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        검색결과 1,159

        461.
        1995.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We evaluated the nutritional and socioeconomical factors of 100 children aged 5~6 years. Forty five children (45%) were selected from families with low socioeconomic status, while 55 children (55%) were from those with high socioeconomic status. Some differences of the nutritional factors (eating behavior, food preference, food frequency) were found between low and high socioeconomic groups. This survey suggest that eating behavior, food preference and food frequency may be useful in estimating nutritional factors. And the nutrition education for the children and their meal planners is necessary to improve the nutritional status of the subjects.
        4,600원
        462.
        1995.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 拉列햇톰훨 .i훌빼의 훌훌훌B分의 효율적인 有限훌素흙析을 위한 보-윷換훌素 및 윷~部分의 요 소를 제시하고자 한다. 먼저 보-윷~훌훌는 보요소와 벽체요소사이의 변형 및 힘의 狗東條件을 근거로하여 보의 기본적인 거동을 동일하게 유지하면서 平面應力훌素의 개념으로 대치된 유사보요소로 간주될 수 있으 며, 이는 뺏뺏部分에서의 보요소와 벽체요소사이의 서로 다른 自由度에 기인한 윷形의 不홉음性을 합리척으 로 해결해준다. 또한 보-윷뺏훌素와 직접 연결되는 윷換部分의 요소는 보-뺑換훌素의 경우와 동일한 狗束 條件이 적용됩으로써 윷~部分에 대한 효율적인 훌훌分훌j方훗을 제시해 준다. 이와 같이 본 연구에서 제시된 요소들은 기본적으로 i호 flJ Ji lfli훌 _i훌~ 뿐만아니라 보요소와 벽체요소의 相효作用이 고려되는 모든 구조물 에 효율적으로 활용될 수 있다.
        4,000원
        463.
        1995.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        케탈이나 아세탈반응에 의하여 이루어진 1, 3-디옥솔란 고리가 산수용액 중에서 불안정해 쉽게 가수분해되는 성질을 이용하여 소수부로는 지방산의 탄화수소사슬을 친수부로는 소디움 카르복시산(Soap)을 도입하여 분해 후 계면활성을 띠지 않는 분해성 계면활성제이다. 이 화합물의 수용액에 대한 표면장력은 31dyne/cm였고, 임계미셀농도는 1.0×10-3mol/L이었다. 기포력은 비교적 좋지 않았으며, 유화력은 콩기름보다 벤젠에서 양호하였다. 또한 이 화합물의 산분해 특성을 1wt% 수용액과 벤젠 사이의 계면장력 변화에 의하여 측정한 결과 pH 1 ~ 4범위에서 약 300분 안에 모두 가수분해됨을 확인하였다.
        4,000원
        464.
        1995.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        미셀반응, 유화중합, 상간이동촉매반응 등에 이용되는 계면활성제가 갖고 있는 문제점을 해결하기 위하여 반응 후 분해되는 분해성 계면활성제를 합성하였다. 케탈이나 아세탈반응에 의하여 이루워진 1,3-디옥솔란 고리가 산수용액 중에서 불안정해 쉽게 가수분해로 계면활성을 띠지 않는 분해성 계면활성제를 합성하였다. 합성된 화합물은 백색결정상태로 얻었으며 수율은 90% 이상이었다. 그리고 이 화합물과 중간생성물은 얇은막 크로마토그래피와 컬럼 크로마토그래피로 분리하여 적외선과 수소핵자기공명 및 원소분석 스텍트라로 그 화합물들의 구조를 확인하였다.
        4,000원
        465.
        1995.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        각종 세정제의 난용 및 과대 사용으로 인한 수질오염이 날로 심각해지고 있으며 이 때 수질오염의 원인은 주로 계면활성제에 의해 발생한다. 본 연구는 이미 다졸린으로부터 유도된 9종의 양쪽성계면활성제와 석유 화학물질로부터 제조하여 대량 사용하고 있는 sodium lauryl sulfate(SLS)에 대한 세정성을 비교하여 보다 우수한 계면활성제를 선정하고자 한다. 또한 세정성의 비교는 세정력의 측정과 세정에 관한 물리화학적 측면에서 그 원인을 규명하고자 한다. 1-(2-hydroxyethyl)-1-(3-sulfonatedropy)-2-undecyl-2-imidazolinum [IV]는 세정성 및 다른 기초적 물성이 우수하여 세정제에 응용할 경우 세정성이 우수한 계면활성제 일수록 오염 부착에 필요한 일이 적게 나타나 오염이 쉽게 제거될 수 있음을 증명하였으며 그로 인한 공업적 응용성에 기대가 크다.
        4,000원
        466.
        1994.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1-(2-hydroxyethyl)-2-undecyl-2-imidazoline[I] was converted into various types of sulfonated or sulfated amphoteric surfactants as following. 1-(2-hydroxyethyl)-1-(3-sulfonatedpropyl)-2-undecyl-2-imidazolium[III] 1-(2-sulfatedethyl)-1-methyl-2-undecyl-2-imidazolium[IV] 1-dioxylethylene methyl sulfonated-1-methyl-2-undecyl-2-imidazoliun[V] N-[N'-(2-hydroxyethyl)-N-(3-sulfonatedpropylammonio]ethyl dodecanoyl amide[VI] Mono sodium N-[N'-(2-hydroxyethyl)-N'-disulfonatedpropylammonio]ethyl dodecanoyl amide[VII] N-[N'-(2-hydroxyethyl-N'-(2-hydroxypropl-N'(3-sulfonatedpropyl)ammonio] ethyl dodecanoyl amide[VIII] The alkylimidazolines could be readily hydrolyzed to give amidoamines, but by quaternerization, hydrolysis stability of imidazoline and amide type amphoteric surfactantes were increased in the alkali and acid conditions. Also, at least three carbon chains introduce to the main group, water solubility was sparingly increased.
        4,000원
        467.
        1994.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Amphoteric surfactants were synthesized by the cyclization of 1-(2-hydroxyethyl)-2-undecyl-2-imidazoline [I] with acrylic acid ethyl ester. Compound [I] was easily hydrolyzed with water, especially in the presence of a alkali, to afford amidoamines. After [I] was hydrolyzed, the reaction mixture was allowed to react with acrylic acid ethyl ester and then soapoinfied. Only sodium salts of N- -(2-carboxyethyl)-N'-(2-hydroxyethyl)aminoethyl]dodecanoyl amide[III] was obtained. However, when the reacton of [I] with acrylic acid ethyl ester was carried out in the presence of water, followed by soapnification, ring cleavage of [I] occurred at 2, 3 position, different from hydrolysis of [I] where the cleavage occurred at 1, 2 position, to give sodium salts of N-[N'-(2-carboxyethyl)aminoethyl]-N-(2-hydroxyethyl)dodecanoyl amide [IV] and N-[N', N'-bis(2-carboxyethyl)aminoethyl]-N(2-hydroxyethyl)dodecanoyl amide [V] as main products.
        4,000원
        469.
        1994.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        All the activities and physical properties including surface tension' foaming power, foam stability, emulsifying power, dispersion effect of 3-(N, N-dimethyl N-alkylammonio)-2-hydroxyY-1-propane sulfonate (HSB)류와 3-CN-alkylamidopropyl-N,N-dimethylamm-onjo)-2-hydroxy-1-propane sulfonate (APSB) aquous solution were measured and critical micelle concentration was evaluated. Their cmc of hydroxy sulfobetaine derivatives evaluated by the surface tension method was 1.0×10-3~1.0×10-4 mol/l, and surface tension of the aquous solution was decreased to 27~38dyne/cm. The experimental results for foaming power, foam stability, emulsifying power in liquid paraffin showed a good surface active properties, especially, dispersion effect in ferric oxide exhibited some efficient surface active properties, and then it would be expected to application as detergent and dispersion agent.
        4,000원
        470.
        1994.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to review industrial application of amphoteric surfactants, new types of hydroxy sulfobetaine, 3-(N, N-dimethyl N-dimethyl-N-alkylammonio)-2-hydroxy-1-propane sulfonate and 3-(N, N-dimethyl N-acylammonio)-2-hydroxy-1-propane sulfonate were prepared by the reaction of quaternized sodium 1-chloro-2-hydroxy-3-propane sulfonate with N, N-dimethyl-N-alkylamine and N, N-dimethyl N-acylamido propylamine that have a straight chain radical of 12, 18 carbon atoms respectively in the presence of alkali catalyst. All the reaction products could be separated by means of column and thin layer chromatography, and the yields of all products ranged in 85~90%, the structure of them could be confirmed from IR and 1H-NMR spectra.
        4,000원
        471.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acornic powder was extracted with methanol and ethylacetate to obtain a crude acornic compounds. And they were examined concerning their antioxidant activities for linoleic acid. The results were as follows: 1. Hydrogen donating activity for DPPH was higher in 100ppm acornic compound than 100ppm BHT and 100ppm α-tocopherol. 2. When the 100ppm acornic compound was added to linoleic acid, which was heated at 50℃ for 48 hours, antioxidant activities by POV and TBA was higher than that of 100ppm α-tocopherol, but the effect was almost the same as the 100ppm BHT. 3. Antioxiodant activity of acornic compound showed synergistic effect along with malic acid, citric acid, tartaric acid, alanine, arginine, histidine, lysine-HCl, galactose, maltose, glucose and sucrose. 4. Acornic compound inhibited peroxidation of linoleic acid induced by heavy metals.
        4,000원
        472.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to search for separate and identify of Quercus acutissima CARRUTHERS tannins. Tannins were extracted with methanol and ethylacetate from acorn powder and identified TLC, UV spectrum, HPLC, IR, GC/MS, and 1H NMR. Three spots(Rf 0.94, 0.84 and 0.29) detected on TLC. These spots gave dark blue color fairly on spraying with 0.3% potassium ferricyanid·0.3% ferricchloride reagent, and these tannins identified as gallic acid, caffeic acid and ellagic acid by UV spectrum, HPLC, IR, GC/ MS, and 1H NMR.
        4,000원
        473.
        1993.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A Stepped beam with immovable ends under forced vibrations with large amplitude is investigated by using the finite element method and the Ritz vectors. Unlike the Eigen vectors, the Ritz vectors are generated by a simple recurrence relation. Moreover the Ritz vectors yield much faster convergence with respect to the number of vectors used than the use of Eigen vectors. The computer program is developed for nonlinear analysis using Ritz vectors instead of Eigen vectors and numerical examples are analysed for deflections and natural frequencies of stepped beam under various support conditions. Results show that the proposed method is valid and efficient.
        4,000원
        474.
        1992.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        외측 보-기둥 접합부에 정착된 곧은 보 주철근의 인발거동을 예견하기 위한 해석모델이 개발되었다. 이 모델은 외측조인트에 수직방향으로 콘크리트를 구속하기 위하여 횡방향 철근을 배치한 상태의 구속조건(confined condition)하에서 이형철근의 부착특성에 관한 정착철근의 직경, 콘크리트 압축강도, 항복강도, 철근간격 및 주압력(column pressure)에 대한 영향을 고려할 수 있는 국부부착에 관한 시뮬레이션을 구체화하였다. 이 연구에서 채택된 해석 기법은 횡방향 철근이 배근된 공시체에 매입한 곧은 이형철근에 대한 인발실험의 결과를 만족하게 예견하였다. ACI-ASCE 352 위원회가 제안하고 있는 외측조인트 상태에서의 정착 철근길이에 관한 규정이 개발된 해석접근법을 사용해 평가 되었다. 이 해석 평가의 결과는 현재의 외측조인트의 구속조건에서의 정착길이에 대한 규정이 너무 안정적인 측면에 있다는 것을 암시하고 있다.
        4,000원
        475.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A microorganism, isolated from soil and designated Pseudomonas sp13, produced two kinds of rhamnolipid in the medium containing glucose as carbon source. There were both rhamnolipid contain L-rhamnose and β-hydroxydecanoic acid. Coumpound A and B elucted chloroform-methanol mixed solution of silicic acid column chromatography and recrystallized from a mixture of ether and n-hexane. Studies on the structure of these products reveled that compound A is L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoic acid and compound B is L-rhamnopyranosyl-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoic acid.
        4,000원
        476.
        1992.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lipases catalyzed the transesterification reaction between esters and various primary and secondary alcohols in a 99% organic medium, porcine pancreatic, yeast, mold lipases can vigorously act as catalysts in a number of nearly anhydrous organic solvents. Various transesterification reactions catalyzed by porcine pancreatic lipase in hexane obey Michaelis-Menten kinetics. The dependence of the catalytic activity of the enzyme in organic media on the pH of the aqueous solution from which it was recovered is bell-shaped, with the maximum coinciding with the pH optimum of the enzymatic activity in water. The catalytic power exhibited by the lipases in organic solvents is comparable to that displayed in water. In addition to transesterification, lipases Can catalyze several other processes in organic media.
        4,000원
        477.
        1992.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        反復혜重올 받는 짧은 I 보 (Beam) 의 慣-비틀림 座때(Lateral-Torsional Buckling) 에 대한 흩윌뼈한 Parametric Study 를 逢行하여 보의 座맴現象올 좀 더 깊이 考흉하고자 한다. 有限한 비틀림햇形의 뒤틀림 (Warping) 이외에 m 少한 맺톨JTft形의 뒤틀립도 고려한 幾何學적 (完全) 非綠形의 一次7ê 보를 껴¥析的 모델 로 사용하고, 또한 金!홉의 周期的뺑性(Cyclic Plasticity) 쌓:tJJ을 보다 잘 나타내기 위해 多빼 週期的뿔性 모 덴올 Consistent Return Mapping Algorithm과 결합시켜 遭用한다. :한ì.ffI때 단방에서 아래와 갇은 여러가지 Parameter Study를 끊行함으로써 反復휴重을 받는 짧은 I 보의 함 -비블립 座며의 -압的 應홈을 ι~.흉한다 : 材料의 降ik~옳度, 降ik플래토 (Yield Plateau) , 뿔形率硬化,U-:tJJ 硬化(Kinematic Hardening) , 웰留應力, 作用倚重의 f.1端中心에 대 한 {f,í ι、率, 作用倚훌의 보 톰面에 대 한 높 이, 作用혜훨의 보 김이방향의 位置, 보 뻐f 面의 置f!{, 作用倚重으로 부터 멀리 떨어진 支持端의 固定度.
        4,600원
        478.
        1992.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lateral bracing has long been used in design practice to enhance the carrying capacity of the lateral buckling of the beam. Many factors. critically important to lateral bracing performance. do not appear in design formulas. Some of these factors are discussed in this study for the application to short 1 - beams under repeated loadings through parametric studies with an analytical model : the brace 10' cation along the length of the beam. the height of the bracing above the shear center of the beam. and the strength and stiffness of the brace. The parametric studies are carried out using a propped cantilever arrangement. and also using a geometrically (fully) nonlinear beam model for the brace as well as the beam to capture the system buckling. An idealized bracing system is configured to restrain lateral motion. but not rotation. A multiaxial cyclic plasticity model is also implemented to better represent cyclic metal plasticity in con. junction with a consistent return mapping algorithm.
        4,000원
        479.
        1991.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The flavor and organoleptic properties of Hongju prepared by Kokja and Koji method were tested. There was no great difference of total acid in Hongju with different fermentation methods. The alcohol content of Hongju prepared by Koji method was higher than that of Kokja method and methanol content was very little as about 0.02~0.03 mg/ml in all samples. The aldehyde content was 7.5~32 mg% and fusel oil was higher in Hongju prepared by Koji method than that of Kokja method. As the result of sensory evaluation, new Hongju, S-N prepared by Kokja method with wheat and rice was to be best quality.
        4,000원
        480.
        1991.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to establish traditional manufacturing process of Hongju, a traditional spirit by traditional Kokja and Koji method based on different materials. In the fermentation process, the changes of temperature, pH, total acid, alcohol, total sugar and microflora in mash were analyzed. During the whole fermentation period, the temperature in mash made by Kokja method was reached to 30℃, and that of Koji method was reached 33℃. There was no significant difference in pH by different treatments and the initial pH in Koji method was pH 6.0 and the final pH was 4.0. The content of total acid was higher in mash processed by Kokja method than that of Koji method. Alcohol content was higher in mash processed by Koji method. The content of total sugar in all samples were reduced gradually according to progress of fermentation. Yeast populations in all samples were increased up to 6 days of fermentation and then decreased gradually. Lactic acid bacteria were increased until 3 days of fermentation and then decreased until the fermentation completed.
        4,000원