• Title/Summary/Keyword: Reaction monitoring

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An Application of Optoacoustic Technique for the CO Oxidation Reaction Catalyzed by $Gd_{1-x}Sr_xCoO_{3-y}$ (광음향분광법을 이용한 CO 산화반응에서의 $Gd_{1-x}Sr_xCoO_{3-y}$ 촉매효과 연구)

  • Kang Hee-Seok;Oum Ka-Won;Hwang Jin-Soo;Yo Chul-Hyun;Choi Joong-Gill
    • Journal of the Korean Chemical Society
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    • v.37 no.1
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    • pp.55-61
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    • 1993
  • An application of the optoacoustic detection method to investigate the catalytic effect of a perovskite, $Gd_{1-x}Sr_xCoO_{3-y}$ (x = 0.00, 0.25, 0.50, 0.75) system, in the oxidation reaction of CO is described. The optoacoustic signals Of $CO_2$ produced from the oxidation reaction were measured for differing x values in $Gd_{1-x}Sr_xCoO_{3-y}$. By monitoring optoacoustic signals with respect to the time, the concentration ratios of CO and $O_2$, and the temperature, the kinetic information on the catalytic properties of the perovskite for CO oxidation reaction can be obtained. The effect of Sr substitution in $Gd_{1-x}Sr_xCoO_{3-y}$ has been found to show the maximum catalytic effect at x = 0.25 and the substantial increase in catalytic activity at temperatures above 200$^{\circ}C$. It demonstrates that the optoacoustic detection method allows the investigation of the integrated catalytic effect not only for the oxidation reaction of CO, but also for many reactions, in general, by continuously and directly detecting the species associated with the reactions.

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A Study on Modeling and Simulation of Wastewater Treatment Process Considering VOC Emissions (VOC 방출을 고려한 폐수처리공정의 모델링 및 모사에 관한 연구)

  • Seong, Kyoung Won;Chun, Sang Ki;Yi, Sung Chul
    • Journal of Environmental Impact Assessment
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    • v.8 no.2
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    • pp.83-93
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    • 1999
  • ASPEN PLUS, a steady-state simulator, was used in this study for predicting emissions of VOCs and tracing the fate of all compounds in biodegradation processes. Mathematical models for the processes such as volatilization, reaction and clarification were adopted from literatures. Unlike most previous simulations that various pollutants were considered as a single component, COD or BOD, four components of water, biomass, VOCs and COD were included in this simulation. Sensitivity analysis of several physical parameters on the performance of the WWTP was conducted. Model predictions of VOCs emissions agreed well with the plant data. The simulator could provide design conditions for a future WWTP as well as monitoring/control regimes to an existing WWTP.

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A newly developed consensus polymerase chain reaction to detect Mycoplasma species using 16S ribosomal RNA gene

  • Hong, Sunhwa;Park, Sang-Ho;Chung, Yung-Ho;Kim, Okjin
    • Korean Journal of Veterinary Service
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    • v.35 no.4
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    • pp.289-294
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    • 2012
  • Mycoplasmas are highly fastidious bacteria, difficult to culture and slow growing. Infections with Mycoplasma species can cause a variety of problems in living organisms and in vitro cell cultures. In this study, we investigated the usefulness of a genus-specific consensus PCR analysis method to detect Mycoplasma species. The developed consensus primer pairs MycoF and MycoR were designed specifically to amplify the 16S ribosomal RNA gene (rRNA) of Mycoplasma species by the optimized PCR system. The developed consensus PCR system effectively amplified 215 bp of Mycoplasma genus-specific region of 16S rRNA. In conclusion, we recommend this consensus PCR for monitoring Mycoplasma species in animals, human and cell culture system.

Interpretation of Voltammetric Data by Neural Networks for Simultaneous Determination of Glucose, Fructose, and Ascorbic Acid

  • Susomrith, Paisit;Surareungchai, Werasak;Chaisawat, Ake
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.269-272
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    • 2002
  • This work describes the use of neural networks (NNs) for interpreting voltammetric data, i.e., current-voltage spectra that obtained from the electrochemical reaction of analyte species at a gold electrode. Current-voltage spectra of glucose, fructose and ascorbic acid in mixtures obtained from dual-pulse staircase voltammetry (DPSV) was in the form of the mixed responses contain characteristics of the individual analytes approximately in proportion to their concentration. Extraction of individual analyte concentration from combined data was subsequently achieved using NNs. The combination of DPSV and NNs opens a possibility for simultaneous determination of mixtures of the species for fruit juices quality monitoring.

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Relative Comparison of Cathode Polarizations in Solid Oxide Fuel Cells Using the Spreading Concept in AC 2 Point Impedance Spectroscopy

  • Lee, Byung-Kook;Kim, Eui-Hyun;Hwang, Jin-Ha
    • Journal of the Korean Ceramic Society
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    • v.50 no.2
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    • pp.163-167
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    • 2013
  • A modified two-point impedance spectroscopy technique exploits the geometric constriction between an electrolyte and a cathode with an emphasis on semispherical-shaped electrolytes. The spatial limitation in the electrolyte/electrode interface leads to local amplification of the electrochemical reaction occurring in the corresponding electrolyte/electrode region. The modified impedance spectroscopy was applied to electrical monitoring of a YSZ ($Y_2O_3$-stabilized $ZrO_2$)/SSC ($Sm_{0.5}Sr_{0.5}CoO_3$) system. The resolved bulk and interfacial component was numerically analyzed in combination with an equivalent circuit model. The effectiveness of the "spreading resistance" concept is validated by analysis of the electrode polarization in the cathode materials of solid oxide fuel cells.

Analysis and Dyeing of Natural Pigments Extracted from Onion Shell(Allium cepa) (양파 외피에서 추출한 수용성 색소의 분석)

  • 배순이;신인수
    • Textile Coloration and Finishing
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    • v.10 no.6
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    • pp.27-32
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    • 1998
  • 도시 Traditionally, dyes extracted from onion shells have been used as natural pigments but dyeing methods with reproducibility have not been developed. In this study, the dyes were analyzed by high performance thin layer chromatography(HPTLC) to obtain the ratio of pigments in water and ethyl acetate extract. Furthermore, the present study was also carried out to obtain the information characteristic of wavelength which proportionally decrease for continuous dyeing reaction. Scanning of water extract showed 4 peaks by the mobile phase of benzene/ethyl acetate/acetic acid(40/10/5) and the peak 1 exhibited yellow color with the maximal absorption spectra of 306nm and 309nm while ethyl acetate extract showed 9 peaks in the same mobile phase. The water extract after ethyl acetate extraction was adjusted to 0.5 of O.D.(optical density) at 550nm by adding of water and compared wavelength of the pigments from 200 to 600nm to find the proportional decrease of wavelength. As the result, it showed that wavelength of 306nm could be the standard of dyeing monitoring points.

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Detection of Salmonella typhi by Loop-mediated Isothermal Amplification Assay

  • Jo, Yoon-Kyung;Lee, Chang-Yeoul
    • Biomedical Science Letters
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    • v.14 no.2
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    • pp.115-118
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    • 2008
  • Salmonella typhi is frequent causes of foodborne illness and its detection is important for monitoring disease progression. In this study, by using general PCR and novel LAMP (Loop Mediated Isothermal Amplification) assay, we evaluated the usefulness of LAMP assay for detection of Salmonella typhi. In this LAMP assay, forward inner primer (FIP) and back inner primer (BIP) was specially designed for recognizing target invA gene. Target DNA was amplified and visualized as ladder-like pattern of bands on agarose gel within 60 min under isothermal conditions at $65^{\circ}C$. When the sensitivity and reproducibility of LAMP were compared to general PCR, there was no difference of reproducibility but sensitivity of LAMP assay was more efficient than PCR (the detection limit of LAMP assay was 30 fg, while the PCR assay was 3 pg). These results indicate that the LAMP assay is a potential and valuable means for detection of Salmonella typhi, especially for its rapidity, simplicity and low cost.

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Monitoring of viruses (IHHNV, TSV, IMNV, YHV, and CMNV) in cultured whiteleg shrimp (Litopenaeus vannamei) between 2018 and 2019 (2018-2019년 양식산 흰다리새우의 바이러스 (IHHNV, TSV, IMNV, YHV, CMNV) 모니터링)

  • Kokkattunivarthil, Shyam;Kim, Wi-Sik
    • Journal of fish pathology
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    • v.33 no.1
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    • pp.71-75
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    • 2020
  • A survey was conducted to investigate viral infections in 184 whiteleg shrimp (Litopenaeus vannamei) collected from nine farms and one wholesale fish vendor during 2018 and 2019. Gill and abdominal muscle of shrimp were tested for the presence of five viruses, viz. infectious hypodermal and haematopoietic necrosis virus, taura syndrome virus, infectious myonecrosis virus, yellow head virus genotype 1, and covert mortality nodavirus by reverse transcription-polymerase chain reaction (RT-PCR) and PCR. These viruses were not detected in any of 184 samples, screened under the study.

Development of Laser Speckle Flowgraphy System for Monitoring Blood Flow in Skin Tissue (레이저 산란 현상을 이용한 피부혈류 화상화 시스템의 개발)

  • Lee, M.C.;Fujii, H.
    • Journal of Biomedical Engineering Research
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    • v.28 no.3
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    • pp.392-396
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    • 2007
  • In this paper, we develop a new system to visualize the blood flow map in skin tissue, using the technique of Laser Speckle Flowgraphy (LSFG). The measuring unit consists of the laser diode, imaging system, line sensor, scanning mirror, and one-board microcomputer. The speckle signal is analyzed and sent to a PC, where the blood flow in a tissue area of $14mm{\times}26 mm$ is evaluated and displayed in a 2-D color map. It is demonstrated that the new LSFG instrument is useful to evaluate the degree of allergic reaction in patch test.

Simultaneous Determination of Benzoic Acid, Caffeic Acid and Chlorogenic Acid in Seeds of Eriobotrya japonica and their Antibacterial Effect

  • Jeong, Jun-Mo;Lee, Kyoung-In;Kim, Sun-Min
    • Journal of Applied Biological Chemistry
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    • v.57 no.1
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    • pp.89-93
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    • 2014
  • We aim to develop a simple method for simultaneous and quantitative determination of benzoic acid, caffeic acid and chlorogenic acid in seeds of Eriobotrya japonica. In addition, antibacterial effect of these three phenolic acids was examined. A basic method is performed on the high performance liquid chromatography system coupled to an UV-detector (230 nm) and reverse phase C-18 column ($4.6{\times}150mm$, $5{\mu}m$). Each phenolic acid was confirmed via liquid chromatography-mass spectrometry (MS)/MS system under the multiple-reaction monitoring with negative-ion electrospray ionization (ESI(-)) mode. It is demonstrated that the method was could be applied to samples for an analytical study of the phenolic acids. On the other hand, three phenolic acids in seeds of E. japonica exhibited antibacterial effect against several pathogenic bacteria. Of these, benzoic acid was found to have stronger antibacterial effect.