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        검색결과 64

        47.
        2003.06 구독 인증기관·개인회원 무료
        Using a developed high-frequency induction heated combustion method. the simultaneous synthesis and densification of WC-xvol.%Co() hard materials was accomplished using elemental powders of W, C and Co. A complete synthesis and densification of the materials was achieved in one step within a duration of 1min. The final relative densities of the composite were over 98.5% for all cases, under the applied pressure of 60 MPa and the induced current. The hardness of the composites decreases and the fracture toughness increases with increasing cobalt content. As the carbon to tungsten ration increases, the hardness increase, but the fracture toughness decreases. The maximum values for the fracture toughness and hardness are 15.1 (at 20vol.%Co, W:C=1:1), and 1928 (at 5vol.%Co, W:C=1:1.3), respectively. Therefore we concluded that the HFIHCS method. which can produce WC-xvol.%Co within 1 minute in one step is superior to conventional ones.
        48.
        2003.06 구독 인증기관·개인회원 무료
        1) Using a developed high-frequency induction heated sintering method, the rapid densification of WC-Co hard materials was accomplished using ultra fine powders with 260 nm size within 1 minute. 2) The relative density of the composite was 99.5% for the applide pressure of 60MPa and the induced current for 90% output of total capacity. 3) The grain size of WC-Co hard materials is about 260nm and the average thickness of the binder phase determined is about 11nm. The fracture toughness and the hardness of this work 12 , respectively. 4) Using pressureless sintering, we produced dense WC-Co hard materials with a relative density of 97% without applying pressure.
        52.
        2001.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Recently, we have set up a new digital CCD camera system, MicroMax YHS-1300 manufactured by Roper Scientific for Hα observation by Solar Flare Telescope at Bohyunsan Optical Astronomy Observatory. It has a 12 bit dynamic range, a pixel number of 1300×1030, a thermoelectric cooler, and an electric shutter. Its readout speed is about 3 frames per second and the dark current is about 0.05 e-/p/s at -10°. We have made a system performance test by confirming the system linearity, system gain, and system noise that its specification requires. We have also developed a data acquisition software which connects a digital camera con-troller to a PC and acquires Hα images via Microsoft Visual C++ 6.0 under Windows 98. Comparisons of high quality Hα images of AR 9169 and AR 9283 obtained from SOFT with the corresponding images from Learmonth Solar Observatory in Australia confirm that our Hα digital observational system is performed properly. Finally, we present a set of Hα images taken from a two ribbon flare occurred in AR 9283.
        4,000원
        58.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        In 2006, 41% of newly-married Korean men living in agriculture or fishery area were married to foreign wives. These foreign wives suffer social, cultural, and psychological maladjustment. They need support in understanding Korean culture & language, economic independence, and mental health. This horticultural therapy program (HT program) was practiced to help the foreign wives gain emotional stability, to help them adapt to rural society, and to help them improve the relationship with their families. The participants of this HT program were 10 foreign wives, 5 Chinese, 2 Vietnamese, 1Japanese, 1 Thai, and 1 Filipina. Total sessions were 12, and each session lasted for two hours. This program started April and ended July in 2007. After this program, selfesteem of participants increased from 29.6 to 33.5, and stress decreased from 77.3 to 64.7. Participants also expressed sense of satisfaction and accomplishment after the program.
        59.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        An Intergenerational Horticultural Program in a rural community in Korea was tried out to enhance social interaction between elderly citizens and children, to promote the positive self-esteem of the elderly in a rural community, to change the attitude of children towards the elderly, and to create a rural community full of vitality. The clients were 20 elderly (60-80 years old) and 40 preschool children (6-7 years old). The activities in this program included seed of hope, round autumn garden, dish garden, in the vegetable patch, flower decoration for the Chuseok Festival, rainbow flower basket, heart card, fragrance of love, and a kimchi party. The results were a decrease in depression among the elderly from 44.0% to 33.7%. General satisfaction among the elderly was 100%. The desire to rejoin among the elderly was 100%. General satisfaction among the children was 100%. The desire to rejoin among the children was 93.5%.
        60.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        This study was performed to analyze the improvement of soil physical property and soil biota characteristics through cultivation of green manure crops for a one-year period before creation of a tea plantation as follows. The study revealed that the contents of available phosphate tended to decrease after sod-culture by green manure cultivation and open-pollination, when compared to the level before cultivation. The ratio soil porosity increased by approximately 30% when Crotalaria juncea and Sorghum bicolar L. Moench were cultivated, while the soil bacteria and fungi also increased. In a research on microfauna using a pit fall trap, the population number of the microfauna was 174 of 27 species in the plot of open-pollinated sod-culture and no organic matter application, and 268 of 26 species in the plot of Sorghum bicolar L. Moench. Consequently, the culturing tool of Crotalaria juncea recorded the highest level of species diversity at 2.5, the evenness index at 3.7 and richness at 4.6, with the lowest level of a dominance index. The ecological quotient of microfauna was 0.76 in the plot of Sorghum bicolar L. Moench, and 0.63 in the plot of Crotalaria juncea.
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