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        검색결과 2,503

        2181.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Isothiazoline derivatives is widely used to food, medical drug and industrial goods, cosmetics etcs, and it makes to restrain and to sterilize a breeding of microbe as a preservative and a sterilizing agent. It differs with the raw material of paraoxybenzoic acid derivatives or imidazolydinyl urea to be in use at present, on the efficacy and effect, and has various characteristics. This synthesis makes 3,3'-dithiodipropionic chloride to add a thionyl chloride in 3,3'-dithiodipropionic acid, and 3,3'-dithiodipropionic methyl amide makes to synthesize in a reflux reaction the mono methyl amine to 3,3'-dithiodipropionic chloride. And last synthesis becomes to make chlorination-cyclization molecule doing a reflux reaction in the temperature of 90~100℃ to mix excessively thionyl chloride and ethylene dichloride to 3,3'-dithiodipropionic methyl amide. The last synthesis material has got in the mixture of 5-chloro-2-methyl-4-isothiazoline-3-one and 2-methyl-4-isothiazoline-3-one, and it is so-called isothiazoline derivatives. The purification of isothiazoline derivatives makes to fuse in ethyl acetate, and makes to decolorize and to deodorize in recrystallization. This experiment has been in synthesis and purification of isothiazoline derivatives, and has tried to measure on the antisepsis and sterilization function of microbe according to pH or content change.
        4,000원
        2182.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        서로 다른 씨클로펜타디엔 유도체가 π-결합된 최초의 비스무스 화합물인 η5-C5(CH3)5Bi(η5-C5H5)2이 디펜타메틸씨클로펜타디에닐 비스무스디메틸아미드 Cp*2BiNMe2[Cp*=C5(CH3)5]와 씨클로펜타디에닐 모노머와의 반응으로 합성되었다. 반응조건은 에테르 용매하에 -78℃ 반응온도 조건하에서 얻어졌다. 합성된 반응물을 노르말 헥산 용매에서 재결정시킨 결과, 검은색 결정이 60% 수율로 얻어졌다. 그리고 재결정시킨 반응물을 190K에서 X-선 단결정 구조 분석 방법에 의해 그 구조를 밝혔다. 그 결과 결정계의 격자계는 I2/a, a=1756.00 picometer, b=906.00 picometer, c=2211.00 picometer, β=104.04, Z=8로 확인되었다. 여기서 a, b, c는 결정?Ю? 상수이고, β는 결정격자 상수인 b와 c간의 각도이며, Z는 단위 결정 격자당 분자의 갯수이다.
        4,000원
        2183.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Tris(8-hydroxyquinoline)-aluminum complex(AlQ3) having greenish luminescent characteristics was synthesized and it was confirmed with UV-Vis absorption spectroscopy, elemental analysis, and FT-IR spectroscopy that AlQ3 was successfully synthesized. Thin films of AlQ3 having multilayer structure were prepared by spin coating method and vacuum evaporation technique. Photopluminescent characteristics of these films were investigated by Luminescence spectroscopy and Current-Voltage(I-V) characteristics of these films were also investigated.
        4,000원
        2184.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ultra-thin films of poly[2-[4-(9-(10-phenyl)anthracenyl)phenoxy)hexyloxy]]-1,4-phenylenevinyleylene(PAHPV) were prepare-d on the hydrophilic ITO substrate by Langmuir-Blodgett(LB) technique. λmax in the photoluminescence spectrum of these films was 458nm at the excitation wavelength of 365nm before thermal treatment, which comes from diphenylanthracene side chain of PAHPV. It was also confirmed with UV-Vis spectrometer that ultra-thin LB films of PAHPV precursor polymer were prepared well. After thermal treatment for conjugation of PAHPV precursor polymer, λmax in the photoluminescence spectrum of these films changed to 365nm, which means that the conjugation of these PAHPV films was completed.
        4,000원
        2185.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The symmetric naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. The stability on the solvents of naphthothiazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in various solvents was 600nm~612nm. But it was identified that only methanol can be used to photographic emulsion.
        4,000원
        2186.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The symmetric naphthothiazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. In this study, green-sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-5-phenyl-benzoxazolium(inner salt) with triethyl orthoacetate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, 1H-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 502nm. Therefore, it was concluded that benzoxazolo carbocyanine dye can be used as green-sensitizing dye for the spectral sensitization of photographic emulsion.
        4,000원
        2187.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It was tested the possibility that EPA and DHA could be separated from fish oil fatty acid ethyl ester(FAEE) in the supercritical carbon dioxide rectification method. Experiments were carried out in the 1800mm tall and temperature gradient packed rectification column at the pressure of 100bar and carbon dioxide flow rate of 52.43NL/min. Experimental results showed that this method was useful to separate the FAEE by the relative volatility of the components. The maximum attainable concentration of EPA, DHA and both of them in product were 41%, 43% and 57% respectively in this rectification column using raw fish oil feed.
        4,000원
        2188.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Separation of EPA and DHA from fish oil fatty acid ethyl ester (FAFE) by urea adductive crystallization method was carried out in the supercritical carbon dioxide (SC CO2) as a solvent. Our results showed that SC CO2 is a good candidate as a solvent in the urea adductive crystallization to separate FAFE by the number of unsaturated bonds. Compared to the separation process using methanol. SC CO2 yielded better performance in the overall selectivity of EPA and DHA. The effect of process variables on separation of EPA and DHA was discussed in detailed. A hybrid technology of SC CO2 fractionation and urea adductive crystallization with SC CO2 was conformed as a viable process to separate and concentrate EPA and DHA from fish oil.
        4,000원
        2189.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The organization of phospholipid monolayers and their monolayers mixed with fatty acid containing azobenzene on the water surface was investigated by means of the displacement current measurement method. The phase transition from the gaseous phase to the gaseous-fluid phase which accompanies the polar ordering of phospholipid molecules was detected in the range of immeasurably low surface pressure. The molecular area which gives the onset of the transition was determined for phospholipid monolayers. The Maxwell displacement current(MDC) pulses were generated across mixed monolayers due to the photoisomerization of fatty acid containing azobenzene by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipids into the monolayers. The displacement currents generated during light irradiation were also investgated in connection with monolayer compression cycles. It was found that the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles.
        4,000원
        2190.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Naphthoquinone-1,2-diazide-5-sulfonyl [NDS]derivatives members of Quinone diazide compound that are utilizable as photoresist for printing plate were synthesized, and photoresist were prepared by mixing these derivatives with a matrix resin(PF, CF) at various weight ratios. Photosensitive characteristics of photoresist were studied by Gray scale method, and SEM to analyze if they can be used as photosensitive material in a printing plate. Experimental results showed using IR, UV, NDS derivatives were photoconverted and developer-soluble photoresist were produced. Photoresist in the mixing ratio of 1:4 of NDS[II] and CF resin gave rise to the highest dissolution rate. In addition, photoresist obtained at this condition resulted in the most superior sensitivity.
        4,000원
        2193.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fluorescent anionic oligo surfactants were synthesized by the condensing products of long chain alkylvinylether-maleic anhydride cooligomers and resorcinol including dye structures. Their various surface activities and dispersing action were studied on the aqueous solution. These oligo surfactants exhibited a remarkable surface tension lowering property, lower foaming and a large dispersing action for the particles of α-copper phthalocyanine blue. Further it was ascertained that the binding of oligo surfactant onto the pigment surface caused the deviation towards lower wavelengths at the maximum fluorescent intensity as compared with aqueous oligo surfactant solutions, These surface active properties of the oligo surfactants may be attributed to rigid and hydrophobic structure of dye groups, besides surface-active groups of alkylether groups and carboxylic group of the anionic oligo surfactants.
        4,000원
        2194.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to separate and identify the antioxidative substances in persimmon leaves. The antioxidative substances in persimmon leaves were extracted by methanol. The extract was fractionnated by SEP-PAK cartridge colum. From these results five fractions(F-I~V) were obtained. Antioxidative activity of each fractions was examined by the DPPH methord. The F-II, III and IV showed antioxidative activity and among them F-II and F-III showed the strongest. Five frations were separated by TLC using ethylacetate : chloroform : formic acid : H2O(8 : 1 : 1 : 1 v /v) as the solvent. From these results were obtained spots of Rf 0.71, 0.35 and 0.25. This spots were scraped from the plate and extracted by methanol. The extracts thuse obtained were used for examination of identify by TLC, UV /VIS-spectrophotometer and HPLC. Among them spot of Rf 0.71 were demonstrated to catechin and the spots of Rf 0.35 and 0.25 was suggested to polyphenol substances.
        4,000원
        2195.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The synthetic method of pyrazole was performed by 1,3-dipolar cycloaddition with dipolarophile instead of the reaction between diazomethane and acetylene. The cycloaddition mechanism and reactivity of 3-phenyloxadiazole derivatives with dipolarophiles was investigated. In order to investigate the mechanism and reactivity of this cycloaddition, the effect of substituents having various kinds of electron withdrawing or releasing groups were examinated. Considering the effect of substituents, an electron withdrawing group attached at the 4-carbon position in 3-phenyloxadiazole derivatives decrease the reaction rate because of the lack of electron density in oxadiazole ring. The reaction rate of 3-phenyloxadiazole derivatives with dipolarophiles were more conveniently measured using UV than using a volumetric analysis which was used before. From the result of this study, it was that the cycloaddition was found to be a first-order reaction depending upon the concentration of 3-phenyloxadiazole only.
        4,000원
        2196.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, ultra-thin films of organic charge transfer complex were deposited on to ordinary microscope slide-glass subtrates with a Langmuir-Blodgett technique. π-A isotherm characteristics of these complex were studied in order to find optimum conditions of deposition by varying temperature of subphase, compression speed, and spreading amount. Transfer ratio of these films were studied during the process of deposition. The UV-visible absorbance spectra of LB films were measured to find state of deposition by varing layer number. The observed optimum conditions of surface, pressure, spreading amount, and dipping speed for depositing LB films(Y-type) were 38m/Nm, 150μl and 5mm/min, respectively. Since the tansfer ratio is close to 100%, the monolayer on the subphase seems to be well transferred to the solid substrate. The thickness of the film was well-controlled as the UV-vis absorbance of films were changed linear according to the number of layers.
        4,000원
        2197.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PFO(pyrolized fuel oil) and C10+ oil, which are the residual heavy oils form a NCC(naphtha cracking center), were heat-treated to produce the precursor-pitch for carbon materials. After PFO was initially distilled near 300℃ to separate the volatile matters recovering as high-quality fuel oil, the residuum of nonvolatile precursor-pitch was then thermally pyrolized in the temperature ranges from 350℃ to 450℃. Spinnable isotropic pitch with the softening point of 200℃ and the toluene insolubles of 36wt% was obtained at 365℃, and then was successfully spun through a spinneret(0.5mm diameter). After spinning, an isotropic carbon fiber of 25μm diameter was obtained via oxidation and craboniation procedures. Mesophase spherules began to be observed from the product pitch pyrolized at 400℃, and bulk mesophase with a flow texture was observed above 420℃. In the case of C10+ was the feed was polymerized in the presence H2SO4 at room temperature to increase the molecular weight and then heat-treated gradually up to 200~250℃. The products obtained with the softening point of 80~190℃ were carbonized at 500 and 1000℃ to examine the morphology.
        4,200원
        2198.
        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
        2199.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Spin finish(NSFs) for synthetic fiber were prepared. NSF-3 was proved to be the best spin finish by testing the properties and emulsion stability, etc. of NSFs. NSF-3 prepared by blending of spindle oil 70g, paraffin wax 10g, glyceryl mono-oleate 5g, POE(10) nonylphenyl ether 4g, POE(20) sorbitan tri-oleate 4g, Na-dioctyl sulfosuccinate 4g, antistatic agent 2g and water 1g was excellent in its characteristics. Optimum physical conditions of nylon filament treated with NSF-3 according to the number of revolution of oil roller were obtained at conditions of 5.5rpm in the number of revolution of oil roller, 1.21% of oil pick up, and denier 69.2D.
        4,000원
        2200.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is the problem point of stability for this study to produce cosmetics and to occur in the circulation process, and specially in a case of alcoholic toilet water the precipitation materials to float on content materials has study on the solubility of perfume, and it has practiced in order to examine the problem point whether the raw materials of plastic vessel is or not harmful in content materials. In testing result, A study on stability of alcoholic toilet water is above all the precipitation materials which floats in content materials, and It is appeared by combination ratio to the raw materials of perfume, ethanol, solubilizer and refining water etcs, and in second the alkali degree which has gushed out of glass vessel can understand the thing that the change of PH is largely increased following to the passage of time, and in third the harmful component of content materials out of raw material in plastics vessel must certainly consider a stability and a safety in quality control of products.
        4,000원