• 태양에너지
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• 제18권3호
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• pp.71-80
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• 1998

In thermal energy storage system, energy collected from many types of heat source is stored in a storage tank and then supply to load for demand. Lately, practical use of thermal energy storage system and attention to essential use of energy have been increased. From this point of view, especially, a study about the energy extraction process from a storage tank is necessary. So in this study, useful rate of hot water and hot water extraction efficiency was analysed respect to dynamic and geometric parameters dominating the hot water extraction process.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.341-342
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• 2012

• 한국화재소방학회논문지
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• 제20권4호
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• pp.58-64
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• 2006

부분배연설비를 가지고 있는 침매터널에서 화재시 배연효율을 분석하기위해 풀화재를 이용하여 축소모형실험을 수행하였다. 화재가 발생하였을 때 주위 유동이 없는 경우인 자연배연과 임계속도로 제트팬을 가동하는 강제배연의 경우에 터널내의 온도와 연소가스 농도를 측정하였다. 자연배연에 비해 강제배연은 화재발생 초기에 화원과 터널 내 기류와의 급격한 혼합에 의해 성층화 정도가 미미해지고 보다 낮은 온도를 화원주위에서 얻을 수 있었다. 이러한 급격한 혼합은 터널 상부에 위치한 부분제연 갤러리의 효율을 변화시키는데, 자연배연인 경우에 약 30%의 배연효율이 증가되었다. 일산화탄소 농도계측으로 얻어진 배연효율은 등온기체모델을 사용한 선행연구와 비교하여 거의 일치하는 결과를 얻을 수 있었다. 이러한 결과는 침매터널 화재시 승객의 안전한 대피를 위한 부분배연설비의 최적 운전방안으로 제시된다.

• 설비공학논문집
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• 제24권1호
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• pp.51-60
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• 2012

Optimization procedures of performance analysis for ORC(Organic Rankine Cycle) system are established to the characteristics of low temperature heat sources such as open-type and closed-type. Effective heat recovery and heat extraction related to maximum power of the cycle as well as heat quality and thermal efficiency must be considered in the case of the open-type low temperature heat source. On the other hand, in the case of the closed-type low temperature heat source, only thermal efficiency is important due to constant heat input. In this study, thermal efficiency and exergy efficiency representing a level of close to Carnot cycle are studied, as useful index for the optimization of the ORC system. To validate the results of cycle analysis, those are compared with appropriate experimental data of ORC system as a thermal efficiency point of view.

• 디지털콘텐츠학회 논문지
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• 제19권4호
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• pp.757-770
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• 2018

열화상 영상기반 감시 시스템에서 전경추출은 매우 중요한 단계이다. 전경추출단계는 계산시간과 메모리 사용측면에서 시스템의 실시간 처리가 매우 효율적이어야 한다. 그러나 이러한 효율성은 ROI 탐지의 정확도와 매우 연관되어 있다. 본 논문에서 열화상 비디오 처리를 위하여 새로운 히스토그램 빈에 기반하여 배경과 전경을 분리하기 위한 두 가지 방법을 제시하는데, 이는 임의의 주어진 환경에서 열화상영상의 시간상에서 일관성을 갖는 다는 점과, 이러한 성질이, 간단한 시간축 메디안 필터링에 비하여 80%이상의 메모리를 절감할 수 있다.

• 태양에너지
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• 제11권2호
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• pp.34-40
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• 1991

Thermal stratification enhancement for the higher extraction efficiency of hot water storage tank was experimentally studied with transparent fiber glass cylindical tank($350{\ell}$, D=516mm, H=1680mm). Height to diameter ratio (H/D =1,2,3), flow rate(Q= 8,10,12LPM), inlet-outlet temperature differences(${\Delta}T=20,25,30^{\circ}C$), and geometry of inlet-outlet port were the parameters. In particular, three kind of distributors were used for geometry of inlet-outlet port. As a result, it was possible to get extraction efficiency of 95% by using the distributor having variable diameter but keeping a constant diameter of perforation. So it is recommendable to design the distributor so that the main pipe decrease in diameter toward the dead end.

• KIEAE Journal
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• 제7권6호
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• pp.17-22
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• 2007

The integration of PV modules into building facades or roof could raise their temperature that results in the reduction of PV system's electrical power generation. Hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. The extraction of hot air from the space will enhance the performance of BIPV systems. The solar collector utilizing these two aspects is called PV/T(photovoltaic/thermal) solar collector. This paper compares the experimental performance of two different types of air type PV/T collector units: the base case of a collector unit with 10cm gap for forced ventilation and the other unit with copper pin attached to PV module to enhance its thermal performance. The experimental results shows that the base case unit had the overall efficiency of 41.9% and the improved unit with copper pin attached to PV module had 50.1% efficiency. For these air type PV/T units, the forced ventilation of the air space improved the electrical performance as well as the thermal performance.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1819-1824
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• 2006

A microlens arrays formed by thermal reflow method is attached to an OLED device and the light extraction efficiency which includes luminance and power information is determined by adjusting the area ratio and the height ratio.

• KSBB Journal
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• 제17권1호
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• pp.44-48
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• 2002

Rhodotorula giutinis KCTC 7989내에 존재하는 카로티노이드를 효율적으로 추출하기 위한 방법에 대해 연구하였다. R. glutinis에 의해 생합성되는 카로티노이드의 조성은 torularhodin 61.7%, $\beta$-carotene 28.8%, torulene 9.5%이었다. 세포 내에 존재하는 카로티노이드를 추출하기 위해 HCI로 세포를 전처리할 경우 열처리의 병행이 중요한 인자였지만, DMSO를 사용한 경우는 열처리 유무에 큰 영향을 받지 않았다. 추출용매에 따라 추출되는 카로티노이드의 조성이 영향을 받았다. 특히 벤젠과 클로로포름은 torularhodin의 추출에 효과적이었으며, 디에틸에테르를 사용했을 때 카로티노이드의 전체 추출농도가 가장 높았다. 건조된 세포나 습한 세포에 비해 냉동 건조된 세포에서 카로티노이드의 추출효율이 높게 나타났다.

• 분석과학
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• 제33권2호
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• pp.76-85
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• 2020

A stainless-steel needle (Hamilton 90022, 22 gauge, 718-㎛ o.d., 413-㎛ i.d., 51-mm length, bevel tip) with an electrochemically coated polyaniline layer having a microbore tunnel was newly prepared as a device for headspace in-needle microextraction. For designing the needle, the polyaniline layer length was optimized, and to evaluate the extraction efficiency for polycyclic aromatic hydrocarbons, numerous cyclic voltammetry scans were conducted. In addition, the optimization of the analytical conditions (including the adsorption and desorption parameters) and the validation of the analytical method were conducted. The optimized adsorption and desorption conditions were 40 ℃ for 30 min and 230 ℃ for 60 s, respectively. Finally, in this study, a polyaniline layer was electrochemically deposited on the in-needle surface, and it exhibited good thermal stability. The needle with the polyaniline layer was repeatedly used more than 200 times during this study. This method has some advantages in terms of the extraction time, extraction efficiency, and analysis cost.