• Clean Technology
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• v.1 no.1
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• pp.8-11
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• 1995

• Clean Technology
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• v.1 no.1
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• pp.12-27
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• 1995

• Clean Technology
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• v.3 no.2
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• pp.87-93
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• 1997

A new process has been developed for nitrate and other salts removals from polluted waters. Alumina cement and calcium oxide served as precipitating agents to remove nitrate with stirring at basic pH. Low content of alumina in the commercialized alumina cements resulted in a increasing in nitrate removal yield. It is found that the compositions of aluminium and calcium are the most important factors in successful nitrate insolubilization. In order to remove high concentration of nitrate in polluted water, multi-stage precipitation was found to be very effective. Sulfate, chloride, and phosphate ions as well as nitrate were also removed by the precipitated reaction. After precipitation, post-treatments including Na2CO3 addition and neutralization with acid alleviated the level of aluminium and calcium in the treated water.

• Clean Technology
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• v.2 no.2
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• pp.192-200
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• 1996

Basic strategies are needed to adopt and implement clean technologies in machine industries. In this paper, hazardous or non hazardous wastes generated from the machine industries are classified based on the origin of the wastes and the importance of the life cycle of the products including gesign stages as well as ultimate disposal is also addressed.

• Clean Technology
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• v.3 no.1
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• pp.9-26
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• 1997

The recent movement toward the better environment urges the shift of pollution prevention strategy from traditional "command/control" and "end-of-pipe" technologies to clean technologies. Development of Clean Technology, which makes products without creating pollutions, is a way to solve Environmental problems fundamentally. The main objective of this study is to define the long-term strategy to develope "Innovative Clean Technology". "Innovative Clean Technology" is an active way of solving the environmental problems arising from industrial activities. It aims to find ways either to make products without creating pollution, to produce environmentally benign end-products, or else to recover and re-use the materials which have hitherto considered waste.

• Clean Technology
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• v.3 no.2
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• pp.31-33
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• 1997

Nitrate contamination in surface water and ground water have increased in Korea. This trend has raised concern because nitrates caused methemoglobinemia in infants. To remove nitrates from waters, various purification processes including ion-exchange, biological denitrification, and chemical denitrification are currently in use for the treatment of water. However, little economically advantageous process exists for the industrial scale treatment of effluents highly polluted with nitrates. A new process has been developed for nitrate and other salts removal from polluted waters. Alumina cement and lime served as precipitating agents to remove nitrate with stirring at basic pH. Decreasing alumina content in alumina cement result in a increasing in nitrate removal yield. Stable removal of nitrate(1000mg/L) was readily achieved by two-stage removal process.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.10
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• pp.697-703
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• 2010

In recent semiconductor manufacturing clean rooms, air washers are used to remove airborne gaseous contaminants from the outdoor air introduced into a clean room. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery is useful for reducing the outdoor air conditioning load required to maintain a clean room. Therefore it is desirable to recover heat from the exhaust air and use it to cool or heat the outdoor air. In the present study, numerical analysis was conducted to evaluate the recovered heat of an exhaust air heat recovery type air washer system, which is the key part of an energy saving outdoor air conditioning system for semiconductor clean rooms. The present numerical results showed relatively good agreement with the available experimental data.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.163-170
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• 1990

Clean rooms are widely used in high technology industries. Currently within the microelectronics industry there is an explosive growth in the number of clean rooms. Therefore, special consideration of clean room workers is needed to the work induced stresses from contamination avoidance, clothing requirements, and confinements [1].

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2005.05a
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• pp.69-74
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• 2005

• Clean Technology
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• v.4 no.2
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• pp.4-10
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• 1998