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        검색결과 60

        1.
        2023.11 구독 인증기관·개인회원 무료
        After the major radioactivation structures (RPV, Core, SG, etc.) due to neutron irradiation from the nuclear fuel in the reactor are permanently shut down, numerous nuclides that emit alpha-rays, beta-rays, gamma-rays, etc. exist within the radioactive structures. In this study, nuclides were selected to evaluate the source term for worker exposure management (external exposure) at the time of decommissioning. The selection of nuclides was derived by sequentially considering the four steps. In the first stage, the classification of isotopes of major nuclides generated from the radiation of fission products, neutron-radiated products, coolant-induced corrosion products, and other impurities was considered as a step to select evaluation nuclides in major primary system structures. As a second step, in order to select the major radionuclides to be considered at the time of decommissioning, it is necessary to select the nuclides considering their half-life. Considering this, nuclides that were less than 5 years after permanent suspension were excluded. As a third step, since the purpose of reducing worker exposure during decommissioning is significant, nuclides that emit gamma rays when decaying were selected. As a final step, it is a material made by radiation from the fuel rod of the reactor and is often a fission product found in the event of a Severe accident at a nuclear power plant, and is excluded from the nuclide for evaluation at the time of decommissioning is excluded. The final selected Co-60 is a nuclide that emits high-energy gamma rays and was classified as a major nuclide that affects the reduction of radiation exposure to decommissioning workers. In the future, based on the nuclide selection results derived from this study, we plan to study the evaluation of worker radiation exposure from crud to decommissioning workers by deriving evaluation results of crud and radioactive source terms within the reactor core.
        2.
        2023.11 구독 인증기관·개인회원 무료
        In Natural Analogue Study, Concrete is one of the important engineering barrier components in the Multi-thin wall concept of radioactive waste disposal and plays the most important role in disposal sites. The concrete barrier at the disposal site loses its role as a barrier due to various deterioration phenomena such as settlement, earthquake, and ground movement, causing the disposed waste to leak into the natural ecosystem. Some of the key factor is deterioration triggered by sulfate attack. Concrete deterioration induced by sulfate is commonly manifested in an extensive scale when a concrete structure makes contact with soil or water, aggravating its performance. In this study, an accelerated concrete deterioration evaluation experiment was performed using a total of three experimental methods to evaluate the reaction between concrete and water. The first experiment was a deterioration evaluation using Demi. Water, the second was a deterioration evaluation using KURT groundwater after extraction, and the last experiment was a concrete deterioration evaluation using KURT groundwater and sodium sulfate. For all of these experiments, accelerated concrete deterioration experiments were conducted after immersion for a total of 365 days, and specimens were taken out at 30-day intervals and characterization analysis such as SEM and EDS was performed. Experimental analyzes have shown that various chemical species are generated or destroyed over time. In the future, we plan to continue to conduct a total of three concrete deterioration evaluation experiments above, and additionally evaluate the chemical reaction between bentonite and concrete.
        3.
        2023.05 구독 인증기관·개인회원 무료
        When decommissioning and operating nuclear power plants, a lot of radioactive waste in concentrated waste powder, slurry, sludge, and powder is generated. The radioactive waste, non-conformity for disposal, cannot be treated or disposed of, but is currently being stored instead. To dispose of the waste, the waste can be solidified by mixing with an appropriate solidification agent. However, when the solidification agent and powder particles are mixed as in the conventional method, the final volume of the waste form to be disposed of increases. In order to solve this problem, in this study, volume reduction was achieved, compared to the existing powder, by applying the roll compaction technology to mold the radioactive waste into compressed pellets. Soil, concrete, concentrate waste, and contaminated soil powder were used as test materials, and pellets were prepared under different operating conditions. Subsequently, a compressive strength test was performed to confirm the integrity and optimal process conditions of the manufactured pellets. However, in order to perform the compressive strength test, the upper and lower surfaces of the pellets must be horizontal, but the pellet has the shape of two tetrahedrons joined together. Hence, test specimens for measuring compressive strength were prepared by making a surface treatment jig. The compressive strength test showed a high strength of 5.20~28.20 MPa. The process conditions showing high compressive strengths were selected as the optimal process conditions. Finally, the volume reduction ratios were calculated by measuring the weight, density and volume of the manufactured pellets. The degrees of volume reduction of the manufactured pellets compared to the existing powder were checked. When the roll gap was 0 mm, the average reduction ratios of the test materials were 3.7 for the soil, 4.0 for the concrete, 4.6 for the concentrate waste, and 3.8 for the contaminated soil. When roll gap was 1 mm, the ratios were 2.7 for the soil, 2.9 for the concrete, 3.4 for the concentrate waste, and 2.8 for the contaminated soil. Therefore, from a conservative point of view (Roll gap = 1 mm), when powdered waste is formed into pellets, it means that the volume is reduced by 1/2.7 for soil, 1/2.9 for concrete, 1/3.4 for concentrated waste, and 1/2.8 for contaminated soil.
        4.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Biomass carbon materials with high rate capacity have great potential to boost supercapacitors with cost effective, fast charging– discharging performance and high safety requirements, yet currently suffers from a lack of targeted preparation methods. Here we propose a facile FeCl3 assisted hydrothermal carbonization strategy to prepare ultra-high rate biomass carbon from apple residues (ARs). In the preparation process, ARs were first hydrothermally carbonized into a porous precursor which embedded by Fe species, and then synchronously graphitized and activated to form biocarbon with a large special surface area (2159.3 m2 g− 1) and high degree of graphitization. The material exhibited a considerable specific capacitance of 297.5 F g− 1 at 0.5 A g− 1 and outstanding capacitance retention of 85.7% at 10 A g− 1 in 6 M KOH, and moreover, achieved an energy density of 16.2 Wh kg− 1 with the power density of 350.3 W kg− 1. After 8000 cycles, an initial capacitance of 95.2% was maintained. Our findings provide a new idea for boosting the rate capacity of carbon-based electrode materials.
        4,300원
        6.
        2021.08 구독 인증기관 무료, 개인회원 유료
        South Korea is one of the strongest countries in the TV drama industry, and its TV dramas are an important way for the spread of national culture to the outside world. Through years of development, a high-quality TV drama industry chain has been formed. Compared with South Korea, Chinese TV drama industry has a certain degree of immaturity in terms of production mode and external communication. The author provides a reference for the future development of Chinese TV drama industry through a comparative analysis of the production and broadcasting modes of TV dramas in China and South Korea .
        4,900원
        9.
        2021.02 구독 인증기관 무료, 개인회원 유료
        In recent years, China's animation market has been gradually prospered with the screening of many high-quality animation works. At the same time, a large number of high-quality national animation IP has also been born. From "Nezha" to "Legend of Deification" Chinese animation has triumphed both in box office and public praise. Sadly, compared with these achievements, the whole animation derivative industry looks depressed. In this paper, the current developing status of domestic and foreign animation derivatives industry is compared and analyzed, and the foreign successful experience of the development of animation derivatives industry and the problems existing in the operation mode of derivatives in China are summarized. Finally, put forward suggestions for the next development of China's animation derivatives industry.
        4,300원
        10.
        2020.12 구독 인증기관 무료, 개인회원 유료
        This study investigates the status of ICT in Education in Turkmenistan for achieving the United Nations’(UN) Sustainable Development Goal 4 (SDG4) targets. The study uses two methods for data collection: a detailed review of the literature and a survey. For data collection through survey, the National Education Institute of Turkmenistan and United Nations Development Programme (UNDP) Turkmenistan Office representatives take in part to capture different dimensions of the same phenomenon; the integration of ICT into education in terms of achieving the SDG4 in the country. The results indicate the specific issues such as harnessing ICT as an access tool for education, using ICT for the equity and quality of education as well as the teachers’ ICT competency which need to be improved for achieving the Education 2030 in Turkmenistan. The study also finds priority areas for upcoming years: ICT for transforming and expanding TVET and higher education, improving teacher competency as well as building and upgrading learning environments in Turkmenistan.
        4,600원
        11.
        2020.11 구독 인증기관 무료, 개인회원 유료
        The emergence and explosive growth of social media platforms such as Instagram, Facebook, Tweeter, etc. has dramatically changed both the way consumers shop and brands advertise. According to a study by Track Maven, Instagram is the most engaging social media platform nowadays with the most average interactions per post per 1,000 followers. It stimulates “Instagram influencer marketing” to develop rapidly and promotes a great variety of brands. It has fundamentally changed the balance of power between customers and brands because it allows peer recommendations to play a much larger role in purchasing decisions [13]. It has become one of the trendiest marketing strategies that focus on influential figures on Instagram rather than targeting on the market as a whole. Instagram influencer marketing highlights content creators who may impact their audiences’ buying habits. For example, shoppers who compare hotel reviews can simply search “hashtag plus hotel name (e.g. #hiltonnewyork) in Instagram and read people’s experiences with that hotel among related posts. Many of those posts were created by influencers who are collaborating with the brands to advertise. Based on activities of more than 12 million Instagram influencers between the first quarter of 2018 and the first quarter of 2019, Social bakers created a report to categorize influencers into three categories: micro-influencers who have fewer than 10,000 followers, macro influencers with 10,000 to 50,000 followers, and celebrities who attracts a million or more followers. The majority of Instagram influencers are “micro-influencers”. Their finding also reveals that the combined amount of sponsored content on Instagram for all three categories of influencers in North America has jumped 150% in the last year.
        4,000원
        13.
        2020.08 구독 인증기관 무료, 개인회원 유료
        In recent years, Chinese animation has been rising, and many well-made animation films have emerged. However, most of its companies fail to design based on user experience, resulting in poor sales and slow development of the animation derivatives industry. This paper mainly starts from the design methods of user experience, discusses the development status of animation derivatives based on user experience, explores the problems existing in China's current animation derivative industry, and finally studies the design strategy of animation derivatives experience through market analysis.
        5,800원
        15.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Heteroatoms in situ-doped hierarchical porous hollow-activated carbons (HPHACs) have been prepared innovatively by pyrolyzation of setaria viridis combined with alkaline activation for the first time. The micro-morphology, pore structure, chemical compositions, and electrochemical properties are researched in detail. The obtained HPHACs are served as outstanding electrode materials in electrochemical energy storage ascribe to the particular hierarchical porous and hollow structure, and the precursor setaria viridis is advantage of eco-friendly as well as cost-effective. Electrochemical measurement results of the HPHACs electrodes exhibit not only high specific capacitance of 350 F g−1 at 0.2 A g−1, and impressive surface specific capacitance (Cs) of 49.9 μF cm−2, but also substantial rate capability of 68% retention (238 F g−1 at 10 A g−1) and good cycle stability with 99% retention over 5000 cycles at 5 A g−1 in 6 M KOH. Besides, the symmetrical supercapacitor device based on the HPHACs electrodes exhibits excellent energy density of 49.5 Wh kg−1 at power density of 175 W kg−1, but still maintains favorable energy density of 32.0 Wh kg−1 at current density of 1 A g−1 in 1-ethy-3-methylimidazolium tetrafluoroborate ( EMIMBF4) ionic liquid electrolyte, and the excellent cycle stability behaviour shows the nearly 97% ratio capacitance retention of the initial capacitance after 10,000 cycles at current density of 2 A g−1. Overall, the results indicate that HPHACs derived from setaria viridis have appealing electrochemical performances thus are promising electrode materials for supercapacitor devices and large-scale applications.
        4,600원
        19.
        2018.04 구독 인증기관·개인회원 무료
        지의류 추출물이 흰줄숲모기(Aedes albopictus)에 대하여 살충활성 및 생장 억제에 미치는 영향을 조사하였다. 2종의 지의류의 메탄올 추출물이 흰줄숲모기 3령 유충에 미치는 치사농도, 사충수, 생장억제를 알아보기 위한 실험을 진행한 결과Parmelia sp.엽상체 추출물경우 LC50농도는 0.13%로 나타났으며 Porpidia albocaerulescens의 LC50농 도는 0.45%로 나타나 Parmelia sp.의 추출물이 더 높은 살충활성을 보였다. 24h, 48h, 72h의 노출시간 따른 농도별 사충 수를 조사한 결과, 전반적으로 지의류의 메탄올 추출물이 고농도일수록, 노출시간이 길어질수록 유충의 사충 수는 증가하였다. Parmelia sp. 엽상체의 추출물에서 사육한 유충의 경우 용화시간은 대조군보다 지연되었고, 추출물의 농도가 높을수록 더 많은 시간이 지연된 것으로 보아 지의류 추출물이 흰줄숲모기 유충의 생장을 억제하는 효과가 있음을 확인하였다.
        20.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study aimed to evaluate the damage persistence during subsequent years in kiwifruit vines defoliated by strong wind such as typhoons. Artificial defoliation was treated on five-year-old ‘Jecy Gold’ kiwifruit vines grown in a plastic house in year 2013 and 2014 by applying four levels of defoliation, i.e., 0, 50, 75, and 100% in August 23, 2013 and 100% defoliation in July 28 and August 29, 2014, respectively. Return bloom and fruit quality were investigated in the following two years, 2014 and 2015. A significant reduction in number of flowers per shoot in the following year, 2014 was recorded for the vines with 50%, 75%, and 100% defoliations treated in 2013 compared to the control vines. The number of flowers per florescence was significantly reduced for defoliated vines. Nevertheless, the fruit quality parameters, i.e., fruit length, width, weight, firmness, TSS, acidity, and dry matter content were not significantly different for the defoliated vines compared to the control vines. The vines defoliated in 2013 at 75% and 100% levels showed a significant reduction of number of flower per inflorescence in 2015 compared to the 0% defoliation. However, the number of flowers per shoot and fruit quality were not significantly different. Also, the number of flowers per inflorescence in 2015 was significantly reduced by July 28, 2014 or August 29, 2014 defoliation compared to non-defoliated vines while the number of flowers per shoot, and fruit quality in 2015 were not significantly different between treatments and control vines. Accordance with the present findings, the flowering is considerably affected by the shortage of carbohydrate supply than the fruit quality of ‘Jecy Gold’ kiwifruit. In addition, the negative impacts of severe defoliation in flowering of ‘Jecy Gold’ kiwifruit might be persisted more than one season from the time of defoliation and consequently, the total yield might be reduced in the following seasons after defoliation.
        4,000원
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