• Journal of Korean Society for Atmospheric Environment
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• v.19 no.3
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• pp.307-314
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• 2003

The sonolytic decomposition of chlorofluorocarbon (CFC 113) and several alternative compounds, such as HCFC 225ca, HCFC 225cb, and HFC 134a, in.aqueous solutions was investigated. The CFC 113 with a high volatility and a low solubility in water was rapidly decomposed with increasing sonication time. The decomposition rates were influenced by the initial concentration of CFC 113, the reaction temperature, and the gas/liquid phase volume ratio but were independant of the pH of solution. The predominant pathway of the decomposition of CFC 113 by sonication was not the oxidation by OH radicals but the pyrolysis with high temperature and pressure inside of the cavitation bubble. The pyrolysis in the cavitation bubble resulted in an almost complete mineralization of CFC 113 with the high efficient formation of inorganic products (Cl$^{[-10]}$ , F$^{[-10]}$ , CO, $CO_2$). The addition of zinc powder on the decomposition of CFC 113 by sonication caused an acceleration of the decomposition. Also, HCFCs and HFC 134a were found to be readily decomposed by the pyrolysis induced from the sonication.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1995.06b
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• pp.28-37
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• 1995

To protect the ozone layer depeletion the CFC (chlorofluorocarbon). HCFC(hydrochlorofluorocarbon) refrigerants will be replaced with HFCs (hydro-fluorocarbon) as an alternative refrigerant. In recent years a good deal of effort has been made to develop new compressors which are compatible to the new referigent. This paper focused on developing accelerated screening test for predicting tribological characteristics of the rotary compressor in atmosphere of R407C as an alternative refrigerant with polyolester lubricant. Falex wear test machine with high pressure chamber has been used to simulate friction and wear behavior of the common contact geometries found in rotary compressors.

• Journal of the Korean Society of Safety
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• v.9 no.1
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• pp.140-145
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• 1994

Contributions of global warming potentials on CFC(Chlorofluorocarbon) and Ozone were calculated by Stefan-Boltzmann's law and environmental effects of its were discussed. As the greenhouse effect on the unit volume of CFC is the most strong in the infrared gases and the destruction of Ozone in stratosphere is also depends on CFC, therefore release of CFC should be prohibited. But the effect of restriction on CFC will be appeared more than 10 years later. Eventhough the Ozone layer is related to global warming, It should be protected because of maitaining food chain mode of life, preventing human disease, for example, cataract, dermatics etc.

• Tribology and Lubricants
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• v.5 no.2
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• pp.7-20
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• 1989

합성윤활유(synthetic lubricant)라 함은 현재까지도 계속되고 있는 광유(mineral oil) 전성시대의 광유에 대응되는 말로써 광유계 윤활유로 부터 얻기 어려운 높은 점도지수, 우수한 저온 유동성 등의 특성을 얻기 위해 유기합성방법에 의해 인위적으로 제조한 윤활유의 총칭이며 작용기의 종류, 합성방법, 등에 따라 다양하게 분류된다. 합성윤활유의 종류에는 합성방법에 따라 폴리머형(P형), 비폴리머형(N형)으로 대별되는데, 폴리머형 합성유에는 poly-butene, poly-$\alpha$-olefin, Polyalky lenglycol, Silicon oil, Chlorofluorocarbon, Perfiuoroalkylpolyether 등이 있으며, 비폴리머형 합성유에는 Alkylbenzene, Dibasicacidester, Polyolester, Silicate-ester Polyphenylether, Complex ester 등이 포함된다. 전자의 경우에는 중합반응 조건을 조절하므로써 여러점도 등급의 합성유들을 얻을 수 있는 반면 후자의 경우에는 분자량이 크지 않으므로 저점도의 것만 얻어지는 것이 특징이다.

• Electrical & Electronic Materials
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• v.9 no.3
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• pp.240-245
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• 1996

Non-ozone layer destructive Chlorofluorocarbon(CFC) altematives(CHCIF$_{2}$ and $C_{2}$H$_{2}$F$_{4}$) have been initially used for laser-induced thenrmochemical etching of GaAs. High etching rate up to 188.mu.m/sec and an aspect ratio of 2.7 have been achieved by a single scan of laser beam, respectively. The etching rate at constant ambient gas pressure was found to saturate for beam power. The chemical compositions of the reaction products deposited on the etched groove were measured by Auger electron microscopy(AES). Etched profile, depth and width were observed by scanning electron microscope(SEM).

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1989.06a
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• pp.1-21
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• 1989

합성윤활유(synthetic lubricant)라 함음 현재까지도 계속되고 있는 광유(mineral oil)전성시대의 광유에 대응되는 말로써 광유계 윤활유로 부터 얻기 어려운 높은 점도지수, 낮은 저온 유동성 등의 특성을 얻기 위해 유기합성 방법에 의해 인위적으로 제조한 윤활유의 총칭이며 작용기의 종류, 합성방법, 등에 따라 다양하게 분류된다. 합성윤활유의 종류에는 합성방법에 따라 폴리머형(P형), 비포리머형(N형)으로 대별되는데, 폴리머형 합성유에는 Poly-butene, $Poly\alpha$-olefin, Polyalkylenglycol, Silicon oil, Chlorofluorocarbon, Perfluoroalkyl polyether등이 있으며, 비폴리머형 합성유에는 Alkylbenzene, Dibasicacidester, Polyolester, Silicate-ester Polyphenylether, Complex ester등이 포함된다. 전자의 경우에는 중합반응 조건을 조절하므로써 여러점도 등급의 합성유들을 얻을 수 있는 반면 후자의 경우에는 분자량이 크지 않으므로 저점도의 것만 얻어지는 것이 특징이다.

• Journal of the Korean Home Economics Association
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• v.30 no.2
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• pp.35-43
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• 1992

This study is to investigate the problems of pollution caused by drycleaning solvents. From the problem of each solvents, safety count-step have to set up. It is following. 1) Solvent: Smong phenomenon of optical chemistry. It has to develop safety tumbler that is attached retrievable device. 2) Perchloroethylene: Pollution of underground water and cause of cancer. Considering the influence on environment and human bing, it has to set up more strong safty plan than now. 3) Chlorofluorocabon : Destory of ozon layer and green house effect on earth. It is being to stop the production until the early part of the year 2000. So it is developing a substitute for chlorofluorocarbon. 4) 1,1,1-trichloroethane : Pollution of underground water and destroy of ozon layzer. At the end of the year 2004, there will be end production of it.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.188.1-188.1
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• 2003

2-Bromopropane (2-BP) is a major component of the mixture of SPG-6AR and Solvent 5200 that is a substitute of chlorofluorocarbon. Many female workers exposed to 2-bromopropane in a Korean electronic company were found to have amenorrhea and male workers were diagnosed with oligospermia. In the present studies, immunotoxic effects of 2-BP and an analog, 1,2-dibromopropane (1 ,2-DBP), were investigated in female BALB/c mice. (omitted)

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.28 no.4
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• pp.300-314
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• 1999

가스구동 흡수식 시스템은 인류와 환경에 여러 가지 유익을 가져다준다. 첫째, 시스템의 고효율에 따른 매력적인 경제성을 제공하고, 둘째 천연가스의 사용으로 인하여 여름철 피크 전력소요(peak electric demand)를 완화하고, 셋째 이산화탄소 ($CO_2$)의 발생을 감소시킴으로써 지구 온난화 현상을 완화한다 실제로 가스구동 흡수식 시스템으로부터의 $CO_2$발생량은 증기보일러를 사용하는 전기구동 냉동기에 비하여 85% 수준인 것으로 보고되었다(Suzuki 등). 넷째로 암모니아 및 물과 같은 환경 친화적인 냉매들을 사용함으로서 오존층을 파괴하는 Chlorofluorocarbon(CFC) 및 Hydrochlorofluorocarbon(FCFC)계 냉매들을 대체할 수 있는 이점이 있다.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1409-1416
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• 2015

The change of temperature influences on the various aspect, especially human health, plant and animal's growth, economics, industry, and culture of the country. In this article, the autoregressive error (ARE) model has been considered for analyzing the monthly temperature data at the Suwon monitoring site in Korea. In the ARE model, five meteorological variables, four greenhouse gas variables and five pollution variables are used as the explanatory variables for the temperature data set. The five meteorological variables are wind speed, rainfall, radiation, amount of cloud, and relative humidity. The four greenhouse gas variables are carbon dioxide ($CO_2$), methane ($CH_4$), nitrous oxide ($N_2O$), and chlorofluorocarbon ($CFC_{11}$). And the five air pollution explanatory variables are particulate matter ($PM_{10}$), sulfur dioxide ($SO_2$), nitrogen dioxide ($NO_2$), ozone ($O_3$), and carbon monoxide (CO). Among five meteorological variables, radiation, amount of cloud, and wind speed are more influence on the temperature. The radiation influences during spring, summer and fall, whereas wind speed influences for the winter time. Also, among four greenhouse gas variables and five pollution variables, chlorofluorocarbon, methane, and ozone are more influence on the temperature. The monthly ARE model explained about 43-69% for describing the temperature.