• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.224-230
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• 1986

Dodecyltrimethylammonium bromide (DTAB) was examined as a counter-ion in the separation of aromatic sulfonic acids on alkylmodified silica (ODS) column by reversed-phase ion-pair chromatography. The capacity factor of acids was investigated and separation was attempted. The capacity factor of samples was influenced by the several factors such as a concentration of counter-ion, concentration of methanol, kinds and concentration of electrolyte in mobile phase as well as kinds and position of functional group in samples. Some mixtures of samples were able to be separated under optimum condition.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.56.1-56.1
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• 2010

A novel electrochemical potentiostatic method has been examined in order to enhance the hole concentration of p-type GaN thin films using KOH and HCl electrolyte. The hole concentration was increased more than 2 times by the electric voltge apply with the mobility of $10{\sim}12cm^2/V.s$. At optimum condition of 3V apply, hole concentration was enhanced more than reference sample from $1.7{\times}10^{-17}cm^{-3}$ to $4.1{\times}10^{-17}cm^{-3}$. Application of this activation method to blue-LED fabrication improved optical output from 18.4mW to 20.6mW, that is ~12% increase. SIMS analysis indicates that nearly 70% of hydrogen atoms could be removed by this method.

• Analytical Science and Technology
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• v.8 no.4
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• pp.643-648
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• 1995

Cyclic voltammetric method is used to survey microscopic environments which take place at the surfactant-modified carbon electrode when the hydrophobic and hydrophilic environments of $Ru(ph){_3}^{2+}$(tris 1,10-phenanthroline ruthenium(II) chloride) is created by the addition of anionic surfactant, sodium dodecyl sulfate(SDS). Critical micelle concentration(CMC) of SDS in $Ru(ph){_3}^{2+}$ measured by cyclic voltammetry(CV) is in aggrement with that by surface tensiometry. Influence of the concentration of supporting electrolyte at surfactant-modified carbon electrode is investigated.

• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.1-6
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• 1997

This research was conducted in the laboratory to investigate an alternative of Copper(Cu) removal from an heavymetal wastewater using the electrochemical precipitation(ECP) process. The ECP unit consisted of an electrolytic cell made of Titanium plate and Steel plate representing anode and cathode. The DC power source applied to the ECP unit had electrical potential(E) of 50$\pm$ 1V, respectively. The synthetic wastewater used in the experiments contained Cu in the 10 mg/l concentration and the electrode separation were 2, 3, 4 cm and the initial pH were 3, 6, 9, 12, and electrolytic concentration were 0.005, 0.0125, 0.025, 0.0375 mole, and the real heavymetal wastewater used in the experiments. From the experiment for removal efficiency according to pH variation, the low pH area doesn't give the coagulation effect by Ti(OH)$_4$ because process interfere with the coagulation and oxidation reaction, therefore the optimum pH was 4-7. The removal rate was 97.75% after the lapse of 30 minutes when copper concentration and electrolytic concentration were respectively 10 mg/l and 0.025 mole. The removal rate was 96.41% after the lapse of 30minutes when the real heavymetal wastewater used. The optimum consumption of power showed 27KWh/m$^3$ when copper concentration, electrolyte concentration and cell potential were respectively 10 mg/l, 0.025 mole and 50$\pm$ 1 Volt.

• Korean Journal of Materials Research
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• v.16 no.2
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• pp.129-136
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• 2006

In order to get basic information on the reference electrode material for the long life Al concentration sensor in zinc galvanizing melt, the workability and stability of fluorine potential cell with $CaF_2$ single crystal electrolyte were examined carefully at constant temperature for six kinds of reference materials (Zn, Sn, Cd, Bi, Pb, Al-Sn alloy + fluorides). Good workability and stability of the sensor were found in sensor with $Bi+BiF_3$ reference electrode. The Al sensor with $Bi+BiF_3$ reference electrode was assembled and was tested in Zn-Al melt with different Al concentration. The EMF was changed rapidly with the change of Al concentration and was stabilized in a short time. Thus the response of EMF was satisfactory for $CaF_2$ sensor. The correlationship between EMF from the sensor and logarithm of Al concentration has been derived from the least square regression method. E/mV=57.515log[wt% Al]+1883.3 R=0.9717 ($0.013{\leq}[wt% Al]{\leq}0.984$) The EMF from Al sensor was increased linearly against logarithm of [wt% Al]. The fluorine potential of Zn-Al melt was also calculated to be in the range of $10^{-60}{\sim}10^{-61}$ Pa for the present experiemental condition.

• Journal of the Korean GEO-environmental Society
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• v.18 no.4
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• pp.23-29
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• 2017

As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, Total Organic Carbon (TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the STP (Sewage Treatment Plant). In this study, a electrolysis utilizing the electrochemical reaction was investigated in lab-scale experiments for the treatment of TOC in sewage effluent. TOC reduction by a electrolysis was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of electrode space ($x_1$), current density ($x_2$) and electrolyte concentration ($x_3$) on the dependent variables removal efficiency of TOC (y). The optimal conditions for electrolysis were determined: electrode space, current density and electrolyte concentration were 50 mm, $10.3mA/cm^2$ and 0.1M, respectively. Statistical results showed the order of significance of the independent variables to be electrode space > current density > electrolyte concentration.

• The Korean Journal of Pharmacology
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• v.19 no.2
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• pp.57-67
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• 1983

The influence of electrolyte concentrations on the action of morphine and naloxone was studied in the myenteric plexus-longitudinal muscle preparation of guinea-pig ileum to examine whether opiate receptor binding obseved in vitro with homogenates represents binding to the pharmacological receptor. The preparations were suspended in a modified Krebs-Henseleit bicarbonate buffer solution and electrically stimulated at 0.2 Hz. Morphine inhibited electrically evoked contractions; the concentration of morphine required for a 50-percent inhibition was 190 nM. This inhibitory action of morphine was potentiated in a medium containing lower concentrations of : $Na^+\;or\;K^+$, or by the addition of $Mn^{2+}$ to the medium, and weakened by increasing the concentration of $Ca^{2+}$ or decreasing the concentration of $Mg^{2+}$. Naloxone antagonized these actions of morphine: however, $pA_2values$ for naloxone (indices of affinity for antagonists, approximately 8.8) were unaffected by these electrolyte concentrations. Thus, changes in the inhibitory action of morphine caused by alterations in electrolyte concentrations are probably not the result of changes in the affinity of the receptor for opiates, but due to alterations in the events which precede or follow the receptor binding. Effects of electrolytes on the affinity of the functional opiate receptor for naloxone in guinea-pig ileum are apparently different from those reported with the specific binding sites for opiates in brain homogenate.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.56-61
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• 2015

In this study, the current-voltage curves for the SCM440 steel by the addition of an organic corrosion inhibitor triethanolamine(TEA) was measured using the conventional three electrodes of cyclic voltammetry. As a result, the C-V characteristics of SCM440 steel were to be for an irreversible process due to the oxidation current from the cyclic voltammetry. Diffusion coefficient according to the twice increasing the concentration of TEA in the corrosion inhibitor from $2.5{\times}10^{-4}M$ to $5.0{\times}10^{-4}M$, the diffusion coefficient was found to be a good corrosion-inhibiting effect is reduced by 1.5 times, so for each $2.561{\times}10^{-6}cm^2s^{-1}$ to $1.707{\times}10^{-6}cm^2s^{-1}$. When according to the electrolyte concentration and the effect is to increase the electrolyte concentration to 1.0 N at 0.5 N, the diffusion coefficient is $2.56{\times}10^{-6}cm^2s^{-1}$ to $5.12{\times}10^{-6}cm^2s^{-1}$, each 2 times decrease in the use of the electrolyte of 1.0 N, because this was more appropriate.

• Membrane and Water Treatment
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• v.1 no.1
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• pp.13-37
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• 2010

The performance of an electrodialyzer for concentrating seawater is predicted by means of a computer simulation, which includes the following five steps; Step 1 mass transport; Step 2 current density distribution; Step 3 cell voltage; Step 4 NaCl concentration in a concentrated solution and energy consumption; Step 5 limiting current density. The program is developed on the basis of the following assumption; (1) Solution leakage and electric current leakage in an electrodialyzer are negligible. (2) Direct current electric resistance of a membrane includes the electric resistance of a boundary layer formed on the desalting surface of the membrane due to concentration polarization. (3) Frequency distribution of solution velocity ratio in desalting cells is equated by the normal distribution. (4) Current density i at x distant from the inlets of desalting cells is approximated by the quadratic equation. (5) Voltage difference between the electrodes at the entrance of desalting cells is equal to the value at the exits. (6) Limiting current density of an electrodialyzer is defined as average current density applied to an electrodialyzer when current density reaches the limit of an ion exchange membrane at the outlet of a desalting cell in which linear velocity and electrolyte concentration are the least. (7) Concentrated solutions are extracted from concentrating cells to the outside of the process. The validity of the computer simulation model is demonstrated by comparing the computed results with the performance of electrodialyzers operating in salt-manufacturing plants. The model makes it possible to discuss optimum specifications and operating conditions of a practical-scale electrodialyzer.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.748-753
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• 2007

Serum biochemical values were measured in blood samples collected from 8 fasted stags from both jugular and femoral veins at 18-day intervals during antler growth. Samples were analyzed for blood substrate, enzyme activity values, minerals and electrolyte. There were no significant differences in total protein, albumin, urea, creatinine, triglyceride, glucose or cholesterol concentration between veins or sampling dates. However, total-bilirubin concentration in the jugular vein on the casting date was three times higher than on the other sampling dates (p<0.05). There were no significant differences in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase with progressing antler growth. The highest level of alkaline phosphatase concentration was on day 55 after casting. There were no significant differences in inorganic phosphorus, sodium and chloride concentration between jugular and femoral samples. Calcium concentration was significantly higher in the femoral vein on the cutting date (55 day) than in the jugular vein (p<0.05). There were few changes in serum biochemical values. However, some electrolytes and minerals had differences during antler growth. It is suggested that despite such a big event as antler growth, blood biochemical values are not variable if feeding conditions are consistently maintained as was the case in this study.