• Title/Summary/Keyword: Natural density

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Effect of Orius laevigatus and Neoseiulus cucumeris on Suppression of Thrips Density on Paprika in Greenhouse in Summer

  • Lim, Y.S.;Lee, M.J.;Shin, Y.S.;Han, Y.Y.
    • 한국유기농업학회지
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    • 제19권spc호
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    • pp.214-217
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    • 2011
  • When paprika is cultivated during summer season, thrips starts to occur in the early growing season and reaches its peak in late June. In the treatment using Orius laevigatus and Neoseiulus cucumeris, natural enemies to thrips, thrips density was 87.6/trap and 51.3/trap on June 23. After Orius laevigatus and Neoseiulus cucumeris were treated twice on June 24 and July 23, the number decreased considerably. On August 23, it was 36.9/trap and 40.3/trap and from the mid August to early September thrips density remained low. Effect of Orius laevigatus and Neoseiulus cucumeris on suppression of thrips density was 35.7% and 44.6% on July 22, however, the number went up to 88.8% and 80.5% on September 3.

옥수수 초형교정이 군락 투광성 및 수량성에 미치는 영향 (Effect of Canopy Reforming on Light Penetration into Crop Community and Yielding in Corn)

  • 이호진;조명제;이홍석
    • 한국작물학회지
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    • 제30권1호
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    • pp.76-83
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    • 1985
  • 옥수수의 밀도를 소(60cm$\times$40cm), 적(60cm$\times$24cm), 밀식(60cm$\times$16cm)으로 심고 초형처리로서 자연초형(남북이랑), 동서향교정(남북이랑), 동서향교정 및 엽각조정(남북이랑), 남북향교정(동서이랑)을 실시하였다. 초형교정은 엽출현이 완료된 뒤 철사가를 옥수수군락에 설치하고 옥수수잎들은 동서향이 되록 유인하여 고정시키고, 엽각조정은 수평에서 80$^{\circ}$가 되도록 직입화시켰다. 옥수수의 자연초형은 남북이랑이든 동서이랑이든 관계없이 모든 방위로 고루 분포하였고 약간의 남북향 경향을 보였으나 현저하지 않았고 엽각은 직입~중간엽형의 분포를 나타내었다. 군락내부에서 광투과는 초형을 동서향으로 교정하거나 엽각을 직립화시킴에 따라 초고의 중간높이에서 일평균 광도가 5~10% 가량 향상되었다. 반면 남북향 초형교정에서는 2~10% 정도 낮아졌다. 황숙기의 건물중집적은 밀식시 동서향초형이 자연초형 보다 6% 증가하였으나 남북향초형은 차이가 없었다. 완숙기의 종실수량에서는 동서향 초형교정은 3~11% 증가하였으나, 엽각조정까지 하였을 때에는 소식에서 10% 감소, 적. 밀식에서는 10%, 3%씩 각각 대조구보다 증가하였다. 반면 남북향초형은 차이가 없거나 감수로 나타난다. 초형을 태양의 방위와 고도를 고려하여 변형한다면 밀식에서도 일사광의 군낙내부로 침투를 용이하게 하며 증수할 수 있음이 확인되었다.

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고속도로 절토 비탈면과 인접 자연식생지의 토양 환경 비교 분석 (A Study on Soil Environment in Highway Cutting Slope and Adjacent Natural Vegetation Area)

  • 박관수;전기성;송호경;김남춘;최재용
    • 한국환경복원기술학회지
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    • 제9권2호
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    • pp.16-22
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    • 2006
  • This study was carried out to estimate the physical and chemical soil characteristics in highway cutting slope areas. The soil was sampled in cutting area and natural vegetation area that was located in the upper areas of the highway cutting slope. The average total soil depth, bulk density, and soil hardness were bad in the highway cutting slope sites. The sandy loam was the most soil texture in the study area. The concentration of soil organic matter and nitrogen were very low in all highway cutting areas. The concentration of exchangeable cations was similar between the highway cutting slope and the natural vegetation sites in each highway. The soil pH was higher in highway cutting slope areas than in natural vegetation sites. In conclusion, chemical and physical properties of soil were bad in the cutting slope than in the natural vegetation area because of the loss of soil by cutting of slope area and less organic matter input by less vegetation in the highway cutting slope area. We should employ possible method to reduce the loss of soil, and compost and fertilization treatment could help to increase soil nutrient content in the cutting slope area.

자외선 조사에 의한 Hairless Mouse 피부구조 변화에 대한 형태학적 연구 (Morphologic Study on the Changes of Skin Structure of Hairless Mouse by Ultraviolet Irradiation)

  • 송선영;윤중식;정민주;정경아;노영복
    • Applied Microscopy
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    • 제28권2호
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    • pp.127-137
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    • 1998
  • This study was observed of the skin that changed after irradiation of the ultraviolet A. All the mouse were hairless which the weight are about 25g and the ages $6\sim8$ weeks old. The mouse were divided into six groups; control, irradiated for 6 hours, 3 days, 7 days, 14 days, 21 days and 28 days. Each group was irradiated with ultraviolet that is $320nm\sim366nm$ of wavelengths. After irradiated, the skin was observed with the electron microscope and the light microscope. The results are as follow: 1) Light microscopy With following irradiation, the epidermis was not changed to most groups but at the 28 days group was thickened and deposit the melanocyte. The elastic fibers within the epidermis were thickened and twisted with following irradiation. 2) Eelectron microscopy The elastic fibers were slightly clumped at 6 hours group, mildly increased and partly aggregated in the 3 days group, branched and tangled at 7 days group, irregulated and electron density at 14 days group, sightly thickened and twisted at 21 days group, and randomly arranged, shortened, twisted, and electron density at 28 days group.

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The Photoreceptor Populations in the Retina of the Greater Horseshoe Bat Rhinolophus ferrumequinum

  • Kim, Tae-Jin;Jeon, Young-Ki;Lee, Jea-Young;Lee, Eun-Shil;Jeon, Chang-Jin
    • Molecules and Cells
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    • 제26권4호
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    • pp.373-379
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    • 2008
  • Recently, we reported the existence of AII "rod" amacrine cells in the retina of the greater horseshoe bat Rhinolophus ferrumequinum (Jeon et al., 2007). In order to enhance our understanding of bat vision, in the present study, we report on a quantitative analysis of cone and rod photoreceptors. The average cone density was $9,535cells/mm^2$, giving a total number of cones of 33,538 cells/retina. The average rod density was $368,891cells/mm^2$, giving a total number of rods of 1,303,517 cells. On average, the total populations of rods were 97.49%, and cones were 2.51% of all the photoreceptors. Rod: cone ratios ranged from 33.85:1 centrally to 42.26:1 peripherally, with a mean ratio of 38.96:1. The average regularity index of the cone mosaic in bat retina was 3.04. The present results confirm the greater horseshoe bat retina to be strongly rod-dominated. The rod-dominated retina, with the existence of AII cells discovered in our previous study, strongly suggests that the greater horseshoe bat retina has a functional scotopic property of vision. However, the existence of cone cells also suggests that the bat retina has a functional photopic property of vision.

백두산 동북부지역 소나무 천연림 biomass 추정모델 (Regression Model for Estimating Biomass of Natural Pinus densifrola Forests in Northeast Area of Mt. Paekdu)

  • 김영환;이돈구;맹헌우
    • 임산에너지
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    • 제17권1호
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    • pp.23-29
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    • 1998
  • 중국 백두산 북부지역 소나무천연림을 대상으로 임분의 biomass를 추정하기 위하여 5개 등급 밀도별로 각각 7본씩 표본목을 선정하여 벌도한 후 4개의 상대생장식(W=aDb, W=a(D2H)b, logW=a b·logD+cD, logW=a+b·log(D2H)+c(D2H)을 이용하여 부위별로 biomass 추정식을 유도하였다. 밀도가 다른 임분에서 부위별로 적합한 biomass 추정식 유형이 다르게 나타났는데 줄기, 수피 및 지상부 전체 biomass량을 추정하는 경우, logW=a+b·log(D2H)+c(D2H)식이 결정계수는 높고 상대오차 추정치는 낮게 나타나 적합도가 높았다. 가지, 잎 biomass량 및 엽면적의 경우는 logW=a+b·logD+cD식이 상관계수가 높고 상대오차 추정치는 낮게 나타나 적합하였다.

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Semi-continuous cultivation of the mixotrophic dinoflagellate Gymnodinium smaydae, a new promising microalga for omega-3 production

  • Lim, An Suk;Jeong, Hae Jin;You, Ji Hyun;Park, Sang Ah
    • ALGAE
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    • 제35권3호
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    • pp.277-292
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    • 2020
  • Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are polyunsaturated fatty acids beneficial to human health. A limited number of microalgae have been used for commercial omega-3 production, which necessitates the identification of new microalgae with high omega-3 contents. We explored the fatty acid composition and EPA and DHA contents of the mixotrophic dinoflagellate Gymnodinium smaydae fed with the optimal algal prey species Heterocapsa rotundata. Cells of G. smaydae were found to be rich in omega-3 fatty acids. In particular, the DHA content of G. smaydae was 21 mg g-1 dry weight, accounting for 43% of the total fatty acid content. The percentage of DHA in the total fatty acid content of G. smaydae was the highest among the reported microalgae except for Crypthecodinium cohnii. Moreover, to determine if the prey supply interval affected the growth rate of G. smaydae and its fatty acid content, three different prey supply intervals (daily, once every 2 d, and once for 4 d) were tested. Daily prey supply yielded the highest total fatty acid and DHA contents in G. smaydae. Furthermore, we successfully produced high-density G. smaydae cultures semi-continuously for 43 d with daily prey supply. During the semi-continuous cultivation period, the highest density of G. smaydae was 57,000 cells mL-1, with an average growth rate of 0.7 d-1. Taken together, the percentage of EPA and DHA in the total fatty acid content was maintained in the range of 54.2-56.9%. The results of this study support G. smaydae as a promising microalgal candidate for commercial DHA production and demonstrate that daily supply of prey can efficiently produce high-density G. smaydae cultures for more than a month.

Carbofuran 입제의 처리방법 및 시기가 벼의 해충과 천적의 밀도에 미치는 영향 (Effect of Density Variation on the Natural Enemies and Rice Pests by Application Method and Time of Carbofuran Granules)

  • 김정부;조동진;하재규;장순덕;박영도
    • 한국응용곤충학회지
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    • 제23권4호
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    • pp.233-236
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    • 1984
  • 본 연구는 경상남도 진주에 위치한 농촌진흥원 해충 시험포장에서 Carbofuran 입제를 본답기에 2회 처리와 농가 관행방제인 살충제 9회 처리간의 벼 해충과 이들 천적의 밀도를 비교 조사하였다. 1. Carbofuran $3\%$ 입제를 기계이앙시 육묘상자 처리와 7월중순 수면 처리등 본답기에 2회만 처리하여도 벼의 주요해충인 멸구 매미충류, 나방류, 굴파리, 총채벌레등의 방제효과가 관행 방제인 살충제 9회 처리와 비등한 경향이었다. 2. 벼 해충의 천적인 거미류와 멸구류의 난기생봉(Anagrus sp.)의 밀도는 Carbofuran 입제 처리가 관행방제보다 2.4배 밀도가 높았다.

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한약재 함유 헤어토닉 및 식품이 C57BL/6 마우스의 탈모 모델에서 모발성장에 미치는 영향 (Effects of Hair Tonic and Food including Korean Medicinal Herbs on Hair Growth in an Alopecia Model of C57BL/6 Mice)

  • 최혜민;황수정;이진상;도은주;김무영;김미려
    • 대한본초학회지
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    • 제26권1호
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    • pp.119-124
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    • 2011
  • Objective : This study was carried out to investigate effect of korean medicinal herbs-included hair tonic (MHT) and food (MF) on hair growth in an alopecia model of C57BL/6 mice. Methods : Six-weeks old mice were given laboratory rodent chow diet for 1 week. Then, we used a depilatory for hair removal on mice. The next day, mice were randomized and separated in 3 groups of 6 mice; normal group (N, vehicle epidermal application+normal diet-treated group), positive control group (C, 3% minoxidil sulfate epidermal application+normal diet-treated group), and the treatment group (T, HT epidermal application+ MF diet-treated group). The hair regrowth was determined by photograph, which was taken at 7, 14 and 21 days. And scoring indices, hair density and hair thickness, were evaluated by Folliscope at same day. In addition, the hair regrowth was analyzed insulin-like growth factor (IGF-1) in the dorsal skin of mice. Results : As a result, not only external appearance but also hair density and hair thickness on dorsal skin were increased more in C, T groups than in N group at 21 days with mixed treatment. Therefore, distinct regrowth pattern is appeared by treatment of herbal tonic and natural food for 21 days. Also, the expressions of IGF-1 on dorsal skin were higher in C, T groups than in N group. Conclusion : These results suggested that this herbal hair tonic and natural food has hair growth promoting activities and may be useful for treatment of bald or alopecia.

파이프의 고유진동수를 이용한 액체밀도측정 센서개발 (Development of Liquid Density Measurement Sensor Using the Natural Frequency of a Pipe)

  • 장경호;이용재;김광표;안병덕
    • 센서학회지
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    • 제4권3호
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    • pp.9-14
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    • 1995
  • 파이프의 고유진동수를 이용하여 유체의 밀도측정 센서개발을 위한 제작원리와 방법을 소개하고 길이 32 cm이고 내경과 외경이 각각 2.3 cm와 2.5 cm인 스테인레스 스틸 파이프를 사용하여 센서를 제작하였다. 제작된 센서는 파이프의 진동과 진동신호를 얻기 위해 가진코일과 포토센서를 사용하고, 지속석인 진동을 위한 궤환회로로 구성되었다. 센서의 고유진동수는 스펙트럼으로 분석한 값과 일치된 결과를 얻었으며, $0.8\;g/cm^{3}$ 부터 $1.4\;g/cm^{3}$까지의 밀도범위의 액체로 시험한 길과 0.0027 %의 직선성과 0.032 %의 감도를 나타냈다. 그리고 $10^{\circ}C$$35^{\circ}C$ 사이의 온도범위에서 고유진동수 변화율은 $0.024\;%/^{\circ}C$임을 보였다.

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