• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.4
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• pp.214-220
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• 2018

Light sources induced by gas discharge using rare gases have been widely used in the thin film deposition, the surface modification and the polymer etching. A dielectric barrier discharge (DBD) has been developed in order to consistently emit light and control the wavelength of the emission light. However, much research on the characteristics of the movement of discharge particles is required to improve the efficiency of the light lamp and the life-time of the light apparatus in detail. In this paper, we developed a He DBD discharge simulation tool and investigated the characteristics of discharge particles which were electrons, two positive ions ($He^+$, $He_2^+$) and 5 excited particles ($He^*(1S)$, $He^*(3S)$, $He^*$, $He^{**}$, $He^{***}$). The discharge currents showed the transition from pulse mode to continuous mode with the increase of power. With the accumulated charges on the barrier walls, the discharge current was rapidly increased and caused oscillation of the discharge voltage. As the gas pressure increased, $He_2^+$ and $He^*(3S)$ became the dominant activated particles. The input power was mostly consumed by electrons and $He_2^+$ ion. And the change curve showed that power consumption by electrons increased more with gas pressure than with source voltage or frequency.

• Textile Coloration and Finishing
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• v.9 no.1
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• pp.15-22
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• 1997

The alkali treated and black dyed PET fabrics were sputter etched under Ar gas atmosphere. The color depth of PET fabrics were increased with sputter etching time only under some limits of discharge power. And above that limits of discharge power the color depth of PET fabrics was decreased by increasing discharge power and treatment time. Minute cracks were made by sputter etching in the whole surface of fabrics to the direction of perpendicular to the longitudinal side of yarns. The fineness and density of minute crack were increased with lowering discharge power. And the size of crack was far smaller than that of microcrater which was obtained by alkali treatment. It is considered that the increase of color depth is related to the minute crack. The water permeation time of sputter etched fabrics was increased with increasing discharge power and treating time. The increase of color depth attained by sputter etching was fully kept through repeated laundering.

• Ocean and Polar Research
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• v.35 no.4
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• pp.299-312
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• 2013

This study analyzed the species composition and density of a macrobenthic community according to variations in the thermal discharge volumes of a nuclear power plant before, during, and after the shutdown of the nuclear power plant during two periods. In this study, 369 macrobenthic fauna species were collected, and their mean density was 1,712 ind. $m^{-2}$. The number of species and diversity of macrobenthic fauna decreased with distance from the thermal discharge area, regardless of whether the nuclear plant shutdown or not. Many macrobenthic taxa appeared near the thermal discharge area, but polychaetes species were more prominent in outer areas than at the discharge area. The density of macrobenthic fauna decreased with distance from the thermal discharge area during a plant shutdown in the fall of 2011, but increased, except at two sites, near the discharge area in the winter of 2012. Cluster analysis indicated that the spatial distribution of the macrobenthic community changed in areas near the nuclear power plant after a shutdown period; that is, the station group I, in areas near the nuclear power plant, became narrower after the shutdown, but it recovered to previously occupied areas after the nuclear power plant began operating again. Opportunistic species, such as the polychaetes Lumbrineris longifolia (= Scoletoma longifolia) and Mediomastus californiensis, which were present in high densities near thermal discharge areas, decreased after the shutdown but recovered after the plant re-opened. The number of species and diversity of the macrofauna and the density of dominant species showed a significant correlation with temperature, except in winter periods. The results of this study revealed that changes in the amount of thermal discharge before and after the shutdown of a nuclear power plant could exert an influence on the structure of macrobenthic community within the thermal discharge areas depending on the season.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1015-1018
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• 1999

Partial discharge patterns were analyzed in the pumped storage generator stator winding. These were measured using partial discharge analyzer(PDA) and digital partial discharge detector(PDD). Slot discharge was discovered in phase A. Discharges at conductor surface were occurred in phase B and in Phase C. Partial discharge patterns from on-line PDA system were compared with those off-line PDD system. The results of two systems are very same in phase A, B and C.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.2
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• pp.355-360
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• 2024

In this paper, in implementing a 4-coil resonant wireless power transmission system, we studied the discharge phenomenon that occurs at the end of the transmitting resonance coil. Resonant wireless power transmission consists of a power supply coil, a transmitting resonance coil, a power receiving resonance coil, and a load coil. The transmitting resonance coil serves to amplify the magnetic field generated from the power supply coil and transmits it to the front receiving resonance coil. When a high current flows through the power supply coil in order to transmit large power, a high voltage is induced at the end of the transmitting resonance coil. It causes line-to-line discharge. Line-to-line discharge phenomenon damages the transmitter case and renders the transmitter unusable. Therefore, in order to eliminate this line-to-line discharge phenomenon, the voltage induced in the transmitting resonance coil that causes line-to-line discharge was analyzed and a solution was proposed.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2214-2216
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• 2005

This paper is researched discharge and ozone generation characteristics of ozonizer using $Al_2O_3$ Ceramic dielectric. The discharge characteristics with variation of the discharge electrode area is studied. The characteristics of ozone concentration. ozone generation and ozone yield were measured to discharge power, discharge electrode area and supplied gas flux for oxygen and air. The solubility of ozone for water concentrations and ozone generations proportional to discharge power and discharge electrode area. Ozone yield has slowly increase with Increasing discharge power at high flow-rate. As the result, the maximum values of ozone characteristics ozone generation and ozone yield, can be obtained 5817[ppm] and 36[g/kWh]. We make enough the ozone concentration as the air in the home. An electric discharge electrode area is apt to shrink gradually into a miniaturization trend of the ozonizer but the enlargement of the occurrence flight of the electric discharge area gives the characteristic enhance the aid in the identity condition through the structure improvement.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.1003-1015
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• 2022

The new methodologies to derive discharge limits considering operational flexibility according to international safety standards were developed to help reduce the environmental releases of radioactive effluents from nuclear power plants (NPPs). To overcome the limitations of the two existing methods to set up discharge limits assuming a specific statistical distribution of the effluent discharge, two modified equations were newly proposed to directly derive a particular discharge limits corresponding to the target 'compliance probability' based on the actual annual discharge data for a specific NPP and radionuclide groups. By applying these to the actual yearly discharge data of 14 Korean NPPs for 7 radionuclide groups for the past 20 years, the applicability of two new methodologies to actual cases was demonstrated. The 'characteristic value' with approximately a 90% compliance probability for each Korean NPP and radionuclide group was proposed based on the results. The new approaches for setting up the discharge limits and the characteristic values developed in this study are expected to be effectively utilized to foster operator's efforts to progressively reduce the environmental releases of radioactive effluents of NPPs relative to the previous discharge data considering operational flexibilities.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.5
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• pp.76-81
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• 2014

The ozone generation is commonly made with silent discharge method using quartz glass dielectric. In this paper, using $Al_2O_3$ dielectric to instead of the traditional quartz glass dielectric to improve the system efficiency is presented. The dielectric was manufactured as tube shape (Internal diameter${\times}$ Outside diameter: $11{\times}15mm$) using 99% $Al_2O_3$ ceramic. The characteristics of dielectric discharge and ozone generation were studied of experiments with variation of discharge power, discharge electrode space and rate of flow for supplied gas ($O_2$/Air). As the experimental results, in the same discharge space, the ozone concentration continuously increased with input power increasing, and ozone yield increased until saturation happened. Also, the expended power increased with discharge space extended due to discharge power increased. In additional, the ozone concentration of oxygen ozone was higher than air that was observed when using oxygen ozone in proposed experiments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.12
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• pp.1055-1059
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• 1998

The correlation between the propagation of electrical tree and distributions of partial discharge(PD) pulses accompanying with electrical tree of bush type in low density polyethylene were discussed. We measured the growth of electrical tree by using optical microscope and PD data simultaneously. The PD data detected and analyzed were PD magnitude, repetition rate, average discharge power, average phase angle, and $\psi$-q-n distribution pattern. The average discharge power and repetition rate of PD had good linear relation with area of tree. Repetition rate and peak discharge magnitude and width of discharge phase angle increased with the tree.

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.73-77
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• 1999

In this study, $SO_2$ and $NO_2$ reduction have been investigated by using coil type plasma reactor. The experiments have been carried out changing discharge power, gas flow rate frequency and electrode style to obtain the decomposition rate. Decomposition rates of $SO_2$ and $NO_2$ were obtained 20~98% at gas flow rate 100ml/min~1,000ml/min and discharge power 5~25w respectively. The energy efficiency is very good at the high frequency power. The decomposition rate of $SO_2$ for 5kHz power supply is only 90%, but for 10kHz power supply is very high, more than 98% for 15w. The decomposition rate is increasing according to the residence time or the power consumption of the discharge. About 15W discharge power for 17$cm^2$ reactor is necessary to obtain the decomposition rate of $SO_2$ and $NO_2$ of more than 85% or 98%. From these experiments, the consumption power of the decomposition rate of 98% in 300ppm $NO_2$ gas in nitrogen gas proved to be 18W and 300ppm $SO_2$ gas to be 15w.