• Journal of the Korean Society of Visualization
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• v.14 no.3
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• pp.46-50
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• 2016

The objective of the present study is to perform experiments for water filled cavity heated and cooled from the side at $Ra=8.5{\times}108$. This experiment can provide validation database of the standard k-${\varepsilon}$ turbulence model for single-phase turbulent natural convection which has been regarded as one of the important phenomena in nuclear safety. For the natural convection inside a cavity, temperature and velocity were obtained by thermometry and PIV (Particle Image Velocimetry) methods. These results would be used for validation of standard k-${\varepsilon}$ turbulence model.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.676-683
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• 2003

A laboratory experiment using artificial fracture rocks was used to understand the 3-dimensional dispersion of a tracer and the mixing process in a fractured network. In this experiment, 12cm polystyrene foam cubes with two electrodes for monitoring electric conductivity (EC) were used as artificial fractured rocks. Distilled water with 0.5mS/m was used as a tracer in water with 35mS/m and the difference of EC between the tracer and the water was monitored by a multipoint simultaneous measurement system of electrical resistance. The results showed that even if the fracture arrangement pattern was not straight in the direction of the flow, the tracer did not diffuse along individual fractures and an oval tracer plume, which was the distribution of tracer concentrations, tended to be form in the direction of the flow. The vertical cross section of the tracer distribution showed small diffusivity in the vertical direction. The calculated total tracer volume passing through each measurement point in the horizontal cross section showed while that the solute passed through measurement points near the direction of hydraulic gradient and in other directions, the passed tracer volumes were small. Using Peclet number as a criterion, it was found that the mass distribution at the fracture intersection was controlled in the stage of transition between the complete mixing model and the streamline routing model.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.729-729
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 1982.07a
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• pp.33-40
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• 1982

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.784-793
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• 2006

As the number of CFRD constructions increases, the necessity of an accurate assessment on its behavior also has been increasing accordingly. The performance of concrete faced rockfill dam (CFRD) under different water levels is greatly concerned by dam engineers and designers in the world. However, domestic research on CFRD design and construction has yet been insignificant. This study deals with three centrifuge model tests, mainly investigates the deformation of the concrete faced slabs with different face slab stiffness under different water levels. The prototype of a centrifugal model dam is half size of domestic CFRD dam. Detailed material preparation, model design, model set-up, model instrumentation and testing procedures are presented. In order to simulate the prototype concrete faced slab, three kinds of thin fiberglass plates with different thickness was adopted in the three model tests. The water level control facility was specially designed for this experiment to control the water level rise and drawdown during centrifuge flight. Although most of the results from the three model tests are satisfactory, it is also required that the centrifuge test results should be compared with those of numerical analysis and field measurements to analyze the centrifuge test results more in detail.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.2
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• pp.103-110
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• 2018

Most of the intake facilities of small agricultural reservoirs are conduits and they are regarded as serious defects due to the structural weakness that penetrates the body of the dam, and countermeasures are needed. This study suggests the application method of siphon type water intake facility by hydraulic model test and physical scale model test of siphon type water intake facility which has high safety and easy maintenance. Experimental results show that sufficient flow rate can be secured for the purpose of intaking water according to the differential head between the reservoir and the discharge part, and the flow rate can be controlled by the valve. The negative pressure was -31.5 kPa, and vibration and noise did not occur during the operation of the siphon. The maximum flow velocity in the discharge outlet was 1.11 m/s which meets the criterion for irrigation canals. Therefore, scour risk would be very low. As a result of the inflow distribution experiment, even if the inflow part is separated by only about 0.8 m, the flow velocity is remarkably decreased, so that the clogging by debris would not appear. When the pump was operated only once for the first time and the inside of the siphon was filled with water, continuous operation was possible by only valve operation. The results of this study are expected to be used for the design guidelines of the water intake facilities and improve safety and maintenance convenience of agricultural reservoirs.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1271-1274
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• 2009

One of the landslide, Debris flow means flow mixed of rocks, gravels, sand and soil with water. Debris flow occurred in summer by passed the rainy season and typhoon. Especially, Localized heavy rain derived from abnormal weather caused debris flow independent of season. It is increase to collapse of house, bridge, roads by debris flow but countermeasure studies about occurrence cause, movement pattern, damage scale about debris flow are insufficient. This study performed debris flow model experiment using dry material and calculated shock force predicted debris flow occurrence.

• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.85-100
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• 2008

Objective: This experiment was designed to investigate the effect of the KSKH hot water extract & ultra-fine powder on microglia and memory deficit model. Method: The effects of the KSKH hot water extract on expression of IL-1$\beta$, IL-6, TNF-$\alpha$ mRNA and production of IL-1$\beta$, IL-6, TNF-$\alpha$ in BV2 microglial cell line treated by lipopolysacchaide(LPS) were investigated. The effects of the KSKH hot water extract & ultra-fine-fine powder on the behavior of the memory deficit mice induced by scopolamine and AChE in serum of the memory deficit mice induced by scopolamine were investigated. Results: 1. The KSKH hot water extract suppressed the expression of IL-1$\beta$, IL-6, TNF-$\alpha$ mRNA in BV2 microglial cell line treated by LPS. 2. The KSKH hot water extract suppressed the production of IL-1$\beta$, IL-6, TNF-$\alpha$ in 100$\mu g/m\ell$ concentration of BV2 microglial cell line culture supernatant. 3. The KSKH hot water extract & ultra-fine powder decreased AChE activation significantly in the serum of the memory deficit mice induced by scopolamine. 4. The KSKH hot water extract & ultra-fine powder showed significant effect on memory impairment in the stop-through latency type of Morris water maze test. Conclusions: This experiment shows that the KSKH hot water extract & ultra-fine powder might be effective for the prevention and treatment of amnesia and Alzheimer's disease. Investigation into the clinical use of the KSKH hot water extract & ultra-fine powder for amnesia and Alzheimer's disease is suggested for future research.

• Journal of Oriental Neuropsychiatry
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• v.19 no.2
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• pp.95-110
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• 2008

Objective : This experiment was designed to investigate the effects of the PMCMT hot water extract & ultra-fine powder on Alzheimer's Disease Model Induced by ${\beta}A$. Method : The effects of the PMCMT hot water extract on expression of proinf1ammatory cytokine mRNA in BV2 microglial cell cell line treated by lipopolysacchaide(LPS). The effects of the PMCMT hot water extract & ultra-fine powder on (1) the behavior (2) AChE in serum (3) the infarction area of the hippocampus, and brain tissue injury in Alzheimer's diseased mice induced with ${\beta}A$ were investigated. Result : 1. The PMCMT hot water extract suppressed the expression of proinflammatory cytokine mRNA in BV2 microglial cell line treated with LPS. 2. The PMCMT hot water extract & ultra-fine powder a significant inhibitory effect on the memory deficit was shown for the mice with Alzheimer's disease induced by ${\beta}A$ in the Morris water maze experiment, which measured stop-through latency and distance movement-through latency 3. The PMCMT hot water extract & ultra-fine powder suppressed the over-expression of AChE activity in the serum of the mice with Alzheimer's disease induced by ${\beta}A$. 5. The PMCMT ultra-fine powder reduced infarction area of hippocampus significantly, and the PMCMT hot water extract & ultra-fine powder controlled the injury of brain tissue in the mice with Alzheimer's disease induced by ${\beta}A$. Conclusions : These results suggest that the PMCMT hot water extract & ultra-fine powder may be effective for the prevention and treatment of Alzheimer's disease. Investigation into the clinical use of the PMCMT hot water extract & ultra-fine powder for Alzheimer's disease is suggested for future research.

• Progress in Medical Physics
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• v.1 no.1
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• pp.75-84
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• 1990

We have claculated the absorbed dose distributions in water phantom irradiated by high energy photon beam. PDD (Percent Depth Dose) and Beam Profile can be represented by functions of depths and distances by using one dimensional model model based on transport theory. The parameters on scattering and absorption are evaluated by using non-linear regression process method. The values neeessary for calculation are obtained by simple experiment. The calculated values are in good agreement with the measured values.