Chemical Characterization
Mostrando 1-12 de 1729 artigos, teses e dissertações.
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1. Characterization of micaceous minerals occurring in phosphate ores in Brazil: emphasis on the interstratified phyllosilicates
Abstract Micaceous minerals were characterized in three phosphatic ores from mines in Western Minas Gerais State, Brazil, all having complex chemical and mineralogical compositions, with emphasis on interstratified phyllosilicates. Knowledge of the relationship between the physical and chemical characteristics of the phyllosilicates contributed to a better u
REM - International Engineering Journal. Publicado em: 2022
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2. Oxigênio no contexto da COVID-19: o que sabemos sobre a molécula que respiramos e o papel central da química
OXYGEN IN THE COVID-19 CONTEXT: WHAT WE KNOW ABOUT THE MOLECULE WE BREATHE AND THE CENTRAL ROLE OF CHEMISTRY. In this work, the role of chemistry in the coronavirus disease 2019 (COVID-19) pandemic is highlighted through the medical oxygen supply crises in Brazil, as an example of oxygen utility in health. Starting from oxygen chemical characterization, the
Química Nova. Publicado em: 2022
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3. Influence of the addition of niobium oxide on the properties of fused aluminum oxide used in abrasive tools
Abstract Fused alumina is a material used in the manufacturing of abrasive tools, due to its high fusion point, great hardness, and mechanical toughness. In this context, this study addressed the influence of niobium addition on the properties of fused alumina for abrasive applications. A comparison was also made between this oxide and the brown fused alumin
Cerâmica. Publicado em: 2022
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4. Development and Chemical Characterization of Pequi Pericarp Flour (Caryocar brasiliense Camb.) and Effect of in vitro Digestibility on the Bioaccessibility of Phenolic Compounds
The pequi pericarp corresponds to the largest portion of the fruit and has a high nutritional value, but it is discarded as an agro-industrial residue. The present study aimed to prepare and characterize flours from the pequi pericarp in terms of their proximate composition, its antioxidant potential before and after the in vitro digestibility process and ch
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Ultrafine quartz flocculation: Part I. System characterization and variables selection
Abstract A characterization study was performed to verify the more relevant physicochemical properties for quartz flocculation with polyacrylamide, as well as to define which variables should be further investigated regarding this flocculation system. Polyacrylamide was evaluated through molecular weight, radius of gyration, and infrared spectrometry. A natu
REM - International Engineering Journal. Publicado em: 2022
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6. Properties and technical characteristics of Casira pottery, Jujuy, Argentina
Abstract In this work, the results of a multi-technique characterization of a type of pottery production with high cultural and economic relevance from the only potter town in Argentina are presented and correlated. Raw materials, a prepared paste, and ceramic samples were studied. Chemical, structural, textural, microstructural, and thermal features were as
Cerâmica. Publicado em: 2022
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7. Physical-chemical characterization, bioactive compounds, and antioxidant activity of pulp and peel of the Jamelão
ABSTRACT The high production of jamelão (Syzygium cumini) during harvest and the lack of information about it emphasize the development of new processing technologies for this fruit since it has been proven that its different parts have functional properties. The objectives of this work were to evaluate the physical-chemical characteristics and to determine
Revista Ceres. Publicado em: 2022
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8. DESENVOLVIMENTO DE ACESSÓRIO PORTÁTIL DE CONTROLE DE TEMPERATURA PARA MEDIDAS ESPECTROSCÓPICAS
Temperature is a natural phenomenon that may modify the structure of chemical compounds and hence their properties. We aimed to develop a simple portable system based on the Peltier principle for spectral characterization of compounds with temperature-dependent structure. The device was constructed and adapted to three pieces of equipment: X-ray diffractomet
Química Nova. Publicado em: 2022
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9. Evaluation of sediment contamination by urban sewage in a stretch of Capibaribe River, Pernambuco, Brazil
Anthropic activities are responsible for the increase in environmental contamination, especially in aquatic systems, demanding studies to assess and monitor contamination levels in different water bodies. We have done a chemical characterization of eleven sediments in order to evaluate the level of contamination by domestic sewage from the Capibaribe River,
Química Nova. Publicado em: 2022
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10. An alternative route to extract nickel and cobalt from non-commercial laterite ore
Abstract Laterite ores, which represent around two-thirds of nickel reserves, became an important source of nickel and cobalt metals. The objective of the present study was to investigate the efficiency of a hybrid route to extract nickel and cobalt present in a laterite ore sample which was not commercially attractive to be processed through the current rou
REM - International Engineering Journal. Publicado em: 2022
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11. Synthesis and Molecular Modeling Study of Two Bromo-Dimethoxybenzaldehydes
This work describes the synthesis, molecular structure, and packaging of the compounds 6-bromo-2,3-dimethoxybenzaldehyde (6-BRB) and 5-bromo-2,3-dimethoxybenzaldehyde (5 BRB). Characterization in the solid-state was carried out by X-ray diffraction, and the analysis of the interactions was described by the Hirshfeld surface, which helps in understanding the
Journal of the Brazilian Chemical Society. Publicado em: 2022
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12. Bioactive compounds, bromatological and mineral characterization of blackberries in a subtropical region
ABSTRACT Given the above, the objective of this study was to evaluate the bromatological, mineral and bioactive compounds of blackberry grown in a subtropical region. Blackberries fruits (Rubus sp.), Grown in an orchard of Unioeste, Campus Marechal Cândido Rondon (Paraná, Brazil), were used. Immediately after harvest, the fruits were taken to the Food Tech
Revista Ceres. Publicado em: 2022