Chemical Knowledge
Mostrando 1-12 de 507 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. ROBÓTICA EDUCACIONAL, ENSINO DE QUÍMICA E APRENDIZAGEM COOPERATIVA: UMA PROPOSTA PARA O CURSO DE ENSINO SUPERIOR EM ENGENHARIA CIVIL
Students, generally, are afraid of studying chemistry because they understand that it is a very complex area of knowledge and that it doesn’t has use in daily lives and in intended profession, which is a problem we identified in a Civil Engineering course. With this, we proposed a project in this course, based on educational robotics and educational cooper
Química Nova. Publicado em: 2022
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3. How Much do the Environmental Conditions Interfere with the Essential Oils of Eugenia spp. L. (Myrtaceae)?
Eugenia is the largest neotropical genus in the Myrtaceae family. The genus has a wide geographical distribution, occurring from Mexico to Argentina. Eugenia species are rich in essential oils. Essential oils have applications in perfumery, cosmetics, food, pesticides and medicines. Several factors can influence the chemical composition and yield of essentia
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Reaching Circular Economy through Circular Chemistry: The Basis for Sustainable Development
Circular chemistry (CC) is an approach for establishing chemical processes to become truly circular and sustainable. It adopts the principles of circular economy (CE), employing life cycle approaches and systems thinking, which help to understand and address the sustainability issues of chemical processes and products. Within this whole context, it is possib
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Perfil cientométrico da Quimiometria no Brasil
The interest of researchers in understanding the stage of development of specific areas of knowledge is a way to understand their scientific maturity and their capacity for consolidation. This “popularization” of the knowledge of researchers working in a specific area of knowledge also allows a greater ability to recognize where science is produced and w
Química Nova. Publicado em: 2022
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6. METABOLIC PROFILING AND CYTOTOXIC ACTIVITY OF METHANOL EXTRACTS FROM CHAMAECRISTA DUCKEANA (P. BEZERRA & A. FERN.) H. S. IRWIN & BARNEBY (LEGUMINOSAE, CAESALPINIOIDEAE)
The genus Chamaecrista comprises more than 330 species, with only a few studies on their chemical composition and biologic activities. In this study, the phytochemical profile of leaf, stems, and fruits extracts of the C. duckeana were examined by UPLC ESI HRMS analysis to determine possibly bioactive constituents. The antioxidant activity was carried out th
Química Nova. Publicado em: 2022
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7. 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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8. 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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9. Identifying conceptions of the covalent bond: an analysis from a systematic review
The covalent bond is a classical topic in science education because it is fundamental to a considerable number of other concepts and by its ability to interpret several chemical phenomena. However, the process of learning this concept presents some difficulties discussed here. This article brings together the conceptions related to the covalent bond, identif
Química Nova. Publicado em: 2022
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10. Sunscreen lotions in the dermatological prescription: review of concepts and controversies
Abstract The skin is regularly exposed to several environmental aggressions, including solar radiation, whose biological effects can induce sunburn, dyschromia, skin aging and cancer. Among the photoprotection measures, sunscreens comprise a relevant part of the strategy aimed to prevent solar radiation damage and, for effective action, the patient must adhe
Anais Brasileiros de Dermatologia. Publicado em: 2022
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11. Integrated UPLC-HRMS, Chemometric Tools, and Metabolomic Analysis of Forage Palm (Opuntia spp. and Nopalea spp.) to Define Biomarkers Associated with Non-Susceptibility to Carmine Cochineal (Dactylopius opuntiae)
Metabolomics, together with analytical methods and chemometric tools, point to new paths for selecting species that are resistant to pests and diseases. In this work, the forage palm species' metabolomic profile was investigated, and the relation between the chemical composition and resistance to Dactylopius opuntiae (carmine cochineal). The study was perfor
J. Braz. Chem. Soc.. Publicado em: 2021-08
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12. A Systematic Pipeline to Enhance the Fecal Metabolome Coverage by LC-HRMS
The comprehended knowledge of the metabolic profile of the fecal matter has been recognized as an important point for understanding metabolic changes in the human systemic metabolism and it can provide precious information about host-gut microbiota interactions. However, few analytical strategies have been addressed for a broad analysis of metabolites with d
J. Braz. Chem. Soc.. Publicado em: 2021-07