• 방사선산업학회지
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• 제6권1호
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• pp.49-54
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• 2012

Various anion exchange membranes were prepared by radiation graft copolymerization of vinylbenzyl chloride onto fluorinated films and subsequent quaternization with various tertiary amines such as trimethylamine, N,N-dimethylbuthylamine, N,N-dimethylaniline, and N-methylpiperidine. The quaternizations of the anion exchange membranes were confirmed by measuring of the ion exchange capacities of the membranes. The mechanical properties and the water uptakes were also measured. The elongation at break was found to be largely dependent on the fluorinated film, the quateranry ammonium, and the degree of grafting. The results indicate that the poly (ethylene-alt-tetrafluoroethylene) with quaternized trimethylamine moiety exhibits higher flexible property compared to the other prepared anion exchange membranes.

• 방사선산업학회지
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• 제5권2호
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• pp.179-184
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• 2011

In this study, several anion exchange membranes were successfully prepared by radiation grafting of vinylbenzyl chloride (VBC) monomer onto a polyethylene-co-tetrafluoroethylene (ETFE) film and subsequent quaternarization with diamins such as 1,4-diazbicyclo[2,2,2]octane, N,N,N',N'-tetramethyl-1,3-diaminopropane, N,N,N',N'-tetramethyl-1,6-diaminohexane, and trimethylamine. The anion exchange capacities of the prepared membranes were determined by using acid-base titration method. The cross-sectional morphology of the membranes was studied by using SEM instrument. The cross-sectional distribution patterns of the grafted polymers with anion exchange functional groups were also studied by EDX analysis.

• Agricultural and Biosystems Engineering
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• 제7권1호
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• pp.42-47
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• 2006

The objective of this study was to investigate the effects of air-phase germination with water-spraying and anion stimuli on germination ratio, sprout growth and ${\gamma}$-aminobutyric acid (GABA) of brown rice. Air-phase germination method with intermittent spraying water improved germination ratio and sprout growth by about 100% compared with the conventional water-soaking method. Anion radiation was applied during the germination process and improved the germination ratio, sprout growth and color quality of the germinated brown rice. Germination ratio and sprout growth were improved up to 9% with anion radiation, and its brightness was higher than brown rice germinated with no anion radiation. The air-phase germination with water-spraying improved the GABA content of germinated brown rice by about 8-9 times compared with that of brown rice.

• Journal of Biosystems Engineering
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• 제36권3호
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• pp.187-194
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• 2011

In this study an automatic germinating system for germinated brown rice (GBR) was developed for accelerating germination and sprouting of brown rice. With the developed germinating system, the effects of anion radiation treatment on germination ratio, sprout growth, color quality and ${\gamma}$-aminobutyric acid (GABA) content of brown rice were investigated. This system can fast produce GBR by controlling the environmental conditions such as ambient temperature, relative humidity, and proper anion radiation. Air-phase germination with intermittent water spraying improved both germination ratio and sprout growth by about 2.2 and 2.3 times, respectively, compared to the conventional water soaking method. Our results strongly suggest that this germinating system that provides air-phase germination with intermittent water spraying and anion radiation can produce germinated brown rice with good color quality, high GABA content, and fast germination ratio as well as sprout growth.

• 방사선산업학회지
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• 제5권3호
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• pp.221-225
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• 2011

To detect superoxide anion ($O_2{\cdot}^-$) or singlet oxygen ($^1O_2$) in biological systems during gamma irradiation, specific chemical probes, 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron) or 2,2,6,6-tetramethyl-piperidine (TEMP), were evaluated. Tiron or TEMP spin adducts was structurally stable in aqueous solution during gamma irradiation up to 500 or 1,000 Gy, respectively. The signal of Tiron semiquinone radical, a spin adduct of Tiron upon reaction with $O_2{\cdot}^-$, was slightly increased by gamma irradiation. This trend was dose-dependently manifested in $O_2$-saturated aqueous solution using nitro blue tetrazolium (NBT), a common probe for both hydrated electron ($e{^-}_{aq}$) and $O_2{\cdot}^-$. In contrast, a spin adduct of TEMP, was never inducible by gamma irradiation, while its signal was substantially enhanced by photosensitization of riboflavin. These results suggest that Tiron and NBT or TEMP could be utilized to detect $O_2{\cdot}^-$ or $^1O_2$ in biological systems during gamma irradiation, although $O_2{\cdot}^-$ or $^1O_2$ are not the main reactive oxygen species produced by water radiolysis.

• Journal of Radiation Protection and Research
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• 제26권3호
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• pp.191-195
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• 2001

An accurate and simple analytical technique for low levels of fallout Pu in the environment was developed using an anion exchange resin. To develop the reliable determination of Pu isotopes in soil samples, decomposition of soil matrix, plutonium oxidation state adjustment on the anion exchange column and source preparation of Pu isotopes have been carried out. The optimum method of Pu isotopes with an anion exchange has been validated by application to IAEA-Reference soils.

• 한국환경과학회지
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• 제25권10호
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• pp.1369-1379
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• 2016

This research assessed the disparity in anion generation according to the vertical structure of a Zelkova Serrata tree for the purpose of creating a pleasant and green city environment. Measurements for the study were conducted between July and August of 2014 in Chung-ju in the central region of the Republic of Korea. The average anion generation of vertical structure trees during active photosynthesis periods was: L Section ($839.0ea/cm^3$) > M Section ($664.6ea/cm^3$) > U Section ($472.0ea/cm^3$). According to DMRT analysis, significant difference was found in the average between the L, or M Locations and the U Locations. During dormant photosynthesis periods, records showed that the anion production at the M Location ($1,212.5ea/cm^3$) > L Location ($1,050.4ea/cm^3$) > H Location ($844.1ea/cm^3$), According to DMRT analysis, the difference within each location was significant for ${\alpha}=0.05$. In a comprehensive analysis of the weather factors in each vertical structure, anion generation during active photosynthesis periods showed a positive correlation with solar radiation and a negative correlation with wind speed. Dormant photosynthesis periods showed negative correlations with both solar radiation and temperature, and positive correlations with relative humidity and wind speed. Predictions from a multicenter retrospective study showed that during active photosynthesis periods, $Y_1=282.443X_1+512.07$, and $Y_2=314.337X_1+16.913X_2$, while during dormant photosynthesis periods, $Y_1=391.009X_1+840.043$, and $Y_2=351.412X_1+32.765X_2$.

• 공업화학
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• 제17권3호
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• pp.303-309
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• 2006

본 연구에서는 음이온 및 요소의 투과유속이 강화된 복막투석용 기능성 음이온 교환막의 제조와 특성에 관한 연구를 수행하였다. 음이온 교환막은 UV와 방사선 그라프트 중합법에 의하여 제조되었다. UV 그라프트 중합법에 의해 제조된 분리막의 경우 HEMA와 VBTAC의 비율이 1:2일때 가장 높은 그라프트율을 보였으며 그 이상의 농도에서는 호모폴리머의 생성이 많아지면서 그에 의한 자외선 침투의 제약으로 그라프트율이 감소하였다. 광개시제의 경우에는 0.2 wt%인 경우에 가장 높은 그라프트율을 나타내었으며 그 이상의 농도에서는 다소 감소하는 경향을 나타냈다. 방사선 그라프트 중합법에 의해 제조된 분리막의 경우 VBTAC/HEMA막의 경우 6 h 반응시 96%, GMA막의 경우 반응시간 2 h에 100% 이상의 그라프트율을 나타내었다. 또한, 음이온 교환막을 제조하기 위해 그라프트율 113% 막을 사용하였으며, 음이온 교환기로는 DEA, TEA를 사용하였다. DEA막의 경우 반응시간 4 h에서 70%, TEA막의 경우 2 h 반응에서 30%의 전화율을 나타내었다. 또한, 두 방법에 의하여 제조된 음이온 교환막은 양이온은 배제시키고 음이온과 요소만을 투과하는 특성을 나타내었다.

• 폴리머
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• 제34권2호
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• pp.126-132
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• 2010

메탄올 용매에서 고분자 촉진 단량체와 소디윰 스티렌 슐포네이트를 방사선 그래프트 방법으로 양이온 교환 PVdF 맴브레인을 제조하였다. 고분자 촉진 단량체로서 스티렌, 아크릴산, 비닐 피롤리돈을 사용하였다. 또한, 음이온 교환 PVdF 맴브레인도 방사선 그래프트 중합법에 의해 제조하였다. 양이온 및 음이온 교환 PVdF 맴브레인은 SEM, XPS 그리고 열분석기기를 통해 특성평가를 하였고 성공적으로 합성됨을 확인할 수 있었다. 그래프트 수율, 이온교환기의 양 및 침투율은 각각 30.0~32.3%, 2.81~3.01 mmol/g 그리고 66.6~147%로 평가되었으며, 20 $^{\circ}C$에서 이온 전도도를 측정한 결과 0.020~0.053 S/cm 이었다. 최종적으로, 제조된 양이온 및 음이온교환 PVdF 맴브레인은 전지격막으로서 충분히 사용될 수 있음을 확인할 수 있었다.

• 폴리머
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• 제30권3호
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• pp.217-223
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• 2006

방사선 동시조사에 의해 폴리올레핀 복합 섬유 표면에 고관능성 아민화 이온교환섬유를 합성하였다. 총 조사선량이 증가할수록 그래프트율도 증가하였으며 GMA 농도 50%에서 그래프트율은 최대 365%로 최대 값을 나타내었다. 또한 그래프트 반응은 극성용매에서 일어나며 Mohr's salt, 황산의 함량 $1.0\times10^{-3}M$, 0.1 M에서 그래프트율은 최대 190% 이었다. 아민화 반응은 아민화제의 종류에 따라 각기 다르게 나타났으며 메틸아민의 경우 반응성이 가장 좋았으며 트리에틸아민의 반응성이 가장 낮게 나타났다. 이온교환섬유의 함수율과 이온 교환용량은 아민화율이 증가할수록 높게 나타났으며 비표면적은 그래프트 반응과 아민화 반응이 진행됨에 따라 급격히 감소하는 경향을 보였다.