• Title/Summary/Keyword: 에셔

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Reversed Micellar Protein Extraction in a Hollow Fiber Membrane Extractor (단백질 추출용 역미셀 실관막장치에 관한 연구)

  • 윤현희;박상준유인상
    • KSBB Journal
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    • v.9 no.3
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    • pp.332-338
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    • 1994
  • Solubilization phenomena of a protein in a reversed micellar solution were investigated and a hollow fiber membrane extractor was tested for reversed micellar protein extraction equipment. Alkaline protease was used as a model protein compound and the reversed micellar solution was consisted of AOT and isooctane. It was found that protein solubilization was strongly influenced by ionic strength and pH. The distribution coefficient of the protease between the aqueous solution and the AOT/isooctane solution was also observed to be as high as 4.0 within the scope of this experiment. A hollow fiber membrane extractor was constructed and tested for the protein extraction. The overall mass transfer coefficient at a typical experimental condition of this study was observed to be $6.7{\times}10^{-5}cm/s$. It was also found that the mass transfer resistance on reversed micellar solution was the dominant resistance for the protein transfer.

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A Study on the Telemetry and Remote Monitoring & Control of Lighting Using LonWorks System (LonWorks 시스템을 이용한 원격검침 및 조명감시.제어에 관한 연구)

  • 홍원표;김종대
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.4
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    • pp.48-56
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    • 2000
  • This paper proposes the new concept & design method and implementation of LonWorks network system for telemetry & remote monitoring and control in BAS. In order to apply this open system, the essential components of Lonworks is analyzed and a new concepts of its design method is proposed. In our experiment, Lonworks network system for telemetry & remote monitoring and control of lighting are designed and fabricated. As a result, it is verified that LonWorks is open, interoperable, reliable network system from the experimental results, especially, node development, network configuration & design, secure communication and MMI.

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Oxidation of Ethanol in the Gas Phase with Alcohol Oxidase and Alcohol Dehydrogenase (Alcohol Oxidase와 Alcohol Dehydrogenase를 이용한 기상에서의 Ethanol의 산화반응)

  • 박현규;장호남김동옥
    • KSBB Journal
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    • v.9 no.3
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    • pp.239-245
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    • 1994
  • The effects of reaction temperature and the level of hydration(water activity) were studied for gas phase reactions of alcohol oxidase and alcohol dehydrogenase immobilized on DEAE-cellulose and controlled pore glass(CPG). Optimum reaction temperature zone of gas phase reaction was similar to that of aqueous phase reaction. The activity of alcohol oxidase increased dramatically and the stability decreased when the water activity was increased from 0.3 to 0.8. The apparent activation energies of the gas phase reaction decreased approaching the values obtained in the aqueous phase reaction as the water activity increased. In the both cases of alcohol oxidase and alcohol dehydrogenase, the rate constants of the gas phase reaction were lower than those of aqueous phase reaction by two orders of magnitude and these results could be correlated to the vapor-liquid equilibrium data of the substrate, ethanol.

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Effect of Ratios Carbon Source to Nitrogen Source on the Yields of PHB Fermentation Variables (탄소원과 질소원의 비가 PHB 발효특성치 수율에 미치는 영향)

  • 백예영;허병기
    • KSBB Journal
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    • v.9 no.4
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    • pp.365-371
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    • 1994
  • The effects of ratios of initial concentration of carbon source to the initial concentration of nitrogen source in the fermentation media on both the yields of PHB fermentation variables and the accumulation of poly-${\beta}$-hydroxybutyric acid(PHB) were investigated. The fermentation media were composed of the combination of varing glucose concentrations, 10, 20, 25, 30, 40, $50g/\ell$ and the NH4Cl concentrations 0.33, 0.4, 0.5, 1.5, 3, $5g/\ell$. The yield of biomass on glucos, Yx/s, decreased very slowly according to the increase of the ratio of C to N. And the yield became constant at 0.35(g biomass/g glucose) with the ratio higher than 70. The yield of residual biomass, Yx/s, also decreased with the ratio of C to N and finally showed a constant value of 0.065(g residual biomass/g glucose) when the ratio was higher than 65. In accordance with the augmentation of the ratio, the yield of PHB, YPHB/S, however, increased and showed the maximum value of 0.35 (g PHB/g glucose) between 40 and 60 of the ratio. The maximum yield of PHB to the change of biomass, YPHB/S, was 0.87(g PHB/g biomass), and the yie1d YPHB/RX, was 4.2(g PHB/g residual biomass). The maximum accumulation percent of PHB to the final biomass was 81% when the ratio was higher than 67.

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A Study on the Ellipsis of Case markers through the Hangul letters of Hyun-Poong Kwak's family (현풍(玄風) 곽씨(郭氏) 언간(諺簡)의 격조사(格助詞) 생략(省略)에 대한 고찰(考察))

  • Jeon, Byeong-Yong
    • (The)Study of the Eastern Classic
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    • no.33
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    • pp.413-435
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    • 2008
  • This study is purposed to analyze the appearances and functions of ellipsis of case markers through the Hangul letters of Hyun-Poong Kwak's family in the early 17th century. Hangul letters appear more colloquial than typography, and ellipsis is the one of main features of it. Generally, 'ellipsis' occurs when a constituent of a sentence deliberately leaves out of a sentence, because it is repeated or can be deduced by the context or occasion. As Hangul letter is written for a specific person, 'ellipsis' occurs more often than typography written for unspecified individuals. The ellipsis of case markers are not an exception. The ellipsis has functions as follow. The first, function is 'brevity.' Communication can be more convenient by ellipsis. Next will be 'informality.' Informality caused by ellipsis can make people express their thoughts and feelings fluently and naturally. It is the reason that spoken language has more frequently occurred ellipses than written language. The third function is 'quickness.' The same information can be delivered more quickly by the sentence using ellipsis than not using. In the 21st Century, ellipsis is misused in netizen communication owing to the quickness. The last function should be 'the effect of a literary style.' The effects can embody through ellipsis such as 'rhythm effect', 'letter style effect', 'translation style effect.' As a result of analyzing ellipsis of case markers, frequency follows the order below.[subjective objective > Locative > Dative > Commutative > Instrumental]

THE NUTATION DAMPING CONTROL OF A SPACECRAFT (인공위성의 미동현상 제어에 관한 연구)

  • 이창훈
    • Journal of Astronomy and Space Sciences
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    • v.11 no.2
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    • pp.281-295
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    • 1994
  • In this paper, the Variable Structure System(VSS) theory with new continuous switching dynamic equation is used to design an automatic controller for the active nutation damping in momentum bias stabilized spacecraft. In the application of VSS theory to a linearized multivariable system with the nutation damping systems, there exist some disadvantages such as how to determine the switching gains and how to reduce the chattering phenomina and reaching phase in input and state trajectories. To solve these drawbacks, this paper presents the continuous switching dynamic equation instead of the discontinuous switching logics to obtain the sliding mode. The new design approach is much simpler than the VSS theory. And there do not exist chattering phenomina in this method because the obtained control inputs are continuous. Simultaneously the reaching phase is reduced by a suitable choice of design factor.

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CRE ECPERIMENT OF KITSAT-1 (우리별 1호에서의 SPACE RADIATION 환경 조사)

  • 신영훈;민경욱;최영완;김성헌
    • Journal of Astronomy and Space Sciences
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    • v.11 no.1
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    • pp.131-145
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    • 1994
  • The Cosmic Ray Experiment (CRE) is one of the modules flown on board the KITSAT-1 satellite and consistes of two sub-systems: the Total Dose Experiment (TDE) and the Cosmic Particl Experiment(CPE). The purpose of CRE is to characterize the space radiation environment as encountered by an Earth-orbiting spacecraft. KITSAT-1 orbit is dominated by the inner Van Allen radiation belt. This region has a large population of high energy protons which contributes significantly to both long-term and transient radiation effects. The data shows that the inner Van Allen radiation belt is very stable and the solar activity influences the CPE, TDE data and SEU(Single Event Upset) rates. The result also shows that much larger high energy particle flux is recorded than the predictions of the CREME code.

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Construction of a Phylogenetic Tree from tRNA Sequences (tRNA 염기 순서를 이용한 계통학적 연구)

  • 이병재;이동훈;김영준;강현삼
    • Korean Journal of Microbiology
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    • v.24 no.4
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    • pp.400-405
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    • 1986
  • We have constructed a phylogenetic tree for eleven species by comparing their tRNA sequences. The tree suggests that prokaryotes diverged very early before the emergence of animals. The fact that H. volcano, an archaebacterium, clusters with eukaryotes implied that eukaryotes did not diverge directly from thier common ancestor with eubacteria. The branching order of phage $T_{4}$ and phage $T_{5}$ indicates that they have diverged separately from thier hosts and they might have evolved independently. A correlation between nucleotide substitution in tRNAs and paleontological record was observed. We verified that our phylogenetic tree fits very well with traditional ones very well by imposing the molecular clock on the tree.

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Studies on the Fractional Precipitation of Dextran by Nonsolvent Addition Method (비용매 첨가법을 이용한 Dextran 분별침전에 관한 연구)

  • 최성우;구윤모
    • KSBB Journal
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    • v.10 no.3
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    • pp.257-263
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    • 1995
  • Fractional precipitation of "native" dextran by the method of nonsolvent addition was studied. Precipitational phenomenon of fractioned dextran was characterized with the quantitative determination of the precipitational capacity of nonsolvents with different dielectric constants. Based upon this characterization, the fractional precipitation process for the dextran production was developed. From the precipitational characteristics, a first-order relationship between the molecular weight of fractioned dextran and the content of nonsolvents was formulated. The slopes of the first-order equation were correlated with the dielectric constants of the nonslovents. A modified fractionation process was constructed on the basis of refractionation method and employed to increase the efficiency of the controlled production of dextran.

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A Study on Alkyl Glucoside Synthesis by Amphiphilic Phase Enzyme Reaction (양친매상 효소반응에 의한 알킬글루코시드의 합성연구)

  • 허주형;임교빈김해성
    • KSBB Journal
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    • v.11 no.5
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    • pp.511-517
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    • 1996
  • An amphiphilic phase enzyme reaction was used to synthesize alkyl glucosides from glucose and alkyl alcohol with immobilized ${\beta}$-glucosidase using four glycol ether cosolvents(monoglyme, diglyme, 2-methoxyethanol, and 1,4-dioxane). Monoglyme was shown to be the best cosolvent for the amphiphilic phase medium composed of water/cosolvent/alkyl alcohol admixture. To obtain high yield of alkyl glucoside by amphiphilic phase enzyme reaction, hydrophilicity-hydrophobicity of amphiphilic media and enzyme microenvironment was optimized from the viewpoints of substrate solubility, enzyme activity, water activity, and dynamic equilibrium between glucose alcoholysis and glucoside hydrolysis. Under optimum reaction conditions, the highest concentrations of hexyl, octyl, decyl, and dodecyl glucosides were 18.2, 9.68, 7.27, and 6.03g/L, respectively.

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