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        검색결과 79

        1.
        2023.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The initial development plans for the six reactor designs, soon after the release of Generation IV International Forum (GIF) TRM in 2002, were characterized by high ambition [1]. Specifically, the sodium-cooled fast reactor (SFR) and very-high temperature reactor (VHTR) gained significant attention and were expected to reach the validation stage by the 2020s, with commercial viability projected for the 2030s. However, these projections have been unrealized because of various factors. The development of reactor designs by the GIF was supposed to be influenced by events such as the 2008 global financial crisis, 2011 Fukushima accident [2, 3], discovery of extensive shale oil reserves in the United States, and overly ambitious technological targets. Consequently, the momentum for VHTR development reduced significantly. In this context, the aims of this study were to compare and analyze the development progress of the six Gen IV reactor designs over the past 20 years, based on the GIF roadmaps published in 2002 and 2014. The primary focus was to examine the prospects for the reactor designs in relation to spent nuclear fuel burning in conjunction with small modular reactor (SMR), including molten salt reactor (MSR), which is expected to have spent nuclear fuel management potential.
        4,000원
        2.
        2023.11 구독 인증기관·개인회원 무료
        When occurring at a nuclear power plant (NPP) by accidents, accurate prediction and identification of the process of radioactive material dispersing into atmosphere is important to protect public and environment. Atmosphere dispersion of radioactive materials is significantly influenced by wind direction and wind speed. The government and nuclear operator continuously monitor wind data at nuclear sites through meteorological tower to prepare for such accidents involving the release of radioactive materials. The purpose of this study is to construct wind rose diagrams at 5 NPP sites (Kori, Saewool, Wolsong, Hanbit, Hanul). Wind roses serve as invaluable tool for identifying wind patterns in each region and visualizing wind directions. This can be utilized to predict the dispersion pathway and extent range of radioactive materials carried by the wind. This program will take on the role of establishing appropriate evacuation routes or shelter locations for residents when reliable wind data is not immediately available during an NPP accident. The wind data used in the study was collected from a meteorological tower located at the NPP site, and measurements were taken at 1-hour intervals for each operation over a period of ten years. The collected data underwent preprocessing, followed by the development of Python code to render the wind rose diagrams in an interpretable format. The future direction of this study will be focused on enhancing this program by integrating geographical mapping capabilities. With these advancements, it will become feasible to superimpose shelter positions on a map in accordance with prevailing wind directions. These improvements will contribute to the development of additional protective measures for residents and the proposal of alternative shelter options in response to potential radioactive material releases.
        3.
        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.
        4.
        2023.05 구독 인증기관·개인회원 무료
        Electricity generation using nuclear power has various advantages, such as carbon reduction, but the treatment of nuclear waste is emerging as a big issue in many countries. The development of technology that can selectively remove radionuclides from liquid radioactive waste is one of the ways to reduce nuclear waste. Here, we assessed a new way of removing radioactive cobalt from a liquid using an aptamer. Aptamers specifically binding cobalt ions were selected through systematic evolution of ligands by exponential enrichment (SELEX). Their binding strength and stability of their complexes with cobalt were analyzed through surface plasmon resonance assay and 2D program Mfold, respectively. The optimal aptamer/bead conjugate conditions for binding cobalt were established using a FA-C1 aptamer with the strongest binding to cobalt. Under these conditions, more than 80% of radioactive cobalt was removed, and more than 99.95% of removed cobalt was recovered. These results proved that radioactive cobalt removal using this aptamer can effectively reduce liquid radioactive waste. This means that the aptamer/bead complex can be utilized to remove various radioactive metal ions.
        5.
        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.
        6.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Grapevine leaf rust (GLR) caused by Phakopsora euvitis results in the reduction of fruit quality and yield loss in grape production. The purpose of this study was to investigate the expression of genes related with defense responses in the grapevines infected with rust pathogens. In two genotypes of Ampelopsis species inoculated with P. euvitis, the real-time PCR with RNAs was performed to investigate transcripts levels of nine defense-related genes, including pathogenesis-related 1 (PR1), β-1,3glutannase (Glu), chitinase (Chi), superoxide dismutases (SOD), glutathione peroxidase (GPX), phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), stilbene synthase 1 (STS1), and resveratrol O-methyltransferase (ROMT). All tested genes were upregulated in YG11030 as well as YG10075, while mostly the expression of genes was higher in YG10075 than that in YG11030. Glu and STS showed significantly high expression in YG10075 than in YG11030. Expression of ROMT was upregulated in YG11030 and downregulated in YG10075 at 24 hours after inoculation. The differential expression pattern of the tested genes seems to be related with the defense responses, considered to be involved in plant-resistant responses against the infection by P. euvitis, and further studies on resistant responses based on the expression of genes would provide valuable information in breeding grapes resistant to diseases.
        4,000원
        7.
        2022.05 구독 인증기관·개인회원 무료
        Once a radioactive material is released from the nuclear power plant (NPP) by accident, it is necessary to understand the behavior of radioactive plume to protect residents adequately. For this, it is essential to measure the radiation dose rate around NPPs at important locations. Our previous study developed a movable radiation detector that can be installed quickly in an accident to measure gamma dose rate in areas where environmental radiation monitoring system is not installed. The data measured by the detector are transmitted to the server in real-time through LoRA wireless communications. There are two methods to use LoRA communications; one is self-network, and the other is the network provided by the mobile carrier. A signal receiver, called a gateway, should be equipped near the installation location of radiation detectors to use a self-network without using the mobile carrier’s system. In other words, the movable radiation detectors we made can function if there should be any gateway near them. The distance capable of communication between gateway and detector is about 8 km in an open area without significant obstacles. Korea has many significant obstacles, such as mountains around most NPPs. Thus, the gateways could be installed in the proper position before the accident to operate the movable radiation detectors without problems. If the gateway is located at a high position like a mountain top, it could cover a wide area. In this study, the elevation database in the area around the NPPs was collected and analyzed to determine where gateways should be installed. The analysis range is limited in the urgent protective action planning zone. The optimization was also performed to minimize the number of gateways.
        8.
        2022.05 구독 인증기관·개인회원 무료
        For transport containers for radioactive wastes, a drop test should be performed at a height of 0.3– 1.2 m on a rigid target depending on the weight as a normal condition in the regulation. In the drop test, a strain gauge is commonly used to measure the local strain, and the position of the strain gauges is determined by the experiences of the engineer in advance of the test. For this reason, the strains can be measured at only predetermined points. The DIC (Digital Image Correlation) method using highspeed cameras can be used to measure the change in strain over the region of interest. In addition, it is possible to measure effectively even in areas with high strain gradients that are difficult to measure with strain gauges. Therefore, the DIC method can measure the strain change according to time over the entire load path. When the drop test of the transport container is performed, the impact load is delivered through the lower corner fittings-corner posts-upper corner fittings-lids. In this study, white spray was sprayed on these main load path, and black speckles were created on the spayed surface to trace the rigid motion of speckles. The images taken during the drop test can be used to create a strain field over region of interest.
        9.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        희생은 아일랜드 민족주의의 중요한 가치이자 독립 투쟁의 수단이기도 했다. 희생은 예이츠 초기희곡 세 작품—『캐슬린백작부인』,『캐슬린 니 훌리한』,『왕의 문지방』—의 주제이다. 이 논문은 이 세 작품을 중심으로 각기 다른 형태의 희생 을 연구한다.『캐슬린백작부인􋺸에서 캐슬린은 가난한 농부들을 구하기 위해 영혼까지 팔고, 『캐슬린 니 훌리한』에서 젊은 농부인 마이클은 아일랜드의 상징인 노파의 부름 에 응해 신부와 가족을 뒤에 두고 노파를 위해 싸우러 떠난다. 『왕의 문지방』에서 국 민시인인 샤나한은 국가평의회 위원이라는 시인의 오래된 권리를 수호하기 위해 목숨 을 희생한다. 이 논문의 목적은 주인공들의 희생의 의미와 그 희생에 대한 예이츠의 태도를 분석하는 것이다.
        5,100원
        10.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The bacterial soft-rot disease is one of the most critical diseases in vegetables such as Chinese cabbage. The researchers isolated two bacteria (Pseudomonas kribbensis and Pantoea vagans) from diseased tissue samples of Chinese cabbages and confirmed them as being the strains that cause soft-rot disease. Lactic-acid bacteria (LAB), were screened and used to control soft-rot disease bacteria. The researchers tested the treatments with hypochlorous acid water (HAW) and LAB supernatant to control soft-rot disease bacteria. The tests confirmed that treatments with the HAW (over 120 ppm) or LAB (Lactobacillus plantarum PL203) culture supernatants (0.5 mL) completely controlled both P. kribbensis and P. vagans.
        4,000원
        11.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 국내산 돌미나리에서 GABA생성능이 있 는 신규 유산균을 분리, 동정한 결과, Enteroccoccus casseliflavus로 확인되었다. 최근까지 Lactobacillus속과 같 은 GABA 생성 유산균에 대한 보고는 많이 되고 있고, 일 부 Enterococcs속 유산균도 보고되고 있으나 E. casseliflavus 종에 대한 보고는 없었다. 따라서 본 연구에서는 E. casseliflavus PL05 균주에 대한 GABA 생성 최적 조건을 찾기 위하여 배지의 유형, 생육 온도, 초기 pH 조건, 배양 시간, MGS 농도 및 탄소원을 포함한 다양한 조건을 테스 트하였다. PL05 균주는 MRS 혹은 TSB 배지보다 BHI 배 지에서 생육이 잘 되었으며, 배지의 초기 pH는 7-9 조건 에서 가장 생육이 왕성하였고, GABA 생성 조건 역시 유 사한 결과로 확인되었다. GABA의 기질에 해당하는 MSG 의 농도별 GABA 생성량을 조사한 결과, 7%에서 가장 높 은 생성량을 나타내었으나 5%에서도 유사한 수준으로 확 인되어 효율적인 측면에서 5%가 적합할 것으로 판단된다. 탄소원에 따른 생육 및 GABA 생성량은 말토오스를 사용 하였을 때 가장 높은 것으로 확인되었고, 이러한 최적의 조건들로 최종 테스트를 진행한 결과, 24시간째 140.06±0.71 mM의 GABA가 생성되었고, 전환율은 78.95%로 확인되 었다. 또한 반코마이신을 포함한 10개의 항생제에 대한 감 수성을 조사한 결과 내성이 없는 것을 확인하였다.
        4,000원
        12.
        2021.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Colon cancer has been considered a leading cause of cancer-associated death. Folic acid is a vitamin necessary for cellular physiological functions and cell viability. However, the association between folic acid intake and colon cancer has been examined in several prospective cohort studies are controversial. This study investigated the effects of folate intake on colon carcinogenesis and oxidative stress in an azoxymethane (AOM)/dextran sodium sulfate (DSS) institute for cancer research (ICR) mouse model. Thirty male ICR mice (5 weeks old) were divided into the control group and the experimental group supplied 0.03% folic acid via drinking water (50 mL/week/mouse) for 6 weeks. To induce colonic pre-neoplastic lesions, the animals were subcutaneously injected three times weekly with AOM (10 mg/kg body weight), followed by 2% DSS in drinking water for a week. Folic acid supplementation significantly suppressed the total number of aberrant crypt foci and aberrant crypts. Histological image data showed that folic acid supplementation attenuated neoplastic change. In addition, we measured the thiobarbituric acid reactive substances concentration of dry feces samples to identify the effect of folic acid on reactive oxygen accumulation. The folic acid supplementation group had reduced reactive oxygen species levels in dry feces compared to the control group. In conclusion, these findings indicate that folic acid suppresses colon carcinogenesis and oxidative stress in an AOM/DSS mouse model.
        4,000원
        13.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 원통형 종이포트 토마토 육묘시 Diniconazole의 처리방법이 도장억제 및 근권발달에 미치는 영향을 검토하기 위하여 수행되었다. 그 결과, 엽면적, LAR, 초장, 충실도, 생체중, RGR 및 R/S 에서 시험구간 유의한 차이를 보였다. 동일한 농도를 처리했을 경우, 근권부와 지상부의 흡수도 차이로 인해 저면관수가 엽면살포에 비해 도장억제에 효과적이었다. 저면관수는 엽면시비의 10분의 1의 농도만으로도, 20~30%정도의 동일한 도장억제 효과를 얻을 수 있었다. 디니코나졸 처리에의한 근권부 반응이 흥미로웠는데, 저면관수시 총근장, 근권부피, 평균 근경 및 근단수가 증가하였다. 특히, 0.3mm 이하의 초미세근이 감소하고 0.3~0.6mm의 세근이 증가하였다. 따라서 원통형 종이포트 육묘시 저면관수를 하는 것이 기존 엽면시비에 비해 사용량이 적으면서도 도장억제 및 근권부 활착률을 높힐 수 있을 것으로 판단된다.
        4,000원
        14.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 원통형 종이포트를 활용한 토마토 육묘시, 염스트레스를 활용하여 고온기 도장 억제가능성을 검토하기 위하여 수행되었다. 시험구는 K2SO4, KCl과 KH2PO4을 각 5, 10 dS·m-1로 처리하였고, 또한, 토마토 모종에 고염도의 칼륨을 처리하여 수분 및 저온스트레스 환경에서의 적응성 및 생존성을 조사하였다. 조사결과, 처리 농도가 높아질수록 지상·지하부 건물중, 옆면적, 순동화율 (NAR)이 감소하고, 경경과 충실도는 증가하였다. 수분 스트레스 처리 이후, 대조구는 심한 위조현상을 보였지만, KCl처리구는 양호하였다. 상대수분함량은 대조구에서 23%, KCl처리구에서 8% 감소 하였다. 또한, 대조구에 비하여 KCl 처리구는 저장시(9, 12 및 15°C) 모종의 손상 비율이 낮았다. 이와 같은 결과로 보아, KCl과 같은 고농도의 칼륨 처리가 원통형 종이포트 토마토 육묘의 도장 억제에 효과적이며 환경 스트레스 내성을 향상시키는 것으로 판단된다.
        4,200원
        15.
        2020.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 고리 1호기 해체 비용 추정을 위해 외국 원자력발전소 해체 비용 데이터를 현가화한 후 원자력발전소 해체 비용 추정 회귀 분석모델을 개발하였다. 이 모델 개발에 사용된 데이터는 해체 또는 진행 중인 BWR 13기, PWR 16기의 해체 비용 데이터이다. 회귀 분석모델 도출을 위해, 해체 비용을 종속변수로 정하고, 해체 원전의 운전 특성을 반영할 수 있게 고 안된 Contamination factor와 해체 기간을 독립변수로 선정하였다. 빅데이터 분석 도구인 R language의 통계패키지를 이용 하여 회귀 분석모델을 도출하였다. 이 회귀 분석 모델을 적용하여 고리 1호기 해체 비용을 예측한 결과, 미화 663.40~928.32 백만 달러, 한화 약 7,828.12억~1조 954.18억 원이 소요될 것으로 예측되었다.
        4,600원
        16.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the effects of heat-moisture treatment (boiling or steaming for 45 min) prior to hot air drying (70 o C for 8 h) on water activity (Aw), moisture (MC), Brix, color, and texture of dried sweet potato slices were investigated to identify the best pretreatment condition for producing dried sweet potato with the best eating quality. Dried sweet potato slices pretreated by boiling (BL) showed significantly lower Aw, MC, and hardness while Brix was significantly higher than with steaming (ST) treatment. There were no significant differences for the color, springiness, cohesiveness, gumminess, and brittleness indexes. At 8 h drying, the Aw, MC, Brix, and hardness of the BL and ST samples were 0.81 and 0.82, 19.71% and 25.53%, 53.80% and 49.40%, and 20.49 kg/cm 2 and 31.98 kg/ cm 2 , respectively. This information will be useful for manufacturers in the production of dried sweet potato slices. These findings provide evidence of the feasibility of heat-moisture treatments in the production of dried sweet potato.
        4,000원
        17.
        2019.12 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the antimicrobial effects of Australia propolis against cariogenic and periodontopathic bacteria. Antimicrobial activity was determined by evaluating the minimal bactericidal concentration (MBC). Cell cytotoxicity of propolis extract on normal human gingival fibroblast (HGF-1) cells was observed using the methylthiazolyldiphenyl-tetrazolium bromide assay. The data indicated that, with the exception of Aggregatibacter actinomycetemcomitans (KCOM 1306), the MBC values of the propolis strains were 0.25–1% without HGF-1 cell cytotoxicity. These results suggest that propolis can be used to develop oral hygiene products for the prevention of oral infectious disease.
        3,000원
        18.
        2019.09 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the antimicrobial activity of the ethanol extract of Garcinia mangostana L. (mangosteen) against Cutibacterium acnes (6 strains) and Staphylococcus aureus (6 strains). The antimicrobial activity of the mangosteen extract was evaluated based on its minimal bactericidal concentration. Cytotoxicity of the mangosteen extract against human embryonic kidney 293 (HEK 293) cells was determined using the cell counting method. The data showed that the mangosteen extract was not toxic to HEK 293 cells at a concentration of up to 16 μg/mL and killed 87.0% and 99.9% of C. acnes and S. aureus after 10 minutes and 1 hour of treatment, respectively. These results suggest that ethanol extract of mangosteen can be used as an anti-acne agent.
        4,000원
        20.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was conducted to evaluate the effects of high levels of nutrients on the growth performance, blood metabolites and carcass characteristics of Hanwoo cattle. Eighteen Hanwoo steers were fed two types of diets: 1) Nine animals were fed the conventional diet including typical levels of crude protein (CP) and total digestive nutrients (TDN), and 2) Nine animals were fed the treatment diet including high levels of CP and TDN. The average body weight (BW) and dry matter intake (DMI) were greater (P < 0.05) in the treatment group than in the conventional group at early and late fattening stages. Also, in the treatment group, the average daily gain (ADG) was greater (P < 0.05) at the late fattening stage. The serum total lipid and cholesterol levels were higher (P < 0.05) in the late fattening stage of treatment group. The carcass weight, total fat weight, longissimus muscle area and the grade of meat quality were also greater (P < 0.05) in the treatment group than the conventional diet group. This study demonstrates that high levels of CP and TDN exhibit a positive effect on the growth performance and carcass characteristics, indicating that high levels of CP and TDN can be used as a cost-effective feeding program for Hanwoo cattle by shortening the feeding period.
        4,000원
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