• Title/Summary/Keyword: 베타계수

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Radioassay of Multiple Beta-Labeled Mixtures using Least-Square Method (최소자승법을 이용한 다수 베타 방출 핵종 혼합물의 방사능 분석)

  • Seon, Kwang-Il;Nam, Uk-Won;Kong, Kyoung-Nam;Kim, Chang-Kyu;Lee, Dong-Myung;Lee, Sang-Kook
    • Journal of Radiation Protection and Research
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    • v.26 no.4
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    • pp.375-384
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    • 2001
  • It is possible to count and perform quench correction on two ${\beta}$ -label samples so long as the maximum ${\beta}$-energies are sufficiently different. However, when 4he conventional technique is applied to the radioassay of a mixture of more than three nuclides, the reliability of the activities determined is considerably reduced, resulting from the large overlapping of liquid scintillation pulse height distributions of each nuclide. A technique that allows the activities of multiple ${\beta}$-labeled samples to be radioassayed was proposed by using the least square method. The technique was applied to mixture samples of $^3H,\;^{14}C,\;^{36}Cl$, and $^{90}Sr$. The analytical values were in good agreement with the reference values within 7% relative error.

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Preparation of an Inorganic Scintillator Loaded Film for the Measurement of Surface Contamination and its Performance Test (표면오염 측정용 무기섬광 함침 필름의 제조 및 성능 평가)

  • 서범경;이근우;임난주;박진호;한명진
    • Journal of Energy Engineering
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    • v.13 no.2
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    • pp.93-100
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    • 2004
  • The smear media possible to sampling and radiation detection was prepared and evaluated for the surface contamination using indirect method. The films were made by impregnating Cerium Activated Yttrium Silicate (CAYS) in a polysulfone membrane. The membranes used solution as a dimethylformamide (DMF) and methylene chloride (MC), polysulfone as a polymer matrix and CAYS as a inorganic scintillator. The proximity membranes were prepared with single- and double-layered structure. The solidified methods were immersion to the nonsolvent bath such at water and ethanol and solvent evaporation. The measurement of the photon produced by interaction with radiation and inorganic scintillator used a photomultiflier tube (PMT), amplifier, and counter. In the comparison with the low background alpha/beta counter, the counter rate using inorganic scintillator proximity membrane for the $\^$14/C surface contamination was about 50%. Also. the $^3$H counting results revealed that the prepared membranes were efficient to monitor the surface contaminated with the low energy be-ray emitter nuclides.

한국에서 일하는 외국인 과학기술자 - 한국표준과학연구원의 폴란드 과학자 '리자드 브로다 박사'

  • Korean Federation of Science and Technology Societies
    • The Science & Technology
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    • v.33 no.3 s.370
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    • pp.76-77
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    • 2000
  • 한국의 우수두뇌유치 프로그램에 의해 지난해 2월부터 한국표준과학연구원에서 근무하고 있는 폴란드 과학자 리자드 브로다박사는 현재 베타방출핵종을 액체섬광계수방법으로 표준화하는 연구를 수행하고 있다. 그가 재직중인 폴란드방사성동위원소센터와 한국표준과학연구원 방사능그룹은 동시계수를 이용한 방사성 핵종의 표준화 등 비슷한 내용을 연구하고 있으므로 계측문제를 함께 풀어나가면서 훨씬 빠른 발전이 이루어질 것이라고 내다보았다.

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Simultaneous analysis of β-lactam antibiotics in surface water (하천수중 잔류 베타-락탐계 항생제의 동시분석법)

  • Huh, Min-Jeong;Myung, Seung-Woon
    • Analytical Science and Technology
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    • v.23 no.2
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    • pp.119-127
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    • 2010
  • An effective method for the simultaneous analysis of ${\beta}$-lactams from surface water was established. After solid-phase extraction with HLB (Hydrophilic Lipohilic Balance) cartridge at pH 2, seven ${\beta}$-lactams (amoxicillin, ampicillin, penicillin G, cefaclor, cefadroxil, cefatrizine and cephradine) were determined using LC/ESI-MS/MS. In this newly established method, correlation coefficients ($r^2$) of calibration curves for seven ${\beta}$-lactams in blank surface water appeared to be 0.9911~0.9995 in the concentration range of 0.01~1.0 ng/mL. The limits of detection (LODs) and the limits of quantificaiton (LOQs) in spiked surface water were shown to be 0.0003~0.0234 ng/mL and 0.0046~0.0778 ng/mL, respectively. The developed method is believed to serve as a rapid and reliable method for the qualitative and quantitative analysis of residual ${\beta}$-lactam antibiotics from aquatic environment.

Influence of organization nature on management outcome in security companies (시큐리티 업체의 조직특성이 경영성과에 미치는 영향)

  • Park, Young-Jin;Cho, Cheol-Kyu
    • Convergence Security Journal
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    • v.13 no.5
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    • pp.147-156
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    • 2013
  • This research tried to find out the influence of organization nature on management outcome in security companies. First, in the relation between organization nature and management outcome (inside viewpoint) in security companies, factors of organization culture (t=2.534, p<.05) and job nature (t=6.425, p<.001), in organization nature, were shown to give statistically meaningful positive (+) influence on inside viewpoint, and the relative influence of independent variables measured in terms of beta coefficient was ${\beta}$=.226 for organization culture and ${\beta}$=.576 for job nature. Second, in the relation between organization nature and management outcome (study growth viewpoint) in security companies, factors of organization culture (t=2.070, p<.05) and job nature (t=10.507, p<.001), in organization nature, were shown to give statistically meaningful positive (+) influence on study growth viewpoint, and the relative influence of independent variables measured in terms of beta coefficient was ${\beta}$=.145 for organization culture and ${\beta}$=.741 for job nature. It may be concluded that the nature of security service organization affects organization culture relatively, with the implication that systematic educational practice system and organizational study should be accompanied for achievement of ultimate purpose of the organization. It is also implied that field support will be needed considering the job nature, because organization nature has a causal relationship with the specialty of security service job.

International Comparison of Absolute Activity Measurement of $^{133}Ba$ Solution ($^{133}Ba$ 용액의 방사능 절대측정의 국제비교)

  • Park, Tae-Soon;Oh, Pil-Jae;Hwang, Sun-Tae
    • Journal of Radiation Protection and Research
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    • v.10 no.2
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    • pp.130-136
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    • 1985
  • The activity measurement of a solution of $^{133}Ba$ which is an electron capture nuclide was carried out by the ${\beta}-{\gamma}$ coincidence method. The counting rates at the ${\beta}-,\;{\gamma}-$, and coincidence-channels were measured using a $4{\pi}$ proportional counter and two NaI(Tl) scintillation detectors. The specific activity of the solution calculated by the efficiency extrapolation was $(1151.01{\pm}2.99)kBqg^{-1}$ at the reference time(00h UT, 03-15-84). According to an international comparison of activity measurements organized by the Bureau International des Poids et Mesures, this result showed the difference of 0.94% to the mean value derived from the comparison.

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Assessment of Effective Doses in the Radiation Field of Contaminated Ground Surface by Monte Carlo Simulation (몬테칼로 시뮬레이션에 의한 지표면 오염 방사선장에서의 유효선량 평가)

  • Chang, Jai-Kwon;Lee, Jai-Ki;Chang, Si-Young
    • Journal of Radiation Protection and Research
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    • v.24 no.4
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    • pp.205-213
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    • 1999
  • Effective dose conversion coefficients from unit activity radionuclides contaminated on the ground surface were calculated by using MCNP4A rode and male/female anthropomorphic phantoms. The simulation calculations were made for 19 energy points in the range of 40 keV to 10 MeV. The effective doses E resulting from unit source intensity for different energy were compared to the effective dose equivalent $H_E$ of previous studies. Our E values are lower by 30% at low energy than the $H_E$ values given in the Federal Guidance Report of USEPA. The effective dose response functions derived by polynomial fitting of the energy-effective dose relationship are as follows: $f({\varepsilon})[fSv\;m^2]=\;0.0634\;+\;0.727{\varepsilon}-0.0520{\varepsilon}^2+0.00247{\varepsilon}^3,\;where\;{\varepsilon}$ is the gamma energy in MeV. Using the response function and the radionuclide decay data given in ICRP 38, the effective dose conversion coefficients for unit activity contamination on the ground surface were calculated with addition of the skin dose contribution of beta particles determined by use of the DOSEFACTOR code. The conversion coefficients for 90 important radionuclides were evaluated and tabulated. Comparison with the existing data showed that a significant underestimates could be resulted when the old conversion coefficients were used, especially for the nuclides emitting low energy photons or high energy beta particles.

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Is the technology in renewable energy converging among countries? : Using the patent data of OECD (재생에너지 분야 국가 간 기술 확산 및 수렴 : OECD 특허 데이터를 이용한 분석)

  • Oh, Keunyeob;Yoo, Jinman
    • Environmental and Resource Economics Review
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    • v.23 no.1
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    • pp.67-89
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    • 2014
  • This paper uses patent data of OECD countries in order to investigate if there is converging tendency in renewable energy area. We used the concepts of sigma convergence and beta convergence to measure the convergence. GINI coefficient, HH index are also borrowed from other area of economics. The results show that technology level does not seem to have been converging in this area. Even though the number of patent in relatively less advanced countries has been increased a lot, we could find no evidence that there is the tendency that the gap among the countries have been narrowed. This is quite different from the results of IT industry or other industry since we could find the converging tendency in the data of those industries. Instead, it seems that there is the convergence club among most advance countries in renewable energy area.