Carbonates
Mostrando 37-48 de 91 artigos, teses e dissertações.
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37. Arsenic mobilization from sulfidic materials from gold mines in Minas Gerais State
Acid drainage results from exposition of sulfides to the atmosphere. Arsenopyrite is a sulfide that releases arsenic (As) to the environment when oxidized. This work evaluated the As mobility in six sulfidic geomaterials from gold mining areas in Minas Gerais State, Brazil. Grained samples (<2 mm) were periodically leached with distilled water, during 70 day
Química Nova. Publicado em: 2008
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38. Sedimentary facies and provenance of the Bebedouro Formation, Neoproterozoic (BA) / Fácies sedimentares e proveniência da Formação Bebedouro, Neoproterozóico (BA)
The sedimentary record of Neoproterozoic age has become a major subject of research since the rebirth of the models of extreme glaciation and rapid climatic changes for the period, including the Snowball Earth hypothesis. These models are founded on the identification, in all continents, of Neoproterozoic diamictites directly overlain by carbonates, which ar
Publicado em: 2008
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39. Geologia, geometalurgia, controles e gênese dos depósitos de fósforo, terras raras e titânio do complexo carbonatítico Catalão i , GO
This work describes the geological and geometallurgical characteristics of the phosphate, titanium, niobium and rare-earth elements deposits in the northeast part of the Catalão I carbonatite complex, Central Brazil. The mineralization controls were determined for magmatic, metasomatic and weathering processes. The ore types were defined on the basis of geo
Publicado em: 2008
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40. Petrography and mineral chemisty from Indaiá I and Indaiá II intrusions, western Minas Gerais State / Petrografia e química mineral das intrusões Indaiá I e Indaiá II, oeste do Estado de Minas Gerais
An integrated petrographic and mineral chemistry study has been carried out on ultramafic, potassic to ultrapotassic and silica-undersaturated rocks of kimberlitic affinity of the Indaiá I and Indaiá II intrusions, Western Minas Gerais State, Brazil. These rocks outcrop at the Alto Paranaíba Igneous Province (PIAP), within a N30W-trending, elongated area,
Publicado em: 2008
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41. ESTUDO DA INTENSIDADE DE CREPITAÇÃO DE MINÉRIOS GRANULADOS DE MANGANÊS DO BRASIL
A common problem in the production of ferromanganese alloys is the lack of knowledge about the mineralogical and metallurgical properties of the manganese lump ores. An important quality parameter of the lump ores is the decrepitation, wich has not been studied adequately yet. This work presents a physical, chemical and mineralogical characterization of the
Publicado em: 2008
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42. 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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43. Zn, Ni, Cu, Fe and S in sewage sludge: chemical behaviour, adsorption and treatment proposal / Zn, Ni, Cr, Cu, Fe e S em Iodo de esgoto: comportamento químico, adsorção e proposta de tratamento
The increase of the wastewater treated volume in Brazil has demanded alternatives to the sewage sludge final disposal. At first, agricultural use is one of the viable recommendations since sludge is rich in organic matter, macro and micronutrients necessary to the fertility of the soil. However, it is necessary to consider the environmental impact of some of
Publicado em: 2008
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44. Efeitos da salinidade e da composiÃÃo iÃnica da Ãgua de irrigaÃÃo sobre o desenvolvimento de plantas de feijÃo-de-corda / Effects of salinity and ionic composition of the water irrigation on the development of cowpea plants [Vigna unguiculata(L.)].
The use of the inadequate water in irrigation can be prejudicial to the plants. The objective of this work was to evaluate the effect of salinity and chemical composition of irrigation water on plant growth, mineral nutrition, gas exchange, and organic solutes contents of cowpea plants [Vigna unguiculata (L.) Walp.]. Plants were cultivated in plastic pots, u
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/03/2007
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45. Carbon and oxygen isotope geochemistry of Ediacaran outer platform carbonates, Paraguay Belt, central Brazil
Após a glaciação do final do Criogeniano, a região central do Brasil foi palco de extensa deposição de carbonatos plataformais do Grupo Araras. Este grupo inclui na sua base uma seqüência de capa carbonática sucedida por depósitos transgressivos de calcilutitos betuminosos e folhelhos de plataforma profunda. Dados de fácies e estratigráficos comb
Anais da Academia Brasileira de Ciências. Publicado em: 2007-09
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46. Synthesis, characterization and thermal behaviour of solid-state compounds of benzoates with some bivalent transition metal ions
Solid-state MBz compounds, where M stands for bivalent Mn, Fe, Co, Ni, Cu and Zn and Bz is benzoate, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), infrared spectroscopy and complexometry were used to characterize and to study the thermal behaviour of these compounds.
Química Nova. Publicado em: 2007-04
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47. Propriedades de biocerâmicas porosas de fosfato de cálcio obtidas com matérias-primas de origem orgânica e sintética
Calcium phosphate ceramics applied to bone tissue repair is an option for functional bone wound healing. Calcium phosphate utilized in this work has been originated from calcined bovine bone samples or a commercial brand of biphasic calcium phosphate (BCP). In this work, calcium phosphate added with alkaline carbonates and other raw-materials have been mixed
Publicado em: 2007
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48. Contribuição ao processo sedimentar atual no Canal do Ararapira, sistema estuarino-lagunar de Cananéia-Iguape (SP) / Contribution for the modern sedimentary process at cananéia-Iguape lagoonal estuarinbe system (SP)
The aim of this study is the analysis of modern sedimentary process taking place in the Ararapira Channel, at Cananéia-Iguape lagoonal estuarine system (SP). The employed parameters for this were the composition and grain size characteristics of the bottom sediments , the distribution of the carbonates , organic matter, and relates these parameters to the g
Publicado em: 2007