• Journal of the Korean Society of Safety
• /
• v.5 no.2
• /
• pp.40-49
• /
• 1990

For the determination of polluant NOx in ambient air, nitrate ion-selective electrode(ISE) was made. To comparison of NOx in each method, the nitrate-ISE, NEBA, Orion electrode were used to determinee NOx in ambient air. In this work, the concentration of NOx in ambient air was average 0.06ppm. The results were good agreement with those obtained by each method within a relative error of 3％, Absorbing efficiency of nitrogen oxides in ambient air was good for Alkali solution. The determination of nitrogen oxides in ambient air using the Aliquat 336N-PVC membrane electrode was one of the useful method. The best characteristics of the Aliquat 336N-PVC me,mbrane electrode were obtained with the ion-exchanger concentration level of 6.5-9.1 percent by weight. The optimal membrane composition, was 9.09wt.％ of ion-exchanger, 30.95wt.％ of PVC, 60.6wt.％ of plasticizer (DBP), and 0.5mm of thickness. Under the above condition, the electrode approached the Nernstian slope most closely, and the linear response ranges produced the best results.

• Journal of Environmental Science International
• /
• v.15 no.11
• /
• pp.1027-1034
• /
• 2006

Antimicrobial powder was made by exchanging silver ion on calcined oyster shell. On the purpose of application to water clarifier, bail-type media mixed with antimicrobial powder and $0{\sim}30%$ white kaoline were made. The sterilization effect, pore size distribution and zeta potential was tested to indicate the condition for the media of water clarifier. From these tests, it was confirmed that this media have an excellent sterilization power on $G^-\;and\;G^+$ germs. As the concentration of the exchanged silver ion increased, the surface charge density of the anions on the surface of the media also increased. The surface pore size decreased with the concentration of silver ion and 20% more white kaoline ratio. Consequently, mixing ratio of white kaoline would appear to indicate the optimun condition as media have sterilization power.

• Journal of the Korean Electrochemical Society
• /
• v.5 no.4
• /
• pp.216-220
• /
• 2002

The effects of electrolytes on electrochemical behavior from an oil thin layer interposed between a graphite electrode and an aqueous solution phase were examined. A hydrophobic electroactive species, tetrachloro-1,4-benzoquinone (TCQ), in a benzonitrile (EN) layer was employed to study ion transfer properties across the BN-water interface. Experimental results showed that hydrophobic cations as well as anions could be successfully used as ionic charge carriers. The addition of various salts into either the oil layers or the aqueous solutions offers deeper insight for the electrochemistry of the liquid thin layer system. When aqueous perchloric acid is interfaced with the BN films, the perchlorate ion of tetrahexylammonium perchlorate (THAP) substantially suppresses the dissociated proton concentration in the layer by the common ion effect while there is only a little change in the total acid concentration. Further approach by theoretical calculation makes it possible to quantitatively understand the effect of the electrolytes to the electrochemical responses of TCQ, which were previously reported (Anal. Chem. 73, 337 (2001)).

• Nuclear Engineering and Technology
• /
• v.55 no.10
• /
• pp.3659-3664
• /
• 2023

The electrochemical behavior of dissolved hydrogen (H₂) was investigated at a Pt electrode in a high temperature LiOH-H₃BO₃ solution. The diffusion current of the H₂ oxidation was proportional to the concentration of the dissolved H₂ as well as the reciprocal of the temperature. In the polarization curve, a potential region in which the oxidation current decreases despite an increase in the applied potential between the H₂ oxidation and the water oxidation regions was observed. This potential region was interpreted as being caused by the formation of a Pt oxide layer. Using the properties of the Cl^- ion that reduces the growth rate of the Pt oxide layer, it was confirmed that there is a correlation between the Cl^- ion concentration and the transient current of the H₂ oxidation.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.5
• /
• pp.1175-1181
• /
• 2013

The aim of this paper is to design and evaluate a high concentration, high penetration unipolar corona ionizer. The electrostatic characteristics in terms of voltage-current relationships of the present ionizer in the discharge zones for positive and negative coronas were discussed. Using ion current measurement, the concentration and penetration of ions were evaluated at corona voltages across the needle electrodes between 1 and 4 kV, flow rates between 1 and 5 L/min, and an operating pressure of 1 atm. In the discharge zone of the ionizer, the highest ion concentrations were found to be about $1.71{\times}10^{14}$ and $5.09{\times}10^{14}\;ions/m^3$ for positive and negative coronas, respectively. At the outlet of the ionizer, it was found that the highest ion concentration was about $1.95{\times}10^{13}$ and $1.91{\times}10^{13}\;ions/m^3$ for positive and negative coronas, respectively. The highest ion penetration for positive and negative coronas through the ionizer was found to be about 98 % and 33 %, respectively. The $N_it$ product for positive and negative coronas was also found to $1.28{\times}10^{13}$ and $7.43{\times}10^{13}\;ions/m^3s$, respectively. From the findings, this ionizer proved to be particularly useful as an aerosol charger for positive and negative charge before the detector in an electrical aerosol detector.

• Bulletin of the Korean Chemical Society
• /
• v.12 no.5
• /
• pp.499-504
• /
• 1991

EPR spectra of the high $T_c$ superconductor $YBa_2Cu_3O_{7-y}$ (YBCO) doped with $Pd^{2+} or Zn^{2+}$ have been measured at several temperatures and dopant concentrations. The spectral intensity of $YBa_2({Cu_{1-x}}{Pd_x})_3O_{7-y}$ is proportional to the dopant concentration. The behavior of $YBa_2(Cu_{1-x}Zn_x)_3O_{7-y}$ is quite different: the spectral intensity remains almost constant up to x=0.10 and then increases rapidly above x=0.10. The results are interpreted in terms of localized and antiferromagnetically spin-paired d holes in both CuO chain and planes. The $Pd_{2+}$ ion substitutes on the CuO chain consisting of "CuOCu dimers", and a $Cu_{2+}$ ion with an unpaired spin is gene rated for each $Pd_{2+}$ ion substituted. On the other hand, $Zn_{2+}$ substitutes on the CuO planes, and all or most of the spins in the two-dimensional plane manage to pair up in the region of low dopant concentration. When the dopant concentration exceeds a certain limit, it becomes more difficult for the spins to find partners, and the number of unpaired spins increases rapidly with increasing dopant concentration. The $Zn_{2+}$ ion is more effective than the $Pd_{2+}$ ion in suppressing the superconductivity of YBCO. This is attributed to the fact that $Zn_{2+}$ substitutes on the CuO planes which are mainly responsible for the superconductivity, while $Pd_{2+}$ substitutes on the CuO chain which is of secondary importance in the superconductivity.

• Membrane Journal
• /
• v.7 no.3
• /
• pp.136-141
• /
• 1997

Humic acid has been extracted and purified from biologically nondegradable humic substances. Using the ion exchange capability of carboxylic acids which are the main component of the humic acids, a membrane was prepared with poly(viny1 alcohol). Its transport behavior of biologically active ions, $K^+$and $Na^+$, were investigated. The ion transport velocity increased with hydrogen ion concentration, especially, in the range of $10^-1$~$10^0$. The selectivity increased with increasing the concentrations of $K^{＋}$ and Na$^{＋}$, In particular, the transport velocity of $K^+$ increased twice compared to that of $Na^+$ at the 100 hydrogen ion concentration. In this regards, humic acid may be used as a new material for ion exchange membranes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.4
• /
• pp.79-84
• /
• 2005

This paper proposes the new type of an ion exchange water generator system. The system has an +/- ion exchange membrane located in center and a diagonal-interdigit type electrode applied to a pulsed power. This system is studied in the liquid for the oxidation/reduction potential and the dissolved oxygen concentration by the polarity effects. Consequently, as a diagonal-interdigit type electrode is installed in each side of device, the oxidation/reduction potential and dissolved oxygen concentration by polarity changes and electrical resistivity differences be observed. An ion concentration in the ion exchange water generator system is increased by dissolved oxygen generated from oxidation/reduction potential changes.

• Journal of Environmental Science International
• /
• v.7 no.1
• /
• pp.89-95
• /
• 1998

Ion exchange performance to remove nitrate in water was studied using commercially available strong base anion exchange resin of Cl- type in the batch and continuous column reactors. The performance was tested using the effluent concentration histories for continuous column or equilibrium conquilibrium between resin and solution. Anion exchange resin used in this study was more effective than activated carbon or zeolite for nitrate removal. With large resin amount or low initial concentration, nitrate removal characteristics for a typical gel-type resin was Increased. On considering the relation between the breakthrough capacity and nitrate concentration of the influent, the use of anion exchange resin were suitable for the hi선or order water treatment. The nitrate removal of above 90% could be possible until the effluent of above 650 BV was passed to the column. Thus, the commercially available strong base anion exchange resin of $Cl^-$ type used in thins study could be effectively used as economic material for treatment of the groundwater. The breakthrough curves showed the sequence of resin selectivity as $SO_4^{2-}$ > $NO_3$ > $NO^{2-}$ > $HCO_3^-$. The results of this study could be scaled up and used as a design tool for the water purification system of the real groundwater and surface water treatment processes.

• Journal of Chest Surgery
• /
• v.12 no.4
• /
• pp.395-402
• /
• 1979

Intracellular pH was determined by distribution of 5.5-dimethyl-2,4-oxazolidlnedione [DMO]in the skeletal muscle of dogs before and after lactic acidosis induced by intravenous infusion of lactic acid solution. After infusion of lactic acid solution arterial pH decreased from 7.40 to around 7.12 [P<0.001]and metabolic acidosis was induced. However, dose-pH change response was not proportional as in the case of hydrochloric acid infusion. During lactic acidosis, intracellular pH changed very little except when venous blood $pCO_2$ increased significantly. The decrease of intracellular pH in lactic acidosis might be due primarily to the increase of intracellular $pCO_2$. And during lactic acidosis, change of extracellular pH was larger than that of intracellular pH, and this was also the case of change In hydrogen Ion concentration in extracellular and intracellular fluid. The fact was estimated that exogenous lactic acid transported into the cell does not contribute to pH change by the participation in the metabolism. Change in plasma potassium Ion concentration was not eminent as metabolic acid-base disturbances by other origin, and changing pattern of Hi/He ratio was not same as Ki/Ke ratio. In spite of no changes in extracellular potassium ion concentration after exogenous lactic acidosis total amount of potassium ion in extracellular fluid increased from 12.62mEg to 18.26mEg [P< 0.05].