• 한국환경보건학회지
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• 제37권2호
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• pp.150-158
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• 2011

This research was conducted to estimate the physicochemical characteristics of waste catalyst and its in-process product from recycling and to suggest fundamental data for religious systems such as quality standards. Mo and V contents were increased from the waste catalyst to calcinated material and oxidized material. In the results of a heavy metals leaching test, Pb was not detected in any catalyst, calcinated and oxidized materials. Cu was not detected in the catalyst. However, it was detected in ${\leq}$1.16 mg/l for calcinated material and in 1.34~13.73 mg/l for $MoO_3$ oxidezed material. Concentrations in recycling in-process products (calcinated and oxidized materials) were higher than those of waste catalyst. Oil content of catalyst waste ranged from 0.01-14.03 wt%. Oil contents of calcinated and oxidized materials were greatly decreased compared to the catalyst waste. Carbon and sulfur contents as chemical poisoning material of catalyst waste ranged from 0.33-76.08 wt% and 5.00-22.00 wt%, respectively. The carbon contents of calcinated and oxidized materials showed below 20 wt%. The sulfur content showed below 8wt% for calcinated material and below 0.22 wt% for oxidized material.

• Journal of Electrochemical Science and Technology
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• 제2권4호
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• pp.204-210
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• 2011

Thin film electrodes have been intensively studied for active materials and current collectors to enhance the electrochemical performance. Here, porous structures of nickel-based oxide films, consisting of nickel oxide and copper (II) oxide, which was derived from the copper substrate during the annealing process, were deposited on metallic copper foils. The half-cell tests revealed excellent capacity retention after $80^{th}$ charge/discharge cycles. Some films showed an excess of the theoretical capacity of nickel oxides, which mainly originate from partially oxidized copper substrates during annealing. These results exhibit that both a preparation method of an active materials and partially oxidized current collectors could be important roles to apply thin film electrodes.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.746-755
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• 2015

To investigate the effect of hydrogen and oxygen contents on hydride reorientations during cool-down processes, zirconium-niobium cladding tube specimens were hydrogen-charged before some specimens were oxidized, resulting in 250 ppm and 500 ppm hydrogen-charged specimens containing no oxide and an oxide thickness of $0.38{\mu}m$ at each surface. The nonoxidized and oxidized hydrogen-charged specimens were heated up to $400^{\circ}C$ and then cooled down to room temperature at cooling rates of $0.3^{\circ}C/min$ and $8.0^{\circ}C/min$ under a tensile hoop stress of 150 MPa. The lower hydrogen contents and the slower cooling rate generated a larger fraction of radial hydrides, a longer radial hydride length, and a lower ultimate tensile strength and plastic elongation. In addition, the oxidized specimens generated a smaller fraction of radial hydrides and a lower ultimate tensile strength and plastic elongation than the nonoxidized specimens. This may be due to: a solubility difference between room temperature and $400^{\circ}C$; an oxygen-induced increase in hydrogen solubility and radial hydride nucleation energy; high temperature residence time during the cool-down; or undissolved circumferential hydrides at $400^{\circ}C$.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 총회 및 춘계 학술발표회 논문집
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• pp.53-60
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• 1998

The effect of chemically oxidized intermediated of PAH compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal. Dehydrogenase activities for the oxidized PAH studies ware enhanced two to five folds to the unoxidized PAHs studies. The chemical oxidation products can serve as a structually very similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.372-378
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• 2003

This study investigates the fractional composition and the leaching characteristics of heavy metals in polluted soils due to mining activities. The fractionated composition of heavy metals is classified into five fractions, adsorbed, carbonate, reducible, organic and residual fraction. The status of humic substances in mine wastes of most sites are polyhumic except tailing from Sangdong mine. According to the sequential extraction procedures (SEPs), leaching probabilities of Cd in coal wastes and tailing are relatively low due to high percentage of residual fraction. 46.4% of Ni in tailings from Sangdong mine is probably leached under oxidized environment, and 39.4% of Cu in these tailings is readily extracted under strongly oxidized environment by organic fraction. According to leaching condition of pH 3.0 and pH 5.6, the amount of heavy metals leached out of coal wastes and tailing increases to 1/2 hours. At pH 3.0 and pH 5.6, concentration of Ni in tailing increases up three times of the initial value. Heavy metals released from coal wastes and tailing were not influenced significantly by leaching time.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.151-152
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• 2002

An oxidized surface layer was intentionally formed on a sputtered $MoS_2$ film by introducing oxygen gas in the final stage of sputtering process. The film showed longer life than the normal Ar-sputtered film when the surface layer was slightly oxidized. A XPS analysis revealed co-existence of $MoS_2$ and $MoO_3$ in the surface layer. suggesting that the existence of some amount of oxides in the surface layer had beneficial effect. A confusing result was obtained: the life was much shorter than normal Ar-sputtered film when the film was exposed to $O_2$ environment for 1 minute after normal Ar-sputtering, although almost no oxide was detected in XPS analysis.

• 한국토양환경학회지
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• 제3권3호
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• pp.87-92
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• 1998

The effect of chemically oxidized intermediates of Polynuclear Aromatic Hydrocarbon (PAH) compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal The chemical oxidation products can serve as a structually similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.122-124
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• 2002

The removal capacity of zero-valent iron for Cr(Ⅵ) was evaluated using batch kinetic tests. The rate constants for zero-valent iron dramatically increased as initial Cr(Ⅵ) concentration decreased. Generally, the reaction rates of Cr(Ⅵ) with zero-valent iron were faster than that of a biotic degradation of Cr(Ⅵ), and furthermore the reaction rates were inversely proportional to the initial Cr(Ⅵ) concentrations. After certain reaction time elapsed. no further decrease of Cr(Ⅵ) was observed, indicating a loss of iron reactivity. The loss of iron reactivity was primarily due to the passivation of iron surfaces with iron-Cr precipitates, but the reactivity of iron was recovered by adding iron-reducing bacteria. Even though the addition of bacteria itself removed Cr(Ⅵ), the combination of iron-reducing bactera and oxidized iron significantly enhanced the reaction rate for Cr(Ⅵ) removal. The results from column tests also confirmed that the innoculation of iron-reducing bacteria to the column containing completely oxidized iron partially enhanced the recovery of the iron reactivity.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.843-848
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• 2017

고온/고압/산화제 과잉 환경에 노출되는 금속들은 급격한 산화(발화 및 연소)가 일어날 수 있다. 본 연구에서는 시편에 전력을 공급하여 시편 온도를 직접 제어하는 방식의 직류전원장치 시험설비를 구축하고 고온/정체/산화제 과잉 환경을 모사하여 STS 계열 금속 재질에 대한 금속 산화 및 발화에 대한 평가를 진행하였다. 그 결과, 선정된 재질의 변형(변색), 표면 거칠기에 변화와 금속 표면의 박리 현상이 관찰되었으며 무게 및 시편 두께에 변화가 있음을 확인하였다. 시편 중 가장 산화가 심한 시편은 STS 304이며 산화가 덜한 시편은 XM-19로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1675-1676
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• 2005