• Nuclear Engineering and Technology
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• 제54권3호
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• pp.1024-1029
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• 2022

Composite scintillation screens on a base of Gd_1.2Y_1.8Ga_2.5Al_2.5O₁₂:Ce (GYAGG) scintillator have been evaluated for neutron detection. Besides the powdered scintillator, the composite includes ⁶LiF particles; both are merged with a binder and deposited onto the light-reflecting aluminum substrate. Results obtained demonstrates that screens are suitable for use with a silicon photomultiplier readout to create a prospective solution for a compact and low-cost thermal neutron sensor. Composite GYAGG/⁶LiF scintillation screen shows a pretty matched sensitivity and γ-background rejection with a widely used ZnS/⁶LiF screens however, possesses forty times faster response.

• 태양에너지
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• 제8권1호
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• pp.13-21
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• 1988

Heat transfer phenomena in a high-temperature heat storage unit were investigated using molten salts. Carbonate salt, an equimolar mixture of $Li_2CO_3$ and $K_2CO_3$, which melts at $505^{\circ}C$ with a latent heat of 82 cal/g, was selected as the most promising latent heat storage material based on its low cost and excellent thermophysical properties at moderately high temperatures. It was also found that nitrate salts were good candidates of sensible heat storage materials. For the carbonate salt to be utilized commercially, however, several means of enhancing thermal recovery must be explored by promoting heat conduction through the solid salt formed during the heat discharge period. These would be achieved by the additions of aluminum screens and wool, and stainless fins. Finally, experimental results of moving boundary of phase change were well compared with predictied values obtained from the approximate solution.

• 설비공학논문집
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• 제11권2호
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• pp.236-243
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• 1999

Aluminum/Freon-22 heat pipes were manufactured and tested which have a special wick geometry combining axial groove and screen mesh. There were 14 axial grooves in a cross-section and these were covered by two layers of 350 mesh screens to enhance the thermal performance. The performance test was conducted by varying the thermal load and tilt angle. Furthermore, the operation limits and overall heat transfer coefficient were investigated. The experimental results will be useful in a variety of applications, especially in design and manufacturing of a high-efficiency heat exchanger and energy recovery systems.

• 생물환경조절학회지
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• 제16권4호
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• pp.284-290
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• 2007

온실보온을 위한 알루미늄반사단열재의 설치위치와 광택부의 설치방향에 따라 보온효과를 구명하고자 알루미늄반사재와 부직포를 조합하여 모듈을 구성하고, 모듈내 가열량을 각각 100W, 40W로 하여 2차에 걸쳐 처리 건구온도와 흑구온도, 상대습도를 재료의 조합에 따라 분석하였다. 1. 알루미늄반사재가 있는 경우가 부직포만 있는 경우보다 보온효율이 높았으며, 알루미늄을 두 층으로 하면 한 층으로 할 때보다 내부온도가 높았다. 알루미늄반사재를 한 층으로 설치할 때는 알루미늄반사재의 광택부분을 외부로 향하게 하는 것이 내부로 향하게 하는 것보다 모듈내 온도가 높았다. 알루미늄반사재를 두 층으로 할 때는 같은 방향으로 하는 것이 높게 나타났으며 이 경우 광택부를 둘 다 외향으로 배치하는 것이 보온효율이 더 높게 나타났다. 외기온도에 따라 모듈내 건구온도는 전 모듈에서 서서히 상승하며 그 변화의 크기는 외기온도의 변화보다 적었다. 2. 모듈내를 가열하지 않는 경우 모듈내 온도는 모듈간 온도차가 $0.5^{\circ}C$를 넘지 않았으며 그 차이를 인정하기 어려웠다. 3. 모듈내의 흑구온도변화는 건구온도변화와 그 경향이 비슷하였다 흑구온도는 대체적으로 건구온도보다 높았으며, 그 경향은 알루미늄반사재광택부가 내향인 경우가 외향인 경우보다 더 강하게 나타났던 바 복사열영향이 큰 것으로 판단되었다. 모듈내 상대습도는 건구온도가 증가하면 비교적 직선적으로 하강하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제5권1호
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• pp.35-43
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• 1982

The authors surveyed the cassettes in 10 general hospitals and compared in experimentation on performances of 6 kinds of cassettes manufactured with several materials in order to discover the present condition and performance of the cassettes being used at present. And the authors got the following results. 1. In distribution of the cassettes in use, Okamoto's(Japan), Picker's and Titan's(U.S.A.) were more than others classified by the manufacture. The rate of using high speed was 72.0%, par speed 28.0% classified by types of intensifying screens in the cassettes and the rate of the year in use for $4{\sim}5$ years was 40.0%, $6{\sim}7$ years 24.0% classified by the years in use. 2. The results of the screen-film contact test were that tile ordinary was 42.7%, the good 36.0%, and the poor 21.3%. 3. The results of the test for light leakage were that fogged area appeared on 1 side or more in 84.0% films. 4. In Aluminum equivalents of front plate, the cassettes with a front plate consisting of carbon fiber were fewest, and the ones of bakelite and aluminum were fewer in order 5. In compared results of the exposure dosage for same density of the films, the exposure of the cassettes used carbon fiber for the material on the front plate was smallest and bakelite, auminum was smaller in order.

• 농업과학연구
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• 제41권3호
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• pp.251-258
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• 2014

In order to set up the basic environmental control systems which the new concept greenhouses have to equip, greenhouse characteristics, environmental management and control systems in domestic glasshouses and plastic houses were investigated and analyzed comparatively. Survey results on the width, length, eaves height, and the number of spans etc. showed that glasshouses were bigger than plastic houses significantly. New concept greenhouses claim to be plastic houses, but it will be reasonable to follow the specifications of the glasshouse. Specifications to be applied to new concept greenhouses were proposed as follows; hot water heating systems, aluminum screens as the thermal curtain, evaporative cooling systems, roof vents on the ridge, circulation fans, $CO_2$ enrichment, hydroponic systems, and automatic irrigation control systems. Environmental measurement systems for the indoor and outdoor temperature, humidity, light, wind speed and indoor $CO_2$ concentration have to be fully equipped. The automatic control system has to be as a complex environmental control system, not a single item control system. Also, for stable dissemination, domestically producing complete greenhouse control system should be made as soon as possible.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.271.1-271.1
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• 2013

Titania is usually used in sun-screens, tooth paste, and other daily used objects as a pigment. However, scientists have focused on titania as photocatalyst due to its excellent activities. By fabricating vanadium doped TiO2 and CuOx co-catalyzed TiO2 nano-size filter, the degradation level of the volatile organic compound (VOC) concentration was tested using 365nm UV LED as light source in a closed chamber. Main purpose for this test is to evaluate the activities of various catalysts for degrading the VOCs which are detrimental to human body and toluene and p-xylene were chosen in the VOC removal test. Target gas materials were injected into the test chamber with dry air as carrier gas which was flowed into the gas washer bottle filled with liquid form of VOC substance. When the VOC gas flows into the chamber, it is circulated by 200 mm fan in order to contact with the set-up filter on the aluminum holder. Target gas concentration in the chamber was monitored using VOC detector (miniRae3000, Raesystems) which was also placed inside the chamber. With the measured concentration, the VOC degradation efficiency and the degradation rate were evaluated and used to compare the catalytic activities.

• 생물환경조절학회지
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• 제30권3호
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• pp.230-236
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• 2021

여름철 수경재배 시 포그 분무와 차광 처리에 의한 하우스 내부의 온도 및 광 변화를 모니터링하였다. 시험 1은 2019년 8월 맑은 날을 기준으로 무처리, 차광, 포그, 포그 + 차광 등 각각 4처리 하였다. 시험 2는 시험 1에서 온도 저감 효과가 가장 좋았던 포그 + 차광 처리를 이용하여 멜론 '달고나', '소풍가자' 2품종에 대해 2020년 여름 기간에 실증 재배를 실시 하였다. 시험 1의 결과 포그 + 차광 혼합처리 시 온도 저감 효과가 뚜렷하여 하우스 내부 온도가 외부 온도보다 가장 낮은 경우 약4℃ 정도 낮게 나타났다. 하우스 내부와 외부의 온도 편차를 살펴보면 포그와 차광 혼합처리에서는 평균 2-4℃ 더 낮아졌고, 포그 또는 차광 단일 처리구는 하우스 내부 및 외부 간의 온도 편차가 거의 없었으며, 무처리는 하우스 내부 온도가 외부 온도보다 평균 3-4℃ 더 높은 것으로 조사되었다. 하우스 내외부 일사량 변화를 측정한 결과 무처리구와 포그 단일 처리의 하우스 내부 일사량 변화가 비슷하였고, 차광 단일 처리와 포그와 차광 혼합처리의 하우스 내부 일사량 변화가 서로 비슷하였다. 무처리와 비슷한 포그만 처리한 경우 일반적인 비닐 피복재에 의한 하우스 내부 일사량 저하의 영향만 관찰되었다. 특히 포그 + 차광 처리의 경우 차광 단일 처리와 매우 유사한 일사량의 변화가 관찰되었다. 이러한 결과를 바탕으로 2020년 여름에 실증 재배를 한 결과, 8월 외부 기온 최대 36.3℃일 때 냉방 처리 하우스 내부 기온은 32.4℃ 정도 유지되었으며, 약3.9℃ 정도 온도 저감 효과가 있었다. 생산된 멜론의 과중은 1.3-1.5kg 다소 작았으나, 가용성 고형물 함량은 12.6-13.3°Brix로 단맛은 양호한 편이었다. 포그와 차광 혼합 냉방처리를 이용 할 경우 여름철 고온기 온도 저감 효과를 가져 올 수 있고 멜론의 정상적인 생육과 과실 수확이 가능하였다.