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        검색결과 2,417

        1102.
        1993.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Contents of vitamin D3 and 25-OH-vitamin D3 in marine animal products(20 species) were determined by HPLC. The isomers of vitamin D, D2 and D3, were not clearly separated on a reversed phase, μ Bonda Pak, with 20% methanol-acetonitrile, and on a normal phase, Zorbax SIL. with 0.4% isopropanol-hexane, but 25-OH-vitamin D2 and-D3 were separated on either μ Bonda Pak with 10% methanol-acetonitrile, or on Zorbax SIL with 2.2% isopropanol-hexane, respectively. Although levels of vitamin D3 and 25-OH-vitamin D3 varied remarkably according to species, their average value(fish : l,l87sim36,007 I.U/sample 100g, mussel : 58~1,706 I.U/sample 100g, pickle: 1,208~79,358 I.U/sample 100g) was greatly higher than that of meat(80~100 I.U/sample 100g) and dairy products(400~800 I.U/sample 100g). Fatty tissues of fish and pickled fish intestines contained high level of vitamin D3 and 25-OH-vitamin D3, while the clam and mussel known to have various kinds of sterol including δ7-sterol showed very low levels of vitamin D3 and its derivative.
        4,000원
        1105.
        1993.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was conducted to investigate the effects of concentrated sulfate on the germination rate, growth rate and the productivity of weight of kudzu (Pueraria thwnbergiana Bentham). The germination rate of kudzu seed by one or two treatment retre
        4,000원
        1106.
        1993.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Emission of hazardous and volatile organic chemicals from solid waste landfill site was become to important issue because of environmental pollution and health risk by such chemicals. Laboratory batch and continuous experiments were conducted respectively to elucidate isothermal sorption behaviors and transport phenomena(by gas through unsaturated solid waste layer) in wet solid waste-gas system. Source separated and size reduced refuse(bulky waste) and incinerated ash were used after controlling water content, and trichloroethylene(TCE) was chosen among many such chemicals because of it's generality among those man-created pollutants. Isothermal TCE sorption equilibria wet solid waste-gas system can be described in linear equation and partition coefficient in this system can be estimated approximately by the simple equation derived from schematic structure of the system. Transport equation modified by instantaneous equilibrium sorption fraction and kinetic sorption rate(overall mass transfer capacity coefficient) simulated well the column experiment results.
        4,800원
        1107.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The syntheses of urocanic acid esters was optimized, starting from p-toluenesulfonic acid salt of this acid and long chain fatty alcohols in the organic solvent and extracting water from it by means of azeotropic Compound. The salts of these urocanic acid esters showed amphoteric properties, but their micellization enhances their rate of hydrolysis leading to the free amine. Nevertheless the long chain gives to the esters themselves an amphoteric character allowing their solubilization in micellar media and in microemulsions the result, yield could enhanced.
        4,000원
        1113.
        1993.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The complex nature of low flow mixing in natural channels has been investigated using both laboratory experiments and the numerical solution of a proposed mathematical model that is based on a set of mass balance equations describing the mixing and mass exchange mechanisms. Laboratory experiments, which involved collection of channel geometry, hydraulic, and dye dispersion test data, were conducted in a model of four pool and riffle sequences in a 49-m long tilting flume. The experimental results show that flow over the model pool-riffle sequences is highly non-uniform. Concentration-time curves are significantly skewed with long tails. Comparison between measured and predicted concentration-time curves shows good agreement in the general shape, peak concentration and time to peak. The proposed model shows significant improvement over the conventional one-dimensional dispersion model in predicting natural mixing processes in open channels under low flow conditions through pools and riffles.
        4,000원
        1114.
        1992.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Current measurements at 3 sections and numerical experiments were carried out in Masan Bay to understand the effect of the wind on the residual currents and pollutant transport. The vertical distribution of horizontal velocities were directly affected by the wind at the depths of 1m and 2m beneath the sea surface. Analysis of the velocity data suggested that changes in the vertical gravitational circulation contributed to the net circulation. The net transport of water through the northern part of the bay was observed to be landward, with wind-induced transport of about 100m super(3)/s. Hence, wind is concluded to be the dominant mechanism driving the net circulation in the northern area of Masan Bay. Numerical experiments are shown that when S wind with 5m/s blew, northern area of the bay was generated the horizontal circulation of clockwise and local gyre. On the contrary of those, N wind made her to the anti-clockwise. In the case of no wind, the tidal residual current(constant flow) is very small or neglected except the bay-mouth. The inflow or outflow pattern of the mouth is considered as the flows generated by tidal residual current only. The distance of wind-induced transport of pollutant was as long as 2 times of no wind during the one tidal period.
        4,500원
        1115.
        1992.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Si(100) 웨이퍼를 사용하여 RTP 장비에서 O2와 N2O 분위기에서 8nm의 oxynitride를 제조 하였다. 기존의 로(furnace) 열산화막과 비교해서 oxynitride는 I-V, TDDB 특성이 우수하였고, flat-band voltage shift도 적었으며 BF2이온 주입에 의한 붕소 투과 억제 특성도 우수하다. 유전상수는 oxynitride가 열산화막에 비해서 크다. Oxynitride는 순수한 SiO2유사하게 V 〉Φ0 구간에서 Fowler-Nordheim 터널링 특성을 나타낸다. SIMS, AES, 그리고 XPS 분석 결과 질소 pile-up이 SiO2/Si 계면에서 나타나고, 이것은 oxynitride 산화막 특성 향상과 깊은 관련이 있다.
        4,000원
        1117.
        1992.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A previously unreported sedimentary complex has recently been discovered in the northern part of Choˇnsu Bay. It overlies both unconformably the Precambrian low-grade metamorphosed sedimentary sequence(Taean Formation) and the Jurassic biotite granite. The sedimentary complex is proposed to be designated as Choˇnsuman Formation. The Formation is composed of conglomerate, tuff, basalt, tuffbreccia, and shale. It is distributed in the northwest and northeast coasts of Choˇnsu Bay and in the Chukdo. Age of the Formation seems to be of late Mesozoic. The Choˇnsu sedimatary basin is considered to be originated by block faulting presumably during the Cretaceous, as suggested by the development of N-S trending structural lineation in the study area and its vicinity. The Chonsuman Formation seems to be formed by sedimantation in close association with block faulting and volcanic activities nearby. Sedimentation is thought to be developed from west to east in the basin.
        4,500원
        1119.
        1991.12 구독 인증기관 무료, 개인회원 유료
        파의 조추출물질(組抽出物質)이 국화과(菊花科) 식물(植物)의 종자발아(種子發芽) 및 유묘생육(幼苗生育)에 미치는 영향(影響)을 조사(調査)한 결과(結果)는 다음과 같다. 파의 모든 부위의 조추출물(組抽出物)은 국화과(菊花科) 식물(植物)의 종자발아(種子發芽) 및 유묘생육(幼苗生育)을 억제(抑制) 혹은 고사(枯死) 시켰는데 그 중 엽신부(葉身部) 조추출물(組抽出物)이 타(他) 부위(部位)에 비(比)해 억제효과(抑制效果)가 현저하게 컸다. 파의 80% 메칠알콜 및 증류수(蒸溜水) 조추출물(組抽出物)은 국화과(菊花科) 식물(植物)의 종자발아(種子發芽)를 억제(抑制)하였는데 특히, 증류수(蒸溜水) 조추출물(組抽出物)이 80% 메칠알콜 조추출물(組抽出物)보다 억제효과(抑制效果)가 컸다. 파 수확후(收穫後) 토괴내(土壞內)에 있는 잔류근부(殘留根部)는 후작(後作)으로 한 국화과(菊花科) 식물(植物)의 유묘생육(幼苗生育)을 억제(抑制)하였다. 국화과(菊花科) 식물(植物)의 종자발아(種子發芽)를 억제(抑制)하는 파의 조추출물질(組抽出物質)은 광(光)과 열(熱)에 안정(安定)하고 그 중에는 휘발성물질(揮發性物質)도 포함(包含)되어 있음이 밝혀졌다.
        4,300원
        1120.
        1991.12 구독 인증기관 무료, 개인회원 유료
        밤과실의 가공 및 저장중 갈변기구를 규명하는 일환으로 밤에 함유된 polyphenol 화합물 및 PPO를 분리, 동정하고 PPO의 생화학적 특성에 대해 연구한 결과는 다음과 같다. 밤의 total phenol 함량은 이었고 ferulic acid, caffeic acid, synapic acid, p-coumaric acid, gallic acid, salicylic acid 순으로 함량이 높았다. PPO를 분리, 정제하여 전기영동한 결과 단일의 단백질 및 효소활성밴드를 확인하였으며 정제된 효소의 비활성도는 260.9이고 조효소액보다 11.7배 정제되었다. PPO의 최적 pH와 온도는 각각 5.9, 였으며 효소활성은 에서 15분 처리시 거의 실활되었다. 무기염의 영향을 본 결과 , , 들은 효소활성을 증가시켰으나 , , 는 활성을 저해시켰다. 저해제로는 L-ascorbic acid, thiourea, sodium chloride, L-cysteine의 저해작용이 강했다. 밤의 PPO는 o-diphenol에 대한 강한 활성을 나타냈으며 특히 catech이에 대해 가장 강했으며 monophenol에는 활성을 나타내지 않았다. PPO의 Km값은 catechol에 대해 5mM이었다.
        4,000원