• BMB Reports
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• v.45 no.4
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• pp.242-246
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• 2012

The use of ionizing radiation (IR) is essential for treating many human cancers. However, radioresistance markedly impairs the efficacy of tumor radiotherapy. IR enhances the production of reactive oxygen species (ROS) in a variety of cells which are determinant components in the induction of apoptosis. Much interest has developed to augment the effect of radiation in tumors by combining it with radiosensitizers to improve the therapeutic ratio. In the current study, the radiosensitizing effects of resveratrol and piperine on cancer cells were evaluated. Cancer cell lines treated with these natural products exhibited significantly augmented IR-induced apoptosis and loss of mitochondrial membrane potential, presumably through enhanced ROS generation. Applying natural products as sensitizers for IR-induced apoptotic cell death offers a promising therapeutic approach to treat cancer.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.2
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• pp.266-275
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• 1995

A numerical investigation on the conduction-natural convection-surface radiation conjugate heat transfer in the enclosure having substrate and chips has been performed. A 2-dimensional simulation model is developed by considering heat transfer by conduction, convection and radiation. The solutions to the equation of radiative transfer are obtained by the discrete ordinates method using S-4 quadrature. The effects of Rayleigh number and the substrate-fluid thermal conductivity ratio on the cooling of chip are analyzed. The result shows that radiation is the dominant heat transfer mode in the enclosure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.2
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• pp.382-390
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• 1992

The problem of natural convection from a vertical fin is solved by coupling the thermal diffusion equation in the fin to the constitutive equations of the ambient medium involving the radiation of the medium. The analysis is accomplished by employing an integral method. The governing equations for the problem are solved by shooting method based on the Runge-Kutta Scheme at Pr= 0.7. For the range of values of the fin parameter and the radiation-conduction parameter in the analysis, the numerical results show that the radiation effects play an important role in the heat transfer and enhance the heat transfer.

• Journal of the Korean Society of Radiology
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• v.9 no.2
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• pp.117-120
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• 2015

The number of campers has been consistently growing thanks to the introduction of a five-day work week and the time increase for a leisure. Thus, many types of facilities for camping are constructed. For instance, there are gravel camp site, which is called crushed stone, and normal soil camp site in case of private camp sites. The amount of natural background radiation, measured from site to site, was analyzed. The value of soil camp site was lower than that of crushed stone camp site. And the amount of natural background radiation from normal camp site was also lower than that from the artificial shade made by tarp. Consequently, it is noted that normal soil camp site with the plenty of woods should be chosen for camping place in order to avoid natural background radiation.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.321-328
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• 2017

The purpose of the study is to provide basic data for the management of individual exposure and the monitoring of natural radiation dose using D-Shuttle dosimeter (Chiyoda Technol Corporation, Tokyo, Japan). The dose was calculated using D-Shuttle dosimeter. The dose was 1.346 mSv when exposed for 400 days, the annual dose per year was 1.228 mSv/year and the average dose per hour was $0.014{\mu}Sv/hr$. Domestic individual external dose (1.295 mSv/year = Korea average natural individual external dose) and domestic additional dose per year is -0.0663 mSv/year. D-Shuttle is a personal dosimeter for radiation monitoring. It can be used as a very useful dosimeter for ALARA because of its excellent detection capability of radiation, real-time radiation exposure management, alarm function of radiation work, and efficient and easy to use personal radiation dose management.. Radiation monitoring equipment for radiation workers and local residents can be used for radiation monitoring in hospitals, industry, medical sites, nuclear accident areas and hazardous areas in non-destructive areas.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.249-259
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• 2018

Radiation technology (RT) has long been applied in various fields for increasing the safety and shelf-life of foods by controlling pathogen-induced poisoning. RT was introduced for the first time in Korea in the 1950s to eliminate harmful microorganisms in food materials. In the 1980s, RT had been scientifically proven to be effective for the sterilization of food and public health products. In recent years, irradiation with gamma rays has also been used for improving physiological properties through the structural modification of natural molecules, which has been proposed to be applicable to various industries. In particular, radiation transformation technology (RTT), which involves the development of new functional compounds through the molecular conversion of natural biomaterials, is becoming a new high-value technology as a fusion technique of RT and biotechnology. The present reports have suggested that RTT can be an effective tool for the development of new functional compounds and improvement of the physiological activity of biomolecules.

• The KIPS Transactions:PartB
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• v.10B no.7
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• pp.785-794
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• 2003

Computer simulation of natural phenomena has been inclined to graphic processing for visual reality. This negligence of cosmic causalities in their occurrence and natural laws in their development should lead to limited degree of immersion to the users. We attempt to develop a logical framework for authentic simulation of diverse, unpredictable occurrence and development of natural phenomena (such as solar radiation and wind) based on their associated inherent laws and principles. To this end we structure the relevant objects organized in an ontology and propose a data management method. Then we describe our simulation method for the natural phenomena as delimited in phases and present modeling techniques for qualitative changes of physical objects due to their factors' values beyond normal ranges.

• The Journal of Korean Society for School & Community Health Education
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• v.7
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• pp.51-58
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• 2006

Background & Objectives: This study investigates the recognition on the necessity of the use of radiation for both college students who are considered that they have a high knowledge level in radiation and proposes basic materials to change the recognition of the use of radiation. Also, the investigation was applied to average people who showed the most negative attitudes on radiation. Methods: A questionnaire was applied to 600 college students for five days from October 10 to 15, 2005 and used in statistical analysis. Results: The average value obtained in the recognition of the use of radiation was 76.60 points in which male respondents who were majored in natural science, health, and engineering department and respondents who have experienced radiation related education, radiation diagnosis, and radiation treatment demonstrated higher levels. Also, the average value obtained in the recognition of the radiation damage was 71.66 points in which respondents who were majored in natural sciences, humanities, engineering, and health department showed higher levels than that of respondents who were majored in art and physical department. Groups that exhibited higher recognition levels in the necessity of the use of radiation were male respondents and respondents who were majored in natural science, humanities, and health department and have experienced radiation diagnosis and radiation treatment. In the results of the correlation analysis on the necessity of the use of radiation and recognition of radiation damages, the recognition of radiation damages was presented as negative attitudes in the case of the higher recognition level in the necessity of the use of radiation. Conclusions: Regarding the frequency of the use of radiation in Korea, a 80.9% of university students who showed a high education level had no experiences in radiation related education. Although they showed a relatively high level of 76.6 points in the recognition level of the necessity of the use of radiation, the negative attitude on the radiation damage was also presented as a high level of 71.7 points. Because the providing chance of radiation related information was limited as compared to the atomic power used in Korea and dependancy of the use of radiation, it is necessary to provide the basic information related in the use of radiation to the public. In addition, various investigations on the use of radiation and such negative attitudes are required in future for the public. Also, the correct information of the radiation safety should be delivered to the public.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.5
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• pp.952-964
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• 1992

The interaction of natural convection and radiation heat transfer in a two dimensional square enclosure containing absorbing, emitting and linear anisotropically scattering gray medium is numerically analyzed. P-1 and P-3 approximation is introduced to calculate radiation heat transfer. The effects of scattering albedo, wall emissivity, scattering anisotropy, and optical thickness on the characteristics of the flow and temperature field and heat transfer are investigated. Temperature and velocity profiles depend a great deal on the scattering albedo, and the importance of this effect increases with decrease in albelo. Planck number is another important parameter in radiation heat transfer. The increase in scattering albedo increases convection heat transfer and decreases radiation heat transfer at hot wall. However, the increase in scattering albedo decreases both convection and radiation heat transfer at cold wall. The increase in optical thickness decreases radiation heat transfer. The scattering anisotropy has important effects on the radiation heat transfer only. The highly forward scattering leads to an increase of radiation heat transfer whereas the highly backward scattering leads to an decrease of radiation heat transfer. The effect of scattering anisotropy decreases when reducing the wall emissivity.

• Journal of Radiation Protection and Research
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• v.35 no.3
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• pp.96-98
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• 2010

Medical use of radiation is increasing in recent times and its influence on the population creates almost the same amount of annual natural background radiation in industrialized countries in particular. Thus, medical radiation has become a social issue. This paper is a brief report on the status of medical exposure in Korea by way of consulting from the radiation-related medical societies in Korea.