• Title/Summary/Keyword: polyester tunnel

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Microclimate in Rice Nursery Bed Covered with Various Materials (벼 보온못자리 피복재질에 따른 상내 미기상 특성)

  • Hwang Kyu Hong;Lee Jeong Taek;Yun Jin Il;Shim Kyo Moon;Hur Seung Oh
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.2 no.3
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    • pp.87-94
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    • 2000
  • To recommend adequate covering materials and shapes of rice nursery bed for mechanical transplanting rice seedling, measuring of microclimate inside the rice nursery protected by polyethylene tunnel type, polyester tunnel type, and polyester flat type was compared to that outside the nursery. The vapor pressure deficit inside the polyester tunnel and polyethylene tunnel was higher than that outside the tunnel during daytime on a sunny day. During daytime on cloudy with rain day, the vapor pressure deficit inside polyester tunnel was higher than that in polyethylene tunnel or outside the nursery tunnel. The heat fluxes in the rice nursery tunnel during daytime flowed more to the soil than to the outside tunnel. Amounts of soil heat fluxes in polyethylene tunnel were higher than in polyester flat and polyester tunnel. The vertical profile of air temperature inside the nursery tunnel came to inversion during daytime and was lapse during nighttime regardless weather condition. The maximum temperature inside the nursery tunnel were 47.2$^{\circ}C$ in polyethylene tunnel and 37.$0^{\circ}C$ in polyester tunnel which was 21.1$^{\circ}C$ and 10.9$^{\circ}C$ higher than outside the tunnels respectively on sunny day. On cloudy with rain day, the temperature inside nursery tunnel was higher 8.4$^{\circ}C$ and 4.$0^{\circ}C$ polyethylene and polyester tunnel respectively then outside. Daily temperature changes became larger in the polyethylene tunnel, polyester tunnel, and outside the nursery tunnel in order. The rice seedling growth in polyester tunnel was better than the other nursery beds.

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Rice Seedling Establishment for Machine Transplanting VI. Effect of Mulching Materials on Raising Rice Seedling at Tray for Machine Transplanting (수도 기계이앙 육묘에 관한 연구 Ⅵ.제6보 상자육묘시 피복자재이용 효과)

  • Yun, Yong-Dae;Yang, Won-Ha;Kwang, Yong-Ho;Park, Seok-Hong;Park, Rae-Kyeong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.31 no.1
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    • pp.9-15
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    • 1986
  • To establish an efficient light control method using three covering materials on tunnel shaped rice seed-bed at greening stage after seedling emergence, four rice cultivars, Nampungbyeo, Taebaegbyeo, Seonambyeo, and Seomjinbyeo were sown on 15 April and 10 May in 1983 and 1984 respectively. After seedling emergence by a simplified emerging methods the seedling boxes were moved onto tunnel shaped seed-bed which was covered with combined matrials of PE film, silverpoly sheet, and spunbonded polyester fabric. For machine transplanting of rice seedlings in cases of early season and optimum season seeding in central part of Korea, PE film tunnel with silverpoly mulched, and PE film tunnel methods with spunbonded polyester fabric mulched reduced injuries of non-parasitic seedling damping-off and a albinism as affected by it, protected rice seedlings from injuries by extremely low temperature in the night, and reduced less differences in diurnal temperature than those in the other covering methods. At late season seeding for double cropping system of paddy field in southern part of Korea, a single silver-poly or a single spunbonded polyester fabric-covered tunnel method showed good green seedlings, and prevent-ed extreme rising of diurnal temperature by light interception in the tunnel.

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Comparison of Primary Stability of Different Femoral Fixation Techniques in Anterior Cruciate Ligament Reconstruction (전 십자 인대 재건술에서 대퇴골측 고정 방법의 초기 안정성의 비교)

  • Song, Eun-Kyoo;Lee, Keun-Bae;Lee, Moon
    • Journal of the Korean Arthroscopy Society
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    • v.2 no.1
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    • pp.85-92
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    • 1998
  • Various methods for fixation of graft have been widely used for reconstruction of anterior cruciate ligament. However, the biomechanical strength of each fixation techniques are not fully understood. The purpose of this study is to compare the pull out strength of different fixation techniques which is probably the most important factor for the success at the initial stage of healing. Biomechanical test was carried out to measure and compare the pull out tensile strength of five different fixation techniques in 35 pig(Yorkshire) knees. ANOVA and Duncan multiple comparison test was applied for statistical analysis. In the two fixation techniques with bone patellar tendon bone graft, the mean maximum tensile strength was $1333.4{\pm}148.5N$ with titanium interference screw, while it was $1310.1{\pm}168.9N$ with biodegradable interference screw. The failure mode were pulled out of bone plugs from the femoral tunnel in majority cases. In the fixations with hamstring tendon, the mean maximum tensile strength were $1405.9{\pm}135.1N$ with SemiFix screw, $820.3{\pm}104.5N$ with biodegradable interference screw, and $682.1{\pm}54.2N$ with Endobutton. The mode of failure was variable in each technique. The tendon was pulled out from the tunnel in biodegradable interference screw fixation, the screw was bent in the SemiFix system, and the polyester tape were ruptured or the buttons were pulled into tunnel in Endobutton fixation. The mean maximum tensile strength of two interference screws with bone patellar tendon bone was statistically comparable to that of SemiFix with hamstring tendon. However biodegradable interference screw and Endobutton with hamstring tendon showed weaker maximum tensile strength than above three fixation techniques (P<0.05).

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A Study on the Protection Method of Mine Site Slope Using Mine Green Framework (식생 방틀공법을 이용한 광산사면 보호공법에 관한 연구)

  • Choi, Gwang-Su;Kim, Tae-Heok;Kwon, Hyun-Ho
    • Tunnel and Underground Space
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    • v.19 no.6
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    • pp.526-533
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    • 2009
  • This study presents Mine Green Framework(M.G.F) which can protect the slope of rock and tailings. M.G.F method provides the fiber frame which helps the growth of the plant in the barren site like mined rock slope. M.G.F system consists of the polyester fiber mat, soil, seeds and anchors for the attachment. The optimum rate of filling materials was figured out by many germination tests in order to improve the effect of filling materials and the optimum rate of filling materials was applied in four test sites individually. High rooting rate over 70% was confirmed in all field tests. Especially the moisturizer was the most important component of filling materials and it could make the better condition for the plants.