• Corrosion Science and Technology
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• v.12 no.6
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• pp.295-303
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• 2013

Silane surface treatments have been developed as an alternative for toxic and carcinogenic chromate-based treatments for years. It is consistently observed that ultra-thin films offer excellent corrosion protection as well as paint adhesion to metals. The silane performance is comparable to, or in some cases better than, that of chromate layers. Based on the tetra-ethylorthosilicate(TEOS) and methlyl trieethoxysilane(MTES), inorganic sol was synthesized and formed hybrid networks with $SiO_2$ nano particle and polypropylene glycol(PPG) on Zn alloyed steel surface. According to SST results, addition of 10nm and 50nm $SiO_2$ nanoparticle in synthesized solution improved anti-corrosion property by its shear stress relaxation effect during curing process. Also, SST results were shown that anti-corrosive property was affected by the amounts of organic compounds.

• Korean Journal of Materials Research
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• v.16 no.9
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• pp.571-577
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• 2006

We fabricated thermal evaporated 10 nm-Ni/(poly)Si and 10 nm-Ni/1 nm-Ir/(poly)Si films to investigate the thermal stability of nickel monosilicide at the elevated temperatures by rapid annealing them at the temperatures of $300{\sim}1200^{\circ}C$ for 40 seconds. Silicides for salicide process was formed on top of both the single crystal silicon actives and the polycrystalline silicon gates. A four-point tester is used for sheet resistance. Scanning electron microscope and field ion beam were employed for thickness and microstructure evolution characterization. An x-ray diffractometer and an auger depth profile scope were used for phase and composition analysis, respectively. Nickel silicides with iridium on single crystal silicon actives and polycrystalline silicon gates showed low resistance up to $1200^{\circ}C$ and $800^{\circ}C$, respectively, while the conventional nickel monosilicide showed low resistance below $700^{\circ}C$. The grain boundary diffusion and agglomeration of silicides led to lower the NiSi stable temperature with polycrystalline silicon substrates. Our result implies that our newly proposed Ir added NiSi process may widen the thermal process window for nano CMOS process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.17-18
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• 2008

In this paper, 1%-nitrogen doped Nickel was used for improvement of thermal stability of Ni-Germanide. Proposed Ni-N(1%)/TiN structure has shown better thermal stability, sheet resistance and less agglomeration characteristic than pure Ni/TiN structure. During the germanidation process, it is believed that the nitrogen atoms in the deposited nickel layer can suppress the agglomeration of Ni germanide by retarding the diffusion of Ni atoms toward silicon layer, hence improve the thermal stability of Ni-germanide.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.421-427
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• 2015

In this paper, a description is given of finite element method (FEM) simulations of the elastic bending modulus of multi-layered graphene sheets that were carried out to investigate the mechanical behavior of graphene sheets with different gap thicknesses through molecular mechanics theory. The interaction forces between layers with various gap thicknesses were considered based on the van der Waals interaction. A finite element (FE) model of a multi-layered rectangular graphene sheet was proposed with beam elements representing bonded interactions and spring elements representing non-bonded interactions between layers and between diagonally adjacent atoms. As a result, the average elastic bending modulus was predicted to be 1.13 TPa in the armchair direction and 1.18 TPa in the zigzag direction. The simulation results from this work are comparable to both experimental tests and numerical studies from the literature.

• Advances in nano research
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• v.9 no.4
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• pp.221-235
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• 2020

The following composition establishes a nonlocal strain gradient plate model that is essentially related to mass sensors laying on Winkler-Pasternak medium for the vibrational analysis from graphene sheets. To achieve a seemingly accurate study of graphene sheets, the posited theorem actually accommodates two parameters of scale in relation to the gradient of the strain as well as non-local results. Model graphene sheets are known to have double variant shear deformation plate theory without factors from shear correction. By using the principle of Hamilton, to acquire the governing equations of a non-local strain gradient graphene layer on an elastic substrate, Galerkin's method is therefore used to explicate the equations that govern various partition conditions. The influence of diverse factors like the magnetic field as well as the elastic foundation on graphene sheet's vibration characteristics, the number of nanoparticles, nonlocal parameter, nanoparticle mass as well as the length scale parameter had been evaluated.

• Journal of the Korean Society for Heat Treatment
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• v.19 no.4
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• pp.219-224
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• 2006

Silver paste with low sintered temperature has been developed in order to apply electronic parts, such as bus electrode, address electrode in PDP (Plasma Display Panel) with large screen area. In this study, nano-sized silver particles with 10-30 nm were synthesized from silver nitrate ($AgNO_3$) solution by chemical reduction method and silver paste with low sintered temperature was prepared by mixing silver nanoparticles, conventional silver powder with the particle size 1.6 um and Pb-free frit. Conductive thick film from silver paste was fabricated by screen printing on alumina substrate. After firing at $540^{\circ}C$, the cross section and surface morphology of the thick films were analyzed by FE-SEM. Also, the sheet resistivity of the fired thick films was measured using the four-point technique.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.341-345
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• 2001

In this study, nano-sized powders of $Si0_2-0^{\sim}15mol%B_2O_3$ composition were prepared by sol-gel processing method using TEOS(Tetra ethyl ortho silicate) and $H_3BO_3$ solution. The powders were tape-cast on High silicate glass sheet(HSG) substrate and sintered to form a layer of undercladding for the planar light wave module, During the sol-gel processing, $H_2O/Si$ mole ratio were varied to modify the size of the powders in a range from 600 to 75nm. The dispersion of the powder was modified by changing the pH of the slurry. Sintering temperature of the tape was observed to decrease with the size of the powder and the $B_2O_3$ content in the powder. When the silica powders of 75-125nm in diameter containing 15mol% $B_2O_3$ were used, 98 TD% was obtained at $1250^{\circ}C$, which is approximately $300^{\circ}C$ reduction in sintering temperature compared with micrometer-sized powders.

• Korean Journal of Materials Research
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• v.13 no.9
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• pp.593-597
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• 2003

Anodic aluminum oxide (AAO) membrane was made of aluminum sheet (99.6%, 0.2 mm thickness). The regular array of hexagonal nano pores or channels were prepared by two step anodization process. A detail description of the AAO fabrication is presented. After the 1st anodization in oxalic acid (0.3 M) at 45 V, The formed AAO was removed by etching in a solution of 6 wt% $H_3$$PO_4$＋1.8 wt% $H_2$$CrO_4$. The regular arrangement of the pores was obtained by the 2nd anodization, which was carried out in the same condition as the 1st anodization. Subsequently, the alumina barrier layer at the bottom of the channel layer was removed in phosphoric acid (1M) after removing of aluminum. Pore diameter, density, and thickness could be controlled by the anodization process parameters such as applied voltage, anodizing time, pore widening time, etc. The pore diameter is proportional to the applied voltage and pore widening time. The pore density and thickness can be controlled by anodization temperature and voltage.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.3
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• pp.89-96
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• 2005

To improve the mean-life and reliability of power cables, we have investigated the volume resistivity and thermal properties demonstrated by changing the content of carbon black, an additive of the semiconductive shield for underground power transmission. Nine specimens were made of sheet form for measurement. Volume resistivity of the specimens was measured by a volume resistivity meter after 10 minutes in a preheated oven at temperatures of both 25$\pm$1[$^{\circ}C$] and 90$\pm$ 1[$^{\circ}C$]. As well, specific heat (Cp) and thermal conductivity were measured by Nano Flash Diffusivity and DSC (Differential Scanning Calorimetry). The ranges of measurement temperature were from 0[$^{\circ}C$] to 200[$^{\circ}C$], and heating temperature was 4[$^{\circ}C$/min]. From these experimental results, volume resistivity was high according to an increase of the content of carbon black. Specific heat was decreased, while thermal conductivity was increased according to a rise in the content of carbon black. Furthermore, both specific heat and thermal conductivity were increased by heating temperature because the volume of materials was expanded according to a rise in temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.341-345
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• 2001

In this study, nano-sized powders of SiO$_2$-0∼15mo1%B$_2$O$_3$ composition were prepared by sol-gel processing method using TEOS(Tetra ethyl ortho silicate) and H$_3$BO$_3$ solution. The powders were tape-cast on High silicate glass sheet(HSG) substrate and sintered to form a layer of undercladding for the planar light wave module. During the sol-gel processing, H$_2$O/Si mole ratio were varied to modify the size of the powders in a range from 600 to 75nm. The dispersion of the powder was modified by changing the pH of the slurry. Sintering temperature of the tape was observed to decrease with the size of the powder and the B$_2$O$_3$ content in the powder. When the silica powders of 75∼125nm in diameter containing 15mo1% B$_2$O$_3$ were used, 98 TD% was obtained at 1250$^{\circ}C$, which is approximately 300$^{\circ}C$ reduction in sintering temperature compared with micrometer-sized powders.