• Journal of Radiation Protection and Research
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• v.14 no.2
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• pp.18-22
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• 1989

In order to calibrate the CR-39 Solid State Nuclear Track Detector (SSNTD), a closed -circulation type SSNTD-Calibration-System containing a radon-cup with the Millipore filter has been set-up, and the tracks produced on the SSNTD were measured for the known amount of radon concentration. Calibration factor for the time integrated radon concentration as a function of the track density on CR-39 was estimated to be $0.24{\pm}0.09(pCi/l)\;day/(Tr/cm^2)$.

• Journal of Radiation Protection and Research
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• v.18 no.1
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• pp.25-35
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• 1993

To develop a technique of theoretical alpha track density calculation for comparison with measured track density, an electrostatic ion spectrometer was specially designed and fabricated. The mobility spectrum of first radon daughter(Po-218) in the range of $0.07{\sim}5.0cm^2/V\;s$ from the radon chamber was measured using-the electrostatic ion spectrometer. Measurement was taken in a radon chamber operated using dry particle free air passed through silica gel, activated charcoal and molecular sieve filters. The mobility of a new-born Po-218 ion measured by the electrostatic ion spectrometer was determined to be $1.92cm^2/V\;s$. A comparison of the theoretical and measured alpha track densities was completed and uncertainties concerning the shape of the spectrum were analyzed. It was found that the discrepancies in track densities are primarily Que to the neglect of wall loss of ions in the theoretical track density calculation.

• Journal of Radiation Protection and Research
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• v.2 no.1
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• pp.1-8
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• 1977

A base of photographic posi-film which is commecially available has been found to be a possible alpha-particle track detector. Its neutron dosimetric characteristics, i. e., alpha-particle track registrating efficiency and optimum condition of track formation by chemical etching, have been determined experimentally. The range of neutron fluence and dose capable of being measured by a neutron dosimeter consisting of alpha-particle radiator foils $(^{10}B\;and\;^{27}Al)$ and posi-flim solid state track detector, has been estimated on the basis of experimental results and theoryetical background. This detector seems to be useful for neutron dosimetry because of many favorable properties, i. e., simplicity, cheapness and a wide range of sensitivitiy.

• Nuclear Engineering and Technology
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• v.5 no.4
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• pp.334-338
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• 1973

The horizontal distribution of the fast neutron flux density in the Bulk Shielding Experimental Tank of the TRIGA Mark-II reactor at the steady power of 250 KW has been measured using a solid state track detector which is natural mica placed in contact with $^{232}$ Th fissile foil. The neutron flux density was calculated on the assumption that the fast neutron spectrum is similar to that from the thermal-induced $^{235}$ U fission. The resulting flux density distribution along the horizontal line from the center of the thermalizing column door is presented in tabular and graphical forms.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.3
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• pp.185-191
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• 2012

Most of Korean farms have been developed in the semi-closed bay, and its position is very vulnerable to the coastal contamination due to the long term and the high density. So, mariculture management is very essential for the sustainable aquaculture. Some of the specific ways would be the assessment of the optimal stocking density for mariculture management zone and this has to consider both the suitable site selection and the assessment of ecological carrying capacity. Habitat suitability index(0.0 totally unsuitable habitat, 1.0 optimum habitat) and ecological indicator(Filtration pressure indicator) was used to assess the stocking density for oyster farms in Geoje-Hansan Bay. Geoje Bay showed the higher habitat suitability index value 0.75 than Hansan Bay 0.53, indicating that Geoje Bay is more suitable for oyster farming. Ecological indicator showed different stocking density according to the coastal characteristics in Geoje-Hansan Bay. Consequently, it is desirable that the stocking density in Geoje Bay should reduce average 40% and Hansan Bay, average 60% than present, in order to meet the ecological carrying capacity. The assessment of the stocking density could solve various problems such as the coastal contamination, environmental aggravation and the productivity decrease and this study could be a scientific basis to establish the policies for mariculture management.