• Electrical & Electronic Materials
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• v.14 no.9
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• pp.25-33
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• 2001

• The Magazine of the IEIE
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• v.39 no.6
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• pp.18-22
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• 2012

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.39-47
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• 2005

• Rubber Technology
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• v.20 no.4
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• pp.231-238
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• 2019

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.80-85
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• 2015

Silicon/carbon composites as anode materials for lithium-ion batteries were examined to find the cycle performance and capacity. Silicon/carbon composites were prepared by a two-step method, including the magnesiothermic reduction of SBA-15 (Santa Barbara Amorphous material No. 15) and carbonization of phenol resin. The electrochemical behaviors of lithium ion batteries were characterized by charge/discharge, cycle, cyclic voltammetry and impedance tests. The improved electrochemical performance attributed to the fact that silicon/carbon composites suppress the volume expansion of the silicon particles and enhance the conductivity of silicon/carbon composites (30 ohm) compared to that of using the pure silicon (235 ohm). The anode electrode of silicon/carbon composites showed the high capacity approaching 1,348 mAh/g and the capacity retention ratio of 76% after 50 cycles.

• Journal of the Korean Electrochemical Society
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• v.12 no.1
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• pp.68-74
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• 2009

The effect of physico-electrochemical properties of carbon bipolar plate(BPP) on hydrogen and formic acid fuel cell performance has been investigated. BPP made of conventional graphite and carbon fiber composite were compared with the factors of interfacial contact resistance (ICR), corrosion behaviours, and hydrophobicity. Among them, the ICR of carbon fiber composite BPP has 50% higher than conventional graphite and the surface of carbon fiber composite BPP became rougher due to weaker corrosion resistance. Fuel cell performance was strongly dependent of ICR value of carbon bipolar plate.

• Resources Recycling
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• v.30 no.1
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• pp.77-82
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• 2021

Reduction of CO2 emissions is an important issue in the steel industry, and the research on carbon materials that can partially replace cokes is necessary to reduce CO2 emissions. Meanwhile, the biomass fuel contains some fixed carbon, and the carbon content in the biomass can be increased by torrefaction. As one of the biomass fuels, coffee grounds contains about 55 mass% of carbon, and its about 270,000 tons are landfilled and incinerated annually in Korea. In addition, research on the recycling process due to the increase in annual coffee consumption is required. In this study, the effect of temperature on the concentration of fixed carbon in coffee grounds was investigated during torrefaction. Moreover, the effects of mixing ratio of torrefied coffee grounds with cokes on the carbon concentration and dissolution efficiency in the metal sample were investigated.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.99-104
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• 2024

In this study, a carbon coated hollow silicon (HSi/C) composite material was prepared for anode material of high-capacity lithiun-ion battery. Hollow silica (HSiO₂) was synthesized by the Stöber method with CTAB (N-Cetyltrimethylammonium bromide). The HSi/C anode composite was manufactured by carbon coating after magnesiothermic reduction of HSiO₂. The physical and electrochemical characteristics of the prepared anode materials were investigated based on CTAB amount. In the FE-SEM analysis, it was found that the HSiO₂ particle size increased as CTAB amount decreased, but shell thickness decreased. The HSi/C composites exhibited high initial discharge capacities of 1866.7, 2164.5 and 2188.6 mAh/g with various CTAB ratios (0.5, 1.0, 1.5), respectively. After 100 cycles of charge-discharge, 0.5-HSi/C demonstrated a high reversible capacity of 1171.3 mAh/g and a capacity retention of 70.9%. Electrochemical impedance spectroscopy (EIS) was employed to analyze the impedance characteristics, and it revealed that 0.5-HSi/C showed more stable resistance characteristics than HSi/C composites with other CTAB amount over 20 cycles.

• Journal of The Korean Association For Science Education
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• v.40 no.3
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• pp.237-251
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• 2020

Issues on climate change we are facing, such as global warming, are very important as it affects our lives directly. To overcome this, efforts to reduce greenhouse gases emissions (e.g., carbon dioxide) are necessary and these efforts should be based on our integrated understanding of carbon cycle. The purpose of this study is to examine the research trend on carbon cycle education and to suggest the value and direction of carbon cycle education for students who will be citizens of the future. We analyzed 52 carbon cycle education related studies collected from academic research databases (RISS, KCI, ERIC, Google Scholar, and others). As a result, we conclude that resources are still limited and more researches on verification and utilization of developed program, development of accurate and comprehensive tools for students' recognition and level assessment, developing educational model or teacher professional development, providing more appropriate curriculum resources, and the use of various topics or materials for carbon cycle education are necessary. Students' comprehensive understanding of the carbon cycle is important to actively react to the changes in the global environment. Therefore, to support such learning opportunities, resources that can be connected to students' daily experiences to improve students' understanding of carbon cycle and replace misconceptions based on the verification of existing programs should be provided in the classroom as well as the curriculum. In addition, sufficient exemplary cases in carbon cycle education including various materials and topics should be provided through professional development to support teachers teaching strategies with carbon cycle.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.511-511
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• 2013

균일한 전기 전도성 및 우수한 광투과성과 내화학성을 갖는 탄소나노튜브(CNT) 기반의 투명전도막(TCF)은 기존의 ITO 박막보다 우수한 유연성을 갖기 때문에 차세대 플렉시블 디스플레이 소재로서 많은 관심을 모으고 있다. 특히 낮은 저항과 투과도가 일정하면서 투명 전도막의 내구성을 향상 및 유지 시키는 연구는 상업화에 가장 필요한 연구 분야이다. 본 연구에서는 PET기판을 이용한 탄소나노튜브로 제작된 투명전도막 위에 오버 코팅을 통한 물성에 따른 내구성 개선 및 유지를 연구하였다. 오버 코팅 물질로는 실리콘계 투명 하드코팅 소재를 기본으로 하고 용매 및 합성 온도을 제어하여 내구성을 개선하고자 하였다. 연구결과 CNT 코팅층과 오버 코팅층과의 젖음성이 물성 향상에 가장 많은 영향을 끼치는 것을 관찰하였고, 특히 젖음성이 증가할수록 투과도와 전기전도도가 향상되는 것을 확인하였다. 구조 분석결과, 이러한 젖음성에 가장 많은 영향을 주는 것은 용매의 비점과 비중 그리고 용질의 합성 온도 임을 확인하였다. 또한 오버코팅 물질 중 고비점 용매가 고온 고습 환경에서 240시간 이상 내구성 테스트 결과, 투명전도성 평가 지수(${\sigma}DC/{\sigma}OP$)가 향상되었고 또한 테스트 전후의 HAZE 변화율이 10%이하 임을 확인하였다.