Thick Oxides
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Influência da adição da lama fina de aciaria a oxigênio nas características físicas e microestruturais de pelotas queimadas de minério de ferro
At the Brazilian steelmaking industry, the estimated annual production of steelmaking BOF sludge is about 230 thousand tons. The BOF sludge is a residue typical of oxygen steel mills. The main chemical and granulometric characteristics of the steelmaking BOF sludge are the following: about 30% of BOF thick sludge, with high metallic content and granulometry
Publicado em: 2009
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2. Petrologia e metalogenia do depósito primário de nióbio do complexo carbonatítico-foscorítico de Catalão I, GO
The Catalão I carbonatite-phoscorite complex is part of the Alto Paranaíba Igneous Province (APIP) and consists of a multi-intrusion body zoned from bebedourite-(piroxenite)-series rocks in the border to carbonatite- and phoscorite-series rocks in the core. The phoscorite-series rocks consist of apatite, magnetite and a Mg-silicate (phlogopite or olivine)
Publicado em: 2009
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3. A história do intemperismo na Província Borborema Oriental, Nordeste do Brasil: implicações paleoclimáticas e tectônicas
Until some years ago, weathering geochronology was primarily based on the K-Ar and 40Ar/39Ar dating of supergene minerals. Recent advances in the analysis of supergene goethite by the (U-Th)/He method expanded the number of suitable minerals for such purpose, as well as the time of application for weathering geochronology. This study represents the first sys
Publicado em: 2008
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4. Geologia e petrologia do prospecto GT-34 : evidência de metassomatismo de alta temperatura e baixa fO2, província mineral Carajás, Brasil
The GT-34 Prospect in the Carajás Mineral Province is located within older gneissmigmatite terrains (Xingu Complex). Sulfide mineralization is hosted by irregular bodies of brecciated rocks and/or orthopyroxene-amphibole bearing rocks outcropping among gneissic rocks. Distribution of sulfide-rich intervals form an irregular NE trend of about 1.5 km-long and
Publicado em: 2008
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5. Glass passivation in power rectifiers. / Passivação a vidro de junções semicondutoras em dispositivos de potência.
The search for better electrical properties, new passivating materials for semiconductors junctions and the process of obtaining those ones have being studied intensively in the latest decades. There are two types of passivation layers: thick film and thin film. The first one is obtained by the deposition of silicon oxides, silicon nitride or silicon carbide
Publicado em: 2006
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6. Caracterização eletroquímica e ótica de filmes de óxido espesso crescidos sobre ouro. / Eletrochemical and optical characterization of thick oxide films on gold electrodes.
Potentiostatic polarization of polycrystalline Au electrodes at various polarization potentials, 1.8, ..., 2.4 V, RHE, for polarization times up to 72h, in acid and basic solutions, leads to formation of four oxide states, OC1, OC2, OC3 and OC4, distinguished, in reduction, using linear-sweep voltammetry. The quasi-2d state (OC1) tends to the limit of two mo
Publicado em: 1995
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7. Isolation, Cultural Maintenance, and Taxonomy of a Sheath-Forming Strain of Leptothrix discophora and Characterization of Manganese-Oxidizing Activity Associated with the Sheath
Leptothrix discophora SP-6 was isolated from the outflow reservoir of an artificial iron seep. Its sheathforming phenotype was maintained by slow growth in a mineral salts-vitamin-pyruvate medium under minimal aeration at 20 to 25°C. A sheathless variant, SP-6(sl), was isolated from smooth colonies that appeared on spread plates after rapid growth of SP-6 i
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8. Biochemical evolution II: Origin of life in tubular microstructures on weathered feldspar surfaces
Mineral surfaces were important during the emergence of life on Earth because the assembly of the necessary complex biomolecules by random collisions in dilute aqueous solutions is implausible. Most silicate mineral surfaces are hydrophilic and organophobic and unsuitable for catalytic reactions, but some silica-rich surfaces of partly dealuminated feldspars
The National Academy of Sciences.