검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 2,503

        2081.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For the synthesis of new antifungal agents, We have synthesized four new ketoconazole derivatives were synthesized by the reaction of cis-[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)-1,3-dioxolan-4-yl]methane sulfonate with isolated fig compounds. These compounds were showed strong antifungal activity against C, albicans ATCC 10231. C, utilis. S, cerevisiae ATCC 9763. A and niger ATCC 9029. Among them, sample No.(13) showed potent inhibition activity. Generally, other samples showed biological activity in vitro test. The above results showed the possibility of the development of new antifungal agents.
        4,000원
        2082.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dual-action agents are unique chemical entities comprised of two different types of antibacterial compounds covalently linked together in a single molecule in such a way that both components are able to exert their bactericidal properties. Crosslinked sulfadiazine-sulfacetamide such as antibiotics synthesized by crosslingking reaction such as glutaraldehyde. These structures of the compounds were confirmed by IR, NMR. 4 strains of Gram(+) and Gram(-) revealed effective susceptibility to synthetic crosslinked sulfadiazine-sulfacetamide.
        4,000원
        2083.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plasma polymerization of Perfluoropropene(PFP) was carried out in a tubular type reactor. The Plasma was generated by coupling inductively under the fixed discharge power of 25W and the pressure of 100, 140, and 200 mTorr of radio frequency generator. PFP plasma polymerization thin films were deposited in acrylic yams. For 1 hours, the acrylic yams treated and untreated by PFP plasma were immersed in boiling water. Then the reduction of contraction coefficient of acrylic yams were measured respectively. As a result of this experiment, untreated acrylic yams were reduced around 23%, while treated yams were contracted about 18-2%.
        4,000원
        2084.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We carried out this subject to observe photoisomerization using 8A5H and phospholipid(DLPC) containing azobenzene group which has reversible to cis-trans by light irradiation. We investigated the photoisomerization and property of the monolayer film on quartz substrate prepared by the mixture of 8A5H and phospholipid deposited using Langmuir-Blodgett(LB) method. It was found that the absorption spectrum of the 8A5H and phospholipid LB monolayer was induced to photoisomerization by alternate light irradiation. And the absorbance of both the solution of mixtures of 8A5H-phospholipid and LB film was reversibly changed by the acid-base exposure and alternate temperatures.
        4,000원
        2085.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to study a reversible photoisomerization of disperse red l(DR 1) attached on natural polymers, cellulose acetate containing DR l(DR 1/CA adduct) was prepared, and the changes of UV/VIS spectra of its solution(benzene, DMAc). thick film, and LB film were investigated by alternate irradiation with two different wave length lights. DR 1/CA adduct was prepared through tosylation of partially hydrolyzed cellulose acetate followed by reaction with DR 1 at 100℃ in pyridine. From the UV/VIS spectra of DR 1/CA adduct dissolved in DMAc solvent including phosphoglyceride before and after irradiation at 360nm and 45Onm, we found out the changes of UV/VIS spectra were reversible. In addition, the change of UV/VIS spectra of this adduct solution was strongly depended on the sorts of solvents and temperature. As the temperature was increased, UV/VIS spectra of this adduct solution in DMF showed blue shift. These results provided this solution could be applied to a temperature sensor. In the thick film case, we also obtained similar results with solution case. LB monolayer and trilayer from DR 1/CA adduct was obtained by scattering the solution including phosphoglyceride on water surface at the surface pressure of 8mN/m. After irradiation on that LB monolayer and trilayer, the reversible photoisomerization was also detected. From these results we concluded DR 1/CA adduct was suitable for the application to data storage and optical switch, etc.
        4,000원
        2086.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We checked the presence of phospholipase A2(PLA)2 which could split the ester bond at the position 2 in the glycerol backbone of glycerophospholipids, in the cells of hyperthermophiles of Pyrococcus horikoshii and Sulfolobus acidocaldarius. The results obtained are as follows; (1). Pyrococcus horikoshii cells were grown in obligate anaerobic conditions at 95℃ and they needed sulfur as energy source instead of oxygen, while Sulfolobus acidocaldarius species grew well in the aerobic medium (pH 2.5) containing yeast and sucrose at 75℃. (2). Pyrococcus horikoshii cells produced phospholipase A2 in the cell culture media although this species did not show lipase activity at least in the pH range of 1.5 ~ 3.5. Sulfolobus acidocaldarius cells produced lipase hydrolyzing triacylglycerols such as triolein, but did not split any kind of phospholipids used as substates. (3). The compound of 1-decanoyl-2-(p-nitrophenylglutaryl) phosphatidylcholine was not suitable for a substrate in this experiment, though frequently used as a subtrate for checking presence of phospholipase A2, for its decomposi-tion in this experiment. The L-α-phosphatidylcholine-β-[N-7-nitrobenz-2-oxa-1, 3-diazol]aminohexanoyl-γ-hexadecanoyl labelled with a fluorescent material, did not show any migration of acyl chains in the molecule during the reaction with phospholipase A2 under a hot condition. (4). Phospholipase A2 in the cells of Pyrococcus horikoshii, showed the optimum activity at pH6.7~7.2 and 95~105℃, respectively, and was activated by addition of calcium chloride solution. Andthe phospholipase A2 specifically hydrolyzed glycero-phospholipids such as phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine and phosphatidyl inositol, but could not split phospholipid containing ether bonds in the molecule such as DL -α-phosphatidylcholine-β-palmitoyl-γ-O-hexadecyl, DL-α-phosphati- dylcholine-β- oleoyl-γ-O-hexadecyl, DL-phosphatidylcholine-dihexadecyl.
        4,000원
        2087.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The new copolymers which contain flexible spacers in main chain were prepared and their properties were studied. the copolymers were synthesized in the melt polymerization melted from diacetoxynaphthalene isomers, α,Ωbis(4-carboxyphenoxy) alkanes and p-acetoxy benzoic acid in the molar ratio of 1:1:2 and characterized for the effects of structure of naphthalenediol isomer moieties and the spacers on thermal crystalline and liquid crystalline properties of the resulting polymers. Diacetoxy naphthalene isomers were used 1. 5-,1. 6-,2. 6-and 2. 7-disubstituted ones and the spacers was either tetramethylene or decamethylene. The polymer was characterized by elemental and spectropic analysis, differential scanning calorimetry (DSC) on a polaring microscope, wide-angle X-ray diffractometry and thermogravimetry (TGA). There glass transition temperatures (Tg) and melting temperature (Tm) on the structure of the naphthalenediol isomer moieties and the length of the spacers. The presence of spacers was found to the helpful in crystallization of 1. 6-naphthalenediol copolyesters. The presence of amide group in the backbone chain of polymer was found to increase transition temperature, crystallization, thermal stability of polymers but to decreas solubility.
        4,000원
        2088.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The N-docosyl N'-methyl viologen-(TCNQ)2, (DMVT) was synthesized. We investigated the π-A isotherm of DMVT to find the optimal deposition condition. Temperature-dependent current-voltage characteristics of the DMVT LB films shows that there is an increase in conductivity at 330K or so. The in-plane electrical conductivity at room temperature is in the range of 10-7~10-6S/cm. From the plot of logarithmic conductivity as a function of reciprocal temperature, two types of activation energies, 0.04eV and 0.73eV, were obtained depending on the temperature range. The Ohmic behaviour was observed below 0.6V and the Schottky effect was confirmed at 2.5~6V, when the I-V characteristics was measured with Al/LB film/Al structure. I-V measurement for Al/LB film/ITO structure showed the asymmetrical I-V relationship, which resulted from the rectification property.
        4,000원
        2089.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the relation of the preservation efficacy reduction with methyl paraben of parahydroxybenzoic acid derivatives was investigated using the dialysis membrane method with tween-80 of surfactant and TiO2/Talc of inorganic powder meterial from emulsion system. It was found that the preservation efficacy of tween-80 and TiO2/Talc from emulsion system was reduced due to the adsorption of methyl paraben. According to the microbe test, In case of tween-80, MBC appeared in 0.19 w/v% and in case of TiO2/Talc, MBC appeared in 0.22w/v% / 0.23w/v%. In general, the equation of Talc's adsorption weight(A·W) has a tendency to show in A·W=11.5C0.745
        4,000원
        2090.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study showed that the optimized cleaning process using non-aqueous cleaning solvents is adaptable in the industrial field for existing 1.1.1-TCE cleaning solvents which is an ozone depleting sustance. Alternative cleaning solvent system substituted for existing cleaning solvent against non-aqueous pollutants(cutting & flux oil), was evaluated for the cleaning efficiency using gravimetric analysis method and surface change of sample by Image analyzer. The results showed that alternative solvents and process had excellent cleaning efficiency.
        3,000원
        2091.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Several instances of synergistic interaction have been identified between alkyl amine oxide and long chain fatty acohol polyethoxylates in various surfactant formulation. The purpose of this study was examined whether these benefits could be observed within the framework of generic hand-surface cleaning formulations. Comparative evaluation were also carried out to determine the performance characteristics of low-and zero-phosphate systems in which amine oxide and alcohol ethoxylates are used. Best cleaning was observed with 1:1 mixtures of the subject surfactants, but substantial improvements over fatty alcohol ethoxylate alone also were noted with formulations that contained lower ratios of amine oxide
        4,000원
        2092.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to determine optimum level of ethanol intake with weanling male rats. The weanling rats and the experimental diets were divided into 5 groups, control, A, B, C, D group in according to the levels of ethanol intake for 10 weeks. In the result of their serum analyses, we suggest that an adequate intake of ethanol is 1.47ml/kg/day. If body weight of any man is 60kg, he can drink about 90ml(1.47*60=88.2) ethanol/day. It corresponds to 360ml [90=360*(25/100)] of 25% SOJU.
        4,000원
        2093.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to synthesis the zeolite using the bituminous coal fly ash emitted from power plant that occurs several environmental problems. In spite of fly ash has contained high content of SiO2 and Al2O3, it disposed mainly landfill. If the effective methods to recover the SiO2 and Al2O3 were developed, the fly ash could be utilized valuable raw materials. In this study, fly ash was used as raw material to synthesize the zeolite by pressurized hydrothermal reaction. Also, experimental parameters included temperature(70~110℃, and pressure(140~200 psi) of crystallization were investigated. The more crystallization pressure was increased, the more Zeolite 4A was synthesized at 70 and 90℃. Zeolite 4A of metastable phase tend to be transformed into sodalite of stable phase at 110℃.
        4,000원
        2094.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to recover the aluminum from water treatment plant sludge containing alumina. The optimum reaction conditions about chlorination of sludge with NH4Cl are as follows: the weight ratio of sludge to NH4Cl is 4, the reaction time is 60min, and the temperature is 300℃. And the result of leaching time test showed that the highest yield of alumina at 160℃ was 96% but the result of leaching test at 160℃ was little better than that of leaching test at 100℃ while the leaching concentration of HCl was 4N. The optimum reaction conditions of chlorinated sludge with NH4Cl, gave the highest yield of 95.41% based on aluminum.
        4,000원
        2095.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Mo(V) di-μ-oxo type [Mo2O4(H2O)2L]Cl2 complexes(L: 4,4'-Diphenyl-2,2'-dipyridyl, 4,4'-Dimethyl-2,2'-dipyridyl, 4,7-Diphenyl-1,10-phenanthroline) have been prepared by the reaction of [Mo2O4(H2O)6]2+ with a series of chelate ligands. These complexes are completed by two terminal oxygens arranged trans to one another and each ligand forms a chelate types. In Mo2O4(H2O)2L two H2O coordinated at trans site of terminal oxgens. The prepared complexes have been characterized by elemental analysis, infrared spectra, electronic spectra, 1H nuclear magnetic resonance spectra, and thermal analysis(TG-DTA). In the potential range -0.00V to -1.00V at scan rate of 50mVs-1, a cathodic peak at -0.83V ~ -0.88V (vs SCE) and an anodic peak at -0.54V ~ -0.88V (vs SCE) have been observed in aquous solution. The ratio of the cathodic to anodic current(Ipc/Ipa) is almost 2, we infer that redox is irreversible as dimer forms broken.
        4,000원
        2096.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The symmetric benzoxazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization of emulsion microcrystals in positive paper and negative film-making. The stability on the solvents of benzoxazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in methanol, acetonitrile, acetone, DMF, dichloromethane, chloroform solvents was 501nm~511nm. But it was identified that only methanol can be used to photographic emulsion. The photographic characteristics have contrast of 2.8, speed of 50-55(lux·sec)-1, fog of 0.07-0.08, respectively.
        4,000원
        2097.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Maxwell displacement current(MDC) measuring technique has been applied on the study of monolayers of fatty acid. The displacement current was generated from monolayers on the water surface by monolayer compression and expansion. Displacement current was generated when the area per molecule was about 130a2. MDCs were investigated in connection with monolayer compression cycles. It was found that the current pulses were generated over the entire range of molecular area, and the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. We investigated the change in absorption spectra of the fatty acid(8A5H) monolayer LB film due to cis-trans photoisomerization. It was found that the absorption spectrum of the 8A5H LB film was induce to photoisomerization by alternate irradiation with UV and visible light irradiation.
        4,000원
        2098.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Burns can be caused by fire, chemicals, heated object and fluids. Distinguishing a minor burn from a more serious burn involves determining the degree of damage to the tissues of the body. Algin is known as natural polymer marine plants, we prepared the official burn ointment which is made by Algin. This burn ointment was covered on the skin wound of artificial burned and their effect of healing was investigated by the evaluation of histological and hematological change as a function of time. The result of rats test showed that burn ointments made from Algin was effective in formation of the new tissue and reduction of inflammation.
        4,000원
        2099.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 연질 폴리우레탄 발포제 제조에서 여러 발포제와 내부온도, 기계적 물성과의 관계에 대해서 연구, 조사하였다. 발포제로는 물을 주발포제로 하여 보조발포제는 CFC-11(trichlorofluoromethane), HCFC-114b(dichlorofluoroethane), dichloromethane, n-pentane, iso-pentane, cyclopentane을 사용하였다. 기계적 물성을 측정하기 위하여 연질 폴리우레탄 발포제의 밀도가 0.015±0.002g/cm3와 0.024±0.002g/cm3인 두 종류의 발포제를 제조하였다. 연질 폴리우레탄의 발포제의 제조시 발포제별로 내부온도를 측정하였으며, 48시간 경과 후 밀도, 인장강도, 신장율, 인열강도, 압축강도, 압축영구변형률을 측정하였다. 연구 결과 dichloromethane과 cyclopentane이 보조발포제로 가장 적합하였다.
        4,000원
        2100.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objectives of this study is to investigate the optimum reaction conditions and to identify the product formula in the synthesis of a silicone/acrylic resin that curing in moisture at room temperature. By the addition polymerization of monomers, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and 3-methacryloxypropyltrimethoxysilane. a quarter polymer was obtained. Among various initiators investigated in this study, 2.2'-azobisisobutyronitrille was found to be the most suitable initiator. The optimum reaction conditions found in this study are 70 wt% of initial solvent amount, 120 minutes of dropping time, 3 times of initiator addition, 82~105℃ of reaction temperature, and 8 hrs of reaction time. Also, number average molecular weight of 11700~33100 and molecular weight distribution of 1.81~3.44 were obtained.
        4,000원