• 제목/요약/키워드: Gamma Detection

검색결과 542건 처리시간 0.031초

Tracing some enzymatic activities in three virulent pathogenic erwiniae

  • Saleh, Youssry E.
    • Archives of Pharmacal Research
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    • 제13권1호
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    • pp.105-107
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    • 1990
  • The absence, in the biomass, of glutamic-oxalacetic and glutamic-pyruvic transaminases and the prevalance of gamma-glutamic transpeptidase were taken as basic criteria to differentiate between Erwinia carotovora var. carorovora from E. carotovora var, citrullis and E. toxica. For further identification, detection of cholesterol in the biomass confirmed the toxica species whereas the absence of glucose confirmed the citrullis variety.

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$4{\pi}{\beta}-{\gamma}$ 동시계수기술에 의한 $^{56}Mn$방사능 절대측정 (Absolute $^{56}Mn$ Activity Measurement by $4{\pi}{\beta}-{\gamma}$ Conincidence Counting Technique)

  • 황선태;최길웅;오필제;이경주;이건재
    • Journal of Radiation Protection and Research
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    • 제12권2호
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    • pp.19-27
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    • 1987
  • 황산망간 용액조장치의 $^{56}Mn\;{\gamma}$선 검출효율을 결정하는데 $^{56}Mn$용액의 방사능을 절대측정하는 것은 필수적이다 $^{56}Mn$시료를 제작하기 위하여 99.99%의 순도를 갖는 Mn금속조각 13.718mg되는 시료를 한국에너지연구소 TRIGA MARK-II 원자로의 중성자선속이 약 $10^{13}n/cm^2{\cdot}s$되는 열중성자장에서 12분간 조사시켰다. 중성자 방사화된 $^{56}Mn$금속시료를 0.1N-HCI 용액 50ml 용해시켜서 $^{56}Mn$시료를 제작하여 $4{\pi}{\beta}-{\gamma}$ 동시계수기술로 방사능을 측정한 결과 불확도 0.366%를 갖는 값으로서 1987년 10월 15일 0 시를 기준하여 408.070kBq/mg을 얻었다.

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Plastic scintillator beta ray scanner for in-situ discrimination of beta ray and gamma ray radioactivity in soil

  • Bae, Jun Woo;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
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    • 제52권6호
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    • pp.1259-1265
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    • 2020
  • A beta ray scanner was proposed for in-situ discrimination of beta and gamma ray radioactivity. This scanner is based on the principle that gamma and beta rays experience different changes in detection efficiency in scintillators with different geometries, especially with regard to the scintillator thickness. The ratios of the counting rates of gamma rays (Rgamma), beta rays (Rbeta), and sample measurements (Rtotal) in a thick scintillator to those in a thin one are reported. The parameter Xthick, which represents the counting rate contributed by beta rays to the total counting rate in the thick scintillator, was derived as a function of those ratios. The values of Rgamma and Rbeta for 60Co and 90Sr sources were estimated as 3.2 ± 0.057 and 0.99 ± 0.0049, respectively. The estimated beta ray contributions had relative standard deviations of 2.05-4.96%. The estimated range of the beta rays emitted from 90Sr was 19 mm as per the Monte Carlo N-Particle simulation, and this value was experimentally verified. Homogeneous and surface contaminations of 60Co and 90Sr-90Y were simulated for application of the proposed method. The counting rate contributed by the beta rays was derived and found to be proportional to the concentration of 90Sr-90Y contamination.

Effects of Irradiation Temperature on the Sensory Quality Improvement of Gamma-irradiated Ganjang-gejang, Korean Traditional Marinated Raw Crab Portunus trituberculatus in Soybean Sauce

  • Park, Jae-Nam;Byun, Eui-Baek;Han, In-Jun;Song, Beom-Seok;Sohn, Hee-Sook;Park, Sang-Hyun;Byun, Eui-Hong;Yoon, Minchul;Sung, Nak-Yun
    • Fisheries and Aquatic Sciences
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    • 제18권2호
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    • pp.115-121
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    • 2015
  • This study was conducted to confirm quality properties of sterilized Ganjang-gejang (marinated crab Portunus trituberculatus) with Korean soy sauce using by gamma irradiation and to improve quality of sterilized Ganjang-gejang. The Ganjang-gejang was irradiated at dose of 3, 6, 9, 12, and 15 kGy by gamma irradiation and there was evaluated in microbiological, physicochemical, and sensory properties. Total aerobic bacteria and fungi contents of non-irradiated samples were about 6 and 4 log CFU/g level, respectively. Gamma-irradiated samples at above 9 kGy did not contain aerobic bacteria or fungi at detection limit less than 2 log CFU/g, but sensory scores were significantly decreased depending on the irradiation dose. To improve the sensory qualities of gamma-irradiated Ganjang-gejang, the temperature was adjusted during sample irradiation. When samples were irradiated under freezing temperatures, especially on dry ice, the TBARS and the deterioration of sensory qualities of Ganjan-Gejang were reduced. Different odor patterns were observed among samples, as observed using electronic nose analysis system. The results of this study indicated that treatment with irradiation under low temperatures may help to preparing high-quality Ganjang-gejang.

소 결핵병 검사에 사용되는 감마인터페론법과 단일피내접종법의 상관관계 비교분석 (A comparative study of the gamma-interferon assay and the single intradermal tuberculin test for the diagnosis of bovine tuberculosis under field conditions)

  • 하민종;오경민;김상윤;도재철;이영주
    • 한국동물위생학회지
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    • 제41권2호
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    • pp.71-78
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    • 2018
  • Bovine tuberculosis (bTB) is a wide-spread zoonotic disease in cattle, which is casued by Mycobacterium bovis that is a part of Mycobacterium tuberculosis complex (MTC). This study describes a field trial conducted in 42 herds with the history of prevalence bovine tuberculosis. Two cell-mediated immunity tests, the gamma-interferon (${\gamma}-IFN$) assay and the single intradermal tuberculin test (SIT) were applied for the diagnosis of bovine tuberculosis in 5,289 animals. The ${\gamma}-IFN$ assay presented 144 (2.7%) head of cattle with the positive result, and 112 (2.1%) head of cattle were shown to be bTB-positive by the SIT. The positive concordance was 45.5%, and the negative concordance was 98.2%. The ${\gamma}-IFN$ assay showed more positive results in younger cattle, especially between 12 and 23 months of age. It is shown that the strategic combination of both cell-mediated immunity test methods is more efficient for the detection of bTB to reduce the number of false positive individuals which are being slaughtered.