• Title/Summary/Keyword: 겹이음

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Control of Gray Blight of Tea Plants Using a Biofungicide (미생물제제를 이용한 차나무 겹둥근무늬병의 방제)

  • Kim, Gyoung-Hee;Lim, Myoung-Taek;Hur, Jae-Seoun;Yum, Kyu-Kim;Koh, Young-Jin
    • Research in Plant Disease
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    • v.14 no.1
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    • pp.37-42
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    • 2008
  • Bacillus subtilis BD0310 isolated from tea leaves was used for the development of a biofungicide against Pestitalotiopsis longiseta causing gray blight of tea plants. After mass culture of the antagonistic bacteria, the biofungicide formulated as a suspension concentrate was evaluated for its control efficacy against the gray blight of tea plant in a greenhouse and a tea plantation, respectively. Spray of the biofungicide 2 days before inoculation of P. longiseta inhibited more efficiently the development of gray blight compared with spray of the biofungicide 2 days after inoculation of the pathogen onto the leaves of tea plants in a greenhouse. In the field investigation under application of the biofungicide in 2005 and 2006, control efficiencies increased according to the number of spray of the biofungicide. Control efficiencies of the biofungicide were 52.4%, 66.7%, 71.4% and 85.7% against gray blight in 4 times spray of the biofungicide alone at 7 days interval, 6 times spray of the biofungicide alone at 7 days interval, 2 times alternate spray of biofungicide and chemical fungicide at 7 days interval and 4 times spray of chemical fungicide alone at 7 days interval, respectively. Therefore, the alternate application of the biofungicide and chemical fungicide at 7 days interval can increase the control efficiency with reduction of the amount of chemical fungicides and the number of spray for the control of gray blight of tea plants in the field.

Design parameters on the fatigue characteristics of a co-cured double lap joint (양면겹치기 동시경화조인트의 피로특성에 영향을 미치는 설계변수에 관한 연구)

  • 신금철;이정주
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.5-8
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    • 2002
  • The use of the co-cured joining method for composite structures is attractive due to several benefits. However, since the design stress level in cyclic loads is often smaller than the joint strength obtained from the static tensile load test, it is important to establish proper fatigue design criteria. Although some researchers have reported on co-cured joints, there are only a few papers published on the fatigue characteristics of co-cured joints. In this paper, the effect of bond parameters on the fatigue characteristics of a steel-composite co-cured double lap joint under cyclic tensile loads was experimentally investigated. We considered the surface roughness of the steel adherend and the stacking sequence of the composite adherend as bond parameters. A fatigue failure mechanism of the co-cured double lap joint was explained systematically by investigating the surfaces of failed specimens.

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An Analytic Study for the Adhesively Bonded Tubular Double Lap Joint (원형 이중겹치기 접착조인트의 해석해에 관한 연구)

  • 이수정;이대길
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.6
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    • pp.1412-1420
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    • 1994
  • The adhesively bonded tubular double lap joint has better torque transmission capability and reliability in bonding operation than the single lap joint. In this paper, an analytic solution for the torque transmission capabilities and stress distributions of the adhesively bonded tubular double lap joint was derived assuming the linear properties of the adhesive and adherends. From the calculation, it was found that the torque transmission capabilities of the double lap joint was more than 40% larger compared to that of the single lap joint.

The Evaluation of Tensile-shear Strength on the Al-Alloy Single-lap Adhesive Joints (AI합금 단순겹치기 접착이음의 인장-전단강도 평가)

  • Oh, S. K.;Yu, Y. C.;Jeong, E. S.;Yi, W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.567-571
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    • 1997
  • Recently, automobile industry has led to increasing use of aluminum alloy for weight reduction. Automobile made of aluminum alloy can be given lighter, stronger and a harder surface by anodizing than one made of steel-alloy. In this paper, we investigate the influence of lap length, adherend thickness and adhesive thickness on adhesive strength of single-lap adhesive joints by conducting tensile-shear tests. Single-lap adhesive joints of aluminum was calculated using joint factor by using adhesive length, adherend thickness of specimen.

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Analysis on the Interface Edge Crack in Aluminum Bonded Single Lap-joint (알루미늄 단순겹치기 접착이음의 에지계면균열에 대한 연구)

  • Yu, Y.C.;Park, J.H.;Jeong, E.S.;Yi, W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.655-659
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    • 1997
  • The analysis of cracks at the interface between dissimilar materilar has received a great deal of attention in recent years. In this paper we conducted the static tensile test for the aluminum bonded single lap-joint with the interface edge crack. Comparing this results, that is ultimate load and strain value of aluminum adherend by strain gauge with the fracture mechanics parameters, compliance and stress intensity factors acquied from the boundary element analysis, we concluded that there are critical value of crack length to provoke the interface fracture.

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