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        검색결과 153

        81.
        2006.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        PFC 제염기술은 원자력연구시설 핫셀 내부의 바닥이나 장치표면에 부착된 고방사능분진을 제거하기 위한 방법 중의 하나이다. 고가의 PFC 제염용액을 회수 정제후 재사용하고, 2차폐기물발생을 획기적으로 줄일 수 있는 여과장치를 개발하였다. PFC 매질 내 현탁성 방사성입자를 제거하기 위해 오염특성에 적합한 여과장치를 개발하고 입자제거 성능평가시험을 수행하였다. 개발된 PFC 여과장치는 핫셀 내부로 들어갈 수 있게 알맞은 크기와 무게로 제작되었으며 바퀴와 고리를 부착하여 이동이 용이하다. PFC 여과장치의 성능평가결과 모의입자의 농도 증가 시 flux가 감소하였고, Pre-filter()와 final-filter() 두개를 장착하여 여과시간에 따른 flux의 감소를 개선하였다. 개발된 PFC 여과장치는 분당 약 0.2L의 PFC 폐액을 처리 할 수 있다.
        4,000원
        83.
        2016.10 서비스 종료(열람 제한)
        Background : Plants live in restricted spaces that are constantly exposed to various environmental stresses. Under these stressful conditions, plants lead to biosynthesize specialized metabolites to adapt to environmental stresses. Here we investigate the effects of cold on the metabolome of tartaty buckwheat, focusing the flavonoid biosynthetic pathway. Methods and Results : From the metabolic profiling based on the GC-TOF-MS analysis, we identified the effect of cold on forty-four metabolites, including sugars, amino acids, and organic acids. Most of sugars and sugar derivatives remain nearly unchanged or slightly decreased in the plants grown at 25 ºC, whereas sugar and sugar derivative contents of cold-treated plants significantly increased, excepting galactose. Some of amino acid and amino acid derivatives contents decrease in cold-treated plants, whereas organic acid derived from tricarboxylic acid (TCA) cycle were increased the cold-treated plants compared with the plants grown at 25 ºC. Particularly, the contents of two anthocyanins, cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside, were significantly increased by cold treatment. Proanthocyanidins such as epicatechin and catechin were also significantly affected by cold. The expression of most flavonoid biosynthetic genes were significantly upregulated in cold-treated buckwheat seedling. Among the flavonoid biosynthetic genes, the expression of FtANS was notably upregulated in response to cold. Conclusion : By analyzing both primary metabolites and secondary metabolites of tartary buchwheat without or with cold, we showed that cold play a critical role in the modulation of the primary metabolites and flavonoid synthesis pathway in tartary buchwheat. Particularly, anthocyanin and proanthocyanidin biosynthetic pathways are strongly up-regulated in response to cold.
        84.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, and its drift trajectory has been monitored with the optical wide-field patrol network (OWL-Net). However, a quantitative analysis of KOREASAT 1 in regard to the attitude evolution has never been performed. Here, two optical tracking systems were used to acquire raw measurements to analyze the rotation period of two inactive satellites. During the optical campaign in 2013, KOREASAT 1 was observed by a 0.6 m class optical telescope operated by the Korea Astronomy and Space Science Institute (KASI). The rotation period of KOREASAT 1 was analyzed with the light curves from the photometry results. The rotation periods of the low Earth orbit (LEO) satellite ASTRO-H after break-up were detected by OWL-Net on April 7, 2016. We analyzed the magnitude variation of each satellite by differential photometry and made comparisons with the star catalog. The illumination effect caused by the phase angle between the Sun and the target satellite was corrected with the system tool kit (STK) and two line element (TLE) technique. Finally, we determined the rotation period of two inactive satellites on LEO and geostationary Earth orbit (GEO) with light curves from the photometry. The main rotation periods were determined to be 5.2 sec for ASTRO-H and 74 sec for KOREASAT 1.
        85.
        2015.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Several optical monitoring strategies by a ground-based telescope to protect a Geostationary Earth Orbit (GEO) satellite from collisions with close approaching objects were investigated. Geostationary Transfer Orbit (GTO) objects, Inclined GeoSynchronous Orbit (IGSO) objects, and drifted GEO objects forced by natural perturbations are hazardous to operational GEO satellites regarding issues related to close approaches. The status of these objects was analyzed on the basis of their orbital characteristics in Two-Line Element (TLE) data from the Joint Space Operation Center (JSpOC). We confirmed the conjunction probability with all catalogued objects for the domestic operational GEO satellite, Communication, Ocean and Meteorological Satellite (COMS) using the Conjunction Analysis Tools by Analytical Graphics, Inc (AGI). The longitudinal drift rates of GeoSynchronous Orbit (GSO) objects were calculated, with an analytic method and they were confirmed using the Systems Tool Kit by AGI. The required monitoring area was determined from the expected drift duration and inclination of the simulated target. The optical monitoring strategy for the target area was analyzed through the orbit determination accuracy. For this purpose, the close approach of Russian satellite Raduga 1-7 to Korean COMS in 2011 was selected.
        86.
        2015.05 서비스 종료(열람 제한)
        In this study, enhancement of phosphorus and nitrogen recovery efficiency from livestock manure through Magnesium Ammonium Phosphate (MAP) crystallization method has been suggested as an alternative to solve the problems of the existing phosphorus resource recovery method. It can become a useful fertilizer. This study focused on improvement of phosphorus resource recovery by changing energy density of ultrasonic dose for MAP crystallization. Solubilization rate (as phosphate/phosphorus) of phosphorus in livestock manure was measured by ultrasonic treatment. The energy density range of 100-50,000 of ultrasonic dose was determined. Optimal ultrasonic energy density was 1,000 dose as 64.5% of phosphate ratio. However, when the higher than 1,000 dose of ultrasonic energy density did not more improve phosphate solubilization ratio. Consequently, when use ultrasonic treatment at 1,000 dose of energy density, the phosphorus could recover approximately 65% from livestock manure by MAP crystallization. Moreover, this MAP becomes more valuable due to its nature as a slow-release fertilizer.
        87.
        2015.02 KCI 등재 서비스 종료(열람 제한)
        부안지역 소나무 집단의 화분유동과 교배양식 모수를 추정 하기 위하여 7개 microsatellite 표지로 모수, 주변 성목 및 종자 에 대한 유전변이를 분석하였다. 이형접합도 기대치(He)와 근 교계수(F)는 각각 모수에서 0.614과 0.018, 종자에서 0.624과 0.087이며, 각 세대간에 차이는 없었다(P > 0.05). MLTR로 추 정한 타가교배율(tm)은 0.967이며, 양친간 근연계수(tm-t s)는 0.057, 부계상관(rp)은 0.012로 나타났다. 기존에 보고된 소나 무의 동위효소 분석 결과에 비하여 타가교배율은 높고 근친교 배 및 부계상관은 낮았으나, microsatellite 표지를 이용한 소나 무류의 결과들과는 유사하였다. TwoGener로 추정한 최적 화분 비산 모델은 유효밀도(d = 220 trees/ha)를 가정한 정규확산모 델로 판명되었으며, 평균 화분비산거리(δ )는 11.42 m로 계산되 었다. 화분원 유전적 분화(Φft)는 0.021이며, Mental 검증에서 모수간 지리적 거리와 화분원의 유전적 분화는 상관성이 없는 것으로 나타났다(r = -0.141, P > 0.05). 부안지역 소나무 집단 은 대부분의 화분이 가까운 거리에서 공급되지만, 화분수의 유 전다양성이 높고 화분원의 유전적 차이가 작은 상태로 추정된 다. 이러한 조건에서 완전한 임의교배가 이루어지기 때문에 종 자의 유전자형이 다양하며 세대간 유전변이의 감소가 없는 것 으로 사료된다.
        88.
        2013.03 서비스 종료(열람 제한)
        JAK2 V617F mutation is a common event in chronic myeloproliferative disorders. However, de novo acute myeloid leukemia with JAK2 V617F is rarely encountered. The authors report the case of a 74-year-old male with de novo acute myeloblastic leukemia without maturation (AML M1) and a JAk2 V617F heterozygotic mutation. Despite treatment with standard AML regimens, the patient died 2 months after a diagnosis of acute leukemia. This case of an AML patient with a JAK2 V617F mutation with a poor prognosis suggests that despite its rarity, a JAK2 V617F mutational study be considered for prognostic purposes in AML.
        99.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        This experiment was conducted to examine the influence of four plant growth regulators on growth, photosynthesis parameters and yield of soybean. To increase dry matter accumulation of seeds, some growth regulators were applied to field grown soybean cv. Sinpaldalkong #2 as determinate type and Muhankong as indeterminate type at dense planting condition. Choline caused significant reduction of stem length, but did not increase seed yield. The number of leaf and total leaf area were showed significant increase in all the treatments, but those increased tremendously in Muhankong treated with ethrel. CO2 assimilation and water use efficiency of a single leaf were showed the highest as 17.2 molm-2s-1 and 9.3 μ mmol mol-1 treated with mepiquat in Sinpaldalkong, respectively. The Photosynthetic rate was closely related to stomatal conductance, transpiration and water use efficiency. Mepiquat treatment mainly produced positive effects on the number of pods, percent of pod setting, number of seeds per pod in two cultivars and also increased their seed yield as compared with control.
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