• Carbon letters
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• 제10권2호
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• pp.114-122
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• 2009

Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

• Transactions on Electrical and Electronic Materials
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• 제1권1호
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• pp.6-11
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• 2000

The hydrogen plasma treatment of silicon wafers in the reactive ion-etching mode was studied for the application to silicon-on-insulator wafers which were prepared using the wafer bonding technique. The chemical reactions of hydrogen plasma with surface were used for both surface activation and removal of surface contaminants. As a result of exposure of silicon wafers to the plasma, an active oxide layer was found on the surface. This layer was rendered hydrophilic. The surface roughness and morphology were examined as functions of the plasma exposing time and power. In addition, the surface became smoother with the shorter plasma exposing time and power. The value of initial surface energy estimated by the crack propagation method was 506 mJ/㎡, which was up to about three times higher as compared to the case of conventional direct using the wet RCA cleaning method.

• 박물관보존과학
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• 제15권
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• pp.56-65
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• 2014

강릉에 위치한 신복사지 석조보살좌상 ^{보물 제84호} 얼굴부에 광택이 있는 수지상 오염물이 고착되어 있었다. 오염의 범위는 백호부터 턱 밑까지이며 광택이 발생하여 미관을 해치고 있었다. 오염물 중 일부를 수거하여 FT-IR 분석을 실시한 결과 시아노아크릴계 순간접착제인 것을 확인하였다. 분석된 접착제는 면봉 등에 아세톤을 묻혀 녹이면서 제거하는 방법이 일반적이다. 그러나 석조보살좌상이 야외에 오랜 시간 노출되어 있어 표면 풍화가 많이 진행된 상태이므로 이를 고려하여 물리적 손상을 최소화하는 방법으로 제거하였다. 기존에 처리된 삼전도비의 페인트 낙서 제거에 적용된 습포법과 도토기의 수지제거에 이용된 증기법을 검토하여 물리적 손상 없이 제거할 수 있는 방법을 찾아보았다. 습포법과 증기법을 같이 적용하면 면봉을 이용한 물리적 작업없이 24시간 이내에 수지가 제거되는 것을 확인하였고 이를 토대로 현장에 적용하였다.

• 한국물환경학회지
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• 제29권4호
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• pp.489-496
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• 2013

지하수계의 근간을 이루는 토양시스템은 유기화학물질에 오염되기 쉬운 환경에 놓인다. 이러한 토양의 유기화학물질 침투 거동을 평가하기 위해 점토, 실트 및 모래로 구성된 실험장치에 유기화학 물질 이동실험을 하였다. Chloroform, 1,1,1-trichloroethane 및 trichloroethylene은 토양을 통해 이동이 쉽게 이루어지며, 투과된 오염물질의 질량은 전체 질량의 최소 4.6에서 최대 19.2% 범위를 보였다. Tetrachloroethylene Tetrachloroethylene, 1,2-dichlorobenzene 및 1,3-dichlorobenzene은 토양 흡착에 의해 이동이 지연되어졌으며, 각 매개체의 0.6 ~ 4.8%가 표층에서 여과되는데 이용되었다. Carbon tetrachloride는 거의 투과되지 못하였고, 단지 0.1 ~ 0.4% 질량만이 침투거동에 도달하였다. Bromoform은 거의 투과되지 못하였으며, 브롬화(Br) 화합물의 중간 전환물질로도 확인되었다. 유기화학오염물들의 이동은 토양입자크기 및 수리전도도 등에 따라 달라진다고 여겨지나 본 연구에서는 유기화학오염물들의 이동은 점토, 실트 토양보다 모래 토양에서 더욱 빠르게 나타났다.

• 터널과지하공간
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• 제13권1호
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• pp.20-32
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• 2003

균열암반에서 콜로이드를 동반한 방사성 핵종의 이동을 핵종붕괴사슬과 주변암반으로제한적 분자확산을 고려하여 모사하였다. 암반 내 핵종 이동을 모사하기 위한 핵종이동 시스템과 지배 방정식 및 초기/경계 조건을 설정하여 반 해석해를 도출하였으며, 수치적 라플라스 역변환을통하여 반해석해의 검증을 실시하였다. 유사콜로이드의 반응상수가 균열 내에 미치는 영향과 콜로이드의 여과작용이 핵종이동에 미치는 영향 그리고 주변 암반으로 제한적 확산이 핵종이동에 미치는 영향에 대하여 알아보았다. 지하수 내에 존재하는 유사 콜로이드의 양이 많아질수록 균열 내 방사성 핵종이동의 가속현상이 크게 나타났으며 여과 계수가 모든 핵종에 대하여 $10^{-3}$ (m$^{-1}$)보다 클 경우 여과에 의한 핵종 지연을 무시할 수 없었다. 콜로이드 존재로 인한 핵종가속과 더불어, 주변암반으로 방사성핵종의 분자확산이 제한적일 경우에 예측된 핵종가속현상은 확산깊이가 적을수록 더 커지는 것을 알 수 있었고, 이때 가속에 영향을 주는 유효확산깊이가 존재하는 것을 발견할 수 있었다. 또한 주변암반의 저지계수가 클수록 제한적 확산깊이에 따른 핵종들의 가속범위의 증가를 볼 수 있었다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.714-719
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• 2008

In a domestic construction field, after floor is constructed, protector for construction surface is set up to prevent the surface of the floor being scratched and polluted. However, the problem is that contaminants discharged with the removal of the protector for construction surface exert a bad influence for the indoor air quality. In the research, it tested to the contaminant reduction performance of the adsorption protector for construction surface using powder of charcoal by the alternative proposal of such protectors for construction surface

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.459-462
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• 2004

This study assesses groundwater vulnerability to contaminants in 12 administrative districts of the city of Changwon, using DRASTIC technique. DRASTIC was originally applied to situations in which the contamination sources are at the ground surface, and the contaminants flow into the groundwater with infiltration of rainfall. However, groundwater contamination in urban areas can also be related to excessive pumping resulting in a lowering of the water level. The correlation coefficient between minimum DRASTIC indices and the degree of poor water quality for 10 districts is low as 0.40. The correlation coefficients between minimum DRASTIC indices and the groundwater discharge rate, and between minimum DRASTIC indices and well density per unit area are 0.70 and 0.87, respectively. Thus, to evaluate the potential of groundwater contamination in urban areas, it is necessary to consider other factors such as groundwater withdrawal rate and well density per unit area with ratings and weights as well as the existing six DRASTIC factors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.597-603
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• 2005

The remediation of railroad contaminated soil is gaining wide attention, recently. In railroad field, modification of diesel supply field, equipment of roll pad, FRP panel, and iron pannel under diesel locomotive storages are used for the prevention of contamination expansions. However, cheap and efficient remediation technology has not been suggested yet. In this study, the contaminated ballast was remediated by blasting technology. Because the contaminants mainly resides on the surface of ballast, blasting these contaminants make it available to recycle the ballast. We carried out the remediation of oil-contaminated ballasts using the blasting technology, and we could remediate them nicely. This technology is expected to be used for the cheap and quick remediation of contaminated ballast.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.269-272
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• 2004

The use of colloidal gas aphron (CGA), as an external oxygen carrier, provides a promising alternative to promote aerobic bioremediation of BTEX in the subsurface environment. CGA is a stable bubble supported by three surfactant layers and can supply oxygen below the soil surface uniformly due to its plug-flow characteristic. Since CGA has a hydrophobic layer that can act as a partitioning medium for hydrophobic contaminants it is known to facilitate desorption of soil-sorbed contaminants. In addition, bioaugmentation and biostimulation are possibly achieved by using CGA when generated from a solution containing BTEX-degrading microorganisms and appropriate nutrients. In this study, we presented the physico-chemical characteristics of CGA generated from a solution composed of microorganisms and nutrients. The applicability of CGA as an in situ aerobic bioremediation technology of BTEX will be further evaluated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.145-146
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• 2005

This study performs a simulation for an accumulation mechanism of contaminants, which were produced in an industrial belt of inland, on the surface of insulators. From the simulation, silicon insulators presented higher accumulation than that of EPDM(Ethylene Propylene Diene Terpolymer : EPDM) insulators on the same distance in the case of the Virgin polymer insulator, and this result presented the same result in the insulator applied in actual fields. In the case of the accumulation test for the Virgin insulator and insulators used in actual fields, it is evident that the Virgin insulator presented more accumulation than that of the insulator used in actual fields. The results can be caused by the generation of LMW (Low Molecular Weight) on the external material of polymer insulators, and the level of the accumulation can be changed according to the degree of the continuous generation of LMW.