• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2155-2161
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• 2013

Composite materials of mesoporous carbon and carbon nanotubes were synthesized using Ni, Co and Pd-loaded CMK3 via a catalytic reaction of methane and $CO_2$. The CNTs grew from the pores of the mesoporous carbon supports, and they were attached tightly to the CMK3 surface in a densely tangled shape. The CNT/CMK3 composite showed both non-graphitic mesoporous structures, and graphitic characteristics originating from the MWCNTS grown in the pores of CMK3. The electrochemical properties of the materials were characterized by their electrorheological effects and cyclic voltammetry. The CNTs/CMK3 composites showed high electrical conductivity and current density. The CNT/CMK3 or KOH-modified CNT/CMK3 particles were incorporated in a PMMA matrix to improve the thermal and electrical conductivity. Even higher thermal conductivity was achieved by the addition of KOH-modified CNT/CMK3 particles.

• YAKHAK HOEJI
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• v.32 no.3
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• pp.187-193
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• 1988

An activated carbon which showed big adsorption capacities of iodine, potassium permanganate and phenol was prepared from the Korean ricechaff. By scanning electron micrographs and IR spectra, it was observed that the organic components in the rice-chaff were decomposed to carbon dioxide and vapor by the pyrolysis and the activation, that activated carbon particles had carbon-carbon structures with a lot of microporosity. The adsorption capacities of iodine, potassium permanganate and phenol were determined. The adsorption isotherm of phenol was well fitted in Freundlich's equation.

• International Journal of Concrete Structures and Materials
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• v.8 no.1
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• pp.27-41
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• 2014

The use of carbon fibers (CF) and glass fibers (GF) were combined to strengthen concrete flexural members. In this study, data of tensile tests of 94 hybrid carbon-glass FRP sheets and 47 carbon and GF rovings or sheets were thoroughly investigated in terms of tensile behavior. Based on comparisons between the rule of mixtures and test data, positive hybrid effects were identified for various (GF/CF) ratios. Unlike the rule of mixtures, the hybrid sheets with relatively low (GF/CF) ratios also produced pseudo-ductility. From the calibrated results obtained from experiments, a new analytical model for the stress-strain relationship of hybrid FRP sheets was proposed. Finally, the hybrid effects were verified by structural tests of concrete members strengthened with hybrid FRP sheets and either carbon or glass FRP sheets.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.162-164
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• 2018

This study quantified the carbon storage and uptake by street trees in Seoul and explored suitable planting and management strategies. A systematic sampling model was used to select 50 plots to survey the structures of street trees. The average density and cover of street trees were approximately 5.8 trees/$100m^2$ and 12.1%, respectively. Trees with a dbh of less than 30 cm accounted for about 66.3% of the total number of trees surveyed. The total carbon storage and uptake by the street trees were approximately 103,641 t and 10,992 t/yr, respectively. The total carbon uptake equaled the amount of annual carbon emissions from driving of about 11,000 cars. Street tree planting and management strategies were proposed to enhance carbon uptake. They included multi-layered and multi-aged planting, securing ground and space for plant growth, and avoiding excessive tree pruning.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12
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• pp.1103-1109
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• 2003

Crystalline carbon nitride films have been deposited by RF reactive magnetron sputtering system with negative DC bias. The carbon nitride films deposited on various substrates showed ${\alpha}$- C$_3$N$_4$,${\beta}$-C$_3$N$_4$ and lonsdaleite structures through XRD and FTIR We can find the grain growth of hexagonal structure from SEMI photographs, which is coincident with the theoretical carbon nitride unit cell. When nitrogen gas ratio is 70 % and RF power is 200 W, the growth rate of carbon nitride film on quartz substrate is about 2.1 $\mu\textrm{m}$/hr.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.149-152
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• 2005

In order to extend the life time of building and civil infra-structure, nowadays, patch type carbon sheets are widely used as repairing meterials. Repaired concrete columns and beams with carbon sheets gain their stiffness and strength, but they lose toughness and show brittle failure behaviors. Usually, the cracks of concrete structures are visible with naked eyes and the status of the structure in the life cycle is estimated with visible inspection. After repairing of the structure, crack visibility is blocked by repaired carbon sheets. Therefore, structural monitoring after repairing is indispensible and self diagnosis method with optical fiber sensor is very useful. In this paper, peel-out effects is detected with optical fiber sensors and the strain difference between main structure and repaired carbon sheets when they separate each other.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.691-696
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• 1997

In recent years, stengthening of beam by steel plate, carbon fiber sheets, and carbon fiber laminate is spotlighted in order to repair and rehabilitation of R/C structures. In this study, 3 method of rehabilitation technic are analyzed from the tests. Test parameters are the width of cracks, the method of repair and rehabilitation, the magnitude of existing load. Deflection, failure load, strains of reinforcing bar, strains of sheet and plates are measured during tests. The failure mode and ultimate load are analyzed from these measured data. Test result shows that the width of cracks and the magnitude of existing load do not make any difference of ultimate flexural capacity.

• Journal of the Korean Electrochemical Society
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• v.6 no.3
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• pp.187-195
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• 2003

The present article is concerned with the overview of carbonaceous materials used as anode materials for lithium ion secondary batteries. This article first classified carbonaceous materials into graphite, soft carbon and hard carbon according to their crystal structures, and then summarised the previous works on the characteristics of lithium intercalation/deintercalation into/from the carbonaceous materials. Finally this article reviewed our recent research works on the mechanism of lithium transport through graphite, soft carbon and hard carbon electrodes from the kinetic view point by the analysis of the theoretical and experimental potentiostatic current transients.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1304-1309
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• 2004

Synthesis of carbon nanotubes and nanofibers on a catalytic metal substrate, using an ethylene fueled inverse diffusion flame, was investigated. Multi-walled carbon nanotubes, with diameters of 20 - 60nm, were formed on the substrate coated with nickel-nitrate in the region of 5 - 6mm from the flame center along the radial direction. The gas temperature for this region was ranging from about 1400 to 900K. Nickel particles originated from the coated nickel-nitrate on the substrate were the major catalyst for the formation of the nanomaterials. HR-TEM and Raman spectrum revealed that synthesized carbon nanotubes had multi-walled structures with some defective graphite layers at walls.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.3011-3016
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• 2015

Representing protein three-dimensional structure by concatenating a sequence of protein fragments gives an efficient application in analysis, modeling, search, and prediction of protein structures. This paper investigated the effective combination of distance measures, which can exploit large protein structure database, in order to construct a protein fragment library representing native protein structures accurately. Clustering method was used to construct a protein fragment library. Initial clustering stage used inter alpha-carbon distance having low time complexity, and cluster extension stage used the combination of inter alpha-carbon distance, Binet-Cauchy distance, and root mean square deviation. Protein fragment library was constructed by leveraging large protein structure database using the proposed combination of distance measures. This library gives low root mean square deviation in the experiments representing protein structures with protein fragments.