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        검색결과 622

        221.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 기존의 중량법과 광산란법과는 원리와 기술이 다른 입도별 부유물질 측정용 분리막 모듈 및 장치를 개발하기 위한 원리를 수립하기 위한 기초 자료를 확립하고자 하였다. 이러한 목적을 위하여, 이산화규소 및 덱스트란(dextran), 카올린(kaolin), PEG (polyethylene glycol) 부유용액을 대상으로 유리섬유 여과지 GF/C와 GF/A를 분리막 모듈에 장착하여 여과시키면서, 디지털 압력계를 사용하여 막간압력차(TMP, Trans-membrane pressure) 변화를 측정하였다. 모사용액의 농도와 TMP 변화율 기울기의 상관관계식을 TMP 변화 실험 결과로부터 구하여, TMP 변화 기울기로부터 시료의 농도를 예측할 수 있도록 하였다.
        4,000원
        223.
        2009.10 구독 인증기관·개인회원 무료
        우리나라 낙엽과수에 큰 피해를 주고 있는 유리나방류 3종(복숭아유리나방, 사과유리나방, 포도유리나방)에 대한 월동 충태, 월동 장소 및 성충 발생소장을 조사하였다. 복숭아유리나방(Synanthedon bicingulata)과 사과유리나방(Synanthedon haitangvora)은 다양한 령기의 유충으로 주간과 주지 속에서 월동하였는데, 전체 월동유충 중에서 노령유충이 차지하는 비율은 복숭아유리나방이 12%였고 사과유리나방의 경우에는 35%였다. 그러나 포도유리나방(Nokona regalis)의 경우에는 모두 노숙 유충으로 피해신초 속에서 월동하였다. 복숭아유리나방과 사과유리나방 성충은 5월부터 페로몬 트랩에 유인되기 시작하였으며 9월까지 지속적으로 발생하였다. 복숭아유리나방의 초기세대에서는 성충 발생최성기가 분명하지 않았으나 후기세대에서는 8월 하순에 뚜렷한 최성기를 나타냈다. 사과유리나방 성충은 6월 중순과 9월 상순에 각각 발생 최성기를 보였다. 한편, 포도유리나방 성충은 5월 하순부터 6월 상순까지 페로몬 트랩에 유인되었으며, 발생 최성기는 5월 하순이었다.
        224.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 현재 대일 수출중인 상업적인 유리온실과 플라스틱 온실에서 파프리카 'Derby'를 공시품종으로 하여 국내 온실 간 생산량 차이 발생을 분석하여, 생산성 차이를 개선하고자 시설내부의 광량, 작물의 생장량 및 수량을 두 온실간 기간별로 비교 분석하였다. 재배기간 동안 평균 일중 광량은 유리온실 9.03MJ/m2/day, 플라스틱 온실 7.37MJ/m2/day로 23%정도 유리온실의 시설내부 광량이 많았다. 총 조사기간 동안 파프리카의 생장량은 유리온실 1759.9g·m-2, 플라스틱 온실 1308.5g·m-2으로 유리온실의 작물 생장량이 높았다. 총 건물생산량 대비 영양생장생식생장 기관의 건물분배는 시설내부 광량이 높은 유리온실에서 생식생장 기관의 건물분배는 높았고, 영양생장 기관의 건물분배는 낮았다. 두 온실의 파프리카 생산성은 유리온실 14.1kg·m-2, 플라스틱 온실 7.8kg·m-2으로 유리온실이 매우 높은 생산성을 보였다. 본 연구결과는 온실 간 파프리카의 기간별 동적인 건물생산량과 건물 분배 패턴, 수량을 분석함으로써 파프리카의 수량을 예측하고 우리나라 파프리카 생산성 향상을 위한 재배기술 분야의 기초 자료와 농가 간 생산성 차이 원인을 분석하고 그에 따른 생산성 극복 기술을 개발하는데 중요한 자료가 될 것이라고 판단된다.
        4,000원
        225.
        2009.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Reflection properties, such as specular reflection and diffuse reflection, are very important optical properties for the reflector, which has high reflectance in the display and architecture industry. Calcite is lowcost, nontoxic, and stable over a wide temperature range. Therefore, it is one of the most widely using fillers in many industries and has some advantages over titania as a filler to improve reflectance. However, optical properties, especially those of ceramic-filled composites, have not been analyzed. We studied the reflectance of calcite composites with their surface roughness. The reflectance of the composites was determined using a UV-visible spectrometer. The surface morphology and the micro-structure of the composites were investigated by atomic force microscope. The reflectance of the composites was improved by increasing the content of calcite in the calcite-frit composite. The reflectance is related with the surface roughness in the composites. However, the reflectance depends on the calcite contents in materials with similar surface roughness.
        4,000원
        226.
        2009.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was undertaken to evaluate the effect of temperature on the results of Charpy impact test for glass fiber reinforced polyurethane(GF/PUR) composites. The Charpy impact test were conducted in the temperature range from -50˚ to 50˚. The impact fracture toughness of GF/PUR composites was considerably affected by temperature and it was shown that the maximum value was appeared at room temperature. It is believed that sensitivity of notch on impact fracture energy were increased with decrease in temperature of specimen. As the GF/PUR composites exposed in low temperature, impact fracture toughness of composites decreased gradually owing to the decrease of interface bonding strength caused by difference of thermal expansion coefficient between the glass fiber/polyurethane resin. And decrease of interface bonding strength of composites with decrease in specimen temperature was ascertained by SEM photographs of Charpy impact fracture surface.
        4,000원
        227.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Without pesticide applications, mass-trapping by sex pheromone was successful to control Spodoptera litura (Fabricius) in a large scale tomato glasshouse (10,000 ㎡) at a low cost of 60 won/㎡. Pheromone traps were placed both inside and outside of the glasshouse. Inside the glasshouse traps were installed in a regular space, one trap per 500 ㎡, to catch the moths that were present in the glasshouse, and traps were also set outside of the glasshouse, at intervals of ca. 20 m, to prevent the moths from invading the glasshouse. In the experiment, more than 400 S. litura were captured per trap.
        4,000원
        232.
        2009.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Glass ceramics were made from coal bottom ash by adding CaO and Li2O as glass modifiers and TiO2 as a nucleating agent in a process of melting and quenching followed by a thermal treatment. The surface of the glass ceramics has 1.6 times more Li2O compared to the inner matrix. When TiO2 was not added or when only 2 wt% was added, the surface parts of the glass ceramics were crystalline with a thickness close to 130μm. In addition, the matrixes showed only the glass phase and not the crystalline phase. However, doping of TiO2 from 4 wt% to 10 wt% began to create small crystalline phases in the matrix with an increase in the quantity of the crystalline. The matrix microstructure of glass ceramics containing TiO2 in excess of 8 wt% was a mixture of dark-gray crystalline and white crystalline parts. These two parts had no considerable difference in terms of composition. It was thought that the crystallization mechanism affects the crystal growth, direction and shape and rather than the existence of two types of crystals.
        4,000원
        233.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to distinguish the causes of broken glass on doors or windows when it is originally kept among the remains on the floor in fire site - whether it was broken due to heating or outer power-through test and characteristics of the broken plane including the pattern on the plane. Addition to it, the study tries to find characteristics to judge the point and direction of breakdown through the analysis of glass broken by outer power. With two assumed causes - a) breakdown due to heating and b) breakdown due to outer power-3 pieces of glass plates (30cm×30cm×5mm) were tested for each case, getting the results as following: First, for the glass broken due to the change of temperature, the broken plane is of slow and smooth curve without any pattern. Second, for the glass broken due to outer power, with the impact point as the center, the glass shows breakdown of radial type and the side shows breakdown of near-perpendicular type. The far the broken piece is from the impact point, the bigger the size is. The broken piece at the impact point is of long triangle type and the two long planes of the triangle shows semi-arc with the center of breakdown point and the other plane shows opposite pattern. Third, when glass that is damaged by outer power is heated, damaged forms and side patterns of the glass that is damaged by outer power are heated and disappeared.
        4,000원
        234.
        2008.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, the additivity factors of compositions to density and glass transition point (Tg) in a xLi2O-(1-x)[(1-y)TeO2-yZnO] (0<x<20, 0<y<20) glass system were analyzed by using mixture design, and the change of ionic conductivity with density and Tg was discussed. As a method for predicting the relation between glass structure and ionic conductivity, density was measured by the Archimedes method. The glass transition point was analyzed to predict the relation between ionic conductivity and the bonding energy between alkali ions and non-bridge oxygen (NBO). The relation equations showing the additivity factor of each composition to the two properties are as follows: Density(g/cm3) = 2.441x1 + 5.559x2 + 4.863x3 Tg(˚C) = 319x1 + 247x2 + 609x3 - 1950x1x3 (x1 : fraction of Li2O, x2 : fraction of TeO2, x3 : fraction of ZnO) The density decreased as Li2O content increased. This was attributed to change of the TeO2 structure. From this structural result, the electric conductivity of the glass samples was predicted following the ionic conduction mechanism. Finally, it is expected that electric conductivity will increase as the activation energy for ion movement decreases.
        4,000원