• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.408-413
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• 2004

An experimental study has been carried out to investigate overheating of oil and bearing housing during pump operation. This problem is of particular interest in the pre diction of lifetime and failure of pump. Transient variation of oil temperature as well as bearing housing temperature is measured to study the effect of oil viscosity, oil amount, and discharge flow rate of pump. It is found that optimal oil quantity as well as proper viscosity of oil is required to keep the safe temperature level of oil and bearing housing in a pump. The oil temperature at steady state is almost not affected by discharge flow rate in the range of discharge flow rates considered in the present study.

• The KSFM Journal of Fluid Machinery
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• v.9 no.3 s.36
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• pp.22-28
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• 2006

The discharge coefficient in segmental wedge haying ninety degrees yeller angle for the five kinds of opening ratio with differential pressure taps located at both upstream and downstream of one diameter of pipe was measured. Main purpose of this work is placed on specifying the characteristic of discharge coefficient of a segmental wedge used as a primary element of flow metering devices, and suggestion for the fixed location of pressure taps useful. Although the range of the opening ratio over this work is more expanded than previous studies. The opening ratios of segmental wedge, namely 0.3, 0.4, 0.5, 0.6 and 0.7 were investigated. The Reynolds number based on the spool inside diameter ranges from 12,000 to 380,000.

• Journal of Korean Society on Water Environment
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• v.34 no.5
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• pp.494-502
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• 2018

The purpose of this study was to understand distribution characteristics of organic matters through concentration of $BOD_5$, $COD_{Mn}$ and TOC in 31 streams in Han River region, and to establish the relationship among organic matter concentration, and discharge load and flow rate. Concentration of $BOD_5$ and TOC in 22 streams were above IV grade except 9, and the average 80.9 % of total organic matter (by TOC) accounted for dissolved organic type. Correlation among organic matter parameters were higher ($r^2$ > 0.78) and the relationship between TOC and $COD_{Mn}$ concentration was higher than $BOD_5$. Ratio of biodegradable organic matter/total organic matter in the 31 streams was estimated at 41.4 % with $BOD_5$ oxidation rate, and 78.0 % with $BOD_5/COD_{Mn}$ concentration ratio. Ratio of $NBOD/BOD_5$ concentration in four sites with $BOD_5/COD_{Mn}$ concentration ratio exceeding 1 ranged from 54.5 % ~ 79.3 %. Among 979 flow rate data measured at 31 streams, 87 % of measured data was below 0.1 cms and increased water pollution under low flow conditions. Correlation between $BOD_5$ concentration and $BOD_5$ discharge load in the watershed was low, and it was revealed that several streams have more $BOD_5$ delivery load than $BOD_5$ discharge load. Results suggest that many biodegradable forms of organic matter are being introduced into the stream from pollutant sources in the watershed.

• Analytical Science and Technology
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• v.7 no.4
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• pp.483-492
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• 1994

Direct solid analysis of various kinds of metal samples has been conducted by glow discharge. In this laboratory, the gas-jet assisted glow discharge(GJGD) device has been developed and characterized. The effect of changes in applied current, cell pressure and flow rate on atomic emission signals obtained from a jet-assisted cathodic sputtering was investigate. The emission intensities of Cu, Zn, and Ar were measured. They were increased with the current. But the intensities were decreased by increasing the flow rate of argon due to the diffusion and transportation of particles into plasma. By increasing the pressure of the cell, the intensities were greatly decreased because of enhancement of redeposition onto the surface of the sample.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.9
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• pp.622-629
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• 2007

Compact semi-center type automotive air handling system(AHS) is developed in this study and it's performance is compared with the conventional 3-pieces type air hand-ling system. The pressure drop is measured at component level and system level, and air flow rate and air distribution of discharge air through each ducts from air handling system are measured. System level characteristics of pressure drop at face and windshield discharge mode and air flow rate are investigated, and also temperature control linearities are tested. The volume of the air handling system package is reduced about 20%. And air flow rate increase about 5 to 20% compared to the conventional 3-pieces type air handling system at each discharge mode with significantly improved air pressure drop both component and system level. Also, air distribution and temperature controllability meet to evaluation criteria.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.76-83
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• 1993

The changes in discharge current, emission and/or oscillation frequency of the electric oscillation of a glow discharge are the potential sensitive measure of the concentration of an impurity in the argon plasma supporting gas. A single jet enhanced glow discharge has been interfaced with the gas chromatograph via 1/8" O.D. tube with a heating pad to study the changes in discharge current. To investigate the optimum operating conditions of the glow discharge system as detector for gas chromatography, pressure, gas flow rate, discharge current, distance between the anode and the cathode have been studied.

• Journal of Korean Society of Transportation
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• v.10 no.2
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• pp.5-24
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• 1992

This research presets the method of determining basic capacity of signalized intersection using the concept of ideal saturation flow rate. Vehicle discharge rates during green time were collected and studied as part of the preparation of Korean Highway Capacity Manual. From the result of this study the ideal saturation flow rate and saturation queue position were determined. In addition, based on the ideal saturation flow rate two geometric adjustment factors(lane width and grade adjustment factors) were studied. The results were presented in this paper.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.203-207
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• 2007

Recently, ozone is utilized in various fields and its needs are expanding. In this paper, plate type ozonizer have been fabricated to investigate discharge parameter(input power, flow rate of supplied gas, electrode form, etc.) effect to discharge. And the conditions of discharge parameter have been investigated for optimum ozone generation. Ozone concentration is continuously increased with increasing input power for same discharge space, and ozone yield is also increased until maximum point after that it is saturated. Ozone concentration is inversely proportional to flow rate of supplied gas but ozone generation and ozone yield characteristics are improved.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.192-193
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• 2006

In this paper, a co-axial type ozonizer varied with discharge gap was designed and manufactured for investigating (1) discharge characteristics with variation of output voltage power supply, flow rate and gap distance (2) ozone generation and solubility characteristics with variation of flow rate, gap distance and discharge power. Pure oxygen was used as process gas of the co-axial type ozonizer.

• Journal of Korean Society on Water Environment
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• v.27 no.5
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• pp.617-624
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• 2011

In order to confirm the creation of the OH radical which influences to RNO bleaching processes, it experimented using laboratory reactor of dielectric barrier discharge plasma (DBDP). The experiments performed in about 4 kind process variables (diameter of ground electrode, diameter of discharge electrode, diameter of quartz tube and effect of air flow rate) which influence to process. In order to examine optimum conditions of design factors as shown in Box-Behnken experiment design, ANOVA analysis was conducted against four factors. The actual RNO removal at optimized conditions under real design constraints were obtained, confirming Box-Behnken results. Optimized conditions under real design constraints were obtained for the highest desirability at 1, 1 mm diameter of ground and discharge electrode, 6 mm diameter of quartz tube and 5.05 L/min air flow rate, respectively.