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        검색결과 563

        24.
        2023.05 구독 인증기관·개인회원 무료
        Cs-137, a radioactive isotope of caesium, is a commonly occurring fission product that is generated during the nuclear fission of U-235 and other fissionable isotopes in both nuclear reactors and weapons. Due to its long half-life of about 30 years and propensity to accumulate in sediments and marine organisms, Cs-137 is considered a major radionuclide for environmental radioactivity monitoring. In April 2021, as the Japanese government decided to discharge Fukushima contaminated water into the sea, the monitoring of marine radioactivity in South Korea has become increasingly significant. In this study, as an initial step towards establishing a standardized procedure for analyzing radioactive caesium in seawater, the radioactivity of Cs-137 was analyzed on a 2 L of seawater spiked with 10 Bq of Cs-137 standard solution supplied by KRISS. The seawater was collected from Im-nang Beach, situated at a distance of approximately 2 kilometers from DIRAMS. The radioactivity of Cs-137 in seawater was determined according to the improved AMP procedure presented by M.Aoyama in 2000. The seawater was pretreated using Ammonium Phosphomolybdate (AMP) coprecipitation, which has a high selectivity for caesium (Kd = ~5500), and the activity of Cs-137 was determined by gammaspectroscopy and subsequently corrected via the weight yield. The weight yield of the dried AMP/Cs compound was more than 93%. For the gamma-spectroscopy analysis, the AMP/Cs compound was dissolved in a cylindrical U8 beaker with NaOH to ensure that its shape and volume were consistent with the CRM (KRISS, 221U890-1) used to calibrate the detector. The dissolved compound was then positioned directly onto the detector housing and subjected to a measurement duration of 80,000 seconds utilizing a p-type HPGe (Ortec, GEM60) with a relative efficiency of 54%. The activity of Cs-137 was determined to be 10.81 Bq, confirming the reproducibility of the AMP coprecipitation and weight yield methods. The present experiment was carried out using a 2 L sample, but a large volume of seawater would be required to achieve a sufficient minimum detectable activity (MDA) for Cs-137 in natural seawater. Thus, a standardized procedure for analysis of radioactive caesium in natural seawater will be established through the analysis of a large volume of seawater in future studies.
        25.
        2023.05 구독 인증기관·개인회원 무료
        In this study, in relation to the demolition of the building as a research reactor, in order to establish a basic design for preparation for relocation and installation of the TRIGA Mark-II, the present conditions such as actual measurements and structural safety were investigated, as well as technologies and cases related to the relocation and installation of cultural properties. Based on this, the basic design for the relocation and installation of cultural assets was established by reviewing the disassembly and transport design of the TRIGA Mark-II and the basic plan for the relocation site. Although the structural safety of the current self-weight of the structure is judged to be reasonable, when lifting the structure, it is necessary to consider a method of lifting the foundation by reinforcing the foundation so that the tensile force can be minimized in the structure. As for the technology to be applied before TRIGA Mark-II, the technology before non-transplacement was confirmed as the most reasonable method in terms of preserving the original form, securing safety, and securing economic feasibility. Among the non-replacement technologies, the methods that can be applied before reactor 1 can be largely classified into three types. The three methods to be reviewed can be largely classified into the traditional rail movement method, the movement method using transport equipment, and the crane movement method. Each required period was calculated from the basic design results, and the modular trailer method was judged to be the most efficient. From the basic design results, the required period for each stage according to the mobile construction method was calculated. Depending on the calculation result, the modular trailer method is judged to be the most efficient. However, the final construction method should be selected according to the detailed design results. Overall, the results obtained through this study suggest that it is possible to create a memorial hall without the previous installation of TRIGA Mark-II if the structure foundation is composed independently of the building foundation after conducting a detailed characteristic investigation on the foundation of the TRIGA Mark-II structure.
        27.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 1959년 일본의 재일조선인 북한송환(북송) 발표 직후인 2월 부터 6월까지 한일 양국의 국회에서는 재일조선인 북송에 대해 어떻게 논의를 전개하였는지 분석하였다. 즉, 본 연구의 질문은 ‘1959년 초반 한국 국회와 일본 국회는 재일조선인 북송 문제에 대해 어떠한 논의를 했는가?’이다. 이에 답하기 위해 본 연구는 한국 국회와 일본 국회의 1959년 회의록을 분석했고 그 결과는 다음과 같다. 우선 한국의 국회는 북한을 주권국가가 아니라고 보며 일본의 재일조선인 북송 계획에 반대 하는 논의를 하였다. 그러나 시간이 지나면서 국회 내의 의견 차이로 한 국 국회가 재일조선인 북송 문제 해결을 위한 구체적이고 본격적인 논의 를 진행하는 것은 어려웠다. 반면 일본의 국회는 한국 정부와의 관계 악 화를 우려해 재일조선인 북송 문제를 한일회담과 구분하여 처리하는 방 안을 논의했다. 또한, 일본 국회는 일본 정부가 북송 문제에 직접 관여하 지 않도록 국제적십자위원회가 재일조선인 북송 문제를 주도하여 해결해 야 한다는 방침을 세우며, 동시에 북송 실행을 위해 북한적십자사와의 회담에서 원만한 해결을 위해 논의를 확장하였다. 그러므로 재일조선인 북송 문제에 대한 1959년 2월부터 6월까지의 한국과 일본의 양국 국회 의 논의를 비교하면, 일본 국회의 논의가 한국의 국회 논의보다 구체적 이고 적극적이었다는 사실을 알 수 있다. 이후 1959년 12월 재일조선인 의 북송은 결국 실행되었다.
        4,800원
        30.
        2023.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        When exposed to different types of bacteria in the oral cavity, denture based resins are prone to bacteria attachment. The purpose of this study was to investigate the physical, biological, and antimicrobial properties of denture base resins coated with Peony extract (200, 400, and 600 μg/mL). Specifically, the surface properties (microhardness, contact angle, and color change of the coated specimens), cell cytotoxicity (measured using MTT assay), and antimicrobial activity (against S. mutans (Streptococcus mutans) and C. albicans (Candida albicans) using a growth inhibition assay) were evaluated. The polyphenol content was measured using ultraviolet-visible (UV-vis) spectrometry. The experimental groups (specimens coated with Peony extract) and a control group (specimens coated without Peony extract) were statistically compared using a one-way analysis of variance and Tukey’s post-hoc tests. No statistically significant differences in surface properties or cell cytotoxicity were observed, which demonstrated their biocompatibility. Conversely, a statistically significant difference in antimicrobial activity was observed between the experimental and control groups after 48 h. This confirms the antimicrobial activity of the denture base resin coated with Peony extract and demonstrates that it is a promising dental material for preventing stomatitis.
        4,000원
        31.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Yam is an important tuber crop nutritionally, socio-culturally, and an income generator for many Nigerian. This explains its high demand both locally and internationally, causing increased production as Nigeria leads world production with about 45.41 million metric tons annually. The peculiarity of yam production in Nigeria entails lower yield, high cost of production, and post-harvest losses. Yam produced in Nigeria falls far below the potential crop yield, therefore, it is essential to close these yield gaps through the provision of solutions to the different constraints that hamper sustainable yam production. Despite the challenges, there is still insufficient information on the impact of policies, weeds, pests, and diseases which constitute major constraints. Nigerian farmers mostly utilize indigenous cultural approaches to manage yam production. Their goal of production is to produce yam cultivars that are suitable mainly for food products leading to the neglect of other cultivars. Few selected institutions with a yam mandate have been working on improving the production of D. rotundata and D. alata through breeding yam cultivars suitable for consumption and resilient against pests and diseases. However, more extensive studies should focus on breeding programs for yam resilient under drought and flooding, with peculiar physicochemical properties that give unique textual qualities considered in pounded yam and other yam food products. In this review paper, the significance and limitations of yam production in Nigeria and her efforts to achieve sustainable production are extensively studied.
        4,000원
        32.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to identify prognostic factors and describe the treatment outcomes of multidrug therapy in dogs with meningoencephalomyelitis of unknown etiology (MUE). A total of 23 dogs diagnosed with MUE were treated with prednisolone in combination with cyclosporine, cytosine arabinoside (CA), leflunomide, and mycophenolate mofetil. Based on the survival time, these dogs were divided into two groups: group A (n = 10), surviving for < 100 days, and group B (n = 13), surviving for > 100 days. Signalment, seizure activity, cerebrospinal fluid (CSF) analysis results, and magnetic resonance (MR) imaging findings were reviewed. Survival studies were conducted to investigate the association of each prognostic factor and treatment with the clinical outcome. There were no significant differences in age, sex, body weight, occurrence of seizures, cell number and protein concentration in the CSF, or location of lesions between groups A and B. Abnormal MR features were more frequently observed in group A than in group B. It was identified that the longest median survival time was administration of multi-drug therapy including CA. In conclusion, abnormal MR features were associated with poor prognosis in dogs with MUE and CA-based multi-drug therapy could be considered the most effective treatment of MUE.
        4,300원
        36.
        2022.10 구독 인증기관·개인회원 무료
        Boric acid-containing B-10 is used in a nuclear reactor as a coolant and absorbs thermal neutrons generated during nuclear fission in the primary circuit. Boron-containing coolant water waste is generated from maintenance, floor drain, decontamination, and reactor letdown flows. There are two options for aqueous solution waste of boric acid. One is recycling and discharge through filtration, ion exchange, and reverse osmosis. The other is immobilization after evaporation and crystallization processes. The dry powder of boric acid waste liquid can be immobilized by cement, polymer, etc. Before the mid-1990s, concentrated boric acid waste was solidified with a cement matrix. To overcome the disadvantage of low waste loading of cement waste form, a method of solidifying with paraffin was adopted. However, paraffin solids were insufficient to be disposed of as final waste. Paraffin is a kind of soft solidified material and has low compressive strength and poor leaching resistance. As a result, it was decided as an unsuitable form for disposal. In KOREA, paraffin waste form was adopted for boric acid waste treatment in the 1990s. A large amount of paraffin waste forms about 20,000 drums (200 l drum) were generated to treat boric acid waste and were stored in nuclear power sites without disposal. In this study, we want to obtain high-purity boric acid waste by oxidizing and decomposing solid paraffin waste form through a boric acid catalytic reaction. In this reaction, paraffin is separated in the form of various by-products, which can then be treated through a liquid waste treatment device or an exhaust gas treatment device. The proper temperature for sample decomposition during the catalytic reaction was set through TGA analysis. Compositions of by-products and residues generated at each stage of the reaction could be analyzed to determine the state during the reaction. Finally, the boric acid waste powder was perfectly separated from paraffin waste form with disposable products through this pyrolysis process.
        39.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Pectoralis minor tightness is associated with reduced glenohumeral internal rotation range of motion (ROM) and scapular anterior tilt alignment. However, the synergistic effects of the pectoralis minor stretching exercise and scapular posterior tilt strategy on glenohumeral internal rotation ROM and pectoralis minor length remain unexplored. Objectives: This study examined the effects of doorway stretching with scapular posterior tilt on pectoralis minor length, scapular alignment, and glenohumeral internal rotation ROM. Design: A case series study. Methods: Fifteen adults with pectoralis minor tightness performed doorway stretching with scapular posterior tilt. Pectoralis minor length, acromion–table distance, and glenohumeral internal rotation ROM were measured before and immediately after stretching. The pectoralis minor length was calculated using the pectoralis minor index. The measured variables were analyzed using a paired t-test. Results: While the pectoralis minor index and glenohumeral internal rotation ROM significantly increased, the acromion–table distance markedly decreased after doorway stretching with scapular posterior tilt (P<.05). Conclusion: Based on the present findings, doorway stretching with scapular posterior tilt could be an effective exercise for increasing glenohumeral internal rotation ROM and pectoralis minor length.
        4,000원
        40.
        2022.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study showcases an International Learning Exchange (ILE) program between North Korean (NK) refugee students in South Korea and American university students from the US. ILE programs connect two or more linguistic/ cultural groups for intercultural awareness, which provide authentic communicative environments. However, the prevalent use of English and research focus mostly on non-native English-speaking students reflect the ideology of native-speakerism embedded in ILE programs. The purpose of this study was to develop an ILE program that resists native-speakerism and to investigate its influences on native as well as non-native English-speaking students. Adopting a case-study approach, data were collected from video-taping, fieldnotes, student documents, surveys, and interviews. Findings show how the authors designed and implemented a principle-based ILE program. The responses of NK students show their growing motivation and communication ability. The responses of American students show their critical reflections on their native-speaker identities. This study offers insights into designing ILE programs based on multilingualism and translanguaging.
        6,400원
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