• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.115-116
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• 2011

This study aimed at establishing the fundamental data needed to evaluate the applicability and practicability in using a bamboo activated carbon as a construction material. The experiment on the flow of mortars mixed with a bamboo activated carbon before the hardening was carried out for the evaluation of basic properties. The compressive and bending strength of mortar mixed with bamboo activated carbon after the hardening was measured. the thermal conduction rate and density were also measured. An comparative analysis on mortars mixed with pine charcoals was conducted to compare it with exiting materials.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1410-1411
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• 2006

To improve density and smoothness of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black and Carbon Nanotube. They were produced as sheets after pressing for 20 minutes at $180[^{\circ}C]$ with a pressure of $200[kg/cm^2]$. The content of conductive carbon black and Carbon Nanotube were 30[wt%] and 2-6[wt%] respectively. As a result the smoothness was measured by JSM-6400.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1663-1664
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• 2006

Carbon films was grown on Si substrates using the method of electrolysis for methanol liquid. Deposition parameters for the growth of the carbon films were current density for the electrolysis, methanol liquid temperature and electrode spacing between anode and cathode. We examined electrical resistance and the surface morphology of carbon films formed under various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes was relatively wider. We found that the electrical resistance in the films was independent of both current density and methanol liquid temperature for electrolysis. The temperature dependence of the electrical resistance in the low resistance carbon films was different from one obtained in graphite.

• Journal of the Korean institute of surface engineering
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• v.52 no.3
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• pp.150-155
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• 2019

The carbon electrode was modified through manganese-catalyzed hydrogenation method for high energy density vanadium redox flow battery (VRFB). During the catalytic hydrogenation, the manganese oxide deposited at the surface of the carbon electrode stimulated the conversion reaction from carbon to methane gas. This reaction causes the penetration of the manganese and excavates a number of cavities at electrode surface, which increases the electrochemical activity by inducing additional electrochemically active site. The formation of the porous surface was confirmed by the scanning electron microscopy (SEM) images. Finally, the electrochemical performance test of the electrode with the porous surface showed lower polarization and high reversibility in the cathodic reaction compared to the conventional electrode.

• Journal of Powder Materials
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• v.28 no.1
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• pp.51-58
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• 2021

The conversion of carbon preforms to dense SiC by liquid infiltration is a prospectively low-cost and reliable method of forming SiC-Si composites with complex shapes and high densities. Si powder was coated on top of a 2.0wt.% Y2O3-added carbon preform, and reaction bonded silicon carbide (RBSC) was prepared by infiltrating molten Si at 1,450℃ for 1-8 h. Reactive sintering of the Y2O3-free carbon preform caused Si to be pushed to one side, thereby forming cracking defects. However, when prepared from the Y2O3-added carbon preform, a SiC-Si composite in which Si is homogeneously distributed in the SiC matrix without cracking can be produced. Using the Si + C → SiC reaction at 1,450℃, 3C and 6H SiC phases, crystalline Si, and Y2O3 were generated based on XRD analysis, without the appearance of graphite. The RBSC prepared from the Y2O3-added carbon preform was densified by increasing the density and decreasing the porosity as the holding time increased at 1,450℃. Dense RBSC, which was reaction sintered at 1,450℃ for 4 h from the 2.0wt.% Y2O3-added carbon preform, had an apparent porosity of 0.11% and a relative density of 96.8%.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.429-433
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• 2015

The binding ability and hydrogen storage capacity of nitrogen doped carbon nanotube with divacancy (4NDCN_xNT) that is decorated with transition metals was investigated based on density functional theory calculations. Results indicate that scandium shows an ideal reversible hydrogen binding capability with promising system-weight efficiency compared with other transition metals when functionalized with 4ND-CN_xNT. The (Sc/4ND)₁₀-CN_xNT can store up to 50H₂ molecules, corresponding to a maximum gravimetric density of 5.8 wt%. Detailed structural stability and electronic properties were reported as hydrogen molecules were absorbed. It takes about 0.16 eV/H₂ to add one H₂ molecule, which assures reversible storage of H₂ molecules under ambient conditions.

• Korean Journal of Materials Research
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• v.13 no.7
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• pp.424-428
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• 2003

The microstructure and field emission properties of carbon nanotubes(CNT) grown by Ni-catalytic chemical vapor deposition(CVD) were investigated. CVD-grown CNT had a high density of curved shape with randomly oriented. It was found that an increase in electric field caused an increase in field emission current and field emission sites of CNT. The maximum field emission current density was measured to be 3.6 ㎃/$\textrm{cm}^2$ at 2.5 V/$\mu\textrm{m}$, while the brightness of 56 cd/$\textrm{cm}^2$ was observed for the CNT-grown area of 0.8 $\textrm{cm}^2$ from a phosphor screen. Field emission current at constant electric field gradually decreased initially and then stabilized with time.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3183-3189
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• 2010

In order to increase the specific capacitance and energy density of supercapacitors, non-aqueous supercapacitors were prepared using lithium transition-metal oxides and activated carbons as active materials. The electrochemical properties were analyzed in terms of the content of lithium transition-metal oxides. The results of cyclic voltammetry and AC-impedance analyses showed that the pseudocapacitance may stem from the synergistic contributions of capacitive and faradic effects; the former is due to the electric double layer which is prepared in the interface of activated carbon and organic electrolyte, and the latter is due to the intercalation of lithium ($Li^+$) ions. The specific capacitance and energy density of a supercapacitor improved as the lithium transition-metal oxides content increased, showing 60% increase compared to those of supercapacitor using a pure activated carbon positive electrode.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.81-84
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• 2012

Cantilevered carbon-nanotube-resonator was investigated via classical molecular dynamics simulations. The resonator system is including the attached nanocluster. A nanocluster with a finite length was modeling by some atomic rings. The mass of the nanocluster was equally distributed on the carbon atoms, composed of the atomic rings. The effective density factor, which could be considered as the single parameter affecting the resonance frequency shift, was significantly influenced by the mass, the position, and the linear density of the attached nanocluster. The linear density of the attached nanocluster was an important parameter to analyze the vibrational behavior of the CNT-resonator, including the attached nanocluster.

• Journal of the Korean Ceramic Society
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• v.21 no.2
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• pp.156-164
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• 1984

The characteristic of pyrolytic carbon deposited in a fluidized bed as measured by density apparent crystallite size and viewed metallographically under polarized light can be easily controlled by adjusting the deposition parameters such as deposition temperature and propane flow rate or silicon content. The density of isotopic pyrolytic carbons deposited from propane between 120$0^{\circ}C$ and 140$0^{\circ}C$ increases with increasing propane flow rate and decreasing deposition temperature from 1, 73g/cc to 2.08g/cc. The apparent crystallite size Lc parameter appears to depend only on deposition temperature being entirely independent of the propane flow rate. The carbon matrix density of the silicon-alloyed carbonds deposited from propane and methyltrichlorosil-ane from 2.05g/cc for a silicon content around 9wt% to 2.67g/cc for a silicon content of 36.7wt% The Lc parameter of the deposition temperature being entirely independent of the silicon content.