via supercritical CO2 extraction of the wet gel at temperature and pressure higher than 31°C and 74 atm, in an autoclave specially developed for the process. The structural characteristics were studied in the dry gel (aerogel). Aerogels were then characterized by nitrogen adsorption and small angle light scattering. The nitrogen adsorption data were analyzed for the determination of the BET specific surface (SBET), the total pore volume Vp, the pore mean size (lP=4Vp/SBET), the particle mean size (lS) and the pore size distribution (PSD). And the data from small angle light scattering were analyzed to determine the correlation function (γ'), the area per unit volume (S/V), average pore size (l ) and the average particle size...
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The ineffectiveness of current design processes has been well studied and has resulted in widespread calls for the evolution and development of new management processes. Perhaps one problem is that with the advent of BIM we are moving from one stage to another without necessarily having resolved all the issues. CAD design technology, if well handled, could have significantly raised the level of quality and efficiency of current processes, but in practice this was not fully realized. Therefore, technology alone can´t solve all the problems and the advent of BIM could result in a similar bottleneck. For a precise definition of the problem to be solved we should start by understanding what are the main current bottlenecks that have yet to be overcome by either new technologies or management processes, and the impact of human behavior related issues despite the advent of new technologies. The fragmented and dispersed nature of the AEC sector and the huge number of small organizations that comprise it would probably be a major limiting factor. Several authors have addressed this issue and more recently IDDS has been defined as the highest level of achievement. However, what is written on IDDS shows an extremely ideal situation on a state to be achieved; it shows a holistic utopian proposition with the intent to create the research agenda to move towards that state. Key to IDDS is the framing of a new management model which should address the problems associated with key aspects: technology, processes, policies and people. One of the primary areas to be further studied is the process of collaborative work and understanding, together with the development of proposals to overcome the many cultural barriers that currently exist and impede the advance of new management methods. The purpose of this paper is to define and delimit problems to be solved so that it is possible to implement a new management model for a collaborative design process.
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This text discusses the project for a garden by Gonçalo Ribeiro-Telles that argues for a different possibility of creating a garden as landscape continuum and exploring picturesque as an apparatus to expand the experience of the place
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Abstract: The present article discusses about the representation of Octavius, Mark Antony and Cleopatra in three coins, to reflect about how the ancient mintage contributed for these personages could shape their images to the populus romanus in general.
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Registra e analisa o processo de elaboração da Lei 9.456, de 25 de abril de 1997, que trata da proteção de cultivares, enfocando a tramitação dos projetos de lei, as polêmicas em torno do tema, os atores em ação e os argumentos técnicos, políticos e ideológicos debatidos. Analisa também as principais disposições da lei e sua interligação com o agronegócio brasileiro.
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Analisa o pronunciamento do Deputado Mário Covas, em dezembro de 1968, em defesa da imunidade parlamentar e da liberdade de palavra, principais ingredientes dos regimes democráticos. Utilizando as propostas formuladas por Norman Fairclough, Patrick Charaudeau e Tereza Halliday, reconstituem-se elementos caracterizadores da enunciação e os principais recursos discursivos utilizados.
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Estudo dos recursos ao poder conclusivo das comissões da Câmara dos Deputados. Faz uma análise de dados do seu cabimento, de suas razões, sua ocorrência e a influência do Executivo. Para tanto, sistematiza as informações através da identificação e estudo dos dados que abrangem a 52ª Legislatura. Aborda os mecanismos regimentais pertinentes, além dos outros fatores intervenientes.
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Analisa a relação entre parlamento, mídia e sociedade na construção de uma democracia forte. Há dois elementos fundamentais para que uma sociedade estabeleça um Estado Democrático: a confiança e a participação cidadã. Parece paradoxal que em uma estrutura em que o voto é direto, haja problemas de confiança entre o Legislativo e os cidadãos. Focando a atuação da CPI dos Grupos de Extermínio no Nordeste, que tratou de um tema federal - a proteção dos direitos humanos em um cenário regional: o nordeste brasileiro, o estudo propõe uma reflexão sobre o papel do deputado no fortalecimento do elo entre a instituição Câmara Federal e o cidadão. A partir da análise feita nos jornais impressos de Pernambuco, indaga o papel da mídia no fechamento da conexão eleitoral, contribuindo ainda para a prestação de contas entre deputados e cidadãos. Pretende, ainda, verificar como se dá o relacionamento da mídia com os representantes populares.
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Consultoria de Orçamento e Fiscalização Financeira.
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Consultoria de Orçamento e Fiscalização Financeira - Núcleo da Saúde.