• 한국수소및신에너지학회논문집
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• 제13권2호
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• pp.119-126
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• 2002

The methanol partial oxidation using commercial $CuO/ZnO/Al_2O_3$ catalysts in a plug flow reactor was studied in the temperature range of $200{\sim}250^{\circ}C$ at atmospheric pressure, It was achieved the high activities by Cu-based catalysts and the selectivity of $CO_2$/$H_2$ was 100% when $O_2$ was fully convened. The reactivity changes and their hysteresis with increasing/decreasing temperatures were observed due to the chemical state differences between the oxidation and the reduction on the Cu surface, It was suggested as the two-step reaction: the complete oxidation and the following steam reforming for methanol, which was indicated by the distributions of final products vs. the residence time. In addition, the complete oxidation step was shown to be extremely fast and the total reaction rate can be controlled by the steam reforming reaction.

• Asian-Australasian Journal of Animal Sciences
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• 제23권3호
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• pp.312-317
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• 2010

Complete oxidation of fatty acid in the liver of ketotic cows was investigated. Serum non-esterified fatty acid (NEFA), beta-hydroxybutyric acid (BHBA) and glucose concentrations were measured using biochemical techniques. Carnitine palmitoyl transferase II (CPT II), 3-hydroxy acyl-CoA dehydrogenase (HAD) and oxaloacetic acid (OAA) concentrations in the liver were detected by ELISA. Serum glucose was lower in ketotic cows than controls (p<0.05). Serum BHBA and NEFA concentrations were higher in ketotic cows than controls (p<0.05). OAA, CPT II, and HAD contents in the liver of ketotic cows were lower than in controls (p<0.05). There were negative correlations between serum NEFA concentration and OAA, CPT II and HAD, but no correlation between serum BHBA concentration and capacity for complete oxidation of fatty acid. Overall, the capacity for complete fatty acid oxidation in the liver of ketotic cows might have been decreased. High serum NEFA concentrations may be unfavorable factors for the pathway of complete oxidation of fatty acid in the liver.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2461-2465
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• 2013

Pd-$Ce/{\gamma}-Al_2O_3-TiO_2$ catalysts were prepared by combined sol-gel and impregnation methods. Transmission electron microscopy, X-ray diffraction, $H_2$-temperature-programmed reduction, $O_2$-temperature-programmed desorption, and ethanol oxidation experiments were conducted to determine the properties of the catalysts. Addition of an optimal amount of Ce improved the performance of the $Pd/{\gamma}-Al_2O_3-TiO_2$ catalyst in promoting the complete oxidation of ethanol. The catalyst with 1% Ce exhibited the highest activity, and catalyzed complete oxidation of ethanol at $175^{\circ}C$; its selectivity to $CO_2$ reached 87%. Characterization results show that addition of appropriate amount of Ce could enrich the PdO species, and weaken the Pd-O bonds, thus enhancing oxidation ability of the catalyst. Meanwhile, the introduction of $CeO_2$ could make PdO better dispersed on ${\gamma}-Al_2O_3-TiO_2$, which is beneficial for the improvement of the catalytic oxidation activity.

• 한국세라믹학회지
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• 제43권12호
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• pp.805-811
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• 2006

The microstructural changes in Ni/YSZ anode substrate and crack formation during Ni oxidation were investigated. The composition of as-sintered anodes was 56 wt% NiO+44 wt% YSZ and that of electrolyte was 8 mol% yttria. After complete reduction, specimens were oxidized in $N_2$ + air at $600\sim800^{\circ}C$. Oxygen partial pressure was controlled in between 0.05 atm and 0.2 atm $O_2$. When the anode was oxidized, at higher than $690^{\circ}C$, three layers were formed in the specimens. The first was fully oxidized layer(NiO/YSZ), the second was a mixed layer and the third, near-intact layer. Under $640^{\circ}C$ such distinctive layers were not observed. Cracks formed at electrolyte layer when weight gain attained at $65\sim75%$ of the total gain due to complete oxidation despite of different oxidation temperature and oxygen partial pressure.

• 한국물환경학회지
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• 제18권2호
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• pp.169-187
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• 2002

The effects of important parameters such as reaction time and pH on the Fenton's process were evaluated using a batch reactor. It was proven that organic materials and heavy metals in leachate could be successfully removed by Fenton's reagent. Favorable operation conditions were investigated. It was observed that the reaction between ferrous iron and hydrogen peroxide with the production of hydroxyl radical was almost complete in 10 minutes. That is, the oxidation of organic materials by Fenton's reagent was so fast that it was complete in 30 minutes with batch experiments. With the formation of carbonic acid, pH of the batch reactor decreased to favorable acidic conditions without acid addition. The oxidation of organic materials in the leachate showed a pH dependence and was most efficient in the pH range of 2-3.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.267-268
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• 2012

Soot formation and oxidation characteristics of air-diluted propane diffusion flames have been experimentally investigated under the elevated pressure conditions. PAH concentrations showed more pressure sensitive behavior comparing to soot volume fractions. The flame/soot temperatures in soot oxidation region were obtained using the MOLLIP technique. Under the complete soot oxidation environment, the flame/soot temperature is increased with pressure. The increased temperature could accelerate the soot oxidation process and then exothermic oxidation reaction, in turn, could further raise the flame/soot temperature, which would result in the enhancement of soot oxidation process.

• 공업화학
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• 제9권4호
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• pp.497-503
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• 1998

알루미나에 담지한 귀금속 촉매를 이용하여 1.2-dichloroethane의 산화분해반응을 수행하였다. 실험결과 전환율은 Ru > Pt > Pd $${\sim_=}$$ Rh 순으로 높게 나타났으나, 완전산화 반응이 일어날 때의 주생성물인 $CO_2$로의 전환율 및 선택도를 기준으로 활성을 비교할 때 Pt/alumina가 Ru/alumina보다 활성이 높게 나타났다. $CO_2$ 및 vinyl chloride가 반응 주생성물로 검출되었는데, 반응 생성물 분포로부터 1.2-dichloroethane의 분해반응 경로는 1단계로 dehydrochlorination에 의해 vinyl chloride가 생성된 후 2단계로 vinyl chloride가 $CO_2$로 oxidation됨을 알 수 있었다. 염소를 포함하고 있는 반응 주생성물인 HCl의 영향을 살펴보기 위하여 반응물에 HCl을 첨가하여 반응을 수행하였는데 $300^{\circ}C$ 이하에서는 HCl이 촉매 표면에 흡착함에 따라 표면의 산도를 증가시켜 1.2-dichloroethane의 전환율은 증가하지만 $300^{\circ}C$ 이상에서는 HCl과 촉매 표면과의 상호작용이 약해져 전환율에는 큰 영향을 주지 않았다. 또한 촉매 표면에 가역적으로 흡착된 HCl은 1.2-dichloroethane의 $CO_2$로의 완전산화 반응을 방해함을 확인하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.800-807
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• 2001

This study was designed to investigate the antioxidative activity of a substance isolated from. The antioxidative activity of procyanidine was higher than that of dl-tocopherol and BHA on low-density lipoprotein (LDL) oxidation by thiobarbituric acid reactive substance (TBARS). Procyanidine inhibited the copper-mediated oxidation of human LDL in a dose dependent manner with almost complete inhibition at $60{\mu}g/mL$. Procyanidine at a concentration of $80{\mu}g/mL$ in hibited oxidation of LDL induced by J774. LDL oxidized by copper-mediated or cell-induced oxidation was degraded at a much greater rate than native LDL. These results suggested the importance of further research to procyanidine in the investigation of atherosclerosis and free radical-induced injury.

• 한국분말재료학회지
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• 제6권3호
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• pp.209-214
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• 1999

The oxidation behavior of the simulated spent fuel of burn up 33 MWD/kgU was investigated to predict that of the spent fuel in the temperature ranges of 400 to $700^{\circ}C$ and was compared with those of $UO_2$. The forms of uranium oxides after the oxidation were conformed by XRD analyses. The oxidation rate at each the temperature and the activation energy were obtained. After complete oxidation, the simulated spent fuel was converted to $U_3O_8$ and pulverized to powder due to the density difference between the simulated spent fuel and uranium oxides. The activation energies were 85.35 and 30.77kJ/mol in the temperature ranges of 400$\leq$T($^{\circ}C$)$\leq$500 and 500$\leq$T($^{\circ}C$)$\leq$700, respectively.

• 한국식품영양과학회지
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• 제26권3호
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• pp.422-429
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• 1997

For the complete and accurate amino acid determination of protein and food samples, 3 different hydrolysis procedures have been conducted in parallel for each sample, which include the alkaline hydrolysis for tryptophan determination, performic acid oxidation prior to the acid hydrolysis for the determination of cysteine and cystine, and the 6N HCl hydrolysis for the determination of the rest of amino acids. In the present study, amino acid concentrations obtained from the modified single hydrolysis procedure were compared with the values from the conventional hydrolysis procedures in casein and nine food and composite dish samples. In most of the samples tested, the modified single hydrolysis procedure gave significantly higher values of cysteins and cystein compared to the performic acid oxidation method, but resulted in a considerable destruction of tryptophan in food and composited dish samples. There was no consistent difference in the rest of amino acid concentrations between the two hydrolysis systems. Therefore, for complete amino acid determination of various foods and composite dishes, the single hydrolysis method may replace the 6N HCl hydrolysis and performic acid oxidation methods, and thereby reduces 3 hydrolyses to 2 steps with much higher recoveries of the sulfur containing amino acids.