• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.76-82
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• 1998

It is necessary to calculate the accurate velocity from the hydraulic model for the reliable prediction of water quality changes in water supply system. To verify the hydraulic analysis of the water supply system, fluoride was used as a tracer to calculate the travel time from the injection point to the sampling points. Results from this field experiment indicate that fluoride can be a good conservative tracer while it showed a little longitudinal dispersion along the pipe lines. And the velocity from the model was verified by these travel times and calibrated by changing the ratio of the unaccountable water. When the ratio of the unaccountable water. When the ratio of the unaccountable water was 20%, the error between the estimation of hydraulic model and the real travel time was minimum.

• International Journal of Fluid Machinery and Systems
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• v.7 no.2
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• pp.80-85
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• 2014

In this study, we visualized the internal flow of a regenerative turbomachinery using the direct injection tracer method. For visualization, the working fluid was water and the tracer was oil colors (marbling colors). Droplets were injected at the inlet of the machinery and the streak were recorded using a high-speed camera with high-power light sources. While circulating inside the groove, the droplets were translated by the rotational motion of the impeller. When the droplets flow out of the impeller groove, relative to the impeller, they moved more slowly. And the droplets repeatedly reentered into the groove and circulated again. Then the droplets either flowed to the outlet or to the stripper. As a result, this experiment has confirmed the internal circulating flow of a regenerative turbomachinery.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2504-2506
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• 2003

In this paper, we propose an algorithm for driving line-tracer robot, considered as a kind of AGV. At first, we introduce the architecture of the line-tracer robot implemented for the experiment, and explain the driving algorithm using path information from infrared sensors. The proposed algorithm can overcome the difference between each sensor's characteristics. Finally, we make some experiments and show the performance of the algorithm in case of straight path.

• Journal of Radiation Industry
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• v.2 no.3
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• pp.155-161
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• 2008

A hydraulic scale model was constructed to investigate the characteristics of flows and pollutant transport in laboratory. The distorted hydraulic scale model by assuming Froude similarity was adopted to represent hydrodynamics and dispersion in a river system. The scale model was composed of water reservoir, slope control part, booster pump, distributing plate and main channel. A constructed scale model will be used to present the overall concentration profiles of tracer and a research will be performed to convert the measured values using a hydraulic scale model to real field scale.

• The Journal of Engineering Geology
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• v.14 no.3 s.40
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• pp.301-311
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• 2004

This study is suggested a new dielectric tracer test method to understand geological structure of porous media and groundwater flow to use the dielectric constant which is one of electrical special quality of various geological materials. To measure their parameters, tracer material is made an ethanol mixing liquid(EML) having a same specific gravity of water. Also, soil materials are prepared a dielectric tracer test using the FDR system that could measure dielectric constant for saturated standard sand and river sand layers which have different initial porosity. To compare with their results, we discussed with the concentration variation of saline water having a saline concentration $3\%$ which is general tracer material by using the electro multi-meter system in the laboratory or field test. In two tracer experiment results, EML tracer test could confirm definitely EML concentration variation from each saturated soil layer as standard and river sands. However, tracer test of saline water $3\%$ concentration could not confirm permeating movement of water by degree of salinity change because these are settled at lower part column in a whole column area continuously. These causes are that specific gravity of saline water is heavier than water. That is, it could know that deposition of saline water is composed of lower part of soil column continuously independently of the direction of water into saturated soil material.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.301-308
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• 2002

As part of perfluorocarbon (PFC) tracer release experiment conducted at the western coastal area of Korea in February 2001, the background concentration level of perfluorocarbons (PFCs) in the atmosphere was determined by gas chromatography with electron capture detector. Prior to the PFC tracer release experiment in the field, air samples were collected using active samplers and the background concentrations of PFCs were determined. The concentrations of perfluoromethylcyclohexane ($C_7F_{14}$, PMCH) in the western coastal area of Korea were in the range of 5.8-8.7 fL/L. The mean concentration of the PMCH in the region exhibited no significant spatial and temporal variations. This concentration level is somewhat higher and has larger standard deviation than those of studies previously conducted in USA and Europe on the background concentration levels of PFCs. Because the background concentration of PMCH in Korea is still very low and consistent temporally and spatially, the PMCH tracer can be used suitably for the studies of long-range atmospheric transport.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.E
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• pp.1-7
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• 1998

This paper presents an experimental study for understanding the indoor air quality in a room. A model room, which had a ceiling-mounted supply and a sidewall-mounted exhaust, was used to examine the effect of air exchange rate (AER) and contaminant source location (CSL) as a function of the elapsed time. A tracer gas method, using carbon monoxide tracer, gas analyzers, and a data acquisition system, was applied to study the ventilation air distribution and the tracer removal efficiency, so-called pollutant removal efficiency, in the model room. The experiment was composed of two parts; firstly the AER was varied to examine its effect on the ventilation air distribution and the ventilation effectiveness and secondly both AER and CSL were considered to determine their effect on the pollutant removal efficiency. It was found that the ventilation effectiveness in the model was proportional to AER but not linearly. It was also found that changing the CSL can improve the pollutant removal efficiency. In some cases, the efficiency improvement by increasing AER was achieved by simply changing CSL.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.2
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• pp.113-122
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• 2016

In this study, the dispersion process of pollutant substances in a port under wave and current environments was evaluated by a hydraulic experiment. Once the contaminants washed ashore into the port of Wolseong nuclear power plant, transport processes of pollutants were investigated by tracking the tracer according to the variations of experimental condition through a hydraulic experiment. Several hydraulic experiments were performed to analyze the pollutant discharge rate of the surface coming from the different coastal environments. From the hydraulic experiment results, the tracer concentration decreased exponentially. These results suggested that, after the tracer was transported to the open sea, a different gradient was shown under different conditions. For the case of a diluted condition, the half-life of flow rate was 2.70, 10.40, and 26.39 days for 30, 20 and 10 rpm in the left-side, respectively. The decrease of the tracer concentration under conditions of 30 rpm was much faster than that under conditions of 10 rpm. For the wave condition, the half-life of flow rate was 4.59 and 15.35 days for the right and left side of the port in a hydraulic scale prototype, respectively.

• Journal of Radiation Industry
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• v.2 no.3
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• pp.135-140
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• 2008

A field tracer experiment using radioisotope was carried out to investigate the characteristics of a pollutant transport and a determination of the dispersion coefficients in a river system. The dispersion coefficients in the longitudinal and transverse directions were determined by using the measured concentration of a radioisotope. The two-dimensional numerical models were applied to calculate the flow and concentration fields at the experimental site. Several numerical simulations were performed to investigate the effects of the numerical results according to variations of the dispersion coefficients. The calculated concentrations agreed well with the measured ones.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.361-361
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• 1999