• 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.

• Journal of the Semiconductor & Display Technology
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• v.12 no.2
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• pp.45-50
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• 2013

This paper focuses on the fundamental issues for improving the efficiency and throughput of the AC PDP (Plasma Display Panel) manufacturing. The properties of the MgO protective layer affect the PDP efficiency. Especially, the secondary electron emission efficiency was affected on the deposition rate of MgO during the evaporation. In this study, the deposition rate of 5 $\AA$/s has given the maximum efficiency value of 0.05 It is demonstrated that the impurity gases such as $H_2O$, $CO_2$, CO or $N_2$, and $O_2$ can be remained inside the PDP panel before sealing and the amount of the impurity gases decreased rapidly as the base vacuum level increased, especially near $10^{-5}$ torr. The fundamental solution in order to overcome these problems is the vacuum in-line sealing process from the MgO evaporation to the final sealing of the panel without breaking the vacuum. We have demonstrated this fundamental process technology and shown the feasibility. The firing voltage was reduced down to 285 V at the base vacuum value of $10^{-6}$ torr, whreras it was about 328 V at the base vacuum value of $10^{-3}$ torr.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.625-627
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• 2002

MgO thin films were deposited on glass and (100) Si substrates by an Arc Ion Plating (AIP) equipment using a magnesium metal target at various oxygen gas flow. In this work, we investigated the relationship between the structural properties and the discharge characteristics of MgO coating layers. X-ray diffraction and AFM have been used to study behaviors of the structure and surface morphology. The optical transmittance and the ion induced secondary electron emission coefficient of the MgO films have been also measured. The resistivity of the deposited MgO films was gradually increased from 0.17 G ohm/${\square}$ to 0.35 G ohm/${\square}$ with the oxygen gas flow. The growth rate of the MgO coating layer was decreased with increasing the oxygen gas flow, while the optical transmittance was improved.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.202-203
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• 2006

In the AC PDP, the MgO film is used as electrode protective film. This film must provide excellent ion bombardment protection, high secondary electron emission, and should be high transparent to visible radiation. In this study, we investigated the relations between the crystal orientation and e-beam evaporation process parameters. The crystal orientation of the MgO layer depends on the conditions of deposition. The parameters are the thickness of the MgO film $1000{\AA}-6500{\AA}$, the deposition rate $200{\AA}/min{\sim}440{\AA}/min$, the temperature $150^{\circ}C{\sim}250^{\circ}C$, and the distance between crucible and substrate 11cm ${\sim}$ 14cm. The temperature of substrate and evaporation rate of source material, or deposition rate of the film, are definitely related to the crystal orientation of the MgO thin film. The crystal orientation can be changed by the distance between the target(MgO tablet) and the substrate. However, the crystal orientation is not much affected by the thickness of MgO thin film.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.739-745
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• 2003

In $N_{x}$ films were deposited on soda-lime glass without substrate heating by reactive dc magnetron sputtering using indium (In) metal target. Depositions were carried out under various total gas pressures ( $P_{tot}$) of mixture gases (Ar+$N_2$ or He+$N_2$). He gas was introduced to $N_2$ gas in order to enhance the reactivity of nitrogen on film surface by the "penning ionization". Plasma impedance decreased greatly when 20% or more introduced the $N_2$ gas. This is due to the In $N_{x}$ layers formed on target surface because a secondary electron emission rate of InN is small compared with In metal. XRD patterns of the films revealed that <001> preferred oriented polycrystalline In $N_{x}$ films, where the crystallinity of the films was improved with decrease of $P_{tot}$ and with increase of $N_2$ flow ratio. The improvement of the crystallinity and stoichimetry of the In $N_{x}$ films were considered to be caused by an increase in the activated nitrogen radicals and also by an increase in the kinetic energy of sputtered In atoms arriving at growing film surface, which should enhance the chemical reaction and surface migration on the growing film surface, respectively. Furthermore, the films deposited using mixture gases of He+$N_2$ showed higher crystallinity compared with the film deposited by the mixture gases of Ar+$N_2$.$.EX>.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.495-502
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• 2005

Copper was plated on the tungsten substrate by use of a direct copper electroless plating. The optimum deposition conditions were found to be with a concentration of $CuSO_4$ 7.615 g/L, EDTA of 10.258 g/L, and glyoxylic acid of 7 g/L, respectively. The solution temperature was maintained at $60^{\circ}C$. The pH was varied from 11.0 to 12.8. After the deposition, the properties of the copper film were investigated with X-ray diffractometer (XRD), Field emission secondary electron microscope (FESEM), Atomic force microscope (AFM), X-ray photoelectron spectroscope (XPS), and Rutherford backscattering spectroscope (RBS). The best deposition condition was founded to be the solution pH of 11.8. In the case of 10 min deposition at the pH of 11.8, the grain shape was spherical, Cu phase was pure without impurity peak ($Cu_2O$ peak), and the surface root mean square roughness was about 11 nm. The thickness of the film turned out to be 140 nm after deposition for 12 min and the deposition rate was found to be about 12 nm/min. Increase in pH induced a formation of $Cu_2O$ phase with a long rectangular grain shape. The pH control seems to play an important role for the orientation of Cu in electroless deposition. The deposited copper concentration was 99 atomic percent according to RBS. The resulting Cu/W film yielded a good adhesive strength, because Cu/W alloy forms during electroless deposition.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.285-294
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• 2011

The abatement of methane emission from ruminants is an important global issue due to its contribution to greenhouse gas with carbon dioxide. Methane is generated in the rumen by methanogens (archaea) that utilize metabolic hydrogen ($H_2$) to reduce carbon dioxide, and is a significant electron sink in the rumen ecosystem. Therefore, the competition for hydrogen used for methanogenesis with alternative reductions of rumen microbes should be an effective option to reduce rumen methanogenesis. Some methanogens parasitically survive on the surface of ciliate protozoa, so that defaunation or decrease in protozoa number might contribute to abate methanogenesis. The most important issue for mitigation of rumen methanogenesis with manipulators is to secure safety for animals and their products and the environment. In this respect, prophylactic effects of probiotics, prebiotics and miscellaneous compounds to mitigate rumen methanogenesis have been developed instead of antibiotics, ionophores such as monensin, and lasalocid in Japan. Nitrate suppresses rumen methanogenesis by its reducing reaction in the rumen. However, excess intake of nitrate causes intoxication due to nitrite accumulation, which induces methemoglobinemia. The nitrite accumulation is attributed to a relatively higher rate of nitrate reduction to nitrite than nitrite to ammonia via nitroxyl and hydroxylamine. The in vitro and in vivo trials have been conducted to clarify the prophylactic effects of L-cysteine, some strains of lactic acid bacteria and yeast and/or ${\beta}$1-4 galactooligosaccharide on nitrate-nitrite intoxication and methanogenesis. The administration of nitrate with ${\beta}$1-4 galacto-oligosaccharide, Candida kefyr, and Lactococcus lactis subsp. lactis were suggested to possibly control rumen methanogenesis and prevent nitrite formation in the rumen. For prebiotics, nisin which is a bacteriocin produced by Lactococcus lactis subsp. lactis has been demonstrated to abate rumen methanogenesis in the same manner as monensin. A protein resistant anti-microbe (PRA) has been isolated from Lactobacillus plantarum as a manipulator to mitigate rumen methanogenesis. Recently, hydrogen peroxide was identified as a part of the manipulating effect of PRA on rumen methanogenesis. The suppressing effects of secondary metabolites from plants such as saponin and tannin on rumen methanogenesis have been examined. Especially, yucca schidigera extract, sarsaponin (steroidal glycosides), can suppress rumen methanogenesis thereby improving protein utilization efficiency. The cashew nutshell liquid (CNSL), or cashew shell oil, which is a natural resin found in the honeycomb structure of the cashew nutshell has been found to mitigate rumen methanogenesis. In an attempt to seek manipulators in the section on methane belching from ruminants, the arrangement of an inventory of mitigation technologies available for the Clean Development Mechanism (CDM) and Joint Implementation (JI) in the Kyoto mechanism has been advancing to target ruminant livestock in Asian and Pacific regions.