• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.27-34
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• 2001

A new functionally gradient metal coating method using an atomic mixing technique was developed. In this work the effect of silver atomic mixing on the tribological characteristics of silver$.$ films. has been investigated experimentally. Atomic mixing was implemented by using the, bombardment .of accelerated Ar ions during the thermal evaporation coating process of silver films. Experiments were performed in dry conditions using a ball-on-disk test rig at a load range of 19.6 mN - 17.64 N and a sliding velocity of 20 mm/sec. Results showed that the life of functionally gradient silver coating was enhanced about 100 times more than that of thermally evaporated silver coating and 2 times more than that of IBAD silver coating. The functionally gradient. film also showed low friction and wear compared to those of the evaporated silver and

• Journal of Powder Materials
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• v.7 no.1
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• pp.6-11
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• 2000

Two kinds of Bi2Te3 powders, pure Bi2Te3/2vol.%ZrO2, have been prepared by a mechanical grinding process process. Effect of mixing of the powders on thermoelectric of the sintered body has been investigated by measuring Seebeck Coeffcient, specific electric resistivity and thermal conductivity. With an increase in the weight fraction of the Bi2Te3/2vol.%ZrO2 powder from 0 to 40wt.%. Especially, the figure of merit of the mixedBi2Te3 sintered body increases and thereafter dedreases above 40wt.%. Especially. the figure of merit of the mixed Bi2Te3 sintered bodies with mixing of Bi2Te3/2vol.%ZrO2 powder increased about 1.3time in comparison with the value of the specimen before mixing. Mixing of two kinds of Bi2Te3 powders which have different theramal and electric propertries with each other seemed to be useful methob to increase the figure of merit of Bi2Te3 sintered body.

• Korean Journal of Optics and Photonics
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• v.10 no.4
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• pp.294-300
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• 1999

The density matrix is solved more rigorously, compared with the third-order pertubation method used in the conventional theory, for a semiconductor laser amplifier. Then the coupled wave equations are derived to explain the wavelength conversion due to the spectral hole burning in the semiconductor optical amplifier. It is shown that our results can explain the effect of saturation of the population density on the electric polarization, which affects the four-wave mixing and wavelength conversion, better than the conventional theroy where the third-order pertubation is used.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.74-78
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• 2003

In this paper, we studied, by numerical calculation, a system, which was composed of metal-film and metal-substrate irradiated by IPIB with beam ion energy 250 keV, current density 10 to 250 A/$\textrm{cm}^2$. While the IPIB irradiation was going on, an induced effect named mixing occurred. In this case, metal-film and part of metal-substrate melted and mixed. The mixing state was kept as it was in melting phase due to the fast cooling rate. Our works were simulating the heating and cooling process via our STEIPIB program and tried to find proper parameters for a specific film-substrate system, 500 nmtitanium film coated on aluminum, to get best mixing results. The parameters calculated for such Ti-Al system were compared with the experimental results and were in good accordance to the experimental results.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.231-237
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• 2003

A numerical study has been conducted to investigate the effect of an inlet flow pulsation on mixing of two solutions with different concentrations in a micro conduit. We treat an unsteady, incompressible and two-dimensional flow through a micro conduit by adopting the momentum equations with the electrostatic force due to streaming current and the concentration equation. The feasibility of the inlet flow pulsation to enhance the mixing process inside the micro conduit is carefully examined by varying the inlet pulsation frequency. When a low-frequency pulsation is induced at the inlet, the interface between two solutions with different concentrations becomes wavy, which results in mixing enhancement. As the pulsation frequency increases, the waviness of the interface becomes meager, and the concentration gradients at the interface approach the value for the non-pulsating steady flow.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.275-281
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• 2005

In this work, Scalar Passive code in Lattice Boltzmann Method was employed to simulate mixing performance of Passive mixer in a micro-channel. It physically analyzed stream line and Pressure drop for passive mixer in a micro-channel. The flow characteristics in a micro-channel was a function of Peclet number. The results indicated that the size of static element was more effect on the mixing than the number of static element and the distance of static elements.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.53-56
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• 2004

The mixing characteristics of a multiple transverse injection system in a scramjet combustor were studied with numerical methods. The distance among injectors on mixing characteristics were investigated. The three-dimensional Wavier-Stokes equations including k-w SST turbulence model were solved. It was shown that the mixing characteristics of a multiple transverse injection system were very different from those of a single and a dual injection system; the rear injection flow was strongly influenced by blocking effect due to the momentum flux of the front injection flow and thus had higher expansion and penetration than the front injection flow. The multiple injection system had higher mixing rate, higher penetration but had more losses of stagnation pressure than the single injection system.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.1-4
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• 1993

This is the study on the feature of mixing method of high strength flowing concrete using the superplasticizing agent which is used to aim considerable reduction effect of water contents in the same level of consistency and workability. It is the aim of this study to compare workability and engineering properties of high strength flowing concrete according to mixing order of materials and the addition time and method of superplssticizing agent.

• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.235-239
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• 1998

Ultrafine $SnO_2$ powder was prepared by the diffusion mixing gas-phase reaction of $SnCl_4$(g) and water vapor. The effects of reaction variables, such as the chloride partial pressure, the reaction temperature, and the residence time is the reactor, on the powder size were examined systematically. Calculated concentration and distribution of chemical species, using the Burke-Schumann diffusion mixing model, were compared with the experimetal results. The effects of the reaction variables on the powder size were also discussed qualitatively.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.582-587
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• 1999

This study has been done to investigate the characteristics of synthetic fiber reinforcement sol with fully satruated . To this end, consolidated undrained triaxial test was performed on synthetic fiber reinforcement soil using the soft clay and plypropylene fiber . From the results of test, it was formed that the mixing ratio for weight and the aspect ratio of synthetic fiber have an effect on the shear characteristic of synthetic fiber rinforcement soil. Especially shear paramter C has line relationship for mixing ratio of fiber, and øhas parabolic relationship for mixing ratio of fiber.