Ceramic Oxides
Mostrando 25-35 de 35 artigos, teses e dissertações.
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25. SÍNTESE E CARACTERIZAÇÃO DE ÓXIDOS COM BAIXA EXPANSÃO TÉRMICA / SYNTHESIS AND CHARACTERIZATION OF LOW THERMAL EXPANSION OXIDES
Negative and low thermal expansion materials have important potential applications as resistance to thermal shock, as well as, for odontological applications, printed circuit boards, optical components and to produce composites to compensate the positive thermal expansion of materials. For this reason, the study and production of materials with controlled th
Publicado em: 2007
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26. Obtenção de fritas vitrocerâmicas a partir de resíduos sólidos industriais / Glassceramics frits attainment from industrial solid wastes
This work studies the residue obtained from the process of aluminum metal extraction activities, a great interest process, because of Brazil own some of the biggest bauxite mineral reserves in all the world. As a useful choice for no residue generation, and a support for environmentally friendly technologies, this work studies the white dross residue (WDR),
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/09/2006
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27. Development, microstructural and mechanical caracterization of SiC ceramics with alumina and rare earth oxides additions / Desenvolvimento, caracterização microestrutural e mecânica de cerâmicas de SiC aditivadas com alumina e óxidos de terras raras
In this work, the mechanical properties are determined at room temperature (hardness and fracture toughness) and high temperatures (compressive creep) of SiC ceramic samples with alumina (Al2O3) and rare earth oxides (REO) additions. The REO is obtained by REC (rare earth concentrate - Nuclemon) calcinations, which contains 76 wt % of yttria (Al2O3). Three c
Publicado em: 2006
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28. Remediação de áreas contaminadas com metais pesados utilizando Acidithiobacillus sp. / Soil remediation with heavy metals using Acidithiobacillus sp.
The "Lake Region" of Santa Gertrudes is one of several contaminated sites with heavy metals in São Paulo State, Brazil. As in other regions of this country, in the 1970s the ceramic industries of Santa Gertrudes disposed their solid wastes and wastewaters directly in soil and contaminated an area of 1.5 km2. Biological solubilization of lead (Pb) and zinc (
Publicado em: 2006
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29. Studies of air pollution in the municipal district of Sete Lagoas, MG using nuclear techniques / Estudos da poluição do ar do município de Sete Lagoas, MG utilizando técnicas nucleares
Toxic metals, such as Ni, V, Zn, Cu, Cr, Mn and metalloids as As and Se and their compositions are associated mainly with the smaller diameter particulates present in the atmospheric aerosols. This fact is important, principally, when it concerns public health, because this is considered the breathable fraction of particles that can penetrate deeply into the
Publicado em: 2006
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30. Microstructural evaluation of rare-earth-zinc oxide-based varistor ceramics
Zinc oxide varistors are nonlinear voltage dependent ceramic resistors used to suppress and limit transient voltage surges. The work reported in this paper involves the relationship between microstructural characteristics and the varistor performance of ZnO ceramics doped with rare-earth oxides. Samples of these ceramics with different nonlinear current-volt
Materials Research. Publicado em: 2005-12
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31. Dilatometric studies of (SiO2-RE2O3-Al2O3) silicon carbide ceramics
Silicon carbide is an important structural ceramic and finds applications as abrasives, as a refractory and in automotive engine components. This material can attain high densities during liquid phase sintering if suitable additives are used. Silicon carbides containing silica, alumina and rare earth oxides have suitable characteristics to promote liquid pha
Materials Research. Publicado em: 2005-06
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32. Thermal and sctructural properties of the CaB4O7-CaB2O4 system viewing the development of thermoluminescent dosimeter / Propriedades térmicas e estruturais do sistema CaB4O7-CaB2O4 visando o desenvolvimento de dosímetro termoluminescente
Borate glasses containing modified oxides have been studied on account of their effective atomic number close to that of the human tissue, what makes them interesting materials for the development of the thermoluminescent dosimeters. The purpose of this work was to study the thermal and structure properties of the xCaB4O7-(100-x)CaB2O4 system with x ranging
Publicado em: 2005
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33. Efeito do recobrimento cerâmico e da atmosfera de ensaio na fluência de liga metálica refratária de titânio / Effect of the ceramic coating the atmosphere on the creep of titanium metallic refractory alloy
Neste trabalho de doutorado, pretende-se dar continuidade às pesquisas já iniciadas nos estudos da liga Ti-6Al-4V. Tais estudos foram efetuados apenas com a liga não recoberta, sob condições de fluência realizada ao ar. O objetivo deste projeto foi a avaliação do efeito de recobrimento cerâmico e da atmosfera de ensaio na fluência de liga refratár
Publicado em: 2005
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34. Efeito do recobrimento cerâmico e da atmosfera de ensaio na fluência de liga metálica refratária de titânio / Effect of the ceramic coating the atmosphere on the creep of titanium metallic refractory alloy
Neste trabalho de doutorado, pretende-se dar continuidade às pesquisas já iniciadas nos estudos da liga Ti-6Al-4V. Tais estudos foram efetuados apenas com a liga não recoberta, sob condições de fluência realizada ao ar. O objetivo deste projeto foi a avaliação do efeito de recobrimento cerâmico e da atmosfera de ensaio na fluência de liga refratár
Publicado em: 2005
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35. Pulsed laser deposition of SiO2 - P2O5 - CaO - MgO glass coatings on titanium substrates
Thin films of bioactive glass-ceramic have been deposited on titanium substrates by the Pulsed Laser Deposition (PLD) technique under different experimental conditions. The effect of parameters such as deposition pressure and temperature of heat treatments was studied. The microstructure and the crystalline phases of the coatings were characterized using SEM
Materials Research. Publicado em: 2004-09