• Journal of Broadcast Engineering
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• v.23 no.6
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• pp.925-930
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• 2018

In this paper, we present a low profile dual-microstripline-fed double 4-arrayed meander monopole antenna with a cross-type element back by separated four-segments mesh-type reflector. The cross-type element and separated four-segments mesh-type reflector leads to enhance radiation patterns and antenna gain characteristics. The measurement value of the proposed antenna show that it has dipole-like radiation pattern characteristics. The experimental peak gain of fabricated antenna is about 2.89 dBi, which presents relatively high gain characteristics for a low profile(small-size) one. This antenna can be applied mobile RFID(radio frequency identification) readers, small medical instruments, broadcasting and home-networking operations, and other low profile high-gain systems.

• Radiation Oncology Journal
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• v.35 no.2
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• pp.137-143
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• 2017

Purpose: To analyze the utilization and fractionation of extreme hypofractionation via stereotactic body radiotherapy (SBRT) in the treatment of prostate cancer. Materials and Methods: Data was analyzed on men diagnosed with localized prostate cancer between 2004-2012 and treated with definitive-intent radiation therapy, as captured in the National Cancer Database. This database is a hospital-based registry that collects an estimated 70% of all diagnosed malignancies in the United States. Results: There were 299,186 patients identified, of which 4,962 (1.7%) were identified as receiving SBRT as primary treatment. Of those men, 2,082 had low risk disease (42.0%), 2,201 had intermediate risk disease (44.4%), and 679 had high risk disease (13.7%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012. Initially SBRT was more commonly used in academic programs, though as time progressed there was a shift to favor an increased absolute number of men treated in the community setting. Delivery of five separate treatments was the most commonly utilized fractionation pattern, with 4,635 patients (91.3%) receiving this number of treatments. The most common dosing pattern was $725cGy{\times}5fractions$ (49.6%) followed by $700cGy{\times}5fractions$ (21.3%). Conclusions: Extreme hypofractionation via SBRT is slowly increasing acceptance. Currently $700-725cGy{\times}5fractions$ appears to be the most commonly employed scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of this modality is expected to continue to increase.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.458-464
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• 2005

This study was conducted to evaluate the effect of gamma irradiation for the reduction of an egg allergy in a cake with the irradiated egg white. A white layer cake was manufactured including 10- or 20-kGy-irradiated egg white. Enzyme-Iinked immunosorbent assays (ELISAs) with immunoglobulin (Ig) E from egg-allergic patient and with rabbit anti-ovalbumin (OVA) IgG were used to identify and quantify native OVA in the samples. Concentrations of native OVA detected by IgE and IgG in the control were $432.88{\mu}g/g$ sanple and $375.46{\mu}g/g$ sample, respectively. However, native OVA in white layer cake prepared with 10- and 20-kGy-irradiated egg white were detected at low concentrations detected by IgE to 14.27 and $8.78{\mu}g/g$ sample, respectively. Whereas, IgG recognized OVA more often in 10- and 20-kGy samples than in control. The result appear to suggest that irradiating egg white might reduce ie allergenicity by the conformational change of OVA. Therefore, gamma irradiation could utilize reduce an egg allergy.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.115-121
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• 2015

This study was conducted to confirm quality properties of sterilized Ganjang-gejang (marinated crab Portunus trituberculatus) with Korean soy sauce using by gamma irradiation and to improve quality of sterilized Ganjang-gejang. The Ganjang-gejang was irradiated at dose of 3, 6, 9, 12, and 15 kGy by gamma irradiation and there was evaluated in microbiological, physicochemical, and sensory properties. Total aerobic bacteria and fungi contents of non-irradiated samples were about 6 and 4 log CFU/g level, respectively. Gamma-irradiated samples at above 9 kGy did not contain aerobic bacteria or fungi at detection limit less than 2 log CFU/g, but sensory scores were significantly decreased depending on the irradiation dose. To improve the sensory qualities of gamma-irradiated Ganjang-gejang, the temperature was adjusted during sample irradiation. When samples were irradiated under freezing temperatures, especially on dry ice, the TBARS and the deterioration of sensory qualities of Ganjan-Gejang were reduced. Different odor patterns were observed among samples, as observed using electronic nose analysis system. The results of this study indicated that treatment with irradiation under low temperatures may help to preparing high-quality Ganjang-gejang.

• Radiation Oncology Journal
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• v.30 no.1
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• pp.27-35
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• 2012

Purpose: To evaluate the effect of common three photon energies (6-MV, 10-MV, and 15-MV) on intensity-modulated radiation therapy (IMRT) plans to treat prostate cancer patients. Materials and Methods: Twenty patients with prostate cancer treated locally to 81.0 Gy were retrospectively studied. 6-MV, 10-MV, and 15-MV IMRT plans for each patient were generated using suitable planning objectives, dose constraints, and 8-field setting. The plans were analyzed in terms of dose-volume histogram for the target coverage, dose conformity, organs at risk (OAR) sparing, and normal tissue integral dose. Results: Regardless of the energies chosen at the plans, the target coverage, conformity, and homogeneity of the plans were similar. However, there was a significant dose increase in rectal wall and femoral heads for 6-MV compared to those for 10-MV and 15-MV. The $V_{20Gy}$ of rectal wall with 6-MV, 10-MV, and 15-MV were 95.6%, 88.4%, and 89.4% while the mean dose to femoral heads were 31.7, 25.9, and 26.3 Gy, respectively. Integral doses to the normal tissues in higher energy (10-MV and 15-MV) plans were reduced by about 7%. Overall, integral doses in mid and low dose regions in 6-MV plans were increased by up to 13%. Conclusion: In this study, 10-MV prostate IMRT plans showed better OAR sparing and less integral doses than the 6-MV. The biological and clinical significance of this finding remains to be determined afterward, considering neutron dose contribution.

• The Korean Journal of Pain
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• v.33 no.1
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• pp.73-80
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• 2020

Background: The aim of this study was to evaluate radiation exposure to the eye and thyroid in pain physicians during the fluoroscopy-guided cervical epidural block (CEB). Methods: Two pain physicians (a fellow and a professor) who regularly performed C-arm fluoroscopy-guided CEBs were included. Seven dosimeters were used to measure radiation exposure, five of which were placed on the physician (forehead, inside and outside of the thyroid protector, and inside and outside of the lead apron) and two were used as controls. Patient age, sex, height, and weight were noted, as were radiation exposure time, absorbed radiation dose, and distance from the X-ray field center to the physician. Results: One hundred CEB procedures using C-arm fluoroscopy were performed on comparable patients. Only the distance from the X-ray field center to the physician was significantly different between the two physicians (fellow: 37.5 ± 2.1 cm, professor: 41.2 ± 3.6 cm, P = 0.03). The use of lead-based protection effectively decreased the absorbed radiation dose by up to 35%. Conclusions: Although there was no difference in radiation exposure between the professor and the fellow, there was a difference in the distance from the X-ray field during the CEBs. Further, radiation exposure can be minimized if proper protection (thyroid protector, leaded apron, and eyewear) is used, even if the distance between the X-ray beam and the pain physician is small. Damage from frequent, low-dose radiation exposure is not yet fully understood. Therefore, safety measures, including lead-based protection, should always be enforced.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.259-266
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• 2011

When plants undergo stress, Reactive oxygen species (ROS) which remove bad elements such as mildew and virus is activated in plant body. However, if ROS is excessively increased, plant will be harmed itself by destruction of cell and signal system and phenomenon of lipid peroxidation. In order to identify content of lipid peroxidation and activity of some enzymes scavenging ROS, phenotypical and physiological analysis was performed with two mutant lines, Till-II-877 and Till-II-894, comparing with cv. Dongan (WT). In phenotype analysis, two mutant lines give to well-conditioned growth better than WT in since 5 days after salt treatment. In enzyme activities, there was a modest difference in the content of catalase (CAT) and peroxidase (POD) between Till-II-877 and Till-II-894, two mutant lines showed high levels in CAT contents than WT. However, they express low levels in POD contents. In MDA analysis, the content of Till-II-877 was higher than that of WT, but Till-II-894 was lower. This result indicates that two mutants have different mechanism against salt stress.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.795-801
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• 2021

The designed drone-based unmanned remote radiation detection module was developed according to the needs of the nuclear power plant decommissioning workshop. Using the Geiger-Mueller tube sensitive to low-level radiation measurement, It was manufactured to measure the amount of radiation leaking into and out of the containment vessel. The drone-based radiation detection module weighs less than 200g, It can be operated inside and outside the containment vessel of a nuclear power plant. To check the performance of the designed equipment, a performance evaluation test was conducted with reference to the international standard (IEC-60864). The stability of the radiation detection module designed to meet the needs of the field the statistical rate of change by repeated measurements in the rate of change experiment to evaluate the measurement accuracy was ±4.6%. The accuracy ±7.3% in the linearity experiment to evaluate the dose rate dependence, the linear The figure satisfies the international performance evaluation standard of ±3.5%. The radiation detection module developed in this study is a customized equipment for a nuclear power plant dismantling workshop. It will be helpful for accurate measurement of space dose rate and safety management of radiation worksites in sites with a lot of radiation dust.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3854-3859
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• 2023

Background: This study aims to develop an evaluator that can quickly and accurately evaluate the shielding of low-energy industrial radiation generators. Methods: We used PyQt to develop a graphical user interface (GUI)-based program and employed the calculation methodology reported in the National Council on Radiation Protection and Measurements (NCRP)-49 for shielding calculations. We gathered the necessary factors for shielding evaluation using two libraries designed for Python, pandas and NumPy, and processed them into a database. We verified the effectiveness of the proposed program by comparing the results with those from safety reports of six domestic facilities. Results: After verifying the effectiveness of the program using the NCRP-49 example, we obtained an average error rate of 1.73%. When comparing the facility safety report and results obtained using the program, we found that the error rate was between 1.09% and 6.51%. However, facilities that did not use a defined shielding methodology were underestimated by 31.82% compared with the program (the final barrier thickness satisfied the shielding standard). Conclusion: The developed program provides a fast and accurate shielding evaluation that can assist personnel that work in radiation generator facilities and government officials in reviewing safety.

• Journal of Radiation Protection and Research
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• v.49 no.1
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• pp.29-39
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• 2024

Background: The gamma emission tomography (GET) device has been reported a reliable technique to inspect partial defects within spent nuclear fuel (SNF) of pin-by-pin level. However, the existing GET devices have low accuracy owing to the high attenuation and scatter probability for SNF inspection condition. The purpose of this study is to design and optimize a Yonsei single-photon emission computed tomography version 2 (YSECT.v.2) for fast inspection of SNF in water storage by acquisition of high-quality tomographic images. Materials and Methods: Using Geant4 (Geant4 Collaboration) and DETECT-2000 (Glenn F. Knoll et al.) Monte Carlo simulation, the geometrical structure of the proposed device was determined and its performance was evaluated for the ¹³⁷Cs source in water. In a Geant4-based assessment, proposed device was compared with the International Atomic Energy Agency (IAEA)-authenticated device for the quality of tomographic images obtained for 12 fuel sources in a 14 × 14 Westinghouse-type fuel assembly. Results and Discussion: According to the results, the length, slit width, and septal width of the collimator were determined to be 65, 2.1, and 1.5 mm, respectively, and the material and length of the trapezoidal-shaped scintillator were determined to be gadolinium aluminum gallium garnet and 45 mm, respectively. Based on the results of performance comparison between the YSECT.v.2 and IAEA's device, the proposed device showed 200 times higher performance in gamma-detection sensitivity and similar source discrimination probability. Conclusion: In this study, we optimally designed the GET device for improving the SNF inspection accuracy and evaluated its performance. Our results show that the YSECT.v.2 device could be employed for SNF inspection.