• 한국식품영양학회지
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• 제11권6호
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• pp.629-634
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• 1998

1-Deoxynojirimycin which is a potent intestinal ${\alpha}$-glucosidase inhibitor was purified from the culture broth by ion exchange chromatography, Sephadex LH20 column chromatography, TSK gel chromatography and HPLC respectively. Acute toxicity of 1-deoxynojirimycin, which was loaded through the oral as dose of 200mg/kg, was investigated in IRC mouse. None of the tested IRC mice were not dead and increase of body weight showed also the same results in comparison with control mice. The antimicrobial susceptibility of 20 pathogenic strains against 3 antidiabetic compounds (1-deoxynojirimycin, AO-128, acarbose) were obtained by agar dilution method. All of the three antidiabetic compounds has very weak antimicrobial activity (MIC>100$\mu\textrm{g}$/ml).

• Journal of Microbiology and Biotechnology
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• 제7권6호
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• pp.378-385
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• 1997

Cation motive ATPases on cell membranes of Helicobacter pylori were investigated using everted membrane vesicles. Latent ATPases could be ascertained from aggregated vesicle using N, N-dimethylformamide (DMF) and Triton X-100. By contrast, ultrasonication or chloroform treatments caused membranes to be disrupted, resulting in an alteration of sensitivities against azide or vanadate. Considerable amounts of vanadate-sensitive enzymes were identified from vesicle micelles, prepared by the dilution method. These were activated in the presence of either $Ni^{2+}\;or\;NH_4^+$. From studies employing H. pylori intact cell systems, we found that ATPase expression of this bacterium was markedly dependent upon air composition. It was interesting that cellular expression of $Ni^{2+}$- or $NH_4^{+}$-motive ATPases was significantly affected by extracellular pH, suggesting that these unique enzymes may physiologically be involved in cellular $Ni^2$ import and $NH_4^+$ export, respectively.

• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.204-208
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• 1993

A fully automatic image analysis method was applied to obtain detailed data on morphological parameters of a glucoamylase fermentation broth with Aspergillus niger No. PFST-38. a mutant strain for glucoamylase hyperproducer. In the initial stage of fermentation. there was an increase in hyphal length. whereas at the end of the fermentation a decrease in hyphal length and increase in hyphal thickness were observed. The percentage of clumps declined with dilution and the influence of shear stress upon hyphal length was negligible. It was found that the slower the decrease in the main hyphal length and the number of tips with the fermentation time. the higher the glucoamylase production rate was recorded. The production rate of glucoamylase was closely related to the increase in the hyphal thickness.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.64.2-64.2
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• 2011

Recently, Silicon Germanium (SiGe) alloys have been received considerable attention for their great potentials in advanced electronic and optoelectronic devices. Especially, microcrystalline SiGe is a good channel material for thin film transistor due to its advantages such as narrow and variable band gap and process compatibility with Si based integrated circuits. In this work, microcrystalline silicon-germanium films (${\mu}c$-SiGe) were deposited by DC/RF magnetron co-sputtering method using Si and Ge target on Corning glass substrates. The film composition was controlled by changing DC and RF powers applied to each target. The substrate temperatures were changed from $100^{\circ}C$ to $450^{\circ}C$. The microstructure of the thin films was analyzed by x-ray diffraction (XRD) and Raman spectroscopy. The analysis results showed that the crystallinity of the films enhances with increasing Ge mole fraction. Also, crystallization temperature was reduced to $300^{\circ}C$ with $H_2$ dilution. Hall measurements indicated that the electrical properties were improved by Ge alloying.

• Tribology and Lubricants
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• 제19권5호
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• pp.251-258
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• 2003

New method and device for the on-line measurement of soot concentration in a diesel engine oil are proposed, where the measurement principle is based mainly on attenuated internal total reflection. The detector were evaluated in various ranges of contaminated oils by carbon black particles. It was found that the proposed detector could be well used to monitor the oil deterioration due to soot contamination. Operational range of the detector was found from 0 to 5 mass percentage of soot content. Test results with water and fuel dilution showed that these effects were not remarkable. However, adsorption of carbon black particles onto the measurement surface was considered to be a critical problem of the detector. Effects of particle deposition on the interface was experimentally evaluated with the oil temperature and flow turbulence and discussed throughout this work.

• International Journal of Control, Automation, and Systems
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• 제4권4호
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• pp.480-485
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• 2006

In this paper, the error investigation of a 3-dimensional GPS attitude determination system using the error covariance analysis is given. New efficient formulas for computing the Euler Angle Dilution of Precision (EADOP) are also derived. The formulas are easy to compute and represent the attitude error as a function of the nominal attitude of a vehicle, the baseline configuration and the receiver noise. Using the formula, the accuracy of the Euler angle can be analytically predicted without the use of computer simulations. Applications to some configurations reveal the effectiveness of the proposed method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.383-384
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• 2010

본 연구에서는 방동제의 동결온도 측정방법 및 국내에서 시판되는 방동제의 동결온도 특성을 조사하였다. 방동제 종류는 아질(초)산계 방동제를 대상으로 하였으며, 방동제와 물의 희석비는 각 종류별 3개 수준으로 하였는데, 방동제와 물의 희석비가 1:3의 경우 $-4.9{\sim}-6.3^{\circ}C$, 1:5의 경우 $-3.3{\sim}-4.2^{\circ}C$, 1:7의 경우 $-2.1{\sim}-3.3^{\circ}C$의 범위를 나타내었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.74.3-74
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• 2001

This paper proposes a nonlinear adaptive controller based on back-stepping method for tracking reference substrate concentration by manipulating dilution rate in a continuous baker´s yeast cultivating process in stirred tank bioreactor. Control law is obtained from Lyapunov control function to ensure asymptotical stability of the system. The Haldane model for the specific growth rate depending on only substrate concentration is used in this paper. Due to the uncertainty of specific growth rate, it has been modified as a function including the unknown parameter with known bounded values. The substrate concentration in the bioreactor and feed line are measured. The deviation from the reference is observed when the external disturbance such as the change of the feed is introduced to the system ...

• 대한기계학회논문집
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• 제18권7호
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• pp.1789-1798
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• 1994

This paper aimed for numerical simulation of complicated gas turbine combustor with swirler. For the convenience of numerical analysis, fuel nozzle and air linear hole areas of secondary and dilution zone, which are issued to jet stream, were simplified to equivalent areas of annular type. In other to solve these problems, imaginary source terms which are corresponded to supplied fuel amount were added to those of governing equation. Chemical equilibrium model of infinite reaction rate and $k-{\epsilon}-g$ model with the consideration of density fluctuation were applied. As the result, swirl intensity contributed to mixing of supplied fuel and air, and to speed up the flame velocity than no swirl condition. Temperature profiles were higher than experimental results at the upstream and lower at the downstream, but total energy balance was accomplished. As these properties showed the similar trend qualitatively, simplified simulation method was worth to apply to complicated combustor for predicting combustion characteristics.

• 한국동물학회지
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• 제3권1호
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• pp.24-30
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• 1960

본실험의 목적은 탄산기에 방사성동위원소 C14를 표식한 sodium acetate ($CH_3$C14 OONA)를 사용하여 염소의 위내에 존재하는 acetate 의 위벽으로부터의 흡수율과 위의 acetate의 평균함량을 측정하는데 있다. C14 로 표식된 sodium acetate(specific activity 1.35$\times$108 cpm./g.)를 급사 3 시간후의 염소의 위내에 주입하고 주입 2분후부터 약 2분간격으로 위 내용물을 추울하여 column chromatograpy를 이용하여 acetate를 분리정량한 후 그의 specific activity를 측정하였다. 주입후 3 분경까지는 위내에 존재하는 acetate에 의한 표식 acetate의 희석으로 말미암아 specific activity 는 급격히 감소되어 갔고 3 분후부터는 감소도가 비교적 완만하였으나 역시 계속적으로 감소되어갔다. 희석완료후의 이 specific activity 감소는 위벽을 통한 acetate를 흡수와 위 내용물로부터의 acetate 생성으로 인한 것으로서, 이 감소율로부터 acetate의 위벽흡수속도를 추정할 수 있다. 상기 specific activity의 감소 graph 로부터 추정된 위내 acetate의 량은 본실험의 제조건하에서 약 30 g이었으며 위내 acetate 의 specific activity가 1/2 로 감소되는데 요하는 평균 시간은 약 4 분이었다. 이는 위내에 존재하는 acetate량의 약 절반은 4 분동안에 위벽을 통과함을 의미한다.