1000 resultados para Energia nuclear -- Aspectes ambientals
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Incluye Bibliografía
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Revisa las aplicaciones, necesidades, problemas y perspectivas para el uso pacifico de la energia nuclear en cinco paises anglo- parlantes del Caribe: Belice, Jamaica, Santa Lucia, Trinidad y Tabago y Barbados.
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Contiene la organizacion y debates de la reunion que tuvo como objetivo analizar la situacion actual, evolucion proyectada, restricciones actuales y previsibles a la introduccion y expansion de la utilizacion de la energia nuclear con fines pacificos a la luz de las necesidades y prioridades de la region.
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Pós-graduação em História - FCHS
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The Nuclear Medicine is a medical specialty which uses different radioisotopes for diagnostic and therapeutic purposes. The isotopes are radioactive elements which are administered in vivo and present distribution to specific organs or cell types. The knowledge of radioactivity and notions related to ionizing radiation allow to contextualize the radiological protection measures to be taken in Nuclear Medicine. So it is possible to minimize unnecessary exposure to patients, the public, and individuals occupationally exposed and the environmental. For this it is necessary to relate the physical and technological bases apply to this mode with the standards established by regulatory agencies, including the CNEN (National Nuclear Energy Commission) and ANVISA (National Agency for Sanitary Vigilance). In this scenario, it is important that the theoretical endorse the activities which are periodically audited for verification of compliance with the standards that aim to radioprotection. One role of the Medical Physicist in these services is, therefore, act as Radiation Protection Supervisor exerting numerous activities and ensuring compliance with these standards. In this context the stage in the area of Nuclear Medicine was developed in many customers of the enterprise Rad Dimenstein & Associados LTDA, among them the hospitals Israelita Albert Einstein (HIAE), Nossa Senhora de Lourdes (HNSL), Santa Paula (HSP), Cruz Azul (CRAZ), Grupo Fleury, among other clinics. Following the routine and then carrying out various activities pertaining to the Medical Physicist in the area, it was noted that the measures and actions are extremely effective and fundamental in terms of radiological protection
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Nuclear medicine uses non-sealed sources for exams and treatments, because the movement of these sources, source of patients injected or not, involve a wide range of environmental radiometric levels. To better control of these levels this study was aimed at monitoring points strategically distributed in all environments Sector Technical Nuclear Medicine, Hospital of the Botucatu Medical School, performing two measurements at random times daily for a period of three months, sampling the normal routine of the sector. The detector Geiger-Muller was used for the acquisition of exposure rates of the points, efficiency and reprodutibility test have shown good performance of this equipment for this purpose. The results allowed to make a projection of annual dose for each environment indicating higher risks for Occupationally Exposed Individuals as well as Public Individuals compared with the limits established by the National Commission of Nuclear Energy. Was developed a spatial map of dose that can be used as a visual warning to the regions with the highest exposure to ionizing radiation, enabling reduced risk of a potential exposure
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Nuclear Medicine is a medical modality of therapy and diagnostic imaging using unsealed radioactive sources for its purposes. This routine activity promotes the transit of radioactive sources for the area of installation, beyond the transit of patients injected with radioisotope, which also contribute to raising the radiometric level of environment. As a consequence, it has exposured workers and public individuals to the ionizing radiation. There are protective mechanisms of radiation exposure, personal protective equipments, and measurement planes established in standard measurement at certain points of the environment in order to identify any increase in radiometric levels and \ or contamination, but do not cover the entire space occupied by workers and patients. To accomplish with the individual dose limits established by the National Commission of Nuclear Energy, it is interesting if there is an individualized classification for each Nuclear Medicine service. This work aimed to promote an analysis of the radiometric level distribution across the extent of the Technical Nuclear Medicine Sector of Hospital of the Botucatu Medical School, and produce a spatial map to identify locations with higher exposure rate to the ionizing radiation, can be used as a risk map to assist the Occupationally Exposed Individuals (IOE). To perform the radiometric levels checking it was used a digital Geiger-Muller detector available in the sector, due to its practicality compared to other detectors. Measurements were carried out at four different times for all days of the week, at points strategically established to cover all the installation
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Esta proposta de pesquisa tem o objetivo de analisar o comportamento dos alunos do Programa de Pós-graduação em Ciência e Tecnologia das Radiações, Minerais e Materiais do Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) na busca de informação por meio do Portal de Periódicos da CAPES (PC) à luz do modelo de comportamento informacional de Ellis, Cox e Hall. São três seus objetivos específicos: a) identificar e caracterizar o perfil dos usuários discentes do Programa de Pós-graduação da área de Energia Nuclear quanto à busca e uso de informações; b) identificar fatores positivos e negativos quanto ao uso do Portal de Periódicos da CAPES; c) verificar a validade do modelo de comportamento de busca da informação e seus contributos para a situação em estudo. Trata-se de pesquisa descritiva com abordagem qualitativa, tendo como método o estudo de caso. A coleta de dados será realizada através de entrevista semiestruturada a ser aplicada a uma amostra intencional da população de alunos de mestrado do Programa de Pós-graduação em Ciência e Tecnologia das Radiações, Minerais e Materiais. Ao final da pesquisa, espera-se como produto técnico uma proposta de criação de um curso de treinamento de usuários para capacitá-los no uso de recursos informacionais disponíveis no Portal de Periódicos da Capes além de outros recursos informacionais disponíveis na biblioteca do CDTN a ser protocolado para o coordenador geral do PPG do CDTN, uma das Unidades de Pesquisa da Comissão Nacional de Energia Nuclear (CNEN), autarquia vinculada ao Ministério da Ciência, Tecnologia e Inovação (MCTI), localizado no campus universitário da Universidade Federal de Minas Gerais – UFMG.
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An experiment was conducted to observe triple- and quadruple-escape peaks, at a photon energy equal to 6.128 MeV, in the spectra recorded with a high-purity Ge detector working in coincidence with six bismuth germanate detectors. The peak intensities may be explained having recourse to only the bremsstrahlung cascade process of consecutive electron-positron pair creation; i.e., the contribution of simultaneous double pair formation (and other cascade effects) is much smaller. The experimental peak areas are in reasonably good agreement with those predicted by Monte Carlo simulations done with the general-purpose radiation-tran sport code PENELOPE.
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A procedure for simultaneous separation/preconcentration of copper. zinc, cadmium, and nickel in water samples, based on cloud point extraction (CPE) as a prior step to their determination by inductively coupled plasma optic emission spectrometry (ICP-OES), has been developed. The analytes reacted with 4-(2-pyridylazo)-resorcinol (PAR) at pH 5 to form hydrophobic chelates, which were separated and preconcentrated in a surfactant-rich phase of octylphenoxypolyethoxyethanol (Triton X-I 14). The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, buffer amount, surfactant concentration, temperature, kinetics of complexation reaction, and incubation time were optimized and their respective values were 5, 0.6 mmol L(-1). 0.3 mL, 0.15% (w/v), 50 degrees C, 40 min, and 10 min for 15 mL of preconcentrated solution. The method presented precision (R.S.D.) between 1.3% and 2.6% (n = 9). The concentration factors with and without dilution of the surfactant-rich phase for the analytes ranged from 9.4 to 10.1 and from 94.0 to 100.1, respectively. The limits of detection (L.O.D.) obtained for copper, zinc, cadmium, and nickel were 1.2, 1.1, 1.0. and 6.3 mu g L(-1), respectively. The accuracy of the procedure was evaluated through recovery experiments on aqueous samples. (C) 2009 Published by Elsevier B.V.
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A flow injection (FI) micelle-mediated separation/preconcentration procedure for the determination of lead and cadmium by flame atomic absorption spectrometry (FAAS) has been proposed. The analytes reacted with 1-(2-thiazolylazo)-2-naphthol (TAN) to form hydrophobic chelates, which were extracted into the micelles of 0.05% (w/v) Triton X-114 in a solution buffered at pH 8.4. In the preconcentration stage, the micellar solution was continuously injected into a flow system with four mini-columns packed with cotton, glass wool. or TNT compresses for phase separation. The analytes-containing micelles were eluted from the mini-columns by a stream of 3 mol L(-1) HCl solution and the analytes were determined by FAAS. Chemical and flow variables affecting the preconcentration of the analytes were studied. For 15 mL. of preconcentrated solution, the enhancement factors varied between 15.1 and 20.3, the limits of detection were approximately 4.5 and 0.75 mu g L(-1) for lead and cadmium, respectively. For a solution containing 100 and 10 mu g L(-1) of lead and cadmium, respectively, the R.S.D. values varied from 1.6 to 3.2% (n = 7). The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. The method was susceptible to matrix effects, but these interferences were minimized by adding barium ions as masking agent in the sample solutions, and recoveries from spiked sample varied in the range of 95.1-107.3%. (C) 2008 Elsevier B.V. All rights reserved.
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Este trabalho apresenta a experi??ncia do programa de mudan??as em busca da excel??ncia do Instituto de Engenharia Nuclear (IEN), unidade da Comiss??o Nacional de Energia Nuclear, implementado por meio de uma abordagem baseada na teoria dos sistemas complexos. Foi desenvolvido um sistema adaptativo de gest??o para organiza????es que lidam com tecnologia perigosa, como a nuclear, baseado no Modelo de Excel??ncia do Pr??mio Nacional da Qualidade e na cultura de seguran??a, sendo a seguran??a tratada como dimens??o estrat??gica para a excel??ncia. A implementa????o pr??tica do sistema foi conduzida por meio de uma interven????o do tipo mudan??a facilitada, que proporcionou certo grau de governan??a ao programa. Foi obtida uma evolu????o de 119% no n??vel de excel??ncia da gest??o do IEN no per??odo entre 2000 e 2003, assim como aprimoramentos na cultura de seguran??a do instituto