• Title/Summary/Keyword: Stripping

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폴리톨루이딘 합성 및 전기화학적 특성분석

  • Park, Su Beom;Lee, Seong Ju;Kim, Eun Ok
    • Journal of the Korean Chemical Society
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    • v.46 no.3
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    • pp.225-228
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    • 2002
  • Poly-o-toluidine (POT) was chemically and electrochemically synthesized for the study of the electronic and steric effect of methyl substituents. It was found that the steric effect was dominant in POT. The IP 4.95 eV, EA 3.24 eV, Eg 1.71 eV of POT were found by the CV (Cyclic Voltammetry) and CCPSA (Constant Current Potentiometric Stripping Analysis).

Preparation of High-purity Zinc Oxalate Powder by the Precipitation Stripping Method (Precipitation Stripping법에 의한 고순도 Oxalate 분말의 제조)

  • 이재천;이강인;유효신
    • Journal of the Korean Ceramic Society
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    • v.29 no.12
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    • pp.963-969
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    • 1992
  • This paper describes the feasibility for a direct production of zinc oxalate powders from zinc-loaded D2EHPA solutions combining the purification and the precipitation in one operation unit. This process has the potential as an alternative to conventional method for the synthesis of zinc oxide precursor particles from the hydrometal-lurgical processes. Zinc was extracted into D2EHPA in kerosene and then zinc-loaded D2EHPA solution was emulsified with oxalic acid-HCl solution to precipitate zinc oxalate powder, which was readily calcined to zinc oxide. The precipitation kinetics and yield were sensitive to experimental conditions. The morphology, size and size distribution of the zinc oxalate powders varied with zinc/oxalate ion riatio, temperature, and the presence of SPAN 60, which affected nucleation, growth, and the emulsion characteristics.

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Detection of Pesticide Thiram in Plant Leafs Using Voltammetric at Nanotube Electrode (나노튜브전극을 사용한 전압전류법에 의한 식물잎에서 살충제 검출)

  • Lee, Chang-Hyun;Ly, Suw-Young
    • Journal of Environmental Science International
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    • v.19 no.12
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    • pp.1335-1341
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    • 2010
  • Voltammetric diagnostics of pesticide thiram was studied in plant leafs in vivo fluid with DNA immobilized on a carbon nanotube electrode (DCE). Sensor properties of carbon nanotube (CE) and DNA immobilized nanotube were compared. DCE was more effective than CE in target detecting. The parameters such as pH strength, stripping accumulation, amplitude, and increment potential were examined to find the optimum condition for detection of pesticide thiram in a sesame leaf. The optimized conditions were as follows 550 Hz frequency, 0.15 V amplitude, 0.005 V increment potential, -1.2 V initial potential, 4.78 pH, 500 sec accumulation time. Under optimum condition, the detection limit of thiram was attained at 0.01ng/L.

Noise Correction of Remote Sensing Imageries: Application to KOMPSAT/OSMI Data

  • Kang, Y.Q.;Ahn, Y.H.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.694-696
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    • 2003
  • The KOMPSAT/OSMI remote sending data of 800 km swath are collected by whisk broom method employing 96 charge coupled devices (CCDs). The stripping noise in the OSMI imageries, which arise mainly due to the non-uniform sensitivities of 96 CCDs, are the major hindrance for oceanographic applications of the OSMI data. The OSMI images are corrected by 'Ensemble Smoothness' method which is based on an assumption that the series of the averages and variances of digital numbers in each line should vary smoothly. The data of each line are corrected by linear regression model of which coefficients are obtained by Ensemble Smoothness method. Our algorithm can be applied not only to OSMI data but also for other remote sensing date collected by whisk broom or push broom.

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Assay of Trace Gold Ion in a Skin Cell Using a Stripping Voltammetry

  • Ly, Suw-Young;Lee, Jin-Hui;Yi, Jae-Hun
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.1
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    • pp.15-21
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    • 2011
  • Threelectrodes systems were used in stripping voltammetry (SW) and cyclic voltammetry (CV) instead of the expensive platinum and Ag/AgCl reference electrodes. Moreover, the electrolyte solution was used with deep seawater, which can reduce water pollution, is more eco-friendly, and has a lower cost. The analytical optimum parameters measured via CV and SW and with working ranges were obtained from 10 to 80 ug/L using fluorine immobilized on a graphite pencil electrode (FE). Under the optimum conditions, the analytical detection limit of 6.30 ug/LAu was obtained. The results of the study can be applied to diagnostic assay for natural minerals and human finger tissue.

A Study on the Separation and Recovery of Magnesium from Waste Bittern (폐해수로부터 마그네슘의 분리.회수에 관한 연구)

  • Ju, Chang-Sik;Lee, Gyeong-Ok;Jeong, Seong-Uk;Park, Heung-Jae;Na, Seok-Eun;Jeong, Gap-Seon
    • Journal of Environmental Science International
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    • v.10 no.5
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    • pp.381-386
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    • 2001
  • The characteristics of precipitation separation and solvent extraction separation of magnesium from the waste bittern were studied experimentally In the result of precipitation separation, the size of magnesium hydroxide precipitated was not affected on pH, but decreased with increasing the precipitation temperature. The purity of magnesium oxide precipitated was increased with pH beyond pH 11. From the solvent extraction separation, the equilibrium extraction ratio of magnesium was increased with pH and temperature of extraction phase, the concentration of stripping phase, and with decreasing pH of stripping phase. The extractant of Aliquat 336 and Acid 810 mixture was more effective than that of DCH18C6 and $D_2EHPA$ mixture in the extraction separation of magnesium.

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Electrochemical Detection of Pesticide in Living Plant and Fish Brain Cell

  • Lee, Chang-Hyun;Ly, Suw-Young
    • Journal of Environmental Science International
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    • v.19 no.8
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    • pp.941-949
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    • 2010
  • The three electrode system was used to detect the pesticide fenitrothion ($C_9H_{12}NO_5PS$. MW=277.24) using cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). The working electrode was mercury immobilized on a carbon nanotube paste electrode (Hg-CNTPE). At the optimized condition, the limit of detection (LoD) was 0.6 ppt ($2.16{\times}10^{-12}\;M$), and the relative standard deviation was 0.035% (n=15). And there is more sensitive in detecting fenitrothion than common type carbon nanotube paste electrode. When it was implanted into the brain of live fish (carp), the existence of fenitrothion was measured without any destruction or damage of tissue.

Voltammetric Assay of Antibiotics for Modified Carbon Nanotube Sensor

  • Ly, Suw-Young;Yoo, Hai-Soo;Lee, Chang-Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.3
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    • pp.443-449
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    • 2012
  • A investigation of electrochemical analysis of antibiotics Neomycin ($C_{23}H_{46}N_6O_{13}$) was searched using electrochemical square wave (SW) stripping and cyclic voltammetry (CV) using working sensor of the modified carbon nanotube combination electrodes, optimum diagnostic parameters were searched by anodic stripping, final conditions were attained to working range of 1.0-14.0 ng/L, detection limit (S/N) was found to be 0.6 ng/L. The developed method was discovered to be fitting in quality control in the food, pharmaceutical and other manufacturing sectors.