• Transactions of the Society of Information Storage Systems
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• v.4 no.1
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• pp.13-18
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• 2008

Scratches are observed on a polymer cover-layer of near-field recording (NFR) media after a servo test with rotating disc. The scratches are formed by the collision of a solid immersion lens (SIL)-media. One of the possible ways to avoid the scratch problem is to coat a dielectric protective film on the polymer cover-layer which enhances the hardness of the surface. The surface with hard characteristics in the surface reduces the scratch problem in the cover-layer. Not only the mechanical properties but also the optical properties should be controlled. Specifically, the refractive index of the dielectric protective film should be matched with the polymer cover-layer not to lose light at the interface due to the difference of the refractive index. The refractive index of the dielectric film can be tailored by controlling process parameters during sputtering and matched with that of the polymer cover-layer.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.27-28
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• 2013

This study investigates the effect of a protective layer on the level of carbonation resistance of concrete. For the protective layer, a PE film, bubble sheets, double layered bubble sheets and styroform were placed in a mold before placing the concrete. In addition, PE film was retrofitted by attaching on the surface of the substrate concrete with a glue. Results showed that the carbonation depths of the control concrete were 4.6 mm and 5.2 mm at one week and two weeks exposure in an accelerated carbonation chamber, whereas the concrete with all types of protective layer except PE flim did not allow the ingress of carbon dioxide during the same period.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.3
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• pp.180-184
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• 2015

Stainless steel (SS) mesh was used to fabricate photoelectrode for flexible dye-seisitzed solar cells (DSSCs) in order to evaluate them as replacements for more expensive transparent conductive oxide(TCO). We fabricated the DSSCs with new type of photoelectrode, which consisted of flexible SS mesh coated with 100 nm thickness titanium (Ti) protective layer deposited using electron-beam deposition system. SS mesh DSSCs with protective layer showed higher efficiency than those without a protective layer. The best cell property in the present study showed the open circuit voltage (Voc) of 0.608 V, short-circuit current density (Jsc) of $5.73mA\;cm^{-2}$, fill factor (FF) of 65.13%, and efficiency (${\eta}$) of 2.44%. Compared with SS mesh based on DSSCs (1.66%), solar conversion of SS mesh based on DSSCs with protective layer improved about 47%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.141-145
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• 2007

The part in the structure that is most affected by changes of external temperature is the protective concrete layer that protects a waterproofing layer. Also, the waterproofing layer that is situated under or on the back of such a protective concrete layer is affected by temperature and the behavior of the protective concrete layer under the condition of consolidation or close adhesion. In particular, in many cases, the damage is serious mainly around the projection (such as a parapet), crack, and joint (expansion joint). However, there is no proper way of examining again the non-exposed waterproofing layer once it has been constructed. Therefore, there is an assessment only on the physical property of materials and the capability of the layer in construction, and there is no actual assessment in consideration of its environmental condition or the condition of the use of buildings after construction. Therefore, in order to create more pleasant buildings and to enhance the durability of structures, this study conducts research into the change of capability of non-exposed waterproofing material after the application of a static load and moving load on the waterproofing layer situated under or on the back of protective concrete.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.760-765
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• 2009

The effects of $Fe_2O_3$ addition on optical and electrical properties of MgO films as a protective layer for AC plasma display panels were investigated. Doped MgO films prepared by the e-beam evaporation have a higher ${\gamma}$ (secondary electron emission coefficient) than pure MgO protective layer. Roughness increased with amount of $Fe_2O_3$ up to 100 ppm and then decreased further addition. These results showed that discharge properties and optical properties of MgO protective layers seemed to be closely related with microstructure factors such as roughness. Good optical and electrical properties of ${\gamma}$ of 0.120, surface roughness of 14.1 nm and optical transmittance of 94.55% were obtained for the MgO + 100 ppm $Fe_2O_3$ protective layer sintered at $1700^{\circ}C$ for 5 hrs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.7
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• pp.620-625
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• 2007

The effects of $Gd_2O_3$ addition and sintering condition on optical and electrical properties of MgO films as a protective layer for AC plasma display panels were investigated. Doped MgO films prepared by the e-beam evaporation have a higher ${\Upsilon}$ (secondary electron emission coefficient) than pure MgO protective layer. Relative density and grain size increased with amount of $Gd_2O_3$ up to 100 ppm and then decreased further addition. These results showed that discharge properties and optical properties of MgO protective layers seemed to be closely related with microstructure factors such as relative density and grain size. Good optical and electrical properties of ${\Upsilon}$ of 0.138, surface roughness of 5.77 nm and optical transmittance of 95.76 % were obtained for the MgO+100 ppm $Gd_2O_3$ protective layer sintered at $1700^{\circ}C$ for 5 hrs.

• Korean Journal of Optics and Photonics
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• v.34 no.5
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• pp.185-191
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• 2023

We report the results of evaluating the hardness, flexibility, and adhesion between the protective layer and the stealth sheet after applying a protective layer to improve the practicality of the flexible stealth sheet. The result of the ISO 15184 pencil hardness test showed that the hardness increased from HB to 3H by three grades when a protective layer was applied. The flexibility evaluation was conducted by bending the material against cylinders of certain diameters and observing whether cracks occurred according to the ASTM D522 test method. The result showed that the minimum diameter was 0.125 inches. The adhesion was evaluated by using the ASTM D3359 test method, attaching and peeling off an adhesive strip to the protective layer and determining the proportion of the protective layer peeling off. The result was 5B, which is better than the military adhesion limit of 4B.

• Journal of Institute of Convergence Technology
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• v.2 no.2
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• pp.25-29
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• 2012

Micro machining technologies have been required to satisfy various conditions in a high-technology industry. Micro electrochemical process is one of the most precision machining methods. Micro electrochemical process has been divided into electrochemical etching through protective layer and electrochemical machining using ultrashort voltage pulses. Micro shaft can be fabricated by electrochemical etching. The various protective layers such as photo-resist, oxide layer and oxidized recast layer have been used to protect metal surface during electrochemical etching. Micro patterning on metal surface can be machined by electrochemical etching through protective layer. Micro hole, groove and structures can be easily machined by electrochemical machining using ultrashort voltage pulses. Recently, the groove with subnanometer was machined using AFM.

• Korean Journal of Materials Research
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• v.18 no.8
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• pp.422-426
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• 2008

The effects of an addition of $ZrO_2$ on the microstructure and electrical properties of MgO films as a protective layer for AC plasma display panels were investigated. MgO + a 200 ppm $ZrO_2$ protective layer prepared by e-beam evaporation exhibited a secondary electron emission coefficient ($\gamma$) that was improved by 21% compared to that of a pure MgO protective layer. The relative density and Vickers hardness increased with a further addition of $ZrO_2$. These results suggest that the discharge properties and optical properties of MgO protective layers are closely related to the relative density and Vickers hardness. The good optical and electrical properties of $\gamma$, at 0.080, a grain size of $19\;{\mu}m$ and an optical transmittance of 91.93 % were obtained for the MgO + 200 ppm $ZrO_2$ protective layer sintered at $1700^{\circ}C$ for 5 hrs.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.197-202
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• 2001

M $g_{1-x}$ Z $n_{x}$O thin films with various composition x of ZnO were fabricated by a RF magnetron sputtering method, which is expected to improve the electro-optical properties of the conventional MgO protective layer for AC-PDP. Test panels with the $Mg_{1-x}$Z $n_{x}$O protective layer have been fabricated in order to investigate the effects of ZnO doping on the electrical characteristics of devices such as the discharge voltages and the memory gain. Experimental results revealed that test panels with the $Mg_{1-x}$Z $n_{x}$O(x=0.5at%) protective layer show lower firing and sustain voltages than those seen in panels with MgO protective layer by 20V. resulting in an increasement of the memory coefficient. In addition, it was found that test panels with the $Mg_{1-x}$Z $n_{x}$O protective layer show higher discharge intensity, i. e., higher plasma density, compared with panels with MgO protective layer.ve layer.layer.