• Journal of Radiation Industry
• /
• v.2 no.1
• /
• pp.43-51
• /
• 2008

Radiation technology is currently used in a number of industrial processes such as sterilization, cross linking of polymer, food irradiation, rubber vulcanization in the tire manufacturing, contaminated medical waste, etc. Gamma ray and electron beam are the key examples of well-established economical applications of radiation processes. The purpose of this paper is to review the recent technological trends and activities for radiation processes in order for the industrial end users to better understand, and obtain useful information about the technology. It is clear that the radiation processing technology has potential for a variety of the industrial applications.

• Journal of Radiation Industry
• /
• v.17 no.2
• /
• pp.161-172
• /
• 2023

Coal-fired power plants handle large quantities of coal, one of the most prominent NORM, and the coal ash produced after the coal is burned can be tens of times more radioactive than the coal. Workers in these industries may be exposed to internal exposure by inhalation of particles while handling NORM. This study evaluated the size, concentration, particle shape and density, and radioactivity concentrations of airborne suspended particles in the main processes of a coal-fired power plant. Finally, the internal radiation dose to workers from particle inhalation was evaluated. For this purpose, airborne particles were collected by size using a multi-stage particle collector to determine the size, shape, and concentration of particles. Samples of coal and coal ash were collected to measure the density and radioactivity of particles. The dose conversion factor and annual radionuclide inhalation amount were derived based on the characteristics of the particles. Finally, the internal radiation dose due to particle inhalation was evaluated. Overall, the internal radiation dose to workers in the main processes of coalfired power plants A and B ranged from 1.47×10^-5~1.12×10^-3 mSv y^-1. Due to the effect of dust generated during loading operations, the internal radiation dose of fly ash loading processes in both coal-fired power plants A and B was higher than that of other processes. In the case of workers in the coal storage yard at power plants A and B, the characteristic values such as particle size, airborne concentration, and working time were the same, but due to the difference in radioactivity concentration and density depending on the origin of the coal, the internal radiation dose by origin was different, and the highest was found when inhaling coal imported from Australia among the five origins. In addition, the main nuclide contributing the most to the internal radiation dose from the main processes in the coal-fired power plants was thorium due to differences in dose conversion factors. However, considering the external radiation dose of workers in coal-fired power plants presented in overseas research cases, the annual effective dose of workers in the main processes of power plants A and B does not exceed 1mSv y^-1, which is the dose limit for the general public notified by the Nuclear Safety Act. The results of this study can be utilized to identify the internal exposure levels of workers in domestic coal-fired power plants and will contribute to the establishment of a data base for a differential safety management system for NORM-handling industries in the future.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.309.1-309.1
• /
• 2002

Ginsan, a polysaccharide extracted from Panax ginseng. was earlier scrutinized for a biological-response modifier. We further studied the protective and restorative activity of Ginsan against sublethal dose irradiation owing to increase production of endogenous hematopoietic growth factors such as IL-1. TNF-${\alpha}$. IL-6, GM-CSF. Which induce strong redox-emzyme elevation. Exposing to radiation induces reactive oxygen species (ROS). which play an important causative role in radiation damage. (omitted)

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.63.2-63.2
• /
• 2010

Solar radiation data are used in several forms and for a variety of purposes. The most detailed information we have is beam and diffuse solar radiation on a horizontal surface, by hours, which is useful in simulations of solar processes. Daily data are more often available and monthly total solar radiation on horizontal surface can be used in some process design methods. However, as performance is generally not linear with solar radiation, the use of average may lead to serious errors if non-linearities ara not taken into account. It is also possible to reduce radiation data to more manageable forms by statistical methods. The control of the quality of most measurements is relegated to the control of the measuring instruments and measuring processes themselves. An accurate measurement will usually result from the use of a high-quality instrument that has been accurately calibrated and is properly used by a qualified individual.

• Journal of Radiation Protection and Research
• /
• v.30 no.1
• /
• pp.31-34
• /
• 2005

The article is devoted to the study of some hi-and tricyclic derivatives of aziridine as materials lot newindicators of ionizing radiation. To create high sensitive materials some aspects of photo induced ring opening processes in aziridine derivatives in ethanol solutions and in polymeric matrix were studied and two steps character of the processes investigated was established. Two types of radioindicators were suggested and preliminary tested. The new way of synthesis of radiochromic derivatives of aziridine was developed and series of target compounds synthesized.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.31 no.4
• /
• pp.342-352
• /
• 2021

Objectives: This study analyzed the local exposure levels of radiation emitted from the equipment with soft X-ray ionizers to investigate the radiation exposure levels in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the local radiation levels for the equipment installed in two LCD manufacturing companies. The equipment were installed at diverse processes and equipped with various number of ionizers. The local radiation levels were measured on the surface of the equipment by using direct reading equipment, and the measurements were converted into annual effective dose by considering the radiation exposure time of workers. Statistical analyses were performed to investigate the radiation exposure characteristics. Results: Annual effective doses for 97.6% of the equipment being measured were less than 1 mSv. However, the range of annual effective doses was 0.004 mSv ~ 2.167 mSv, which indicated a large variation among the equipment. Statistical analyses of the study found that this large variation was raised due to improper shielding of the equipment rather than process and/or equipment characteristics. To pinpoint the cause of this large variation in annual effective dose, this study improved the shielding of the equipment being radiated over 1 mSv and found that their average effective dose was reduced from 1.604 mSv to 0.126 mSv after shielding improvement. Conclusions: Relatively high exposure levels of radiation were observed in some equipment where their shielding were insufficiently thick and/or sealed. This finding implies that the shielding of the equipment is an important engineering countermeasure to control the radiation exposure levels in industries.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.1
• /
• pp.39-48
• /
• 2013

The solar radiation is the primary energy source that drives many of the earth's physical and biological processes and climate change. Understanding its importance to the solar radiation observation is a key to understanding a broad range of natural processes, agricultural, energy and human activities. The purpose of this study is to estimate solar radiation using sunshine duration, and to estimate distribution of solar radiation using a topography factor considering surface slope and aspect in complex terrain. The result of regression analysis between ratio of solar radiation and sunshine duration from 2001 to 2010 shows high $R^2$ value of 0.878. Regression analyses indicated that topographic attributes including elevation, slope and aspect had significant effects on solar radiation. The variation of topographic factor with aspect and slope for the summer and winter are considered. The highest month of daily mean solar radiation at Jeju island appears in April of 20.61 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$, and the lowest month appears in December of 6.90 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$. These results provided useful quantitative information about the influence of topography on solar radiation in the island region.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.194-196
• /
• 2002

While ultraviolet radiation alters various cutaneous cell functions, little is known about photo-immunological and photobiological effects of infrared radiation (IR) on the skin except its local thermal effects. The fIrst part of this study demonstrated that single exposure of mouse skin to near IR (0.7 - 1.3 $\mu$m) reversibly suppressed the proliferating activity of the epidermis, the density of Langerhans cells, and the ability of skin to induce contact hypersensitivity reaction. The second part demonstrated that the rate of wound closure was significantly accelerated by repeated exposures in animal models. The production of transforming growth factor-$\beta$l and matrix metalloproteinase-2, which are responsible for the wound healing processes, was significantly upregulated by irradiation, as shown by enzyme immunoassay, zymography, and reverse transcription polymerase chain reaction. Thermal controls were negative. The results suggest that near-IR irradiation can modulate the epidermal proliferation and part of the skin immune system, and stimulate the wound healing processes, presumably by non-thermal effects.

• Journal of the Korean Vacuum Society
• /
• v.3 no.2
• /
• pp.147-157
• /
• 1994

Valence or core electron excitations induced by Synchrotron radiation (SR) irradiation and ensuing chemical reactions can be applied for semiconductor processes i, e, deposition etching and modifications of thin film materials. Unique selectivity can be achieved by this photochemical reactions in deposition and etching. Some materials can be ecvaporated by SR irradiation which can be utilized for low temperature surface cleaning of thin films. Also SR irradiation significantly lowers the reaction temperature and photon activated surface reactions can be utilized for direct writing or projection lithography of electronic materials. This technique is especially effective in making nanoscale feature size with abrupt and well defined interfaces for next generation electronic devices.

• Nuclear Engineering and Technology
• /
• v.55 no.11
• /
• pp.4204-4212
• /
• 2023

Background: Storage reservoirs of radioactive waste could be the source of atmospheric pollution due to the efflux of aqueous aerosol from their water areas. The main mechanism of formation of aqueous aerosols is the collapse of gas bubbles at the water surface. In this paper, we discuss the potential influence of biological factors on gas ebullition in the water areas of the radioactively contaminated industrial reservoirs R-9 (Lake Karachay) and R-4 (Metlinsky pond) of the Mayak PA. The emission of the released non-dissolved gases captured with gas traps in reservoir R-9 was (88-290) ml/m² per day (2015) and in reservoir R-4 (270-460) ml/m² per day (2016). The analysis of gas composition in reservoir R-4 (60% methane, 35% nitrogen, 2.4% oxygen, 1.5% carbon dioxide) confirms their biological origin. It is associated with the processes of organic matter destruction in bottom sediments. The major source of organic matter in bottom sediments is the dying phytoplankton developing in these reservoirs. Conclusion: The obtained results form the basis to set a task to quantify the relationship between the phytoplankton development, gases ebullition and radioactive atmosphere contamination.