• 한국초전도ㆍ저온공학회논문지
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• 제13권1호
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• pp.51-55
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• 2011

In this study, the liquid-vapor (L-V) separator equipped with liquid-level meter is developed. In the developed L-V separator, the flange is designed to be attachable so that the separator can be flexibly applied under any cases where the volumetric of L-V separator is varied by the system requirement. The leak-tightness between the attachable flange and the chamber is experimentally confirmed with the use of double groove indium wire sealing even under the high pressure up to 20 bar. In addition, the liquid-level meter is designed and fabricated to figure out the inner state of L-V separator. It consists with 19 carbon composition resistors in series. All resistors are separately calibrated in the temperature range from 77 K to 200 K. The performance of the L-V separator and the liquid-level meter is investigated with experimental tests, and the result is presented in this paper.

• 한국산업융합학회 논문집
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• 제2권1호
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• pp.77-83
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• 1999

Grown in the secondary broth of production media, the strain Streptomyces albulus has increased more the production of its metabolite ${\varepsilon}$-poly-L-lysine, one of poly(amino acid)s used as disinfecting food additives, than the strain in the primary culture of growth nutrients. Having the strain removed, the large concentrate obtained by ultrafiltrating the secondary culture broth. The concentrated production broth exchanged into followed by detecting in UV flowcell at 220nm the peptide bond of the components eluting the adsorbed proteins and polylysine with NaCl salt of gradient concentration, and has separated into five components. Among them the component in the fourth peak fraction has proved to be the pure ${\varepsilon}$-poly-L-lysine after the portion being hydrolyzed the fraction with HCl into amino acid followed by being the composing amino acid analysis.

• 약학회지
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• 제34권4호
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• pp.262-266
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• 1990

Acetylshikonine, isolated from the root of Lithospermum erythrorhizon showed a strong cytotoxic activity ($ED_{50}=0.10\;ug/ml$) against L1210 cell and T/C = 182% in ICR mice bearing S-180 at a dose of 5 mg/kg. Administrations of 10 mg/kg and 15 mg/kg reduced the T/C values to 60 and 77% respectively. Higher doses reveal toxicity. Seven naphthazarin derivatives synthesized showed good cytotoxic activities against L1210 cell. Especially, naphthazarin and hydronaphthazarin have strong activities ($ED_{50}=0.05\;ug/ml$ for both). Naphthazarin showed a severe toxic effect on ICR mice bearing S-180; no significant toxic effect was observed at a dose of 1 mg/kg or 2 mg/kg, but a severe toxicity (T/C = 23%) by administration of 5 mg/kg. Alkylation of C-2 of naphthazarin is necessary for reducing the toxic effect on ICR mice bearing S-180.

• 한국정밀공학회지
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• 제19권10호
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• pp.77-83
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• 2002

Magnesium alloys casting are gaining increased acceptance in the automotive and electronic industeries and die casting is the most efficient method of manufacturing such mass produced parts. This study has been investigated the microstructures and mechanical properties of Mg-9Al-lZn alloy fabricated by die casting process for development of air bag case. The microstructure of die casted specimen were composed of pro-eutectic magnesium solid solution and $\beta$(Mg17Al12) precipitates. The tensile strength of as-fabricated Mg-9Al-lZn alloy revealed 231.4MPa. It was found that Mg-9Al-lZn alloy have good corrosion resistance in electrochemical polarization test.

• 환경위생공학
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• 제11권3호
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• pp.69-77
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• 1996

The result of isolated and selected to the strain having the emulsifying activity from soil's strain the strain was identified as Candida genus. The strain was investigated with culture condition at pH culture temperature, flow rate of air, strring rate etc., and physicochemical properties of the biosurfactant were examined. The optimum composition of medium for a strain cultivation were obtained as follow : glucose ; 100g/L, yeast extract ; 10g/L, urea ; 1.0g/L, KH$_{2}$PO$_{4}$ ; 50mg/L, MgSO$_{4}$ ; 500mg/L, and the op condition of cultivation was as follow : pH ; 3.0, temperatlue ; 24$\circ $C, strring rate ; 40rpm. The maximum yield of biosurfactant was obtained by pH ; 3.0-3.5, and temperature ; 25$\circ $C. The degree of emulsification of syntesized biosurfactant was increased clearly by increasing concentration of biosurfactant and it's stability was maintained for a long time. The surface tension of biosurfactant was varied with pH, especially it was showed that the surface tension was high at acidic pH.

• 한국초지조사료학회지
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• 제8권3호
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• pp.165-168
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• 1988

This study was conducted at the rice field of Livestock Experiment station, Suweon to investigate the effects of harvesting time on forage production and quality of rye (Secale cereale L.) on paddies. The results obtained are summarized as follows; 1. Fresh matter yield was peaked at the 10 days (May 10) after heading, however, dry matter yield was increased in proportion to maturity. 2. Digestibility (in vitro) showed the 83-77% by heading stage (Apr. 25-30) but decreased to 66-58% after heading stage. 3. Digestible yield reached to maximum level, 619.2 kg/lOa at the 10 days after heading (May 10). 4. The content of crude protein and crude fat in forage rye was decreased with advancing the maturity. 5. The lactic acid content of rye silage ranged from 1.3% to 2.0%.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1974년도 학술대회지
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• pp.77-93
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• 1974

The sapogenins of two-and four-year-old A-merican ginseng plants (Panax quinquefolium L.) (Araliaceae) collected in July and September were studied. American ginseng saponins (panaquilins) differ from Korean ginseng (Panax ginseng C. A. Meyer) saponins (ginsenosides). The American ginseng saponins separated and named were panaquilins A, B, C, D, E-l, E-2, E-3, G-l, G-2, (c) and (d). One-dimensional thin-layer chromatography did not completely separate panaquilin mixture and were subject to misinterpretation. The panaquilins were more accurately separated and identified by the two-dimensional thin-layer method established. Some differences in American ginseng saponins were dependent upon the plant age, time of collection, and part extracted. The American ginseng sapogenin components are panxadiol (panaquilins B and C), oleanolic acid (panaquilin D) and panaxatriol (panaquilin G-l). The panaquilins E-l, E-2 and E-3 mixture contains both panaxadiol and panaxatriol. The genins of panaquilins A, (c), (d) and G-2 were not identified. In addition, ${\beta}-sitosterol$ and stigmasterol were identified from the root ether extracts.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.75-77
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• 1994

This paper presents a method of obtaining transmission network equivalents from the network's driving-point admittance characteristic. Proposed method is based on modal decomposition representation for the large-scale interconnected system. As a result, Norton-type of discrete-time filter model can be generated. It can reproduce the driving-point admittance characteristic of the network. Furthermore proposed model can be implemented into the EMTP in a direct manner. The simulation results with the full system representation and the developed equivalent system showed a good agreement.

• 한국임상수의학회지
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• 제15권1호
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• pp.79-82
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• 1998

This study was performed to determine the changes of serum enzyme activities in rats with hepatic injury induced by the administration of AAPH. Minor behavioral change, brittleness of skin hair and decreased water and fled intake were observed in rats administered intraperitoneally with AAPH. Serum AST and ALT activities pre-treatment were $65{\pm} 13.8 and 32{\pm}$ 12.6 IU/L, respectively and increased sharply from 2 hours of administration and reached $1248{\pm} 77.6 and 946{\pm}$ 45.6 IU/L, respectively at 48 hours of administration. Serum ALP and $\gamma -GTP activities pretreatment were 221 {\pm} 75.6 and 2.2{\pm}$ 0.35 IU/L respectively and increased sharply from 8 hours of administration and reached $767{\pm} 44.9 IU/L and 8.0{\pm} 1.23 IU/L,$ respectively at 48 hours of administration.

• 동굴
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• 제77호
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• pp.53-58
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• 2007

From the computer or the library the use of the place about lower the case which gives a damage to the different person occurs with four three anger backs. It became from the hazard which manages the library place efficiently it used the AVR and a RF communication to make a system.