• Proceedings of the Membrane Society of Korea Conference
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• 1999.10b
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• pp.55-58
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• 1999

• Proceedings of the Membrane Society of Korea Conference
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• 2000.04a
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• pp.101-104
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• 2000

• Journal of Adhesion and Interface
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• v.11 no.1
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• pp.9-14
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• 2010

O/W emulsions were prepared with the phase inversion emulsification methods. The emulsifiers were used the UNIQ-1 (isopropylamine alkyl aryl sulphonate) and UNIQ-2 (alkoxylated glycol ether). Investigated effect that HLB value, agitator velocity and manufacture temperature get in mean particle size of emulsions. Mean particle size receives much effect of HLB value. Also, estimated stability about storage temperature and light. Emulsion's mean particle size was 193 nm lastly, reduced VOC amount used 90% than existing alkyd resin.

• Journal of Environmental Impact Assessment
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• v.20 no.2
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• pp.217-226
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• 2011

This paper was inspired by the fact that Real-time Traffic Information Service could play a key role in reducing incomplete combustion time remarkably since it can provide traffic jam information in real-time basis. Emission characteristics of experimental engines were studied with variable travel distances and speed of car in terms of traffic information provided. 12 Km distance road of Susung district in Daegu is taken as an experimental area to examine this new approach. The emission was tested while the driving was done at 8 AM, 3 PM, 6 PM which represents various traffic conditions. The reduced emission has been measured for a travel distance running at different loads (conventional shortest route and Real-time Traffic Information) and various loads (CO, VOC and NOx) are all inventoried and calculated in terms of existing emission factors. The emission has been shown to reduce linearly with travel distance : carbon monoxide (20.56%), VOC (29.21%), NOx(8.86%).

• Membrane Journal
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• v.11 no.1
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• pp.50-59
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• 2001

Influence of concentration polarization has been investigated on the vapor permeation of VOCs/$N_2$ mixture. Po]y(dimethylsiloxane)(PD,vIS) membrane which had a good affinit~, toward VOCs was emploj,'c'Cl in this study. The chlorinated hydmcarbons which were part of homologous series of chrolomelhane and chrolocthane were used as organic vapor. The vapor permeation experiments were calTied out at various VOCs feed concentrations. operating temperatures and feed flow rates. With decreasing feed flow rate. the membrane perfonnance, that is. penneation rate and selectivity were reduced in the permeation of VOCs/$N_2$ mixture. Especially the reducing of the membrane performance was founel to be more significant when the condensibility of voe was greater. voe content in the feed mixture was higher or operating temperature was lower. These observations were discussed in terms of the influence of con-centration polarizalion on the permeation of VOCSINl mixture through the PDMS membrane.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.361-361
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• 2011

Cu(InGa)(SeS2) (CIGS) thin film solar cells have recently reached an efficiency of 20%. Recent studies suggest a double graded band gap structure of the CIGS absorber layer to be a key issue in the production of high efficiency thin film solar cell using by sputtering process method. In this study, Cu(InGa)(SeS2) absorbers were manufactured by selenization and surfulization, we have deposited CIG precusor by sputtering and Se layer by evaporation before selenization. The objective of this study is to find out surfulization effects to improve Voc and to compare with non-surfulization Cu(InGa)Se2 absorbers. Even if we didn't analysis Ga depth profile of Cu(InGa)(SeS2) absorbers, we confirmed increasing of Eg and Voc through surlization process. In non-surfulization Cu(InGa)Se2 absorbers, Eg and Voc are 0.96eV and 0.48V. Whereas Eg and Voc of Cu(InGa)(SeS2) absorbers are 1.16eV and 0.57V. And the efficiency of 9.58% was achieved on 0.57cm2 sized SLG substrate. In this study, we will be discussed to improve Eg and Voc through surfulization and the other method without H2S. gas.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.125-125
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• 2003

우리나라 대기질은 자동차의 급격한 증가와 산업활동이 활달해짐에 따라 VOC, NOx 의 배출량이 급격히 늘어나고 있으며 이에따라 광화학 오존등 2차오염물질에 대한 대기오염문제가 심각해지고 있다. 오존에 의한 대기오염문제를 해결하기 위하여 환경부에서는 2002년부터 서울의 정동, 불광동 둥 수도권 8개 지점에서 광화학평가측정망을 운영하고 있으며, 본 연구에서는 이들 광화학평가측정망의 정도관리현황을 검토하고 측정지점별 오존전구물질(VOCs) 농도분포 특성을 분석하였다. (중략)

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.5
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• pp.480-496
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• 2017

CMAQ (Community Multiscale Air Quality)-HDDM (High-order Direct Decoupled Method) simulations with MICS-Asia 2010 and INTEX-B 2006 emissions inventories were performed to investigate the impact of Chinese $NO_x$ and VOC emissions on 1-hr ozone concentrations over South Korea during May to July in 2014. Chinese $NO_x$ and VOC emissions in MICS-Asia 2010 were 60% higher and 100% lower than those in INTEX-B 2006 during the simulation period. It makes the ratio of Chinese VOC to $NO_x$ emissions in INTEX-B 2006 (Case 1) is 3.2 times higher than that in MICS-Asia 2010 (Case 2). When the observed period mean 1-hr ozone concentration averaged across 106 air monitoring sites in the SMA (Seoul Metropolitan Area) was 37.6 ppb, the modeled values were similar to each other; 37.3 ppb for Case 1, and 40.4 ppb for Case 2. Both cases show that daily maximum 1-hr ZOC (Zero-Out Contribution) of Chinese $NO_x$ and VOC emissions were as high as 55 ppb and 35 ppb for the episode respectively. Correlation coefficients between ZOC of Chinese $NO_x$ and VOC emissions and the SMA daily maximum 1-hr ozone were 0.49~0.69. It indicates that Chinese emissions occasionally affect the SMA daily ozone peaks. On the other hand, Case 2 predicted 7 ppb and 1 ppb higher ZOC of Chinese $NO_x$ and VOC emissions than Case 1, when simulated ozone in the SMA is over 80 ppb. It implies that upwind $NO_x$ emissions would be more important than upwind VOC emissions for the long-range transport of ozone in Northeast Asia.

• Membrane Journal
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• v.11 no.2
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• pp.74-82
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• 2001

By using a phenomenological approach, model equations incorporating the resistance-in¬series concept were established to evaluate quantitatively concentration polarization in the boundary layer in feed adjacent to the membrane surface in the vapor permeation and separation of volatile organic compounds (VOCS)/$N_2$ mixture through po]y(dimethylsiloxane) (PDMS) membrane. The vapor permeations of various VOCS/$N_2$ mixtures through PDMS membrane were carried out at various feed flow rates. Chlorinated hydrocarbons, such as, methylene chloride, chlorofonn, 1,2-clichloroethane and 1,1,2-trichloroethane were used as organic vapor. By fitting the model equations to the experimental penneation data. the model parameters were detennined. respectively. Both the mass transfer coefficient of VOC across tbe boundary layer and concentration polarization modulus as a measure of the extent of concentration polarization were eitimated Quantitatively by the mooe1 equations with the determined model parameters. From the analysis on the detennined model parameters, the boundary layer resistance due to the concentration polarization of VOCs component was found to be more significant when the condensability of voe was greater. This study seeks to emphasize the importance of the boundary resistance on the vapor penneation of the vapor/gas mixtures with high permeability and high selectivity towards the minor component VOC.

• Journal of Environmental Science International
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• v.16 no.4
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• pp.415-423
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• 2007

This study assessed the characteristic of BTEX (Benzene, Toluene, Ethylbenzene, Xylene) concentration ratios of industrial emission sources and the neighborhoods of industrial area, fuel such as gasoline, light oil, LPG, and similar gasoline, and ambient air in Daegu. The BTEX in aromatic compounds was the most abundant VOC in Daegu. The BTEX ratios were (0.2:2.6:1.0:1.8) for the neighborhoods of industrial area, (2.6:11.3:1.0:1.2) for residential area, (2.2:11.0:1.0:1.6) for commercial area, (1.0:14.9:1.0:1.3) for industrial area, and (0.2:2.6:1.0:1.8) for the neighborhoods of industrial area. Average BTEX ratios in Daegu were B/T ratio (0.1), B/EB ratio (1.5), B/X ratio (1.1), T/EB ratio (12.6), T/X ratio (10), EB/X ratio (0.7), Expecially, B/T ratio in Daegu was similar as the other cities, Bangkok, Manila, and Hongkong. Comparing other cities with B/T ratio, the main sources of VOC were vehicular exhaust and emission of industrial facilities. Furthermore, BTEX correlation were evaluated at the emission sources and regional areas. Results showed that correlation coefficient values of emission sources, fuels and neighborhood of industry were significant magnitude above 0.65(p<0.01). Also, there showed highly significant correlations among BTEX. Calculated correlation coefficients of ambient air sampling sites were $0.61{\sim}0.954$ for commercial /residential area and $0.613{\sim}0.998$ for industrial area. However, they showed different correlation between commercial/residental area and industrial area. It implied that the emission sources were different from each area.