• 한국농촌건축학회논문집
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• 제26권2호
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• pp.9-16
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• 2024

In order to achieve carbon neutrality in the architectural field by 2050, this study analyzed the energy impact proportional to CO2 emissions of each technique, such as design methods, the properties of building structures, prefabrication methods, passive houses, and active facilities. In addition, the results were presented quantitatively in terms of carbon reduction, and corresponding housing cases were analyzed. The research method is limited to residential buildings at the Passive House energy level, and carbon reduction techniques and elements in architecture are examined through various literature and materials, and empirical cases are analyzed to determine the specific possibility of realizing carbon reduction in architecture. We want to secure it. Based on these analysis results, it was possible to suggest that it is possible to explore various approaches to carbon reduction in future residential construction. By combining the most efficient techniques according to the energy reduction level or goal setting of the building in question, we expect the possibility of achieving the goal of carbon reduction in the residential sector more realistically.

• 멤브레인
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• 제28권4호
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• pp.221-232
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• 2018

Poly(imide siloxane)(Si-PI)와 polyvinylpyrrolidone (PVP)를 혼합한 고분자를 사용하여 실리카가 함유된 탄소 분리막을 제조하였다. 고분자 혼합물의 열분해에 의해 제조 된 다공성 탄소 구조의 특성은 두 고분자의 미세 상 분리 거동과 관련이 있다. Si-PI와 PVP의 고분자 혼합물의 유리 전이 온도(Tg)는 시차 주사 열량계를 사용하여 단일 Tg로 관찰되었다. 또한 $C-SiO_2$ 막의 질소 흡착 등온선을 조사하여 다공성 탄소 구조의 특성을 규명했다. Si-PI/PVP로부터 유도 된 $C-SiO_2$ 막은 IV형 등온선을 나타내었고 중간기공의 탄소 구조와 관련된 히스테리시스 루프를 가지고 있었다. 분자 여과 확인을 위해서, Si-PI/PVP의 비율과 열분해 온도 및 등온 시간과 같은 열분해 조건을 다르게 하여 $C-SiO_2$ 막을 제조하였다. 결과적으로, 120분 간의 등온 시간 동안 $550^{\circ}C$에서 Si-PI/PVP의 열분해에 의해 제조된 $C-SiO_2$ 막의 투과도는 820 Barrer ($1{\times}10^{-10}cm^3(STP)cm/cm^2{\cdot}s{\cdot}cmHg$)이었으며, $O_2/N_2$ 선택도는 14이었다.

• 한국수소및신에너지학회논문집
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• 제19권2호
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• pp.163-170
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• 2008

Carbon nanofibers with nano-sized structures were evaluated as a active material using supercacitor electrode which could store electrochemical energy reversibly. A feasibility of EDLC electrode was estimated with specific surface area measurement by BET method and mesopore structure of carbon nanofiber surface could be explained electrochemical absorption-desorption in aqueous electrolyte. A capacitance of carbon nanofiber electrode was increased gradually, depending on the ratio of Ketjenblack as a conducting material. Ketjen Black $20{\sim}25\;wt.%$ ratio in electrode was observed a suitable amount of conducting material by cyclic voltametry results.

• 한국환경과학회지
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• 제9권4호
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• pp.339-343
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• 2000

Activated carbons were prepared from Youngwall coal by steam activation in this study. The feasibility of the Youngwall coal to commercial activated carbon was examined. The variation of pore structures and the development of porosity in activated carbons were investigated by changing activation conditions in batch type apparatus. The values of BET surface area and adsorption capacity of iodine and methylene blue of the resulting activated carbons were obtained as high as 1,000$m^2$m^2$$/g, 900mg/g, 150$m\ell$/g, respectively. Youngwall activated carbon prepared in this study showed much higher pore volume in pore diameter over 10 than that of commercial reference activated carbon(Ningxia Taihua ZJ-15C) produced from China anthracite.

• Carbon letters
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• 제17권1호
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• pp.29-32
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• 2016

This paper addresses the effect of dopants on the electronic properties of zigzag (8, 0) semiconducting single walled carbon nanotubes (SWCNTs), using extended Hückel theory combined with nonequilibrium Green’s function formalism. Through appropriate dopant concentrations, the electronic properties of SWCNTs can be modified. Within this context, we present our ongoing investigation on (8, 0) SWCNTs doped with nitrogen. Quantum confinement effects on the electronic properties of the SWCNTs have also been investigated. The obtained results reveal that the electronic properties of SWCNTs are strongly dependent on the dopant concentration and modification of electronic structures by hydrogen confinement.

• Carbon letters
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• 제10권1호
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• pp.19-22
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• 2009

In this work, the hydrogen storage behaviors of carbon nanotubes (CNTs)/metal-organic frameworks-5 (MOF-5) hybrid composites (CNTs/MOF-5) were studied. Hydrothermal synthesis of MOF-5 was conducted by conventional convection heating using 1-methyl-2-pyrrolidone (NMP) as a solvent. Morphological characteristics and average size of the CNTs/MOF-5 were also obtained using a scanning electron microscopy (SEM). The pore structure and specific surface area of the CNTs/MOF-5 were analyzed by N2/77 K adsorption isotherms. The capacity of hydrogen storage of the CNTs/MOF-5 was investigated at 298 K/100 bar. As a result, the CNTs/MOF-5 had crystalline structures which were formed by hybrid synthesis process. It was noted that the CNTs/MOF-5 can be potentially encouraging materials for hydrogen adsorption and storage applications at room temperature.

• Carbon letters
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• 제12권2호
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• pp.112-115
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• 2011

The scope of this work investigates the relationship between the amount of oxygen-functional groups and hydrogen adsorption capacity with different concentrations of phosphoric acid. The amount of oxygen-functional groups of activated carbons (ACs) is characterized by X-ray photoelectron spectroscopy. The effects of chemical treatments on the pore structures of ACs are investigated by $N_2$/77 K adsorption isotherms. The hydrogen adsorption capacity is measured by $H_2$ isothermal adsorption at 298 K and 100 bar. In the results, the specific surface area and pore volume slightly decreased with the chemical treatments due to the pore collapsing behaviors, but the hydrogen storage capacity was increased by the oxygen-functional group characteristics of AC surfaces, resulting from enhanced electron acceptor-donor interaction at interfaces.

• Carbon letters
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• 제4권3호
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• pp.140-145
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• 2003

Antibacterial behaviors of PAN-based activated carbon fibers (ACFs) containing silver metal were investigated. The effects of surface and pore structures of the ACFs were studied by $N_2$/77 K adsorption and D-R plot as a function of silver loading content. The antibacterial activities were investigated by a dilution test against Staphylococcus aureus (S. aureus; gram positive) and Klebsiella pnemoniae (K. pnumoniae; gram negative). As experimental results, the ACFs showed some decreases in specific surface areas, micropore volumes, and total pore volume with an increase of silver content. However, the antibacterial activities of the ACFs were strongly increased against S. aureus as well as K. pnumoniae, which could be attributed to the presence of antibacterial metal in the ACFs system.

• Carbon letters
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• 제13권3호
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• pp.157-160
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• 2012

In this work, iron oxide ($Fe_3O_4$) nanoparticles were deposited on multi-walled carbon nanotubes (MWNTs) by a simple chemical coprecipitation method and $Fe_3O_4$-decorated MWNTs (Fe-MWNTs)/polypyrrole (PPy) nanocomposites (Fe-MWNTs/PPy) were prepared by oxidation polymerization. The effect of the PPy on the electrochemical properties of the Fe-MWNTs was investigated. The structures characteristics and surface properties of MWNTs, Fe-MWNTs, and Fe-MWNTs/PPy were characterized by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The electrochemical performances of MWNTs, Fe-MWNTs, and Fe-MWNTs/PPy were determined by cyclic voltammetry and galvanostatic charge/discharge characteristics in a 1.0 M sodium sulfite electrolyte. The results showed that the Fe-MWNTs/PPy electrode had typical pseudo-capacitive behavior and a specific capacitance significantly greater than that of the Fe-MWNT electrode, indicating an enhanced electrochemical performance of the Fe-MWNTs/PPy due to their high electrical properties.

• 한국공작기계학회논문집
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• 제10권1호
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• pp.88-93
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• 2001

Carbon fiber epoxy composite are widely used in airframe structures, space vehicles, sports equipment, and high speed reciprocating parts for industrial machinery. In this paper, the groove processing characteristics of carbon fiber epoxy com-posite was experimentally investigated in order to study the endmill operation of fiber reinforce epoxy composites. Followings are main finding from the experimental results. First, the cutting and bending force in groove processing of the carbon fiber epoxy composite increased as the spindle speed deceased. They also deceased as the table feed increased. Second, the good cutting status obtained at the entrance of groove while delamination occurred at the exit of groove, Third, the regular high speed steel endmill was not efficient, thus the new endmill such as coated carbide rooter endmill or dia-mode endmill should be used for the effective endmll operation of carbon filber epoxy composites.