• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.142-145
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• 2005

The life expectancy of a transformer largely depends on the temperature-rise it experiences. If the temperature-rise exceeds limits specified in the design standards, the aging of insulating materials is accelerated and the capability of the cooling medium is deteriorated. Consequently, applicable limits for the temperature-rise are essential in designing the transformer and the coolers, demanding the estimation of the transformer's thermal behavior. In order to analyze the temperature characteristics of the transformer, numerical analysis by way of the commercial CFD code has been carried out, and temperature-rise testing to verify computed results was performed. The results obtained in this study show that there is a good agreement between computed outcomes and experimental outcomes.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.841-844
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• 2001

Free radicals cause many diseases and aging. In our body coexist useful and harmful bacteria. Some useful intestinal bacteria such as L. plantarum, B. adolescentis, B .bifidum, B. infantis, C. butyricum were presented positive growth in culture medium bearing natural products. L. plantarum was more effectively grown by mixed natural products of CORNI FRUCTUS+THEAE FOLIUM+COPTIDIS RHIZOMA+PAEONIA JAPONICA, B. adolescentis was BEIAMCANDA CHINENSIS+ANGELICAE GIGANTIS RADIX+EPIMEDII HERBA+PAEONIA JAPONICA, B. bifidum was NELUMBO NUCLFERA GAERTNER+THEAE FOLIUM+BEIAMCANDA CHINENSIS+CORNI FRUCTUS, B. infantis was THEAE FOLIUM+CHELIDONIUM MAJUS L.+ASTRAGALI RADIX+EPIMEDII HERBA, C. butyricum was EPIMEDII HERBA+PUERARIAE RADIX+NELUMBO NUCLFERA GAERTNER+PAEONIA JAPONICA,etc. These natural products will support an important role in bio-industry.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.388-393
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• 1998

This study was performed to investigate the influence of vadrious dietary fiber sources such as mugwort, apple, sea mustard, butterbur on the intestinal in aged rats. Nine groups of aged rats (12months after weanling) were fed each experimental diet containing 5% and 15% dietary fibers for 4 weeks. The contents in large intestine of aged rats used for the measurement of intestinal microflora. Total viable counts and the numbers of Bifidobacterium, Lactobacillus, Clostridium, E. coli and Staphylococcus were determined by nonselective medium and various selective media. The intake of dietary fiber sources employed did not show any differece in the number of total microorganisms, Lactobacillus and Bifidobacterium. It was remarkable that Clostridium perfringens appeared in the colon of aged rats. The prpulations of Peptococcus and Clostridium were significantly larger in the apple 5% group than in other dietary fiber groups while the number of Staphylococcus was significantly smaller in the dietary fiber groups than in cellulose group. And the Streptococcus populations decreased in the mugwort 15% group. Accordingly, the mugwort 15% group is effective in improving intestinal flora of aged rats.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.482-486
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• 2007

Industry for mobile camera module is a complex one based on various technologies, including mechanics, communication technology, material engineering, and electronics which are connected closely. This industry has been already known to a higher value-added business, and as going into an aging society, is expected a market growth. Also, it is a knowledge based component industry and each components assembled into product is almost home made items. This characteristics made many small and medium and venture enterprises participate in this area. Using this study, related companies refer the status and make the decision for commercialize the technology in the internal and world market.

• Journal of the Korean Ceramic Society
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• v.28 no.5
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• pp.365-372
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• 1991

LAS (lithium aluminosilicate) sol was synthesized using the hydrolysis-condensation reaction of TEOS, chelated Al(OBus)3 and Li-salt with H2O in alcohol (EtOH+2-Propanol) medium. Effects of important reaction parameters on the properties of sol and gel-derived LAS were examined. The crystallization of the sol-gel derived LAS with ${\beta}$-spodumene composition began at ∼600$^{\circ}C$, and a series of polymorphic transformations occurred as temperature was increased to 1100$^{\circ}C$: amorphous LAS\longrightarrowhexagonal LiAl(SiO3)2\longrightarrow${\beta}$-spodumene. Lowering Li content in the gel enhanced densification and retarded the crystallization significantly. Optimum reaction conditions of LAS sol formation for thin coating applications were derived from rheological measurements, and these can be summarized as: H2O/total alkoxides molar ratio=4, pH=∼2.5, and aging time of ∼250h.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.280-285
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• 2003

The cosmetic industry associated L-ascorbic acid (LAA) or not with its salts and esters, to be employed for fighting the cutaneous aging process. In large part, in the segment of cosmetics, the salts and esters of the LAA alone are employed more frequently than the pure LAA, since the former are chemically more stable, but result in less effective products. The present work refers to a process for stabilizing LAA in an aqueous medium, which includes the step of placed the LAA in contact with Polyvinylalcohol (PVA) through weak force like Van der Waals interaction. The PVA provides stability for LAA aqueous solution, which is stable for 106 days with a LAA content decrease only of 10% w/v.

• Transactions of Materials Processing
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• v.13 no.5
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• pp.403-408
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• 2004

Hydroformability of 6061 and 7075 aluminum tube materials was studied by warm hydroforming experiments. A special tooling and heating system was designed and manufactured in order to perform warm hydroforming between room temperature and $300^{\circ}C$. The control of tube temperature for warm hydroforming was made by the control of temperature of oil medium. Warm hydroformability was analyzed by tube appearances, tube elongation and hardness values. Hydroforming characteristics of 6061 and 7075 tubes showed different temperature dependence between room temperature and $300^{\circ}C$. The difference in hydroformabilities of 6061 and 7075 at elevated temperatures was interpreted by the different sensitivity to dynamic strain aging of both aluminum materials.

• Fire Science and Engineering
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• v.33 no.6
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• pp.181-185
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• 2019

In this study, Exit light installed in offices, malls, hospitals, and factories were analyzed to analyze the luminance performance of CCFL and LED light sources. In addition, fire protection products with electrical characteristics such as Exit light may change their performance due to ambient temperature, humidity, and dust. So it was extracted by installation place and analyzed its characteristics. As a result of the experiment, Exit light for CCFL type showed the value of 'ratio of luminance 2' for large, medium and small. Considering that the reference value was 'lower than 9', the value was very good and it can be seen that there is almost no change in ratio of luminance due to aging. The Exit light for LED type showed a value of 'ratio of luminance 5', which means that the light on the display surface is not uniform. In addition, there was almost no change in ratio of luminance due to ageing, but the ratio of luminance was larger than Exit light for LED type. This is an unsatisfactory result from a visual point of view. To improve this, it is necessary to disperse the light of LED light source and strengthen the regulation on ratio of luminance.

• Journal of the Korean Society of Tobacco Science
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• v.1 no.1
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• pp.63-70
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• 1979

In order to improve the quality of greenish tobacco leaves, fermentation experiments by microbial treatment and periodical variations of fermentation temperature were performed. More than twenty strains were isolated from Hyangcho ( Sun cured Korean native leaves ) and Perique tobacco leaves. Among them, five strains which showed good growth in Nicotine Broth medium were selected. Identification experiments of these strains as well as checking the effects of fermentation by these treatment on the quality and aging rate of greenish tobacco leaves were carried out. The results were like following ; 1. Selected strains were identified as pseudomona.f for H-82, for P-4 and Bacillus for H-81. p- 4 and P-7. 2. Among the five strains, strain H- 82 showed the best effect on the forced aging and the quality of greenish tobacco leaves, The rate of oxygen uptaking, pH and nicotine contents were decreased. However, total volatile acids and petroleum ether extracts were increased. 3. After fermentation, taste from greenish tobacco leaf were removed and smoking characteristics were improved. Color was also changed from greenish yellow to dark brown.

• The Korea Journal of Herbology
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• v.26 no.4
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• pp.67-74
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• 2011

Objectives : The purpose of the study is to determine the neuroprotective effects of the water extract of Angelicae Acutilobae Radix(AA) on ischemia reperfusion-induced apoptosis in SK-N-SH human brain neuronal cells. Methods: SK-N-SH cells were treated with different concentrations of AA water extract (0.1, 0.2, 0.5 and 1.0 mg/ml) for 2 hr and then stimulated with Dulbecco's phosphate-buffered saline containing CI-DPBS: 3mM sodium azide and 10 mM 2-deoxy-D-glucose for 45 min, reperfused with growth medium, and incubated for 24 h. Cell viability was determined by WST-1 assay, and ATP/ADP levels were measured by ADP/ATP ratio assay kit. The levels of caspase-3 protein were determined by Western blot and apoptotic body was observed by Hoechst 33258 staining. Results : AA extract significantly inhibited decreasing the cell viability in ischemia-induced SK-N-SH cells. AA also increased the ratio of ADP/ATP in ischemia-induced neuronal cells and decreased the expression levels of apoptotic protein, caspase-3 and apoptotic DNA damage. Conclusions : Our results suggest that AA extract has a neuroprotective property via suppressing the apoptosis and increasing the energy levels in neuronal cells, suggesting that AA extract may has a therapeutic potential in the treatment of ischemic brain injury.