• 충청수학회지
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• 제32권4호
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• pp.491-508
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• 2019

In this paper, we study the mathematical hyperstructures of ozone(O₃) depletion by Freon gas.

• 충청수학회지
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• 제33권4호
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• pp.469-487
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• 2020

In this paper, we investigate the mathematical structures of chemical reactions for stratospheric ozone depletion.

• 한국환경과학회지
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• 제12권4호
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• pp.367-373
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• 2003

The focus of this study was to identify and describe environmental preconceptions held by pre-service elementary teachers about three issues : greenhouse effect, ozone layer depletion and acid rain. Two hundred and twenty nine pre-service elementary teachers participated in this study. A 36 question survey was created by one of the authors. The questions focused on the cause, effects, and interactions of three environmental issues greenhouse effect of one layer depletion and acid rain. Pre-service elementary teachers answered the questions on a Likert scale. An analysis of the survey data indicated that the majority of pre-service elementary teachers possess an array of incorrect conceptions about the causes and effects of the greenhouse effect ozone layer depletion, and acid rain. and also many pre-service elementary teachers thought that there were causal relationships among the increase in greenhouse effect, the destruction of ozone layer, and the increase of acid rain.

• 환경위생공학
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• 제4권2호
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• pp.1-14
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• 1989

There is increasing concern that depletion of the ozone layer may have important health consequences. Each $1\%$ decline in ozone concentration is expected to cause a $2\%$ increase in ultraviolet radiation this in turn has been suggested to lead to up to a $4-6\%$ increase in certain kinds of skin cancer. In Colorado state, malignant melanoma patients increased form 7.4 cases per 100,000 to 12.6 per 100,000 in the general population between 1979 and 1985. In Australia, 4,000 new melanomas are diagnosed each year and 800 people die every year from melanoma. Strong international controls CFCs production are necessary to lower the destruction of ozone in the stratosphere. Only then will the increase in ultraviolet radiation to the skin be halted and the incidence and mortality from melanomas be reduced.

• 설비공학논문집
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• 제14권4호
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• pp.332-340
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• 2002

In these days, environmental concerns have been increased throughout the industry and community worldwide. To prevent the ozone depletion, ozone depletion potential of a refrigerant must be zero. Simultaneously, a refrigerant with low GWP (global warming potential) is very demanding to induce green house effect. Chlorine-free HFC-l34a is a refrigerant widely used for automotive air-conditioning system because its destruction potential is ecologically zero. Although HFC-l34a has no ozone depletion potential, its global warming potential is so high that it is not considered as a perfect alternative refrigerant that is acceptable for long-term use. In this paper, experimental measurement has been carried out to analyze the performance characteristics of automotive air-conditioning system using HFC-152a, which has low GWP and zero ODP. Also mixed refrigerant that is composed of HFC-152a and $CF_3$ was applied to investigate an alternative possibility for the automotive airconditioning system. As a result of this study, we could draw following conclusions; With respect to the variation of the rotational speed of compressor, outside air temperature and flow rate, the heat amount of evaporator and compressor and performance coefficient was varied.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권3호
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• pp.140-149
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• 2003

In these days, environmental concerns have been increased throughout the industry and community worldwide. To prevent the ozone depletion, ozone depletion potential of a refrigerant must be zero. Simultaneously, a refrigerant with low GWP (global warming potential) is very demanding to reduce green house effect. Chlorine-free HFC-l34a is a refrigerant widely used for automotive air-conditioning system because its destruction potential is ecologically zero. Although HFC-l34a has no ozone depletion potential, its global warming potential is so high that it is not considered as a perfect alternative refrigerant that is acceptable for long-term use. In this paper, experimental measurement has been carried out to analyze the performance characteristics of automotive air-conditioning system using HFC-152a, which has low GWP and zero ODP. Also mixed refrigerant that is composed of HFC-152a and $CF_3$ was applied to investigate an alternative possibility for the automotive air-conditioning system. As a result of this study, we could draw following conclusions; With respect to the variation of the rotational speed of compressor, outside air temperature and flow rate, the heat amount of evaporator and compressor and performance coefficient was varied.

• Journal of Advanced Marine Engineering and Technology
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• 제28권5호
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• pp.728-734
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• 2004

Environmentally friendly refrigerants with zero ozone layer depletion potential are required to be used in refrigerators and air conditioners due to the difficulties related to ozone layer depletion and global warming. A rigorous study for the system performance with new refrigerants having zero ozone layer depletion potential is inevitable before adopting that as a new fluid. The HFC(Hydrofluorocarbon) potential has been recommended as alternatives. In this paper. system performance in the heat pump facilities were studied using R-290, R-600a. R-1270 as an environment friendly refrigerant. R-22 as a HCFC's refrigerant. The experimental apparatus has been set-up as a conventional vapor compression type heat Pump system. The test section is a horizontal double pipe heat exchanger. A tube diameter of 12.70mm with 1.315mm wall thickness is used for this investigation. The test results showed that the COP of hydrocarbon refrigerants were superior to that of R-22 and the maximum increasing rate of COP was found in R-1270. The refrigeration capacity of hydrocarbon refrigerants were higher than that of R-22. The compressor work was obtained with the maximum value in R-1270 and the minimum one in R-22.

• 대기
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• 제18권4호
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• pp.429-439
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• 2008

The lower-stratospheric polar temperature in winter and spring for both hemispheres is investigated based on the NCEP/NCAR 50-year reanalysis data with respect to the strength of the stratospheric eddy heat flux. Both the polar temperature and the eddy heat flux show significant variation on the decadal and year-to-year time scales except during the Southern Hemisphere winter. The year-to-year variation in the polar temperature is mainly determined by the eddy heat flux convergence. The eddy heat flux convergence is compared with the diabatic heating rate obtained from a two-dimensional model. Radiative heating caused by absorption of solar radiation is comparable to the heating caused by the eddy heat flux convergence in the Southern Hemisphere. The effect of ozone depletion on diabatic heating has been found to be secondary in the Northern Hemisphere, even in March 1997 when the record depletion of ozone took place.

• 한국환경보건학회지
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• 제34권1호
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• pp.62-69
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• 2008

The life cycle assessment method for environmental impact assessment was used, in this study, to assess the production process of wheat flour which is the most important material in the food industry. Environmental impact assessments were compared between that of the Ministry of Environment, Republic of Korea (method I) with that of the Ministry of Commerce, Industry and Energy (method II). Life cycle inventories (LCI) was performed using internal and external databases and the production statistics database of company S. The procedure of life cycle impact assessment (LCIA) was followed in terms of classification, characterization, normalization and weighting to identify the key issues. The impact categories of method I were divided into 8 categories with consideration of : abiotic resources depletion, global warming, ozone depletion, photochemical oxidant creation, acidification and eutrophication. The impact categories of method II were divided into 10 categories with consideration of: abiotic resources depletion, global warming, ozone depletion, photochemical oxidant creation, acidification, eutrophication, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity and terrestrial ecotoxicity.

• 한국환경과학회지
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• 제23권6호
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• pp.1067-1074
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• 2014

Life Cycle Assessment(LCA) has been carried out to evaluate the environmental impacts of glass bottle recycle. The LCA consists of four stages such as Goal and Scope Definition, Life Cycle Inventory(LCI) Analysis, Life Cycle Impact Assessment(LCIA), and Interpretation. The LCI analysis showed that the major input materials were water, materials, sand, and crude oil, whereas the major output ones were wastewater, $CO_2$, and non-hazardous wastes. The LCIA was conducted for the six impact categories including 'Abiotic Resource Depletion', 'Acidification', 'Eutrophication', 'Global Warming', 'Ozone Depletion', and 'Photochemical Oxidant Creation'. As for Abiotic Resource Depletion, Acidification, and Photochemical Oxidant Creation, Bunker fuel oil C and LNG were major effects. As for Eutrophication, electricity and Bunker fuel oil C were major effects. As for Global Warming, electricity and LNG were major effects. As for Ozone Depletion, plate glasses were major effects. Among the six categories, the biggest impact potential was found to be Global Warming as 97% of total, but the rest could be negligible.