• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.497-502
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• 2011

In order to examine the effects of combination of plug flow reactors in series on hydraulic characteristics, comparative tracer tests were conducted for the cases of the existing clear well and clear wells combined in series. From the results of tests, $T_{10}$/T within existing clear well was 0.62~0.68 depending on inlet flowrate, and that in the case of combination in series was 0.69~0.78. While it would be minor improvement in contact efficiency, it would be appropriate to combine two clearwell with pipe in series for expansion.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2019.05a
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• pp.163-164
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• 2019

• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.49-56
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• 2004

Tracer tests were conducted to investigate leachate outflow through damaged parts on HDPE liner subject to puncture loads in a closed landfill. Natural gradient tracer test was used with two different types of tracers, iodide and Rhodamine WT. Tracers were selected under careful consideration of chemical components of leachate. Five injection wells with fourteen detection points were installed and operated throughout the test site. In this study, it is found that Iodide and Rhodamine WT are applicable and effective for leachate leakage investigation on waste landfills. Also, it is concluded that considerable amount of leachate was leaked through the rain water drain box and side wall of drain box.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1642-1646
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• 2011

In this paper, A Design of 2.45GHz and GPS antenna Integrated Board using Container security Device(ConTracer) for container cargo transportation is proposed and experimentally evaluate. Integrated antenna board include 2.4GHz chip and Ceramic GPS antenna is also consider the impact of RF interference based on simulation for applied to steel container. After a careful comparison and analysis a part of the container door for its best performance, We conduct tests to characterize. The proposed integrated antenna board is suitable for container cargo transportation application in steel container field.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.799-802
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• 2008

General behaviors based on hydraulic characteristics of natural streams and channels have been recently analyzed and developed via various numerical models. However in the states of natural hydraulics, an experimental research must be performed simultaneously with the mathematical analysis due to effects of hydraulic properties such as meander, sediment, and so on. In this study based on 2-D advection-dispersion equation, flow and tracer experiments were performed in the S-curved meandering laboratory channel with a rectangular cross-section. The channel was equipped with instrument carriages which was equipped with an auto-traversing system to be used with velocity measuring sensors throughout the depth and breadth of the flow field. To measure concentration distribution of the salt solution was adjusted to that of the flume water by adding methanol and a red dye (KMnO4) was added to aid the visualization of the tracer cloud, the tracer was instantaneously injected into the flow as a full-depth vertical line source by the instantaneous injector and the initial concentration of the tracer was 100,000 mg/l. The secondary current as well as the primary flow pattern was analyzed to investigate the flow distribution in the meandering channels. The velocity distribution of the primary flow for all cases skewed toward the inner bank at the first bend, and was almost symmetric at the crossovers, and then shifted toward the inner bank again at the next alternating bend. Thus, one can clearly notice that the maximum velocity occurs taking the shortest course along the channel, irrespective of the flow conditions. The result of the tracer tests shows that pollutant clouds are spreading following the maximum velocity lines in each cases with various mixing patterns like superposition, separation, and stagnation of pollutant clouds. Flow characteristics in each cases performed in this study can be compared with tracer dispersion characteristics with using evaluation of longitudinal and transverse dispersion coefficients(LDC, TDC). As expected, LDC and TDC in meandering parts have been evaluated with increasing distribution and straight parts have effected to evaluate minimum of LDC and TDC due to symmetric flow patterns and attenuations of secondary flow.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.17-28
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• 2010

As a preliminary survey to improve efficiency of well-based permeable reactive barrier system for groundwater remediation, this site-scale study was carried to identify the flowpaths and controlling factors of plume at a remediation site in Suwon City, Korea. A total of 22 monitoring wells were installed as a grid system in the $4m{\times}4m$ square area by 1-m interval. For the groundwater characterization, various tests were performed including water-level monitoring, water sampling & analysis, pumping and slug tests, and tracer tests. The aquifer appeared to be unconfined with hydraulic conductivities (K) ranging from $2.6{\times}10^{-4}cm/s$ to $9.5{\times}10^{-3}cm/s$. The average linear velocity of groundwater was estimated to be $2.94{\times}10^{-6}m/s$, and the longitudinal dispersivity of a conservative tracer to be $5.94{\times}10^{-7}m^2/s$. Groundwater plume moves preferentially through the high-K zones, and the relatively high ion concentrations along the low-K zones implying deterred groundwater flow. Consequently, the spatial variation of hydraulic conductivity caused by aquifer heterogeneity and anisotropy appears to be the most important factor to maximize the effect of plume treatment system for application of in-situ groundwater remediation techniques.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.4
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• pp.351-362
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• 2000

To set the similarity conditions between a prototype usually in the field and its reduced-scale model is a crucial part in model tests. No technique is available to keep perfect similarity for this procedure so far. The experimental work using a wind tunnel is not exceptional. based on the field measurements, the effect of stack parameters and wind conditions on the dispersion of stack plume has been investigated in the laboratory. in this paper intensive methodology is focused on matching these similarities. Due to the limitations to keep perfect similarity conditions some simplifications are involved in common. In this study geometric conditions and kinematic conditions using Froude number and Reynolds number have been con-sidered to keep the similarity conditions required. From the tests it is found that the critical Reynolds number (Recrit) is 2,700 when the height of stack discharge is 50mm. The dispersion has a similar trend for the higher Reynolds number than the critical Reynolds number. It is also found that different Froude number does not make any significant influence for the normalized tracer gas concentrations at the recipient providing the same ratio of the wind speed to the discharge speed. No significant effect of stack diameter is observed in the normalized tracer gas concentrations with the same Frounde number. The similarity conditions therefore used in this study are reliable to simulate the conditions in prototype into the wind tunnel tests.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1245-1252
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• 2010

Many industrialized countries are confronted with a difficulty about reuse of closed waste landfill. facilities. Especially, the demand of closed waste landfill maintenance and reuse nearby urban area has been increased, because of the shortage of usable land and extend of urban area. For the safe reuse of closed waste landfill, the most important check point is the effect of waste landfill on environment abound them. However, the non-sanitary closed waste landfill generally have no leachate lining system, therefore, the in-situ lining system such as sheet-pile, and vertical slurry wall etc. was needed to prevent the leachate outgoing from the waste landfill. In this paper present the case history of performance evaluation of vertical slurry wall by tracer tests.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.585-589
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• 2010

In order to evaluate the performance of a powdered activated carbon (PAC) contactor, two water treatment plants (WTP) were selected as target sites. The result of tracer tests showed that the plug flow portion of a bisymmetry-type contactor (H WTP) was more than 70%. A maze-type contactor (C WTP) also had more than 70% of plug flow portion after intra-basin baffles were installed. According to the operating data of the target WTPs, there was no clear evidence that the addition of PAC contributed to the removal of organics. However, the results of jar tests, conducted with the raw water taken from the H WTP, proved that PAC could remove dissolved organic carbon (DOC) to some extent when the proper velocity gradient was maintained. It was estimated that the production rate, defined as the ratio of the operating flowrate to the design flowrate, of the C and H WTPs was only 27 and 50%, respectively. Because of these lower production rates, the mixing intensity in the contactor was much less than the designed value and, finally, the performance of the PAC contactor was much lower than what was expected.

• Journal of radiological science and technology
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• v.44 no.2
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• pp.109-115
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• 2021

In this study, a physical evaluation of internal radiation exposure in children was conducted using nuclear medicine test(Renal DTPA Dynamic Study) to simulate the distribution and effects of the radiation throughout the tracer kinetics over time. Monte Carlo simulations were performed to determine the internal medical radiation exposure during the tests and to provide basic data for medical radiation exposure management. Specifically, dose variability based on changes in the tracer kinetic was simulated over time. The internal exposure to the target organ (kidney) and other surrounding organs was then quantitatively evaluated and presented. When kidney function was normal, the dose to the target organ(kidney) was approximately 0.433 mGy/mCi, and the dose to the surrounding organs was approximately 0.138-0.266 mGy/mCi. When kidney function was abnormal, the dose to the surrounding organs was 0.228-0.419 mGy/mCi. This study achieved detailed radiation dose measurements in highly sensitive pediatric patients and enabled the prediction of radiation doses according to kidney function values. The proposed method can provide useful insights for medical radiation exposure management, which is particularly important and necessary for pediatric patients.