• Title/Summary/Keyword: Cylindrical extension

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Soil Failure Mode of a Buried Pipe Around in Soil Undergoing Lateral Movement (측방변형지반속 매설관 주변지반의 파괴모드)

  • Hong, Won-Pyo;Han, Jung-Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.5
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    • pp.11-21
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    • 2002
  • A series of model tests is performed to evaluate the relationship between soil and a buried pipe in soil undergoing lateral movement. As the result of the model tests, a wedge zone and plastic flow zones could be observed in front of the pipe. And also an arc failure of cylindrical cavity could be observed at both upper and lower zones. Failure shapes in both cohesionless and cohesive soils are nearly same, which was investigated failure angle of $45^{\circ}+{\phi}/2$. In the cohesionless soil, the higher relative density produces the larger arc of cylindrical cavity. On the basis of failure mode observed from model tests, the lateral earth pressure acting on a buried pipe in soil undergoing lateral movement could be applying the cylindrical cavity extension mode. The deformation behavior of soils was typically appeared in three divisions, which are elastic zones, plastic zones and pressure behavior zones.

Development of Equations for Static Design Loads of Sphere Type LNG Tank with Cylindrical Extension (원통 확장부를 갖는 구형 LNG 탱크의 정적 설계하중 산출식 개발)

  • Shin, Sang-Hoon;Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5060-5066
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    • 2015
  • The number of shop needed for the fabrication of sphere type LNG tank is proportional to that of the tank radius to be constructed. Due to limitation of facility investment including building sites, it is practically difficult to fabricate various size tanks of perfectly spherical shape in the yards. The efficient method to increase cargo tank capacity is to extend vertically the conventional sphere type LNG tank by inserting a cylindrical shell structure. In this study, equations for static design loads are developed for sphere type LNG tank with central extension. The results of this study will be combined with dynamic design loads to build the simplified analysis method which enable the precise initial estimate instead of time consuming finite element analysis.

Anthracnose of Rapsberry(Rubus coreanus) Caused by Colletotrichum coccodes in Korea

  • Kim, J. H.;S. S. Cheong;J, Ryu;Park, J. S.;Park, Y. G.;Lee, W. H.
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.132.2-132
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    • 2003
  • Anthracnose occurred on rapsberry grown in Gochang areas of Korea in 2003. The disease incidence was ranged from 1.1 to 2.6%. Anthracnose of rapsberry appeared as dark brown circular spots on naturally infected stems. The symptoms of infected stems were small brown to dark brown spots and gradually enlarged larger cylindrical dark brown lesions. The causal fungus of anthracnose isolated from the diseased plants was identifed as Colletotrichum coccodes based on the morphological and cultural characteristics. All isolates of C. coccodes were produced similar symptoms on the host leaves by artificial inocultion.

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A MULTI-DIMENSIONAL MAGNETOHYDRODYNAMIC CODE IN CYLINDRICAL GEOMETRY

  • Ryu, Dong-Su;Yun, Hong-Sik;Choe, Seung-Urn
    • Journal of The Korean Astronomical Society
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    • v.28 no.2
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    • pp.223-243
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    • 1995
  • We describe the implementation of a multi-dimensional numerical code to solve the equations for idea! magnetohydrodynamics (MHD) in cylindrical geometry. It is based on an explicit finite difference scheme on an Eulerian grid, called the Total Variation Diminishing (TVD) scheme, which is a second-order-accurate extension of the Roe-type upwind scheme. Multiple spatial dimensions are treated through a Strang-type operator splitting. Curvature and source terms are included in a way to insure the formal accuracy of the code to be second order. The constraint of a divergence-free magnetic field is enforced exactly by adding a correction, which involves solving a Poisson equation. The Fourier Analysis and Cyclic Reduction (FACR) method is employed to solve it. Results from a set of tests show that the code handles flows in cylindrical geometry successfully and resolves strong shocks within two to four computational cells. The advantages and limitations of the code are discussed.

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Development of Equations for Dynamic Design Loads of Sphere Type LNG Tank with Cylindrical Extension (원통 확장부를 갖는 구형 LNG 탱크의 동적 설계하중 산출식 개발)

  • Shin, Sang-Hoon;Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.262-267
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    • 2017
  • The number of shops needed for the fabrication of a sphere type cargo tank for an LNG carrier is proportional to the size of the tank to be constructed. Due to the limitations of facility investment, it is difficult to fabricate various size tanks with a perfectly spherical shape in the (factory). An efficient method of increasing the capacity of the cargo tank is to extend the conventional sphere type LNG tank vertically by inserting a cylindrical shell structure. In this study, equations for the dynamic pressure distribution due to horizontal acceleration are derived for a sphere type LNG tank with central extension. The derived equations can be easily applied to the design and structural assessment of a sphere type LNG tank with central extension. Furthermore, the results of this study can be combined with the static design loads previously reported by Shin & Ko [9], in order to establish a simplified analysis method which enables a precise initial estimate to be obtained, thereby obviating the need for a time consuming finite element analysis.

Analysis of Patched Cylindrical Shells with Circumferential Through-Wall Cracks (원주방향 관통균열을 갖는 원통형 쉘 구조의 패치보강 해석)

  • Ahn, Jae-Seok;Kim, Young-Wook;Woo, Kwang-Sung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.6A
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    • pp.411-418
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    • 2012
  • In this study, behavior of unpatched and patched cylindrical shells with through-wall cracks has been estimated using numerical experiments, and patching effect of them has been investigated according to various patching parameters. To show credibility of numerical models considered, two ways such as h- and p-methods have been adopted. Also, domain integral method and virtual crack extension method have been considered to calculate energy release rates based on linear elastic fracture mechanics. For examples, the unpatched cylindrical shells with circumferential cracks under remote tension have firstly been analyzed to show the validity of finite element modeling with h-method or p-method, and then the results have been compared with literature values published. Next, the sensitive analysis of patch repaired problems in terms of thickness of patch and adhesive, shear modulus of adhesive, composite material type of patch, crack length, etc. has been carried out.

Fruit Soft Rot of Sweet Persimmon Caused by Mucor piriformis in Korea

  • Kwon, Jin-Hyeuk;Ahn, Gwang-Hwan;Park, Chang-Seuk
    • Mycobiology
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    • v.32 no.2
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    • pp.98-101
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    • 2004
  • A fruit soft rot caused by Mucor piriformis occurred on sweet persimmon storages in Jinju, Changwon and Gimhae, Gyeongnam province, Korea, 2003. The disease infection usually started from wounding after cracking of fruits. At first, the lesions started with water soaked and rapidly softened and diseased lesion gradually expanded. Colonies on potato dextrose agar at $20^{\circ}C$ were whitish to olivaceous-buff Sporangia were globose, black and $96{\sim}153{\mu}m$ in size. Sporangiophores were $26{\sim}42{\mu}m$ in width. Sporangiospores were ellipsoid and $5.8{\sim}10.6{\times}4.3{\sim}7.6{\mu}m$ in size. Columella was obovoid, cylindrical-ellipsoidal, pyriform, subglobose and $80{\sim}125{\mu}m$ in size. Optimal temperature for mycelial growth was $20^{\circ}C$ on PDA. The causal organism was identified as M. piriformis. This is the first report of fruit soft rot on sweet persimmon caused by M. piriformis in Korea.

Anterior Cervical Discectomy and Fusion Using a Double Cylindrical Cage versus an Anterior Cervical Plating System with Iliac Crest Autografts for the Treatment of Cervical Degenerative Disc Disease

  • Kim, Seong Joon;Kim, Sang Don
    • Journal of Korean Neurosurgical Society
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    • v.55 no.1
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    • pp.12-17
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    • 2014
  • Objective : Anterior cervical discectomy and fusion (ACDF) is often complicated by subsidence, pseudoarthrosis, kyphosis, and graft donor site morbidities. To decrease the occurrence of these complications, various types of cages have been developed. We designed this retrospective study to analyze and compare the efficacy and outcomes of ACDF using double cylindrical cages (DCC) (BK Medical, Seoul, Korea) versus an anterior cervical plating system with autogenous iliac crest grafts. Methods : Forty-eight patients were treated with autograft and plating (plate group), and 48 with DCC group from October 2007 to October 2011. We analyzed construct length, cervical lordotic curvarture, the thickness of the prevertebral soft tissue, segmental instability, and clinical outcomes. Results : There were no significant differences between the two groups with regard to the decrease in construct length or cervical lodortic curvature at the 3-, 6-, and 12-month follow-ups. The prevertebral soft tissue was thinner in the DCC group than the plate group immediately after surgery and at the 3-, 6-, and 12-month follow-ups. The difference in interspinous distance on flexion-extension was shorter in the plate group than the DCC group at the 3- and 6-month follow-ups. However, there was no significant difference in this distance between the two groups at the 12-month follow-up. Conclusion : A double cylindrical cage is a good alternative for fusion in patients with cervical degenerative diseases; the surgical method is relatively simple, allows good synostosis, has less associated prevertebral soft tissue swelling, and complications associated with autografting can be avoided.

Sclerotinia Rot of Broad Bean (Vicia faba) Caused by Sclerotinia sclerotiorum (Sclerotinia sclerotiorum에 의한 잠두 균핵병)

  • Kwon, Jin-Hyeuk;Bae, Yeoung-Seuk
    • Research in Plant Disease
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    • v.13 no.2
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    • pp.115-118
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    • 2007
  • Sclerotinia rot occurred on the stem and pod of broad bean (Vicia faba) at Gyeongsangnam-do Agricultural Research and Extension Services in Korea from 2004 to 2006. The infected plants showed the typical symptoms; wilted, water-soaked, rotted and eventually died. The colony of the isolated fungus on PDA was white to faintly gray color. Apothecia were cup-shaped and $5{\sim}10\;mm$ in size. Asci were cylindrical in shape and $90{\sim}180{\times}8{\sim}12\;{\mu}m$ in size. Ascospores were ellipsoid and $8{\sim}12{\times}4{\sim}6\;{\mu}m$ in size. Sclerotia formed on the PDA were globose to cylindrical or irregular in shape with black color. The optimum temperature for mycelial growth was $25^{\circ}C$ and sclerotia formation was at $20^{\circ}C$ on PDA. This is the first report on sclerotinia rot of broad bean (Vicia faba) caused by Sclerotinia sclerotiorum (Lib.) do Bary in Korea.

First Report of Anthracnose on Bitter Gourd Caused by Colletotrichum gloeosporioides in Korea (Colletotrichum gloeosporioides에 의한 쓴오이 탄저병)

  • Kim, Ju-Hee;Kim, Ju;Choi, In-Young;Cheong, Seong-Soo;Uhm, Mi-Jeong;Lee, Wang Hyu
    • Research in Plant Disease
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    • v.21 no.1
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    • pp.32-35
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    • 2015
  • Anthracnose occurred in bitter gourd grown in Jeongup areas of Korea in 2011. Anthracnose of bitter gourd appeared as dark brown circular spots on naturally infected leaves and fruits. The symptoms of infected leaves and fruits were small brown to dark brown spots and gradually enlarged to larger cylindrical dark brown lesions. The causal fungus of anthracnose isolated from the diseased plants was identified as Colletotrichum gloeosporioides based on the morphological and cultural characteristics and ITS rDNA sequence analysis. All isolates of C. gloeosporioides produced symptoms on the host leaves by artificial inoculation. This is the first report of anthracnose on bitter gourd caused by C. gloeosporioides in Korea.