• Nuclear Engineering and Technology
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• 제31권5호
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• pp.522-528
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• 1999

The effect of a water-soluble extract from natural materials on radiation-induced mutations was studied by means of TSH assay in Tradescantia 4430 stamen hair cells. Inflorescence cuttings, with or without pretreatments of natural extracts for 3 hours, were exposed to 1 Gy of gamma ray. Comparisons were made on the basis of pooled data during the peak interval between the mean pink mutation frequencies of the experimental groups. Pretreatments of FB or FB-I resulted in about two-fold increases of the pink mutation frequencies, compared to those of the control group. Synergism between certain fractions and radiation was a possible cause of the increased DNA damage. FB and FB-I had a radiosensitizing effects on the pink mutations in Tradescantia 4430 stamen hair cells (p<0.001). On the other hand, the extract PP in a proper concentration significantly reduced the pink mutation frequencies (p<0.05). The result means that PP has a protective effect on the radiation-induced cell damage.

• 한국재료학회지
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• 제18권2호
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• pp.61-64
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• 2008

Electrical optical switching and structural transformation of $Ge_{15}Sb_{85}$, $Sb_{65}Se_{35}$ and N2.0 sccm doped $Sb_{83}Si_{17}$ were studied to investigate the phase change characteristics for PRAM application. Sb-based materials were deposited by a RF magnetron co-sputtering system and the phase change characteristics were analyzed using an X-ray diffractometer (XRD), a static tester and a four-point probe. Doping Ge, Se or Si atoms reinforced the amorphous stability of the Sb-based materials, which affected the switching characteristics. The crystallization temperature of the Sb-based materials increased as the concentration of the Ge, Se or Si increased. The minimum time of $Ge_{15}Sb_{85}$, $Sb_{65}Se_{35}$ and N2.0 sccm doped $Sb_{83}Si_{17}$ for crystallization was 120, 50 and 90 ns at 12 mW, respectively. $Sb_{65}Se_{35}$ was crystallized at $170^{\circ}C$. In addition, the difference in the sheet resistances between amorphous and crystalline states was higher than $10^4{\Omega}/{\gamma}$.

• 방사선산업학회지
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• 제5권2호
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• pp.113-118
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• 2011

Hydrogels from a mixture of poly(N-vinylpyrrolidone) (PVP), ${\kappa}$-carrageenan and microorganism fermentation celluose were prepared by $^{60}Co$ gamma-ray irradiation. PVP and ${\kappa}$-carrageenan were mixed with the different ratios. Microorganism fermentation celluose were added to the mixture of PVP and ${\kappa}$-carrageenan to evaluate the effect of microorganism fermentation celluose on the gel strength. The gel strength of the hydrogel was evaluated for application of a wound dressing. The results showed that gelation and gel strength were increased with increasing the content of the microorganism fermentation celluose.

• 방사선산업학회지
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• 제2권1호
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• pp.43-51
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• 2008

방사선처리기술은 현재 멸균, 폴리머가교, 식품조사, 생고무가황 등 산업적으로 많은 곳에서 이용되고 있다. 현재 감마선과 전자선을 이용한 것은 방사선처리기술의 대표적인 기술이다. 이 논문의 목적은 최근의 방사선 기술을 이해하기 위해 외국의 방사선기술 동향을 살펴보고 산업현장 작업자가 방사선 관련 기술이 친숙해지기를 목적으로 그들에게 유용한 정보를 제공하기 위함이다. 본 조사를 통해 방사선이용기술이 지속적으로 성장함을 알 수 있었고, 또한 이 기술을 이용하면 제품의 다양성을 줄 수 있다는 사실도 알아냈다.

• Bulletin of the Korean Chemical Society
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• 제14권6호
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• pp.722-726
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• 1993

Organotin(IV) complexes of ylidenemalonates $(R_xSn)_{x-1}(O_2C)_2C=C(SR')_2\;(R=n-C_4H_9,\;C_6H_5,\;cyclo-C_6H_{11},\;CH_3OOCCH_2CH_2;\;x=2,3;\;R'=CH_3,\;R_2'=-CHCH-,\;-CH_2CH_{2^-})$ have been synthesized and characterized by means of various spectroscopic methods. The X-ray crystal structure of $(Ph_3Sn)_2(O_2C)_2C=C(SCH_3)_2$ has been determined (Pi; a= 9.704(2) ${\AA}$, b= 14.412(1) ${\AA}$, c= 14.760(3) ${\AA}$, ${alpha}$=74.26(1)$^{\circ}$, ${beta}$=99.38(l)$^{\circ}$, ${\gamma}$=79.09(1)$^{\circ}$, $V= 1950.7(7){\AA}^3$) and refined to R= 0.045. The crystal structure discloses a discrete molecule with bidentate-like carboxylate ligand. For diorganotin analogues, the structures are discussed in terms of IR, $^1H-NMR,\;^{13}C-NMR$, and FAB mass spectrometry. The mass spectrum indicates that the diorganotin complexes of ylidenemalonates are dimeric.

• Nuclear Engineering and Technology
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• 제47권7호
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• pp.924-933
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• 2015

The correlation of the isotopic composition of uranium, plutonium, neodymium, and cesium with the burnup for high burnup pressurized water reactor fuels irradiated in nuclear power reactors has been experimentally investigated. The total burnup was determined by Nd-148 and the fractional $^{235}U$ burnup was determined by U and Pu mass spectrometric methods. The isotopic compositions of U, Pu, Nd, and Cs after their separation from the irradiated fuel samples were measured using thermal ionization mass spectrometry. The contents of these elements in the irradiated fuel were determined through an isotope dilution mass spectrometric method using $^{233}U$, $^{242}Pu$, $^{150}Nd$, and $^{133}Cs$ as spikes. The activity ratios of Cs isotopes in the fuel samples were determined using gamma-ray spectrometry. The content of each element and its isotopic compositions in the irradiated fuel were expressed by their correlation with the total and fractional burnup, burnup parameters, and the isotopic compositions of different elements. The results obtained from the experimental methods were compared with those calculated using the ORIGEN-S code.

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.562-568
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• 2017

Background: The chemical characterization of metallic alloys and oxides is conventionally carried out by wet chemical analytical methods and/or instrumental methods. Instrumental neutron activation analysis (INAA) is capable of analyzing samples nondestructively. As a part of a chemical quality control exercise, Zircaloys 2 and 4, nimonic alloy, and zirconium oxide samples were analyzed by two INAA methods. The samples of alloys and oxides were also analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and direct current Arc OES methods, respectively, for quality assurance purposes. The samples are important in various fields including nuclear technology. Methods: Samples were neutron irradiated using nuclear reactors, and the radioactive assay was carried out using high-resolution gamma-ray spectrometry. Major to trace mass fractions were determined using both relative and internal monostandard (IM) NAA methods as well as OES methods. Results: In the case of alloys, compositional analyses as well as concentrations of some trace elements were determined, whereas in the case of zirconium oxides, six trace elements were determined. For method validation, British Chemical Standard (BCS)-certified reference material 310/1 (a nimonic alloy) was analyzed using both relative INAA and IM-NAA methods. Conclusion: The results showed that IM-NAA and relative INAA methods can be used for nondestructive chemical quality control of alloys and oxide samples.

• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1298-1305
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• 2018

The use of System-on-Chip (SoC) solutions in the design of on-board data handling systems is an important step towards further miniaturization in space. However, the Total Ionizing Dose (TID) and Single Event Effects (SEE) characterization of these complex devices present new challenges that are either not fully addressed by current testing guidelines or may result in expensive, cumbersome test configurations. In this paper we report the test setups, procedures and results for TID testing of a SoC microcontroller both using standard $^{60}Co$ and low-energy protons beams. This paper specifically points out the differences in the test methodology and in the challenges between TID testing with proton beam and with the conventional gamma ray irradiation. New test setup and procedures are proposed which are capable of emulating typical mission conditions (clock, bias, software, reprogramming, etc.) while keeping the test setup as simple as possible at the same time.

• 방사선산업학회지
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• 제12권4호
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• pp.349-353
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• 2018

Metronidazole (MD), which is used as an antibiotic, is largely used as an oral and skin application agent, and has inhibiting effect on the production of the fungus causing malodor. However, the maximum drug inclusion concentration is 0.75% of skin ointment in commercially available. In this study, hydrogels containing high concentration of metronidazole were prepared by using radiation crosslinking technique based on biocompatible polymers, and release characteristics and antimicrobial properties were evaluated. This study was preliminary carried out to investigate whether it could be used effectively as antibacterial dressing materials.

• Bulletin of the Korean Chemical Society
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• 제15권3호
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• pp.245-249
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• 1994

NaMg[$Cr(C_2O_4)_3]{\cdot}10H_2O$ crystallizes in the trigonal space group P$\bar{3}$c1, with a=b= 16.969(3), c=12.521(3) ${\AA}$, ${\alpha}={\beta}=90^{\circ},\;{\gamma}=120^{\circ},\;{\rho}=1.734 \;gcm^{-3},\;{\mu}=6.46\;cm^{-1}$, Z=6. Intensities for 1062 unique reflections were measured on a four-circle diffractometer with Mo K${\alpha}$ radiation (${\lambda}=0.71069\;{\AA}$). The structure was solved by direct methods and refined to a final ${\omega}$R value of 0.084. X-ray crystal structure showed that magnesium ion appears to be occupied over two sites with the occupancy ratio of 2:1. The crystal possesses 10 water molecules instead of previously estimated 9 water molecules.