This is Part A. / <p> The equipment necessary to measure the loss in an optical fibre has been constructed. The details of the design and the results of testing the equipment are given. This equipment was designed to measure the loss induced in fibres by ionizing radiation, but can also be used to measure undamaged samples. A "dual-beam" system is used to increase the accuracy of the equipment.</p> <p> The equipment will measure the spectral attenuation of an optical fibre to an accuracy of ±1 dB/km between .9 and 1.65 μm if the fibre is at least 175m long and has an attenuation of less than 115 dB/km. Simple modifications to the equipment would reduce the sample length required for ±1 dB/km accuracy to 60 m.</p> <p> The minimum sample length is determined by the accuracy with which samples can be connected into the system. The maximum sample attenuation is determined by the signal to noise ratio. Methods of increasing the signal to noise ratio and the sample connection accuracy are discussed. Calculations based on the suggested improvements show that the sample length can be reduced to 45 m and the maximum attenuation increased to 750 dB/km for ±1 dB/km accuracy. The use of a testing method which does not require removal of the sample could give ±1 dB/km accuracy for 10 m samples.</p> <p> The operating and adjustment procedures for the equipment are given in the appendices to this report.</p> / Thesis / Master of Engineering (MEngr)

Micro-irradiation systems are used to analyse the effect of ionizing radiation at the cellular and tissue level, targeting individual cells within a population with a controlled low dose. Cell survival experiments using micro-irradiation systems are limited by factors including: 1) the radiation attenuation and optical properties of the chosen cell dish substrate, 2) the registration of the cell dish before and after irradiation or between multiple imaging modalities and 3) the analysis of the cell or colony growth after irradiation. In this thesis, a set of tools have been developed to improve micro-irradiation experiments and to increase the accuracy of information provided by the cell survival data. The first contribution, the substrate cell dish evaluation, provides a set of characteristics defining the substrates used for micro-irradiation experiments based on minimal energy loss and optical clarity using unstained cell imaging. The second contribution was the development of a novel and low cost fiducial marking device for micro-irradiation experiments using an 808 nm laser and providing marks suitable for imaging with multiple modalities. The minimum focused spot diameter was calculated as 22.9 urn and the device was used to create fiducial marks with diameters ranging from 20 urn to 130 urn. The third contribution, the development of a cell counting methodology for use with a lens-free imaging device, has been shown to accurately count thousands of cells suitable for immediate analysis. Approximately 1000 cell colonies, containing 17 729 cells on 11 cell dishes were used for testing and training for automatic cell counting. Validation of the cell counting method showed that 76% and 89% of the cell colonies were counted within a ± 20% and ± 30% error of the ground truth, respectively. Further development of the fiducial marking device, by modifying the choice of laser and making it suitable for multiple types of cell dish substrates, would increase the applications of the device. Development of the cell counting methodology for different cells line, and for cells grown on multiple types of substrates, would make the system suitable for analysis of a wide variety of cell survival studies. The cell counting methodology, applied to the CyMap lens-free imaging device, has the potential to be an extremely useful and cost effective tool for cell survival studies.

This dissertation is divided in two parts: a theoretical, and a practical one. The purpose of the theoretical part is to introduce the reader to the elementary terms of ionizing and non-ionizing radiation, their types, sources, influence on humans, as well as possible manners of their use and abuse. The goal of the thesis is to evaluate possible use and abuse of ionizing and non-ionizing radiation. In the interest of clarity, the gathered information was included in the results chapter as a chart. The practical part deals primarily with the first research question whose aim was to establish the level of public awareness about ionizing and non-ionizing radiation. To get answers, the method of data collection by means of a questionnaire survey was employed. The questionnaire consisted of 19 questions in total. The first 3 questions split the respondents into categories based on their gender, age, and educational attainment. The main part of the questionnaire involved 12 closed-ended questions, evaluated by a test. The survey was concluded by 4 opened-ended questions. The questionnaire survey provided a multitude of findings, most importantly that the average public awareness of ionizing and non-ionizing radiation is 57.7%. Finally, the discussion part answers the second research question which sought to determine whether there's a greater danger of ionizing radiation sources being abused.

Thesis (DTech (Biomedical Technology))--Cape Technikon, 2001 / Ionising radiation has the ability to induce, inter alia, DNA damage and is well established as a causative agent of carcinogenesis and mutagenesis. The effects of high doses of short duration have been well documented, whereas the effects of continuous exposure to low doses of ionising radiation have not, nor are they as clearly understood and current risk estimates are largely extrapolated from high-dose data of atomic bomb survivors. This study evaluated the clastogenic effects of low dose ionising radiation on a population of bats (Chiroptera) residing in an abandoned monazite mine. Bats were sampled from two areas in the mine, with external radiation levels measuring around 20 µSv/h (low dose) and 100 µSv/h (high dose). A control group of bats was collected from a cave with no detectable radiation above normal background levels. The most frequently encountered genetic event in human malignancy is the alteration of the p53 gene. Mutant p53 proteins have a longer half-life than the wild-type variant and accumulate to high levels in the nucleus of tumour cells. The study showed that not only was there a significant increase in p53 positive cells of radiation exposed bats, but also in the degree of positivity, especially in the cells lining the bronchioles of the lungs. Although experimental studies have shown that exposure to radiation may lead to the onset of fibrosis and an inflammatory response in the lung and other tissues, the magnitude of the dose exposure was not comparable to this study and histological examination of bat lung and liver tissues showed no morphological changes in radiation exposed bats when compared to the control group. It has been documented that chronic radiation exposures may give rise to a number of specific haematological defects which are collectively termed "preleukemia" or myelodysplastic syndrome. Full blood counts on bat samples showed a significant decrease in the MCV indicating microcytic erythrocytes from the radiation exposed bats. Differential counts performed on the peripheral blood of the bats showed a marked neutropenia. Neutrophils also showed marked dysplasia including psuedo-Pelger Huet cells in radiation-exposed bats. Cytochemical analysis using DAB myeIoperoxidase showed that control bats had hypogranular neutrophils andradiation-exposedbats had largely '1granularneutrophils. Bonemarrow biopsies were taken from both control and radiation-exposed bats and evaluated for ceIlularity, granulocyte: lymphocyte: erythrocyte (GLE) ratio and megakaryocyte morphology. A hypocelIular bone marrow, a decreased granulocytic haematopoeisis and dysplastic megakaryocyte morphology were observed in radiation-exposed bats. Mineralisation of bone osteoid was determined using image analysis and showed a highly significant decrease in the bone matrix from radiation-exposed bats. All haematological features observed are congruent with current literature describing secondary (radiation-induced) myelodysplastic syndrome.

This thesis is focused on the legal protection of the environment and human health from the effects of selected physical factors, especially noise, vibration and ionizing and non- ionizing radiation. In the introduction the thesis defines the every singe physical factor, reminds their effects on the environment and the health and life of humans and especially suggests possible measures to eliminate the negative effects of these factors. The emphasis is placed on clarifying the consistency of these measures with the means of protection. Subsequently, the thesis includes separate chapters devoted to European, Czech and selected international legal instruments of protection from selected physical factors and their comparison. One of the key questions to be dealt in the thesis is the effort to clarify whether and how does the legislation in different countries exploit physical similarity between the studied factors. Another question to answer is to what extent is it (for the effective protection of the environment, life, health and other values) useful to accurately identify and name the sources of threat, and whether the case-focused legal protection, anchoring extensively detailed rules for each previously known source of threat, actually leads to more efficient protection against various sources of risk. It...

Foi pesquisado a termoluminescência (TL) do LiF dopado com diversas concentrações de Mg e/ou Cu. O efeito do tratamento técnico em cada ciclo (recozimento, irradiação com raios gama e leitura) foi estudado para cinco ciclos sucessivos. Três diferentes tratamentos técnicos foram pesquisados: 230°C- 10 min, 400°C -1h e 400°C-1h + 100°C-2h. Este último foi o tratamento utilizado em todas as amostras para o resto do trabalho, pois provocou o aparecimento de um único pico (IVG) na curva de emissão na temperatura de (242±4)°C, com sensibilidade razoável, para amostras dopadas com Mg ou Mg + Cu, expostas aos raios gama. As curvas de emissão de todas as amostras foram analisadas quanto à sensibilidade TL e temperatura de máximo dos picos, após uma exposição com 0,26 mC/kg de raios gama ou com 0,4 J/cm² de radiação ultravioleta ou ainda após as duas exposições anteriores consecutivamente. Para as exposições citadas, de um modo geral, o pico a (242±4°)C devido aos raios gama é bem mais alto que os picos a (102±3)°C e (168±4)°C resultantes da iluminação com os raios ultravioleta. Foi constatado que nessas amostras a radiação ultravioleta preenche as armadilhas diretamente, sem promover a fototransferência de portadores de carga de armadilhas profundas, preenchidas após exposição à radiação ionizante, para as mais rasas. Além disso os dois tipos de radiação preenchem preferencialmente armadilhas com profundidades diferentes. Esses fatos nos permitem propor o uso do LiF dopado com 0,1 ou 0,2 mol% de Mg com 0,03 mo/% de Cu entre as amostras estudadas para fins de dosimetria da radiação gama e ultravioleta simultaneamente. O efeito das impurezas de Mg e Cu na sensibilidade do LiF à radiação gama foi estudado, através de uma análise empírica, ajustando uma curva às alturas do pico IVG de todas as amostras. Dessa análise é possível concluir que se o LiF for dopado somente com Mg ele pode atingir uma grande sensibilidade à radiação ionizante sendo, porém, muito critica a concentração de Mg para a obtenção da sensibilidade máxima. Essa situação critica pode ser contornada com a adição de Cu que desempenha, de uma certa forma, o papel de desativador diminuindo a proporção dos Mg responsáveis pela TL. / Thermoluminescence (TL) of LiF doped with different concentrations of Mg and/or Cu has been investigated. The effect of the thermal treatment on the crystals in each cycle (annealing, gamma ray exposure and readout) was studied for five successive cycles. Tree different thermal treatments were examined: 230°C for 10 min, 400°C for 1h and 400°C for 1h followed by 100°C for 2h. LiF doped with Mg or Mg + Cu submitted to the last quoted thermal treatment and radiated with 137 Cs gamma rays showed a reasonable sensitivity and glow curve with only one peak (IVG) at (242±4)°C. From these data, this annealing was adopted for all samples. TL sensitivity and glow peak temperatures for all available samples exposed to 0,26mC/kg of gamma rays or 0,4 J/cm² of UV or to both radiations consecutively were also analysed. The glow peak due to gamma rays appears at (242±4)°C and is higher than the peaks at (I02±3)°C and (I68±4)°C due to UV light. It has been shown experimentally that UV radiation fills directly the traps, producing no phototransference of charge carriers from deep traps, filled by ionizing radiation, to the shallow ones. Furthemore, each radiation, gamma or UV, fills different depth traps preferentially. These characteristics show the potential usefulness of LiF:Mg,Cu in gamma and UV radiation dosimetry simultaneously. The best choise amongst all the analysed samples is LiF doped with 0,1 or 0,2 mol% of Mg and 0,03 mol% of Cu. Also the influence of dopants (Mg and Cu) on the TL sensitivity of LiF to gamma rays was investigated performing an empirical analysis. An excellent fit between the experimental data and a mathematical relation was obtained. From this study it was possible to conclude that if LiF has only Mg as impurity, its glow curve can exhibit a high sensitivity to ionizing radiation, being however the maximum sensitivity extremely dependent on the Mg concentration. This fact can be avoided adding small quantity of Cu, which behaves as a poisoner, decreasing the quantity of Mg responsible for TL signal.

O propósito deste estudo foi investigar o conhecimento de segmentos da população (constituídos por leigos, por estudantes e profissionais de áreas com possíveis aplicações da radioatividade) em relação aos benefícios da radiação ionizante sobre polímeros de embalagens para alimentos. As questões básicas aqui levantadas foram idealizadas para que suas respostas fornecessem parâmetros de análise para se afirmar ou negar que a população, de um modo geral, desconhece radioatividade e sua aplicação no campo dos alimentos e não se mostra preparada para mudar seus paradigmas, arraigados por impressões que persistem fortes de acidentes nucleares noticiados principalmente em mídia televisiva. Este estudo qualitativo é fundamentado por Bachelard (1996), que avulta a necessidade de uma preparação muito bem estruturada quando se quer extrair as verdades de classes que insistem, por vergonha de seu não-saber, em falsear respostas que, se sinceras, poderiam indicar importantes caminhos a se seguir pelo campo educacional para que se mudassem as características tão conhecidas neste país de um conhecimento de senso comum que ficou pouco ou nada científico. Portanto, este trabalho está norteado por um veio acadêmico que mostra, em seus objetos de pesquisa, elementos (questionários e entrevistas) necessários para que se possa conhecer a verdadeira opinião das pessoas frente à radioatividade. Infelizmente, as repostas não são animadoras, mostrando que há um grande desconhecimento mesmo dos profissionais, sobre o tema. Finalmente, o objetivo maior deste trabalho de pesquisa não foi somente uma investigação, mas a elucidação da necessidade de serem iniciadas ações educacionais que mudem a realidade que hoje se desenha neste país e que, somente com essa mudança, poderá haver, satisfatoriamente, pelo apoio e aceitação social, avanços significativos na área de tecnologia nuclear. / The purpose of this study was to investigate the level of knowledge of parts the population (represented by layman and students, and professionals who work in areas with possible applications of radioactivity) related to the benefits of ionizing radiation on polymer packaging foodstuff. The basic questions raised here were intended to prompt answers that could supply parameters of analysis to confirm or to deny that the population in general ignore radioactivity and its applications in the field of foodstuff, besides not appear to be prepared to shift its paradigms, deep-rooted by impressions that remain strong, which are fed by occurrences of nuclear accidents broadcast mainly through the television media. This qualitative study is grounded by Bachelard (1996), who emphasize the need of a well structured preparation when the aim is to extract the truths from classes that insist, for being shame of not knowing, in misrepresent answers, which otherwise sincere, could point important ways to be followed along by the education field to change well-known characteristics in this field of a knowledge, based on a common sense that became slightly or no scientific at all. Therefore, this work is guided by an academic bias that shows, in its objects of research, elements (questionnaire and interviews) necessary to find out the true beliefs of people on the radioactivity. Unfortunately the answers are not encouraging, showing that there is a huge unknowing, even from professionals, about the theme. Finally the major goal of this research has not been only an investigation, but the elucidation of the need to give start to educational actions that could change the reality that is drawn in this country today and, only through this change, it is possible to reach in a satisfactory level a breakthrough in the nuclear technology field though social support and acceptation.

O principal problema relativo aos acidentes com vazamentos de óleos combustíveis nos ambientes marinhos e costeiros é a contaminação pelos compostos benzeno, tolueno e xileno, (BTX), que possuem toxicidade elevada. O objetivo deste trabalho foi avaliar a contaminação da água do mar por BTX na região de Ubatuba, SP, entre 23º26’S e 23º46’S de latitude e 45º02’W e 45º11’W de longitude, que é uma área de transporte e produção de petróleo e estudar a eficiência da remoção destes compostos pela exposição à radiação ionizante proveniente de uma fonte de 60Co. A metodologia analítica utilizando o sistema de concentração “Purge and Trap" e o cromatógrafo CG-DIC, apresentou maior sensibilidade em água do mar do que o sistema de concentração “headspace" associado ao cromatógrafo CG-EM, com limite mínimo de detecção, LMD, de 0,50 &#956;g/L de benzeno, 0,70 &#956;g/L de tolueno e 1,54 &#956;g/L de xileno com uma variabilidade experimental (N=10) de cerca de 15%. Enquanto que o sistema CG-EM apresentou um LMD de BTX em água do mar de 9,30 mg/L para o benzeno, 8,50 mg/L para o tolueno e 9,80 mg/L para o xileno, com uma variabilidade experimental calculada nas mesmas condições de cerca de 10%. Foram realizadas quatro coletas de novembro de 2003 a julho de 2005 e a concentração de benzeno na água do mar variou de 1,0 &#956;g/L a 2,0 &#956;g/L, a de tolueno variou de <0,70 &#956;g/L a 3,24 &#956;g/L e para o xileno o valor máximo detectado foi de 2,92 &#956;g/L. No caso das amostras de água do mar contaminadas com padrões de BTX e expostas à radiação ionizante, a eficiência de remoção para o benzeno foi menor do que para os outros compostos considerando-se as mesmas concentrações, a taxa de remoção variou de 10% a 40% para dose absorvida de 20kGy e concentrações de 35,1 mg/L a 70,2 mg/L, respectivamente. O tolueno apresentou 20% a 60% de remoção para concentrações similares, mas com 15kGy de dose absorvida. Finalmente, o xileno foi removido com eficiência de 20% a 80% e 15 kGy de dose absorvida. / A major concern with leaking petroleum is the environmental contamination by the toxic and low water-soluble components such as benzene, toluene, and xylenes (BTX). These hydrocarbons have relatively high pollution potential because of their significant toxicity. The objective of this study was to evaluate the contamination of seawater by the main pollutants of the output and transport of petroleum, such as benzene, toluene, and xylene, and their removal by the exposure to the ionizing radiation. The studied region was Ubatuba region, SP, between 23º26’S and 23º46’S of latitude and 45º02’W and 45º11’W of longitude, area of carry and output of petroleum, and samples were collected from November, 2003 to July, 2005. For BTX in seawater analysis, the Purge and Trap concentrator with FIDGC detector showed significantly higher sensibility than Head Space concentrator with MSGC detector. The minimal detected limits (MDL) obtained at FIDGC were of 0.50 &#956;g/L for benzene, 0.70 &#956;g/L for toluene, and 1.54 &#956;g/L for xylene, and the obtained experimental variability was 15%. While the concentrator type Headspace system with MS detector showed higher MLD, about of 9.30 mg/L for benzene, 8.50 mg/L for toluene, and 9.80 mg/L for xylene, and 10% of experimental variability. In the studied area the benzene concentration varied from 1.0 &#956;g/L to 2.0 &#956;g/L, the concentration of toluene varied from < 0.70 &#956;g/L to 3.24 &#956;g/L and the maximum value of xylene observed was of 2.92 &#956;g/L. The seawater samples contaminated with BTX standard and exposed to ionizing radiation using a source of 60Co, presented a removal from 10% to 40% of benzene at 20 kGy absorbed doses and concentration of 35.1 mg/L and 70.2 mg/L, respectively; from 20% to 60% of toluene removal with 15 kGy absorbed dose and from 20% to 80% of xylene with 15 kGy absorbed dose in similar concentrations.

O mecanismo de \"troca de fônon\" de Feshbach e Zabek é revisto e uma discussão detalhada é fornecida sobre o papel das leis de conservação e relação \"tipo fônon\" entre energia e momento transferidos. São investigados os efeitos de correlações de curto alcance na emissão de nucleons em colisões periféricas de íons pesados relativísticos. A seção de choque é calculada na aproximação de Born usando uma adaptação conveniente do modelo de Karol para o estado inicial e ondas planas, explicitamente ortogonalizadas ao estado inicial, para estados finais. Comparações com os resultados obtidos por Bertulani et al. usando ondas planas puras para o estado final mostram que a ortogonalização desempenha um papel relevante no valor obtido para a seção de choque. Discute-se também a sensibilidade do resultado aos parâmetros usados na discussão do estado inicial. / Abstract The \"phonon exchange\" mechanism of Feshbach and Zabek is reviewed and the role of the conservation laws and of the \"phonon-like\" relation between energy and transfered momentum is discussed. The effects of short range correlations for the emission of pair in peripheral relativistic heavy ions collisions are investigated. The cross section is calculated in Born approximation using a suitable modification of Karol\'s model for the initial state and plane waves, explicitly ortogonalized to the initial state, for the final states. Comparisons with the results obtained by Bertulani et al. using pure plane waves for the final state show that the ortogonalization has a non-negligibe effect on the magnitude of the resulting cross-sections. Sensitivity to the parameters involved in the description of the initial state is also discussed.

Asma é uma doença de elevada prevalência e morbidade, constituindo-se um importante problema de saúde pública em todo o mundo. Muitos diagnósticos médicos por imagem dependem da utilização de raio X; entretanto, no caso da asma, o diagnóstico é clínico, particularmente na criança. Os pacientes são frequentemente submetidos a procedimentos radiológicos, preferencialmente o raio X de tórax. A escassez de dados na literatura referentes aos riscos da exposição à radiação ionizante em pacientes com asma e os possíveis benefícios relacionados à oportunidade de coleta de informações justificaram a investigação no programa municipal infantil de controle da asma de Ipatinga, Minas Gerais (Programa Respirar). Foi realizado estudo retrospectivo referente ao ano de 2014, com caso controle, do qual participaram 363 pacientes do Programa Respirar e número semelhante de controle, sem diferença sociodemográfica significativa entre os grupos. Encontramos que uma criança do grupo respirar tem 1,59 vez mais chance de realizar um raio X, e para o raio X de tórax essa chance aumenta para 6,56 vezes. A maioria dos raios X de tórax foi solicitada nas visitas aos serviços de urgência, mas 90% dos raios X realizados e laudados no grupo respirar e 84,2% do grupo controle revelaram resultado normal ou com alterações típicas, possibilitando o questionamento a respeito da indicação do exame. / Asthma is a disease of high prevalence and morbidity, constituting an important public health problem throughout the world. Patients are often submitted to radiological procedures, preferably the chest X ray. Many medical imaging diagnoses depend on the use of X ray, however, in the case of asthma, the diagnosis is clinical, particularly in the child. The scarcity of data in the literature regarding the risks of exposure to ionizing radiation in patients with asthma and the possible benefits related to the opportunity to collect information justified the investigation in the municipal infant asthma control program in Ipatinga, Minas Gerais (Programa Respirar). A retrospective study was carried out for the year 2014, with a control case involving 363 patients from the Programa Respirar and a similar number of controls, with no significant sociodemographic difference between the groups. We found that a child in the group respirar is 1.59 time more likely to have an X ray and for the chest X ray this chance increases to 6.56 times. The majority of chest X rays were requested at emergency department visits, but 90% of the X rays performed and lauded in the Programa Respirar and 84.2% of the control group revealed normal results or with typical alterations, making it possible to question the indication of the examination.