Lead Isotope
Mostrando 1-12 de 30 artigos, teses e dissertações.
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1. Differentiation Among Brazilian Wine Regions Based on Lead Isotopic Data
For the first time, the isotope ratio of lead is reported in Brazilian red wines. The lead concentration and the ratios of 204Pb/206Pb, 207Pb/206Pb and 208Pb/206Pb were determined in 94 red wines produced in Campanha Gaúcha, Serra Gaúcha, Vale dos Vinhedos in Southern Brazil and Vale do São Francisco in Northeastern Brazil. The values observed for the iso
J. Braz. Chem. Soc.. Publicado em: 2016-06
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2. Preparação e caracterização de um material de referência de peixe / Preparation and characterization of the fish reference material
The certified reference materials (CRMs) play an important role in obtaining measurement results traceable to the International System of Units, through an unbroken chain of comparisons. Thus, the demand for new certified reference materials (CRMs) increases every day in all areas of knowledge. The availability of reference materials, mainly in Brazil is sti
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/03/2011
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3. Os Depósitos de Cu-Au-Mo do tipo pórfiro de Bajo de La Alumbrera e Água Rica, Argentina : considerações genéticas sobre formação e fonte de minério
The world-class deposits of Bajo de la Alumbrera and Agua Rica in NW Argentina, are of the Cu-Au-Mo porphyry type (although Agua Rica has some epithermal characteristics). Both deposits are closely related to the activities and formation processes of the Miocene Farallón Negro Volcanic Complex. They are also controlled by the Tucuman Transfer Zone, which is
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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4. A fonte dos metais da mina de ouro Schramm, Santa Catarina: evidências de dados de isótopos de Pb e elementos terras raras
The source of the ore elements in the Schramm gold mine, localized in central part of Santa Catarina shield, has been constrained based on lead isotope composition of galena and sulfosalts, and the rare earth element (REE) patterns of the ore. The Pb207/ Pb206 model age obtained in galena and lillianite-gustavite series from the mineralization yields an age
Publicado em: 2010
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5. Uranium-lead dating method at the Pará-Iso isotope geology laboratory, UFPA, Belém - Brazil
Os procedimentos analíticos para análises U-Pb por diluição isotópica no Laboratório de Geologia Isotópica (Pará-Iso) da Universidade Federal do Pará (UFPA) são descritos detalhadamente. Esses procedimentos são aplicados para análises de zircão, titanita, rutilo, apatita, columbita-tantalita e rocha total. A purificação dos reagentes e os proc
Anais da Academia Brasileira de Ciências. Publicado em: 2007-03
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6. Application of inductively coupled plasma quadrupole mass spectrometry for the determination of monazite ages by lead isotope ratios
A fim de avaliar a aplicabilidade da espectrometria de massa com plasma indutivamente acoplado à determinação de idades Pb/Pb, U/Pb e Th/Pb de monazitas, estudos foram realizados, inicialmente, em padrões isotópicos de referência para chumbo (NIST SRM 981 e 982). Posteriormente, a metodologia otimizada foi aplicada a areias monazíticas de três difere
Journal of the Brazilian Chemical Society. Publicado em: 2007
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7. Lipid hydroperoxides as a biological source of singlet oxygen: studies using isotopic labelling, mass spectrometry and luminescence / Hidroperóxidos de lipídios como fonte biológica de oxigênio singlete: estudos com marcação isotópica, espectrometria de massas e luminescência
Evidences point to the involvement of lipid peroxidation in several diseases. Lipid hydroperoxides (LOOH) are the primary products of lipid peroxidation and their decomposition generates more reactive and toxic compounds, such as peroxyl radicals. These radicals play an important role in the propagation of lipid peroxidation and may also generate singlet mol
Publicado em: 2005
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8. Modelagem computacional e anÃlise da salinizaÃÃo dos aqÃÃferos na Ãrea central de Recife
Groundwater is an important water source either for usual exploitation or to be kept as a strategic reserve, regionally and locally, and it needs to be protected. Groundwater quality depends on social and economic activities, depends on land use, and groundwater contamination has become more frequent. Nowadays salinization is the most common type of groundwa
Publicado em: 2004
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9. Total contribution of airborne lead to blood lead.
A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone.
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10. New isotopic evidence for chronic lead contamination in the San Francisco Bay estuary system: Implications for the persistence of past industrial lead emissions in the biosphere
Measurements of lead isotope compositions in unfiltered San Francisco Bay waters from 1989 to 1998 have brought new insights into the cycling of anthropogenic lead in estuaries. Isotopic compositions of lead in the shallow (<2 m) southern reach were essentially invariant (∼90% derived from 1960s–1970s leaded gasoline) during the study period because
The National Academy of Sciences.
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11. Isotopic Fractionation Associated With Symbiotic N2 Fixation and Uptake of NO3− by Plants 1
Isotopic fractionation associated with N2 fixation and NO3− uptake by plants are relevant to the accuracy of estimates of N2 fixation based on differences in the natural abundance of 15N between N2 fixing and nonfixing plants. The isotope effect on N2 fixation by soybeans (Glycine max [L] Merrill, variety Harosoy) and red clover (Trifolium pratense [L]) wa
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12. High accuracy (stable isotope dilution) measurements of lead in serum and cerebrospinal fluid.
The concentration of lead in blood, serum, cerebrospinal fluid, and urine was measured in patients with neurological disease and in control subjects including cases of plumbism. A plot of blood lead versus serum lead resembles the familiar curves of blood lead versus either free erythrocyte porphyrin or urinary delta-aminolaevulinic acid in that serum lead i