• Journal of the Optical Society of Korea
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• v.10 no.1
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• pp.48-54
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• 2006

White-light scanning interferometry (WLI) and phase shifting interferometry (PSI) are increasingly used for surface topography measurements, particularly for areal measurements. In this paper, we compare surface profiling results obtained from above two optical methods with those obtained from stylus instruments. For moderately rough surfaces ($Ra{\approx}500\;nm$), roughness measurements obtained with WLI and the stylus method seem to provide close agreement on the same roughness samples. For surface roughness measurements in the 50 nm to 300 nm range of Ra, discrepancies between WLI and the stylus method are observed. In some cases the discrepancy is as large as 109% of the value obtained with the stylus method. By contrast, the PSI results are in good agreement with those of the stylus technique.

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.869-872
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• 2009

Double-doped magnetic particles that incorporated magnetites into both the surface and inside the silica cores were fabricated via the sol-gel reaction of citrate-stabilized magnetites with silicon alkoxide. Double-doped magnetic particles were easily fabricated and exhibited an higher magnetism in comparison to the singledoped magnetic particles that were prepared by the erosion of surface-deposited magneties from double-doped magentic particles. Thin gold layer was formed over magnetic silica nanospheres via nanoseed-mediated growth of gold clusters. The plasmon-derived absorption bands of double-doped magnetic silica-gold nanoshells were more broadened and shifted down by ca. 20 nm as compared to those of single-doped magnetic silicagold nanoshells, which were attributed to not only the surface scattering of incident light due to relatively rough surafce morphology, but also heterogeneous permittivity of dielectric cores due to surface-deposited magnetites.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1927-1929
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• 2005

Colloidal Silica(CS)/methyltrimethoxy silane(MTMS) sol solutions were prepared in variation with synthesizing parameters such as kinds of CS, acidity and reaction time. In order to understand its surface properties, sol-gel coating films on glass were fabricated. The coating film obtained from CS/MTMS sol had stable contact angle and more enhanced flat surface at reaction time of 24 hours. In case of the initial and final period of reaction, the coating films had unstable contact angle and more rough surface. In addition, surface of CS/MTMS sol-gel coating film was more rougher with increasing of acidity.

• Journal of the Korean institute of surface engineering
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• v.37 no.6
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• pp.326-334
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• 2004

Deposit charateristics of Electroless nickel(EN) were investigated with various complexing agents. As expected, the deposition rate of nickel is increased with pH and that of Phosphorous is decreased with pH. The result of SEM investigation shows that the rough surface crystallization is appeared with pH. It is show that the surface resistance of EN deposit is decreased with pH at 85$^{\circ}C$.

• Journal of the Korean institute of surface engineering
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• v.22 no.4
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• pp.168-178
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• 1989

The compositions and microstructures of Pb-Sn alloy electrodeposits were investigated in terms of the electrolysis conditions conditions by using fluoborate bath. The Pb content of alloy deposit decreased with increasing dreasing current density until the limting content was obtained. The proferred orientation of Pb-phase in the alloy changed in the sequence of (110)longrightarrow(100)longrightarrow(100)+(110)(311)longrightarrowrandom distribution of crystals with increasing cathode overpotential, while that of $\beta$-Sn phase was (110)(301)(211)n mixed texture. The smooth surface with granular crystallites was obtained below medium current desity, while the rough surface texture was formed at high current density.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.1033-1036
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• 2005

The effect of surface roughness on the contact fatigue was investigated in this study. To accomplish this goal, contact analysis based on the influence functions and the rectangular patch solution was performed to obtain the subsurface stress. Mesoscopic multiaxial fatigue criterion is then applied to predict fatigue damage. Suitable counting method and damage rule were used to evaluate the fatigue life of random loading caused by rough surface. As a result of the analysis, relationship between the life and roughness as well as the creack initiation depth was revealed. Below the critical roughness, It is observed that the fatigue life has hardly changed and creack is initiated around the depth at which the maximum shear stress occurs. Different behavior, however, is observed in case that the roughness is above the critical value.

• Bulletin of the Korean Chemical Society
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• v.22 no.8
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• pp.889-896
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• 2001

The reaction of gas-phase atomic bromine with highly covered chemisorbed hydrogen atoms on a silicon surface is studied by use of the classical trajectory approach. It is found that the major reaction is the formation of HBr(g), and it proceeds th rough two modes, that is, direct Eley-Rideal and hot-atom mechanism. The HBr formation reaction takes place on a picosecond time scale with most of the reaction exothermicity depositing in the product vibration and translation. The adsorption of Br(g) on the surface is the second most efficient reaction pathway. The total reaction cross sections are $2.53{\AA}2$ for the HBr formation and $2.32{\AA}2$ for the adsorption of Br(g) at gas temperature 1500 K and surface temperature 300 K.

• Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.79-87
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• 2015

Surface segmentation and edge feature lines extraction from fractured fragments of relics are essential steps for computer assisted restoration of fragmented relics. As these fragments were heavily eroded, it is a challenging work to segment surface and extract edge feature lines. This paper presents a novel method to segment surface and extract edge feature lines from triangular meshes of irregular fractured fragments. Firstly, a rough surface segmentation is accomplished by using a clustering algorithm based on the vertex normal vector. Secondly, in order to differentiate between original and fracture faces, a novel integral invariant is introduced to compute the surface roughness. Thirdly, an accurate surface segmentation is implemented by merging faces based on face normal vector and roughness. Finally, edge feature lines are extracted based on the surface segmentation. Some experiments are made and analyzed, and the results show that our method can achieve surface segmentation and edge extraction effectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.636-641
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• 2000

The purpose of this study is assessing the characteristics of surface aging and recovery of hydrophobicity for silicone rubber which takes a great interest as outdoor insulation recently subjected to the combined stressed of salt fog and AC power. The methods for assessing are contact angle ATR-FRIR, AFM and XRD. In addition salt fog method is adopted as the artificial contamination experiment and AC power is applied 24 hour on and 24 hour off repeatedly for 5 cycles. The results suggest that degraded surface was more rough than virgin but was restored water repellency through the off cycle. It was due to not only the formation of fractal surface but also maintenance of hydrophobic surface by diffusion of low molecular oil. Although surface recovers initial hydropohbicity there are possibilities of decreasing electrical performance due to irreversable changes such as depolymerization of surface and loss of filler particles. This fact is confirmed by surface conductivity measurement showing that the degradation is significant and the recovery of hydrophobicity is imperfect as the energized cycle increases.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.329-337
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• 2010

Purpose: The surfaces and compositions of rigid gas permeable (RGP) contact lenses were analyzed with the consistent methods, and the basic informations for the composition design of lens materials were suggested. Methods: The bulk structures were analyzed by using Fourier infrared spectroscopy (FTIR), the compositions of surface components were observed by using x-ray photoelectron spectroscopy (XPS), the surface morphology and roughness were observed using atomic force microscopy (AFM), and the wettabilities were estimated by the surface wetting angles. The relations and trends of those results were analyzed. Results: The high oxygen permeability RGP lenses showed the trend that the fluorine decreases and the silicon increases. As the silicon and fluorine contents increased, the carbon and oxygen contents of RGP lens materials decreased at a constant ratio. The decreasing ratio of the carbon contents was three times larger than the decreasing ratio of oxygen contents. The composition of the surface treated lens was far from these tendency line. When the silicon contents increased, the rough surface was formed with the cohered particles. When the fluorine contents increased, the rough surface was formed with the deep flaws. The surface roughness increased and then wettabilities decreased as the silicon and fluorine contents increased. For the surface roughness changes, the increasing ratio of the silicon contents was two times larger than the increasing ratio of fluorine contents. The surface of RGP lens materials appeared the hydrophobic character of which the wettabilities decreased when the roughnesses increased. Conclusions: The surfaces and compositions of RGP contact lenses were measured by the same methods. Those results and relationships were compared and analysed. It is considered that these research results will be applied with the basic data for the composition design of lens materials.