• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.4
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• pp.646-651
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• 1987

The photoconductive multilayer composed of glassy, porous, and fine-grained layers was fabdricated with Se and Sb2S3 by vacuum evaporation in order to be used as vidicon target. And its electrical, optical properties were investigatee. The fabrication conditions were as follow: the glassy layer was first deposited to have the thickness of 6500 \ulcornerat the deposition rate of 250\ulcornersec. High photosensitivity(\ulcorner=1) was obtained but its shortcoming was high dielectric constant. Therefore, the porous layer was added to lower dielectric constant and had 7500\ulcornerthick in the argon gas ambikent of 7x10-\ulcorner And the fine-grained layer was formed to prevent secondary electron emission and obtain good resolution. Its thickness was about 1700\ulcorner For the given vidicon target, the light transfer characteristic, that is, photosensitivity (\ulcorner) was measured to be 0.8 at the applied voltage of 25V. The spectral sensitivity was quite similar to that of the human eyes.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.255-264
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• 1999

Friction characteristics of automotive friction materials containing different metallic fibers rubbing against Al-MMC and cast iron disk specimens have been studied. Friction materials containing aluminum, copper or low steel carbon fiber were tested. Friction tests were composed of three different phases to investigate the effect of temperature, pressure, speed, and drag time. The results showed that the friction material containing Al fibers has lower friction force and wear amount than the others with Cu or Steel fiber. On the other hand, the wear of friction material was severe in the case of using Al-MMC rotors. These results showed that the thermal decomposition of solid lubricants (and organic components), formation of transfer layer, and SiC particles in the AI-MMC rotor play crucial roles in determining the friction characteristics.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.154-162
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• 1998

A planar Bi-Sb multijunction thermal converter with high thermal sensitivity and small ac-dc transfer error has been fabricated by preparing the bifilar thin film Pt-heater and the hot junctions of thin film Bi-Sb thermopile on the $Si_{3}N_{4}/SiO_{2}/Si_{3}N_{4}$-diaphragm, which functions as a thermal isolation layer, and the cold junctions on the dielectric membrane supported with the Si-substrate, which acts as a heat sink, and its ac-dc transfer characteristics were investigated with the fast reversed dc method. The respective thermal sensitivities of the converter with single bifilar heater were about 10.1 mV/mW and 14.8 mV/mW in the air and vacuum, and those of the converter with dual bifilar heater were about 5.1 mV/mW and 7.6 mV/mW, and about 5.3 mV/mW and 7.8 mV/mW in the air and vacuum for the inputs of inside and outside heaters, indicating that the thermal sensitivities in the vacuum, where there is rarely thermal loss caused by gas, are higher than those in the air. The ac-dc voltage and current transfer difference ranges of the converter with single bifilar heater were about ${\pm}1.80\;ppm$ and ${\pm}0.58\;ppm$, and those of the converter with dual bifilar heater were about ${\pm}0.63\;ppm$ and ${\pm}0.25\;ppm$, and about ${\pm}0.53\;ppm$ and ${\pm}0.27\;ppm$, respectively, for the inputs of inside and outside heaters, in the frequency range below 10 kHz and in the air.