• Title/Summary/Keyword: tapering

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Morphological Description of Cynoglossus joyneri Larvae Collected from the Yellow Sea (황해 참서대(Cynoglossus joyneri) 자어의 형태기재)

  • Gu, Seon-Ok;Hwang, Hak-Jin;Kim, Jin-Koo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.6
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    • pp.725-728
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    • 2009
  • Four specimens of Cynoglossus larvae (3.2-7.3 mm in notochord length, NL) collected from the middle Yellow Sea in August, 2008 were identified as Cynoglossus joyneri larvae based on morphological characteristics; (1) the two elongated dorsal fin rays on the parietal region, (2) protruded abdomen, (3) no melanophores on the mediolateral trunk and tail. Larva of 3.2 mm NL is compressed with a little big head and tapering, long tail. Larva of 7.0 mm NL has 115 dorsal fin and 85 anal fin rays, which are the same to those of adult. Larva of 7.3 mm NL tended to have concave part in the fringe of forehead, in which left-side eye may move to the other side.

New Dictyostelid in Mt. Surak, Korea;Dictyostelium valenstemmum sp. nov. (한국산 세포성 점균의 신종 : Dictyostelium valenstemmum sp. nov.)

  • 심규철;장남기
    • Asian Journal of Turfgrass Science
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    • v.10 no.2
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    • pp.117-124
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    • 1996
  • One new cellular slime mold, Dicivostelium valenstemmun sp. n. Shim et Chang, is isolated from the fermentation layer of soils in the cool temperate forests of Surak mountain, Korea. This species has the sori and sorophore yellow-pigmented, and sparse or irregular branches. And it is characterized by tall and robust sorocarps, well-form basal disks, mucoroides-type aggregations and large spores. This species has sorophores gradually tapering from bases to tips, simple capi- tate sorophore tips and conical bases. When prostrates on the plates, it has sparsely clavate bases. Spores are considerably large, 6.8~9.9 x 3.4~5.1 $\mu$m(avg. 8.5 x 4.1 $\mu$m), L /W index l.84~2.43(avg. 2.07) without polar granules. Key words: Diccyostelium valeustemmum, Cool temperate forests, Surak mountain.

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Calculations of Thickness Uniformity in Molecular Beam Epitaxial Growth (MBE 장치에 의한 에피 성장 두께 균일도 계산)

  • 윤경식;김은규;민석기
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.8
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    • pp.81-87
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    • 1993
  • The growth thickness uniformity of epitaxial layers deposited using a moiecular beam epitaxy system is calculated from the arrangement of molecular beam source and the substrate and the geometric dimensions of the crucible in order to predict the optimum design conditions of the prototype MBE system. The thickness uniformity better than 5% over a 3-inch wafer can be obtained by keeping the distance between the substrate and the crucible's orifice longer than 20cm, the tapering angle of the crucible larger than 6$^{\circ}$, and the angle between the normal to the substrate at the center and the crucible axis as larger as possible. In addition, the growth yield decreases to below 51% as the distance between the substrate and the orifice becomes longer than 25cm.

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Study on Structural Efficiency of Super-Tall Buildings

  • Jianlong, Zhou;Lianjin, Bao;Peng, Qian
    • International Journal of High-Rise Buildings
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    • v.3 no.3
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    • pp.185-190
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    • 2014
  • Based on a 405m high super-tall building, the influence of outriggers, different shapes and layouts of structural plane and elevation on structural efficiency under lateral forces is studied in this paper. A calculation formula concerning the structural efficiency is given. The study shows that structural efficiency can be improved by triangulating the plane shape, using mega columns, the peripherization of the plane layout, tapering the elevation shape and setting bracing structure in the elevation. The arrangement of outriggers between the core tube and flange frame can reduce the shear lag effect in order to improve structural efficiency. The essence of improving structural efficiency of super-tall buildings is to maximize the plane bending stiffness and to make its deformation approach to plane section assumption.

Morphological Characters and Seed Transmission of Bipolaris panici-miliacei Causing Leaf Spot of Common Millet (기장 점무늬병균 (Bipolaris panici-miliacei)의 형태적 특징과 종자전염)

  • 이두형
    • Korean Journal Plant Pathology
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    • v.13 no.1
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    • pp.18-21
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    • 1997
  • Bipolaris panici-miliacei, Cercospora fusimaculans, Fusarium moniliforme and Rhizoctonia solani were pathogenic fungi detected from 5 seed samples of common millet (Panicum miliaceum). Morphological characters of B. panici-miliacei were as follows. Conidiophores were dark olivaceous brown, simple, cylindrical, geniculate, and septate. Conidia were fusoid, dark olivaceous brown, tapering gradually toward the ends, straight to slightly curved, 3~13 distoseptate, and 29.4~155.4$\times$10~26 ${\mu}{\textrm}{m}$ in size with dark hilum included within the contour of the basal cell. Seed infection with B. panici-miliacei caused seed rotting, coleoptile spot, and seedling blight of common millet plants. According to the inoculation experiments, B. panici-miliacei showed strong virulence on the young seedlings of common millet, but very weak virulence on the young seedlings of rice (Oryza sativa) and foxtail millet (Setaria italica).

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Enthalpy Flow Loss by Steady Mass Streaming in Pulse Tube Refrigerators (맥동관냉동기의 정상상태 질량흐름에 의한 엔탈피손실)

  • 백상호;정은수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.7
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    • pp.623-631
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    • 2000
  • Effects of the taper angle and the angular velocity of a pulse tube on the enthalpy flow loss associated with the steady mass streaming were analysis by two-dimensional analysis of a pulse tube with variable cross-section. It was shown that the steady mass flux can lead to a large steady second-order temperature. The enthalpy flow loss associated with the steady mass streaming increases as the angular velocity increases. For a pulse tube where the viscous penetration depth is far thinner than the inner radius, the enthalpy flow loss can be significantly reduced by tapering the pulse tube since both the steady mass flux and the steady second-order temperature decrease as the taper angle increase.

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Phylogenetic Analysis of Dinoflagellate Gonyaulax polygramma SteinResponsible for Harmful Algal Blooms Based on the Partial LSU rDNASequence Data

  • Kim, Keun-Yong;Kim, Young-Soo;Hwang, Choul-Hee;Lee, Chang-Kyu;Lim, Wol-Ae;Kim, Chang-Hoon
    • ALGAE
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    • v.21 no.3
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    • pp.283-286
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    • 2006
  • This study carried out phylogenetic analysis of dinoflagellate Gonyaulax polygramma which was responsible for a harmful algal bloom episode in Korea in 2004. Molecular phylogenetic tree inferred from the partial LSU rDNA data showed that G. polygramma came up among the monophyletic Gonyaulax clade, but did not have apparent genetic affiliation to other Gonyaulax species. This result appears to be consistent with characteristic morphological features of G. polygramma such as epitheca sharply tapering to the apex and thecal plates ornamented with numerous longitudinal striations.

Fruit and Vine Rot of Watermelon Caused by Phytophthora capsici (Phytophtora capsici에 의한 수박 역병)

  • 김병수
    • Korean Journal Plant Pathology
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    • v.11 no.1
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    • pp.98-99
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    • 1995
  • A disease causing fruit rot and leaf and vine blight on watermelon was found in Euseong in July, 1991 and in Bonghwa, Kyungpook province in August, 1993. Abundant zoosporangia characteristics of Phytophthora capsici were formed on the surface of the infected fruits. The zoosporangia were ovoid to ellipsoid, tapering to the base and with conspicuous papilla. The fungus isolated from the infected fruits was pathogenic on seedlings of watermelon, pumpkin, and pepper. The morphological characteristics and host range agreed with those of P. capsici. The watermelon disease caused by P. capsici was reported long time ago in Japan and America but rot yet in Korea. Thus, the disease on watermelon caused by P. capsici is reported as a new record in Korea.

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Vertically Integrated Waveguide Thermo-Optic Switch for Three-Dimensional Optical Interconnection (3차원 광연결용 수직방향 광도파로 열광학 스위치)

  • 김기홍;신상영;최두선
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.111-114
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    • 2002
  • We propose and fabricate a vertically integrated waveguide thermo-optic switch. It controls the optical path between two vertically stacked waveguide. As a first step, we fabricate polymeric waveguides. The measured propagation loss is ranged from 0.3 db/cm to 0.4 dB/cm at the wavelength of 1.55 $\mu\textrm{m}$. We fabricate the proposed vertically integrated waveguide thermo-optic switch to demonstrate its preliminary feasibility. The measured crosstalk is better than -10 db. The power consumption is about 500 mW. Further effort is necessary to improve its performance.

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Synthesis of $\beta$-SiC Whiskers by the Carbothermal Reduction of Kaolin (카올린의 환원 열탄화법에 의한 베타 탄화규소 휘스커의 합성)

  • 오세정;류종화;조원승;최상욱
    • Journal of the Korean Ceramic Society
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    • v.35 no.12
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    • pp.1249-1256
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    • 1998
  • ${\beta}$-Silicon carbide(${\beta}$-SiC) whiskers could be synthesized by the carbothermal reduction of kaolin at tem-peratures between 1400 and 1500$^{\circ}C$. The whiskers were grown up to about 1150 of aspect ratio by VS mechanism (showing tapering tips) and to about 45 of that by VLS mechanism (showing round droplet tips) respectively. Hydrocarbon like methane in the reaction atmosphere promoted the formation of gaseous il-icon monoxide(SiO) from silicon dioxide(SiO2) and subsequently reacted with it to form whiskers. The for-mation of ${\beta}$-SiC whiskers increased with increasing carbon content(to 30 wt%) and reaction temperatures. The max. yield of ${\beta}$-SiC whiskers was 15% at 1500$^{\circ}C$ under 20%CH4/80%H2.

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