• Journal of the Korean Ceramic Society
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• v.13 no.2
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• pp.8-16
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• 1976

The conductive transparent film is prepared by spraying thin salt solution. In stannic chloride solution as a base solution, various dopants such as Al, Co, Cu and Ni were dissolved respectively as a chloride state and then the films were made by spraying solutions on hot glass plates. The properties of them were compared with those of the stannic salt single component film. The films doped with copper oxide and nickle oxide were improved by decreasing their sheet resistivity and temperature coefficient of resistivity. In comparison with the sheet resistivity and temperature coefficient of resistivity of stannic oxide single component film, being 2.5 K ohm/$\textrm{cm}^2$ and -1650ppm/$^{\circ}C$ respectively, its values of the film containing 15 mol % of copper oxide and formed at 40$0^{\circ}C$ were 2.5K ohm/$\textrm{cm}^2$ and -920ppm/$^{\circ}C$ respectively. The film containing 15 mol % of nickel oxide and formed at 50$0^{\circ}C$ has shown its sheet resistivity and temperature coefficient 0.7 K ohm/$\textrm{cm}^2$ and -940ppm/$^{\circ}C$ respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.12
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• pp.996-1003
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• 2002

Heat transfer characteristics were investigated for the falling film flowing down the outside of an electrically heated vertical tube. Water was used for the falling film, and its Reynolds number was varied in the range of 70～500. Because water is heated and evaporated as it flows down, both sensible and latent heat transfer should be considered. The effect of the surrounding air movement was investigated by changing the direction of the air injection; without air injection, parallel-flow, and counter-flow. For all cases, sensible teat transfer rate was almost linearly increased with the increasing film flow rate. It was found that the film heat transfer coefficient was hardly influenced by the parallel air flow. However, the counter-flow of air reduced the heat transfer coefficient, which might be caused by the uneven distribution or flooding of the film. At high heat flux, a sudden change of the film heat transfer coefficient was detected as the film flow rate reached the transition value. It is supposed that this phenomenon was caused by the change in the film flow pattern.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.351-352
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• 2006

BSCCO thin films are fabricated by an ion beam sputtering method, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element in BSCCO film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about $730^{\circ}C$ and decreased linearly over about $730^{\circ}C$. In contrast, Sr and Ca, displayed no such remarkable temperature dependence. This behavior of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of $Bi_2O_3$. It was concluded that Bi(2212) thin film constructs from the partial melted Bi(2201) phase with the aid of the liquid phase of $Bi_2O_3$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.11
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• pp.997-1002
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• 2002

BSCCO thin films are fabricated by an ion beam sputtering method, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element in BSCCO film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about 730$^{\circ}C$ and decreased linearly over about 730$^{\circ}C$ In contrast, Sr and Ca, displayed no such remarkable temperature dependence. This behavior of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of Bi$\sub$2/O$\sub$3/. It was concluded that Bi(2212) thin film constructs from the partial melted Bi(2201) phase with the aid of the liquid phase of Bi$\sub$2/O$\sub$3/.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.252-255
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• 2002

BSCCO thin films are fabricated by an ion beam sputtering method, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element in BSCCO film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about $730^{\circ}C$ and decreased linearly over about $730^{\circ}C$. In contrast, Sr and Ca, displayed no such remarkable temperature dependence. This behavior of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of $Bi_{2}O_{3}$. It was concluded that Bi(2212) thin film constructs from the partial melted Bi(2201) phase with the aid of the liquid phase of $Bi_{2}O_{3}$.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.368-376
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• 2003

In this research, DLC thin films are produced as several hundred nm thickness by PE-CVD method. And then these thin films are estimated tribological characteristics to find out useful possibilities as a protecting film for high-quality function and life extension at MEMs by mechanical properties observation . These are measured thickness and residual stress of DLC coating. Compared after measuring friction coefficient, adhesion force, hardness, cohesive force of coating films. As results all test, we can decide several conclusions. First, friction coefficient decreased, as the load increased. otherwise, friction coefficient increased, as thickness of coating film increased under low load$(1\~50mN)$. Secod, adhesion force increased as thickness of coating films. Third, hardness of coating film is affected by substrate coating film when it is less than thickness of 300nm and it has general hardness of DLC coating film when it is more than thickness of 500nm. Fourth, cohesive force of coating film is complexly affected by hardness, adhesion force, residual stress, etc.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.8-15
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• 2018

Films with special properties (e.g., water-repellent films, optical films, anti-reflection films, and flexible films) are referred to as functional films. Recently, there has been interest in fine patterning methods for film fabrication. In particular there have been many studies that use a UV nanoimprint process involving a UV curing method. In this paper, a polymer film was fabricated by the UV nanoimprint process with a micro-pattern, and its durability was evaluated by a wear test and a nano-indentation test. The film mechanical properties (such as coefficient of friction, hardness, and modulus of elasticity) were measured. Moreover, the choice of PUA type resin used in the UV nanoimprint process was confirmed to impact the durability of the thin film. Despite making the polymer film samples using the same method and PUA type resin, different coefficient of friction, hardness, and modulus of elasticity values were obtained. PUA 4 resin had the most favorable coefficient of friction, hardness, and modulus of elasticity. This material is predicted to produce a high durability functional film.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.8
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• pp.1122-1130
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• 2001

Film cooling performance from two rows of holes with opposite orientation angles is evaluated in terms of heat flux ratio. The film cooling hole has a fixed inclination angle of 35°and orientation angle of 45°for the downstream row and -45°for the upstream row. Four film cooling hole arrangements including inline and staggered configurations are investigated. The blowing ratio studied was 1.0. Boundary layer temperature distributions are measured to investigate injectant behaviors and mixing characteristics. Detailed distributions of the adiabatic film cooling effectiveness and the heat transfer coefficient are measured using TLC(Thermochromic Liquid Crystal). For the inline configuration, there forms a downwash flow at the downstream hole exit to make the injectant well attach to the wall, which gives high adiabatic film cooling effectiveness and heat transfer coefficient. The evaluation of heat flux ratio shows that the inline configuration gives better film cooling performance with the help of the downwash flow at the downstream hole exits.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.4
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• pp.185-189
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• 2004

The temporal variation of a secondary electron emission coefficient (${\gamma}$ coefficient) of hydrogenated amorphous silicon (a-Si:H) was investigated in a dc silane plasma. Estimated ${\gamma}$ coefficients have a value of 2.73 ${\times}$ 10$^{-2}$ on the pure aluminum electrode and 1.5 ${\times}$ 10$^{-3}$ after 2 hours deposition of -Si:H thin films on a cathode. It showed an abrupt decrease for about 30 minutes before saturation. The variation of the ${\gamma}$ coefficient was estimated as a function of the thin film thickness, and the film thickness was about 80 nm after 30 minutes deposition time. These results are compared with the results of a computer simulation for ion penetration into a cathode.

• The Korean Journal of Ceramics
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• v.5 no.4
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• pp.409-413
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• 1999

A two-beam polarization (TBP) interfermeter with a reflection configuration for measuring the linear electroptic coefficient is described and investigated experimentally and theoretically. It is shown that a TBP interferometer can be used for measuring the Pockels coefficient of thin film with a strong Fabry-Perot effect. The TBP interferometer technique is used to measure the effective differential linear electro-optic coefficient $re=r_{33}-(n_0/n_0)^3r_{13}$of lead zirconate titanate (PZT) thin film. The results are in agreement with known data.