• Title/Summary/Keyword: ${\gamma}$-ray irradiation method

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Effect of Irradiation on Growth, Bulblet Formation, and Germination of Pollen and Seed of Several Lily Cultivars (나리 생장, 자구 발달 및 화분과 종자발아에 미치는 방사선의 영향)

  • Park, In Sook;Suh, Dong Hee;Hwang, Yoon Jung;Chung, Jae-Dong;Kang, Si-Yong;Lim, Ki-Byung
    • FLOWER RESEARCH JOURNAL
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    • v.16 no.3
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    • pp.211-217
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    • 2008
  • To build up data for mutation breeding of lily, sensitivity to irradiation of bulb, seed and pollen was investigated. The bulbs of seven cultivars including 'New Wave' were very sensitive to gamma rays. Non-irradiated bulbs produced plants with bloom as normal. However, irradiated bulbs showed retarded growth and did not flower. Bulbs of 'New Wave' and 'Tiny Dino' irradiated with 125Gy gamma rays survived, but their growth rate dropped considerably. Part or whole leaves of the other cultivars except 'New Wave' and 'Tiny Dino' withered. Moisture content of individual scale was 72~78% depending on cultivar. Bulblet formation from untreated scales was 100%. Among all irradiated scales only 'Siberia' scales showed 8.5% bulblet formation when irradiated with 50Gy gamma rays. Pollen germination as affected by gamma ray irradiation had no consistent tendency. When dosage of $F_1$ 'Augusta' seeds reached 300Gy, their survival ratio was drastically decreased. Bulblet formation in vitro was observed only in non-irradiated seeds. Lethal dose ($LD_{50}$) of seed was less than 100Gy. Height and width of $F_1$ 'Augusta' bulblets in vitro irradiated with gamma rays decreased as dosage increased regardless of the culture method. The percentage shoot formation was 100% in non-irradiated bulblets and 15~60% in irradiated ones.

Application of Gamma Irradiation on Manufacturing Changran Jeotgal (aged and seasoned intestine of Alaska pollack) : Microbiological and Sensory Characteristics (양념 창란젓갈 제조시 감마선 조사기술 적용: 미생물학적 및 관능적 품질특성)

  • Jo, Cheorun;Kim, Dong-Ho;Lee, Won-Dong;Lee, Jae-Jin;Byun, Myung-Woo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.5
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    • pp.673-678
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    • 2003
  • Changran Jeotgal (aged and seasoned intestine of Alaska pollack) was prepared as the same method as commercial one and irradiated at 0, 2.5, 5.0 and 10 k㏉ by gamma ray for industrial application. Changran Jeotgal using 10 k㏉-irradiated red pepper powder was also prepared to compare with control (0 k㏉). Commercial red pepper powder was already contaminated at 3.8$\times$10$^{6}$ CFU/$m\ell$ level by total plate count and 10k㏉ of irradiation reduced the number about 4 log cycles. Gamma irradiated Changran Jeotgal at 2.5,5.0, and 10k㏉ showed 3 6, and 7 log cycles of reduction compared to the non-irradiated control in the total plate count after 12 weeks of storage at 1$0^{\circ}C$. Using irradiated (10k㏉) red pepper powder reduced the microbial contamination significantly by 2 log cycles compared to the control. Sensory evaluation showed that the sample irradiated at 2.5 k㏉ was the most acceptable, followed by the sample using irradiated red pepper powder and non-irradiated control. Thus, 2.5 k㏉ of irradiation of Changran Jeotgal was effective to improve safety during distribution and storage without change of sensory quality. Furthermore, using the irradiated red pepper powder is also recommended for safety enhancement of the products.

The Visualization and the Fast Detection of Gamma Radiation Source using Stereo Image Processing (영상처리기반 감마선원 거리탐지 고속화 및 가시화 연구)

  • Hwang, Young-Gwan;Lee, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.10
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    • pp.2001-2006
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    • 2016
  • The stereo radiation detection system detects the gamma source and acquires two dimensional left and right images for gamma source and visible objects using the detection result. And then the system measures the distance to the radiation source from the system in 3D space using stereo vision algorithm. In this paper, we implemented the fast detection algorithm for gamma source from the system in 3D space to reduce the detection time with image processing algorithms. Additionally, the system's performance is verified through experiments on gamma irradiation facilities. As a result, if the fast detection algorithm applied to the system, we can confirm that the detection system represents a 35% better performance than the conventional detection method that is full scanning to acquire the stereo image. We also have visualized a gamma source distribution through a 3D monitor using the stereo vision algorithm in order to provide the information of radiation spatial distribution to the user efficiently.

Crystallization and Preliminary X-Ray Crystallographic Analysis of PAS Factor from Vibrio vulnificus

  • Lee, Jun Hyuck;Kim, Soo Young;Rho, Seong-Hwan;Im, Young Jun;Kim, Young Ran;Kim, Mun-Kyoung;Kang, Gil Bu;Rhee, Joon Haeng;Eom, Soo Hyun
    • Molecules and Cells
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    • v.20 no.3
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    • pp.361-363
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    • 2005
  • Plasmid Achromobacter secretion (PAS) factor is a putative secretion factor that induces the secretion of periplasmic proteins. PAS factor from Vibrio vulnificus was crystallized at 294 K by the hanging drop vapor-diffusion method. It was isolated as a monomer during the purification procedures. The native crystal belongs to the F222 space group with unit cell parameters a = 56.1, b = 74.4, $c=80.0{\AA}$, ${\alpha}={\beta}={\gamma}=90^{\circ}$. The crystal was soaked in cryoprotectant containing 1 M NaBr for 1 h for MAD phasing. The diffraction limit of the Br-MAD data set was $1.9{\AA}$ using synchrotron X-ray irradiation at beam line BL-18B at the Photon Factory, Japan.

Brachytherapy for Head and Neck Cancer (두경부암의 근접방사선 치료)

  • Yoo Seong-Yul
    • Korean Journal of Head & Neck Oncology
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    • v.7 no.1
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    • pp.3-9
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    • 1991
  • Brachytherapy is a method of radiotherapy in advantage to achieve better local control with minimum radiation toxicity in comparison with external irradiation because radiation dose is distributed according to the inverse square low of gamma-ray emitted from the implanted sources. The main characteristics of brachytherapy are delivering of higher dose to target volume shortening of total treatment period and sparing of normal tissue. Recent development of iridium ribbons for low dose rate implant provides improvement of technology of brachytherapy in terms of safety and efficiency. High dose rate method. on the other hand, is effective to avoid unnecessary expoure of medical personnel.

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Experimental Study on the Determination of Absorbed dose Index (흡수선량지수결정(吸收線量指數決定)에 관한 실험적(實驗的) 연구(硏究))

  • Jun, Jae-Shik;Rho, Chae-Shik;Ro, Seung-Gy;Ha, Chung-Woo;Yoo, Young-Soo;Lee, Hyun-Duk
    • Journal of Radiation Protection and Research
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    • v.7 no.1
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    • pp.34-48
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    • 1982
  • The prime purpose of this study is to realize an index quantity, absorbed dose index, defined by the ICRU for the characterization of ambient radiation level at any location for the purpose of radiation protection. The experiment has been designed to be carried out in two phases, namely, preliminary and main experiment. In the primary study a 30cm diameter sphere of polyethylene was used, while in the main experiment that of tissue equivalent material was fabricated and used. Both experiments were performed in the gamma-ray fields of $^{137}Cs\;and\;^{60}Co$, and in a neutron beam of thermal column of the TRIGA MARK-II research reactor. In the measurement of gamma-ray absorbed dose TLD-700 $(^{7}LiF)$ chips were used, and for the neutron dose both Au activation foils and TLD chips (TLD-600 $(^{6}LiF)$ and TLD-700 for the discrimination of gamma-ray contribution) were used. Theoretical assessment of the absorbed dose in the sphere phantom has been carried out in accordance with the Ehrlich's idea that deduced on the basis of Burlin's cavity theory in the case of gamma-ray irradiation. For the analysis of neutron dose fluence-KERMA rate conversion method was used. The explanation on the dose assessment is given in detail. Results obtained were numerically and statistically analyzed and the depth dose distributions are presented in the graphic forms with normalized values. In the concluding remarks, the possibility and difficulty of realizing the index quantity, including questions and problems to be solved are mentioned.

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Calculation of the Air-Scattering Dose Rate by the Single Scattering Approximation (단일산란근사법(單一散亂近似法)에 의한 공기중(空氣中) 산란방사선량(散亂放射線量)의 계산(計算))

  • Yook, Chong-Chul;Ha, Chung-Woo;Lee, Jai-Ki;Moon, Philip S.
    • Journal of Radiation Protection and Research
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    • v.4 no.1
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    • pp.21-28
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    • 1979
  • A calculation is presented of air-scattered gamma rays using the modified single-scattering approximation. The air-scattered tissue dose rates are calculated for a general purpose taking into account (a) the buildup and exponential attenuation, (b) the energy spectrum at the position of question and (c) the geometrical scattering volume in three dimensions. These calculations have been further modified to render them applicable to a typical field irradiation facility which is surrounded by a shield wall and in which the source is fitted with a beam collimating device. The results of the calculation include the energy spectra, angular distribution and tissue does rates at source-receiver separation distances of from 35m to 300m. The comparison shows that the present method developed may be generally adequate for the gamma-ray air-scattering problems in field irradiation facilities if energy and angular distribution at the shield are unimportant.

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Radiation Preparation and Characterization of Antimicrobial Hydrogels (방사선 이용 항균성 천연추출물 함유 하이드로겔 제조 및 특성 연구)

  • Gwon, Hui-Jeong;Park, Eun Ji;Choi, Jong-Bae;Lim, Jong-Young;Jeong, Jin-Oh;Shin, Young Min;Jeong, Sung In;Park, Jong-Seok;Lim, Youn-Mook
    • Journal of Radiation Industry
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    • v.7 no.1
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    • pp.87-91
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    • 2013
  • Taraxacum platycarpum (TP) has been used for years without restriction on usual dose for its non-toxic nature and nonexistence of the side effects. To develop antimicrobial hydrogel, poly (vinylalcohol) (PVA) hydrogels containing the aqueous extracted TP as an antimicrobial agent were prepared by using gamma-rays irradiation. The antimicrobial activities of the TP hydrogels were tested against Staphylococcus aureus and Staphylococcus epidermidis by disc diffusion method. The inhibition zones (IZ) of the TP extracts and TP hydrogels against S. aureus were 16 mm and 20 mm and against S. epidermidis was 10 mm and 13 mm, respectively. In conclusion, the TP hydrogel that has an excellent antimicrobial activity was proved to be a valuable material for functional skin care.

Fermentation Properties of Irradiated Kochujang (방사선 조사 고추장의 발효 특성)

  • Kim, Moon-Sook;Oh, Jin-A;Kim, In-Won;Shin, Dong-Hwa;Han, Min-Su
    • Korean Journal of Food Science and Technology
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    • v.30 no.4
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    • pp.934-940
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    • 1998
  • Kochujang, fermented hot pepper soybean paste, was prepared by traditional method, and irradiated with gamma ray of $^{60}Co{\;}up{\;}to{\;}15{\pm}1.5{\;}kGy$ for confirming main factor of kochujang fermentation. Nonirradiated (control) and irradiated samples kochujang were fermented at $25^{\circ}C$ and analyzed biochemical properties including enzyme activities and viable cell count during fermentation for 60 days. The total viable count in irradiated kochujang decreased to $10^4{\;}CFU/g$ which was $10^8{\;}CFU/g$ in the control. Because of a little changing enzyme activities of ${\alpha}{\cdot}{\beta}{\;}amylase$ and acid neutral protease by irradiation at the above level, amino type nitrogen which is the main quality reference of kochujang was comparable to the control. By irradiation, gas production was completely stopped which is one of biggest problems during distribution of kochujang. Total volume of gas produced at $25^{\circ}C$ from the control kochujang was 453 mL/100 g which was composed of over 90% of $CO_2$. The odor of irradiated kochujang was inferior to the control which seemed to be related to reduced microbial populations.

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A study on the HTS-NAA/γ-spectrometry for the analysis of alpha-particle emitting impurities in silica (고순도 실리카중 알파방출 불순물 분석을 위한 HTS-NAA/γ-spectrometry 연구)

  • Lee, Kil Yong;Yoon, Yoon Yeol;Cho, Soo Young;Yang, Myung Kwon;Shim, Sang Kwon;Kim, Yongje;Chung, Yong Sam
    • Analytical Science and Technology
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    • v.18 no.1
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    • pp.5-12
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    • 2005
  • It has been established that soft error of high precision electronic circuits can be induced by alpha particles emitted from the naturally occurring radioactive impurities such as U, and Th. As the electronic circuits have recently become lower dimension and higher density, these alpha-particle emitting radioactive impurities have to be strictly controlled. The aim of this study is to develop of NAA (Neutron Activation Analysis) and gamma-spectrometry to improve the analytical sensitivity and precision of U and Th. A new NAA method has been established using the HTS (Hydrulic transfer system) irradiation facility which has been used to produce radioisotopes for industries and medicines instead of the PTS (pneumatic transfer system) irradiation facility which has been used in general NAA. When the ultratrace impurities have to be analyzed by NAA, background gamma-ray spectra induced from $^{222}Rn$ and its progenies in air is serious problem. This unstable background has been eliminated or stabilized by the use of a nitrogen purging system. Ultra trace amounts of U (0.1 ng/g) and Th (0.01 ng/g) in high purity silica used for EMC could be analyzed by the use of HTS-NAA and low background gamma-spectrometry.