• Journal of the Korean Wood Science and Technology
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• v.27 no.4
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• pp.57-64
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• 1999

This research was carried out to investigate the effects of density, resin and particle types on the physical and mechanical properties of the composites made from various wood particles mixed with coating paper. The experiment was designed to apply with three particles (flake, chip, and fiber) and three resin types (urea, phenol and PMDI resin). The mixed ratio of coating paper to wood particle was fixed on 50 to 50% in each board making. And also it was designed to apply for four density levels (0.6, 0.7, 0.8 and 0.9 g/$cm^3$) and four mixed formulations of coating paper to wood particle (10:90, 20:80, 30:70, and 40:60 %) to analyze clearly the effects of PMDI resin. Coating paper-wood particle composites have acceptable bending strength (MOR, MOE) though the mixed ratio of coating paper was increased, but have low internal bond strength and poor dimensional stability (WA, TS, LE). Composites with high density had higher mechanical properties but showed lower physical properties than composites with low density. In conclusion, at least up to 20% mixed ratios, coating paper-wood particle composites have acceptable physical and mechanical properties, and PMDI resin has possibility for coating paper-wood particle composite manufacture.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1061-1065
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• 1999

The effect of particle size of coating powder and coating temperature on the thickness of coating layer formed on metal surface was studied by using XRD, SEM and EDXS. Coating powder was separated according to particle size by 3 steps and coating temperatures were varied from $950^{\circ}C$ to $980^{\circ}C$. Calorizing carried out at air and Ar conditions for 5 hrs, respectively. XRD result show that $Al_2O_3$ and AlN were formed during calorizing at air condition. The thickness and Al content of coating layer increased as the particle size of coating powder decreased and coating temperature increased.

• Corrosion Science and Technology
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• v.14 no.2
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• pp.76-84
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• 2015

The components in ultra super critical (USC) steam turbine, which is under development for high efficient power generation, are encountering harsher solid particle erosion by iron oxide scales than ones in the existing steam turbines. Therefore, the currently used boride coating will not be able to hold effective protection from particle erosion in USC system and should be replaced by new particle erosion resistant coatings. One of the best protective coatings developed for USC steam turbine parts was found to be vanadium-boride (V-boride) coating which has a hardness of about 3000 HV, much higher than that of boride, 1600~2000 HV. In order to evaluate particle erosion resistance of the various coatings such as V-boride, boride and Cr-carbide coatings at high temperature, particle erosion test equipments were designed and manufactured. In addition, erosion particle velocity was simulated using FLUENT software based on semi-implicity method for pressure linked equations revised (SIMPLER). Based on experimental results of this work, the vanadium-boride coating was found to be superior to others and to be a candidate coating to replace the boride coating.

• Journal of Information Processing Systems
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• v.1 no.1 s.1
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• pp.36-40
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• 2005

TRISO (Tri-Isotropic)-coated fuel particle is widely applied due to its higher stability at high temperature and its efficient retention capability for fission products in the HTGR (high temperature gas-cooled reactor), one of the highly efficient Generation IV reactors. The typical ball-type TRISO-coated fuel particle with a diameter of about 1 mm is composed of a nuclear fuel particle as a kernel and of outer coating layers. The coating layers consist of a buffer PyC, inner PyC, SiC, and outer PyC layer. In this study, a digital image processing algorithm is proposed to automatically measure the thickness of the coating layers. An FBP (filtered backprojection) algorithm was applied to reconstruct the CT image using virtual X-ray radiographic images for a simulated TRISO-coated fuel particle. The automatic measurement algorithm was developed to measure the coating thickness for the reconstructed image with noises. The boundary lines were automatically detected, then the coating thickness was circularly by the algorithm. The simulation result showed that the measurement error rate was less than 1.4%.

• Journal of the Korean institute of surface engineering
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• v.35 no.3
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• pp.165-171
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• 2002

TiN coating were deposited onto different WC-Co substrates using arc ion plating (AIP) technique. The structure and morphology for the deposited coating were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The adhesion behavior of the deposited TiN coating was investigated with a conventional scratch test. Effects of WC particle size and Co content on the adhesion strength between the deposited TiN coating and substrate were studied. During the scratch test, the value of critical load was dependent of WC particle size and Co content on substrate. As the WC particle size and Co content on substrate decreased, the critical load increased. The highest critical load, approximately 110N, was obtained at WC particle size of 1$\mu\textrm{m}$ and Co content of 10wt.%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.1
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• pp.49-54
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• 2000

The effect of Particle size of coating Powder and coating temperature on the Properties of coating layer was studied by calorizing(or aluminizing). The surface properties of coating layer were fully characterized, using SEM and EDXS. Coating powders were separated according to the particle size by 3 steps and the coating temperature was varied from $950^{\circ}C$ to $980^{\circ}C$. Calorizing with pack cementation method carried under Ar atmosphere for 5 hrs. Results show that the thickness and Al content of coating layer increased as the size of coating powder decreased and coating temperature increased. And pores formed on the coating layer reduced and homogeneity of coating layer increased with smaller particle size of coating powder.

• Journal of Welding and Joining
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• v.25 no.4
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• pp.42-48
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• 2007

An inert gas atomized NiTiZrSiSn bulk metallic glass feedstock was sprayed onto the copper plate using vacuum plasma spraying process. In order to change the in-flight particle energy, that is, thermal energy, the hydrogen gas flow rate in plasma gas mixture was increased at the constant flow rate of argon gas. Coating and single pass spraying bead were produced with the least feeding rate. Regardless of the plasma gas composition, fully melted through unmelted particle could be observed on the overlay coating. However, the frequency of the unmelted particle number density was increased with the decrease of the hydrogen gas flow rate. The amorphous phase fraction within coating was also affected by the number density of the unmelted particle.

• Journal of Powder Materials
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• v.19 no.5
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• pp.348-355
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• 2012

Cold spray deposition using Titanium powder was carried out to investigate the effects of powder morphology and powder preheating on the coating properties such as porosity and hardness. The in-flight particle velocity of Ti powder in cold spray process was directly measured using the PIV (particle image velocimetry) equipment. Two types of powders (spherical and irregular ones) were used to manufacture cold sprayed coating layer. The results showed that the irregular morphology particle appeared higher in-flight particle velocity than that of the spherical one under the same process condition. The coating layer using irregular morphology powder represented lower porosity level and higher hardness. Two different preheating conditions (no preheating and preheating at $500^{\circ}C$) were used in the process of cold spraying. The porosity decreased and the hardness increased by conducting preheating at $500^{\circ}C$. It was found that the coating properties using different preheating conditions were dependent not on the particle velocity but on the deformation temperature of particle. The deposition mechanism of particles in cold spray process was also discussed based on the experimental results of in flight-particle velocity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.4
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• pp.29-37
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• 2007

The effects of latex particle size, basis weight of base paper and coating color concentration on the printing quality of coated paper were investigated. Coating colors were prepared with five types of latexes having different particle sizes. Coated papers were produced with high solid coating colors and with low solid coating colors in a industrial coater, respectively. In high solid coating colors, rheology modifier was used and GCC content was high. It was concluded that, in order to control binder migration and hence print mottle, latex particle sizes shall be controlled as well as formation, sizing degree and roughness of basis paper.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.53-61
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• 2001

This study was carried out to evaluate the effect of coating pigments on the printability by investigating the pore structure of casting layer such as the number, size and distribution of pores and the pore rate. The coating structure was mainly determined by the interaction between pigment and binder. It means that the structure of pores was chiefly affected by the shape and size distribution of pigments and their packing rate. The physical properties of pore have close relationships with ink set-off, the speed of ink penetration and printing gloss. The results suggested that the rate and number of pores were greatly affected by the particle size distribution and shape of pigments. The rate of pore increased with the reduction of particle size distribution of pigments. Calcite was effective to improve greatly the printability of coated paper.