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        검색결과 553

        41.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The creation of marine protected areas is an important aspect of marine ecosystem sustainability. However, South Korea has not achieved its Aichi Biodiversity Target to designate 10% of its sea as marine protected by 2020. Local residents have strong opposition to the designation of protected areas in South Korea; there has been little trust in the government since the 1970s, when residents felt that their property rights were being ignored in favor of creating national parks. Here, we present a case where creation of a marine protected area was led by residents of TongYeong City. The success of a participation income project to remove marine debris in the city seems to be an important factor that led to the designation of the marine protected area. The case of TongYeong City is compared with that of nearby Geoje City, where an ecologically important stream has not been designated as a wetland protection area, although a similar participation income project enrolled the city's residents. The comparison provides a tentative assessment of the conditions needed to increase trust among residents. The results suggest that, if the projects are well-designed and well-managed, participation income projects to remove marine debris can be effective in building trust among stakeholders in potential marine protected areas.
        4,200원
        42.
        2023.05 구독 인증기관·개인회원 무료
        Since the National R&D Innovation Act was enacted in 2022, it became a crucial issue how to qualify or improve R&D activities and disseminate their outcomes. Many organizations have referred to various quality management standards such as the American National Standards Institute/American Society for Quality (ANSI/ASQ) Z1.13, International Organization for Standardization (ISO) 9001, and the American Society of Mechanical Engineers Nuclear Quality Assurance-1 (ASME NQA-1), as a means to set up their own quality system. ISO is the international standard for implementing a quality management system (QMS), which provides a framework and principles for managing an organization’s QMS, with the aim of ensuring that the organization consistently provide products or services that meet regulatory requirements. ISO 9001 can cover all aspects of an organization’s operations, and it can also be expanded to include R&D areas. The introduction of ISO 9001 to R&D aims to improve R&D practices and establish a standardized process framework for conducting R&D. ANSI/ASQ Z1.13 provides quality guidelines for research and consists of 10 sections covering various aspects of research quality, emphasizing ethical conduct, clear objectives, reliable data collection, and analysis. ASME NQA-1 is one of quality assurance standards for nuclear facility applications, but it has been extended and applied to R&D activities in the nuclear fields. It just focuses on planning, procedures, documentation, competence, equipment, and material control. KINAC has conducted extensive research on verifying and regulating nuclear activities while providing support for national nonproliferation technologies and policies. In addition to the quantitative growth achieved so far, efforts are being made to establish a qualitative and integrated management system. As a first step to achieve this goal, this study reviewed international standards and methodologies for research quality and derived the key components for R&D quality management. Moreover, the appropriate outline of quality management system framework was proposed for R&D as a regulatory support process, based on the ISO 9001. The implementation of quality management standards and procedures for R&D in KINAC, which could lead to improved research practices, more reliable data collection and analysis and increased efficiency in conducting R&D activities.
        43.
        2023.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Water electrolysis holds great potential as a method for producing renewable hydrogen fuel at large-scale, and to replace the fossil fuels responsible for greenhouse gases emissions and global climate change. To reduce the cost of hydrogen and make it competitive against fossil fuels, the efficiency of green hydrogen production should be maximized. This requires superior electrocatalysts to reduce the reaction energy barriers. The development of catalytic materials has mostly relied on empirical, trial-and-error methods because of the complicated, multidimensional, and dynamic nature of catalysis, requiring significant time and effort to find optimized multicomponent catalysts under a variety of reaction conditions. The ultimate goal for all researchers in the materials science and engineering field is the rational and efficient design of materials with desired performance. Discovering and understanding new catalysts with desired properties is at the heart of materials science research. This process can benefit from machine learning (ML), given the complex nature of catalytic reactions and vast range of candidate materials. This review summarizes recent achievements in catalysts discovery for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The basic concepts of ML algorithms and practical guides for materials scientists are also demonstrated. The challenges and strategies of applying ML are discussed, which should be collaboratively addressed by materials scientists and ML communities. The ultimate integration of ML in catalyst development is expected to accelerate the design, discovery, optimization, and interpretation of superior electrocatalysts, to realize a carbon-free ecosystem based on green hydrogen.
        4,600원
        46.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This paper explores possibilities of using language learning autobiographies as a form of identity texts in order to produce suggestions for critical teacher education. Specifically, we examined what insights we might gain by reframing Korean pre-service teachers’ autobiographies as a form of identity texts to develop reflective teachers, who affirm their identities and language learning histories. We thematically analyzed autobiographical reflection papers on English learning experiences of 73 undergraduate students enrolled in a compulsory elementary English education course at a public university in South Korea. The analysis revealed the predominance of referral to English private education experiences and a sense of linguistic insecurity felt by these pre-service teachers, who would later teach in public schools. Based on these findings, we provide suggestions for critical teacher education to foster critical language awareness and identity investment for the students. We conclude that language learning autobiographies, while incorporating characteristics of identity texts, might be a useful tool for critical pedagogies.
        6,600원
        47.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Subunit vaccines are being developed as a potential therapy for preventing microbial pathogen infection. In this study, the immunogenicity of recombinant Brucella (B.) abortus Fe/Mn superoxide dismutase (rFe/Mn SOD) protein as a subunit vaccine against B. abortus was investigated in BALB/c mice model. Brucella Fe/Mn SOD gene was cloned into a pcold-TF DNA vector. The bacterial recombinant protein was expressed using the Escherichia coli DH5α strain with a size of 82.50 kDa. The western blotting assay showed that rFe/Mn SOD reacted with Brucella-positive serum, indicating the potential immunoreactivity of this recombinant protein. After the second and third vaccinations, the peripheral CD4+ T cell population was increased significantly in the rFe/Mn SOD-immunized mice group compared to the PBS control group. Moreover, immunization of this recombinant protein increased the CD4+ T cell population from the first vaccination to the third vaccination. Meanwhile, the CD8+ T cells were slightly enhanced after the second vaccination compared to the first vaccination and compared to control groups. Fourteen days after the bacterial infection, the splenomegaly and the number of bacteria in the spleen were evaluated. The result showed that both rFe/Mn SOD and positive control RB51 decreased the bacterial replication in the spleen and the splenomegaly compared to control groups. Altogether, these results suggested that rFe/Mn SOD could induce host immunity against B. abortus infection.
        4,000원
        48.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The surfactant, 2-{2-[2-(4-nonylphenoxy)ethoxy]ethoxy}ethan-1-ol, is used in detergents, pesticides, cosmetics, and disinfectants. Since it is found in products that can be inhaled, we evaluated its toxicity to humans upon exposure. A total of 18 rats were exposed to nasal inhalation for 4 hr to determine the acute inhalation toxicity of 2-{2-[2-(4-nonylphenoxy) ethoxy]ethoxy}ethan-1-ol; the exposure concentrations were 5.0, 1.0, and 0.5 mg/L, with three males and three females at each concentration. After the end of the exposure, mortality, general symptoms, and weight changes were observed for 14 days, and autopsy findings were confirmed. The actual concentrations of the test substance in the chamber during the exposure were measured as 3.29, 1.03, and 0.52 mg/L, respectively. The delivered dose was 552.72, 173.04, and 87.36 mg/kg/day for males, and 829.08, 259.56, and 131.04 mg/kg/day for females. As a result of the test in the OECD Test Guideline 436, all animals exposed to a concentration of 3.29 mg/L died; three males and one female died out of six exposed to the 1.0 mg/L concentration. In addition, one died out of six males exposed to a 0.5 mg/L concentration. As a result, 2-{2-[2-(4-nonylphenoxy)ethoxy]ethoxy}ethan-1-ol was considered to be Globally Harmonized System of Classification and Labelling of Chemicals Category 2 (> 0.5–1 mg/L).
        4,000원
        49.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        MRI는 인체에 수소 밀도에 따른 재현성의 차이가 상대적으로 기존의 영상 장비들에 비교하여 큰 차이가 있으므로 임상 에서 이를 증명하고 문제 발견 시 이를 보완하는 것이 딥러닝 알고리즘은 매우 중요하다. 따라서 본 연구에서는 현재 특수 의료장비에서 권하는 미국 방사선 의학회(American College of Radiology, ACR)의 두부 전용 MRI 팬텀을 사용하여 영상 품질기준에 현재 임상 적용되고 있는 딥러닝 알고리즘 방법을 적용하여 딥러닝 알고리즘 적용 전후 변화를 평가해 보고자 하였다. 연구 결과 분해능을 측정하는 항목인 고대조도 공간 분해능과 같이 해상도와 관련된 영상 품질은 분해능은 개선되었음을 알 수 있었고, 그뿐만 아니라 위치의 정확도 역시도 기존에 딥러닝 알고리즘의 적용 전 영상과 통계적으로 차이가 있었다. 또한 딥러닝 알고리즘의 강도 차이에도 영상 간 차이는 없었다. 이러한 결과는 특수의료장비 영상품질관리 규정에 적용되고 있는 ACR 팬텀의 평가 기준에 부합 하나, 딥러닝 알고리즘 적용 전후 차이가 통계적으로 있었으며, 이러 한 차이가 재현성과 관련하여 추후에 조금 더 관련된 연구기 필요할 것으로 사료된다.
        4,000원
        54.
        2022.10 구독 인증기관·개인회원 무료
        In NPP (nuclear power plant), boric acid is used as a neutron absorbent. So radioactive boric acid waste are generated from various waste streams such as discharge or leakage of reactor coolant water, floor drains, drainage of equipment for operation or maintenance, reactor letdown flows and etc. Depending on KHNP, 20,015 drum (200 L drum) of concentrated boric acid waste were stored in KOREA NPP until 2019. In previous study, our group suggested the waste up-cycling process synthesizing B4C neutron absorber using boric acid waste and activated carbon waste to innovatively reduce radioactive wastes. Radioactive activated carbon waste was utilized in off gas treatment system of NPP to capture nuclide such as I-131, C-14 and H-3. Activated carbon waste is treated as low-level radioactive waste and pre-treatment system for removing nuclide from the activated carbon waste is needed to use B4C up-cycling process. In this study, microwave treatment system is suggested to treat the activated carbon waste. Activated carbon waste was exposed to microwave for a few minutes and temperature of the waste was dramatically increased over 400°C. Nuclide in the activated carbon waste were selectively removed from the waste without massive production of secondary off gas waste.
        55.
        2022.10 구독 인증기관·개인회원 무료
        As the management procedure for self-disposal wastes stored in the radiation controlled area within the Korea Atomic Energy Research Institute (KAERI) have been established, and the types and quantities of wastes are increasing. In order to carry out the disposal of wastes with various generation histories, we expanded the processing range from surface contaminated waste, which was already in progress, to volumetric contaminated waste. In this paper, a case study of self-disposal of volumetric contaminated radioactive waste for which final disposal has been completed is described. In order to carry out of self-disposal of volumetric contaminated waste, it is important to collect representative samples and prove their representativenss. Based on this, a treatment plan was established after reviewing the history of the waste to be disposed of, and the treatment work was carried out as follows; waste collection, classification by size and shape, radiation (activity) measurement, sampling of representative samples, radioactivity concentration analysis, notification to regulatory bodies and question-and-answer, final disposal. The waste is judged have no potential for contamination because the polywood used to set the flat floor between the steel frame and floorboards in the experimental greenhouse didn’t come into contact with radioactive material. However, due to the conservative approach to the presence or absence of contamination, the treatment plan was established assuming volumetric contaminated waste. The type of waste is single wood, and the major contaminating radionuclides are Sr-85 and Cs-137. After the waste was collected and sorted by size and shape, it was weighed and a representative sampling amount and sampling method were set up. A direct method of surface contamination was performed on the entire area, and the representative sample was divided into three groups of homogenized population samples using the trisection method, with three points (upper/middle/below) were sampled at a 200:1 ratio, and radioactivity concentration analysis was conducted. After confirming that the concentration was below the allowable concentration for selfdisposal, the final disposal was completed after receiving approval after reporting to the regulatory body. As a result of radioactivity concentration analysis of representative samples, the maximum radioactivity concentration for each nuclide was Sr-85: < MDC (0.00178), Cs-137 : 0.00183 Bq/g (Sr-85 : 1 Bq/g, Cs-137 : 0.1 Bq/g), which meets the nuclide allowable concentration standard. It was confirmed that the total maximum fraction of 0.02 Bq/g satisfies the criteria (In the case of mixed nuclides, the sum of the fraction is less than 1). This paper introduces the establishment and implementation of self-disposal procedures based on the experience of self-disposal of radioactive waste with volumetric contaminants, and is going to utilize it as a basic material for self-disposal of radioactive waste with volumetric contaminants that will continue in the future and contribute to the reduction of radioactive wastes.
        56.
        2022.10 구독 인증기관·개인회원 무료
        In a nuclear power plant, the activated corrosion products are deposited on the reactor coolant system. The activated corrosion products must be removed to reduce the radiation exposure to workers before maintaining or decommissioning of the nuclear power plant. In order to remove the remove the activated duplex oxide layer generated on the reactor coolant system in the pressurized water reactor (PWR), the Cyclic SP (Sulfuric acid/Permanganate)-HyBRID (Hydrazine Based Reductive metal Ion Decontamination) process developed by KAERI (Korea Atomic Energy Research Institute) can be used. After applying the Cyclic SP-HyBRID process, a sulfate-rich waste powder containing the radionuclide is generated, and the radioactive powder has to be stabilized for final disposal. In the previous study, it was confirmed that the low-temperature sintering method can be applied to immobilize the sulfate-rich waste powder. Thus, immobilization of the Cyclic SP-HyBRID process waste powder was carried out by the low-temperature sintering method using a low melting point glass, and the physicochemical and radiological characteristics of a waste form were evaluated in this study. As a result, the compressive strength of the waste form increased with increasing sintering temperature and sintering time. It is considered that the result was caused by the difference in the band gap between the bismuth borate and zinc borate, which are the products during the sintering process. It was verified that the physical stability was maintained after the 107 Gy of irradiation test. In addition, it was confirmed that the radioactive metal hydroxides contained in the waste powder converted to metal oxide forms, which have the lower solubility, at the sintering temperature. Finally, the waste form was evaluated as a low-level radioactive waste from the concentration of radionuclides contained in the waste form.
        57.
        2022.10 구독 인증기관·개인회원 무료
        In operating or permanently shut down nuclear power plants which were built between 1970s and 1990s, asbestos was widely used for ceiling materials, wall materials, and gaskets. Furthermore, it was mainly treated as a heat-resistant material like insulation. In Kori Unit 1, radioactive asbestos was replaced or removed through maintenance and repair in the containment building during the operation period of about 40 years, but radioactive asbestos still remains that need to be partially dismantled. Generally, it is more difficult to handle because it belongs to two different waste categories, radioactive waste and hazardous waste. In addition, the risk increases further due to radioactivity with the asbestos hazards itself. Therefore, it is very important to accurately determine the amount of radioactive asbestos waste and to evaluate the treatment method and disposal reduction rate before the decommissioning is started. According to the Korean Waste Management Act, three methods are recommended for the asbestos (hazardous waste) treatment: landfill, solidification, and high-temperature melting. Landfill is commonly used in Korea and the United States while high-temperature melting and solidification are additionally recommended only in Korea. Considering the situation in Korea, landfill is not appropriate due to the limitations of landfill capacity and potential risks (hazards still remain). Therefore, the other two methods can be considered sufficiently in terms of safety, detoxification, and reduction rate. This paper evaluates the amount of radioactive asbestos waste at Kori Unit 1 based on the actual asbestos building material data (as of February 2022) of the Asbestos Management Comprehensive Information Network. Vitrification is considered as a sufficient alternative for treating radioactive asbestos waste. And, it is checked whether the vitrified waste through the high-temperature melting method, plasma torch, meets the requirements such as detoxification, compressive strength and leachability for storage and disposal stability. It is expected to be useful to prepare a radioactive mixed waste management standard and to reduce the disposal cost through the reduction of final waste.
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