SANDRA REGINA DAMATTO
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Artigo IPEN-doc 29126 Counting efficiency in gamma-ray spectrometry with different sample volumes for the same geometry2022 - NISTI, M.B.; MADUAR, M.F.; DAMATTO, S.R.; ALENCAR, M.M.The aim of this study is to determine an easy and fast method to calculate efficiencies in different volumes, in the same counting geometry, for gamma-ray spectrometry technique. Reference Material Soil IAEA 326 was packed in a 100 mL capacity polyethylene bottle with different masses and volumes, and sealed for about four weeks, prior measurement, in order to ensure that radioactive equilibrium had been reached between 226Ra and its progeny. After this time, they were measured by gamma-ray spectrometry with a hyper-pure germanium detector. The masses of the reference material used were 25, 60, 80, 95 and 128g. The energies of gamma-rays used in this paper are recommended due to the considerations: gamma intensity value, peak quality, spectral region without interference and the gamma- ray energies of the 238U and 232Th series very important for determining the natural radioactivity. The efficiency values obtained compared to the adjusted efficiency values were similar and presented a good correlation coefficient. The performance was acceptable for all different masses studied, indicating results consistent for the method. The proposed method could be useful as a tool for laboratories, dealing with of samples on a routine basis, by reducing the cost on the purchase of another counting geometry and optimizing the use of the detection system, thus improving their performance.Artigo IPEN-doc 27905 Inorganic chemical composition by X-ray fluorescence spectrometry of the mineral waters from the Minas Gerais Water Circuit, Brazil2021 - WAKASUGI, D.S.M.; DAMATTO, S.R.; MENEGHINI, A.A.; SANTOS, L.A.B.; SALVADOR, V.L.R.The water parks located in the cities of Cambuquira, Caxambu, Conceição do Rio Verde, Lambari and Marimbeiro are part of the Water Circuit of Minas Gerais and have their mineral waters regularly consumed by the local population and tourists motivated by the medicinal use of these waters, characterized as mineral waters. Therefore, the objective of this work was to determine the inorganic chemical composition of the mineral water from these parks, analysing the elements Ag, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K. Mn, Ni, Pb, Se, Ti, V and Zn using the energy dispersive X-ray fluorescence – EDXRF. Despite the proximity to one another, each park has different chemical elements and concentrations. The elements presenting the highest concentrations were the major elements Ca, Fe, K and Mn. However, among the five water parks studied, the Water Park of Caxambu presented the highest concentrations for all the determined elements.Artigo IPEN-doc 27892 Natural radionuclides in soil profiles and sediment cores from Jundiaí reservoir, state of São Paulo2021 - GONÇALVES, P.N.; DAMATTO, S.R.; LEONARDO, L.; SOUZA, J.M.The activity concentration of natural radionuclides in soils and sediments is dependent on many factors, such as the rock parental material, pedogenic and weathering processes, physical and chemical properties of the environment, anthropogenic sources, among other aspects. There are few studies about the levels of natural radionuclides in reservoirs in both, international and national, literature. The objective of this paper was to evaluate the activity concentrations of 238U and 232Th by Instrumental Neutron Activation Analysis and 226Ra, 210Pb, 228Ra, 228Th and 40K by gamma spectrometry in two soil profiles and three sediment cores collected in the catchment area of Jundiai reservoir, located in the state of São Paulo, Brazil. Principal component analysis was applied to verify the correlation of the activity concentrations of the natural radionuclides with physical and chemical properties of soil and sediment samples. The mean activity concentrations of the radionuclides in the soil profiles 1 and 2 were, respectively: 238U – 37(1) and 32(1) Bq.kg-1; 232Th – 91(1) and 60(1) Bq.kg-1; 226Ra – 66(1) and 51(1) Bq.kg-1; 210Pb – 35(1) and 37(1) Bq.kg-1; 228Ra – 34(1) and 27(1) Bq.kg-1; 228Th – 78(1) and 58(1) Bq.kg-1; 40K – 96(2) and 171(7) Bq.kg-1. For the three sediment cores analyzed, the average activities concentrations of the radionuclides were, respectively: 238U – 64(0.5), 47(0.1) and 44(0.2) Bq.kg-1; 232Th – 122(2), 100(1) and 64(1) Bq.kg-1; 226Ra – 74(2), 71(1) and 45(1) Bq.kg-1; 210Pb – 70(3), 56(2) and 55(2) Bq.kg-1; 228Ra – 53(1), 41(1) and 33(1) Bq.kg-1; 228Th – 100(2), 92(1) and 63(2); 40K – 316(5), 237(1) and 136(2) Bq.kg-1.