• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.65-68
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• 2008

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.356-359
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• 2004

Prelaunch thermal analysis of the KSLV (Korea Space Launch Vehicle)-I PLF (Payload Fairing) was performed to predict maximum/minimum liftoff temperatures and to evaluate of air conditioning performance. Prelaunch thermal analysis includes internal air conditioning effect, external convective heating/cooling, radiation exchange with the ground and sky, radiation between spacecraft and PLF, and solar radiation incident on PLF. Analysis was performed at two extreme conditions, hot day condition and cold day condition. The results showed that the maximum liftoff temperature was $53^{\circ}C$ and the minimum liftoff temperature was $-3.8^{\circ}C$. It was also found that conditioned air supplying, in $20{\pm}2^{\circ}C\;and\;1200\;m^3/hr$, is sufficient to keep the internal air in required temperature range.

• Journal of Radiation Protection and Research
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• v.30 no.4
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• pp.167-174
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• 2005

The concentrations of natural and artificial radionuclides in soil and gamma ray dose rate in air at 233 locations in Korea have been determined. The national mean concentrations of $^{232}Th,\;^{226}Ra,\;^{40}K,\;^{137}Cs\;and\;^{90}Sr$ in soil were $60{\pm}31,\;33{\pm}14,\;673{\pm}238,\;35{\pm}9.3\;and\;5.0{\pm}3.4\;Bq\;kg^{-1}$, respectively. The mean gamma-ray dose rate at 1 m above the ground was $7918\;nGy\;h^{-1}$. $^{137}Cs$ concentration had highly significant correlation with organic matter content and cation exchange capacity. $^{90}Sr$ concentration had slightly coherent with pH. The results have been compared with other global radioactivity and radiation measurements.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.25-33
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• 2003

The automatic system for $^{67}Ga$ production using for the diagnosis of malignant tumor has been developed. A solvent extraction and an ion exchange chromatography were used for the separation $^{67}Ga$ from the irradiated enriched $^{68}Zn$. This system consisted of a solvent separation unit which was composed of micro conductivity cells, air supply tubes, solvent transfer tubes, solenoid valves and glasses, a PLC based controller and a PMU user interface unit for automation. The radiation exposure to the workers and the production time can both be reduced by employing this system during the $^{67}Ga$ production phase. After all, the mass production of $^{67}Ga$ with high efficiency was possible.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.226-234
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• 2018

Even though the nuclear power plants has many advantages, safety issues of nuclear power plants are crucial factors of reliable operation. A tritium detector is a useful sensor to analyze amount of exposed radiation from the nuclear power plants. Currently, concentration of underwater tritium is measured precisely but it takes very long time. Since electrolysis is extracted hydrogen from the coolant of nuclear power plant, it can motivate to develop new type of real-time sensor. In this study, Proton Exchange Membrane (PEM) electrolyzer is studied for candidate as preprocessor of real-time tritium detector. Characteristics of the unit PEM electrolyzer were experimentally investigated. A simulation model is developed to understand physical behavior of unit PEM electrolyzer under dynamic operation.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.16.2-16.2
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• 2007

• Proceedings of the Membrane Society of Korea Conference
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• 2000.11a
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• pp.65-68
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• 2000

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2016.09a
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• pp.11-14
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• 2016

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.10
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• pp.92-98
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• 2006

An 1 lbf of NASA standard monopropellant thruster, MRE-1, is used for KOMPSAT (Korea Multi-Purpose Satellite) which is launched in 2006 and provides reliable and cost-effective means for attitude and maneuvering control system. The monopropellant thruster obtains required thrust by thermal decomposition process of propellant through catalyst bed. During firing, the decomposition plays a role of a heat source that may occur an excessive radiation heat transfer to peripheral structures and electronics in relatively low temperature condition.Therefore, the radiation heat shield is needed to prevent the critical radiative heat exchange between thruster and satellite during firing. This paper summarizes an overall development process of radiation heat shield from the design engineering up to the manufacturing.

• Journal of Environmental Science International
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• v.20 no.8
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• pp.1061-1068
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• 2011

Evapotranspiration is one of the important elements related water cycle and there is many kind of measurement method of evapotranspiration today. This study developed mini lysimeter for the purpose of direct measurement of evapotranspiration and installed on 5th, July, 2010 at the field of MRI which located at Tsukuba, Ibaraki, Japan for continuous measurement and understand relation between evapotranspiration and meteorological elements expecially radiation elements. And compared the evapotranspiration data of lysimeter with Bowen Ratio Method. The result of this study is as follows; There is high related with solar radiation and evapotranspiration with $R^2$=0.947. and 46 % of solar radiation converted into evapotranspiration during clear 5 days. In net radiation also highly related with evapotranspiration, we can derive evapotranspiration is mainly controlled by radiation energy in clear days. From the 104 days data, there is only 9 % difference between Bowen Ratio Method and evapotranspiration of lysimeter which was developed from this study is very useful to estimate evapotranspiration at field site with simple and high accuracy. High accuracy and resolution measurement of evapotranspiration by lysimeter can give a chance further study of meteorological phenomena of on ground expecially in night time condensation which means abnormal energy flow.