• 설비공학논문집
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• 제25권9호
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• pp.477-483
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• 2013

A numerical analysis of solid-liquid phase change was performed on a heat transfer module which consisted of circulating water path (BRINE), heat transfer plate (HTP) and phase change material (PCM) layers, such as high temperature PCM (HPCM, $78{\sim}79^{\circ}C$) and low temperature PCM (LPCM, $28{\sim}29^{\circ}C$). There were five arrangements, consisting of BRINE, HTP, LPCM and HPCM layers in the heat transfer module. The time and heat transfer rate for melting/solidification was compared to their arrangements, against each other. As results, the numerical time without convection was longer than the experimental one for melting/solidification. Moreover, the melting/solidification with the BRINE I-LPCM-BRINE II-HPCM arrangement was faster(10 hours) than the others; HPCM-BRINE-LPCM, BRINE I-HPCM-LPCM-BRINE II one.

• 접착 및 계면
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• 제6권1호
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• pp.11-18
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• 2005

심물질(core)이 상변화물질(Phase Change Material, PCM)이고, 벽물질(shell)이 멜라민 포름알데히드 수지인 마이크로 캡슐을 제조하였다. 제조된 캡슐의 크기가 아크릴 코팅(acrylic coating)의 물성에 미치는 영향을 알아보기 위하여 PCM 캡슐의 크기를 $3{\sim}25{\mu}m$로 조절하여 제조하였다. 제조된 캡슐의 심물질 함량과 캡슐의 크기는 DSC와 SEM을 이용하여 확인하였다. 아크릴 에멀젼은 butyl acrylate, methyl metacrylate와 acrylic acid를 공중합하여 제조하였다. 제조된 PCM 캡슐과 아크릴 에멀젼을 혼합하여 필름으로 제조하였다. 캡슐의 크기가 작을수록 아크릴 코팅 필름 내에 캡슐이 잘 분산됨을 확인할 수 있었고, 캡슐의 크기가 클수록 필름 표면이 매끄럽지 않음을 관찰할 수 있었다. 필름의 수분 흡수율은 PCM 캡슐의 크기에 큰 영향을 받지 않았지만 필름의 인장 강도와 신율은 캡슐의 크기가 작을수록 증가하였다.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2008년도 제39차 학술발표회
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• pp.151-152
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• 2008

PCM has the ability to change their state, these materials absorb energy during the heating process as a body contact and release energy during a reverse cooling process as phase change take place. Using the thermal energy storage of PCM which has a melting point 15 to $35^{circ}C$ is one of the most effective ideas for utilization in textile finish. In this study, microencapsulated PCM(MCPCM) were synthesized by sol-gel method using the octadecane(or nonadecane) as PCM and the silica as microcapsule materials. To develop smart temperature adaptable textile, coating process was applied to textile substrate using a composition included MCPCM.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.162-167
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• 2011

Thermal storage plays an important role in building energy saving, which is greatly assisted by the incorporation of latent heat storage in building materials. A phase change material is a substance with a high heat of fusion which, melting and solidifying at a certain temperature, can be storing and releasing large amount of energy. Heat is stored or released when the material changes from solid to liquid. Integration of building materials incorporating PCMs into the building envelope can result in increased efficiency of the built environment. The aim of this research is to identify thermal performance of PCMs impregnated building materials which is applied to interior of building such as gypsum and red clay. In order to analyze thermal performance of phase change materials, test-cell experiments and simulation analysis were carried out. The results show that micro-encapsulated PCM has an effect to maintain a constant indoor temperature using latent heat through the test-cell experiments. PCM wallboard makes it possible to reduce the fluctuation of room temperature and heating and cooling load by using EnergyPlus simulation program. Phase change material can store solar energy directly in buildings. Increasing the heat capacity of a building is capable of improving human comfort by decreasing the frequency of indoor air temperature swings so that the interior air temperature is closer to the desired temperature for a long period of time.

• Applied Science and Convergence Technology
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• 제23권1호
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• pp.34-39
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• 2014

The programmable switches which control the delivery of electrical signals in programmable logic devices are fabricated using memory technology. Although phase change memory (PCM) technology is one of the most promising candidates for the manufacturing of the programmable switches, the threshold switching material should be added to a PCM cell for realization of the programmable switches based on PCM technology. In this work, we report the impurity-doped $Ge_2Sb_2Te_5$ (GST) chalcogenide alloy exhibiting threshold switching property. Unlike the GST thin film, the doped GST thin film prepared by the incorporation of In and P into GST is not crystallized even at the postannealing temperature higher than $200^{\circ}C$. This specific crystallization behavior in the doped GST thin film is attributed to the stabilization of the amorphous phase of GST by In and P doping.

• Fibers and Polymers
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• 제6권4호
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• pp.343-347
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• 2005

The purpose of this study was to investigate the appropriate amounts of phase change materials to give objective and subjective wear sensations. Vapor-permeable water-repellent fabrics with (WR-PCM) and without (WR) octadecane containing microcapsules were obtained by wet-porous coating process. Then, calculating the area of the WR-PCM treated clothes, we estimated the total calories of the clothing by multiplying the heat of fusion and heat of crystallization of PCM to the calculated area. Wear tests were conducted in both warm environment $(30^{\circ}C,\;65\%\;RH)$ and cold environment $(5^{\circ}C,\;65\%\;RH)$ with sports warm up style experimental garments made with WR and WR-PCM fabrics. Rectal, skin, and clothing microclimate temperatures, saliva and subjective evaluation measurements were done during the wear test. There was no difference of rectal and mean skin temperatures between WR and WR-PCM, but the clothing microclimate temperature of WR-PCM under warm environment was slightly lower than that of WR. In cold environment, WR-PCM showed much higher temperature than in WR. Saliva change did not appear between clothes, but did between two environments. Although subjective sensation between WR and WR-PCM was not significantly different, WR-PCM was rated as cooler than WR in warm environment and as warmer than WR in cold environment. The results of this study indicated that octadecane containing microcapsules in water-repellent fabric provide cooling effect.

• 대한화학회지
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• 제65권2호
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• pp.145-150
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• 2021

The present study describes a hands-on experiment to help students understand the concept of phase change or phase transition and its application in a phase change material (PCM). PCMs are substances that have the capability of storing and releasing large amounts of thermal energy. They act as energy storage materials that provide an effective way to save energy by reducing the electricity required for heating and cooling. Lauric acid (LA) was selected as an example of the PCM. Students investigated the temperature change of LA and the temperature (of air) inside the test tube. The differences in the temperatures of the systems helped students understand how PCMs work. A one-group pretest and posttest design was implemented with 34 grade-11 students in science and mathematics. Students' understanding was assessed using a multiple-choice test and a questionnaire. The findings revealed that the designed activity helped students understand the concept of phase change and its application to materials for thermal energy storage.

• Composites Research
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• 제30권5호
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• pp.288-296
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• 2017

본 연구에서는 전자기기 사용에 이슈가 되고 있는 발열 문제를 해결하고자 상변화물질(PCM)의 잠열 특성을 이용하여 폴리메틸메타크릴레이트(PMMA) 복합필름을 제조하고 방열 성능을 평가하였다. 이를 위해 용융온도가 서로 다른 두 가지의 상변화물질을 사용하여 제작한 PCM/PMMA 복합필름의 열적 특성을 비교 분석하여 다양한 사용조건에 따른 유효성을 검증하였고, Compression Molding 방법과 PCM Paste Sealing 방법에 따른 PCM/PMMA 복합필름의 방열 특성을 비교 분석하여 최대의 방열 효과를 달성할 수 있는 최적의 방법을 도출하였다. 또한 PCM/PMMA 복합필름의 방열 성능을 최대화하기 위해 열전도율이 높은 흑연과 그래핀을 추가로 적층하여 제조한 Hybrid 복합필름의 열적 특성을 분석하였고, 이들을 통해 향상된 방열 성능을 실험적으로 검증하였다. 본 연구를 통해 개발된 방열 성능이 우수한 복합필름은 다양한 전자기기에 활용되어 발열 문제를 효과적으로 해결할 수 있을 것으로 기대된다.

• 콘크리트학회논문집
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• 제28권6호
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• pp.665-672
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• 2016

본 연구는 상전이물질이 시멘트 모르타르의 수화특성 및 강도특성에 미치는 영향을 평가하기 위하여 실시되었다. 이를 위하여 바륨 및 스트론튬계 상전이물질을 사용하였으며, 상전이물질 혼입률 1~5%에 대한 실험을 수행하였으며, 시멘트 모르타르 작업성 평가, 간이단열온도상승 실험, 압축 및 휨 강도 평가를 실시하였다. 실험결과 상전이물질의 혼입은 시멘트 모르타르의 수화열 감소에 효과적인 것으로 나타났으며, 바륨 기반 PCM을 사용할 경우 흐름성능이 다소 감소하는 것으로 나타났다. 압축 휨 강도의 경우 상전이물질의 혼입률이 증가함에 따라 감소하는 경향을 나타내었으며, PCM을 사용할 경우 혼입률에 따라 압축강도 발현추이의 변화가 발생하였다. 따라서 본 연구에서는 상전이물질이 혼입률에 따른 압축강도 추정식을 제시하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.322-322
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• 2016

Phase change memory (PCM) has attracted much attention as one of the most promising candidates for next-generation nonvolatile memory. In that regard, the purposes of the study are to propose reference of effective pulse parameter to control phase switching operation and to invest the effect of nitrogen doped in PCM materials for improved cycling stability and economic energy consumption. Switching operation of PCM is affected by electric pulse parameter and as shown in figure.1 are composed to RT(rising time), ST(setting time), FT(falling time) and the effect of these parameter was precisely investigated. Transmission electron microscope (TEM) was used to confirm fine structure and retention cycle test was conducted to confirm reliability. Finally improvement reliability and economic power consumption in quantitatively are obtainable by optimum pulse parameter and nitrogen doping in GST material. these study is related to the engineering background of other semiconductor industries and it have confirmed to possibility further applications.