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        검색결과 13

        2.
        2018.05 구독 인증기관·개인회원 무료
        촉진수송막이란 특정기체의 이동을 촉진시키기 위한 운반체를 포함하고 있는 분리막을 말하며 일반적으로 올레핀/파라핀 분리에는 π-complexation을 할 수 있는 은이온이 운반체로 사용된다. 본 연구에서는 올레핀/파라핀 분리를 위해 은이온이 함침된 아민계 고분자를 이용하여 촉진수송막을 제조하였고 이들의 프로필렌/프로판 분리특성을 알아보았다. 순수가스 테스트를 통해 압력변화에 따른 투과도와 선택도를 구하였으며, 혼합가스 테스트를 통해 stage-cut에 따른 투과측 프로필렌 농도 및 회수율 변화를 알아보았다. 그 결과, 2bar, 25°C에서 95%의 프로필렌을 99.6%까지 농축 시킬 수 있음을 확인하였다.
        4.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent days, there is much interest in the biocidal activity of silver since silver is known to be safe and effective as disinfectant and biocidal material against bacteria and viruses. There is also increased interest in the nano-sized silver particles which can be used as effective bactericidal material. The purposes of this study were to investigate the effect of silverized elastomers on growth of oral pathogenic microorganisms, including Streptococcus mutans, Fusobacterium nucleatum, Porphyromonas gingivalis by comparing with conventional non-silverized elastomers. The antibacterial efficacy of silverized elastomer against oral pathogenic microbes was investigated by modified disk diffusion test and growth inhibition test. In modified disk diffusion test, silverized elastomer showed no antibacterial activity against S. mutans, F. nucleatum and P. gingivalis, In culture medium, the growth of S. mutans, F. nucleatum, P. gingivalis was not inhibited by silverized elastomer. Silverized elastomer exhibited no bacteriostatic and/or bacteriocidal effects against some experimental strain.nd clinical indications and diseases.
        4,000원
        5.
        2010.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        고준위방사성폐기물에서 유출되어 나오는 아이오딘의 이동을 저지하기 위하여 은을 흡착시킨 벤토나이 트 블록에 NaI 용액을 흘려주었을 때 대부분의 아이오딘이 흡착되었다. 이 은이온에 의한 아이오딘의 저지 메커니즘을 상세히 조사하기 위하여 아이오딘과 접촉하기 전후의 은이 흡착된 벤토나이트의 X-ray Absorption Near Edge Structure (XANES)와 Extended X-ray Absorption Fine Structure (EXAFS) 스펙트 럼과 표준물질로서 AgO, Ag2O, AgI의 스펙트럼을 비교하였다. 그 결과, 벤토나이트에 흡착되었던 은이 떨 어져 나와 AgI 침전 클러스터를 형성함으로서 아이오딘의 이동이 지연되는 것으로 생각된다.
        4,000원
        6.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effect of silver ion solution on the growth of Microcystis aeruginosa UTEX 2388 (cyanobacterium) and Chlorella sp. KCTC AG20136 (green alga) was investigated using separated and mixed culture in filtered natural water and BG11 medium. In separated cul
        4,000원
        7.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        On the analysis of triacylglycerol (TG) from the kernels of Acanthopanax sessiliflorus by reversed phase-HPLC, it was separated into three main fractions of PN 44, 46 and 48, according to partition number (PN). On the contrary, it could be clearly classified into seven fractions of SMM, MMM, SMD, MMD, SDD, MDD and MDT by silver ion-HPLC by the number of double bond in the acyl chains of TG species. But resolution of so-called critical pairs of TG molecular species such as molecular pairs of PeLL [C18:1Ω12/(C18:2Ω6)2] and OLL [C18:1Ω9/(C18:2Ω6)2] and OOL [(C18:1Ω9)2/C18:2Ω6], and PePeL [(C18:2Ω12)2/C18:1Ω6] was not achieved (Pe; petroselinic acid, L; linoleic acid, O; oleic acid). On the other hand, TG extracted from Aralia continentalis kernels were also fractionated into seven groups of SSM, SMM, MMM, SMD, MMD, SDD and MDD (S; saturated acid, M; monoenoic acid, D; dienoic acid) by silver ion-HPLC, although it's were classified into three groups of PN 44, 46 and 48 by reversed phase-HPLC. The fractions of SMM, MMM, MMD and MDD were divided into two subfractions, respectively; the fractions of SMM, MMM, MMD and MDD were resolved into the subfraction of PPe/Pe and POO (critical pairs from each other), that of Pe/Pe/Pe and OOO, that of Pe/Pe/L and OOL, and that of Pe/L/L and OLL.
        4,000원
        8.
        2003.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        원자력시설에서 방사성요오드 제거용으로 사용되는 TEDA 첨착활성탄의 고온공정에서치 메틸요오드의 제거성능을 은이온제올라이트(AgX)와 상호 비교하였다. 3-40 온도범위에서 온도에 따른 메틸요오드의 흡착량 및 탈착후 잔존량을 측정한 결과, 비첨착활성탄의 흡착성능은 온도가 증가함에 따라 급격히 감소하지만 TEDA 첨착활성탄의 흡착성능은 10 부근에서도 AgX-10과 거의 유사한 값을 나타내었고, 탈착후 잔존량은 25 까지도 비첨착활성탄에 비하여 매우 높은 값을 유지하였다. 또한 10 이상의 고온공정에서 AgX 및 TEDA 첨착활성탄을 충전한 고정층 파과특성을 상호 비교한 결과 10 이상에서 AgX-10의 메틸요오드 흡착량 및 잔존량은 TEDA 첨착활성탄에 비하여 평균 30%정도 높은 값을 나타내어 고온에서 더 흡착성능이 우수함을 보여주고 있다. 흡착반응 후 생성된 기체의 성분을 분석한 결과를 토대로 AgX-10 흡착제를 충전한 고정층에서 메틸요오드 제거 메카니즘을 제안하였다.
        4,000원
        10.
        2002.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A mixture of methyl ester derivatives of fatty acids from the oils of pine nuts was well resolved to five fractions differing by degree of unsaturation by silver ion solid-phase extraction column chromatography (Ag+-SEC). Polyunsaturated fatty acid with non-methylene interrupted conjugated double bond (NMiDB) radical held more strongly to silver ions in the column than methylene interrupted conjugated double bond (MiDB) one when they had the same number of double bonds. Although both the picolinyl ester and DMOX derivative provided clear mass ion species powerful enough to elucidate the structure of the polyunsaturated fatty acid (PUFA) with NMiDB and/or methylene interrupted conjugated double bond (MiDB) radical in the oils, the picolinyl ester of PUFA with NMiDB radical did not provide a cluster of mass ions neighboring diagnostic mass ions induced by the double bond in the proximal to the carboxyl group. However, the DMOX derivative of PUFA with NMiDB group as well as MiDB showed abundant mass ion species differing by gaps of 12 amu, which made it possible with greater ease to locate the double bonds in the molecule. The oil contained C18:2Ω6 (46.2 %) and C18:1Ω9 (25.4 %) as main components, and considerable amounts of PUFAs with NMiDB radical such as δ5. 9. 12-C18:3 (16.0 %), δ5. 9-C18:2 (2.3 %) and δ5. 11. 14-C20:3 (0.8 %).
        6,000원
        11.
        2001.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Conjugate trienoic acids (CTA) occurred in triacylglycerols (TGs) of the seed oils of Trichosanthes kirilowii, Momordica charantia and Aleurites fordii, and they were easily converted to their methyl esters in a mixture of sodium methoxide-methanol without any structural destruction. The main fatty acids in triacylglycerol (TG) fraction of the seed oils of Trichosanthes kirilowii are C18:2Ω6 (32.2 mol %), C18:3 9c.11t,13c (38.0 mol %) and C18:1Ω9 (11.8 mol %), followed with C16:0 (4.8 mol %) and C18:0 (3.1 mol %). The TG fraction was resolved into 20 TG molecular species according to the partition number (PN) by reversed-phase (RP)-HPLC. The main TG species were DTc2, MDTc and D2Tc, of which amounts reached 63 mol % of total TG molecular species. The TG sample was fractionated into 11 fractions according to the number of double bond in the molecule by Ag+-HPLC and the species of DTc2, MDTc and D2Tc were also eluted as main components. The TG species containing CTA showed unusual behaviours in the order of elution by HPLC ; first, TG moleular species of DTc2 (D; dienoic acid, Tc; punicic acid, Tci; α-eleostearic acid, M ; monoenoic acid, St; stearic acid) was eluted earlier than Mtc2, although they have the same PN number of 40, and, secondly, the species of DTci2 with eight double bonds was eluted earlier than that of D2Tci with seven double bonds. Intact TG of the seed oils of Momordica charantia contained mainly fatty acids such as C18:3Ω9c,11t,13t (57.7 mol %), C18:1Ω9 (17.4 mol %), C18:0 (12.3 mol %) and C18:2Ω6 (10.6 mol %), and was classified into 13 fractions by RP-HPLC. The main TG species were as follows ; MTci2 [(C18:1Ω9)(C18:3 9c,11t,13t)2, 39.1 mol %] and StTci2 [(C18:0)(C18:3 9c,11t,13t)2, 33.9 mol %] comprising about 73 mol % of total TG species, accompanied by DTci2 [(C18:2Ω6)(C18:3 9c,11t,13t)2, 7.3 mol %], D2Tci [ (C18:2Ω6)2(C18:3 9c,11t,13t), 3.6 mol %] and MDTci [(C18:1Ω9)(C18:2Ω6)(C18:3 9c,11t,13t), 3.5 mol %]. Simple TG species of Tci3 [(C18:3 9c,11t,13t)3] was present in a small amount of 1.4 mol %, but other simple TG species were not detected. The TG was also resolved into 11 fractions according to the number of double bond by Ag+-HPLC, and the species were mainly occupied by MTci2 [(C18:1Ω9)(C18:3 9c,11t,13t)2, 39.4 mol %] and StT-ci2 [(C18:0)(C18:3 9c,11t,13t)2, 35.4 mol %] DTci2 species with eight double bonds was also developed faster than D2Tci one with seven double bonds as indicated in the analysis of TG of the seed oils of T. kirilowii, and MTci2 species with cis, trans, trans-configurated double bond was eluted earlier than MTc2 species with cis, trans, cis-configurated double bond. The main components of fatty acid in total TG fraction isolated from the seed oils of of Aleurites fordii were in the following order ; C18:3 9c,11t,13t (81.2 mol %)〉 C18:2Ω6 (8.5 mol %)〉 C18:1Ω9 (5.4 mol %). With resolution of the TG by RP-HPLC, eight fractions such as Tci3, Dtci2, D2Tci, MTci2, PTci2 (P; palmi..
        5,100원
        12.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Triacylglycerols of the seeds of Ginkgo biloba have been resolved by high-performace liquid chromatography(HPLC in the silver-ion and reverse-phase modes. The fatty acids were identified by a combination of capillary gas chromatography and gas-chromatography /mass spectrometry as the methyl and /or picolinyl ester. The main components are C18:2Ω6(39.0mol%), C18:1Ω7(asclepic acid 21.5mol%), and C18:1Ω9(oleic acid, 13.8mol%). Considerable amounts of unusual acid such as C20:3δ5,11,14 (5.7mol%), C18:2δ5,9(2.8mol%), and C18:3δ5,9,12(1.6mol%), were checked. In addition, an anteiso-branched fatty acid, 14-methylhexadecanoic acid, was also present as a minor component(0.9 mol%). The triacylglycerols were separated into 17 fractions by reverse-phase HPLC, and the fractionation was achieved according to the partition numnber(PN) in which a δ5-non methylene interrupted double bond(5-NMDB) showed different behaviour from a methylene interrupted double bond in a molecule with a given cahinlength. Silver-ion HPLC exhibited excellent resolution in which fractions(23 fractions) were resolved on the basis of the number and configuration of double bonds. In this instance, the strength of interaction of a δ5-NMDB system with silver ions seemed to be weaker than a methylene interrupted double bond system. The principal triacylglycerol species are as follows ; (C18:2Ω6)2/C18:1Ω7, C18:1Ω9/C18:1Ω7/C18:2Ω6, (C18:1Ω7)2/C18:2Ω6, C16:1Ω7/C18:1Ω9/C20:3δ5,11,14, C16:1Ω7/C18:1Ω7/C20:3δ5,11,14, C18:1Ω9/C18:1Ω7/C18:2Ω6, C18:1Ω9/C18:2δ5,5/C20:3δ5,11,14, (C18:1Ω7)2/C18:2Ω6 and (C18:1Ω9)2/C18:2Ω6, while simple triacylglycerols without C18:2Ω6)3 were not present. Stereospecific analysis showed that fatty acids with δ5-NMDB system and saturated chains were predominantly located at the site of sn-3 carbon of glycerol backbones. It is evident that there is asymmetry in the distribution of fatty acids in the TG molecules of Ginkgo nut oils.
        4,900원
        13.
        2012.08 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to evaluate bacteria removal ability of the metallic silver which was baked silver ion impregnated ceramic filter at heating condition. Silver leaking from baked ceramic filter was tested to sustain bacteria removal for a long time. Silver impregnated ceramic filter could remove E. coli completely at 1012 MPN/100ml to 1013 MPN/100ml of influent. However, ceramic filter without silver did not remove E. coli completely under the same condition. After baking, the silver impregnated ceramic filter almost didn’t leak out the silver ion from filter. Photo of TEM (Transmission Electron Microscopy) showed that absorbed silver ions remained in ceramic filter after baking process and most of silver were less than 10 nm. According to the increase in the amount of silver in the ceramic filter, removal efficiencies of E. coli were increased but turbidity removal was decreased. It can be accounted that increased removal efficiency of E. coli was from disinfection of silver that is in the ceramic filter. Simulated concentrations of bacteria agree well with the observed experimental effluent concentration data. Moreover, first-order decay coefficients increased to 0.0034/min after silver was added in the ceramic filter. Increase of first-order decay coefficient proves that silver-added ceramic filter can remove bacteria easily.