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        검색결과 183

        162.
        2005.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Cs 이온에 대해 선택성을 갖는 ferrocyanide-음이온 교환수지를 제조하여 모의 제 염폐액 내에 존재하는 Cs 이온에 대한 흡착실험을 수행하였다. 제조된 이온교환 수지가 citric acid를 주제염제로 하는 제염폐액 내에 존재하는 Cs+ 이온에 대한 흡착능력은 상용 양이온교환수지에 비해 4배 이상 효과적인 것으로 나타났다. 모의 제염폐액과 선택성 이온교환수지를 접촉시킨 후 360분이 경과하면 금속이온에 대한 흡착반웅이 평형에 도달하였다. 본 연구범위에서 Co 이온농도가 필요이상 증가하게 되면 Cs 이온의 흡착율은 감소하였다. 과산화수소와 히드라진을 사용한 선택성 폐 이온교환수지의 재생실험 결과 전기중성화조건을 만족시키기 위해 Cs 이온이 수지로부터 용출됨을 확인하였고 열화없이 재 사용가능성을 확인하였다.
        4,000원
        163.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The interaction between anion and zwitterionic surfactants was investigated by means of surface tension, NMR spectroscopy, and fluorescence studies. These systems are N-tetradecyloxymethyl-N,N-dimethyl betaine (C14, TDB), N-octadecyloxymethyl-N,Ndimethyl betaine (C18, ODB), and sodium dodecylethoxy sulfate (SDE). These systems show a composition dependency in micellar properties. When the molar fraction of TDB and ODB was about 0.6, the cmc values of these systems showed minima, whereas the solubilized amount of a water insoluble dye, NMR line width showed maxima. These changes comes from the intramolecular complexes formed in the mixed micelles. The complexes are due to the electrostatic interaction of oppositely charged head groups of betaine and sodium dodecylethoxy sulfate. A comparison of betaine and SDE alkyl methylene group line widths to those of n-methyl group indicates that the interior of the micelle in the restricted region is more immobile than the head group.
        4,000원
        164.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        상전환 방법으로 제조된 음이온 성 Poly(his[4-(3-aminophenoxy)phenyl]sulfone pyromellite)imide(ACPI) 한외여과막의 순수 투과유속과 용질 배재도 측정치로 투과성능을 연구하였다. ACPI 한외여과막의 투과성능은 캐스팅 용액의 조성과 막 제조 및 측정조건에 영향을 받았다. Bovine serum albumin (BSA) 용액을 pH 2.5-9.0 상태에서 ACPI 한외여과 막의 상대투과유속과 membrane filtration index (MFI) 측정한 결과 BSA의 등전점에서 멀어 질수록 상대투과유속은 증가하고 막 오염정도를 나타내는 MFI는 감소하였다. 또한, 친수성인 ACPI 한외여과막의 이온교환용량(IEC)이 증가할수록 상대투과유속은 증가하고, MFI는 감소하였다.
        4,200원
        165.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        피리디니움 (pyridunium) 그룹을 포함한 음이온교환막의 제조 및 전기화학적 특성 평가를 수행하였다. 실험 결과, 제조된 피리디니움 음이온교환막은 상용막과 대등한 전기저항 (3.0 Xicm2>, in 0.5 mol dm-3 NaCl) 및 높은 이온선택도 (Cl- 이온수송수 약 0.97)의 우수한 전기화학적 특성을 나타내었다. 또한 피리니디움 그룹을 함유한 음이온교환막에서의 물분해는 상용막 (AM-1, Tokuyama Corp., Japan)에 비해 동일한 전류밀도 하에서 약 100배 내지 1000배 가량 낮게 측정되었는데 이는 4차 아로마틱 피리디니움 그룹의 공명효과 (resonance effect)가 이온교환기의 분자구조적 안정성에 영향을 미쳤기 때문으로 사료되었다. 또한 피리디니움 음이온교환막의 전기투석 특성이 semi-pilot 스케일에서 평가되었다.
        4,000원
        166.
        2000.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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 determi
        4,000원
        167.
        1998.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구는 붕소이온 분리를 위하여 4-Vinylpyridine-divinylbenzene(이하 4-VP-DVB라 칭함) 음이온 교환수지를 합성하고, polyethylene(이하 PE라 칭함)을 지지체로 사용하여 불균질계 음이온교환막을 제조하였다. 또한 그들의 구조와 기계적 성질 및 전기화학적 특성ㅇ르 FT-IR, conductometer와 pH meter 등의 기기로 측정하였으며, 유속과 전압의 변화에 따른 막의 성능을 평가하였다. 막의 분리성능은 PE 지지체 내에 4VP-DVB 이온교환 수지의 함량이 50wt%인 불균질막이 가장 우수하였으며, 산처리한 막이 수처리한 막의 그것보다 우수하였다. 막을 이용한 전기투석 실험에서 붕소이온 분리시 최적유속, 전압 및 시간은 각각 10mol/min, 18volt, 4시간이었다.
        4,000원
        168.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이온교환막을 이용하는 확산투석은 농도차가 구동력인 막공정으로서 철강 산업, 금속 제련 산업, 전기 도금 산업 등으로부터 발생되어지는 폐산으로부터 염산 및 기타 산들을 회수하는데 사용된다. 이론적으로는 초기산 농도가 증가함에 따라 구동력인 농도차가 커지므로 선형적으로 산의 투과속도가 증가하게 된다. 그러나 염산의 경우 약 3 N 이상의 고농도 범위에서는 투과속도 증가율이 농도차가 커짐에 따라 감소하였다. 본 연구에서는 막흡수 실험과 확산투석조 실험을 통해 염산을 회수하기 위한 확산투석에 산의 농도가 미치는 영향과 농도 범위에 따른 음이온 교환막 내부에서의 산의 이동 기작을 고찰하였다. 실험 결과 저농도(<2 N)산의 경우에는 산의 분자확산, 그리고 고농도 (>2 N)산의 경우에는 수소이온 투과현상 (proton leakage)이 막에서의 지배적인 이동 기작임을 알 수 있었다. 또한 고농도 범위에서는 삼투압에 의한 물분자의 이동과 막의 탈수현상이 수소이온의 이동을 방해하므로 막에서의 산 플럭스 증가율이 감소하였다.
        4,000원
        169.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transesterification reactions (methyl methacrylate with diethanolamine, ethylene glycol with dimethylphthalate) were kinetically investigated in the presence of zinc compound catalysts at 120~170℃ The amount of reactants was measured by gas chromatography. and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively, The overall reaction order was 2nd. The apparent rate constant (k') was found to obey first kinetics with respect to the concentration of catalyst. It shows that according to an increase in basicity of anionic species the rate constant increase, and that a linear relationship exists between ln k and pKa in transesterification reaction of methyl methacrylate with diethanolamine.
        4,000원
        170.
        1989.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        山地草地開發파 聯關된 草地士爆改良 및 施R巴法 改善올 薦하여 Homes의 Systematic variations 方法으로 多量要素 ΣAnion : ΣCation 適正施服比率 및 適正總養分(ΣA+ ΣC) 施肥量을 決定코자 Grass-clover 混播我培條件에서 山地土壞을 供試한 Pot 試驗으로 遂行한 結果는 1. 混播條件에서 各構成草種別 收量提高를 위한 ΣA/Σ
        4,000원
        171.
        2018.10 서비스 종료(열람 제한)
        When the reinforced concrete structure is in a high salinity environment, chlorine ions penetrate from the surroundings, resulting in corrosion of the reinforcing bars, resulting in low durability. Therefore, studies on the immobilization of chlorine ions are underway, and anion exchange resin, one of them, was used in this study. In this study, chloride ion fixing ability was confirmed by replacing OPC, conventional bead anion exchange resin, and powder anion exchange resin with mortar and then using an electron probe X-ray micro-analyzer. The bead anion exchange resin replaced 3% of the fine aggregate volume and the powder anion exchange resin 5% of the cement volume. The fabricated specimens were cured for 28 days, immersed in NaCl solution for 28 days, and confirmed by electron probe X-ray micro-analyzer.
        172.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        Recently, self-healing concrete has been researched as maintenance and repair of concrete structures are important challenges we face. This paper focused on possibility of ion exchange resin as a novelty material directly and actively controlling harmful ions of concrete, whereas most self-healing concrete researches have been focused on methods to automatically filling and repairing internal crack of concrete. Because equilibrium properties between ion exchange resin and harmful ion is important before design of cement mixing proportion, it was conducted to remove chloride or sulfate in saturated Ca(OH)2 solutions containing NaCl or Na2SO4. The removal performance was analyzed using kinetic equation and isothermal equation. Consequently, the removal properties of anion exchange resin were relatively more dependent on pseudo second reaction equation and Langmuir equation than pseudo first reaction equation and Freundlich equation. And it was concluded that each chloride and sulfate can be removed to the maximum 1068 ppm and 1314 ppm.
        173.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        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 (839.0 ea/cm3) > M Section (664.6 ea/cm3) > U Section (472.0 ea/cm3). 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 (1,212.5 ea/cm3) > L Location (1,050.4 ea/cm3) > H Location (844.1 ea/cm3), According to DMRT analysis, the difference within each location was significant for α=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, Y1 = 282.443X1 + 512.07, and Y2 = 314.337X1 + 16.913X2, while during dormant photosynthesis periods, Y1=391.009X1 + 840.043, and Y2=351.412X1 + 32.765X2.
        174.
        2015.08 KCI 등재 서비스 종료(열람 제한)
        This study is mainly focused on micellar effect of tetradecyltrimethyl ammonium bromide(TTABr) solution including alkylbenzimidazole(R-BI) on dephosphorylation of diphenyl-4-nitrophenylphosphinate(DPNPIN) in carbonate buffer(pH 10.7). Dephosphorylation of DPNPIN is accelerated by BI⊖ ion in 10-2 M Carbonate buffer(pH 10.7) of 4×10-4 M TTABr solution up to 80 times as compared with the reaction in Carbonate buffer by no benzimidazole(BI) solution of TTABr. The value of pseudo first order rate constant(kψ) of the reaction in TTABr solution reached a maximum rate constant increasing micelle concentration. The reaction mediated by R-BI⊖ in micellar solutions are obviously slower than those by BI⊖, and the reaction rate were decreased with increase of lengths of alkyl groups. It seems due to steric effect of alkyl groups of R-BI⊖ in Stern layer of micellar solution. The surfactant reagent, TTABr, strongly catalyzes the reaction of DPNPIN with R-BI and its anion(R-BI⊖) in Carbonate buffer(pH 10.7). For example, 4×10-4 M TTABr in 1×10-4 M BI solution increase the rate constant(kψ=99.7×10-4 1/sec) of the dephosphorylation by a factor ca. 28, when compared with reaction(kψ=3.5×10-4 1/sec) in BI solution(without TTABr). And no TTABr solution, in BI solution increase the rate constant(kψ=3.5×10-4 1/sec) of the dephosphorylation by a factor ca. 39, when compared with reaction (kψ=1.0×10-5 1/sec) in water solution(without BI).
        175.
        2014.10 KCI 등재 서비스 종료(열람 제한)
        This research investigated the feasibility of rice husk (RH) as a biosorbent for the removal of anions from aqueoussolution. RH-g-GMA-Am biosorbent, which possesses anionic exchangeable function, was prepared through graftpolymerization of glycidyl methacrylate (GMA) in the presence of N,N'-methylene-bis-acrylamide as a cross-linker usingpotassium peroxydisulphate as a redox initiator and subsequent amination reaction using ethylenediamine (EDA),diethylenetriamine (DETA), dimethylamine (DMA) and trimethylamine (TMA) as a amine source. Fourier transforminfrared (FTIR) and scanning electron microscopy (SEM) analysis as well as the sorption capacity for anions verifiedthe presence of grafted GMA polymers and amine groups on the RH surface. The zero point of surface potential ofaminated RH-g-GMA-Am sorbent was 6.4, which facilitated the sorption of anions on the positively charged sorbent atpH<6.4. The sorption capacity of RH-g-GMA-Am depending on the amination chemicals increased in the order:DETA≥EDA>DMA>TMA, i.e., primary amine>secondary amine>tertiary amine. The sorption selectivity of RH-g-GMA-Am sorbent aminated with DETA and EDA in the presence of equimolar anions and at pH 4.7 increased in theorder: SO4>PO4>NO3>F. Furthermore, their sorption capacities for PO4 were much higher than those of commercialanion-exchange resins. The results obtained suggest that the RH-g-GMA-Am biosorbent prepared by the GMA graftcopolymerization and subsequent amination can be used as an effective anion-exchanger comparable to commercial anion-exchange resins.
        176.
        2014.07 KCI 등재 서비스 종료(열람 제한)
        This study were performed on roadside buffer green in Songpa-dong, Songpa-gu, Seoul in order to analyze the anion concentration according to the type of composition of roadside buffer green. Buffer green separating the physical structure of the measurement points and measurement locations were separated by roadside, green interior, the other side of the road. planting density and deposit of trees per each buffer green was measured in the order of mounding type> slope type> the plain type. If the measured temperature of the location-specific weather elements roadside> inside> the other side of the road in order of measurement and the temperature is lowered farther away from the road. If the relative humidity of the road on the other side> inside> the roadside in order to measure and this is the opposite of the temperature tendency. According to physical structure reduction of the temperature on the other side of the road and roadside in order of mounding type> the plain type> slope type was measured. As a result of measuring a anion therefore concentration of the anion inside of melt is in order of mounding type> the plain type> slope type, tended to match the melt characteristics. According to measured positions anion concentration is in the order of the other side of the road> inside> the roadside was measured. As a result of correlation analysis, in the case of measurement location-specific weather and anions the temperature is positive correlation, relative humidity is negative correlation and that's results of previous studies were supported.
        177.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        In order to verify the healing effect in the variety of effects according to fountain type, anion which is the representatives factor of healing, as the center of case studies which in Gwanghwamun(Ground fountain), Cheonggyecheon(Waterfall) and Myeongdong(Formative fountain). According to fountain type, the anion distribution as follow, figures typically 15,721 ± 419 ea/cm³, Formative fountain 40,190 ± 788 ea/cm³, Waterfall 4,480 ± 290 ea/cm³ and ground fountain 2,492 ± 180 ea/cm³. It is usually exceed to the distribution in natural green, which is 1070∼2100 ea/cm³. The interrelation between air temperature, relative humidity, wind speed and relative humidity, and wind speed is that, the relative humidity is directly proportional to wind speed and inversely proportional to temperature. As the temperature goes up, the distribution of anion goes down. And as the wind speed and relative humidity goes up, the distribution of anion decrease sharply. The result of interrelation between fountain type and the anion distribution is that, the distance of water falling is directly proportional to the anion distribution in the formative fountain and inversely proportional in the ground fountain. And the distribution of anion is largest in formative fountain. The distribution of anion in ground fountain is lower than in formative fountain, but it is far more than in natural greenery. And as the distance from fountain increase, the distribution of anion goes down.
        178.
        2012.05 KCI 등재 서비스 종료(열람 제한)
        This study is mainly focused on micellar effect of cetyltrimethyl ammonium bromide(CTABr) solution including alkylbenzimidazole(R-BI) on dephosphorylation of isopropyl-4-nitrophenylphosphinate(IPNPIN) in carbonate buffer(pH 10.7). The reactions of IPNPIN with R-BI⊖ are strongly catalyzed by the micelles of CTABr. Dephosphorylation of IPNPIN is accelerated by BI⊖ ion in 10-2 M carbonate buffer(pH 10.7) of 4×10-3 M CTABr solution up to 89 times as compared with the reaction in carbonate buffer by no benzimidazole(BI) solution of 4×10-3 M CTABr. The value of pseudo first order rate constant(kψ) of the reaction in CTABr solution reached a maximum rate constant increasing micelle concentration. Such rate maxima are typical of micellar catalyzed bimolecular reactions. The reaction mediated by R-BI⊖ in micellar solutions are obviously slower than those by BI⊖, and the reaction rate were decreased with increase of lengths of alkyl groups. It seems due to steric effect of alkyl groups of R-BI⊖ in Stern layer of micellar solution. The surfactant reagent, CTABr, strongly catalyzes the reaction of IPNPIN with R-BI and its anion(R-BI⊖) in carbonate buffer(pH 10.7). For example, 4×10-3 M CTABr in 1×10-4 M BI solution increase the rate constant(kψ=98.5×10-3 sec-1) of the dephosphorylation by a factor ca.25, when compared with reaction(kψ=3.9×10-4 sec-1) in 1×10-4 M BI solution(without CTABr). And no CTABr solution, in 1×10-4 M BI solution increase the rate constant(kψ=3.9×10-4 sec-1) of the dephosphorylation by a factor ca.39, when compared with reaction (kψ=1.0×10-5 sec-1) in water solution(without BI). This predicts that the reactivities of R-BI⊖ in the micellar pseudophase are much smaller than that of BI⊖. Due to the hydrophobicity and steric effect of alkyl group substituents, these groups would penetrate into the core of the micelle for stabilization by van der Waals interaction with long alkyl groups of CTABr.
        179.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        Several adsorbents were tried to remove the selenium ions from industrial wastewater and the following ascending order of the adsorption performance for the selenium at pH 9 was observed: cation exchange resin < chelate resin < zeolite < brown marine algae < granular activated carbon < anion exchange resin. Initial concentration of selenium(146 mg/L) in industrial wastewater was reduced to 63 mg/L of selenium at pH 9 by neutralization process. The maximum uptake of Se calculated from the Langmuir isotherm with anion exchange resin was 0.091 mmol/g at pH 10 and that with granular activated carbon was 0.083 mmol/g at pH 6. The affinity coefficients of Se ion towards anion exchange resin and granular activated carbon were 3.263 L/mmol at pH 10 and 0.873 L/mmol at pH 6, respectively. The sorption performance of anion exchange resin at the low concentration of Se, namely, was much better than that of granular activated carbon. The Se ions from industrial wastewater throughout neutralization process and two steps of adsorption using anion exchange resin was removed to 97.7%.
        6 7 8 9 10