• Title/Summary/Keyword: radiation concentration

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Effect of Soild Content on the Physicochemical Properties of Rice Porridge After Reheating (쌀의 농도가 죽 재가열시 이화학적 특성에 미치는 영향)

  • Yang, Yun-Hyoung;Kim, Min-Hee;Kwon, Oh-Yun;Lee, Jeong-Hee;Lee, Kun-Jong;Lee, Ju-Woon;Kim, Mee-Ree
    • Korean journal of food and cookery science
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    • v.23 no.5
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    • pp.671-676
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    • 2007
  • The effect of solid content on the physicochemical properties of rice porridge after reheating. The concentration of rice porridge was classified as solid content (12%, 10%, and 8%) by traditional Korean cooking methods. For reheating, packed rice porridge was boiled in water for 3 min and then cooled at room temperature ($25^{\circ}C$). The viscosity, soluble solid content and reducing sugar content of the rice porridge increased according to the solid content, while the blue value decreased. After reheating, the viscosities ($25^{\circ}C$) of all rice porridges decreased to 2.9-8.4%, compared to those of freshly made rice porridge, whereas the soluble solid content and reducing sugar content increased inversely according to the solid content of rice porridge. The SDI (starch digestion index) increased according to the solid content, whereas SDS (slowly digestible starch) the lowest in the solid content 12% porridge. Based on these results, it is favorable that the viscosity decrease after reheating was to be considered to ready-to eat rice porridges preparation.

Influence of Radioactive Contamination to Agricultural Products Due to Dry and Wet Deposition Processes During a Nuclear Emergency (원자력 사고 중 핵종의 건. 습침적에 따른 농작물 오염 영향)

  • Hwang, Won-Tae;Kim, Eun-Han;Suh, Kyung-Suk;Han, Moon-Hee;Choi, Pong-Ho;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
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    • v.27 no.3
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    • pp.165-170
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    • 2002
  • Combined with deposition model onto the ground of radionuclides, the influence of radioactive contamination to agricultural products was analyzed due to wet deposition as well as dry deposition from radioactive air concentration during a nuclear emergency. The previous dynamic food chain model, in which initial input parameter is only radionuclide concentrations on the ground, was improved for the evaluating of radioactive contamination to agricultural products from either radionuclide concentrations in air or radionuclide concentrations on the ground. As the results, in case of deposition onto the ground, wet deposition was more dominant process than thy deposition. While the contamination levels of agricultural products were dependent on the a variety of factors such as radionuclides and rainfall rate. It means that the contamination levels of agricultural products are determined from which is more dominant process between deposition on the ground and interception onto agricultural plants.

Development of a Fission Product Transport Module Predicting the Behavior of Radiological Materials during Severe Accidents in a Nuclear Power Plant

  • Kang, Hyung Seok;Rhee, Bo Wook;Kim, Dong Ha
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.237-244
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    • 2016
  • Background: Korea Atomic Energy Research Institute is developing a fission product transport module for predicting the behavior of radioactive materials in the primary cooling system of a nuclear power plant as a separate module, which will be connected to a severe accident analysis code, Core Meltdown Progression Accident Simulation Software (COMPASS). Materials and Methods: This fission product transport (COMPASS-FP) module consists of a fission product release model, an aerosol generation model, and an aerosol transport model. In the fission product release model there are three submodels based on empirical correlations, and they are used to simulate the fission product gases release from the reactor core. In the aerosol generation model, the mass conservation law and Raoult's law are applied to the mixture of vapors and droplets of the fission products in a specified control volume to find the generation of the aerosol droplet. In the aerosol transport model, empirical correlations available from the open literature are used to simulate the aerosol removal processes owing to the gravitational settling, inertia impaction, diffusiophoresis, and thermophoresis. Results and Discussion: The COMPASS-FP module was validated against Aerosol Behavior Code Validation and Evaluation (ABCOVE-5) test performed by Hanford Engineering Development Laboratory for comparing the prediction and test data. The comparison results assuming a non-spherical aerosol shape for the suspended aerosol mass concentration showed a good agreement with an error range of about ${\pm}6%$. Conclusion: It was found that the COMPASS-FP module produced the reasonable results of the fission product gases release, the aerosol generation, and the gravitational settling in the aerosol removal processes for ABCOVE-5. However, more validation for other aerosol removal models needs to be performed.

Influence of Surrounding Gas and Coal Characteristics on Flame Propagation in Oxy-Fuel Combustion of Pulverized Coal (미분탄 순산소 연소에서 주위 기체와 석탄 특성이 화염전파에 미치는 영향)

  • Kang, Young-Min;Shim, Young-Sam;Moon, Cheor-Eon;Sung, Yon-Mo;Seo, Sang-Il;Kim, Tae-Hyung;Choi, Gyung-Min;Kim, Duck-Jool
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.1
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    • pp.38-45
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    • 2009
  • Oxy-fuel combustion of pulverized coal is one of the promising new technologies to reduce $CO_2$ and NOx from coal combustion. However, the stability of pulverized coal flame is reduced in the oxy-fuel combustion. This flame stability is concerned with the flame propagation that is affected by surrounding gas and coal characteristics, such as gas temperature, gas composition, coal volatile, coal activation energy and coal size. In this paper, a study on the influence of surrounding gas and coal characteristics on the flame propagation velocity in oxy-fuel combustion of pulverized coal was preformed. One dimensional model was used to calculate the flame propagation velocity of pulverized coal clouds. In this model, the radiation is considered to be the main source of heat exchange, and Monte Carlo method was adopted for accurate calculation of radiation heat flux. It was found that the flame propagation velocity become higher with the decrease of coal activation energy and the increase of coal volatile. Also, according to the increase of gas temperature and $O_2$ concentration, flame propagation velocity increased.

Study on Leaching Characteristics of $^{137}Cs\;and\;^{90}Sr$ from Cement-Solidified Radwastes (방사성 폐기물 시멘트 고화체로 부터의 $^{137}Cs$$^{90}Sr$ 용출특성 연구)

  • Hwang, Sun-Tae;Lee, Kyung-Ju;Choi, Kil-Oung;Park, Hun-Whee;Kim, Hwan-Young
    • Journal of Radiation Protection and Research
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    • v.10 no.2
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    • pp.113-121
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    • 1985
  • For the safety assessment of radwaste treatment and disposal, the leaching characteristics of $Cs^+\;and\;Sr^{++}$ from the cement-solidified radwastes was investigated by means of the survey and analysis of the activity leach rate and cumulative leach fraction of $^{137}Cs\;and\;^{90}Sr$ leaching from solidified radwastes. The cylindrical cement-solidified samples were made by the sodium silicate method and neutralization method changing the mole density of simulated liquid radwaste, type of cement, adding material and concentration of boric acid. The leaching study was carried out by the method using simulated PWR concentrated liquid radwaste solidified in cement that had been processed following the recommendations of IAEA. All the experimental results are in well accordance with the research data reported previously, but the watertight cement-solidified radwastes show rather high leach rate of radioactivity. It is learned, therefore, that the watertight cement is not adequate as the material for the solidified radwastes.

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OBT Concentrations of Marine Organisms around Wolsung Nuclear Power Plants (월성 원자력발전소 주변 해양생물중의 조직결합 삼중수소 농도)

  • Kim, Do-Sung;Park, Gyu-Jun;Lin, Xiu-Jing;Kim, Wan;Kang, Hee-Dong;Doh, Sih-Hong;Kim, Chang-Kyu
    • Journal of Radiation Protection and Research
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    • v.28 no.1
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    • pp.75-78
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    • 2003
  • The organically bound tritium(OBT) concentrations of the marine organisms(seaweed and shellfish) around Wolsung nuclear power plants were measured. The OBT concentrations of seaweeds were in the range of $0.372{\sim}2.72$ Bq/kg-fresh. The OBT concentrations of shellfish were in the range of $0.239{\sim}2.02$ Bq/kg-fresh. The internal dose due to the OBT concentration of seaweed was estimated as $3.4{\times}10^{-7}$ mSv/year.

Interpretation of Uranium Bioassay Results with the ICRP Respiratory Track and Biokinetic Model (ICRP 호흡기 및 생체역동학적 모델을 이용한 우라늄 생물분석 결과의 해석)

  • Kim, H.K.;Lee, J.K.
    • Journal of Radiation Protection and Research
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    • v.28 no.1
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    • pp.43-50
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    • 2003
  • This study describes a practical method for interpretation of bioassay results of inhaled uranium to assess the committed effective doses both for chronic and acute intake situations. Organs in the body were represented by a series of mathematical compartments for analysis of the behavior of uranium in the body according to the gastrointestinal track model, respiratory track model and biokinetic model recommended by the ICRP. An analytical solutions of the system of balance equations among the compartments were obtained using the Birchall's algorithm, and the urinary excretion function and the lung retention function of uranium were obtained. An initial or total intakes by intake modes were calculated by applying excretion and retention functions to the urinary uranium concentration and the lung burden measured with a lung counter. The dose coefficients given in ICRP 78 are used to estimate the committed effective doses from the calculated intakes.

Enzyme activity changes by intraperitoneal injection of uranium in the carp liver (우라늄 투여후 간조직에서의 효소활성도의 변화)

  • Kim, In-Gyu;Kim, Kug-Chan;Kim, Jin-Kyu;Kim, Sang-Bok;Chun, Ki-Chung;Park, Hyo-Kook;Lee, Kang-Suk
    • Journal of Radiation Protection and Research
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    • v.18 no.2
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    • pp.61-69
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    • 1993
  • We examined various enzyme activity changes by intraperitoneal injection uranium in the carp liver. These enzyme activity changes can be used as biochemical indicators of internal exposure to uranium. The results were followings ; 1) Total protein concentration decreased by intraperitoneal injection in the carp liver. 2) Lysosomal acid pretense and ${\beta}-glucuronidase$ activities increased in the liver until sixth intraperitoneal injection of uranium, but Lysosomal acid phosphatase activities decreased in the liver until the sixth injection of uranium. 3) Alkaline phosphatase activities sharply increased and Glutamate oxaloacetate Transaminase activities steadily decreased in the liver until the sixth injection of uranium. 4) Creatine %kinase activities steadily decreased and malate dehydrogenase activities sharply decreased in the liver after the primary injection of uranium. Any malate dehydrogenase activities was not detected after sixth injection of uranium.

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Introduction of Various Amine Groups onto Poly(glycidyl methacrylate)-g-MWNTs and their Application as Biosensor Supports (폴리(글리시딜 메타크릴레이트)가 그래프트된 다중벽 탄소나노튜브에 다양한 아민 그룹의 도입과 바이오센서 지지체로서의 응용)

  • Chung, Da-Jung;Kim, Ki-Chul;Choi, Seong-Ho
    • Polymer(Korea)
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    • v.36 no.4
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    • pp.470-477
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    • 2012
  • A tyrosinase-immobilized biosensor was developed based on various amine-modified multi-walled carbon nanotube (MWNT) supports for the detection of phenolic compounds. MWNTs with various amine groups were prepared by radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto MWNT supports and the subsequent amination of poly(GMA) graft chains. The physical and chemical properties of the poly(GMA)-grafted MWNT supports and the aminated MWNT supports were investigated by SEM, XPS, and TGA. Furthermore, the electrochemical properties of the prepared tyrosinase-modified biosensor based on MWNT supports with amine groups were also investigated. The response of the enzymatic biosensor was in the range of 0.1-0.9 mM for the concentration of phenol in a phosphate buffer solution. Various parameters influencing biosensor performance have been optimized: binder effects, pH, temperature, and the response to various phenolic compounds. The biosensor was tested on phenolic compounds contained in two different commercial red wines.

Pore Characterisitics and Adsorption Performance Evaluation of Magnesium Oxide Matrix by Active Carbon Particle Size (활성탄소 입도에 따른 산화마그네슘 경화체의 공극특성과 흡착성능 평가)

  • Pyeon, Su-Jeong;Lee, Sang-Soo
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.1
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    • pp.59-65
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    • 2018
  • Radon gas is a colorless, odorless, tasteless gas that occurs when uranium, a natural radioactive material in rocks and soils, collapses. 85% of the annual radiation exposure of the human body is due to natural radiation, of which 50% is radon. According to the US Environmental Protection Agency (EPA) survey, 62 out of 1,000 smokers and 7 out of 1,000 nonsmokers are exposed to lung cancer when exposed to radon gas for a long time. In order to reduce the risk of radon gas, activate carbon was used to fabricate matrix, and the pore properties and radon reduction properties were investigated. When the activate carbon was used, the radon gas concentration was drastically reduced and the graph was changed as the measurement period became longer. The pore distribution and microporous properties, which are one of the material properties of activate carbon, can be grasped.