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        검색결과 4

        1.
        2023.11 구독 인증기관·개인회원 무료
        Detectors utilized for nuclear material safeguards have been using scintillation detectors which are inexpensive and highly portable, and electrically cooled germanium detectors which are expensive but have excellent energy resolution. However, recently IAEA, the only international inspectorate of nuclear material safeguards for the globe, have replaced the existing scintillation detector and electrically cooled germanium detector with a CdZnTe detector owing to the improved performance of room-temperature semiconductors significantly. In this paper, we will examine the spectrum features of the CdZnTe detector such as spectrum shape, energy resolution, and efficiency in the energy region of interest, which are the important characteristics for measuring Uranium enrichment. For this purpose, it would be conducted to compare its spectrum features using CdZnTe, NaI, HPGe detectors. The main energies of interest include 185.7 keV and 1,001 keV, which are the decay energies of uranium 235 and uranium 238. The results of this study will provide a better understanding of the spectral features of various detectors used in uranium enrichment analysis, and are expected to be used as basic data for future related software development.
        2.
        2023.07 구독 인증기관 무료, 개인회원 유료
        This study suggests that using AI chatbots with highly human-like characteristics could reduce the effectiveness of personalized AI chatbot advertising because they will likely worsen consumer concerns about privacy. Conversely, using AI chatbot with less human-like characteristics will not heighten consumer privacy concerns, thereby increasing the impact of personalized AI advertising.
        4,000원
        3.
        2023.05 구독 인증기관·개인회원 무료
        Detectors used for nuclear material safeguards activities are using scintillator detectors to quickly calculate the uranium enrichment at various nuclear material handling facilities. In order to measure the uranium enrichment, a region of interest is set around 185.7 keV which is the main gamma emission energy of uranium-235 in which the proportional relationship between the amount of uranium-235 and the net count is used. It is necessary to perform channel/energy calibration that a specific channel of the multi-channel analyzer is set to 185.7 keV. Most detector manufacturers have a built-in calibration source so that it is automatically performed when the detector starts to operate. In addition, the scintillator detector requires attention because the channel/energy gain may change depending on the ambient temperature so that a calibration source is used to compensate for this. In this paper, the spectral features are examined from among the scintillator detectors seeded with calibration sources used for safeguards activities. For this purpose, FLIR’s Identifinder-2 R400 T2 model and Canberra’s NAID model were used. HM-5 contains about 15nCi of Cs-137 and a photoelectric peak occurs at 662.1 keV. NAID contains about Am-241 of 55 nCi which alpha decays and subsequently emits gamma rays of 59.5 keV and 26.3 keV. The major difference among the detectors occurs in the background spectrum due to the difference in the source. From that kind of spectral features, it can be confirmed that the equipment is operating properly only when the spectrum by the corresponding calibration source is accurately known. The results of this study will enable a better understanding of the characteristics of scintillator detectors used for uranium enrichment analysis. Therefore, it is expected to be used as basic research for related software utilization as well as development in the future.
        4.
        2011.10 구독 인증기관·개인회원 무료
        Hz-2V, which belongs to nudiviridae, is a sexually transmitted insect virus of corn earworm, Helicoverpa zea. Hz-2V is transmitted during mating or mating attempt of infected individuals, and specifically replicates in the reproductive tissues to cause abnormal development of testes and ovary in the adult moths of next generations. The malformation of Hz-2V reproductive tissues started during the early pupal stage without clear sign of virus replication. The virus replication started at the late pupal stage to cause sterility of the emerged moths. Interestingly, the infected female moths showed a unique pathology, so called ‘waxy-plug’, which is filled with virus particles, and abnormal mating behavior while they produced 6~7 times more of pheromone than the normal female moths did. To investigate the factors of Hz-2V which control the physiological, and behavioral changes of the infected moths, the whole genome sequence of Hz-2V was determined. Bioinformatics analysis demonstrated that Hz-2V contains 113 putative ORFs including juvenile hormone esterase (JHE) and histone binding protein homologues, and a miRNA candidate which probably controls the expression of viral JHE.