Carbon And Oxygen Isotopes
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Background and the use of isoscapes in the Brazilian context: essential tool for isotope data interpretation and natural resource management
Resumo Padrões de distribuição espacial de isótopos estáveis podem ser apresentados em mapas chamados de isoscapes e têm sido amplamente utilizados para rastrear processos biogeoquímicos em sistemas naturais e antrópicos. Isoscapes têm o potencial de melhorar a disseminação e interpretação dos padrões espaciais de isótopos estáveis, aumentar
Rev. Ambient. Água. Publicado em: 25/03/2019
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2. Cretaceous carbonatites of the southeastern Brazilian Platform: a review
ABSTRACT: This paper reviews general aspects of alkaline-carbonatitic rocks of Brazilian, Paraguayan and Bolivian terrains. Although 30 such occurrences are known in literature, only the major ones have been thoroughly investigated. The carbonatites are of Cretaceous age, with two well-defined Lower Cretaceous and Upper Cretaceous generation episodes. A clea
Braz. J. Geol.. Publicado em: 2018-06
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3. Mapping Ethanol Production Sources in Brazil Through Stable Isotopes
Ethanol is a biofuel produced in Brazil through fermentation of sugarcane, requiring vast plantation areas and water availability. The present work aimed at testing isotopic markers as tools for ethanol source appointment or certification of origin. For this, oxygen and hydrogen isotopic patterns were determined in plant-water, soil-water, rainwater, and wat
J. Braz. Chem. Soc.. Publicado em: 2015-06
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4. Reconstrução da hidrografia superficial do Atlântico Sul Ocidental desde o Último Máximo Glacial a partir do estudo de foraminíferos planctônicos / Sea surface hydrography reconstruction of the Western South Atlantic since the Last Glacial Maximum based on the study of planktonic foraminifera
The goal of this thesis is to document the paleoclimatic and paleoceanographic changes occurred at the millennial scale since the Last Glacial Maximum at the surface Western South Atlantic. Paleotemperature, paleosalinity and paleoproductivity estimates were obtained for this purpose based on faunal changes of foraminifera assemblages, carbon and oxygen stab
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/03/2010
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5. Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C-
This paper presents the geology, chemical data, Pb-Pb zircon ages, sulfur, carbon, oxygen, strontium isotopes and fluid inclusions of Cerro dos Martins copper deposit. The deposit is hosted by the Neoproterozoic volcano-sedimentary sequence of the Camaquã Basin in the Rio Grande do Sul Shield, southern Brazil. The ores consist of a set of Cu-sulfide NW-tren
Publicado em: 2010
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6. Fossils in quaternary micrites of Bodoquena Range, Bonito-MS and their application in paleoenvironmental studies / Fósseis em micritos quaternários da Serra da Bodoquena, Bonito-MS e sua aplicação em estudos paleoambientais
Bonito town and surrounding areas in Mato Grosso do Sul state are tourist attractions related with many quaternary carbonate deposits which form waterfalls, dams and render almost zero turbidity waters. That area is part of the National Park of Bodoquena Range and Pantanal Biosphere Reserve (UNESCO). Calcareous tufa are porous rocks formed by calcium carbona
Publicado em: 2009
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7. GeoquÃmica de carbonatos da plataforma continental nordeste do Brasil
Com o objetivo de detectar sinais geoquÃmicos de diagÃnese meteÃrica em sedimentos relÃquia, localizados em profundidades inferidas em estudos anteriores como correspondentes a antigas linhas de costa, ao longo da plataforma continental do CearÃ; alÃm de estudar a distribuiÃÃo dos Ãxidos principais analisados em sedimento total em sedimentos de plat
Publicado em: 2008
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8. Marine phosphate oxygen isotopes and organic matter remineralization in the oceans
We show that the isotopic composition of oxygen (δ18O) in dissolved inorganic phosphate (Pi) reveals the balance between Pi transport and biological turnover rates in marine ecosystems. Our δ18Op of Pi (δ18Op) measurements herein indicate the importance of cell lysis in the regeneration of Pi in the euphotic zone. Depth profiles of the δ18Op in the Atlan
National Academy of Sciences.
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9. Photosynthetic Fractionation of the Stable Isotopes of Oxygen and Carbon.
Isotope discrimination during photosynthetic exchange of O2 and CO2 was measured using enzyme, thylakoid, and whole cell preparations. Evolved oxygen from isolated spinach thylakoids was isotopically identical (within analytical error) to its source water. Similar results were obtained with Anacystis nidulans Richter and Phaeodactylum tricornutum Bohlin cult
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10. Stable isotopes (δ13C and δ15N) of organic matrix from coral skeleton
The evolutionary success of reef-building corals in nutrient-poor tropical waters is attributed to endosymbiotic dinoflagellates. The algae release photosynthetic products to the coral animal cells, augment nutrient flux, and enhance the rate of coral calcification. Natural abundance of stable isotopes (δ13C and δ18O) provides answers to modern and paleobi
National Academy of Sciences.
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11. Oxygen isotope ratios of PO4: An inorganic indicator of enzymatic activity and P metabolism and a new biomarker in the search for life
The distinctive relations between biological activity and isotopic effect recorded in biomarkers (e.g., carbon and sulfur isotope ratios) have allowed scientists to suggest that life originated on this planet nearly 3.8 billion years ago. The existence of life on other planets may be similarly identified by geochemical biomarkers, including the oxygen i
The National Academy of Sciences.
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12. Distribution of extravascular fluid volumes in isolated perfused lungs measured with H215O.
The distributions per unit volume of extravascular water (EVLW), blood volume, and blood flow were measured in isolated perfused vertical dog lungs. A steady-state tracer technique was employed using oxygen-15, carbon-11, and nitrogen-13 isotopes and external scintillation counting of the 511-KeV annihilation radiation common to all three radionuclides. EVLW