• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.4 s.34
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• pp.75-95
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• 1999

A colloid refers to dispersed particles of a solid or liquid having the diameter of about $10^{-5}-10^{-7}cm$. Such colloidal silver is produced by electrolysis. In this paper, colloidal silvers of various concentrations according to charge amount and time are produced, and their anti-microbial activities are measured. And optimum conditions for emulsion are measured by varying the concentration of colloidal silvers. Further, stability of the emulsion is measured with a Zeta potential, chrome meter by applying colloidal silvers to creams (W/Si, O/W, MLV).

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.340-346
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• 1994

2.5Gbps 광통신시스템용 수광소자로서 charge plate층을 갖는 링구조의 separate absorption grading multiplication avalanche photodiode를 제작하고 그 특성을 조사 분석하였다. Avalanche Photodiode의 제작은 Metal-Organic Chemical Vapor Deposition 과 Liquid Phase Epitaxy법을 이용한 에피성장과 Br:Methanol을 이용한 채널식각 방법을 사용하였고, passivation과 평탄화는 photosensitive polyimide를 이용하였다. 제작된 ADP는 10nA 이하의 작은 누설전류를 나타내었고, -38~39 V의 항복전압을 나타내었다. 제작된 ADP를 GaAs FET hybrid 전치증폭기와 결합하여 2.5Gbps 속도에서 $2^{23}-1$의 길이를 갖는 입력 광신호에 대해 $ 10^{-10}$ Bit Error Rate에서 -31.0dBm의 수신감도를 얻었다.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1685-1687
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• 1996

Recently, conducting polymer has been much attracted as novel materials because of its electronic behavior and functional application by doping process. In this paper, we electrochemically synthesized polyaniline films under potential sweep conditions, which exhibit high electric conductivity about 200 S/cm. Specific energy of 600 Wh/kg and Ah efficiency 98% were achieved during the charge/discharge cycling using liquid electrolyte system. On the other hand, consequences of the cycling were 260 Wh/kg and 95% Ah efficiency using polyethylene oxide(PEO) based solid-state electrolyte system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.164-168
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• 1996

The relation between crystallinity and thermal history in low density polyethylene thin films and their effect on electric conduction phenomena and dielectric breakdown was studied. The low density polythylene thin films obtained by the solution growth method heat-treated at 140[$^{\circ}C$] for 2 h and subsequently cooling to various ways. The degree of crystallinity was estimated by the X-ray diffraction measurement for the specimen of slowly cooling, ICE quenching and liquid nitrogen quenching. The result shows that the crystallinity decreases become faster as the cooling speed increased, and that conduction phenomenon is governed by the space charge limited current in high field. It was found that the dielectric breakdown field increases with an increase in cooling speed and test number in self-healing breakdown method.

• Journal of ILASS-Korea
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• v.22 no.4
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• pp.190-196
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• 2017

The aim of this work is to investigate the combustion and exhaust emission characteristics of low-temperature combustion (LTC) at various EGR test conditions using a single cylinder common-rail diesel engine. In high EGR rate combustion mode with DME fuel, 30% (${\Phi}=0.61$) and 50% (${\Phi}=0.86$) of EGR were respectively examined, and then the combustion, exhaust emissions, nano-particle characteristics of each cases were measured. From these results, it revealed that The ignition delay and combustion duration are prolonged as the increase of EGR rate. In addition, at an advanced injection timing (BTDC $30^{\circ}$), ignition delays were fairly increased because the dilution effect of EGR and also low charge in-cylinder temperature created a lean mixture, thus decreased the peak release rate.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.1
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• pp.48-73
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• 1998

Colloid refers to dispersed particles of solid or liquid having diameters of $10^{-5}$ to $10^{-7}$cm, among which colloidal silver is produced by electrolysis. Colloidal silver of various concentrations according to charge and time were formed, antimicrobial activity of colloidal silver was measured. And, the optimum conditions for emulsion were determined by changing the concentration of coloidal silver. Also, the stability of the emulsion was measured by zeta potential and chroma meter by applying colloidal silver to creams(W/S, O/W, MLV)

• Journal of the Korean Ceramic Society
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• v.25 no.6
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• pp.615-622
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• 1988

To develope good slip and microstructure of Si3N4 the knowledge of the interaction of particles in liquid systems is required. In this work polyethyleneimines was tested as a stabilizer for Si3N4-water system. The stability of slip dispersed with polyethyleneimines was good over a wide range of pH and concentrated slips with low viscosity could be cast. This work comprises a systematic investigation including determination of electrical mobility in order to estimate the particle surface charge, determination of sedimentation rate, as well as measurements of the viscosity as a function of dispersants, pH and shear rates. The influence of deflocculation on the microstructure of slip cast Si3N4 was discussed.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1202-1205
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• 2000

Germicidal lamps efficiently emit a large amount of ultraviolet rays 253.7nm which have excellent germicidal effect. The lamps are primarily useful for sterilization of air, the surface of various materials and water or liquid. In this paper, analysis of the charge pump power factor correction inverter for driving a 65W UV lamp and electrical characteristics of the lamp are discussed. The operation of the inverter circuit. in which the lamp is included as a load, is analyzed. Experimental results of the inverter circuit are also presented.

• Proceedings of the Safety Management and Science Conference
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• 1999.11a
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• pp.345-354
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• 1999

A new type of capacitor named "Super Capacitor" has been developed, in which the properties of electric double layer formed at the interface of activated carbon electrode- liquid organic electrolyte is applied. This capacitor is small In size, light in weight, wide In temperature range(-25~$70^{\circ}C$), large in charge-discharge capability and good in voltage preservation. And this super capacitor is applied as a power back-up for electricity failure in volatile memory devices etc., a power source for a short time and a power source for operating actuators. At present the development of high power back-up types of the capacitor system and improvement of their characteristics are being actively conducted in order to find wider applications.lications.

• Proceedings of the SCSK Conference
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• 1999.10a
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• pp.75-95
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• 1999

A colloid refers to dispersed particles of a solid or liquid having the diameter of about $10^{-5}$ - $10^{-7}$. Such colloidal silver is produced by electrolysis. In this paper. colloidal silvers of various concentrations according to charge amount and time are produced, and their anti-microbial activities are measured. And optimum conditions for emulsion are measured by varying the concentration of colloidal silvers. Further, stability of the emulsion is measured with a Zeta potential. chrome meter by applying colloidal silvers to creams (W/Si. O/W, MLV).