• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1094-1100
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• 1997

Effects of sodium hypochlorite (NaOCl) concentration, temperature and pH on oxidation mechanism of corn starch were investigated. The rate of oxidation was dependent on the concentration of hypochlorite, pH and temperature of oxidation. The reaction was either first or second order depending on the concentration of NaOCl. At oxidant concentration of $0.75{\sim}3.0%$ active Cl/g starch, the reaction was first-order and it was second-order at $3.75{\sim}4.5%$ active Cl/g starch. The first-order rate constants were increased with increasing oxidant concentration. The rate of oxidation of starch was highest at pH 7 and decreased with increasing acidity or alkalinity of the medium. As the reaction temperature increased, the rate of oxidation was increased.

• Journal of the Korean Electrochemical Society
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• v.24 no.1
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• pp.7-12
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• 2021

In this study, we investigated the formation of the metal oxide nanostructure by anodization of aluminum 3104H18 alloy. The anodization was performed in pyrophosphoric acid (H4P2O7) electrolyte. By the control of anodization condition such as concentration of electrolyte, anodization temperature and applied voltage, nanoporous or nanofiber structures were obtained. The optimal anodization condition to form nanofiber structures are 75 wt% of H4P2O7 at 30 V and 20℃. When anodization was performed at over 40 V, nanoporous structures were formed due to accelerated dissolution reaction rate of nanofiber structures or increasing thickness of channel wall.

• Journal of fish pathology
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• v.3 no.2
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• pp.69-77
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• 1990

Tilapia, Oreochromis niloticus, weighing 100g on average was fed on the oxidized pellet diets in peroxide value (POV) 102 meq/kg, with or without the vitamin mixture of C and E for 67 days. After administration of vitamin mixture for 67 days, the fish fed them displayed better growth than the fish fed oxidized pellet only. The fish fed low level of the vitamin mixture or the oxidized pellet retained visceral ceroidosis but did not show myopathy. But the fish administered high level of the vitamin mixture lossed macrophages disposing of ceroid in the viscera. Based on the results, the administration of vitamin mixture at high level was effective as prophylaxis for ceroidosis.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.660-666
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• 2008

This study was designed to compare the thermal oxidative stability of lard, soy bean oil, and hot pepper seed oil for 0-3 d at $100^{\circ}C$, and to evaluate the effect of capsaicin on thermal oxidative stability in lard and soy bean oil. As result, thermal oxidation stability was shown in the order hot pepper seed oil>soy bean oil>lard for 0-3 d at $100^{\circ}C$. In blended oils, hot pepper seed oil effectively inhibited lipid oxidation when mixed with lard than soy bean oil by showing the ratio of 30% pepper seed oil plus 70% lard and 60% pepper seed oil plus 40% soy bean oil inhibited lipid oxidation during storage periods. And to investigate the antioxidative effect of antioxidants such as capsaicin and alpha-tocopherol in hot pepper seed oil, 1,200 and 2,400 ppm capsaicin, or 0.3% alpha-tocopherol were added in soy bean oil and lard and stroed for 0-3 d at $100^{\circ}C$. Capsaicin inhibited lipid oxidation in lard but not in soy bean oil, however alpha-tocopherol exhibited a prooxidaton effect in soybean oil. Therefore, it suggests that the application of hot pepper seed oil or capsaicin in lard may be better for thermal oxidative stability.

• Resources Recycling
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• v.26 no.2
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• pp.18-24
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• 2017

The $FeCl_3$ solution has been used as an etchant for etching of metal. It is necessary to reuse the etching solution because waste $FeCl_3$ etchant generated after use has provided environmental and economic problems. In this study, HCl was mixed with the $FeCl_2$ solution and then $H_2O_2$ was added into the mixed solution to oxidize the $Fe^{2+}$. During the oxidation process, oxidation-reduction potential (ORP) was measured and the relationship between ORP and oxidation ratio was investigated. As a result, this study found that the ORP was increased with increasing the concentration of HCl and $H_2O_2$, while the ORP is decreased with oxidation progress. Such a behavior was in good agreement with Nernst's equation. Also, the oxidation efficiency reached about 99% when a sufficient amount of HCl and $H_2O_2$ were added.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.10
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• pp.558-562
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• 2015

This study was tested to evaluate the effect of the six different combinations of microbubble, catalyst, and air as oxidant on the sludge and organic matter reduction. When all of microbubbles and catalyst, and an oxidizing agent (under Conditions 1) such as air were used, the sludge was removed more than 99%, and TCOD and SCOD removal was 58% and 13%, respectively. This result was the highest value of six conditions. In the following order, the sludge reduction of the microbubbles with air (Condition 2) and catalyst with air (condition 4) was 95% and 93.1%, respectively. TCOD removal was found to be each 53% and 47%. When the microbubbles were used with oxidant like air, the removal of sludge and organic matter was high. All of these values were higher than that of using only microbubbles and catalyst without air. In the microbubbles and catalyst react under air supply condition, OH-radicals were generated in the reaction process. These OH-radicals in the reaction process decomposed the pollutants by the strong oxidizing power. In all conditions with air, the sludge reduction was high removal rate more than 93% and TCOD removal was over 47%.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.30-31
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• 2002

100 Gbit/in$^2$ 이상의 자기기록밀도를 달성하기 위해서는 재생헤드로 사용되고 있는 스핀밸브의 자기저항비가 10% 이상을 가지면서 열적 특성이 우수해야 한다. 현재까지 연구되어진 스핀밸브 구조 중 NiO([,2,3], $\alpha$-Fe$_2$O$_3$[4]등의 산화물 반강자성 층을 사용한 스핀밸브의 경우 기본 스핀밸브 구조를 사용하고도 이미 20% 이상의 자기저항비를 달성하였다. 이러한 높은 자기저항비는 절연층인 산화물 반강자성층과 금속 자성층 계면에서 일어나는 전자의 스펙큘라 반사(specular reflection)로부터 기인한다고 보고하고 있다.[2] (중략)

• Journal of the Korean Magnetics Society
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• v.12 no.4
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• pp.127-131
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• 2002

We fabricated MTJ devices that have doubly oxidized tunnel barrier using plasma oxidation method to from oxidized AlO$\sub$x/ tunnel barrier. Doubly oxidation I, which sputtered 10 ${\AA}$-bottom Al layer and oxidized it with oxidation time of 10 s. Subsequent sputtering of 13 ${\AA}$-Al was performed and the metallic layer was oxidized for 50, 80 and 120 s., respectively. Doubly oxidation II, which sputtered 10 ${\AA}$-bottom Al layer and oxidized it varying oxidation time for 30∼120 s. Subsequent sputtering of 13 ${\AA}$-Al was performed and the metallic layer was oxidized for 210 sec. Double oxidation process specimen showed MR ratio of above 27％ in all experiment range. Singly oxidation process. 13 ${\AA}$-Al layer and oxidized up to 210 s, showed less MR ratio and more narrow process window than those of doubly oxidation. Cross-sectional TEM images would that doubly oxidized barrowers were thinner and denser than singly oxidized ones. XPS characterization confirmed that doubly oxidation of Fe with bottom insulating layer. As a result, doubly oxidation could have superior MR ratio in process extent during long oxidation time because of preventing oxidation of bottom magnetic layer than singly oxidation.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.116-116
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• 2011

바이오 가스 플랜트의 혐기소화 공정에서 발생하는 바이오 가스는 중 유해가스인 황하수소($H_2S$)는 부식성 가스로 수천 PPM농도를 함유하여, 발전기나 가스보일러로 이용하는 경우에는 $H_2S$를 제거하는 탈황공정이 반드시 필요하다. 탈황방식에는 산화철 탈황(건식 탈황)과 생물 탈황이 현재 많이 사용되고 있어나 산화철 탈황은 산화철 pellet이 유화철에 변화하면 탈황능력이 저하되어 pellet을 교환해야 하며 많은 비용이 발생한다. 생물 탈황 방식은 유황산화세균의 서식활동조건(온도, 반응시간, 산소량)확보가 반드시 필요하여 높은 운전기술을 필요로 한다. 본 연구에서는 바이오가스 전처리 기술 중 활성탄 또는 약액을 이용한 기존의 탈황정제방식보다 흡착성능이 뛰어난 이온교환섬유를 이용하여, 황화수소($H_2S$)를 95% 이상 제거할 수 있는 고효율 섬유상 이온촉매 악취제거 시스템 개발을 수행하였다. 이온교환섬유는 방사선 조사를 이용하여 부직포에 라디칼을 인위적으로 형성시켜(그라프트 중합) 양이온 또는 양이온을 교환할 수 있도록 제조된 섬유상의 흡착제로, 이온교환 섬유의 화학적 이온교환과 물리적 흡착 및 탈착반응이 동시에 발생되고, 활성탄/실리카켈 보다 흡착능력이 2~4배 높다. 또한 이온섬유의 재생기능을 이용하여 장기적 다양한 악취($H_2S$, $NH_3$, 아민계, 메르갑탄류, 알데히드 등) 및 유해가스(VOCs, NOx, SOx) 등을 95% 이상 제거할 수 있다.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.636-643
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• 2006

Supercritical water oxidation of DMMP using continuous flow reactor was studied at temperature ranging from 440 to $540^{\circ}C$ and a fixed pressure of 242 bar. The range of residence times in the reactor was from 10 to 26 s, and oxygen excess value varied from -40 to 200%. Destruction efficiencies (DE) of DMMP were greater than 99.7% at $540^{\circ}C$, and increased as the DMMP concentrations were increased. DE of DMMP were significantly affected by oxygen concentration under stoichiometric amount, but showed little difference over stoichiometric amount. On the basis of 30 data with conversions greater than 85%, kinetic correlations for the DE of DMMP were developed. The pre-exponential factor was $(1.10{\pm}0.76){\times}10^6$, and the activation energy was $90.66{\pm}3.87kJ/mol$, and the reaction orders for DMMP and oxygen were $1.02{\pm}0.03$, $0.32{\pm}0.03$, respectively. The model predictions agreed well with the experimental data.