BRIGITTE ROXANA SOREANU PECEQUILO

Resumo

Bachelor in Physics, University of São Paulo (1967), Master in Nuclear Technology, University of São Paulo (1971) and PhD in Nuclear Technology, University of São Paulo (1977). Was researcher at the Institute of Energy and Nuclear Research (IPEN) from 1969 to 2014. Currently is a collaborator of IPEN with the project "Gamma Spectrometry and trace detectors as tools for evaluation of natural and artificial radioactivity in several samples" and superviser at the Graduate Program of IPEN. Has experience in nuclear engineering, with emphasis on Radioisotopes Applications, acting on the following topics: nuclear instrumentation, dose assessment, environmental monitoring, natural radioactivity, alpha and gamma spectrometry, gross alpha and beta radioactivity measurements and nuclear trace detectors . As IAEA expert in the determination of radioactivity concentrations with alpha and gross beta counting systems with low background proportional detector had been in Asuncion, Paraguay (2004) and in Cuenca, Ecuador (2007). Since 1978 is professor in charge of the graduate course of IPEN, Advanced Topics in Nuclear Measurements. (Text obtained from the Currículo Lattes on October 6th 2021)


Possui graduação em Bacharel Em Física pela Universidade de São Paulo (1967), mestrado em Tecnologia Nuclear pela Universidade de São Paulo (1971) e doutorado em Tecnologia Nuclear pela Universidade de São Paulo (1977). Foi pesquisadora do Instituto de Pesquisas Energéticas e Nucleares (IPEN) de 1969 a 2014. Atualmente é colaboradora do IPEN com o projeto "Espectrometria gama e detectores de traços como ferramentas para avaliação de radioatividade natural e artificial em amostras diversas" e orientadora no Programa de Pós-Graduação do IPEN. Tem experiência na área de Engenharia Nuclear, com ênfase em Aplicações de Radioisótopos, atuando principalmente nos seguintes temas: instrumentação nuclear, avaliação de dose, monitoracao ambiental, radioatividade natural, espectrometria alfa e gama, medidas de radioatividade alfa e beta total e detectores de traços. Como expert da AIEA na operacionalização de sistemas de contagem alfa e beta total com detector proporcional de baixa radiação de fundo para a determinação da concentração de radioatividade em água potável, esteve em Assunção, Paraguai (2004) e em Cuenca, Equador (2007). Desde 1978 é professora-responsável do curso de pós-graduação do IPEN, Tópicos Avançados de Medidas Nucleares. (Texto extraído do Currículo Lattes em 06 out. 2021)

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Agora exibindo 1 - 3 de 3
  • Resumo IPEN-doc 27040
    Activity concentrations of natural and artificial radionuclides in feline dry food
    2015 - CAVALCANTE, F.; PECEQUILO, B.R.S.; LEONARDO, L.
    Natural radiation exposure is an inherent condition to all living species, once radionuclides from the 238U and 232Th chain can nearly be found in all places. Information on radionuclides concentration and exposure levels, from natural and anthropogenic sources are absolutely necessary to investigate the possible effects that ionizing radiation can induce. These can be very different depending on the organism considered and the exposure pathway. In recent decades, the exposure of non-human species to ionizing radiation has been specially considered and investigated (ICRP, 2014) by a vast number of scientists and organizations, once they differ widely from the exposure of human beings. Brazil holds the second largest cat and dog population in the world, consuming over 2 million tons of feed every year. The country also stands out for its production of pet food that produced 2.4 million of tons of feed in 2014, representing the world’s second largest industry. A novel study regarding the radionuclide content in different dog and cat food is being developed since 2013 and preliminary results have been presented by Cavalcante, F. and Pecequilo (2014), for selected dry dog food. The present study presents an evaluation of the radionuclide and radioactivity content of different brands of dry cat food, commonly found in local markets in the city of Sao Paulo, Brazil. Thirteen different samples were crushed into powder and kiln dried before tightly sealed in 100 mL HDPE flasks, with a plan screw cap and bubble spigot. These samples, after resting for 30 days to ensure secular equilibrium, were placed in an extended range coaxial germanium detector (Canberra XtRa GX4020 detector) for 150 ks and the acquired spectra were analyzed with the InterWinner 6.0 software (InterWinner, 2004). The natural radionuclides considered were 238U, 232Th and 40K, the anthropogenic radionuclides investigated were 60Co, 131I, 137Cs and 134Cs. The results for the considered artificial radionuclides have shown activity concentration values below the detector’s MDA (Minimum Detectable Activity), as in Table 1. The concentrations of natural radionuclides ranged from 1.12 ± 0.29 Bq/kg to 3.77 ± 0.36 Bq/kg for 226Ra; from 1.48 ± 0.40 Bq/kg to 6.27 ± 0.78 Bq/kg for 232Th and from 216.8 ± 11.2 Bq/kg to 361.7 ± 16.8 Bq/kg for 40K, as shown in Figure 1. The results suggest that the samples evaluated have no contamination of artificial radionuclides and the natural radionuclides concentration will not contribute to significant absorbed dose by their ingestion. Therefore, the authors conclude that these studied brands carry no radiological risk for the animals ingesting them.
  • Resumo IPEN-doc 25938
    Self-attenuation factors in gamma-ray spectrometry of samples containing radionuclides of natural origin
    2018 - PECEQUILO, B.R.S.; CAVALCANTE, F.; BARROS, L.F.; FERREIRA, A.O.; FONSECA, L.M.; MATEUS, C.
    High resolution gamma-ray spectrometry is currently the most widely used analytical technique for qualitative and quantitative determination of radionuclides. Quantification of elements relies on the correct analysis of the spectra, depending strongly on the efficiency calibration of the measurement apparatus, most often performed with aqueous standard multi-radionuclide solutions. For efficiency calibration curves obtained by this method and for samples containing radionuclides of natural origin such as sand, soil, rocks and wall paint with apparent typical densities higher than that of water, self-attenuation correction factors were experimentally determined for hundreds of different samples using the Cutshall transmission technique. The results show that, to obtain more reliable analyses, correction factors for the self-attenuation behaviour, especially in the lower part of the energy spectrum, should be used. Since attenuation depends not only on the density of the sample but also on its chemical composition, correction factors have to be determined for each sample.
  • Resumo IPEN-doc 22816
    Self-attenuation factors in gamma-ray spectrometry of NORM samples
    2016 - PECEQUILO, BRIGITTE R.S.; CAVALCANTE, FERNANDA; BARROS, LIVIA F.; FERREIRA, ADEMAR O.; FONSECA, LEANDRO M.; MATEUS, CRISLENE