• Economic and Environmental Geology
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• v.53 no.2
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• pp.213-220
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• 2020

When CO₂ foam is injected into the saline aquifer, the relative permeability of CO₂ decreases and its viscosity increases, thereby reducing mobility in porous media and ultimately improving CO₂ storge with enhanced sweep efficiency. In general, surfactants were used to fabricate CO₂ foam. Recently, nanoparticles have been used to form stable foam than surfactant. This paper introduces CO₂ storage technology using nanoparticle stabilized CO₂ foam. If the surface of the hydrophilic nanoparticles is partially modified into a CO₂-philic portion, the particles have an affinity for CO₂ and water, thus forming a stable CO₂ foam even in deep saline aquifers under high temperature and high salinity conditions, thereby it can be stored in the pores of the rock. In terms of economics, injection method using nanopaticle-stabilized CO₂ foam is more expensive than the conventional CO₂ injection, but it is estimated that it will have price competitiveness because the injection efficiency is improved. From an environmental point of view, it is possible to inject chemical substances such as surfactants and nanomaterials into aquifers or reservoirs for specific purposes such as pollutant removal and oil production. However, some studies have shown that nanoparticles and surfactants are toxic to aquatic animals, so environmentally proven substances should be used. Therefore, further research and development will be needed to study the production and injection of nanoparticle-stabilized CO₂ foam that are environmentally safe and economically reasonable.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.283-286
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• 2002

유류로 오염된 부지에 토양세정기법을 적용하기 위한 전 단계로, 실험실 규모의 컬럼실험을 통하여 pilot 규모 현장 적용을 위한 설계인자 및 최적 운전조건을 규명하고자 적정 세척제 종류와 농도, 배합비 및 세정용액 주입유량을 고찰하였다. 회분식실험 결과 POE$_{14}$와 SDS(1:1)를 1%로 적용한 흔합계면활성제의 효율이 가장 우수하였으나, 예비실험 결과 음이온계 계면활성제인 SDS는 미생물에 독성을 끼치는 경향이 있는 것으로 나타나 같은 농도에서 효율이 거의 유사한 POE$_{5}$와 POE$_{14}$ 혼합계면활성제를 이용하여 실험하였다. 선정된 혼합계면활성제를 적용하여 디젤 오염토양 세척능력을 검토한 결과 세척제 농도 1%까지는 효율이 증가하다가 1% 이상의 농도에서는 다시 감소하는 경향을 나타내었으며, 계면활성제 배합비는 1:1로 혼합하였을 경우 세척효율이 가장 우수하였다. 따라서 POE$_{5}$와 POE$_{14}$ (1:1) 1% 혼합계면활성제를 세척제로 선정하였다. 컬럼실험 결과, 주입 flux가 클수록 세정 제거된 총 유류의 양이 증가하였으며, 같은 pore volume의 세정용액 통과 시에는 flux가 작을수록 제거효율이 좋았다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.41-44
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• 2003

UV/$TiO_2$ 공정을 이용한 수중 MTBE의 광분해에 관한 연구 결과 다음과 같은 결론을 얻을 수 있었다. MTBE는 초기농도가 낮을수록 제거효율이 증가하는 것을 볼 수 있었으며, 공기주입량이 4L/min인 경우 반응시간 160분 후 완전히 제거되었으며, 공기주입이 없는 경우에 비해 제거효율이 40%정도 높게 나타났다. 과산화수소 농도와 반응시간에 따른 MTBE 제거효율은 1M-$H_2O_2$ 300mL를 첨가한 경우 반응시간 160분 후에 완전히 제거되었으며, 1M-$H_2O_2$ 200m1는 반응시간 180분 후 거의 제거되었으며 $H_2O_2$를 첨가하지 않은 경우 반응시간 180분 후 68%의 제거효율을 보여 과산화수소 첨가시 제거효율이 증가하는 경향을 보였다.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.985-991
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• 1996

In chromatographic separation, HETP(height equivalent to a theoretical plate) is a useful quanititive parameter and it is wildely designated as column efficiency. The effects of operating conditions (sample concentration, injection volume, flow rate and mobile phase composition) on HETP were investigated in perparative liquid chromatography (PLC). Water and organic modifier of methanol were used as mobile phase. The sample of thymidine was injected into preparative C18 columns. The system was run by a isocratic mode in 1.5~5.5ml/min. The larger amounts of sample and higher flow rates of mobile phase increased HETP, which means that column efficiencies were worse. As the weight of sample injected into a chromatographic system could be prepared with different concentrations and injection volumes, for the same amount of sample, HETP was approximately increased two times with the ten-fold injection volume. HETP was mainly affected by the resistance of stationary and mobile phase mass transfer in the intraparticle section of packings at higher velocities.

• Analytical Science and Technology
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• v.19 no.2
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• pp.181-187
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• 2006

This study was carried to survey the removal characteristics of BPA using coagulation process by PAC and PAHCS. BPA removal for PAC and PAHCS was 20.4 with 8.7 Al mg/L and 6.8 Al mg/L, respectively. Removal of BPA was lower than $UV_{254}$ and DOC but removal characteristics were similar. BPA removal for PAC and PAHCS was most high in pH 6.5 and 7.0 respectively. The time for removal by mixing time was 40 min in PAC and 30 min in PAHCS. When powdered activated carbon 50 mg/L was added in coagulation process, a high remove of BPA (61%) was noticed. Specially BPA was highly increase powdered activated carbon 5 mg/L alone. These results will be appliable in the conventional water treatment plants for improvement of water treatment system.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.04a
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• pp.97-99
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• 1999

본 연구에서는 디젤로 오염된 토양을 효율적으로 정화하기 위해, 알칼리제와 과산화수소를 이용하는 새로운 방식의 토양세척기법에 대하여 일련의 회분식 실험을 통하여 최적의 운전조건을 검토하고자 하였다. 알칼리제인 NaOH를 이용하여 세척수의 pH를 상승시켜, 강알칼리 상태에서 과산화수소를 주입하면 미세기포가 발생되며, 이 미세기포에 의해 토양에 흡착되어 있는 유류 오염물질이 효과적으로 탈착.부상된다. #60(0.25mm) 이하의 자연토양을 6,500 mg TPH/kg dry soil로 오염시켜 사용하였으며, 세척수의 pH, 진탕비(토양 중량 : 세척용액 부피), 과산화수소 주입량, 세척시간에 의한 영향을 살펴보았다. 세척수의 pH는 12, 진탕비는 1:5, 과산화수소 주입량은 1%, 세척시간은 1시간으로 적용한 결과 최대효율(60%)을 얻을 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.78-78
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• 2007

• Journal of IKEEE
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• v.24 no.3
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• pp.706-712
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• 2020

To improve light-emitting performance of green phosphorescent organic light-emitting diodes (OLEDs), we introduced new hole injection materials-hexaazatrinaphthylene (HATNA) derivatives as a solution processed hole injection layer (HIL). The HATNA derivative has a low the lowest unoccupied molecular orbital (LUMO) energy level, similar to the work function of Indium Tin Oxide (ITO), showing a different concept of hole injection mechanism. It was confirmed that the device efficiency of OLEDs using HATNA-HIL showed the improved external quantum efficiency from 10.8% to 15.6% and current efficiency from 32.7 cd/A to 42.7 cd/A due to the balance of electrons and holes in the emissive layer.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.434-441
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• 2011

To improve T-N and T-P removal efficiencies, removal efficiencies of pollutants in full-scale livestock wastewater treatment plant by natural purification method with water plant filtration and activated sludge beds were investigated under different re-injection rates and injection methods of livestock wastewater. The removal rates of COD, SS, T-N, and T-P in effluent in full-scale livestock wastewater treatment plant were in the order of 30% < 70% ${\leq}$ 100 % at different re-injection rates. The removal rates of pollutants in effluent in full-scale livestock wastewater treatment plant were higher as re-injection rate of livestock wastewater increased. Removal rates of COD, SS, T-N, and T-P by continuous injection were slightly higher than those by intermittent injection method in full-scale livestock wastewater treatment plant. Removal rates of COD, SS, T-N, and T-P by continuous injection method in full-scale livestock wastewater treatment plant with water plant filtration and activated sludge beds were 99.5, 99.8, 99.0 and 99.8%, respectively.

• Journal of the Korean Vacuum Society
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• v.3 no.3
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• pp.322-330
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• 1994

다결정실리콘 위에 저압 화학 증착법으로 비정질 WSix를 증착시킨 후에 질소 분위기, 87$0^{\circ}C$ 온 도에서 2시간 동안 열처리를 실시하여 결정화를 이룩한 다음 표면의 산화막을 희석된 불산용액으로 제 거한 후 산화를 실시하면 이상산화막이 형성이 되었다. 이와 같은 이상산화막 형성은 산화 공정전에 P 또는 As 이온 주입을 실시함으로써 억제되고 있었으며 P이온 주입 처리가 As 이온조입보다 이상산화 막 발생 억제에 보다 효율적임이 확인되었다. P이온 주입처리가 보다 효과적인 것은 산화시 산화막내에 형성되는 P2O5 가 산화막의 용융점을 크게 낮추어 양질의 산화막을 형성하는 데 기인하는 것으로 여겨 진다. 마지막으로 이온주입 처리에 의하여 비정질화된 텅스텐 실리사이드 표묘의 산화 기구에 대하여 제안하였다.