• Title/Summary/Keyword: Gamma source

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Comparison of Growth Characteristics and Chemical Composition of Kenaf (Hibiscus cannabinus L.) Varieties as a Potential Forage Crop (케나프 신육성 및 수집 품종의 생육과 사료적 특성 조사)

  • Lee, Ji-Yeon;Velusamy, Vijayanand;Koo, Ja-Yong;Ha, Bo-Keun;Kim, Dong-Sub;Kim, Jin-Baek;Kim, Sang-Hoon;Kang, Si-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.57 no.2
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    • pp.132-136
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    • 2012
  • Kenaf (Hibiscus cannabinus) is an annual herbaceous plant of the family Malvacease that has been planted in tropical Africa and Asia region for more than 4000 years and use as source of fiber, energy and feed stock. In this study, the physiological characters and chemical compositions of kenaf mutant variety "Jangdae" developed using gamma irradiation at the Korea Atomic Energy Research Institute (KAERI) were compared with three genetic resources (Auxu, C12, and C14-DRS). Jangdae showed the highest productivity growth rates in fresh yield, dry weight (DW) yield (leaf and stem), node number, and stem thickness. Especially, leaf DW yield of Jangdae was 1.6-3.1 times higher than that of three genetic resources. Also, stem DW yield of Jangdae was 1.6-2.1 times higher than that of three genetic resources. In the analysis of chemical composition, Jangdae showed 16.9% of crude protein content that was 0.86-0.94 times lower than three cultivars. However, Jangdae showed the highest neutral detergent fiber (NDF) contents in leaf (32.5%) and stem (75.2%). Also, acid detergent fiber (ADF) contents of stem and leaf in Jangdae were 64.4% and 33.9%, respectively. Total polyphenol and total flavonoid contents were 22.1 mg/g and 7.4 mg/g in Jangdae. Based on these results, Jangdae would have the potential to become a successful forage crop.

Molecular Cloning and Phylogenetic Analysis of PERVs from Domestic Pigs in Korea (env gene sequences) (국내 돼지에 존재하는 내인성 레트로 바이러스의 엔밸로프 유전자 클로닝 및 분자 계통학적 분석)

  • Lee, Dong-Hee;Yoo, Jae-Young;Lee, Jung-Eun;Kim, Gye-Woong;Park, Hong-Yang;Lee, Hoon-Taek;Kim, Young-Bong
    • Journal of Animal Science and Technology
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    • v.47 no.2
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    • pp.177-186
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    • 2005
  • Xenotransplantation may help to overcome the critical shortage of human tissues and organs for human transplantation, Swine represents an ideal source of such organs owing to their anatomical and physiological similarities to human besides their plentiful supply, However, the use of organs across the species barrier may be associated with the risk of transmission of pathogens, specially porcine endogenous retroviruses (PERVs).• Although most of these potential pathogens could be eliminated by pathogen-free breeding, PERVs are not eliminated by this treatment. PERVs are integrated into the genome of all pigs and produced by normal pig cells and infect human cells. They belong to gamma retroviruses and are of three classes viruses: A, B and C. In the present study, PCR based cloning was performed with chromosomal DNA extracted from pigs from domestic pigs in Korea. Amplified PCR fragments of about 1.5 Kb, covering the partial env gene, were cloned into pCR2.l-TOPO vectors and sequenced. A total of 91 env clones were obtained from domestic pigs, Berkshire, Duroc, Landrace and Yorkshire in Korea. Phylogenetic analysis of these genes revealed the presence of only PERV class A and B in the proportion of 58 % and 42 %, respectively. Among these, 28 clones had the correct open reading frame: 18 clones in class A and 10 clones in class B. Since both these PERV classes are polytropic and have the capacity to infect human cells, our data suggest that proviral PERVs have the potential to generate infectious viruses during or after xenotransplantation in human.

Biological Activities of Licorice F1 Lines and Content Analysis of Phytochemical Constituents

  • Park, Chun-Geon;Lee, Ah Young;Lee, Jeong Hoon;Lee, Jeong Min;Park, Jun Yeon;Lee, Sang-Hoon;Choi, Ae Jin;Park, Chung Berm;Cho, Eun Ju;Lee, Sanghyun
    • Natural Product Sciences
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    • v.20 no.3
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    • pp.137-145
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    • 2014
  • The biological activities of licorice F1 (Glycyrrhiza glabra ${\times}$ G. uralensis) lines (G) were investigated, revealing strong radical scavenging activity targeting 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl (${\cdot}OH$) radicals. At a concentration of $100{\mu}g/mL$, most of the licorice F1 lines scavenged DPPH and ${\cdot}OH$ by more than 80%. Gs-1, -2, and -6 can be considered good scavengers of DPPH radical and G-7 have higher antioxidant activity against ${\cdot}OH$ radical. In addition, licorice F1 lines exerted effective anti-microbial activities against Escherichia coli (Gs-12, -17, and -18) and Staphylococcus aureus (Gs-3, -4, -5, -21, and -26). Moreover, Gs-2, - 20, -31, and -32 effectively inhibited the growth of Helicobacter pylori. Among licorice F1 lines, Gs-25 exhibited high anti-inflammatory effects on nitric oxide produced by lipopolysaccharide- and interferon-${\gamma}$-activated RAW 264.7 cells. Furthermore, Gs-1, -12, and -20 inhibited the growth of AGS human gastric adenocarcinoma cells by more than 60% at a concentration of $100{\mu}g/mL$ and Gs-5, -11, -19, and -32 showed inhibitory effects against rat lens aldose reductase ($IC_{50}$ values, 1.69, 6.07, 6.12, and $4.54{\mu}g/mL$, respectively). The total content of glycyrrhizin (1), glycyrrhetinic acid (2), glabridin (3), and isoliquiritigenin (4) in licorice F1 lines was high in Gs-11, -15, and -30. The present study therefore indicated that Gs-2, -26, -31, and -32 of licorice F1 possessing strong anti-oxidative, anti-microbial, anti-inflammatory, anti-cancer, and aldose reductase inhibitory effects may be used as a possible source material for natural health supplements in the future.

Study of 4π Compton Suppression Spectrometer by Monte Carlo Simulation (몬테카를로 시뮬레이션을 통한 4π 컴프턴 억제 분광기 연구)

  • Jang, Eun-Sung;Lee, Hyo-Yeong
    • Journal of the Korean Society of Radiology
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    • v.11 no.3
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    • pp.123-129
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    • 2017
  • Compton suppression apparatus using the Compton scattering response, by inhibiting part of the spectrum Compton continuum Compton continuum in the area of the peak analysis of the gamma rays that enables a clearer device. In order to find out the geometry structure of high-purity germanium detector(HPGe) -NaI(TI) and to optimize the effect of movement, Monte Carlo simulation was used to grasp the behavioral characteristics of Compton suppression and compare several layout structures. And applied to the cylinder beaker used for the environmental measurement by using the efficiency according to the distance. For the low-energy source such as 81 keV, the Compton continuum is scarcely developed and the suppression effect is also insignificant because the scattering cross-section of the Compton effect is relatively low. In the spectrum for the remaining energy, it can be seen that the Compton continuum part is suppressed in a certain energy range. Compton suppression effect was not significantly different from positional shift. average reduction factor(ARF) value was about 1.08 for 81 keV and about 1.23 for 1332.4keV energy at the highest value. It can be seen that suppression over the Compton continuum region of the energy spectrum is a more appropriate arrangement. Therefore, it can be applied to various environmental sample measurement through optimized structure.

Analysis of physiological activities of wild Flammulina velutipes (야생 팽나무버섯의 생리활성 분석)

  • Yoon, Hyang-Sik;Choi, Jae-Sun;Kim, Ki-Sik;Noh, Jae Goan;Park, Jae Seong;Rho, Chang Woo
    • Journal of Mushroom
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    • v.8 no.1
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    • pp.22-26
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    • 2010
  • In this study, for the development of useful food materials, the proximate composition(total carbohydrates, crude fiber, crude protein, fat and ash) and biological activities(electron donating activity, total polyphenol contents, ACE inhibitory and ${\gamma}$-glucosidase inhibitory effects) were determined in the Garlmoe and the four wild Flammulina velutipes. As a results, the dry matter of mushrooms contained large amounts of carbohydrates, from 65.9 to 70.5 g/100g dry weight. the wild collected Flammulina velutipes proved to be an especially good source of crude fiber(7.9~18.1 g/100 g dry weight). Crude protein, fat, and ash contents of the mushrooms ranged 17.1~21.3, 4.1~5.2, and 5.7~8.4 g/100g dry weight, respectively. The electron donating activity ranged from 63.35 to 69.31% and total polyphenol contents ranged from 9.83 to 11.14 mg/g in these mushrooms. ACE inhibitions were high in Garlmoe and CBMFV-02 strain. ${\alpha}$-glucosidase inhibition was the highest in CBMFV-01(46.56%) strain and lowest in Garlmoe(15.91%).

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Growth and Electrical Properties of ZnAl2Se4 Single Crystal Thin Film by Hot Wall Epitaxy (Hot Wall Epitaxy(HWE)법에 의한 ZnAl2Se4 단결정 박막 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Park, Hyangsook;Bang, Jinju;Lee, Kijung;Kang, Jongwuk;Hong, Kwangjoon
    • Korean Journal of Materials Research
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    • v.23 no.12
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    • pp.714-721
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    • 2013
  • A stoichiometric mixture of evaporating materials for $ZnAl_2Se_4$ single-crystal thin films was prepared in a horizontal electric furnace. These $ZnAl_2Se_4$ polycrystals had a defect chalcopyrite structure, and its lattice constants were $a_0=5.5563{\AA}$ and $c_0=10.8897{\AA}$.To obtain a single-crystal thin film, mixed $ZnAl_2Se_4$ crystal was deposited on the thoroughly etched semi-insulating GaAs(100) substrate by a hot wall epitaxy (HWE) system. The source and the substrate temperatures were $620^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single-crystal thin film was investigated by using a double crystal X-ray rocking curve and X-ray diffraction ${\omega}-2{\theta}$ scans. The carrier density and mobility of the $ZnAl_2Se_4$ single-crystal thin film were $8.23{\times}10^{16}cm^{-3}$ and $287m^2/vs$ at 293 K, respectively. To identify the band gap energy, the optical absorption spectra of the $ZnAl_2Se_4$ single-crystal thin film was investigated in the temperature region of 10-293 K. The temperature dependence of the direct optical energy gap is well presented by Varshni's relation: $E_g(T)=E_g(0)-({\alpha}T^2/T+{\beta})$. The constants of Varshni's equation had the values of $E_g(0)=3.5269eV$, ${\alpha}=2.03{\times}10^{-3}eV/K$ and ${\beta}=501.9K$ for the $ZnAl_2Se_4$ single-crystal thin film. The crystal field and the spin-orbit splitting energies for the valence band of the $ZnAl_2Se_4$ were estimated to be 109.5 meV and 124.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $ZnAl_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n = 1 and $C_{21}$-exciton peaks for n = 21.

Measurement of the Radiolysis Gases Generated in Several Waste Forms by External Irradiation (${\gamma}$-조사에 의한 방사성폐기물의 방사분해가스 발생량 평가)

  • Kwak, Kyung-Kil;Ryue, Young-Gerl;Kim, Ki-Hong;Je, Whan-Gyeong;Kim, Dong-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.4
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    • pp.345-352
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    • 2006
  • The cemented and paraffin wastes form which are incorporated the concentrated wastes, the cemented waste form which is incorporated the spent ion-exchange resins, and the miscellaneous waste(decontamination paper) were irradiated up to $10^{+8}$ rads at $5.43{\times}10^{+5}$ rads/hr with Co-60(72,023.9 Ci) as an external irradiation source. As a result, the radiolysis gases such as $H_2,\;CH_4,\;N_2,\;C_2H_6,\;O_2,\;CO\;and\;CO_2$, were measured in all the wastes. The major gas which was generated in all the wastes was hydrogen($H_2$). The volume of the generated gases showed a difference from $0.029{\sim}0.788\;cm^3.atm/1.1g$ according to the type of wastes, and more was generated in the cemented waste form incorporated a spent ion-exchange resin than in the other wastes. More hydrogen($H_2$) gas was generated in the decontamination paper waste than in the other wastes, and the G($H_2$) value was 0.12.

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Photocurrent Study on the Splitting of the Valence Band and Growth of BaIn2Se4 epilayers by Hot Wall Epitaxy (Hot Wall Epitaxy(HWE)법에 의한 BaIn2Se4 에피레어 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Jeong, Junwoo;Lee, Kijeong;Jeong, Kyunga;Hong, Kwangjoon
    • Journal of Sensor Science and Technology
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    • v.23 no.2
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    • pp.134-141
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    • 2014
  • A stoichiometric mixture of evaporating materials for $BaIn_2Se_4$ epilayers was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaIn_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $620^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the epilayers was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaIn_2Se_4$ epilayers measured from Hall effect by van der Pauw method are $8.94{\times}10^{17}cm^{-3}$ and 343 $cm^2/vs$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaIn_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)$=2.6261 eV-$(4.9825{\times}10^{-3}eV/K)T^2/(T+558 K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaIn_2Se_4$ have been estimated to be 116 meV and 175.9 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaIn_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1-$, $B_1$-exciton for n = 1 and $C_{21}$-exciton peaks for n=21.

Characteristic Evaluation of Exposed Dose with NORM added Consumer Product based on ICRP Reference Phantom (ICRP 기준팬텀 기반의 천연방사성핵종이 포함된 가공제품 사용으로 인한 피폭선량 특성 평가)

  • Yoo, Do Hyeon;Lee, Hyun Cheol;Shin, Wook-Geun;Choi, Hyun Joon;Min, Chul Hee
    • Journal of Radiation Protection and Research
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    • v.39 no.4
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    • pp.159-167
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    • 2014
  • In Korea, July 2012, the law as called 'Act on Safety Control of Radioactive Rays Around Living Environment' was implemented to control the consumer product containing Naturally Occurring Radioactive Material (NORM), but, there are no appropriate database and effective dose calculation system. The aim of this study was to develop evaluation technique of the exposure dose with the use of the consumer products containing NORM and to understand the characteristics of the exposed dose according to the radiation type and energy. For the evaluate of exposure dose, the ICRP reference phantom was simulated by the MCNPX code based on Monte Carlo method, and the minimum, medium, maximum energy of alphas, betas, gammas from the representative NORM of Uranium decay series were used as the source term in the simulation. The annual effective doses were calculated by the exposure scenario of the consumer product usage time and position. Short range of the alpha and beta rays are mostly delivered the dose to the skin. On the other hand, the gamma rays mostly delivered the similar dose to all of the organs. The results of the annual effective dose with $1Bq{\cdot}g^{-1}$ radioactive stone-bed and 10% radioactive concentration were employed with the usage time of 7 hours 50 minute per day, the maximum annual effective dose of alphas, betas, gammas were calculated 0.0222, 0.0836, $0.0101mSv{\cdot}y^{-1}$, respectively.

SHIELDING ANALYSIS OF DUAL PURPOSE CASKS FOR SPENT NUCLEAR FUEL UNDER NORMAL STORAGE CONDITIONS

  • Ko, Jae-Hun;Park, Jea-Ho;Jung, In-Soo;Lee, Gang-Uk;Baeg, Chang-Yeal;Kim, Tae-Man
    • Nuclear Engineering and Technology
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    • v.46 no.4
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    • pp.547-556
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    • 2014
  • Korea expects a shortage in storage capacity for spent fuels at reactor sites. Therefore, a need for more metal and/or concrete casks for storage systems is anticipated for either the reactor site or away from the reactor for interim storage. For the purpose of interim storage and transportation, a dual purpose metal cask that can load 21 spent fuel assemblies is being developed by Korea Radioactive Waste Management Corporation (KRMC) in Korea. At first the gamma and neutron flux for the design basis fuel were determined assuming in-core environment (the temperature, pressure, etc. of the moderator, boron, cladding, $UO_2$ pellets) in which the design basis fuel is loaded, as input data. The evaluation simulated burnup up to 45,000 MWD/MTU and decay during ten years of cooling using the SAS2H/OGIGEN-S module of the SCALE5.1 system. The results from the source term evaluation were used as input data for the final shielding evaluation utilizing the MCNP Code, which yielded the effective dose rate. The design of the cask is based on the safety requirements for normal storage conditions under 10 CFR Part 72. A radiation shielding analysis of the metal storage cask optimized for loading 21 design basis fuels was performed for two cases; one for a single cask and the other for a $2{\times}10$ cask array. For the single cask, dose rates at the external surface of the metal cask, 1m and 2m away from the cask surface, were evaluated. For the $2{\times}10$ cask array, dose rates at the center point of the array and at the center of the casks' height were evaluated. The results of the shielding analysis for the single cask show that dose rates were considerably higher at the lower side (from the bottom of the cask to the bottom of the neutron shielding) of the cask, at over 2mSv/hr at the external surface of the cask. However, this is not considered to be a significant issue since additional shielding will be installed at the storage facility. The shielding analysis results for the $2{\times}10$ cask array showed exponential decrease with distance off the sources. The controlled area boundary was calculated to be approximately 280m from the array, with a dose rate of 25mrem/yr. Actual dose rates within the controlled area boundary will be lower than 25mrem/yr, due to the decay of radioactivity of spent fuel in storage.