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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Sistema de gestão integrado: melhores práticas para laboratórios radioecológicos / Integrated management system best practices in radioecological laboratories

Claudia Aparecida Zerbinatti de Carvalho 08 September 2010 (has links)
A pesquisa tem por objeto estudar as melhores práticas existentes para subsidiar uma proposta conceitual de SGI - Sistema de Gestão Integrado (qualidade, meio ambiente, segurança e saúde no trabalho) aplicável a Laboratórios Radioecológicos. O planejamento da pesquisa está organizado nas seguintes etapas: realizou-se, numa primeira etapa, a pesquisa bibliográfica e documental em SGI, levantamento e estudo das normas aplicáveis (SGQ NBR ISO 9000 (2005), NBR ISO 9001 (2008), NBR ISO 9004 (2000), SGA NBR ISO 14001 (2004) e SGSST OHSAS 18001 (2007) e OHSAS 18002 (2008)), identificação e caracterização de processos em Laboratórios Radioecológicos e estudo de metodologia de melhores práticas e benchmarking; na segunda etapa da pesquisa desenvolveu-se o estudo de caso (pesquisa qualitativa, com a aplicação de questionários via correio eletrônico e entrevistas presenciais, quando possível), precedido de um levantamento e seleção de Laboratórios Radioecológicos internacionais e nacionais estudados e, em seguida, esses laboratórios foram contatados e parte deles concordou em participar na pesquisa; na terceira etapa da pesquisa foi construída a matriz de melhores práticas que mostrou resultados que puderam subsidiar uma proposta conceitual de SGI para Laboratórios Radioecológicos; a quarta e última etapa da pesquisa consistiu na construção da referida proposta conceitual de estrutura de SGI para Laboratórios Radioecológicos, tendo sido, então alcançado objetivo inicial da pesquisa. / The research aims to study the best practices to support a conceptual proposal for IMS - Integrated Management System (quality, environment, safety and health) applicable to Radioecology laboratories. The research design is organized into the following steps: in a first step, it was developed the bibliographic and documentary research in IMS, survey and study of standards (QMS ISO 9000 (2005), ISO 9001 (2008), ISO 9004 (2000), EMS ISO 14001 (2004) and OHSMS OHSAS 18001 (2007) and OHSAS 18002 (2008)), identification and characterization of processes in Radioecology Laboratories and study of best practices methodology and benchmarking; in the second stage of the research it was developed a case study (qualitative research, with questionnaires via email and interviews, when possible), preceded by a survey and selection of international and national radioecology laboratories and then these laboratories were contacted and some of them agreed to participate in this research; in the third stage of the research it was built the framework of best practices that showed results that could support the conceptual proposal for the IMS Radioecology Laboratory; the fourth and final stage of research consisted in the construction of the proposed conceptual framework of SGI for Radioecology Laboratory, being then achieved the initial objective of the research.
12

Monitoração de trabalhadores expostos à radiação natural em minas no Seridó do nordeste brasileiro

SPACOV, Isabel Cristina Guerra 09 December 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-27T13:49:02Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) ISABEL CRISTINA GUERRA SPACOV -TESE DE DOUTORADO - PROTEN.pdf: 6093450 bytes, checksum: ace1719e245c067e138dff5b29870857 (MD5) / Made available in DSpace on 2017-04-27T13:49:02Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) ISABEL CRISTINA GUERRA SPACOV -TESE DE DOUTORADO - PROTEN.pdf: 6093450 bytes, checksum: ace1719e245c067e138dff5b29870857 (MD5) Previous issue date: 2016-09-09 / A Província Pegmatítica da Borborema no Nordeste é uma das mais importantes áreas geoeconômicas do Brasil. A atividade de mineração, entretanto, pode elevar a exposição de trabalhadores do setor, às radiações ionizantes. A exposição às radiações no setor mineral depende de uma série de fatores, incluindo o tipo de mina e geologia local, com elevadas concentrações de radionuclídeos que compoem as séries do 238U e do 232Th. Este trabalho teve como objetivo realizar a dosimetria radiométrica ambiental externa, estimando a taxa de dose efetiva em doze minas de extração de caulim, granito, feldspato e scheelita, localizadas nos municípios de Junco do Seridó-PB, Salgadinho-PB, Santa Luzia-PB, São José do Sabugi-PB, Equador-RN e Santana do Seridó-RN. O monitoramento foi executado utilizando um espectrômetro gama portátil NaI(Tl) e BGO, com medições realizadas no ar e os resultados obtidos foram comparados a dose efetiva média mundial da exposição à fontes naturais de radiação, de 2,40 mSv/a, baseada no relatório da UNSCEAR. O valor obtido da média aritmética das taxas de doses efetivas foi de 3,34 mSv/a e desvio padrão de 2,47 mSv/a para as minas em conjunto, estando acima do valor de referência mundial, bem como as taxas de doses efetivas das minas de granito (5,80 mSv/a), feldspato (3,28 mSv/a) e scheelita (2,80 mSv/a). Com base nesse estudo, foi evidenciada uma maior radioatividade ambiental na mina de granito (E), em Santa Luzia-PB (11,60 mSv/a), estando superior, cerca de cinco vezes, ao valor de referência mundial. É, portanto, considerada uma área de elevado backgound natural, com taxa de dose variando de 5 a 20 mSv/a, assim como a zona rural de São José de Espinharas-PB, onde se encontra a jazida de urânio com média de 10,83 mSv/a, ambos na região do Seridó. Por sua vez, apesar do valor médio da taxa de dose efetiva das minas de caulim (1,78 mSv/a) estarem abaixo do valor de referência mundial, a caracterização radiométrica da mina de caulim (D) em Salgadinho-PB, se faz necessária, tendo em vista o valor de 2,94 mSv/a. Desta forma, recomenda-se também, estudos epidemiológicos de casocontrole, coorte e correlação geográfica, que tratem de padrões, causas e quantificação dos valores obtidos na dosimetria ambiental deste estudo, bem como da relação da incidência e prevalência das doenças causadas pela exposição em áreas de elevado background natural. / The Pegmatitic Borborema Province located in the Northeast of Brazil, is one of the most important geo-economic areas in the country. The mining activity, however, can increase the exposure of workers to ionizing radiation. Exposure to radiation in the mineral industry depends on a number of factors, including the type of mine and local geology, with high concentrations of radionuclides which compose the series of 238U and 232Th. This study aimed to carry out the external environmental radiometric dosimetry, estimating the effective dose rate in twelve mines of kaolin, granite, feldspar and scheelite extraction, located in Junco do Seridó-PB, Salgadinho-PB, Santa Luzia-PB, São José do Sabugi-PB, Equador-RN and Santana do Seridó-RN. The monitoring was performed using a spectrometer portable gamma NaI(Tl) and BGO, with measurements in the air and the results were compared to the global average effective dose of exposure to natural sources of radiation of 2.40 mSv/y, based on the UNSCEAR report. The obtained value of the arithmetic mean of the effective dose rate was 3.34 mSv/y from the twelve mines, being above the global reference value, as well as the rates of effective doses of granite mine (5.80 mSv/y), feldspar (3.28 mSv/y) and scheelite (2.80 mSv/y). Based on this study, greater environmental radioactivity in granite mine (E) was observed in Santa Luzia-PB (11.60 mSv/y), being higher, about five times to the global reference value. It is therefore considered an area of high natural background with dose rate ranging from 5 to 20 mSv/y, as well as the São José de Espinharas-PB, where the uranium deposit is located, with an average of 10.83 mSv/y, both in the Seridó region. Meanwhile, although the average value of the effective dose rate of kaolin mine (1.78 mSv/y) is below the world reference value, the radiometric characteristics of the kaolin mine (D) Salgadinho-PB are necessary, in view of the value of 2.94 mSv/y. Thus, also recommended are studies, epidemiological case-control, cohort and geographical correlation, to address patterns, causes and quantization of values obtained in the environmental dosimetry of this study, as well as the relationship of the incidence and prevalence of diseases caused by exposure in areas of high natural background.
13

Analyse d'incertitude en situation accidentelle : transfert de radionucléides dans l'environnement et évaluation de l'exposition humaine par voie alimentaire / Uncertainty analysis in accidental situation : environmental transfer of radionuclides and assessment of the human food exposure pathway

Sy, Mouhamadou Moustapha 21 March 2016 (has links)
L’évaluation des risques, en situation d’urgence nucléaire, est entachée d’incertitudes sur le transfert de substances radioactives dans les écosystèmes terrestres et vers l’homme à travers la chaîne alimentaire pouvant altérer les décisions. L’ampleur des répercutions des accidents de Tchernobyl et de Fukushima a mis en évidence la difficulté de gérer les conséquences post-accidentelles de tels événements et d’appréhender les incertitudes dans les prises de décision. L’objectif de cette thèse est de développer une méthodologie pour la prise en compte des incertitudes dans les modèles d’évaluation de risque environnemental et alimentaire afin d’améliorer les outils d’aide à la décision en situation accidentelle. Différents modèles bayésiens hiérarchiques visant à saisir, dans un cadre unique de modélisation, l’incertitude et la variabilité sur des paramètres radioécologiques d’intérêt en situation post-accidentelle ont été développés. Les paramètres de ces modèles ont été estimés par inférence bayésienne sur des données collectées à partir d’une revue étendue de la littérature. L’influence sur les modèles d’évaluation de risque, des incertitudes autour de ces paramètres radioécologiques, a été évaluée par simulations probabilistes et analyses de sensibilité, appliquées à deux cas d’études : un accident hypothétique et l’accident de Fukushima. Les travaux réalisés dans cette thèse contribuent à améliorer la connaissance autour des processus clés de transfert de radionucléides dans l’environnement et la paramétrisation des modèles radioécologiques d’évaluation de risque en ligne avec les axes de recherche prioritaires définis par la communauté scientifique en radioécologie. / Risk assessment, in case of nuclear emergency, is confronted to uncertainties on the transfer of radioactive substances in terrestrial ecosystems and to human population through the food chain, which could affect the reliability of decisions. The extent of the repercussions of Chernobyl and Fukushima accidents highlighted the difficulty of managing the consequences of such disasters and specifically to accommodate the different sources of uncertainty within decision-making processes. The objective of this research is to develop a methodology to account for uncertainties within environmental and food risk assessment models to improve decision support tools used for accidental situations. Different hierarchical Bayesian models aiming at capturing, within a unique modelling framework, uncertainty and variability about radioecological parameters of great importance for accidental situation were developed. Models parameters were estimated by Bayesian inference applied on databases obtained by an extended literature review. The impact on the risk assessment models of uncertainties about these radioecological parameters was then assessed by stochastic simulations and sensitivity analyses applied on two case-studies: a hypothetical accident simulating a standardized deposition of radionuclides and the accident of Fukushima nuclear power plant. The works developed in this project contribute to enhance knowledge on key processes governing environmental transfer of radionuclides and to improve the parameterization of the radioecological risk assessment models with respect to the research lines outlined by the scientific community in radioecology.
14

Use of GIS software to map contaminant distributions and determine integrated dose for purposes of assessing impact to biota

Myers, Margaret C. 13 July 2012 (has links)
The objective of this research was to estimate the radiological impact on various non-human biotas by the Fukushima Daiichi Nuclear power plant radiation release resulting from Japan's tsunami in March 2011 consistent with the recent recommendations of the International Commission on Radiological Protection. Soil concentration data given by Japan's Ministry of Education, Culture, Sports, Science and Technology in Japan (MEXT) were used to approximate doses to various organisms. Cumulative doses and dose rates were plotted in ArcGIS 10, geographic information system (GIS) software, and Kriging interpolations were performed between the sampling points. The conclusion of this preliminary investigation that there appears to be the potential for adverse biological impacts of the studied biota; however, the magnitude of the impact will require further investigation. / Graduation date: 2013
15

Establishment of concentration ratios for riparian and shrub steppe areas of the eastern Washington Columbia basin

Napier, Jonathan Bamberger 12 September 2012 (has links)
Concentration ratios are used to determine the transfer of nuclides from soil to biota to fauna. Some nuclides have limited associated data though, this has not prevented predictions from being performed at sites without associated data. These ratios are site specific and are not fully applicable when applied to other locations. A recent literature review for a waste repository performance assessment determined that a significant portion of the environmental data was based on recursively published material. To address this deficiency neutron activation analysis (NAA) was used to determine concentration ratios of certain biota. Three sites, two riparian and one shrub steppe, were sampled in the eastern Washington Columbia basin, near the Hanford site. Two hundred and fifty eight samples of opportunity were collected. This included 15 soil samples, 10 water and sediment samples, 40 different species of biota, and 2 terrestrial animal species and 3 aquatic animal species. These samples were prepared for NAA by drying, weighing, and in certain cases ashing to improve detection efficiency. After activation, the samples were placed in a HPGe detector to perform spectral analysis. The concentration results of 26 elements of interest are presented, along with newly established concentration ratios for all of the species sampled. / Graduation date: 2013

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