• Korean Chemical Engineering Research
• /
• v.54 no.2
• /
• pp.145-151
• /
• 2016

In response to the cavitation caused by the partial vacuum caused by the fluid flow, a paint was developed by dispersing the lamella-shaped glass-flake in resin for anti-cavitation. This composite paint was developed by using the inorganic filler (lamella shaped glass-flake) and the NBR (Acrylonitrile-butadiene rubber) which was modified epoxy resin. Especially, the glass-flake was a thin film with a thickness of about 100~200 nm and length of about $20{\sim}30{\mu}m$, the aspect ratio was about 200 to 300 times that of the plate-shaped. So the paint for anti-cavitation have shown excellent performance in corrosion resistance. The results of evaluating anti-cavitation performance was below, tensile strength $4.8{\sim}6N/mm^2$ or more, rupture elongation 30% or higher, abrasive speed $10mm^2/h$ or less. In particular, it showed more than twice the superior performance compared to existing advanced foreign products in anti-cavitation performance evaluation.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.2
• /
• pp.123-127
• /
• 2020

This paper reports four species of Erebidae from the southern part of Korea: two Boletobiinae, Honeyania ragusana (Freyer, 1845), Enispa masuii Sugi, 1982, one Hermininae, Adrapsa ablualis Walker, 1859, and one Arctiinae, Stictane rectilinea (Snellen, 1879). Honeyania ragusana can be distinguished by the following: a blackish dot on the apex of the forewing with strongly curved medial lines, a long slender uncus and a strongly distally bifurcated valva with a large distally expanded costa and a thumb-shaped process of sacculus on the male genitalia as well as a sclerotized antrum, strongly tapered ductus bursae, and large corpus bursae on the female genitalia. Enispa masuii, a lichen feeder, can be distinguished by the whitish medial lines of the grayish fore- and hindwings, and a pair of rounded ball-shaped lamella antevaginalis, long, sclerotized ductus bursae, and pear-shaped corpus bursae without signum of the female genitalia. Adrapsa ablualis can be distinguished by the whitish medial lines of the fore- and hindwings and large medial process of the costa and dentate distal margin of the valva of the male genitalia. Stictane rectilinea can be distinguished by the broad dark grayish medial band of the forewing and the long knife-shaped valva with a strongly hooked process on the distal part of the sacculus of the male genitalia.

• Korean Journal of Materials Research
• /
• v.26 no.6
• /
• pp.320-324
• /
• 2016

Porous SiC beads were prepared by freeze-drying a polycarbosilane (PCS) emulsion. The water-in-oil (w/o) emulsion, which was composed of water, PCS dissolved p-xylene, and sodium xylenesulfonate (SXS) as an emulsifier, was frozen by dropping it onto a liquid $N_2$ bath; this process resulted in 1~2 mm sized beads. Beads were cured at $200^{\circ}C$ for 1 h in air and heat-treated at $800^{\circ}C$ and $1400^{\circ}C$ for 1 h in an Ar gas flow. Two types of pores, lamella-shaped and spherical pores, were observed. Lamellar-shaped pores were found to develop during the freezing of the xylene solvent. Water droplets in the w/o emulsion were changed into spherical pores under freeze-drying. At $1400^{\circ}C$ of heat-treatment, porous SiC was synthesized with a low level of impurities.

• Korean Journal of Crystallography
• /
• v.3 no.2
• /
• pp.120-128
• /
• 1992

Single crysals of BaTiO3 were grown by TSSG technique at various cooling rates. Morpolo girts, defects and domain structures of the grown crystals were investigated. At the cooling rates below 0.5℃/hr, equant single crystals were obtained and the 11111 faces were dominantly developed. If the cooling rate was much faster or if the vortical temperature gradient in the so lotion was very large, the solution became unstable and the needle formed BasTil04 o crystals were precipitated. Two sets of parallel lamella domains are arranged perpendicular to each other and the irregularly shaped boundaries are fixed between them. These sets of domains show remarkable orientation contrast in x-ray topography. Heating the crystal above 127℃, the phase transition from tetragonal to cubic occurs. The phase transition front (PTF) moves in the direction of temperature gradient. Domains in the tetragonal phase are successively rearranged and regular strain patterns appear in the cubic phase. The habit plane of PTF in BaTi03 is found to deviate from a l1101 lattice plane by app roximately 9°.

• Journal of fish pathology
• /
• v.18 no.2
• /
• pp.125-131
• /
• 2005

Amoebic gill disease of flounder, Paralichthys olivaceus was diagnosed at commerical culture facility in South Korea. The amoeba was identified as a species of the genus Neoparamoeba based on the morpholgical characteristics of trophozoites. Transmisson electron microscopy revealed the presence of a symbiotic organism, parasome in the cytoplasm and dense glycocalyx on the surface of the trophozoites. They lacked the boat-shaped microscales on the surface and contained numerous vacuoles and channels, mitochondria in the cytoplasm. Colonization of amoebae on gill tissue elicited extensive fusion and hyperplasia of gill lamella.

• Korean Journal of Plant Taxonomy
• /
• v.43 no.3
• /
• pp.161-164
• /
• 2013

Neottia japonica (Blume) Szlach. (Orchidaceae), previously known to be native in southern part of Japan and Taiwan, was found in Seogwipo-si, Jeju-do, Korea. This species is distinguished from the related taxa of Neottia pinetorum (Lindle.) Szlach and N. nipponica (Makino) Szlach. by smaller plant, lip with T-shaped lamella and auricles embracing column, and flowering in the spring. The local name was given as "A-gi-ssangnip-nan-cho" based on the cuter and smaller plant than N. pinetorum. The description and illustrations of the species on morphological characters, voucher specimens, and photograph at the habitat are provided.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.27 no.1
• /
• pp.209-217
• /
• 2013

The objective of this study was to evaluate the bone regeneration capability of silk membrane plus 3% 4-hexylresorcinol (3% 4-HR plus SM) in a rabbit calvarial defect model. Twenty New Zealand white rabbits were used in this study. Bilateral round shaped defects were created in the parietal bone (diameter: 8.0 mm). And the defects were covered with (1) 3% 4-HR plus SM, (2) collagen membrane (CM), (3) no graft material. After surgery, the animals were sacrificed at 4 weeks and 8 weeks. Bone regeneration was analyzed in each section by micro-computerized tomography (${\mu}$-CT). And Hematoxylin and eosin stains were used for histological analysis. As measured by ${\mu}$-CT analysis 4 weeks after surgery, the average of new bone formation in animals treated with 3% 4-HR plus SM was greater than that of animals treated with CM. and the difference was statistically significant. And well organized lamella bones were observed in the histological view of the 3% 4-HR plus SM group. Therefore, more bone regeneration was seen in animals treated with 3% 4-HR plus SM than in those treated with CM or uncovered control.

• Journal of the Korean Society of Costume
• /
• v.62 no.4
• /
• pp.32-45
• /
• 2012

The purpose of this research is to better understand the Dongmyo, the Eastern Shrine of GuanYu and the military costumes of the Joseon period andto develop different cultural contents. By studying relevant literature, confirmations were made about the various types of costumes and their historical changes. During the reign of King Yeongjo, the ceremonial conductors often wore armors, and the king wore a different military costume. During the reign of King Jeongjo thereafter, the ceremonial costumes were codified in the book, the Chun-gwan tonggo(General Outline for the Ministry of Rites), along with the costumes for the musicians and lower officials. However, the military features were weakened in the late Imperial Joseon years. In terms of costumes, it would be best today to restore the ceremonies of the Shrine of Guan Yu during the period of King Jeongjo. All the costumes for different figures of the Shrine are clearly confirmed, and by emphasizing the main features of the ceremonials of the Shrine, it is possible to differentiate the ceremony from other restoration activities in Korea. For the Guan Yu statue, the hat is square shaped and decorated with nine bead strings, it is dressed with a red dragon coat and a violet inner coat. This study presents methods for the restorations of the original costumes for the individual figures of the ceremonials, with necessary theoretical explanations. The king wears the lamella gold armor, while different ceremonial officials wear differentiated armors according to their different ranks. All the civil and military officials who attend the ceremony wear military clothes with horse's mane hats and swords. The musical conductor and directors are expected in armors and participating musicians also have to wear armors according to the Akhak Gwebeom (Basics of Music).

• Journal of the Mineralogical Society of Korea
• /
• v.15 no.3
• /
• pp.147-159
• /
• 2002

Weathered bentonites occcur as surficial alterations of some domestic bentonite deposits in the Tertiary formations, with the thickness of less than about 50 cm, along naturally-formed weathering surface with slopping in gentle. 7 $\AA$-halloysite was found together with montmorillonite in the weathered bentonite. Compared to normal bentonite, the weathered one is generally more clay-rich and contains little amounts of original rock-forming minerals and residues. In the electron microscopy, fine-scale occurrence of the clay minerals tends to be somewhat discrete and segregated rather than closely associated. h curled margin of montmorillonite lamella is deformed to become obtuse in the weathered bentonite. Halloysite occurs as acicular to tubular crystals with the length of less than 2 $\mu$m and the width of about 0.3 $\mu$m, which commonly forms bundle-shaped aggregates. Electron microscopic observations on the fine-scale occurrence and texture of the wtathered bentonites indicate that the clay mineral transition from montmorillonite to halloysite has undergone without accompanying any intermediate phases of both clay minerals such as a mixed-layered type (M/H). The alteration reaction between these two clay minerals probably took place in the form of dissolution and precipitation mechanism in oxidation condition. An intense chemical leaching of SiO$_2$, Na, K and Ca might occur during the alteration reaction, forming a lot of dissolution cavity and residual concentration of A1$_2$O$_3$ and Fe, relatively. As the result of the chemical change, a fsvorable condition for halloysite formation seemed to be provided.

• Korean Journal Plant Pathology
• /
• v.2 no.1
• /
• pp.1-11
• /
• 1986

Negatively stained dip preparations from Euonymus showing vein clear symptoms revealed bacilliform particles. The particles tentatively referred to as the Euonymus vein clear virus(EVCV) have a relatively complex structure, measuring 230-280nm in length and 70-80nm in diameter. They have an envelope, 8-10nm thick, provided with evenly spaced beadlike projection about 5-6nm long. The inner tubular core which had no envelope showed helical structures, 200-220nm long, and 50-55nm in diameter. This inner tubular core is interpreted as the virus nucleocapsid. A striking association of virus particles with the nuclei of infected cells was apparent from sections which showed numberous virus particles at the nuclear periphery and in what appeared to be intranuclear virus particle inclusions. Careful examination of these apparent inclusions revealed the presence of the nuclear envelope surrounding them, in addition to cytoplasmic organelles within them. Such profiles were interpreted as having arisen when the sections passed through invaginations of the cytoplasm into the nucleus. In all the sections showing virus particles associated with the nucleus, large number of virus particles were found to be present in expanded areas between the two lamellae of the nuclear envelope. This location is suggested as a possible site of virus assembly. Serveal micrographs of particles found in this location suggested incorporation of the inner lamella of the nuclear envelope into the viral envelope. Various micrographs indicated a possible helical arrangement of certain components present in the virus core.