• Korean Journal of Plant Resources
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• v.10 no.3
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• pp.271-273
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• 1997

This study was carried out to obtain basic envirinmental information of the native area and growth characteristics at different age of Dendropanax morbifera LEV. In the southern Korea. The Dendropanax morbifera LEV. Was grown naturally at Wando, Cheju(Mt. Halla), Yecheon(Kermoon island),Sinan(Hong isand), Jindo(Mt. Chermchill) and Haenam(Mt. Taeroon), all between 30 to 450m above the sea level. The soil characterisitics of the native area had a pH of 5.3 to 5.4 with 8.4 to 9.8% content of organic matter and 18.2 to 21.3% soil moisture. Flowering starting in the middle of July begun when the trees were 6 years old. Six year old trees are 129 cm in stem height, 34 mm in stem diameter,15.4 in number of leaves with petioles 12.9 cm long. Xylem sap can be obtained from over 10 year old trees that grew well and have over 10 cm stems in diameter.

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.330-337
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• 1996

A rf reactive sputter deposition technique was adopted to deposit ferroelectric lead zirconate titanate (PZT) thin films with high rate from a ZrTi alloy target combined with PbO pellets. Deposition characterisitics including the effects of PbO are ratio were discussed. A new deposition mode called the quasi-metallic mode was observed. Perovskite PZT films were prepared at a growth temperature as low as$ 450^{\circ}C$. However, because the target structure is unstable, weproposed a mixture target consisted of Zr, Ti and PbO. Fundamental experiments were investigated using the powder target. Perovskite PZT film could be obtained at $450^{\circ}C$ with better electrical properties also.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.80-86
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• 1995

The bacterial strain WC-17 able to produce chitinase was isolated from soil using an enrichment technique. The isolated strain was identified as Acinetobacter sp. judging by their morphological and physiological characterisitics. The optimal culture conditions for the production of chitinase of Acinetobacter sp. WC -17 are 1.5% colloidal chitin and 1 % tryptone at $30^{\circ}C$ with pH 6.5. Since the enzyme was rapidly produced in a culture supplied with chitin, glucose, or N-acetylglucosamine but not with other polymers and monosaccharide, the enzyme was considered to be an inducible enzyme. Notably N- acetylglucosamine and glucose were found to be effective inducers at low concentrations but repressors at excessive concentrations. The cultural supernatant of Acinetobacter sp. WC-17 inhibited the growth of phytopathogenic fungi such as P.oryzae, R.solani, and F.solani. Among the phytopathogenic fungi tested, P.oryzae was the most sensitive. The conventional agar plate (PDA containing 1 % colloidal chitin) method also produced the same result.

• Journal of Mushroom
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• v.18 no.4
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• pp.311-316
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• 2020

The effect of the nitrogen content of sawdust medium (1.2~1.8%) and the restriction stage temperature (2, 4, and 6℃) on the growth and storage characteristics of Flammulina velutipes (winter mushroom) were investigated. With increased nitrogen content, the growth days shortened and the yield of the fruiting body increased. The effect of restriction temperature on the growth of the fruiting body differed depending on the nitrogen content. No difference in restriction temperature was evident for T1 with a low nitrogen content of 1.28%. In medium with a nitrogen content ≥1.55%, the yield and length of the pileus and stipe increased as the restriction temperature decreased. The weight loss ratio according to the storage period did not change according to the nitrogen content in the medium. A low weight loss ratio of 1.50 to 1.93% was observed at a restriction temperature <4℃. When T3 with high nitrogen content in the medium was treated at a restriction temperature of 4℃, the fruiting body color values after 31 days of storage were 84.81 (L) and 6.3 (ΔE). This color change was minute compared to that after other treatments. The sensory characteristics score was 5.2 after 31 days of storage, and the quality remained acceptable for consumption.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.44-51
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• 2021

Centella asiatica (L.) Urban is a medicinal plant containing madecassic acid, triterpenoids and asiaticoside, and has a wound healing effect. However, since it grows only in some regions of Korea, it is necessary to breed stable varieties. In this study, it were analyzed for the growth characteristics, asiaticoside, anxiodant components and 2,2-diphenyl-1picryl hydrazyl (DPPH) radical scavening activity of C. asiatica collected from domestic natural habitat (Hapcheon, Gyeongnam). In the growth characteristics of each resource, CA9 and CA10 were superior in characteristics of aerial part and in dry weight. In asiaticoside content analysis, CA5 and CA3 were high with 53.96 mg/g and 52.40 mg/g, respectively. CA12 showed the possibility of development because the resource showed high in total flavonoid (7.3 mg/g), total polyphenol (10.64 mg/g) and DPPH activity (11.96 mg AAE/g) among other resources. However, it is necessary to select a resource suitable for each characteristic of C. asiatica and to study charateristics through additional resources collection since the excellent growth characteristics of the collected resources do not necessarily coincide with the content and antioxidant activities.

• Journal of Powder Materials
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• v.25 no.2
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• pp.144-150
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• 2018

$Al_2O_3-SiC$ ceramic composites are produced using pressureless sintering, and their plasma resistance, electrical resistance, and mechanical properties are evaluated to confirm their applicability as electrostatic-discharge-safe components for semiconductor devices. Through the addition of Mg and Y nitrate sintering aids, it is confirmed that even if SiC content exceeded 10%, complete densification is possible by pressureless sintering. By the uniform distribution of SiC, the total grain growth is suppressed to about $1{\mu}m$; thus an $Al_2O_3-SiC$ sintered body with a high strength over 600 MPa is obtained. The optimum amount of SiC to satisfy all the desired properties of electrostatic-discharge-safe ceramic components is obtained by finding the correlation between the plasma resistance and the electrical resistivity as a function of SiC amount.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.403-410
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• 2021

The aim of this study was to investigate the growth characteristic and ginsenoside contents of 7 and 13 year-old wild-simulated ginseng (Panax ginseng C.A. Meyer) according to rusty root. The root growth characteristics of wild-simulated ginseng were did not shows significant difference according to the rusty root. The results of ginsenoside contents of wild-simulated ginseng according to rusty root, ginsenoside Rb1 and Rg1 of 7 year-old wild-simulated ginseng were had shows a significantly higher in rusty root compare to general root. On the other hand, ginsenodie Rc, Rd, Re and Rg2 were significantly higher in gerneral root. In the case of 13 year-old wild-simulated ginseng, the contents of ginsenoside did not shows to significant difference according to rusty root. The results of correlation analysis between growth characteristics and ginsenoside content of general root, the ginsenoside Rb2, Rc, Rd, Rf, Rg1 were positive correlation with root length, while as the ginsenoside Rd of rusty root was shows significantly negative correlation with root length. The results of this study was might be able to improve awareness of consumer related to rusty root of wild-simulated ginseng. Moreover, might be help to provide useful information on the establish quality standard and distribution system of wild-simulated ginseng.