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        검색결과 29

        21.
        2014.10 구독 인증기관·개인회원 무료
        We investigated the insect community along altitudinal gradient to gather basic data for distributional monitoring of insect species in the forest ecosystem. The investigation area was Seon-gaksan (Mt.) in Jinan-gun, Jeollabuk-do province, where the bucket-light trap and pit-fall trap for quantification were installed in Quercus vegetation at altitude of 300m, 600m and 900m. The field collecting was performed on May, July and September 2013 respectively. ANOVA analysis was conducted to analyze the significance between insect species along altitude using the collected insect community data. Analysis of variance (ANOVA) results showed statistically significant differences among ground-beetles and ants abundance with altitude as a response variable. Although we expected a distinct cluster with the difference of altitude at each study site, nonmetric multidimensional scaling (NMS) showed distinct clusters with the moth, ground-beetles, and ant assemblage at altitudinal increase and sampling month. In the result, a total of 309 species in 18 families of nocturnal moths were collected by bucket-light trap. The insects collected in pit-fall trap were ground-beetles with 196 individuals of 26 species and ants with 11,276 individuals of 14 species respectively.
        22.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dinitramide(N(NO2)2)염 화합물은 현재 고체 산화제로 로켓추진제의 중요한 원료 물질 중 하나이며, 환경 및 인체에 독성이 적은 친환경 에너지물질로 알려져 군사적 목적 외에 다양한 가스발생 제로서 사용되고 있다. 특히 무기염이 아닌 유기염인 Guanidine 염(GDN)은 수분에 대한 안정성이 향 상되어 안정적 보관 및 제조가 가능하므로 고순도 물질의 대량 생산이 가능하다. GDN의 출발물질로 guanidine의 음이온 염인 acetate, chloride, carbonate, nitrate, sulfate를 사용하여, GDN(GDN-1,2,3,4,5)을 최대 99%의 수율로 합성하였고, 이들의 물성을 다양한 분석기기를 이용하여 평가하였다. 흡수파장은 3452, 3402, 3354, 3278, 3208, 1642, 1570, 1492, 1416, 1337, 1179, 1000 cm-1이 공통적으로 관찰되었으며, 열적 특성 변화는 130 ℃에서 일어나기 시작하며 150℃~160 ℃에서 는 발열반응과 함께 물질의 변화가 관찰되었다.
        4,000원
        23.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Indoor air quality including metro subway is of recent interests in large cities. Inflow air to the inside of the train and circulating air flow through MVAC of stations contain large amount of iron based fine particles. This paper evaluated the collection of such a dust by magnetic filters as comparing to conventional particle capturing mechanisms such as inertia, direct impaction and diffusion. It was found that filtration velocity, magnetic field intensity, and fiber size were the most important parameters for magnetic filtration. Application of magnetic force obviously enhances the collection efficiency particularly in fine modes smaller than 10 mm. However, its effect was found greater in 2.5 mm than submicron particles.
        4,000원
        24.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ammonia is one of typical index substances of environmental odor. This study describes a rapid and simpleadsorption tube type detector to be able to measure the level of strict emission standards with quantitativeconcentration of gaseous ammonia as the regulations are enhanced. a gas detector tube can be measured theammonia gas concentration of 0.23ppm, 0.5ppm, 1ppm, 1.5ppm and 2ppm through the relation between theSampling rate Kog (=DA/L) and the discoloration reaction rate by physico-chemical analysis. Also this study canbe predicted the relation between the sampling volume and the sampling time. and it can be designed to measuringthe range of various concentrations. In this case study, an optimum design was found with an sampling rate, 42ml/min and with a tube diameter, 3.0mm. Adsorption and diffusion rate was evaluated by Fick's law.
        4,000원
        25.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 활성탄의 CO2 흡착능을 향상시키기 위하여 화학적 전처리 방법을 개발하는 것이다. 다양한 방법과 이론이 존재하지만 이번 연구에서는 아미노화와 분해를 비교하여 흡착능을 비교하기로 하였다. 본 연구에서는 4가지 유형의 활성탄 입자를 원료 물질과 크기에 따라 준비하였고, 수산화칼륨으로 전처리하여 열처리 및 아민화과정을 거 친 후, CO2 흡착능을 비교 평가하였다. 실험결과, 단순 열처리과정만 적용할 때는 600℃ 가 가장 우수하였고, 800℃에서 아민화시킨 시료가 1.4 mmol/g의 가장 좋은 흡착능을 보 였다. 400~600℃에서 아민화를 시킨 시료는 처리온도와 비례하는 선택도를 보여주었다. 분해시간 또한 흡착능과 정비례하는 관계가 나타났다.
        4,000원
        26.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Various efforts have been explored to save the cost in many industrial fields. In order to recover the residual thermal energy from the flue gas, an extreme high efficiency heat exchanger is planning to install at a power plant. The gas temperature will be reduced to 40°C from 115°C. Thus gas buoyancy decreases, and dispersion of nitrogen oxides is expected to deteriorate as increasing relative humidity. In this study, the conversion of nitrogen monoxide to nitrogen dioxide and dispersion regime are investigated through computational modeling. Nitrogen dioxide which indicates 0.1 ppm at 85 m from the ground could be propagated to 620 m at 115°C of the flue gas, whilst when cooled down to 40°C, it expands up to 750 m. The ground level influence area showed more expansion of dispersion, approximately to 930 m.
        4,200원
        29.
        2004.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have been developing a solar observing system based on a fast CCD camera 1M30P made by the DALSA company. Here we examine and present the characteristics and performance of the camera. For this we have analyzed a number of images of a flat wall illuminated by a constant light source. As a result we found that in the default operating mode 1) the mean bias level is 49 ADU/pix, 2) the mean dark current is about 8 ADU /s/pix, 3) the readout noise is 1.3 ADU, and 4) the gain is about 42 electrons/ ADU. The CCD detector is found to have a linearity with a deviation smaller than 6%, and a uniform sensitivity better than 1%. These parameters will be used as basic inputs in the analysis of data to be taken by the camera.
        4,000원
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