Activation Energy
Mostrando 1-12 de 1076 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. Tuning the Photocatalytic Activity of Tin Oxide through Mechanical Surface Activation
Tin oxide (SnO2) nanoparticles were synthesized by the co-precipitation method and mechanically modified by high-energy ball milling. The experimental results demonstrate that the collision with zirconia balls produces slight changes in the crystalline, electronic, morphological, and surface properties of SnO2, which lead to an increase in the redox potentia
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Catalytic Effects of Ruthenocene Bimetallic Compounds Derived from Fused Aromatic Ring Ligands on the Main Oxidizing Agent for Solid Rocket Motor
We report the catalytic effect of three ruthenocene bimetallic compounds derived from fused aromatic rings of general formula [{Cp*Ru}2L], with Cp*: pentamethylcyclopentadiene and L = pentalene (1), 2,6-diethyl-4,8-dimethyl-s-indacene (2), and 2,7-diethyl-as-indacene (3), on the thermal decomposition of ammonium perchlorate (AP). The new compound 3 was chara
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Heterogeneous Fenton-like catalytic degradation of phenazine dye over CeO2 (CP-2) nanoscale powder
Abstract A heterogeneous Fenton-like process was explored for oxidation of phenazine dye using ceria polishing material (CP-2). XRD, SEM, FTIR, UV-vis DRS, and pHPZC techniques were applied to characterize the catalyst features. The performance of the heterogeneous Fenton-like process was investigated under various parameters (reaction time, pH, H2O2 concent
Cerâmica. Publicado em: 2022
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5. Morphology Behavior of Copper Films Deposited after Wet Surface Treatment on Polished Alumina
In this paper, a pre-treatment process for electroless copper (Cu) deposition on the polished alumina (Al2O3) 99.9% and the behavior of Cu plating by electroless process after Al2O3 surface treatment were explored. Our work was carried out by changing the roughness of Al2O3 through micro-etching (coarsening), nucleation its surface by a two-step method (sens
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. Mathematical modeling of whey foam mat drying
ABSTRACT This study aimed to fit mathematical models to whey foam drying processes in different air temperature conditions, to determine the effective diffusion coefficient and to obtain the activation energy. For foam formation, 5.0% Emustab® was added to the serum in mass and subjected to stirring in a domestic shaker for 15 min. After, it was spread onto
Rev. Ceres. Publicado em: 2021-08
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7. Sintering mechanisms of partially stabilized zirconia (TZ3Y) with ZnO and Co3O4 as sintering additives
Abstract In this work, the sintering mechanisms of 3 mol% yttria-stabilized zirconia (TZ3Y) and TZ3Y containing 0.3 wt% of ZnO or Co3O4 were analyzed by determining the apparent activation energy of sintering from dilatometry data and observing the evolution of microstructure. Dilatometry test was performed at a heating rate ranging from 5 to 20 °C/min from
Cerâmica. Publicado em: 2021-06
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8. 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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9. Ferrimagnetic to paramagnetic transition and dielectric relaxation in Ni1-xZnxFe2O4 ferrites
Abstract The spinel ferrite system Ni1-xZnxFe2O4 (x=0-0.7, Δx=0.1) was prepared by wet chemical co-precipitation method using sulfates of respective metal ions. The electrical resistivity and dielectric properties of the prepared samples have been studied as a function of temperature, frequency, and Zn content (x). The DC resistivity (ϱ) was measured in th
Cerâmica. Publicado em: 2021-06
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10. 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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11. 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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12. Thermoelectric properties of barium doped calcium cobaltite obtained by simplified chemical route
Abstract Calcium cobaltite (CCO) thermoelectric ceramics in Ca3Co4O9 and Ca2.95Ba0.05Co4O9 compositions were produced by a simplified chemical route developed in this study. Undoped ceramics sintered at 1193 K for 12 h presented a bulk density equivalent to 77% of the theoretical density, one of the highest values ever found for conventionally sintered undop
Cerâmica. Publicado em: 2021-03