• Title/Summary/Keyword: radiation concentration

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Preliminary assessment of derived concentration guideline level (DCGL) for a hypothetical contaminated site planned for Ninh Thuan 1 nuclear power plant project in Vietnam by using RESRAD-ONSITE code

  • Bui Thi Hoa;Yongheum Jo;Jun-Yeop Lee
    • Nuclear Engineering and Technology
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    • v.56 no.6
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    • pp.2274-2281
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    • 2024
  • RESRAD-ONSITE v7.2 code is used to assess the radiation effects on a farmer resident located in a hypothetical contaminated site planned for the first nuclear power plant project in Vietnam, namely Ninh Thuan 1, after decommissioning. Derived concentration guideline levels are preliminarily calculated for 17 radionuclides that are assumed to remain on a contaminated surface soil with an initial concentration of 1 pCi/g in the protected area of NPP site. For a reliable estimation, the site-specific conditions regarding the geological, hydrological, climate, and occupancy data gathered from the Feasibility Study Report (FSR) and relevant literatures for the Ninh Thuan 1 NPP site is employed as input parameters. The calculation results indicate that the peak of total exposure dose is estimated to be ca. 0.191 mSv/yr at the time of decommissioning, and then decrease over time. Furthermore, the protected site is assessed to be released at ca. 6.71 years after decommissioning under the regulation on radiation protection in Vietnam. Through this study, a radiation exposure model for residents living near the Ninh Thuan 1 NPP is preliminarily established by using the RESRAD-ONSITE code, which are expected to be useful for future implementation of the Ninh Thuan 1 NPP project in Vietnam.

Radiation Effects on the Flame Structure and Extinction Limit of Counterflow Partially Premixed Methane Flames Diluted with Water Vapor in the Air Stream (공기류측에 수증기가 첨가된 대향류 메탄 부분예혼합화염의 화염구조 및 소화한계에 미치는 복사효과)

  • Park, Ji-Woong;Oh, Chang Bo;Kim, Ook Joong
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.325-328
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    • 2012
  • Radiation effects on the partially premixed methane flames diluted with water vapor in the air stream were numerically investigated. OPPDIF code and GRI-v3.0 were used in the numerical simulation. Adiabatic condition was compared with two different radiation models, optically-thin and WSGGM models. It was found that the radiation effect on the flame structure for the equivalence ratio (${\Phi}$) of 2.5 was less than ${\Phi}=1.5$. Extinction limit was not affected significantly, however, local flame structure was markedly influenced by the radiation models as increasing the water vapor concentration.

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Effect of Radiotherapy on the Ascorbate (Vitamin C) Levels in Whole Blood and Plasmas (방사선 조사가 체내 아스코베이트(비타민 C)농도에 이치는 영향)

  • Choi, Gyu-Young;Yoon, Sang
    • Radiation Oncology Journal
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    • v.11 no.2
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    • pp.227-231
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    • 1993
  • The role of ascorbate as an antioxidant in the prevention and cure of disease that result from free radicals has been of considerable interest and controversy lately. As an antioxidant, we can expect it to protect against radiation damage caused by free radicals that are produced when radiation, especially sparsely ionizing radiation, interacts with living tissues. The plasma and whole blood concentration of ascorbate was analyzed before and just after the radiation therapy for the purpose of estimating the consumption amount of ascorbate during radiotherapy. Whole blood ascorbate was decreased from 1.82 mg/dl to 1.58 mg/dl, plasma ascorbate was decreased from 1.13 mg/dl to 1.08 mg/dl, and urine ascorbate was decreased from 9.33 mg/dl to 6.96 mg/dl after radiotherapy. Although the difference was not significant statistically, further human study should be followed to define the role of ascorbate as a radioprotector.

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Chemical Inhibition of Cell Recovery after Irradiation with Sparsely and Densely Ionizing Radiation

  • Evstratova, Ekaterina S.;Kim, Jin-Hong;Lim, Young-Khi;Kim, Jin Kyu;Petin, Vladislav G.
    • Journal of Radiation Industry
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    • v.10 no.4
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    • pp.199-204
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    • 2016
  • The dependence of cell survival on exposure dose and the duration of the liquid-holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage.

Kenalog modified by ionizing radiation induces intrinsic apoptosis mediated by elevated levels of reactive oxygen species in melanoma cancer

  • REMIGIUS AMBROSE KAWALA;FATUMA JUMAPILI RAMADHANI;HYO JIN CHOI;EUN-HEE LEE;CHUL-HONG PARK;BYUNG YEOUP CHUNG;HYOUNG-WOO BAI
    • Oncology Letters
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    • v.41 no.3
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    • pp.1837-1850
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    • 2019
  • Kenalog is a synthetic glucocorticoid drug used to treat various cancers including ocular and choroidal melanoma. However, the drug achieves rarely sustainable results for patients. To overcome this difficulty, the structure of Kenalog was altered by ionizing radiation (IR) to develop a more effective anticancer agent for treatment of various skin cancers. The anticancer effect of modified Kenalog (Kenalog-IR) was assessed in melanoma cancer cells in vitro. The assessment of mitochondrial functions by MTT assay revealed significant inhibition of melanoma cancer cell viability by Kenalog-IR compared to Kenalog. Moreover, Kenalog-IR-induced apoptotic cell death was associated with the intrinsic mitochondrial pathway by triggering the release of intrinsic apoptosis molecules through activation of caspase-related molecules in concentration and time-dependent manners. Furthermore, it was observed that Kenalog-IR-induced apoptosis was associated with the generation of reactive oxygen species (ROS) with increased G2/M cell cycle arrest. Collectively, Kenalog-IR may be a potential suppressor of skin-related cancer in particular melanoma cancer.

CO2 Suppression Characteristics of the Nitrogen-diluted Methane Counterflow Non-premixed Flame (질소로 희석된 대향류 메탄 비예혼합화염에서 CO2에 의한 소화특성)

  • Lee, Ho-Hyun;Oh, Chang Bo;Hwang, Cheol Hong
    • 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.

Carbon Monoxide Emission and Radiation Properties in Ceramic Fiber Radiant Burner (세라믹 화이버 버너의 CO 배출과 복사강도 특성)

  • Jeong, Yong-Ki;Kim, Young-Soo;Lee, Dae-Rae;Yang, Dae-Bong;Ryu, Jung-Wan;Yun, Alexander;Chang, Young-June;Jeon, Chung-Hwan
    • 한국연소학회:학술대회논문집
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    • 2007.05a
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    • pp.176-183
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    • 2007
  • An experimental study was performed to investigate the effects of mixing quality, inlet pressure, nozzle diameter on CO emission and radiation characteristics in porous ceramic fiber radiant burners. Observations of combustion characteristics occurring inside the burner system which was insulated fiber mat, were investigated by measuring temperature, CO emission and radiation characteristics. Combustion was achieved at the firing rate of $88{\sim}99$ kcal/hr, inlet pressure of $100{\sim}250$mm$H_2O$. CO emissions were found to be strongly dependent on the operating conditions. There was a tendency that CO concentration increased as the firing rate increases. The reason for rise of CO concentration is that it becomes the relatively rich condition. The fiber burner exhibit significant both spectral intensity peaks in the bands at 2.5${\mu}m$ and 4.0${\mu}m$ relatively, There is a small difference in the variable mixing tube. However spectral intensity increased with the firing rate.

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Effects of High-Protein Diet and/or Resveratrol Supplementation on the Immune Response of Irradiated Rats

  • Kim, Kyoung Ok;Park, Hyunjin;Kim, Hyun-Sook
    • Preventive Nutrition and Food Science
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    • v.19 no.3
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    • pp.156-163
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    • 2014
  • We investigated the effects of a high-protein diet and resveratrol supplementation on immune cells changes induced by abdominal irradiation in rats. Female Wistar rats were divided into 5 groups: 1) control diet, 2) control diet with irradiation 3) 30% high-protein diet with irradiation, 4) normal diet with resveratrol supplementation and irradiation, and 5) 30% high-protein diet with resveratrol supplementation and irradiation. We measured blood protein and albumin concentrations, lipid profiles, white blood cell (WBC) counts, proinflammatory cytokine production, and splenocyte proliferation in rats that had been treated with a 17.5 Gy dose of radiation 30 days prior. A high-protein diet affected plasma total cholesterol and very low density lipoprotein-cholesterol levels, which were increased by the radiation treatment. In addition, the lymphocyte percentage and immunoglobulin M (IgM) concentration were increased, and the neutrophil percentage was decreased in rats fed a high-protein diet. Resveratrol supplementation decreased the triglyceride (TG) level, but increased the IgM concentration and splenocyte proliferation. Proinflammatory cytokine production was lower in rats fed a high-protein diet supplemented with resveratrol than in rats fed a control diet. The results of the present study indicate that high-protein diets, with or without resveratrol supplementation, might assist with recovery from radiation-induced inflammation by modulating immune cell percentages and cytokine production.

Statistical Analysis of the Meteorological Elements for Ozone and Development of the Simplified Model for Ozone Concentration (오존 농도에 영향을 미치는 주 기상요소의 도출 및 예측모형 수립)

  • 전의찬;우정헌
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.3
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    • pp.257-266
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    • 1999
  • In order to analyze the effect of meteorological elements on ozone concentration, we carried out cross-correlation of the elements with ozone concentraton, and time series analysis on them. As a result, it revealed that temperature, wind speed and humidity are not independent variables with ozone concentrations, and also, solar radiation and mixing height are the major elements that affect them. We developed models for ozone with solar radiation and mixing height as dependent variables to verify the effect of major meteorological elements. The predicted ozone concentration has strong correlation coefficients, So, We could conclude that we can predict ozone concentreation only with solar raidation and mixing height as dependents.

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One-Year Continuous Measurement of Outdoor Radon Progeny Concentration in Beijing Area

  • Zhang, Lei;Wang, Yunxiang;Guo, Qiuju
    • Journal of Radiation Protection and Research
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    • v.45 no.3
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    • pp.95-100
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    • 2020
  • Background: Compared with reported data of radon concentration, data of radon progeny concentration is limited in general, especially in outdoor environment. Materials and Methods: To know both the level and the variation of radon progeny concentration in outdoor environment in Beijing area, one-year continuous measurement with a cycle of 60 minutes was carried out by a step-advanced filter (SAF) monitor for radon progeny measurement. The observation site was located in a park in Eastern Beijing area, and the observation period was from October 17, 2018 to September 29, 2019. Results and Discussion: The equivalent equilibrium concentration (EEC) of radon progeny varies from 0.7 to 19.1 Bq·m-3, with an annual average of 4.9 ± 2.7 Bq·m-3. A clear diurnal variation of EEC, higher in the early morning and lower in the late afternoon, is observed due to the high sensitivity of the SAF monitor. Conclusion: Vertical convection of atmospheric boundary layer is thought to be the main reason of this phenomenon. For annual variation, the lowest monthly average EEC appeared in April, while the highest appeared in November, which might attribute to the atmospheric stability in different seasons.