• Nuclear Engineering and Technology
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• 제54권2호
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• pp.486-492
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• 2022

Nitrogen oxides (NO_x; NO and NO₂) are major air pollutants and can cause harmful effects on the human body. Electron Beam Flue Gas Treatment (EBFGT) is a technology that generates electrons with an energy of 0.5-1 MeV using electron accelerators and effectively processes exhaust gases. In this study, NO_x was removed using an electron beam accelerator with spraying additives (NaOH and NH₄OH). NO and NO₂ were 100% and more than 94% removed, respectively, at an electron beam absorbed dose of 20 kGy and an additive concentration of 0.02 M (mol/L). In most cases, NO_x was removed better with lower initial NOx concentrations and higher electron beam absorbed doses. As the irradiation strength (mA) of the electron beam increases, the probability of electron impact on the material accordingly rises, which may lead to increase removal efficiency. The results of the present study show that the continuous electron beam process using additives achieved more effective removal efficiency than either individual process (wet-scrubbing or EB irradiation only).

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 동계학술발표회 논문집
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• pp.321-322
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• 2007

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.1034-1035
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• 2005

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.246.1-246.1
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• 2003

• 대한방사선기술학회지:방사선기술과학
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• 제22권2호
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• pp.53-56
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• 1999

A Gaussian distribution was parametrized for the initial distribution of the electron beam emitted from a 6MeV medical linear accelerator. A percent depth dose was measured in a water phantom and the corresponding Monte Carlo calculations were performed starting from a Gaussian distribution for a range of standard deviations, ${\sigma}=0.1$, 0.15, 0.2, 0.25, and 0.3 with being the mean value for the Incident beam energy. When measurement and calculation were compared, the calculation with the Gaussian distribution for ${\sigma}=0.25$ turned out to agree best with the measurement. The results from the present work can be utilized as input energy data in planning an electron beam therapy with a Monte Carlo calculation.

• 한국분말재료학회지
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• 제15권6호
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• pp.466-470
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• 2008

Experiments with a URT-0.5 accelerator (0.5 MeV, 50 ns, 1 kW) generating a nanosecond electron beam for irradiation of silver nitrate in various liquid solutions (water and toluene) were performed with the aim of producing silver nanopowders. A radiochemical reaction allows making weakly agglomerated pure Ag powders with particles of 10-15 nm and 30-50 nm in size by irradiation in toluene and water respectively. The injection of the nanosecond electron beam energy to the solution is optimal. As the absorbed dose increases, the output of the radiochemical reaction does not grow, but more agglomerated powders are synthesized.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.55-63
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• 2016

Calculation of the core neutronic parameters is one of the key components in all nuclear reactors. In this research, the energy spectrum and spatial distribution of the neutron flux in a uranium target have been calculated. In addition, sensitivity of the core neutronic parameters in accelerator-driven subcritical advanced liquid metal reactors, such as electron beam energy ($E_e$) and source multiplication coefficient ($k_s$), has been investigated. A Monte Carlo code (MCNPX_2.6) has been used to calculate neutronic parameters such as effective multiplication coefficient ($k_{eff}$), net neutron multiplication (M), neutron yield ($Y_{n/e}$), energy constant gain ($G_0$), energy gain (G), importance of neutron source (${\varphi}^*$), axial and radial distributions of neutron flux, and power peaking factor ($P_{max}/P_{ave}$) in two axial and radial directions of the reactor core for four fuel loading patterns. According to the results, safety margin and accelerator current ($I_e$) have been decreased in the highest case of $k_s$, but G and ${\varphi}^*$ have increased by 88.9% and 21.6%, respectively. In addition, for LP1 loading pattern, with increasing $E_e$ from 100 MeV up to 1 GeV, $Y_{n/e}$ and G improved by 91.09% and 10.21%, and $I_e$ and $P_{acc}$ decreased by 91.05% and 10.57%, respectively. The results indicate that placement of the Np-Pu assemblies on the periphery allows for a consistent $k_{eff}$ because the Np-Pu assemblies experience less burn-up.

• 대한방사선치료학회지
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• 제20권2호
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• pp.123-130
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• 2008

목적: 의료환경의 변화와 교육환경의 변화에 신속하게 대처하기 위하여 대학에서는 필요한 실습 장비를 갖추고 있어야 한다. 그러나 재정적인 부담과 그것들을 유지 관리하는데 생기는 어려움으로 인해 국내의 대학들이 고가의 방사선 치료 장치를 설치하기는 불가능하다. 이로 인한 실습의 제약을 해소하기 위하여 김천대학 방사선과에서는 모형 선형가속기 및 모형 부속기구를 제작하여 학생들의 실습 시간에 활용하고 있으며 그 유용성에 대해 보고하고자 한다. 대상 및 방법: 우리가 자체 제작한 모형 선형가속기(DLINAC-001)는 실제 선형가속기와 동일한 회전지지축(gantry)과 조사 head의 회전이 가능하도록 제작하였다. 또한 실습교육의 극대화를 위해 우리는 자체적으로 모형 맞춤블록, 모형 쐐기필터, 모형 전자선 조사통과 환자고정기구를 제작 하였다. 결 과: 선형가속기의 기계적인 기능과 동일하게 모형 선형가속기를 활용할 수 있으며, 다양한 용도의 모형 부속기구들을 실습 시 활용할 수 있다. 결 론: 김천대학 방사선과에서 제작된 모형 선형가속기와 부속기구를 제작하여 학생들의 실습시간에 활용함으로서 다양한 영역의 임상실습이 가능하다. 또한 현장감 있는 실습을 시행함으로서 학습 효과를 극대화 할 수 있으며, 임상에서 요구하는 실무능력을 함양할 수 있다.

• Journal of Ginseng Research
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• 제22권4호
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• pp.252-259
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• 1998

Electron beam, electrically produced from an electron accelerator, was compared with gamma energy in terms of its influence on color and organoleptic qualities of ginseng powders when exposed to the energy used for their microbial decontamination. Hunter color L and b values were suitable for measuring color characteristics of ginseng powders, which were not significantly changed by the exposure to 5 to 7.5 kGy electron beam and gamma energy. Fifty percent ethanol extracts of irradiated ginseng powders at 10 key showed negligible differences from the non-irradiated control in the pattern of absorption spectra at 280∼800 am, but showed increased values in overall color difference (AE) as compared with powdered samples. Irradiation more than 10 kGy and storage at ambient temperature for 4 months caused browning of powdered samples. Irradiation at more than 10 kGy of electron beam was found a critical level to bring about appreciable changes (p<0.05) in or-ganoleptic qualities such as color and odor of sterilized samples, and red ginseng powder was more susceptible than white one to organoleptic changes by irradiation.

• Journal of Magnetics
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• 제19권1호
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• pp.15-19
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• 2014

In this study, for 6-20 MeV electron beam energy occurring in a linear accelerator, the authors attempted to investigate the relation between the effective source-skin distance and the relation between the radiation field and the effective source-skin distance. The equipment used included a 6-20 MeV electron beam from a linear accelerator, and the distance was measured by a ionization chamber targeting the solid phantom. The measurement method for the effective source-skin distance according to the size of the radiation field changes the source-skin distance (100, 105, 110, 115 cm) for the electron beam energy (6, 9, 12, 16, 20 MeV). The effective source-skin distance was measured using the method proposed by Faiz Khan, measuring the dose according to each radiation field ($6{\times}6$, $10{\times}10$, $15{\times}150$, $20{\times}20cm^2$) at the maximum dose depth (1.3, 2.05, 2.7, 2.45, 1.8 cm, respectively) of each energy. In addition, the effective source-skin distance when cut-out blocks ($6{\times}6$, $10{\times}10$, $15{\times}15cm^2$) were used and the effective source-skin distance when they were not used, was measured and compared. The research results showed that the effective source-skin distance was increased according to the increase of the radiation field at the same amount of energy. In addition, the minimum distance was 60.4 cm when the 6 MeV electron beams were used with $6{\times}6$ cut-out blocks and the maximum distance was 87.2 cm when the 6 MeV electron beams were used with $20{\times}20$ cut-out blocks; thus, the largest difference between both of these was 26.8 cm. When comparing the before and after the using the $6{\times}6$ cut-out block, the difference between both was 8.2 cm in 6 MeV electron beam energy and was 2.1 cm in 20 MeV. Thus, the results showed that the difference was reduced according to an increase in the energy. In addition, in the comparative experiments performed by changing the size of the cut-out block at 6 MeV, the results showed that the source-skin distance was 8.2 cm when the size of the cut-out block was $6{\times}6$, 2.5 cm when the size of the cut-out block was $10{\times}10$, and 21.4 cm when the size of the cut-out block $15{\times}15$. In conclusion, it is recommended that the actual measurement is used for each energy and radiation field in the clinical dose measurement and for the measurement of the effective source-skin distance using cut-out blocks.