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        검색결과 183

        41.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        6,100원
        50.
        2000.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        산화티탄의 광촉매 반응을 이용하여 휘발성 유기화합물(VOC)를 분해제거 하기 위하여 산화티탄을 glass bead에 sol-gel법으로 코팅하였다. 코팅막의 물성은 XRD, BET, SEM을 통해 분헉하였으며, 산화티탄이 galss bead를 채운 실험실규모의 광촉매 반응기를 이용 VOC중 벤젠 및 TCE 가스의 광촉매반응에 의한 분해효율에 대해 연구 컴토하였다. 반응기내의 잔류시간에 따른 가스농도 차이를 gas chromatography로 비교 분석하여 그 분해효율을 계산하였다. 이와 같은 정적인 상태의 실험결과, 400ppmv의 농도의 TCE인 경우 80%의 분해효율을 얻었으며, 50ppmv에서 300ppmv 농도의 벤젠인 경우 65%의 분해효율을 얻었다.
        4,000원
        52.
        1998.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        RTCVD법으로 증착된 다결정 Si1-xGex박막에서 Ge조성 증가에 따른 결정립크기변화가 표면거칠기 및 cluster크기에 미치는 영향에 대해 알아본결과, Ge조성 증가에 따라 결정립크기가 증가했으며 증가된 결정립에 의해 Cluster 크기와 표면거칠기값(RMS)들이 증가함을 알 수 있었다. 또한 증착된 다결정 Si1-xGex박막을 RF power와 온도변화에 따라 Ar/H2플라즈마를 이용한 수소화처리를 행하여, 수소화 효과와 표면거칠기값 그리고 비저항값 변화에 대해 조사하였다. 수소화처리 후 cluster크기와 표면거칠기값은 기판온도와 RF power 증가에따라 감소함을 알 수 있었으며 특히 기판온도 300˚C에서는 비저항값이 상당히 증가하였다.
        4,000원
        53.
        1995.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Oxidized Si wafer 위에 반응가스로 Si H4과 Ge H4을 사용하여 RTCVD(rapid thermal chemical vapor deposition)법으로 증착온도 450~550˚C에서 다결정 S i1-xG ex 박막을 증착하였다. 증착된 S i1-x, G ex 박막은 증착온도와 Ge H4Si H4입력비 변화에 따른 Ge몰분율 변화와 증착속도에 대해 고찰하였으며, XRD와 AFM(atomic force microscopy)등을 이용하여 결정상과 표면거칠기 등을 조사하였다. 실험결과, 다결정 S i1-xG ex 박막은 32~37 Kcal/mole의 활성화에너지 값을 가졌으며 증착속도는 증착온도와 입력비 중가에 따라 증가하였다. 또한 조성분석으로부터 입력비 감소와 증착온도 증가에 따라 Ge몰분율이 감소함을 알 수 있었다. 증착된 S i1-xG ex 박막은 450, 475˚C에서 임력비가 0.05일때 비정질 형태로 존재하였으며 그 이외의 실험영역에서는 다결정 형태로 존재하였다. 기존의 다결정 Si 중착온도(600˚C이상)와 비교하여 Ge H4을 첨가함으로써 비교적 낮은온도(550˚C이하) 영역에서 다결정 S i1-xG ex 박막을 얻을 수 있었다. 또한 증착층의 표면거칠기를 측정한 결과, 증착온도와 입력비가 증가함에 따라 표면 거칠기( Ri )가 증가함을 알 수 있었다.을 알 수 있었다.
        4,000원
        55.
        1994.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 반응기체 PaCl5 (99.99%)와 N2O(99.99%)를 사용하여 PECVD법으로 P-type(100) Si기판위에 Ta2O5 박막을 증착시킨후 RTA 후처리를 통하여 누설전류를 개선시키고자 하였다. 실험결과, 증착온도 증가에 따라 굴절율은 일정하게 증가하였고 500˚C에서 최대 증착속도를 보였다. 증착된 Ta2O5막의 FT-IR 분석결과 증착온도 증가에 따라 Ta-O bond peak intensity가 증가함을 알 수 있었으며, 누설전류 특정결과 증착온도가 증가함에 따라 누설전류값이 감소함을 알 수 있었다. 또한 증착된 Ta2O5막을 RFA방법을 이용하여 후처리 한 결과, as deposited 상태보다 누설전류가 감소함을 알 수 있었으며 이는 RTA처리후 AES와 FT-IR 분석을 통하여 Ta2O5막 내의 oxygen농도와 Ta-O bond peak intensity를 측정한 결과 RTA 후처리에 의하여 Ta2O5막내의 존재하는 O-deficient 구조들이 감소한 때문이었다.
        4,000원
        56.
        2021.09 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to extract climate element affecting coffee yield by growth period using data of production and cultivation area of coffee and climate data for 2000-2018. During the analysis period, the production of coffee in Vietnam has been consistently increasing, but Ðăk Lăk in the Central Highlands, the main cultivation area for coffee production, has recently stagnated in the trend of increasing yield. The yield of Lâm Đồng, located in the relatively highlands of the Central Highlands, is steadily increasing. Coffee yields of Ðăk Lăk is negatively correlated with the temperature during flowering period, and is also significantly negatively correlated with the maximum temperature and precipitation during the late growing period. On the other hand, Lâm Đồng, located at a relatively high altitude, has a positive correlation with temperature during the late growing period. It is analyzed that the lower the altitude, the higher the temperature, the lower the coffee productivity due to the high temperature appearance, and the lower the low temperature appearance in the high altitude region.
        57.
        2020.09 KCI 등재 서비스 종료(열람 제한)
        This study is about the change of Inuit traditional culture. Inuit has their specific culture due to the Arctic’s harsh environment. But recently, because of the climate change and newcomers, traditional culture has changed. Hunting, the base of Inuit’s traditional culture decreased and was getting hard. And shelter and transportation for hunting has been modified. According to the change of hunting, food and adoption culture also changed. Inuit is in a situation to consume junk food and processed food instead of fresh food. Those food induce many problems to Inuit including health. And Inuit trade the food, not share. It means the community spirit weakened. Reduction of the importance of IQ (Inuit Qaujimajatuqangit) and the role of the senior also contributes to the weakening of community spirit. Inuit adopt non-Inuit child and adopt the child according to the law. It makes Inuit difficult to adopt child. As a result, climate change and newcomers makes today’s Inuit culture. Therefore, we have to know climate change and newcomers to understand the culture of the Arctic and residents.
        58.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to examine the effect of climatic elements on the arabica coffee yield during the various growth stages of coffee plant for the period of 1996-2017 over Costa Rica. For the future scenario, change rate of arabica coffee yield is also estimated using the data of production and cultivated area. The cultivation area and the yield of arabica coffee has been decreasing since the 1990s in Costa Rica. The decreasing trend in arabica coffee yield could have a negative effect on Costa Rica’s coffee industry in the future. During the dry season, the yield of arabica coffee has significant negative correlation with precipitation at the stage of flowering in the month of February. In case of wet season, coffee yield and temperature were negatively correlated while precipitation showed positive association with coffee yield at the stage of growing period in the month of August. However, the observation revealed the excessive precipitation drastically reduced arabica coffee yield in 2013 during August, the month of wet season. According to the RCP 4.5 and RCP 8.5 climate change scenarios, due to high temperature and fluctuated precipitation the yield of arabica coffee is unstable and the future of coffee industries is also insecure.
        59.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        This study aims to analyze the change of onset and end dates of extreme temperature events and examine their relationships with global warming. The data used for this study are daily maximum temperature, daily minimum temperature, and global mean temperature anomaly. Results were similar to the trend of global temperature, showing that the onset date of extreme high temperature is advanced while the end date of extreme high temperature is delayed. Also, the change of onset (end) dates of extreme low temperature were clear, with coming later (earlier). There is more distinct change in extreme low temperature than extreme high temperature. The length between onset date and end date of extreme high (low) temperature is significantly longer (shorter). The onset (end) date of extreme high temperature has a negative (positive) relationship with global mean temperature. The onset (end) date of extreme low temperature has a positive (negative) relationship with global mean temperature. It might be concluded that the change of onset and end date of extreme temperature in South Korea has been affected by global warming.
        60.
        2019.04 KCI 등재 서비스 종료(열람 제한)
        Ginseng (Pnanx ginseng C. A. Meyer) is famous worldwide, and is very important cash crop and medicinal herb in Korea. It takes four to five years to produce harvestable ginseng roots, and ginseng is attacked by several pathogens during cultivation. We investigated the disease rate caused by ginseng root rot from 6 years old ginseng cultivation fields (Chungnam; 9 fields, Chungbuk; 11 fields, Gangwon 5 fields). The highest disease severity was Dangjin D (2.9) and the lowest one was Gaesan C (0.6). Of the 625 isolations, 340 isolations were classified as Ilyonectria radicicola and Fusarium solani. Finally, genetic diversity of I. radicicola and F. solani was confirmed by sequence analysis. Among the I. radicicola group, I. mors-panacis, which is known as highly virulent pathogen, and I. liriodendri, I. robusta and I. cyclamicicola, which are weakly virulent pathogens, were identified. In the case of F. solani, it is divided into two groups, but it is necessary to conduct diversity research through genetic analysis and pathogenetic studies using various markers. Based on these results, it could be used as a basic data for control of ginseng root rot pathogens.
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