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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.
191

Étude rétrospective sur l’efficacité du peroxyde d’hydrogène dans les pulpotomies de molaires primaires

Dumais Pelletier, Sarah-Eve 07 1900 (has links)
Objectif : L’objectif de cette étude rétrospective est d’évaluer l’efficacité clinique et radiologique du peroxyde d’hydrogène 3% dans les pulpotomies de molaires primaires et de les comparer aux pulpotomies faites avec une dilution 1:5 de la formule de formocrésol de Buckley. Méthode : Les données cliniques et radiologiques de 401 molaires primaires traitées par pulpotomies avec un suivi minimum de 24 mois, sauf en cas d’échec, ont été obtenues des dossiers de 216 enfants. Résultats : Aucune différence statistiquement significative n’a été observée entre les résultats des pulpotomies au formocrésol et au peroxyde d’hydrogène à l’analyse clinique (p=0,435) et radiologique (p=0,2447). La probabilité cumulative de survie clinique était supérieure ou égale à 98% pour les molaires traitées au formocrésol et 99% pour celles traitées au peroxyde d’hydrogène, à tous les temps de suivi, variant de 19 mois à 106 mois. Radiologiquement, la probabilité cumulative de survie au 24e mois était de 81% pour le formocrésol et de 91% pour le peroxyde d’hydrogène. Conclusions : Le peroxyde d’hydrogène a démontré des taux de succès clinique et radiologique comparables à ceux du formocrésol pour les pulpotomies de molaires primaires. / Purpose: The objective of this retrospective study was to evaluate the clinical and radiological success of 3% hydrogen peroxide in primary molar pulpotomies and compare them to pulpotomies made with a 1:5 dilution of Buckley’s formocresol formula. Methods: Clinical and radiographic data of 401 pulpotomized primary molars with a minimum follow-up of 24 months, except in cases of failure, were obtained from the records of 216 children. Results: No statistically significant difference was observed between the results of formocresol and hydrogen peroxide pulpotomies clinically (p = 0.435) and radiologically (p = 0.2447). The cumulative probability of clinical survival was greater than or equal to 98% for molars treated with formocresol and 99% for those treated with hydrogen peroxide at all follow-up periods, ranging from 19 to 106 months. Radiologically, the cumulative probability of survival at 24 months was 81% for formocresol and 91% hydrogen peroxide. Conclusion: Hydrogen peroxide has demonstrated clinical and radiological success rates comparable to those of formocresol in primary molar pulpotomies
192

Efeitos decorrentes do preparo para radioiodoterapia do câncer de tireoide no ritmo de filtração glomerular renal: estudo randomizado comparando suspensão hormonal tireoidiana  com o uso do hormônio estimulador da tireoide recombinante humano (TSHrh) / Effects due radioiodine therapy for thyroid cancer in renal glomerular filtration rate: randomized study comparing thyroid hormone withdrawal with the use of recombinant human thyroid stimulating hormone (rhTSH)

George Barberio Coura Filho 25 February 2016 (has links)
Foi estudado o ritmo de filtração glomerular (RFG) de pacientes com câncer bem diferenciado da tireoide submetidos à radioiodoterapia (RIT). O estudo avaliou o RFG durante estímulo do hormônio estimulador da tireoide (TSH) por suspensão da reposição hormonal tireoidiana (RHT) ou no uso do hormônio estimulador da tireoide recombinante humano (TSHrh), correlacionou o RFG com o perfil hormonal tireoidiano, avaliou o RFG durante e na semana após a RIT, avaliou o RFG e a dose efetiva de radiação para corpo inteiro e correlacionou métodos de estimativa de RFG. Vinte e oito pacientes incluídos em estudo clínico randomizado não cego foram divididos em dois grupos de 14 pacientes, sendo o grupo A (GA) submetido à suspensão da RHT e o grupo B (GB) ao uso do TSHrh. Os pacientes tiveram antes e após o estímulo do TSH a determinação do RFG por 51Cr-EDTA e coletas séricas do perfil hormonal tireoidiano e creatinina, albumina e ureia, e, após a RIT, colheram exames séricos de creatinina, albumina e ureia, e tiveram estimadas suas doses efetivas de corpo inteiro. Os exames de creatinina, albumina e ureia foram utilizados para estimar o RFG pelas equações de creatinina sérica, Modified Diet in Renal Disease (MDRD), e Cockcroft-Gault. O GA apresentou, pelo 51Cr-EDTA, variação de -18,5% do RFG de 94,4±18,6 mL/min antes da suspensão da RHT para 76,2±15,7 mL/min (p=0,0002) e o GB apresentou pelo 51Cr-EDTA variação de 4% do RFG de 90,8±18,4 mL/min antes do TSHrh para 92,6±15,2 mL/min (p=0,64). O RFG variou significativamente só no GA, sem apresentar proporcionalidade entre as variações do hormônio tireoidiano e do RFG. Não houve correlação do RFG com elevação do TSH. Por equações baseadas em creatinina, houve, no GA, queda do RFG durante toda a suspensão da RHT e estabilidade após o retorno da RHT, e, no GB, houve estabilidade do RFG durante todo o estudo. A dose efetiva de corpo inteiro não apresentou diferenças significativas entre os grupos (p=0,76). Na comparação entre o 51Cr-EDTA e as equações para estimativa de RFG, a correlação de Pearson foi de 0,78 para creatinina sérica, 0,79 para MDRD e 0,66 para CockcroftGault, e a comparação das variações do RFG observadas no GA entre o 51Cr-EDTA e a equação por creatinina sérica foram estatisticamente diferentes. Concluiu-se que o RFG apresenta redução na suspensão da RHT, relacionado ao hipotireoidismo e não à elevação de TSH, voltando a estabilizar após retorno da RHT, e que não varia no uso do TSHrh, que a dose efetiva de corpo inteiro não varia entre os grupos proporcionalmente ao RFG, e que a melhor correlação foi do 51Cr-EDTA com a equação MDRD / Glomerular filtration rate (GFR) was studied in well differentiated thyroid cancer patients referred for radioiodine therapy (RIT). The study evaluated GFR during thyroid stimulating hormone (TSH) stimulation after thyroid hormone withdrawal (THW) or after recombinant human thyroid stimulating hormone (rhTSH), correlated GFR with thyroid hormone profile, evaluated GFR during and in the week after RIT, evaluated GFR and whole body radiation effective dose, and correlated different methods for GFR determination. 28 patients were included in a non-blinded randomized clinical trial and divided in two groups of 14 patients, being group A (GA) stimulated by THW and group B (GB) stimulated by rhTSH. Patients had GFR determined by 51Cr-EDTA, as well as serum thyroid hormone profile, creatinine, albumin and urea before and after TSH stimulation, and after RIT had determined their serum creatinine, albumin and urea and whole body radiation effective dose. Creatinine, albumin and urea were used to estimate GFR by serum creatinine, Modified Diet in Renal Disease (MDRD), and Cockcroft-Gault equations. GA presented a -18,5% GFR variation by 51CrEDTA varying from 94,4 ± 18,6 mL/min before THW to 76,2±15,7 mL/min after THW (p=0,0002) while GB presented a 4% GFR variation by 51Cr-EDTA varying from 90,8 ± 18,4 mL/min before TSHrh to 92,6 ± 15,2 mL/min after rhTSH (p=0,64). GFR significantly varied only in GA without presenting proportionality with thyroid hormone variation. There was no correlation between rise in TSH levels and GFR. Creatinine equations demonstrated a sustained reduction in GFR during THW and GFR stability after thyroid hormone reposition, while GB presented stable GFR during the whole study. Whole body radiation effective dose didn\'t present significant differences between the two groups (p=0,76). Comparing 51Cr-EDTA and GFR estimative equations presented Pearson correlation score of 0,78 for serum creatinine, 0,79 for MDRD and 0,66 for Cockcroft-Gault, while comparison between variances in GA between 51Cr-EDTA e serum creatinine equation was significantly different. In conclusion GFR presents a reduction during THW related to hypothyroidism and not to TSH rise and stabilizing after thyroid hormone therapy, GFR does not vary during rhTSH, whole body radiation effective dose does not vary between the two groups proportionally to GFR, and that MDRD equation had the best correlation with 51Cr-EDTA
193

Efeitos decorrentes do preparo para radioiodoterapia do câncer de tireoide no ritmo de filtração glomerular renal: estudo randomizado comparando suspensão hormonal tireoidiana  com o uso do hormônio estimulador da tireoide recombinante humano (TSHrh) / Effects due radioiodine therapy for thyroid cancer in renal glomerular filtration rate: randomized study comparing thyroid hormone withdrawal with the use of recombinant human thyroid stimulating hormone (rhTSH)

Coura Filho, George Barberio 25 February 2016 (has links)
Foi estudado o ritmo de filtração glomerular (RFG) de pacientes com câncer bem diferenciado da tireoide submetidos à radioiodoterapia (RIT). O estudo avaliou o RFG durante estímulo do hormônio estimulador da tireoide (TSH) por suspensão da reposição hormonal tireoidiana (RHT) ou no uso do hormônio estimulador da tireoide recombinante humano (TSHrh), correlacionou o RFG com o perfil hormonal tireoidiano, avaliou o RFG durante e na semana após a RIT, avaliou o RFG e a dose efetiva de radiação para corpo inteiro e correlacionou métodos de estimativa de RFG. Vinte e oito pacientes incluídos em estudo clínico randomizado não cego foram divididos em dois grupos de 14 pacientes, sendo o grupo A (GA) submetido à suspensão da RHT e o grupo B (GB) ao uso do TSHrh. Os pacientes tiveram antes e após o estímulo do TSH a determinação do RFG por 51Cr-EDTA e coletas séricas do perfil hormonal tireoidiano e creatinina, albumina e ureia, e, após a RIT, colheram exames séricos de creatinina, albumina e ureia, e tiveram estimadas suas doses efetivas de corpo inteiro. Os exames de creatinina, albumina e ureia foram utilizados para estimar o RFG pelas equações de creatinina sérica, Modified Diet in Renal Disease (MDRD), e Cockcroft-Gault. O GA apresentou, pelo 51Cr-EDTA, variação de -18,5% do RFG de 94,4±18,6 mL/min antes da suspensão da RHT para 76,2±15,7 mL/min (p=0,0002) e o GB apresentou pelo 51Cr-EDTA variação de 4% do RFG de 90,8±18,4 mL/min antes do TSHrh para 92,6±15,2 mL/min (p=0,64). O RFG variou significativamente só no GA, sem apresentar proporcionalidade entre as variações do hormônio tireoidiano e do RFG. Não houve correlação do RFG com elevação do TSH. Por equações baseadas em creatinina, houve, no GA, queda do RFG durante toda a suspensão da RHT e estabilidade após o retorno da RHT, e, no GB, houve estabilidade do RFG durante todo o estudo. A dose efetiva de corpo inteiro não apresentou diferenças significativas entre os grupos (p=0,76). Na comparação entre o 51Cr-EDTA e as equações para estimativa de RFG, a correlação de Pearson foi de 0,78 para creatinina sérica, 0,79 para MDRD e 0,66 para CockcroftGault, e a comparação das variações do RFG observadas no GA entre o 51Cr-EDTA e a equação por creatinina sérica foram estatisticamente diferentes. Concluiu-se que o RFG apresenta redução na suspensão da RHT, relacionado ao hipotireoidismo e não à elevação de TSH, voltando a estabilizar após retorno da RHT, e que não varia no uso do TSHrh, que a dose efetiva de corpo inteiro não varia entre os grupos proporcionalmente ao RFG, e que a melhor correlação foi do 51Cr-EDTA com a equação MDRD / Glomerular filtration rate (GFR) was studied in well differentiated thyroid cancer patients referred for radioiodine therapy (RIT). The study evaluated GFR during thyroid stimulating hormone (TSH) stimulation after thyroid hormone withdrawal (THW) or after recombinant human thyroid stimulating hormone (rhTSH), correlated GFR with thyroid hormone profile, evaluated GFR during and in the week after RIT, evaluated GFR and whole body radiation effective dose, and correlated different methods for GFR determination. 28 patients were included in a non-blinded randomized clinical trial and divided in two groups of 14 patients, being group A (GA) stimulated by THW and group B (GB) stimulated by rhTSH. Patients had GFR determined by 51Cr-EDTA, as well as serum thyroid hormone profile, creatinine, albumin and urea before and after TSH stimulation, and after RIT had determined their serum creatinine, albumin and urea and whole body radiation effective dose. Creatinine, albumin and urea were used to estimate GFR by serum creatinine, Modified Diet in Renal Disease (MDRD), and Cockcroft-Gault equations. GA presented a -18,5% GFR variation by 51CrEDTA varying from 94,4 ± 18,6 mL/min before THW to 76,2±15,7 mL/min after THW (p=0,0002) while GB presented a 4% GFR variation by 51Cr-EDTA varying from 90,8 ± 18,4 mL/min before TSHrh to 92,6 ± 15,2 mL/min after rhTSH (p=0,64). GFR significantly varied only in GA without presenting proportionality with thyroid hormone variation. There was no correlation between rise in TSH levels and GFR. Creatinine equations demonstrated a sustained reduction in GFR during THW and GFR stability after thyroid hormone reposition, while GB presented stable GFR during the whole study. Whole body radiation effective dose didn\'t present significant differences between the two groups (p=0,76). Comparing 51Cr-EDTA and GFR estimative equations presented Pearson correlation score of 0,78 for serum creatinine, 0,79 for MDRD and 0,66 for Cockcroft-Gault, while comparison between variances in GA between 51Cr-EDTA e serum creatinine equation was significantly different. In conclusion GFR presents a reduction during THW related to hypothyroidism and not to TSH rise and stabilizing after thyroid hormone therapy, GFR does not vary during rhTSH, whole body radiation effective dose does not vary between the two groups proportionally to GFR, and that MDRD equation had the best correlation with 51Cr-EDTA
194

Faktorer som kan påverka röntgensjuksköterskans kommunikation med patienten. : En litteraturstudie / Factors that may impact radiographers’ communication with the patient. : A literature review

Allén Oltegen, Pia, Rosengren, Katarina January 2019 (has links)
Bakgrund: I Sverige har alla personer rätt till lika vård. För att kunna utföra sitt arbete krävs en god kommunikation mellan röntgensjuksköterskan och patienten. Kommunikation innefattar verbala- och icke verbala uttryck, som är ytterst essentiellt för arbete inom vården. Genom omdöme, kunskap och noggrannhet måste röntgensjuksköterskan kunna ge adekvat information som berör undersökningen eller behandlingen. Informationen bör anpassas utefter patientens förmåga och vitala tillstånd att tillgodose sig denna. Syfte: Syftet var att sammanfatta faktorer som kan påverka kommunikationen mellan röntgensjuksköterskan och patienten. Metod: Denna studie genomfördes som en allmän litteraturstudie där databaserna PubMed och Cinahl användes. Totalt inkluderades och analyserades 10 artiklar i studien.  Resultat: Studiens resultat sammanfattades i 7 olika faktorer; professionalism, språk, information, hög arbetsbelastning, tid, sjukdom och ångest/rädsla. Alla faktorer kunde förbättra kommunikationen, men också försvåra den. Slutsats: Mer kunskap och medvetande om kommunikation hos röntgensjuksköterskan behövs, samt ett samarbete med kollegor för uppmuntran till kommunikation som är individanpassad. Att sammanfatta dessa faktorer kan hjälpa röntgensjuksköterskan i dennes arbete med kommunikationen till patienten i olika situationer. / Background:In Sweden, all persons are entitled to equal health care. In order for the radiographer to carry out their work, good communication between the radiographer and the patient is required. Communication with both verbal expressions and also body language which is necessary when working in health care. Through judgment, knowledge and accuracy, the radiographer must be able to provide adequate information regarding the examination or treatment.The information should be adapted according to the patient's ability and vital condition to accommodate this. Purpose: The purpose of the thesis was to summarize factors that may affect communication between the radiographer and the patient.Method: In order to achieve this, it was decided to make a qualitative, general literature study using the PubMed and Cinahl databases. A total of 10 articles were selected for the thesis. Results: The results were summarized in 7 different factors; professionalism, language, information, high workload, time, illness and anxiety/fear. All factors could improve communication, but some parts could also make it difficult. Conclusion: More knowledge and awareness of communication skills is necessary for the radiographer, as well as collaboration with colleagues to encouraging individualized communication. Summarizing these factors can help us as radiographer in our work on communicating to the patient in different situations.
195

Ethical Aspects of Radiation Risk Management

Wikman-Svahn, Per January 2012 (has links)
This thesis is based on the assumption that the intersection of moral philosophy and practical risk management is a rewarding area to study. In particular, the thesis assumes that concepts, ideas, and methods that are used in moral philosophy can be of great benefit for risk analysis, but also that practices in risk regulation provide a useful testing ground for moral philosophical theories. The thesis consists of an introduction and five articles. Article I is a review article on social and ethical aspects of radiation protection related to nuclear power generation. The paper concludes that four areas of social and ethical issues stand out as central: The first is uncertainty and the influence of value judgments in scientific risk assessments. The second is the distributions of risks and benefits between different individuals, in both space and time. The third is the problem of setting limits when there is no known level of exposure associated with a zero risk. The fourth is related to stakeholder influence and risk communication. Article II discusses ethical issues related to the proposal that doses (or risks) below a certain level should be excluded from the system of radiation protection, without any regard for the number of people exposed. Different arguments for excluding small radiation doses from regulation are examined and a possible solution to the problem of regulating small risks is proposed in the article: Any exclusion of small doses (or risks) from radiation protection ought to be based on a case-by-case basis, with the condition that the expected value of harm remains small. Article III examines what makes one distribution of individual doses better than another distribution. The article introduces a mathematical framework based on preference logic, in which such assessments can be made precisely in terms of comparisons between alternative distributions of individual doses. Principles of radiation protection and from parallel discussions in moral philosophy and welfare economics are defined using this framework and their formal properties analyzed. Article IV argues that the ethical theory of “responsibility-catering prioritarianism” is well positioned to deal with the reasonable requirements in an ethical theory of risk. The article shows how responsibility-catering prioritarianism can be operationalized using a prioritarian social welfare function based on hypothetical utilities. For this purpose, a hypothetical utility measure called ‘responsibility-adjusted utility’ is proposed, which is based on the utility that would normally be expected given circumstances outside of the control of the individual. Article V was written as a response to the Fukushima disaster. Several authors have called the Fukushima disaster a ‘black swan.’ However, the article argues that the hazards of large earthquakes and tsunamis were known before the accident, and introduces and defines the concept of a ‘black elephant,’ as (i) a high-impact event that (ii) lies beyond the realm of regular expectations, but (iii) is ignored despite existing evidence. / QC 20120816
196

Radiological aspects of petroleum exploration and production in the sultanate of Oman

Al-Farsi, Afkar Nadhim January 2008 (has links)
This thesis is a study of naturally occurring radioactive materials (NORM) activity concentration, gamma dose rate and radon (222Rn) exhalation from the waste streams of large-scale onshore petroleum operations. Types of activities covered included; sludge recovery from separation tanks, sludge farming, NORM storage, scaling in oil tubulars, scaling in gas production and sedimentation in produced water evaporation ponds. Field work was conducted in the arid desert terrain of an operational oil exploration and production region in the Sultanate of Oman. The main radionuclides found were 226Ra and 210Pb (238U - series), 228Ra and 228Th (232Th - series), and 227Ac (235U - series), along with 40K. All activity concentrations were higher than the ambient soil level and varied over several orders of magnitude. The range of gamma dose rates at a 1 m height above ground for the farm treated sludge had a range of 0.06 0.43 µSv h 1, and an average close to the ambient soil mean of 0.086 ± 0.014 µSv h 1, whereas the untreated sludge gamma dose rates had a range of 0.07 1.78 µSv h 1, and a mean of 0.456 ± 0.303 µSv h 1. The geometric mean of ambient soil 222Rn exhalation rate for area surrounding the sludge was mBq m 2 s 1. Radon exhalation rates reported in oil waste products were all higher than the ambient soil value and varied over three orders of magnitude. This study resulted in some unique findings including: (i) detection of radiotoxic 227Ac in the oil scales and sludge, (ii) need of a new empirical relation between petroleum sludge activity concentrations and gamma dose rates, and (iii) assessment of exhalation of 222Rn from oil sludge. Additionally the study investigated a method to determine oil scale and sludge age by the use of inherent behaviour of radionuclides as 228Ra:226Ra and 228Th:228Ra activity ratios.
197

Factors influencing patients' demand for x-ray examinations in rural Kwa-Zulu Natal

Mungomba, Bernard 02 1900 (has links)
The focus of this study was on the problem of unwarranted demand for radiological imaging by patients in rural KZN of South Africa. Literature in the context of this topic is scarce. Consequently the aim of this study was to describe sociodemographic factors that might influence patients demand for x-ray examinations. A quantitative in the form of a cross sectional survey was done. A convenient sample of 110 patients was surveyed using a structured questionnaire. Results of the study indicate that age, and educational level might influence patients’ demand for x-ray examinations. The study also revealed that very few respondents 10.9% (n=12) had knowledge about x-rays. The study further revealed that there might be other factors such as patients’ perceived benefits of x-rays, beliefs, lack of public health awareness as well as lack of effective communication between patients and health care providers. / Health Studies / M.A. (Public Health)
198

Avaliação do impacto radiológico atmosférico de uma unidade de mineração e beneficiamento de urânio / Assessment of atmospheric radiological impact of uranium mining and processing unit

Rodolfo de Oliveira Rosa 29 October 2014 (has links)
Este trabalho teve como objetivo avaliar o impacto radiológico atmosférico da Unidade de Concentrado de Urânio URA, Caetité, BA, através da modelagem da dispersão de radionuclídeos e a estimativa da dose efetiva anual (em mSv.ano-1). Para tal, utilizou-se o programa MILDOS-AREA que foi desenvolvido pelo Argonne National Laboratory (ANL) em conjunto com a U.S. Nuclear Regulatory Commission (USNRC), para avaliar impacto radiológico ambiental atmosférico nas instalações de mineração e beneficiamento de urânio. O incremento de dose efetiva anual para três grupos críticos hipotéticos e oito grupos populacionais reais foi estimado com base na medida de fluxos de radônio e na estimativa das concentrações de radionuclídeos em particulados no ar dos principais termos fontes da URA (cava da mina, depósito de estéril e britador). Paralelamente, as medidas de concentração de radônio e taxa de kerma no ar, reportadas nos relatórios dos programas de monitoração ambiental pré-operacional (PMAPO) e operacional (PMAO) da URA, foram avaliadas. Os valores de dose efetiva anual estimados para os grupos críticos hipotéticos variaram de 1,78E-02 a 2,10E-02 mSv.ano-1, enquanto que para os grupos populacionais, variaram de 7,49E-05 a 1,56E-02 mSv.ano-1. A maior contribuição para o incremento da dose foi devida a inalação do radônio, sendo responsável por quase a totalidade da dose efetiva anual estimada. A média da concentração de atividade de radônio no entorno da URA foi 137,21 Bq m-3 e não sendo observada diferenças significativas entre as concentrações de radônio reportadas nos programas de monitoramento ambiental pré-operacional (valores de background) e operacional. Os valores médios de taxa de kerma no ar no entorno da URA foram de 0,136 μGy h-1. No entanto, em todos os pontos de monitoramento, os valores reportados no programa operacional foram inferiores aos valores reportados no programa pré-operacional (background), o que sugere problemas de medidas ou de coleta de dados durante a realização deste programa. O operador da URA utilizou para avaliação de impacto radiológico atmosférico, resultados apresentados em seus relatórios finais de análise de segurança (RFAS), um modelo próprio de simulação de dispersão, denominado Impacto Ambiental Radiológico (IAR7). Uma comparação entre o MILDOS-AREA e o IAR7, utilizando os mesmos parâmetros de entrada reportados no RFAS sugere que o IAR7 subestimou as concentrações de radônio no ar para os grupos críticos hipotéticos. Os resultados de simulação com o MILDOS-AREA mostram que as doses efetivas estimadas para os grupos críticos hipotéticos são inferiores a 0,3 mSv.ano-1 que é a restrição de dose estabelecida pela Comissão Nacional de Energia Nuclear. Recomenda-se que o código MILDOS-AREA seja utilizado no Brasil, para fins de licenciamento e controle, tendo em vista que o mesmo é um código validado e já utilizado em outros países para avaliar impacto radiológico ambiental atmosférico em instalações de mineração e beneficiamento de urânio / This work aimed to evaluate the atmospheric radiological impact of the Uranium Concentration Unit - URA, Caetité, BA, by modeling the dispersion of radionuclides and estimating the annual effective dose (in mSv.year-1). For this purpose, we used the MILDOS-AREA program that was developed by Argonne National Laboratory (ANL) jointly with the US Nuclear Regulatory Commission (USNRC) specifically to evaluate the atmospheric radiological impact of uranium mining and processing facilities. Taking into account estimative of particulate radionuclide concentration and radon flux measurements performed in the main source-terms of URA (open pit, heap leaching and tailing deposit), we estimated the increase of annual effective dose for three hypothetical critical groups and eight population groups. In addition, we evaluated results of radon activity concentration and kerma rate concentration in air reported in the pre-operational environmental monitoring program (PMAPO) and in the operational environmental monitoring programs (PMAO) from URA. The estimated annual effective dose to the hypothetical critical groups ranged from 1,78E-02 a 2,10E-02 mSv.year-1. For real populations, effective doses ranged from 7,49E-05 to 1,56E-02 mSv.year-1. The largest contribution to the total dose was due to inhalation of radon, accounting for almost the entire estimated annual effective dose. The average radon activity concentration in the vicinity of the URA was 137.21 Bq m-3 and there was no apparent difference between the radon concentrations reported in the pre-operational environmental monitoring program (background values) and post-operational. The average values of kerma rate in air surrounding the URA were 0.136 μGy h-1. However, for all the monitoring points, the values reported in operational environmental monitoring program were lower than the values reported in pre-operational environmental monitoring program (background), suggesting measurements or data collection problems during the pre-operational program. The miner industry used in their final report of safety analysis (RFAS), a proper dispersion model simulation, called Environmental Impact Radiological (IAR7). A comparison between the MILDOS-AREA and the IAR7 using the same input parameters in IAR7 suggested that IAR7 underestimated the radon concentrations in the air to the hypothetical critical groups. In conclusion, MILDOS-AREA simulation showed that the estimated effective doses for the hypothetical critical groups are less than 0.3 mSv.year-1, which is the operational dose limit to the public established by the National Nuclear Energy Commission. It is recommended that the MILDOS-AREA code should be used in Brazil, considering that it is a validated code and already used in other countries to assess atmospheric radiological impact on mining and uranium processing facilities
199

Avaliação do impacto radiológico atmosférico de uma unidade de mineração e beneficiamento de urânio / Assessment of atmospheric radiological impact of uranium mining and processing unit

Rodolfo de Oliveira Rosa 29 October 2014 (has links)
Este trabalho teve como objetivo avaliar o impacto radiológico atmosférico da Unidade de Concentrado de Urânio URA, Caetité, BA, através da modelagem da dispersão de radionuclídeos e a estimativa da dose efetiva anual (em mSv.ano-1). Para tal, utilizou-se o programa MILDOS-AREA que foi desenvolvido pelo Argonne National Laboratory (ANL) em conjunto com a U.S. Nuclear Regulatory Commission (USNRC), para avaliar impacto radiológico ambiental atmosférico nas instalações de mineração e beneficiamento de urânio. O incremento de dose efetiva anual para três grupos críticos hipotéticos e oito grupos populacionais reais foi estimado com base na medida de fluxos de radônio e na estimativa das concentrações de radionuclídeos em particulados no ar dos principais termos fontes da URA (cava da mina, depósito de estéril e britador). Paralelamente, as medidas de concentração de radônio e taxa de kerma no ar, reportadas nos relatórios dos programas de monitoração ambiental pré-operacional (PMAPO) e operacional (PMAO) da URA, foram avaliadas. Os valores de dose efetiva anual estimados para os grupos críticos hipotéticos variaram de 1,78E-02 a 2,10E-02 mSv.ano-1, enquanto que para os grupos populacionais, variaram de 7,49E-05 a 1,56E-02 mSv.ano-1. A maior contribuição para o incremento da dose foi devida a inalação do radônio, sendo responsável por quase a totalidade da dose efetiva anual estimada. A média da concentração de atividade de radônio no entorno da URA foi 137,21 Bq m-3 e não sendo observada diferenças significativas entre as concentrações de radônio reportadas nos programas de monitoramento ambiental pré-operacional (valores de background) e operacional. Os valores médios de taxa de kerma no ar no entorno da URA foram de 0,136 μGy h-1. No entanto, em todos os pontos de monitoramento, os valores reportados no programa operacional foram inferiores aos valores reportados no programa pré-operacional (background), o que sugere problemas de medidas ou de coleta de dados durante a realização deste programa. O operador da URA utilizou para avaliação de impacto radiológico atmosférico, resultados apresentados em seus relatórios finais de análise de segurança (RFAS), um modelo próprio de simulação de dispersão, denominado Impacto Ambiental Radiológico (IAR7). Uma comparação entre o MILDOS-AREA e o IAR7, utilizando os mesmos parâmetros de entrada reportados no RFAS sugere que o IAR7 subestimou as concentrações de radônio no ar para os grupos críticos hipotéticos. Os resultados de simulação com o MILDOS-AREA mostram que as doses efetivas estimadas para os grupos críticos hipotéticos são inferiores a 0,3 mSv.ano-1 que é a restrição de dose estabelecida pela Comissão Nacional de Energia Nuclear. Recomenda-se que o código MILDOS-AREA seja utilizado no Brasil, para fins de licenciamento e controle, tendo em vista que o mesmo é um código validado e já utilizado em outros países para avaliar impacto radiológico ambiental atmosférico em instalações de mineração e beneficiamento de urânio / This work aimed to evaluate the atmospheric radiological impact of the Uranium Concentration Unit - URA, Caetité, BA, by modeling the dispersion of radionuclides and estimating the annual effective dose (in mSv.year-1). For this purpose, we used the MILDOS-AREA program that was developed by Argonne National Laboratory (ANL) jointly with the US Nuclear Regulatory Commission (USNRC) specifically to evaluate the atmospheric radiological impact of uranium mining and processing facilities. Taking into account estimative of particulate radionuclide concentration and radon flux measurements performed in the main source-terms of URA (open pit, heap leaching and tailing deposit), we estimated the increase of annual effective dose for three hypothetical critical groups and eight population groups. In addition, we evaluated results of radon activity concentration and kerma rate concentration in air reported in the pre-operational environmental monitoring program (PMAPO) and in the operational environmental monitoring programs (PMAO) from URA. The estimated annual effective dose to the hypothetical critical groups ranged from 1,78E-02 a 2,10E-02 mSv.year-1. For real populations, effective doses ranged from 7,49E-05 to 1,56E-02 mSv.year-1. The largest contribution to the total dose was due to inhalation of radon, accounting for almost the entire estimated annual effective dose. The average radon activity concentration in the vicinity of the URA was 137.21 Bq m-3 and there was no apparent difference between the radon concentrations reported in the pre-operational environmental monitoring program (background values) and post-operational. The average values of kerma rate in air surrounding the URA were 0.136 μGy h-1. However, for all the monitoring points, the values reported in operational environmental monitoring program were lower than the values reported in pre-operational environmental monitoring program (background), suggesting measurements or data collection problems during the pre-operational program. The miner industry used in their final report of safety analysis (RFAS), a proper dispersion model simulation, called Environmental Impact Radiological (IAR7). A comparison between the MILDOS-AREA and the IAR7 using the same input parameters in IAR7 suggested that IAR7 underestimated the radon concentrations in the air to the hypothetical critical groups. In conclusion, MILDOS-AREA simulation showed that the estimated effective doses for the hypothetical critical groups are less than 0.3 mSv.year-1, which is the operational dose limit to the public established by the National Nuclear Energy Commission. It is recommended that the MILDOS-AREA code should be used in Brazil, considering that it is a validated code and already used in other countries to assess atmospheric radiological impact on mining and uranium processing facilities
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Porovnání radiologických a chemických zbraní v rámci jejich použití při teroristických útocích proti civilnímu obyvatelstvu / Comparison of radiological and chemical weapons in the context of their use in terrorist attacks against civilians

GUBRICKÝ, Václav January 2010 (has links)
The thesis is focused on radiological and chemical weapons in the context of their use in terrorist attacks against the civilian population in relation to rescue and clean up operations of the Integrated Rescue System (IRS) of the Czech Republic. The objective of the thesis is to specify the terms of radiological and chemical weapons, to assess potential negative consequences of their use with the emphasis on the threat to life and health of the population, to evaluate the economic impact on society and to compare the IRS activities during the immediate intervention carried out after a terrorist attack. The topic is dealt with based on the research and the analysis of rules of law in force regulating activities of the IRS components in these major incidents and also of documents of the IAEA (International Atomic Energy Agency) and other works focused on the misuse of radioactive and chemical agents in terrorist attacks. Severity and complexity of the issue is illustrated by information given on the radiological accident in Goiana in Brazil, sarin attacks of the Japanese sect Óm šinrikjó and consequences of the model example of the use of radionuclide 137Cs. In the thesis the current methodology on which the IRS components operate in such emergencies is analyzed, and some aspects that are subject of the set of type activities, worked out by the Civil Emergency Planning Committee and DG Fire Rescue Service of the CR, which may become weak points during a real action of the IRS, are pointed out. One of major issues analyzed in this study is comparison of radiological and chemical attacks with the focus on the initial phase of the intervention of the IRS components. Presentation of differences in individual activities of the IRS components in such interventions can contribute significantly to understanding and subsequently managing the activities carried out by the IRS components in these major incidents.

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