• Title/Summary/Keyword: gamma value

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Changes of the phsico-Chemical Characteristics of oils treated by the ${\gamma}$-ray irradiation (I) -The Extracted soybean oil- (방사선 조사선량에 따른 유지의 이화학적 성질변화 (I))

  • 임국이
    • Journal of the Korean Home Economics Association
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    • v.30 no.4
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    • pp.77-88
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    • 1992
  • To investigate the oxidative stabilities of the ${\gamma}$-ray irradiated soybean during storage and heating and some physico-chemical characteristics of soybean and the extracted soybean oil (SBO) with/without the ${\gamma}$-ray irradiation were determined. The ${\gamma}$-ray level use in irradiation for soybean were 2.5, 5.0 and 10.0 KGY respectively and Acid Value, Peroxide Value, Conjugated Diene Value, Composed Fatty Acids amounts, and Trans Fatty Acid occurrence were determined for all samples, which were incubated at 45$\pm$1$^{\circ}C$ for 25 days heated at 180$\pm$1$^{\circ}C$ for 30 hours. And these values of the ${\gamma}$-ray treated samples were compared to those of nontreated samples. The results were obtained as follows : 1. According to the increased level of the ${\gamma}$-ray irradiation, there was little difference in Dielectric Constant, Viscosity, and the Induction Period by Rancimat. But, in case of 5.0 KGY, oxidative stability was increased more twice than that of non-irradiation. In the quantity of fatty Acids composition of the extracted soybean oil irradiated with 10.0 KGY, palmitic, oleic and linoleic acids were less increased thanb those of non-irradiation, while stearic, linolenic acids were decreased. In the case of 2.5 KGY irradiation, stearic and oleic acids were increased. 2. The Acid Value of SBO according to the ${\gamma}$-ray irradiation level was almost not change, but was 0.1 lower than that of non-irradiation during incubation (45$\pm$1$^{\circ}C$). The Peroxide Value of SBO with the ${\gamma}$-ray irradiation, was very lower than that of non-irradiation, but its effect on oxidative stability was better of SBO treated with 5.0 KGY and 10.0 KGY. In the Fatty Acids composition of SBO, palmitic, stearic, oleic acids were increased, while linoleic, linolenic acids were decreased during incubation(45$\pm$1$^{\circ}C$). This tendency was more obvious due to the ${\gamma}$-ray level. While heating(180$\pm$1$^{\circ}C$), the Acid Value of SBO treated with the ${\gamma}$-ray irradiation was decreased, the Acid Value of SBO irradiated with 2.5 KGY was the lowest. Also the peroxide Values of SBO treated with 5.0 KGY, 10.0 KGY were very lower than that of non-irradiation. Conjugated Diene Value of SBO was almost unchanged according to the ${\gamma}$-level and heating time. 3. When the methyl linoleate was irradiated with the ${\gamma}$-ray, the Trans Fatty Acid was little produced. In case of SBO with non-irradiation, the trans C18:1 was occured about 6.5~7.9%, but trans C18:2 and C18:3 were not shown, while SBO irradiated with the ${\gamma}$-ray 2.5, 5.0, 10.0 KGY, trans C18:3 and C18:2 amount in SBO were increased according to heating time, but trans C18:3 was little occured. As these results, the effects of the ${\gamma}$-ray irradiation to oil containing food were to cut down the energy for food storage and to increase oxdative stability during storge. And also it was shown to be the best that 10.0 KGY of the ${\gamma}$-ray irradiation would be applied to soybean.

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Study on irradiation effect by $Co^{60}$ to the carbon resistor (탄소저항체에 대한 $Co^{60}$조사효과에 관한 연구)

  • 지철근;조성욱
    • 전기의세계
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    • v.22 no.4
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    • pp.7-10
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    • 1973
  • The characteristics of all the instruments and materials used in atomic industry is changed due to radiation damages by the effects of radiation activities. In this study, when the Carbon Resistor, main element of electrical circuits, is irradiated by Gamma-Ray, variations in its electrical properties have been investigated. The following results are obtained: 1) The resistance value in Carbon Resistor is exponentially increased as the quantity of irradiation by Gamma-Ray is increased, but in case of more than 10$^{6}$ R/hr. of quantity of irradiation it has saturated-state value. 2) The rate of change inrestistance value has been independent on the intensity of Gamma-Ray source when Carbon Resistor is irradiated in the same quantity of irradiation. 3) The resistance value in irradiated Carbon Resistor has not been varied with elapse of time. 4) The more the distance from the Carbon Resistor to the Gamma-Ray source the more greatly the resistance value is decreased and that it has been shown that the more quantity of irradiation by Gamma-Ray, the greater the rate of decrease in resistance value. Through the above results it has been concluded that the measurement values obtained by the high-precision instruments in the radiation field have to be corrected with proper consideration to radiation damages.

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Bentonite based ceramic materials from a perspective of gamma-ray shielding: Preparation, characterization and performance evaluation

  • Asal, Sinan;Erenturk, Sema Akyil;Haciyakupoglu, Sevilay
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1634-1641
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    • 2021
  • Exposure to gamma-rays is hazardous for humans and other living beings because of their high penetration through the materials. For this reason, shielding materials (usually lead, copper and stainless steel) are used to protect against gamma rays. This study's objective was to prepare ceramic materials for gamma radiation shielding by using different natural bentonite clays. Gamma-ray attenuation performances of the prepared shielding materials at different thicknesses were investigated and evaluated for different gamma-ray energies from different standard point gamma radiation sources (251Am, 57Co, 137Cs, 60Co, and 88Y). The mass and linear attenuation coefficients of the prepared ceramics vary between 0.238 and 0.443 cm2 g-1 and between 0.479 and 1.06 cm-1, respectively, depending on their thicknesses. Results showed that these materials could be prioritized because of their evidential properties of gamma radiation protection in radiation applications.

A Retrospective cohort study on the effect of health counselling through the level of $\gamma-GTP$ after screening test (스크리닝을 이용한 건강진단후 건강상담이 $\gamma-GTP$의 변화에 미치는 영향 조사)

  • Lee, Yong-Jin;Ahn, Jae-Eog;Kim, Joo-Ja;Lee, Byung-Kook
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.3 s.58
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    • pp.518-529
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    • 1997
  • 1,281 male subjects who had been examined more than 3 times for regular check-up in one human dock center of the university hospital were studied between 1990-1995, to evaluate the effect of health counselling with life style and $\gamma-GTP$ value between 1054 normal group without intervention and 227 abnormal group with intervention, ages from 30 to 69 years old. Total mean value of $\gamma-GTP$ was $45.7{\pm}40.7$ unit with highest $\gamma-GTP$ value in age group 50-59 on initial examination. Total abnormal rate was 17.7% with the highest abnormal rate of 18.6% in age group 50-59. Initially, the value of $\gamma-GTP$ was significantly different according to the degree of alcohol intake, relative weight and smoking in normal group(p<0.01) not in abnormal group. In conclusion, the value of $\gamma-GTP$ were significantly increasing in normal group without intervention and significantly decreasing in abnormal group with intervention(p<0.05), which suggests the effect of health counselling, such as the recommendation to change the health behaviour.

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Separation Effect Analysis for Rainfall Data (강우자료의 분리효과)

  • 김양수;허준행
    • Water for future
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    • v.26 no.4
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    • pp.73-83
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    • 1993
  • This study focuses on the separation effect analysis of rainfall data for 2-parameter log-normal, 3-parameter log-normal, type-extreme value, 2-parameter gamma, 3-parameter gamma, log-Pearson type-III, and general extreme value distribution functions. Difference in the relationship between the mean and standard deviation of skewness for historical data and relations derived from 7 distribution functions are analyzed suing the Monte Carlo experiment. The results show that rainfall data has the separation effect for 6 distribution functions except 3-parameter gamma distribution function.

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Functional and Rheological Properties of ${\gamma}$-Polyglutamic Acid Produced by Alkalophilic Alcaligenes sp. (호 알카리성 Alcaligenes sp.가 생산하는 ${\gamma}$-Polyglutamic Acid의 기능성 및 리올로지 특성)

  • 이신영;강태수
    • KSBB Journal
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    • v.10 no.5
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    • pp.547-552
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    • 1995
  • Some functional and rheological properties of the ${\gamma}$-polyglutamic acid(${\gamma}$-PGA) produced from alkalophilic Alcaligenes sp. were investigated. Viscosity synergism with thickening agents, capacities for gelling, entrapig of heavy metals, and flocculability of ${\gamma}$-PGA were not observed, but the relatively good compatability with various polyvalent metallic ins, excellent absorption ability and spinability were observed. The ${\gamma}$-PGA solution showed non-Newtonian flow behavior and exhibited pseudoplastic property with a yield stress at above 1% concentration. The values of flow index for 1% solution were in the range of 0.41∼0.75 showing shear rate dependency and the value of yield stress was 2.28 Pa. The value of consistency index was 0.868 Pa$.$Sn and was exponentially dependent on concentration.

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Performance Analysis of Retinex-based Image Enhancement According to Color Domain and Gamma Correction Adaptation (Color Domain 및 Gamma Correction 적용에 따른 Retinex 기반 영상개선 알고리즘의 효과 분석)

  • Kim, Donghyung
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.15 no.1
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    • pp.99-107
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    • 2019
  • Retinex-based image enhancement is a technique that utilizes the property that the human visual characteristics are sensitive to the difference from the surrounding pixel value rather than the pixel value itself. These Retinex-based algorithms show different characteristics of the improved image depending on the applied color space or gamma correction. In this paper, we set eight different experimental conditions according to the application of color space and gamma correction, and analyze the objective and subjective performance of each Retinex based image enhancement algorithm and apply it to the implementation of Retinex based algorithm. In the case of gamma correction, quantitative low entropy images and low contrast images are obtained. The application of Retinex technique in HSI color space rather than RGB color space is found to be high in overall subjective image quality as well as maintaining color.

Analytical Approximation Algorithm for the Inverse of the Power of the Incomplete Gamma Function Based on Extreme Value Theory

  • Wu, Shanshan;Hu, Guobing;Yang, Li;Gu, Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.12
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    • pp.4567-4583
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    • 2021
  • This study proposes an analytical approximation algorithm based on extreme value theory (EVT) for the inverse of the power of the incomplete Gamma function. First, the Gumbel function is used to approximate the power of the incomplete Gamma function, and the corresponding inverse problem is transformed into the inversion of an exponential function. Then, using the tail equivalence theorem, the normalized coefficient of the general Weibull distribution function is employed to replace the normalized coefficient of the random variable following a Gamma distribution, and the approximate closed form solution is obtained. The effects of equation parameters on the algorithm performance are evaluated through simulation analysis under various conditions, and the performance of this algorithm is compared to those of the Newton iterative algorithm and other existing approximate analytical algorithms. The proposed algorithm exhibits good approximation performance under appropriate parameter settings. Finally, the performance of this method is evaluated by calculating the thresholds of space-time block coding and space-frequency block coding pattern recognition in multiple-input and multiple-output orthogonal frequency division multiplexing. The analytical approximation method can be applied to other related situations involving the maximum statistics of independent and identically distributed random variables following Gamma distributions.

Investigation on radiation shielding parameters of cerrobend alloys

  • Tellili, Borhan;Elmahroug, Youssef;Souga, Chedly
    • Nuclear Engineering and Technology
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    • v.49 no.8
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    • pp.1758-1771
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    • 2017
  • In this study, to determine the most effective alloy for shielding against gamma-rays, the gamma-ray shielding parameters of six types of cerrobend alloys have been investigated. Gamma-ray interaction with the cerrobend alloys has been discussed mainly in terms of total mass attenuation coefficient (${\mu}_t$), half value layer (HVL), tenth value layer (TVL), effective atomic number ($Z_{eff}$), and effective electron density ($N_{eff}$). These parameters have been calculated by theoretical approach using the ParShield program in a photon energy range between 0.1 MeV and 100 GeV. The dependence of these parameters on the incident photon energy and chemical composition of the cerrobend alloys has been studied.

Gamma Ray Shielding Study of Barium-Bismuth-Borosilicate Glasses as Transparent Shielding Materials using MCNP-4C Code, XCOM Program, and Available Experimental Data

  • Bagheri, Reza;Moghaddam, Alireza Khorrami;Yousefnia, Hassan
    • Nuclear Engineering and Technology
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    • v.49 no.1
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    • pp.216-223
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    • 2017
  • In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and $10^{th}$ value layer values of barium-bismuth-borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium-bismuth-borosilicate glasses have good gamma ray shielding properties from the shielding point of view.