• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.103.2-103.2
• /
• 2011

리튬이차전지의 음극물질로서 상용화되고 있는 탄소재료중 흑연은 전기자동차에 적용하기에는 낮은 용량과 나쁜 출력특성을 갖고 있어 지금보다 두배이상의 용량과 출력특성이 좋은 음극소재의 개발이 필요하다. 또 다른 음극물질로 실리콘은 흑연에 비해 월등히 높은 이론용량을 나타내고 있지만 실리콘이 리튬이온과 만나면 부피가 4배이상 팽창하여 사이클이 진행될수록 충방전 용량이 급격히 감소하게 된다. 그래서 본 연구에서는 이 두 음극소재를 상호보완하기 위해 천연흑연을 산처리 과정을 통해 제조된 팽창흑연을 매트릭스로 사용하여 팽창흑연에 실리콘을 충진 시키는 연구를 진행하였다. 팽창흑연에 실리콘을 충진시킴으로써 1C일 때 약 650mAh/g의 용량을 나타내었으며, 50cycle이 진행된 후에도 비교적 안정한 사이클 특성을 나타내었다.

• Cement
• /
• s.108
• /
• pp.57-60
• /
• 1987

이 논문에서는 통상의 포졸란 대신에 제올라이트 물질 즉, 화산 응회암을 적절히 분쇄한 후 혼합해서 만든 시멘트의 특성 변화에 대해 논하였다. 이러한 치환이 알칼리-골재 팽창 반응을 최소화시키고 장기강도를 향상시키는 장점이 있다는 사실도 밝혀냈다. 특히 제올라이트를 미리 열처리해서 첨가했을 때 이러한 팽창감소 효과가 현저하다는 것도 발견하였다. 강도증진 효과는 포졸란 유리상의 활성도에 비해 제올라이트 광물의 활성도가 높기 때문으로 해석되며 팽창의 감소는 비정질 수화 규산염이 먼저 알칼리와 반응을 하는 성질이 있기 때문으로 판단된다.

• Journal of Korean Medical classics
• /
• v.18 no.3 s.30
• /
• pp.9-16
• /
• 2005

종의역학적각도간(從醫易學的角度看), 우주적팽창일수축반복가설부합음양소장과정. 우주팽창시(宇宙的膨是)‘양생음장(陽生陰長)’, ‘양성음쇠(陽盛陰衰)’적과정(的過程) ; 우주수축시(宇宙收縮是)‘양살음장(陽殺陰藏)’, ‘음성양쇠(陰盛陽衰)’적과정(的過程). 종수축도팽창(從收縮到膨脹), 종팽창도수축(從膨脹到收縮), 기전환점시양극혹음극적상태(其轉換點是陽極或陰極的狀態), 응용(應用)’음극변양(陰極變陽), 양극변음(陽極變陰)‘적음양극변원리(的陰陽極變原理). ${\lceil}$내경(內經)${\rfloor}$인위물질화시공(認爲物質和時空), 시간화공간본질상시일치적(時間和空間本質上是一致的), 도시종기파생출래적(都是從氣派生出來的). ${\lceil}$내경(內經)${\rfloor}$이경인식도료시공적통일성화상대성(已經認識到了時空的統一性和相對性). 저여애인사탄상대론적시공관유상동지처(這與愛因斯坦相對論的時空觀有相同之處). 서방과학적시공관시통과대물질실체이급물질상호관계적관찰이형성적물리시공관(西方科學的時空觀是通過對物質實體以及物質相互關係的觀察而形成的物理時空觀) ; 의역시공관시통과대포괄인류재내적천지만물적일절생명활동현상적관찰이형성적생명시공관(醫易時空觀是通過對包括人類在內的天地萬物的一切生命活動現象的觀察而形成的生命時空觀).

• Journal of the Society of Disaster Information
• /
• v.18 no.1
• /
• pp.1-9
• /
• 2022

Purpose: In this study, we used hydrophilic waterstop used in geosynthetics vertical barrier system to evaluate the performance of impermeability under sealing conditions. Method: ASTM D5887 and ASTM D6766 were applied to determine the capability of the connection during the geosynthetics vertical barrier system. Hydrophilic waterstop was saturated in each solution and the weight, thickness, and volume changes were analyzed over elapsed time. Hydrophilic waterstop was installed at the geosynthetics vertical barrier system connection to evaluate the permeability characteristics. Results: As the expansion reaction time of hydrophilic waterstop increased relatively under saline conditions, the decrease in permeability also showed a smaller decrease in fresh water. Furthermore, the method of engagement of the geosynthetics vertical barrier system showed somewhat better performance of the impermeability due to the large pressure resistance caused by the roll joint type than interlock type. Conclusion: In urban pollutants, which can estimate the outflow of pollutants such as oil storage facilities and industrial complexes, proactive response technologies that can prevent the contaminant diffusion can significantly reduce the damage.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.5
• /
• pp.35-40
• /
• 2012

In this study, adsorption characteristics of expanded graphite (EG) were investigated by a series of batch adsorption tests using p-Xylene as a model volatile organic compounds (VOCs). After acid treatment, graphite were expanded at various temperature from $600^{\circ}C$ to $1000^{\circ}C$ for one minute. The optimal temperature was $800^{\circ}C$, where the expansion ratio reached 195 times of original volume. The BET specific surface area of EG was $92.4m^2/g$, which was only 1/10 of granular activated carbon (GAC), however the adsorption of p-Xylene by EG was almost completed within 5 minutes while that of GAC continued for 7 days because the majority of pores of EG was consisted with meso- and macro-pores. According to the Langmuir isotherm analysis, the maximum specific adsorption of p-Xylene onto EG was 24.0 mg/L with the adsorption constant of 7.94. In conclusion, the adsorption capacity of EG was much less than that of GAC due to the significantly lower specific surface area, but the first order kinetic constant was more than 500 times larger than GAC. Overall, EG might be effective where the fast adsorption is required.

• Toxicological Research
• /
• v.13 no.1_2
• /
• pp.1-21
• /
• 1997

염증반응이란 우리 신체에 외부 물질이 침입했을 경우 대처하는 정상적인 현상이다. 외부에서 물리, 화학, 생물학적 물질에 노출되었을 경우 혈관이 팽창하고, 비특이적 면역반응이 시작된다. Selectin, integrin, immunoglobulin superfamily와 같은 adhesion molecule에 의해 macrophage 및 neutrophil과 같은 leukocyte의 반응을 촉진하기 위해 exudation이 일어나고 침입 부위에 모여 hyperemia가 발생된다.(Govan 등, 1995)

• Applied Chemistry for Engineering
• /
• v.25 no.5
• /
• pp.463-467
• /
• 2014

In this paper, the thermal behaviors of expanded graphite(EG)/erythritol composites with different contents of EG were studied. The surface and structure properties of the composites were determined by using scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD), respectively. The thermal properties were investigated by differential scanning calorimetry (DSC) and thermal conductivity (TC). As experimental results, the thermal conductivity of the composites increased with increasing the EG content. However, the latent heat was somewhat decreased in the presence of EG. We could concluded that EG was highly promising materials for improving the heat transfer enhancement and energy storage capacity of phase change materials (PCMs).

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.2
• /
• pp.183-189
• /
• 2020

The purpose of this study is to investigate the compressive and tensile properties of high volume slag cement-based fiber-reinforced composite incorporating phase change material. Four mixtures were determined according to calcium hydroxide and expansive admixture, and the compressive strength and tension tests were performed. Test results showed that four mixtures showed a compressive strength over 51MPa and a tensile ductility over 3.2%. It was observed that calcium hydroxide and expansive admixture influenced the compressive and tensile performance, and the strength, ductility, and cracking patterns of composite could be improved by including proper amount of calcium hydroxide and expansive admixture.

• Journal of the Korean Institute of Gas
• /
• v.18 no.2
• /
• pp.28-34
• /
• 2014

In the natural gas pressure regulation station, high pressure natural gas is decompressing using pressure regulation valves. Waste pressure occurred in the pressure regulation process can be recovered through adopting turbo expanders. However, in the waste pressure recovery process, Joule Thompson effect causes below $0^{\circ}C$ and this low temperature freezes outside land of pipeline or generates methane hydrate in the pipeline which can block the pipeline. Therefore, turbo expander systems are accompanying with a boiler for preheating natural gas. Molten carbonate fuel cell (MCFC), one of the high temperature fuel cell, can use natural gas as a direct fuel and is also exhausting low emission gas and generating electricity. In this paper, a thermodynamic analysis on the hybrid MCFC-turbo expander system is conducted. The fuel cell system is analyzed for the base load of the hybrid system.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1796_1797
• /
• 2009

원자력발전소의 금속파편감시설비는 원자로냉각 재계통에서 발생되는 충격신호에 대한 정보를 운영자에게 제공하여, 금속이물질로 인한 관련 구조물 파손을 미연에 방지하기 위한 설비이다. 운전 중에 발생되는 충격신호 중 대부분을 차지하는 거짓경보는 열팽창이나 구조물마찰에 의한 신호이나, 국내외에 설치되어 운전 중인 금속파편감시설비에는 열팽창과 구조물마찰에 의한 충격신호를 판단할 수 있는 알고리즘이 탑재되어 있지 않다. 따라서 본 연구에서는 대부분의 거짓 경보를 발생시키는 열팽창 및 구조물마찰에 의한 충격신호를 신호 검출단계에서 배제할 수 있는 알고리즘을 제시하고자 한다.