• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.591-595
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• 2020

Intensive pulsed light (IPL) technique enables energy to be transferred to a target substance in a short time per millisecond at room temperature under an ambient atmosphere. Due to the growing interest in flashlights with excellent functionality among various technologies, light-sintering research on metal particles using IPL has been carried out representatively. Recently, examples of the application of IPL to various material synthesis have been reported. In the present article, various strategies using IPL including the manufacture of flexible electrodes and the synthesis of metal-organic frameworks were discussed. In particular, the process of improving oxidation resistance and electrical conductivity of electrodes, and also the metal-organic framework synthesis from metal surface were explained in detail. We envision that the review article can be of great help to researchers who investigate electrode manufacturing and material synthesis using IPL.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.381-383
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• 2021

Light-activated metal oxide gas sensors have been investigated in recent decades. Light illumination enhances the sensing attributes, including the operational temperature, sensitivity, and selectivity. Unfortunately, high operating temperature is a major problem for gas sensors because of the huge energy consumption. Therefore, the importance of light-activated room-temperature sensing has increased. This paper reviews recent light-activated sensors and their sensing mechanisms with a specific focus on metal oxide gas sensors. Studies use the outstanding ZnO and SnO₂ sensors to research photoactivation when illuminated by various sources such as ultraviolet (UV), halogen lamp, or monochromatic light. Photon induction generates electron-hole pairs that increase the number of adsorption sites of gas molecules and ions improving the sensor's sensing properties.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.787-790
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• 2009

High contrast red, green and blue organic light-emitting diodes were fabricated using inorganic metal multi layer composed of thin Al, KCl and thick Al and then were compared to optical and electrical characteristics with the attached polarizer and conventional OLEDs. Ambient light reflection of OLED using inorganic metal layer, polarizer and conventional metal layer were 29.2, 31.1 and 82.5% respectively. Optical characteristics of OLEDs using inorganic metal layer were max luminescence of 13040 cd/m2 and luminous efficiency of 2.12 cd/A at 8V whereas OLEDs using polarizer has 8456 cd/m2 and 1.43 cd/A at 8V each. OLEDs including inorganic metal multi layers show significant technical advantages in achieving high performance of OLED display with improved contrast ratio of 251:1, specifically in Red OLED.

• Clean Technology
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• v.6 no.1
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• pp.71-78
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• 2000

Removal rates of hydrogen sulfide were investigated to known effects of several light sources with external and internal irradiation on the desulfurization using C. thiosulfatophilum. In the case of internal illumination system, optical-fiber photobioreactor was applied to increase the light availability. Furthermore, sunlight was used as the main light energy in the daytime and metal-halide lamp was applied as an additional light energy at night. Light energy of 99% was saved by the application of the LED's array in comparison with the incandescent light source. $H_2S$ removal rates at 5,000 lux in a 4-L photobioreactor were shown as 0.040, 0.138, 0.136, and 0.134 (${\mu}mol$ $H_2S/min$)/(mg protein/L), respectively, in the following order of light sources, when several light sources such as fluorescent, energy-saving, incandescent, halogen lamp, and filtered light at 460 nm were applied. Removal rate per unit cell concentration with the internal light diffused optical-fibers increased about 1 six times as much as that with the external light sources. Removal rate per unit cell concentration, using sunlight in the daytime and a metal-halide lamp at night, was 0.41 less than 0.869 (${\mu}mol$ $H_2S/min$)/(mg protein/L) using a 400 W metal-halide lamp day and night, since the automatic sunlight collection system can transmit the light intensity as only 10% of that with a metal-halide lamp.

• The korean journal of orthodontics
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• v.22 no.2 s.37
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• pp.289-296
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• 1992

The purpose of this study was to evaluate and compare the shear bond strengths and failure sites of metal brackets bonded with chemically cured adhesive and light-cured adhesive. 10 brackets were bonded on prepared enamel surfaces with $Transbond^{circledR}$ (Unitek/3M; U.S.A.) light-cured orthodontic adhesive and another 10 brackets were bonded with $Ortho-one^{\circledR}$ (Bisco:U.S.A.) chemically cured orthodontic adhesive. 24 hours after bonding, the Instron universal testing machine was used to measure the shear bond strengths. The failure sites were examined under streoscopic microscope. The results were as follows: 1 . The mean shear bond strength of metal brackets bonded with light-cured adhesive was lower than that of metal brackets bonded with chemically cured adhesive, but the difference was not statistically significant (p < 0.05). 2. Regardless of the type of adhesives, the brackets were failed primarily at the bracket base-adhesive interface. 3. Bonding of metal brackets with light-cured adhesive is considered to be clinically acceptable.

• The korean journal of orthodontics
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• v.40 no.1
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• pp.27-33
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• 2010

Objective: The need to bond orthodontic brackets onto various alloys has increased because of the increasing demand for adult orthodontic treatment. This study tried to evaluate the shear bond strength between gold alloy and metal bracket using light emitting diode (LED) light curing after metal primer and silicoating surface conditioning. Methods: Half of the type III gold alloy plates were treated with sandblasting with aluminum oxide and metal primer containing 4-META. the other half were treated with silica and silane. Metal brackets were bonded with Transbond XT light curing adhesive on these plates and shear bond strength were evaluated 1 hour, 6 hours, and 24 hours later. The differences of shear bond strength between groups were evaluated with two-way ANOVA. Results: The results showed higher bond strength in the silicoating group and a tendency of bond strength increase over time. Conclusions: When using LED curing lights for metal bracket bonding to alloy surfaces, long curing time and silicoating can produce a reliable bonding strength.

• Journal of Conservation Science
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• v.34 no.4
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• pp.245-257
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• 2018

To investigate the deterioration of textiles with metal thread, I surveyed 40 textile objects, dating from the 11th to the 19th century from Korea, China, Japan, and Central Asia at the Metropolitan Museum of Art, New York. This survey included various types, widths, and thicknesses of metal thread. In addition, deterioration was examined under the microscope and color information was collected using the spectrophotometer. While investigating metal thread in the collections, I fabricated 12 different types of metal samples with metal leaf(24K gold, silver, and copper leaf), adhesive (hide animal glue and a mixture of hide animal glue and iron oxide red), and paper substrate(Korean mulberry and Taiwanese kozo paper). The accelerated deterioration process of those fabricated samples was carried out using a light box(UV and daylight), and a humidity cabinet. In the light experiment with blue scales textile fading card(aka, blue wool standard), the metal leaf began to peel off during the deterioration process with 756,000 lux-hours UV and daylight. In the temperature and humidity experiment, I could observe the reddish tarnish on copper, and some part of it began to peel off. Color reading on the light exposed samples showed that the degree of color change on the surface follows the amount of exposure as it increased over time. On the other hand, color change on the samples after artificial deterioration using temperature and humidity factors showed random change of color with occasional spikes. Distortion of original shape worsened in the samples exposed to temperature and humidity.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.115-118
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• 1997

When the light metals such as $Ca^{++}$ and $Mg^{++}$ were added to heavy metal solution, the adsorption of heavy metals was increased by 20 to 30% more, but there were no differences between species. $Pb^{++}$ was the most adsorbed metal(99.5%), and the adsorption ratio of $Cd^{++}$ was significantly improved. In addition, when the light metal concentration was increased to 100ppm, the adsoption ratios of all four heavy metals were reached to 92 to 99%, while coniferous barks showed only 85 to 92%. On the mixture of four heavy metals, the adsorbed amount of each metal was significantly reduced, compared with that of one heavy metal, while $Zn^{++}$ showed the adsorption improvement to 95%. On the column experiment, $Pb^{++}$ was almost completely adsorbed in the upper part of column, and the adsorbed amount of $Cu^{++}$ was gradually decreased depending on column depth. However, $Cd^{++}$ and $Zn^{++}$ were not influenced by column height, and constantly adsorbed on various column height. Based on the above results, each heavy metal had different adsorption mechanism.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.10
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• pp.938-942
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• 2008

Electrical and optical properties of semitransparent Ag and Al layer were studied, which are used for the electrodes in top-emission organic light-emitting diodes. Sheet resistance and transmittance of visible light through a thin layer were measured and analyzed. Several thin metal layers of Ag and Al were deposited onto a glass substrate up to a thickness of 50 nm using a thermal evaporation. Sheet resistance measurements show that a layer thickness is needed more than 15 nm and 20 nm for Ag and Al, respectively, when a proper sheet resistance is assumed to be less than $50{\Omega}/sq$. From the measurements of transmittance of visible light through a thin-metal layer, metallic behavior was observed when the layer thickness is over 25 nm for both films. Thus, from a study of sheet resistance and transmittance of visible light, a minimum proper thickness of semitransparent metal layer is 20 nm and 25 nm for Ag and Al, respectively.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.350-355
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• 2009

The crysralline silicon solar cell where the solar cell market grows rapidly is occupying of about 85% or more high efficiency and low cost endeavors many crystalline solar cells. The fabricaion process of high efficiency crystalline silicon solar cells necessitate complicated fabrication processes and Ti/Pd/AG contact, This metal contacts have only been used in limited areas in spite of their good srability and low contact resistance because of expensive materials and process. Commercial solar cells with screen-printed solar cells formed by using Ag paste suffer from loe fill factor and high contact resistance and low aspect ratio. Ni and Cu metal contacts have been formed by using electroless plating and light-induced electro plating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Copper and Silver can be plated by electro & light-induced plating method. Light-induced plating makes use the photovoltaic effect of solar cell to deposit the metal on the front contact. The cell is immersed into the electrolytic plating bath and irradiated at the front side by light source, which leads to a current density in the front side grid. Electroless plated Ni/ Electro&light-induced plated Cu/ Light-induced plated Ag contact solar cells result in an energy conversion efficiency of 16.446 % on 0.2~0.6${\Omega}$ cm, $20{\times}20mm^2$, CZ(Czochralski) wafer.