• YAKHAK HOEJI
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• v.42 no.4
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• pp.395-402
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• 1998

Mori Cortex Radicis, the root bark of mulberry tree, has been used in the treatment of bronchial asthma and other lung diseases in traditional medicine. There was a recent repor t that the water soluble part with molecular weight of above 10,000 has anti-allergic activity. Therefore, we intended to isolate and purify the anti-allergic compound from hot water extract of the Mori Cortex Radicis. Crude extract of Mori Cortex Radicis was prepared by hot-water extraction, and anti-allergic compound was further purified by alcohol precipitation, successive ultrafiltration, anion exchange chromatography and gel filtration chromatography. This compound had homogeneity which was shown by the sharp single peak in HPLC chromatogram (TSK-GEL G400OPW column, RI detector). The molecular weight of the compound was estimated as 23Kda on the basis of calibration curve plotted against protein standards. This compound was identified as complex of sugar, protein and lignin (19.2: 5.9: 72.7), and proteolysis could not decrease the anti-allergic activity but mild delignification decreased the activity remarkably. Therefore, we concluded that the anti-allergic compound of Mori Cortex Radicis was a lignin-carbohydrate complex.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.187-194
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• 1999

In the design of catalytic converter, velocity distribution is more important than pressure drop because monolith pressure drop is about 80% of overall pressure drop. For the catalytic converter with single diffuser, pressure drop is decreased as the angle of diffuser decrease, but when the angle is below 18$^{\circ}$, the effect is almost negligible . For the catalytic converter with double diffuser, variation of the angle of the first diffuser shows the same trend as the pressure drop while the shape of diffuser gives little influence on that The outlet shape gives negligible effect on the pressure drop and velocity . distribution . Results show that recirculation region of commercial model is aoubt 30% of the total area in the front of monolith. For the catalytic converter with Model 11 that was presented in the study, recirculation region was not detected more uniform velocity distribution was obtained, and pressure drop was also decreased.

• Preventive Nutrition and Food Science
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• v.4 no.4
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• pp.236-240
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• 1999

The characteristics of natural lactic acid fermentation of radish juice were investigated at different salt concentrations (0~2%) and temperatures (10~3$0^{\circ}C$). Major lactic acid bacteria isolated from the radish juice fermented at 2% slat concentration were Leuconostoc mesenteroides, Lactobacillus plantarum, and Lactobacillus brevis. The percentage of lactic acid bacteria against total microbe in the fermented radish juice was over 80% at 0~1% salt concentrations, suggesting the possibility of fermentation even at low salt concentration, but was still active even at 1$0^{\circ}C$. The time to reach pH 4.0 during fermentation of juice of 1% salt concentration was 281~301 hrs at 1$0^{\circ}C$ and 50-73 hrs at 3$0^{\circ}C$. The concentrations of sucrose and glucose in the fermented juice were low at high temperatures and were the lowest at a 1.0% salt concentration. However, the content of mannitol showed the opposite trend. Although sour taste, ripened taste, and acidic odor of the fermented juice showed no significant differences among various temperatures and salt concentrations, sensory values of ripened taste and sour acidic were high at high temperatures. The overall quality was the best at 1.0% salt concentration, irrespective of the temperature.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.97-105
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• 2005

As construction project is becoming larger, construction progress and works are more various and complex according to recent Korean construction tendency. The growth of construction induces much pollution on the progress of construction and the problems due to the construction pollution are raised into social problem strongly, because it is increasing the need on the quality of lift and the desire of clean environment. This study aimed to seek far the effective solving plan of the construction popular complaints by surveying the real condition of construction popular complaints and analyzing the cause and tansaction period of popular complaints. For this study, the laws related and popular complaints were analysed focusing on the documents in low district offices of Gwangju from 2000 to 2004. As a result, the types of construction popular complaints were divided into 17 and the causes were as follows in order: crack and subsidence of ground(14.90%), infringement of private life(11.55%), noise(10.80%), infringement of a right to sunshine(10.07%) and breakdown(6.7%). Consequently, it is considered that these complaints are occurred by physical and environmental causes.

• Korean Journal of Veterinary Service
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• v.23 no.2
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• pp.153-163
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• 2000

This study was carried out the antimicrobial resistance of staphylococcus aureus isolated from bovine mastitic milk, chickens, korean native cattle, korean native goats, pigs, dog and mice in northern area of kyongbuk. The result were summarised as follows ; A total of 149 S aureus were isolated from bovine mastitic milk, chickens, korean native cattle, korean native goats, pigs, dog and mice. In 80 isolates of S aureus from bovine mastitic milk, 60% of isolates revealed resistance to penicillin and ampicillin, 19% to gentamicin, 6% to tetracycline. In 36 isolates of S aureus from chickens, 72% of isolates revealed resistance to tetracycline, 58% to penicillin and ampicillin, 42% to streptomycin, 31% to lincomycin, 25% to norfloxacin, 22% to gentamicin. In 17 isolates of S aureus from korean native cattle, 100% of isolates revealed resistance to penicillin and ampicillin, 88% to lincomycin, 76% to tetracycline. 2 MRSA were isolated from the isolates of S aureus from bovine mastitic milk and revealed multi-drug resistance.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.79-80
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• 2018

Citrobacter freundii is a facultative anaerobic and a Gram-negative bacterium of Enterobacteriaceae family, and is an opportunistic pathogen. Bacteriophages infecting C. freundii can be an effective treatment for C. freundii infections. Here, the complete genomic sequence is announced for a lytic bacteriophage CF1 infecting C. freundii isolates.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.4
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• pp.71-80
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• 2010

The KSLV-II(Korea Space Launch Vehicle-II) which being a successor of the KSLV-I is a space launch vehicle capable of delivering 1.5 ton-class satellite into a low earth orbit. The development of a 75 tonf-class liquid rocket engine(LRE) is planned on the basis of the technologies mastered through the preceded research of a 30 tonf-class LRE. The thrust chamber of the LRE is required to have higher combustion stability, structural integrity and thermal durability. This paper deals with the design requirements of the 75-tonf thrust chamber and a variety of technical considerations which have been conducted analytically in the course of the design for the realization of the requirements.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.2
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• pp.271-278
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• 2021

In this study, a chlorination technique for recycling Li₂ZrO₃, a reaction product of ZrO₂-assisted rinsing process, was investigated to minimize the generation of secondary radioactive pyroprocessing waste. It was found that the reaction temperature was a key parameter that determined the reaction rate and maximum conversion ratio. In the temperature range of 400-600℃, an increase in the reaction temperature resulted in a profound increase in the reaction rate. Hence, according to the experimental results, a reaction temperature of at least 450℃ was proposed to ensure a Li₂ZrO₃ conversion ratio that exceeded 80% within 8 h of the reaction time. The activation energy was found to be 102 ± 2 kJ·mol^-1·K^-1 between 450 and 500℃. The formation of LiCl and ZrO₂ as reaction products was confirmed by X-ray diffraction analysis. The experimental results obtained at various total flow rates revealed that the overall reaction rate depends on the Cl₂ mass transfer rate in the experimental condition. The results of this study prove that the chlorination technique provides a solution to minimize the amount of radioactive waste generated during the ZrO₂-assisted rinsing process.

• Transactions of Materials Processing
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• v.30 no.3
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• pp.134-141
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• 2021

In order to improve excessive spring-back behavior as a result of the roll forming process using ultra high strength steel (UHSS) sheet, local softening in region of a partial area expected to be deformed on an initial blank is considered in this study. With SPFC1470 UHSS sheet with initial blank thickness of 1.20mm, the local softening is performed with the following conditions: temperatures of 500℃, 550℃, 600℃ and 650℃, and holding time of 20s, 40s, 80s and 160s. Mechanical properties, such as yield stress and tensile strength, as well as elongation, are evaluated through uniaxial tensile tests, while the microstructural characteristics as a result of local softening are also investigated using the heat-treated specimens. As a result, it is shown that the spring-back behavior of the roll-formed prototype was reduced about by 78.9%, when the local softening at about 500℃ was performed for 160s considering the practical manufacturing condition.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.75-77
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• 2013

In this study, the characteristics of temperature history was evaluated for three hot wires with different capacity installed in slab concrete which are relatively thin. Results can be summarized as follows. First, for the case of material using 5W hot wire, all decreased to below zero at or around 24 hours. Similarly, the material using 20W hot wire decreased to 2℃ below zero at or around 80 hours but satisfied the accumulative temperature of 45° D·D at 7 days of material age. On the other hand, the case of 30W hot wire, the biggest capacity, showed the high temperature history of 5℃ in average at all areas except the corners. Thus, the target accumulative temperature was secured at or around the 3 days of material age. Considering the above, the initial damage by freezing can be prevented only if 20W or higher hot wires are used for the slabs at -10℃ of extremely low temperature environment.