• Title/Summary/Keyword: transverse ribs

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Immediate Effect of Serratus Posterior Inferior Muscle Direction Taping on Thoracolumbar Junction Rotation Angle During One Arm Lifting in the Quadruped Position

  • Kim, Nu-ri;Ahn, Sun-hee;Gwak, Gyeong-tae;Yoo, Hwa-ik;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.28 no.3
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    • pp.227-234
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    • 2021
  • Background: The serratus posterior inferior (SPI) muscle originates from the spinous process of T11-L2 and inserts at the lower border of the 9-12th ribs. This muscle is involved in thoracolumbar rotation and stability. Several positions can be used to improve trunk stability; the quadruped position is a good position for easily maintaining a neutral spine. In particular, during one arm lifting, various muscles act to maintain a neutral trunk position, and the SPI is one of these muscles. If trunk stability is weakened, uncontrolled trunk rotation may occur at this time. Tape can be used to increase trunk stability. There have been no studies on the effect of taping applied to the SPI muscle on thoracolumbar junction (TLJ) stability. Objects: This study compared the TLJ rotation angle between three different conditions (without taping, transverse taping, and SPI muscle direction taping). Methods: Thirty subjects were recruited to the study (18 males and 12 females). The TLJ rotation angle was measured during one arm lifting in a quadruped position (ALQP). Two taping methods (transverse and SPI muscle direction taping) were applied, and the TLJ rotation angle was measured in the same movement. Results: SPI muscle direction taping significantly reduced TLJ rotation compared to that without taping (p < 0.001) and with transverse taping (p < 0.001). There was a significant difference in the TLJ rotation angle between transverse taping and SPI muscle direction taping (p < 0.017). Conclusion: SPI muscle direction taping reduces the TLJ rotation angle during ALQP. Therefore, SPI muscle direction taping is one method to improve TLJ stability and reduce uncontrolled TLJ rotation during ALQP.

Effects of Bleed Hole on Heat/Mass Transfer in a Rotating Channel with Transverse Ribs (90도 요철이 설치된 회전덕트에서 유출홀이 열/물질전달에 미치는 영향)

  • Park, Suk-Hwan;Jeon, Yun-Heung;Kim, Kyung-Min;Lee, Dong-Hyun;Cho, Hyung-Hee
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.178-184
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    • 2005
  • The present study investigates the effects of bleed flow on heat/mass transfer and pressure drop in a rotating channel with transverse rib turbulators. The hydraulic diameter ($D_h$) of the square channel is 40.0 mm. The bleed holes are located between the rib turburators on leading surface and the hole diameter (d) is 4.5 mm. The square rib turbulators are installed on both leading and trailing surfaces. The rib-to-rib pitch is 10.0 times of the rib height (e) and the rib height-to-hydraulic diameter ratio ($e/D_h$) is 0.055. The tests were conducted at various rotation numbers (0, 0.2, 0.4), while the Reynolds number and the rate of bleed flow to main flow were fixed at 10,000 and 10%, respectively. The results suggest that the heat/mass transfer characteristics in the internal cooling passage are influenced by rib turbulators, bleed flow and the Cariolis force induced by rotation. For the rotating ribbed passage with bleed flow, the heat/mass transfer on the leading surface is hardly affected by bleed flow, but that on the trailing surface decreases due to the diminution of main flow. The results also show that the friction factor decreases with the bleed flow.

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Heat Transfer of a Two-Dimensional Jet Impinging on the Wall with Transverse Repeated Ribs of Square Cross-Section (四角리브를 갖는 傳熱面에 衝突하는 2次元 噴流의 熱傳達에 관한 硏究)

  • 김상필;서정윤
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.2
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    • pp.214-221
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    • 1987
  • The purpose of this study is augmentation of heat transfer without additional power in the case of rectangular air jet which impinges vertically on the heating surface. The experimental results are obtained heat transfer augmentation of a two-dimensional impinging jet using the surface roughness of transverse repeated-rib type. The integral average heat transfer coefficient of ribbed plate is about two times larger than that of flat plate. In order to supplement the information about the mechanism of heat transfer augmentation, the flow structure in the stagnation region is visually studied by using the smoke wire technique. The heat transfer augmentation is due to the effect of stretching of large scale vortex in the stagnation region.

Friction Factor and Heat Transfer in Equilateral Triangular Ducts with Surface Roughness

  • Ahn, Soo-Whan
    • Journal of Mechanical Science and Technology
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    • v.15 no.5
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    • pp.639-645
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    • 2001
  • Experimental investigations were conducted to study forced convection of fully developed turbulent flows in horizontal equilateral triangular ducts with different surface roughness pitch ratios (P/e) of 4, 8, and 16 on one side. The ducts bottom wall was heated uniformly and the other surfaces were thermally insulated. To understand heat transfer enhancement mechanism, heat transfer rates were measured. Smooth triangular ducts were also tested for benchmark purposes. The results were compared with previous results for similarly configured channels, at which they were roughened by regularly spaced transverse ribs in the rectangular and circular channels.

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Heat Transfer and Pressure Drop Characteristics of Triangular Ducts with One Side Rib-Roughened (한 측에서만 거칠기가 설치된 삼각덕트의 마찰계수와 열전달)

  • 안수환;이영석
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.2
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    • pp.17-23
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    • 2000
  • Experimental investigations were conducted to study the forced convection of fully-developed turbulent flow in horizontal equilateral duct fabricated with the same length and equivalent diameter, but different surface roughness pitch ratio(P/e) of 4, 8 and 16 on the one side wall only. The experiments were performed with the hydraulic diameter based Reynolds number ranged from 70,000 to 10,000. The entire bottom wall of the duct was heated uniformly and the other surfaces were thermally insulated. To understand the mechanisms of the heat transfer enhancement, measurements of the heat transfer were done to investigate the contributive factor of heat transfer promotion, namely, the fin effect. And the results were compared with those of previous investigations for similarly configured channels, at which they were roughened by regularly spaced transverse ribs in the rectangular and circular channels.

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Heat Transfer and Pressure Drop Characteristics of Triangular Ducts with One Side Rib-Roughened (한 측에서만 거칠기가 설치된 삼각덕트의 열전달과 압력강하 특성)

  • Ahn, S.W.;Lee, Y.S.;Lee, B.C.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.65-70
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    • 2000
  • Experimental investigations were conducted to study the forced convection of fully-developed turbulent f)on· in horizontal equilateral duct fabricated with the same length and equivalent diameter, but different surface roughness Pitch ratio(P/e) of 4, 8 and 16 on the one side wall only The experiments were performed with the hydraulic diameter based Reynolds number ranged from 70.000 to 10,000 The entire bottom wall of the duct was heated uniformly and the other surfaces were thermally insulated. To understand the mechanisms of the heat transfer enhancement. measurements of the heat transfer were done to investigate the contributive factor of heat transfer promotion. namely the fin effect. And the results were compared with those of Previous investigations for similarly configured channels, at which they were roughened by regularly spaced transverse ribs in the rectangular and circular channels.

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Marlex mesh Support for the Correction of Severe Pectus Excavatum

  • Lee, Doo-Yun;Kim, Hong-Suk;Cho, Bum-Koo
    • Journal of Chest Surgery
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    • v.23 no.3
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    • pp.609-615
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    • 1990
  • Pectus excavatum is a congenital anomaly of the anterior chest wall with a sharp concave curvature of the body of the sternum, from above downward and from side to side, especially just before the junction of the glandioloxiphoid. There are two major operative procedures -"Ravitch" or "Wada" operation- for the correction of pectus excavatum. We used the modified Ravitch operation which consists of mobilization of the sternum, transverse osteotomy, and parasternal resection of the costal cartilages followed by placement of Marlex mesh using methyl methacrylate behind the sternum and suturing the edge of the Marlex mesh to the peripheral stump of the resected ribs. This was performed in a patient with severe pectus excavatum with good results at the Department of Thoracic and Cardiovascular Surgery Yonsei University College of Medicine in Seoul, Korea on January 12, 1989.anuary 12, 1989.

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Analytical Studies on the Steel Plate-Concrete Structures under Compressive Load (압축력을 받는 강판-콘크리트 구조의 해석적 고찰)

  • Choi, Byong Jeong;Han, Hong Soo
    • Journal of Korean Society of Steel Construction
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    • v.20 no.2
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    • pp.269-278
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    • 2008
  • The primary object of the paper is to understand the compressive buckling characteristics of steel-concrete structures through the finite element analysis. The buckling pattern, compressive strength and stiffness of the steel plate concrete structures were investigated by the FEM analysis using the variations of B/t ratios and stud pitches. The investigation was focused on steel plate concrete structures with and without ribs placed on the surface of steel plates. The results of the FEM analysis were compared with the previous results from the theoretical equations. Conclusively, the buckling of the steel plate concrete structures occurred in the transverse direction of the loading direction. The stiffness of the steel plate concrete structure with ribs is greater than the one without the stiffened rib. The compressive strength in the FEM analysis is similar to that of JEAG 4681 and it showed 20% greater value than that of the proposed equations.

Experimental investigation of shear connector behaviour in composite beams with metal decking

  • Qureshi, Jawed;Lam, Dennis
    • Steel and Composite Structures
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    • v.35 no.4
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    • pp.475-494
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    • 2020
  • Presented are experimental results from 24 full-scale push test specimens to study the behaviour of composite beams with trapezoidal profiled sheeting laid transverse to the beam axis. The tests use a single-sided horizontal push test setup and are divided into two series. First series contained shear loading only and the second had normal load besides shear load. Four parameters are studied: the effect of wire mesh position and number of its layers, placing a reinforcing bar at the bottom flange of the deck, normal load and its position, and shear stud layout. The results indicate that positioning mesh on top of the deck flange or 30 mm from top of the concrete slab does not affect the stud's strength and ductility. Thus, existing industry practice of locating the mesh at a nominal cover from top of the concrete slab and Eurocode 4 requirement of placing mesh 30 mm below the stud's head are both acceptable. Double mesh layer resulted in 17% increase in stud strength for push tests with single stud per rib. Placing a T16 bar at the bottom of the deck rib did not affect shear stud behaviour. The normal load resulted in 40% and 23% increase in stud strength for single and double studs per rib. Use of studs only in the middle three ribs out of five increased the strength by 23% compared to the layout with studs in first four ribs. Eurocode 4 and Johnson and Yuan equations predicted well the stud strength for single stud/rib tests without normal load, with estimations within 10% of the characteristic experimental load. These equations highly under-estimated the stud capacity, by about 40-50%, for tests with normal load. AISC 360-16 generally over-estimated the stud capacity, except for single stud/rib push tests with normal load. Nellinger equations precisely predicted the stud resistance for push tests with normal load, with ratio of experimental over predicted load as 0.99 and coefficient of variation of about 8%. But, Nellinger method over-estimated the stud capacity by about 20% in push tests with single studs without normal load.

Characteristic of Local Behavior in Orthotropic Steel Deck Bridge with Open Ribs according to Running Vehicle (주행차량에 따른 개단면 강바닥판 교량의 국부거동 특성)

  • Lee, Sung-Jin;Kyung, Kab-Soo;Park, Jin-Eun;Lee, Hee-Hyun
    • Journal of Korean Society of Steel Construction
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    • v.24 no.1
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    • pp.101-108
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    • 2012
  • The orthotropic steel deck bridge made by using relatively thin steel plate, and structural members such as transverse and longitudinal ribs, cross beam, etc. in the bridge are fabricated with complex shape by welding. Therefore, the possibility occurring deformation and defects by welding is very high, and stress states in the welded connection parts are very complex. Also, the fatigue cracks in orthotropic steel deck bridge are happening fromthe welded connection parts of secondary member than main member. However, stress evaluation for main members is mainly carried out in the design process of the bridge, detailed stress evaluation and characteristic analysis is not almost reviewed in the structural details which fatigue crack occurred. For the orthotropic steel deck bridge with open ribs which has been serviced for 29 years, in this study, the cause of fatigue crack is investigated and the fatigue safety of the bridge is examined based on fieldmeasurement by the loading test and real traffic condition. Also, structural analyses using gridmodel and detailed analysis model were carried out for the welded connection parts of longitudinal rib and diaphramthat fatigue crack occurred. Additionally, the behavior characteristics due to running vehicles were investigated by using influence area analysis for these structural details, and the occurrence causes of fatigue crack in the target bridge were clarified.