Reaction Kinetics
Mostrando 13-24 de 1045 artigos, teses e dissertações.
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13. KINETIC STUDIES OF HYDROLYSIS REACTION OF NaBH4 WITH γ-Al2O3 NANOPARTICLES AS CATALYST PROMOTER AND CoCl2 AS CATALYST
Abstract Solid-state hydrogen storage is of considerable concern as a potential hydrogen source for portable fuel cell applications. This study mainly focuses on kinetics of NaBH4/Al2O3 nanoparticles (20 nm)/H2O system with CoCl2 as catalyst and the factors that affect the hydrogen generation rate (HGR). It is observed that the reaction rate increases consid
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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14. Kinetics of the Carbonation Reaction of Lithium Orthosilicate Using a Typical CO2 Concentration of Combustion Gases
The aim of this work was to investigate the carbonation kinetics of lithium orthosilicate (Li4SiO4) by thermogravimetry and via thermodynamic simulations, using CO2 concentrations of 15 vol.% (typical of combustion gases) and 100 vol.%. Tests were performed in a thermogravimetric analyzer, in two sequential steps: (1) pre-treatment at 750 ºC with N2 and (2)
Mat. Res.. Publicado em: 05/09/2019
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15. Effect of drying temperature on color and desorption characteristics of oyster mushroom
Abstract Oyster mushroom (Pleurotus ostreatus) slices were dried in a hot air dryer at three temperatures (45, 55 and 65 °C). The sorption isotherm of dried samples in the water activity (aw) range of 0.556-0.970 was also determined at three temperature levels. Moisture desorption isotherms were obtained from changes in water activities of oyster mushroom s
Food Sci. Technol. Publicado em: 15/08/2019
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16. POLYPHENOL OXIDASE AND PEROXIDASE ENZYME ASSAYS IN SWEET POTATO CULTIVARS HARVESTED AT DIFFERENT TIMES
RESUMO Ensaios enzimáticos são baseados em metodologias descritas na literatura. Entretanto, a cinética enzimática deve ser ajustada para resultados mais confiáveis. Objetivou-se ajustar os ensaios testando diferentes volumes de extrato de polifenoloxidase (PPO) e peroxidase (POD) e tempos de reação em cultivares de batata-doce colhidas em diferentes
Rev. Caatinga. Publicado em: 18/07/2019
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17. Avaliação e estabilidade da cor em filés de burriquete (Pogonias cromis) utilizando um sistema de visão computacional
Resumo A cor da superfície da carne é a primeira sensação que o consumidor percebe e utiliza como uma ferramenta para aceitar ou rejeitar um alimento. A medição e a avaliação da cor da carne podem também ser feitas por um indicador químico (metamioglobina) ou pela avaliação física, utilizando espaços da cor (a* e R). O objetivo deste trabalho f
Braz. J. Food Technol.. Publicado em: 13/06/2019
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18. Kinetic modeling of sugarcane juice clarification by ozonation in batch reactor with ozone saturation control
Abstract This work presents the mathematical modeling of clarification kinetics of the sugarcane juice by ozonation in batch reactor considering the reaction occurs homogeneously and ozone saturation in the juice is guaranteed. The sugarcane juice color was considered proportional to the light absorbance at wavelength λ = 420 ηm, according to the Internat
Food Sci. Technol. Publicado em: 11/04/2019
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19. Effects of gamma radiation on the stability and degradation kinetics of phenolic compounds and antioxidant activity during storage of (Oryza sativa L.) black rice flour
Abstract The effects of gamma radiation (0, 1, 2 and 3 kGy) were used to evaluate the stability and thermal degradation kinetics of anthocyanins, as well as the stability of total phenolic compounds (TPC) and antioxidant activity at different temperatures (4, 25, 35 and 45 °C) during the storage (0, 30, 60, 90 and 120 days) of black rice flour. This flour c
Braz. arch. biol. technol.. Publicado em: 28/03/2019
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20. COD removal from sucrose solution using hydrodynamic cavitation and hydrogen peroxide: a comparison between Venturi device and orifice plate
RESUMO O objetivo deste estudo foi comparar a eficiência de remoção de DQO de um Venturi e de uma placa de orifício. Adicionalmente, a otimização da pressão de entrada dos dispositivos, o estudo da cinética da degradação, e o efeito sinérgico resultante da combinação da cavitação e H2O2 foram realizados. Um aparato experimental em escala labo
RBRH. Publicado em: 28/02/2019
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21. Influence of Electrooxidation of Ni Wire Electrodes on the Kinetics of Oxygen Evolution Reaction Studied in 0.1 mol dm-3 NaOH
This work reports on oxygen evolution reaction (OER), studied at nickel wire electrode material. Electrocatalytic behavior of non-oxidized and electrooxidized Ni wire samples was evaluated in 0.1 mol dm-3 NaOH solution for the potential range: 1600-2000 mV vs. RHE. The performance of nickel electrodes was examined by alternating current (a.c.) impedance spec
J. Braz. Chem. Soc.. Publicado em: 2019-02
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22. Effect of Blanching on Enzyme Activity and Bioactive Compounds of Blackberry
ABSTRACT The inactivation of peroxidase and polyphenol oxidase and the degradation of phenolic compounds, anthocyanins, and antioxidant activity in blackberry were investigated during blanching in water at 80-90 °C, and in steam, from 0 to 10 minutes. The enzyme kinetics indicated the presence of two isoenzymes with different thermal stability, following tw
Braz. arch. biol. technol.. Publicado em: 14/11/2018
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23. Non-isothermal decomposition kinetics of conductive polyaniline and its derivatives
Abstract The non-isothermal decomposition kinetics of conductive polyaniline (PANI) and its derivatives, poly(o-methoxyaniline) (POMA) and poly(o-ethoxyaniline) (POEA), was investigated by thermogravimetric analysis (TGA), under inert and oxidative atmospheres, using Flynn-Wall-Ozawa’s approach to assess the kinetic parameters of the decomposition process
Polímeros. Publicado em: 21/09/2018
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24. Estudio de la cinética de la disolución de los barros residuales de las industrias borateras con soluciones de glicerina
ABSTRACT In this paper the dissolution kinetics of industrial boron wastes residual with glycerin solutions (C3H8O3), effluent from the biodiesel industry, with the aim of enhancing the utilization both wastes, were investigated. It is based on the complexation of boron with the polyol. The dissolution is carried out in a batch reactor at atmospheric pressur
Matéria (Rio J.). Publicado em: 19/07/2018