Silicon
Mostrando 1-12 de 899 artigos, teses e dissertações.
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1. Evaluation of the self-healing capacity of ceramics produced with alumina and silicon carbide
Abstract The self-healing capacity of a ceramic material produced by uniaxial pressing with alumina (Al2O3), silicon carbide (SiC), and magnesium oxide (MgO) was evaluated. To assess self-healing, a discontinuity was generated on the surface of the specimens. The healing time in the oven, at a temperature of 1000 ºC, was 1, 30, and 60 min. The specimens wer
Cerâmica. Publicado em: 2022
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2. Preparation of Silicon Oxycarbide (SiCO) Ceramics from Different Polymer Architectures and Assessment on the Performance as Electrodic Materials for Voltammetric Sensing of Antioxidant Phenolic Compounds
Silicon oxycarbide (SiCO) ceramics obtained from polymer pyrolysis and with varied carbon contents were prepared and evaluated as new electrodic materials for sensing of tert butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) antioxidants. Three polymers were synthesized varying molecular architecture and aromatic carbon groups, followed by pyrolysi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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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. PHYSIOLOGICAL ADJUSTMENTS, YIELD INCREASE AND FIBER QUALITY OF 'BRS RUBI' NATURALLY COLORED COTTON UNDER SILICON DOSES
RESUMO Globalmente, demanda por alimentos e bens de consumo tem acompanhado o crescimento populacional, pressionando o setor agropecuário a otimizar os sistemas de produção. No caso específico da agricultura, a utilização de cultivares de plantas alimentícias e energéticas melhoradas e associadas ao uso de substâncias atenuadoras dos estresses abió
Revista Caatinga. Publicado em: 2022
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5. Mix design formulation range for metakaolin-based geopolymer synthesis
Abstract This article presents a range of mix design formulations to obtain metakaolin-based geopolymer synthesis. Geopolymer samples were synthesized from metakaolin, a 10 M sodium hydroxide solution, and alkaline sodium silicate. These three components were mixed in different proportions to form a paste which was molded in a cylindrical shape, set at room
REM - International Engineering Journal. Publicado em: 2022
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6. Production of nanostructured crystalline composite using residual ashes from flocculated sludge burning process in a poultry slaughterhouse wastewater treatment system
Abstract Nanostructured crystalline composite (activated carbon) was synthesized from residual ashes of the burning process of the sludge generated in the flotation step of a poultry slaughterhouse and was used for Allura red dye adsorption. The ashes were chemically activated using two types of reagents, H2O2 and H3PO4, and the structure, morphology, and su
Cerâmica. Publicado em: 2022
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7. Silicon in wheat crop under water limitation and seed tolerance to water stress during germination
ABSTRACT Water stress during wheat seed germination and seedling establishment for affect the percentage and speed of germination. Silicon (Si) is related to plant tolerance to different types of stress, then the application of this nutrient in the mother plant during seed production could contribute to the improvement of the seed quality and, consequently,
Rev. Ceres. Publicado em: 2021-08
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8. Adsorption of Calcium(II), Cadmium(II) and Copper(II) Ions from Water by Prepared Silicon-Aluminum-Zirconium Oxide Using Sol-Gel Process
Ternary oxide silica-alumina-zirconia (SiO2/Al2O3/ZrO2) obtained by the sol-gel process was applied as novel adsorbent of ions in aqueous solution. Batch isotherms were performed using standard CuII, CdII and CaII solutions at variable pH and different concentrations. Adsorption capacity was best at weakly acidic pH. The maximum adsorption capacities were 2.
J. Braz. Chem. Soc.. Publicado em: 2021-07
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9. Silicon carbide hollow fiber membranes developed for the textile industry wastewater treatment
Abstract In order to reduce the impacts of the industrial effluent on the environment, silicon carbide hollow fiber membranes were prepared by the precipitation-immersion technique and sintered at 1450 and 1500 °C. The membranes were characterized by X-ray diffraction, their surface structure was characterized by scanning electron microscopy and atomic forc
Cerâmica. Publicado em: 2021-06
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10. Study of Crystallization and Composition on Silicon Oxycarbide (SiOC) and Silicon Boron Oxycarbide (SiBOC) Ceramics Obtained from Alkoxysilanes Precursors
This work deals on the preparation of silicon oxycarbide (SiOC) and silicon boron oxycarbide (SiBOC) ceramics from pyrolysis involving alkoxysilanes with different organic groups. Boron content, organic substituent and annealing time were evaluated on crystallization and composition of resulting ceramics. B-free precursors composed of methyltriethoxysilane (
J. Braz. Chem. Soc.. Publicado em: 2021-06
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11. Compatibility by a Nonisothermal Kinetic Study of Azathioprine Associated with Usual Excipients in the Product Quality Review Process
Azathioprine is an immunosuppressive drug for several inflammatory disorders. Due to its clinical relevance, to explore the solid-state properties for excipient compatibility in the product quality review process is essential. Fourier transform infrared spectroscopy, powder X-ray diffraction and thermal analysis (thermogravimetry/derivative thermogravimetry
J. Braz. Chem. Soc.. Publicado em: 2021-03
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12. Magnetic and Mesoporous Silica-Niobia Material as Modifier of Carbon Paste Electrode for p-Nitrophenol Electrochemical Determination
In the present work, the sol-gel synthesis method was employed as strategy to obtain a magnetic and mesoporous silica-niobia material. The planned synthesis was based on the hetero-condensation of niobium and silicon alkoxide precursors, in the presence of spherical magnetite particles. The resulting material presented interesting characteristics such as mag
J. Braz. Chem. Soc.. Publicado em: 2021-03