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        검색결과 56

        1.
        2023.11 구독 인증기관·개인회원 무료
        The domestic Pressurized Heavy Water Reactor (PWHR) nuclear power plant, Wolsong Unit 1, was permanently shut down on December 24, 2019. However, research on decommissioning has mainly focused on Pressurized Water Reactors (PWRs), with a notable absence of both domestic and international experience in the decommissioning of PHWRs. If proper business management such as radiation safety and waste is not performed, it can lead to increased business risks and costs in decommissioning. Therefore, the assessment of waste volume and cost, which provide fundamental data for the nuclear decommissioning process, is a crucial technical requirement before initiating the actual decommissioning of Wolsong Unit 1. Decommissioning radiation-contaminated structures and facilities presents significant challenges due to high radiation levels, making it difficult for workers to access these areas. Therefore, technology development should precede decommissioning process assessments and safety evaluations, facilitating the derivation of optimal decommissioning procedures and ensuring worker safety while enhancing the efficiency of decommissioning operations. In this study, we have developed a program to estimate decommissioning waste amounts for PHWRs, building upon prior research on PWR decommissioning projects while accounting for the specific design characteristics of PHWRs. To evaluate the amount of radioactive waste generated during decommissioning, we considered the characteristics of radioactive waste, disposal methods, packaging container specifications, and the criteria for the transfer of radioactive waste to disposal operators. Based on the derived algorithm, we conducted a detailed design and implemented the program. The proposed program is based on 3D modeling of the decommissioning components and the calculation of the Work Difficulty Factor (WDF), which is used to determine the time weighting factors for each task. Program users can select the cutting and packaging conditions for decommissioning components, estimate waste amount based on the chosen decommissioning method, and calculate costs using time weighting factors. It can be applied not only to PHWRs, but also to PWRs and non-nuclear fields, providing a flexible tool for optimizing decommissioning process.
        2.
        2022.10 구독 인증기관·개인회원 무료
        With the aging of nuclear power plants (NPPs) in 37 countries around the world, 207 out of 437 NPPs have been permanently shutdown as of August 2022 according to the IAEA. In Korea, the decommissioning of NPPs is emerging as a challenge due to the permanent shutdown of Kori Unit 1 and Wolsong Unit 1. However, there are no cases of decommissioning activities for Heavy Water Reactor (HWR) such as Wolsong Unit 1 although most of the decommissioning technologies for Light Water Reactor (LWR) such as Kori Unit 1 have been developed and there are cases of overseas decommissioning activities. This study shows the development of a decommissioning waste amount/cost/process linkage program for decommissioning Pressurized Heavy Water Reactor (PHWR), i.e. CANDU NPPs. The proposed program is an integrated management program that can derive optimal processes from an economic and safety perspective when decommissioning PHWR based on 3D modeling of the structures and digital mock-up system that links the characteristic data of PHWR, equipment and construction methods. This program can be used to simulate the nuclear decommissioning activities in a virtual space in three dimensions, and to evaluate the decommissioning operation characteristics, waste amount, cost, and exposure dose to worker. In order to verify the results, our methods for calculating optimal decommissioning quantity, which are closely related to radiological impact on workers and cost reduction during decommissioning, were compared with the methods of the foreign specialized institution (NAGRA). The optimal decommissioning quantity can be calculated by classifying the radioactivity level through MCNP modeling of waste, investigating domestic disposal containers, and selecting cutting sizes, so that costs can be reduced according to the final disposal waste reduction. As the target waste to be decommissioning for comparative study with NAGRA, the calandria in PHWR was modeled using MCNP. For packaging waste container, NAGRA selected three (P2A, P3, MOSAIK), and we selected two (P2A, P3) and compared them. It is intended to develop an integrated management program to derive the optimal process for decommissioning PHWR by linking the optimal decommissioning quantity calculation methodology with the detailed studies on exposure dose to worker, decommissioning order, difficulty of work, and cost evaluation. As a result, it is considered that it can be used not only for PHWR but also for other types of NPPs decommissioning in the future to derive optimal results such as worker safety and cost reduction.
        4.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Functional dyspepsia (FD) is a gastrointestinal disorder with diverse symptoms but no structural or organic manifestations. Benachio-F® (herein named ‘BF-1’) is an over-the-counter liquid digestive formulated with multiple herbal extracts, which has been reported to improve symptoms of FD. A total two experiments were conducted. First, we examined whether BF-1 can modulate the progression of FD through two experimental rat models. A total of three doses (0.3x, 1x, 3x of the human equivalent dose) were used. In the gastric emptying model, both 1x (standard) or 3x (3-fold-concentrated) BF-1 enhanced gastric emptying was compared with that of vehicle-treated animals. In a feeding inhibition model induced by acute restraint stress, treatment with 1x or 3x BF-1 led to a similar degree of restoration in food intake that was comparable to that of acotiamide-treated animals. Among the constituents of BF, fennel is known for its choleretic effect. Thus, we next investigated whether a novel BF-based formula (named ‘BF-2’) that contains an increased amount of fennel extract (3.5-fold over BF-1), has greater potency in increasing bile flow. BF-2 showed a superior choleretic effect compared to BF-1. Furthermore, the postprandial concentration of serum secretin was higher in animals pretreated with BF-2 than in those pretreated with BF-1, suggesting that the increased choleretic effect of BF-2 is related to secretin production. Our results demonstrate that BF-1 can modulate the pathophysiological mechanisms of FD by exerting prokinetic and stress-relieving effects, and that BF-2 has a better choleretic effect than BF-1.
        4,000원
        5.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have prepared MIL-101/graphene oxide (GO) composites with various mixing molar ratio of Fe-containing metal– organic frameworks (MOFs) against GO. When synthesizing MOFs, it was possible to synthesize uniform crystal powders using hydrothermal method. MIL-101 consists of a terephthalic acid (TPA) ligand, with the central metal composed of Fe, which was the working electrode material for supercapacitors. Field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis had been done to ascertain microstructures and morphologies of the composites. Cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge measurements were performed to analyze the electrochemical properties of the composite electrodes in 6 M KOH electrolyte. By controlling the metal ligand mole ratio against GO, we prepared a changed MOF structure and a different composite morphology, which could be studied as one of the promising optimized electrode materials for supercapacitors.
        4,200원
        6.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mesenchymal stem cells (MSCs) have been recognized as a therapeutic tool for various diseases due to its unique ability for tissue regeneration and immune regulation. However, poor survival during in vitro expansion and after being administrated in vivo limits its clinical uses. Accordingly, protocols for enhancing cell survivability is critical for establishing an efficient cell therapy is needed. CDDOMe is a synthetic C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid, which is known to stimulate nuclear factor erythroid 2-related factor 2 (Nrf2)- antioxidant response element (ARE) pathway. Herein, report that CDDO-Me promoted the proliferation of MSCs and increased colony forming units (CFU) numbers. No alteration in differentiation into tri-lineage mesodermal cells was found after CDDO-Me treatment. We observed that CDDO-Me treatment reduced the cell death induced by oxidative stress, demonstrated by the augment in the expression of Nrf2-downstream genes. Lastly, CDDO-Me led to the nuclear translocation of NRF2. Our data indicate that CDDO-Me can enhance the functionality of MSCs by stimulating cell survival and increasing viability under oxidative stress.
        4,000원
        8.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        ‘다하’는 농촌진흥청 국립식량과학원 고령지농업연구소에서 2018년도 육성한 사계성 딸기 신품종이다. ‘다하’는 ‘새봉3호’ 를 모본으로 하고 ‘고하’를 부본으로 2012년 교배하여, 고온 장일 조건에서 과실이 크고 화방이 연속적으로 출현되는 우수한 사계성 개체를 선발한 것이다. 대관령의 여름재배 작형에서 2015년부터 2016년까지 생산력 및 특성검정을 거쳐 ‘새봉 10호’로 계통명을 부여하고, 지역적응성 시험을 거쳐 ‘다하’로 명명하였다. ‘다하’의 초형은 반개장형이며, 초세가 왕성하다. 과실모양은 원추형이며, 과색은 붉은 색이다. ‘다하’의 화방장은 25.3 cm 로 대조품종인 ‘고하’보다 14.1 cm 더 짧았다. 또한 ‘다하’의 출현화방수는 12.3개로 ‘고하’의 15.0개보다 2.7개 더 적게 발 생하였다. ‘다하’의 평균과중은 12.0 g으로 ‘고하’의 9.0 g보다 3.0 g 더 무거웠다. 그러나 과실품질은 두 품종 모두 비슷하였다. ‘다하’의 상품수량은 45,972 kg·ha-1로 ‘고하’의 21,481 kg·ha-1 보다 214% 증수되었다. 따라서 ‘다하’는 대과성이며 수확량이 많은 사계성 품종으로 농가보급 시 높은 소득이 기대된다.
        4,000원
        10.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hepatic stellate cells (HSCs) play essential roles in normal and pathophysiological function in liver. In steady state, HSCs contribute to retinoid storage, immune tolerance, and extracellular matrix (ECM) homeostasis. Upon liver injury, they become activated and lead to morphological and functional changes. Studies have demonstrated that activation of HSCs by various stimuli such as toxins, microbial infection, or metabolic overload can promote the fibrotic changes in liver by production of ECM. Herein, we provide current knowledge about the basic characteristics of HSCs and the mechanism by which they are activated.
        4,000원
        11.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고슬’은 농촌진흥청 국립식량과학원 고령지농업연구소에서 2016년도 육성한 중일성 딸기 신품종이다. ‘고슬’은 ‘Albion’을 모본으로 하고 ‘설향’을 부본으로 2012년 교배하여, 고온장일조건에서 과실이 크고 화방이 연속적으로 출현되는 우수한 중일성 개체를 선발한 것이다. 대관령의 가을재배 작형에서 2015년부터 2016년까지 생산력 및 특성검정을 거쳐 ‘새봉 9호’로 계통명을 부여하고, 지역적응성 시험을 거쳐 ‘고슬’로 명명하였다. ‘고슬’의 초형은 개장형이며, 엽형은 둥근형이며, 초세는 중간이다. 과실모양은 원추형이며, 과색은 붉은색이다. ‘고슬’의 화방수는 2.5개로 ‘Redpearl’보다 1.5개 더 많았다. ‘고슬’의 경도는 31.6 g·mm-2으로 매우 단단하였다. 또한 수확기간 2개월 동안 8.4개의 상품과일이 수확되었다. 가을에 수확된 ’고슬‘의 상품수량은 19,580 kg·ha-1로 경제적 재배가 가능하였다. 신품종 딸기 ‘고슬’은 고온에서도 화방이 잘 발생하고 착과되어 우리나라 고랭지 및 동남아 고원지대에서 재배가 가능한 중일성 딸기 품종이다.
        4,000원
        13.
        2019.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        As automation systems become more common, there is growing interest in functional labeling systems using organic and inorganic hybrid materials. Especially, the demand for thermally and chemically stable labeling paper that can be used in a high temperature environment above 300 oC and a strong acid and base atmosphere is increasing. In this study, a composite coating solution for the development of labeling paper with excellent thermal and chemical stability is prepared by mixing a silica inorganic binder and titanium dioxide. The silica inorganic binder is synthesized using a sol-gel process and mixed with titanium dioxide to improve whiteness at high-temperature. Adhesion between the polyimide substrate and the coating layer is secured and the surface properties of the coating layer, including the thermal and chemical stability, are investigated in detail. The effects of the coating solution dispersion on the surface properties of the coating layer are also analyzed. Finally, it is confirmed that the developed functional labeling paper showed excellent printability.
        4,000원
        14.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        ‘무하’품종은 농촌진흥청 국립식량과학원 고령지농업연구소에서 2015년도 육성한 사계성 딸기 신품종이다. ‘무하’는 ‘매향’ 품종을 모본으로 하고 ‘Selva’ 품종을 부본으로 2010년 교배하여, 고온장일조건에서 당도가 높고 꽃대가 연속적으로 출현되는 우수한 사계성 개체를 선발한 것이다. 대관령의 여름재배 작형에서 2013년 생산력 검정, 2014년 특성검정을 거쳐 ‘새봉 7호’로 계통명을 부여하고, 2015년에 지역적응성 시험을 거쳐 ‘무하’로 명명하였다. ‘무하’의 초형은 반개장형이며 , 엽형은 타원형이며, 초세가 강하다. 과실모양은 원추형이며, 과색은 붉은색이다. ‘무하’의 화방수는 18.7개로 ‘Flamenco’보다 10.0개보다 8.7개 더 발생한다. ‘무하의 경도는 ’Flamenco‘ 와 비슷하다. ‘무하’의 상품과수는 37.2개 였으며, 상품수량은 23,981 kg·ha-1으로 ‘Flamenco’ 품종보다 159% 더 많았다. 신품종 사계성 딸기 ‘무하’는 고온에서도 꽃대가 잘 발생하고 착과되어 동남아 북부 및 고원지대에서 재배가 가능한 사계성 딸기 품종이다.
        4,000원
        16.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 국내 유통 중인 농산물 9품목(n = 578)에 대한 납과 카드뮴 함량을 조사하고 이들의 섭취로 인한 위해성을 평가하고자 하였다. 납과 카드뮴의 함량은 마이크로웨이브 분해 후 ICP-MS로 분석하였다. 조사대상 농산물의 납 평균 함량은 각각 보리 0.014 mg/kg, 완두콩 0.010 mg/kg, 강낭콩 0.008 mg/kg, 녹두 0.006 mg/kg, 파인애플 0.008 mg/kg, 살구 0.016 mg/kg, 매실 0.015 mg/kg, 자두 0.021 mg/kg, 대추 0.019 mg/kg이었고, 카드뮴 평균함량은 보리 0.017 mg/kg, 완두콩 0.004 mg/kg, 강낭콩 0.007 mg/kg, 녹두 0.005 mg/kg, 파인애플 0.001 mg/kg, 살구 0.002 mg/kg, 매실 0.002 mg/kg, 자두 0.002 mg/kg, 대추 0.003 mg/kg이었다. 모든 시료의 납, 카드뮴 함량은 EU, CODEX 및 국내 기준보다 낮은 수준이었다. 조사 대상 농산물에 대한 납, 카드뮴의 인체노출량을 산출한 결과, 납은 잠정주간섭취허용량(PTWI, 25 μg/kg b.w./week)의 0.067%, 카드뮴은 월간잠정섭취허용량(PTMI, 25 μg/kg b.w./month)의 0.28%이었다. 이상의 결과는 조사 대상 농산물의 납, 카드뮴 오염도와 이들의 섭취에 의한 위해성이 모두 낮은 수준이라는 것을 보여준다.
        4,000원
        19.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effects of ultrasound and enzyme treatments on reducing sugar production from Korean 6-row barley Dahyang during the mashing process of brewing were studied. The concentration of reducing sugar produced by the traditional method was 41.5 mg/mL. The treatment of both the ultrasound at 400 W and amyloglucosidase (0.1 U/mL) increased the reducing sugar concentration produced in the mashing process by 15% compared to the traditional method. In addition, both treatments reduced the total mashing time from 115 min to 70 min. The combination of ultrasound and amyloglucosidase treatment increased the reducing sugar production yield by 17% during mashing, in comparison with the traditional method.
        4,000원
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