• 한국표면공학회지
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• 제11권1호
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• pp.5-13
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• 1978

本 실험에서는 熔融亞鍍金工程에서 다른 諸要因을 一定하게 하고 鋼金溫度와 浸積時間에 따른 亞鉛附着量과 銑損失을 組織학的인 면에서 考察하였다. 銑損失에 要하는 活性化에너지를 구하였으며 試料範위內에서 附着量에 미치는 최적조건을 찾으므로서 不당한 銑損失을 막고 亞鉛原단位를 줄이는데 目的이 있다. 銑損失量과 드로스(Dross)발생량이 상호 密接한 關係에 있으며 도로스 발생량이 감소되면 亞鉛原단位가 감소되었다. 실驗結論은 다음과 같다. 1. 同一時間內에서 詩片-I은 470$^{\circ}$까지 도금층 두께 형성이 온도에 비례하며 浸積時間 8分정도에서 最大값을 나타낸다. 2. 詩片-5는 浸積時間에 比例해서 附着量이 급증함을 나타내었는데 이는 Si의 영향이 지배적이며 그 이외의 試料에서는 20分이후 附着量增加率이 극히 적었다. 浸積時間은 20分이 가장 적당하며 더 이상 오해 浸積시키면, 銑損失量만, 증가할 것이다. 3. 銑損失에 要하는 活性化에너지는 다음과 같으며 이와같은 값은 ${\gamma}$相의 成長에 미치는 活性化에너지 값과 거의 비슷하리라 생각됨. 詩片 - I = 18,500 Cal/mole 詩片 - III = 22,000 Cal/mole 詩片 - V = 42,300 Cal/mole

• 펄프종이기술
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• 제34권1호
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• pp.30-36
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• 2002

The objective of this study was to investigate the viscosity of coating colors and ink-jet printing properties with different coating colors with various blending ratios of silica based pigments. The volume of pigments was measured to evaluate the effect of the pigments on the viscosity of coating colors. Contact angle, the change of ink diameter, optical density, and the area and perimeter of a printed let-ter were evaluated to examine the effect of the ink absorption on the ink-jet printing properties. Generally, as the amount of silica pigments Increased the ink-jet printing quality improved. But this caused an increase of the overall coating viscosity.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.721-726
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• 2003

The Durability of Concrete Structure is serverely degraded due to mainly carbonation, sulfate attack and chloride ion diffusion in concrete. The ultimate purpose of this study is to obtain how much the durability of Concrete Structure is improved according to the variation of physical properties in concrete or the frequency of surface coating on concrete. Where, variation of physical properties is a water-cement ratio or amount of air. The experiments are the chliride ion diffusion test, the lapid corrosion test, the lapid carbonation test, the test on resistance to freezing and thawing. Finally, this study shows that the effect by the surface coating method is better than the variation of physical properties in concrete.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.234-235
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• 2006

In this study, the plasma sprayed $Al_2O_3$ and $Y_2O_3$ coatings have been investigated for applications of microelectronic components. The plasma sprayed coatings had a well-defined splatted lamellae microstructure, intersplat pores and a higher amount of microcracks within the splats. The plasma sprayed $Y_2O_3$ coating had a relatively lower hardness of 300-400Hv, compared to 650-800Hv for $Al_2O_3$ coating, and would be readily damaged by mechanical attacks such as erosion, wear and friction. For a reactive ion etching against F-containing plasmas, however, the $Y_2O_3$ coating had a much higher resistance than the $Al_2O_3$ coating because of the reduced erosion rate of by-products.

• Journal of Pharmaceutical Investigation
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• 제8권1호
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• pp.27-36
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• 1978

Spherical granules of anti-inflammatory enzyme were prepared by mixer granulation and the recovery rate of enzyme activity by processing was compared with tablet ones. In the enteric granule coating .processing, the effect of the amount of coating solution and the conentration of fatty alcohol on disintegration and stabilities on the accelerated conditions were also studied. Being prepared in non-pressure and non-aqueous condition, spherical granules of enzyme made better recovery of enzme activity than tablet ones by 10 times. Combined processing of both mixer granulation and enteric granule film coating provided the noble enteric coated granules, in the sense of disintegration and stabilities, was obtained from using 0.125% fatty alcohol in coating solution.

• 한국가시화정보학회지
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• 제21권3호
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• pp.15-22
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• 2023

This research introduces an innovative approach for fabricating microstructure surfaces using spray-coating deposition. The resulting surface, referred to as Magnetically Responsive Microstructures (MRM), exhibits hierarchically structured micro-pillar arrays with remarkably high aspect ratios. The fabrication process involves precisely mixing PDMS and hexane with Carbonyl iron powders, followed by ultrasonication and spray-coating on the top of a PDMS substrate placed on the neodymium magnet. The MRM surface shows hydrophobic properties, characterized by a contact angle surpassing 150° and an aspect ratio exceeding 10. Through a comprehensive exploration of critical parameters, including spray amount, magnet-substrate distance, and solution ratio enhanced dynamic tunability and exceptional hydrophobic characteristics are attained. This novel approach holds significant potential for diverse applications in the realm of dynamically tunable microstructures and magnetically responsive surfaces.

• 한국분말재료학회지
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• 제22권2호
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• pp.87-92
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• 2015

Metallic porous materials have many interesting combinations of physical and geometrical properties with very low specific weight or high gas permeability. In this study, highly porous Cu foam is successfully fabricated by a slurry coating process. The Cu foam is fabricated specifically by changing the coating amount and the type of polyurethane foam used as a template. The processing parameters and pore characteristics are observed to identify the key parameters of the slurry coating process and the optimized morphological properties of the Cu foam. The pore characteristics of Cu foam are investigated by scanning electron micrographs and micro-CT analyzer, and air permeability of the Cu foam is measured by capillary flow porometer. We confirmed that the characteristics of Cu foam can be easily controlled in the slurry coating process by changing the microstructure, porosity, pore size, strut thickness, and the cell size. It can be considered that the fabricated Cu foams show tremendous promise for industrial application.

• 한국레이저가공학회지
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• 제13권1호
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• pp.11-15
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• 2010

Indium tin oxide (ITO) provides high electrical conductivity and transparency in the visible and near IR (infrared) wavelengths. Thus, it is widely used as a transparent electrode for the fabrication of liquid crystal displays (LCDs) and organic light emitting diode displays (OLRDs), photovoltaic devices, and other optical applications. Lasers have been used for removing coating on polymer substrate for flexible display and electronic industry. In selective removal of ITO layer, laser wavelength, pulse energy, scan speed, and the repetition rate of pulses determine conditions, which are efficient for removal of ITO coating without affecting properties of the polymer substrate. ITO coating removal with a laser is more environmentally friendly than other conventional etching methods. In this paper, pattering of ITO film from polymer substrates is described. The Yb:KGW femtosecond laser processing system with a pulse duration of 250fs, a wavelength of 1030nm and a repetition rate of 100kHz was used for removing ITO coating in air. We can remove the ITO coating using a scanner system with various pulse energies and scan speeds. We observed that the amount of debris is minimal through an optical and a confocal microscope, and femtosecond laser pulses with 1030nm wavelength are effective to remove ITO coating without the polymer substrate ablation.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.397-402
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• 2007

Restenosis after percutaneous coronary intervention (PCI) continues to be a serious problem in clinical cardiology. To solve this problem, drug eluting stents (DES) with antiproliferative agents have been developed. Variable local drug delivery systems in the context of stenting require the development of stent manufacture, drug pharmacology and coating technology. We have worked on a system that integrates electrophoretic deposition (EPD) technology with the polymeric nanoparticles in DES for local drug delivery and a controlled release system. The surface morphology and drug loading amount of DES by EPD have been investigated under different operational conditions, such as operation time, voltage and the composition of media. We prepared poly-D,L-lactide-co-glycolic acid (PLGA) nanoparticles embedded with curcumin, which was done by a modified spontaneous emulsification method and used polyacrylic acid (PAA) as a surfactant because its carboxylic group contribute negative charge to the surface of CPNPs (?53.5 ± 5.8 mV). In the process of ‘trial and error' endeavors, we found that it is easy to control the drug loading amount deposited onto the stent while keeping uniform surface morphology. Accordingly, stent coating by EPD has a wide application to the modification of DES using various kinds of nanoparticles and drugs.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제26회 추계학술대회
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• pp.93-99
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• 1997

High Temperature wear behavior of plasma sprayed ZrO$_2$ and MoS$_2$, $Fe_2O_3$ coatings were investigated for high temperature wear resistance applications. The MoS$_2$, $Fe_2O_3$ added powders containing 2.5, 5.0, 7.5, 10.0 mol% of $MoS_2$, $Fe_2O_3$ for plasma spray were made by spray drying method. Wear test were performed at temperature ranges from room temperature to 600$\circ$C. The microstructural change of coatings and the worn. surface were examined by SEM and XRD. In ZrO$_2$ coating, the coefficient of friction and wear amount of room temperature to 400$\circ$C was increased with temperature and decreased with temperature over 400$\circ$C. The coefficient of friction and wear amount of MoS$_2$ added coatings were increased with temperature, but those of $Fe_2O_3$ added coatings had lower coefficient of friction and higher wear resistance than ZrO$_2$ coating.