• Nuclear Engineering and Technology
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• 제44권7호
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• pp.773-780
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• 2012

The article presented is concerned with an evaluation of the corrosion behavior of SA-508 low alloy steel (LAS) and Type 309L stainless steel (SS) cladding of a reactor pressure vessel under the simulated primary water chemistry of a pressurized water reactor (PWR). The uniform corrosion and galvanic corrosion rates of SA-508 LAS and Type 309L SS were measured in three different control conditions: power operation, shutdown, and power operation followed by shutdown. In all conditions, the dissimilar metal coupling of SA-508 LAS and Type 309L SS exhibited higher corrosion rates than the SA-508 base metal itself due to severe galvanic corrosion near the cladding interface, while the corrosion of Type 309L in the primary water environment was minimal. The galvanic corrosion rate of the SA-508 LAS and Type 309L SS couple measured under the simulated power operation condition was much lower than that measured in the simulated shutdown condition due to the formation of magnetite on the metal surface in a reducing environment. Based on the experimental results, the corrosion rate of SA-508 LAS clad with Type 309L SS was estimated as a function of operating cycle simulated for a typical PWR.

• Corrosion Science and Technology
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• 제16권4호
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• pp.183-186
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• 2017

Galvanic corrosion tests of Zn/steel couples were conducted in 1 M NaCl and $1M\;MgCl_2$ solutions to investigate the impact of magnesium ion on corrosion behavior of the couples. Two types of Zn/steel couples were used for measurements of open circuit potential (OCP) and galvanic current. From the results of OCP transient of Zn/steel couples, the corrosion potential in $1M\;MgCl_2$ was a more positive value than that in 1 M NaCl during the sacrificial dissolution of Zn. However, earlier increase of OCP of the couples in $1M\;MgCl_2$ solution indicates that the sacrificial dissolution rate of Zn in $1M\;MgCl_2$ was enhanced more than that in 1 M NaCl, agreeing with the results on transients of galvanic current. This result is due to that cathodic reaction on the steel surface of the Zn/steel couple was enhanced in $1M\;MgCl_2$ by the occurrence of hydrogen evolution reaction.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.479-482
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• 2005

The galvanic currents between carbon steel and Cr-bearing rebars have been studied in concrete subjected to carbonation and chloride attack. The results revealed that in case of SD345 contacted with Cr-bearing rebar in concrete under chloride attack environment and carbonation environment, the corrosion acceleration by galvanic corrosion is not generated. Therefore, Cr-bearing rebar can be used together with the carbon steel in the new establishment structure.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3227-3231
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• 2014

Bamboo-like Te nanotubes were synthesized via the galvanic displacement reaction of NiFe nanowires with Ni-rich and Fe-rich segments. The thick and thin components of the synthesized Te nanotubes were converted from the Ni-rich and Fe-rich segments in the NiFe nanowires respectively. The dimensions of the Te nanotubes were controlled by employing sacrificial NiFe nanowires with tailored dimensions as the template for the galvanic displacement reaction. The segment lengths of the Te nanotubes were found to be dependent on those of the sacrificial NiFe nanowires. The galvanic displacement reaction was characterized by analyzing the open circuit potential and the corrosion resistance.

• The Korean Journal of Physiology and Pharmacology
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• 제7권5호
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• pp.275-278
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• 2003

Antioxidative activity is an important factor in inhibiting oxidative stress. The usual methods for determining antioxidative activity are time-consuming and cumbersome. They are also indirect processes that use biological material such as brain or liver microsome. This study therefore proposed a new method. Redoxpotential was determined using galvanic cell with or without the addition of various antioxidants or herbal extracts in zinc sulfate solution. The result was compared with the results from the TBA method and the peroxide value from sodium thiosulfate titration. All methods showed significant and dose-dependent enhancement of antioxidative activity by adding ascorbic acid, quercetin, ginseng, or gingko biloba extract. The result of redox potential using galvanic cell showed the smallest standard deviation and took the shortest time among the three methods. Therefore, the antioxidative potential of chemical substances and herbal extracts can be determined simply, directly and accurately in a short period of time using galvanic cell.

• 한국표면공학회지
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• 제21권2호
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• pp.39-46
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• 1988

Corrosion behavior of 5-26wt% Ni-Zn electrodeposited alloys was investigated by means of dipping electrochmical polarization measurement and galvanic coupling test. The weight loss and anodic polarization curve of coatings were measured by means of dipping and polarization measurement respectively. The galvanic protection effect of alloy coatings was measured by galvanic coupling test and the surface morpholgy of coatings was observed after corrosion testing. Our findings support thous of previous investigations showing that ${\gamma}$single phase coatings, while galvanic pprotection effect of dual phase coatings improved in comparison with ${\gamma}$single phase coating. The formation of colony in coating of ${\gamma}$and η+${\gamma}$ dual phsae caused the localized corrsion and increased the corrosion rate of the Ni-Zn coating.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.152-157
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• 2001

This paper was studied on the characteristics of crevice corrosion prevention of SS 400 in marine environment. In NaCl solution, polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 applied cathodic protection and non cathodic protection was measured according to the NaCl concentration. The main results obtained are as follows : The weight loss rate of Al-alloy galvanic anode was increased as the concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, that of Al-alloy galvanic anode become decreased. The protective potential of SS 400 used Al-alloy galvanic anode becomes more cathodic polarization with increasing concentration of NaCl solution. Effects of oxygen on the weight loss rate of Al-alloy sacrificial anode for cathodic protection as the concentration of 3.5% NaCl solution become sensitive than that of 0% NaCl solution.

• 한국멀티미디어학회논문지
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• 제21권12호
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• pp.1379-1386
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• 2018

In this paper, we proposed eyeglass type periorbital wrinkle treatment device for reducing and improving periorbital wrinkles using near infrared LED of 850nm wavelength and galvanic current. The proposed periorbital wrinkle treatment device is equipped with a control system based on F-PCB. It consists of eight near-infrared LEDs and four indicator LEDs for treatment of right and left periorbital wrinkles. The eyeglass frame is coated with conductive material, so galvanic current can flow to the skin of periorbital wrinkle contacted to it. One male adult in the mid-40s was allowed to use the device for 10 minutes every day for 4 weeks. After 4 weeks, image analysis using optical equipment for measuring wrinkles indicated that wrinkle indexes were reduced.

• 콘크리트학회지
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• 제8권2호
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• pp.163-172
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• 1996

• Corrosion Science and Technology
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• 제12권1호
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• pp.40-49
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• 2013

Effects of magnesium and pH on corrosion of aluminum galvanically coupled to iron have studied by using potentio- dynamic and static tests for polarization curves, Mott-Schottky test for analysis of semiconductor property, and GD-AES and XPS for film analysis. Pitting potential was sensitive to magnesium as an alloying element but not to pH, while passive current was sensitive to pH but not to magnesium. It was explained with, instead of point defect model (PDM), surface charge model describing that the ingression of chloride depends on the state of surface charge and passive film at film/solution interface is affected by pH. In addition, galvanic current of aluminum electrically coupled to iron was not affected by magnesium in pH 8.4, 0.2M citrate solution but was increased by magnesium at the solution of pH 9.1. The galvanic current at pH 9.1 increased with time at the initial stage and after the exposure of about 200 minute, decreased and stabilized. The behavior of the galvanic current was related with the concentration of magnesium at the surface. It agreed with the depletion of magnesium at the oxide surface by using glow discharge atomic emission spectroscopy (GD-AES). In addition, pitting potential of pure aluminum was reduced in neutral pH solution where chloride ion maybe are competitively adsorbed on pure aluminum. It was confirmed by the exponential decrease of pitting potential with log of [$Cl^-$] around 0.025 M of [$Cl^-$] and linear decrease of the pitting potential. From the above results, unlike magnesium, alloying elements with higher electron negativity, lowering isoelectric point (ISE), are recommended to be added to improve pitting corrosion resistance of aluminum and its alloys in neutral solutions as well as their galvanic corrosion resistance in weakly basic solutions.