Effect of gamma irradiation on Korean traditional multicolored paintwork

Yoon, Minchul,Kim, Dae-Woon,Choi, Jong-il,Chung, Yong-Jae,Kang, Dai-Ill,Hoon Kim, Gwang,Son, Kwang-Tae,Park, Hae-Jun,Lee, Ju-Woon Elsevier 2015 Radiation physics and chemistry Vol.115 No.-

<P><B>Abstract</B></P> <P>Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, <I>Sukganju</I> (Hematite; Fe<SUB>2</SUB>O<SUB>3</SUB>), <I>Jangdan</I> (Minium; Pb<SUB>3</SUB>O<SUB>4</SUB>), <I>Whangyun</I> (Crocoite; PbCrO<SUB>4</SUB>), and <I>Jidang</I> (Rutile; TiO<SUB>2</SUB>), were irradiated by gamma radiation at doses of 1, 5, and 20kGy. After irradiation, changes in Commision Internationale d’Eclairage (CIE) color values (<I>L</I>*, <I>a</I>*, <I>b</I>*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 <I>dE</I>* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of gamma irradiation on the Dancheong were evaluated. </LI> <LI> We confirmed that optical and structural properties of Dancheong were maintained. </LI> <LI> Irradiation can contribute the decontamination for wooden cultural heritages. </LI> <LI> It also can be used for preservation of painted-wooden cultural heritages. </LI> </UL> </P>

Gamma-ray irradiation effects on electrical properties of bismuth layer-structured ferroelectric ceramics

Cho, S.Y.,Choi, G.P.,Kim, E.Y.,Lee, G.J.,Lee, M.K.,Bu, S.D. Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.17

<P><B>Abstract</B></P> <P>In this study, we prepared the bismuth layer-structured ferroelectric (BLSF)-type Bi<SUB>4</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> (BiT), Bi<SUB>3.25</SUB>La<SUB>0.75</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> (BLaT), and Bi<SUB>3.1</SUB>Nd<SUB>0.9</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> (BNdT) ceramics using the solid-state reaction method. The prepared ceramics were irradiated at room temperature by using a <SUP>60</SUP>Co gamma-ray source in a dose range of 0–3000kGy with a dose rate of 10kGy/h to compare the structure and electrical properties of the irradiated ceramics. The X-ray diffraction analysis shows that the BLSF structure was well formed in all ceramics without a secondary phase. There was no structural change such as grain size change and secondary phase formation despite the cumulative gamma-ray dose of 3000kGy. A comparison of the electrical properties with gamma-ray irradiation shows that the BiT ceramics exhibits a larger reduction ratio compared to the BLaT and BNdT ceramics. The rate of change of the remnant polarization (2<I>P</I> <SUB>r</SUB>) value with the gamma-ray irradiation doses was − 14.2%, − 8%, and − 3.4% in BiT, BLaT, and BNdT ceramics, respectively, at a cumulative gamma-ray dose of up to 3000kGy. Furthermore, the dielectric relaxation phenomenon in BiT ceramics at low frequency was observed when gamma rays of 1000kGy or more were irradiated. Based on these results, in this study, we investigated the structure and electrical properties of BLSF ceramics with gamma-ray irradiation.</P>

Effects of irradiation source and dose level on quality characteristics of processed meat products

Ham, Y.K.,Kim, H.W.,Hwang, K.E.,Song, D.H.,Kim, Y.J.,Choi, Y.S.,Song, B.S.,Park, J.H.,Kim, C.J. Pergamon 2017 Radiation physics and chemistry Vol.130 No.-

<P>The effect of irradiation source (gamma-ray, electron-beam, and X-ray) and dose levels on the physicochemical, organoleptic and microbial properties of cooked beef patties and pork sausages was studied, during 10 days of storage at 30 +/- 1 degrees C. The processed meat, products were irradiated at 0, 2.5, 5, 7.5, and 10 kGy by three different irradiation sources. The pH of cooked beef patties and pork sausages was unaffected by irradiation sources or their doses. The redness of beef patties linearly decreased with increasing dose level (P < 0.05), obviously by e-beam irradiation compared to gamma-ray and X-ray (P < 0.05). The redness of pork sausages was increased by gamma-ray irradiation, whereas it decreased by e-beam irradiation depending on absorbed dose level. No significant changes in overall acceptability were observed for pork sausages regardless of irradiation source (P> 0.05), while gamma-ray irradiated beef patties showed significantly decreased overall acceptability in a dose-dependent manner (P < 0.05). Lipid oxidation of samples was accelerated by irradiation depending on irradiation sources and dose levels during storage at 30 degrees C. E-beam reduced total aerobic bacteria of beef patties more effectively, while gamma-ray considerably decreased microbes in pork sausages as irradiation dose increased. The results of this study indicate that quality attributes of meat products, in particular color, lipid oxidation, and microbial properties are significantly influenced by the irradiation sources. (C) 2016 Published by Elsevier Ltd.</P>

방사선 조사 마우스에서 오가피의 면역활성 효과

김계엽,정현우,김경윤,Kim, Gye-Yeop,Jeong, Hyun-Woo,Kim, Kyung-Yoon 대한동의생리학회 2006 동의생리병리학회지 Vol.20 No.6

This experimental study was carried out to investigate the immunostimulating effect of Acanthopanax, as Oriental rhizomata herbs, on jejunal survival, endogenous spleen colony formation, apoptosis in jejunal crypt cells and lipid peroxidation in the liver of mice following Gamma-ray irradiation. The subject of this study includes 72 mice which were divided into each 7 groups. Acanthopanax experiment groups were Acanthopanax. Gamma-ray(lOGy), Acanthopanax. Gamma-ray(3Gy), Acanthopnax. Gamma-ray(1Gy), Gamma-ray control(1OGy), Gamma-ray control(3Gy), Gamma-ray control(1Gy), Normal groups. The results of this study were as follows : Treatment with Acanthopanax showed significantly increased(p<0.05) on the cell death apoptosis in crypt, intestine crypts survival of intestine in mice following low-dose(1Gy) Gamma-ray radiation. And that significantly increased(p<0.05) on jejunal crypt survival and reduced(p<0.05) on lipid peroxidation in mice following high-dose(1OGy) Gamma-ray radiation. The above results suggest that Acathopanax were immunostimulating effectively reduced Gamma-ray irradiation.

Change of photoluminescence property of ferroelectric compounds with the gamma-ray irradiation

Lim, Junhwi,Lee, Y.S.,Yang, Sun A,Choi, Gi Ppeum,Bu, Sang Don Elsevier 2017 Journal of luminescence Vol.188 No.-

<P><B>Abstract</B></P> <P>We investigated the emission properties of Bi<SUB>3.25</SUB>La<SUB>0.75</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> polycrystals and (K<SUB>0.5</SUB>Na<SUB>0.5</SUB>)(Mn<SUB>0.005</SUB>Nb<SUB>0.995</SUB>)O<SUB>3</SUB> thin films with strong gamma (γ)-ray irradiation by using temperature dependent photoluminescence spectroscopy. At the lowest temperatures, sizable visible emissions were identified for the γ-ray irradiated samples as well as un-irradiated ones. In both kinds of compounds, the visible emission intensity tended to be increased without changing the spectral shape, as the γ-ray dose increased. This indicates that the γ-ray irradiation should increase all kinds of already-existing defects evenly, without preferring the formation of some particular type of defect.</P>

Electrical conduction and photoresponses of gamma-ray-irradiated single-stranded DNA/single-walled carbon nanotube composite systems

Hong, W.,Lee, E.M.,Kim, D.W.,Lee, Cheol Eui Elsevier 2015 Nuclear instruments & methods in physics research. Vol.349 No.-

<P><B>Abstract</B></P> <P>Effects of gamma-ray irradiation on the electrical conductivity and photoresponse have been studied for single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite films. The temperature-dependent electrical conductivity of the ssDNA/SWNT composite films, well described by a fluctuation-induced tunneling model, indicated modification of the barrier for thermally activated conduction by the gamma-ray irradiation. Besides, the photoresponse measurements indicated modified photoexcited charge carrier generation and oxygen photodesorption in the composite systems due to the gamma-ray irradiation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of gamma-ray irradiation on single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite films. </LI> <LI> Barrier for thermally activated conduction in the composite systems modified by the gamma-ray irradiation. </LI> <LI> Photoresponses reveal photoexcitation and oxygen photodesorption modified by gamma-ray irradiation. </LI> </UL> </P>

Effect of Electron Beam and ${\gamma}$-Ray Irradiation on the Curing of Epoxy Resin

Kang, Phil-Hyun,Park, Jong-Seok,Nho, Young-Chang The Polymer Society of Korea 2002 Macromolecular Research Vol.10 No.6

The effect of an electron beam and ${\gamma}$-ray irradiation on the curing of epoxy resins was investigated. Diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of bisphenol F (DGEBF) as epoxy resin were used. The epoxy resins containing 1.0-3.() wt% of triarylsulphonium hexafluoroantimonate(TASHFA) and triarylsulphonium hexafluorophosphate(TASHFP) as initiator were irradiated under nitrogen at room temperature with different dosage of EB and ${\gamma}$-rays from a Co$^{60}$ u source. The chemical and mechanical characteristics of irradiated epoxy resins were compared after curing of EB and ${\gamma}$-ray irradiation. The thermal properties of cured epoxy were investigated using dynamic mechanical thermal analysis. The chemical structures of cured epoxy were characterized using near infrared spectroscopy. Mechanical properties such as flexural strength, modulus were measured. The gel fraction of DGEBA with ${\gamma}$-ray was higher than that of the epoxy with EB at the same dose. Young's modulus of the sample irradiated by ${\gamma}$-ray is higher than that of sample cured by EB. From the result of strain at yield, it was found that the epoxy cured by ${\gamma}$-ray had a higher stiff property compared with the irradiated by EB.

보문: 감마방사선 조사에 의한 큰느타리버섯의 돌연변이 유발

김종군 ( Jong Kun Kim ),임선화 ( Seon Hwa Lim ),김일중 ( Il Jong Kim ),이윤혜 ( Yun Hae Lee ),강희완 ( Hee Wan Kang ) 한국균학회 2012 韓國菌學會誌 Vol.40 No.2

본 연구는 큰느타리버섯(Pleurotus eryngii)에 감마 방사선을 조사하여 형태적, 생리적 특성이 향상된 새로운 큰느타리버섯 품종을 개발하기 위하여 수행되었다. 큰느타리버섯에서 분리한 원형질체에 0.25-1.25 KGy의 감마 방사선을 조사하였다. 원형질체는 YPMGA 배지에서 80%의 치사율을 나타냈고 이들 중 무작위로 500개의 변이체를 선발하여 PDA 배지에 배양하였다. 그 결과, 대부분의 변이체가 대조구와 비슷한 형태와 생장률을 나타냈으며, 이 중 100개의 변이체가 대조구와 약간의 차이를 보였다. 67개 변이체에 대해 cellulase 활성과 laccase 활성을 조사하였다. 그 결과, 대체적으로 대조구와 유사한 효소 활성을 나타내었고, 5개의 변이체가 대조구에 비해 더 높은 cellulase 활성을 나타내었다. 또한 감마 방사선 조사 변이체의 유전적 변이를 조사하기 위하여 UFPF-PCR을 이용하여 다형성을 조사하였다. Gamma ray irradiation mutagenesis was employed to get variants of Pleurotus eryngii with functionally enhanced and improved characteristics. Protoplasts released from P. eryngii were treated with gamma ray radiation under 0.25-1.25KGy. Protoplast sample that showed fatality rate of 80% at the 0.25KGy was spreaded on YPMGA (yeast, peptone, malt-extract, glucose, agar) and 500 mycelial colonies were randomly selected from the medium, Of them, 100 mutant strains with mycelial morphology and growth rate that differ to control strain were observed on PDA. The cellulase and laccase activity of 67 gamma ray-irradiated P. eryngii isolates with morphological variation were investigated. Among these, 5 isolates were higher cellulase. In addition, the genetic variation of the mutant strains was analyzed by PCR fingerprinting.

Gamma-ray irradiated graphene nanosheets/polydopamine hybrids as a superior anode material for lithium-ion batteries

Jo Kyoung-Il,김혜리,정희성,기진호,Oh Seung-Hwan,Song Seok Hyun,Kim Hyungsub,Koo Jaseung 한국탄소학회 2022 Carbon Letters Vol.32 No.1

Despite having a low electrical conductivity, graphene oxide (GO) is used as an anode material in lithium-ion batteries (LIBs) owing its good processability in large quantities. GO is reduced by chemical or thermal treatments to enhance its electrical conductivity. In this study, high-performance GO anodes with polydopamine (PDA) and polyethylenimine (PEI) as binders were fabricated. Gamma (γ)-ray irradiation was applied to the GO–PDA–PEI hybrid sheets to covalently cross-link the GO sheets and binders with an amide bond. The covalent crosslinking was confirmed by Fourier-transform infrared spectroscopy analysis. Further, X-ray photoelectron spectroscopy results showed that γ-ray irradiation produced a reduced GO sheet, which resulted in an increase in the electrical conductivity by 30%. By characterizing the electrochemical properties, we found that the γ-ray irradiation facilitates the stability and increases the charge/discharge capacity by crosslinking GO and PDA–PEI binders and reducing the GO sheets.

A proposed new configuration of a shuffle-dwell gamma irradiator

Wu Hsingtzu 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.8

A gamma irradiator is a well-developed installation for gamma radiation sterilization. A “shuffle-dwell” mode is preferable for high dose applications. A novel configuration of a shuffle-dwell gamma irradiator is proposed to increase energy utilization and throughput, which would result in higher profitability. While the minimum distance between any irradiation position and each source pencil, the minimum distance between the neighboring irradiation positions and the size of source pencils are kept the same as the current configuration, the irradiation positions and source pencils are rearranged based on the fact that radiation is emitted in an isotropic fashion. The computational results suggest that the proposed configuration requires an 8.7% smaller area and exposes the product to 11.8% more gamma radiation in a 10.7% shorter irradiation time. In other words, the proposed configuration needs a smaller area and shorter irradiation time to have a better performance compared to the current shuffle-dwell gamma irradiator. Note that the claim is based primarily on an analytical calculation. Experimental and manufacturing among other practical considerations will be taken into account in the future work to exhaustively evaluate the performance of the proposed configuration and to compare it with that of the traditional configuration