• Applied Microscopy
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• v.28 no.4
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• pp.591-601
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• 1998

The neurotoxic effects of radiation have been studied in NSC-34 hybrid cells derived from embryonic mouse spinal cord cells. NSC-34 cells irradiated at 25Gy were decreased the cell viability in a time and dose dependent manner. The decrease in cell viability induced by the irradiation was blocked by catalase. Antagonists of the N-methyl-D-aspartate (NMDA) receptor, including D-2-amino-5-phosphonovaleric acid (APV) and chlorokynurenic acid (CKA), similarly blocked radiational induced in cell viability. We performed morphological analysis of light and electron microscope. NSC-34 cells irradiated at 25Gy were decreased the cell density and increased lysosomes and vacuoles in the cytoplasm. Especially chromatin modification was observed. These results indicated that radiation was involved in the oxidant-initiated neurotoxicity and the compounds catalase, APV and CKA were shown to be neuroprotective against radiation.

• Korean Journal of Organic Agriculture
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• v.3 no.1
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• pp.11-22
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• 1994

Exposing plant organs to high doses of ionizing irradiation, penetrating into the plant tis-sues and cells, along the track structure of particles, lesions, and sublesions are formed on the molecules and organelles. As a result, disorders in the growth and development as well as chlorophyll-deficiency symptoms occur. The time scale of their reparation, recovery and over compensation during ontogenesis, constitutes a question of high theoretical and practical importanced, with special regard to nuclear fallout. With an aim to model the “ut supra”stated phenomena, the seeds of bean, Echo elit licensed variety, were irradiated by 300 Gy dose of X-ray-irradiation (120 kV:4.5 mA). According to the data obtained, the biosynthesis of photosynthetic pigments, will have been completed by the beginning of flowering. In consequence of the overcompensation of the repairing processes, the organs of plants developed from irradiated seeds, showed a partly differing correlative growth, compared to those of control plants. In order to characterize the vivo response of radiation-injured plants, a new method and approach were used. The changes of the electric capacitance of the plants during their ontogenesis, were continously monitored and recorede via a computer-aided and controlled measurement. In view of the data collected in such a way, the repairing plants may respond more quickly and intensively to the changes of environmental factors.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.216-223
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• 2001

A study was carried out to examine the effect of sample form and storage conditions on the accumulated PPSL signals. Korean perilla and sesame seeds were tested as whole samples and separated minerals. Radiation-induced PPSL signals of perilla and sesame seeds themselves significantly increased with irradiation dose up to 5 kGy. On the other hand, a slight decrease in the accumulated PPSL signals was shown at 10 kGy. Similar results were also found in separated minerals. The accumulated PPSL signals of irradiated samples decreased with increasing storage periods. The decay rate was higher in 5 or 10 kGy-irradiated samples than in 1 kGy, in room conditions than in darkroom conditions, and in sesame and perilla seeds themselves than in separated minerals. The accumulated PPSL signals of the irradiated samples measured fur 120 s were higher than those measured for 60 s. These results indicated that although the PPSL signal of all samples decreased with increasing the storage time, detection of irradiated samples was still possible after 12 months of storage regardless of sample form and measurement times (60 and 120 s) in both room and darkroom conditions.

• Journal of Radiation Industry
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• v.5 no.1
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• pp.41-46
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• 2011

Polyacrylonitrile (PAN) fibers are the most widely used precursor of the materials for carbon fibers. The conventional process of carbon fibers from PAN precursor fiber includes two step; stabilization at low temperature and carbonization at high temperature. Compared to thermal stabilization, the stabilization process by electron beam (E-beam) irradiation is a advanced and brief method. However, a stabilization by E-beam irradiation was required a high dose (over 5,000 kGy) and spend over 1.5 hr (1.14 MeV, 1 mA). In the present work the main goal is exploring a quick stabilization process by cotrolling E-beam currents. The effect of various E-beam currents on stabilization of PAN precursor fiber was studied by gel fraction test, thermo gravimertic analysis (TGA), differential scanning calorimetry (DSC), tensile strength, and scanning electron microscopy (SEM) images.

• Journal of Radiation Industry
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• v.5 no.1
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• pp.69-73
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• 2011

Polyamide 66 (PA66) nanofibers with Triallyl cyanurate (TAC) were obtained by electrospinning of formic acid and chloroform solution. Electron beam irradiation of PA66 nanofiber with and without TAC was carried out over a range of absorbed doses (20~100 kGy) in nitrogen. The characterization of the irradiated PA66 nanofibers and PA66 nanofibers with TAC was done by scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA) and universal testing machine (UTM). The results of the SEM image analysis confirmed that the morphology of PA66 nanofibers was not altered by electron beam. The amount of TAC in PA66 nanofiber with TAC was identified by $^1H-NMR$ analysis. The degradation temperature of PA66 nanofibers with TAC at an absorbed dose of 20~100 kGy was higher than the irradiated PA66 nanofiber without TAC. On the other hand, the decreasing rate of modulus of irradiated PA66 nanofibers with TAC was less than PA66 nanofibers.

• Journal of Radiation Industry
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• v.9 no.2
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• pp.57-62
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• 2015

In this study, we fabricated effect of storage conditions on graft of polypropylene (PP) non-woven fabric induced by electron beam. The electron beam irradiations on PP non-woven fabric were carried out over a range of irradiation doses from 25 to 100 kGy to make free radicals on fabric surface. The radical measurement was established by electron spin resonance (ESR) for confirming the changes of the alkyl radical and peroxy radical according to effect of storage time, storage temperature and atmosphere. It was observed that the free radicals were increased with irradiation dose and decreased with storage time due to the continuous oxidation. However, the radical extinction was significantly delayed due to reduced mobility of radicals at extremely low temperature. The degree of graft based on the analysis of ESR was investigated. The conditions of graft reaction were set at a temperature: $60^{\circ}C$, reaction time: 6 hours and styrene monomer concentration: 20 wt%.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.199-204
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• 2016

The dependence of cell survival on exposure dose and the duration of the liquid-holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3335-3343
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• 2021

The impact of gamma radiation on a commercial off the shelf microcontroller board has been investigated. Three different tests have been performed to ascertain the radiation tolerance of the device from a nuclear decommissioning deployment perspective. The first test analyses the effect of radiation on the output voltage of the on-board voltage regulator during irradiation. The second test evaluated the effect of gamma radiation on the voltage characteristics of analogue and digital inputs and outputs. The final test analyses the functionality of the microcontroller when using an external, shielded voltage regulator instead of the on-board voltage regulator. The results suggest that a series of latch-ups occurs in the microcontroller during irradiation, causing increased current drain which can damage the voltage regulator if it does not have short-circuit protection. The analogue to digital conversion functionality appears to be more sensitive to gamma radiation than digital and analogue output functionality. Using an external, shielded voltage regulator can prove beneficial when used for certain applications. The collected data suggests that detaching the voltage regulator can extend the lifespan of the platform up to approximately 350 Gy.

• Journal of Medicine and Life Science
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• v.16 no.1
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• pp.23-26
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• 2019

Total scalp irradiation is a challenging treatment because of unique concave target volume and difficulty with bolus applying. There are few reports about bolus applying methods to the entire scalp in detail. Application of conventional bolus (wax or superflab) is widely used, and it is considered effective. However, the curvature and irregularity of the scalp can produce significant air gap, resulting in inadequate radiation dose distribution. We describe a new method to applying the bolus to the entire scalp. We sutured 1 cm thickness superflab bolus on the thermoplastic mask using cotton string. This method can reduce the air gap between the bolus and scalp and be reproducible.

• 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).