Project report (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 116-123). Also available via the Internet.

Thesis (Ph.D.)--George Mason University, 2009. / Vita: p. 267. Thesis director: Douglas Mose. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Science and Public Policy. Title from PDF t.p. (viewed June 10, 2009). Includes bibliographical references (p. 259-266). Also issued in print.

Thesis (M. Phil.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 139-144).

Thesis (M. Sc.)--University of Hong Kong, 2002. / Includes bibliographical references.

Thesis (Ph. D.)--Princeton University, 1931.

Orientador: Julio Cesar Hadler Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-23T10:31:20Z (GMT). No. of bitstreams: 1 MestanzaMunoz_SegundoNilo_M.pdf: 2203053 bytes, checksum: a984b587348db17de90413f80488d787 (MD5) Previous issue date: 1996 / Resumo: Para determinar a influência da ventilação (fluxo direcionado de ar produzido por um ventilador) sobre a distribuição espacial do Rn-222 e seus produtos de decaimento (filhos) presentes em ambientes de convívio humano, obteve-se um conjunto de resultados experimentais, por meio da técnica de traços nucleares deixados por partículas alfa sobre detectores plásticos adequados (CR-39). A exposição destes detectores foi realizada num ambiente fechado, considerando a influência da ventilação para diferentes ângulos, velocidades e distâncias do ventilador. Nesta presente pesquisa, os resultados mostram que uma quantidade relativa de filhos do Rn-222 são retirados do ambiente pelos efeitos de ventilação e plateout. Apresentamos também estudos preliminares dos efeitos de borda nos detectores (CR-39), assim como a dependência da densidade dos traços como função da seção transversal do detector. Apresenta-se resultados de calibração do tempo de ataque químico em função do diâmetro dos traços. Fez-se também um modelo analítico que explica este fenômeno e que nos ajuda a compreender nossos resultados experimentais / Abstract: Not informed. / Mestrado / Física / Mestre em Física

No description available.

<p>Measurements of radon (&sup2 / &sup2 / &sup2 / Rn) concentration in soil gas are routinely used to locate geological fault zones. This study was undertaken to investigate the systematic effects that influence radon soil-gas measurements, in preparation for the first such fault zone measurements in South Africa.</p>

Radon has been identified as an important factor that could result in a health hazard by studies all around the world. The health risks can be minimised by preventive measures where radon is highly concentrated as in some mines and homes. Measuring and modelling the radon concentrations in the mine dump soil, can help to deduce the radon flux to identify the problem areas for rehabilitation especially in the cases of gold and uranium mine tailings. Rehabilitation in those cases usually consists of a multilayer cover of solids like crushed rock or clay. A passive method incorporating electret technology was used in this study to determine the radon emanation coefficient of the soil. This investigation also describes the modelling of a depth profile with respect to the radon activity concentration to understand from how deep radon might be migrating, as well as the effect of different diffusion lengths.

Radon has been identified as an important factor that could result in a health hazard by studies all around the world. The health risks can be minimised by preventive measures where radon is highly concentrated as in some mines and homes. Measuring and modelling the radon concentrations in the mine dump soil, can help to deduce the radon flux to identify the problem areas for rehabilitation especially in the cases of gold and uranium mine tailings. Rehabilitation in those cases usually consists of a multilayer cover of solids like crushed rock or clay. A passive method incorporating electret technology was used in this study to determine the radon emanation coefficient of the soil. This investigation also describes the modelling of a depth profile with respect to the radon activity concentration to understand from how deep radon might be migrating, as well as the effect of different diffusion lengths.