• Journal of Radiation Protection and Research
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• v.42 no.2
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• pp.98-105
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• 2017

Background: By examining the safety issues involved in on-site training sessions conducted at specialized vocational high schools, and by analyzing the effects of non-destructive testing (NDT) safety training, this study aims to contribute to ensuring the general safety of high school students. Materials and Methods: Students who expressed an interest in participation were surveyed regarding current NDT training practices, as well as NDT safety training. A total of 361 students from 4 schools participated in this study; 37.7% (136 students) were from the Seoul metropolitan area and 62.3% (225 students) were from other areas. Results and Discussion: Of the respondents, 2.2% (8 students) reported having engaged in NDT. As a result of safety training, statistically significant improvements were observed in most areas, except for individuals with previous NDT experience. The areas of improvement included safety awareness, acquisition of knowledge, subjective knowledge levels, objective knowledge levels, and adjustments to existing personal attitudes. Conclusion: Even at absolutely necessary observation-only training sessions, it is crucial that sufficient safety training and additional safety measures be adequately provided.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.34.1-34.1
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• 2011

Combining a detailed non-grey radiative transfer computation with the three dimensional hydrodynamics, we investigate a reliable numerical scheme for turbulent convection in the solar surface. The solar photosphere is the extremely turbulent region composed of partly ionized compressible gases in high temperature. Especially, the super adiabatic layer (SAL) near the solar photosphere is the shallow transition region where the energy transport varies steeply from convection to radiation. In order to describe physical processes accurately, a detailed treatment of radiative transfer should be considered as well as the high resolution computation of fluid dynamics. For a direct computation of radiation fields, the Accelerated Lambda Iteration (ALI) methods have been applied to hydrodynamical medium, incorporating the Opacity Distribution Function (ODF) as a realistic schemes for non-grey problems. Computational domain is the rectangular box of dimensions $42{\times}3Mn$ with the resolution of $1202{\times}190$ meshed grids, which covers several granules horizontally and 8 ~ 9 pressure scale heights vertically. During several convective turn-over times, the 3-D snapshots have been compiled with a second order accuracy. In addition, our radiation-hydrodynamical computation has been compared with the classical approximations such as grey atmospheres and Eddington approximation.

• Radiation Oncology Journal
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• v.25 no.2
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• pp.101-108
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• 2007

[ $\underline{Purpose}$ ]: To compare radiation therapy alone to combined modality therapy about survival rate and tolerance of elderly patients ($70=or{\geq}$) with non-small-cell lung cancer (NSCLC). $\underline{Materials\;and\;Methods}$: Between 1998 and 2002, 57 patients given radiation therapy due to NSCLC (Stage III) were analysed retrospectively. Radiation therapy alone (RT), concurrent chemoradiation (CRT), and sequential chemoradiation (SCRT) was done to 33, 16 and 8 patients, respectively. Patients' median age was 74 (range $70{\sim}85$). Male and female are 51 patients and 6 patients, respectively. 23 patients were stage IIIa and 34 were stage IIIb. Patients' characteristic distribution of RT and CRT was not significantly different except mass size that RT has a bigger than CRT. The fraction size of radiation therapy was 1.8 Gy in CRT and $1.8{\sim}3\;Gy$ in other groups. Total radiation dose was $51{\sim}63\;Gy$ according to the fraction size. If the prescribed total radiation dose was successfully irradiated, we stated that it was completion of radiation therapy. $\underline{Results}$: 52 patients were dead. Median period of radiation therapy was as follow: RT, 35 days, CRT, 60.5 days and SCRT, 35 days. Overall median survival time (MST) was 10.1 months. The 1 yr- and 2 yr-overall survival rate was 39.8% and 17.6%, respectively. MST of RT, CRT and SCRT was 8.9, 8.2 and 11.7 months, respectively. The 1 yr survival rate of RT, CRT and SCRT was 38.4%, 37.5% and 50% (not significant). Patients given incomplete radiation therapy were 12 (RT, 5 CRT, 6 SCRT, 1). N stage (p=0.081) and the difference of treatment methods (p=0.079) were the factors affecting incompletion of radiation therapy, but it was not significant. In case of combined-agents chemotherapy, 4 of 8 ceased radiation therapy. T stage ($T{\geq}3$), mass size (${\geq}5\;cm$), Karnofsky performance scale (${\leq}70$) and completion of radiation therapy were the prognostic factors in uni- and multi-variate analysis. $\underline{Conclusion}$: In elderly patients with NSCLC, radiation therapy alone was a treatment method with similar survival period compared with other methods. Generally, patients given radiation therapy alone was tolerable to a treatment. Before planning concurrent chemoirradiation in elderly patients with NSCLC, physicians pay attention to a selection of patients and chemotherapy agents considering general condition and toxicity.

• Journal of Radiation Protection and Research
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• v.47 no.1
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• pp.1-7
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• 2022

Background: In Japan, new regulations that revise the dose limit for the lens of the eye (hereafter the lens), operational quantities, and measurement positions for the lens dose were enforced in April 2021. Based on the international safety standards, national guidelines, the results of the Radiation Safety Research Promotion Fund of the Nuclear Regulation Authority, and other studies, the Working Group of Radiation Protection Standardization Committee, the Japan Health Physics Society (JHPS) developed a guideline for radiation dose monitoring for the lens. Materials and Methods: The Working Group of the JHPS discussed the criteria of non-uniform exposure and the management criteria set not to exceed the dose limit for the lens. Results and Discussion: In July 2020, the JHPS guideline was published. The guideline consists of three parts: main text, explanations, and 26 examples. In the questions, the corresponding answers were prepared, and specific examples were provided to enable similar cases to be addressed. Conclusion: With the development of the guideline on radiation dose monitoring of the lens, radiation managers and workers will be able to smoothly comply with revised regulations and optimize radiation protection.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.256-260
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• 2015

Purpose: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. Materials and Methods: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or $100{\mu}M$) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. Results: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at $100{\mu}M$ of MEF (38% decrease), providing maximal protection against ionizing radiation. Conclusion: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7559-7562
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• 2014

Currently the most important prognostic factor in lung cancer is the stage. In the current lung TNM classification system, N category is defined exclusively by anatomic nodal location though, in other type of tumours, number of lymph nodes is confirmed to be a fundamental prognostic factor. Therefore we evaluated the number of mediastinal lymph nodes as a prognostic factor in locally advanced NSCLC after multimodality treatment, observing a significant effect of the number of lymph nodes in terms of OS (p<0.01) and DFS (p<0.001): patients with a low number of positive mediastinal nodes have a better prognosis.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.209-219
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• 2013

RI-Biomics field comes into the limelight as a new fusion radiation technology. These rapid development of RI-Biomics cause the necessity of establishment of a new methodical education program model for consistent training of professional manpower in RI-ADME, Biomics field. But domestic current status is not satisfied to training human resource development in RI-Biomics. Actually domestic educational organization related to RI-Biomics just run educational programs oriented basic theory, so practical and fusion education are not existed nowadays for preliminary RI-Biomics expert. Therefore we established a new education program model for educate of the expert in RI-Biomics field to overcome current problem about the route of knowledge that has more monotonous and concentrated tendency and non-professional education. To improve universality and practicality, we conduct education-training model survey about domestic and foreign country. This new human resource development model will contribute to fostering new expert in RI-Biomics field.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.42-48
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• 2013

The $CO_2$ suppression characteristics and flame structure of nitrogen-diluted methane counterflow non-premixed flame were studied experimentally and numerically. To mimic a situation where combustion product gases are entrained into a compartment fire, fuel stream was diluted with $N_2$. A gas-phase suppression agent, $CO_2$, was diluted in the air-stream to investigate the suppression characteristics by the agent. For numerical simulation, an one-dimensional OPPDIF code was used for comparison with experimental results. An optically-thin radiation model(OTM) was adopted to consider radiation effects on the suppression characteristics. It was confirmed experimentally and numerically that suppression limit decreased with increasing nitrogen mole fraction in the fuel stream. A turning point was found only when a radiation heat loss was considered and the extinguishing concentration for turning point was differently predicted compared to the experiment result. Critical extinguishing concentration when neglecting radiation heat loss was also differently predicted compared with the experimental result.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.306-310
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• 2005

Exposure to UVB radiation can cause diverse biological photodamage to skin. Eeb 761 and Korean red ginseng are the major and most effective natural drug against a variety of oxidative damage. But, the protective effects against UVB radiation have not been clearly identified. In this study, we investigated the protective effect of topical EGb 761 and Korean red ginseng on pigmentation by UVB radiation. Pro-inflammatory cytokines($IL-l{\beta}$, IL-6 and $TNF-{\alpha}$) and melanogenesis proteins(tyrosinase, TRP-1 and TRP-2) mRNA were measured by reverse transcription-polymerase chain reaction(RT-PCR) analysis. The in vivo protection against pigmentation was calculated using chromameter. The mRNA level of IL-lf and TNF-a were increased by UVB irradiation in treated and non-treated group, while no significant changes were observed in IL-6 level. Topical treatment with EGb 761 and Korean red ginseng remarkably reduced expression of tyrosinase, TRP-1 and TRP-2 in the non-irradiated and irradiated skin. Application of EGb 761 and Korean red ginseng significantly protected the WB-induced skin pigmentation and Korean red ginseng was more effective. Our study suggests that topical ECb761 and Korean red ginseng can regulate melanogenic proteins and protect UVB radiation on skin pigmentation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.3
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• pp.43-49
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• 2010

Recently, the use of fumigants for pest control of paper cultural heritages are limited because of the high toxicity of fumigants and the production of environment-harmfully compounds. Therefore, many non-chemical methods have been discussed and experimented. And it is recently focused on gamma radiation, which is one of non-chemical methods, for pest control of paper cultural heritage in Korea. In this paper, we carried out a gamma ray irradiation of papers including Hanji, copy paper, filter paper and then analyzed a physical properties and optical properties of paper sample to estimate the effect of gamma ray irradiation on paper properties. In result, gamma radiation have adverse effect on a physical properties and optical properties of paper, especially Hanji. Therefore, we have to carefully consider about using of gamma ray for pest control of paper cultural heritages.