• Journal of Plant Biology
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• 제34권3호
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• pp.215-221
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• 1991

Photoxynthetic properties of polyvinylalcohol (PVA)-immobilized chloroplast especially regarded to stability of photosynthetic electron transport and the fluorescence induction pattern were studied. When isolated spinach chloroplasts were immobilized with PVA, it showed good preservation of photosynthetic electron transport activity, especially PS II activity, during storage at -15$^{\circ}C$, 4$^{\circ}C$ and 2$0^{\circ}C$. And immobilized chloroplasts revealed similar thermostability of whole chain electron transport to free chloroplsts. And the absorption peak of red band of chloroplasts showed the blue-shift of 2-4 nm after immobilization. Fv/Fm ratio of chlorophyll fluorescence slightly decreased after immobilization. White light pulse after continuous light do not induced the additional fluorescence rise. This means chlorophyll fluorescence at room temperature reached to Fmax under continuous light in the immobilized chloroplasts. It seems that PVA may be a good candidate for immobilization matrix for the preservation of photosynthetic function of thylakoids and for the continuous use of chloroplast membranes of higher plants for solar energy storage and conversion.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.43-46
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• 2007

To find out the optimum design of hydrogen storage and supply tank using Metal Hydride (briefly MH) and to make clear the performance characteristics under various conditions are our research purpose. In order to use the low-temperature exhaust heat, $LaNi_{4.7}Al_{0.3}$ which operates under the low pressure of 1MPa is chosen, and we measure the basic properties, namely density, specific heat, PCT(Pressure-Concentration-Temperature) characteristic, and effective thermal conductivity. Then, a numerical calculation model of hydrogen storage using MH alloy is suggested and this thermal diffusion equation of model is solved by the backward difference method. This calculation results rate compared with the experimental results of the systems which installed 1kg MH alloy and, it is found out that our calculation model can well predict the experimental results. By the experimental using MH alloy, it is recognized that the hydrogen flow rate can control by the step adjustment of brine temperature.

• 정보저장시스템학회논문집
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• 제1권2호
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• pp.132-136
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• 2005

It is widely accepted that the reading mechanism of Super-RENS(super-resolution near field structure) and Super-ROM(super-resolution read only memory) is closely related with non-linear temperature dependent material properties such as refractive indices, phase change. Furthermore, the dynamic change of the temperature distribution also an essential part of reading mechanism of Super-RENS/ROM. Therefore, the knowledge of the temperature distribution as a function a time is one of the important keys to reveal the physics of reading mechanism in Super-RENS/ROM. We calculated time-dependent temperature distribution in a 3-dimensional Super-ROM disk structure when moving laser beam is irradiated. With a help of commercial software FEMLAB which employed finite element method, we simulated the temperature distribution of ROM structure whose pit diameter is 120-nm with 50-nm depth. Energy absorption by moving laser irradiation, time variations of heat transfer processes, heat fluxes, heat transfer ratios, and temperature distributions of the complicate 3-dimensional ROM structure have been obtained.

• 한국기계가공학회지
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• 제17권1호
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• pp.153-160
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• 2018

A pressure vessel consists of an inner tank and the outer tank; the material of the inner tank is austenite stainless steel, and the outer tank is general carbon steel. As the storage amount increase, the size of the inner tank for LNG also increases, which eventually increases the weight of the LNG storage tank. The Cold Stretch method can transport and store the LNG in a larger amount than the conventional pressure container, and the weight of the pressure vessel can also be reduced at 50 70% due to the reduction of the thickness, which is excellent from an economic and energy consumption perspective. Although the Cold Stretch method has these advantages, the domestic situation has not developed any related legislation. In this study, the actual production of pressure vessels using the Cold Stretch method will be processed and the volume expansion after the Cold Stretch will be checked and compared with the mechanical properties.

• 정보저장시스템학회논문집
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• 제6권2호
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• pp.68-73
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• 2010

The interest in acquiring high efficiency solar cells has been steadily increasing due to various advantages such as low-cost installation, pollution free and everlasting energy generation. In order to raise the cell efficiency, there has been a lot of effort to develop effective anti-reflection coatings. In this work, the main objective was to investigate the effects of particle size and annealing temperature of silica anti-reflection coatings to maximize the cell efficiency as well as reliability. It was shown that the light transmittance could be increased by a few percent over a certain range of wavelength using the silica coating. Also, the tribological properties of the coating could be improved through the annealing process, which led to better reliability of the coating.

• 대한설비공학회지:설비저널
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• 제9권3호
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• pp.161-169
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• 1980

In order to enhance the thermal energy storage capacity of cement mortar and to improve the effective thermal conductivity of paraffin waxes, cement- sand- paraffin wax mixture was investigated. By means of finite difference method, the transient temperature distribution in a hollow cylinder with phase change using average composite properties was obtained, and compared with experimental results. It was shown that the heat absorbed by mixture with $25\%$ paraffin fraction was as much as $50\%$ more than either a concrete mortar or pure paraffin wax in the case of ${\Delta}T=\;18.25^{\circ}C$.

• 폴리머
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• 제38권2호
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• pp.250-256
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• 2014

본 연구에서는 이축 스크류식 압출기를 이용하여 폴리프로필렌(PP)에 도전성 필러인 다중벽 탄소나노튜브 (MWNT)와 스테인레스강 단섬유(SSF)를 첨가하여 복합체를 제조하였으며, 이에 대한 표면저항 및 기계적 특성을 조사하였다. 표면저항을 측정한 결과 PP/MWNT에 소량의 SSF를 첨가하였을 때 더 낮은 MWNT 함량에서 percolation threshold가 나타났다. 그리고 제조된 복합체에 대한 인장시험 결과 순수 PP와 비교해서 파괴점 신장률은 감소하였으나 탄성률과 강도는 증가하였다. 또한 동역학분석을 통하여 MWNT와 SSF 복합체의 저장탄성률과 tan ${\delta}$에 미치는 영향을 조사하였으며, SEM을 이용하여 필러들의 모폴로지 및 복합체의 파단면을 관찰하였다.

• 한국수산과학회지
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• 제24권5호
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• pp.340-344
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• 1991

각종 어육의 동결 및 가열과정 중의 이화학적 품질변화의 규명하고 저온저장 및 가열조건의 확립과 장치의 설계를 위하여 필요로하는 열물성과 변성온도를 DSC를 이용 측정함으로서 다음의 결과를 얻었다. 1. 어육의 발열반응개시온도는 냉각속도가 증가할수록 강하하였으며, 활성화에너지, 엔탈피 및 엔트로피는 냉각속도의 증가와는 상반되는 경향을 보였다. 동결잠열은 냉각속도에 관계없이 거의 -정한 값을 나타내었다. 2. 어육의 동결과정 중의 자유에너지의 변화는 냉각속도와 조성성분의 영향보다는 온도에 의한 영향이 큰 것으로 나타났다. 3. 어육속의 지질 및 단백질의 변성온도는 가열속도와 상관관계를 나타내었으며, 지질의 함양이 많을수록 변성온도가 낮게 나타났다. 변성엔탈피는 각각 0.04-0.13, 0.07-0.17cal/g 값을 얻었다.

• 설비공학논문집
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• 제29권3호
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• pp.97-104
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• 2017

Reinforcement of insulation in apartment buildings reduces the heating and cooling energy consumption by lowering the heat transfer in the building envelope. There are differences between internal and external insulation methods in heat transmission properties. However, some building load calculation programs cannot analysis the differences between the two. This is because these programs do no account for the timelag or thermal storage effect of the wall according to the location of insulation. In this study, the heat transmission characteristics of internal and external insulation were analyzed by EnergyPlus, and heating and cooling energy demand was compared. The results showed that external insulation system had lower heating and cooling loads than internal insulation system. Also the heat transfer rate of external insulation is steadier than internal insulation. About 13.6% of heating and cooling energy demand decreased when the outdoor wall was finished with external insulation compared to the demand with internal insulation.

• 멤브레인
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• 제34권1호
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• pp.10-19
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• 2024

바이폴라막은 양이온교환층과 음이온교환층 및 양극접합층으로 이루어진 이온교환막으로 물 분해 특성을 기반으로 하여 프로톤과 수산화 이온을 생성시키는 막이다. 이러한 특성을 이용하여 화학 산업, 식품 가공, 환경 보호, 에너지 변환 및 저장과 같은 다양한 응용 분야에서 연구가 되고 있다. 본 논문에서는 바이폴라막 기술에 대한 종합적인 이해를 제공하기 위해 바이폴라막의 개념 및 물 분해 메커니즘과 물 분해 촉매에 대한 조사하였다. 마지막으로 최근 에너지 기술에 적용되고 있는 바이폴라막 프로세스를 조사하였다.