• 상하수도학회지
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• 제24권6호
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• pp.713-722
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• 2010

This paper has assessed the flow patterns and settling efficiency in the sedimentation basin using the particle tracking method of the CFD code and has reached the following conclusions: In the original design where no baffle is installed in the sedimentation basin, a large recirculating area where the flow stagnates is created in the right side of the sedimentation basin, with most of the particles moving to the left side of the sedimentation basin following the flow. This biased flow structure in the sedimentation basin reduces the residence time of particles and thereby undermines settling efficiency. The biased flow toward the left side of the sedimentation basin is alleviated by installing a baffle in the sedimentation basin, promptly reducing the fast flow of over 0.7 m/s in the inlet of the sedimentation basin to the rate below 0.2 m/s. In this paper's simulation conditions, if a one-sided baffle is to be installed in the sedimentation basin, placing it 15 meters away from the basin's inlet leads to the best settling efficiency; it has also been analyzed that installing a two-sided baffle-rather than a one-sided one-is a better option in terms of settling efficiency. The highest settling efficiency of 96.2% is achieved when the underwater length of the two-sided baffle is set at 8 meters.

• Water Engineering Research
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• 제2권1호
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• pp.21-31
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• 2001

In this study, laboratory experiments were performed to investigate the flow characteristics of a two-dimensional neutrally buoyant jet in the inlet region of a rectangular laboratory settling tank. Velocity measurements were made with a three-component ADV. Two types of baffles were installed in front of two-dimensional slot; a one-sided and a two-sided baffle. The flow fields from a plane jet impinging on these two types of baffles and a plane jet without a baffle showed quite different characteristics. To concentrate on investigating these flow characteristics, the effects of density currents due to temperature difference or the presence of sediments were not studied. Results of the experiments reveal that the use of the two-sided baffle results in the shortest inlet region. Also shown is that, in addition to the types of baffles, the Froude number turns out to be an important factor in the extent of the inlet region.

• Journal of Chest Surgery
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• 제21권5호
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• pp.948-953
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• 1988

A technique applicated for physiologic correction of complex congenital cardiac disease suitable for Fontan procedure in which drainage of left superior vena cava and hepatocardiac vein to left atrium combined is described. We made one systemic venous baffle from left hepatocardiac vein to left superior vena cava and another systemic venous baffle from right inferior vena cava to the right superior vena cava with rigid prosthetic material[0.5mm thickness PTFE patch]. And then we anastomosed directly between the right sided atrial appendage and right pulmonary artery, and left-sided atrial wall beneath the appendage and left pulmonary artery. We believe that this procedure is superior to the method using intraatrial tube graft to divert the left hepatocardiac venous blood to right atrium, and applicable for physiologic correction of any complex congenital cardiac disease suitable for Fontan-type procedure in which anomalies of systemic venous drainage combined.