• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.58-66
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• 2021

Spiral-wound woven wire meshes packed bed rotating cylinder electrode was used for the simultaneous removal of cadmium (Cd) and copper (Cu) from a binary solution. The effects of weight percent of each metal on the removal and current efficiencies were studied at an operating current of 345A, while the effect of current on the removal efficiency of both metals was investigated at three levels of current (240, 345.and 400 mA). The experiments were carried out at constant rotation speed 800 rpm, pH = 3, and a total concentration of metals (500 ppm). The results showed that the removal efficiency of copper increased from 89% to 99.4% as its weight percent increased from 20% to100%. In a similar fashion, the removal efficiency of cadmium increased from 81% to 97% as its weight percent increased from 20% to100%. The results confirmed that the removal efficiency of any metals declined in the presence of the other. Increasing of current resulted in increasing the removal efficiency of both metals at different weight percents. The results confirmed that current efficiencies for removing of copper and cadmium simultaneously decline with increasing of electrolysis time and weight percent of cadmium or with decreasing the weight percent of copper. Current efficiency was higher at the initial stage of electrolysis for all weight percents of metals. The results showed that the decay of copper concentration was exponential at all weight percents of copper, confirming that the electrodeposition of copper is under mass transfer control in the presence of cadmium. While the decay of cadmium concentration was linear at lower weight percent of cadmium then changed to an exponential behavior at high weight percent of cadmium in the presence of copper.

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.352-356
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• 2006

In this paper, we developed enzyme electrode of a new form to improve performance of disposable glucose sensor. We could fabricate electrode of Cu/Ni/Au structure which has very low electrical resistance (0.1 $\Omega$) by sticking copper film to plastic film with laminating method and electro-plated nickle and gold on it. The enzyme electrode was completed by immobilizing enzyme on the fabricated electrode. The fabricated glucose sensor has very quick sensing time as 3 seconds, and excellent reproducibility, fabrication yield as well.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.620-625
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• 2011

A simple, rapid potentiometric back titration of Isoniazid (INH) in the presence of Rifampicin (RIF) in tablets and syrups is described. The method is based on the oxidation of INH by a known excess of copper (II) ion and the back titration of unreacted copper (II) ion potentiometrically with ascorbic acid using a lab-made Copper Based Mercury Film Electrode (CBMFE). The titration conditions have been optimized for the determination of 1.0-10.0 mg of INH in pure and dosage forms. The precision and accuracy of the method have been assessed by the application of lack-of-fit test and other statistical methods. Interference was not caused by RIF and other excipients present in dosage forms. Application of the method for INH assay in tablets and syrups was validated by comparison of the results of proposed method with that of the British Pharmacopoeia (BP) method using F- and t- statistical tests of significance.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.5
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• pp.53-59
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• 1997

This study has been performed to inmvestigate MRR(metal removal rate), REW(relative electrode wear), surface roughness, heat transumutation layer and microhardness distribution in cross-section of the machined surface with various pulse-on duration and peak pulse current, using the copper and graphite electrode on the heat treated STD11 which is extensively used for metallic molding steel with the EDM. The results obtained are as follows; a) There exists critical pulse-on duration(If Ip equals 5A, .tau. on is 50 .mu. s) which shows the the maximum MRR in accordance with peak oulse current and the MRR decreases when the pulse-on duration exceeds the critical pulse-on during because of the abnormal electric discharge. b) Safe discharge is needed to make maximum of MRR and the metalic organization must be complicated for discharge induction. c) Graphite has much more benefits than copper electrode when rapid machining is done without electrode wear. d) The most external surface has the highest microhardness because of car- burizing from heat analysis of the dielectric fluid and the lower layar of the white covered layer has lower microhar dness than base matal because of softening.

• 한국전기화학회:학술대회논문집
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• 2001.04a
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• pp.3-4
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• 2001

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.293-296
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• 2008

In this paper, we carried out an comparative analysis on ground impedance of single copper-, three linked copper- and single carbon- electrodes by the application of various current sources such as sine, square, and surge with fast risetime. Impedance of single-copper electrode was the highest among them and was affected as the amplitude and the frequency of applied current. However, impedance characteristics of the three linked copper- and the single carbon- electrodes showed a similar tendency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.11
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• pp.721-726
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• 2015

In this study, the properties of C-V degradation for thermal conductivity silicone rubber sample which is attached by copper-copper, copper-aluminum, aluminum-aluminum on upper-side and under-side has been measured at temperature of $80^{\circ}C{\sim}140^{\circ}C$. The results of this study are as follows. In case the frequency is increased, it found that the electrostatic capacity increased with increasing temperature to $80^{\circ}C$, $110^{\circ}C$, $140^{\circ}C$ regardless of kind of electrode. It found that the electrostatic capacity increased with becoming high temperature range of frequency regardless of kind of electrode. This result is considered to be caused by thermal absorption on the thermal conductivity silicone rubber sample. It found that the electrostatic capacity decreased with increasing temperature and frequency. This result is considered to be caused by molecular motion of C-F radical or OH radical.

• Journal of Integrative Natural Science
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• v.7 no.2
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• pp.120-123
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• 2014

When a hydrophobic and hydrophilic environments of bis(2,2'-bipyridyl) copper(II) ($Cu(bpy)_2{^{2+}}$) are produced in the presence of anionic surfactant sodium dodecyl sulfate (SDS), cyclic voltammetry is used to investigate the microscopic environments which occurs at the glassy carbon electrode. In order to see the relation between ${\Delta}E_p$ and a critical micelle concentration (CMC), ${\Delta}E_p$ vs. -Log[SDS] for the redox couples are plotted. The concentration at the intersection of two lines is 2.57 mM SDS, and this concentration can be determined as the CMC (relative error: below 0.03%; 2.63 mM SDS by surface tensiometry).

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.568-574
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• 1997

The effect of microencapsulation of maetal hydride (MH) with copper on the electrode performance of a Ni/MH battery has been investigated. The MH electrodes were prepared with a combination of cold press and paste methods. The discharge capacity of the electrode increased with an addition of small amounts if CMC into the electrode, but decreased when heat-treated in an oxygen-free nitrogen flow. The capacity of a Cu-coated $LaNi_5$ electrode was higher than that of LaNi5electrode. The discharge capacity of the electrode prepared with Cu-coated $LaNi_5$ increased with the increase of copper content in the electrode. It is considered that the increase of copper content enhanced the current density on the electrode surface, leading to the increase of the discharge capacity The MH electrode coated by an acidic electroless plating method showed much higher discharge capacity than that using an alkaline electroless plating method. The discharge capacity of the $LaNi_{4.5}Al_{0.5}$ electrode was higher than that of the $LaNi_5$ electrode. Also, the effect of microencapsulation on the deactivation of $LaNi_5$ was studied using an absorption-desorption cycle in CO-containing hydrogen.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.43-46
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• 2003

To develop bevel gear dies that have characteristics of high precision and enough life time, the technology of die manufacturing and design which increase the resistance of wear and fatigue is essentially needed. Here in the study, we have investigated several materials for dies and electrode. And, the most economical and suitable electrode material has been selected through the characteristic analysis of electrode materials such as copper, graphite and chromium copper. With the help of CAD/CAM/CAE, the total manufacturing system of high precision electrode for bevel gear has been established.