• Journal of Korean Society for Atmospheric Environment
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• v.14 no.5
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• pp.397-410
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• 1998

Tracer experiments were performed 4 times in December 1992 on the relatively flat terrain and nearby building area adjacent to the Taedok Science Town in Korea. Each experiment was continued for relatively short period of 1 or 2 hours with intermittent release of SF6 up to 2.07g/s at 10m height. Movement of tracer plume was tracked by a continuous tracer analyzer installed on an air monitoring van. Simulation with INPUFF was carried out to analyze and predict experiments. Measured profiles of tracer plume were narrow and sharp while predicted profiles by INPUFF were broad and slowly varied. Tracer plumes were detected at a short distance of 0.5 to 2.2 km mainly due to intermittent release and high value of lower detectable limit. Various experimental conditions were tested by INPUFF simulation in order to find desirable conditions. Higher wind speed and less variable wind direction could yield longer distance of plume tracking only when the lower detectable limit was sufficiently low. Distance of plume tracking was long and did not much depend on the lower detectable limit in stable atmospheric conditions.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.529-534
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• 2008

Interzonal air movements are important to characterize overall ventilation performance of complicated multi-zone buildings. Tracer gas techniques are widely used to measure ventilation rates, ventilation effectiveness, and interzonal air movements. Depending on the number of gases used, they are divided into single and multi tracer gas methods. This paper deals with the comparison of the tracer gas methods in measuring air exchange rate between rooms. Experiments have been conducted in a simple two-room model with known airflow rates. In multi-gas procedure, the concentration decays of two tracer gases, i.e SF6 and R134a are measured after simultaneous injections in each room. The single tracer gas method is also applied by injecting SF6 gas with a time lag between two rooms. The data reduction procedures are developed to obtain the interzonal airflow rate using the matrix inversion, and various data manipulation methods are tested, such as data shift, interpolation, and smoothing. Uncertainty for each airflow rate is investigated depending on the parameters based on the setting values.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.11
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• pp.606-612
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• 2009

Interzonal air movements are important to characterize overall ventilation performance of complicated multi-zone buildings. Tracer gas techniques are widely used to measure ventilation rates, ventilation effectiveness, and interzonal air movements. Depending on the number of gases used, they are divided into single and multi tracer gas methods. This paper deals with the comparison of the tracer gas methods in measuring air exchange rate between rooms. Experiments have been conducted in a simple two-room model with known airflow rates. In multi-gas procedure, the concentration decays of two tracer gases, i.e SF6 and R134a are measured after simultaneous injections in each room. The single tracer gas method is also applied by injecting SF6 gas with a time lag between two rooms. The data reduction procedures are developed to obtain the interzonal airflow rate using the matrix inversion, and various data manipulation methods are tested, such as data shift, interpolation, and smoothing. Uncertainty for each airflow rate is investigated depending on the parameters based on the setting values.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.99-104
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• 2007

Tracer gas technique is widely used to measure the ventilation rates and/or ventilation effectiveness of building spaces. However, the conventional method using a single tracer gas can measure only outdoor air change rates in a single zone. This paper deals with the multi-gas tracer technique to measure air exchange rates between rooms. Interzonal air movements are important to characterize overall ventilation performance of complicated multi-zone buildings. Experiments are conducted in a simple two-room model with known airflow rates using tracer gases of SF6 and R134a. The concentration decays of two tracer gases are measured after simultaneous injections in each room. The governing equations are derived from the continuity and the mass balance of each room. The data reduction procedure are developed to obtain the inter-room airflow rates using the governing matrix inversion, and various data manipulation methods are tested, such as data shift, interpolation, smoothing, and etc, to improve the estimate and interpretation of the results.

• Geosciences Journal
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• v.22 no.6
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• pp.1041-1052
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• 2018

A single-well push-drift-pull tracer test using two different tracers ($SF_6$ and salt) was performed at the Environmental Impact Test (EIT) site to determine suitable locations for monitoring wells and arrange them prior to artificial $CO_2$ injection and leak tests. Local-scale estimates of hydraulic properties (linear groundwater velocity and effective porosity) were obtained at the study site by the tracer test with two tracers. The mass recovery percentage of the volatile tracer ($SF_6$) was lower than that of the non-volatile tracer (salt) and increased drift time may make degassing of $SF_6$ intensified. The $CO_2$ leakage monitoring results for both unsaturated and saturated zones suggest that the $CO_2$ monitoring points should be located near points at which a high concentration gradient is expected. Based on the estimated hydraulic properties and tracer mass recovery rates, an optimal $CO_2$ monitoring network including boreholes for monitoring the unsaturated zone was constructed at the study site.

• Journal of Biosystems Engineering
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• v.24 no.6
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• pp.479-486
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• 1999

A measurement method for the deposition amount of spray, using tracer and spectrophotometer was developed. Food colors was selected as tracer, because it was cheep and easily treatable. Using NIRS(Near Infrared Reflection Spectrophotometer), regression curves between absorbance spectrum and concentration of the tracer were obtained. Yellow food colors showed the peak of spectrum at 452nm, and absorbance of peak showed a tendency to increase as concentration increased. Also, the possibility of concentration control by heating was investigated.

• Asian-Australasian Journal of Animal Sciences
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• v.1 no.4
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• pp.189-193
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• 1988

Distribution of tracer particles in carrier conform to Poisson distribution and the effect of Poisson distribution on mixing uniformity can be reduced by increasing the tracer particle number per unit weight. In this paper, above-mentioned theory has been demonstrated by using three kinds of rotor whose pitches are different.

• Journal of the Korean Society of Visualization
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• v.5 no.1
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• pp.22-29
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• 2007

In the present study, naturally generated bubbles were investigated to be sure if they could be adopted as the tracer for PIV techniques. The bubble can be grown from the nuclei melted in the water of tunnel and the size of bubbles is changed through the variation of tunnel pressure. Since the trace ability and appropriate size of tracer are so important for PIV techniques, the characteristics of bubbles as tracer are revealed in terms of trace ability and bubble size with the variation of flow speed and tunnel pressure in this study. In addition, PIV measurements of (low behind a rotating propeller are conducted to confirm the trace ability of bubbles even in a highly vortical flow.

• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.90-94
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• 1998

Self diffusion coefficients of $^{67}$Co and impurity diffusion coefficients of $^{51}$Mn and $^{65}$Zn in single crystalline CoO have been measured by applying different radioactive isotopes simultaneously. To compare the residual activity method and the tracer sectioning method we analyzed our tracer diffusion experiments by using both methods simultaneously. According to our experimental results, the diffusion coefficients obtained from both methods are identical within experimental error, demonstrating the relibility of our experimental procedures. The diffusion coefficients of all the isotopes obtained during these test experiments for the methodology are similar in magnitude and show similar dependences on oxygen partial pressure. These first observations indicate that impurity diffusion of Mn and Zn occur via a vacancy mechanism as known for self diffusion of cobalt.

• Journal of Soil and Groundwater Environment
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• v.16 no.3
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• pp.3-9
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• 2011

Partitioning tracers have been used with non-partitioning, inert tracer such Br, for detection, estimation, and monitoring of remediation performance of the subsurface contaminated with nonaqueous phase liquids (NAPLs). Various partitioning tracers with different partition coefficients between aqueous and nonaqueous phase liquids can be used to determine the hydraulic conductivity, dispersivity, and residual mass of NAPLs in the subsurface soil matrices. Temporal moment-generating equations were used to analyze the field pilot-scale test results. The pilot-scale tests included conservative tracer tests and partitioning tracer tests. Analyses of nonaqueous phase liquid distribution and characteristics of groundwater bearing soil media were performed.