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        검색결과 192

        61.
        2018.04 구독 인증기관·개인회원 무료
        환경부 지정 보호지역인 특정도서는 현재 249개소로 이들을 대상으로 지형․경관, 지질, 식생, 동・식물상 및 해안무척 추동물, 해조류 분류군 대상으로 1차 특정도서기본계획(‘05~’14) 이후 2차 특정기본계획(‘15~’24)에 따라 매년 10~15개 씩 정밀조사가 수행되고 있다. 특정도서의 곤충조사는 2006~2008년 3년간 39개 도서를 제외하고 전무하였다. 특정도서 의 지정사유 중 자연경관․지질의 우수성이 가장 높고 식생이 우수가 다음으로 높아 시간이 지남에 따라 식생과 관련된 해충 및 외래종의 기착지로도 이용될 수 있는 특성을 가지고 있어 2015년부터 곤충에 대한 조사가 이루어지고 있다. 본 연구는 2016년 인천광역시 옹진군 일대 소초지도, 신도, 어평도, 항도, 뭉퉁도, 서만도, 할미염 7개 특정도서에 대한 곤충상 및 군집분석 결과와 각 도서별 과거 2007년 보고된 곤충상을 비교한 결과를 보고하는 바이다.
        62.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        배초향은 항동맥경화나 항박테리아의 특성을 가지는 한약재에 널리 사용되는 영년생 약용식물이다. 연구의 목적은 수경재배에서 배양액의 종류와 PPFD값에 따른 배초향의 생장 및 항산화 물질의 변화를 조사하는 것이다. 배초향은 주야간 16:8 시간의 일장조건에서 150과 200 μmol·m-2·s-1 PPFD 조건과 일본원시(HES), 서울시립대(UOS), 유럽채소연구소(EVR), 오오츠카 배양액(OTS)을 이용하여 6주간 재배하였다. OTS 배양액조 건에서 자란 배초향의 지상부 및 지하부 건물중은 다른 배양액 처리구와 비교하여 유의적으로 높았다. 배초향의 틸리아닌 함량은 OTS 처리에서 가장 높았으며 다음으로 EVR, HES, UOS 순서로 낮아졌다. 총 아카세틴의 함량은 EVR처리에서 가장 높았으나 OTS처리와는 유의적 차이를 보이지 않았다. 또한 200 μmol·m-2·s-1 PPFD 조건에서 자란 배초향은 PPFD 150처리구와 비교하여 유의적으로 생체중과 건물중이 증가하였으며 기능성 물질은 틸리아닌과 아카세틴의 함량도 높았다. 본 연구는 수경재배 방식을 이용하여 식물공장에서 배초향을 재배할 경우 200 μmol·m-2·s-1 PPFD 조건과 OTS 배양액 조건에서 경제적인 광원조건으로 최적 바이오매스 생산량과 틸라아닌과 아카세틴의 함량을 증가시킬 수 있을 것으로 제안한다.
        4,000원
        64.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        경주 방사성폐기물 처분시설은 향후 80만 포장물을 처분할 계획이며 다양한 처분방식 및 관리형태를 가진 복합계가 될 것 이다. 본 논문에서는 전체부지 처분용량(80만 포장물) 처분시설의 단계별 개발에 따른 영향을 평가하기 위하여 처분시설 종 합개발계획(안)에 따른 예비안전성평가를 수행하였다. 각 시나리오에 대한 안전성평가결과 처분시설의 성능목표치를 만족 하였다. 다만, 전체처분시설의 안전성 평가결과에 중준위 방사성폐기물로 인하여 1단계 동굴 처분시설이 가장 크게 영향을 미치므로 처분시설의 안전성 향상을 위하여 처분방사능량제한 설정 등 관리방안이 필요하다. Safety Case 단계별 구축을 통 하여 중·저준위 방사성폐기물 처분시설 종합개발 과정에서 인지된 불확실성을 저감하여 안전성을 증진 시킬 수 있을 것으 로 판단된다.
        6,400원
        67.
        2016.10 구독 인증기관·개인회원 무료
        For useful research animal to study human’s disease and for xenotransplantation donor, pig was studied to improve the quality of in vitro production (IVP). But, still the developmental ability of in vitro porcine embryos is still lower than in vivo embryos. Using a antioxidant is one of the strategy to overcome the drawback of in vitro producted embryos by protecting the oocyte from free radicals during in vitro maturation (IVM). Resveratrol, one of the plant-derived polyphenol antioxidants, have been used as effective antioxidants. Therefore, resveratrol treatment during IVM of porcine oocytes is expected to improve efficiency of the IVP by reducing free radical accumulation. In this study, we designed control (no treated) and resveratrol treatment groups (0, 2 and 4uM), evaluated maturation rate, cleavage rate, blastocyst formation rate and total cell number. Additionally GSH and ROS accumulation levels were measured via staining oocytes. In the results, maturation rate had not shown significant difference among the groups. However, in further development, not only the results of cleavage rate (0uM : 84.64±2.65 vs 4uM : 93.67±2.36, p<0.05) and blastocyst formation rate (0uM : 6.39± 0.90, vs 4uM : 13.67±2.32, P<0.05) were significantly increased in 4uM resveratrol treated group, and result of total cell number (0uM : 22.47±0.76 vs 2, 4uM : 30.35±1.76, 27.65±1.23, P<0.05) also shown significant difference in 2, 4uM resveratrol groups with control. GSH accumulated levels of matured oocytes in resvetrol treated groups were significantly higher than control. Meanwhile ROS levels of treated groups were significantly reduced [GSH (0uM : 142±10.49 vs 2, 4uM : 163.2±3.29, 169.7±0.94, P<0.05), ROS (0uM : 170.2±7.76 vs 2, 4uM : 118.6±7.90, 130±7.07, P<0.05)]. From these results, we conclude the treatment of resveratol improved further development of porcine embryos by regulating intracellular GSH, ROS levels during porcine IVM. Therefore, exogenous antioxidants such as a resveratol can be supportive substances for obtaining the improved quality of IVP.
        68.
        2016.10 구독 인증기관·개인회원 무료
        Euzophera batangensis (Lepidotera: Pyralidae) is seriously damaging trunks or branches of persimmon tree (Diospyros sp.). We tested the attractiveness of (Z)-9-tetradecen-1-ol (Z9-14OH) and (Z9,E12)-tetradeca- 9,12-dien-1-ol (Z9,E12-14OH) with single or blended baits at southern parts of Korea in 2014 and 2015. The monoene was not attractive at all at three places during the two years. In 2014, diene was equally or more attractive than the mixture in Jinju and Suncheon, respectively. In 2015 too, the attractiveness of diene and mixture was not different in Jinju and Munsan. Monitoring of the seasonal occurrence of E. batangesis with the sex pheromone components revealed that it occurred three times a year; the first occurrence from early April to mid May, the second from early Jun to mid July, and the third from late August to late September.
        69.
        2016.07 구독 인증기관·개인회원 무료
        The purpose of this study is to present theoretical and experimental evidence for a niche strategy for small and medium online shopping malls to run business against large famous shopping malls prevailing the E-commerce market. For this, the present study demonstrates how chronic construal levels of consumers may affect their alternative choice for online shopping via various contexts (Experiment 1-3) and categories (Experiment 3-5). This series of experiments suggests that consumers with high construal level can be defined as a group that is relatively less susceptible to reputation of the shopping malls. Thus, strategically targeting this group of consumers will help small and medium-sized online malls lacking store reputation to mitigate their competitive disadvantage. Based on both existing literature and the experimental results as above, this research discusses possible methods for small and medium-sized online shopping malls to target high-construal segmentation.
        70.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The squid Todarodes pacificus is a commercially important fishery species in East Asia. As East Asians consume raw or lightly cooked squids, there has been growing concern about parasitic infections associated with squid consumption. In the current study, five squids caught in the East Sea were sampled for parasitological research from the biggest fishery market in Seoul, Republic of Korea. They were dissected and examined for parasites using a light microscope. Proteocephalus sp. was isolated and identified using field emission scanning electron microscopy, PCR, and sequencing. Given that Proteocephalus spp. can be affected by water temperature and geographical characteristics, further research on Proteocephalus spp. with respect to changes in water temperature in the East Sea is important.
        3,000원
        71.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Graphene was grown on molybdenum (Mo) foil by a chemical vapor deposition method at different growth temperatures (1000°C, 1100°C, and 1200°C). The properties of graphene were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and Raman spectroscopy. The results showed that the quality of the deposited graphene layer was affected by the growth temperature. XRD results showed the presence of a carbide phase on the Mo surface; the presence of carbide was more intense at 1200°C. Additionally, a higher I2D/IG ratio (0.418) was observed at 1200°C, which implies that there are fewer graphene layers at this temperature. The lowest ID/IG ratio (0.908) for the graphene layers was obtained at 1200°C, suggesting that graphene had fewer defects at this temperature. The size of the graphene domains was also calculated. We found that by increasing the growth temperature, the graphene domain size also increased.
        4,000원
        72.
        2016.04 구독 인증기관·개인회원 무료
        Oxalic acid has a nematicidal activity against the root-knot nematode Meloidogyne incognita. High producer of oxalic acid was isolated, and then named as Aspergillus niger F22. Oxalic acid production was investigated under various temperatures from 20 – 33oC and rotational speeds in 5 L jar fermenters. Yield of oxalic acid increased with decreasing temperature. The highest yield was obtained at 23oC, showing the yield of oxalic acid of 8.7 g/L, whereas oxalic acid production was least at 33oC. At 20oC, the yield was lower than that of 23oC. At a rotational speed of 300 rpm, serious oxygen depletion was present from 48 - 72 h, resulting in low productivity of 26.2 mg /L·h. When a rotational speed was set at 600 rpm, dissolved oxygen tension was over 40% and oxalic acid production increased up to approximately 55%. Viscosity during the culture differed with temperatures. Viscosity increased with the increment of temperatures. When A. niger F22 was cultured at 23oC, viscosity was 810 cP, which was favorable for oxalic acid production.
        75.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The sintering mechanisms of nanoscale copper powders have been investigated. A molecular dynamics (MD) simulation with the embedded-atom method (EAM) was employed for these simulations. The dimensional changes for initial-stage sintering such as characteristic lengths, neck growth, and neck angle were calculated to understand the densification behavior of copper nano-powders. Factors affecting sintering such as the temperature, powder size, and crystalline misalignment between adjacent powders have also been studied. These results could provide information of setting the processing cycles and material designs applicable to nano-powders. In addition, it is expected that MD simulation will be a foundation for the multi-scale modeling in sintering process.
        4,000원
        76.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Powder injection molding is an important manufacturing technology to mass produce superalloy components with complex shape. Injection molding step is particularly important for realizing a desired shape, which requires much time and efforts finding the optimum process condition. Therefore computer aided engineering can be very useful to find proper injection molding conditions. In this study, we have conducted a finite element method based simulation for the spiral mold test of superalloy feedstock and compared the results with experimental ones. Sensitivity analysis with both of simulation and experiment reveals that the melt temperature of superalloy feedstock is the most important factor for the full filling of mold cavity. The FEM based simulation matches well the experimental results. This study contributes to the optimization of superalloy powder injection molding process.
        4,000원
        77.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To compensate for the critical shortage of human organs for allotransplantation, xenotransplantation studies using genetically modified pigs are being performed in Korea. Two types of pigs that are used are α1,3-galactosyltransferase gene knockout (GalT KO) pigs and GalT KO+hCD46 (human complement regulatory protein) pigs. The present study measured the gestation time, birth weight, daily growth rate, and heart weight of both kinds of transgenic minipigs. The gestation period for both types of pigs was 117∼119 days. There was no difference in the body weight of GalT KO (—/+) and GalT KO (—/—) piglets, but GalT KO+hCD46 (—hCD46+/+) pigs were significantly heavier at birth than were GalT KO+hCD46 (—hCD46+/—hCD46+) pigs. During the first 10 weeks of life, the daily weight gain of GalT KO+hCD46 (—hCD46+/—CD46+) piglets, which are considered the optimal type for xenotransplantation, was 0.19 kg. The weight of hearts from GalT KO piglets up to two months of age was affected more by body weight than by age. Transgenic pigs showed no differences in gestation period or reproductive ability compared with normal pigs. These results comprise basic data that may be used in xenotransplantation studies and transgenic animal production in Korea.
        4,000원
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