• 제목/요약/키워드: heterosis

검색결과 167건 처리시간 0.036초

Vibration and buckling analyses of laminated panels with and without cutouts under compressive and tensile edge loads

  • Rajanna, T.;Banerjee, Sauvik;Desai, Yogesh M.;Prabhakara, D.L.
    • Steel and Composite Structures
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    • 제21권1호
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    • pp.37-55
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    • 2016
  • In this study, the influence of centrally placed circular and square cutouts on vibration and buckling characteristics of different ply-oriented laminated panels under the action of compressive and/or tensile types of non-uniform in-plane edge loads are investigated. The panels are inspected under the action of uniaxial compression, uniaxial tension and biaxial, compression-tension, loading configurations. Furthermore, the effects of different degrees of edge restraints and panel aspect ratios are also addressed in this work. Towards this, a nine-node heterosis plate element has been adopted which includes the effect of shear deformation and rotary inertia. According to the results, the tensile buckling loads are higher than that of compressive buckling loads. However, the tensile buckling load continuously reduces with the increased cutout sizes irrespective of ply-orientations. This is also true for compressive buckling loads except for some particular ply-orientations with higher sized cutouts.

Competitive Performance of Hybrid Rice with Barnyardgrass

  • Lin, Wenxiong;Kim, Hak-Yoon;Shin, Dong-Hyun;Lee, In-Jung;Kim, Kil-Ung
    • 한국작물학회지
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    • 제44권4호
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    • pp.391-395
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    • 1999
  • Barnyardgrass had relatively higher growth vigor at the earlier growth stage than inbred rice did, showing the 2 fold higher $\alpha$-amylase activity during the periods of germination and large leaf area Expansion with high net photosynthetic rate at the earlier autotrophic stage, but it performed weak growth at the late growth stage. However, the hlybrid rice Shanyou 63 had significantly higher $\alpha$-amylase activity and net photosynthetic rate than that of barnyardgrass, exhibiting heterosis for two physiologica1 traits during the germination (6~12 days) and autotrophic phase, respectively. Accordingly, hybrid rice, Shanyou 63, exhibited heterotic effect at the early growing stage when were presented with barnyardgrass. Shanyou 63 exhibited stronger tillering ability, faster leaf area expansion and higher net photosynthetic rate than those of barnyardgrass.

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Estimation of Hybrid Vigor of Some Egyptian Single Local Hybrids of Mulberry Silkworm, Bombyx mori L.

  • Ghazy, Usama Mohamed Mohamed
    • International Journal of Industrial Entomology and Biomaterials
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    • 제25권2호
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    • pp.147-151
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    • 2012
  • Fifteen races resulted from silkworm breeding program at Sericulture Research Department (SRD) were used for hybridization. Fourteen hybrids were obtained and coded as; Giza C, D, R, S, T, U, A, V, W, P, H, L and Qanater 1, 2. The traits of cocoon weight, cocoon shell weight, pupal weight, cocoon shell ratio, silk productivity, fifth instar duration, total larval duration, number of cocoon per liter and pupation ratio were evaluated. Data were analyzed by using three formulae of heterosis over better, mid and check parent values. Hybrids of Giza V, C, N, Qanater 1 and 2 are promising and could be used in commercial cocoon production. Generally, there are some new hybrids can be exploited in commercial scale. Also, the local races can be evolved using the hybridization, inbreeding and selection program.

IMPROVEMENT AND UTILIZATION OF GENETIC RESOURCES IN NATIVE CHICKEN : RECIPROCAL CROSS BETWEEN TAIWAN COUNTRY CHICKEN AND SINGLE COMB WHITE LEGHORN

  • Lee, Yen-Pai;Huang, Hwei-Huang
    • Asian-Australasian Journal of Animal Sciences
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    • 제2권2호
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    • pp.103-114
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    • 1989
  • Reciprocal crosses were conducted between three strains of Taiwan Country chickens, developed in the National Chung-Hsing University, and two strains of Single Comb White Leghorns, developed in the Taiwan Livestock Research Institute. Traits studied were growing performances, laying performances, egg quality traits and traits concerning disease resistance, including resistance to Marek's disease virus and immune responses to Newcastle disease virus vaccine and to sheep red blood cell. Results indicated that laying performances of Taiwan country chickens were much inferior to White Leghorns, but they matured earlier, their eggs had better shell strength and larger proportion of yolk, and their general disease resistance was much better than White Leghorns. Heterosis were found in laying performances and egg quality traits. The heterosis in laying traits was so large that the hybrid laid as many eggs and as large eggs as did pure strains of White Leghorns. Strategies on the improvement of native chickens and the utilization of genetic merits of native chickens were also discussed.

Mindlin 평판 유한요소의 개선 (Improvement of Finite Element for Mindlin Plate Bending)

  • 김선훈;최창근
    • 전산구조공학
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    • 제1권2호
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    • pp.83-90
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    • 1988
  • 본 연구에서는 평판 구조물의 해석을 위한 개선된 유한요소를 제시하였다. 이 요소는 Mindlin 평판이론에 의하여 수식화되었으며, 'Heterosis'평판요소의 변위장에 비적합변위형을 추가함으로써 유도되었다. 본 연구에서 제시한 평판요소는 요소의 강체운동과 관련된 Zero Eigenvalue만을 갖고 있으므로 Spurious Zero Energy Mode를 보이지 않는다. 대표적인 문제에 대한 수치해석을 해 본 결과 본 연구에서 제시한 평판요소는 우수한 수렴도를 보여 주었으며, 아주 얇은 평판문제에서도 요소의 형상에 관계없이 Shear Locking현상을 극복하였다.

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세포질 유전자적 웅성불임계통을 이용한 유체 Heterosis 육종 개발에 관한 연구 제2보 웅성불임계통에 Non-Isogenic Maintainer를 활용한 유체 3원교잡F_1의 형질발현과 F_1종자생육 (Studies on Heterosis Breeding in Rapeseed Using Cytoplasmic Male Sterility 2, Agronomic Characteristics of F_1 Seed Production Procedure in the Three-way Crossing of Cytoplasmic-genetic Male Sterile, Non-Isogenic Maintainer and Restorer on Rape (Brassica napus L.))

  • 이정일;권병선
    • 한국작물학회지
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    • 제25권2호
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    • pp.49-57
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    • 1980
  • A $F_1$ hybrid out of 143 crosses of rape (Brassica napus) using cytoplasmic-genetic male sterility yielded 5.18 tons per hectare. European and native varieties used, were found out to have 78% and 58% of genes restoring fertility, respectively. The $F_1$ hybrids of three way cross using non-isogenic maintainer showed higher heteroses than those of double cross. To produce F 1 hybrids of three way cross, three stages of crossing operations are needed and seeds produced from about 60 hectares can be covered to 60, 000 hectares.

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재래종과 Orient종 연초 $F_1$의 잡종강세와 조합능력 (Heterosis and Combining Ability in $F_1$ Hybrids of Korea Local and Oriental Tobacco Varieties (Nicotiana tabacum L.))

  • 이정덕;장권열
    • 한국연초학회지
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    • 제6권1호
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    • pp.3-11
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    • 1984
  • In order to obtain the basic information for the successful breeding of aromatic tobacco (Nicotiana tabacum L.), the heterosis, combining ability and gene distributions in 28 Fl hybrids by diallel crosses between Korea local and Oriental varieties were investigated. The yield were higher, stalk height, leaf length and leaf width were larger and days to flower was shorter for the Fl hybrids when compared to mid-parent. Estimates of general combining ability were significant for all characters investigated, and specific combining ability were significant for yield, stalk height, leaves Per Plant, leaf width and days to flower. In vr-wr graph, partial dominane was exhibited by all characters investigated.

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