• Journal of the Speleological Society of Korea
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• no.61
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• pp.17-46
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• 2000

Mt. Jabyeong(872.5m), limestone region in the Taebaek mountains, located in 37° 32'N, 129° 25'E and in Sangye-ri, Okgye-myeon, Gangreung-si and Samok-ri, Imgye-myeon, Jeongseon-gun, Gangwon-do. The purposes of this study were to investigate the floristic composition from 1997 to 1998 in Mt. Jabyeong and report the distribution of Korean endemic plants, rare and vulnerable plants, calcicoles and calci fuges, The vascular plants in this area were composed of 93 families, 313 genera, 3 subspecies, 57 varieties, 13 forms, 495 species, totaling 568 taxa. Among the vascular plants, 21 taxa were Korean endemic plants and 7 taxa were rare and vulnerable plants. Calcicole and calcifuge plants in this study area were composed of 21 families, 30 genera, 36 species and 14 families, 15 genera, 17 species. The soil pH values of study site in Mt. chabyoung were ranging 7.4∼8, which showed that this site was a mostly limestone area with alkaline soil. And soil depth was formed to a relative thin layer, mostly 2～4cm thickness. This site showed high content of moisture and organic matter which were ranging 40-45% and 15-25%, respectively.

• Animal cells and systems
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• v.2 no.3
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• pp.389-393
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• 1998

We localized a calcium-binding protein, calretinin, in the superior colliculus of the mouse and studied the distribution and effect of eye enucleation on the distribution of this protein. Calretinin was localized with immunocyto-chemistry. A dense plexus of anti-calretinin-labeled fibers was found within the superficial layers. The highest density was found in the deep superficial gray layer. Monocular enucleation produced an almost complete reduction of calretinin-immunoreactive fibers in the superficial layers of the superior colliculus contralateral to the enucleation. Furthermore, many calretinin-labeled cells appeared in the contralateral superior colliculus. These newly appeared neurons had small oval or round cell bodies. The results demonstrate that calretinin identify unique neuronal sublaminar organizations in the superior colliculus of the mouse. They also suggest that the retinal projection may control in part the content of calretinin in some neurons in the superficial layers of the mouse superior colliculus.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.133-137
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• 2006

Wheat gluten-chitosan composite film (WGCCF) can prevent moisture migration and enhance the antimicrobial properties of gluten in intermediate-moisture foods like sandwiches. To mimic the structure of actual sandwich-type products we developed multi-layer food models, where moisture content and water activity differ. Water activity gradients direct moisture migration and therefore determine product characteristics and product stability. A 10% wheat gluten film-forming solution was mixed with chitosan film-forming solution (0-3%, w/w) and evaporated to generate WGCCF. Addition of 3% chitosan enhanced the mechanical properties of the film composite, lowered its water vapor permeability, and improved its ability to protect against both, Streptococcus faecalis and Escherichia coli, in a 24 hr sandwich test (reduction of 1.3 and 2.7 log cycles, respectively, compared to controls). Best barrier and antimicrobial performance was found for 3% chitosan WGCCF at pH 5.1. Film of this type may find application as barrier film for intermediate-moisture foods.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1097-1098
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• 2006

The Powder characteristics and sintering behavior of $SiO_2$ coated $BaTiO_3$ were studied. Silica coated $BaTiO_3$ powders were prepared by sol-gel method. The particle size of the $BaTiO_3$ powders were $\sim35$ nm and the thickness of the $SiO_2$ coating layer was $\sim5$ nm. As the $SiO_2$ content increased, the $SiO_2$ layers improved the powder dispersion. The Zeta potential of $SiO_2$ coated $BaTiO_3$ was getting close to that of pure silica with a more negative charge, compared with that of the uncoated $BaTiO_3$. The onset temperature of shrinkage curves shifted to higher temperatures with increasing $SiO_2$ contents

• Journal of Surface Science and Engineering
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• v.31 no.2
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• pp.101-108
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• 1998

The effect of oxidation-reduction heating conditions on coating adherence of hot-dip galvanized steel containing silicon has beeninvestigated. The presence of a stbke sillicon oxide formed on the steel surface has been shown to be very detrimenal to proper wetting by liquid zinc. When the steel has more than the critical sillicon content neeled to from a stable external oxide, the use of oxidation-reduction method has been found successful in obtaining a good quality, coated product with excellence adhreence. This can be explained by the formation of an iron oxide. The iron oxrtion of the scale is reduced, leaving the stable oxides dispersed in a fresh metallic iron surface layer. This reduced iron surface is easily wetted by the liquid zinc and excellent adherence is obtained.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1785-1787
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• 2000

This paper present the result of the investigation, the electric properties of insulators due to non-soluble contamination. In general, the humidity and the amount of soluble salts such as NaCl, $MgCl_2$ are the most dominant factor. Though the non-soluble do not distribute on conductivity of contaminant layer, that has the hygroscopic property. For this study, we make a mini-fog chamber with transparent acryl and the kaoline was used for non-soluble contaminant. The kaoline was applied with sprayer to get the specific ESDD and NSDD value, then the specimen was dried and installed horizontally. And to measure the leakage current a DAS system was developed with LabView. With the result, we could know the influence of non-soluble content and the relationship between NSDD and ESDD.

• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.957-960
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• 2003

A method of preparation of magnetite nanoparticles in ordered systems, as in vesicle and microemulsion, consisting of soybean lecithin and water has been introduced. The size of magnetite grain was controlled by the content of soybean lecithin and size of liposomes in the systems. It was found by experiment that magnetite nanoparticles were formed inside the double layer vesicles. The magnetite nanoparticles were separated by magnetic separation and centrifugation and the dispersion of the magnetite nanoparticles prepared at 10% (w/w) soybean lecithin was particularly stable. The formation of pure magnetite nanoparticles was confirmed by analyses of XRD and electron diffraction pattern.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.09a
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• pp.85-90
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• 1998

Reactive ion etching (RIE) of Ta-Al alloy thin film and SiO2 thin films was observed during the etching with the CF4 gas and the could be used effectively to etch the Ta-Al alloy thin film. The etching rate of the thin film at a Ta content of 50 mol% was about 67$\AA$/min. No selectivity between the Ta-Al alloy thin film and SiO2 thin films was observed during the etching with the CF4 gas and the etching rate of the SiO2 layer was 12 times faster than that of the Ta-Al alloy thin film. In addition, it was observed that photoresist of AZ5214 was more useful than Shiepley 1400-2 in RIE with the CF4 gas.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.483-491
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• 1992

Plasma silicon oxynitride film has been applied as a final passivation layer for semiconductor devices, because it has high resistance to humidity and prevents from alkali ion's penetration, and has low film stress. Structure properties of plasma silicon oxynitride film have been studied experimentally by the use of FT-IR, AES, stress gauge and ellipsometry. In this experiment,Si-N bonds increase as NS12TO/(NS12TO+NHS13T) gas ratio increases. Peaks of Si-N bond, Si-H bond and N-H bond were shifted to high wavenumber according to NS12TO/(NS12TO+NHS13T) gas ratio increase. Absorption peaks of Si-H bond were decreased by furnace anneal at 90$0^{\circ}C$. The atomic composition of film represents that oxygen atoms increase as NS12TO/(NS12TO+NHS13T) gas ratio increases, to the contrary, nitrogen atoms decrease.

• International Journal of Safety
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• v.8 no.2
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• pp.20-25
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• 2009

In this study, an experiment in the field was performed to analyze the mechanical properties and the influence of steel fiber and silica fume on the rebound ratios of shotcrete. The experimental parameters which are the reinforcing methods (steel fiber, wire mesh), steel fiber contents (0.0%, 0.5%, 0.75%, 1.0%), silica fume contents (0.0%, 10.0%), layer thickness (60 mm, 80 mm, 100 mm), and the placing parts (sidewall, shoulder, crown) were chosen. From the mechanical test, it was found that the flexural strength and toughness is significantly improved by the steel fiber and/or silica fume. According to the results for the side wall in this test, the larger the fiber contents are in case of steel fiber reinforced shotcrete, the less the rebound ratios are within the range of 20-35%, compared to the wire mesh reinforced shotcrte. And also, the reduced rebound ratios were very larger in using steel fiber reinforced shotcrete with silica fume content of 10%, and these results are true of the shoulder and the crown. respectively.