• Journal of the Korean institute of surface engineering
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• v.29 no.4
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• pp.253-260
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• 1996

Regular spangle hot dip galvanized steel sheets were made in the zinc bath containing a small amount of Al and with the addition of Pb, Sb, Sb-Mg, Sb-Cu and Bi respectively whose average glosses were measured. Zero-spangle hot dip galvanized steel sheets were also made by spraying a 2% $NH_4H_2PO_4$ solution on molten coating surfaces with exactly the same chemical compositions as above used for regular spangle and whose glosses and corrosion losses were also evaluated. For manufacturing zero- spangle hot dip galvanized steel sheets with high brightness, the zinc bath with 0.02%Sb and the spraying of a 2% $NH_4H_2PO_4$ solution were proposed and for better brightness and corrosion resistance, the zinc bath with 0.02% Sb-0.50%Mg and the spraying of a 2% $NH_4H_2PO_4$ solution were also proposed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1477-1478
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• 2011

Solution processed zinc tin oxide (ZTO) thin films were studied using a spin coating for the fabrication of thin film transistors and simple circuits. The solution processed thin film transistors (W/L = 100/10 ${\mu}m$) have the average saturation mobility of 1.9 $cm^2$/Vs, threshold voltage of 20 V, and subthreshold slope of 0.5 V/decade. The dc characteristics of an inverter with $W_{load}=100\;{\mu}m$ and $W_{drive}=10\;{\mu}m$, measured under votage supply of $V_{DD}$ = +50 V. The inverter beta ratio is 20 ($R=(W_{drived}/L_{drive})/(W_{load}/L_{load})=20$) and $gain_{max}$ is 2. The characteristics of an oscillator were measured under voltage supply of $V_{DD}$ = +60 V.

• Corrosion Science and Technology
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• v.3 no.3
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• pp.107-111
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• 2004

Corrosion resistance of coating system consisting of zinc-rich primer (ZRP) and topcoat based on polyurethane resin with the presence of 3-aminopropyl-triethoxysilan (APS) and 2-(benzothialylthio) succinic acid (BSA) was studied by electrochemical impedance and wet adhesion. The interface metal/primer/topcoat was analyzed by scanning electronic microscopy. It was found that the presence of APS and BSA improved adhesion and barrier property of the topcoats.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.346.2-346.2
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• 2014

To use the GaN based light-emitting diodes (LEDs) as solid state lighting sources, the improvement of light extraction and internal quantum efficiency is essential factors for high brightness LEDs. In this study, we suggested the new materials system of a zinc tin oxide (ZTO) layer formed on blue LED epi-structures to improve the light extraction. ZTO is a representative n-type oxide material consisted of ZnO and SnO system. Moreover, ZTO is one of the promising oxide semiconductor material. Even though ZTO has higher chemical stability than IGZO owing to its SnO2 content this has high mobility and high reliability. After formation of ZTO layer on p-GaN layer by using the spin coating method, structural and optical properties are investigated. The x-ray diffraction (XRD) measurement results show the successful formation of ZTO. The photoluminescence (PL) and absorption spectrum shows that it has 3.6-4.1eV band gap. Finally, the light extraction properties of ZTO/LED chip using electroluminescence (EL) measurement were investigated. The experimental and theoretical analyses were simultaneously conducted.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.386-386
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• 2011

sol-gel 및 hydrothermal growth method를 이용한 zinc oxide nanorod는 제작 시 고가의 장비가 필요치 않기에 저비용 대면적 박막을 제작하는데 적합하지만 rod들의 array 및 density 조절에서 어려움을 가지고 있다. 본 연구에서는 이러한 nanorod array 형상 조절을 위하여 zinc oxide seed layer 형성 과정 중 precursor solution에 이종 나노 입자를 첨가하였다. 첨가한 seed precursor solution을 spin coating한 이후에 후처리 하여 hydrothermal method를 이용해 성장시켰다. 합성한 rod들을 optic과 FE-SEM으로 측정해 rod들의 density 변화를 확인할 수 있었다.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.1
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• pp.88-93
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• 2004

Electrochemical impedance spectroscopy was used to evaluate the anticorrosive properties of resin(alkyd, epoxy, urethane) and pigment(hydroxy apatite(HAp), zinc potassium chromate(ZPC). red lead(RL)). The corrosion behavior of coatings applied on steel has been investigated during exposure to 0.5M-NaCl The anticorrosive performances of resins were found to depend on their chemical nature and decreased in the order of urethane > epoxy > alkyd resin coating. Hydroxy apatite and zinc potassium chromate pigment which have property to passivate the substrate showed relatively high anticorrosive performance.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.345-351
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• 2007

The research which it sees will confront to the coating with paint material and a coating with paint public law application of the river bridge and it will present it will sleep and it will execute, it will reach and a comparison - an analysis from the research which it tries to respect middle of special environment the polyurethane system which is a method coating with paint system and fluorine resin system, against a ceramic system it executed more an objectivity and rational fundamental data. With research method against each coating with paint evening sunlight a research investigation material and structure, it separated with spatial-temporal characteristic and economic viewpoint it executed. When considering overview from material viewpoint, fluorine resin system ceramic system polyurethane system pure with it is judged with the fact that it is excellent. There is a possibility of saying that the coefficient of friction of the fluorine resin system which uses the weapon quality zinc end coating compound ever so hard and polyurethane system is excellent ceramic system than from structure viewpoint. That fluorine resin system = polyurethane system ceramic system pure with it is excellent, it is judged from spatial-temporal characteristic viewpoint. It measures but it considered an internal troubles year grudge in the standard which becomes disturbance the place where it executes the market the expectation life person of the general bridge against 100 years the result fluorine resin system polyurethane system ceramic system which compares a materials unit cost pure with it appeared.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.37-37
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• 2012

The coated steels, mainly with zinc by either hot-dip galvanizing or electroplating, are widely used for panels of automotive, electrical appliances and construction, whose size of world market have reached 130 million tons in 2008. Current issues for the coated steels can be integrated in terms of high functionality, low cost, environment-friend and available resource. The best solution can be provided if thin layer coating with higher quality is produced by an eco-friendly process, and PVD, physical vapor deposition, can be an alternative practice to existing coating processes. PVD technologies have been very common ones in electronic and semiconductor industries, but recognized as non-profitable processes for the coated steels due to low process speed and lack of continuous operation skills. Systematic researches from 1990s in Europe, even though discouraged by a shutdown of the first Japanese PVD coating plant in 1999, have realized several continuous PVD coating plants, and also enhanced launching of developments in steel industries. To be successful with PVD coating technologies over existing ones, productivity to meet economics should be created from a highly sophisticated process. Some PVD technologies fit for the high-speed process will be introduced together with experiences from industrial applications.

• Journal of the Korean Society for Heat Treatment
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• v.19 no.4
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• pp.200-207
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• 2006

In addition to the basic properties of the base and top coating agents, corrosion resistance of non-chrome magni 565 coating and characteristics of coating film when coated to steel substrate were studied. The system had a good wettability at room temperature. Moreover, both the contact angle and surface tension were affected little by the viscosity of coating agent and surface roughness of the steel substrate. And the samples coated with optimal conditions showed a great corrosion resistance in salt spray test with 1500 hours or longer of initial appearance time of rust. The coating film was composed of overlapping layer of zinc and aluminium flakes, and the thickness of base coat increased with an increase of base coat viscosity. Based on the C-F peaks of 1,1-Difluoroethaen homo-polymer, it was thought that the base coat was an inorganic polymer bond layer. Meanwhile, the top coat showed C-F peaks of polytetrafluoroethylene with C-H peaks of phenol in FT-IR analysis. From the lower weight loss of base coat in TG analysis, it was thought that cross linking density of base coat was larger than that of top coat. It was thought that the small exothermic reactions observed in DSC curves were due to the thermosetting resins contained in the coating agents. Compared to the non-coated specimen, the coated sample showed more higher polarization resistance and corrosion potential with lower corrosion current density.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.13-16
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• 2005

Generally, as corrosive protection processing of a steel structure, zinc galvanizing and heavy duty coating paint are applied. However, zinc galvanizing has the difficulty of restriction of a size, or on-site construction. Moreover, heavy duty coating paint has a problem with many administrative and maintenance expenses with short problem of adhesion, corrosion generating of a damage portion, and maintenance management cycle. In this study, a salt water spray test, CASS test, and the electrochemistry examination were carried out for the thermal metal spray method of construction for corrosive protection performance evaluation. Moreover, the corrosive protection life of a thermal metal spray method of construction was quantitatively calculated on the basis of this experiment. in consideration of LCC, the economical efficiency of a general corrosive protection method of construction and a thermal metal corrosive protection method of construction was compared. Consequently, although initial construction expense was estimated 16 to $30\%$ high, as for a thermal metal spray method of construction, it turns out that the administrative and maintenance expenses for 100 years became cheap 9.3 to 13 or more times.