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        검색결과 4

        1.
        2022.10 구독 인증기관·개인회원 무료
        Kori Unit 1, Korea’s first commercial nuclear power plant is preparing to dismantle after 40 years of power supply. However, unlike the public dose assessment for nuclear power plants in operation, the dose assessment for the public due to abnormal events during the decommissioning of nuclear power plants is insufficient. Therefore, in this study, the steam generator chamber is selected as hypothetical events target among metal waste, which is a major radioactive material generated during the decommissioning of nuclear power plant. In addition, the possible abnormal event scenarios and effective does to public in the Exclusion Area Boundary due to the released radioactive materials are predicted during the disassembly and transportation of the steam generator. For the source term that can be released during the dismantling of the steam generator, the inventory of each radionuclide is evaluated based on the smear test results of the steam generator replaced in Kori Unit 1 in 1998. To evaluate the diffusion of radioactive material, the atmospheric dispersion factor (χ/Q, sec/m3) is calculated through the PAVAN code of the US NRC using the meteorological data of the Kori nuclear power plant for 3 years from 2019 to 2021 according to IAEA recommendations. For the assessment of the public dose, the external dose coefficient and inhalation coefficient of the ICRP and the inhalation rate of the NRC Regulatory Guide 1.3 are referred. It is confirmed that the effective dose to the public in the Exclusion Area Boundary due to the abnormal event during the dismantling of the steam generator is much lower than the effective dose standard value of 250 mSv for 2 hours after the event in the Exclusion Area Boundary.
        2.
        2013.10 구독 인증기관·개인회원 무료
        In recent, habitat fragmentation is one of the major factors to threat to biodiversity loss, because habitat fragmentation caused by urbanization and land-use change affect reducing of habitat amount and changing of environmental condition. In particular, increasing of forest edges by habitat fragmentation cause changing of microclimate and distribution of organisms in forest. This study was conducted to examine the distributional patterns of ground beetle assemblages along forestedge- crop gradients in Hoengseong-gun, Gangwon-do. We selected 8 study sites as line gradients from forest interior to crop (+80m, +40m, +20m, 0m, -20m, -40m, -80m). Ground beetles were collected by pitfall traps from May to October in 2012. A total of 61 species were identified from 3,739 collected beetles. Species richness was the highest at forest edge (GLM with Tukey’s test, F6, 49=2.56, P=0.031). Although abundance was higher at both forest interior and edge, but not showed statistical significance (F6, 49=2.06, P=0.076). Species composition of forest interiors were significantly different from forest exteriors (crops) by non-metric multidimensional scaling (NMDS) and cluster analysis with similarity profile test (SIMPROF), while forest edges showed intermediate characteristics. Although our study sites may not represent the overall Korean forest, we confirmed that forest edges are important habitats for generalists and open-habitat species as well as forest specialists. In conclusion, management of both forest edge and its surroundings are needed to conserve biodiversity in forest,
        3.
        2016.10 서비스 종료(열람 제한)
        Background : Campanula takesimana is a herb(Jabanpungnyeoncho) used traditionally in the korea private and we tried the development on a medicinal material. It was known that it has chlorogenic acid, as a immunoadjuvant activity. In this study we investigated the contents of the chlorogenic acid in Companula takesimana at different harversting time by the high performance liquid chromatographic(HPLC)-PDA. Campanula takesimana was collected on May maddle (Flower buds farmed), June middle (flowers opened) and July middle (seeds were mature). Methods and Results : HPLC analysis was carried out using X-bridge C18 column (5um, 250*4.6mm) and a mobile phase consisting of acetonitrile and water containing 0.1% formic acid at a flow rate of 1.0 ml/min. The optimum wavelength for the detection of the Chlorogenic acid was 330 nm using Photo Diode Array Detector. The contents of the chlorogenic acid in the Campanula takesimana extrat were 1.00% (May middle), 0.84% (June middle), 0.05% (July middle), respectively. As the different parts of Campanula takesimana, chlorogenic acid contents in May middle extrat were 2.73% (aerial part), 0.05% (root) and in June middle extrat were 1.61% (aerial part), 0.03% (root), 0.70% (flower) and in July middle were 0.13% (aerial part), 0.03% (root), 0.00% (seed), respectively. Conclusion : From the above results, the highes content of chlorogenic acid was observed in aerial part and May middle extract of Campanula takesimana.
        4.
        2015.05 서비스 종료(열람 제한)
        Reuse, recycling and recovery (3R) of industrial wastes are common and encouraging in Korea. Industrial symbiosis is one of typical methods for implementing 3R and has been defined as engaging “traditionally separate industries in a collective approach to competitive advantage involving physical exchange of materials, energy, water, and by-products”. The keys to industrial symbiosis are collaboration and the synergistic possibilities offered by geographic proximity. Recently, several countries in East Asia such as Taiwan, South Korea, Japan and China are promoting ‘designed’ symbiosis networks in various industrial complexes based on their national Eco-industrial Park (EIP) demonstration programs. Despite the recently promoted EIP initiatives worldwide, only very few studies furnish the operational and functional details of ‘designed’ industrial symbiosis networks, starting from the planning to implementation stage. The production of terephthalic acid (TPA) in Korea is 6.5 million ton based on 2011. The production of waste generated in the process of TPA is about 15,000 ton/yr and included useful materials like residue TPA as well as isophthalic acid (iPA), benzoic acid (BA) and p-toluic acid (p-TL). Until now, TPA waste was incinerated due to high caloric value. This study was conducted for recovery of valuable materials from industrial waste and utilization of recovered material as an example of Korean EIP. In this study, the experiment was performed to separate above four materials from the waste by solvent (methanol and water) extraction. The solubility of TPA (0.1g/100g) for methanol is relatively low compared to other materials. Also the solubility of BA (68g/L at 95℃) and p-TL (11.6g/L at 98℃) for water is relatively high in comparison with other materials. Finally, BA was separated from p-TL by molecular distillation system. The purity of recovered materials was analyzed by ultra-high performance liquid chromatography (Waters Xevo TQ system). The recovery rate and purity of BA is 90% and 93%. The recovered BA could be recycled the companies which are produced plastic plasticizer and paints.