• Title/Summary/Keyword: Yamada

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Morphology and Reproduction of Symphyocladia latiuscula (Harvey) Yamada (Rhodophyta, Rhodomelaceae) in Korea (한국산 홍조 참보라색우무(Symphyocladia latiuscula (Harvey) Yamada)의 형태와 생식)

  • 최도성
    • Journal of Plant Biology
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    • v.34 no.1
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    • pp.59-66
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    • 1991
  • The morphotaxonomic characters and life history of Symphyocladia latiuscula (Harvey) Yamada were investigated with field and laboratory culture materials. The species is well defined by a 5-15 cm hight, entirely corticated thallus and congenital fusion of 5-7 segments between main axis and laterals. Although all the reproductive structures are basically similar to those of other species of the genus, it is characteristic that the pinnulae are transformed into the flabellated tetrasporangial stichidia. Vegetative trichoblasts are known to be absent in the Pterosiphonieae, but their presence in S latiuscula does not accept its taxonomic position in that tribe. As a result, the occurrence of vegetative trichoblast is not useful for a taxonomic character to distinguish the tribes. The species shows a Polysiphonia-type life history involving a dimorphic alternation of gametophytes and sporophytes in culture and field. It grows below the middle intertidal zone in all the coasts of Korea throughout the year, although fertile plants are normally found during the summer months.months.

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Strength of Glass/Epoxy Fabric Joints under the Pin-Loading (핀하중을 받는 유리/에폭시 평직 적층판의 체결부 강도)

  • 박노희;권진희;김종훈;변준형;양승운
    • Composites Research
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    • v.15 no.2
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    • pp.1-10
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    • 2002
  • The strength of glass/epoxy fabric joints under pin-loading is estimated based on the characteristics length method and experiment. To investigate the effect of finite element idealization for the contact between pin and laminate, three modeling cases are analyzed; assuming the cosine load distribution around the contact area, constraining the radial displacement at the hole boundary, and using the contact element. To study the effect of failure criteria, Tsai-Wu and Yamada-Sun methods are applied on the characteristic curve. The results of the nonlinear analysis using the contact element showed good agrements with experimental data in both laminates made of uni-directional prepreg tapes and fabrics. In terms of failure criteria, Tsai-Wu method showed better agreement with experimental results than the one by Yamada-Sun laminate.