• Journal of Environmental Health Sciences
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• v.8 no.1
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• pp.81-97
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• 1982

Ethylene oxide gas has been used as a cold sterilant for heat-sensitive medical equipments and as a fumigant for food for more than 30 years, and it is used more widely than radiation although radiation sterilization has made significant inroads in recent years. But according to recent studies of toxicities such as mutagenicity, haemolytic effect and possible carcinogenicity of Ethylene oxide (ETO) and its two main reaction products, Ethylene chlorohydrin (ETCH) and Ethylene glycol (ETG), Environmental Protection Agency in U.S.A. has suggested some regulations on residual gas in drug products and medical devices for human use. The mutagenic activity of ETO compared with that of X-ray has an equivalency of 1 ppm/hr for ETO as compared to 20 mrad for X-ray, and one could suggest the present maximum allowable concentration for ETO (50 ppm) should be 400 times lower than the radiation standard (2.5 mrad/hr). Although radiation sterilization has advantages of simplicity of operation and complete reliability, changes of physico-chemical properties with possible formation of toxic substances may occur. It is therefore necessary to make some regulations of our own for residual toxicities orginated from each sterilization method.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1781-1788
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• 2022

The containment building Kori Unit 1 may require sequential steps for full decommissioning. This study assumes that the containment building is to be used as an auxiliary building that handles nuclear power systems and materials during decommissioning before conversion into a greenfield. Through the derivation of guidelines and dose evaluation, it was confirmed whether the radiation workers were satisfied with the ALARA decision. The specific modeling of the external radiation exposure was performed based on the facility investigation procedures. The external radiation specific derived concentration guideline levels (DCGLs) for radiation workers in containment building were obtained using the RESRAD-BUILD code and were applied to the VISIPLAN 3D ALARA Planning Tool code to calculate the working dose and check worker safety. The derivation of site-specific and realistic DCGLs and dose evaluation via 3D modeling can contribute to the scenario development for the decommission and remediation of containment building.

• 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.

• Journal of Nutrition and Health
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• v.39 no.2
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• pp.115-120
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• 2006

The purpose of this study is to investigate the concentration of plasma choline of Korean and to clarify the relationship between plasma choline concentration and choline intake. Plasma choline concentration of 30 young adults (15 males, 15 females) aged 20-30 years living in Deajeon metropolitan city are analyzed and their dietary choline intake. Choline content of one day meal was directly analyzed with the use of enzymatic method. Plasma choline concentration from more than 12 hr fasting blood was analyzed by using HPLC-MS. Choline intakes of male subjects were in the range of 253.51-1724.14 mg and those of female subjects were in the range of 240.85-938.06 mg. Mean intakes of choline were $634.53{\pm}353.68mg$ in male subjects and $473.99{\pm}183.76mg$ in female subjects. Plasma choline concentration of total subjects was in the range of 5.08-14.01 ${\mu}mol/L$. Mean plasma choline concentration was $9.19{\pm}2.05{\mu}mol/L$ in male subjects and $8.11{\pm}1.70{\mu}mol/L$ in female subjects. Plasma choline concentration did not show significant correlation with choline intake in male and total subjects, but showed positive correlation with choline intake in female subjects (p<0.05). This result shows that more studies on large scaled samples are needed.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.183-190
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• 2013

Mistletoe (Viscum album) has been widely used as a functional food material for various therapeutic purposes from ancient time. In this study, we examined anti-diabetic and cytotoxic activities of heated-treated mistletoe and the effects of gamma-irradiation on its activities. Heat-treated mistletoe extract was prepared by heating during different time (3, 6, 9 and 12 h) and gamma-irradiated with different doses of 0, 10, 30, 50, 70 and 100 kGy. Heat-treated mistletoe extracts showed a concentration-dependent cytotoxicity on rat insulinoma RINm5F cells and the effect was gradually decreased as heating time increased up to 12 h. 12 h heat-treated extract was no cytotoxic. Gamma-irradiation enhanced the reduction of heat-treated mistletoe-induced cytotoxicity and the decreasing effect was an irradiating dose-dependent. In particular, all of 70 kGy irradiated and heat-treated mistletoe extracts did not showed the cytotoxicity and the effect was comparable to 12 h heat-treated mistletoe extract. Among those extracts, 3 h heat-treated mistletoe extract gradually increased the insulin secreting activity by gamma-irradiation and the effect was the best at 70 kGy, whereas 12 heat-treated extract was no effect. On the test of ${\alpha}$-glucosidase inhibitory activity, 3 h heat-treated mistletoe extract showed the concentration dependent effects and gamma-irradiation induced more activity at 70 kGy, compared to non-irradiated 3 h and 12 h heated mistletoe extracts. These results suggest that the combination of heat treatment and gamma-irradiation might be more effective than only heat-treatment for improving the anti-diabetic activity of mistletoe extract and reducing its cytotoxicity.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.5
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• pp.604-612
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• 2008

The ozone concentration is one of the important environmental issue for measurement of the atmospheric condition of the country. This study focuses on applying the Autoregressive Error (ARE) model for analyzing the ozone data at middle part of the Gyeonggi-Do, Anyang monitoring site in Korea. In the ARE model, eight meteorological variables and four pollution variables are used as the explanatory variables. The eight meteorological variables are daily maximum temperature, wind speed, amount of cloud, global radiation, relative humidity, rainfall, dew point temperature, and water vapor pressure. The four air pollution variables are sulfur dioxide $(SO_2)$, nitrogen dioxide $(NO_2)$, carbon monoxide (CO), and particulate matter 10 (PM10). The result shows that ARE models both overall and monthly data are suited for describing the oBone concentration. In the ARE model for overall ozone data, ozone concentration can be explained about 71% to by the PM10, global radiation and wind speed. Also the four types of ARE models for high level of ozone data (over 80 ppb) have been analyzed. In the best ARE model for high level of ozone data, ozone can be explained about 96% by the PM10, daliy maximum temperature, and cloud amount.

• Journal of Power System Engineering
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• v.16 no.4
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• pp.5-11
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• 2012

There were some papers for diesel engine performance tests using BDF, but few article deals with the temperature and soot concentration of Bio diesel flame. Since the flame temperature of diesel engines is so high and change rapidly, an optical method for measurement of flame temperature is known as the most effective one. The two-color method regarding the visible wavelength radiation for the soot particles in flame was applied on Bio diesel flame in order to measure flame temperature and soot concentration in a diesel engine. Photo detecting device was newly designed and employed TSL250R, photo-diode, to pick-up the light information emitted from the combustion flame. As a result, real flame temperature T, as a flame brightness temperature, through Ta1, Ta2, were obtained and finally the characteristics of KL value as a soot concentration reveal the difference of combustion information between diesel fuel, blending oil and Bio diesel fuel oil.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.9
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• pp.2933-2943
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• 1996

A grating composed of elliptical cylinders (GEC), specially designed, is applicable to control of radiation heat transfer from a heated surface, as reported in our previous work. In this study, an analysis of radiation heat transfer is performed for a physical model in which the GEC is placed in front of a heated black-base surface and the major axes of the elliptical cylinders are inclined as a certain angle from the normal to the row of elliptical cylinders. Numerical solutions are obtained. Variations of the direction and the radiative energy concentration with slant angle of the major axis are shown for some parameters. It is verified that the GEC is able to widely change the direction of radiation heat transfer from the heated surface.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.858-867
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• 1995

Characteristics of premixed flames in counter-flow system are numerically studied using a detailed chemical reaction mechanism including gas phase radiation. Without radiation effect accounted, low CO and high NO$_{x}$ emission indices are observed, when strain rate decreases, due to increased residence time and higher flame temperature. Higher NO$_{2}$ production has been also observed when two premixed flames are interacting or cold air stream is mixed with burned gas. The rate of NO$_{x}$ production and destruction is dependent upon the diffusional strength of H and OH radicals, the existence of NO and the concentration of HO$_{2}$. For radiating flames, the peak temperature and NO$_{x}$ production rate decreases as the strain rate decreases. At high strain rate, it is found that the effect of radiation on flame is little due to its negligible radiating volume. It is also found that NO$_{x}$ production from the interacting premixed flame is reduced due to reduced temperature resulting from radiation heat loss. It is concluded that the radiation from gas has significant effect of flame structure and on emission characteristics.ristics.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.365-372
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• 2010

Irradiation has been recognized as a highly suitable tool to aid in the formation of hydrogel. The radiation process has various advantage, such as easy process control and the lack of necessity for initiators and crosslinker. In this study, the hydrogel containing the citrus fermentation gel for the wound healing were successfully synthesized. The strength of hydrogel was increased as a function of a increasing the concentration of citrus and the irradiation doses. In addition, this hydrogel have been evaluated by the cytotoxicity and animal experiment.