• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.123-123
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• 2008

In this work, amorphous carbon thin films were deposited for hard mask applications by a reactive particle beam (RPB) assisted sputtering system at room temperature. The depositing characteristics of the films were investigated as functions of operating parameters such as reflector bias voltage and RF plasma power. It was confirmed that the deposition rate increased with increasing the reflector bias voltage and RF plasma power. By an atomic force microscope (AFM), it was revealed that the surface roughness was also increased. The total stress in films was determined by the use of the substrate curvature and its result will be discussed.

• Journal of the Korean Society of Safety
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• v.11 no.1
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• pp.84-89
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• 1996

The adsorption characteristics of active carbon used as a cartridge filler of organic vapor respirator were examined by humidity, particle size, challenge concentration and specific surface area. As a result, the 1% breakthrough time of Carbon Tetrachloride($CCl_4$) was decreased with increase of relative humidity, challenge concentration and particle size (0.6～2.0mm) of active carbon. The adsorbed amount of $CCl_4$ was about 1. 1mg/$m^2$ at RH 40% and 0. 5mg/$m^2$ at RH 80% . However in the case of prehumidified active carbon, humidity did not affected to 1% breakthrough time up to RH 40%.

• Carbon letters
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• v.14 no.2
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• pp.121-125
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• 2013

In this study, PtRu nanoparticles deposited on binary carbon supports were developed for use in direct methanol fuel cells using carbon blacks (CBs) and multi-walled carbon nanotubes (MWCNTs). The particle sizes and morphological structures of the catalysts were analyzed using X-ray diffraction and transmission electron microscopy, and the PtRu loading content was determined using an inductively coupled plasma-mass spectrometer. The electrocatalytic characteristics for methanol oxidation were evaluated by means of cyclic voltammetry with 1 M $CH_3OH$ in a 0.5 M $H_2SO_4$ solution as the electrolyte. The PtRu particle sizes and the loading level were found to be dependent on the mixing ratio of the two carbon materials. The electroactivity of the catalysts increased with an increasing MWCNT content, reaching a maximum at 30% MWCNTs, and subsequently decreased. This was attributed to the introduction of MWCNTs as a secondary support, which provided a highly accessible surface area and caused morphological changes in the carbon supports. Consequently, the PtRu nanoparticles deposited on the binary support exhibited better performance than those deposited on the single support, and the best performance was obtained when the mass ratio of CBs to MWCNTs was 70:30.

• Journal of Mechanical Science and Technology
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• v.15 no.6
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• pp.804-812
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• 2001

A triboelectrostatic separation system for removing unburned carbon from coal fly ash is designed and evaluated. Fly ash from a coal-fired power plant is used as an accepted additive in concrete where it adds strength, sulfate resistance and reduced cost, provided acceptable levels of unburned carbon are maintained. Unfortunately, unburned carbon in coal fly ash absorbs some of other additives and reduces the concrete strength. This paper describes to investigate dry triboelectrostatic process to separate unburned carbon from coal fly ash and utilize it into economically valuable products. The laboratory-scale triboelectrostatic separation system consists of a particle feeding system, a tribocharger, a separation chamber, and collection systems. Particles of unburned carbon and fly ash can be imparted positive and negative surface charges, respectively, with a copper tribocharger due to differences in the work function values of the particles and the tribocharger, and can be separated by passing them through an external electric field. Results showed that fly ash recovery was strongly dependent on the electric field strength and the particle size. 70wt% of fly ash containing 6.5wt% of carbon contents could be recovered at carbon contents below 3%. The triboelectrostatic separation system showed a potential to be an effective method for removing unburned carbon from coal fly ash.

• Korean Journal of Materials Research
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• v.20 no.2
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• pp.104-110
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• 2010

The characteristics of all polymer composites containing carbon materials are determined by four factors: component properties, composition, structure and interfacial interactions. The most important filler characteristics are particle size, size distribution, specific surface area and particle shape. As a consequence, in this paper we discuss the aspects of the mechanical, electrical and thermal properties of composites with different fillers of carbon black, carbon nanotube (CNT), graphene and graphite and focus on the relationship between factors and properties, as mentioned above. Accordingly, we fabricate rubber composites that contain various carbon materials in carbon black-based and silica based-SBR matrixes with dual phase fillers and use scanning electron microscopy, Raman spectroscopy, a rhometer, an Instron tensile machine, and a thermal conductivity analyzer to evaluate composites' mechanical, fatigue, thermal, and electronic properties. In mechanical properties, hardness and 300%-modulus of graphene-composite are sharply increased in all cases due to the larger specific surface. Also, it has been found that the thermal conductivity of the CNT-composite is higher than that of any of the other composites and that the composite with graphene has the best electrical properties.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.459-462
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• 2008

In manufacture of slurry fuel, the effects of process parameters on the carbon dispersion stability have been investigated. The particle size and contents of the carbon slurry taken from 3 (top, medium, bottom) positions in fuel reservoir were analyzed to estimate the dispersion of the carbon in Jet A-1. Through the application of various additives, it was found that NB463S84 additive showed the best dispersion and stability of carbon at accelerated gravity condition. The mixer performance was compared by the observation of height change of carbon-containing layer and measurement of particle sizes at the same conditions. Application of the mixing conditions obtained from the lab-scale to bench scale manufacture confirmed the practical feasibility of our research.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.104-113
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• 2018

A three-dimensional electrochemical process using nanosized zero-valent iron (NZVI)/activated carbon (AC) particle electrode and persulfate (PS) was developed for oxidizing pollutants. X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were performed to characterize particle electrode. XRD and SEM-EDS analysis confirmed that NZVI was impregnated on the surface of AC. Compared with the conventional two-dimensional electrochemical process, the three-dimensional particle electrode process achieved three times higher efficiency in phenol removal. The system with current density of $5mA/cm^2$ exhibited the highest phenol removal efficiency among the systems employing 1, 5, and $10mA/cm^2$. The removal efficiency of phenol increased as the Fe contents in the particle electrode increased. The particle electrode achieved more than 70% of phenol removal until it was reused for three times. The sulfate radical played a predominant role in phenol removal according to the radical scavenging test.

• Ocean and Polar Research
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• v.44 no.3
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• pp.221-233
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• 2022

A sediment trap had been deployed at 1250 m depth in the Eastern Tropical Pacific (ETP) from September 2009 to July 2010, with the aim of understanding the temporal and vertical variability of particle flux. During the monitoring period, total particle flux varied from 12.4 to 101.0 mg m^-2day^-1, with the higher fluxes in January-March 2010. Biogenic particle flux varied in phase with the total particle flux. The increase in total particle flux during January-March 2010 was attributed to the enhanced biological production in the surface layer caused by wind-driven mixing in response to the seasonal shifts in the location of the Intertropical convergence zone. The export ratio (e-ratio) was estimated using the particulate organic carbon flux and satellite-derived net primary production data. The estimated e-ratios changed between 0.8% and 2.8% (1.4±0.6% on average). The ratio recorded in the negative phase of Pacific decadal oscillation (PDO) was similar to the previous results obtained from the ETP during the 1992/93 periods in the positive phase of PDO. This suggests that the regime shift of the PDO is not related to the carbon export ratio.

• Clean Technology
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• v.24 no.3
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• pp.157-165
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• 2018

In this study, the removal of $Si_3N_4$ particles from the surface of a silicon wafer was investigated by using supercritical carbon dioxide, the IPA co-solvent and cleaning additive chemicals. First, the solubility of several surfactants and binders in supercritical carbon dioxide solubility and particle dispersibility in the binders were evaluated in order to confirm their suitability for the supercritical cleaning process. Particle removal experiments were carried out with adjusting various process parameters and reaction conditions. The surfactants used in the experiment showed little particle removal effect, producing secondary contamination on the surface of wafers. On the other hand, 5 wt% (with respect to $scCO_2$) of the cleaning additive mixture of trimethyl phosphate, IPA, and trace HF resulted in 85% of particle removal efficiency after $scCO_2$ flowing for 4 minutes at $50^{\circ}C$, 2000 psi, and the flow rate of $15mL\;min^{-1}$.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.310-313
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• 2005

The conical fluidizing system of a binary mixture of Geldart C powders and Geldart A particles was defined as the conical powder-particle fluidized bed. We used a cold conical powder-particle fluidized bed model having a 0.104m-I.D. and 0.6m-high with an apex angle of $10^{\circ}$ for fluidization of a binary powder-particle mixture of 50 $vol\%$ fine carbon black powders (HI-900L, Korea Carbon Black Co.) and coarse alumina particles $(90{\mu}m)$ under different superficial gas velocities (0-0.1 m/s). The differential bed pressure drop increases with increasing gas velocity, and it goes from zero to a maximum value with increasing or decreasing gas velocity. In the conical fluidized beds of fine powders, demarcation velocities of the partial fluidization, full fluidization, partial defluidization was not observed.