• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.153-156
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• 2008

The use of high Xe content gas is a powerful method for improving the discharge efficacy in PDP, but the accompanying high driving voltage prevents it from being used aggressively. In this paper, we tried to find a method to lower the driving voltage under high Xe gas condition with a new protecting layer. The effective secondary electron emission caused by Xe ions can result in the low voltage driving in panels with high Xe content gas and more importantly high luminous efficacy which were confirmed with the computer simulation and panel experiment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1566-1571
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• 2009

The discharge electrodes in ac PDP are coated with dielectric layer, and transparent MgO thin films are deposited on the dielectric layer. The main role of the MgO thin films in ac PDP is to protect the dielectric layer from sputtering by ion bombardment in the glow-discharge plasma. An additional important role of the MgO thin film is the high secondary electron emission coefficient which leads the low firing voltage and low cost of the PDP. In this paper, we investigated the relations of the crystal orientation about deposition thickness, deposition rate, temperature of substrate, and distance between the MgO tablet and the substrate. Additionally, we investigated the discharge characteristics of the AC PDP using nano-powder MgO tablet

• BMB Reports
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• v.35 no.6
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• pp.590-594
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• 2002

To elucidate the effect of gamma-irradiation on the molecular properties of myoglobin, the secondary and tertiary structures, as well as the molecular weight size of the protein, were examined after irradiation at various irradiation doses. Gamma-irradiation of myoglobin solutions caused the disruption of the ordered structure of the protein molecules, as well as degradation, cross-linking, and aggregation of the polypeptide chains. A SDS-PAGE study indicated that irradiation caused initial fragmentation of the proteins and subsequent aggregation, due to cross-linking of the protein molecules. The effect of irradiation on the protein was more significant at lower protein concentrations. Ascorbic acid protected against the degradation and aggregation of proteins by scavenging oxygen radicals that are produced by irradiation. A circular dichroism study showed that an increase of the irradiation decreased the a-helical content of myoglobin with a concurrent increase of the aperiodic structure content. Fluorescence spectroscopy indicated that irradiation increased the emission intensity that was excited at 280 nm.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.765-769
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• 2001

The refuse-derived fuel(RDF) is manufactured using waste plastics-based materials and its physical and chemical properties are analyzed. The manufacturing process consists of hand picking, primary magnetic separation, crushing, secondary magnetic separation, feeding and extrusion. The RDF products have a higher calorie content of over 6, 000 ㎉/kg and high stability because the waste plastics and paper are mainly selected. The combustion flue gas of RDF products is satisfied with the emission criteria of incinerator. The heavy metal concentration of combustion byproduct from the RDF boiler is also satisfied with the criteria and appears to be lower concentration than that of a common municipal waste incinerator.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.234-234
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• 1999

AC-PDP(Plasma Display Panel)에 사용하는 MgO 보호막의 이차전자 방출계수(${\gamma}$)는 AC-PDP의 방전특성을 결정짓는 중요한 요소이다. MgO 보호막의 이차전자 방출계수는 AC-PDP에 주입하는 기체의 종류에 영향을 받는다. 현재 AC-PDP에는 방전특성의 향상과 VUV 발생을 위하여 He, Ne, Ar, Xe 등의 비활성기체를 두가지 혹은 세가지로 혼합한 혼합기체가 사용되고 있다. 기체를 혼합할 경우 Penning 효과에 의해 더 좋은 방전특성을 얻을 수 있는 것으로 알려져 왔으며, 이때의 적절한 혼합비율을 찾는 것은 AC-PDP의 효율 개선에 매우 중요하다. 이번 실험에서는 (111), (100), (110) 각각의 방향으로 배향된 MgO Bulk Crystal과 MgO 보호막의 이차전자방출계수를 He+Ne+Xe 삼원기체를 사용하였다. MgO 보호막은 실제 21inch 규격의 Panel을 사용하였으며, 혼합기체의 혼합비율의 Ne:Xe을 99:1, 98:2, 96:4, 93:7과 He+Ne+Xe의 삼원기체로 다양하게 변화시켜 가며 실험하였다.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2441-2445
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• 2009

The effects of Si -doped MgO have been investigated in order to improve the material properties of the MgO protective layer in plasma display panels. A small amount of Si is added to the MgO pellet while the MgO layer is being deposited by using an electron-beam evaporation method. Both the surface characteristics of the protecting layer and the electro-optical properties of 4 in. test panels are investigated, such as XRD patterns, SEM images, firing and sustain voltages, secondary electron emission coefficient($\gamma$), luminance, luminous efficacy and lifetime. The firing and sustain voltage are minimized when Si concentration is 0.038%, where the luminance and luminous efficacy increase up to 17% and 26% compared with that of the pure MgO film, separately, and lifetime also shows good characteristics.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.10
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• pp.2690-2698
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• 1995

Fuel atomization and mixture formation in an gasoline engine has influence on the engine performance and pollutant emission. The throttle valve installed in an intake system plays a greater role in control of mixture quantity in accordance with engine drive condition. In this study, the characteristics of secondary atomization developed at the downstream of the valves were observed using an image processing method. Two major kinds of valves, solid and perforated ones, are chosen in order to compare the valve performance with the experimental parameters of air flow rate, valve opening angle, and valve shapes. For the perforated valve, we can obtain the relatively small sized droplets, and nearly uniformed and dense distributed sprays with low loss coefficient than for the solid valve.

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.208-208
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• 2003

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.202-202
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• 2000

AC-PDP(Plasma Display Paner)는 기체 방전을 이용한 디스플레이로서 기체에 직접 노출되는 MgO 보호막의 2차전자 방출계수(${\gamma}$는 AC-PDP의 방전특성을 결정짓는 중요한 요소이다. MgO 보호막의 이차전자 방출계수는 AC-PDP에 주입하는 기체의 종류, 결정 방향성과 표면오염상태 등에 영향을 받는다. 본 연구에서는 유리 기판위에 Al 전극을 증착, 에칭후 screen printing으로 유전체를 도포, 소성 한 21inch 규격의 test panel에 MgO 보호막을 E-Beam으로 5000$\AA$ 증착한 후 MgO 보호막을 대기에 노출되는 시간간격을 변수로 하여 대기 열처리 한 MgO보호막의 2차 전자방출계수를 ${\gamma}$-FIB(Focused Ion Beam) 장치를 이용하여 측정하였다. 그리고 대기 노출 간격은 1분, 5분, 20분으로 하여 2차 전자방출계수를 측정하였고, 2차전자방출계수 측정 시 가속전압은 50V에서 200V까지 변화를 주었으며, Ne+을 사용하여 1.2$\times$10-4Torr의 진공도를 유지하며 측정하였다. 또한 각각의 MgO막의 에너지 갭을 광학적 방법을 이용하여 구하였다.