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        검색결과 1,430

        101.
        2023.05 구독 인증기관·개인회원 무료
        The soils contaminated with radionuclides such as Cs-137 and Sr-90 should be solidified using a binder matrix, because radioactively contaminated soils pose environmental concerns and human health problems. Ordinary Portland cement has been widely used to solidify various radioactive wastes due to its low cost and simple process. In this study, simulant soil waste was solidified using cement waste form. The soils were collected around ‘Kori Nuclear Power Plant Unit 1’ and they were contaminated with the prepared simulant liquid waste containing Fe, Cr, Cs, Ni, Co, and Mn. The water-to-dry ingredients (W/D) ratio of cement waste form was 0.40. The cement paste was poured into a cubic mold (5×5×5 cm) and then cured for 28 days at room temperature. The 28-day compressive strength, water immersion, and EPA1311-toxicity characteristic leaching procedure (TCLP) tests were performed to evaluate the structural stability of cement waste form. The compressive strength was not proportional to soil waste loading, and the lowest compressive strength (4±0.1 MPa) was achieved in cement waste form containing 50wt% soil waste. After the water immersion test for 90 days, the compressive strength of cement waste form with 50wt% soil waste increased to 7.5±0.6 MPa, meeting the waste form acceptance criteria in the repository. It is believed that long-term water immersion test contributed to the additional curing and hydration reaction, resulting in the enhanced compressive strength. As a result of the TCLP test, the released amount of As, Ba, Cd, Cr, Pb, Se, Co, Cs, and Sr was less than the domestic and international standards. These results imply that cement waste form can be a promising candidate for the solidification of radioactive soil wastes.
        102.
        2023.05 구독 인증기관·개인회원 무료
        The homogeneity of radioactive spent ion exchange resins (IERs) distribution inside waste form is one of the important characteristics for acceptance of waste forms in long-term storage because heterogenous immobilization can lead to the poor structural stability of waste form. In this study, the homogeneity of metakaolin-based geopolymer waste form containing simulant IERs was evaluated using a laser-induced breakdown spectroscopy (LIBS) and statistical approach. The cation-anion mixed IERs (IRN150) were used to prepare the simulant spent IERs contaminated by non-radioactive Cs, Fe, Cr, Mn, Ni, Co, and Sr (0.44, 8.03, 6.22, 4.21, 4.66, 0.48, and 0.90 mg/g-dried IER, respectively). The K2SiO3 solution to metakaolin ratio was kept constant at 1.2 and spent IERs loading was 5wt%. For the synthesis of homogeneous geopolymer waste form, spent IERs were mixed with K2SiO3 solution and metakaolin first, and then the fresh mixture slurry was poured into plastic molds (diameter: 2.9 cm and height: 6.0 cm). The heterogeneous geopolymer waste form was also fabricated by stacking two kinds of mixtures (8wt% IERs loading in bottom and 2wt% in top) in one mold. Geopolymers were cured for 7d (1d at room temperature and 6d at 60°C). The hardened geopolymers were cut into top, middle, and bottom parts. The LIBS spectra and intensities for Cs were obtained from the top and bottom of each part. Cs was selected for target nuclide because of its good sensitivity for measurement. Shapiro-Wilk test was performed to determine the normality of LIBS data, and it revealed that data from the homogeneous sample is normal distribution (p-value = 0.9246, if p-value is higher than 0.05, it is considered as normal distribution). However, data from the heterogeneous sample showed abnormal distribution (p-value = 7.765×10-8). The coefficient of variation (CoV) was also calculated to examine the dispersion of data. It was 31.3% and 51.8% from homogeneous and heterogeneous samples, respectively. These results suggest that LIBS analysis and statistical approaches can be used to evaluate the homogeneity of waste forms for the acceptance criterion in repositories.
        103.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the beginning of the seventh century, Islamic law has played an essential role in protecting the personal, economic, judicial, and political rights of civilians during armed conflict. Fourteen centuries before the Universal Declaration of Human Rights was drafted in 1948, it had already initiated a human revolution consisting of a set of human principles. In addition, Islamic law has made a significant contribution to international humanitarian law (IHL). This paper focuses on two specific legal constructs in warfare: the definition of the combatant and the principle of distinction. This article comparatively examines how these two laws deal with different aspects of war that fall under jus ad bellum, jus in bello, and jus post bellum. A comparative analysis of the various elements and aspects of just war theory in Islamic and contemporary international law provides a much deeper understanding of its limitations. We can safely conclude that there is a unique relationship between the Islamic law of war and IHL.
        5,500원
        104.
        2023.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study assessed the influences of fluorine introduced into DLC films on the structural and mechanical properties of the sample. In addition, the effects of the fluorine incorporation on the compressive stress in DLC films were investigated. For this purpose, fluorinated diamond-like carbon (F-DLC) films were deposited on cobalt-chromium-molybdenum substrates using radio-frequency plasma-enhanced chemical vapor. The coatings were examined by Raman scattering (RS), Attenuated total reflectance Fourier transform infrared spectroscopic analysis (ATR-FTIR), and a combination of elastic recoil detection analysis and Rutherford backscattering (ERDA-RBS). Nano-indentation tests were performed to measure hardness. Also, the residual stress of the films was calculated by the Stony equation. The ATR-FTIR analysis revealed that F was present in the amorphous matrix mainly as C-F and C-F2 groups. Based on Raman spectroscopy results, it was determined that F made the DLC films more graphitic. Additionally, it was shown that adding F into the DLC coating resulted in weaker mechanical properties and the F-DLC coating exhibited lower stress than DLC films. These effects were attributed to the replacement of strong C = C by feebler C-F bonds in the F-DLC films. F-doping decreased the hardness of the DLC from 11.5 to 8.8 GPa. In addition, with F addition, the compressive stress of the DLC sample decreased from 1 to 0.7 GPa.
        4,000원
        105.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        예이츠의 가이어는 유동적이고 변화무쌍하며 움직이는 정체성을 보여주는 완벽한 은유이다. 이 논문은 예이츠 󰡔환상록󰡕의 가이어 은유를 통해 실비아 플라스의 인생과 시인으로서의 명성이 보여주는 반비례 관계를 연구한다. 시인으로서의 실비아 플라스의 여정은 한 사람으로서의 여정과 다르다. 그녀는 고백시 시인으로, 머리와 심장 사이에 있는 고통을 덜어주기 위해 글을 썼는데, 이 논문은 플라스가 겪었던 모든 사건들이 서로 어떻게 연관되는가를 논의한다. 예이츠의 가이어는 플라스의 인생과 명성의 반비례적 패턴을 예시적으로 보여준다. 인물로서의 플라스는 점차적으로 기본 가이어가 줄어드는 반면, 시인으로서의 플라스를 상징하는 대립 가이어는 점점 커지고 넓어진다.
        6,100원