• 분석과학
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• 제17권5호
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• pp.434-437
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• 2004

Alpha track technology can provide useful isotopic information of boron in the primary coolant water. In the quantitative analysis using the alpha track analysis, the shape or area of sample on the solid track detector becomes very important, especially for the analysis of liquid samples. In this research, a multi-dot plate has been developed for this purpose. The multi-dot plate provides fixed standard shape of the sample solution that stays inside of the printed circle, and consequently increases the reproducibility of the boron analysis.

• Nuclear Engineering and Technology
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• 제38권4호
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• pp.353-358
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• 2006

Alpha track analysis for the determination of the trace amount of alpha emitting nuclides in a very small particle was performed as an efficient and powerful technique during safeguard inspection. Metal particles with well-defined spherical shape, size and isotopic compositions as a reference material were used to correlate the number of tracks or track diameter with an isotopic composition eventually to identify the uranium enrichment in the environmental swipe samples. Slopes in the number of tracks versus the exposure time curve provide a simple insight into the uranium enrichment of an unknown particle. Low enriched uranium metal particles result in slopes still steeper than the depleted or natural uranium metal particles. In addition, a linear relationship between track diameter and particle size Is thought to be a useful first stage analytical tool as an efficient and convenient inspection guide. The significance of the simple linear model was also judged using the usual statistical tests.

• Bulletin of the Korean Chemical Society
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• 제27권10호
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• pp.1609-1612
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• 2006

The determination of the boron isotopic ratio in solutions was achieved by means of a solid state track detector by using an alpha track. The neutron flux was optimized by using a Cd-foil to find the optimum conditions for counting the number of alpha tracks on the selected solid detector caused by the (n, $\alpha$) nuclear reaction of boron. The home-made multi-dot detector plate was utilized in this study to increase the reproducibility of the measurement by uniformly drying the boron solution within the marked circle area on the detector plate. The experimental results of this study verified that the $^{11}B/^{10}B $ isotopic ratio can be measured by observing the number of alpha tracks for different concentrated standard solutions with various isotopic compositions. This technique was applied to the determination of $^{10}B$ enrichment factor in a biological sample for a boron neutron capture therapy.

• 분석과학
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• 제18권4호
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• pp.263-270
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• 2005

핵분열트랙은 우라늄, 플루토늄, 토륨 등의 방사성핵종 분석이나, 리튬이나 붕소와 같이 열중성자와 핵반응을 하는 원소분석에 매우 유용하다. 이 방법은 대기 중의 방사성핵종 분석을 통해 핵무기 실험을 검출한다거나, 우주공간의 중이온에 대한 선량측정이나 운석의 우주선 조사과정 추정, 원자력분야의 핵분열률 측정, 암석의 연대 및 역사를 파악하거나, tracer로 사용하는 등 여러 분야에 적용 가능하다. 현재 원자력연구소에서는 알파트랙기입법을 이용한 미량의 보론 분석이나, 핵분열트랙을 이용한 우라늄 등의 핵물질을 포함한 입자분석에 적용하고 있다. 본 총설에서는 트랙형성의 이론적 배경, 에칭된 트랙을 얻는 실제 과정 및 앞으로의 전망 등에 대해 살펴보았다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1184-1189
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• 2006

Railway vehicle have three translational motions-longitudinal, vertical and lateral, and three rotational motions-rolling, pitching and yawing caused by track irregularity, wheel and rail characteristic, dynamic behaviors etc. The rolling motion in vehicle mainly happens in cases of the vehicles stationary and running on canted track. When the vehicle positioned in stationary on canted track, vehicle is inclined toward inside of installed cant due to gravity component. When the vehicle has running on a track with cant deficiency, vehicle is inclined toward outside of installed cant due to centrifugal force. The roll coefficient(s) is defined as the ratio between the angle of inclination of the vehicle($\eta$) and the angle of the rail level($\alpha$). This paper has noted the test method, test result and analysis result to calculate the roll coefficient according to UIC505-5, international standard

• Journal of Radiation Protection and Research
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• 제12권1호
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• pp.26-33
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• 1987

알파입자 검출을 위한 고체 비적 검출기인 CA 8-15와 LR 115-1은 그 부식조건이 검출기 제조 회사에서 이미 주어지고는 있으나 이들 검출기에 대한 최적부식에 관한 실험적 검토를 다시 행하였는바 최적부식시간에 현저한 차이가 있음을 발견하였다. 검출기의 방사선 조사는 이미 설정된 기하학적 배치조건하에서 $0.1{\mu}Ci$수준의 $^{241}Am$ 알파선원으로 수행하였다. 부식시간과 용액 농도의 함수로서의 비적크기에 대한 분석과 검출기에 검출된 단위면적당 비적의 이론적 기대치에 대한 비교 조사를 행하였으며, 입사 알파입자의 유효 에너지에 대한 검출효율의 변화에 대해서도 연구하였다.

• 산업공학
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• 제16권spc호
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• pp.111-115
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• 2003

Railroad system is consisted of resources of rail track, signal system, and vehicles. Railway operation must use these limited resources and maximize resource utilization. Line capacity(number of trains throughput/day) is determined by such as parameters, line utilization rate($\alpha$), dummy rate for the break-through hour($\beta$), and dummy rate for the number of rail track intervals($\delta$). Line capacity simulation(LCS) determined the line capacity through simulation given $\alpha$, $\beta$, and $\delta$. This paper deals with the development of parameter evaluation simulation(PES). PES presents the decision maker with the relationship of line capacity and measurement of robustness for various scenarios in different parameters and then the decision maker can determine the appropriate parameters.

• Journal of Radiation Protection and Research
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• 제11권2호
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• pp.130-138
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• 1986

CA 80-15 및 LR 115-1 cellulose nitrate 비적검출기를 사용하여 지표공기중의 ${\alpha}$방사능을 측정 해석하였는바 이 검출기의 검출효율은 $0.1{\mu}Ci$의 $^{241}Am\;{\alpha}$선을 사용하여 결정하였다. 지표에서 방출되는 라돈과 그 자핵종들에 의한 ${\alpha}$방사능을 검출하기 위하여 두가지의 라돈컵을 사용하였으며 이들을 각각 지름이 15cm, 깊이가 45cm인 이웃한 두개의 땅구덩이를 만들어 그 안에 설치하여 일정기간 ${\alpha}$방사능에 노출하였다. 두 라돈컵중 하나는 구덩이 지표면에 거꾸로 밀착시켜 밀폐공간이 되게 하고 다른 하나는 바닥에서 일정한 거리를 띄우고 컵 윗면에 구멍을 뚫어 공기의 소통이 가능하도록 하여 그 검출결과를 비교 검토하였다. ${\alpha}$입자에 피폭된 비적검출기는 부식처리한 후 현미경으로 판독하고 통계분석 하였으며 그 결과를 지표공기 단위부피당 ${\alpha}$방사능농도로 환산 평가하였다.

• Nuclear Engineering and Technology
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• 제30권6호
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• pp.518-530
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• 1998

A natural analogue study has been performed for the Koongarra uranium ore deposit in Australia as an international agreement of the Analogue Studies in the Alligator Rivers Region (ASARR). Rocks obtained from the Koongarra deposit, Northern Territory of Australia, were examined in order to understand uranium migration processes of primary and secondary ore-body in both weathered and unweathered zones. Total alpha activities of rock samples were measured to compare the relative amount of uranium in the sample. Uranium distributions have been investigated by means of both the alpha-autoradiography and the fission track registration technique after irradiation in a flux of thermal neutrons (~10$\times$$10^{13}$nㆍ$cm^{-2}$ㆍs$^{-1}$) for 2 minutes. The mineral phases corresponding to the registered alpha-tracks and fission tracks were identified by petrological observation with optical microscope as well as X-ray diffraction and electron microprobe analysis (EPMA). Uranium was found mostly inside of the fracture of the quartzite and its mineral phase was identified as sklodowskite. The mineral phase associated with high uranium concentration was found as illeminite by petrological observation with optical microscope as well as EPMA.

• 천문학회보
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• 제41권1호
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• pp.71.1-71.1
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• 2016

Photometric reverberation mapping is an effective alternative to time consuming spectroscopy. It usually employs narrow bands to track the luminosity variations of broad emission lines, such as Balmer lines, and broadbands for the continuum variability. Here, we investigate the feasibility of substituting these for medium bands, with 50nm widths, that are currently being used on the SED Camera for QUasars in EArly uNiverse (SQUEAN) installed on the 2.1m Otto Struve Telescope at McDonald Observatory. Three targets with recent variability and/or short expected time lags were selected, and observed for 15 minutes each in the medium band containing $H{\alpha}$, and the two adjacent bands for continuum subtraction afterwards. Analysis shows that for one of the objects, SDSS J0350+0037, the pure $H{\alpha}$ emission line flux has a S/N ~ 12, so that variabilities up to ~ 8% are detectable. Thus, future observations using these medium bands on SQUEAN seem to be practical.