• 반도체디스플레이기술학회지
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• 제11권3호
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• pp.7-11
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• 2012

Among various wet cleaning methods, megasonic and jet spray gained their popularity in single wafer cleaning process for the efficient removal of particulate contaminants from the wafer surface. In the present study, we evaluated these two cleaning methods for particle removal efficiency (PRE) and pattern damage on the aluminum layered wafer surface. Also the effect of $CO_2$ dissolved water in jet spray cleaning is assessed by measuring PRE. It is observed that the jet spray cleaning process is more effective in terms of PRE and pattern damage compared to megasonic cleaning and the mixing of $CO_2$ in the water during jet sprays further increases the PRE. We believe that the outcome of the present study is useful for the semiconductor cleaning process engineers and researchers.

• 한국레이저가공학회지
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• 제6권3호
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• pp.29-35
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• 2003

In semiconductor processing, there are two types of particle contaminated onto the wafer, i.e. dry and wet state particles. In order to evaluate the cleaning performance of laser shock wave cleaning method, the removal of 1 m sized alumina particle at different particle conditions from silicon wafer has been carried out by laser-induced shock waves. It was found that the removal efficiency by laser shock cleaning was strongly dependent on the particle condition, i.e. the removal efficiency of dry alumina particle from silicon wafer was around 97％ while the efficiencies of wet alumina particle in DI water and IPA are 35％ and 55％ respectively. From the analysis of adhesion forces between the particle and the silicon substrate, the adhesion force of the wet particle where capillary force is dominant is much larger than that of the dry particle where Van der Waals force is dominant. As a result, it is seen that the particle in wet condition is much more difficult to remove from silicon wafer than the particle in dry condition by using physical cleaning method such as laser shock cleaning.

• 상하수도학회지
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• 제26권6호
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• pp.841-849
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• 2012

The effluent quality of phosphorus is strengthened by the national standard to conserve water resources to lessen the eutrophication threat. The soluble phosphate in the wastewater effluent can be removed using the converter slag as solid waste produced through the steel making process. The experiments for removal efficiencies and removal constants were performed for this research with the artificial wastewater following several different conditions, particle size, phosphate concentration and initial pH. The correlation coefficients of Freundlich adsorption isothem were 0.9505 for $PS_A$, 0.9183 for $PS_B$, respectively. The removal efficiency was 87-94 % for $PS_A$ and 90-96 % for $PS_B$ respectively. The pH of the wastewater was elevated to pH 11.8 for the initial pH 8.5, phosphate removal efficiency was the highest as 84 % ~ 98 %. In case of 10 mg/L of the intial phosphate, the removal efficiency was 96 ~ 98 %. The more initial pH increases, the higher the reaction rate constant is.

• 한국대기환경학회지
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• 제29권2호
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• pp.163-170
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• 2013

The fine-particles, moisture and variety of hazardous gases are produced during electronic manufacture process. Most of the fine-particles are 0.1~10 ${\mu}m$ in size and the hazardous gases such as HF, $SiH_4$, CO, $NH_3$, etc. seriously affect environment, human's body and manufacturing process. To remove these characterized gases and fine-particles, Water-Cyclone designed and tested for removal efficiency on fine-particles and $NH_3$ under -980Pa negative pressure condition. As a result, under 0.1~1.0 $m^3/min$ flow condition, the efficiency on 5 ${\mu}m$ particles was 80~96%, 10 ${\mu}m$ particles was 86~96%, and 20 ${\mu}m$ particles was 91~99%. Besides, the removal efficiency on soluble gas $NH_3$ was 56.5% at 0.5m3/min and 79.1% at 1.0m3/min under 500 ppm flow concentration and 70.0% at 1.0 $m^3/min$ under 1,000 ppm flow concentration. Therefore, on particles, as the flow rate and particle size increased, the collection efficiency rate was increased. On soluble gas, as the flow rate increased, the removal efficiency was increased under the same concentration.

• 환경위생공학
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• 제14권4호
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• pp.69-76
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• 1999

This research was carried but to investigate the characteristics of mist removal with the change of operating conditions in the plasma reactor of impulse streamer corona based on the distribution of particle size measured by laser diffraction spectrometers. The operating conditions in this experiment were power of impulse streamer corona, gas velocity, collection time, and SOx/NOx concentration. The collection efficiency T(d) was estimated by distribution of particle size in the collection zone through the advanced model.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권6호
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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.

• 한국입자에어로졸학회지
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• 제12권4호
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• pp.135-143
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• 2016

Removal of water contents in a gas is needed in industrial field of gas processing related on energy production/conversion, and environmental treatment. Inertial separators are economic devices for separating droplets from the gas stream. For accurate understanding of removal process in a curved vane mist eliminator, a numerical model including turbulent dispersion, evaporation and condensation of water vapor at surface of droplets is required. A two-stage curved vane mist eliminator has been modeled, and fluid flow of mixture of air and water vapor and droplet trajectories were solved simultaneously with taking into account two-way coupling. Removal efficiency of droplets with various inlet condition of relative humidities (RH, 40%, 90%, and 100%) were compared. As RH increased, the effect of evaporation decreased and inertial separation efficiencies of droplets obtained increased especially for droplets of diameter below 10 micrometers.

• 한국환경보건학회지
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• 제22권4호
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• pp.1-9
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• 1996

Experiments have been made to test the practical feasibility of using calcined manganese ore to desulfurize hot reducing gas. In this study, the effects of particle size of sorbents, temperature of sulfidation, flow rate and sorbent characteristics on the $H_2S$ removal efficiency of calcined manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about 800$\circ$C and that the smaller particle size the higher the $H_2S$ removal efficiency. When the temperature was above 800$\circ$C, the reactivity of sorbent has lowered because agglomeration of sorbent increased intraparticle transport resistance, and this phenomenon was confirmed by SEM photographs. As the temperature increases, capacity for the $H_2S$ removal was increased but the equilibrium concentration of $H_2S$ was not affective.

• 한국입자에어로졸학회지
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• 제14권4호
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• pp.121-133
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• 2018

In this study, we developed a flat-plate type wet electrostatic precipitator that generates stable corona discharge compared to wire type discharge electrode. In order to compare the particle removal efficiency according to the shape of the discharge electrode such as the variation of the horizontal and vertical distance between spiked edges, and the variation of the height of discharge pin support were tested. As a result, when the horizontal distance between spiked edges was increased up to 36 mm, the vertical distance between spiked edges was increased up to 54 mm, and the height of the discharge pin support was increased up to 76 mm, the removal efficiency of PM10 was maintained at approximate 60.0%. Furthermore, the removal efficiency of particles over $5{\mu}m$ was about 80% or more. When the flow rate was 4 m/s, the gap between collection plates was 60 mm, and -14 kV was applied to the discharge electrode. The particle removal efficiency of the flat-plate type electrostatic precipitator was maintained when the horizontal and vertical distance between spiked edges, and the height of the discharge pin support was below a certain level. Those variables may be the important design factors for the shape of the discharge electrode. Therefore, when designing the electrostatic precipitator with multiple channels, the horizontal and vertical distance between spiked edges, and the height of discharge pin support must be selected in consideration of the weight of the discharge electrode and the processing cost.

• 한국환경보건학회지
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• 제32권5호
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• pp.478-484
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• 2006

There was no significant difference in the CADR (Clean Air Delivery Rate) between physical aerosols, NaCl and smoke, and biological aerosols, airborne MS2 virus and P. fluorescens, which implicate that the hybrid-type of air purifier, applying the unipolar ion emission and the radiant catalytic ionization, imposed identical reduction effect on both physical aerosol and bioaerosol. Ventilation decreases the efficiency of air cleaning by unipolar ionization because high ventilation diminishes the particle concentration reduction effect. The particle removal efficiency decreases with increase in the chamber volume because of the augmented ion diffusion and higher ion wall loss rate. Particle size affects the efficiency of air ionization. The efficiency is high for particles with very small diameter because reduction of charge increases with particle size. If there is no increasing supply of ions, the efficiency of air cleaning by unipolar ionization increases with respect to initial concentration of particles because of the large space charge effect at high particle concentration and amplified electric field.