• 방사선산업학회지
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• 제8권1호
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• pp.1-5
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• 2014

This study investigated the reduction of microbial population and sensory properties in red pepper powders irradiated by gamma ray, electron beam, and X-ray. Populations of total aerobic bacteria and yeast & molds in red pepper powders were decreased by irradiation treatment in a dose-dependent manner. Gamma ray, electron beam, and X-ray at doses above 8 kGy caused 100% inhibition on growth of aerobic bacteria in red pepper powders. Inhibitory activity of X-ray on sterilization of red pepper powders was significantly equal to or higher compared to gamma ray and electron beam. Color and off flavor in red pepper powders were no significant difference among the control and samples irradiated with gamma ray, electron beam, and X-ray. As a result, the gamma ray, electron beam, and X-ray irradiation can be used to sterilize the microbial growth in red pepper powders without quality loss.

• 방사선산업학회지
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• 제7권2_3호
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• pp.167-170
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• 2013

Lignin can be a valuable natural chemical resource. Structurally, lignin is a three-dimensional polymer made up of condensed C-C bonds and some ether linkages, most of which are not readily degraded. In this study, lignin carbonization under various electron beam pretreatment conditions was characterized through a thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Raman spectroscopy. Lignin stabilization was controlled by various doses of electron beam irradiation corresponding to 50, 100, 200, 500 and 1,000 kGy; the carbonization process was performed under a nitrogen gas atmosphere at $1000^{\circ}C$ for 1 h. The TGA results showed that a 1,000 kGy lignin dose increased the residue weight from 39.96% to 45.23%, compared to non-irradiated lignin. This observation is in agreement with the XRD and Raman spectroscopy results, in which the two theta degrees and the degree of crystallization were improved by increasing the electron beam irradiation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제14회 학술발표회 논문개요집
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• pp.68-69
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• 1998

Nano-crystalline silicon(nc-Si) thin films were directly depposited by ion beam assisted electron beam depposition (IBAED) method. The visibe luminescence in IBAED sampples were originated from not an oxygen bond but Si nano-crystallites. And we can conclude that the ion beam would be contribute to the suppression of the Si-O bond formation.

• 한국산학기술학회논문지
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• 제9권1호
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• pp.23-28
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• 2008

마이크로칼럼에 사용되는 전자렌즈는 MEMS 공정으로 정밀하게 가공되어 기존의 전자칼럼에 비하여 광학수차를 최소화 할 수 있으며, 이는 전자칼럼의 성능 향상에 주요한 요소로 작용한다. 습식 식각과 건식 식각에 의해 형성되는 전자렌즈의 모양과 배열조합에 따른 전자 광학계 연구는 중요한 의미가 있다. 마이크로칼럼은 전자방출원, source 렌즈, deflector, focus 렌즈(Einzel 렌즈)로 구성되는데, 전자빔의 특성에 가장 큰 영향을 주는 source 렌즈의 구성 요소 중 extractor와 limiting aperture의 모양에 따른 전자빔 특성을 조사하여 마이크로칼럼 제작에 있어서 최적화된 전자렌즈 조합을 도출하였다.

• Journal of Welding and Joining
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• 제15권4호
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• pp.166-177
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• 1997

The high strength AlZnMgCu0.5 alloy is a light metal with good age hardenability, and has a high tensile and yielding strength. Therefore, it can be used for structures requiring high speciple strength. Even though high strength AlZnMgCu alloy has good mechanical properties, it has a lot of problems in TIG and MIG welding processes. Since lots of high heat absorption is introduced into the weldment during TIG and MIG processes, the microstructural variation and hot cracks take place in heat affected zone. Therefore, the mechanical properties of high strength AlZnMgCu0.5 alloy can be degraded in weldment and heat affected zone. Welding process utilizing high density heat source such as electron beam should be developed to reduce pore and hot cracking, whichare usually accompanied by MIG and TIG welding processes. In this work, electron beam welding process were used with or without AlMg4.5Mn as filler material to avoid the degradation of mechanical properties. Mechanical and metallurgical characteristics were also studied in electron beam weldment and heat affected zone. Moreover hot cracking mechanism was also investigated.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.942-948
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• 2003

This paper about the small electron beam irradiator for solar cell's efficiency. Many things are studied by method to increase conversion efficiency of solar cell. We selected electron beam by method for conversion efficiency of solar cell. Energy bands of this electron beam irradiator is 80keV(max.). And, solar cells that apply in this paper are crystal Si. Average efficiency of solar cell that applies in this experiment is 10$\%$. This system manufactured low energy electron beam irradiator. And, electron beam irradiation to solar cell in vacuum chamber of this irradiator. Irradiation area is 20*20 [mm2] by 40[keV].

• KSBB Journal
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• 제29권4호
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• pp.297-302
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• 2014

The autoclaving assisted by an irradiation pretreatment method was developed without toxic chemicals to produce fermentable sugars for their conversion to bioethanol. In the first step, electron beam irradiation (EBI) of rice straw was performed at various doses. The electron beam-irradiated rice straw was then autoclaved with DI water at $120^{\circ}C$ for 1 h. A total sugar yield of 81% was obtained from 300 kGy electron beam-irradiated rice straw after 72 h of enzymatic hydrolysis by Cellulase 1.5L (70 FPU/mL) and Novozyme-188 (40 CbU/mL). Also, the removal of hemicellulose and lignin was 32.0% and 32.5%, respectively. This result indicates that the environmentally-friendly pretreatment method of rice straw by an electron beam irradiation could be applied for bioethanol production in plant.

• 한국축산식품학회지
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• 제18권3호
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• pp.232-239
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• 1998

This experiment was conducted to investigate radurization effects of gamma ray and electron beam irradiation at 1.5 and 3.0 kGy on beef steaks during 8 days of storage at 5$^{\circ}C$. Total bacteria count, psychrotrophs, mesophiles and thermophiles were analyzed at 2 days intervals. Nonirradiated beef steak was used a scontrol Total bacteria counts, psychrotrophs, mesophiles and thermophiles of the control samples showed 3.03∼4.72 logCFU / g at 0 day and increased to 7.67∼10.90 logCFU / g during 8 days storage except thermophiles. Total bacteria counts, psychrotrophs and mesophiles of beef steaks at 8 days were significantly (p＜0.05) decreased to 3.61∼5.43 logCFU / g by gamma ray and to 3.83∼7.02 logCFU / g by electron beam irradiation at 1.5 and 3.0 kGy. Thermophiles of all irradiated samples at any dose were not detectable through 8 days storage. These results suggested that both gamma ray and electron beam irradiation were effective to extend lag phase of bacterial growth of refrigerated beef. Gamma ray irradiation was better than electron beam irradiation in terms of radurization effects of beef.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.193-195
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• 1996

Low-density polyethylene(LDPE ; thickness 100[${\mu}m$] as a experimental specimen is irradiated with electron beam by using electron beam accelerator, and as an experimental specimen, the nonirradiated specimen and the specimen irradiated with electron beam is produced according to the classification of dose. From the analysis of DSC, the crystalline melting point of the specimen irradiated with electron beam is lower than that of virgin specimen. It is confirmed thai the volume resistivity is increased from the temperature over $50[^{\circ}C]{\sim}60[^{\circ}C]$ to the crystalline melting point because of the defects of solid structure and the formation of many trap centers by means of electron beam irradiation, but decreased in the temperature over the crystalline melting point because of the melt of crystalline.

• 방사선산업학회지
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• 제6권2호
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• pp.125-128
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• 2012

Kenaf (Hibiscuc cannabinus L.) is a renewable resource for industry and kenaf lignin is syringyl-guaiacyl lignin. The electron beam irradiated on kenaf core various doses range from 200 to 1,000 kGy to improve delignification. The yield of lignin, which is 2.53 g from 10 g of electron beam irradiated kenaf core. A comparison extracted lignin between from native kenaf core and electron beam irradiated kenaf core was then studied through chemical structure and bonding property by a Fourier transform infrared spectroscopy (FT-IR). Thermal stability of the extracted-purified lignin was performed via differential scanning calorimetry (DSC). These results were explained that electron beam irradiation increased performance of extracting efficiency.