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        검색결과 44

        1.
        2023.11 구독 인증기관·개인회원 무료
        When the parent radionuclide decays, the progeny radionuclide is produced. Accordingly, the dose contribution of the progeny radionuclide should be considered when assessing dose. For this purpose, European Commission (EC) and International Atomic Energy Agency (IAEA) provide weighting factors for dose coefficient. However, these weighting factors have a limitation that does not reflect the latest nuclide data. Therefore, in this study, we analyzed the EC and IAEA methodology for derivation of weighting factor and used the latest nuclide data from ICRP 107 to derive weighting factors for dose coefficient. Weighting factor calculation is carried out through 1) selection of nuclide, 2) setting of evaluation period, and 3) derivation based on ICRP 107 radionuclide data. Firstly, in order to derive the weighting factor, we need to select the radionuclides whose dose contribution should be considered. If the half-life of progeny radionuclides sufficiently short compared to the parent radionuclide to achieve radioactive equilibrium, or if the dose coefficient is greater of similar to that of the parent radionuclide and cannot be ignored, the dose contribution of the progeny radionuclide should be considered. In order not to underestimate the dose contribution of progeny radionuclides, the weighting factors for the progeny nuclides are taken as the maximum activity ratio that the respective progeny radionuclides will reach during a time span of 100 years. Finally, the weighting factor can be derived by considering the radioactivity ratio and branch fraction. In order to calculate the weighting factor, decay data such as the half-life of the radionuclide, decay chain, and branch fraction are required. In this study, radionuclide data from ICRP 107 was used. As a result of the evaluation, for most radionuclides, the weighting factors were derived similarly to the existing EC and IAEA weighting factors. However, for some nuclides, the weighting factors were significantly different from EC and IAEA. This is judged to be a difference in the half-life and branch fraction of the radionuclide. For example, in the case of 95Zr, the weighting factor for 95mNb showed a 35.8% difference between this study and previous study. For ICRP 38, when 95Zr decays, the branch fraction for 95mNb is 6.98×10-3. In contrast, for ICRP 107, the branch fraction is 1.08×10-2, a difference of 54.7%. Therefore, the weighting factor for the dose coefficient based on ICRP 107 data may differ from existing studies depending on the half-life and decay information of the nuclide. This suggests the need for a weighting factor based on the latest nuclide data. The results of this study can be used as a basis for the consideration of dose contributions for progeny radionuclides in various dose assessments.
        2.
        2023.11 구독 인증기관·개인회원 무료
        In Korea, most temporary storage facilities for spent nuclear fuel are nearing saturation. As an alternative to this, the 2nd basic plan for high-level radioactive waste management specified the operation plan of dry interim storage facility. Meanwhile, the NSSC No. 2021-19 stipulates that it is necessary to evaluate the possibility and potential effect of accident before operating interim storage facility. Therefore, this study analyzed the categories of accident scenarios that may occur in dry storage facility as part of prior research on this. We investigated the case of categorization of dry storage facility accident scenarios of IAEA, NRC, KAREI, and KINS. The IAEA presented accident scenarios that could occur in on-site dry storage facility operated with silo and cask method. NRC has classified accident scenarios in dry storage facility and estimated the probability of accidents for each. KAERI and KINS selected major accident scenarios and analyzed the processes for each, in preparation for the introduction of dry storage facility in Korea in the future. Overall, a total of 10 accident scenarios were considered, and the scenarios considered by each institution were different. Among 10 scenarios, cask drop and aircraft collision were included in the categorization of most institutions. The results of this study can be used as basic data for cataloging accidents subject to safety evaluation when introducing dry interim storage facility in Korea in the future.
        3.
        2023.05 구독 인증기관·개인회원 무료
        As nuclear power plants are operated in Korea, low and intermediate-level radioactive wastes and spent nuclear fuels are continuously generated. Due to the increase in the amount of radioactive waste generated, the demand for transportation of radioactive wastes in Korea is increasing. This can have radiological effect for public and worker, risk assessment for radioactive waste transportation should be preceded. Especially, if the radionuclides release in the ocean because of ship sinking accident, it can cause internal exposure by ingestion of aquatic foods. Thus, it is necessary to analyze process of internal exposure due to ingestion. The object of this study is to analyze internal exposure by ingestion of aquatic foods. In this study, we analyzed the process and the evaluation methodology of internal exposure caused by aquatic foods ingestion in MARINRAD, a risk assessment code for marine transport sinking accidents developed by the Sandia National Laboratory (SNL). To calculate the ingestion internal exposure dose, the ingestion concentrations of radionuclides caused by the food chain are calculated first. For this purpose, MARINRAD divide the food chain into three stages; prey, primary predator, and secondary predator. Marine species in each food chain are not specific but general to accommodate a wide variety of global consumer groups. The ingestion concentrations of radionuclides are expressed as an ingestion concentration factors. In the case of prey, the ingestion concentration factors apply the value derived from biological experiments. The predator's ingestion concentration factors are calculated by considering factors such as fraction of nuclide absorbed in gut, ingestion rate, etc. When calculating the ingestion internal exposure dose, the previously calculated ingestion concentration factor, consumption of aquatic food, and dose conversion factor for ingestion are considered. MARINRAD assume that humans consume all marine species presented in the food chain. Marine species consumption is assumed approximate and conservative values for generality. In the internal exposure evaluation by aquatic foods ingestion in this study, the ingestion concetration factor considering the food chain, the fraction of nuclide absorbed in predator’s gut, ingestion rate of predator, etc. were considered as influencing factors. In order to evaluate the risk of maritime transportation reflecting domestic characteristics, factors such as domestic food chains and ingestion rate should be considered. The result of this study can be used as basis for risk assessment for maritime transportation in Korea.
        4.
        2022.10 구독 인증기관·개인회원 무료
        Currently, low and intermediate-level radioactive wastes and spent nuclear fuels are continuously generated in Korea. For the disposal of the radioactive wastes, the transport demand is expected to increase. Prior to transportation, it is necessary to evaluate the radiation risk of transportation to confirm that is not high. In Korea, there is no transportation risk assessment code that reflects domestic characteristics. Therefore, foreign assessment codes are used. In this study, before developing the overland transportation risk assessment code that reflects domestic characteristics, we analyzed the radiation risk assessment methodology in transportation accident codes developed in other countries. RADTRAN and RISKIND codes were selected as representative overland transportation risk assessment codes. For the two codes we analyzed accident scenarios, exposure pathways, and atmospheric diffusion. In RADTRAN, the user classifies accident severity for possible accident scenarios, and the user inputs the probability for each accident severity. On the other hand, in the case of RISKIND, the accident scenarios are classified and the probabilities are determined according to the NRC modal study (LLNL, 1987) in consideration of the cask impact velocity, cask impact angle, and fire temperature. In the case of RISKIND, the accident scenarios are applied only to transportation of spent nuclear fuel, and cannot be defined for low and intermediate-level radioactive waste. However, in the case of RADTRAN, since the severity and probability of accidents are defined by user, it can be applied to low and intermediate-level radioactive wastes. As the exposure pathways considered in transportation accident, both RADTRAN and RISKIND consider external exposure (cloudshine and groundshine), and internal exposure (inhalation, resuspension inhalation and ingestion). In the case of RADTRAN, additionally, external exposure due to loss of shielding (LOS) is considered. Atmospheric diffusion calculation is essential to determine the extent to which radioactive materials are diffused. In both RADTRAN and RISKIND, atmospheric diffusion calculations are based on Gaussian diffusion model. Users must input Pasquill stability class, release height, heat release, wind speed, temperature and mixing height, etc. Additionally, RADTRAN can input weather information relatively simply by inputting only the Pasquill stability class fraction and selecting the US average weather option. This study results will be used as a basis for developing radioactive waste overland transportation risk assessment code that reflects domestic characteristics.
        13.
        2018.10 구독 인증기관·개인회원 무료
        전라북도 완주군 구이면에서 채집한 사마귀목(Mantodea) 사마귀과(Mantidae) 넓적배사마귀속(Hierodula)의 한국 미기록종 Hierodula formosana Giglio-Tos, 1912, 붉은긴가슴넓적배사마귀(신칭)을 처음 보고한다. 이 종은 그동안 국내에 알려진 Hierodula patellifera (Serville, 1839), 넓적배사마귀와 동일하게 느티나무, 벚나무 등 활엽수의 우거진 수관부에 매달려 전 생애를 보내는 생태적 특징이 있다. 형태적으로 같은 속 넓적배사마귀와 비교하였을 때, 수컷생식기의 차이가 뚜렷하고 앞다리 기절부에 9~11개의 돌기가 있다. 또한 전흉이 뚜렷이 길고 앞가슴 아랫면이 붉은 빛을 띠는 등 구별이 가능한데, 현재 일본에서 확산되고 있는 외래종 Hierodula sp.와 동일종으로 여겨진다. 2017년 9월 전주에서 처음 암컷 3개체가 비공식적으로 채집된 이후, 2018년 9월 완주군 구이면 일대를 조사하였을 때, 총 암컷 4개체, 수컷 10개체를 채집할 수 있었다. 또한 유충의 탈피각, 전년도 알집 등이 함께 확인됨으로써 국내에 최근 정착한 외래종으로 의심되어 이를 보고하고자 한다.
        15.
        2017.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Reactive Ion Etching (RIE) and wet etching are employed in existing texturing processes to fabricate solar cells. Laser etching is used for particular purposes such as selective etching for grooves. However, such processes require a higher level of cost and longer processing time and those factors affect the unit cost of each process of fabricating solar cells. As a way to reduce the unit cost of this process of making solar cells, an atmospheric plasma source will be employed in this study for the texturing of crystalline silicon wafers. In this study, we produced the atmospheric plasma source and examined its basic properties. Then, using the prepared atmospheric plasma source, we performed the texturing process of crystalline silicon wafers. The results obtained from texturing processes employing the atmospheric plasma source and employing RIE were examined and compared with each other. The average reflectance of the specimens obtained from the atmospheric plasma texturing process was 7.88 %, while that of specimens obtained from the texturing process employing RIE was 8.04 %. Surface morphologies of textured wafers were examined and measured through Scanning Electron Microscopy (SEM) and similar shapes of reactive ion etched wafers were found. The Power Conversion Efficiencies (PCE) of the solar cells manufactured through each process were 16.97 % (atmospheric plasma texturing) and 16.29% (RIE texturing).
        4,000원
        16.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the antidiabetic effect of amaranth grain ethanol extract (AEE) in a diabetic animal model, db/db mouse. The mice were divided into 4 groups: normal control mice (C57BL/6J), diabetic mice (C57BL/6J db/db), diabetic mice fed a lower concentration of AEE (0.3 mg/kg), and diabetic mice fed a higher concentration of AEE (0.5 mg/kg). After 10 weeks of treatment, body weights, blood insulin levels and blood glucose levels of each group were compared. At the end of treatment, the results showed that both AEE supplemented groups had lower body weights than those in the diabetic groups although higher than those in the normal groups. Moreover, in both AEE supplemented groups, serum insulin levels were higher and blood glucose levels were lower than those in the diabetic groups although both values were higher than those in the normal groups. The results of this study suggest that AEE can alleviate many of the common symptoms of diabetes in diabetic mice and, therefore, has potential as a therapeutic supplement for normalization of blood glucose and insulin levels in humans.
        4,000원
        17.
        2015.10 구독 인증기관·개인회원 무료
        This study was carried out to investigate insect community structure from different habitats. We performed day and night collection at three different habitats (mountain, coast and rural area) of island Deokjeok, island Soya and island Mungap from May to September in 2014. A total of 3,482 individuals of 725 species, 119 families belonging to 10 orders were collected and identified. A dominant species was Corymbia rubra (Cerambycidae) despite a very low percentage of the species among the catches. Results of ANOVA test showed a significant effect of habitats typeon species diversity. Also, combination of seasons and habitats types were significantly influential with species abundance and species diversity. Indicator species analysis (ISA) result identified 121 significant (p < 0.05) indicator species; one species for the habitats cluster, 93 species for the season cluster and 27species for combination of habitats with seasons.
        18.
        2015.04 구독 인증기관·개인회원 무료
        An insect faunal survey was carried out to investigate insect community structure along the vegetation community to monitor insect species in forest ecosystem. We performed day and night collections from June to August along three vegetation communities of Is. Nam-hae in 2014: the first stand with Pinus thunbergii, the second P. thunbergii with Quercus serrata and the third P. thunbergii with various Quercus species. In total 2,259 individuals of 532 species, 99 families, 13 orders are identified. Cluster Analyses (CA) showed that all three vegetation communities were relatively similar between vegetation community types. According to indicator species analysis (ISA) result, nine significant indicator species were identified (p < 0.05); five species were found to be affected by the vegetation cluster and four species the month cluster.
        19.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        직파품종 개발을 위한 특성검정으로 저온발아성을 조사하여 직파적응성에 알맞은 품종개발을 위한 기초자료로 활용하고자1994년부터 2008년까지 육성된 89개 품종을 이용하여 저온발아성을 검정한 결과 최근에 육성한 품종일수록 저온발아율이80% 이상으로 높았으며, 조생종이나 중생종보다는 중만생종의 저온발아율이 높은 경향이었으나 통계적인 유의차는 인정되지 않았다. 또한 최고품질이나 고품질 품종이 초다수성이나안전성 품종보다 저온발아율이 높았다. 품종이 육성된 기관별로 볼때는 직파품종 개발을 담당하고 있는 익산의 벼맥류부육성품종의 저온발아율이 다른 기관에서 육성된 품종보다 높게 조사되었다.
        4,000원
        20.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        장애인들은 신체적 조건으로 인해 학습 활동에 어려움이 많다. 특히 청각 장애인들은 커뮤니케이션의 문제가 존재한다. 따라서 본 연구에서는 청각 장애인들에게 정보전달 훈련을 제공하여 수화를 자유롭게 사용하는데 의미를 둔다. 그리고 정상인에게는 수화를 게임으로 쉽게 배울 수 있게 하는데 목적을 두고 있다. 이를 통해 청각장애인에 대한 인식 개선을 형성시키고자 한다.
        4,000원
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