• Korean Journal of Materials Research
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• v.34 no.7
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• pp.355-362
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• 2024

AR (alkali resistant)-glass fibers were developed to provide better alkali resistance, but there is currently no research on AR-glass fiber manufacturing. In this study, we fabricated glass fiber from AR-glass using a continuous spinning process with 40 wt% refused coal ore. To confirm the melting properties of the marble glass, raw material was put into a (platinum) Pt crucible and melted at temperatures up to 1,650 ℃ for 2 h and then annealed. To confirm the transparent clear marble glass, visible transmittance was measured and the fiber spinning condition was investigated by high temperature viscosity measurement. A change in diameter was observed according to winding speed in the range of 100 to 700 rpm. We also checked the change in diameter as a function of fiberizing temperature in the range of 1,240 to 1,340 ℃. As winding speed increased at constant temperature, fiber diameter tended to decrease. However, at fiberizing temperature at constant winding speed, fiber diameter tended to increase. The properties of the prepared spinning fibers were confirmed by optical microscope, tensile strength, modulus and alkali-resistance tests.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.1
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• pp.25-30
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• 2020

Oxide (SiO₂)/Metal(Ag)/Oxide(SiO₂, ITO, ZnO) multilayer films were fabricated using a magnetron sputtering technique at room temperature on Si (p-type, 100) and a glass substrate. The electrical and optical properties of the asymmetric multilayer films depended on the thickness of the mid-layer film and the type of oxide in the bottom layer. As the metal layer becomes thicker, the sheet resistance decreases. However, the transmittance decreases when the metal layer exceeds a threshold thickness of approximately 10~12 nm. In addition, the sheet resistance and transmittance change according to the type of oxide in the bottom layer. If the oxide has a large resistivity, the overall sheet resistance increases. In addition, the anti-reflection effect changes according to the refractive index of the oxide material. The optical and electrical properties of multilayer films were investigated using an ultraviolet visible (UV-Vis) spectrophotometer and a 4-point probe, respectively. The optimum structure is SiO₂ (30 nm)/Ag (10 nm)/ZnO (30 nm) multilayer, with the highest FOM value of 7.7×10^-3 Ω^-1.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.162-169
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• 2017

Indium tin oxide (ITO) thin films show a low sheet resistance and high transmittance in the visible range of the spectrum. Therefore, they play an important role as transparent electrodes for flat panel displays. However, their resistivity is rather high for use as a transparent electrode in large displays. One way to improve electrical and optical properties in large displays is to use ITO/Ag/ITO multilayer films. ITO/Ag/ITO multilayer films have lower sheet resistance than single layer ITO films with the same thickness. Prior to the ITO/Ag/ITO multilayer experiments, optimal condition for thickness change are necessary. Their thicknesses were deposited differently in order to analyze electrical and optical properties. However, when optimal single film characteristics are applied to ITO/Ag/ITO multilayer films, other phenomena appeared. After analyzing the electrical and optical properties by changing ITO and Ag film thickness, ITO/Ag/ITO multilayer films were optimized. By combining ITO film at $586\;{\AA}$ and Ag film at 10 nm, the ITO/Ag/ITO multilayer films showed optimized high optical transmittance of 87.65%, and the low sheet resistance of $5.5{\Omega}/sq$.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.66-71
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• 2009

To reduce the building energy consumption, the major advanced nations are conducting actively many researches on so called a "self-sufficient building(or other words zero energy building)" which can support its required energy by itself. Given this background, KIER(Korea Institute of Energy Research) built full size test-bed of the zero energy solar house in early 2002, and has studied on the self-sufficient heating load up to now. We analyse the sensitivity between the heating load and the solar radiation gain according to the change the effective transmittance of windows. The authors classified 9 cases by solar transmittance of glass. The results demonstrate the solar radiation amount is 0.466 MWh from the eastern zone of Fl.,1(the first floor), 0.332 MWh from Fl.,2(the second floor), 1.194 MWh form the southern zone of F1., and 0.822 MWh from the southern zone of Fl.,2 on the case 1(each cases are classified by window types). On the case 9, the solar radiation amount is 3.127 MWh, 2.662 MWh, 8.799 MWh and 6.078 MWh from the same condition. For the Fl.,1, the amount of Heat Load that is saved per year ranged 10.5 to 48 %, and the reduction was anywhere from 0.2 to 17.9% for Fl.,2

• Journal of the Microelectronics and Packaging Society
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• v.22 no.1
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• pp.63-67
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• 2015

In this study, we demonstrate the change of optical characteristic by thickness of metal deposition on nano metal grid polarizer film fabrication. Nano metal grid polarizer film consists of aluminium grid polarizer layer on PET (Polyethylene phthalate) substrate. We aim at metal grid layer formation for the large nano wire grid polarizer fabrication. we draw process conditions of the nano metal grid polarizer film fabrication to improve transmittance and extinction ratio and Nano wire grid polarizer film (NWGP) film is fabricated with 140 nm pitch, 70 nm width, and 70 nm depth of metal grid on optimum design conditions. As a result, we get high optical properties of nano wire grid polarizer which is the maximum transmittance of 80% and the extinction ratio of $10^6$ at 600 nm wavelength respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.818-821
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• 2006

We demonstrate the vertical alignment of liquid crystal on $a-SiO_x$ film surface using the ion beam exposure. Liquid crystal can be aligned vertically by the rotational oblique evaporation of $a-SiO_x$ film. However, the electro-optic switching behavior of liquid crystal along random directions results in disclination lines. We found that we can achieve highly uniform alignment of liquid crystal without disclination lines by using the ion beam exposure. We found from XRD and XPS data that the vertical alignment can be achieved when x approaches 1.5 at the $a-SiO_x$ film surface. We have shown that the pretilt angle can be controlled by changing ion beam parameters, such as the ion beam energy, the angle of incidence, and the exposure time. We found that whether liquid crystals can be aligned vertically or homogeneously on $a-SiO_x$ film can be predicted simply by measuring the change in optical transmittance by deposition of $a-SiO_x$ thin film layers. We also have shown that a liquid crystal cell aligned vertically by the ion beam exposure exhibits the voltage-transmittance curve similar to that of a rubbed polyimide cell.

• Elastomers and Composites
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• v.48 no.4
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• pp.249-255
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• 2013

Hydroxypropyl terminated PDMS was synthesized by the hydrosilylation reaction with allyl alcohol in the presence of Karstedt's catalyst. And them, an one-pot reaction with HDI isocyanurate trimer and hydroxyethyl methacrylate was conducted to give a silicone-modified urethane acrylate oligomer (PUA oligomer) having 9000 g/mol, weight average molecular weight. The synthesized PUA oligomer was characterized by using FT-IR and GPC. The UV-curable coatings were prepared by PUA oligomer blending with a reactive monomer (phenylthioethyl acrylate) under the different mole ratios. It was found that the refractive index of cured film increased when the reactive monomer was added but there was no relationship between the refractive index and amount of reactive monomer. Also, their transmittance for cured films was not change as increasing the content of reactive monomer.

• Korean Journal of Optics and Photonics
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• v.10 no.6
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• pp.443-447
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• 1999

To investigate the effect of a shaded apodizer on the read-out signal in an optical disc system, we consider the is apodizer in which the amplitude transmittance decreases gradually from the center of pupil toward its edge and the iH apodizer in which the amplitude transmittance increases gradually from the center of pupil toward its edge, using the scalar diffraction theory. We also consider the bump shapes which are a cylindric, a semi-conic, and a conic bump, and bump height which is given by $\lambda/4$ and occurs to the phase change $(\pi)$). The read-out signal of is apodizer increases from S = 0 upto maximum value, and then decreases for increasingly larger values of bOo While the iH apodizer has two maximum values. When an optical disc system has a spherical aberration $(W_{40}=0.5\lambda)$, the maximum read-OUt signal of is apodizer is higher than that of iv apodizer which has no apodizer.odizer.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.6
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• pp.794-800
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• 2004

The purpose of this study is to propose a method of controlling freshwater algae which grows abundantly and forms water bloom in the eutrophic water body with $H_2O_2$. Both laboratory and field methodologies were used. For the laboratory test $H_2O_2$ was injected into the different growth phases of incubated Microcystis aeruginosa and the resulting algae growth control rate was examined. For the field test, $H_2O_2$ was dispersed into a lake. Lake water quality was evaluated using a pre-test and post-test analysis of chlorophyll-a, luminance, transmittance, etc., which allowed a comparative evaluation of water quality change. From the experimental results, the growth of algae can be controlled with the small amount of 1mg/L of $H_2O_2$ at the lag phase of growth. The field test results show that the green colour of lake water was removed completely by the reduction of chlorophyll-a and improved transmittance, luminance, TKN, TP, TOC and SS. These indicators of water quality were improved significantly after $H_2O_2$ injection. Toxicity test results using the lake fish show no evidence of detrimental effect of $H_2O_2$ up to 15mg/L. The results of $EC_{50}$ with P. phosphoreum show that the toxicity of $H_2O_2$ was negligible compared to copper which was commonly used for algae control.

• Transactions on Electrical and Electronic Materials
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• v.6 no.2
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• pp.73-77
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• 2005

In this study, we investigated response characteristics of liquid crystal display (LCD) with different operating mode of nematic liquid crystals (NLCs) such as 45 $^{circ} twisted nematic (TN), 67.3 $^{circ} TN and electrical controlled birefringence (ECB) on the rubbed polyimide (PI) surface with side chains. The pretilt angles generated on polyimide surfaces of the three kinds of LCD operating modes were about 12 $^{circ} that was higher than those of conventional TN-LCOs. Also, the Electro-optical (EO) performance of these LCOs showed stable condition. Low transmittance of the 45 $^{circ} TN and 67.3 $^{circ} TN cell on the rubbed PI surface were measured by using low cell gap d. The fast response time in ECB cell among the three kinds of LCD operating modes was achieved. Also, thermal ability of fast 90 $^{circ} TN-LCD was investigated. The threshold voltage and the response time of thermal stressed TN-LCOs showed the same performances on no thermal stressed TN-LCOs. There was little change of value in these TN cells. However, the transmittances of TN-LCOs on the rubbed PI surface decreased while increasing thermal stress time. Therefore, the thermal stability of TN-LCD was decreased by the high thermal stress for the long duration.