Chemical Kinetics
Mostrando 1-12 de 436 artigos, teses e dissertações.
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1. Chemical and antioxidant characterization, sensory and shelf-life analysis of cereal bars with almonds from pequi (Caryocar brasiliense Camb.)
Abstract The study aimed to know how almonds from Pequi (Caryocar brasiliense Camb.), a byproduct of this fruit from Brazilian Cerrado, can be used to improve value to cereal bars. To respond to this question, the study characterized pequi almonds and cereal bars with pequi, and evaluate sensory acceptance. The preparation of cereal bars enriched with pequi
Food Sci. Technol. Publicado em: 2021-06
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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. Estudo e validação de uma progressão de aprendizagem em cinética química de estudantes de nível superior
This work aims to study the learning progression of students from two federal universities in Rio de Janeiro within the scope of Chemical Kinetics. For the elaboration of the research questionnaire, 46 professors from eleven Brazilian universities were consulted and from the collected data, a questionnaire was elaborated and applied to 452 students of Pharma
Quím. Nova. Publicado em: 2021-03
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4. IMIDAZOL E CATÁLISE: UM PAR PERFEITO
The imidazole (IMZ) ring presents several chemical properties that turns it into a versatile acid-basic/nucleophilic catalyst. The discovery of the biological properties of histidine (amino acid with IMZ ring) instigates the study of this class of compounds. It is found in nature in several enzymes such as chymotrypsin and RNAses due to these properties. Thi
Quím. Nova. Publicado em: 2021-03
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5. Structural and Functional Stabilization of Sericin from Bombyx mori Cocoons in a Biopolysaccharide Film: Bioorigami for Skin Regeneration
Development and optimization of a bioorigami film with silk sericin was pursued for skin regeneration. Several formulations were produced, with varying integrated sericin contents, viz. 0, 1, 2, 5, 10, 20 and 50 mgsericin mLfilm-1. The physico-chemical characteristics of the bioorigami films produced were evaluated via infrared spectrophotometry, X-ray diffr
J. Braz. Chem. Soc.. Publicado em: 2020-04
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6. Residue-Based CaO Heterogeneous Catalysts from Crab and Mollusk Shells for FAME Production Via Transesterification
The production of fatty acid methyl esther (FAME) via transesterification was studied, assessing the influence of CaO heterogeneous catalysts obtained from four different fishery residues: sururu, crab, clam and mussel. Characterization and properties of the residues were obtained via thermogravimetric analysis, X-ray diffraction, X-ray fluorescence, Fourier
J. Braz. Chem. Soc.. Publicado em: 2020-04
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7. ELECTROCHEMICAL INCINERATION OF SHORT-CHAIN CARBOXYLIC ACIDS WITH NB‑SUPPORTED BORON DOPED DIAMOND ANODE: SUPPORTING ELECTROLYTE EFFECT INTO THE ELECTROGENERATED OXIDANT SPECIES (HYDROXYL RADICALS, HYDROGEN PEROXIDE AND PERSULFATE)
This work describes the electrochemical oxidation study of three short chain carboxylic acids (acetic, oxalic and formic 0.18 mol L-1) using different electrolysis conditions (electrolyte composition and current density) in an electrochemical reactor fitted with niobiumsupported/BDD electrode (Nb/BBD) as anode and titanium plate as cathode. The experiments w
Quím. Nova. Publicado em: 2020-03
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8. 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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9. 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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10. Characterization of Austenite Decomposition in Steels with Different Chemical Concepts and High Potential to Manufacture Seamed Pipes for Oil and Gas Industry
This work presents the characterization of austenite decomposition kinetics in two steels during continuous cooling considering non-deformed austenite grains. Two different chemical concepts of steels were evaluated: low carbon - high manganese and a relatively new concept based on low carbon - low manganese - high niobium contents. Dilatometric experiments,
Mat. Res.. Publicado em: 21/10/2019
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11. 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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12. Lithium catalyst concentration influence on bio-polyols structure and polyurethane adhesives properties
ABSTRACT Polyol structure can be affected by the catalyst used for its synthesis and may affect the curing kinetics and mechanical strength of the final polyurethane (PU). This work aimed to study the influence of catalyst concentration on the structure of bio-based polyols and on the final properties of the polyurethane adhesive obtained from these polyols.
Matéria (Rio J.). Publicado em: 16/09/2019