• Title/Summary/Keyword: effective diameter

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Effects of Sowing Method and Planting Density on Growth and Root Yield of Cynanchum wilfordii Hemsly (백하수오의 파종방법과 재식밀도에 따른 생육 및 근수량)

  • 김민자;김인재;남상열;이철희;송범헌
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.6
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    • pp.418-421
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    • 2002
  • This study was carried out to clarify the effect of sowing method in four planting densities on growth and root yield of Cynanchum wilfordii. vine diameter, number of branches, number of branched roots, and root length, were greater in seedling transplanting than in direct sowing. In planting densities, main vine length, number of branches, and number of tillers were increased at higher planting density, but vine diameter, leaf length, leaf width, root length, and root diameter were increased at lower planting density. fresh root yield was greater in seedling transplanting than in direct sowing. In seedling transplanting, it was 53% higher in 27 plants per unit area than 1,680 kg/10a in 17 plants per unit area. Therefore, seedling transplanting in 27 plants per unit area showed most effective for increasing root yield of Cynanchum wilfordii.

Effective Utilization of Hemp Fiber for Pulp and Papermaking (I) -Morphological Characteristics of Hemp Fiber- (펄프.제지용 원료로서의 삼 섬유 이용에 관한 연구(제 1보) -대마 구성 세포의 현미경적 관찰-)

  • Yoon, Seung-Lak;Lee, Myoung-Ku
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.1
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    • pp.7-12
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    • 2010
  • Morphological characteristics of hemp fiber were investigated using a light microscope in order to provide fundamental data for the use of hemp as a papermaking law material. Phloem of hemp is composed of cortical parenchyma cells and bast fiber with thick walls while xylem is composed of vessel, wood fiber and ray parenchyma cells. Also there are solitary pore and radial pore multiple which exist in diffuse porous pattern. Ray cells consist of uniseriate rays and thin walled ray parenchyma cells. Wood fibers are composed of three types: a large diameter fiber with longer length; a large diameter fiber with shorter length; a small diameter fiber with medium length. Vessel elements are composed of: a medium length one; a longer length one; the one whose both end walls have ligules or tails. Parenchyma cells in xylem and pit parenchyma cells have completely different size and shape. For bast fiber, the average length is about 4.4 mm and the width is about $30.5\;{\mu}m$; for vessel element, $600.0\;{\mu}m$ in length and $493.6\;{\mu}m$ in width; for wood fiber, $1000\;{\mu}m$ and $38.9\;{\mu}m$; for parenchyma cell, $50\;{\mu}m$ and $26.4\;{\mu}m$.

Evaluation of Mesoporous Alumina Adsorbent for the Purification of Paclitaxel (Paclitaxel 정제를 위한 메조기공 알루미나 흡착제 평가)

  • Oh, Hyeon-Jeong;Jung, Kyeong Youl;Kim, Jin-Hyun
    • Microbiology and Biotechnology Letters
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    • v.41 no.2
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    • pp.176-182
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    • 2013
  • Several types of mesoporous alumina adsorbents with different physical properties were prepared by spray pyrolysis and were used for the separation/purification of the anticancer agent paclitaxel. The pore diameter of the adsorbents had a greater effect than did the surface area and the pore volume on the removal of plant-derived impurities. An appropriate pore diameter (~10.8 nm) was required for effective impurity removal. At a constant pore diameter, the surface area of the adsorbent affected not only the purity but also the yield of paclitaxel. Also, increasing the surface area of the adsorbent resulted in an increase in the adsorption of paclitaxel and impurities (biomass-derived tar and wax components). Removal of these impurities was confirmed by HPLC analysis of the absorbent after the treatment and TGA of the organic substances that were bound to the adsorbent.

Design of an Optical System for Iris Photographing (홍채 촬영용 광학계 설계)

  • Park, Seung-Hwan;Lee, Dong-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.4
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    • pp.39-44
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    • 2009
  • Purpose: To design a mini optical system photographing the iris, which is used in the iridology. Methods: We designed a mini optical system photographing the iris by using the Sigma 2000 design program. Results: We designed a mini optical system photographing the iris, which is suitable in the CCD using a micro actuator for auto-focusing, of which characteristics have the TCL of 30 mm, a magnification of -0.65, about 8.0 mm distance from the 1st lens to the last lens, the max barrel diameter of 11 mm, and about 1 mm of the effective stop diameter. Also the resolution line width of this system is characterised by 92 lps/mm at the 30% MTF value criterion. Conclusions: By designing an optical system of which characteristics have the TCL of 30 mm, about 8.0 mm distance from the 1st lens to the last lens, the max barrel diameter of 11 mm, and the resolution line width of $5.4{\mu}m$ at the 30% MTF value criterion, we could miniaturize the iris photographing optical system.

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The Comparison of Tree Growth by the Residual Stand Density in Artificial Coniferous Forests (침염수 조림지에서의 잔존임분밀도에 따른 임목생장 비교에 관한 연구)

  • 강성기;김완수;이원섭;김지홍
    • Journal of Korea Foresty Energy
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    • v.20 no.2
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    • pp.46-57
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    • 2001
  • This study was conducted to provide tending operation information for the effective management in unmanaged artificial forests of Pinus densiflora for. erecta, Pinus rigida, and larix leptolepis, based on the study of the comparison of tree growth pattern by residual stand density after thinning practices. Followings are summarized results of this study. 1. The diameter growth of residual trees was increased as residual stand density decreased by thinning practices in the stands of Pinus densiflora for. erecta, and Pinus rigida, and subcompartment (Ga) and (Na) of Larix leptolepis. The statistical analysis noted that the tree growth was significantly different by the residual stand density. 2. The height growth did not show corresponding results by stand density treatment pattern, which indicated that the height growth was not directly influenced by residual stand density, but by site quality of the stand. 3. The diameter increment for the last six years was proportionately increased in larger diameter classes and less dense stands.

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Structural Behavior of Holed RC Beam mixed with Sawdust (폐톱밥 혼입 RC 유공보의 구조거동에 관한 실험적 연구)

  • Son, Ki-Sang;Lee, Jae-Hyeong
    • Journal of the Korean Society of Safety
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    • v.21 no.1 s.73
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    • pp.96-104
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    • 2006
  • This study is to find out how the sawdust-mixed RC beam with holes acts compared to two case of normal one with sawdust without hole, without sawdust. variables are ED3H1, ED3H2, ED3H1UB, ED3H2L, ED5H1, ED5H1UB, ED5H2, ED5H2L, Normal with sawdust PLA without sawdust. All sand, aggregate, cement are in accordance with KS. mixing design is also in accordance with KS and done at D remicon company in order to decrease any error in mixing manually. ED3H1 showed 7tone of maximum load capacity having only minor tensile deformation around hole, compared to the center of the beam. ED5H2L showed almost same shape of tensile strain between hole area and center of two beam length, while having 9.5 tone load capacity, incase of two holes being in the longitudinal axis. But ED5H2 in case of two holes being in same forcing direction showed 8.4tone of load capacity while having minor tensile chape around hole and normal tensile shape in the center of beam length. Two diameter 3cm hole in longitudinal axis give more effective behavior than the other case, practically. Capacity decrease between 5cm and 3cm in eccentric position form the longitudinal axis is less than percents. There is minor capacity difference between hole diameter 3cm hole, but 13tone difference of load capacity between hole diameter 5cm.

Soil and ribbed concrete slab interface modeling using large shear box and 3D FEM

  • Qian, Jian-Gu;Gao, Qian;Xue, Jian-feng;Chen, Hong-Wei;Huang, Mao-Song
    • Geomechanics and Engineering
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    • v.12 no.2
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    • pp.295-312
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    • 2017
  • Cast in situ and grouted concrete helical piles with 150-200 mm diameter half cylindrical ribs have become an economical and effective choice in Shanghai, China for uplift piles in deep soft soils. Though this type of pile has been successful used in practice, the reinforcing mechanism and the contribution of the ribs to the total resistance is not clear, and there is no clear guideline for the design of such piles. To study the inclusion of ribs to the contribution of shear resistance, the shear behaviour between silty sand and concrete slabs with parallel ribs at different spacing and angles were tested in a large direct shear box ($600mm{\times}400mm{\times}200mm$). The front panels of the shear box are detachable to observe the soil deformation after the test. The tests were modelled with three-dimensional finite element method in ABAQUS. It was found that, passive zones can be developed ahead of the ribs to form undulated failure surfaces. The shear resistance and failure mode are affected by the ratio of rib spacing to rib diameter. Based on the shape and continuity of the failure zones at the interface, the failure modes at the interface can be classified as "punching", "local" or "general" shear failure respectively. With the inclusion of the ribs, the pull out resistance can increase up to 17%. The optimum rib spacing to rib diameter ratio was found to be around 7 based on the observed experimental results and the numerical modelling.

Theoretical Analysis on the Heat Transport Limitation of a Sintered Metal Wick Heat Pipe (소결윅 히트파이프의 열수송 한계에 관한 이론적 해석)

  • Kim Keun-Bae;Kim Yoo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.8 no.4
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    • pp.16-25
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    • 2004
  • Theoretical analysis for predicting the heat transport limitation of a copper powder sintered wick heat pipe was performed. The heat pipe diameter was 8mm and water was used for working fluid. The particle diameter was classified by 5 different meshes, and each capillary pressures and heat transport limitations. thermal resistances were analyzed according to the operating temperatures, wick thicknesses and inclination angles, based on the effective capillary radius($r_c$), porosity($\varepsilon$), Permeability (K). The wick capillary limitation was increased according as the particle diameter and the wick thickness and the operating temperature were increased. As the porosity and the capillary radius were larger. then the heat transport limitation was higher. The thermal resistance was greatly increased according as the wick thickness was increased.

Analysis of Standard Cost and the Construction Period Applied TBM Excavation Method (TBM 굴착 공법 적용 구경별 표준 공사비 및 공사기간 분석 연구)

  • Park, Hong Tae
    • Journal of the Society of Disaster Information
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    • v.8 no.4
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    • pp.319-327
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    • 2012
  • This research collected work drilling report of TBM method site developed by WRITH company to TBM equipment company in Germany and analyzed work operating productivity. Based the data analyzed TBM operating productivity, This research derived and presented excavation speed(m/day) by TBM diameter (2.6m, 3.0m, 3.5m, 5.0m, 8.0m) and rock. Also, based on the excavation speed(m/day) by TBM diameter, This research estimated a day direct construction cost and total direct construction costs by applying a direct construction cost which spent on per 1m. Based on hard rock 40.0%, soft rock 30.0%, usually rock 20%, weathered rock 10.0%, TBM boring velocity, m per cost, total construction period shall estimate the construction cost and the construction period by the effective use by diameter when future applying TBM method to the basic planning stages and in the preliminary design phase.

Estimation of Yield strength and Slip Modulus for Helically Threaded Nail Connection (나선형 철선못 접합부의 항복내력 및 강성 예측)

  • Hwang, Kweonhwan;Shim, Kug-Bo
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.6
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    • pp.524-530
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    • 2009
  • In the post-beam structure, the infilled light-frame construction provides most shear strengths. Shear properties of the light-frame structure can be estimated from the shear properties of nailed connection for the sheathings, and those of nailed connections can be done from nail bending strengths. For the basic study to predict the yield strength and the slip modulus of a nailed sheathing shear wall, those of a nailed joint were examined from nail bending strengths. To estimate shear properties of a nailed connection, referenced bearing strength and bearing constant for the wood members and the experimental nail bending strengths of the helically threaded nail were applied. The yield strength using the diameter at grooves instead of shank diameter was well coincided with the experimental value, but the slip modulus was estimated much smaller. The effective factors, specific gravity for the main member, withdrawal by nail head diameter to the side member, and embedment and moment at the nail head were considered, and further examinations are needed for the precise prediction of the nailed connections.