• 열처리공학회지
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• 제24권1호
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• pp.31-36
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• 2011

$TiO_2$ films were deposited on a glass substrate with RF magnetron sputtering and then surface of $TiO_2$ films were electron beam irradiated in a vacuum condition to investigate the effect of electron bombardment on the thin film crystallization, surface roughness and gas sensitivity for hydrogen. $TiO_2$ films that electron beam irradiated at 450eV were amorphous phase, while the films irradiated at 900 eV show the anatase (101) diffraction peak in XRD pattern. AFM measurements show that the roughness is depend on the electron irradiation energy. As increase the hydrogen gas concentration and operation temperature, the gas sensitivity of $TiO_2$ and $TiO_2$/ZnO films is increased proportionally and $TiO_2$ films that electron beam irradiated at 900 eV show the higher sensitivity than the films were irradiated at 450eV. From the XRD pattern and AFM observation, it is supposed that the crystallization and rough surface promote the hydrogen gas sensitivity of $TiO_2$ films.

• 열처리공학회지
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• 제2권3호
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• pp.1-4
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• 1989

• 대한방사선치료학회지
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• 제1권1호
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• pp.79-83
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• 1985

Carcinoma of the breast has been treated by surgery followed by irradiation of the chest wall and regional lymphatics treatment planning of the breast cancer is required that lung must be spared as much as possible. However megavoltage irradiation of the internal mammary chain results in high dose to underlying heart, esophagus and spinal cord. Electron beam can be used for the irradiation of the internal mammary chain instead of megavoltage beam. We studied dose distribution of single anterior electron field, compared with traditional treatment methods. 12 and 15MeV electron beam with bolus has good dose distribution to spare underlying lung tissue and other organs.

• 펄프종이기술
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• 제45권3호
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• pp.27-35
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• 2013

Cotton linter pre-treatment methods using electron beam and sulfuric acid were investigated to prepare high quality regenerated fibers for fabrics. So far, NaOH was used to reduce the degree of polymerization (DP) of the cotton linter for ease of dissolving by cellulose solvent. Two pre-treatment methods were developed to reduce the consumption of the chemicals (NaOH) and to control the DP of cellulose more precisely. Changes in ${\alpha}$-cellulose contents and brightness by the pre-treatments were also important concerns. Both electron beam irradiation and sulfuric acid were shown to be effective on controlling the DP of cellulose and to reduce the chemical consumption, but reduced ${\alpha}$-cellulose contents as well in this study. Sulfuric acid pre-treatment, which needed additional washing process after the pre-treatment when comparing to the electron beam irradiation method, gave the highest brightness and the highest reduction of ${\alpha}$-cellulose content.

• Journal of Radiation Protection and Research
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• 제43권1호
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• pp.10-19
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• 2018

Background: Monte Carlo (MC) simulation is the most accurate for calculating radiation dose distribution and determining patient dose. In MC simulations of the therapeutic accelerator, the characteristics of the initial electron must be precisely determined in order to achieve accurate simulations. However, It has been computation-, labor-, and time-intensive to predict the beam characteristics through predominantly empirical approach. The aim of this study was to analyze the relationships between electron beam parameters and dose distribution, with the goal of simplifying the MC commissioning process. Materials and Methods: The Varian Clinac 2300 IX machine was modeled with the Geant4 MC-toolkit. The percent depth dose (PDD) and lateral beam profiles were assessed according to initial electron beam parameters of mean energy, radial intensity distribution, and energy distribution. Results and Discussion: The PDD values increased on average by 4.36% when the mean energy increased from 5.6 MeV to 6.4 MeV. The PDD was also increased by 2.77% when the energy spread increased from 0 MeV to 1.019 MeV. In the lateral dose profile, increasing the beam radial width from 0 mm to 4 mm at the full width at half maximum resulted in a dose decrease of 8.42% on the average. The profile also decreased by 4.81% when the mean energy was increased from 5.6 MeV to 6.4 MeV. Of all tested parameters, electron mean energy had the greatest influence on dose distribution. The PDD and profile were calculated using parameters optimized and compared with the golden beam data. The maximum dose difference was assessed as less than 2%. Conclusion: The relationship between the initial electron and treatment beam quality investigated in this study can be used in Monte Carlo commissioning of medical linear accelerator model.

• 상하수도학회지
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• 제27권6호
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• pp.797-803
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• 2013

Recently, a number of countries are now considering the reuse of effluents from wastewater treatment for various water applications. To improve the reuse of wastewater effluent, the development of appropriate micro-pollutant removal technology is necessary. Although several researche have been studied for removing micro-pollutants in water, little study has been conducted for the removal of emerging contaminant such as antibiotic resistant genes (ARGs) by disinfection processes. Therefore, the aim of this study is to compare the capacity of disinfection technologies such as chlorination, ozone, and electron beam, for removing antibiotic resistant bacteria (ARB) and ARGs. Based on this study, better ARG removal can be achieved by ozonation and electron beam. Relatively, high CT values of chlorination or ozonation are needed to remove ARB and ARG compared to conventional pathogens.

• 방사선산업학회지
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• 제3권1호
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• pp.1-5
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• 2009

The variation of MgO surfaces, in which fluorine was contained (F-MgO), by high energy electron-beam (EB) was studied using X-ray photoelectron spectroscopy (XPS). Fluorine on the MgO surface was eliminated by EB treatment with the consequence that the electronic structures of Mg, O and C were varied. Moreover, as a result of oxidation of carbon species on the surface by high dose EB treatment (90 kGy), the concentration of carbonate and carboxyl species on the surface was increased. In this experiment, it was confirmed that the structure of oxidized metal surface can be adjusted by varying conditions of EB treatment (energy and dose). This result implies that EB can be applied for developing new catalysts.

• 펄프종이기술
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• 제44권4호
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• pp.51-61
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• 2012

The new alkali pulping process combined with electron beam treatment was applied to utilize hemp bast tissues as a new valuable fibrous resource. Hemp bast tissues have some chemical properties with high lignin contents and holocellulose not to be defiberized by alkali pulping only, compared with the bast tissue of paper mulberry. To make up for the weakness of traditional alkali pulping process, electron beams were directly irradiated into the swelled bast tissue of hemp in NaOH solution and distilled water, and then facilitated the defiberization of hemp bast tissues. The papermaking from hemp bast fibers manufactured by the combination pulping process showed good apparent density, formation structure and air permeability, and had some mechanical properties with lower tensile, tear, burst strength and folding endurance. It is finally concluded that the combination pulping process with electron beam treatment could be suggested a new alternative for non-woody fibers.

• 한국식품저장유통학회지
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• 제10권2호
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• pp.206-212
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• 2003

인삼분말에 대한 전자선(electron beam)의 이용가능성을 연구하고자, 방사선 살균처리(2.5∼15 kGy)가 백삼 및 홍삼분말의 사포닌 함량 및 패턴, 페놀함량, 산성다당체 함량, amylase activity, 단백질 패턴 등에 미치는 영향을 감마선 조사와 비교하였다. 사포닌 함량과 패턴을 TLC 및 HPLC로 분석해 본 결과, 조사선량과 에너지원에 따른 변화는 확인되지 않았으며, 실온 저장 4개월 이후에도 안정된 경향을 보였다. 총페놀성분 및 산성다당체 함량은 홍삼이 백삼 보다 높은 함량을 보였으며, 산성다당체 함량은 조사선량의 증가로 높은 추출량을 보였다. 백삼분말의 amylase activity는 방사선조사 직후 증가하였으나, 4개월 이후에는 대조구 보다 낮은 간을 보였으며, 추출단백질의 전기영동 패턴은 15 kGy의 전자선 및 감마선구에서도 대조구와 차이가 없었다.

• Journal of Biosystems Engineering
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• 제39권3호
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• pp.205-214
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• 2014

Purpose: Phytosanitary irradiation treatment can effectively control regulated pests while maintaining produce quality. The objective of this study was to establish the best irradiation treatment for mangosteen, a popular tropical fruit, using a Monte Carlo simulation. Methods: Magnetic resonance image (MRI) data were used to generate a 3-D geometry to simulate dose distributions in a mangosteen using a radiation transport code (MCNP5). Microsoft Excel with visual basic application (VBA) was used to divide the image data into seed, flesh, and rind. Radiation energies used for the simulation were 10 MeV (high-energy) and 1.35 MeV (low-energy) for the electron beam, 5 MeV for X-rays, and 1.25 MeV for gamma rays from Co-60. Results: At 5 MeV X-rays and 1.25 MeV gamma rays, all areas (seeds, flesh, and rind) were irradiated ranging from 0.3 ~ 0.7 kGy. The average doses decreased as the number of fruit increased. For a 10 MeV electron beam, the dose distribution was biased: the dose for the rind where the electrons entered was $0.45{\pm}0.03$ kGy and the other side was $0.24 {\pm}0.10$ kGy. Use of an electron kinetic energy absorber improved the dose distribution in mangosteens. For the 1.35 MeV electron beam, the dose was shown only in the rind on the irradiated side; no significant dose was found in the flesh or seeds. One rotation of the fruit while in front of the beam improved the dose distribution around the entire rind. Conclusion: These results are invaluable for determining the ideal irradiation conditions for phytosanitary irradiation treatment of tropical fruit.