• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1210-1210
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• 2004

• 방사선산업학회지
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• 제4권3호
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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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• 제19권1호
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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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• 제10권3호
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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.

• 한국산학기술학회논문지
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• 제16권3호
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• pp.1605-1610
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• 2015

본 논문은 냉장고의 열손실의 약 30%를 차지하고 있는 가스켓 주위의 열전달 해석시 복사열전달을 고려하지 않은 경우와 고려한 경우가 많은 차이가 있어서 가스켓 주위의 열전달 해석시 복사열전달 고려 여부에 따른 열손실 효과를 살펴보는 연구이다. 이를 위해 가스켓 주위를 단순화한 형상으로 모델링하여 열전달 전산해석을 수행하였다. 본 연구를 통해서 가스켓 내부의 공기층을 단순히 전도열전달만 고려한 경우 열손실이 $25.6W/m^2$이고 복사열전달을 함께 고려한 경우 $55.0W/m^2$로 약 2.2배 크게 나타남을 알 수 있었다. 가스켓 내부에 복사열전달 차단판을 0에서 7개로 변화하면서 복사열전달 저감 효과를 살펴본 결과 차단판 개수가 증가하여 7개 인 경우는 설치하지 않은 경우에 비하여 열손실이 $55.0W/m^2$에서 $36.7W/m^2$로 33% 감소함을 알 수 있었다. 또한 같은 개수의 복사 차단판일 경우는 냉장고 내부와 외부에 치우치는 쪽으로 설치하는 것이 가스켓의 가운데에 설치하는 것 보다 효과적임을 알 수 있었다.

• Biomolecules & Therapeutics
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• 제13권4호
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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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• 제1권4호
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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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• 제8권4호
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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.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.1022-1023
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• 2005

• 대한기계학회논문집
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• 제11권2호
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• pp.331-344
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• 1987

본 연구에서는 직사각형 밀폐공간내에서 자연대류와 복사의 상호 영향에 대해 서 P-1 근사를 이용하여 수치적으로 해석하였다.밀폐공간내에서의 온도분포, 속도 분포 및 열전달계수를 구하였으며 열경계층내에서의 전도와 복사의 상호 영향에 대하 여 고찰하였다. 표면 복사만이 존재하는 경우에 대해서도 고찰함으로써 P-1 근사의 적용한계를 규명하였다. 벽면을 산광 방사 및 반사체(diffuse emitter and reflec- tor)로, 기체는 회색체(gray body)로 가정하였다. 이는 복사 물성치의 파장에 따른 변화를 고려할 때의 대단히 복잡한 계산 과정을 피할 수 있고, 현재의 이론적 수준에 비추어 복사 열전달의 열향을 정성적으로 규명하는데 타당한 가정이다.