Rate Constants
Mostrando 1-12 de 1000 artigos, teses e dissertações.
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1. Nicotine as a Catalyst for Chlorination Promoted by Hypochlorous Acid: Experimental and Theoretical Studies
There is robust evidence of the hypochlorous acid (HClO)-mediated damage in biomolecules, and nicotine boosts the chlorination potency of HClO. We present experimental and theoretical evidence of the mechanism by which nicotine catalyzes the chlorination of pyranine. The rate constants for chlorination of pyranine by HClO were measured in the presence (5.3 �
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Theoretical Study of the Reactivity of Phenyl Radicals Toward Enol Acetates
Arylation reactions are an important class of reactions and allow the synthesis of natural and synthetic products. Despite the efficient, but high cost and toxic methodologies involving transition metals, radical arylations have gained importance after the advent of photoredox catalysis. Arylation of enol acetates is an important tool for obtaining aryl keto
J. Braz. Chem. Soc.. Publicado em: 2021-02
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3. Mitral Valve Replacement with Regent Aortic Valve in Severe Mitral Stenosis
Arylation reactions are an important class of reactions and allow the synthesis of natural and synthetic products. Despite the efficient, but high cost and toxic methodologies involving transition metals, radical arylations have gained importance after the advent of photoredox catalysis. Arylation of enol acetates is an important tool for obtaining aryl keto
Int. J. Cardiovasc. Sci.. Publicado em: 2021-02
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4. Additions and Corrections
The degradation of a pharmaceutical mixture (gemfibrozil, hydrochlorothiazide and naproxen) by TiO2/UV-A in different aqueous matrices was evaluated. The matrix components affected the operational conditions, rate constants, and removal efficiency of the pharmaceuticals, as well as toxicity. For sewage treatment plant effluent, a TiO2 concentration three-fol
J. Braz. Chem. Soc.. Publicado em: 2020-06
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5. Matrix Effects on the Degradation of Gemfibrozil, Hydrochlorothiazide, and Naproxen by Heterogeneous Photocatalysis
The degradation of a pharmaceutical mixture (gemfibrozil, hydrochlorothiazide and naproxen) by TiO2/UV-A in different aqueous matrices was evaluated. The matrix components affected the operational conditions, rate constants, and removal efficiency of the pharmaceuticals, as well as toxicity. For sewage treatment plant effluent, a TiO2 concentration three-fol
J. Braz. Chem. Soc.. Publicado em: 2020-06
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6. Kinetic modeling and evaluation of free radical-scavenging behavior in oils: application to four tropical and subtropical fruits in a DPPH system
Abstract A kinetic model was developed to represent the radical-scavenging capacity (RSC) for the oxidation of oils. The model was developed using second-order rate constants (k2) to represent the RSC. The RSC of the oils can be compared by the k2 values indicating their scavenging capacity. Furthermore, the k2 values can be used to determine the decay kinet
Food Sci. Technol. Publicado em: 2020-06
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7. The Catalytic Action of Copper Ions and the Rosemary Extract Antioxidant Effect in the Biodiesel Oxidation Reaction and the Implication in Arrhenius Behavior
Biodiesel contains esters in its composition which make it susceptible to oxidation. Among the factors that cause this reaction is the contamination with metal ions. In the present work, it was analyzed biodiesel samples obtained from a mixture containing 39.0% m/m soybean oil, 22.0% m/m beef tallow and 39.0% m/m poultry fat using a methyl route. Copper ions
J. Braz. Chem. Soc.. Publicado em: 2020-06
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8. Chemically Reduced Graphene Oxide on Gold Electrodes from Recordable CDs: Characterization and Potential Sensing Applications
This work presents the development and characterization of a new chemically modified electrode exploiting recordable Au-rewritable compact discs (AuCDs) as substrate for drop casting of a chemically-reduced graphene-oxide slurry focusing on simple and low-cost electrochemical sensors. Increase in electrochemical responses in cyclic voltammetric and amperomet
J. Braz. Chem. Soc.. Publicado em: 2020-03
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9. Mathematical Modeling of the Transesterification Reaction by Finite Elements: Optimization of Kinetic Parameters Using the Simplex Sequential Method
The use of biodiesel as fuel has been presented as a viable alternative in the search for renewable energies. It can be produced from the transesterification reaction of vegetable oils with methanol in the presence of sodium or potassium hydroxide as catalysts. In the present research, the transesterification reaction of soybean oil was modeled considering t
J. Braz. Chem. Soc.. Publicado em: 2020-02
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10. Hardening and Dynamic Recovery During Hot Compression Test of Copper Simulated as Viscoplastic Material
The Norton-Bailey equation was used to simulate by finite elements the hardening and dynamic recovery of copper during the hot compression tests. The constants of Norton-Bailey equation were determined from the Voce-Kocks model. The simulation assumes a Mortar Contact with Coulomb friction and axial symmetry. Numerical results were compared with experiments.
Mat. Res.. Publicado em: 05/12/2019
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11. Kinetic modeling and evaluation of free radical-scavenging behavior in oils: application to four tropical and subtropical fruits in a DPPH system
Abstract A kinetic model was developed to represent the radical-scavenging capacity (RSC) for the oxidation of oils. The model was developed using second-order rate constants (k2) to represent the RSC. The RSC of the oils can be compared by the k2 values indicating their scavenging capacity. Furthermore, the k2 values can be used to determine the decay kinet
Food Sci. Technol. Publicado em: 09/09/2019
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12. CaTiO3 Perovskite in the Photocatalysis of Textile Wastewater
Resumo O material CaTiO3 do tipo perovskita foi sintetizado pelo método dos precursores poliméricos e caracterizado. Os parâmetros da reação fotocatalítica foram otimizados pela metodologia de análise de superfície de resposta na degradação do azul de metileno sob radiação UV. Após a otimização, as águas residuais têxteis e de curtume foram
Rev. Ambient. Água. Publicado em: 03/06/2019