• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.54-54
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• 2009

AFM anodic oxidation has the capability of patterning complex nano-patterns under relatively high speeds and low voltage. We report the fabrication using a atomic force microscopy (AFM) of silicon nano-ribbon and nano-field effect transistors (FETs). The fabricated nano-patterns have great potential characteristics in various fields due to their interesting electronic, optical and other profiles. The results shows that oxide width and the separation between the oxide patterns can be optimally controlled. The subsequently fabricated silicon nano-ribbon and nano-FET working devices were controled by various tip-sample bias-voltages and scan speed of AFM anodic oxidation. The results may be applied for highly integration circuits and sensitive optical sensor applications.

• Journal of Welding and Joining
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• v.18 no.3
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• pp.97-105
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• 2000

The stress corrosion cracking(SCC) and hydrogen embrittlement cracking(HEC) characteristics of a weathering steel weldment were investigated in aerated acid-chloride solution. The electrochemical properties of weldment were investigated by polarization test and galvanic corrosion test. Weathering steel did not show passive behavior in the acid-chloride solution. Galvanic corrosion between the weld metal and the base metal was not observed because the base metal was anodic to the weld metal. The slow-strain-rate tests(SSRT0 were conducted at a constant strain rate o 7.87×{TEX}$10^{-7}${/TEX}/s at corrosion potential, and at potentiostatically controlled anodic and cathodic potentials. The weldment of weathering steel was susceptible to both anodic dissolution SCC and hydrogen evolution HEC.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.188-191
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• 2003

In this wort. the effect of anodic oxidation on surface characteristics of high strength PAN-based carbon fibers is investigated in terms of surface and mechanical interfacial properties of the composites. As a result, the acidity of carbon fiber surfaces is increased, due to the development of oxygen functional groups in the presence of anodic oxidation. Also. it is found that the critical stress intensity factor ($K_{IC}$) is improved in the oxidized fibers-reinforced composites. which can be attributed to the good wettability between fibers and epoxy resin matrix.

• Journal of Information Display
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• v.8 no.4
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• pp.19-22
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• 2007

A new front plate structure of ac-PDP using fence-type aluminum electrode coated with anodic aluminum oxide was investigated. In this structure, ITO and glass dielectric layer were eliminated and expensive Ag BUS electrode was replaced with aluminum. Test panels were prepared using the new structure and their luminance and discharge characteristics were examined. These results indicate that the new structure provide a new way of cost reduction and enhancement of performance of ac-PDPs

• Journal of the Korean institute of surface engineering
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• v.43 no.5
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• pp.248-254
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• 2010

Porous $Al_2O_3$ film can be utilized as template for fabrication of nano-structured materials. Porous anodic alumina layer as template was prepared by anodization of aluminum in oxalic acid, and the pore diameter and barrier-type alumina layer can be controlled for proper anodizing parameter by widening process in $H_3PO_4$ solution. The $SiO_2$ nanodot and Ni nanowire was fabricated using anodic alumina template and their characteristics were investigated using SEM and TEM with EDS. Especially the growth mechanism of $SiO_2$ nanodot in alumina membrane compared with thinning of the alumina barrier layer during anodization was also investigated.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.127-130
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• 2007

A new front plate structure of ac-PDP was explored using fence-type aluminum electrode coated with anodic aluminum oxide.[1] In this structure, ITO and glass dielectric layer were eliminated and expensive Ag BUS electrode was replaced with aluminum. Test panels were prepared using the new structure and their luminance and discharge characteristics were examined. These results indicate that the new structure provide a new way of cost reduction and enhancement of performance of ac-PDPs

• Carbon letters
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• v.4 no.1
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• pp.21-23
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• 2003

In this work, the effect of anodic oxidation treatment on Cr(VI) ion adsorption behaviors of activated carbon fibers (ACFs) was investigated. The aqueous solutions of 10 wt% $H_3PO_4$ and $NH_4OH$ were used for acidic and basic electrolytes, respectively. Surface characteristics and textural properties of ACFs were determined by XPS and $N_2$ adsorption at 77 K. The heavy metal adsorption of ACFs was conducted by ICP. As a result, the adsorption amount of the anodized ACFs was improved in order of B-ACFs > A-ACFs > pristine-ACFs. In case of the anodized treated ACFs, the specific surface area was decreased due to the pore blocking or pore destroying by acidic electrolyte. However, the anodic oxidation led to an increase of the Cr(VI) adsorption, which can be attributed to an increase of oxygen-containing functional groups, such as, carboxylic, lactonic, and phenolic groups. It was clearly found that the Cr(VI) adsorption was largely influenced by the surface functional groups, in spite of the reduced specific surface area of the ACFs.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.3
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• pp.343-355
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• 2006

Statement of problem. The success of osseointegration can be enhanced with an implant that has improved surface characteristics. Anodic oxidation is one of the surface modifying method to achieve osseointegration. Voltage of anodic oxidation can change surface characteristics and cell activity Purpose. This study was performed to evaluate MG63 cell responses such as affinity, proliferation and to compare surface characteristics of anodic oxidized titanium in various voltage. Material and method. The disks for cell culture were fabricated from grade 3 commercially pure titanium,1 m in thickness and 12 mm in diameter. Surfaces of 4 different roughness were prepared. Group 1 had a machined surface, used as control. Group 2 was anodized under 220 V, group 3 was anodized under 300 V and group 4 was anodized under 320 V. The microtopography of specimens was observed by scanning electron microscope (JSM-840A, JEOL, Japan) and atomic force microscope(Autoprobe CP, Park Scientific Instrument, USA). The surface roughness was measured by confocal laser scanning microscope(Pascal, LSM5, Zeiss, Germany). The crystal structure of the titanium surface was analyzed with x-ray diffractometer(D8 advanced, Broker, Germany). MG63 osteoblast-like cells were cultured on these specimens. The cell morpholgy was observed by field emission electron microscope(Hitachi S-4700, Japan). The cell metabolic and proliferative activity was evaluated by MTT assay Results and conclusion. With in limitations of this in vitro study, the following conclusions were drawn. 1. In anodizing titanium surface, we could see pores which did not show in control group. In higher anodizing voltage, pore size was increased. 2. In anodizing titanium surface, we could see anatase. In higher anodizing voltage, thicker oxide layer increased crystallinity(anatase, anatase and rutile mixed). 3. MG63 cells showed more irregular, polarized and polygonal shape and developed more lamellipodi in anodizing group as voltage increased. 4. The activity of cells in MTT assay increased significantly in group 3 and 4 in comparison with group 1 and 2. However, there was no difference between group 3 and 4 at P<0.05. Proliferation of MG63 cells increased significantly in pore size($3-5.5{\mu}m$) of group 3 and 4 in comparison with in pore size($0.2-1{\mu}m$ ) of group 2.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.5
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• pp.702-711
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• 1998

The characteristics of corrosion resistance for the surface of medium high carbon steels and low alloy steels utilizing as manufacturing the machinery structures and machining tools and treating by plasma/ion nitriding process have been studied in terms of electrochemical polarization behav-iors including corrosion potential(Ecorr) anodic polarization trends and polarization resistance(Rp) The seven base materials showed a clear passivation behavior for the polarization tests in the ASTM standard solution 1N ${H_2){SO_4}$ Although the treated surface by plasma nitriding for the seven test materials showed a significant increase in hardness the treatment gave a detri-mental effect in corrosion resistance. The various characteristics including corrosion potential polarization curves microstructures corrosion current polarization resistance among non-treat-ed nitriding and/or soft-nitriding treated specimens have been investigated and some of the mechanisms discussed.

• Nuclear Engineering and Technology
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• v.5 no.1
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• pp.30-37
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• 1973

The Nishitani's equations for impedance of anodic oxide films have been derived based on a p-i-n model under the assumption of $\omega$$\varepsilon$$\rho$$_{ο}$<<4$\pi$<<$\omega$$\varepsilon$$\rho$$_{\omega}$, where $\omega$ is angular frequency, $\varepsilon$ is dielectric constant, and $\rho$$_{ο}$ and $\rho$$_{\omega}$ are the resistivity of the interface region and the intrisic region of the anodic oxide film, respectively. Since it is not possible to evaluate all parameters in the equations, however, any clear physical picture cannot be obtained from the equations. Therefore, the equations are modified under the assumption of $\omega$$\tau$$_{\omega}$>>1 and In(1+$\omega$$^2$$\tau$$_{ο}$$^2$)<<1, where $\tau$$_{\omega}$=$\varepsilon$$\rho$$_{\omega}$(4$\pi$) and $\tau$$_{ο}$=$\varepsilon$$\rho$$_{ο}$/(4$\pi$). The modified equations are then used to explain the change in the frequency characteristics of anodic oxide films when they are heated. The change in impedance of anodic oxide films when they are heated is attributed mainly to the increase in the diffusion layer and to the decrease in the resistivity of anodic oxide films.s.