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        검색결과 24

        21.
        1996.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To use effectively the solar energy in greenhouse heating, a high performance solar collector should be developed. And then the size of the solar collector and thermal storage tank should be determined through the calculation of heating load. The solar collector must be set in the optimum tilt angle and direction to take daily solar radiation maximally, and the flow rate of heat transfer fluid through the solar collector should be kept in the optimum range. In this research, the performance tests of a capillary tube solar collector were performed to determine the optimum water flow rate and the results summarized as follows. 1. The regressive equations for efficiency estimations of the capillary tube solar collector in the open loop were modeled in the water flow rate of 700-l,000 l/hr. 2. The optimum water flow rate of the solar collector was estimated by the second order polynomial regression and the maximum efficiency was 80% at the water flow rate of 850 l/hr. 3. The solar thermal storage system consisted of a capillary tube solar collector and a water storage tank was tested at the water flow rate of 850 l/hr in the closed loop, and obtained the solar thermal storage efficiency of 55.2%. 4. As the capillary tube solar collector engaged in this experiment was made of non-corrosive polyolefin tubes, its weight was as light as 1/30 of the flat plate solar collector made of copper tubes. Therefore it was considered to be suitable for the greenhouse heating system.
        4,000원
        22.
        1995.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        God created the havens and earth and god gave man every seed-bearing plant and every tree that has fruit with seed in it. These food is all vegetable food that don`t take diseases of adult people. But God gave Noah the green plants. Everything that lives and moves will be food for Noah. Just as God gave man the green plants. And then man must not eat meat (animal protein food) that has its lifeblood still in it and God must not eat fat in it. The fat contains much fat(saturated fatty acids) and cholesterol that have susceptibility to disease of coronary heart, hypertension and atheriosclerosis etc. God must not eat these fat before we don`t know that it have susceptibility to disease of adult people.
        4,000원
        23.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        경 X선 형광분석 기법에 사용되는 X선 튜브는 X선의 휘도가 낮아 분석의 정밀도가 떨어지고 분석 시간 또한 오래 걸린다. 모세관 집광소자를 이용하면 X선 휘도의 이득(gain)을 최소 10 이상 얻을 수가 있다. 모세관 광학소자는 8.4keV의 텅스텐 특성방사선을 효율적으로 집광할 수 있도록 설계되었다. 파이렉스 유리로 된 모세관 모재를 풀러 (puller)를 이용하여 45 g의 추에 650˚의 온도를 가하여 모세관 광학소자를 제작하였다. 모세관 광학소자의 제작은 총 460분이 소요되었으며 제작된 모세관 광학소자의 길이는 87 mm, X선 입사부의 직경은 300 ㎛, 출구부의 직경은 192 ㎛로 제작되었다. 제작된 모세관 광학소자를 경 X선 형광분석에 적용하면 황(S)과 같은 경원소 검출의 정밀도를 높일 수 있을 것이다.
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