Chemical Composition
Mostrando 1-12 de 2764 artigos, teses e dissertações.
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1. Study of Catalytic Pyrolysis of Biomass Sorghum (Sorghum bicolor L. Moench) Using Design of Experiments and Surface Response Methodology
This study proposes a screen of variables that have an influence on the modification of the bio-oil chemical composition as a unique critical quality attribute (CQA) throughout the pyrolytic process (zeolite, ZSM-5) by using a 24 full factorial design, followed by optimization through a response surface methodology (RSM) based on central composite design (CC
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. 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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3. TANINOS E FLAVONOIDES DAS FLORES DE EUGENIA UNIFLORA (MYRTACEAE)
Eugenia uniflora, popularly known as pitanga, is a native species of the Brazilian flora, widely used in folk medicine for the treatment of various diseases and which has several bioactive chemical constituents. The aim of this work was to analyze the chemical composition of flowers visited by bees from Eugenia uniflora by Ultra-Performance Liquid Chromatogr
Química Nova. Publicado em: 2022
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4. Effects of chemical straighteners on the hair shaft and scalp
Abstract Background The effects of chemical straighteners on the scalp and hair shaft are not fully known, although such substances are widely used. Hair straightening became popular in Brazil with the use of formaldehyde and its derivatives, despite the prohibition by the current legislation. Objective To identify changes in hair shaft and scalp caused by
Anais Brasileiros de Dermatologia. Publicado em: 2022
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5. 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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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. 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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8. Alumina applied in bone regeneration: Porous α-alumina and transition alumina
Abstract Alumina is a polymorphic bioceramic that has been extensively investigated for application in bone regeneration. Dense α-alumina has been considered a suitable biomaterial for dental and orthopedic implants due to its superior mechanical properties. However, its use is limited due to its high inertia in a biological environment. Recent investigatio
Cerâmica. Publicado em: 2022
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9. Thermostimulated crystal structure transformation of the polymineral clay submicron particles
Abstract Changes in the structure of phyllosilicate microparticles of submicron fractions of polymineral clay with an average size of 290 nm, as well as changes in the positions of impurity ions of transition metals in the crystal lattice, were studied by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and high-resolution electron parama
Cerâmica. Publicado em: 2022
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10. 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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11. Effect of somatic cell count on milk composition and some chemical properties of milk
RESUMO A mastite subclínica é uma doença muito importante para as fazendas de gado leiteiro. Como resultado da deterioração da qualidade do leite, ela causa perdas econômicas nas empresas. Amostras de leite de 180 vacas foram divididas em cinco grupos de acordo com o nível de contagem de células somáticas (SCC). Algumas propriedades químicas e comp
Arquivo Brasileiro de Medicina Veterinária e Zootecnia. Publicado em: 2022
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12. 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