• Proceedings of the PSK Conference
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• 2003.10b
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• pp.109.1-109.1
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• 2003

The aim of this study was to investigate the biological effects of blood and testis by neutron or gamma-ray irradiation in black mouse. Six-week-old C57BL male mice were irradiated with neutron (flux: 1.036739E+09) or Co60 gamma rays(dose rate: lGy/min.) The irradiation method of animal was abdominal irradiation and dose of irradiation was 10 and 20 Gy added with 5 and 15Gy in neutron irradiation.. After that, the mice were sacrificed 3 days later. Blood and testis were taken and then composition of blood in blood cell were investigated. (omitted)

• ETRI Journal
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• v.31 no.5
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• pp.604-606
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• 2009

The primary dose effects on an insulated gate bipolar transistor (IGBT) irradiated with a $^{60}Co$ gamma-ray source are found in both of the components of the threshold shifting due to oxide charge trapping in the MOS and the reduction of current gain in the bipolar transistor. In this letter, the IGBT macro-model incorporating irradiation is implemented, and the electrical characteristics are analyzed by SPICE simulation and experiments. In addition, the collector current characteristics as a function of gate emitter voltage, VGE, are compared with the model considering the radiation damage of different doses under positive biases.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.29-34
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• 1993

This study was undertaken to investigate the effect of red ginseng extract (5.5 mg/mouse ip) on the activities of superoxide dismutase (SOD), peroxidase and catalase in the liver of the gamma ray irradiated male mice. The experimental groups consisted of control, red ginseng extract injection group, irradiation (8 $Gy^{60}$Co) group and red ginseng extract injection after irradiation group. in red ginseng extract injection group, SOD, peroxidase and catalase activities were similar to that in the control group. In irradiation group SOD, peroxidase and catalase activities increased progressively until the 2nd day after the treatment and then decreased thereafter, whereas red ginseng extract injection after irradiation group recovered more rapidly than irradiation group. The above results suggested that red ginseng extract injection after irradiation group have the recovery effects on the activities of SOD, peroxidase and catalase after radiation injury in the liver of male mice.

• 전기의세계
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• v.30 no.10
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• pp.639-644
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• 1981

PVC is a kind of electric insulation polymer. But we get some deteriorations in electrical characteristics of the PVC, when it is used on the radioactive field. In order to find out the cause of the deterioration, we investigate the surface-resistance, volume-resistance, dielectric constant and dielectric loss angle of the soft and hard PVC which is irradiated by the Co$^{60}$ .gamma. radioactivity. From the experiment, we can conclude the followings 1. Radio-activity proof characteristic in the soft PVC is stronger than in the hard PVC. 2. The resistance of PVC which is irradiated by the radio-activity decrease exponentially. 3. The dielectric constant and the dielectric loss angle of PVC irradiated by Co$^{60}$ .gamma.ray reach maximum value in first few time.

• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.35-40
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• 2008

A distillation tower is one of the important facilities which separates and refines a crude oil stream according to certain boiling points. Its operation efficiency can affect the productivity of a refinery substantially. The objective of this study is to elucidate some operational information on the internal conditions of a distillation tower from a measurement of density profile by using a sealed gamma-ray source and a radiation detector. Gamma radiation counts were measured by a BGO detector positioned diametrically outside the tower-wall, opposite to the gamma source(Co-60) as the detector and the source were lowered concurrently. From the results, structural abnormality of the trays was not found inside the tower. Considering the flow distribution patterns, however, a vapor phase was dominantly formed at the upper part of the tower and a liquid phase at the lower part. From the gamma scanning of the distillation tower, it is anticipated that the gamma absorption technique can be used as an important tool for confirming the structural soundness of trays and investigating flow distribution in refinery facilities.

• Polymer(Korea)
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• v.31 no.6
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• pp.512-517
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• 2007

The grafting of styrene, glycidylmethacrylate (GMA) or acrylic acid (AAc) onto kapok fiber were performed by $Co_{60}\;{\gamma}-ray$ radiation-induced graft copolymerization. Degree of grafting (DG) of copolymers were increased with increasing monomer concentration and radiation dose. In addition to we confirmed the introduced functional group and measured ion exchange capacity. Morphology of the ion exchange fibers and their structures were analyzed by SEM and FT-IR.

• Journal of Astronomy and Space Sciences
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• v.14 no.1
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• pp.80-86
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• 1997

High energy particles in the earth's radiation belts cause transient and long term effects on electronic materials, devices, and integrated circuits on board the satellites. Hence, it is very important to have the information on the space radiation environment and the damage on the electronics caused by the se high energy particles. One of the radiation monitor devices frequently used in space is RADFET, a specially designed MOSFET with a thick gate oxide region. The present study focuses on the calibration of RADFET TOT500 using the $Co^{60}{\gamma}-ray$ source. The result shows that the response of RADFET is very sensitive to the change of temperature. The peculiar behavior observed in the TDE (Total Dose Experiment) on board the KITSAT-1 is identified as the thermal effect due to the change in the eclipse rate of the satellite.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2690-2697
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• 2024

With advancements in machine learning technologies, artificial neural networks (ANNs) are being widely used to improve the performance of gamma-ray spectroscopy based on NaI(Tl) scintillation detectors. Typically, the performance of ANNs is evaluated using test datasets composed of actual spectra. However, the generation of such test datasets encompassing a wide range of actual spectra representing various scenarios often proves inefficient and time-consuming. Thus, instead of measuring actual spectra, we generated virtual spectra with diverse spectral features by sampling from categorical distribution functions derived from the base spectra of six radioactive isotopes: ⁵⁴Mn, ⁵⁷Co, ⁶⁰Co, ¹³⁴Cs, ¹³⁷Cs, and ²⁴¹Am. For practical applications, we determined the optimum counting time (OCT) as the point at which the change in the Kullback-Leibler divergence (ΔKLDV) values between the synthetic spectra used for training the ANN and the virtual spectra approaches zero. The accuracies of the actual spectra were significantly improved when measured up to their respective OCTs. The outcomes demonstrated that the proposed method can effectively determine the OCTs for gamma-ray spectroscopy based on ANNs without the need to measure actual spectra.

• Polymer(Korea)
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• v.31 no.1
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• pp.1-7
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• 2007

In this study, the sulfonated ion exchange fiber was synthesized by $Co^{60}\;{\gamma}-ray$ radiation-induced graft copolymerization. Degree of grafting (DG) increased with increasing the total dose and showed the highest value at 50 v/v% styrene monomer. And also, the degree of sulfonation (DS) increased with increasing the DG and reaction temperature. DS showed the maximum value at 20 min. Ion exchange capacity and swelling ratio of ion exchange fibers increased with increasing the DS and their maximum values were 4.76 meq/g and 23.5%, respectively. Ammonia adsorption increased as increasing the ammonia concentration and ion exchange capacity and remained constant over 10 cycles.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.191-199
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• 2021

The purpose of this research is to analyze the radiation shielding effect of soft magnetic material to confirm the applicability to the military facilities. The soft magnetic material is known to be effective in shielding EMP. If this material is also effective in radiation shielding, it is expected that it has a lot of applicability in military protection. In particular, this material contains boron, so it will be effective in shielding neutrons. In this research, experiments were conducted using Cs-137 and Co-60 sources to check the gamma ray shielding effect. In addition, the Monte Carlo N-Particle(MCNP) modeling was applied to evaluate the gamma ray and neutron shielding effect of a military command tent. As a result, as the soft magnetic thickness increased, the shielding performance improved according the linear attenuation law of gamma ray and neutron. Therefore, this research verified that the application of soft magnetic material for military purposes in radiation shielding would be effective.