• Title/Summary/Keyword: Gamma ray protection

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Experimental examination on physical and radiation shielding features of boro-silicate glasses doped with varying amounts of BaO

  • M.I. Sayyed;Abdelmoneim Saleh;Anjan Kumar;Fatma Elzahraa Mansour
    • Nuclear Engineering and Technology
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    • v.56 no.8
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    • pp.3378-3384
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    • 2024
  • Investigations were conducted on the addition of barium's impact on the radiation shielding and physical attributes of five different glasses, designated S1-S5, with varying BaO contents. Using two point sources namely Co60 and Cs137 along with a scintillation detector [NaI(TL)], experimental measurements were made of the shielding parameters of γ-rays, namely the effective atomic number (Zeff), electron density (Nel), half-value layer (HVL), linear attenuation coefficient (μ), mass attenuation coefficient (μm), mean free path (λ), and radiation protection effectiveness at the energies of 0.664, 1.177, and 1.334 MeV, and comparisons made with recently considered glasses as well as frequently employed materials for γ-ray shielding. The results show that the examined glasses' physical and radiation shielding qualities are improved by the addition of BaO. The μ values increased from 0.245 to 0.275 cm-1 (0.662 MeV), from 0.174 to 0.198 cm-1 (1.173 MeV), and from 0.161 to 0.189 (1.332 MeV). The observed values of HVL decreased from 2.83, 3.98, and 4.3 cm to 2.5, 3.5, and 3.62 cm at 0.662, 1.173, and 1.332 MeV, respectively, for the samples S1 and S5. In addition, the S5 glass sample was determined to have the best protection against photon among all the samples that were evaluated, as well as against recently considered glasses and those materials often utilized for gamma-ray shielding purposes.

Development of a New Coreopsis Variety 'Uridream Pink' by Gamma-ray Irradiation (감마선 조사에 의한 코레옵시스 신품종 'Uridream Pink' 육성)

  • Park, Kong-Young;Hwang, Hyeon-Jeong;Chae, Won-Byoung;Choi, Geun-Won
    • Horticultural Science & Technology
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    • v.32 no.6
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    • pp.906-911
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    • 2014
  • A new coreopsis cultivar, 'Uridream Pink', was developed by mutation breeding using gamma-ray irradiation. Rooted cuttings of 'Uridream 01', developed at Uriseed Company, were exposed to various gray ranges of gamma-rays from a $^{60}CO$ source for 24 h in 2009 at the Korea Atomic Energy Research Institute. Using gamma-rays with the range of 10-100 Gy, a chimeric mutant with pastel pink flowers was induced at 30 Gy from 'Uridream 01', which blooms red-purple flowers (Red-purple group, 59A). Clones that produced flowers with modified pink color were separated from the chimeric mutant and fixed by more than three rounds of cutting back from 2009 to 2010. The separated mutant clones with modified pink color were found to bloom flowers with marketable color and be free of any abnormal plant characteristics. The typical color of the flowers was pastel pink (Red-purple group, 67B), and the clones were registered as 'Uridream Pink' at the Korea Seed and Variety Service (plant variety protection number: 4410). Although the size of flowers and leaves of 'Uridream Pink' are smaller than those of 'Uridream 01', the number of flowers per plant is greater. 'Uridream Pink' can be used as both a pot and a garden plant because of its long blooming period from late spring to late autumn.

Induced Activity and Space Dose Distribution from Medical Linear Accelerator (의료용(醫療用) 선형가속기(線型加速器)에 의한 산난공간(散亂空間) 선량분포(線量分布)와 유도방사능(誘導放射能))

  • Chu, Sung-Sil;Park, Chang-Yun
    • Journal of Radiation Protection and Research
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    • v.11 no.1
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    • pp.51-56
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    • 1986
  • It is important to measure and protect from the radiation space dose and induced activity at the high energy medical linear accelerator facilities. These are to consider the additional risk to patients undergoing treatment, machine operators and staff members. Measurements of the space dose distribution and induced radioactivity at the 18 MeV medical linear accelerator facility in the Yonsei Cancer Center. 1. Exposure space dose for 300 rads monitor doses of 18 MeV electron are measured as 50 mR at 1 meter from patients. 2. Exposure space dose for 300 rads monitor doses of 10 MV X-ray are detected as 350 mR at 1 meter from phantom. 3. Induced radioactivity by photonuclear reaction was measured as 0.65 mR/hr from collimater after 30 Gy(3,000 rads) irradiated. 4. Analyzing the decay curves and energy spectrum of induced radioactivity, detected a few materials to be activated by photoneutron reaction, $^{65}Cu({\gamma}{\cdot}n)\;^{64}Cu,\;^{186}W({\gamma}{\cdot}n)\;^{185}W,\;^{181}Ta({\gamma}{\cdot}n)\;^{180}Ta,\;^{199}Au({\gamma}{\cdot}n)\;^{198}Au$.

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Effect of black sand as a partial replacement for fine aggregate on properties as a novel radiation shielding of high-performance heavyweight concrete

  • Ashraf M. Heniegal;Mohamed Amin;S.H. Nagib;Hassan Youssef;Ibrahim Saad Agwa
    • Structural Engineering and Mechanics
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    • v.87 no.5
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    • pp.499-516
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    • 2023
  • To defend against harmful gamma radiation, new types of materials for use in the construction of heavyweight concrete (HWC) are still needed to be developed. This research introduces new materials to be employed as a partial replacement for fine aggregate (FA) to manufacture high-performance heavyweight concrete (HPHWC). These materials include hematite, black sand, ilmenite, and magnetite, with substitution ratios of 50% and 100% of FA. In this research, the hardening and fresh characteristics of HPHWC were obtained. Concrete samples' Gamma-ray linear attenuation coefficient was evaluated utilizing a gamma source of Co-60 through the thicknesses of 2.5, 5, 7.5, 10, 12.5, and 15 cm. High temperatures were studied for HPHWC samples, which were exposed to up to 700℃ for two hours. Energy-dispersive x-rays and a scanning electron microscope carried out microstructure analyses. Magnetite as an FA attained the lowest compressive strength of 87.1 MPa, but the best radiation protection characteristics and the highest density of 3100 kg/m3 were achieved. After 28 days, the attenuation efficiency of concrete mixtures was increased by 6.5% when fine sand was replaced with black sand at a ratio of 50%. HPHWC, which contains hematite, black sand, ilmenite, and magnetite, is designed to reduce environmental and health dangers and be used in medicinal, military, and civil applications.

Effects of Low Dose Gamma-irradiation on Alleviation of Salt Stress in Rice (Oryza sativa L.) Seedling (저선량 감마선 조사가 벼 유묘의 염 스트레스 경감에 미치는 영향)

  • Baek, Myung-Hwa;Kim, Jin-Hong;Wi, Seung-Gon;Lee, In-Jung;Lee, Kyu-Seong;Kim, Jae-Sung
    • Korean Journal of Environmental Agriculture
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    • v.24 no.2
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    • pp.153-158
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    • 2005
  • To investigate alleviation effects of salt stress by low dose gamma-irradiation on seedling growth of rice (Oryza shrive L), in plants of two rice cultivars (Ilpumbyeo and Gancheokbyeo), seeds were irradiated with the different doses $(0{\sim}32\;Gy)$ of gamma-ray by irradiator ($^{60}Co$, ca.150 TBq of capacity, AECL). The salt stress caused a remarkable decrease of seedling growth, particularly for dry weight. In addition, relative growth rate was decreased over 50% by the salt stress. However, the salt stress-induced inhibition of growth was alleviated by gamma-irradiation. Especially, the relative growth rate of shoot showed the reduction effect over 30% at 4 Gy-irradiated groups as compared with that of control. Also, electrolyte leakage and relative water content were damaged, respectively 4 times and 30% by the salt stress but the damages were alleviated by the gamma-irradiation. These alleviation effects were observed similarly in both the cultivars tested. These results suggest that the low dose gamma-irradiation may have a better protection or the salt stress.

Protective Effects of Chitosanoligosaccharide on Gamma Ray-Induced Hepatic Damage in Mice (생쥐에서 키토산올리고당의 감마선 저항 효과)

  • Kim, Jung-Sam;Roh, Young-Bok
    • Applied Microscopy
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    • v.33 no.2
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    • pp.155-168
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    • 2003
  • The purpose of this study was to evaluate the effect the radiation-resistance of chitosan on the mice. A healthy male ICR mice were used for experiment. The SOD and MDA activity was measured from the liver of mice at 48 and 72 hours after the irradiation. The ultrastructural changes of the liver by irradiation was observed at 24, 48 and 72 hours after irradiation. The experimental groups were divided into three groups. Group 1 was the control group which was not treated with chitosanoligosaccharide before or after iradiation. Group 2 was the prefeeding group which chitosanoligosaccharide solution was supplied by feeding ad libitum for 30 days before irradiation. Group 3 was the postfeeding group which chitosanoligosaccharide solution was supplied by feeding after irradiation. In all groups 10 mice were used. The results were as follow: The SOD and MDA activity of the prefeeding group was decreased significantly (P<0.01). Control group - The nuclei were condensed. The mitochondria and rough endoplasmic reticulum (rER) were extended and the ribosome was dropped from the rER. Prefeeding group - The nuclei were rounded. The mitochondria was elongated. And the rER attached ribosomes. Postfeeding group - The nuclei were slightly condensed. The mitochondria and the rER were extended and the ribosome was dropped from the rER. It was concluded that the chitosanoligosaccharide was effective in the radiation-protection. So, chitosan would have the potential as the radiation-protection materials.

Comparative Study on Human Risk by Ionizing Radiation and Pesticide as Biological Information about Environmental Disaster (환경재해에 관한 생물정보로서의 이온화 방사선과 살충제의 인체 위해성 비교 연구)

  • Kim, Jin-Kyu;Hyun, Soung-Hee
    • Journal of Radiation Protection and Research
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    • v.26 no.4
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    • pp.385-392
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    • 2001
  • Environmental risk factors such as ionizing radiations, heavy metals, and pesticides can cause environmental disasters when they exist in excess. The increases in use of ionizing radiation and agricultural pesticide are somewhat related to the possibility of the disaster. The risk of radiation and pesticide was evaluated by means of the single cell gel electrophoresis (SCGE) assay on the human blood lymphocytes. The lymphocytes were irradiated with $0{\sim}2.0Gy$ of $^{60}Co$ gamma ray. Another groups of lymphocytes were exposed to various concentrations of parathion. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed a clear dose- or concentration-response relationship. Parathion of a recommended concentration for agricultural use ($1mg {\ell}^{-1}$ ) has a strong cytotoxic effect on lymphocytes, which is equivalent to damage induced by 0.1 Gy of ${\gamma}$-ray. Furthermore, $2mg{\ell}^{-1}$ of parathion can give rise to DNA damage equivalent to that induced by 0.25 Gy at which the radiation-induced damage can start to develop into clinical symptoms. The comparative results of this study can provide an experimental basis and biological information for the prevention of environmental disaster.

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The Transport Characteristics of 238U, 232Th, 226Ra, and 40K in the Production Cycle of Phosphate Rock

  • Jung, Yoonhee;Lim, Jong-Myoung;Ji, Young-Yong;Chung, Kun Ho;Kang, Mun Ja
    • Journal of Radiation Protection and Research
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    • v.42 no.1
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    • pp.33-41
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    • 2017
  • Background: Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., $^{238}U$ and $^{226}Ra$), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$ levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Materials and Methods: Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. Results and Discussion: The concentration ratios of $^{226}Ra$ and $^{238}U$ in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was $^{40}K$, and the median $^{40}K$ activity was $8.972Bq{\cdot}g^{-1}$ and $1.496Bq{\cdot}g^{-1}$, respectively. For the $^{238}U$ series, the activity of $^{238}U$ and $^{226}Ra$ was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Conclusion: Although the activity of $^{40}K$ in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of $^{226}Ra$ and $^{238}U$ in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

Determination of Personnel Exposures in the Lower Energy Ranges of X-Ray by Photographic Dosimeter (저(低)에너지 X-선장(線場)에서 필름배지에 의한 개인피폭선량(個人被曝線量)의 결정(決定))

  • Ha, C.W.;Kim, J.R.;Suh, K.W.
    • Journal of Radiation Protection and Research
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    • v.11 no.1
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    • pp.57-64
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    • 1986
  • This paper described an improved technical method required for proper evaluation of personnel exposures by means of the photographic dosimeter developed by KAERI in lower gamma or X-ray energy regions, with which response of the dosimeter varies significantly. With calibration of the dosimeter in the energy range from 30 to 300 keV, the beam spectrum was carefully selected and specified it adequately. The absorber combinations and absorber thickness used to obtain the specified X-ray spectra from a constant potential X-ray machine were determined theoretically and also experimentally. A correlation between the density and exposure for the four separate energies, such as $49\;keV_{eff},\;154\;keV_{eff}\;250\;keV_{eff}\;and\;662\;keV$, is experimentally determined. As a result, it can be directly evaluated the exposure from the measured response of dosimeter.

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Synergistic Effect of Green Tea EGCG Treatment with Gamma Radiation in Ieukemia Cell Necrosis (방사선조사와 병행 처리한 녹차 EGCG의 혈구암세포 사멸촉진 효과)

  • Lee, Hong-Soo;Kim, Jae-Man
    • Journal of radiological science and technology
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    • v.29 no.4
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    • pp.285-291
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    • 2006
  • During cancer therapy, gamma-ray irradiation and treatment of anti-cancer chemicals destroy the normal cells as well as cancer cells. In this study, we investigated the effect of epigallocathechin-gallate(EGCG) extracted from green tea, which is known to have anti-cancer and anti-oxident activities, in order to find out the feasible method to protect the normal cells and to kill the cancer cells efficiently. We investigated the effect of EGCG on the leukemia cell growth and cell necrosis, especially when treated along with gamma radiation. The EGCG inhibited the leukemia cell, HL-60, growth at the appropriate concentration while it exhibited no influence on the normal cell growth. More significantly, it enhanced leukemia cell necrosis when its treatment was combined with gamma irradiation. Simultaneous treatment of EGCG and gamma radiation increased leukemia cell necrosis up to 35% compared with separate treatments. These results suggest that drinking of green tea or co-treatment of EGCG during gamma irradiation therapy may result in better prognosis through enhancement of the tumor cell necrosis and protection of the normal cells.

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