Reduction Kinetics
Mostrando 1-12 de 636 artigos, teses e dissertações.
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1. Evaluation of the influence of sodium and magnesium lignosulfonates on the hydration kinetics of cementitious paste
Abstract Motivated by their low cost, lignosulfonate-based water reducers are the most used type of admixture in the concrete industry worldwide. Due to the plurality of types of lignosulfonates (LSs) and the recent update to the Brazilian standard for admixtures for concrete, the objective of this work was to investigate the impact of sodium (Na-LS) and mag
Cerâmica. Publicado em: 2022
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2. Unified comprehension of the kinetics of isothermal ceramic processes under field-free and resonant wave-field conditions
Abstract This paper proposes a unified comprehension of the isothermal ceramic process kinetics stemming from mesoscopic irreversible thermodynamics. Accordingly, a unified process kinetic equation (UPKE) is derived, which predicts that the global isothermal process rate of any ceramic process is, in general, nonlinearly related both to its activation energy
Cerâmica. Publicado em: 2021-03
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3. ANALYTICAL EXPRESSIONS FOR THE CONCENTRATION AND CURRENT IN THE REDUCTION OF HYDROGEN PEROXIDE AT A METAL-DISPERSED CONDUCTING POLYMER FILM
A mathematical model describing the reduction of Hydrogen peroxide (H2O2) to water in a metal dispersed conducting polymer film is discussed. The model is based on a system of reaction-diffusion equations containing a non-linear term related to Michaelis-Menten kinetics of the enzymatic reaction. The approximate analytical expressions corresponding to the co
Quím. Nova. Publicado em: 2020-01
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4. 3D numerical investigation of mixture formation and combustion in a DISI engine at part-load under stratified operation
This work investigates through numerical simulation, the operation of a big bore direct fuel injection spark ignition engine, at part load under stratified operation. It evaluates fuel-air mixture preparation and combustion process with the adoption of detailed chemical kinetics mechanisms for both Isooctane and Ethanol, and applying adaptive mesh refinement
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2020
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5. DETERMINATION OF REACTIVITY AND THERMODYNAMIC ANALYSIS OF NICKEL-BASED OXYGEN CARRIERS FOR CHEMICAL-LOOPING COMBUSTION
Abstract This work aimed to study nickel-based oxygen carriers (OC) for Chemical Looping Combustion (CLC) using H2 and CH4 as fuel. The reactivity and reaction kinetics of the OC were investigated, applying the shrinking core, nucleation and diffusion models in three dimensions, as well as whether the OC is thermodynamically favorable for the reaction. The r
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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6. Preparation and application of Zero Valent Iron immobilized in Activated Carbon for removal of hexavalent Chromium from synthetic effluent
RESUMO Diferentemente dos contaminantes orgânicos, os metais pesados não são biodegradáveis e tendem a se acumular nos organismos vivos e também são reconhecidos por serem tóxicos ou carcinogênicos. A utilização de nanopartículas de ferro zero valente (nFVZ) é relatada como uma técnica alternativa e de elevado potencial para remediação in situ
Rev. Ambient. Água. Publicado em: 03/10/2019
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7. Estudo do envelhecimento e do tratamento térmico de rejuvenescimento da superliga GTD111
RESUMO A superliga de níquel GTD111 é comumente utilizada na fabricação de pás de turbinas a gás, destinadas a geração de energia e aplicações aeronáuticas. O presente estudo investiga o comportamento desta superliga “como fornecida” pelo fabricante e previamente tratada termicamente à fim de diminuir o tamanho de γ’ e transformá-lo de mo
Matéria (Rio J.). Publicado em: 16/09/2019
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8. STUDY OF THE CHROMIUM(VI) REMOVAL FROM AQUEOUS SYSTEMS BY COBALT NANOPARTICLES
The cobalt nanoparticles (NPs-Co) were synthesized and applied in the removal of Cr(VI). The obtained nanomaterials presented magnetic properties and were characterized by the techniques of Transmission Electron Microscopy and X-ray diffraction. The NPs-Co, with a diameter of less than 50 nm, had a composition based on metallic cobalt and cobalt oxide. The N
Quím. Nova. Publicado em: 18/07/2019
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9. Kinetics drying of silver banana (Musa spp.) in hybrid dryer
RESUMO A busca pela redução de custos de produção e diversificação de comercialização de produtos agrícolas torna-se necessária para autonomia e aumento de renda dos produtores rurais. A utilização de secadores solares para produção de frutas secas consiste em excelente alternativa a ser adotada. No entanto, para a introdução desta tecnologia
Rev. Ciênc. Agron.. Publicado em: 04/07/2019
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10. Softening Behavior During Annealing of Overaged and Cold-rolled Aluminum Alloy 7075
This work proposes studying the softening kinetics of aluminum alloy 7075-T6. Firstly, AA 7075 strips were overaged (300°C and 5 hours). Then, the overaged strips were cold-rolled at room temperature (45% in thickness reduction) and, after that, annealed at different temperatures (200°C and 250°C) and time intervals (30 minutes - 4 hours). By using polari
Mat. Res.. Publicado em: 30/05/2019
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11. Commercial and non-commercial pectinase and cellulase on the enzymatic hydrolysis efficacy of rice husk and Tifton 85 hay
ABSTRACT. The aim of this study was to evaluate the action of commercial and non-commercial cellulase and pectinase on rice husk and Tifton 85 hay hydrolyses. The hydrolysis kinetics of the substrates with commercial cellulase and pectinase were evaluated and the hydrolysis at different temperature and agitation conditions was maximized using experimental de
Acta Sci., Anim. Sci.. Publicado em: 29/04/2019
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12. Phosphate Adsorption by Montmorillonites Modified with Lanthanum/Iron and a Laboratory Test using Water from the Jacarepaguá Lagoon (RJ, Brazil)
Montmorillonites modified with lanthanum(III) and iron(III) were prepared from two commercial clays. These materials were characterized by powder X-ray diffraction analysis, X-ray fluorescence, infrared spectroscopy, N2 adsorption, and scanning electron microscopy. The incorporation of lanthanum(III) and iron(III) varied from 0 to 4.00%. The amount of these
J. Braz. Chem. Soc.. Publicado em: 2019-03