RESUMO
Neste trabalho, o dosímetro Fricke foi utilizado para verificação dos rendimentos de quatro qualidades de radiação produzidas por um aparelho de raios-X Pantak de 160 kV com potenciais entre 30 e 100 kV. Para tanto, foram utilizadas as qualidades de radiação recomendadas pela "Deutsh Internationale Normung" DIN 6809. As medidas foram realizadas em simuladores de plexiglas. Os resultados obtidos demonstraram que o dosímetro Fricke pode ser utilizado não apenas para a dosimetria desses equipamentos, mas também, para a manutenção do fator de calibração de sistemas de medidas para baixas energias.
RESUMO
The present work was carried out to assess the (210)Pb content in "black-powder" found in pigging operations on gas pipelines in Brazil, in particular, on the Campos Basin gas pipeline. Additionally, the chemical composition of such deposits was determined and an eventual correlation with (210)Pb concentration evaluated. Typical "black-powder" generated in the natural gas pipeline from Campos Basin oilfield contains mainly iron oxide ( approximately 81%) and residual organic matter ( approximately 9%). The (210)Pb content ranges from 4.9 to 0.04k Bqkg(-1) and seems to be inversely correlated with the distance to the platforms. On the other hand, (226)Ra concentration is higher on the pipeline branch between the platform and the onshore installations. (228)Ra was only observed in few samples, in particular, in the samples with the highest (226)Ra content.
