• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.2
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• pp.137-143
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• 2016

The sedimentary environment and sediment were surveyed at the West-Northern site of Chagwi-do nearby Jeju Island for the design of the embedded suction anchor system of 10 MW-class floating wave-offshore wind hybrid power generation system. According to the classification scheme of Chough et al.[2002], the echo type of the seismic profiles using the chirp III was classified. As a results, the center and west-northern area of survey site were proved to be type I-3 where subbottom layer with thickness 5~15 m exists under the flat seafloor. On the other hands, the east-southern area were regarded to be type I-1, I-2 and III-1 where seafloor reflection is much stronger than type I-3. Also, the physical tests (unit weight, moisture content, grain size, liquid limit, specific gravity) were performed with samples taken from 8 fixed locations. It is found that the sand (SP), the sand blended with silt (SM) and the mixture of SP-SM are distributed uniformly on the survey area.

• Journal of the Korean Society for Heat Treatment
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• v.20 no.2
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• pp.84-93
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• 2007

Microstructural changes during tempering at the temperature range of $300^{\circ}C{\sim}700^{\circ}C$ for the nitrogen-permeated STS 410 and 410L martensitic stainless steels has been investigated. After nitrogen permeation at temperature between 1050 and $1150^{\circ}C$, the surface layer appeared fine $Cr_2N$ of square and rod types in the martensite matrices. Hardness of the nitrogen-permeated surface layer represented 680Hv and 625Hv, respectively, for 410 and 410L steels. It is considered that the fine homogeneously dispersive effect of precipitates by nitrogen caused the increased hardness. Due to the counter current effect of carbon from interior to surface during nitrogen diffusion from surface to interior, the 0.1%C alloyed 410 steel showed the low nitrogen content of 0.025% compared with 0.045% of 410L steel at the distance of $100{\mu}m$ from the surface. Tempering of nitrogen-alloyed 410 and 410L showed the maximum hardness at $450^{\circ}C$. This maximum hardness was considered to be the secondary hardening effect of very fine carbide and nitride. The decrease in hardness at $700^{\circ}C$ was the softening effect of the matrix due to the precipitation of many needle-shaped $Cr_2N$ for 410 steel and the precipitation of coarse nitride of $Cr_2N$ in line with the spherical precipitates with directionality for 410L steel. For 410 steel, the corrosion resistance of nitrogen permeated surface in the solution of 1 N $H_2SO_4$ were nearly unchanged, however the superior corrosion resistance was obtained for nitrogen permeated 410L steel compared to the solution annealed condition.

• Korean Journal of Environmental Agriculture
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• v.12 no.3
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• pp.209-218
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• 1993

The behaviour of insectcide ethoprophos (O-ethyl S,S-propyl phosphorodithioate) in soil was investigated. In a laboratory study, the degradation of ethoprophos in soil followed first-order reaction kinetics. The half-life of the insecticide in the soil incubated with 10, 18 and $25^{\circ}C$ was 12.4, 5.5 and 2.5 days, respectively. Arrhenius activation energy was 73.8 KJ/mole. The half-life was 46.4, 17.6 and 6.9 day in the soil with 7, 14 and 19% of soil water content, respectively. The moisture dependence B value in empirical equation was 1.67. The adsorption isotherm for ethoprophos in the soil agreed with freundlich equation. The adsorption distribution coefficient (Kd) was 0.27. In a field study prepared in autumn with undisturbed soil column in a mini-lysimeter system, ethoprophos residues were largely distributed in the top $0{\sim}2cm$ soil layer and moved down to the top 6cm soil layer. Persistence of ethoprophos in field soil was correlated with variation in weather pattern during the period of experiments. The half-life of ethoprophos treated at March and October was about 17 and 5 days, respectively. The ethoprophos woil was degraded up to 90% at 37day after the both treatment. In persistence and mobility of ethoprophos in field soil, the observed data were reasonably corresponded with predicted data by some computer model of pesticide behaviour.

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.205-212
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• 2004

Phosphorus cycle was studied in a deep stratified reservoir in summer monsoon area (Lake Soyang, Korea) by surveying phosphorus input from the watershed and the movement of phosphorus within the reservoir. And the spatial and temporal distribution of phosphorus was modeled with a 2-dimensional water quality model (CE-QUAL-W2), Phosphorus loading was calculated by measuring TP in the main inflowing river (the Soyang River) accounting for 90% of watershed discharge. TP of the Soyang River showed a large daily variation with the flow rate. High phosphorus loading occurred during a few episodic storm runoff laden with suspended sediments and phosphorus. Because storm runoff water on rainy days have lower temperature, it plunges into a depth of same temperature (usually below 20m depth), forming an intermediate turbidity layer with a thickness of 20 ${\sim}$ 30 m. Because of stable thermal stratification in summer the intermediate layer water of high phosphorus content was discharged from the dam through a mid-depth outlet without diffusing into epilimnion. The movement of runoff water within the reservoir, and the subsequent distribution of phosphorus were well simulated by the water quality model showing a good accuracy. The major parameter for the calibration of phosphorus cycle was a settling velocity of detritus, which was calibrated to be 0.75 m ${\cdot}$ $day^{-1}$. It is concluded that the model can be a good simulator of limnological phenomena in reservoirs of summer monsoon area.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.3
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• pp.193-198
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• 2010

Melanin is synthesized by the melanocytes in basal layer of epidermis and distributed over all the layers of skin including corneocytes in stratum corneum, outermost layer of the epidermis. Melanin of corneocytes was stained using Fontana-Masson method and quantified by image analysis. The correlation between melanin contents and skin color value was estimated in the skin of 71 Korean women. Melanin covering area (MCA) showed good correlation with $L^*$ value and $ITA^{\circ}$ (Individual Typology Angle) (r = 0.6049, 0.6651, respectively). MCA can be used as new parameter for skin color study and has potential application for evaluating the efficacy of the skin whitening cosmetics.

• Korean Journal of Plant Resources
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• v.12 no.2
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• pp.125-132
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• 1999

This study has investigated the growing features and vegetation of Acanthopanax chiisanensis and Acanthopanax koreanum in Mt. Jiri and Halla from Sep. 1997 to Aug. 1998. As to Acanthopanax chiisanensis, it occupied surrounding areas of Nogodan in Mt. Jiri of the height of 1,507m, ImgeolyoungJae of 1,300m and the Mt. Halla. of 1,100m of There were rather high constancy degree with Quercus mongolica, Schizandra chinensis, Hydrangen serrate for. acuminata, Acer pseudo-sieboldianum, Dryopteris crassirhizoma, Actaea asiatica, Thalictrum filamentosum, Abies koreana, Arundinella hirta from the sorts. The common species in Mt. Jiri and Halla are Acer pseudo-sieboldianum, Dryopteris crassirhizoma, Callicarpa japonica, Parthenocissus tricuspidata, Acer mono, Ligularia fischeri, Disporum smilacinum, Viola acuminata Aconitum kusnezofii. On the other hand, concerning of Acanthopanax koreanum community, it possessed the small areas of wedo weoltae village in Chejudo. In this area, a liana e.g. Dioscorea tenuipes, Hedera rhombea, Lygodium japonicum, Akebia quinata, Vitis thunbergii, Dunbaria villosa, Trachelospermum asiaticum var. intermedium, Vitis amurensis, Paederia scandens, lives with Pinux thunbergii, Celtis aurantiaca, Mallotus japonicus and so forth in tree layer and subtree layer. There is artificial change no move in the researching sites, Acanthopanax chiixanensis will be transformed into Abies koreana - Acanthopanax chiisanensis community. Soil characteristics showed the high value such as pH 6.56 and conductivity 0.258mmho/cm in Acanthopanax koreanum community of Mt. Jiri, they also indicated digit as follows: the content of organic matter and total nitrogen are from 25.16 through 25.35% and 7.58 through 9.30mg/g respectably. The soil characteristics at Acanthopanax chiisanensis community in Mt. Jiri and Halla, was high as like pH 5.76, conductivity 0.238mmho/cm, total nitrogen 9.30mg/g, total phosphorus 0.126mg/g in Mt. Halla.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.228-242
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• 2016

This research was conducted for understanding the evergreen forest community structure of the Bijin Island. The island was worth of vegetational value because of the representative warm temperate species such as Castanopsis cuspidata was distribute there. According to the results of community classification by TWINSPAN and DCA, the Bijin Island evergreen forest were classified by 9 communities, such as C. cuspidata, C. cuspidata-Pinus thunbergii, Neolitsea sericea-Camellia japonica, Platycarya strobilacea, Quercus serrata-Decidus broad-leaved, Alnus firma, P. thunbergii. Due to the C. cuspidata, N. sericea, Ca. japonica etc. were still dominated at canopy and under-canopy layer, so the evergreen forest will be sustain current conditions for a while if there is no artificial disturbances that were caused by human. Pl. strobilacea community will be expected to replace N. sericea and also Q. serrata-Decidus broad-leaved community will be changing caused by mutual competition. Normally, in the way of the succession process of the warm temperate forest, P. thunbergii will be expect via deciduous broad-leaved to evergreen forest such as Machilus thunbergii, C. cuspidata var. sieboldii, and N. sericea. In case of species diversity index, P. thunbergii comm.(1.2739), Q. serrata-Decidus broad-leaved comm.(1.2325), Decidus broad-leaved comm.(1.1807), and A. firma comm.(1.0854) are relatively high, while C. cuspidata and N. sericea-Ca. japonica that was dominated by evergreen species at canopy layer and P. thunbergii that was damaged by fire are relatively low(0.7380~0.8416). Soil pH was 4.72~6.33, electric conductance was 0.035~0.128dS/m, and content of organic matter was 3.4~17.4%.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.586-590
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• 2009

Horsehair worms (Chordodes koreensis) develop as parasites in the bodies of grasshoppers, crickets, cockroaches, and some beetles. Chordodes koreensis is an accidental parasite of humans, livestock, or pets and poses no public health threat. The male of Chordodes koreensis in the later larval stage from canine vomitus was investigated by the scanning and transmission electron microscopy. In cross sections, the body wall is composed of four components namely epicuticle, cuticle, epidermis, and muscle layers. The parenchymal tissue fills the rest of the body and surrounds the visceral organs such as intestine, and ventral nerve cord but testes were not found. The epicuticle is a thin superficial layer whose surface shows rows of polygonal elevations called areoles. The cuticle has 17 layers of collagenous fibers spirally wound about the long axis of the worm. The section through the cuticle reveals the layers of large fibers cut obliquely lengthwise, alternating with layers of fibers sectioned obliquely crosswise. The layers of large fiber formed a double helix about longitudinal axis of the worm. The epidermis is a single layer. The muscles were interrupted by the nervous lamella in the only midventral portion. The medulla of muscle plate is composed of lightly stained cytoplasm, mitochondria, weakly developed endoplasmic reticulum, and glycogen granules. Between the medulla of a cell and the plasmalemma lies a broad cortical zone of myofilaments. The circular muscles are absent. The characteristic feature of the cytoplasm is that there was no content in peripheral mesenchyme, but was an abundance of large clear vacuoles which give the cytosome a foamy appearance. The nucleus of mesenchyme is not easily identified in our specimens.

• Applied Biological Chemistry
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• v.26 no.1
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• pp.19-27
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• 1983

The lipid and fatty acid compositions of neutral lipid, glycolipid and phospholipid were identified and quantified by thin-layer chromatography and gas chromatography. Main constituents of the neutral lipid were triglyceride, free sterol and esterified sterol in the free lipid, and free fatty acid and monoglyceride in the bound lipid. In the outer part, there existed 25.7% triglyceride in the free lipid and it was not nearly found in the bound lipid. Main constitutents of the glycolipid were digalactosyl diglyceride and esterified steryl glycoside in the free lipid, and digalactosyl diglyceride in the bound lipid. Free lipid didn't contain trigalactosyl diglyceride but bound lipid contained 2.0% of it. Main constituents of the phospholipid were lysophosphatidyl choline, phosphatidyl inositol, phosphatidyl choline, phosphatidyl glycerol and phosphatidyl ethanolamine in the free lipid, and phosphatidyl choline and phosophatidyl inositol in the bound lipid. The predominant fatty acids of three fractions, neutral lipid, glycolipid and phospholipid showed almost the same pattern as that of the total free and bound lipids. The content of palmitic acid was relatively higher in the polar lipids(glyco and phospholipid). Therefore, saturated fatty acid ratio of polar lipid was higher than that of neutral lipid. found lipid contained more saturated fatty acids as compared with the free lipid.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.2
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• pp.65-69
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• 2014

Crystallographic phases of Plasma electrolytic oxidized Al alloy, A1100, A5052, A6061, A6063, A7075, were investigated. Two types of electrolyte $Na_2Si_2O_3$ and Na2P2O7 were also compared. Bipolar pulse, $2000{\mu}sec$ with $400{\mu}sec+420V$ impulse and $300{\mu}sec$ - impulse were applied for 20 min. ${\alpha}-alumina$, ${\gamma}-alumina$, ${\eta}-alumina$, $Al_{4.95}Si_{1.05}O_{9.52}$, and $(Al_{0.9}Cr_{0.1})_2O_3$ were mainly observed. Si, component of electrolyte, were moved into the PEO layer by bipolar pulse. Glassy phase was also observed at the surface of $Na_2Si_2O_3$ electrolyte treated PEO layer, and increased with the Mg content of Al alloy. It is concluded that at first glassy phase was formed by the micro plasma, and the high temperature of plasma turns glassy phase to several crystalline phases. And we could expect that many other crystalline phase could be formed by PEO process.