검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 2,609

        2201.
        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
        2202.
        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
        2203.
        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
        2204.
        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
        2205.
        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
        2206.
        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
        2207.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Spherical alumina powders were prepared by the controlled hydrolysis of aluminum iso-propoxide in a solution consisting of n-octyl alcohol and acetonitrile. As aluminum alkoxide's concentration increased, the particle size was increased and size distribution was more broad. As-prepared particle morphology was not spherical when acetonitrile volume fraction was increased over than 60%. As-prepared amorphous powders crystallized to γ-alumina at 1000℃ and converted to α-alumina at 1150℃. The particle morphology was retain after crystallization α-alumina. When aluminum iso-propoxide was used as aluminum source, the optimum preparation condition of spherical alumina was 0.1M AIP, 0.2M H2O, 0.1g/l HPC with a volume fraction (1/1) of the n-octyl alcohol/acetonitrile, 10min of reaction time and 30min of aging time.
        4,000원
        2208.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Red pepper powder (Capsicum annum L.) is an important seasoning as a kimchi ingredient in korea and most korean consumer tend to eat the korean red pepper powder as the better than other oriental country such as China. Near infrared reflectance spectroscopy (NIRS) was applied for discrimination according to geographical origin (Korea, China) of red pepper powder. The objective of this study is to determine if NIR technique could be used to discriminate between the korean red pepper powder and non-korean red pepper powder according to seed content and maxing ratio in red pepper powder by using the new method. Rapid, precise and nondestructive analysis method for determination of the geographical origin of red pepper powder by near infrared spectroscopy and chemometrics were performed. It has been observed discriminant analysis with PLS is adequate to determinate the geographical origin of red pepper powder. It tend to difficult the discrimination of geographical origin according to increase the seed content of red pepper powder. The accuracy of discrimination in mixed red pepper powder was range from 95.2% to 100%.
        4,000원
        2209.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        소포제의 주성분으로 소수성 알킬기 탄산수가 12에서 18까지의 고급지방알코올, 고급지방산, 고급지방산에스테르를 사용하였다. 제조한 소포제의 입도분포, 온도, 농도에 대한 소포 특성을 1L/min의 유속하의 ASTM 방식의 Air Injection Method로 측정하였고, 표면장력과 유화력을 측정하였다. 이들 소포제의 입도분포에 대한 소포특성은 입도분포가 5.5~6.8μm 범위인 소포제 조성물이 우수한 소포제 특성을 보였다. 묽은 수용액상에서 소포제의 표면장력은 농도가 10-2wt%에서 33~34 mN/m 범위였고, 고급 지방산 알코올을 사용한 소포제 조성물의 유화력이 우수하였다.
        4,000원
        2210.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, Quercetin in the Onion ethanolic extract was affected as eliminator of the Mercury, Lead, and Cadmium.Abstracts In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, quercetin in the Onion ethanolic extract was affected as eliminator of the mercury, lead, and cadmium.
        3,000원
        2211.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A synthesis of Dimer acid was studied from a tall oil fatty acid. Catalytic activity measured as reactant conversion in a autoclave reactor increase in accordance with the acidity. The optimization of process conditions were tested by an experimental design method. Optimization synthetic conditions of dimer acid and were reaction of tall oil fatty acid during 2 hour at 250℃, used of 7.3 wt% active clay and 1.2~1.4wt% water, and found reation pressure 8~9Kg/cm2. The maximum conversion rate was researched 74~76%.
        4,000원
        2212.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        New electroluminescent materials base on anthracene chromophore, [9.10-bis(α-naph -thylethenyl) anthracene (α-BNA)] were newly synthesized. The anthracene derivatives with bulky substituent possessed high melting point and they gave stable amorphous films through vacuum - sublimation methods. Three types of electroluminescent devices were fabricated with double layer and triple layer structure : ITO/TPD/emission layer/MgAg, ITO/emission layer/ OXD-7 and ITO/ TPD/ emission layer/OXD-7/MgAg, respectively. In three types of devices with the emissive layer of α-BNA, efficient orange electroluminescence was observed. In the triple layer device whit a emitting layer of 20 nm thickness , maximum luminance was about 10000 cd/ m2 at an applied voltage of 10v and maximum external quantum efficiency was 1.0%.
        4,000원
        2213.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The alkylation benzene with 1-dodecene of Mordenite, Zeolite β and Zeolite Y was studied in the stirring batch reactor. The kinds of zeolites were found to have influenced the reaction conversion and distribution of phenyldodecane isomer in the product. Compared to the alkylation conducted over Zeolite Y and Zeolite β, the alkylation over Mordenite exhibited higher distribution of 2-phenyldodecane and the alkylation conducted over Zeolite Y and Mordenite, the alkylation over Zeolite β exhibited higher distribution of heavy alkylate which formed through oligomerization reaction readily deactivated the Lewis acid sites. A special feature of the effect of the benzene to 1-dodecene ratio the reaction conversion and selectivity of phenyldodecane isomer was found. At alkylation of benzene with 1-dodecene over Zeolite β, when the catalyst content in the system was high, the reaction will reach the optimal conversion at the higher B/D. When the benzene to 1-dodecene ratio was high, the selectivity of phenyldodecane isomer is high. It was also found that at the similar reaction conversion there was the same product distribution regardless of D/C ratio.
        4,000원
        2214.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        P-type의 단결정 실리콘 위에 1000a의 열산화막을 성장시킨후 5500a의 다결정 실리콘으로 증착된 시료를 가지고 HBr/Cl2/He-O2 혼합기체로 식각할 때 시료의 식각 특성에 관한 H2-O2 기체함량. RF 전력, 압력에 대한 영향을 XPS(X-ray photoelectron Spectroscopy)와 SEM(Scanning Electron Microscopy)으로 조사하였다. HBr/Cl2/He-O2 혼합기체로 식각되는 동안 형성된 다결정 실리콘 식각속도는 H2-O2 함량 증가에 따라 증가하였으며 식각잔유물은 RF 전력과 압력변화에 의해 영향은 받지 않는 것으로 나타났으며, 다결정 실리콘 측벽에서의 증착속도는 낮은 RF전력과 높은 압력에서 높게 나타났다. 다결정 실리콘 식각 잔유물의 결합에너지는 안정한 SiO2인 열산화막의 경우보다 높으므로 식각 잔유물은 SiOχ(χ>2)의 화합결합을 가지는 산화물과 같은 잔유물로 생각된다.
        4,200원
        2215.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the separation of toluene/n-heptane mixture by the emulsion type liquid membrane in a batch system, the effect of surfactants on the separation factor and membrane stability were studied over the surfactant concentration ranging from 0.1 to 1.5 wt% at the contact time of 5 and 10 minutes and the settling time 5 and 10 minutes. The surfactants used were triethanol amine lauryl sulfate. The separation factor reached its maximum value at the surfactant concentration of 0.5 wt%. It was found that the percentage of membrane breakup reached its minium values and the separation factor showed its maximum value at the surfactant concentration of 0.5 wt%, which confirmed that efficient separation could be effect when emulsion liquid membrane were stable because of low membrane break up.
        4,000원
        2216.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Glycoside fatty acid esters were synthesized by lipase-catalyzed glycosylation of fatty acids with methyl glycoside in solvent and solvent free process. Optimum condition of solvent process using 2-methyl-2-propanol were : moral ratio of methyl glycoside to fatty acid 1:3: initial concentration of methyl glycoside 50g/l:enzyme(immodilized lipase Novozym 435 from Candidia antarctica) content 1%(w/v) : desiccant content 9%(w/v); reaction temperature 60℃: reaction time 10hrs. The yield of 99% was obtained. Solvent-free process was carried out in total absence of solvent at 70℃ under reduced pressure, 5-20mmHg. To give meximum yield of 99% at the optimum condition of molar ratio of methyl glycoside to fatty acid 1:3, enzyme content 10%(w/w), and reaction time 10hrs. The glycosylation reactivity of different glycosylation agents were sequent to Methyl-β-D-fructofuranoside. Methyl-β-D-glucopyranoside. Methyl-β-D-fructofuranosi de, and Methyl-α-D-glucopyranoside.
        4,300원
        2217.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        HF purification performance of an ion exchange membrane(IEM) was evaluated with 0.5% HF spiked with 10ppb of Fe, Ni and Cu nitrates. The result show that after less than five turnovers through an IEM, the metallic impurity concentration drops below 1ppb. The decrease rate can be fitted to a model assuming the experimental tanks to be continuously stirred tank reaction and that the metallic impurity concentration after the IEM is a function of the single-pass purification efficiency of the membrane, the concentration before purification and the metals desorbed form the IEM. The Concentration after purification was investigated up to a cumulative Fe loading of 300ppb in the 23 liter recirculated loop. It increases linearly vs. cumulative loading and can be explained by the Langmuir theory resulting in a purification efficiency at the equilibrium of close to 99.5% in this loading regime.
        4,000원
        2218.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chitosan and Algin are known as a natural polymers. Biodegradable films were prepared by solution blend method in the weight ratio of natural polymer(low, medium, high-Chitosan, Algin) for the purpose of useful bioimplants. The possibility of bioimplants, which were prepared from natural polymers as a skin substitute and food wrapping materials were evaluated by measuring biodegradability. This biodegradable films were inserted in the back of rats and their biodegradability was investigated by hematological change evaluation as a function of time to biotransformation. It was found that these values of biodegradable films give some good results with short period test.
        4,000원
        2219.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For a cosmetic plant wastewater containing surfactants of high concentration, adsorption treatment by granular activated carbon(GAC) having different pore size distribution was studied. Three sorts GACs were used and regenerated afterwards with methanol. Experiments were composed of batch process and column test for both virgin and regenerated GACs. Following conclusions were drawn from the study: Methylene blue activating substance(MBAS) adsorption data from the batch tests for three GACs are described well by BET isotherm and Freundich isotherm. Simulation with the BET isotherm shows that maximum adsorption appears to be affected not only by specific surface area but also by pore size distribution. Maximum adsorption from the BET isotherm for MBAS appears to diminish as the number of reactivation increases. The diminishing ratio of maximum adsorption appears to decrease as the pore size decreases. Recovery ratio of the methanol by vacuum evaporation from the spent methanol ranges from 95% to 97%.
        4,000원
        2220.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was designed to examine the effect of Ω-3 fatty acid, linlenic acid, EPA, DHA on serum lipid and cytokines of male rats(Sprague-Dawley). Animals of 3 groups were administrated perilla oil, salmoon oil, and tuna oil of 0.4 ml/day for 8 weeks respectively. These oils were used for a source of linolenic acid, EPA and DHA. Ω-3 polyunsaturated fatty acid decreases significantly body weight, serum PGE2 content and serum cytokines content of the rat, and increases internal organs weight, specially liver weight and serum HDL-cholesterol level of the rat. In the results, authors propose to use perilla oil for source of effective Ω-3 poly-unsaturated fatty acid(linolenic acid) to Prevent cardiovascular and immune diseases.
        4,500원