Kinetic Constant K
Mostrando 1-12 de 196 artigos, teses e dissertações.
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1. Influência do etanol como cosubstrato na biorremediação de água contaminada com formulação comercial à base de glifosato
RESUMO O presente trabalho objetivou avaliar a eficiência e a cinética de degradação de formulação comercial à base de glifosato em amostras de água, previamente contaminadas, via processo aeróbio, utilizando etanol como cosubstrato no processo. Utilizou-se um reator aeróbio com capacidade volumétrica de 1 L, operado em sistema de batelada sequenc
Eng. Sanit. Ambient.. Publicado em: 25/11/2019
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2. 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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3. Experimental study of the kinetics of the adsorption of nitrogen by coal containing different amounts of water
Abstract: Useful insight can be gained into the underlying adsorption mechanism by studying the adsorption of nitrogen by primary structure coal with different water content. In this work, a coal-adsorption gas experimental system is used to investigate the adsorption of nitrogen by coal samples containing different amounts of water ( 2.894%, 1.871%, 0.897%,
An. Acad. Bras. Ciênc.. Publicado em: 02/09/2019
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4. Determinação da cinética de ozonização de efluente têxtil na remoção de cor e matéria orgânica
RESUMO A oxidação do afluente e efluente têxtil foi feita em batelada durante 5 e 2 h, respectivamente. A geração de h-1 ozônio utilizada foi de aproximadamente 1085,25 mgO3 com vazão de ar de 8 L min-1. Foram determinados os seguintes parâmetros físico-químicos: temperatura, pH, turbidez, condutividade, cor verdadeira, alcalinidade a bicarbonato,
Matéria (Rio J.). Publicado em: 20/05/2019
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5. EFFECTIVE ALKALINE PEROXIDE OXIDATION PRETREATMENT OF SHEA TREE SAWDUST FOR THE PRODUCTION OF BIOFUELS: KINETICS OF DELIGNIFICATION AND ENZYMATIC CONVERSION TO SUGAR AND SUBSEQUENT PRODUCTION OF ETHANOL BY FERMENTATION USING Saccharomyces cerevisiae
Abstract Shea tree sawdust delignification kinetic data during alkaline peroxide pretreatment were investigated at temperatures of 120 °C, 135 °C, and 150 °C. The activation energy during delignification was 76.4 kJ/mol and the Arrhenius constant was calculated as 8.4 x 106 per min. The reducing sugar yield for the treated to the untreated biomass was abo
Braz. J. Chem. Eng.. Publicado em: 2016-03
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6. Potentiometric Titration and Out-Of-Equilibrium pH Response of the Biotite‑Water System
Minerals in soils contribute significantly to the capacity of soils to buffer pH disturbance. In this paper, we present the pH buffering capacity of a common soil phyllosilicate mineral, biotite. We performed equilibrium potentiometric titrations and we also monitored the pH response kinetics of the mineral-water system in order to develop an out-of-equilibr
J. Braz. Chem. Soc.. Publicado em: 2015-09
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7. DETERMINATION OF THE KINETIC PARAMETERS OF OXY-FUEL COMBUSTION OF COAL WITH A HIGH ASH CONTENT
Abstract The aim of this study was to determine the kinetic parameters of the oxy-fuel combustion of char from a Brazilian bituminous coal with a high ash content. The char, with a particle diameter of 715 μm, was prepared in a N2 atmosphere at 1173 K. The oxy-fuel combustion assays were performed using a thermobalance at different temperatures and O2/CO2 g
Braz. J. Chem. Eng.. Publicado em: 2015-03
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8. Wet oxidation of glycerol into fine organic acids: catalyst selection and kinetic evaluation
The liquid phase oxidation of glycerol was performed producing fine organic acids. Catalysts based on Pt, Pd and Bi supported on activated carbon were employed to perform the conversion of glycerol into organic acids at 313 K, 323 K and 333 K, under atmospheric pressure (1.0 bar), in a mechanically agitated slurry reactor (MASR). The experimental results ind
Braz. J. Chem. Eng.. Publicado em: 2014-12
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9. Fluid volume kinetics of dilutional hyponatremia; a shock syndrome revisited
OBJECTIVE: To evaluate whether the pathophysiology of shock syndromes can be better understood by comparing central hemodynamics with kinetic data on fluid and electrolyte shifts. METHODS: We studied the dilutional hyponatremic shock that developed in response to overhydration with electrolyte-free irrigating fluid - the so-called ‘transurethral resecti
Clinics. Publicado em: 2014-02
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10. Decaimento de íons cianato e a formação de carbamato de etila
Cyanate ion stability was studied in aqueous/ethanolic solutions, pH = 4.5 (CH3COOH/NaCH3COO), at different temperatures. Following the decay [(OCN)-] versus time, in the presence of excess C2H5OH, the rate constant for this reaction (k1) was calculated as (2.5 ± 0.3) x 10-4 s-1 at 25 ºC, for 0 < [C2H5OH] < 13.7 x 10-1 mol L-1. For [C2H5OH] > 2.0 mol L-1 a
Quím. Nova. Publicado em: 2013
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11. Cefuroxime axetil loaded gastroretentive floating tabletsbased on hydrophilic polymers: preparation and in vitro evaluation
The aim of this work was to study the formulation and in vitro characterization of hydro dynamically balanced floating matrix tablets using Cefuroxime axetil (CA) as model drug. Different excipients such as hydroxy propyl methyl cellulose (HPMC) K15M, E5LV (gelling agent), sodium bicarbonate (gas generating agent) and sodium lauryl sulfate (SLS) (solubility
Brazilian Archives of Biology and Technology. Publicado em: 2012-04
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12. Effect of dye structure and redox mediators on anaerobic azo and anthraquinone dye reduction
We investigated the biological decolourisation of dyes with different molecular structures. The kinetic constant values (k1) achieved with azo dye Reactive Red 120 were 7.6 and 10.1 times higher in the presence of RM (redox mediators) AQDS and riboflavin, respectively, than the assays lacking RM. The kinetic constant achieved with the azo dye Congo Red was 4
Química Nova. Publicado em: 2012