• Journal of Radiation Industry
• /
• v.6 no.3
• /
• pp.231-237
• /
• 2012

This paper introduces a gamma-ray measurement system for a transportable tomography which is applicable for an industrial process diagnosis. The gamma-ray measurement system consists of pulse mode operating 72 channel CsI detectors, main AMP-pulse shaper, single channel analyzer, counter and control PC. The CsI crystal is coupled with a PIN diode which is connected to an amplifier and pulse shaper. For a compact design, the amplifier and pulse shaping circuit are included in a single package. 36 sets of CsI detectors are connected to a multi-channel counter through single channel analyzers. A computer controls and collects data from two multi-channel counters. This configuration results in 72 channel counting system in total. The CT rotator and radiation measurement system are controlled by a PC with LabVIEW program. Tomographic data were measured for a phantom by the measurement system and transportable gamma-ray CT. From the experimental data image reconstructions were performed by ML-EM algorithm. The result showed that the CsI detector system can be a suitable component for transportable gamma-ray CT system.

• 대한방사선방어학회:학술대회논문집
• /
• 2011.11a
• /
• pp.122-123
• /
• 2011

• Proceedings of the Mineralogical Society of Korea Conference
• /
• 2001.06a
• /
• pp.40-40
• /
• 2001

The sorption behavior of Cs(I), Sr(II), and U(VI) on representative single minerals(oxide and clay) and rocks were comparatively studied by using batch type sorption experiment. The effects of pH, ionic strength and the sorption mechanism were also discussed. It was found that mineral structure played as a main factor governing the sorption characteristics of Cs(I), Sr(II). The sorption of Cs(I) and Sr(II) on minerals showed ionic strength-dependency, which is a indirect sign of weak binding between metal cation and mineral surfaces. However, the sorption behavior of U(VI) was quite different compared with that of Cs(I), and Sr(II). Fe-oxide minerals showed strong tendency for U(VI) sorption, dominating the sorption in the composite/mixture systems. The surface characteristics which arise from mineral structure, and the affinity of metal ions to the sorption sites of minerals are the key to understand the role of minerals in the radionuclide sorption.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.07b
• /
• pp.778-780
• /
• 2005

본 논문에서는 학습을 통해 JPEG 영상의 잡영을 제거하는 방법을 제안한다. 주어진 영상을 low-pass filtering 하면 JPEG 영상의 잡영 제거는 남아있는 저주파 성분으로부터 원래의 고주파 성분을 복원하는 문제가 된다. 다수의 영상과 이를 JPEG 압축한 영상의 쌍들이 주 어졌을때, low-pass filter된 영상으로부터 원하는 고주파 성분을 추정하는 함수를 학습함으로써 JPEG 영상의 잡영을 제거하였다.

• Analytical Science and Technology
• /
• v.13 no.5
• /
• pp.565-572
• /
• 2000

In this paper it was described on the standards for Xe analysis by Wavelength Dispersive X-ray Spectrometer (WDS) of Electron Probe Micro Analyser. According to the experimental results, CsI and $BaCO_3$ are appropriate compounds as standard specimen for Cs, I and Ba which has not suitable pure metal standards. In the beam current of 10-30 nA range, the Cs x-ray intensity measured from CsBr and CsI was proportional to the beam current. It was found that the linear regression factor R, showing the linearity between the atomic number and x-ray intensity between In and Nd elements, was higher than 0.99 at 25 kV and PET crystal. The caJlculated x-ray intensity of Xe standard from this linear regression equation was 1.095 times higher than that ofTe at 25 kV.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.11a
• /
• pp.204-204
• /
• 2003

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2002.11a
• /
• pp.118-118
• /
• 2002

• Advances in materials Research
• /
• v.7 no.1
• /
• pp.73-81
• /
• 2018

$TiO_2/CH_3NH_3Pb_{1-x}Sb_xI_{3-3x}Br_{3x}-based$ photovoltaic devices were fabricated by a spin-coating method using mixture solutions with $SbBr_3$. Effects of $SbBr3$, CsI or RbBr addition to $CH_3NH_3PbI_3$ precursor solutions on the photovoltaic properties where investigated. The short-circuit current densities and photoconversion efficiencies were improved by adding a small amount of $SbBr_3$, CsI or RbBr to the perovskite phase, which would be due to the doping effect of Sb, Br and Cs/Rb atom at the Pb, I and $CH_3NH3$ sites, respectively.

• Journal of the Optical Society of Korea
• /
• v.18 no.3
• /
• pp.256-260
• /
• 2014

Columnar-structured cesium iodide (CsI) scintillators doped with thallium (Tl) are frequently used as x-ray converters in medical and industrial imaging. In this study we investigated the imaging characteristics of CsI:Tl films with various reflective layers-aluminum (Al), chromium (Cr), and titanium dioxide ($TiO_2$) powder-coated on glass substrates. We used two effusion-cell sources in a thermal evaporator system to fabricate CsI:Tl films on substrates. The scintillators were observed via scanning electron microscopy (SEM), and scintillation characteristics were evaluated on the basis of the emission spectrum, light output, light response to x-ray dose, modulation transfer function (MTF), and x-ray images. Compared to control films without a reflective layer, CsI:Tl films with reflective layers showed better sensitivity and light collection efficiency, and the film with a $TiO_2$ reflective layer showed the best properties.

• Korean Journal of Food Science and Technology
• /
• v.47 no.6
• /
• pp.789-792
• /
• 2015

Samples of fishery products were tested for radioactivity by using the intake frequency data from Korea Health Statistics. The radioactivity of $^{40}K$, $^{137}Cs$, $^{134}Cs$, and $^{131}I$ was analyzed using gamma spectrometry with a simplified sample pre-treatment procedure. The radioactivity range for $^{40}K$ was 21.9-3050 Bq/kg, whereas the radioactivities of $^{137}Cs$, $^{134}Cs$, and $^{131}I$ were under minimum detectable activity which were in the range of 0.140-1.97, 0.0900-1.89 and 0.124-1.94 Bq/kg, respectively, for the three species. The results suggest that the Fukushima accident did not have a significant impact on domestic fishery products, which were analyzed during the period from 2013 to 2015. Additionally, there seemed to be no significant impact of additional exposure dose by the analyzed radionuclides.