• Title/Summary/Keyword: annulus

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Pulmonary Atresia with Intact Ventricular Septum (둔형 폐동맥 폐쇄증 1)

  • 손영상
    • Journal of Chest Surgery
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    • v.20 no.2
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    • pp.432-437
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    • 1987
  • Pulmonary atresia with intact ventricular septum is a extremely rare congenital cardiac anomaly. With the history of cyanosis and failure to thrive, this anomaly should not be excluded and emergency management is necessary. Our patient was 69 day-old male with pulmonary atresia which was confirmed by cardiac angiography. Prostaglandin E1 was used for maintenance of pulmonary blood flow preoperatively. Right ventricular outflow reconstruction with pericardial patch and concomitant pulmonary valvotomy were done on beating heart for palliation. With this method, growing of right ventricle and tricuspid annulus are highly expected.

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Numerical Analysis of Stall Propagation in Linear Cascade (선형 익렬에서의 실속 전파에 관한 수치적 해석)

  • Seo, Young-Seok;Baek, Je-Hyun
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.416-421
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    • 2000
  • The performance of gas turbine engines is affected by instabilities, like as rotating stall and/or surge. Rotating Stall is a transient intermediate stage between normal flow and complete flow breakdown leading to engine surge. Rotating Stall is associated with large amplitude nonaxisymmetric flow variations rotating around the compressor annulus. This paper presents the evolutions of stall propagation in a compressor cascade by numerical analysis. The flow phenomena due to stall cells and propagation speed are examined using 2 dimensional Navier - Stokes equations.

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Two New Species of Amanita from Korea

  • Cho, Duck-Hyun
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2002.11b
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    • pp.70-70
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    • 2002
  • Two new species of Amanita were collected in central areas of Korea from 1997 to 2000. They were identified, described and illustrated. One of them, Amanita longstipeta has turtle-shaped warts of crust and its base is longer under the soil than is above the soil. The other A. aureofarinosa is covered with golden yellow farina and annulus is absent. Both are solitary in soil with sand.

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BIFURCATIONS IN A HUMAN MIGRATION MODEL OF SCHEURLE-SEYDEL TYPE-II: ROTATING WAVES

  • Kovacs, Sandor
    • Journal of applied mathematics & informatics
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    • v.16 no.1_2
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    • pp.69-78
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    • 2004
  • This paper treats the conditions for the existence of rotating wave solutions of a system modelling the behavior of students in graduate programs at neighbouring universities near each other which is a modified form of the model proposed by Scheurle and Seydel. We assume that both types of individuals are continuously distributed throughout a bounded two-dimension spatial domain of two types (circle and annulus), across whose boundaries there is no migration, and which simultaneously undergo simple (Fickian) diffusion. We will show that at a critical value of a system-parameter bifurcation takes place: a rotating wave solution arises.

Natural Convection in a Horizontal Cylindrical Annulus Enclosing Heat Generating Core (發熱核 주위의 수령圓環 에서의 자연대류)

  • 장근식;오세윤
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.9 no.5
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    • pp.663-676
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    • 1985
  • 수평원통형의 복합유동층에서의 층류자연대류를 수치적으로 연구하였다. 외측의 동심원환이 내 의 발열유체로 형성된 원통형 핵을 둘러싸고, 그 사이에 두께가 유한하거나 두께를 무시할 수 있 는 간막이 벽이 존재한다. 유동특성과 열전달에 관한 매개변수적 고찰을 시행하거나 직경비, Prandt1수, 발열강도에 기준을 둔 Rayleigh수 등의 영향을 이해하게 되었다. 간막이 벽의 두께나 열전도의 효과도 제한된 범위 안에서 고려하였다.

Tetralogy of Fallot with Absent Pulmonic valve - A case Report - (폐동맥판막 결손을 동반한 활로씨 4징증: 1례 치험)

  • Son, Dong-Seop;Kim, Chang-Ho;Lee, Gyu-Hwan
    • Journal of Chest Surgery
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    • v.19 no.1
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    • pp.160-164
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    • 1986
  • Tetralogy of Fallot with absent pulmonic valve is a rare cardiac malformation. The most significant symptoms during early infancy are secondary to bronchial compression resulting from the dilated pulmonary arteries. The clinical diagnosis was confirmed by echocardiography, cardiac catheterization and cardioangiography. A case of TOF with absent pulmonic valve was successful operated upon without insertion of the pulmonic valve. The narrow pulmonic valve annulus was enlarged with a transannular pericardial patch graft. The postoperative course was uneventful.

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Surgical Experience of Congenital Tricuspid Stenosis - A Report of Case - (선천성 삼첨판 협착증의 수술치험 1례)

  • Kim, Jhin-gook;Ahn, Hyuk;Oh, Byung-Hee
    • Journal of Chest Surgery
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    • v.21 no.4
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    • pp.700-705
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    • 1988
  • A case of congenital tricuspid stenosis in 24 year old male patient is presented. The lesion was successfully corrected with prosthetic valve replacement and closure of atrial and ventricular septal defects. Especially, this is the first reported case of successful large prosthetic valve replacement to a small annulus in tricuspid valve.

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Application and Assesment of Regrouting Method for Improperly Constructed Wells in Jeju Island (제주도의 오염 방지 시공이 부실한 지하수 관정에 대한 구간 차폐 공법의 적용과 평가)

  • Kim, Mijin;Kang, BongRae;Cho, Heuy Nam;Choi, Sung Ouk;Yang, Won-Seok;Park, Wonbae
    • Journal of Soil and Groundwater Environment
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    • v.25 no.3
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    • pp.43-51
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    • 2020
  • About 90% of groundwater wells in Jeju Island are reported to be under the threat of contamination by infiltration of the surface pollutants. Most of those wells have improperly grouted annulus which is an empty space between the well and the inner casing. As a remedy to this problem, some of the wells were re-grouted by filling the annulus with cement without lifting an inner casing. In order to evaluate whether this method is appropriate for the geological structure of Jeju Island, two wells (W1 and W2) were selected and this method was applied. The water holding capacity did not decrease while the nitrate levels decreased from 16.8 and 20.2 to 6.8 and 13.8 mg/L in W1 and W2, respectively. The higher nitrate level in W2 is deemed to be influenced by the livestock farms located in the upper area of the well. In addition, transmissivity of the vedose zone was higher in W2 than W1, potentially facilitating the transport of nitrate to the groundwater. The overall result of this study suggests re-grouting of wells for the purpose of protecting water quality of goundwater should take into account geological structure of vadose zone as well as appropriate source control of the contaminants.

Heat Transfer Characteristics in the Evaporator of a Soft Ice Cream Maker (소프트 아이스크림 제조기 증발기의 전열 특성)

  • Byun, Ho-Won;Lee, Jin-Wook;Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1466-1473
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    • 2012
  • Soft icecream is made by scraping an ice formed on the inside of the cylindrical evaporator, where R-404A is evaporating in the annulus. The heat transfer characteristics of the refrigerant evaporation and those during icecream formation were experimentally investigated. Results show that the refrigerant-side heat transfer coefficients are highly dependent on the location in the evaporator due to the complex annulus configuration. The heat transfer coefficient at the inlet is generally lower than those of other locations. The average heat transfer coefficient increases as heat flux increases or saturation temperature decreases. A correlation is developed to predict the refrigerant-side heat transfer coefficient. The icecream-side heat transfer coefficient oscillates continuously due to the periodic removal of ice formed on the surface. The average heat transfer coefficient during icecream formation is approximately 280 W/$m^2K$, and that during single-phase cooling increased from 150 W/$m^2K$ to 250 W/$m^2K$.