• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.929-933
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• 1999

Under the condition of water electrolysis in aqueous hydrochloric acid as the electrolyte, the lead removal from the lead-loaded activated carbon packed on the anode was investigated. The adequate flow condition is a total flow rate of 10 mL/min in the same flow rate ratio to both electrodes. The increase of current decreases pH values at the anode and the decrease of pH leads to the lead removal. This work shows that the water electrolysis is an efficient method for the lead removal from the lead-loaded activated carbon with a reduction in quantity of the chemical used in comparison with the acid rinse.

• Journal of the Korean Chemical Society
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• v.17 no.5
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• pp.378-384
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• 1973

To investigate the mechanism of the reaction of electrolytic oxidation of iodide to iodate ions, polarization curves are determined in various kinds of solution using electrodeposited lead peroxide and platinum anodes. It was observed from the polarization curves that the limiting current is exists at concentration 1.5 M of potassium iodide, and these limiting current disappeared as potassium hydroxide was added up to concentration of 0.1 M. while in case of platinum anode, limiting current did not appear in dilute potassium iodide solution. These results are owing to the chemical reaction, $PbO_2+2I^{-}+2H^+{\to}PbO+I_2+H_{2}O$ ocurring at the surface of lead peroxide anode. Also, we studied to obtain the optimum conditions of electrolytic preparation of iodate from iodide solution using a cell without the diaphragm. The results are that; (a) addition of potassium dichromate at the anti-reducing agent is proper in concentration of 0.1 g/l, (b) electrolytic temperature is not so much effective in raising the current efficiency, (c) current efficiency is increased with current density, and (d) electrolysis is the most effective in weak alkaline solutions.

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.347-355
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• 2007

The aim of this study was to evaluate the differences of salivary lead (Pb) and cadmium (Cd) concentrations, using ASV analysis, after various pre-treatment procedures. 10 unstimulated whole saliva samples of non-exposed subjects to Pb and Cd were collected. Each sample was divided into 6 aliquots and centrifugation was performed in only 3 aliquots. After centrifugation, 3 different types of pre-treatment procedures were carried out. Also, these pre-treatment procedures were carried out for another 3 aliquots, without centrifugation. Pre-treated aliquots were analyzed electrochemically, by ASV. The results are as follows: 1. Mean concentration of Pb in saliva after centrifugation was significantly higher than that of non-centrifugation. 2. In the detection sensitivity of Pb in saliva, those of simple dilution technique by HCl and acid digestion technique by nitric acid were significantly higher than that of simple dilution technique by electrolyte. 3. Mean concentration of Cd in saliva after centrifugation was significantly higher than that of non-centrifugation. 4. In the detection sensitivity of Cd in saliva, those of simple dilution technique by HCl and acid digestion technique by nitric acid were higher than that of simple dilution technique by electrolyte. But, there were no significant differences between them.

• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.505-509
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• 2012

In this study, we investigate the use of new carbon nanotube paste electrode (CNPE) for promoting the detection of lead (Pb) heavy metal in the a drinkable water, which negatively affects human brain and nerve system. For the evaluations, CNPE is served as a working electrode, while sensitivity and limit of detection (LOD) of Pb are measured in DI and tap water based electrolytes using squarewave anodic stripping voltammetry (SWASV). As a result of that, in the 25~150 ppb range of $Pb^{2+}$ ions, its sensitivity and calculated LOD are $12.85\;{\mu}A/{\mu}M$ and 26 ppb in DI water based 0.1 M $H_{2}SO_{4}$ electrolyte while they are $10.36\;{\mu}A/{\mu}M$ and 38 ppb electrolytes respectively. In addition, experimentally measured LOD values of Pb are 4 ppb and 10 ppb in the two water electrolytes. The stripping of $Pb^{2+}$ ion is also controlled by surface reaction. Our experimental data are then compared with those of other already published references. With the comparison, it is proved that our electrode outperforms other electrodes in terms of the sensitivity and LOD of trace Pb metal.

• Journal of the Korean Electrochemical Society
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• v.13 no.2
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• pp.128-131
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• 2010

Graphite sheet electro-deposited with lead was evaluated as a possible candidate for current collectors of lead acid batteries. Cyclic voltammetry was performed on the materials to evaluate the electrochemical properties. The graphite sheet electro-deposited with lead is electrochemically stable in the cathodic potential sweep. However, in the anodic potential sweep, the graphite sheet electro-deposited with lead is electrochemically unstable due to the oxygen evolution and the intercalation of sulfuric acid. Lead acid batteries were prepared by using a graphite sheet and a cast grid as current collectors for anode and performance test using those batteries was carried out. A lead acid battery with graphite sheets showed higher capacity and energy density than a conventional lead acid battery with cast grid.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.485-490
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• 2009

The inhibitive action of the aqueous extract of lawsonia, licorice root and carob toward the corrosion of tin electrode in 0.1 M $NaHCO_3$ solutions was investigated using galvanostatic polarization measurements. It was found that the corrosion rate decreases in the presence of these extracts indicating the inhibiting of these compounds. The inhibition efficiency increases with increasing extract concentration. The inhibition action of these extracts was explained in view of adsorption of its compounds onto the tin surface, making a barrier to mass and charge transfer. The adsorption of these extracts on the tin surface was found to be a spontaneous process and follow Freundlich adsorption isotherm. It is also found that these extracts provide a good protection to tin against pitting corrosion in chloride containing solution using potentiodynamic anodic polarization technique.

• Electronics and Telecommunications Trends
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• v.26 no.1
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• pp.89-98
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• 2011

OLED 조명은 점이나 선광원 뿐 아니라 넓은 면적의 패널조명도 구현이 가능해 두께 2~3mm의 초슬림 제품도 제작할 수 있고, 눈부심도 거의 없어 은은한 빛이 필요한 실내조명에 적합하다. 그리고 수은 납 등 중금속을 사용하지 않고 친환경 유기소재를 이용한 발광다이오드로 양극구조의 면광원 조명으로 차세대 환경친화적인 조명이며, 에너지 절감효과가 우수한 고효율 특성을 갖고 있어 LED 조명과 함께 기존 조명을 대체할 차세대 광원으로 주목을 받아 왔다. 본 고에서는 OLED 조명의 산업구조와 시장전망 및 국내외 업체들의 개발현황을 분석하고자 한다.

• Journal of the Korean Chemical Society
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• v.15 no.5
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• pp.223-228
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• 1971

In the electrolytic preparation of persulphate from sulphate solution, the current efficiency decrease with temperature increase at the platinum anode. But in case of electrodeposited lead peroxide anode, the current efficiency increase with temperature of the solution. The reason seems to be that the ozone formation is faster in platinum anode than in lead peroxide as temperature increase.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.9-16
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• 2003

A new method has been proposed and developed that solves the problem of decreasing electroosmotic flow rate by excess $H^{+}$ and precipitation of heavy metal by $OH^{-}$. An electrolytic solution was circulated between the anode and cathode compartments that enabled the pH at the anode and cathode to be controlled. The change of the soil pH by circulation systems affects the operation time, by lowering the rate of increase of the electric potential gradient, and the removal efficiency of heavy metals, by affecting the soil pH. Since there was no effluent from the cathode compartment in circulation system, there was no need to treat the wastewater after the experiment, which resulted in the reduction of influent electrolyte volume.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.277-283
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• 2015

MS(Mild Steel), HTS(High Tensile Steel), HYS(High Yield Steel), AL(Aluminum Alloy) and Composite Materials are used for vessels. Steel Materials are mostly used for vessels because body of a ship have to perform the basic functions such as watertight, preserving the strength and supporting the equipments. The vessels primarily carry out a mission at ocean, so that body of a ship is necessarily rusted. There are several methods to protect the corrosion of vessels such as painting, SACP(sacrificial anode cathodic protection) and ICCP(impressed current cathodic protection). For the sacrificial anode cathodic protection, Al and Zn alloys are normally used. Heavy metals are added to the Al and Zn Alloys for improving the corrosion properties but they are so harmful to the human and environment. Therefore, the use of these heavy metals is strictly regulated in the world. In this paper, Al and Zn Alloys are made by adding the trace elements(Ma, Ca, Ce and Sn) which is not harmful to the human and environment. SEM, XRD, Potentiodynamic Polarization test and Current Efficiency test are conducted for evaluation of Al and Zn Alloys. As a result of the experiment, Al-3Zn-0.6Sn and Zn-3Sn Alloys are more efficient than other Alloys.