Energy Absorption
Mostrando 1-12 de 571 artigos, teses e dissertações.
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1. Technological properties of a self-bloating clay and expanded-clay aggregate for the production of lightweight concrete
Abstract The global interest in an increasingly sustainable economy, with a reduction in the consumption of raw materials and energy, can be supported by the growth in the use of lightweight concrete (LC) produced with expanded-clay aggregates (EA). The main qualities of natural self-bloating clay for the production of EA were studied, analyzing the paramete
Cerâmica. Publicado em: 2023
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2. VIBRATION CHARACTERISTICS, CHEMICAL BONDS AND WEAK INTERACTIONS OF 4- AND 5-HYDROXYSALICYLIC ACID INVESTIGATED BY TERAHERTZ SPECTROSCOPY AND DENSITY FUNCTIONAL THEORY
The terahertz (THz) absorption spectra of 4- and 5-hydroxysalicylic acid were measured by terahertz time-domain spectroscopy (THz-TDS) in the range of 0.4-2.8 THz. The unit cells of both were calculated by density functional theory (DFT), and the theoretical simulation and experimental data were basically in agreement. To further interpret the origin of the
Química Nova. Publicado em: 2022
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3. A química analítica aplicada aos estudos de pigmentos rupestres: uma revisão
Instrumental advances have been employed in the study of archeological remains such as prehistoric rupestrians paintings with the objective of chemically characterizing them in order to reconstruct the cultural technologies of a prehistoric human group and/or to support conservation science studies. The analytical techniques most commonly used in archaeometr
Química Nova. Publicado em: 2022
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4. DFT, Molecular Docking, and ADME/Tox Screening Investigations of Market-Available Drugs against SARS-CoV-2
A series of drugs was investigated to determine structural, electronic and pharmacological properties, as well as the molecular affinity for the main protease of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The drugs were submitted to density functional theory calculations to optimize structures and predict binding preferences. The optimized
J. Braz. Chem. Soc.. Publicado em: 2021-08
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5. Obesity-associated Pathways of Anthocyanins
Abstract Anthocyanins have a great potential for human health, as a sub-group of phenolic compounds. Interactions of anthocyanin involved in digestion and thus in obesity consist of inhibition of pancreatic lipase, regulation of lipolysis and lipogenesis, activation of an activated protein kinase enzyme, controlling of digestion hormones (leptin, insulin, gh
Food Sci. Technol. Publicado em: 2021-06
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6. Gold Nanorods Capped with Different Ammonium Bromide Salts on the Catalytic Chemical Reduction of p-Nitrophenol
It is known that the reactivity of the nanocatalytic systems is related to the particle size and shape and also to the features of the capping agents on the nanostructures. In this study, gold nanorods (AuNRs) were synthesized by the seed-mediated method using different tetra-alkylammonium bromide salts as capping agents, that are, cetyltrimethylammonium (CT
J. Braz. Chem. Soc.. Publicado em: 2021-06
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7. Study of structural, optical, and morphological characteristics of manganese titanate (MnTiO3) obtained by combustion reaction using microwave energy
Abstract MnTiO3 is a semiconductor that has relevant dielectric and optical properties. For the synthesis of manganese titanate (MnTiO3) powders, the combustion method via microwave and subsequent calcination at 500, 700, and 900 °C were used. The structural, morphological, and optical properties of the samples were investigated. X-ray diffraction analyzes
Cerâmica. Publicado em: 2021-03
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8. Development of a Methodology Based on Extraction Induced by Emulsion Breaking for Copper Determination in Gasohol by Graphite Furnace Atomic Absorption Spectrometry
The development of a method based on extraction induced by emulsion breaking (EIEB) aiming copper determination in gasohol using graphite furnace atomic absorption spectrometry (GF AAS) is reported. Emulsification of the gasohol samples was carried out using nitric acid solution, (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol surfactant (Triton X-114),
J. Braz. Chem. Soc.. Publicado em: 2021-02
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9. Biosorption Potential of the Aspergillus sp. and Insights into Secondary Metabolism in the Presence of Copper and Lead
The fungus Aspergillus sp. was isolated from copper mining rejects and cultured in a liquid culture medium (potato dextrose, PD) enriched with CuSO4.5H2O and Pb(NO3)2 in different concentrations. By flame atomic absorption spectrometry (FAAS) it was observed that fungus absorbed 86% of both copper and lead, with initial concentrations of 100, 500 and 1000 mg
J. Braz. Chem. Soc.. Publicado em: 2020-03
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10. JUDD-OFELT ANALYSIS OF Tb3+ AND UPCONVERSION STUDY IN Yb3+-Tb3+ CO-DOPED CALIBO GLASSES
We report on the study of the spectroscopic properties in Ytterbium-Terbium (Yb3+-Tb3+) co-doped calcium lithium borate (CaLiBO) glasses, with the study’s focus being on the upconversion process. Intensity parameters Ωλ for CaLiBO:Tb3+ are determined by the Judd-Ofelt method to be Ω2 = 15.5 × 10-20 cm2, Ω4 = 1.90 × 10-20 cm2 and Ω6 = 3.69 × 10-20 c
Quím. Nova. Publicado em: 2020-02
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11. DENSITY CALCULATIONS OF AQUEOUS AMINE SOLUTIONS USING AN EXCESS GIBBS BASED MODEL
Abstract Accurate representation of the physical properties of a solvent is essential for design and simulation of processes. Density and viscosity, for instance, have an important role in modelling and designing absorption and desorption towers. In the present work, a model to accurately calculate the density of aqueous amine solutions used in CO2 capture w
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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12. Evaluation of the Effect of the Incorporation of Blends of Fuel and Fluxing Wastes in Red Clay Ceramics
The clay samples endure the incorporation of industrial and urban wastes, which do not cause large variations in their properties if added in controlled quantities. Wastes can be classified as fuel, fluxing and property affecting wastes. The fuel wastes usually have a high amount of organic matter, that when heated cause exothermic reactions, releasing heat
Mat. Res.. Publicado em: 09/12/2019