• Journal of radiological science and technology
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• v.37 no.2
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• pp.135-141
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• 2014

This study was evaluated the linearity and reproducibility according to dose, and reproducibility according to delay time by changing tube current amount (5 mAs, 10 mAs, 16 mAs, 20 mAs, 25 mAs, 32 mAs respectively, which are low energy radiations) using Glass Dosimeter (GD) and piranha semiconductor dosimeter which are used for measuring exposure dose. Measurements of radiation dose were performed using external detector of piranha 657 which is multi-function QA device (RTI Electronic, Sweden). Conditions of measurement were 80 kVp, SSD 100 cm and exposure region is $10cm{\times}10cm$. Glass dosimeter was exposed to radiation. Twenty-four glass dosimeters were divided into six groups (5 mAs, 10 mAs, 16 mAs, 20 mAs, 25 mAs, 32 mAs respectively), then measured. This study was resulted by measuring the linearity and reproducibility according to change of tube current in low energy field. In dose characteristic of GD, this study could be useful as previous study with regard to dose characteristic according to change of tube voltage in low energy field.

• Radioisotope journal
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• v.18 no.4
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• pp.81-88
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• 2003

• Radioisotope journal
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• v.18 no.3
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• pp.66-76
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• 2003

• Horticultural Science & Technology
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• v.19 no.4
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• pp.515-520
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• 2001

To observe the stimulating effect of low dose ${\gamma}$ radiation on the dormancy breaking and growth, microtubers of two potato cultivars (Solanum tuberosum L. cv. Dejima and cv. Superior) were irradiated at the dose of 0.5-30 Gy. Though it varied with cultivars and storage duration, sprouting rate, plant growth and tuber yield were promoted by 2-8 Gy irradiation in microtuber of 'Dejima' stored at low temperature. On the other hand, in microtuber of 'Superior', sprouting rate was promoted by 2 and 4 Gy irradiation, and the growth and tuber yield by 4 Gy irradiation. These results suggest that low dose of ${\gamma}$ radiation could have stimulating effects on the dormancy breaking of microtuber and potato growth.

• Journal of Radiation Protection and Research
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• v.32 no.4
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• pp.184-189
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• 2007

In order to investigate the enhancement effects of low dose radiation on biological activation, this study applied low dose X-ray to the whole body of male rats to find out whether hormesis is induced in male germ cells. Total 36 Sprague-Dawley(SD) rats as experimental animal were subdivided into 6 groups(in 6 rats per group) such as control, 10 mGy, 20 mGy, 50 mGy, 100 mGy and 200 mGy radiation group All the groups showed slightly increasing number of sperms per 0.1g semen ($14.216{\times}10^6,\;13.901{\times}10^6,\;14.153{\times}10^6,\;13.831{\times}10^6,\;14.137{\times}10^6,\;14.677{\times}10^6$ respectively), and the motility of sperms amounted to 50.9%, 49.5%, 55.1%, 54.3%, 48.0% and 52.2% respectively. Particularly, compared to the control, the other 5 groups showed higher male hormone level, and the microscopic observations of testicle tissues showed no vacuolization in seminiferous tubules and testis cells. In the results of this experiment, no harmful effect was observed on Sprague-Dawley (SD) rats for which the dose of radiation was controlled as regulated legally by the Ministry of Science and Technology and the Ministry of Health and Welfare. However, as these results were obtained from a limited number of animals, we cannot maintain that the same effect will be observed in the human body. Therefore, there should be further research on the effect on other animals and ultimately on the human body.

• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.344-348
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• 1999

To investigate hormetic effect of low dose ${\gamma}$-ray on the uptake of mineral nutrients in Chinese cabbage (Brassica campestris var. Hekjinju var. Surim and) and radish (Raphanus sativas var. Chung-un), seeds of these plants were irradiated with the dose of 1 to 10 Gy. Germination rate and dry weight were examined at pot experiment in greenhouse. Samples for analysis of mineral nutrient were harvested at 17 days and at 59 days after seedling and were analyzed by ICP. Brassica campestris varieties showed higher germination rate and dry weight production with increasing ${\gamma}$ ray dose. Dry weight of Hekjinju Surim and were 143% and 138% at 10Gy dose. respectively. There was no tendency in germination rate and dry weight production for Raphanus sativas var. Chung-un with ${\gamma}$-ray irradiation. The pattern of mineral nutrient content of these plants showed ${\gamma}$ or ${\delta}$ type of dose-reaction curve with no siginificant. This investigation suggests that the more results can be required to understand the hormetic effect of low dose ${\gamma}$ ray on the uptake of mineral nutrient for these plants.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.64-70
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• 2005

To investigate the synergistic effects of low dose gamma irradiation and growth regulators on the growth and photosynthesis in rice (Oryza sativa L.), laboratory and greenhouse experiments were conducted using 4-year-old rice seeds. In the laboratory experiment, the germination rate was increased in 0.001 ppm IBA treatment, showing the synergistic effect of gamma irradiation and growth regulators. The seedling growth was increased by treatment of GA₃ and IBA, the irradiated groups having higher than the non-irradiated ones. Particularly, it was remarkable in 0.001 ppm IBA. In greenhouse experiment, seedling growth was increased in response to a combination of gamma irradiation and 0.001 ppm IBA. Effective quantum yield of PSⅡ(Ф/sub PSⅡ/) and photochemical quenching (qP) were increased, while non-photochemical quenching (qN) was decreased by 0.001 ppm IBA. A synergistic effect of gamma irradiation and IBA was only found in seedling growth. The present results suggest that low dose gamma irradiation and growth regulator could synergistically stimulate seedling growth.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.393-400
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• 2017

The purpose of this study is to suggest a method to reduce the dose by Analyzing the dose area product (DAP) and image quality according to the change of tube current using NEMA Phantom. The spatial resolution and low contrast resolution were used as evaluation criteria in addition to signal to noise ratio (SNR) and contrast to noise ratio (CNR), which are important image quality parameters of intervention. Tube voltage was fixed at 80 kVp and the amount of tube current was changed to 20, 30, 40, and 50 mAs, and the dose area product and image quality were compared and analyzed. As a result, the dose area product increased from $1066mGycm^2$ to $6160mGycm^2$ to 6 times as the condition increased, while the spatial resolution and low contrast resolution were higher than 20 mAs and 30 mAs, Spatial resolution and low contrast resolution were observed below the evaluation criteria. In addition, the SNR and CNR increased up to 30 mAs, slightly increased at 40 mAs, but not significantly different from the previous one, and decreased at 50 mAs. As a result, the exposure dose significantly increased due to overexposure of the test conditions and the image quality deteriorated in all areas of spatial resolution, low contrast resolution, SNR and CNR.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.519-526
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• 2022

Electronic personal dosimeter (EPD) provide real time monitoring and a direct indication of the accumulated dose or dose rate in terms of personal dose. Most EPD do not perform well in low energy photon radiation fields present in medical radiation environments. It has poor responsibility and large error rate for low energy photon radiation of medical radiation environments. This study evaluated to optimal additional filtration for EPD using silicon PIN photodiode detector form 40 to 120 kVp range in medical radiation environments. From 40 to 80 kVp energy range, Al 0.2 mm and Sn 1.0 mm overlapped filtration showed good responsibility to dose rate and from 80 kVp to 120 kVp energy range, Al 0.2 mm and Sn 1.6 mm overlapped filtration showed good responsibility to dose rate.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.357-363
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• 2009

The current population of elderly is increasing and the with an extended average lifespan, the frequency of cancerous occurrences have also increased, with these increases and the increase in radiotherapy for cancer patients, recognitions of harm and importance have become known. This article was known tumor treatment of patients with hematopoietic disorder by doing a comparative study on the changes in blood cells caused by the acute effects of trace dose to high dose of radiation exposed to mice. According to the sensitizer injection may give rise to harm to the components of peripheral blood. This material needs to be considered when for treating tumor patients and the risks of hematopoietic harm and believe that radiation therapy will be reasonable.