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        검색결과 2,503

        1941.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Squid ink was added to the low salt fermented squid by 4% of concentration and ripened at 10˚C for 6 weeks and at 20˚C for 28 days. The effect of the squid ink on the non-volatile organic acids of low salt fermented squid were investigated. The results are as follows; The non-volatile organic acid in the salt fermented squid without addition of the squid ink was examined and the result showed that lactic and acetic acids were the major organic acids even if very small amount of citric and oxalic acids were detected. In the squid ink added to the low salt fermented squid, total quantity of non-volatile organic acid in the latter part of the ripening was lower than no treatment groups.
        4,000원
        1942.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An intermediate, tetramethylene bis (orthophosphate), was prepared by the esterification of pyrophosphoric acid and l,4-butanediol. Then pyrophosphoric-containing modified polyesters (ATTBs) were synthesized by polycondensation of tetramethylene bis(orthophosphate), trimethylolpropane, adipic acid, and l,4-butanediol. The content of l,4-butanediol was varied from 10 to 20wt% for the reaction. The increase of the amount of l,4-butanediol in the synthesis of ATTBs resulted in increase in average molecular weight and decrease in kinematic viscosity owing to the excellent flowability and reactivity of l,4-butanediol.
        4,000원
        1943.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Garlic extract using super-critical carbon dioxide is influenced by temperature and pressure, and the optimum condition can make under super-critical state. We can know the defects in process of super-critical extration, It can indicate the drop of product rate, energy loss and equipment expense etcs. The minimum inhibition concentration of microbe which garlic extract contains has apperared the concentration more than 800ppm in this experiment. According to the result of this experiment, we can know that the antibiosis effect in the microbe of staphylococcus and fungus has disappeared in the incubation time more than 12 hours.
        4,000원
        1944.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We studied on the preparation and evaluation of O/W type microemulsion containing "wax, liquid paraffine and quaternary ammonium salt". And also it was obtained to stability of microemulsions by mono ethylene glycol(MEG) addition. The microemulsions were generally prepared at 96~97℃ by the phase inversion method. We used polyoxyethylene(20) sorbitan monooleate(POE(20)SMO) and distearyl dimethyl ammonium chloride(D.D.A.C.) as the emulsifiers at microemulsion preparation. From the results, we could get best condition for microemulsion preparation, in case of oil phase, montanic ester wax ; 1.1wt%, paraffine wax ; 1.1wt%, liquid paraffine ; 3.1wt%, propylene glycol ; 0.6wt% and ethylene glycol monobutyl ether ; 0.6wt%, when the ratio(wt%) of D.D.A.C. and POE(20)SMO were 2 : 3. And also we could obtained that the distributed particle size of the final microemulsions were about 8±1.5nm and the mean particle size was 7±0.5nm. We got following results from final microemulsions that the percent of transmittance; 96~98% at 700nm. And the microemulsion blended with MEG of 5~15wt% showed smaller particle size and more stable distribution than non-containing MEG.
        4,000원
        1945.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        LiMn2O4 catalyst for CO2 decomposition was synthesized by oxidation method for 30 min at 600℃ in an electric furnace under air condition using manganese(II) nitrate (Mn(NO3)2·6H2O), Lithium nitrate (LiNO3) and Urea (CO(NH2)2). The synthesized catalyst was reduced by H2 at various temperatures for 3 hr. The reduction degree of the reduced catalysts were measured using the TGA. And then CO2 decomposition rate was measured using the reduced catalysts. Phase-transitions of the catalysts were observed after CO2 decomposition reaction at an optimal decomposition temperature. As the result of X-ray powder diffraction analysis, the synthesized catalyst was confirmed that the catalyst has the spinel structure, and also confirmed that when it was reduced by H2, the phase of LiMn2O4 catalyst was transformed into Li2MnO3 and Li1-2δMn2-δO4-3δ-δ' of tetragonal spinel phase. After CO2 decomposition reaction, it was confirmed that the peak of LiMn2O4 of spinel phase. The optimal reduction temperature of the catalyst with H2 was confirmed to be 450℃(maximum weight-increasing ratio 9.47%) in the case of LiMn2O4 through the TGA analysis. Decomposition rate(%) using the LiMn2O4 catalyst showed the 67%. The crystal structure of the synthesized LiMn2O4 observed with a scanning electron microscope(SEM) shows cubic form. After reduction, LiMn2O4 catalyst became condensed each other to form interface. It was confirmed that after CO2 decomposition, crystal structure of LiMn2O4 catalyst showed that its particle grew up more than that of reduction. Phase-transition by reduction and CO2 decomposition ; Li2MnO3 and Li1-2δMn2-δO4-3δ-δ' of tetragonal spinel phase at the first time of CO2 decomposition appear like the same as the above contents. Phase-transition at 2~5 time ; Li2MnO3 and Li1-2δMn2-δO4-3δ-δ' of tetragonal spinel phase by reduction and LiMn2O4 of spinel phase after CO2 decomposition appear like the same as the first time case. The result of the TGA analysis by catalyst reduction ; The first time, weight of reduced catalyst increased by 9.47%, for 2~5 times, weight of reduced catalyst increased by average 2.3% But, in any time, there is little difference in the decomposition ratio of CO2. That is to say, at the first time, it showed 67% in CO2 decomposition rate and after 5 times reaction of CO2 decomposition, it showed 67% nearly the same as the first time.
        4,200원
        1946.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The core-shell latex particles were prepared by sequential emulsion polymerization of alkyl methacrylate and styrene(ST) by using an water-soluble initiator(APS) after preparing monomer pre-emulsion in the presence of an anionic surfactant(SDBS). In organic/organic core-shell polymerization, the pre-emulsion method, which minimized required quantity of sulfactant, has been used to increase the conversion rate and the stability of core-shell latex particles as well as to reduce the formation of secondary particle that cause problems of soap-free emulsion during shell polymerization. We used several methods to observe the core-shell structure. The core-shell structure was studied by measuring pH change during hydrolysis by NaOH, glass transition temperature(Tg) by differential scanning calorimeter(DSC), morphology of latex by transmission electron microscope(TEM) and change of particle size and distribution by a particle analyzer.
        4,000원
        1947.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acidic degreasing agent(AADA) was prepared by blending sorbitol, Newpol PE-68, Na-dioctyl sulfosuccinate, Tetronix T-70l, MJU-100A, n-octanoic acid, and phosphoric acid, The physical properties of AADA tested with aluminum specimen showed the following results ; when 3wt% AADA-5 was performed at 70℃, the degreasing rate was 95% which is comparitively good, and the percentage of etching was 0.277% which was found to be less than that of commercialized product. when 20wt% of AADA-5 was added at 65℃, the percentage of derusting was 91% and the good defoaming effect proved by following low foaming power tests respectively : Ross and Miles, and Ross and Clark methods.
        4,000원
        1948.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Environmental friendly acrylics/urea high-solid paints (BEHCU) were prepared through the curing reaction of acrylics resin(BEHC) containing 70wt% of solids content and butylated urea curing agent. BEHC was synthesized by addition copolymerization of caprolactone acrylate(CLA), 2-hydroxypropyl methacrylate(2-HPMA), ethyl methacrylate, and n-butyl acrylate. The addition polymerization of these monomers, especially including flexible CLA monomer and 2-HPMA monomer with OH funtional group, under appropriate reaction conditions resulted in polymers with controlled glass transition temperature(Tg) and crosslinking density. The molecular weight(Mw) of these polymers(BEHCs) was 2940~3240 and polydispersity (Mw/Mn) was in the range of 1.61~1.72. The viscosity and the molecular weight of these acrylic resins increased with increasing Tg. The coated films were prepared using curing reaction between BEHC resin and butylated urea curing agent at 100℃ for 30 minutes. Our experimental resulted showed that enhancement of the coating properties such as adhesion, flexibility, impact resistance, water resistance, and abrasion resistance could be expected through introducing CLA component in acrylic resin for the high-solid content acrylics/urea coatings.
        4,300원
        1949.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to prepare a softener, alkyl imidazoline salt, fatty carbamide salt, and fatty polyamide salt were synthesized first, and then the synthesized salts were blended. The prepared softeners were applied to acrylic fibers, and then several properties were tested. As a result, the prepared softeners show good softening and lubricating properties, and they also show a little antistatic property. Through bending resistance tests and measurements of feeling change of acrylic fibers treated with the softeners, it was proved that the prepared softeners are durable softeners.
        4,000원
        1950.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Self-diffusion coefficients of colloidal ass9Ciation structures in the aqueous solutions of anionic ammonium dodecyl sulfate (ADS) and cationic octadecyltrimethylammonium chloride (OTAC) surfactants were measured by pulsed-gradient spin echo NMR. The results were interpreted on the basis of the ADS/OTAC/water phase diagram. Crossing the phase boundaries, significant changes in self diffusion coefficients were observed and well correlated to the phase diagram. For the micelles their apparent radii were obtained from Stokes-Einstein equation. Their values were 15 for the ADS micelles and 54 a for the OTAC micelles, respectively. For vesicles which were formed spontaneously at different relative amounts of the surfactants and total surfactant concentrations, the radius was measured as 50 to 200 nm. This result is in fair agreement with those by TEM and light scattering.
        4,000원
        1951.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new process for polymeric gate insulator in field-effect transistors was proposed. Fourier transform infrared absorption spectra were measured in order to identify ODPA-ODA polyimide. Its breakdown field and electrical conductivity were measured. All-organic thin-film transistors with a stacked-inverted top-contact structure were fabricated to demonstrate that thermally evaporated polyimide films could be used as a gate insulator. As a result, the transistor performances with evaporated polyimide was similar with spin-coated polyimide. It seems that the mass-productive in-situ solution-free processes for all-organic thin-film transistors are possible by using the proposed method without vacuum breaking.
        3,000원
        1952.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transesterfication of vegetable oils and methanol with alkaline catalyst was carried out to produce biodiesel fuel by continuous process. The process consists of two static mixers, one tubular reactor and two coolers and gave 96~99% of methyl ester yield from soybean oil and rapeseed oil. Experimental variables were the molar ratios of methanol to vegetable oil, alkaline catalyst contents, flow rates, mixer element number. The optimum ranges of operating variables were as follows; reaction temperature of 70℃, l:6 of molar ratio of methanol to oil, O.4%(w/w) sodium hydroxide based on oil, static mixer elements number of 24 and 4 min. residence time.
        4,000원
        1953.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Natto, one of Japanese traditional food is made from steamed whole soybeans fermented with Bacillus natto. In this study, the effects of Natto mucilage- feeding on griwth, organ weight and serum nitrogen compounds of rats were investigated. Male rats in Sprague-Dawley strain were fed on basal diets supplemented with aqueous Natto mucilage of several percentages for 10 weeks. Natto mucilage had no significant effects on the body and organ weights. The levels of GOT, GPT, LDH. and total bilirubin in serum of rats fed Natto mucilage diets were significantly lower than those in the control group ' The levels of total protein and albumin were higher than those in the control group. The level of calcium in serum indicates a growing tendency. but creatinine, uric acid, and BUN had declining. And the most component of free am1no acids in Natto mucilage were glutamin acid.
        4,000원
        1954.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Environmental friendly acrylic/urea high-solid paint(MUHC) were prepared through the curing reaction of acrylics resin(EBHC) containing 70wt% of solids content and butylated urea curing agent. The synthesis of EBHC Was done at 150℃ for 6 hours, and the results were obtained as follows : Mn=1830~2190, Mw 3290~4000, Mw/Mn=1.80~1.83 viscosity=110~352 cps, and conversion=82~92%. After the film was coated with MUHC, the various physical properties were measured. They showed that enhancement of the coating properties such as adhesion, flexibility, abrasion resistance, impact resistance, and water resistance could be expected through introdl1cing caprolactone acrylate component in acrylics resin for the high-solids content acrylics/urea coatings.
        4,000원
        1955.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Demand for organic analysis increase as industries are growing and many products are spreaded in the daily life. One of many products is oil spill dispersant. It was used for oil accident in the ocean. When oil spill dispersant spread at the ocean, the petroleum in the ocean is dispersed. The oil spill dispersant is made of non ionic surfactant and petroleum oil. The non ionic surfactant disperse petroleum from oil accident. The other part is petroleum oil which has aromatic hydrocarbon. Because the aromatic hydrocarbon is cancerogenic material, it directly injure animals in the ocean. This cause the second pollution in the human body. Many oil accidents still are controlled by oil spill dispersant. Therefore quality control of the oil spill dispersant become important and this also demand for the exact quantitative analysis of aromatic hydrocarbon. Hereupon the first we develop separate petroleum oil from surfactant. The second standardize analytical method of aromatic hydrocarbon in the separated petroleum oil.
        4,000원
        1956.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the effect of electron injection layer on the performance of organic light emitting devices (OLEDs). As an electron injection layer, the quinolate metal complexes were used. We optimized the device efficiency by varying the thickness of the quinolate metal complexes layer. The device with 1 nm of the quinolate metal complexes layer showed significant enhancement of the device performance and device lifetime. We also compared the effect of 8-hydroxyquinolinolatolithium (Liq) with that of bis(8-quinolinolato)-zinc (Znq2) and 8-hydroxyquinolinolatosodium (Naq) as an electron injection layer. As a result, Liq is considered as a better materials for the electron injection layer than Znq2 and Naq.
        4,000원
        1957.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fatty polyamide that gives softness, lubrication and bulky property and alkyl imidazoline that gives durable softness and antistatic property were synthesized. then, an O/W-type durable softener (DSN) was prepared by the emulsion of the synthesized fatty polyamide and alkyl imidazoline. Emulsion stability of the DSN was good, and the mixed HLB value was 11.2. From the measurement of softness, lubrication, antistatic property, bending resistance, and color fastness, it was proved that the prepared DSN was a good durable softener for nylon.
        4,000원
        1958.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dermorphin is a hepta peptide(H-Tyr-DAla-Phe-Gly-Tyr-Pro-Ser-NH2)with exceptionally potent and long-lasting peripheral and central activity. Dermorphin analogues, dermorphionyl(DMP)-Lys-NH2 and DMP-Lys-Lys-NH2 have been prepared in order to examine the effect of opiod activity. Dermorphin analogues were synthesized by the solid phase method. The crude peptide was purified by gel filter on a Sephadex LH-20, characterized with HPLC and amino acid analyzer. Analgesic potency was estimated by writhing syndrome method and Randall-Selitto method. As a result, dermorphin analogues have lower potency than that of morphine.
        4,000원
        1959.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Thermal decomposition of the copolymer of butyl methacylate(BMA) with styrene(St) was investigated. The copolymer Was obtained at 80 ℃ in a continuous stirred tank reactor(CSTR) using toluene and benzoyl peroxide(BPO), as solvent and initiator, respectively. The reactor volume was 0.3 liters and residence time was 3 hours. The thermal decomposition followed the second order kinetics for BMA/St copolymer. The activation energies of thermal decompositon were in the ranges of 38 ~43 kcal/mol for BMA with St copolymer and a good additivity rule was observed with the composition of copolymer. The thermogravimetric trace curve agreed well with the theoretical calculation.
        4,000원
        1960.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        CaCO3 absorbed sodium lauryl sulfate (SLS) surfactant was prepared, Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using styrene(St) as a shell monomer and potasium persulfate (KPS) as an initiator, We found that when CaCO3; core prepared by adding 2,0 wt% SLS, CaCO3 core/PSt shell polymerization was carried out on the surface of CaCO3 particle without forming the new PSt particle during St shell polymerization in the inorganic/organic core-shell polymer preparation, The structure of core-shell polymer were investigated by measuring the degree of decomposition of CaCO3 using HCl solution, thermal decomposition of polymer composite using thermogravimetric analyzer and morphology by scanning electron microscope.
        4,000원