• 분석과학
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• 제28권5호
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• pp.341-346
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• 2015

In order to understand the counter anionic effects in a non-aqueous vanadium redox flow battery (VRFB), we synthesized four types of electrolyte salts (1-ethyltriethamine tertafluoroborate, [E-TEDA]⁺[BF₄]⁻, 1-ethyltriethamine hexafluorophosphate, [E-TEDA]⁺[PF₆]⁻, 1-butyltriethylamine tertafluoroborate, [B-TEDA]⁺[BF₄]⁻, and 1-buthyltriethamine hexafluorophosphate [B-TEDA]⁺[PF₆]⁻) by counter anion exchange reaction after the SN₂ reaction. We confirmed the successful synthesis of the electrolyte salts [E-TEDA]⁺[Br]⁻ and [B-TEDA]⁺[Br]⁻ via ¹H-NMR spectroscopy and GC-mass analysis before the counter anion exchange reaction. The electric potential of the vanadium acetylacetonate, V(acac)₃, as an energy storage chemical was shown to be 2.2 V in the acetonitrile solvent with each of the [E-TEDA]⁺[BF₄]⁻, [E-TEDA]⁺[PF₆]⁻, [B-TEDA]⁺[BF₄]⁻, and [B-TEDA]⁺[PF₆]⁻ electrolyte salts. In a non-aqueous VRFB with a commercial Neosepta AFN membrane, the maximum voltages reached 1.0 V and 1.5 V under a fixed current value of 0.1 mA in acetonitrile with the [E-TEDA]⁺[BF₄]⁻ and [E-TEDA]⁺[PF₆]⁻ electrolyte salts, respectively. The maximum voltage was 0.8 V and 1.1 V under a fixed current value of 0.1 mA in acetonitrile with the [B-TEDA]⁺[BF₄]⁻ and [B-TEDA]⁺[PF₆]⁻ electrolyte salts, respectively. From these results, we concluded that in the non-aqueous VRFB more of the [PF₆]⁻ counter anion than the [BF₄]⁻ counter anion was transported onto the commercial Neosepta AFN anion exchange membrane.

• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.851-854
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• 2007

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2004년도 춘계총회 및 학술발표회
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• pp.32-32
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• 2004

• Bulletin of the Korean Chemical Society
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• 제10권2호
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• pp.214-216
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• 1989

• 대한화학회지
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• 제42권4호
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• pp.383-390
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• 1998

몇 가지 양이온 계면활성제(DTAB, TTAB, CTAB, CDEAB 및 CTAC)의 마이셀과 Phenoxide 음이온과의 상호작용을 연구하기 위하여 UV/Vis분광광도법을 이용하였다. Phenoxide 음이온의 용액에 양이온 게면활성제를 녹였을 때 일어나는 흡광도의 변화로부터 Phenoxide 음이온의 가용화상수($K_s$)와 양이온 계면활성제의 임계마이셀농도(CMC)값을 함께 측정하였다. 각 양이온 계면활성제의 수용액에서 Phenoxide 음이온의 가용화상수값($K_s$)은 다음의 순서로 변하였다: $K_s(CTAC)>K_s(CDEAB)>K_s(CTAB)>K_s(TTAB)>K_s(DTAB).$ 또한 Phenoxide 음이온의 가용화에 미치는 염(NaCl 및 NaBr)과 n-알코올(부탄올, 펜탄올 및 헥산올)의 효과에 대하여 조사하였으며, 그 결과 염과 n-알코올의 첨가로 Ks와 CMC값은 크게 감소하는 경향을 보였다. 그리고 온도에 다른 Ks값의 변화로부터 Phenoxide 음이온의 가용화에 대한 표준자유에너지, 엔탈피, 및 엔트로피의 변화를 계산하고 분석하였다.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1386-1391
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• 2009

Crude polysaccharides from rapeseed meal (PRM) were extracted with 0.3% NaOH aqueous solution, followed by further purifications and 2 fractions, namely PRM1 and PRM2, were separated with a DEAE-cellulose DE-52 column. Their primary compositions were analysed and antioxidant activity was determined, including scavenging activity toward superoxide anion radicals, hydroxyl radicals, and nitric oxide radicals, reducing power, and inhibitory effects against the microsomal lipid peroxidation, compared to that of L-ascorbic acid. The results indicated that PRM1 and PRM2 exhibited not only good reducing power and inhibitory effects on the microsomal lipid peroxidation, but also strong scavenging activity toward superoxide anion radicals, nitric oxide radicals, and hydroxyl radicals. In addition, positive correlations were also observed between the superoxide anion radical scavenging activity and the protein contents of the polysaccharides, and the reducing power and the sulfate contents. These findings thus clearly suggest the polysaccharides possess direct and potent antioxidant activity.

• 한국식품영양과학회지
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• 제30권3호
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• pp.421-425
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• 2001

Antioxidative effects of crude chlorophylls and carotenoids extracts from mustard leaf kimchi on the lipid peroxidation in rat liver homogenate, egg phosphatidyl choline (EPC) liposome and superoxide anion radical were examined. The extracts were found to inhibit the increase of the thiobarbituric acid (TBA) value and show the effect of antioxidative activity on the liposomal phospholipid membrane. The oxidation index of EPC liposome was markedly decreased in the prescence of the extracts. The antioxidative activity of the extracts from mustard leaf kimchi was not related with fermentation period of the kimchi. The extracts from mustard leaf showed the similar antioxidative activity of $\alpha$-tocopherol within in the given level of addition. However, the oxidation index. When the effect of the extracts from mustard leaf kimchi on free radical scavenging was observed by the determination of the superoxide anion radical scavenging activity, it had similar value to that of $\alpha$-tocopherol.

• 대한한의학회지
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• 제26권3호
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• pp.204-214
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• 2005

Objectives : The verity extract of the Gagam-Hyungbang-Gihwang-tang (GHG) was assessed to determine the mechanisms of its antioxidant activity. Methods : The fellowing effects were measured : GHG exhibited a concentration-treatment; scavenging ${\alpha},\;{\alpha}-diphenyl-\beta-picrylhydrazyl$ (DPPH) radical, linoleic acid oxidation in a thiocyanate assay system, and superoxide anion, hydroxyl radical-induced DNA nicking. We investigated mRNA levels such as superoxide-dismutase. Results : The GHG extract showed dose-dependent free radical scavenging activity, including DPPH radicals, hydroxyl radicals, and superoxide anion, using different systems. The GHG was also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals in Fenton's reaction mixture. Furthermore, SOD-1 mRNA expression levels increased in tat hepatoma H4IIE cells Conclusions : We expect that GHG will to helpful to the development of antioxidant activity treatments.

• 한국토양비료학회지
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• 제6권3호
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• pp.193-197
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• 1973

1. 두 다년생(多年生) 사막식물(沙膜植物) (Lycium andersonii, Atriplex confertifolia)이 Na($NO_3{^-}$, $Cl^-$, $H_2PO_4{^-}$)의 다른 기원으로 식물체내(植物體內) cation-anion 균형에 대(對)한 영향을 평가하기 위해 온실에서 토양재배(土壤裁培)를 하였다. 2. 각(各) anion은 다른 anion과 상호작용(交互作用)이 있을지라도 시비(施肥)에 따라 주(主)로 엽(葉)에 증가되였다. 3. 측정(測定)된 전(全) anion(N. P. Cl)은 각(各) 식물(植物) 부분(部分)에 증가되였다. 4. 동시에 전(全) cation도 증가현상을 보였다. 5. Cation-action의 비율은 $NaNO_3$의 경우 현저(顯著)히 감소(減少)되였다. cation-anion 비율(比率)은 보통 1을 넘고 있다. 6. 염내(鹽內) Cl 및 N의 최고(最高) 함량은 이들 성분(成分)이 부여(附加)될 때 Lycium andersonii에서 13.51% 및 6.37%로 각각(各各) 나타나고 있다. 7. Na 농도(濃度)는 Lycium andersonii 보다 Atriplex confertifolia 에서 더 높았다. 8. Na의 각 처리간에 유의차가 있을지라도 전(全) cation은 일정(一定)하게 유지(維持)되는 것으로 봐 처리구(處理區)에서 Na가 증가 됨으로서 다른 Cation들 사이에 약간의 보상작용(補償作用)이 나타났다. 9. Lycium andersonii는 Li의 축적자(蓄績者)로 나타나고 있다.

• 한국초지조사료학회지
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• 제20권4호
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• pp.265-274
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• 2000

To investigate the effects of anion replacement on NO3- concentration in Italian ryegrass. Plants weregrown hydroponically to the full vegetative stage. NO3 supply(control) was replaced with SO1- (Tl), C1-(T2) and water (T3) to during 14 days. The determination of inorganic nutrient uptake and quantification ofprincipal metabolites (nitrate. protein and sugar) followed. Relatively high uptake of ~ a a'n d Ca" for controlplants, K+ and POJ- for T2 plants, and C 1 for TI plants was observed, respectively. Proteins in shoot andstubble were relatively higher in control and TI plants, which coupled N source. In root proteins largelydecreased (especially in T3 plants) during experimental period. Sugars in shoot of all four treatments tendedto decrease during the first 7 days and recovered afterward. Sugars in stubble also markedly decreased duringthe first 7 days, while those in root was much less varied during experimental period. After 14 days oftreatment, nitrate concentration in shoot of control plants was 13mgIg FW. Comparing to control: nitrate inshoot reduced by 27%, 46% and 50% in TI, T2 and T3 plants, respectively. Dry weight was slightlyincreased or not significantly changed in control, T1 and T2 plants, while a significant decrease(31.3% ofcontrol) occurred in T3 plants.(Key words : Italian ryegrass, Anion replacement, Ion uptake, Protein, Sugar, Nitrate)ptake, Protein, Sugar, Nitrate)