• Journal of Information Display
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• v.13 no.4
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• pp.139-143
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• 2012

In this study, optical simulation was used to compare three optical structures that could be applied to the typical organic light-emitting diode to increase the outcoupling efficiency. These were spherical scattering particles (treated as Mie scatterers) embedded in the glass substrate, microlenses formed on the glass substrate, and a diffusing layer (DL) with a Gaussian scattering distribution function inserted between the indium tin oxide (ITO) and the glass substrate. It was found that the application of microlens array and that of scattering particles in the glass substrate exhibited similar enhancements in the outcoupling efficiency when the density and the refractive index of the scattering particles were optimized. The DL located at the interface between the glass and the ITO further enhanced the efficiency because it could further extract the trapped light in the waveguide mode. The appropriate combination of these three structures increased the outcoupling efficiency to about 42%, which is much greater than the typical values of 15-20% when there is no optical structure for light extraction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.263-266
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• 2000

Effects of excess Pb(50 mole ％) on the crystallization properties of amorphous PZT thin films on the glass substrates by post-annealing in oxygen ambient were investigated to lower the crystallization temperature of the PZT thin films with a single perovskite phase. The PZT thin films(350nm) were prepared on Pt/Ti/corning glass(1737) substrates. The PZT thin films and bottom electrode were deposited by RF magnetron sputtering. Crystallization properties of PZT thin films were strongly dependent on RTA(Rapid Thermal Annealing) temperature. We were able to obtain a perovskite structure of PZT at 600$^{\circ}C$ for 10min. After thermal treatments were done, electrical properties such as I-V, P-E, and fatigue were measured.

• Korean Journal of Materials Research
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• v.26 no.10
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• pp.549-555
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• 2016

We have investigated a glass-forming region of $V_2O_5-P_2O_5-ZnO$ glass and the effects of the addition of modifier oxides ($B_2O_3$) to the glass systems as a sealing material to improve the adhesion between the glass frits and a soda lime substrate. Thermal properties and coefficient of thermal expansion were measured using a differential scanning calorimetry, a dilatometer and a hot stage microscopy. Structural changes and interfacial reactions between the glass substrate and the glass frit after sintering (at $400^{\circ}C$ for 1 h) were measured by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscope. The results showed that the adhesion strength increases as the content of $B_2O_3$ at 5 mol% increases because of changes in the structural properties. It seems that the glass structures change with $B_2O_3$, and the $Si^{4+}$ ions from the substrate are diffused to the sealing glass. From these results, we could understand the mechanism of strengthening of the adhesion of soda lime silica substrate by ion-diffusion from the substrate to the glass.

• Journal of the Korean Ceramic Society
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• v.55 no.2
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• pp.135-139
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• 2018

The glass structure and antibacterial properties of $(65-x)ZnO-xB_2O_3-35P_2O_5$ glasses were investigated. Zinc borophosphate glasses were prepared using a conventional melt-quenching technique at $1000^{\circ}C$. Glass transition temperature and CTE were studied and the structure of zinc borophosphate glasses was evaluated by FTIR. The $Zn^{2+}$ state increase with increasing ZnO content was investigated by XPS and a single sharp Zn $2P_{3/2}$ peak was confirmed, showing that Zn $2P_{3/2}$ exists as $Zn^{2+}$. In order to to evaluate the antimicrobial activity, Escherichia coli (E. coli) was used following the Japanese Industrial Standard JIS Z 2801; the E. coli death rate was found to increase with increasing $Zn^{2+}$ content of glasses.

• Journal of the Korean Society for Heat Treatment
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• v.12 no.3
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• pp.199-205
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• 1999

The quaternary Ti-Al-V-N films have been grown on glass substrates by reactive dc and rf magnetron sputter deposition from a Ti-6Al-4V target in mixed Ar-$N_2$ discharges. The Ti-Al-V-N films were investigated by means of X-ray diffraction(XRD), electron probe microanalysis(EPMA) and scratch tester. Both XRD and EPMA results indicated that the Ti-Al-V-N films were of single B1 NaCl phase having columnar structure with the (111) preferred orientation. Scratch tester results showed that the adhesion strength of Ti-Al-V-N films which treated with substrate heating and vacuum annealing was superior to that of as-deposited film. The good adhesion strength was also achieved in the double-layer structure of Ti-Al-V-N/Ti-Al-V/Glass.

• Macromolecular Research
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• v.15 no.2
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• pp.185-190
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• 2007

Poly(norbornene dimethyl dicarboxylate)s, (PNDMD)s, were prepared by addition polymerization with palladium(II) catalyst from pure exo-monomers, and their structure and properties were compared with those of poly(norbornene dicarboxylic acid dialkyl ester)s, (PNDADA)s. Both polymer series exhibited good solubility in general organic solvents and excellent thermal stability up to $330^{\circ}C$. Wide-angle X-ray scattering (WAXS) study indicated the presence of nano-scale layer-like order in amorphous PNDADAs, while PNDMDs showed random amorphous structure. The glass transition temperatures and dielectric constants of solid polymers were found to decrease as the alkyl side-chain length increases for both polymer series. However, PNDMDs showed lower glass transition temperatures and higher dielectric constants, as compared with those of PNDADAs containing the same alkyl substituents. This difference, caused by the higher side-group mobility of PNDMDs, may be closely related to the nano-scale order in amorphous PNDADAs and its absence in PNDMDs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.91-91
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• 2008

$SnO_2-B_2O_3-P_2O_5$ system were prepared by melt-quenching technique in the compositional series containing 50, 55 aod 60mol.% of $SnO_2$. A large glass-forming region was found at the phosphate side of the ternary system with homogeneous glasses containing up to 5-25mol.% of $B_2O_3$. For these glasses, thermal expansion coeffient($\alpha$), glass transition temperature(Tg), and glass softening temperature(Ts), were determined. The values a decrease with increasing $B_2O_3$ content, while Tg and Ts increased. The reason for the observed changes is local structure of the glasses. Local structure of the glasses was investigated by Raman and FT-IR measurements, suggesting that the number of bridging oxygens decreased whereas the non-bridging oxygen concentration increased with increasing $SnO_2$ content in the glasses.

• Korean Journal of Materials Research
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• v.12 no.7
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• pp.545-549
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• 2002

Potassium-Calcium-Phosphate glasses in range $XCaO\cdot(50-X)K_2O$ \cdot $50P_2$$O^{5}$were investigated. Glass transition temperature(Tg) of prepared glasses were below $520^{\circ}C$, thermal expansion coefficient from $270.3$\times$10^{7}$ to $604.5$\times$10^{7}$/$^{\circ}C$. The structure of XCaO.(50-X)$K_2$O\cdot$50P_2$$O^{5}$ glasses were examined by FT-IR spectroscopy indirectly. As CaO was increased, Ts, Tg, P-O-P bonding strength and chemical durability were increased. Glass surface change was observed with increasing dissolution time using bulk specimen, weight loss and pH change were measured as function of the dissolution time.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.6
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• pp.121-128
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• 2019

There is a big move to build zero-energy buildings in the form of passive houses that reduce energy waste worldwide. Korea has set a goal of reducing its greenhouse gas emissions by 37% by 2030 through the activation of green buildings, such as strengthening the energy levels of new buildings and improving the energy efficiency of existing buildings. The use of insulation with high insulation performance is one of the key technologies to realize this, and vacuum insulation is the next generation insulation that blocks the energy flow of the building. In this study, we measured the bonding structure of dry and wet processing glass fiber core materials and compared the insulation performance of vacuum insulation panel. In addition, the insulation performance of vacuum insulation panel was measured according to the thickness of the laminated core. It can be confirmed that the lamination structure of the core and the lamination thickness are important factors for the heat insulating performance of the vacuum insulating panel.

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.489-504
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• 1996

The purpose of this study was to compare the adaptation to the tooth structure of five light cured glass ionomer cements (Fuji II LC. VariGlass VLC, Vitremer, Dyract and Geristore). Human, non-carious fifty extracted permanent premolars stored in normal saline were used. Class V cavity preparations were created on the buccal surfaces. The occlusal margin of each cavity was placed on the enamel and the gingival margin was placed on the cementum/dentin. The teeth were then distributed at random into five groups of 10 teeth each. Group 1: Fuji II LC, Group 2 : VariGlass VLC, Group 3 : Vitremer, Group 4: Dyract, Group 5 : Geristore. The prepared cavities were restored with one of the five light cured glass ionomer cements. The manipulation of each material was handled according to the manufacturer's instructions. All samples were placed in incubator of 100% relative humidity at $37^{\circ}C$ for 24 hours. The roots of the teeth were removed with the tapered fissure bur and the remaining crowns were sectioned buccolingually through the center of restorations. The cut interfaces were gradually hand polished on sandpapers from 300 up to 1200 grit. The adaptation at the tooth/cements interface was assessed by SEM (JSM-840A, JEOL Ltd.). The results of this study were as follows : 1. Group 2 revealed the best adaptation and groups 1, 4 and 5 revealed similar adaptation pattern to the cavity walls. Group 3 revealed the worst adaptation to the cavity walls. 2. Enamel margins showed better adaptation than dentin/cementum margins with each material except group 3. 3. The hybrid layers were observed between the glass ionomer cement and dentin in groups 2, 4 and 5.