1000 resultados para Fragmentação da produção


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Cosmic radiation has been identi ed as one of the main hazard to crew, aircraft and sensitive equipments involved in long-term missions and even high-altitude commercial ights. Generally, shields are used in spatial units to avoid excessive exposure, by holding the incident radiation. Unfortunatelly, shielding in space is problematic, especially when high-energy cosmic particles are considered, due to the production of large number of secondary particles, mainly neutrons, protons and alpha particles, caused by spallation reactions and quasi-elastic processes of the corpuscular radiation with the shield. Good parameters for checking the secondary particle production at target material are diferential cross section and energy deposited in the shield. Addition experiments, some computer codes based on Monte Carlo method show themselves a suitable tool to calculate shield parameters, due to have evaluated nuclear data libraries implemented on the algorithm. In view of this, the aim of this work is determining the parameters evaluated in shielding materials, by using MCNPX code, who shows good agreement with experimental data from literature. Among the materials, Aluminium had lower emission and production of secondary particles

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

O jornalismo é um dos principais meios de oferta de temas para a discussão e formação da opinião pública, porém depende de um sistema técnico para ser transmitido. Durante mais de cem anos as informações produzidas pela imprensa foram emitidas, armazenadas, transmitidas e recebidas pelos chamados veículos de comunicação de massa que utilizam a rede centralizada cujas características estão na escassez material, produção em série e massificação. Esse sistema separa no tempo e no espaço emissores e receptores criando uma relação desigual de força em que as grandes empresas controlaram o fluxo informativo, definindo quais fatos seriam veiculados como notícia. Em 1995, a internet cuja informação circula sob a tecnologia da rede distribuída, foi apropriada pela sociedade, alterando a forma de produção, armazenamento e transmissão de informação. A tecnologia despertou a esperança de que esta ferramenta poderia proporcionar uma comunicação mais dialógica e democrática. Mas aos poucos pode-se perceber novas empresas se apropriando da tecnologia da rede distribuída sob a qual circula a internet, gerando um novo controle do fluxo informativo. Realizou-se nessa pesquisa um levantamento bibliográfico para estabelecer uma reflexão crítica dos diferentes intermediários entre fato e a notícia tanto da rede centralizada como na rede distribuída, objetivando despertar uma discussão que possa oferecer novas ideias para políticas, bem como alternativas para uma comunicação mais democrática e mais libertária.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Inclui notas explicativas, bibliográficas e bibliografia

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In Brazil, the discussion about the urban voids appear related to the capitalist urban expansion process, when the urban growth act the cities were expanding toward the periphery, leaving in the interstices vacant land, kept out of the market waiting for the real estate valuation. In Natal, the formation of voids was triggered by the process of fragmentation of space promoted mainly by the urban sprawl with the emergence of new neighborhoods, lots of openings, housing developments and the emergence of new lines of commercial centrality. In this sense, this study aims to understand the role played by urban voids in the real estate dynamics and the production process of the Natal city space. For this, it was adressed the concept building on the conception of different authors and were characterized four types of gaps that best explained the phenomenon in the context of the work proposal addressed, such as idle, empty expectant, empty-brownfield areas and institutional areas. For each of these events were considered an example in the general context of the city through semi-structured interviews with technicians, managers and public officials in promoting the city and /or related to management of urban voids.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The present work analyzes the fast evolution of gated communities in Natal-RN´s urban space. Characterized by the occupation of large areas, providing private security and utilities, this kind of real estate use arises a long list of questions and issues from society and scholars, due to privatization of urban space, bending of law constraints and the lack of an integrated planning of the cities where they are built. The reasons for its fast growth in Brazil s urban areas are analyzed, considering the impact on formal urban planning and municipal services and on the identification of urbanistic, architectural pattern and constraints, as well as legal, social and economic issues. This study is based on the detailed analysis of the first three units of gated communities built in the urban space in Natal, between 1995 and 2003, including their evolution throughout time and the specific social and economic reasons for its present widespread adoption in Brazilian real estate market and, particulary, in our city. The main objective of this piece of work is to answer the why s and how s these phenomena evolved, setting a basis for the definition of adequate public policies and regulation of this kind of urban land use

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A recuperação de metais a partir de resíduos é uma actividade ligada à valorização de resíduos que se afigura essencial à preservação de recursos naturais. O tratamento de resíduos metálicos é essencial para o sucesso da reciclagem. O tratamento permite diminuir contaminações com outros materiais, melhorar a valorização e diminuir os custos de transporte. Ao tratamento encontram-se associadas diferentes operações, cuja finalidade é preparar os metais de acordo com os requisitos de processo dos recicladores. A fragmentação é uma das operações de pré-tratamento mais relevantes pela sua capacidade de processamento e pela possibilidade de permitir separar resíduos contaminados com outros materiais. O presente trabalho efectua uma análise inicial ao sector e às tecnologias existentes permitindo introduzir posteriormente o caso de estudo, a instalação em Vila Nova de Gaia da empresa Constantino Fernandes Oliveira & Filhos, SA. O enfoque ao caso de estudo aborda o tema da eficiência energética, um dos principais custos de produção. Nesta perspectiva identifica pontos críticos e estabelece medidas de eficiência energética que permitam reduzir o consumo energético. As medidas propostas foram a colocação de um variador electrónico de velocidade no ventilador principal da fragmentadora e no compressor e a substituição da iluminação existente por iluminação LED. As medidas propostas permitem a redução do consumo específico de energia de 9,39 kgep/t para 8,81 kgep/t. Sendo a fragmentação uma das operações mais relevantes na actividade da instalação estudada, no presente trabalho, efectuou-se a análise do modelo operatório com recurso à aplicação STAN de análise de fluxos de materiais. O procedimento de análise envolveu a criação de vários cenários de exploração no tratamento de resíduos. O objectivo das simulações é a contabilização dos custos referentes ao tratamento dos resíduos permitindo melhorias na vertente operacional, ambiental e económica. Um dos cenários simulados foi a remoção dos veículos em fim de vida dos resíduos a fragmentar, onde se constatou que apesar de uma redução dos resíduos processados, os proveitos por quantidade processada não alteram relativamente ao modelo operatório de base. Este facto deve-se sobretudo aos custos elevados de tratamento de resíduos gerados no processo de fragmentação dos veículos em fim de vida.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The present work analyzes the fast evolution of gated communities in Natal-RN´s urban space. Characterized by the occupation of large areas, providing private security and utilities, this kind of real estate use arises a long list of questions and issues from society and scholars, due to privatization of urban space, bending of law constraints and the lack of an integrated planning of the cities where they are built. The reasons for its fast growth in Brazil s urban areas are analyzed, considering the impact on formal urban planning and municipal services and on the identification of urbanistic, architectural pattern and constraints, as well as legal, social and economic issues. This study is based on the detailed analysis of the first three units of gated communities built in the urban space in Natal, between 1995 and 2003, including their evolution throughout time and the specific social and economic reasons for its present widespread adoption in Brazilian real estate market and, particulary, in our city. The main objective of this piece of work is to answer the why s and how s these phenomena evolved, setting a basis for the definition of adequate public policies and regulation of this kind of urban land use

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The production of ethyl esters by alcoholysis is an alternative for splitting triacylglycerols due to the possibility of using low temperatures, which results in oxidative protection of the polyunsaturated fatty acids. Ethyl esters produced under mild conditions of temperature could be used as substrate for obtaining structured lipids. The reaction parameters of production of ethyl esters from fish oil with high content of omega-3 fatty acids by alcoholysis were optimized using response surface methodology. An experimental design (2³) (with levels +1 and -1, six axial points with levels -alpha and +alpha and three central points) was applied. The variables investigated were concentration of catalyst, amount of ethyl alcohol and temperature. Ethyl ester conversion was monitored by high performance size exclusion chromatography (HPSEC) and the best result obtained was 95% conversion rate. The optimal conditions were 40 °C, 1% of NaOH and 36% of ethanol.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Isomaltulose, a functional isomer of sucrose, is a non-cariogenic reducing disaccharide; has a low glycemic index; selectively promotes growth of beneficial bifidobacteria in the human intestinal microflora; and has greater stability than sucrose in some foods and beverages. Isomaltulose is a nutritional sugar that is digested more slowly than sucrose, and has health advantages for diabetics and nondiabetics. Immobilization techniques, especially entrapment of the cells, are widely used for conversion of sucrose into isomaltulose. Immobilization offers advantages such as minimum downstream processing, continuous operation and reusability of cells. Isomaltulose is currently considered to be a promising sugar substitute.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Alginate microparticles were prepared by an emulsion method aiming oral controlled release of antigens to fish. The effects of emulsification temperature and impeller type on particle morphology, average diameter, and size distribution were evaluated. Microparticles contaning formalin-killed Flavobacterium columnare cells (a model antigen) were prepared and characterized regarding bacterial release and particle stability when exposed to Nile tilapia (Oreochromis niloticus) typical gastrointestinal conditions. This methodology allowed the production of microparticles containing up to 14.3 g/L of bacterin, stable at a pH range from 2.0 to 9.0 for 12 h and smaller than 35 μm.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Poorly soluble drugs have low bioavailability, representing a major challenge for the pharmaceutical industry. Processing drugs into the nanosized range changes their physical properties, and these are being used in pharmaceutics to develop innovative formulations known as Nanocrystals. Use of nanocrystals to overcome the problem of low bioavailability, and their production using different techniques such as microfluidization or high pressure homogenization, was reviewed in this paper. Examples of drugs, cosmetics and nutraceutical ingredients were also discussed. These technologies are well established in the pharmaceutical industry and are approved by the Food and Drug Administration.