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        검색결과 24

        2.
        2022.10 구독 인증기관·개인회원 무료
        Investigations and monitoring of environmental radiation are important for preventing expected accidents or for early detection of unexpected accidents, in nuclear facilities and the surrounding. In the event of an environmental radiation accident, it should be possible to identify and analyze the radiation-contaminated area. Therefore, a rapid radiation monitoring system is required for immediate response and necessary measures. In this study, the distribution of radiation mapping is performed on a contaminated area using 2-dimensional or 3-dimensional contour mapping techniques. The entire surrounding area can be understood at a glance by displaying the radiation contour line on the map of the measured area.
        3.
        2022.10 구독 인증기관·개인회원 무료
        When decommissioning a nuclear power plant, the structure must be made to a disposable size. In general, the cutting process is essential when dismantling a nuclear power plant. Mainly, thermal cutting method is used to cutting metal structures. The aerosols generated during thermal cutting have a size distribution of less than 1 μm. The contaminated structures are able to generate radioactive aerosols in the decommissioning. Radioactive aerosols of 1 μm or less are deposited in the respiratory tract by workers’ breathing, causing the possibility of internal exposure. Therefore, workers must be protected from the risk of exposure to radioactive aerosols. Prior knowledge of aerosols generated during metal cutting is important to ensure worker safety. In this study, the physical and chemical properties of the aerosol were evaluated by measuring the number and mass concentrations of aerosols generated when cutting SUS304 and SA508 using the laser cutting method. High-resolution aerosol measuring equipment (HR-ELPI+, DEKATI) was used to measure the concentration of aerosols. The HR-ELPI+ is an impactor-type aerosol measuring equipment that measures the aerosol number concentration distribution in the aerodynamic diameter range of 6 nm to 10 um in real-time. And analyze the mass concentration of the aerosol according to the diameter range through the impactor. ICP-MS was used for elemental mass concentration analysis in the aerosol. Analytical elements were Fe, Cr, Ni and Mn. For the evaluation of physical and chemical properties, the MMAD of each element and CMAD were calculated in the aerosol distribution. Under the same cutting conditions, it was confirmed that the number concentration of aerosols generated from both materials had a uni-modal distribution with a peak around 0.1 um. CMAD was calculated to be 0.072 um for both SUS304 and SA508. The trend of the CMAD calculation results is the same even when the cutting conditions are changed. In the case of MMAD, it was confirmed that SUS304 had an MMAD of around 0.1 μm in size for only Fe, Cr and Mn. And SA508, Fe, Cr, Ni and Mn were all confirmed to have MMAD around 0.1 μm in size. The results of this study show that a lot of aerosols in the range of less than 1 μm, especially around 0.1 μm in size, are generated when metal is cut using laser cutting. Therefore, in order to protect the internal exposure of workers to laser metal cutting when decommissioning NPPs, it is necessary to protect from nano-sized aerosols beyond micron size.
        13.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Multiple starters consisting of two Bacillus amyloliquefaciens strains (MJ1-4 and EMD17), Pichiafarinosa SY80, and Rhizopus oryzae were used for Doenjang making. Bacillus strains were selected based on their abilities to inhibit toxinogenic fungi and Bacillus cereus, fibrinolytic activity, and their ability to confer good flavor to Cheonggukjang. P. farinosa SY80 and R. oryzae, previously isolated from soy sauce, were selected because they were not inhibited by two bacilli. Doenjang was prepared by inoculation of multiple starters (A1 Doenjang). Control Doenjang was prepared by inoculation of B. subtilis KACC 16750 (Natto strain) and Aspergillus oryzae KCCM 60166 (A2 Doenjang). Another control (A3 Doenjang) was prepared by inoculation of microorganisms present in rice straw. Doenjang samples were fermented for 70 days at 20℃. pH of 3 samples decreased from the initial value of 6.4 to 5.8~6.0 and titratable acidity (TA) increased from 0.6 to 1.1~1.3. The amount of amino-type nitrogen increased during fermentation. There were slight differences in moisture, crude-protein, and crude-fat contents after 70 days. Contamination of fungi was observed only in A3 Doenjang and B. cereus was not detected from all 3 samples. A1 Doenjang showed the highest fibrinolytic activity and A2 Doenjang the second. These results indicate that Doenjang made with carefully selected starters was functionally improved and microbially more safe.
        4,000원
        14.
        2005.12 구독 인증기관 무료, 개인회원 유료
        Resveratrol (3,4',5-trihydroxy-trans-stilbene), a naturally occuring polyphenol compound which present in the skin of grapes and red wine has been considered to posses chemopreventive and antioxidant properties. However, little is known about the cellular actions by which resveratrol mediates its therapeutic effects. In this study, the effect of resveratrol on cell proliferation and induction of apoptosis in human osteogenic sarcoma (HOS) cells was investigated. IC50 value was determined to be approximately 60μg/mℓ. Chromosomal DNA framgmentation analysis showed the appearance degraded DNA in time-and dose-dependent manner upon treatment of resveratrol. In order to observe the molecular mechanism involved in resveratrol-induced apoptosis, Western blot analysis was performed. We observed the decrease in the level of procaspase-3, the zymogen form of active caspase-3 in resveratrol-treated cells. This result implies that caspase-3 is activated upon treatment of resveratrol. The activation of caspase-3 was confirmed by the cleavage of poly(ADP-ribose) polymerase. Taken together, our data demonstrate that resveratrol has anti-proliferative effect on HOS cells and induced apoptosis through activation of caspase-3 and PARP cleavage.
        4,000원
        16.
        2009.09 KCI 등재 서비스 종료(열람 제한)
        A new yellow waxy corn hybrid "Daehakchal Gold 1" was developed from single cross between Yeongdeok Jaera and Okchen Jaera at Chungnam National University in 2007. Inbred CNU57 derived from Yeongdeok Jaera was used as the seed parent of Daehakchal Gold 1, and inbred CNU 27 derived from Okchen Jaera as the pollen parent. Tasseling date of this hybrid was seven day later than that of check hybrid, Chalok 1. Daehakchal Gold 1 was 19.7cm in ear length and 4.5cm in ear diameter. The yield of Daehakchal Gold 1 and check hybrid in dry matter were 146.5g and 113.9g per plant, respectively. On yield trial, which were increased 29.7% compared with a check hybrid, Chalok 1. Especially, Daehakchal Gold 1 had yellow kernels and good eating quality. The ratio of kernel set length/ear length was similar to Chalok 1. It is moderately resistant to Bioporalis maydis and corn borer. The yields of Daehakchal Gold 1 in fresh ear weight and in number of fresh ear were 16% and 8%, respectively, higher than those of a check hybrid in regional yield trials for three years. Seed production of this hybrid has gone well due to good match during crossing between seed and pollen parents.
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