• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.296-302
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• 2006

The kinetics of the thermal-oxidative decomposition of waste polyurethane (PU) according to oxygen concentration has been studied using a non-isothermal thermogravimetric technique at several heating rates from 10 to $50^{\circ}C/min$. A kinetic model accounting for the effects of the oxygen concentration by the differential and integral method based on Arrhenius equation was proposed to describe the thermal-oxidative decomposition of waste PU. To obtain the information on the kinetic parameters such as activation energy, reaction order, and pre-exponential factor, the thermogravimetric analysis curves and its derivatives have been analyzed using the kinetic analysis method proposed in this work. From this work, it was found that reaction orders for oxygen concentration had a negative sign, and activation energy decreased as the oxygen concentration increased. It was also found that the kinetic parameters obtained from the integral method using the single heating rate experiments varied with heating rates. Therefore, it is thought that the differential method using the multiple heating rate experiments more effectively represents the thermal-oxidative decomposition of waste polyurethane.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.709-716
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• 2009

A Kinetics pathway of oxidation of Cefpodoxime Proxetil by permanganate in alkaline medium at a constant ionic strength has been studied spectrophotometrically. The reaction showed first order kinetics in permanganate ion concentration and an order less than unity in cefpodoxime acid and alkali concentrations. Increasing ionic strength of the medium increase the rate. The oxidation reaction proceeds via an alkali-permanganate species which forms a complex with cefpodoxime acid. The latter decomposes slowly, followed by a fast reaction between a free radical of cefpodoxime acid and another molecule of permanganate to give the products. Investigations of the reaction at different temperatures allowed the determination of activation parameters with respect to the slow step of proposed mechanism and fallows first order kinetics. The proposed mechanism and the derived rate laws are consistent with the observed kinetics.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.146-146
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• 2019

• Journal of Energy Engineering
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• v.18 no.4
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• pp.239-246
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• 2009

A fundamental investigation has been conducted on the combustion of single particle of a sub-bituminous coal char burning at different temperatures and residence times. The lab-scale test setup consisted of a drop tube furnace where gas temperatures varied from $900^{\circ}C$ to $1400^{\circ}C$. A calibrated two color pyrometer, mounted on the top of the furnace, provided temperature profiles of luminous particle during a char oxidation. An amount of char mass reacted during the reaction is measured with thermogravimetry analyzer by using an ash tracer method. As a result, mass and area reactivity as well as reaction rate coefficients are determined for the char burning at atmospheric pressure condition.

• Journal of the Korean Chemical Society
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• v.18 no.2
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• pp.117-125
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• 1974

The catalytic reaction between carbon monoxide and oxygen was investigated in the presence of catalysts which were specially treated by applying an annealing method at different monoxide and oxygen and at reaction temperatures in the region of partial pressures of carbon $40^{\circ}C$ to $95^{\circ}C$. The oxidation rate is highest on NiO annealed at low temperature in vacuum. The data has been correlated with the first order kinetics, and the activation energies from the Arrhenius equation are found to be 4Kcal/mole in the region of the experimental temperatures. The excess oxygen in NiO obtained from the decomposition of $NiCO_3$does not cause activation at $95^{\circ}C$. But NiO catalysts annealed again in vacuum display activation even at $40^{\circ}C$. The quantity of the excess oxygen in NiO surfaces seems to be the controlling factor in determining the rates of oxidation of carbon monoxide.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.125-130
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• 2010

In the present work, we have investigated the adsorption efficiency of carbon/iron oxide nanocomposite towards removal of hazardous brilliant green (BG) from aqueous solutions. Carbon/iron oxide nanocomposite was prepared by chemical precipitation and thermal treatment of carbon with ferric nitrate at $750^{\circ}C$. The resulting material was thoroughly characterized by TEM, XRD and TGA. The adsorption studies of BG onto nanocomposite were performed using kinetic and thermodynamic parameters. The adsorption kinetics shows that pseudo-second-order rate equation was fitted better than pseudo-first-order rate equation. The experimental data were analyzed by the Langmuir and Freundlich adsorption isotherms. Equilibrium data was fitted well to the Langmuir model with maximum monolayer adsorption capacity of 64.1 mg/g. The thermodynamic parameters were also deduced for the adsorption of BG onto nanocomposite and the adsorption was found to be spontaneous and endothermic.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.05a
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• pp.82-82
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• 1999

• 한국전기화학회:학술대회논문집
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• 2001.10a
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• pp.9-9
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• 2001

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.121-125
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• 1994

The antioxidant activity of gingerol according to temperature on soybean oil were examined by measuring peroxide value(POV). The induction period(IP) of soybean oil was 45; 276.0, 65; 17.0 and 105$^{\circ}C$ : 4.7 hours respectively by-measuring POV. The relative antioxidant effectiveness(RAE) of ginge-rol group were 45; 191, 65; 200, 65: 150, 85: 132 and 105$^{\circ}C$;106%. 'The activation energies(Ea) and temperature coefficients(Q10) for Arrhenius equations at 45∼105$^{\circ}C$, was estimated in order to find out the influence of temperature on the oxidation of soybean oil contai-ning various antioxidants. The soybean oil was more unstable at 45∼65$^{\circ}C$ than at 65∼105$^{\circ}C$ in the Ea and Q10. The soybean oils containing gingerol were more stable than the control group at 45∼105$^{\circ}C$, however, BHT group was unstable compared to gingerol group at 85∼105$^{\circ}C$.

• Applied Biological Chemistry
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• v.32 no.1
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• pp.8-13
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• 1989

The rate constant and reaction order of the autoxidation of methyl linolenate were determined by using nuclear magnetic resonance spectrometer, and the applicability of nmr to the kinetic study was examined. The autoxidation was carried out under a mild condition, i.e., the air flow rate of 90m1/min and room temperature. The autoxidation of methyl linolenate followed the first-order kinetics, and the rate constant was found to be $1.96{\times}10^{-2}hr^{-1}$.