• Korean Journal of Materials Research
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• v.13 no.3
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• pp.150-154
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• 2003

Amorphous carbon nitride films were deposited on Si(001) substrates by a plasma enhanced chemical vapor deposition technique (PECVD) using $CH_4$and $N_2$as reaction gases. The growth and film properties were investigated while the gas ratio and the working pressure were changed systematically. At 1 Torr working pressure, an increase in the $N_2$partial pressure results in a significant increase of the deposition rate as well as an apparent presence of C ≡N bonding, while little affecting the microstructure and amorphus nature of the films. In the case of changing the working pressure at a fixed $N_2$partial pressure of 98%, a film grown at a medium pressure of $1${\times}$10^{-2}$ Torr shows the most prominent C=N bonding nature and photoluminescent property.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.3
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• pp.122-126
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• 2012

The properties of Al-doped ZnO (AZO) films were investigated as a function of $H_2/(Ar+H_2)$ gas ratio using an AZO (2 wt% $Al_2O_3$) ceramic target in a radio frequency (RF) magnetron sputtering system. The deposition process was done at $200^{\circ}C$ and in $2{\times}10^{-2}$ Torr working pressure and with various ratios of $H_2/(Ar+H_2)$ gas. During the AZO film deposition process, partial $H_2$ gas affected the AZO film characteristics. The electron resistivity (${\sim}9.21{\times}10^{-4}\;{\Omega}cm$) was lowest and mobility (${\sim}17.8\;cm^2/Vs$) was highest in AZO films when the $H_2/(Ar+H_2)$ gas ratio was 2.5 %. When the $H_2/(Ar+H_2)$ gas ratio was increased above 2.5 %, the electron resistivity increased and mobility decreased with increasing $H_2/(Ar+H_2)$ gas ratio in AZO films. The carrier concentration increased with increasing $H_2/(Ar+H_2)$ gas ratio from 0 % to 7.5 %. This phenomenon was explained by reaction of hydrogen and oxygen and additional formation of oxygen vacancy. The average optical transmission in the visible light wavelength region over 90 % and an orientation of the deposition was [002] orientation for AZO films grown with all $H_2/(Ar+H_2)$ gas ratios.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.5
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• pp.86-96
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• 2000

This study is to consider that the helical intake port flow and fuel injection system have effects on the characteristics of engine performance and emissions in a turbocharged DI diesel engine of the displacement 9.4L. The swirl ratio for ports was modified by hand-working and measured by impulse torque swirl meter, For the effects on performance and emission, the brake torque, BSFC were measured by engine dynamometer and NOx, smoke were by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased, And as the swirl is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by the following applied parameter; the swirl ratio is 2.43, injection timing is BTDC $13^{\circ}$CA and compression is 15.5.

• Journal of Information Display
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• v.2 no.4
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• pp.29-33
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• 2001

The luminance and discharge characteristics of an AC PDP may be significantly affected by a small amount of impurity gas in working gas. Impurity gases such as $O_2$, O , C and $H_2$ can be mixed in the manufacturing and lor discharge processes. In this paper, a small amount of impurity gas in AC PDP are introduced intertimally and the relationship between the amount of impurity gas and the luminance/discharge characteristics are investigated. The luminous efficiency decreased seriously with the increase in the partial pressure of impurity gases, especially in $H_2$, $O_2$ and $CO_2$, Under the condition of the impurity gas ratio of 2x $10^{-3}$ for Ar, $N_2$, $H_2$, $CO_2$ and $O_2$, the luminous efficiency decreased to about 8%, 8%, 32%, 36% and 50%, respectively.

• Journal of the Semiconductor & Display Technology
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• v.4 no.4 s.13
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• pp.5-8
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• 2005

In this study, we prepared the ITO thin film for TOLED(Top-emitting OLED) or flexible display at room temperature using the FTS(Facing Targets Sputtering Apparatus). We observed characteristics of deposited thin films as a function of sputtering conditions. XRD patterns were independence trom oxygen gas flow and input current. But electrical and optical properties were strongly dependence. In the results, we could prepare good properties of ITO thin films resistivity of $4.27X10^{-4}[\Omega-cm]$, transmittance of over 80% at working gas pressure 1[mTorr], input current 0.6[A], oxygen gas ratio 0.3[sccm], at room temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.617-624
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• 2000

Zinc Oxide(ZnO) thin films on Si(100) substrate were deposited by RF magnetron reactive sputtering. The charcteristics of ZnO thin films on argon/oxygen(Ar/O$_2$)gas ratios RF power and substrate temperature were investigated by XRD, SEM, and AFM analyses. C-axis preferred orientation resistivity and surface roughness highly depended on Ar/O$_2$gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of 9$\times$10$^{7}$ $\Omega$cm was obtained at a working pressure of 10 mTorr with Ar/O$_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with Ar/O$_2$=50/50 showed the excellent roughness value of 28.7$\AA$.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.2
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• pp.31-36
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• 2001

Teflon-like fluorocarbon thin film was deposited by using difluoromethane$(CH_2F_2$) added with Ar, $O_2$, and $CH_4$ on Si, $SiO_2$, TEOS, and Al substrate. The deposited thin film was characterized by static contact angles for measuring hydrophobicity in various additive gas ratio. temperature, and working pressure. In case of addition with Ar, the static contact angles decreased as additive gas ratio and power increased. But the static contact angles increased as working pressure increased. Specially, super-hydrophobic surface was obtained using the powder-like fluorocarbon thin film above 2 Torr. Added with $O_2$, the static contact angles decreased as the $O_2$ ratio and working pressure increased. And the static contact angles did not change in 100W, but hydrophilic surface was obtained at 200W. In case of addition of CE$_4$, static contact angles dramatically increased in $CH_4/CH_2F_2$ ratio 5. And continuous static contact angles obtained above ratio 5. As compare with previous experiments by thermal evaporation, the fluorocarbon thin film by plasma polymerization was obtained very low hysteresis. This results shows more homogenous surface by plasma polymerization than thermal evaporation process.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1477-1479
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• 2005

In this work, the ITO thin films were prepared by FTS (Facing Targets Sputtering) system under different sputtering conditions which were varying $O_2$ gas flow, input current at room temperature. As a function of sputtering conditions, electrical and optical properties of prepared ITO thin films were measured. The electrical, optical characteristics and surface roughness of prepared ITO thin films were measured. In the results, as increasing $O_2$ gas 0.1[sccm] to 0.7[sccm], resistivity of ITO thin film was increased with a decreasing carrier concentration, $O_2$ gas over 0.3[sccm] the carrier mobility have a similarly value. Transmittance of prepared ITO thin films were improved at increasing $O_2$ gas 0.1[sccm] to 0.7[sccm]. And transmittance of all of the prepared ITO thin films was over 80%. We could obtain resistivity $6.19{\times}10^{-4}[{\omega}{\cdot}cm]$, carrier mobility $22.9[cm^2/V{\cdot}sec]$, carrier concentration $4.41{\times}10^{20}[cm^{-3}]$ and transmittance over 80% of ITO thin film prepared at working pressure 1mTorr, input current 0.4A without any substrate heating.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.899-905
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• 2000

The characteristics of air flow and engine performance with swirl ratio variance of intake port In a turbocharged DI diesel engine was studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer and NOx, smoke were measured by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. And as the swirl ratio is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.47-54
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• 2015

To prevent safety hazards in dangerous working area, we have proposed an intelligent image analysis system. Six common patterns of safety violations of workers' are defined and its motion detection algorithms are developed for alarm to CCTV monitoring system. Developed algorithms are implemented at 195 dangerous areas such as chemical and gas treated room. The results of violated motion detection ratio by developed system shows 94.95% of true positive cases, and 0.21% of false positive cases from all 587,645 event cases in one month implementation period. In the period, it is observed that the number of safety rule violations and the following accidents are decreased.