• 공업화학
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• 제31권6호
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• pp.591-595
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• 2020

Intensive pulsed light (IPL) 기술은 빛을 millisecond 단위의 짧은 시간에 상온, 상압 환경에서 대상 물질에 조사하여 에너지를 전달한다. 이렇게 단시간에 조사되는 특징을 가진 플래시라이트(flashlight)에 대한 관심의 증대로 IPL을 이용한 금속입자의 광소결 연구가 대표적으로 이루어져 왔으며, 최근에는 IPL을 다양한 물질 합성에 적용한 사례가 발표되고 있다. 본 총설 논문은 지금까지 연구되어 밝혀진 IPL을 활용한 다양한 물질 합성 전략들에 대한 것으로 IPL 기술을 이용한 물질 합성에 대한 이해를 증진시키고자 한다. 특히, 금속나노입자의 소결을 이용한 유연 전극제작 및 금속유기골격체(metal-organic framework, MOF) 합성을 다루었다. 전극제작의 핵심 요소인 전극의 산화 저항성과 전기전도도 향상을 위한 과정을 다루었고, 금속기판으로부터 금속유기골격체를 합성하는 과정을 설명하였다. 이를 향후 IPL을 이용한 전극 제작 및 물질 합성 응용에 관한 연구를 하는 연구자에게 이해하기 쉽게 설명하고자 하였다.

• 센서학회지
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• 제30권6호
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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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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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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.

• 청정기술
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• 제6권1호
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• pp.71-78
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• 2000

본 연구는 광합성 균주인 C. thiosulfatophium을 이용한 황화수소의 생물학적 탈황공정시 광에너지를 저감시키기 위해 광원의 종류와 광조사 유형에 따른 탈황효율을 조사하였다. 광에너지를 저감시키기 위해서는 반응기내 광분산 효율을 극대화시켜야 한다. 광이용효율을 높이기 위해, 세균농도와 생성부산물의 증가에 의한 빛의 산란과 흡수가 세균성장에 미치는 영향에 관한 연구와 미생물이 필요로 하는 파장의 빛을 최대로 공급하기 위해 LED, 백열등, 태양광 등을 이용한 광원의 최적화 연구, 그리고 외부조사형 광반응기의 광투과 효율의 한계를 극복하기 위한 광섬유를 이용한 내부조사형 광반응기에 대한 연구를 수행하였다.

• 대한치과교정학회지
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• 제22권2호
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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.

• 대한치과교정학회지
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• 제40권1호
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• pp.27-33
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• 2010

성인 교정환자의 수요가 증가하면서 보철물 표면에 교정장치를 부착해야 하는 빈도가 늘어나고 있다. 본 연구는 금속표면에 교정장치를 직접 접착하고자 할 때 사용하는 metal primer와 silicoating으로 각각 금합금의 표면을 처리한 후 light emitting diode (LED) 광중합기를 사용하여 광중합을 시행하여 접착력을 평가해 보고자 하였다. Type III gold alloy 표면에 aluminum oxide를 이용한 sandblasting 후 4-META 계열의 metal primer로 처리한 시편과 silica를 이용한 sandblasting 후 silane으로 처리한 시편에 광중합형 접착레진인 Transbond XT를 이용하여 금속 브라켓을 접착하고 접착 후 1시간, 6시간, 24시간 후 전단접착강도의 변화를 비교, 관찰하였다. 측정된 값을 이원분산분석(two-way analysis of variance)을 이용하여 비교하고 두 가지 표면처리 방법 간에 접착강도에 차이가 있는지도 살펴보았다. 연구결과, metal primer에 비하여 silicoating을 시행한 시편에서 높은 전단접착강도가 관찰되었으며, 시간이 경과할수록 접착강도가 증가하는 경향을 보였다. Adhesive remnant index (ARI)에서는 군 간 유의한 차이를 보이지 않았다. LED를 이용하여 광중합을 시행하는 경우 법랑질에 비하여 긴 시간의 광중합을 실시하고 metal primer보다는 silicoating 방법을 사용하는 것이 금합금표면에 교정장치를 부착할 때 더 높은 접착강도를 얻을 수 있을 것이다.

• 보존과학회지
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• 제34권4호
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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.

• 한국환경농학회지
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• 제16권2호
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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.

• 한국전기전자재료학회논문지
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• 제21권10호
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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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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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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.