• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2310-2316
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• 2016

We studied the effect of $Co^{60}$ gamma-radiation on the fiber Bragg gratings (FBGs) by irradiation time of UV Krypton fluoride (KrF) excimer laser among grating processing parameters. The FBGs were fabricated in a different UV laser irradiation time at 30, 60, 90, and 120 seconds using the same commercial Ge-doped silica core fiber (SMF-28e). It was exposed to gamma-radiation up to a high dose of 34.3 kGy at the dose rate of 106 Gy/min, and then it was analyzed radiation effects by measuring the radiation-induced change in the temperature sensitivity coefficient and Bragg wavelength shift. According to the experimental results, We confirmed that the UV laser irradiation period for grating inscription has a highly effect on the radiation sensitivity of the FBGs. The radiation-induced Bragg wavelength shift by the change of laser irradiation conditions showed a difference more than about 50 %.

• 월간산업보건
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• s.309
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• pp.68-70
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• 2014

• Nuclear industry
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• v.10 no.3 s.85
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• pp.25-27
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• 1990

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.119-125
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• 2024

The purpose of this study is to examine the radioprotection effect of mixtures of selenium and arginine for development of radioprotection agents that can minimize radiation damage to police special operation unit in the event of radioactive terrorism. In this study 72 male rats were classified into 4 groups: normal group(NC Group), selenium and arginine mixtures administration group(SeAr Group), radiation exposure group(IR Group), and selenium and arginine mixture administration group followed by radiation exposure(SeAr+IR Group). The 7Gy of X-ray was irradiated to whole body of SD rats. And selenium and arginine were dministered orally at 3mg/kg and 150mg/kg once a day for 14 days. And then hematological and histological analyzes were performed on days 1, 7, and 21 after radiation exposure. In hemotological analysis, significant radioprotection wes observed in lymphocytes(p<0.05) on day 1, platelet(p<0.01) on day 7, red blood cell(p<0.01) on day 21 of radiation exposure in SeAr+IR group compared to IR group. In histological analysis, it was observed that the border of small crypt cells in the small intestine was less collapsed and the length of small crypts was relatively recovered on day 7 and showed that the number of cells and cell wall thickness were better in the prostate on day 21 in SeAr+IR group compared to IR group. Therefore, it is judged that selenium and arginine mixtures have radioprotection effect on blood and tissues due to radiation exposure. it will be helpful for research on radioprotection agents to reduce radiation damage to police special operation unit.

• Journal of radiological science and technology
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• v.15 no.1
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• pp.51-63
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• 1992

• Journal of radiological science and technology
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• v.27 no.1
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• pp.23-27
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• 2004

• Journal of Radiation Protection and Research
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• v.37 no.3
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• pp.159-166
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• 2012

The present study was performed to investigate the toxicity of low-dose-rate irradiation in BALB/c mice. Twenty mice of each sex were randomly assigned to four groups of five mice each and were exposed to 0 (sham), 0.02, 0.2, or 2 Gy, equivalents to low-dose-rate irradiation to 3.49 $mGy{\cdot}h^{-1}$. Urine, blood, and blood biochemistry were analyzed, and organ weight was measured. The low-dose-rate irradiation did not induce any toxicologically significant changes in mortality, clinical signs, body weight, food and water consumption, urinalysis, and serum biochemistry. However, the weights of reproductive organs including the testis, ovary, and uterus decreased in a dose-dependent manner. Irradiation at 2 Gy significantly decreased the testis, ovary, and uterus weights, but did not change the weights of other organs. There were no adverse effects on hematology in any irradiated group and only the number of neutrophils increased dose dependently. The low-dose-rate irradiation exposure did not cause adverse effects in mice at dose levels of 2 Gy or less, but the reproductive systems of male and female mice showed toxic effects.

• Journal of radiological science and technology
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• v.47 no.3
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• pp.167-173
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• 2024

This study purpose to establish an appropriate target exposure index(EIT) using dose area product(DAP) and exposure index(EI) based on chest radiography. First, the system response experiment was conducted with radiation quality of RQA5 to compare the dosimetry and dose area product of equipment. Next, EI and DAP were acquired and analyzed while varying the dose in the diagnostic at 70kVp using a human body model phantom. The signal to noise ratio(SNR) of the obtained results was analyzed in the diagnostic with in the diagnostic reference level(DRL) application range. The DRL at percentage 25% had a dose of 0.17 mGy and EI was 83, and at percentage 75% the dose was 0.68 mGy and EI was 344. As the dose increased, the SNR in the subdiaphragm increased. To set the EIT, calibration must first be performed using a dosimeter and set within the DRL range to reflect the needs of the medical institution.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.1-6
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• 2017

Visual evaluation of chest radiograph images is the most practical and effective method. This study compared the Body Mass Index, waist circumference, and mAs with chest radiographs of 351 women. The Bureau of Radiological Health method was used to evaluate the image quality of chest X-ray images by anatomical and physical methods. The average age of the subjects was $30.17{\pm}4.73$ and the average waist circumference was $66.91{\pm}4.67cm$. The mean Body Mass Index value was $20.21{\pm}2.23$, the mean value of mAs was $3.04{\pm}0.78$, and the mean value of Bureau of Radiological Health was $79.83{\pm}8.45$. When the Body Mass Index value increased, waist circumference and mAs mean value increased. The mean value of Body Mass Index was statistically significant(p<0.05) in Group 4 compared to Groups 1 and 2, with increasing Body Mass Index. Exposure control of the automatic exposure control system is considered to be well performed according to body thickness or Body Mass Index at the time of chest radiography. As the Body Mass Index increases, the thickness of the body increases and the breast thickness of the woman also increases. Therefore, it is considered that the exposure amount is changed by the automatic exposure control device to affect the image quality.

• Journal of the Korean Society of Radiology
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• v.10 no.2
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• pp.139-144
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• 2016

The study of radiation-hazard in the human skin tissue is carried out by direct irradiating to experimental animals. The influences of a radiation to the animal's skin tissue are analyzed from this experiment. However, this also accompanies losses in terms of both time and economy. In this study, we simulated human tissue by using a swine skin tissue. The depth of the swine skin tissue for the experiment is determined, and the amount of the direct radiation below this skin depth is analyzed numerically. The amount of the radiation occurred by exposure below the skin tissue can be inferred. Moreover, it is possible to use only cells effectively and animal experiments to analyze the body-hazard by radiation.