• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.97-103
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• 2015

This paper presents the characteristics of partial discharge and radiated electromagnetic waves in the existence of a poor contact for the insulation diagnosis of eco-friendly power equipment. AC surface discharge experiment was conducted to simulate the poor contact between a hive voltage electrode (anode) and a solid insulator in $N_2/O_2$ mixture gas under a non-uniform field. The partial discharge voltage to be measured at 0.3MPa increased with the increase of the poor contact gap and was saturated with the gap. In addition to the partial discharge characteristics, it was verified that the defect of the poor contact can be diagnosed using the radiated electromagnetic waves due to the partial discharge, which measured by a biconical EMC antenna and a spectrum analyzer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1803-1808
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• 2013

To maintain contact between catenary and pantograph copper is important in order to transmit power smoothly on Current collection system. But, Arc discharge with strong light is generated because of contact loss. Therefore, Arc discharge detection is important measurement factor judging performance of current collection system. In this paper, It is described to results of arc discharge applying UV detection technology using arc generator. And Arc discharge was detected using the most commonly used processing catenary and rigid catenary and pantograph copper of electric rolling stock for securing arc detection instrument reliability. Results of contact loss detection instrument in this paper will be used for maintenance of current collection quality and system.

• Journal of Korean Academy of Nursing
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• v.35 no.5
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• pp.842-849
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• 2005

Purpose: The main purpose of this study was to establish a nursing intervention data base to improve maternal attachment. Method: The first group of mothers( control group), experienced their first physical contact with their infants after being discharged from the hospital. The second group (experimental group) practiced early initial mother-infant postpartum contact known as the most sensitive period for founding maternal-infancy attachment. The subjects of this study gave birth to normal infants at M hospital from Aug.25 to Sept.30, 2004. During the same time, data was collected through direct observation, with instruments designed by Cropley et al., to assess the behaviors of normal attachment. The statistical methods for data analysis were percentage, mean, standard deviation and t-test with an SPSS program. Result: The group practicing initial mother-infant contact, showed a higher degree of physical and functional bonding than the group experiencing the first contact after discharge from the :10spital (control group)(p<.0l). The group practicing initial mother-infant contact, showed higher degrees of bonding attachment assessments than the group experiencing their first initial contact after their discharge from the hospital(p<.01). Conclusion: The group practicing early mother-infant contact, showed more maternal-infant interaction than the group experiencing their initial contact after their discharge from the hospital. These results show that maternal attachment behavior increases according with an early initial mother-infant contact.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.3
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• pp.148-151
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• 2004

For turn on high pressure sodium vapor lamp, Starting Voltage is very important factor. This starting voltage supply to high pressure sodium vapor lamp as electric discharge lamp, Electric field is producted in electric discharge tube, So accelerative electron collide against vapor atom and second electron is generated, And rapidly the current flow to electric discharge tube. This starting voltage is high voltage and source for melting contact that relay is according as turn on/off high pressure sodium vapor lamp. Consequently, This paper propose that the prevention of melting contact in accordance relay of controller for turn on/off high pressure sodium vapor lamp.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.266-269
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• 2001

This paper investigated the aging characteristic under long-term corona discharge on roan temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge. the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains $(CH_3)$ and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.266-269
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• 2001

This paper investigated the aging characteristic under long-term corona discharge on loon temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge, the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains (CH$_3$) and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.320-326
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• 2019

Recently, the application of atmospheric plasma technology in air filtration is increasing. Sterilization by an atmospheric plasma device is very effective. However, ozone gas, which is generated during atmospheric plasma formation, poses a hazard to human health. To reduce the ozone gas during plasma discharge, we fabricated a one-plate hybrid plasma discharge device with a heating element, which can decompose ozone gas effectively by a simple heating action. In this study, we evaluated the plasma discharge characteristics and ozone concentrations with various Ar flow rates and temperatures. With increasing Ar gas flow rate, the ozone concentration and spectrum intensity increased till an Ar gas flow rate of 60 sccm, and decreased thereafter. When discharged in high temperature, the ozone concentration and spectrum intensity decreased. Further, to evaluate the state of the treated surface under various plasma discharge and heating conditions, we measured the variation in the contact angles on the surface. Regardless of the temperature, the contact angle increased with increasing discharge voltage. However, the contact angle increased when discharged at high temperature.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.184-190
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• 2009

Tri-acetyl-cellulose(TAC) film surface was modified by atmospheric-pressure plasma technique to obtain the hydrophilic functional groups and improve the contact angle. TAC film was modified with N2 plasma ionized in dielectric barrier discharge(DBD) reactor under atmospheric pressure. We measured the change of the contact angle and the surface energy with respect to the plasma treatment conditions such as plasma treatment power, discharge gap and Ｎ2 gas flow rate. As the plasma treatment speed of 100[mm/sec], the plasma treatment power of 1.5[kW], discharge gap 2[mm] and the $N_2$ gas flow rate 140[LPM], the best contact angle and the highest surface energy were obtained. The degree of hydrophilization depended strongly on the plasma-treating time and discharge power.

• Korean Journal of Materials Research
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• v.16 no.9
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• pp.543-549
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• 2006

Polyimides (PI) are treated with $He/O_2$ and $He/O_2/NF_3$ atmospheric pressure rf dielectric barrier discharge in order to investigate the roles of $NF_3$ that is one of the PI etching gases. Surface changes are analyzed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurement. The surface roughness of PI and the ratio of C=O, which is hydrophilic functional group, is more increased by $He/O_2/NF_3$ discharge than by $He/O_2$ discharge. The C=O species on the PI surface is increased up to 30 percent with rf power. The surface roughness of PI is increased from 0.4 to 11 nm with rf power. The water drop contact angles on PI, however, are reduced from $65^{\circ}\;to\;9^{\circ}$ by plasma treatment independently of $NF_3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.503-506
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• 2004

In this paper we investigated the changes of surface hydrophobic characteristics on silicone rubbers by corona discharge treatment and also investigated the distribution and the behavior of low molecular weight(LMW) silicone fluid which was extracted by solvent-extraction with gel permeation chromatography(GPC). It was shown that contact angle was $110.5^{\circ}$ on initial sample but contact angle was approximately decreased to $10^{\circ}$ after 45 minutes. However the surface hydrophobic characteristic on silicone rubbers which were removed from corona discharge was recovered within 5 hours. It was shown that corona discharge insured the increase of diffusible LMW chains, which could lead to recover the surface hydrophobicity. The surface hydrophobic characteristics on silicone rubbers and the recovery mechanism based on our results were discussed.