• 한국자원식물학회지
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• 제20권3호
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• pp.255-257
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• 2007

This study was conducted to investigate the effect of sta-green and activated carbon on leaf and stem growth of Agastache rugosa as it is affected by different amounts of sta-green and activated carbon. The results obtained are summarized as follows. Growth characteristics including plant height and leaf number were the highest when treated with 30% of sta-green. The weight of fresh leaf and stem of Agastaches rugosa was very low in control. Also, fresh weight of Angelica acutiloba was higher in 10% treatment of activated carbon. However, when the plants were grown in 10% activated carbon. all these promoters were the biggest. Sta-green and activated carbon can be utilized as a soil conditioner in agricultural crop areas.

• Carbon letters
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• 제4권3호
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• pp.133-139
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• 2003

Carbon/carbon composites are ideal candidates for a number of aerospace applications including structural materials for advanced vehicles, leading edges, structures of re-entry and hypersonic vehicles and propulsion systems. One serious defect for such application of the carbon/carbon composites is their poor oxidation resistance in high temperature oxidizing environments. SiC coating was employed to protect the composites from oxidation. It is mechanically and chemically stable under extreme thermal and oxidative environments, provides good adhesion to the substrate, and offers good thermal shock resistance. The SiC layer on the nozzle machined from the carbon/carbon composites was formed by pack-cementation method. Then, erosion characteristic of SiC coated carbon/carbon nozzle was examined by combustion test using a liquid rocket motor. The erosion rates were measured as function of combustion pressure, ratio of oxygen to fuel, combustion time, density of the composites and geometry of reinforced carbon fibre in the composites. The morphology change of the composites after combustion test was investigated using SEM and erosion mechanism also was discussed.

• Composites Research
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• 제35권2호
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• pp.80-85
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• 2022

본 연구에서는 항공기 방빙을 위해서 탄소계 소수성 입자인 탄소나노튜브의 코팅 횟수에 따른 테프론-폴리우레탄 탑코트의 나노입자 부착력과 표면 소수성 특성을 평가하기 위하여 실험을 진행하였다. 나노입자 부착력을 측정하기 위해서 인발접착시험을 진행하였고, 표면소수성 특성을 측정하기 위해서 정적접촉각 시험과 거칠기 평가를 진행하였다. 거칠기평가를 통하여 탄소나노튜브가 테프론-폴리우레탄 탑코트에 함침된 정도를 할 수 있었고, USB-현미경을 통하여 테프론-폴리우레탄 탑코트에 탄소나노튜브가 함침 및 분산정도를 확인하였다. 그 결과 코팅횟수가 많을수록 탄소나노튜브가 응집되고 이에 의하여 접착력이 감소한다는 것을 확인하였다. 실험결과 코팅 횟수에 따라 테프론-폴리우레탄의 소수성은 커지고 접착력은 감소하였다. 그로 인해 테프론-폴리우레탄 탑코트 와의 접착력 향상과 최적화된 소수성을 가지는 탄소나노튜브의 코팅횟수를 파악할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1207-1210
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• 2003

The effect of solvent structure on the slope in the plot of ln K vs. solute carbon number was examined. It was found that the free energy of methylene group transfer from the gas phase into a solvent was always negative and that the absolute magnitude of interaction free energy between the methylene group and the solvent was always larger than the absolute magnitude of cavity formation free energy of the methylene group in the solvent. Thus, the slope in the plot of ln K vs. solute carbon number was always positive and its value decreases with increase of solvent polarity since the cavity formation energy of the CH₂ unit increases with increase of solvent polarity while the dispersive interaction energy of the CH₂ unit is virtually invariant. We also examined the effect of sequential addition of CH₂ unit to a solvent molecule upon ln K for three homologous series of solvents: n-alkanes, n-alcohols, and n-nitriles. Characteristic trends in the plots of ln K vs. solvent carbon number were observed for individual solvent groups. A decrease of ln K with solvent carbon number was observed for n-alkanes. An abrupt increase in ln K followed by levelling off was observed for n-alcohols while a final slight decrease in ln K after an abrupt increase followed by rapid levelling off was noted for n-nitriles. All of theses phenomena were found related to variation in cavity formation energy. It was clearly shown that a structural change of a polar solvent by sequential addition of CH₂ units causes an abrupt polarity decrease initially, then gradual levelling off, and finally, conversion to a virtually nonpolar solvent if enough CH₂ units are added.

• 대한기계학회논문집B
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• 제39권6호
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• pp.527-534
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• 2015

본 연구에서는 직접 탄소 연료전지(DCFC)에서 세 종류의 탄화수소(메탄, 에탄, 프로판) 열분해를 이용하여 다공성 니켈 연료극에 탄소를 직접 생성시켜 연료극과 연료간의 물리적 접촉을 향상시켰다. 전자현미경으로 각각의 탄화수소로부터 생성된 탄소 입자들이 탄소 수가 증가함에 따라 각각 탄소구형체(CS), 탄소나노튜브(CNT), 탄소나노섬유(CNF)임을 확인하였다. 그리고 탄소 샘플들의 결정성을 알아보기 위해 라만 산란 분석을 수행하였고, 탄화수소의 탄소 수가 증가할수록 생성된 탄소의 결정성이 떨어지고 더 유연하였다. 동일한 질량의 탄소로 채워진 연료극의 DCFC 성능을 $700^{\circ}C$ 에서 측정하였고, CNT 와 CNF 가 CS 보다 반응성이 좋아 각각 148%, 210% 높은 전력밀도를 보였다. 이는 결정성이 떨어지는 CNT 와 CNF 의 낮은 전하전달저항에 의한 것으로 사료된다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.174-176
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• 2002

A total of 134 patients with stage 1 of non-small cell lung cancer treated by carbon ion beam of HIMAC NIRS were investigated for control rate and delivered dose. The delivered dose of every patient was converted to biological effective dose (BED) of LQ model using fraction number, dose per fraction and alpha beta ratio which shows the maximum correlation between BED and tumor control. The BED of every patient was classified to establish a BED response curve for control. Assuming fraction numbers, dose response curves were introduced from BED response curve. The total doses to realize several control rates were obtained for the treatment of small fraction number.

• Bulletin of the Korean Chemical Society
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• 제20권7호
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• pp.809-814
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• 1999

Computations are reported for the very floppy cumulenones H2CnO (n = 3-7). The structures, harmonic frequencies and dipole moments are computed using the DFT and MP2 methods. H2C6O and H2C7O are treated for the first time. The carbon skeletons in ground states of these molecules with smaller number of carbon atoms are found to be bent, but very floppy. Those of the cumulenones with higher number of carbon atoms are predicted to be nearly linear. All the molecules are predicted to be of Cs symmetry by the present results. Good agreement with the available experimental observations is obtained.

• Elastomers and Composites
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• 제56권3호
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• pp.113-116
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• 2021

In this study, we report a facile fabrication of multi-walled carbon nanotubes (MWCNTs)-CuO composites synthesized by a microwave method using MWCNTs and copper oxide (CuO). The number of copper hydrate precursors affect the size and number of CuO domains formed along the MWCNTs in the composites. The domain size is controllable from 239 nm to 348 nm. The composites are characterized by transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction (XRD), Raman spectroscopy, and UV-Vis spectroscopy. The CuO produced in the composites is confirmed to be tenorite with a monoclinic crystal structure through the XRD patterns of (-111), (111) and (-202).

• 전기학회논문지
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• 제60권6호
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• pp.1091-1096
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• 2011

Currently, the concern about the environment is the issue all over the world, and in particular, carbon emissions of the power plants will not be able to disregard from the respect of generation cost. This paper proposes DR (demand response) as a method of reducing carbon emissions and therefore, carbon emissions cost. There are a number of studies considering DR, and in this paper, the effect of DR is focused on the side of carbon emission reduction effect considering Time-Of-Use (TOU) program, which is one of the most important economic methods in DSM. Demand-price elasticity matrix is used in this paper to model and analyze DR effect. Carbon emissions is calculated by using the carbon emission coefficient provided by IPCC (Intergovernmental Panel on Climate Change), and generator's input-output characteristic coefficients are also used to estimate carbon emission cost as well as the amount of carbon emissions. Case study is conducted on the RBTS IEEE with six buses. For the TOU program, it is assumed that parameters of time period partition consist of three time periods (peak, flat, off-peak time period).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.355-356
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• 2006

This work describes the effect of the number of roll pressing and the composition of carbon black on the electric and mechanical properties of carbon-PTFE electrode, in which composition is MSP20 : carbon black: PTFE = 95-X : X : 5 wt.%. It was found that the best electric and mechanical properties were obtained for sheet electrode roll pressed about 15 times and for sheet electrode, in which composition is MSP20 carbon black : PTFE = 80 : 15 : 5 wt%. These behaviors could be explained by the network structure of PTFE fibrils and conducting paths linked with carbon blacks, respectively. On the other hand, cell capacitor using the sheet electrode with 15 wt.% of carbon black attached on aluminum current collector with the electric conductive adhesive, in composition is carbon black : CMC = 70 : 30 wt.%, has exhibited the best rate capability between 0.5 $mA/cm^2$ ~ 100 $mA/cm^2$ current density and the lowest ESR.