vii, 99 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / We investigate Cesàro summability of the Fourier orthogonal expansion of functions on B d × I m , where B d is the closed unit ball in [Special characters omitted] and I m is the m -fold Cartesian product of the interval [-1, 1], in terms of orthogonal polynomials with respect to the weight functions (1 - z ) α (1 + z ) β (1 - |x| 2 ) λ-1/2 , with z ∈ I m and x ∈ B d . In addition, we study a discretized Fourier orthogonal expansion on the cylinder B 2 × [-1, 1], which uses a finite number of Radon projections. The Lebesgue constant of this operator is obtained, and the proof utilizes generating functions for associated orthogonal series. / Committee in charge: Yuan Xu, Chairperson, Mathematics; Huaxin Lin, Member, Mathematics Jonathan Brundan, Member, Mathematics; Marcin Bownik, Member, Mathematics; Jun Li, Outside Member, Computer & Information Science

Made available in DSpace on 2014-06-11T19:26:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-12-13Bitstream added on 2014-06-13T18:54:11Z : No. of bitstreams: 1 000734203.pdf: 4108685 bytes, checksum: 907a22e00f6cd0dcfc4a21f9eaae98e6 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A avaliação de dose devido o gás torônio (220Rn), durante muito tempo, foi desprezada devido sua meia-vida curta, 55 segundos, e disponibilidade no ambiente. Estudos recentes mostram que, em certas regiões, a exposição ao gás torônio e sua progenia pode igualar ou até exceder a do gás radônio (222Rn), que é uma das mais importantes fontes de radiação ionizante de origem natural que as pessoas estão expostas, sendo considerado pela OMS (Organização Mundial da Saúde) como o segundo maior causador de câncer de pulmão, depois do cigarro. 220Rn e 222Rn são frequentemente encontrados em conjunto no ambiente. Para suas analises é necessário utilizar uma metodologia que os discrimine de forma individual. Este trabalho apresenta resultados de análises de águas subterrâneas, utilizadas para consumo público, de algumas estâncias hidrominerais tradicionais do sudeste brasileiro, situadas nas cidades de Poços de Caldas, Águas de Lindóia, Águas de São Pedro e Águas da Prata, visando desenvolver protocolos analíticos para a caracterização do220Rn em águas subterrâneas. Foram analisadas vinte e três fontes, nas quais foi determinado, além da concentração de atividade 220Rn, a concentração de 222Rn e valores de alguns parâmetros físicos, físico-químicos e químicos, utilizados para compreender o ambiente de circulação das águas subterrâneas e também para observar sua relação com o 220Rn. Para a determinação da concentração de 220Rn e 222Rn dissolvido nas amostras, foi utilizado a câmara de ionização RAD7 do fabricante Durridge, que é um monitor menos suscetível a interferências torônio/radônio devido sua capacidade de distinguir cada gás, pela análise espectrométrica da energia de suas partículas alfa. A concentração de 220Rn e 222Rn variou de 0,01 a 0,93 Bq/L e 0,06 a 104 Bq / L, respectivamente. As maiores concentrações foram obtidas nas cidades de Poços de Caldas e Águas da Prata,... / The dose evaluation due to thoron gas (220Rn) has not been considered for a long time due to its short half life, 55 seconds, and availability in environment. Recent studies have shown that, in certain regions, the exposure to thoron gas and progeny can be the same or exceed that of the radon gas (222Rn), which is one of the most important sources of ionizing radiation of natural origin which people are exposed, and considered by WHO (World Health Organization) as the second major cause of lung cancer after cigarette. 220Rn and 222Rn are often found together in the environment. For their analysis is necessary to use a methodology that discriminates individually. This work presents results of analysis of groundwater used for public consumption, of some traditional spas in southeastern Brazil, located in the cities of Poços de Caldas, Águas de Lindóia, Águas de São Pedro and Águas da Prata, aiming to develop analytical protocols for characterization of 220Rn in groundwater. Twenty-three sources were analyzed, in which were determined, the activity concentration of 220Rn, the concentration of 222Rn and values for some physical, physicochemical and chemical parameters used to understand the environment movement of groundwater and also to observe its relationship with 220Rn. To determine the concentration of 220Rn and 222Rn dissolved in the samples, was used the ionization chamber RAD7 of the Durridge manufacturer , which is a monitor less susceptible to interference thoron / radon due to their ability to distinguish each gas, by spectrometric analysis the energy of their alpha particles. The thoron and radon activity concentrations varied from 0,01 to 0,93 Bq/L and from 0,06 to 104 Bq/L, respectively. The highest concentrations were obtained in the cities of Pocos de Caldas and Águas da Prata, located in Pocos de Caldas plateau, a region characterized by high natural radioactivity. According to the Brazilian Code for Mineral Waters,...

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Diversos métodos geofísicos têm sido empregados para a identificação de zonas fraturadas em rochas cristalinas a fim de locar pontos de perfuração de poços tubulares. Os métodos geoelétricos têm tido um papel importante na identificação destas zonas fraturadas, no entanto, em áreas urbanas sofrem com a falta de espaço e interferências diversas, o que limita suas aplicações. O presente trabalho visou correlacionar as anomalias geoelétricas típicas de zonas fraturadas em rochas cristalinas, com medidas de emanação natural de radônio a fim de estabelecer parâmetros que possam ser aplicados em áreas onde os fatores externos impeçam a execução dos métodos geoelétricos, uma vez que os fatores que interferem na aplicação desses métodos não interferem na emanação do radônio. Os resultados encontrados nas áreas investigadas mostraram uma boa correlação entre as anomalias geoelétricas e as anomalias de emanação de radônio, bem como foram boas as correlações com os resultados de vazão dos poços existentes nas áreas investigadas. A metodologia aqui proposta alcançou os objetivos podendo ser uma excelente ferramenta para prospecção de água subterrânea, tanto como método auxiliar, quanto como ferramenta principal de prospecção de aqüíferos em áreas onde outros métodos não possam ser aplicados devido a interferências diversas tais como: tubulações metálicas, fiações elétricas, entre outras. Estes tipos de interferências são bastante comuns em áreas urbanas, justamente onde a perfuração de poços é mais requerida. / A several geophysical methods have been used for the identification of shear zones in crystalline rocks in order to mark points to water well drilling. The geoelectrical methods have had an important role on the identification of these shear zones. However, in urban areas they suffer with the lack from space and diverse interferences, what it limits the application of these ones. The present research aimed to correlate the typical electrical anomalies of shear zones in crystalline rocks, with measures of natural emanation of radon, in order to establish parameters that can be applied in areas where the external factors hinder the execution of the geoelectrical methods, because the factors that intervene with the application of these methods do not intervene with the emanation of the radon. The results found in the investigated areas had shown a good correlation with the electrical anomalies and the radon emanation anomalies, as well as had been good the correlations with the results of yield of water wells on the investigated areas. The methodology proposal reached the objectives being able to be an excellent tool for groundwater prospection, as a auxiliary method auxiliary, as a main tool of prospection of fractured aquifers in areas where other methods cannot be applied due several interferences, as metallic pipes, electric wirings, and others. These types of interferences are sufficiently common in urban areas, exactly where the water well drilling its more necessary.

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Orientador: Julio Cesar Hadler Neto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-03T13:45:16Z (GMT). No. of bitstreams: 1 Santos_NarcisoFerreira_D.pdf: 3163623 bytes, checksum: b1421a9ac7f2e1a74969770dd60e8db1 (MD5) Previous issue date: 2003 / Resumo: O objetivo desse trabalho foi o de caracterizar o detector de traços nucleares de estado sólido CR-39 para uma espectroscopia alfa adequada à medição das atividades do radônio e filhos, separando-se a atividade de 222Rn e filhos da atividade de 220Rn e filhos. Foi obtida a atividade do 222Rn separada da atividade do 220Rn mediante a exposição do CR-39 em uma seqüência regularmente espaçada de filmes finos de ar. Obtivemos um diagrama de tamanhos de traços e densidade óptica que distingue de forma inequívoca os traços produzidos por filhos de cada uma das cadeias. Obtivemos ainda uma medida da atividade dos filhos do 220Rn referidas à atividade do 222Rn em um ambiente sem ventilação. Para obter estes resultados produzimos uma fonte de chumbo 212 e construímos um dispositivo adequado à calibração do CR-39, para espectroscopia alfa. Indicamos um caminho para estender o método também a ambientes ventilados / Abstract: The aim of this work was to characterize the solid state nuclear track detector CR-39 to do an alpha spectroscopy suitable for measuring radon and radon daughter activities, distinguishing between 222Rn and daughters and 220Rn and daughters. The 222Rn and 220Rn activities were obtained separately through a regular sequence of thin films of air. We obtained diagrams of track size and optical density, which unequivocally distinguish the tracks yielded by daughters of each decay chain. We obtained a measurement of the 220Rn daughters¿ activity relative to the 222Rn activity in an environment without ventilation. In order to obtain these results we manufactured a lead-212 source and a device suitable for the calibration of the CR-39 for alpha spectroscopy. Finally, we give directions for applying the method also in ventilated environments / Doutorado / Física / Doutor em Ciências

We present a new theoretical model and reconstruction results for a new class of fast x-ray CT machine -- the Real Time Tomography (RTT) system, which uses switched sources and an offset detector array. We begin by reviewing elementary properties of the Radon and X-ray transforms, and limited angle tomography. Through the introduction of a new continuum model, that of sources covering the surface of a cylinder in R³, we show that the problem of three-dimensional reconstruction from RTT data reduces to inversion of the three-dimensional Radon transform with limited angle data. Using the Paley-Wiener theorem, we then prove the existence of a unique solution and give comments on stability and singularity detection. We show, first in the two-dimensional case, that the conjugate gradient least squares algorithm is suitable for CT reconstruction. By exploiting symmetries in the system, we then derive a method of applying CGLS to the three-dimensional inversion problem using stored matrix coefficients. The new concept of source firing order is introduced and formalised, and some novel visualisations are used to show how this affects aspects of the geometry of the system. We then perform a detailed numerical analysis using the condition number and SVD of the forward projection matrix $A$, to show that the choice of firing order affects the conditioning of the problem. Finally, we give reconstruction results from both simulated phantoms and real experimental data that support the numerical analysis.

The theoretical part of the thesis is divided into four chapters dealing with the problems of radon and its influence on the human organism. The first chapter summarizes the basic issues of human environment, interaction and division of the environment based on its function (use for life). The second chapter focuses on the radioactivity of environment, specifically on ionizing radiation, its formation and division, as well as its effect on human health. The next chapter is about radon, its formation, sources of radon, its distribution in the environment, measurements, protection against radon, the history of problems with radon and the Radon Programme of the Czech Republic. The last chapter of the theoretical part is dedicated to lung carcinoma, its origin, distribution, diagnosis, treatment and relationship with the incidence of radon based on surveys of selected epidemiological studies. The practical part of the thesis includes description of source data and methodology of processing data sets of radon equilibrium equivalent concentration (EEC), number of deaths by causes and population status. Chapter of results includes map outputs of radon EEC, mortality rates of carcinoma lung for men, women, and both sexes. Other parts of the outputs are the results of the correlation analysis of the...