JOSELENE DE OLIVEIRA
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Artigo IPEN-doc 28848 Use of 223Ra and 224Ra as chronometers to estimate the residence time of Amazon waters on the Brazilian continental shelf2022 - LEON, MORGANE; BEEK, PIETER van; SCHOLTEN, JAN; MOORE, WILLARD S.; SOUHAUT, MARC; OLIVEIRA, JOSELENE de; JEANDEL, CATHERINE; SEYLER, PATRICK; JOUANNO, JULIENWhen rivers mix into the ocean, radium isotopes are released into the dissolved phase allowing us to apply these isotopes as powerful tracers of river plumes spreading into the ocean. We report 223Ra and 224Ra radium activities that were determined in the Amazon River mouth and along the Amazon plume that extends off the coasts of Brazil and French Guyana into the Atlantic Ocean. We summarize 223Ra and 224Ra data from AmasSeds (1991), AMANDES (GEOTRACES process study GApr01; 2007–2008) and M147 (2018) projects, which were conducted in different seasons corresponding to different Amazon discharge rates. We determined the 224Raex/223Ra activity ratios (AR) along the Amazon plume to derive apparent ages and to estimate the residence time of the Amazon waters on the Brazilian continental shelf. Our data suggest that it takes 9–14 d for the Amazon waters to reach the northern continental shelf off French Guyana and 12–21 d to reach the eastern part of the Brazilian continental shelf. These time scales are in good agreement with those derived from a high-resolution numerical simulation of the regional ocean dynamics. We do not find any relationship between the discharge rate of the Amazon River and the residence time of the waters on the Brazilian continental shelf, suggesting that the residence time of the Amazon waters is primarily driven by the ambient northwestward current. Using the apparent ages along the plume, we estimate an average velocity of 26 cm s−1 for the northward transport of the Amazon waters on the continental shelf.Artigo IPEN-doc 24970 Variação sazonal das concentrações de 226Ra, 228Ra e 210Pb das fontes de água mineral do Parque das Águas de Cambuquira e Marimbeiro, MG2017 - SANTOS, LAISSA A.B. dos; DAMATTO, SANDRA R.; OLIVEIRA, JOSELENE deOs elementos radioativos podem sem extraídos e arrastados pelas águas subterrâneas, porém quando se fala de águas minerais provindas de fontes subterrâneas uma característica marcante são as concentrações dos radionuclideos 226Ra e 222Rn originalmente dissolvidos. No entanto, outros radionuclídeos naturais como 228Ra e 210Pb, quando presentes, também contribuem para a irradiação interna do individuo. Assim determinou-se as concentrações de 226Ra, 228Ra e 210Pb em dez fontes minerais localizadas no Parque das Águas de Cambuquira e Marimbeiro. Os radionuclideos foram determinados por procedimento radioquimico em quatro coletas em diferentes estações do ano. As concentrações variaram de 4 ±1 mBq/L a 509 ± 32 mBq/L para 226Ra, de < 3,7 ± 0,1 mBq/L a 594 ±35 mBq/L para 228Ra e 5 ± 1 mBq/L a 59 ± 4 mBq/L para 210Pb.Artigo IPEN-doc 24438 Determinação da concentração de 226Ra, 228Ra e 210Pb e os efeitos da sazonalidade em águas mineirais da cidade de Caxambu, MG2017 - MENEGHINI, ARTHUR A.; DAMATTO, SANDRA R.; OLIVEIRA, JOSELENE; CARMO, AMANDA P.Com o crescente aumento no consumo das águas minerais, a caracterização de sua composição e a regulamentação dessas águas são essenciais, por ser a água uma parte fundamental da dieta humana. Nessas águas, além dos elementos e compostos químicos estáveis que lhe conferem características físico-químicas, há também os radionuclídeos naturais que são responsáveis pela característica radioativa das mesmas. A utilização das águas minerais com objetivo medicamentoso é uma prática realizada no mundo todo; o Brasil abriga a maior estância hidromineral do mundo, o Parque das Águas de Caxambu, em Minas Gerais. O parque dispõe de 12 fontes de águas minerais, um balneário e também o único gêiser classificado no Brasil. O objetivo desse trabalho foi determinar a concentração de 226Ra, 228Ra e 210Pb nas águas minerais das fontes do Parque das Águas e verificar a influência da sazonalidade nos níveis de concentração desses radionuclídeos.Artigo IPEN-doc 24052 Natural radionuclides, 226Ra, 228Ra and 210Pb, determined in mineral water springs from Parque das Águas de Caxambu, and assessment of the committed effective doses2017 - MENEGHINI, ARTHUR A.; DAMATTO, SANDRA R.; OLIVEIRA, JOSELENE; PRILIP, AMANDAThe increase of mineral water consumption and its medicinal use results in the necessity of characterization of these waters sources, once that water is a vital part of human diet. In the mineral waters, besides stable elements, responsible of the chemical composition, the presence of natural radionuclides from the 238U, 232Th, 235U series and 40K gives the radiation property. The incorporation of these radionuclides through the ingestion and external treatment of mineral waters are a very important point, due the ionizing radiation of these radionuclides are harmful to the organism. The largest mineral water park of the world is situated in Brazil, in the city of Caxambu, called “Parque das Águas de Caxambu”. In this park are 12 fountains distributed in the park, also a tubular well of 60 meters of depth which regularly provide water spouts, geyser, and another spring located inside the Gloria Hotel. Therefore, the aim of this work was to evaluate the activity concentrations of the radionuclides 226Ra, 228Ra and 210Pb in the mineral waters springs collected at the “Parque das Águas de Caxambu” and in the Gloria Hotel, as well as to estimate the committed effective doses due to the consumption of these waters. In six campaigns, the radionuclides with the highest concentrations were 226Ra and 228Ra in the springs D. Ernestina, Beleza and Venâncio. These springs also presented the highest values of the committed effective dose.Artigo IPEN-doc 23172 Applications of radon and radium isotopes to determine submarine groundwater discharge and flushing times in Todos os Santos Bay, Brazil2017 - HATJE, VANESSA; ATTISANO, KARINA K.; SOUZA, MARCELO F.L. de; MAZZILLI, BARBARA; OLIVEIRA, JOSELENE de; MORA, TAMIRES de A.; BURNETT, WILLIAM C.Todos os Santos Bay (BTS) is the 2nd largest bay in Brazil and an important resource for the people of the State of Bahia. We made measurements of radon and radium in selected areas of the bay to evaluate if these tracers could provide estimates of submarine groundwater discharge (SGD) and flushing times of the Paraguaçu Estuary and BTS.We found that there were a few areas along the eastern and northeastern shorelines that displayed relatively high radon and low salinities, indicating possible sites of enhanced SGD. A time-series mooring over a tidal cycle at Marina do Bonfim showed a systematic enrichment of the short-lived radium isotopes 223Ra and 224Ra during the falling tide. Assuming that the elevated radium isotopes were related to SGD and using measured radium activities from a shallow well at the site, we estimated groundwater seepage at about 70 m3/day per unit width of shoreline. Extrapolating to an estimated total shoreline length provided a first approximation of total (fresh þ saline) SGD into BTS of 300 m3/s, about 3 times the average river discharge into the bay. Just applying the shoreline lengths from areas identified with high radon and reduced salinity results in a lower SGD estimate of 20 m3/s. Flushing times of the Paraguaçu Estuary were estimated at about 3e4 days based on changing radium isotope ratios from low to high salinities. The flushing time for the entire BTS was also attempted using the same approach and resulted in a surprisingly low value of only 6e8 days. Although physical oceanographic models have proposed flushing times on the order of months, a simple tidal prism calculation provided results in the range of 4e7 days, consistent with the radium approach. Based on these initial results, we recommend a strategy for refining both SGD and flushing time estimates.Resumo IPEN-doc 23035 Evaluation of the activity concentrations of Ra-226, Ra-228 and Pb- 210 in sediments from Antarctica, in the admiralty bay region2016 - MORA, T.A.; OLIVEIRA, J.; FIGUEIRA, R.C.L.; MAHIQUES, M.M.; SOUSA, S.H.M.The natural radionuclides of U-238, U-235 and Th-232 series have been used as tracers in research of oceanic processes and management of the coastal region. Some of the natural radionuclides are especially used as tracers of the flux of particulated material into the ocean, which occur both in the water column and/ or in the sediment. The Ra-226, Ra-228 and Pb-210 have helped scientists understand some environmental phenomena occurring on the planet. In this study we performed a radiochemical characterization of a sedimentary column called (1B) of 248 cm collected in the Admiralty Bay, South Shetland archipelago – Antarctica region to determine the activity concentrations (mBq g-1) of Ra-226, Ra-228 and Pb-210 and the its application in a geochronological model to calculate the sedimentation rate. The sediment samples were submitted an acid leaching and then the radiochemical separation of Ra-226, Ra-228 was performed by coprecipitation of the Ba(Ra)SO4 and sequential separation of the Pb-210 by co-precipitation of PbCrO4. These precipitates were measured in gas-flow low background proportional detector. The Ba(Ra)SO4 was measured after 21 days of the precipitation and the PbCrO4 precipitate were measured after 10 days from the final date precipitation. The Pb-210 was detected via gross beta counting of its Bi-210 decay products. The time interval of 21 days for Ra-226 measurement was required for its achieve secular equilibrium with their daughters and the contribution of alpha emitting radioisotopes Ra-223 an Ra-224 were nil. This time interval was also enough to allow the equilibrium Ra-228/Ac-228. The activity concentration of Ra-226 ranged from 11±1 (mBq g-1) to 54±5 (mBq g-1), and the Ra-228 ranged from 48±5 (mBq g-1) to 155±13 (mBq g-1). With the values obtained from activity concentrations of Ra-226 and Pb-210, it was determined the activity concentration of unsupported Pb-210, which is Pb that comes from the atmosphere. The activity concentration of Pb-210 ranged from 7±1 (mBq g-1) to 458±23 (mBq g-1), while unsupported Pb-210 ranged from 7±3 (mBq g-1) to 434±25 (mBq g-1). Based on CIC (Constant Initial Concentration) geochronological model, the sedimentation rate of 0.59±0.05 cm year-1 was estimated in the sedimentary column (1B) coming from the Admiralty Bay region.Resumo IPEN-doc 23813 Preliminary results of 226Ra, 228Ra and 210Pb concentration in mineral waters from Parque das Águas de Cambuquira and Marimbeiro (MG)2016 - SANTOS, LAISSA A.B. dos; DAMATTO, SANDRA R.; OLIVEIRA, JOSELENE de; CARMO, AMANDA P. doResumo IPEN-doc 23803 Preliminary results of seasonal variation of 226Ra, 228Ra and 210Pb concentrations in mineral waters from Caxambu, Brazil2016 - MENEGHINI, A.A.; DAMATTO, S.R.; OLIVEIRA, J.; CARMO, A.P.Artigo IPEN-doc 22831 Radium isotope (223Ra, 224Ra, 226Ra and 228Ra) distribution near Brazil's largest port, Paranaguá Bay, Brazil2016 - DIAS, THAIS H.; OLIVEIRA, JOSELENE de; SANDERS, CHRISTIAN J.; CARVALHO, FRANCIANE; SANDERS, LUCIANA M.; MACHADO, EUNICE C.; SA, FABIANThis work investigates the 223Ra, 224Ra, 226Ra and 228Ra isotope distribution in river, estuarine waters and sediments of the Paranaguá Estuarine Complex (PEC). The stratification of the Ra isotopes along water columns indicate differing natural sources. In sediments, the radium isotope activities was inversely proportional to the particle size. The highest concentrations of 223Ra, 224Ra, 226Ra and 228Ra in the water column were found in the bottom more saline waters and towards the inner of the estuary. These relatively high concentrations towards the bottomof the estuarymay be attributed to the influence of tidally driven groundwater source and desorption from particles at the maximum turbidity zone. The apparent river water ages from the radium isotope ratios, 223Ra/224Ra and 223Ra/228Ra, indicate that the principal rivers that flow into the estuary have residence times from between 6 and 11 days.Resumo IPEN-doc 21546 Activity concentration analysis of Ra-226, Ra-228 and Pb-210 in a sedimentary profile of Admiralty Bay, South Shetland archipelago - Antarctica2015 - MORA, TAMIRES de A.; OLIVEIRA, JOSELENE de; FIGUEIRA, RUBENS C.L.