• 제목/요약/키워드: dilution method

검색결과 816건 처리시간 0.026초

Effect of hydrothermal extract from Codonopsis lanceolata Benth. et Hook on the growth of lactic acid bacteria and harmful bacteria

  • Kim, Se-young;Lee, Jinsil;Geong, Ga-Jin;Yi, Seh-Yoon
    • 한국식품조리과학회:학술대회논문집
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    • 한국식품조리과학회 2003년도 추계학술대회 및 사단법인 창립총회
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    • pp.75-75
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    • 2003
  • The objective of this study is to investigate the effect of Codonopsis lanceolata Bentk et Hook on the growth of lactic acid bacteria and some harmful bacteria. Extract of C. lanceolata was obtained by hydrothermal extraction method and used intactly without concentration. To investigate the inhibitory effect on the growth of harmful bacteria, we used agar dilution method. On agar plate containing more than 25% extract, they showed decreased number of colonies. (omitted)

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IEEE 802.11 RSSI 기반 무인비행로봇 실내측위를 위한 AP 선택 기법 (AP Selection Criteria for UAV High-precision Indoor Positioning based on IEEE 802.11 RSSI Measurement)

  • 황준규;박준구
    • 제어로봇시스템학회논문지
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    • 제20권12호
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    • pp.1204-1208
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    • 2014
  • As required performance of UAV (Unmanned Aerial Vehicle) becomes more complex and complicated, required positioning accuracy is becoming more and more higher. GPS is a reliable world wide positioning providing system. Therefore, UAV generally acquires position information from GPS. But when GPS is not available such as too weak signal or too less GPS satellites environments, UAV needs alternative positioning system such as network positioning system. RSSI (Received Signal Strength Indicator) based positioning, which is one method of network positioning technologies, determines its position using RSSI measurements containing distance information from AP (Access Point)s. In that method, a selected AP's configuration has strong and tight relationship with its positioning errors. In this paper, for, we additionally account AP's configuration information by adopting DOP (Dilution of Precision) into AP selection procedures and provide more accurate RSSI based positioning results.

지반주입용 활성 실리케이트 약액 (ASG) 의 개발 및 적용 (Development and Application of Activated Silicate for Chemical Grouting)

  • 천병식;류동성;조산연
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 가을 학술발표회 논문집
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    • pp.131-136
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    • 1999
  • In this study, novel activated silicate grout solution for injection grouting was prepared by the reaction of ordinary waterglass with alkaline earth metal salts mixture by means of the high-speed stirring method with strong shearing force, and its chemical and physical properties were investigated. The variation of its gelation time plotted with the amount of dilution water showed that this novel silicate had better gelation characteristics in comparison with ordinary waterglass. And some other engineering characteristics of this grout such as durability and mechanical properties were investigated experimentally. The whole experimental results established that this novel silicate grout was a good alternative with an existing ordinary waterglass grouting method.

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Quantitative Assay of Bioemulsifier by Turbidometric Method

  • Jeong, Yong-Leen;Park, Oh-Jin;Yoon, Byung-Dae;Yang, Ji-Won
    • Journal of Microbiology and Biotechnology
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    • 제7권3호
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    • pp.209-211
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    • 1997
  • A quantitative method for assaying bioemulsifiers in culture broth was developed and applied to cultivation of Pseudomonas aeruginosa YPJ80. SED(Standard Emulsification Dilution), an indirect measure of bioemulsifier concentration, was proposed. Production of bioemulsifier and rhamnolipid reached their maximum simultaneously. However, the bioemulsifier/rhamnolipid ratio decreased with cultivation time. This indicates the presence of another bioemulsifier other than rhamnolipid. The bioemulsifier seems to be protein-like activator which showed emulsification activity in addition to rhamnolipid.

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Ion Chromatography에 의한 혈액중에서 양이온의 분석에 관한 연구 (A Study on the Analysis of Cation in Blood by Ion Chromatography)

  • 박성우;김을환
    • 한국환경보건학회지
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    • 제17권1호
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    • pp.89-94
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    • 1991
  • There are many pretreatment and detection methods for divalent cations in blood. But our purpose was to study the pretreatment of blood for the determination of cations by Ion Chromatography. We compared with recovery of Mg$^{++}$, and Ca$^{++}$ contained in plasma according to four pretreatment methods, that is, add of trichloroacetic acid and perchloric acid, dilution with distilled water and membrane filter method. As a result, add of trichloroacetic acid was found to be the most suitable method for good recovery of Mg$^{++}$ (98.0%) and Ca$^{++}$(96.0%) in plasma, and the Mg$^{++}$ and Ca$^{++}$ contents in plasma was 20 and 102 ($\mu$g/ml)

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Analysis of the Irradiated Nuclear Fuel Using the Heavy Atom and Neodynium Isotope Correlations with Burnup

  • Kim, Jung-Suk
    • Nuclear Engineering and Technology
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    • 제29권4호
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    • pp.327-335
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    • 1997
  • The correlation of isotope composition of uranium, plutonium and neodymium with the burnup in M uranium dioxide fuel has been investigated experimentally. The total and fractional($^{235}$ U) burnup were determined by Nd-148 and, U and Pu mass spectrometric method respectively. The isotope compositions of these elements, after their separation from the fuel samples were measured by mass spectrometric. The content of the elements in the irradiated fuel ore determined by isotope dilution mass spectrometric method using $^{233}$ U, $^{242}$ Pu and $^{150}$ Nd as spikes. The content of plutonium in the irradiated fuel was expressed by the correlation with uranium isotopes. The correlations between isotope compositions themselves and the total and fractional burnup ore compared with those calculated from ORIGEN2 code.

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Nonlinear Adaptive Control of Fermentation Process in Stirred Tank Bioreactor

  • Kim, Hak-Kyeong;Nguyen, Tan-Tien;Nam soo Jeong;Kim, Sang-Bong
    • Transactions on Control, Automation and Systems Engineering
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    • 제4권4호
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    • pp.277-282
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    • 2002
  • 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. The effectiveness of the proposed controller is shown through simulation results in continuous system.

갓 정유의 조성 및 항진균작용에 관한 연구 (Studies on Compositions and Antifungal Activities of Essential Oils from Cultivars of Brassica juncea L.)

  • 강찬아;신승원
    • 생약학회지
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    • 제32권2호통권125호
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    • pp.140-144
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    • 2001
  • The composition of essential oils in the leaves of three cultivars (Ban-Chung-Gat, Chung-Gat and Dolsan-Gat) of Brassica juncea L. were analyzed and their antifungal activity were investigated in this study. Allyl isothiocyanate, 2-phenyl ethyl isothiocyanate, 4-isothiocyanato-1-butene, 5-methyl isothiazole, benzene acetaldehyde, benzene propane nitrile and beta-ionone have been identified in all of the experimented oils. The main component of the oils from Ban-Chung-Gat and Chung-Gat was 2-phenyl ethyl isothiocyanate while allyl isothiocyanate was the representing compound in the oil of Dolsan-Gat. The antifungal activities of the oils were tested by micro broth dilution method and disc diffusion method. As the result the oils exhibited significant inhibiting activities against Aspergillus niger, A. flavus, Trichoderma viride, Candida albicans, C. utilis, C. tropicalis, Cryptococcus neoformans, Trichosporon mucoides, Trichophyton tonsurans and Geotrichum capitatum.

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Bactericidal Activity of Grapefruit (Citrus paradisl) Seed Extract-Based Disinfectant

  • Han, Jae-Hong;Kim, Yong-Ung;Kim, Ki-Yeon;Hahm, Young-Tae
    • Journal of Applied Biological Chemistry
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    • 제49권3호
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    • pp.90-94
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    • 2006
  • Bactericidal activity of grapefruit seed extract (GSE)-based disinfectant, as a safe disinfectant, was measured against five bacteria by Korean Food & Drug Administration (KFDA) dilution-neutralization method. GSE-based disinfectant showed a 99.9999% bactericidal activity against Escherichia coli ATCC 10536, Salmonella typhi ATCC 29629, Staphylococcus aureus ATCC 6538, Bacillus cereus ATCC 11778, and Listeria monocytogenes ATCC 1911 at the concentration of 2.15% GSE. It showed better bactericidal activity against Gram-negative bacteria of E. coli ATCC 10536 and S. typhi ATCC 29629 at lower concentration of GSE (0.43%). Based on the results, it was suggested that a possible bactericidal mechanism of GSE active ingredients was due to the abrupt osmotic shift during the bactericidal activity test by KFDA method.

고효율 항균 필터의 항균력 평가에 관한 연구 (A Study on Antibacterial Assesment of High Efficiency Antibacterial Air Filter)

  • 권혁구;정진도;류해열;정우성;박덕신
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 춘계학술대회 논문집
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    • pp.549-554
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    • 2002
  • Recently, interest in hygiene has been arouse in the health care field. Consequently, Filters with antibacterial agent applied to improve air quality by sterilizing bacteria, fungi, etc. We actually installed antibacterial air filter containing 2.5wt%Ag zeolite on the air intake route to air-conditioner in passenger cu, and evaluated filter's performance on antibacterial effect. By the microbe liquid spattering method, we found that the antibacterial air filter has notably sufficient antibacterial efficiency against standard strains and wild type strains. Antibacterial effect was observed at whole area of filter media by zone of inhibition test. The evaluation of microbe quantity was conducted through mixing dilution plate culture method. In comparison with ordinary filter, the amount of germs attached on antibacterial air filters was larger. The amount of germs attached on ordinary filters was very small since ordinary filters contained less dust. In comparison in antibacterial air filter with thickness, the amount of germs attached on 9mm filter was smaller than that of on 6mm filter. i.e. thicker filter, superior efficiency.

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