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        검색결과 91

        61.
        2008.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Nano-sized TiO2-60 wt% SrO composite powders were synthesized by a sol-gel method using titanium isopropoxide and Sr(OH)2 · 8H2O as precursors. 3, -5, -7 wt%Ag spot-coated TiO2-60 wt% SrO composite powders were synthesized by a Ag electroless deposition method using TiO2-60 wt% SrO composite powders calcined at 1050˚C, which mainly exhibited the SrTiO3phase. However, a small number of rutile TiO2, Sr2TiO4 and SrO2 phases were also detected. In the Ag spot-coated powders synthesized by electroless deposition, nano-sized particles about 5-25 nm in diameter adhered to the TiO2-60 wt% SrO composite powders. The photocatalytic activity of Ag spot-coated TiO2-SrO and TiO2-SrO composite powders for degradation of phenol showed that all of TiO2-SrO composite powders were highly active under UV light irradiation. 7 wt%Ag spot-coated TiO2-60wt.%SrO composite powders had a relatively higher photocatalytic activity than did TiO2-SrO composite powders under visible light.
        4,000원
        62.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the vibration characteristic of marine N2 generator is improved by finite element analysis and experimental test. The vibration test adopted the rule of KR(Korean Register of Shipping) for the type approval. We investigate 4 type of design using finite element method and choose the best candidate. After making prototype we also test it using excitor and choose that for final design.
        4,000원
        70.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한우의 혈액성분과 도체형질간의 상관관계를 구명하여 도체 품질을 예측하고 예견되는 능력에 따른 사양관리로 도체품질을 향상시키고자 한우에서 도축 2개월 전과 수송전 그리고 도살시 혈청성분 농도와 도체 형질간의 표현형 상관을 분석한 결과는 아래와 같다. 1. 거세우의 도살 2개월 전 혈청 성분 농도와 도체 형질간의 상관에서 육량지수는 total protein (0.23), albumin(0.26), calcium(0.31)과 정의상관이나 BUN (-0.30)
        4,800원
        74.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 시험은 한우에서 연령에 따라 혈청성분들의 변화를 알아보기 위하여 한우 866두(거세 638, 비거세 228)에 대하여 혈청 농도를 분석하여 채혈시 일령을 독립 변량으로 하고 혈청 성분들을 종속변수로 하는 다항 회귀방정식으로 추정한 결과는 다음과 같다. 거세우나 비거세우 모두 같은 차수의 회귀방정식이 접합한 혈청 성분은 IGF- I (3차식) calium(1차식) 및 IP(1차식)이었고 거세우에서는 1차식이 적합하고 비거세우에서는 3차식이 적합한 혈청
        4,200원
        75.
        2018.10 서비스 종료(열람 제한)
        In this study, the purpose of this study was to develop concrete structural walls including the functions of the barrier and EMP shielding performance as the concrete structure itself. Mix of highly challenging metal fibers in super-high strength concrete. The EMP measurement frequency was evaluated for EMP card performance using a waveguide measurement method in the range of 0.8 GHz to 1.0 GHz. Performance evaluation shows that steel fiber has an increased compression strength and shielding effect as amount of mixing increases. In addition, shielding performance increased due to the increased thickness of the specimen. Therefore, it is judged that steel fiber is a good blend for shielding effects.
        76.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        This study evaluated the standard consistency, setting time, hydration heat, and compressive strength of binary blended cement concrete (general and high strength) using air cooled ladle furnace slag (LFS) of 3, 5, 7, 10wt.% as an admixture for ordinary portland cement (OPC). Results showed that binary blended cements using the LFS of lower than 5wt.% shortened the setting time and reinforced the compressive strength of concrete (general and high-strength) compared to OPC concretes although binary blended cements needed more water to achieve the standard consistency. This indicated that LFS could be used as a useful admixture for manufacturing binary blended cement. Thus, we expected that the upcycling of LFS would be contributed to save energy consumption and reduce the greenhouse gas emission from the field of cement industry.
        77.
        2015.02 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to show the geographical distribution and the temporal variation of the emission amount of biogenic volatile organic compounds(BVOCs) emanated from forests at Jeju Island. The total emission amount of BVOCs calculated by using the CORINAIR Methodology is 3612 ton yr-1 at Jeju Island. More than half of BVOCs emissions is come from coniferous forest, and 45 per cent from broad leaved forest. The others is attributed to grassland. Of total emission of BVOCs, isoprene accounts for 28 per cent, monoterpene for 32 per cent, and other VOCs for about 40 percent, respectively. It can be shown that 3000~10000 kg yr-1 of BVOCs is emitted at the zone with dense forest from an altitude of 500 m to the top of Mt. Halla, and less than 1500 kg yr-1 at the zone an altitude of below 500 meters. The monoterpene emission is more than 1500 kg yr-1 due to the existence of a colony of Abies koreana at the place with more than 1500 meters and a community of Pinus thunbergii and Cryptomeria japonica at the elevation of 500~700 m. In the case of isoprene emission, there is 1500~3000 kg yr-1 at the zone of an elevation from 700 m to 1500 m due to dense broad leaved forest and very little of its emission at an elevation of more than 1500 meters because there is hardly broad leaved trees grown. In this study, emission of BVOCs according to the altitude above sea level is estimated under the situation of lack of the data for broad leaved tree. More detailed data and information for the distribution of broad leaved trees are needed in order to calculate more realistic BVOC emission.
        78.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to estimate the BVOCs emissions with the emission factors which reflected the native conditions of forests in Jeju Island. This study made effective use of the previous data for the weather data and the emission rate of each organic volatile component measured at 10 species of conifers and broad leaved trees. The CORINAIR method and the grid system of 1km×1km for whole area of Jeju Island were adopted in calculating the BVOCs emission emitted from forest. The vegetation information for Jeju Island was referred to GIS and a government report. By the results of BVOCs emission for Jeju Island, the 85% of monoterpene emission was emitted from conifers and the others was from broad leaved trees. Most of monoterpene emission was attributed to Pinus thunbergii and Cryptomeria japonica. The broad leaved trees greatly contributed to the isoprene emission and Quercus serrata played a dominant role in emission of isoprene. The total amount of BVOCs emission was estimated as 3612 ton yr-1 in Jeju Island. The 51.1% of total emission was contributed to conifers, the 44.9% to broad leaved trees, and the 4.0% to grassland. Of total emission of BVOCs, monoterpene accounted for 32.3%, isoprene for 28.0%, and OVOCs for 39.7%. The BVOCs emission estimated by this study was less than that estimated by other previous study. This means that it is important to survey the emission rate at native conditions and gather the detailed information for various species of vegetation on target region.
        79.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        We analyzed with HPLC (High Performance Liquid Chromatography) analysis photosynthetic pigments and environmental factors, microscopic observations of the phytoplankton and zooplankton in the seawater every month from February 2009 to November 2010 in Haengam Bay. The level of dissolved inorganic nutrients was the highest between July and September, when freshwater influx was at its peak, whereas chlorophyll a levels were the highest in April and August. Also, phytoplankton pigment concentration increased when dissolved inorganic nutrients are carried into nearshore waters by rainfall runoff. Based on identification of phytoplankton and photosynthetic pigments results, diatoms were mainly dominant while dinoflagellate populations increased at July and August 2009, May 2010. The zooplankton communities are dominated in terms of Noctiluca scintillans. The contribution of Noctiluca scintillans in 2010 accounts for approximately 77.3% of the total zooplankton. Distribution patterns over time of zooplankton in the seasonal distribution of phytoplankton showed a different pattern.
        80.
        2014.10 서비스 종료(열람 제한)
        Using the wave forces obtained from ANSYS AQWA, the structural analysis of the gravity substructure for 5MW offshore wind turbines is carried out through ANSY Mechanical. Moreover, the comparison of natural frequency between the wind turbine and the gravity substructure is made to investigate the resonance. It is found that the suggested gravity substructure can be an effective substructure for 5MW offshore wind turbines.
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