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        검색결과 216

        1.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the efficacy of a wild boar repellent (Repellent A) consisting of tannins and plant oils (castor oil, garlic oil, and cinnamon oil). Sixty farmed wild boars (4-8 months old) were divided into three groups: the normal control group (NC, n=20), the experimental group (EP, n=20), and the comparative experimental group (C-EP, n=20), which used Repellent B consisting of guaiacol, eugenol, menthol, thymol, and indole. EP and C-EP were equipped with four repellents per feeder, while no repellents were installed in the NC feeder. The feed intake and the number of feeding approaches were measured for one week in all groups. The number of approach of wild boars in feeders was monitored daily using a CCTV camera. The daily feed intake per farmed wild boar in EP and C-EP was significantly decreased compared to NC (p<0.05), and EP was significantly decreased compared to C-EP (p<0.05). In the average number of daily approaches, EP and C-EP were significantly decreased compared to NC (p<0.05), and EP was significantly decreased compared to C-EP (p<0.05). In conclusion, Product A has been confirmed to have excellent repellent effects on wild boars, and it could be used to prevent wild boars from approaching pig farms.
        3,000원
        4.
        2023.11 구독 인증기관·개인회원 무료
        The design and fabrication of suitable waste forms with high thermal and structural stability are essential for the safe management and disposal of radioactive wastes. In particular, the thermal properties and temperature distribution of waste form containing high heat-generating nuclides such as Cs and Sr can be used to evaluate its thermal stability, but also provide useful information for the design of canisters, storage systems, and repositories. In this study, a new program code-based thermal analysis framework has been developed to facilitate the characterization, design, and optimization of the waste form. Matlab was used as a software development platform because it provides powerful mathematical computation and visualization components such as the partial differential equation (PDE) toolbox for solving heat transfer problems using finite element method, the App Designer for graphical user interface (GUI), and the MATLAB Compiler for sharing MATLAB programs as standalone applications and web applications. The thermal analysis results such as temperature distribution, heat flux, maximum/ minimum temperature, and centerline/surface temperature profile are visualized with graphs and tables. To evaluate the effectiveness of the developed program, several design and optimization studies were carried out for the SrTiO3 waste form, selected as a stable form of strontium nuclide.
        5.
        2023.11 구독 인증기관·개인회원 무료
        While many countries consider direct disposal of the spent nuclear fuels, they need to consider long-term disposal scenarios with severe accidents such as the contact between underwater and the spent nuclear fuel due to large defect of the canister. Radionuclides releases rapidly with contacting water or slowly with dissolution of UO2 matrix. The former is known as the ‘Instant Release’, and the latter is ‘Congruential Release’. Even though the instant release fractions (IRF) are much smaller than the congruential ones, IRF has to be treated carefully due to the fact that the instant releases lead to much larger value of the exposure dose rates than the congruential ones which proceed very slowly. It is known that the exposure dose rates by the instant releases are ~25 times larger than the one by the congruent release. The radionuclides from UO2 matrix migrate to the grain boundary, make bubbles, and make tunnels, which leads to instant releases of some radionuclides. The radionuclides in the gap between UO2 pellet and cladding can be also instantly released. In addition, the radionuclides in the crud are instantly released. But in this paper, nuclides from the crud are not regarded, due to the lack of the leaching data. Meanwhile, there’re some nuclides that released from the construction materials like the cladding, the Rod Cluster Control Assembly (RCCA), or the other metal parts. In this work, IRF values for major IRF nuclides such as Cs, I, Cl, Se for the reference PWR spent fuels of South Korea were evaluated based on the rationale from literatures’ review. In particular, these evaluations were done as the function of fission gas release (FGR), average discharge burnup, and fuel dimensions. In addition, the values of IRF for the other nuclides were also suggested based on the other institutes.
        9.
        2023.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The second generation of stars in the globular clusters (GCs) of the Milky Way (MW) exhibit unusually high N, Na, or Al, compared to typical Galactic halo stars at similar metallicities. The halo field stars enhanced with such elements are believed to have originated in disrupted GCs or escaped from existing GCs. We identify such stars in the metallicity range −3.0 < [Fe/H] < 0.0 from a sample of ∼36,800 giant stars observed in the Sloan Digital Sky Survey and Large Sky Area Multi-Object Fiber Spectroscopic Telescope survey, and present their dynamical properties. The N-rich population (NRP) and N-normal population (NNP) among our giant sample do not exhibit similarities in either in their metallicity distribution function (MDF) or dynamical properties. We find that, even though the MDF of the NRP looks similar to that of the MW’s GCs in the range of [Fe/H] < −1.0, our analysis of the dynamical properties does not indicate similarities between them in the same metallicity range, implying that the escaped members from existing GCs may account for a small fraction of our N-rich stars, or the orbits of the present GCs have been altered by the dynamical friction of the MW. We also find a significant increase in the fraction of N-rich stars in the halo field in the very metal-poor (VMP; [Fe/H] < −2.0) regime, comprising up to ∼20% of the fraction of the N-rich stars below [Fe/H] = −2.5, hinting that partially or fully destroyed VMP GCs may have in some degree contributed to the Galactic halo. A more detailed dynamical analysis of the NRP reveals that our sample of N-rich stars do not share a single common origin. Although a substantial fraction of the N-rich stars seem to originate from the GCs formed in situ, more than 60% of them are not associated with those of typical Galactic populations, but probably have extragalactic origins associated with Gaia Sausage/Enceladus, Sequoia, and Sagittarius dwarf galaxies, as well as with presently unrecognized progenitors.
        4,800원
        10.
        2022.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        담낭암은 드물지만 치명적인 악성 종양으로 초기에는 증상이 없어 대부분의 담낭암이 늦게 진단되고, 급속하게 인접 장기로 전이되기 때문에 예후가 불량하다. 따라서 담낭암을 조기에 발견하는 경우는 드물고, 담낭담석이나 용종으로 수술적 절제를 시행한 후 우연히 발견되는 때가 대부분이다. 저자들은 급성 무결석 담낭염 환자에서 초음파 내시경을 통해 비교적 조기에 담낭관암을 발견하여 성공적으로 치료할 수 있었던 증례를 경험하였다. 이에 문헌고찰과 함께 보고한다.
        4,000원
        11.
        2022.10 구독 인증기관·개인회원 무료
        We established pretreatment method of solidified cement ion-exchange resin samples generated before 2003 in nuclear power plants for measurement of non-volatile radionuclide activity. A microwave digestion system (MDS) with mixed acid (HCl-HNO3-HF-H2O2) was used to dissolve cement and to desorb non-volatile elements such as Ce, Co, Cs, Fe, Nb, Ni, Re, Sr and U from mixed ion-exchange resin. The content of Ce, Co, Fe, Nb, Ni, Re, Sr, U and Cs after pretreatment of cement plus mixed ion-exchange resin was measured by ICP-AES and ICP-MS, respectively. As iron and strontium are also present in cement, their content after dissolving a certain amount of cement was measured by ICP-AES. All elements except Nb were quantitatively recovered. Especially since the Nb recovery was low at 72.0±2.5%, the MDS following addition of the mixed acid to the resin was operated once more for desorbing Nb from it. Finally the recovery of Nb was over 95%. This sample pretreatment method will be applied to solidified cement ion-exchange resin samples generated in nuclear power plants for assessment of radionuclide inventory.
        12.
        2022.10 구독 인증기관·개인회원 무료
        According to the Nuclear Safety and Security Commission (NSSC) Notice No. 2021-26 “Delivery Regulations for the Low- and Intermediate Level Radioactive Waste (LILW)”, the activity of 3H, 14C, 55Fe, 58Co, 60Co, 59Ni, 63Ni, 90Sr, 94Nb, 99Tc, 129I, 137Cs, 144Ce, and gross alpha must be identified. Currently, the scaling factor of the dry active waste (DAW) for LILW is applied as an indirect evaluation method in Korea. The analyses are used the destructive methods and 55Fe, 60Co, 59Ni, 63Ni, 90Sr, 94Nb, 99Tc, and 137Cs, which are classified as nonvolatile nuclides, are separated through sequential separation and then measured by gamma detector, liquid scintillation counter (LSC), alpha/beta total counter (Gas Proportional Counter, GPC), and ICP-MS. We will introduce how to apply the existing nuclide separation method and improve the measurement method to supplement it.
        13.
        2022.10 구독 인증기관·개인회원 무료
        The safe, efficient and cost-effective decommissioning and dismantling of radioactive facilities requires the accurate characterization of the radionuclide activities and dose rate environment. And it is critical across many nuclear industries to identify and locate sources of radiation accurately and quickly. One of the more challenging aspects of dealing with radiation is that you cannot see it directly, which can result in potential exposure when working in those environments. Generally, semiconductor detectors have better energy resolution than scintillation detectors, but the maximum achievable count rates are limited by long pulse signals. Whereas some high pure germanium detectors have been developed to operate at high count rates, and these HPGe detectors could obtain gamma-ray spectra at high count rates exceeding 1 Mcps. However, HPGe detectors require cooling devices to reduce the leak currents, which becomes disadvantageous when developing portable radiation detectors. Furthermore, chemicalcompound semiconductor detectors made of cadmium telluride and cadmium zinc telluride are popular, because they have good energy resolution and are available at room temperature. However, CdTe and CZT detectors develop irradiation-induced defects under intense gamma-ray fields. In this Review, we start with the fundamentals of gamma rays detection and review the recent developments in scintillators gamma-ray detectors. The key factors affecting the detector performance are summarized. We also give an outlook on the field, with emphasis on the challenges to be overcome.
        14.
        2022.10 구독 인증기관·개인회원 무료
        In KAERI, Waste storage facility in the radiation management area has stored a large amount of wood waste. The amount of waste is approximately 27,000 kg, it accounts for 17% of the total waste in waste storage facility. Proper disposal of wood waste improves the fire resistance performance, secure storage space and reduce disposal costs. In order to self-disposal of wood waste, it is necessary to satisfy the self-disposal standards stipulated by the domestic Atomic Energy Act and the treatment standards of the Waste Management Act. The main factors of standards are surface contaminant, radionuclide activity and radiation dose effects. To confirm the contamination of wood waste, direct indirect measurement methods and gamma nuclide analysis were performed. To evaluate radiation dose, various computational programs were used. The results of the analysis were satisfied with domestic regulations on the classification and self-disposal of radioactive wastes. Based on this results, KAERI submitted the report on wood waste self-disposal plan to obtain approval. After final approval, wood waste is to be incinerated and incineration ash is to be buried in the designated place. The objective of this study is to provide total procedure of wood waste self-disposal and effective representative sampling method.
        15.
        2022.10 구독 인증기관·개인회원 무료
        In 2004, in order to comply with UN Security Council Resolution 1540, the European Union (EU) came into force with Regulation 428/2009 for the export control of dual-use items, which has been working to prevent the proliferation of weapons of mass destruction (WMDs). In August 2021, it amended the EU 821/2021 to include mandating the introduction of ICPs for exporters in the member countries in order to strengthen controls over the transfer of tangible and intangible technologies. The main contents are as follows; 1) Mandatory introduction of Internal Compliance Program (ICP): Exporters within the EU countries should introduce a transaction review procedure through the ICP in consideration of their size and organization. 2) Export control on Cyber Surveillance Items to protect human rights: In order to protect human rights and comply with the obligations of international human rights law, EU countries should implement export controls on cyber-monitoring items exported from customs zones in the EU. Cyber surveillance items are specially designed to monitor, extract, collect or analyze data such as biometrics through intrusion of information and communication systems or deep packet hijacking. However, items used for purely commercial programs such as billing, marketing, quality service, user satisfaction or network security are excluded. 3) Expansion of the Catch-all system: EU countries should utilize the catch-all system to strengthen export controls on cyber-monitoring items, including dual-use items. 4) Strengthening control over the cloud: Exporters and EU countries should extend the scope of intangible technology transfer, such as electronic media, fax, and telephone, outside the EU’s customs territory, and apply export control regulations such as general or comprehensive licenses to cloud transmissions outside the EU territory. 5) Introduction of large-scale project authorization: To reduce the administrative burden on enterprises (especially small and medium-sized enterprises) and authorities when exporters with individual or collective licenses export to one or more specific end-users for the purpose of large scale projects, provided that they ensure the implementation of an appropriate level of export controls; EU countries may introduce large-scale project license systems in the form of general authorization. Recently, there is a possibility that the ROK would export its nuclear technologies including APR1400 to the EU member countries in the midst of the EU adoption of carbon-zero policy. In this paper, we have analyzed the EU export control regulations and suggested the future direction of nuclear export control programs in the ROK.
        17.
        2022.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ship reporting systems are used to exchange information between ship and shore. To realize the digital ship reporting concept, the International Maritime Organization (IMO) recently developed revised guidelines and descriptions of Maritime Service for ship reporting systems in the context of e-navigation. To improve the existing ship reporting system, each Administration should follow the IMO guidelines for ship reporting system. The purpose of this paper is to identify follow-up measures to be taken by the Korean Government as a member State according to the recently developed IMO guidelines in the context of e-navigation, and to present the considerations for the implementation of follow-up measures in Korea. In this study, a ship reporting system in Korea was investigated to identify the considerations for the digital ship reporting system. Consequently, a digital reporting system and digital traffic clearance were proposed and considerations for ship reporting system are presented. This paper is expected to be helpful for the safe operation of ships by presenting the considerations necessary for the implementation of an automated and standardized ship reporting system.
        4,000원
        18.
        2022.05 구독 인증기관·개인회원 무료
        The fabrication of waste forms with high thermal and structural stability is an essential technology for the safe management and disposal of radioactive wastes. In particular, the thermal characteristics of waste forms containing high heat-generating nuclides such as Cs and Sr can be used for the optimized design of the waste form to secure its thermal safety, and they also provide basic design data for the safe management of canisters, storage systems, and repositories. The Korea Atomic Energy Research Institute is actively developing processes and equipment for fabricating various types of high-level wastes into a stable glass or ceramic waste form. In previous research related to the thermal analysis of the waste form, a relatively simple analysis was performed by using the analytic solution of the one-dimensional steady-state heat conduction equation considering the decay heat properties of the waste. As a specific application study, the optimized diameter of the cylindrical glass waste form was proposed by evaluating the centerline temperature of the waste form. In this study, we extended previous research by introducing a more complicated model, and the main results are summarized as follows. First, an analytical solution was derived by applying the temperaturedependent thermal conductivity expressed in the general form of polynomial function to the onedimensional heat conduction problem previously studied. Second, the two-dimensional axisymmetric steady-state heat conduction problem with a more realistic cylinder model with finite length was modeled and solved by using the finite element method via Matlab’s PDE (partial differential equation) toolbox. Third, thermal analysis was performed on the SrTiO3 waste form, selected as a stable form of strontium nuclide, using the developed analytical and numerical methods. The differences in the temperature distribution and computation time were evaluated through a comparative study of both solutions. Although the problem considered in this study could easily be solved by using commercial CFD software such as ANSYS or SolidWorks, a code-based program was developed to facilitate parametric design study in conjunction with optimization algorithms. The analysis results could be used to evaluate the thermal stability of waste form and to optimize the shape and size of the waste form in consideration of the design constraints of storage systems or repositories.
        20.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        영양은 모든 생명활동의 근본이며, 생물의 진화적 적응도를 결정하는 가장 중요한 요인이다. 곤충영양학은 곤충생리학의 전통적인 연구영 역이며, 최근 산업곤충의 대량사육 필요성이 증가함에 따라 그 중요성이 부각되고 있다. 이러한 중요성에도 불구하고, 곤충의 영양현상을 정확히 이해하기란 어려운데, 이는 영양의 다변량적 특성, 영양소 간의 교호작용 등으로 설명되는 영양적 복잡성에 기인한다. 영양기하학(Nutritional Geometry)은 이러한 난점을 극복하기 위해 고안된 통합적이고 다차원적인 분석모형으로서, 최근 곤충영양학이 급격하게 발전할 수 있는 이론적 및 실험적 기반을 제공하였다. 본 종설은 영양기하학의 기본개념을 소개하고, 이러한 방법론이 어떻게 최근 곤충영양학의 급속한 학문적 진보를 가능케 하였는지, 그리고 영양이 어떻게 생리학, 생태학, 진화생물학을 통합하는 구심점이 될 수 있었는지를, 최신 연구사례를 중심으로 살펴볼 것이다. 또한 본 종설은 향후 영양기하학을 적용함으로써 발전할 가능성이 높은 연구분야를 고찰할 것이다.
        4,600원
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