• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1530-1532
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• 1994

This paper describes the discharge characteristics of liquid nitrogen for plane-plane, needle-plane electrode at variation of gap spacing at atmospheric pressure. The important results obtained from this study are as follows. (1) Breakdown voltage of $LN_2$ for needle-plane electrode is higher than that of for plane-plane electrode and discharge duration tine is longer with increase of gap spacing at atmospheric pressure. (2) The formation of bubbles by evaporation is observed in spite of non-applying source at atmospheric pressure and the creation of corona confirmed for plane-plane electrode results from the bubbles. (3) The applied voltage-discharge magnitude( V-Q) characteristics of $LN_2$ showed hysteresis and the discharge magnitude decreasing and corona voltage increasing proportional to the pulse per second at atmospheric pressure.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.139-141
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• 1989

The characteristics of the hollow cathode discharge were investigated. Temperature distribution of the hollow cathode was investigated and I-V curves of the hollow cathode discharge were obtained. In this paper variables are chamber pressure, Ar gas flow rate injected through the cathode tube and the gap distance between cathode and anode. The inter electrode electron temperature and density were measured by Langmuir probe.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.795-798
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• 2008

The discharge characteristics of a flat plasma backlight with long electrode gap are investigated. The effect of operating voltage and repetition rate on brightness and luminance efficiency is investigated. A new high efficacy mode is found at low frequencies around 15-40 KHz; a lumen efficacy of 15.3 lm/W is achieved at a luminance of $2400\;cd/m^2$. In the high brightness mode, present at high voltage, we find a maximum luminance of $5900\;cd/m^2$ at 30KHz.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.63-68
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• 2002

ADC(Automatic Discharge Connector) is commonly used for the easy maintenance of the submersible pumps. However, the small gap between the flange of the base plate and that of the pipe due to the head rise, the flow momentum change and the mis-installation makes leakage flow that may be a great loss to the pumping system. In this study, the performance degradation was predicted with the simple leakage flow model through the gap. The newly developed ADC was tested and the leakage performance was compared with the old one and also no-leakage piping system. The newly developed ADC reduced the leakage flow in a satisfactory way in comparison with the old model.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.69-75
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• 2006

In this paper, micro electrical discharge milling using deionized water as dielectric fluid was investigated. In EDM, dielectric fluid is an important factor which affects machining characteristics. When deionized water was used as dielectric fluid, machining characteristics were investigated according to voltage, capacitance, and resistivity of deionized water. Machining gap increased with increasing voltage and capacitance. As the resistivity of deionized water decreased, the machining gap increased. The wear of a tool electrode and machining time can be reduced by using deionized water instead of EDM oil. Surface roughness was also improved when deionized water was used.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.55-61
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• 1998

Recently, the needs of machining technologies of very small parts have been increasing with advent of micro-revolution. These technologies have mostly used the method applied to semi-conductor production process such as LIGA, etc. But they have serious difficulties to settle down in terms of workpiece materials, machining thickness, 3-dimensional structure. Therefore. mciro-machining technology using EDM(Electrical Discharge Machining) was proposed. It is very difficult to machine the micro-parts (microshaft, microhole) using conventional machining. Micro-machining using BDM can machine the micro-parts easily because it requires little machining force. This MEDM(Micro-EDM) need the capabilities to move a electrode and control a discharge energy precisely, and the gap control strategy to maintain the optimal discharge condition is necessary. Therefore, in this study, the new EDM machine with high precision motion stage and high-performance EDM device was developed. Using this MEDM machine, we have machined microshaft and microhole with various shapes and sizes.

• The KSFM Journal of Fluid Machinery
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• v.6 no.2 s.19
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• pp.23-28
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• 2003

ADC (Automatic Discharge Connector) is commonly used for the easy maintenance of the submersible pumps. However, the small gap between the flange of the base plate and that of the pipe due to the head rise, the flow momentum change and the mis-installation make a leakage flow that may be a great loss to the pumping system. In this study, the performance degradation was predicted with the simple leakage flow model through the gap. The newly developed ADC was tested, and the leakage performance was compared with the old one and also no-leakage piping system. The newly developed ADC reduced the leakage flow in a satisfactory way in comparison with the old model.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.145-148
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• 1999

In this paper, multi gap type ozonizer(MGO) 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: $\circled1$ The characteristics of discharge with variation of output voltage of AC H.V source, flux of oxygen supplied gas and discharge voltage. $\circled2$ The characteristics of ozone generation by varying flux and discharge power.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.152-152
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• 2012

In this work we measured electron temperature and electron density of a microplasma by optical emission spectroscopy. The plasma is generated from a small discharge gap of a microwave parallel stripline resonator (MPSR) in Helium at atmospheric pressure. The microwave power supplied for this plasma source from 0.5 to 5 watts at a frequency close to 800 MHz. The electron temperature and electron density were estimated through Collisional-radiative model combined with Corona-equilibrium model. The results show that the electron density and temperature of this plasma in the case small discharge gap width are higher than that in larger gap width. The diagnostic techniques and associated challenges will be presented and discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.480-484
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• 2006

We propose a new PDP cell structure named DIDE (Dual Ignition Discharge Electrodes) structure with a long electrode gap to realize a high luminous efficacy. Suggested DIDE structure basically has a long electrode gap $(200{\mu}m{\sim}400{\mu}m)$, nevertheless, because of auxiliary electrodes formed on the front panel, can be driven at relatively low voltage. The discharge characteristic of DIDE structure was much different from that of conventional structure, which was analyzed by IR emission images using IICCD (Image Intensified Charge Coupled Device). The study can explain some particular characteristics of DIDE structure. As a result, the long electrode gap and low voltage effect can be expected in DIDE structure, and a very high luminous efficacy of 7.5 lm/W has been achieved in monochrome green test panel adopting the new cell structure with Ne-Xe (12%) mixture at 400 torr.