• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.1210-1210
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• 2004

• Journal of Radiation Industry
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• v.4 no.3
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• pp.203-207
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• 2010

Radiation-induced late injury to normal tissue is a primary area of radiation biology research. The present study was undertaken to investigate whether the late effect of the ionizing radiation appears as an age-related oxidative status in the brain. Three groups of 4-month old C57BL/6 mice that were exposed to $^{137}Cs$ ${\gamma}-rays$ at a single dose (5 Gy) or fractionated doses ($1Gy{\times}5times$, or $0.2Gy{\times}25times$) at 2 months old were investigated for the oxidative status of their brains with both young (2-month) and old (24-month) mice. A significant (p<0.05) decrease in superoxide dismutase (SOD) activity was observed in old mice brains compared with that of the young mice. malondialdehyde (MDA) content was significantly (p<0.05) increased in the old mice brain. However, any significant difference in SOD activity and MDA contents of the irradiated brain was not observed compared to age-matched control group mice. SOD activity and MDA content were observed within good parameters of brain aging and there were no late effects on the age-related oxidative level in the ${\gamma}-ray$ irradiated mice brains.

• Molecules and Cells
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• v.19 no.1
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• pp.143-148
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• 2005

Heptaplatin, cis-malonato [(4R,5R)-4,5-bis (amino-methyl)-2-isopropyl-1,3-dioxolane] platinum(II) (SKI-2053R, Sunpla) is a new platinum derivative with antitumor activity comparable to cisplatin on various cancer cell lines. Preclinical studies suggest that it is less nephrotoxic than cisplatin. This study was undertaken to examine the combined effect of heptaplatin and ionizing radiation on two established human squamous carcinoma cell lines (NCI-H520, SQ20B). The cytotoxic activity of heptaplatin was concentration-dependent in both cell lines. When low dose heptaplatin was combined with high dose ionizing radiation, there was an additive cytotoxic effect on NCI-H520 cells (P < 0.05), while a moderate dose of heptaplatin and a low dose of ionizing radiation had an additive cytotoxic effect on the growth of SQ20B cells (P < 0.05). FACS analysis and DAPI staining showed that their additive cytotoxic effects were correlated with the induction of apoptosis. Further studies are warranted using heptaplatin and ionizing radiation in squamous cell carcinoma as a substitute for cisplatin.

• International Journal of Air-Conditioning and Refrigeration
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• v.10 no.3
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• pp.162-175
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• 2002

To investigate smoke movement with radiation in a room fires, a numerical and experi-mental analysis were performed. In this paper, results from a field model based on a self-developed SMEP (Smoke Movement Estimating Program) were compared with Stockier's ex-periment and the experiments on various sized pool fires in a room with door The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k- $\varepsilon$ turbulence model with buoyancy term. Also it solves the radiation equation using the S-N discrete ordinates method (DOM). The result of the cal-culated smoke temperature considering radiation effect has shown good agreement compared with the experimental data, although there are large discrepancy in the hot smoke layer be-tween the temperature predicted by the SMEP with only convection effect and obtained by the experimental result. This large discrepancy is caused from the radiation effect of $H_2O$ and $CO_2$ gas under smoke productions. Hence the radiation effect under smoke in fire is the point to be specially considered in order to produce more realistic result.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1605-1610
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• 2015

The present study has been accomplished to elucidate the effect of radiation heat transfer in the heat transfer analysis of refrigerator gasket, which has near 30% of refrigerator heat loss. The numerical heat transfer analysis has been conducted with the simplified modeling of refrigerator gasket. From the present CFD analysis, heat loss at the gasket is $25.6W/m^2$ for the case without radiation effect and that for the case with radiation effect is $55.0W/m^2$, which is 2.2 times greater heat loss. The radiation protection layers were installed in the gasket from 0 to 7 and the case with 7 layers has 33% reduction effect of heat loss compared with the case without any radiation protection layer. Additionally, it is better effect of radiation heat loss reduction that the radiation protection layers would be placed to the outer or inner side of gasket rather than placing to the center of gasket.

• Biomolecules & Therapeutics
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• v.13 no.4
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• pp.220-226
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• 2005

The present study was performed to evaluate combination effect of 7$\beta$-hydroxycholesterol (7$\beta$-OHC) and $\gamma$-radiation in NCI-H460 human lung cancer cells. 7$\beta$-OHC in combination with $\gamma$-irradiation has an enhanced effect in decreasing clonogenic survival and increasing cellular DNA damage. Pretreatment of cells with 7$\beta$-OHC enhanced radiation-induced apoptosis. Apoptosis of the cells by combined treatment of 7$\beta$-OHC and $\gamma$-irradiation was associated with reactive oxygen species generation and loss of mitochondrial membrane potential, resulting in the activation of caspase 9 and caspase 3. The combined treatment also resulted in an increased G1 cell cycle distribution. These results indicate that 7$\beta$-OHC shows the additive effect of radiation sensitivity in human lung carcinoma cells in vitro.

• Current Optics and Photonics
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• v.1 no.4
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• pp.263-270
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• 2017

Solar radiation data measured by pyranometers is of fundamental use in various fields. In the field of atmospheric optics, the measurement of solar energy must be precise, and the equipment needs to be maintained frequently. However, there seem to be many errors with the existing type of pyranometer, which is an element of the solar-energy observation apparatus. In particular, the error caused by the thermal dome effect occurs because of the thermal offset generated from a temperature difference between outer dome and inner casing. To resolve the thermal dome effect, intensive observation was conducted using the method and instrument designed by Ji and Tsay. The characteristics of the observed global solar radiation were analyzed by classifying the observation period into clear, cloudy, and rainy cases. For the clear-weather case, the temperature difference between the pyranometer's case and dome was highest, and the thermal dome effect was $0.88MJ\;m^{-2}\;day^{-1}$. Meanwhile, the thermal dome effect in the cloudy case was $0.69MJ\;m^{-2}\;day^{-1}$, because the reduced global solar radiation thus reduced the temperature difference between case and dome. In addition, the rainy case had the smallest temperature difference of $0.21MJ\;m^{-2}\;day^{-1}$. The quantification of this thermal dome effect with respect to the daily accumulated global solar radiation gives calculated errors in the cloudy, rainy, and clear cases of 6.53%, 6.38%, and 5.41% respectively.

• International Journal of Contents
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• v.8 no.4
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• pp.64-69
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• 2012

The heart is a major dose-limiting organ for radiotherapy of cancer in the thoracic region. The purpose of this study was to examine the protective effect of tranilast on the radiation-induced heart fibrosis model using the C57BL/6 murine strain. A significant reduction in the expression of TGF-${\beta}1$, collagen type I and collagen type III was observed in the radiation plus tranilast group. The authors also suggest the use of tranilast in a clinical trial for the prevention of radiation-induced heart fibrosis.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1022-1023
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• 2005

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.331-344
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• 1987

A numerical analysis has been conducted on the interaction of the thermal radiation and natural convection in a rectangular enclosure filled with a gray fluid. P-1 approximation is adopted for the radiative transfer and its application limit is examined. Considered are the Stark number effect, the optical thickness effect and the wall emissivity effect on the flow and heat transfer characteristics. As the Stark number increase or the optical thickness decreases, the boundary layer thickness and the flow velocity increase. Transition to turbulence is retarded with the increase of the radiation effect. When the optical thickness is one, the radiation effect is negligible for the Stark numbers larger than 10.