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        검색결과 36

        1.
        2023.11 구독 인증기관·개인회원 무료
        Nuclear power plants use ion exchange resins to purify liquid radioactive waste generated while operating nuclear power plants. In the case of PHWR, ion exchange resins are used in heavy water and dehydration systems, liquid waste treatment systems, and heavy water washing systems, and the used ion exchange resins are stored in waste resin storage tanks. The C-14 radioactivity concentration in the waste resin currently stored at the Wolseong Nuclear Power Plant is 4.6×106 Bq/g, exceeding the low-level limit, and if all is disposed of, it is 1.48×1015 Bq, exceeding the total limit of 3.04×1014 Bq of C-14 in the first stage disposal facility. Therefore, disposal is not possible at domestic low/medium-level disposal facilities. In addition, since the heavy water reactor waste resin mixture is stored at a ratio of about 20% activated carbon and zeolite mixture and about 80% waste resin, mixture extraction and separation technology and C-14 desorption and adsorption technology are required. Accordingly, research and development has been conducted domestically on methods to treat heavy water waste resin, but the waste resin mixture separation method is complex and inefficient, and there are limitations in applying it to the field due to the scale of the equipment being large compared to the field work space. Therefore, we would like to introduce a resin treatment technology that complements the problems of previous research. Previously, the waste resin mixture was extracted from the upper manhole and inspection hole of the storage tank, but in order to improve limitations such as worker safety, cost, and increased work time, the SRHS, which was planned at the time of nuclear power plant design, is utilized. In addition, by capturing high-purity 14CO2 in a liquid state in a high-pressure container, it ensures safety for long-term storage and is easy to handle when necessary, maximizing management efficiency. In addition, the modularization of the waste resin separation and withdrawal process from the storage tank, C-14 desorption and monitoring process, high-concentration 14CO2 capture and storage process, and 14CO2 adsorption process enables separation of each process, making it applicable to narrow work spaces. When this technology is used to treat waste resin mixtures in PHWR, it is expected to demonstrate its value as customized, high-efficiency equipment that can secure field applicability and safety and reflect the diverse needs of consumers according to changes in the working environment.
        2.
        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
        3.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The vehicle routing problem is one of the vibrant research problems for half a century. Many studies have extensively studied the vehicle routing problem in order to deal with practical decision-making issues in logistics. However, developments of new logistics strategies have inevitably required investigations on solution methods for solving the problem because of computational complexity and inherent constraints in the problem. For this reason, this paper suggests a simulated annealing (SA) algorithm for a variant of vehicle routing problem introduced by a previous study. The vehicle routing problem is a multi-depot and multi-trip vehicle routing problem with multiple heterogeneous vehicles restricted by the maximum permitted weight and the number of compartments. The SA algorithm generates an initial solution through a greedy-type algorithm and improves it using an enhanced SA procedure with three local search methods. A series of computational experiments are performed to evaluate the performance of the heuristic and several managerial findings are further discussed through scenario analyses. Experiment results show that the proposed SA algorithm can obtain good solutions within a reasonable computation time and scenario analyses show that a transportation system visiting non-dedicated factories shows better performance in truck management in terms of the numbers of vehicles used and trips for serving customer orders than another system visiting only dedicated factories.
        4,500원
        4.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 제주지역에서 초식동물의 방목을 위해 주로 이용되고 있는 한지형 목초의 경우에 여름철 하고기에 생산성이 저하되고 있어 여름철에 생산성을 높일 수 있는 난지형 목초를 도입하여 이용하기 위한 목적으로 수행되었다. 시험에 사용된 난지형목초는 Bermudagrass 품종(Cynodon dactylon (L.) Pers. : Giant, Cheyenne, Mohawk, Panchero Frio, Common, Tifton 85)과 Bahiagrass 품종(Paspalum notatum : TifQuik, Tifton 9)을 이용하였으며, 해발 450m고지에서 월동 후에 수확시기별 생산성 및 영양소 함량의 변화를 조사하였다. 시험구는 품종별로 8처리 3반복 난괴법으로 배치하여 수행하였다. 파종방법은 산파와 조파형태로 파종되었으며, Tifton 85 품종은 줄기 파종되었다. 시험결과를 보면 월동 후에 Bermudagrass와 Bahiagrass 품종 모두에서 동해에 의한 피해로 봄철에 재생이 대체로 늦었으며, 이중 줄기 파종되었던 Bermudagrass의 Tifton 85와 TifQuik, Tifton 9 품종이 다른 품종에 비해 동해에 비교적 강한 것으로 평가되었다. 생초와 건물수량은 품종에 따라 유의성 있는 차이를 보여 주었는데(p<0.05). Tifton 85, TifQuik 및 Tifton 9 품종의 생초 수량이 다른 품종에 비하여 우수하였으며, 건물수량은 Tifton 85와 Tifton 9 품종이 다른 품종에 비하여 우수하였다. 건물 함량에 있어서도 품종에 따라서 유의있는 차이를 보여주었고(p<0.05), Giant 품종이 다른 품종에 비하여 높은 결과를 나타내었다. 수확시기별 건물 함량은 Bermudagrass의 모든 품종에서 수확시기에 따른 차이를 보였다(p<0.05). 조단백질 함량도 품종에 따라 유의있는 차이를 나타내었고(p<0.05), Cheyenne, Mohawk, Panchero Frio와 Common 품종이 다른 품종에 비하여 높은 결과를 보여주었으며, Giant 품종에서는 파종방법과 수확시기에 따른 차이를 나타내었다(p<0.05). 조섬유 함량도 품종에 따라 차이를 나타내었으며(p<0.05), Tifton9 품종이 다른 품종에 비하여 유의있게 높은 함량을 보여주었고, 수확시기별 조섬유 함량은 Mohawk과 Tifton 85 품종에서 유의있는 결과를 나타내었다(p<0.05). 그리고 조회분 함량에 있어서도 품종에 따른 유의있는 차이를 보였으며(p<0.05), Cheyenne이 다른 품종에 비하여 유의있게 높은 함량을 보였다. 수확시기별 조회분 함량은 Cheyenne, Panchero Frio와 Tifton 85 품종에서 유의있는 결과를 나타내었고(p<0.05), 파종방법에 따른 차이는 Giant 품종에서 유의있는 결과를 보였다(p<0.05). 이러한 결과에 따르면 난지형 목초류는 품종에 따라 동해에 따른 재생능력, 생산성, 영양소 함량이 차이가 크게 나타나고 있어 이용목적에 따라 선택할 필요가 있으며, 이용을 확대하기 위하여서는 다양한 해발고도에서의 평가가 필요한 것으로 사료되었다.
        4,000원
        5.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Agriculture and rural development is the most important sector in international development cooperation business in Korea. The significance, given to this sector is manifested in the increase of ODA (Official Development Assistance) budget, the crafting of relevant legislations, and the development of organizations, and institutions. Although many studies have been conducted on international cooperation in the agricultural sector, thus far, bibliographical research has not been done. This study aimed to analyze research trends using meta-data searching method based on three database sites. The main findings revealed that: 1) majority of the literature contains the keyword, ‘ODA’; 2) research area highly focuses on rural development policy studies including “Saemaul Undong”, which implies limited literature on agricultural logistics, marketing, and trade; and 3) methodologically, more researches need to focus on theoretical and quantitative analyses.
        4,000원
        6.
        2014.09 구독 인증기관 무료, 개인회원 유료
        Oral exposure of humans by excess amounts of arsenic may cause disturbances of the reproductive system. In the present study, such exposure was modelled in rats, with the support of sperm principal parameters and histopa-thological observations. Male Sprague–Dawley rats were randomly divided into three groups where the group I was served as a normal control, group II was received sodium meta-arsenite as arsenic (10 mg/kg b.w/day) and a combi-nation of sodium meta- arsenite and sodium selenite (3 mg/kg b.w/day) in group III. After 6 weeks, there was no significant change in testis weight and in total motility of all the three experimental groups, whereas, rapid moving spermatozoa, moderately moving spermatozoa and slow moving spermatozoa were significantly decreased in arsenic treated rats as compared to control rats. The other sperm principal parameters like progressiveness, average path velocity, straightness linear velocity (VSL), curvilinear velocity (VCL), straightness, linearity sperm head elongation ratio, area, linearity amplitude of lateral head department (ALH) and beat cross frequency (BCF) were found to be reduced in arsenic intoxicated rats. These results are not correlated with the histological studies. On oral admini-stration of selenium ameliorated the adverse effects of arsenic as compared to arsenic alone treated rats. Our findings clearly demonstrate that administration of selenium could prevent some of the deleterious effects of arsenic in the testis.
        4,000원
        7.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 시험은 육성기 흑염소에 있어서 조사료원이 볏짚 위 주일 때, 농후사료 급여 수준이 발육, 사료이용성 및 경제 성에 미치는 영향을 구명하기 위해 실시하였다. 육성기 암 컷 흑염소 40두를 공시하여 농후사료 급여수준을 체중의 1.5% (T1), 1.8% (T2), 2.1% (T3) 및 자유채식구(T4)로 나누 어 급여 하였고 조사료원은 볏짚을 자유채식 하도록 하였 다. 그 결과, 일당 증체량은 T1 (1.5%), T2 (1.8%), T3 (2.1%) 및 T4(자유채식)구가 각각 50.23, 60.37, 71.46 및 98.90 g으로 농후사료의 급여 수준이 높아질수록 유의하게 높았으며(p<0.05), 조사료인 볏짚의 사료 섭취량은 농후사 료 급여수준이 증가 할수록 유의적으로 감소하는 결과를 보였다(p<0.05). 경제성 분석에 있어서 육성기 흑염소 경영 비는 농후사료를 1.5%, 1.8%, 2.1% 및 자유 채식하였을 때 각각 46,704원, 49,998원, 54,701원 및 74,613원으로 농후사 료의 급여수준이 증가할수록 경영비는 증가하였다. 이는 증체량에 있어서 T4(자유채식)구가 가장 많이 증가하였지 만 T3 (2.1%)구보다 사료비에 있어서 두당 19,912원 더 많 이 들었다. 이상의 시험 결과를 종합하여 고려할 때, 육성 기 흑염소에 있어서 조사료 원이 볏짚 단용일 경우에는 농 후사료를 2.1% 수준으로 급여하는 것이 가장 바람직할 것 으로 사료 된다.
        4,000원
        8.
        2013.09 구독 인증기관 무료, 개인회원 유료
        Spermatogenesis is initiated from spermatogonial stem cells (SSCs) that has an ability of self-renewal and unipotency to generate differentiating germ cells. The objective of this study is to develop the simple method for derivation of SSCs using non-sorting of both spermatogonia and feeder cells. Simply uncapsulated mouse testes were treated with enzymes followed by surgical mincing, and single cells were cultured in stempro-34TM cell culture media at 37℃. After 5 days of culture, aciniform of SSC colony was observed, and showed a strong alkaline phosphatase activity. Molecular characterization of mouse SSCs showed that most of the mouse SSC markers such as integrin α6 and β1, CD9 and Stra8. In addition, pluripotency embryonic stem cell (ESC) marker Oct4 were expressed, however Sox2 expression was lowered. Interestingly, expression of SSC markers such as Vasa, Dazl and PLZF were stronger than mouse ESC (mESC). This data suggest that generated mouse SSCs (mSSCs) in this study has at least similar biomarkers expression to mESC and mSSCs derived from other study. Immunocytochemistry using whole mSSC colony also confirmed that mSSCs generated from this study expressed SSC specific biomarkers such as c-kit, Thy1, Vasa and Dazl. In conclusion, mSSCs from 5 days old mouse testes were successfully established without sorting of spermatogonia, and this cells expressed both mESC and SSC specific biomarkers. This simple derivation method for mSSCs may facilitate the study of spermatogenesis.
        4,000원
        9.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was investigated the effects of marinating beef with thirteen different commercial vinegars on quality traits of Biceps femoris (BF) muscle of Hanwoo. Samples were divided into thirteen portions and injected with vinegar which was equivalent to 10% of the sample weight. The samples were all marinated for 15 hrs at 4℃ for experiments. The pH and cooking loss were tended to decrease (p<0.05) on all the vinegars and swollen rate was increased only on pomegranate vinegar. Shear force was decreased on all the thirteen commercial vinegars except persimmon vinegar. Most of commercial vinegars had influenced on water holding capacity, excluding omija-persimmon, pomegranate and grape vinegars. The yield was the greatest with the aloe-apple (p<0.05). Redness (a) was stable on aloe-apple and omija-persimmon vinegars. With an improvement of experimental design and process for future work, the results could be suggested to industrial utilization wherein low-quality meat could be improved by simple marination.
        4,000원
        10.
        2011.09 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of donor cell treatments on the production of transgenic cloned piglets. Ear fibroblast cell obtained from NIH MHC Inbred minipig was used as control. The GalT knock-out/CD46 knock-in (GalT/CD46) transgenic cell lines were established and used as donor cells. The reconstructed GalT/CD46 embryos were surgically transferred into oviduct of naturally cycling surrogate sows (Landrace × Yorkshire) on the second day of standing estrus. Unlike control (1.2 kV/cm,, 75.4%), the fusion rate of the GalT/CD46 donor cells was significantly higher in 1.5 kV/cm, (84.5%) than that of 1.25 kV/cm, (20.2%) (p<0.01). When the number of the transferred embryos were more than 129, the pregnancy and delivery rates were increased to 13/20 (65%) and 5/20 (25%) compared to less than 100 group [1/6 (16.7%) and 0/6 (0%)], respectively. To analyze the effect of donor cell culture condition on pregnancy and delivery rates, the GalT/CD46 donor cells were cultured with DMEM or serum reduced medium. In serum reduced medium group, the pregnancy and delivery rates were improved to 8/12 (66.7%) and 5/12 (41.7%) compared to DMEM group [3/7 (42.9%) and 0/7 (0%)], respectively. In conclusion, it can be postulated that an appropriate fusion condition and culture system is essential factors to increase the efficiency of the production of transgenic cloned piglets.
        4,000원
        20.
        2019.02 KCI 등재 서비스 종료(열람 제한)
        본 연구는 의료용 선형가속기 시설을 차폐하는 콘크리트에 대한 중성자 방사화 연구로써, 일반 콘크리트 와 저 방사화 콘크리트를 비교 분석하였다. 실험 방법은 MCNPX (Ver. 2.5.0)와 FISPACT-2010를 사용하여 모의실험을 진행하여, 광자선과 중성자선에 대한 차폐능을 산정하고 중성자 방사화 평가를 진행하였다. 그 결과 차폐능은 일반 콘크리트에서 20~50 ㎝ 효율적이였으며, 방사화 평가의 경우 저 방사화 콘크리트에서 방사능이 낮게 계산되었으나, 모두 자체처분허용 농도를 초과하지 않는 수준으로 산정되었다. 이를 종합적 으로 분석한 결과 일반 콘크리트를 사용하는 것이 효율적인 것으로 판단된다.
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