• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.269-272
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• 2005

Due to the high density and heating value, liquid fuel is attractive for ramjet propulsion system. Liquid fuel requires time to evaporation and mix with incoming air before ignition; insufficient evaporation and mixing result in low combustion efficiency and instability. So the numerical studies are conducted to investigate the spray and combustion characteristics of a liquid-fueled dump type Integrated Rocket Ramjet combustor. The governing equations are solved by means of a finite-volume using time derivative preconditioning method for chemical reacting flow. The liquid phase is treated by solving Lagrangian equations of motion and transport for the life histories of a statistically significant sample of individual droplets.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.329-332
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• 2012

The droplet behavior of 83.9 wt.% HAN water solution was investigated experimentally with various ambient temperature and nitrogen environment. At the initial stage of evaporation under thermal decomposition temperature of HAN, gradual decreasing of droplet diameter was observed. After that, the droplet started to expand due to the internal pressure build up by water nucleation inside the droplet. The micro explosion was observed at higher temperature than the decomposition temperature of HAN and the remaining droplet showed similar behavior of single composition droplet. The decreasing rate was augmented as the ambient temperature increasing.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1664-1667
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• 2007

The belt source evaporation is for the large size AMOLED devices to re-sublimate the organic film deposited on the metal plate. Using the plane source, the PL spectrum of the doped organic film has been studied for the first time. The PL peak of the pure Alq3 film was 512nm and that of the pure Rubrene was 557nm. The PL peak of the 2% Rubrene doped Alq3 film was shifted to $536{\pm}2nm$. The PL peak wavelength measured at the front surface of the film and at the back surface of the film was measured as nearly same as that the doping ratio maintains uniform within the film thickness. In conclusion, the doping control of the organic film becomes real using the belt type plate sublimation deposition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.3
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• pp.199-205
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• 2005

Polycrystalline cadmium sulfide(CdS) thin films were deposited on glass substrate by chemical bath deposition(CBD) and vacuum evaporation (VE) techniques. VE-CdS films consisted primarily of hexagonal phase, whereas CBD CdS films containing primarily the cubic form. VE-grown films were shown to have better crystallinity than CBD-grown films. The grain size of the CBD films is smaller than the ones of VE films. VE-CdS films exhibited relatively high transmittance in the above-gap region and band gap compared with CBD films. However, CdTe solar cells with these low quality CBD-CdS layers yield higher and more stable characteristics. Current-voltage-temperature measurements showed that the current transport for both cells was controlled by both tunneling and interface recombination but the cells with CBD-CdS displayed less tunneling.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.845-848
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• 2002

The study of photoconductor materials is demanded for development for flat-panel digital x-ray Imager. In this paper, We investigated the feasibility of application as x-ray image sensor using Cd(Zn)Te compound with high stopping power on high radiation. These Cd(Zn)Te samples were fabricated by vacuum thermal evaporation method to large area deposition and investigated I-V measurement as applied voltage. The experimental results show that the additional injection Zn in CdTe film reduced the leakage current, for the $Cd_{0.85}Zn_{0.15}Te$ detector, the net charge had the highest value as $144.58pC/cm^2$ at 30 V.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.1023-1025
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• 1998

This paper presents the fabrication of a micro pump consisting of a pair of Al f1ap wave and a phase change actuator. The phase change actuator is composed of a heater, a silicone rubber diaphragm and a working liquid chamber. The diaphragm is actuated by the evaporation and the condensation of the working liquid. The actuator pumps fluid through the valves. The micro pump is fabricated by the anisotropic etch, the boron deposition and the metal evaporation. The forward and the backward flow characteristics of the f1ap valves were obtained. Also, the flow rate of the micro pump has been measured. When the square wave input of 12 V, 60% duty ratio and 0.2 Hz is applied, the average flow rate is $0.15{\mu}{\ell}/sec$ for zero pressure difference.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.85-89
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• 2008

This study carried out field observations of measuring thermal environment, especially evaluating amount of water evaporation at roof Pond by field observations during the summer. Thermal environment measuring was categorized as air temperature, water temperature of roof pond, surface temperature, globe temperature, short and long wave radiation, net radiation, and amount of water evaporation by water level measurement. Results from this study could be used as fundamental for reducing heat Island phenomena.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.47-54
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• 1998

An experimental study was performed to discover the effect of environmental conditions on the rolling resistance behavior of pure silver and lead coated 52100 bearing steel. Pure silver and lead coating were produced by a thermal evaporation coating method. Experiments using a thrust ball bearing-typed rolling test-rig were performed under vacuum, dry air and controlled humidity conditions. Results showed that agglomeration of particles were prevented in vacuum environment and as it showed low and stable rolling resistance by shakedown phenomena. Also, humidity relates closely to the agglomeration of particles and increased the rolling resistance after the failure of coated layer.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.04a
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• pp.101-110
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• 1997

An experimental study was performed to discover the tribological behaviors of pure silver coated 52100 bearing steel. Pure silver coatings ranging from 80 nm to several micrometers were produced by a thermal evaporation coating method. Experiments using a thrust ball bearing-typed rolling test-rig were performed for the investigations of the influence of coating thickness on the tribological rolling behavior. The existence of optimum film thickness which revealed minimum rolling resistance was discovered. A careful analysis on the contact surfaces for the optimum film thickness has been performed. The contact patches produced by the transferred silver films played an important role for the rolling resistance to keep low.

• Tribology and Lubricants
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• v.8 no.1
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• pp.63-69
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• 1992

In order to gain better understanding of wear behaviors of TiN-coated boron cast iron, tests and analyses were conducted with block-on disc type tribometer. TiN layer of thickness $2 \mu m$ and $4 \mu m$, coated by cathodic arc evaporation process, were experimentally investigated with the variation of applied load and sliding speed under dry sliding condition. Wear characteristics were expressed in terms of the three-dimentional wear map as well as the wear rate vs sliding speed and load. Comparisons of wear and friction characteristics between coated cast irons and uncoated cast irns were also made. Wear mechanism of TiN layer was explained in view of surface interaction between the mating surfaces. The thicker coating exhibited higher hardness and adhesion strength. the significance of stresses at the surface and in the subsurface was briefly discussed in relation to the wear behavior.