• Journal of Magnetics
• /
• v.16 no.4
• /
• pp.403-407
• /
• 2011

Metal-insulator type, nano-granular soft magnetic films have been reviewed from the viewpoint of high frequency magnetic materials. The formation of nano-granular structure is related to the magnitude of heat of formation of intergranule materials. Variation of the ratio of granule phase to intergranule phase in the film is found to produce various characteristics in the magnetic properties of the film. The HRTEM observation reveals that neighboring granules in the film with above 60 at.% Co, contact at considerable points and the films show soft magnetic properties which are explainable in terms of the random anisotropy model for nano-crystalline materials. Addition of Ni group elements in Co-O based films enhances their anisotropy field up to 400 Oe and they exhibit excellent frequency response of permeability. Also, large electromagnetic noise suppression effect is demonstrated as one of their potential applications.

• Mycobiology
• /
• v.37 no.3
• /
• pp.243-246
• /
• 2009

In this study, the antifungal activities of limonene against Trichophyton rubrum were evaluated via broth microdilution and vapor contact assays. In both assays, limonene was shown to exert a potent antifungal effect against T. rubrum. The volatile vapor of limonene at concentrations above $1{\mu}l$/800 ml air space strongly inhibited the growth of T. rubrum. The MIC value was 0.5% v/v in the broth microdilution assay. The antifungal activity of limonene against T. rubrum was characterized as a fungicidal effect.

• Journal of Ginseng Research
• /
• v.30 no.3
• /
• pp.95-99
• /
• 2006

When the inhibitory effect of ginsenoside (G) Re isolated from ginseng and its metabolites G-Rg1, G-F1, G-Rh1 and protopanaxatriol in mouse ear skin psoriasis stimulated by oxazolone was investigated, G-Re and its metabolites suppressed mouse ear swelling stimulated by oxazolone. Among these agents tested, G-Rh1 most potently suppressed ear swelling as well as mRNA expression of COX-2 and proinflammatory cytokines $IL-1{\beta},\;TNF-{\alpha}$ and $interferon-{\gamma}$. These findings suggest that G-Rh1 may improve chronic dermatitis and psoriasis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.84-86
• /
• 2007

Aluminum sheets were asymmetrically cold rolled without lubrication by using different roll velocities of upper and lower rolls in order to intensify the shear deformation. During asymmetrical cold rolling of aluminum sheets, a reduction per a rolling pass, initial sheet thickness, roll diameter, roll velocity ratio were varied to investigate the effect of rolling parameters. The formation of through thickness shear texture was related to the ratio of the contact length between the roll and sample($l_c$) to the sheet thickness(d). The strain states associated with asymmetrical rolling were investigated by the finite element method (FEM) simulation. FEM results indicated that the evolution of deformation texture in a thickness layer is strongly governed by integrated values of strain rates $\dot{\varepsilon}_{13}$ and $\dot{\varepsilon}_{11}$ along the streamline in the roll gap.

• Journal of the Korean Society for Railway
• /
• v.9 no.1 s.32
• /
• pp.18-22
• /
• 2006

The dynamic characteristics of the current collection system are investigated by conducting a test run in which signals from accelerometers and load cells attached to the various parts of the pantograph are analyzed in both the time and frequency domains. The dynamic characteristics of the current collection system are found to be strongly influenced by the train speed; the fluctuation in the pantograph motion increases in direct proportion to the train speed. There exist two major fequency components in the pantograph motion related to the current collection, a speed-dependent component arising from the train traversing a span of the catenary, and a speed-independent component related to the pantograph resonant frequency. The train acceleration is also found to exert strong influence on the current collection system characteristics. The effect of the train motion is found to be stronger on the speed-dependent frequency component than on the speed-independent one.

• Journal of Ocean Engineering and Technology
• /
• v.14 no.4
• /
• pp.62-97
• /
• 2000

Recently the research for utilization of waste heat produced from electric power plants, casting factories, heat treating factories or commercial are being afforded by the need for energy saving. The objective of this study is to develop a thermoelectric generation system which unused energy from close-at-hand sources such as garbage incineration heat and industrial exhaust etc. into electricity. This paper a thermoelectric technology on a optimum system design method and efficiency and cost effective thermoelectric element on order to extract the maximum power output from energy conversion of waste energy. It is shown that the longitudinal stresses of module contacted with two point constrained Al tubes could be released more than those with a one-point constrained.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.721-728
• /
• 2008

Top-Base Method is a stabilization method for light weight structures particularly in the soft ground. It is widely used for the increment of bearing capacity and the effect of restraining settlement when the bearing capacity of the ground is not enough. Top-shaped cone concrete foundations are installed in graveled laid over soft ground. The principle of the basic method is to maximize effect of dispersing the overburden pressure by increasing the contact area of the top-shaped cone. Therefore, the bearing capacity is increased and the settlement is decreased by the embedded resistance of pile part in the ground. In this paper, the plate bearing test was conducted to evaluate the feasibility of Top-Base foundation. Based on the test results, the coefficient of subgrade reaction, elastic modulus, and settlement of foundation on reclaimed land was derived.

• Archives of Pharmacal Research
• /
• v.29 no.8
• /
• pp.685-690
• /
• 2006

The effect of a main constituent ginsenoside Rg5 isolated from red ginseng and its metabolite ginsenoside Rh3 in a chronic dermatitis model was investigated. Ginsenosides Rg5 and Rh3 suppressed swelling of oxazolone-induced mouse ear contact dermatitis. These ginsenosides also reduced mRNA expressions of cyclooxygenase-2, interleukin $(IL)-1{\beta}$, tumor necrosis factor $(TNF)-{\alpha}$ and interferon $(IFN)-{\gamma}$. The inhibition of ginsenoside Rh3 was more potent than that of ginsenoside Rg5. These findings suggest that ginsenoside Rh3 metabolized from ginsenoside Rg5 may improve chronic dermatitis or psoriasis by the regulation of $IL-1{\beta}$ and $TNF-{\alpha}$ produced by macrophage cells and of $IFN-{\gamma}$ produced by Th cells.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.421-425
• /
• 2013

The effect of pretreatment on indium-tin oxide (ITO) electrodes has been rarely studied, although that on metal and carbon electrodes has been enormously done. The electrochemical and surface properties of ITO electrodes are investigated after 6 different pretreatments. The electrochemical behaviors for oxygen reduction, $Ru(NH_3){_6}^{3+}$ reduction, $Fe(CN){_6}^{3-}$ reduction, and p-hydroquinone oxidation are compared, and the surface roughness, hydrophilicity, and surface chemical composition are also compared. Oxygen reduction, $Fe(CN){_6}^{3-}$ reduction, and p-hydroquinone oxidation are highly affected by the type of the pretreatment, whereas $Ru(NH_3){_6}^{3+}$ reduction is almost independent of it. Interestingly, oxygen reduction is significantly suppressed by the treatment in an HCl solution. The changes in surface roughness and composition are not high after each pretreatment, but the change in contact angle is substantial in some pretreatments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.5
• /
• pp.340-346
• /
• 1998

In this study, we intended to investigate aging effect of polyimide prepared by VDPD(vapor deposition polymerized method). The prepared polymide was treated by the oxygen and argon gas plasma. And we evaluated the polyimide treated by plasma from contact angle, surface leakage current, FT-IR and SEM. We know that the structure of polyimide at surface are changed to amide structure by plasma treating. It seems that strong energy of plasma causes breaking the molecular chin of the polyimide. And surface roughness increases with plasma treating time increased and sequentially the wettability and leakage current increases.