• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.185-190
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• 2008

In order to increase the surface area of electrodes for electrosorption, porous carbon electrodes were fabricated by a wet phase inversion method. A carbon slurry consisting of a mixture of activated carbon powder (ACP), polyvinylidene fluoride (PVdF), and N-methyl-2-pyrrolidone (NMP) as a solvent was cast directly on a graphite sheet. The cast film was then immersed in pure water for phase inversion. The physical and electrochemical properties of the electrodes were investigated using scanning electron microscopy (SEM), porosimetry, and cyclic voltammetry. The SEM images verified that the pores of various sizes were formed uniformly on the electrode surface. The average pore sizes determined for the electrodes fabricated with various NMP contents ranged from 64.2 to 82.4 nm and the size increased as the NMP content increased. All of the voltammograms showed a typical behavior of charging and discharging characteristic at the electric double layer. The electrical capacitance ranged from 3.88 to $5.87F/cm^2$ depending on the NMP contents, and the electrical capacitance increased as the solvent content decreased. The experimental results showed that the solvent content is an important variable controlling pore size and ultimately the capacitance of the electrode.

• Journal of Adhesion and Interface
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• v.23 no.1
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• pp.1-7
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• 2022

As the wind blades become larger, they tend to be made by mixing glass fiber and carbon fiber, and it is important to increase the properties of the adhesive which adheres the two materials. The physical properties of the adhesive vary depending on the content of the additive and curing conditions. In this study, the change in adhesion strength with the difference between the CNT (Carbon Nanotube) content of the epoxy adhesive and the humidity during curing was evaluated. GFRP and CFRP specimens were prepared and adhered using an epoxy adhesive, and to examine changes in characteristics with carbon nanotube contents and with the humidity during curing of the epoxy adhesive, adhesion strength was evaluated by dividing the difference between carbon nanotube content and humidity. To find out the change with the CNT contents, the intelaminar shear strength (ILSS) test was performed by dividing the contents of the CNT into 0, 0.1, 0.3, 0.5, and 1 wt%, and to confirm the change with the humidity conditions, the adhesive was cured by dividing the humidity by 20, 50, and 80%. From the result of the experiment, the adhesive force decreased when the content was excessively large, although the adhesive property was enhanced by adding CNT to the epoxy adhesive. In addition, it was confirmed that the adhesion characteristics were not changed as the humidity increased.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.4
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• pp.409-414
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• 2008

Porous carbon electrode for electrosorption was prepared by a wet phase inversion method. Carbon slurry that was a mixture of activated carbon powder(ACP) and PVdF solution was cast directly upon a graphite sheet by means of a casting knife. Porous carbon electrodes were fabricated by immersing the cast film in pure water as a non solvent. Physical and electrochemical properties of carbon electrodes prepared with various ACP contents(50.0, 75.0, 83.3, 87.5, 90.0 wt %). From the SEM images we can verify that the electrode was porous. The average pore sizes determined for the electrodes fabricated with various ACP contents ranged from 72.7 to 86.4 nm and the size decreased as the ACP content increased. The electrochemical properties were characterized by cyclic voltammetry(CV) method. All of the voltammograms showed typical behavior of an electric double layer charging/discharging on the carbon surface. The capacitance increased with the ACP content and the values ranged from 2.18 F/cm$^2$ for 50 wt% ACP to 4.77 F/cm$^2$ for 90 wt% ACP.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.2
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• pp.101-106
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• 1999

The down-core distribution of chlorophyll a, organic carbon contents and ${\delta}^{13}C$ in the bottom sediments were measured to understand the evolution of eutrophication in Masan Bay. Bottom sediment were collected in January 1994. The chlorophyll a and organic carbon contents in the sediment core decreased with increasing sediment depth, respectively. Bottom sediments (0~20 cm) in Masan Bay was rich in chlorophyll a (avg. 9.6 ${\mu}g\;g^{-1}$ dryweight) and organic C (avg. 2.5%). The down-core distribution of chlorophyll a suggests that the inner part of Masan Bay has experienced the acceleration of chlorophyll a supply since 1960s. Flux of organic carbon to the sea floor is in the range of 10 $gCm^{-2}\;yr^{-1}$ assuming the C:Chl a ratio of 25. It suggests tht approximately 1.3% of the fixed carbon by phytoplankton appears to be deposited in the bottom sediments.

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.121-125
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• 2013

In this work, we prepared the carbon paper from chopped carbon fibers using a gas diffusion matrix in polymer electrolyte membrane fuel cells by wet processing. The process of making carbon paper using wet processing is consisted of the three steps involving the dispersion of chopped carbon fibers, the preparation of the carbon fiber web, the impregnating of phenol resin. This work was focused on finding the optimal surfactant to make the carbon paper with 2D orientation of carbon fibers by investigating the dispersion state of carbon fibers in different dispersion solutions. Furthermore, the effect of phenol resin and carbon black contents on properties of electric conductivity was analyzed. As a result, it is confirmed that the carbon fiber was well dispersed when using sodium dodecyl sulfate as a surfactant, and the carbon paper with 8 wt% of phenol and 5 wt% of carbon black contents showed the most excellent electrical property.

• Resources Recycling
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• v.19 no.3
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• pp.16-23
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• 2010

Coal briquette use has dramatically increased because of high oil prices. Hence, it is necessary to develop an environment-friendly recycling technique of the coal briquette ash. The coal briquette ash contains a large amount of an unburned carbon content and a mullite with high thermal property, so it is considered to be used as raw materials of sintered eco-brick. This study aimed to investigate on how the unburned carbon affects properties of the sintered eco-brick. The eco-brick was mixed with the ratio of 50 wt% coal briquette ash having the unburned carbon 10.5 wt% and 50 wt% cullet, then being sintered at $950^{\circ}C$, which of the compressive strength was in line with the first class of the sintered clay brick standard(KS L 4201). In particular, the compressive strength of the sintered eco-brick was equal to the first class of the KS L 4201 despite the increase of mixing ratio for coal briquette ash with 1.0 wt% unburned carbon to 70 wt%.

• Composites Research
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• v.29 no.5
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• pp.262-268
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• 2016

In this work, the pitch-based carbon paper (P-CP) was prepared by re-impregnating of binder pitches and PAN-based milled carbon fibers (MCF) at low temperature carbonization process. The influence of MCF content on physicochemical properties of MCF/P-CP was investigated. As a result, the tensile strength of MCF/P-CP was increased sharply from 10 wt.% to 20 wt.% of MCF. Also, the increase of MCF content led to the decrease of interfacial contact resistivity and the improvement of electrical and thermal conductivity of MCF/P-CP. These results were probably due to the increase of density of MCF/P-CP, resulting in the formation of electrically and thermally conductive paths of the carbon paper.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.232.1-232.1
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• 2015

흑연 박리를 통해 형성된 탄소나노플레이트를 탄소나노튜브 합성을 위한 지지체로 적용하여 탄소나노플레이트 위에 직접 탄소나노튜브를 합성함으로써 3차원 구조의 탄소나노튜브/탄소나노플레이트 나노혼성체를 합성하였음. 흑연의 박리를 통해 탄소나노플레이트를 제조하기 위해서 층간화합물 삽입과 열처리를 통해 팽창흑연을 제조하고, 물리적 분쇄 과정과 액상 고압균질기 방법을 통해 두께 30nm 이하, 수 마이크론 크기의 탄소나노플레이트를 제조하고 동결건조 방법으로 탄소나노플레이트를 제조하였음. 제조된 탄소나노플레이트 상에 탄소나노튜브 합성을 위해서 탄소나노플레이트 표면처리 공정을 적용하였는데, 표면처리 방법 및 물질에 따라 금속 촉매의 담지량 및 담지 형상이 결정되어 합성되어지는 탄소나노튜브의 합성 수율과 합성된 탄소나노튜브의 형성이 다르게 나타났다. 표면처리 방법으로는 산처리방법, 흡착성 고분자 처리법, 무전해 도금법, 무기산화물 처리법이 적용되었다. 또한 담지되는 촉매 종류 및 함량, 조촉매 적용에 따라 탄소나노튜브 합성 거동을 분석하여 최적 촉매시스템을 구축하여 촉매담지체 질량 대비 700% 이상의 고수율의 탄소나노튜브/탄소나노플레이트 혼성체 합성법을 개발하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1349-1355
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• 2006

This study was conducted to investigate the effect of methanol extract of Allomyrina dichotoma larva (MEAL) on carbon tetrachloride $(CCl_4)-induced$ hepatotoxicity in mice. ICR mice were divided into 5 groups [Vehicle control, $CCl_4\;(10{\mu}g/g)$ alone, $CCl_4$ plus a low dose $(50{\mu}g/g)$ of MEAL, $CCl_4$ plus a high dose $(100{\mu}g/g)$ of MEAL]. Silymarin $(2{\mu}g/g)$ was used as the reference in the experiment. Administration of MEAL tended to decrease the serum alanine transaminase (ALT) activity induced by $CCl_4$ treatment in mice. Hepatic concentration of thiobarbituric acid-reactive substances (TBARS) in a high-dose group of diet decreased to the level of silymarin-treated group. Hepatic activity of glutathione S-transferase in MEAL-treated group was lower than that of $CCl_4-treated$ group. Serum concentration of bilirubin was significantly increased by $CCl_4$ treatment, but MEAL or silymarin recovered the level. These results suggest that MEAL may exert the protective effect against $CCl_4-induced$ hepatotoxicity in mice. However, more intensive studies would be needed to elucidate the protective mechanism of the beetle on hepatotoxicity of mice.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.181-195
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• 2020

Characteristics of carbonized biomass obtained from a Wood charcoal briquette manufacturing process using an open hearth kiln are analyzed in this research, and differences in the characteristics based on the results of a mechanical screening process and the position within the kiln. One type of biomass and five types of carbonized biomass were collected from a Wood charcoal briquette manufacturer. After screening and grinding processes were performed on samples of 1 type of biomass and 5 types of carbonized biomass extracted from a Wood charcoal briquettes manufacturer to classify by particle size, fixed carbon, ash, volatile matters, elemental composition, and high heating value (HHV) were measured. Experimental results showed that the carbonized biomass collected from the middle layer had the highest HHV, 20.4 MJ/kg, and therefore had the highest fuel quality. In terms of particle size, the carbonized biomass below 100 mesh had the lowest ash content and the highest HHV, carbon content, and fixed carbon content. Correlation analyses showed that ash content had negative correlations with HHV, volatile matters, fixed carbon, and carbon content, which suggested that ash content affected negatively on fuel quality.