• Journal of Radiation Industry
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• v.6 no.3
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• pp.205-209
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• 2012

The decomposition of 50 pesticides present in an aqueous solution using ${\gamma}-irradiation$ from a $^{60}Co$ gamma-ray source was investigated using laboratory-scale experiment. The rates of decomposition were determined using a gas chromatography-electron capture detector (GC-ECD), high-performance liquid chromatography-photo diode array detector (HPLC-PDA), and HPLC-fluorescence detector (FLD). When the initial concentration of pesticides was 10 ppm, and the radiation dose was 2, 5, 10, 20, and 30 kGy, respectively, 14 pesticide samples showed high removal rates (>50%) at absorbed doses of more than 10 kGy. With the exception of procymidone, they were all completely removed at a 30 kGy irradiation dose. These results provide fundamental data on the reactivity between gamma-irradiation and pesticides in an aqueous solution. Further, an evaluation of the toxicity of radiolytic intermediate products is required.

• Journal of radiological science and technology
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• v.44 no.2
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• pp.123-131
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• 2021

In this study, safety education contents for medical radiation workers were produced based on Mixed Reality(MR). Currently, safety training for radiation workers is based on theory. This is insufficient in terms of worker satisfaction and efficiency. To address this, we created ICT(Information and Communication Technologies)-based MR radiation worker safety education content. The expected effect of Mixed Reality worker safety education content is that education is possible without space and time constraints, realistic education is possible without on-site training, and interaction between images is possible through reality-based 3D images, enabling self-directed learning Is that. In addition, learning in a virtual space expressed through HMD(Head Mounted Display) is expected to make education more enjoyable and increase concentration, thereby increasing the efficiency of education. A quantitative evaluation was conducted by an accredited institution and a qualitative evaluation was performed on users, which received excellent evaluation. The MR safety education conducted in this study is expected to be of great help to the education of medical radiation workers, and is expected to develop into a new educational paradigm as online education in accordance with Corona 19 progresses.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.486-492
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• 2022

Nitrogen oxides (NO_x; NO and NO₂) are major air pollutants and can cause harmful effects on the human body. Electron Beam Flue Gas Treatment (EBFGT) is a technology that generates electrons with an energy of 0.5-1 MeV using electron accelerators and effectively processes exhaust gases. In this study, NO_x was removed using an electron beam accelerator with spraying additives (NaOH and NH₄OH). NO and NO₂ were 100% and more than 94% removed, respectively, at an electron beam absorbed dose of 20 kGy and an additive concentration of 0.02 M (mol/L). In most cases, NO_x was removed better with lower initial NOx concentrations and higher electron beam absorbed doses. As the irradiation strength (mA) of the electron beam increases, the probability of electron impact on the material accordingly rises, which may lead to increase removal efficiency. The results of the present study show that the continuous electron beam process using additives achieved more effective removal efficiency than either individual process (wet-scrubbing or EB irradiation only).

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.209-212
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• 2002

Main radionuclides of the soil waste stored in Korea Atomic Energy Research Institute are Co-60 and Cs-137. Moisture content of soil is 12%, pH of soil is 5.8, and content of organic matter is 2.2 %. Radioactive concentrations of the soil particle size of which is less than 0.063mm and soil in the drum surface of which is more than radiation dose rate 0.05mR/hr are higher. Meanwhile, radioactive concentration of soil in the drum surface of which is less than radiation dose rate 0.02 mR/hr are mostly lower. On using the mixing solution of ammonium sulfate and citric acid, 62% Co was removed from soil and 41% Cs was removed. Also, on using the mixing solution of ammonium nitrate and citric acid, 61% Co was removed from soil and 39% Cs was removed, and on using the mixing solution of ammonium potassium oxalate, 36% Co was removed and only 3% Cs was removed. And on using only water, removal efficiency is less than 5%.

• YAKHAK HOEJI
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• v.3 no.1
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• pp.26-34
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• 1957

The solar evaporation method is one of the most important and popular salt manufecturing method in Korea. The rate of evaporation of sea water depends on a complex climate factors. Of these factors, the most important is solar radiation and in particular the extent to which it is absorbed in the brine. By the addition of suitable dyestuff, a further increase in absorption is obtained and can result in all the radiation entering the brine being made available as heat. "Solivap Green", one of several dyestuffs which have been suggested for accelerating solar evaporation, was tested in this experiment. The results of the experiment. 1. Increase the evaporation rate of brine up to 20-25%. 2. Elevate the temperature of brine 2-$4^{\circ}C$. higher than that of brine adding no dyestuff. 3. Optimum dyestuff concentration is 25-30 mg/L and allowable maximum concentration can not exceeded 1000 mg/$m^2$ (50 mg/L). 4. Addition of dyestuff does not cause the degradation of salt produced. 5. A conversion table which indicates the concentrations for various depths of brine was prepared for engineering purpose. 6. Absorption spectrum of the dyestuff was studies, but toxicological and structural studies for the dyestuff have not been done in this experiment.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1636-1644
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• 2017

The main purpose of this article is to describe the magnetohydrodynamic stagnation point flow of Walter-B nanofluid over a stretching sheet. The phenomena of heat and mass transfer are based on the involvement of thermal radiation and chemical reaction. Characteristics of Newtonian heating are given special attention. The Brownian motion and thermophoresis models are introduced in the temperature and concentration expressions. Appropriate variables are implemented for the transformation of partial differential frameworks into sets of ordinary differential equations. Plots for velocity, temperature, and nanoparticle concentration are displayed and analyzed for governing parameters. The skin friction coefficient and local Nusselt and Sherwood numbers are studied using numerical values. The temperature and heat transfer rate are enhanced within the frame of the thermal conjugate parameter.

• Journal of Radiation Industry
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• v.4 no.3
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• pp.247-252
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• 2010

The present study has been performed to select the osmotic tolerant lines using polyethylene glycol (PEG 6000) through an in vitro and in vivo mutagensis with a gamma-ray. During the screening, we selected three mutant lines that seemed to confer elevated osmotic tolerance in high concentrations of PEG 6000. Fruits of these mutants (Os-HK101, Os-HK102 and Os-HK103) were increased to sugar concentration, L-glutamine acid, vitamin C content and lycopine content than those of the wild type. Also the chlorophyll contents were few decreased more in the three mutant lines than the WT plants. Our results suggest that the Os-HK101 is characterized as osmotic stress tolerance considering the sugar concentration and lycopine content. It is expected that the result of this study can be used for breeding more competitive species with respect to contents in sugar or functional chemicals from the selected osmotic resistant lines.

• Journal of Radiation Industry
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• v.2 no.3
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• pp.135-140
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• 2008

A field tracer experiment using radioisotope was carried out to investigate the characteristics of a pollutant transport and a determination of the dispersion coefficients in a river system. The dispersion coefficients in the longitudinal and transverse directions were determined by using the measured concentration of a radioisotope. The two-dimensional numerical models were applied to calculate the flow and concentration fields at the experimental site. Several numerical simulations were performed to investigate the effects of the numerical results according to variations of the dispersion coefficients. The calculated concentrations agreed well with the measured ones.

• Journal of Environmental Impact Assessment
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• v.12 no.4
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• pp.303-313
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• 2003

This study was carried out to survey the high ozone episode of summertime in Busan. The selected day was July 18, 1999 and August 24, 2001 which recorded exceed to 12ppb/hr at 3 station in Busan simultaneously. In case July 18, 1999, thick cloud and variable wind made weak ozone concentration during morning hour. And increase of ozone concentration by revolution of mixed layer for morning hour did not occur in this case study day. Photochemical reaction by strong radiation after 1100LST made sharp increase rate of ozone concentration(50ppb/hr). In case August 24, 2001, the meteorological condition of this day was not general wind with gradient force, very clear day with less cloud amount, high insolation and sunshine. Dongsamdong, Beomcheondong, Daeyeondong, and Sinpyeongdong had double peak which twice maximum concentration in the early afternoon and late afternoon. Ozone concentration of this day was in inverse proportion to Nitrogen oxide strongly. Ozone concentration exceed to 60ppb/hr occurred at 1400LST, continued to 2300LST.

• Polymer(Korea)
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• v.35 no.5
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• pp.478-482
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• 2011

In this study, several poly(styrene-co-(trimethoxysilyl)propyl methacrylate)-grafted ETFE films were prepared by a simultaneous irradiation grafting method. After mixing of styrene/(trimethoxysilyl)propyl methacrylate(TMSPM) monomers with various solvents, the effects of various irradiation conditions such as total dose, dose rate and monomer concentration on the degree of grafting of the prepared membranes were investigated. Results indicated that the higher degree of grafting was obtained when acetone was used as a solvent. The formation of poly(styrene-co-TMSPM) grafts on the ETFE films was verified using FTIR spectrometry and the distribution of the poly(PTMSPM) graft polymer over the cross-section of the grafted film was confirmed using SEM-EDX instrument.