• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.390-393
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• 1989

Diamond is synthesized from the gaseous mixture of carbon monoxide and hydrogen by microwave PECVD. $10{\times}10mm^2$ silicon wafers are used as the substrate,and it can be raised more than $900^{\circ}C$ by microwave absorption, radiation by plasma and bombardment of ions. The changes of the morphology and the growth rates of the deposits with the experimental conditions are examined by Scanning Electron Microscopy. The d values of all the deposited films concide with those of powder diffraction data in XRD. In Raman spectra, the peak of the deposit coincides with that of the natural diamond which has a value of 1332.5 $cm^{-1}$, and the broad peak from 1360 $cm^{-1}$to 1600 $cm^{-1}$which represents the amorphous graphite was observed in the higher concentration of carbon monoxide.

• 한국정밀공학회지
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• 제27권12호
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• pp.28-32
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• 2010

Technical demands for aspheric glass lens formed in market increases its application from simple camera lens module to fiber optics connection module in optical engineering. WC is often used as a metal core of the aspheric glass lens, but the long life time is issued because it fabricated in high temperature and high pressure environment. High hard thin film coating of lens core increases the core life time critically. Diamond Like Carbon(DLC) thin film coating shows very high hardness and low surface roughness, i.e. low friction between a glass lens and a metal core, and thus draw interests from an optical manufacturing industry. In addition, DLC thin film coating can removed by etching process and deposit the film again, which makes the core renewable. In this study, DLC films were deposited on the SiC ceramic core. The process variable in FVA(Filtered Vacuum Arc) method was the substrate bias-voltage. Deposited thin film was evaluated by raman spectroscopy, AFM and nano indenter and measured its crystal structure, surface roughness, and hardness. After applying optimum thin film condition, the life time and crystal structure transition of DLC thin film was monitored.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.443-443
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• 2011

Atomic layer deposition (ALD) was used to deposit $TiO_2$ on Ni particles, and changes in the catalytic activity of Ni for $CO_2$ reforming of methane (CRM) were studied. In the presence of $TiO_2$ islands on Ni surfaces, the onset temperature of the CRM reaction was lower than that of bare Ni. During the CRM reaction, carbon was deposited on the surface, reducing the catalytic activity of the surface, but $TiO_2$ was able to remove the carbon deposits from the surface. When the Ni surface was completely covered with $TiO_2$, catalytic activity disappeared, indicating that tuning of $TiO_2$ coverage on Ni is important for maximizing the activity of the CRM reaction.

• 한국전기전자재료학회논문지
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• 제19권7호
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• pp.631-635
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• 2006

The properties of metal interlayered DLC films between the Si substrate and the DLC films were studied. DC magnetron sputtering method has been used to deposit intermediate layers of metals. And RF-PECVD method has been employed to synthesize DLC onto substrates of the silicon and metal layers. After we used metal Inter-layers, such as chromium, nickel, titanium and we studied tribological properties of the DLC films. The thickness of films were observed by field emission scanning electron microscope (FE-SEM). Also the surface morphology of the films were observed by an atomic force microscope (AFM). The crystallographic properties of the films were analyzed with X-ray diffraction (XRD), the friction coefficients were investigated by AFM in friction force microscope (FFM) mode. Tribological performances of the films were estimated by nano-indenter, stress tester measurement.

• Tribology and Lubricants
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• 제26권5호
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• pp.277-282
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• 2010

The purpose of this paper is to study and analysis the failure examples for parasitic current leakage produced in starting system on gasoline engine. It verified the discharge of battery by electric leakage because of internal wiring damage problem for CD auto changer installed in car. Also, it verified the no-stating phenomenon because of deposit forming by chemical reaction of battery fluid between battery post and cable fixing parts. It verified the damage for brush holder and commutator mixing by internal short phenomenon because of brush carbon a particle and engine oil that was flowed into internal of starting motor. It verified the working phenomenon of audio by a point of contact even if the driver turn to "LOCK" position the key.

• 한국대기환경학회지
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• 제16권2호
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• pp.191-198
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• 2000

For a characterization of the pretreated waste automotive catalyst the following analysis techniques were applied : EA(Elemental Analysis) BET(Brunaure-Emmett-Teller) and ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry). The combustion activity of waste automotive catalyst was investigated for methanol acetaldehyde and toluene as model VOCs in a fixed bed reactor. carbon deposit amount was decreased with increasing catalyst showed a good catalytic activity for VOCs combustion at 40$0^{\circ}C$. Catalytic activity for methanol acetaldehyde and toluence combustion was very excellent and decreased with mileage. The catalytic activity of a waste automotive catalyst for methanol combustion increased after acid treatment. The acid effect of catalytic activity was summarized as follows: HNO3>HCI>H2SO4>CH3COOH. The waste automotive catalyst regenerated by the pretreatment method might have a excellent catalytic activity for VOCs combustion.

• 한국세라믹학회지
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• 제32권6호
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• pp.685-696
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• 1995

The most important techniques in the synthesis of SiC/C function gradient material (FGM) are to control the SiC/C ratio and to obtain the moderate deposition rate. For these, various gas systems and flow rates were attempted and evaluated. It turned out that the CH4＋SiCl4＋H2 system was suitable for the deposition of SiC-rich layers, the C3H8＋SiCl4＋Ar system for the deposition of carbon-rich layers, and the C3H8＋SiCl4＋H2＋Ar system was good to deposit the layers between them.

• 한국세라믹학회지
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• 제24권6호
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• pp.519-526
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• 1987

TiC was deposited onto several substrate steels by the Chemical Vapor Deposition technique from TiCl4-CH4-H2 gas mixtures in the horizontal resistance furnace. Deposition rates and morphologies of the coatings were investigated with the carbon contents. Deposition thickness increased linearly with the deposition time in the Presence of CH4 gas. The various interlayers of coating by EDS and X-ray Diffraction were proved as Cr7C3 and Fe3C. Chromium contents did not affect the preferred orientation of TiC deposit. The deposition was controlled by a mass transport and a surface reaction in case of 1 wt% C-5.25 wt% Cr steel irrespective of deposition temperature.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.670-673
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• 2003

Fabrication of three dimensional microstructures by laser-assisted chemical vapor deposition of material is investigated. To fabricate microstructures, a thin layer of deposit in desired patterns is first written using laser direct writing technique and on top of this layer a second layer is deposited to provide the third dimension normal to the surface. By depositing many layers. a three dimensional microstructure is fabricated. Optimum deposition conditions for direct writing of initial and subsequent layers with good surface quality and profile uniformity are determined. Using an arson ion laser and ethylene as the light source and reaction gas, respectively, fabrication of three-dimensional carbon microstructures is demonstrated.

• 자원환경지질
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• 제17권3호
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• pp.171-177
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• 1984

Representative sulphide samples from the Sangdong skarn orebody and quartz veins show relatively narrow ranges of sulphur isotope values ranging from $^+5.5$ to $^+6.9$ permil and average $^+5.0$ permil with a standard deviation of 0.77 permil. Much higher temperature isotopic temperatures than homogenization temperatures may indicate even minerals in contact did not form together in isotopic equilibrium. Under conditions of formation of the skarn and quartz veins, ${\delta}^{34}\;H_2S$ ranges from $^+4.5$ to $^+5.3$ permil, suggesting a magmatic origin for the sulphur. Carbon and oxygen isotope values seem to show some of the spread of increasing ${\delta}^{13}C$ values of the interbedded limestone with distance from the central zone of the Sangdong mineralization. Negative values of ${\delta}^{13}C$ fluids appear to be typical of many ore deposits including those of magmatic origin. Calculated ${\delta}^{18}C$ values of the fluids are typical of those derived from magmatic sources.