• Transactions of Materials Processing
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• v.24 no.2
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• pp.89-94
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• 2015

Medical catheter tubes are disposable devices that are inserted into the body cavities such as the pleura, trachea, esophagus, stomach, urinary bladder, ureter, or blood vessels for surgical procedures. Each hole of the inner tube is called a lumen, which is used as a passage for drug injections, waste discharge, polypus removal, blood transport, or injection of a camera or sensor. The catheter tube is manufactured by extrusion. The flow in the inner extrusion die affects the thickness and diameter of the tube. In the current study computer simulation of flow in an extrusion die for catheter tubing was performed. Velocity, pressure, shear rate, and shear stress were investigated and the die design was examined.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.5
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• pp.69-82
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• 1988

Heat transfer experiment is carried out during the performance test of the 4-cylinder 4-stroke cycle turbo-charged gasoline engine. Cycle simulation employing the measured pressure in cylinder, the cooling water temperature and flow rate and others is carried out in order to calculate the gas temperature in cylinder. In this simulation combustion process was simulated by Annand's two zone model and suction, compression, and other processes are calculated completely. From this simulation, we can obtain not only the heat transfer coefficient but also the flame speed, turbulent burning velocity, flame factor and the boiling condition of cooling passage. The results are investigated with engine speed, equivalence ratio and spark advance.

• YAKHAK HOEJI
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• v.33 no.3
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• pp.149-155
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• 1989

To predict the influence of carbon monoxide poisonining on cerebral energy metabolism, rats were exposed to 5000 ppm environment for 30 minutes. Carboxyhemoglobin (HBCO) saturation rate in this condition was 72% equally in male and female rats. Cerebral cortex in the rats showed lower level of ATP, glucose, creatine phosphate and higher level of lactate, pyruvate by anaerobic glycolysis. As for the levels of ATP, creatine phsphate and glucose, the cerebral cortex contents of them were larger in female rats of estrus than in male rats, whereas there was no difference between sexes in the levels of pyruvate and lactate. According to time passage from CO intoxication, the mode of changes in cerebral energy metabolite contents was similar in both sexes.

• Korean Journal of Microbiology
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• v.11 no.3
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• pp.129-133
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• 1973

The authors have investigated about the microbial contamination of goods which is a criterion of hygienic control. Conducting on investigation, a special attention has been paid on the rate of microbial contamination in the goods, especially in manufacturing process of the softdrink. The authors also made an experiment on total microbes which is the criterion of contamination in each step of the process and in raw materials together with materials to be used for subdividing. Results obtained were as follows : 1) The orgin of microbial contamination was found in bottle cap and in tap water, that is, there appeared 9 colony per ml in bottle cap and 31-74 colony per ml in tap water, respectively. 2) It was found that microbial contamination are 4 colony per ml in average through year. However, it appeared 1 colony per ml in winter and 8 colony per ml in summer. 3) Coliform groups are not detected in goods through a year. 4) There was no variation in number of total microbes after ion exchange resin passage in purification process of tap water. 5) The number of microbes in goods are decreased when the raw materials are treated in high temperature short time (HTST) sterilization.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.44-45
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• 2018

In this study, water vapor pressure of high strength concrete reinforced with amorphous steel fiber(AF) was evaluated. Experimental results show that spalling occurs when the incorporation rate of amorphous steel fiber is 0.5 vol.% or more. This is because the ratio of AF increased per unit area influenced the formation of the water vapor pressure discharge passage by the polypropylene fiber(PPF) melting. Therefore, it is necessary to find the proper mixing ratio of AF and PPF to prevent spalling.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2600-2605
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• 2008

Turbo-fans for a FFU unit should be aerodynamically designed to provide the FFU system with the given flow-rate at the lowest rotational-speed by considering the interaction effect with the FFU casing. In this study, slim and highly efficient turbo-fans are designed to satisfy the given performance at the specific speed by using the hybrid-stacking method of an inducer and a 2D-bladed turbo fan. The mean-line analysis, cascade theory, and CFD technique are all together applied to control the passage areas on the meridional plane from the inlet to the exit of the blade. Furthermore, the torque control algorithm is adopted to improve the performances within the constraints by the motor rpm-torque characteristics, and the resulting measured performances of mock-up fans are discussed.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.89-94
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• 2008

In this study it was evaluated that hybrid air conditioning and ventilation system to reduce energy consumption and keep on comfortable indoor environment in an underground shopping center. Room temperature by hybrid HAVC system was controled as $1.8{\sim}2.1^{\circ}C$ low and indoor humidity was controled as $4.1{\sim}5.0%RH$ low, and response was fast in $2.0{\sim}2.5$ times compared with conventional system. And also transportation efficiency of hybrid HVAC system was improved in about 27%, and total energy consumption rate of hybrid HVAC system is decreased in 16% compared with conventional system.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.586-591
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• 2005

We deal with the headway which effects on the performance of the PRT(Personal Rapid Transit) system and the system safety. The headway, time between passage of one vehicle and the next, is one of the important factors to assess the line capacity, which has a cue to solve the problem of the congestion in public transportation. To decide the headway there are many important factors, especially such as the failure vehicle deceleration rate, the following simple analytical equation can be made to assess the relation between the line speed and the minimum headway. In this paper we employ a numerical analysis method using a simple analytical equations for the evaluation of the minimum headway and show simple simulation results.

• Journal of ILASS-Korea
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• v.9 no.4
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• pp.77-82
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• 2004

This paper describes the improvement of engine cooling system. To improve engine cooling performance, the authors approached in two ways. One is to increase water pump performance, changing of impeller shape and lightening of material were carried out. The second one is cooling efficiency rise, which were investigated with head gasket coolant flow passage optimization with flow visualization technique. The test results show that water pump performance was increased effectively, reduction of pump drive torque, and increase of pump flow-rate and pressure rise. Gasket hole pattern optimization test results represent an optimized head coolant flow which stands cross flow from exhaust to intake port side and small vortex were removed.

• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.270-275
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• 2010

An electromagnetic pump using a tubular induction motor (TLIM) has been proposed to pump liquid metal fluids. TLIM has been designed for liquid metal flow systems with a motor with a thrust force of 40~77[N]. The flow characteristics have been investigated by solving the Navier-Stokes equation, where the Lorentz force was included simply by considering it as a constant in the Navier-Stokes equation. A wood metal was chosen to simulate the liquid metal. The effect of Lorentz force on the flow rate was investigated. An experiment was conducted and its results were compared with those of the simulation. The simulation result showed an overestimation of about 17% compared with the experimental one.