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        검색결과 44

        1.
        2023.11 구독 인증기관·개인회원 무료
        One of the important components of a nuclear fuel cycle facility is a hot cell. Hot cells are engineered robust structures and barriers, which are used to handle radioactive materials and to keep workers, public, and the environment safe from radioactive materials. To provide a confinement function for these hot cells, it is necessary to maintain the soundness of the physical structure, but also to maintain the negative pressure inside the hot cell using the operation of the heating, ventilation, and air conditioning (HVAC) systems. The negative pressure inside the hot cells allows air to enter from outside hot cells and limits the leakage of any contaminant or radioactive material within the hot cell to the outside. Thus, the HVAC system is one of the major components for maintaining this negative pressure in the hot cell. However, as the facility ages, all the components of the hot cell HVAC system are also subject to age-related deterioration, which can cause an unexpected failure of some parts. The abnormal operating condition from the failure results in the increase of facility downtime and the decrease in operating efficiency. Although some major parts are considered and constructed in redundancy and diversity aspects, an unexpected failure and abnormal operating condition could result in reduction of public acceptance and reliability to the facility. With the advent of the 4th Industrial Revolution, prognostics and health management (PHM) technology is advancing at a rapid pace. Korea Hydro & Nuclear Power, Siemens, and other companies have already developed technologies to constantly monitor the integrity of power plants and are applying the technology in the form of digital twins for efficiency and safety of their facility operation. The main point of PHM, based on this study, is to monitor changes and variations of soundness and safety of the operation and equipment to analyze current conditions and to ultimately predict the precursors of unexpected failures in advance. Through PHM, it would be possible to establish a maintenance plan before the failure occurs and to perform predictive maintenance rather than corrective maintenance after failures of any component. Therefore, it is of importance to select appropriate diagnostic techniques to monitor and to diagnose the condition of major components using the constant examination and investigation of the PHM technology. In this study, diagnostic techniques are investigated for monitoring of HVAC and discussed for application of PHM into nuclear fuel cycle facilities with hot cells.
        3.
        2018.04 구독 인증기관·개인회원 무료
        Insect growth regulators (IGRs) are insecticides that disrupt the normal development of target insects. Among the IGR insecticides, juvenile hormone (JH)-related IGRs are of particular interest because they stimulate or interfere with the formation of JH receptor complex. In the precious studies, novel JH-related IGRs with JH agonist (JHA) and antagonist (JHAN) activity were identified by using yeast two-hybrid system transformed with the Aedes aegypti JH receptor complex. In this study, the transcriptomic responses of Aedes albopictus were investigated upon JHA and JHAN, respectively. These results will provide important information about understanding of impact of JH-related IGRs in transcription level.
        4.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 NIH3T3와 HepG2 세포에서 에탄올유도 세포독성 및 유전독성에 대하여 녹차엑기스(GTE)와 epigallocatechin-3-gallate (EGCG)의 보호작용을 평가하는데 있다. 세포생존율은 MTT assay를 실시하였으며 DNA 손상도는 Comet assay로 실시한 결과 에탄올은 농도의존적인 세포독성과 유전독성을 나타내었다. 한편 GTE와 EGCG는 에탄올 유도 세포독성 및 DNA 손상에 대하여 유의성 있는 억제효과를 나타내었으며 DPPH시험과 LDL oxidation 및 8OH-2``dG 생성시험에서 항산화효과를 나타내었다. 한편 녹차성분 함유 시판 리큐르주도 순수 에탄올에 비하여 세포독성억제 및 DNA 손상억제효과를 나타내었다. 이상의 시험결과 GTE와 함유 EGCG는 항산화성 유전독성억제기전을 통한 에탄올독성저감 물질로 판단된다.
        4,000원
        5.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 용액 캐스팅법을 이용하여 각기 다른 함량의 VMT가 첨가된 SPAES/VMT 복합막이 제조되었다. SPAES 매트릭스 내의 VMT입자 분산은 전자주사현미경으로 관찰된 평균분포에 의해 확인되었다. 1 wt%보다 적은 함량을 포함한 복합막은 고분자 매트릭스 내에 좋은 분산성을 나타내어 막의 상부층과 하부층에 매끈한 표면을 가졌다. 복합막의 함수율은 온도가 증가함에 따라 급격하게 증가되었으며 VMT는 높은 이온교환능력으로 인하여 강한 수분친화도를 가짐으로 인해 높은 모든 흡착된 수분은 bound water인 것으로 확인하였다. VMT의 함량이 1 wt%보다 적게 첨가된 복합막에서 증가된 이온전도도와 낮아진 메탄올 투과도를 확인할 수 있었다. 모든 복합막 중에서 SPAES/VMT 1.0 wt% 복합막은 선택도 측면에서 가장 뛰어난 연료전지 성능을 가졌으며 Nafion 112과 비교하여 두배 이상 우수한 값을 나타내었다. 이것은 SPAES/VMT 1.0 wt% 복합막이 직접메탄올 연료전지의 구동을 위한 가장 우수한 조건이 될것이라 사료된다.
        4,000원
        6.
        2011.10 구독 인증기관·개인회원 무료
        Nicotine, a major teratogen of cigarettes smoke induces embryonic abnormalities during the early stages of organogenesis. In this study, the protective effect of β-carotene against nicotine–induced embryos was evaluated by morphologic scoring, nile blue staining, lipid peroxidation, SOD activity assay and real-time PCR. The embryos exposed to nicotine (1 μM) revealed remarkable morphological anomalies compared to normal control group (p<0.05), but when β-carotene (1×10‒4 μM or 5×10‒4 μM) was added concurrently to the embryos exposed to nicotine, morphological parameters were significantly improved (p<0.05). Nicotine induced oxidative stress by increased lipid peroxidation, expression of proinflammatory cytokines (TNF-α and IL-1β), caspases-3 and decreased SOD activity. However, administration of β-carotene (1×10‒4 μM or 5×10‒4 μM) restored the SOD level and decreased oxidative damage in the embryos. These results indicate that β-carotene effectively counteracts the deleterious effects of nicotine on embryos and attenuates oxidative damage possibly through its antioxidant effects.
        7.
        2011.10 구독 인증기관·개인회원 무료
        Nicotine, a major toxic component in tobacco smoke, leads to severe embryonic damages on organogenesis. We investigated if resveratrol can inhibit the nicotine–induced teratogenesis in the cultured mouse embryos (embryonic day 8.5) for 48 hours using a whole embryo culture system. The embryos exposed to nicotine (1 μM) revealed severe morphological anomalies, the increased levels of caspase-3 mRNA and lipid peroxidation, and further the lowered levels of mitochondrial manganese superoxide dismutase (SOD), cytosolic glutathione peroxidase (GPx), phospholipid hydroperoxide GPx, hypoxia-inducible factor 1α, and sirtuin mRNAs and SOD activity significantly compared to normal control group (p<0.05). However, whenre sveratrol(1×10‒5 μMor1 ×10‒4 μM) was added concurrently to the embryos exposed to nicotine, these all parameters were significantly improved (p<0.05).These findings indicate that resveratrol has a protective effect against nicotine-induced teratogenesis in mouse embryos throughout antioxidative and anti-apoptotic activities.
        10.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        6,100원
        11.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        On June 14, 2008 (the first experiment) and July 24, 2008 (the second experiment), the shores of the Boseong River and the sandy beaches, Seokgok-myun, Moksadong-myun, Gokseong-gun in Jeollanam Province were investigated and a total of 29 soft-shelled turtle (Tryonyx sinensis) eggs in the natural spawning nest eggs were collected (13 eggs were collected in the first experiment and 16 eggs in the second experiment). The temperatures in the natural spawning nests were 25.9- 36.9±0.5℃, the depth of the eggs was 5.2-7.5±0.5 cm as the distance of the average 6.4±0.5 cm. 29 eggs were scattered at least 0.2 cm interval. Artificial incubation of 29 eggs was conducted in artificial nest boxes in thermo-plastic composition of the incubator, and then incubated at 26.5-35.5±0.5℃, and an average constant temperature was 31.2-32.1±1.0℃. The incubation days ranged from 53 to 55. In case of most turtles, incubation at 31℃ (higher temperatures) generally produces all or mostly females, while incubation at 25℃(cooler temperatures) produces all or mostly males. Exceptionally, in case of genus Trionyx, the sex ratio of female : male of T. sinensis of a freshwater soft-shelled turtle was approximately 1:1, which differs from other genera of turtles and makes T. sinensis Strauch only turtles presently known to lack temperature-dependent sex determination.
        12.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng rain cover farming is expanding around Jinan county and Jangsu country of North Jeolla Province. Some farmers doing ginseng rain cover farming have suffered from difficulties due to hot weather damages. However, it is a situation that the study on mitigation techniques for high temperature damage do not exist with ginseng rain cover farming. Methods and Results : The test covering work was firstly done on April 28th for heat block film+90% black light blocking net, blue double sided film, and PE film+75% black light blocking net and when it comes to second treatment, 30% and 40% shading were implemented for heat block film group and blue double sided film group respectively and 75% black light blocking net was installed on PE film+75% shading group. When it comes to micro-climate measurement in rain cover facility, temperature, humidity and light intensity were measured during the growing period of ginseng. The results are as follows. Regarding the light transmittance (per PAR, 10 am in clear day) in facility with 1st covering, light block film covered group (LBF), blue double sided film group (BDF) and PE film group have 12.9±1.8%, has 11.6±1.0% and 27.1±1.1% respectively and after 2nd covering, in LBF groups, 30% blocking, 40% blcoking and no blocking have 10.6±1.3%, 8.2±0.9% and 12.9±1.8% and in BDF groups, 30% blocking, 40% blcoking and no blocking have 9.4±0.8%, 7.9±0.7% and 11.6±1.0 respectively and PE film group has 10.6±0.7%. Relative humidity also showed the same trend as temperature. The average monthly amount of light and maximum light intensity were lower in 30% and 40% light blocking groups of LBF and BDF and a little higher in no light blocking group compared to PE film group. The degree of high temperature damage was 1 in no LBF of BDF, but no LBF of LBF was so bad like 3. However, there was no high temperature damage in the test groups of blocking films or BDF with 30% and 40% light blocked light screens. Regarding root weight, all secondly treated groups of LBF group and BDF group were lighter compared to 4.36g of PE film group and especially, prism sheetof no light blocking group has 2.5g and BDF of of no light blocking group has 3.21g. 30 % and 40% light blocking groups of LBF group and BDF group were light with 3.20~4.07g. Conclusion : Regarding the analysis result on micro-climate in facility with different cover materials for 2 years old ginseng in ginseng rain cover farming of Gyeonggi Province, the covering method suitable for high temperature damage mitigation in ginseng rain cover farming was that 1st covering was done by PE film+75% black light blocking net and then 75% black light blocking net is additionally covered at a time when outside temperatures reaches 30℃.
        13.
        2016.05 서비스 종료(열람 제한)
        Background : Recently, there is a urgent demand for development of new varieties with enhanced resistance to various biotic/abiotic stresses. In order to develop ginseng varieties with such traits, systematic breeding program and comprehensive field studies are prerequisite. Methods and Results : ‘Cheonmyeong' seeds were collected in 2008 from the farmer field of Buyeo. Physiological investigation and propagation were conducted from 2009 to 2011. It was given the name 'Eumseong No. 8 through the observed yield trial from 2012 to 2013 and local adaptability was carried out from 2014 to 2015. All phenotypes including agronomic characteristics, seed yield, and physiological response to biotic/abiotic stresses were investigated according to the ginseng GAP and UPOV guidelines. Yellow-red leaf and pink berry at maturing stage were observed. The time of emergence, flowering and berry maturity of the ‘Cheonmyeong’ were faster than those of ‘Chunpoong’. Stem length of ‘Cheonmyeong’ was shorter than that of ‘Chunpoong’, whereas stem diameter was thicker than that of ‘Chunpoong’. Main root length was shorter but main root diameter is thicker than that of ‘Chunpoong’. Number of seeds of ‘Cheonmyeong’ was fewer than that of ‘Chunpoong’ but 1,000-seeds weight and stratification rate were higher than those of ‘Chunpoong’. The yield performance of this variety was 661 kg/10 a in local adaptability test for two years, which is 22% higher than that of ‘Chunpoong’. ‘Cheonmyeong’ showed strong resistance to phytophthora blight, mulberry mealybug and nematode and moderate resistance to alternaria blight. ‘Cheonmyeong’ did almost not occur yellow spot of aerial part and rusty skin of root, show moderate resistance at high temperatures. Conclusion : Our study demonstrated that ‘Cheonmyeong’ is an ideal variety with heavier root weight and enhanced stress resistance and contribute will enhance biotic/abiotic stress resistance and increase the farmers' income.
        14.
        2016.05 서비스 종료(열람 제한)
        Background : The research is designed to investigate the optimal cultivation technology and the growth of above-ground and below-ground sections as well as the photosynthetic characteristics for new ginseng variety “K-1” by differentiating the planting density under the conditions of transplanting and direct seedling. Methods and Results : The K-1 variety and hybrid variety (Jakyungjong) were selected for the research and the ginseng varieties were transplanted and directly sown in Yeoncheon area in 2013. The transplanting was made in the form of 5 lines × 9 rows (45 plants), 6 lines x 9 rows (54 plants), 7 lines × 9 rows (63 plants) and 8 lines × 9 rows (72 plants) in each lot (1.65㎡) while the direct seedling for testing was conducted three times in randomly blocked design in the form of 11 lines × 14 rows (154 plants), 12 lines × 14 rows (168 plants), 13 lines × 14 rows (182 plants). Various measures were collected from the 4-year transplanted ginseng and 3-year direct seedling ginseng in 2015 to find out the growth features and photosynthesis of above-ground section (rate of germination, leaf length, leaf width, stem length and leaf area index (LAI)) and the below-ground section (length, diameter, weight and class of roots). Conclusion : After the planting of the ginseng, the germination rate of K-1 for the transplanting was 85.1 ~ 92.0% across different plantation densities while that for the direct seedling was 67.7% ~ 77.9% across plantation densities, thus showing no significant difference between the two planting methods. LAI was higher for the higher planation density for both transplanting and direct seedling. As for the photosynthesis speed, the form of 6 lines × 9 rows showed the higher speed in transplanting while the form of 12 lines x 14 rows showed the higher speed in direct seedling. The photosynthesis of K-1 was higher than that of Jakyungjong. In the 4-year ginseng cultivated under the transplanting, diameter of roots, number of branch roots and weight of raw ginseng were the highest in the plantation density of 5 lines × 9 rows. The distribution of root weight was high with 23.3% and 20.0% for the 51~70g group and the 71g or above group, respectively, for the 4 year transplanted plants in the form of 5 lines × 9 rows. The growth for above-ground and below-ground sections for K-1 was better than that for Jakyungjong. As a result, it was found that the proper plantation density for the 4-year root in the transplanted K-1 was 5 lines × 9 rows considering the growth of the above-ground section, quantity and distribution of root weight.
        15.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        We constructed marine forest to restore barren grounds which are expanding in the east coast of Korea using 2 methods of (1)seedlings transplantation method and (2)underwater floating ropes method. We transplanted 3 macroalgae species, Ecklonia cava, Undaria pinnatifida, and Saccharina. japonica to construct marine forest. Blade length of Undaria pinnatifida on underwater floating ropes was 56.70±8.69㎜ in April and grew 68.75±22.30㎜ in May and 70.75±14.36㎜ in July. Blade length of S. japonica was shown 97.95-143.00㎜ in April to June. Blade length of Ecklonia cava was 30.50±1.91㎜ in May, 41.55±1.84㎜ in August, 45.30±2.57㎜ in November, 2009 and 45.30±1.99㎜ in February, 2010. The survey on Dangsa area, Ulsan-city in January, 2009 found a total number of 15 algal species(1 brown algae, 14 red algae species) with the highest variety at 5m depth of A station and the lowest at 8m depth of A and B stations. The March survey showed a total of 24 species (1 green algae, 1 brown algae, 22 red algae species) with the highest variety of 11 at depths of 3m and 5m of B station and the lowest of 6 at 10m of B station. In May, total biomass was 3,755.4g (green algae 1.2g, brown algae 199.0g, red algae 3,555.2g). From January, 2009, we found that E. cava was dominant at the depths of 3m and 5m of A and B stations while Peyssonnelia capensis was dominant at the depth of 8m of A station. The 8m depth of B station was dominated by Acrosorium polyneurum. In May, Grateloupia lanceolata was dominant at 8m depth of A station while other depths were dominated by Phycodrys fimbriata. In June, the dominant species were G. lanceolata at the 3m depth, E. cava at the 5m and P. fimbriata at the depths of 8m and 10m of A station. Under B station, G. lanceolata was dominant at the depths of 3m and 5m while P. fimbriata was dominant at the depths of 8m and 10m.
        17.
        2012.07 서비스 종료(열람 제한)
        Sorghum is the fifth most important cereal in the world as one of the staple food. For the use of natural dye, we have done some researches about sorghum red pigments extracted from stalk and leaves on its physiochemical properties, extracting methods and applications. The researches involved maximum extraction of sorghum pigment and analysis of its processing condition. Total polyphenol and tannin contents were measured by varieties and different plant parts. The stabilities of pigment by irradiation and heat treatment for processing were measured by colorimeter and thermal gravimetric analysis (TGA). In addition, hybrid nano-silica composites with sorghum pigment were made by combining with polyvinyl alcohol, polyvinyl acetate and sodium silicate. Water silica hybrids with sorghum pigment were performed by emulsion treatment. Nano-silica particles were identified and measured their size to be about 200 ~ 400 nm by SEM analysis.
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