• Journal of Applied Biological Chemistry
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• 제51권3호
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• pp.117-122
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• 2008

Inactivation of Agrobacterium tumefaciens was evaluated on the inoculated fresh Radix Ginseng by electron beam irradiation or aqueous chlorine dioxide ($ClO_2$) treatment. Two groups of fresh ginsengs were prepared and inoculated with A. tumefaciens. One group was then irradiated at 0, 2, and 4 kGy using an electron beam accelerator, and the other group was treated with 0, 50, and 100 ppm of aqueous $ClO_2$. Microbiological data indicated that populations of A. tumefaciens significantly decreased with increasing irradiation dose or aqueous $ClO_2$ concentration. In particular, A. tumefaciens was eliminated by irradiation at 4 kGy, and 100 ppm $ClO_2$ treatment reduced the populations of A. tumefaciens by 1.44 log CFU/g. These results suggest that electron beam irradiation or aqueous $ClO_2$ treatment can be useful in improving the microbial safety of fresh ginsengs during storage.

• 한국물환경학회지
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• 제20권4호
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• pp.376-381
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• 2004

The use of electron beam irradiation was investigated to disinfect total coliforms in the secondary sewage treatment effluent. Unchlorinated secondary effluent was irradiated at different dose of 0.2~1.0 kGy by 1 MeV, ELV-4 Model electron beam accelerator. It is interesting to note that a 100 % reduction in total coliforms and total colonies were achieved until a dose of approximately 0.8 kGy. Even at low dose of 0.2 kGy, the total coliforms and total colonies were successfully inactivated to the level of satisfying the new effluent discharge guideline. Besides disinfection of total coliforms, approximately a 50% removal in biochemical oxygen demand was pronounced at a dose of 0.2 kGy. More than 20 % removal in suspended solids and turbidity was also observed at a dose of 1.0 kGy. The application of electron beam irradiation appeared to be one of options to reuse sewage treatment effluent as agricultural or industrial water.

• 한국의학물리학회지:의학물리
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• 제3권2호
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• pp.59-65
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• 1992

유방암은 여성암 가운데 세계에서 가장 빈도가 높으며, 한국에서도 세번째로 많은 것으로 보고하고 있다. 유방암에서 방사선치료는 photon beam를 이용하여 tangential field로 치료하거나 electron beam를 이용하여 치료하는 것이 보편적이다. 치료범위 내부의 밀도와 tumor까지의 깊이는 방사선치료에서 선량분포를 결정하는 중요한 요소들이다. CT planning를 이용하면 이러한 요소들을 정확하게 산출하여 선량과 선량분포를 결정하는데 이용할 수 있다. 저자들이 유방암 환자 65명중 전자선으로 치료를 받은 45명을 분석한 결과 cheast wall의 두께와 internal mammary lyphnode의 깊이가 1.5cm 이하인 경우에는 6MeV의 에너지가 적적함을 보여 주었으며, 1.5cm에서 2.0cm까지는 9MeV의 에너지가, 2.0cm에서 2.5cm까지는 12MeV의 에너지가 적절함을 보였다.

• 한국레이저가공학회지
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• 제18권3호
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• pp.6-8
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• 2015

Finishing process includes deburring, polishing and edge radiusing. It improves the surface profile of specimen and eliminates the alien substance on surface. Deburring is the elimination process for debris of edges. Polishing lubricates surfaces by rubbing or chemical treatment. There are two types for electron finishing. The one is using pulse beam. The other is using the convergent and scanning electron beam. Pulse type device appropriates the large area process. But it does not control the beam dosage. Scanning type device has advantages for dosage control and edge deburring. We design the convergence and scan type. It has magnetic lenses for convergence and scan device for scanning beam. Magnetic lenses consist of convergent and objective lens. The lenses are designed by the specification(beam size and working distance). In this paper, we evaluate the convergence performance by pattern process. Also, we analysis the results and important factors for process. The important factors for process are beam size, pressure, stage speed and vacuum. These results will be utilized into systematizing pattern shape and the factors.

• 대한방사선치료학회지
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• 제14권1호
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• pp.175-186
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• 2002

The purpose of this study is directly measure and evaluate about absorbed dose change according to nominal energy and electron cone or medical accelerator on isodose curve, percentage depth dose, contaminated X-ray, inhomogeneous tissue, oblique surface and irradiation on intracavitary that electron beam with high energy distributed in tissue, and it settled standard data of hish energy electron beam treatment, and offer to exactly data for new dote distribution modeling study based on experimental resuls and theory. Electron beam with hish energy of $6{\sim}20$ MeV is used that generated from medical linear accelerator (Clinac 2100C/D, Varian) for the experiment, andwater phantom and Farmer chamber md Markus chamber und for absorbe d dose measurement of electron beam, and standard absorbed dose is calculated by standard measurements of International Atomic Energy Agency(IAEA) TRS 277. Dose analyzer (700i dose distribution analyzer, Wellhofer), film (X-OmatV, Kodak), external cone, intracavitary cone, cork, animal compact bone and air were used for don distribution measurement. As the results of absorbed dose ratio increased while irradiation field was increased, it appeared maximum at some irradiation field size and decreased though irradiation field size was more increased, and it decreased greatly while energy of electron beam was increased, and scattered dose on wall of electron cone was the cause. In percentage depth dose curve of electron beam, Effective depth dose(R80) for nominal energy of 6, 9, 12, 16 and 20 MeV are 1.85, 2.93, 4.07, 5.37 and 6.53 cm respectively, which seems to be one third of electron beam energy (MeV). Contaminated X-ray was generated from interaction between electron beam with high energy and material, and it was about $0.3{\sim}2.3\%$ of maximum dose and increased with increasing energy. Change of depth dose ratio of electron beam was compared with theory by Monte Carlo simulation, and calculation and measured value by Pencil beam model reciprocally, and percentage depth dose and measured value by Pencil beam were agreed almost, however, there were a little lack on build up area and error increased in pendulum and multi treatment since there was no contaminated X-ray part. Percentage depth dose calculated by Monte Carlo simulation appeared to be less from all part except maximum dose area from the curve. The change of percentage depth dose by inhomogeneous tissue, maximum range after penetration the 1 cm bone was moved 1 cm toward to surface then polystyrene phantom. In case of 1 cm and 2 cm cork, it was moved 0.5 cm and 1 cm toward to depth, respectively. In case of air, practical range was extended toward depth without energy loss. Irradiation on intracavitary is using straight and beveled type cones of 2.5, 3.0, 3.5 $cm{\phi}$, and maximum and effective $80\%$ dose depth increases while electron beam energy and size of electron cone increase. In case of contaminated X-ray, as the energy increase, straight type cones were more highly appeared then beveled type. The output factor of intracavitary small field electron cone was $15{\sim}86\%$ of standard external electron cone($15{\times}15cm^2$) and straight type was slightly higher then beveled type.

• Carbon letters
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• 제15권2호
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• pp.129-135
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• 2014

Spinnable pitch for melt-electrospinning was obtained from pyrolized fuel oil by electron beam (E-beam) radiation treatment. The modified pitch was characterized by measuring its elemental composition, softening point, viscosity, molecular weight, and spinnability. The softening point and viscosity properties of the modified pitch were influenced by reforming types (heat or E-beam radiation treatment) and the use of a catalyst. The softening point and molecular weight were increased in proportion to absorbed doses of E-beam radiation and added $AlCl_3$ due to the formation of pitch by free radical polymerization. The range of the molecular weight distribution of the modified pitch becomes narrow with better spinning owing to the generated aromatic compounds with similar molecular weight. The diameter of melt-electrospun pitch fibers under applied power of 20 kV decreased 53% ($4.7{\pm}0.9{\mu}m$) compared to that of melt-spun pitch fibers ($10.2{\pm}2.8{\mu}m$). It is found that E-beam treatment for reforming could be a promising method in terms of time-savings and cost-effectiveness, and the melt-electrospinning method is suitable for the preparation of thinner fibers than those obtained with the conventional melt-spinning method.

• 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).

• Advanced Composite Materials
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• 제16권4호
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• pp.315-334
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• 2007

In the present study, chopped henequen natural fibers without and with surface modification by electron beam (E-beam) treatment were incorporated into a polypropylene matrix. Prior to composite fabrication, a bundle of raw henequen fibers were treated at various E-beam intensities from 10 kGy to 500 kGy. The effect of E-beam intensity on the interfacial, mechanical and thermal properties of randomly oriented henequen/polypropylene composites with the fiber contents of 40 vol% was investigated focusing on the interfacial shear strength, flexural and tensile properties, dynamic mechanical properties, thermal stability, and fracture behavior. Each characteristic of the material strongly depended on the E-beam intensity irradiated, showing an increasing or decreasing effect. The present study demonstrates that henequen fiber surfaces can be modified successfully with an appropriate dosage of electron beam and use of a low E-beam intensity of 10 kGy results in the improvement of the interfacial properties, flexural properties, tensile properties, dynamic mechanical properties and thermal stability of henequen/polypropylene composites.

• Radiation Oncology Journal
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• 제1권1호
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• pp.41-45
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• 1983

To obtain 7 MeV electron beam which is suitable for treatment of the chest wall after radical of modified radical mastectomy, the authors reduced the energy of electron beam by means by Lucite plate inserted in the beam. To determine the proper thickness of the Lucite plate necessary to reduce the energy of 9 MeV electron beam to 6 MeV, dosimetry was made by using a parallel plate ionization chamber in polystyrene phantom. Separation between two adjacent fields, 7 MeV for chest wall and 12 MeV for internal mammary region, was studied by means of film dosimetry in both polytyrene phantom and Humanoid phantom. The results were as follows. 1. The average energy of 9 MeV electron beam transmitted through the Lucite plate was reduced. Reduction was proportional to the thickness of the Lucite plate in the rate of 1.7 MeV/cm. 2. The proper thickness of the Lucite plate necessary to obtain 6 MeV electron beam from 9 MeV was 1.2 cm. 3. 7 MeV electron beam, 80% dose at 2cm depth, is adequate for treatment of the chest wall. 4. Proper separation between two adjacent electron fields, 7 MeV and 12 MeV, was 5mm on both flat surface and sloping surface to produce uniform dose distribution.

• 한국식품영양과학회지
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• 제41권11호
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• pp.1632-1638
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• 2012

치콘의 미생물학적 안전성을 확보하기 위해 50 ppm 이산화염소수와 5 kJ/$m^2$ UV-C 및 2 kGy 전자빔 조사 병합처리에 따른 저장 중 미생물 수 및 품질 변화를 $4{\pm}1^{\circ}C$에서 11일 동안 저장하면서 측정하였다. 이산화염소수와 UV-C 병합처리 후 치콘의 총 호기성 세균 수는 대조구와 비교하여 1.49~2.92 log CFU/g, 효모 및 곰팡이는 1.63~1.78 log CFU/g의 감소를 보였다. 반면에, 이산화염소수와 2 kGy 전자빔 병합처리구의 경우 총 호기성 세균은 저장기간 동안 검출되지 않았으며, 효모 및 곰팡이 역시 11일 간의 저장기간 동안 나타나지 않았다. 이산화염소수와 전자빔의 병합처리는 대조구와 비교하여 치콘의 저장 중 Hunter 색도 값에 부정적 영향을 미치지 않았다. 관능검사에 있어서도 저장기간 동안 대조구와 비교 시 유의적인 차이가 없는 것으로 나타났다. 따라서 본 연구결과, 이산화염소수와 전자빔 조사의 병합처리가 치콘의 저장 중 오염될 수 있는 위해미생물의 감소와 외관적 품질유지에 효과적인 살균처리 기술이라고 판단된다.