Sio2
Mostrando 1-12 de 841 artigos, teses e dissertações.
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1. The influence of compositional variability of dimension stone residues on the properties of rustic porous ceramic tiles
Abstract This study analyzed how the compositional variability of dimension stone residues influences the characteristics of rustic porous ceramic tiles. The specimens were prepared by adding 20 wt% of dimension stone residue to the clay and sintered at 1000 °C for 1 h. The testing assays performed were physical properties and structural analysis through sc
Cerâmica. Publicado em: 2023
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2. Bioactive SiO2-K2O-CaO-P2O5 glass-ceramic scaffold prepared using polyurethane foam template
Abstract A glass-ceramic in the SiO2-K2O-CaO-P2O5 quaternary system was prepared by substituting the Na2O component with K2O to avoid Na2Ca2Si3O9 formation upon thermal treatment since this phase decreases apatite formation kinetics on glass material. To form the glass-ceramic, a modified sol-gel method involving solution precipitation, followed by reagents
Cerâmica. Publicado em: 2023
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3. Microstructural characteristics, properties, synthesis and applications of mullite: a review
Abstract Mullite, an intermediate phase of the binary alumina-silica system, is one of the most important phases of ceramic products containing alumina and silica in the initial composition. Its stoichiometry ranges from 3Al2O3.2SiO2 (3:2) to 2Al2O3.SiO2 (2:1) and its crystalline structure is orthorhombic, characterized by the presence of octahedral chains o
Cerâmica. Publicado em: 2022
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4. Physical-mechanical behavior of alkali-activated materials produced by the one-part method based on fly ash and rice husk ash
Abstract The study on the physical-mechanical properties of alkali-activated materials (AAM) produced by the ‘one-part’ method was carried out. For this, residues such as fly ash and rice husk ash (RHA) were used. The alkaline activator (NaOH) was calcined together with RHA for 2 h at 750 °C. Dry mixes were prepared by replacing fly ash with 10%, 20%, a
Cerâmica. Publicado em: 2022
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5. Dispersive Solid-Phase Extraction Using 3-Mercaptopropyltrimethoxysilane Functionalized Magnetic MWCNT-Based Nanocomposite for Selective and Efficient Preconcentration of Pb2+ with FAAS Determination
A novel nanocomposite based on magnetic multiwalled carbon nanotubes coated with SiO2 and functionalized with 3-mercaptopropyltrimethoxysilane (3-MPTMS) was prepared for the efficient extraction and quantification of lead ions from water samples. The adsorption capacity of this adsorbent could reach 1.995 mg g-1 Pb2+ in an equilibrium time of 30 min. Under o
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. Use of glass waste in the production of metakaolin-based geopolymer submitted to room temperature and thermal curing
Resumo O metacaulim é a principal matéria-prima utilizada na síntese de geopolímeros, embora a relação entre os teores de sílica e alumina não seja a ideal. Normalmente, o teor de SiO 2 é ajustado com o uso de silicatos presentes na solução ativadora. Uma opção ecoeficiente seria o uso de resíduos de vidro como fonte adicional de sílica. Este
Ambiente Construído. Publicado em: 2022
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7. Caracterização de resíduos siderúrgicos visando à aplicação em matrizes cimentícias
Resumo A siderurgia, apesar de ter relevância na economia global, é responsável pela geração de um elevado volume de resíduos em sua cadeia produtiva. Buscando o desenvolvimento sustentável, a construção civil absorve resíduos siderúrgicos ao oferecer alternativas de matérias-primas e reduzir a extração de recursos naturais. Nesta pesquisa, des
Ambiente Construído. Publicado em: 2022
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8. MLA and optical microscopy as complementary techniques to the iron ore geometallurgical studies
Abstract Mineral liberation is an important variable to be considered in the iron ore geometallurgical studies, especially since it provides information leading to the understanding of the ore’s behaviour in the beneficiation process, mainly when harder ores are concerned. Nowadays, the professionals and researchers in the mineral industry have been using
REM - International Engineering Journal. Publicado em: 2022
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9. Short-term mine scheduling targeting stationary grades
Abstract In short-term mine planning, mining scheduling is generally defined by designing dig-lines, allocated on benches. The mined ore will be sent to stockpiles, homogenization piles, or a concentration plant. The process to design dig-lines is usually done manually, whereby multiple simultaneous mining fronts are time-consuming and labour-intensive. The
REM - International Engineering Journal. Publicado em: 2022
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10. Characterization and mechanical properties of one-part geopolymer based on a pure metakaolin
Abstract Geopolymers are amorphous silicate polymers that have been extensively studied due to their applications, scientific and technical relevance, and their potential as cement in substitution to Portland. Much of the focus has been in the use of precursors and aggregates that are rarely pure and homogeneous with the use of tailings being very common. Th
REM - International Engineering Journal. Publicado em: 2022
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11. Fluoride concentration in toothpaste marketed to children in Brazil and Mexico, and discussion on current regulations
Resumo Os dentifrícios fluoretados comercializados para crianças devem conter concentração mínima de 1000 ppm de fluoreto (F), que deve ser quimicamente solúvel para ter efeito anticárie. Portanto, determinamos as concentrações de fluoreto total (FT) e fluoreto solúvel total (FST) em dentifrícios comercializados para crianças no Brasil e no Méxi
Brazilian Dental Journal. Publicado em: 2022
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12. Magnetic concentration route for recovering pellet feed fines stored in a mining dam
Abstract The greatest and noblest challenge of mining engineering for the present and the future of iron ore treatment could be considered as the pursuit of optimizing the use of mineral resources. The use of mining tailings, in the mineral sector itself, or in another industrial branch, meets the needs of circular economy as it increases the useful service
REM - International Engineering Journal. Publicado em: 2022