• Title, Summary, Keyword: electron-beam irradiation

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Stabilization of PAN Nanofibers Using Electron Beam Irradiation and Thermal Compression Technique (전자선 조사와 열압축공정을 이용한 PAN 나노섬유의 안정화 및 특성분석)

  • Kim, Du Yeong;Jeun, Joon Pyo;Shin, Hye Kyoung;Kang, Phil Hyun
    • Journal of Radiation Industry
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    • v.6 no.1
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    • pp.55-59
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    • 2012
  • Polyacrylonitrile (PAN)-based carbon fibers have been widely used due to their unique chemical, electrical, and mechanical properties. Electron beam irradiation has been extensively employed as means of altering properties of polymeric materials. Electron beam irradiation can induce chemical reactions in materials without any catalyst. Electron beam irradiation may be useful in accelerating the thermal compression stabilization of PAN nanofibers. To investigate the irradiation effect on PAN fibers, PAN nanofibers were irradiated by electron beam at 1,000~5,000 kGy. Irradiated and non-irradiated PAN nanofibers were heated at 180 and $220^{\circ}C$ without applying pressure for 15 min. Then 1 metric ton has been applied for 5 min. SEM images have been found that the fiber kept its morphological behavior after the hot pressing up to electron beam irradiated 1,000 kGy. DSC thermograms showed that the peak temperatures of the exothermic reactions were found to decrease with increasing electron beam irradiation doses and temperature. FT-IR spectra have been found to decrease $C{\equiv}N$ stretch band with increasing the electron beam irradiation dose. These results indicate that the modification of PAN via reactions such as cyclization is significantly enhanced by electron beam irradiation and thermal compression technique.

Degardatrion of Cellulosic Fibers by Electron Beam Irradiation

  • Han, Sung-Ok;Seo, Yung-Bum;Lee, Chun-Han
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.5
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    • pp.20-25
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    • 2007
  • Henequen fibers were treated by electron beam irradiation and by NaOH to make surface modification for better bonding in the manufacture of biocomposite. Impurity removal and carbonyl group formation were noticed in the previous study by electron beam irradiation, but extensive cellulose degradation were also noticed. To evaluate the effects of electron beam irradiation on cellulosic fibers further, henequen fibers, cotton pulp, cotton fibers, and cellophane were irradiated by electron beam, and their changes of cellulose viscosity, chemical composition, and tensile strength were measured and analyzed.

Effects of Electron Beam Irradiation on Pathogen Inactivation, Quality, and Functional Properties of Shell Egg during Ambient Storage

  • Kim, Hyun-Joo;Yun, Hye-Jeong;Jung, Samooel;Jung, Yeon-Kuk;Kim, Kee-Hyuk;Lee, Ju-Woon;Jo, Cheor-Un
    • Food Science of Animal Resources
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    • v.30 no.4
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    • pp.603-608
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    • 2010
  • This study investigated the effects of electron beam irradiation on pathogens, quality, and functional properties of shell eggs during storage. A 1st grade 1-d-old egg was subjected to electron beam irradiation at 0, 1, 2, and 3 kGy, after which the number of total aerobic bacteria, reduction of inoculated Escherichia coli and Salmonella Typhimurium, egg quality, and functional properties were measured. Electron beam irradiation at 2 kGy reduced the number of E. coli and S. Typhimurium cells to a level below the detection limit (<$10^2$ CFU/g) after 7 and 14 d of storage. Egg freshness as measured by albumen height and the number of Haugh units was significantly reduced by 1-kGy irradiation. The viscosity of irradiated egg white was also significantly decreased by increased irradiation, whereas its foaming ability was increased. Electron beam irradiation also increased lipid oxidation in egg yolks. These results suggest that electron beam irradiation reduces the freshness of shell eggs while increasing the oxidation of egg yolk and improving important functional properties such as foaming capacity. Electron beam irradiation can also be applied to the egg breaking process since the irradiation reduces the viscosity of egg white, which can allow egg whites and yolks to be separated with greater efficiency.

Effect of Electron Beam Irradiation on the Properties of Softwood Unbleached Kraft Pulp (전자선 전처리에 따른 침엽수 미표백 크라프트 펄프의 특성평가)

  • Kim, Eun Hea;Lee, Ji Young;Jeun, Joon Pyo;Kim, Sun Young;Kim, Chul Hwan;Park, Jong Hye
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.5
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    • pp.68-73
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    • 2015
  • Electron beam irradiation is also an eco-friendly treatment compared to other physical and chemical treatments. In this study, we attempted to evaluate the possibilities of energy savings by applying electron beam irradiation to the refining process. After softwood unbleached kraft pulp (UKP) was irradiated with electron beams at 50 and 100 kGy, it was beaten in a laboratory beater, and then its freeness and fiber properties were analyzed. The physical properties of their fiber handsheet were also and measured. As the irradiation dose of the electron beam and the beating time increased, lower freeness and fiber lengths of the UKP were observed. Handsheets made from UKP that was irradiated by electron beam and beaten showed a reciprocal relationship with the irradiation dose of the electron beam, in particular, the strength of the handsheets decreased dramatically at 100 kGy of irradiation. Therefore, it was confirmed that electron beam irradiation is effective in reducing the beating time or beating energy. But the irradiation dose must be controlled under 50 kGy to minimize the loss of paper strength.

Application of electron beam irradiation for studying the degradation of dye sensitized solar cells (전자선 조사를 통한 염료감응형 태양전지의 분해 연구)

  • Akhtar, M.Shaheer;Lee, Hyun-Cheol;Min, Chun-Ji;Khan, M.A.;Kim, Ki-Ju;Yang, O-Bong
    • 한국신재생에너지학회:학술대회논문집
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    • pp.179-182
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    • 2006
  • The effect of electron beam irradiation on dye sensitized solar cell (DSSC) has been studied to examine degradation of DSSC. The high-energy electron beam irradiation affects on the materials and performance of dye sensitized solar cells. We have checked the effects of electron beam irradiation of $TiO_2$ substrate with and without dye adsorption on the photovoltaic performances of resulting DSSCS and also studied the structural and electrical properties of polymers after irradiation. All solar cells materials were irradiated by electron beams with an energy source of 2MeV at different dose rates of 60 kGy, 120 kGy 240 kGy and 900 kGy and then their photoelectrical parameters were measured at 1 sun $(100 mW/cm^2)$. It was shown that the efficiency of DSSC was decreased as increasing the dose of e-beam irradiation due to lowering in $TiO_2$ crystallinity, decomposition of dye and oxidation of FTO glasses. On the other hand, the performance of solid-state DSSC with polyethylene oxide based electrolyte was improved after irradiation of e-beam due to enhancement of its conductivity and breakage of crosslinking.

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Microbial Decontamination of Angelica gigas Nakai Using Electron Beam Irradiation

  • Jin, You-Young;Shin, Hee-Young;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • v.11 no.4
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    • pp.344-347
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    • 2006
  • This study evaluated the use of electron beam irradiation for decontamination of the Korean medicinal herb, Angelica gigas Nakai. Herb samples were irradiated at doses of 2, 8, and 16 kGy, respectively. Populations of microorganisms in Angelica gigas Nakai decreased by 2$\sim$3 log cycles at 8 kGy irradiation. Electron beam irradiation caused negligible changes in Hunter color L, a, and b values. Sensory evaluations of Angelica gigas Nakai confirmed that irradiation caused no significant changes in the organoleptic properties of the samples. These results suggest that electron beam-irradiated herbs retain a better microbial safety and sensory qualities, compared with the non-irradiated.

Inactivation of Agrobacterium tumefaciens Inoculated on Fresh Radix Ginseng by Electron Beam Irradiation and Aqueous Chlorine Dioxide Treatment

  • Chun, Ho-Hyun;Kim, Ju-Yeon;Song, Kyung-Bin
    • Journal of Applied Biological Chemistry
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    • v.51 no.3
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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.

The Effect of Electron Beam Irradiation on Physicochemical Properties of Hansan Ramie (전자빔 조사된 한산모시의 물리화학적 특성변화)

  • Choi, Hae-Young;Lee, Jung-Soon
    • Textile Science and Engineering
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    • v.47 no.4
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    • pp.253-260
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    • 2010
  • Hansan ramie fibers were irradiated with an electron beam to improve the interfacial bonding in the manufacture of composites. The effect of electron beam irradiation was examined by SEM, chemical component analysis and the mechanical properties. The impurities on the surface of ramie and lignin were removed by electron beam irradiation, which increased the tensile strength of the ramie fibers. However, the excessive electron beam energy caused the degradation of ramie fibers, due probably to the reduced ${\alpha}$-cellulose. The reduction of ${\alpha}$-cellulose indicates the degradation of the cellulose chain, which usually leads to a decrease in fiber strength.

Effect of Electron-beam Irradiation on Polymethoxylated Flavones Content of Citrus unshiu Pomaces

  • Kim, Jong-Wan;Kim, Min-Chul;Nam, Ki-Chang;Lee, Seung-Cheol
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.362-366
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    • 2009
  • To determine the effect of electron-beam irradiation on the contents of polymethoxylated flavones (PMFs) extracts from citrus pomaces (CP), CP was irradiated at 0, 1, 2, or 5 kGy. Methanol extract of the irradiated CP were prepared and the PMF (nobiletin, sinensetin, and tangeretin) content of the extract was determined. Nobiletin and sinensetin of CP extract significantly increased with irradiation dose-dependent. However, electron-beam irradiation decreased the amount of tangeretin in the CP extract. These data suggest that irradiation can liberate phenolic compounds such as nobiletin or sinensetin, but tangeretin might have different pathway of conversion by irradiation. Therefore, irradiation can be a tool to change the composition of PMFs in CP.

Effect of Electron Beam Irradiation on Microbial Growth and Qualities in Astragalus membranaceus

  • Jin, You-Young;Shin, Hee-Young;Ku, Kyoing-Ju;Song, Kyung-Bin
    • Journal of Applied Biological Chemistry
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    • v.49 no.4
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    • pp.176-179
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    • 2006
  • Electron beam irradiation was applied to examine the microbial growth and qualities of vacuum-packaged Astragalus membranaceus, a Korean medicinal herb. Samples were irradiated at dose of 2, 4, 8, 12, and 16 kGy, respectively. Microbiological data on A. membranaceus showed that populations of total bacteria, yeast and mold, total coliforms were significantly reduced with increase of irradiation dose. Populations of microorganisms in A. membranaceus were decreased by 2-3 log cycles at 8 kGy irradiation. Color measurements showed that electron beam treatment caused negligible changes in Hunter color L, a, and b values of A. membranaceus. Sensory evaluations showed that there were no significant changes among the samples. These results suggest that electron beam irradiated A. membranaceus have better microbial safety and qualities, compared with the non-irradiated control.