• 조명전기설비학회논문지
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• 제30권3호
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• pp.30-38
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• 2016

In this research, a 6W white LED package with a Glass Remote Phosphor was developed to improve the life of an LED package. The Glass Remote Phosphor was fabricated by the Phosphor in Glass (PiG) method, wherein phosphor YAG:Ce was mixed with glass frit and then heat treated. A paste with 75wt.% of a phosphor substance and 25wt.% glass frit was coated on a glass substrate two times using the screen-printing technique and heat-treated at $800^{\circ}C$ ; this structure gave a luminous efficacy of 136.1lm/W, color rendering index of 74Ra, and color temperature of 5,342K, thus satisfying the requirements as a light source for lighting. Moreover, an IES LM-80 accelerated life test was conducted on the same LED package for 6,000h in order to estimate the L70 lifetime based on IES TM-21. The results showed guaranteed lifetimes of 213,000h at $55^{\circ}C$, 245,000h at $85^{\circ}C$, and 209,000h at $95^{\circ}C$.

• 한국레이저가공학회지
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• 제15권3호
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• pp.16-19
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• 2012

We have successfully formed brown colored patterns inside of a transparent borosilicate glass generally known as BK7, laying the focus of near infrared Ti: sapphire femtosecond laser beam in the bulk BK7 glass. It is important to keep the laser power well below the damage threshold of BK7 in forming the color center. According to the low laser power, there was no laser induced mechanical damage such as cracks or threads in the color formed area. From the absorbance spectrum and its gaussian fitting, we found the band gap of BK7, 4.21eV, and three absorption edges.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.209-210
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• 2006

We have successfully termed brown colored patterns inside of a transparent borosilicate glass generally known as BK7, laying the focus of near infrared Ti: sapphire femtosecond laser beam in the bulk BK7 glass. It is important to keep the laser power well below the damage threshold of BK7 in forming the color center. Thanks to the low laser power, there was no laser induced mechanical damage such as cracks or threads in the color formed area. From the absorbance spectrum and its gaussian fitting, we found the band gap of BK7, 4.21eV, and three absorption edges.

• 대한소아치과학회지
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• 제49권4호
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• pp.428-441
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• 2022

이 연구의 목적은 알카자이트 수복재와 소아치과 영역에서 널리 사용되고 있는 수복재들의 색 안정성을 비교하고, 다양한 음료에서의 색상 변화를 비교하는 것이다. 글라스아이오노머, 레진강화형 글라스아이오노머, 알카자이트 수복재, 복합레진의 시편을 준비하였고, 열순환 후 색 안정성을 측정하였다. 침전 전과 7일, 14일, 21일, 28일 후 CIE L^*a^*b^*값의 색상 변화를 분석하기 위해 각 수복재료의 시편을 5개의 군으로 나누어 각각 PBS, 커피, 녹차, 콜라, 오렌지주스 용액에 침전시켰다. 열순환 후 복합레진에서 가장 높은 색 안정성을 보였고, 알카자이트 수복재, 글라스아이오노머, 레진강화형 글라스아이오노머 순으로 높은 안정성을 보였다. 7일간 다양한 용액에 침전시킨 결과 모든 시편에서 색상 변화가 나타났으며, 알카자이트 수복재는 글라스아이오노머 계열보다 낮은 색상 변화를 보였고, 복합레진보다는 높은 색상 변화를 나타냈다. 알카자이트 수복재는 커피에서 가장 많은 색상 변화가 나타났으며 그 다음은 녹차, 오렌지주스 순이었으나, 콜라와 PBS 용액에서는 침전 28일 이후에도 색상 변화를 거의 보이지 않았다.

• 구강회복응용과학지
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• 제18권2호
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• pp.93-99
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• 2002

This study was performed to investigate the color stability of IPS Empress 2 glass-ceramic after heat-pressing and/or heat-treatments. Three types of IPS Empress 2 ingots (shade 100, 300, 500) were tested. For this study, three groups were prepared as follows: group 1 is as-received material, group 2 is heat-pressed material, and group 3 is fully heat -treated material. The color of the specimens was measured with a colorimeter. The data were statistically evaluated with one-way ANOVA and Scheffe's multiple test. The results obtained were as follows: 1. IPS Empress 2 glass-ceramic demonstrated less color stability according as the shade is lighter. Namely, the shade 500 showed the lowest color shifts and the shade 100 showed the greatest color shifts after heat-pressing and heat-treatments. 2. In the cases of shade 100 and 300, the changes of ${\Delta}E^*$ were affected mostly by the changes of $L^*$ and $b^*$. 3. In ${\Delta}E^*$ of the shade 100, there were significant differences among the group 1, 2, and 3 (P<0.001). 4. In ${\Delta}E^*$ of the shade 300, there were significant differences between the group 1 and 2, and the group 1 and 3 (P<0.001). 5. In ${\Delta}E^*$ of the shade 500, there was significant difference only between the group 1 and 3 (P<0.001).

• The Journal of Advanced Prosthodontics
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• 제8권6호
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• pp.449-456
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• 2016

PURPOSE. This in vitro study evaluated the effects of four different cements on the color attributes of a zirconia ceramic. MATERIALS AND METHODS. 40 zirconia ceramic disk specimens (0.5 mm thickness, 10 mm diameter, 0.1 mm cement space) were fabricated by a computer-aided design and computer-aided manufacturing system. The specimens were divided into 4 groups of 10 specimens and cemented to composite substrates using four different cements including: Glass Ionomer, Panavia F2.0, Zinc Phosphate, and TempBond. The $L^*$, $a^*$, and $b^*$ color attributes of the specimens were measured before and after cementation by a spectrophotometer. Additionally, ${\Delta}E$ values were measured to determine color changes for the groups and then compared with the perceptional threshold of ${\Delta}E=3.3$. Repeated Measures ANOVA, Tukey Post Hoc, Bonferroni, One-way ANOVA, and One-sample t-test tests were used to analyze the data. All tests were carried out at the 0.05 level of significance. RESULTS. Statistically significant differences were detected in the ${\Delta}E$ values for Zinc Phosphate (P<.0001) and TempBond (P<.0001) groups. However, there were no statistically significant differences in this respect for Glass Ionomer (P=.99) and Panavia F2.0 (P=1) groups. The means and standard deviations of the ${\Delta}E$ values for Glass Ionomer, Panavia F2.0, Zinc Phosphate, and Tempbond groups were $2.11{\pm}0.66$, $0.94{\pm}0.39$, $5.77{\pm}0.83$, and $7.50{\pm}1.16$ Unit, respectively. CONCLUSION. Within the limitations of this study, it was concluded that Zinc Phosphate and Tempbond cements affected the color attributes of the tested zirconia ceramic beyond the perceptional threshold. However, Glass Ionomer and Panavia F2.0 cements created acceptable color changes.

• 한국재료학회지
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• 제26권1호
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• pp.22-28
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• 2016

In this study, we fabricated high quality color conversion component with green/red phosphor and low melting glass frit. The color conversion component was prepared by placing the green and red phosphor layer on slide glass via screen printing process. The properties of color conversion component could be controlled by changing coating sequence, layer thickness and heat treatment temperature. We discovered that optical properties of color conversion component were generally determined by the lowest layer. On the other hand, the heat treatment temperature also affected to correlated color temperature (CCT) and color rending index (CRI). The color conversion component with a green (lower) - red (upper) layer which was sintered at $550^{\circ}C$ showed the best optical properties: CCT, CRI and luminance efficacy were 3340 K, 78, and 56.5 lm/w, respectively.

• 콘크리트학회논문집
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• 제14권3호
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• pp.440-448
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• 2002

산업의 발달과 더불어 폐유리의 발생량은 점차 증가되고 있다. 콘크리트에 폐유리를 사용할 경우 알칼리 실리카 반응(ASR)에 의한 팽창으로 콘크리트에 균열이 발생하여 성능저하를 일으킬 수 있다. 본 연구에서는 폐유리의 색깔(갈색, 녹색), 입도 및 폐유리로 인해 발생되는 ASR팽창을 저감시키기 위해 산업부산물의 종류(플라이애시, 고로슬래그 미분말)와 혼입율에 따른 ASR팽창과 강도특성을 분석하였다. 또한, 포졸란 재료로서 폐유리 분말의 사용가능성을 분석하였다. 연구결과, 폐유리의 색깔에 관계없이 폐유리의 퍼시멈 입도는 2.5~l.2mm로 나타났으며, 폐유리의 입도가 2.5~l.2 mm보다 작을수록 팽창은 점차 감소하는 것으로 나타났다. 또한, 폐유리에 산업부산물의 혼입은 ASR로 인한 팽창과 강도저하를 억제시키는데 효과적이며, 0.075 mm미만의 폐유리 분말이 포졸란 재료로서 적용이 가능한 것으로 나타났다.

• Journal of Information Display
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• 제3권1호
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• pp.11-16
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• 2002

This paper presents a study on the tubeless Plasma Display Panel (PDP) packaging using glass-to-glass electrostatic bonding with intermediate amorphous silicon. The bonded sample sealing the mixed gas with three species showed high strength ranging from 2.5 MPa to 4 MPa. The glass-to-glass bonding for packaging was performed at a low temperature of $180^{\circ}C$ by applying bias of 250 $V_{dc}$ in ambient of mixed gases of He-Ne(27 %)-Xe(3 %). The tubeless packaging was accomplished by bonding the support glass plate of $30mm{\times}50mm$ on the rear glass panel and the capping glass of $20mm{\times}20mm$. The 4-inch color AC-PDP with thickness of 8 mm was successfully fabricated and fully emitted as white color at a firing voltage of 190V.

• 한국전기전자재료학회논문지
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• 제31권5호
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• pp.324-329
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• 2018

Red phosphor in glasses (PiGs) for automotive light-emitting diode (LED) applications were fabricated with 620-nm $CaAlSiN_3:Eu^{2+}$ phosphor and Pb-free silicate glass. PiGs were synthesized and mounted on high-power blue LED to make a monochromatic red LED. PiGs were simple mixtures of red phosphor and transparent glass powder. After being fabricated with uniaxial press and CIP at 300 MPa for 20 min, the green bodies were thermally treated at $550^{\circ}C$ for 30 min to produce high dense PiGs. As the phosphor content increased, the density of the sintered body decreased and PiGs containing 30% phosphor had a full sintered density. Changes in photoluminescence spectra and color coordination were studied by varying the thickness of plates that were mounted after optical polishing. As a result of the optical spectrum and color coordinates, PiG plate with $210{\mu}m$ thickness showed a color purity of 99.7%. In order to evaluate the thermal stability, the thermal quenching characteristics were measured at temperatures of $30{\sim}150^{\circ}C$. The results showed that the red PIG plates were 30% more thermally stable compared to the AlGaInP red chip.