• 청정기술
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• 제14권2호
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• pp.103-109
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• 2008

본 연구에서는 솔더페이스트(solder paste)로 솔더링후 표면에 잔류하는 플럭스(flux)의 효과적인 세정성능 평가방법 개발을 목적으로 하였다. 솔더링시 플럭스의 퍼짐오차를 줄이기 위해 본 연구에서 고안한 금속치구를 이용하여 1,1,1-TCE 및 플럭스 제거용 몇 가지 대표 준수계 대체세정제에 대하여 세정시간에 따른 플럭스 제거율을 무게측정법으로 측정, 비교하였다. 세정시간 변화에 따른 각 세정제의 세정효율을 측정한 결과 측정값들의 상대표준편차(RSD)가 약 4%이하로 data의 신뢰성이 확인되었다. 따라서 솔더페이스트로 솔더링후 대체세정제의 잔류플럭스의 세정성능 평가시험에 본 연구에서 적용한 금속치구(metal test tool)를 이용한 평가방법이 유력한 방법으로 적용가능할 것으로 판단된다. 그리고 이 평가방법을 적용한 결과 현재 상용화 되어 있는 우수하다고 알려진 몇 가지 대표 준수계 대체세정제 중 ST100SX와 750H가 고활성 플럭스에 대한 세정력이 우수한 성능을 나타냈으나 기존의 1,1,1-TCE에 비해서는 현저히 떨어짐을 확인할 수 있었다.

• 한국농공학회논문집
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• 제52권3호
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• pp.19-29
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• 2010

In South Korea, as the living standard has been getting higher, meat consumption is steadily increasing. To meet the country's demand, livestock houses become larger and wider with increased raising density. In larger livestock houses, pollutants such as flake of pig skin, excrement, odor, various dusts and noxious gas like ammonia are excessively accumulated inside the facility. These will cause weak immunity for the pigs, diminution of productivity and degeneration of working condition. These problems can be solved through the ventilation performance of the facility. In the winter time, ventilation must be controlled to minimum to maintain a suitable thermal condition. However, this affects the other internal environmental condition because of the minimum ventilation. The installation of "wet air cleaner" especially in the winter time can be an alternative solution. For efficient application of this machine, there is a need to understand the existing ventilation condition and analyze the interaction of existing ventilation system with the wet air cleaner considering its appropriate location. In this study, the existing ventilation system as well as the internal environmental condition negatively inside the facility with the wet air cleaner has been studied using CFD technology. The CFD simulation model was validated from the study conducted by Seo et al. (2008). Results show that the elimination rate of ammonia was 39.4 % and stability could be improved to 35.1 % (Comparing case 5 to 1 where wet air cleaner machine was not used). It can therefore be concluded that case 5 shows the optimum location of a wet air cleaner in the livestock house.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2000년도 추계학술발표회 초록집
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• pp.60-61
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• 2000

• 전력전자학회논문지
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• 제22권3호
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• pp.193-198
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• 2017

This paper discusses the design and control of a switched reluctance motor (SRM) drive system for a built-in car vacuum cleaner. The growing popularity of outdoor activities and recreation has led the automobile industry to expand technologies that increase the convenience of vehicles, and thus, a built-in car vacuum cleaner was introduced. However, the existing DC motor of a vacuum cleaning system has several disadvantages, such as maintenance cost and lifespan issues of its commutator-brush structure. An SRM can be a good alternative to the existing DC motor because of its high-speed capability, long lifespan, low maintenance cost, and high efficiency, among other advantages. A prototype SRM drive is designed and manufactured to verify its feasibility for use in a built-in car vacuum cleaning system. Dynamic simulation is conducted to determine the optimal switching angle for maximum efficiency and minimum torque ripple. Load test, noise measurement, and suction-power tests are also carried out.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1297-1301
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• 2007

The indoor air quality guideline of public transportation means was prepared recently. therefore we consider a countermeasure for the indoor air quality improvement of public transportation means. In this work, air-cleaner with roll filter system which developed alternative of indoor air quality guideline. The develpoed roll filter system is two function. the first function harmoniously circulated to heating and cooling air through HVAC system and secondary function removed PM(particluatie matters) which re-scatting to passenger's movement and suppled from outdoor air. Filter media of roll filter system select optimum electret mesh filter out of many filter media. Selected filter media was performanced tests of pressure drop, collection efficiency and dust holding capacity. Finally developed roll filter system was performanced bench test.

• 청정기술
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• 제3권2호
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• pp.36-46
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• 1997

CFC 및 유기염소계 용제는 정밀기기 및 전자산업에서 세정제로 여러 가지 우수한 성질이 있어 오랫동안 사용하여 왔지만 오존층을 파괴하는 물질로 규명되어 대체 세정제로의 사용이 불가피한 실정이다. 대체 세정제로서는 여러 종류가 있지만 수계/준수계 세정제가 환경친화적이라 장기적으로 가장 바람직하여 이의 사용과 개발이 선진국을 중심으로 점차 증가일로에 있다. 그러나 이에 대한 국내의 이용 및 연구는 빈약하다. 본 연구에서는 수계세정제중 알칼리성, 중성, 산성, 비휑금형과 이의 주요구성성분, 그리고 준수계세정제중 테르펜계 및 glycol ether계를 분석하였다. 또한 수계/준수계세정제를 사용함으로써 이용가능한 여러 세정장치를 비교평가하였고 산업체에서 세정시스템의 선정시 중요 고려사항을 분석제안하였다.

• Current Photovoltaic Research
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• 제7권4호
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• pp.85-96
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• 2019

Renewable energy is emerging as a reliable alternative source of energy, it is much safer, cleaner than conventional sources and has contributed significantly in this sector. However, there are still some challenges that needed to address this evolving technology. Artificial Intelligence (A. I.) can assess the past, optimize the present, and forecast the future. Therefore, A. I. will resolve most of these problems. Artificial intelligence is complex in nature, but it reduces error and aims to reach a greater degree of precision which make renewables smarter. This paper provides an overview of frequently used A. I. methods in solar energy applications. A sample algorithm is also provided for literature purposes and knowledge transfer.

• 전기학회논문지
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• 제59권4호
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• pp.700-706
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• 2010

Carbon costs, either in the form of a carbon tax or through permit prices in an emissions trading scheme, would ultimately be reflected in higher electricity prices. This price "pass-through" is very critical to the effective design of new policies to curb the amount of carbon emissions. This paper sets out in a structured way the factors that determine price pass-through and how carbon costs would impact on the electricity market and the existing coal-fired power plants. It is shown that pass-through can vary drastically if the underlying dispatch potential of generators varies significantly across alternative emissions reduction scenarios. It can also vary depending on the availability of competing cleaner forms of generation. Pass-through as a measure of business performance is therefore hard to generalize across different circumstances and should be interpreted carefully.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.1.1-2
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• 2002

Ultimate objective of industrial hygiene is the prevention of health impairment that may result from exposure to chemicals at workplaces. This implies the definition of permissible levels of exposure, that is, levels that according to the present status of knowledge are estimated to cause no adverse health effects during the lifetime of the workers, and the regular assessment of the possible health risk associated with exposure by comparing the current or the integrated exposure with the permissible exposure limits. Workers in solvent thinner-using occupation environment might be highly exposed to VOCs(volatile organic compounds) because solvent thinner has been used extensively such as painting, spraying, degreasing, coating and so on in Korea. The purpose of this study was to recognize, evaluate and propose the alternative control the VOCs from solvent thinner-using workplace.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.43-46
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• 2003

The economy of I.R.Iran is so related to oil that has had many environmental problems especially air pollution in urban areas in recent years. Statistics show that most of the time, the condition of air quality is in crisis level especially during fall and winter seasons. Rapid and high population growth has had large amount of fossil fuels consumption in all sectors including transportation, industry, agriculture, residential and commercial and public services and air pollution and healthy problems. Iran＇s abundance of fossil fuel resources has tended to discourage the country＇s incentive to shift to cleaner alternative energy sources for its energy needs that must be considered in future programming. These are discussed in this paper.