• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.335-338
• /
• 2000

Carbon is an attractive candidate for use in eletrochemical supercapacitors that depend on charge storage in the electrode/electrolyte international double layer. Property of an electrical double layer capacitor depend both on the technique used to prepare the electrode and on the current collector structure. The study is to research that V$_2$O$_{5}$-flyash-AC composite electrode for supercapacitor. The discharge capacitance of V$_2$O$_{5}$-flyash-AC(70wt%) in 1st and 50th cycle was 18.6F/g and 15.13F/g at current density of 0.5mA/cm$^2$. The discharge process of V$_2$O$_{5}$-flyash (3 : 97)-AC composite electrode is larger than that others.thers.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2001.11a
• /
• pp.39-46
• /
• 2001

The plasma display panel with the electrode structure of new discharge AND gate was developed and the driving system for experiment was developed. And discharge AND gate operation was verified. Discharge AND gate operated by the operation speed of 8$mutextrm{s}$ and the operation margin of 20V. It was known to be able to control the discharge of the adjoining scan electrode accurately. Because this method uses the DC discharge, the control of the discharge can be facilitated compared with conventional discharge AND gate. Moreover, because the imput discharge and the output discharge of AND gate are separate, the display discharge can be prevented from passing AND gate. Therefore, it is possible to apply to the large screen plasma display. And the decrease of contrast ratio does not occur because the scanning electrical discharge does not influence the picture quality.

• Journal of the Korean Society of Safety
• /
• v.14 no.3
• /
• pp.63-68
• /
• 1999

In this paper, characteristics of ozone generation by using coil and SPCP + DC corona reactor was studied. The ceramic-based surface discharge electrode, which was first invented as a high-efficiency ozonizer, has been used as an experimental plasma chemical reactor.(Surface Induced Plasma Chemical Processing, SPCP.) The electrode, however, has a structural disadvantage that a highly energetic plasma region is localized near the electrode surface, which may make it impossible for higher efficiency to realize. In an attempt to overcome this advantage, we have developed a hybrid reactor which employs a corona discharge unit together with the surface discharge unit. Experimental results suggest that the efficiency of the ozone production rate is improved when positive corona discharge is added.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1636-1639
• /
• 2002

We proposed the new reset waveform for reducing reset period. The square pulse is applied to the address electrode when the ramp pulse increases before a discharge occurs between sustain electrodes. If the discharge occurs between address electrode and X electrode, the wall charge is reversely accumulated between sustain electrodes compared with the applying voltage before the discharge occurs between sustain electrodes. So the next discharge more weakly occurs between sustain electrodes. If the more weak discharge is obtained, it can make the low background luminance and the high contrast ratio and reduce ramp up time in the ramp reset waveform.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2248-2250
• /
• 1999

In this paper, showering discharge type ozonizer has been designed and manufactured. The ozonizer is equipped with three electrodes(central electrode of screw shape, internal electrode and external electrode) of cylinder shape. This paper describes the following two characteristics: (1) The characteristics of discharge with variation of output voltage of AC H.V source, flux of oxygen supplied gas and discharge voltage. (2) The characteristics of ozone generation by varying flux and discharge power.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.05a
• /
• pp.105-110
• /
• 1999

Wire electrical discharge machining (WEDM) is one of the unconventional machining processes, which is utilizing electrical energy to remove work-piece. In recent years WEDM used widely in die-sinking industry because WEDM can machine any hard materials if only it has conductivity and can machine accurately to the complex geometry, for fine wire is used in WEDM for the tool electrode. However WEDM is non-contact machining process, which is utilizing discharge phenomena occurring between two electrodes, the size of the machined part is larger than that of the tool electrode size. It is called discharge gap or clearance the difference size between the tool electrode and the machined part in WEDM. By the experiment clearances according to the machining condition was investigated.

• Proceedings of the KIEE Conference
• /
• 1994.11a
• /
• pp.267-269
• /
• 1994

Various types of plasma display panels(PDPs) have been developed to realize the flat panel display device. But, many of its characteristics must be improved before it can be commercialized. In order to investigate tile characteristics of micro discharge in a PDP ceil, we have constructed a micro-gap discharge system whose electrode gap can be adjustable between $100-1000{\mu}m$ within $0.1{\mu}m$ accuracy. We measured the minimum sustain voltage, current, delay time of discharge while changing parameters(electrode gap distance, electrode surface area, pressure) which influence discharge characteristics.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.10a
• /
• pp.48-53
• /
• 1998

In this paper, the new electrochemical machining method is proposed for the micro unit fabrication by using the point electrode tools. The precision shape control capacity is improved by using the point electrode method. It was observed that an electric discharge phenomenon occurs during the electrochemical machining process by using the spraying and torrent type electrolyte supply method.

• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.2
• /
• pp.179-185
• /
• 2013

The behavior of surface film formation was greatly dependent on the speed of potential cycling. In $LiClO_4$ / EC + DEC, cyclic voltammetry results showed that the peaks originated from surface film formation on graphite electrode at the high charge-discharge rate was shifted to the lower potentials as the charge-discharge rate decrease. This indicates that surface films with different morphology and thickness were formed by different charge-discharge rate. Transmission electron microscopy (TEM) results indicated that the properties such as thickness and morphology of the surface film were greatly affected by the charge-discharge rate. Electrochemical impedance spectroscopy (EIS) showed that the resistance of surface film was affected by the speed of potential cycling. In addition, the charge transfer resistance was also dependent on the charge-discharge rate indicating that the charge transfer reaction was affected by the nature of surface film. TEM and EIS results suggested that the chemical property as well as the physical property of the surface film was affected by the charge-discharge rate.

• Korean Journal of Materials Research
• /
• v.25 no.2
• /
• pp.100-106
• /
• 2015

Plasma properties of dielectric barrier discharges (DBDs) at atmospheric pressure were measured and characterized using optical emission spectroscopy. Optical emissions were measured from argon, nitrogen, or air discharges generated at 5-9 kV using 20 kHz power supply. Emissions from nitrogen molecules were markedly measured, irrespective of discharge gases. The intensity of emission peaks was increased with applied voltage and electrode gap. The short wavelength peaks (315.9 nm and 337.1 nm) measured at the middle of DBDs were significantly increased with applied voltage. The optical emission from DBDs decreased with the addition of oxygen gas, which was especially significant in argon discharge. Emission from oxygen molecules cannot be measured from air discharge and argon discharge with 4.8% oxygen. The emission intensity at 337.1 nm and 357.7 nm related with nitrogen molecule was sensitively changed with electrode types and discharge voltages. However, the pattern of argon emission spectrum was nearly the same, irrespective of electrode type, oxygen content, and discharge voltage.