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        검색결과 18

        2.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mechanically enhanced supramolecular carbon nanotube (CNT) films were prepared in water by employing the π-electronrich phenyl, naphthalenyl, and pyrenyl end-functionalized polyethylene oxides (PEOs) as supramolecular linkers, followed by vacuum filtration. Among them, the supramolecular CNT film produced by the pyrenyl end-functionalized PEO (PEOPy) exhibited the highest mechanical strength, which was ~ 1.5–2 times higher than that of the CNT films produced using the typical dispersant, Triton X-100, although the functionality of PEO-Py was lower than that prepared using other linkers, and the content of PEO-Py in the CNT films was lower than that obtained using Triton X-100. Fluorescence and UV–Vis spectroscopy demonstrated that the improved mechanical properties of the supramolecular CNT film result from the formation of π–π interactions between the CNT and the pyrene moieties of the PEO-Py linker. Finally, the supramolecular CNT film exhibited a 40–50 dB electromagnetic shielding efficiency through hybridization with silver nanowires.
        4,000원
        4.
        2009.08 구독 인증기관·개인회원 무료
        Perennial ryegrass (Lolium perenne L.) is one of the most important grass species in the world's temperate zones. It is used as high-quality forage in pastures and for recreational use as turf in golf courses, lawns and parks. Genetic improvement of perennial ryegrass is difficult due to its self-incompatibility. Consequently, progress by conventional breeding can be slow. Genetic transformation is an alternative that permits direct introduction of useful genes into a plant's genome and is becoming a powerful tool to complement conventional breeding. To improve environmental stress tolerance and quality of perennial ryegrass by introducing better and useful genes into the genome, we have developed a rapid and efficient transformation system using Agrobacterium-mediated gene transfer system.
        5.
        2009.08 구독 인증기관·개인회원 무료
        In the present study, we have used an annealing-control-primer (ACP)-based differentially display RT-PCR method to identify salt-stress-induced differentially expressed genes (DEGs) in barley leaves. Using 120 ACPs, a total of 11 up-regulated genes were identified and sequenced. Temporal expression patterns of some up-regulated DEGs in response to salt stress were further analyzed by Northern blot analysis. The possible roles of these identified genes are discussed within the context of their putative role in response to salt stress. Thus, the identification of some novel genes-such as SnRK1-type protein kinase; 17 kDa, class I, small heat shock protein; and RNase S-like protein precursor genes-may offer a new avenue for better understanding the salt stress response in plants, knowledge which might be helpful for developing future strategies.
        7.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Base isolation is an innovative design strategy that provides a practical alternative for the seismic design of structures. Base isolators, mainly employed to isolate large structures subjected to earthquake ground excitations and to rehabilitate structures damaged by past earthquakes, deflect and absorb the seismic energy horizontally transmitted to the structures. This study demonstrated that the base isolation system may offer effective performance for bridges during severe seismic events through shaking table tests. Two base isolation systems using laminated rubber bearings with and without hydraulic dampers are tested. The test results strongly show that the laminate rubber bearings cause the natural period of the bridge structure increased considerably, which results in the deck acceleration and the shear forces on the deck acceleratino and the shear forces on the piers reduced significantly. The results also demonstrate that the hydraulic dampers enhance the system's capacity in dissipating energy to reduce the relative displacement between the bridge deck and the pier.
        4,000원
        8.
        2019.01 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 비슬산 이중편파 Radar 자료와, GPM 위성자료 및 21개 (Korea Meteorological Administration, KMA) 지상강우자료를 활용하여 분포형 강우-유출 모형(KIneMatic wave STOrm Runoff Model2, KIMSTORM2)을 이용해 남강댐 유역(2,293 km2)을 대상으로 유출해석을 수행 하였다. 모형의 유출 해석은 2016년 10월 5일 02:00∼09:00 총 8시간 동안 최대강우강도 33 mm/hr, 유역평균 총 강우량 82 mm이 발생한 태풍 차 바(CHABA)를 대상으로 하였으며, Radar 및 GPM 자료와 조건부합성(Conditional Merging, CM) 기법을 적용한 Radar (CM-corrected Radar) 및 GPM (CM-corrected GPM) 자료를 각각 활용하여 결과를 비교하였다. 이 때, 공간 강우자료에 유출 검보정은 남강댐 유역 내 3개의 수위관측 지점(산청, 창촌, 남강댐)을 대상으로 실시하였으며, 모형의 매개변수 초기토양수분함량, 지표와 하천의 Manning 조도계수를 이용하여 검보정하였다. 유출 결과는 결정계수(Determination coefficient, R2), Nash-Sutcliffe의 모형효율계수(NSE) 및 유출용적지수(Volume Conservation Index, VCI)를 산정하였다. 그 결과 CM-corrected Radar, GPM 자료가 평균 R2는 0.96, NSE의 경우 0.96, 유출용적지수(VCI)는 1.03으로 가장 우수한 결과를 나타내었다. 최종적으로 CM 기법을 이용한 보정된 공간분포자료는 기존의 자료에 비해 시공간적으로 정확한 홍수 예측에 사용 될 것으로 판단된다.
        9.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 보령댐 유역(163.6 km2)을 대상으로 SWAT (Soil and Water Assessment Tool) 모델, GCM (General Circulation Model) 기 후변화 시나리오와 다중회귀분석으로 산정한 미래 방류량을 활용하여 극한 기후변화 사상이 반영된 보령댐의 물부족을 평가하였다. 유역의 물수지 분석을 위해 보령댐 유역을 대상으로 기상자료, 보령댐 운영자료를 수집하였으며, SWAT 모형의 신뢰성 있는 유출량 보정을 위해 보령댐의 실 측 방류량을 이용하여 댐 운영모의를 고려하였고 유입량 및 방류량 자료를 활용하여 모형의 보정(2007~2010)과 검증(2010~2016)을 실시하였다. 기후변화를 반영하기 위해 APCC의 26개 CMIP5 GCM 자료 중 RCP (Representative Concentration Pathway)4.5와 RCP 8.5 시나리오를 SPI와 극한 가뭄지수로 분석하여 RCP 8.5 BCC-CSM1-1-M을 극한 가뭄 시나리오로 선정하였다. 2005년부터 2016년까지의 일별 관측자료로 다중회귀분석하여 월별 방류량 추정식을 만들었고, 1월부터 12월까지 각 식들의 결정계수 R2는 0.57 이상으로 나타났다. 선정된 극한 가뭄 시나리오 기상자료를 방류량 추정식에 대입하여 미래기간 일별 방류량을 구축하였다. SWAT 수문평가 결과, S3 (2037~2046) 기간 봄철 저수량이 34.0% 감소하는 것으로 분석되었다. Runs 이론을 바탕으로 물부족의 심도를 구한 다음 재현기간에 따른 빈도해석을 하였다. 5~10년 빈도의 심 도로 발생하는 물부족이 미래기간에 발생하는 빈도로 보령댐의 물부족을 평가하였다. 물부족 평가 결과, S3 (2037~2046) 기간에서 5~10년 빈도의 심도를 가지는 물부족이 기준기간(2007~2016) 보다 2회 더 발생하였으며 S3 (2037~2046)에 물부족 계획 수립이 필요하다고 판단하였다.
        10.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Italian Ryegrass, also called annual ryegrass, is a high productivity and feed value, and an upright grass that behaves like a biennial or short-lived perennial. It grows vigorously in winter and early spring. Italian ryegrass and a related species, perennial ryegrass, Lolium perenne, are the two common weedy ryegrassses. Italian ryegrass and perennial ryegrass can hybridize, resulting in offspring that are difficult to identify as either species. Ryegrasses are cultivated for turf and forage. Sometimes Italian ryegrass is grown as cover crop. It has the potential to produce high yields and, with proper management, can be high quality with good animal performance. To develop of a high quality, productivity and early variety, 11 varieties were in the seven different irradiation conditions (0Gy, 100Gy, 200Gy, 300Gy, 400Gy, 500Gy, 1,000Gy) and examined growth and germination characters of each plant as like plant height, number of tillers. As a increase of irradiation, germination rate of 11 Italian ryegrass varieties are somewhat reduced.
        14.
        2003.08 KCI 등재 서비스 종료(열람 제한)
        “Daeyou” was developed at the National Crop Experiment Station, RDA in 2001 through the crossing lines of high oil content Yeupsildlkkae and Heukim's hybrid line and it was combined by Pakesa and low seedcoat ratio variety Suwon 8 in 1991. Daeyou has grey
        15.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        “Kwangim” was developed at the National Crop Experiment Station, RDA in 2001 through induced mutations breeding by EMS treatment on the Suwon 38 perilla seeds in 1993. Kwangim has dark brown seedcoat colour with abundant and long clusters. Anthesis of Kwa
        16.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        “Dasil” was developed at the National Crop Experiment Station, RDA in 2001 through induced mutation by γ-ray irradiation on local perilla accession “Yechon” in 1994. Dasil is characterized as short plant height, dark-brown seedcoat color, medium size of s