• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.7
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• pp.697-703
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• 2012

In this study, duodenogastric reflux has been investigated according to pyloroplasty and the path of the gastric tube in esophageal reconstruction. The paths of the gastric graft (front and rear paths) were determined from the CT images of ten patients, and the gastric tube model was constructed using an RP technique. The gastric tubes were connected to the pylorus models with and without pyloroplasty. Various distal pressures and pulse widths were applied, and the volume and maximum height of the refluxate were measured. The results show that the volume and height of the refluxate increase with the distal pressure, and the front path leads to a smaller volume and lesser height of the refluxate than the rear path if pyloroplasty is conduced. The volume of the refluxate is markedly increased by a larger pulse width, but its effect on the maximum height depends on whether pyloroplasty is conducted.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.1
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• pp.37-43
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• 2002

Recently, the construction of tunnels longer than one kilometer has increased rapidly. Considering characteristic of limiting structure of longer tunnel, if fires inside tunnel broke out because of vehicle incidents, the catastroph would have high possibility to take place due to toxic smoke and heat of fire. In case of highway tunnel, safety facilities which can cope with tunnel fire are installed in the tunnel but according to rapid increase of heavy good traffic, dangerous goods and enlargement of tunnel magnitude, the research has to carry out about heat fluxes and smoke behaviour during tunnel fire. Therefore, through full-sized fire experiment the paper analyzed temperature distribution, wind velocity, smoke behaviour during tunnel fire.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2386-2396
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• 1996

A numerical simulation has been performed for isothermal and reacting flows in an exisymmetric, bluff-body research combustor. The present formulation is based on the density-weighted averaged Navier-Stokes equations together with a k-epsilon. turbulence model and a modified eddy-breakup combustion model. The PISO algorithm is employed for solution of thel Navier-Stokes system. Comparison between measurements and predictions are made for a centerline axial velocities, location of stagnation points, strength of recirculation zone, and temperature profile. Even though the numerical simulation gives acceptable agreement with experimental data in many respects, the present model is defictient in predicting the recoveryt rate of a central near-wake region, the non-isotropic turbulence effects, and variation of turbulent Schmidt number. Several possible explanations for these discrepancies have been discussed.