• 제목/요약/키워드: Passage number

검색결과 352건 처리시간 0.03초

전방십자인대 재건술의 합병증 (Complications of Anterior Cruciate Ligament Reconstruction)

  • 송은규;김종석
    • 대한정형외과스포츠의학회지
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    • 제2권1호
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    • pp.15-19
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    • 2003
  • Although the number of anterior cruciate ligament reconstruction is increasing, complications after primary ACL reconstruction are more difficult to determine. Intraoperative and postoperative complications can lead to ultimate failure of a primary reconstructive procedure. Therefore, surgical success in ACL reconstruction requires detailed knowledge and technical advancements about ACL reconstruction. Preoperatively surgeon must pay attention to selection of grafts and methods of fixation, and intraoperatively, attention to the harvest of graft, passage of graft, intraarticuar placement of the graft, notchplasty, proper tensioning of the graft, and others. Postoperative complications must be detected early, including infection, abnormal healing responses, arthrofibrosis, graft rejection, and reflex sympathetic dystrophy. Careful patient selection, appropriate surgical timing, careful surgical technique, and supervised preoperative and postoperative rehabilitation can minimize postoperative complications.

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마늘 추출물의 약리적 특성 및 분석 (Pharmacetical Characteristics and Analysis of Garlic Extract)

  • 성기천
    • 한국응용과학기술학회지
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    • 제24권3호
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    • pp.301-308
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    • 2007
  • From the experiment result on pharmacetical characteristics and analysis of Garlic extract, some conclusions were obtained as follows. From the results on extract experiment of Garlic, extraction ratio was about 6.0%, and after dried with dry oven from Garlic extract, it obtained about 50%-Garlic extract of solid state. From results on antimicrobial experiment of Garlic extract, number of staphylococcus and fungus in microbe decreased more and more according to time passage. This phenomenon showed that Garlic extract keeps antimicrobial effect. From results on antioxidation experiment of Garlic extract, DPPH scavenging activity of free radical showed that Garlic extract appears more remarkable reduction ability than reference samples. This phenomenon means that antioxidation of Garlic extract appears higher than Vitamin-C and BHA. From results on instrument analysis, inorganic components of K, Na, Ca, Si, Mg, Zn etcs from Garlic extract were detected with ICP/OES and the fatty and aromatic components of trimethyl sulfide, diallyl disulfide, diallyl trisulfide, 2-mercaptobenzothiazole etcs from Garlic extract were detected with GC/MS.

비정상후류가 선형터빈익렬의 유동 특성 및 익형의 열전달에 미치는 영향에 관한 연구 (Influence of Unsteady Wake on Flow Characteristics and Heat Transfer from Linear Turbine Cascade)

  • 윤순현;심재경;이대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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    • pp.1061-1064
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    • 1998
  • To examine the influence of unsteady wake on the flow and heat transfer characteristics, an experiment has been conducted in a four-vane linear cascade. Flow and heat transfer measurements are made for the inlet Reynolds number of 66000(based on chord length and free-stream velocity). Turbulent intensity and stress were measured using hot wire anemometer, and to measure the convective heat transfer coefficients on the blade surfaces liquid crystal/gold film Intrex technique was used. The disturbance by the unsteady wake is characterized by the unresolved unsteadiness. The unsteady wake enhances the turbulent motion of flow in the cascade passage. It also promotes the boundary layer development and transition. The results show that heat transfer coefficients on the suction surface increase with increasing unresolved unsteadiness.

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장기 재령 콘크리트 구조물의 탄산화 현상 조사 (A Research on the Carbonization Status of Aged Concrete Structures)

  • 김광기;박승기;김우재;조영길;송병창;정상진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.70-73
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    • 2003
  • Although there has been an upcoming recognition in the repairing reinforcement and remodeling of currently existing buildings with a regard to economic and resource saving effects of buildings roughly exposed to the open air for a long-term period, followed by a number of problems with the construction business operations that support economy-oriented projects within the limits of their short-term period durability, it is true that reasonable decisions of concrete performance are insufficient owing to the lack of proper history management for those existing buildings. This research attempted to comparatively analyze the compression strength together with investigation of carbonization depth and alkali concentration according to the passage of years on the subjects of aged buildings, and to provide basic data for remodeling and/or reconstruction of future construction structures by indirectly estimating durability lifetime expectancy according to carbonization phenomenon.

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Rotating Choke and Choked Surge in an Axial Pump Impeller

  • Watanabe, Toshifumi;Sato, Hideyoshi;Henmi, Yasuhiko;Horiguchi, Hironori;Kawata, Yutaka;Tsujimoto, Yoshinobu
    • International Journal of Fluid Machinery and Systems
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    • 제2권3호
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    • pp.232-238
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    • 2009
  • Unlike usual turbopump inducers, the axial flow pump tested operates very stably at design flow rate without rotating cavitation nor cavitation surge. Flow visualization suggests that this is because the tip cavity smoothly extends into the flow passage without the interaction with the leading edge of the next blade. However, at low flow rate and low cavitation number, choked surge and rotating choke were observed. Their correlation with the performance curve under cavitation is discussed and their instantaneous flow fields are shown.

인공 천공돔과 헬리오돈의 개발 및 성능실험 사례 연구 (Validation and Development of Artificial Sky Dome Facilities with a Heliodon)

  • 김정태;김곤
    • KIEAE Journal
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    • 제3권1호
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    • pp.21-29
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    • 2003
  • Scale model measurements should be conducted under an actual sky or in a simulated sky where conditions can be held constant. A number of successful attempts have been made to develop artificial sky domes with man-made sun emulators. With reference to formerly-developed examples, sky simulator facility has recently been activated in oder to provide desirable sky conditions for teaching and studies. The structure is a 6m-diameter dome and promises to set various condition for energy related and lighting research activities. The sky dome is also equipped a heliodon, the tilt table, to facilitate additive direct sun impact under clear skies. Shading studies, using scale models with the heliodon, reveal how a building's design blocks or permits light's passage to the interior; solar access studies, and tests of the reflection and transmittance characteristics of new daylighting technologies. The design and construction specification and the initial operating experience with a building configuration are reported.

CFD Study on Particle Effect and Erosion in the Axial Compressor Blades and Shroud of Turbomachinery

  • Yoon J.S.;Chang Keun-Shik
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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    • pp.233-234
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    • 2003
  • Fly ash enters axial compressor when a turbomachinery is operated in an adverse environment. We have numerically investigated erosion of the blade and shroud in the turbulent compressor passage flow under the influence of gas-particle two-phase interaction. There have appeared quasi-three dimensional calculations on this subject but not the complete three-dimensional gas-particle interaction as done in the present work. Lagrangian particle tracing technique is used on the base of parallel processing for efficient calculation. Accuracy of the present code is tested using the benchmark lPL nozzle. In the DFVLR compressor blades, we have shown that a large number of particles passing through the tip clearance make impact on the blade tip and on the shroud. Higher degree of erosion is resulted by the heavier particles due to the centrifugal force.

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Computational Study on Particle Effect and Erosion in the Axial Compressor Blades and Shroud

  • Yoon J.S.;Chang Keun-Shik
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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    • pp.203-204
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    • 2003
  • Fly ash enters axial compressor when a turbomachinery is operated in an adverse environment. We have numerically investigated erosion of the blade and shroud in the turbulent compressor passage flow under the influence of gas-particle two-phase interaction. There have appeared quasi-three dimensional calculations on this subject but not the complete three-dimensional gas-particle interaction as done in the present work. Lagrangian particle tracing technique is used on the base of parallel processing for efficient calculation. Accuracy of the present code is tested using the benchmark JPL nozzle. In the DFVLR compressor blades, we have shown that a large number of particles passing through the tip clearance make impact on the blade tip and on the shroud. Higher degree of erosion is resulted by the heavier particles due to the centrifugal force.

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블레이드 앞전 3차원 형상 변형에 의한 터빈 캐스케이드 내의 이차유동 제어 (Secondary flow Control in the Turbine Cascade with the Three-Dimensional Modification of Blade Leading Edge)

  • 김정래;문영준;정진택
    • 대한기계학회논문집B
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    • 제26권11호
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    • pp.1552-1558
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    • 2002
  • The blade leading edge is modified to control the secondary flow generated in the turbine cascade with fence by intensifying the suction side branch of the horseshoe vortex. The incompressible Navier-Stokes equations are numerically solved with a high Reynolds number k-$\varepsilon$ turbulence closure model for investigating the vortical flows in the turbine cascade. The computational results of total pressure loss coefficients in the wake region are first compared with experiments for validation. The structure and strength of the passage vortex near the suction surface are examined by testing various geometrical parameters of the turbine blade leading edge.

평면 제트류 응집구조의 근사적 표현에 관한 연구 (Approximation for the coherent structures in the planar jet flow)

  • 이찬희;이상환
    • 대한기계학회논문집
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    • 제19권3호
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    • pp.751-762
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    • 1995
  • The snapshot method is introduced to approximate the coherent structures of planar jet flow. The numerical simulation of instantaneous flow field is analyzed by SIMPLE algorithm. An ensemble of realizations is collected using a sampling condition that corresponds to the passage of a large scale vortex at positions 4 and 6 diameters downstream from the nozzle. With snapshot mothod we could treat the data efficiently and approximate coherent structures inhered in the planar jet flow successfully 94% of total turbulent kinetic energy with 10 terms of Karhunen-Loeve expansions. Finally, In accordance with the recent trend to try to explain and model turbulence phenomena with the existence of coherent structures, in the present study, we express the underlying coherent structures of planar jet flow in the minimum number of modes by calculating Karhunen-Loeve expansions in order to improve to understanding of jet flow and to make the information storage and management in computers easier.