• Title/Summary/Keyword: Light-emitting Diode

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Development of Current Control System for Solar LED Street Light System

  • Kim, Byun-Gon;Kim, Kwan-Woong;Jang, Tae-Su;Lee, Jun-Myung;Kim, Yong-Kab
    • International journal of advanced smart convergence
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    • v.1 no.1
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    • pp.52-56
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    • 2012
  • As inexhaustible clean energy, solar energy will be the most ideal green energy in the 21st century. The effective method to convert solar energy into electrical energy is by solar photovoltaic power generation technologies. LED Emitting Diode is a kind of component which can transform electricity into visible light. As the smart current control system for photovoltaic street lights, the proposed system has improved the battery charging and discharging mechanism to extend the lifespan and effectively controls the LED discharge current according to battery charge state and lighting.

Postantibiotic Effects of Photodynamic Therapy Using Erythrosine and Light Emitting Diode on Streptococcus mutans

  • Yoo, Min Seok;Lee, Si Young
    • International Journal of Oral Biology
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    • v.41 no.1
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    • pp.39-43
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    • 2016
  • Dental caries, the most common oral disease, is a multifactorial disease caused by interactions among bacteria within the dental plaque, food, and saliva, resulting in tooth destruction. Streptococcus mutans has been strongly implicated as the causative organism in dental caries and is frequently isolated from human dental plaque. Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. Postantibiotic effect (PAE) is defined as the duration of suppressed bacterial growth following brief exposure to an antibiotic. In this study, the in vitro PAE of PDT using erythrosine and light emitting diode on S. mutans ATCC 25175 was investigated. The PAE of PDT for 1 s irradiation and 3 s irradiation were 1.65 h and 2.1 h, respectively. The present study thus confirmed PAE of PDT using erythrosine on S. mutans.

White Light Emitting Diode with the Parallel Integration of InGaN-based Multi-quantum Well Structures (InGaN계 다중양자우물구조를 병렬 집적화한 백색광소자의 특성 연구)

  • 김근주;이기형
    • Journal of the Semiconductor & Display Technology
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    • v.3 no.4
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    • pp.39-43
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    • 2004
  • The parallel multi-quantum well structures of blue and amber lights were designed and grown in metal-organic chemical vapor deposition by utilizing integration process on epitaxial layers. Samples were deposited for 5 periods-InGaN multi-quantum well layers for blue light emission and partially etched in order to regrow the 3 periods-InGaN multi-quantum wells for amber light. The blue and amber photoluminescence spectra were observed at the peak wavelengths of 475 and 580 nm, respectively. The chromatic coordinates of the white emitting diode were 0.31 and 0.34.

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Wide Color Gamut Backlight from Three-band White LED

  • Kim, Il-Ku;Chung, Kil-Yoan
    • Journal of the Optical Society of Korea
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    • v.11 no.2
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    • pp.67-70
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    • 2007
  • A Wide Color Gamut Backlight system was studied using a three-band white Light-Emitting Diode. A three-band white light-emitting diode (LED) was fabricated using an InGaN-based blue LED chip that emits 445-nm blue peak, and a green phosphor and red phosphor that emit 535-nm green and 621-nm red peak emissions, respectively, when excited by 450-nm blue light. Using for this three-band white LED, wide color gamut backlight unit (BLU) was attained. The luminance of BLU and CIE 1931 chromaticity coordinates was $1,700Cd/m^2$ and (0.337, 0.346). Color filter matching simulations for this configuration show that the three-band white LED backlight can be enhanced by up to 16% over conventional white LED backlight color gamut.

Dentin shear bond strength and degree of conversion of the dentin bonding agents irradiated with light emitting diode

  • Kim, Sun-Young;Um, Chung-Moon
    • Proceedings of the KACD Conference
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    • 2003.11a
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    • pp.576-577
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    • 2003
  • I. Objectives This study investigated the dentin shear bond strength and the degree of conversion (DC) of currently used dentin bonding agents (DBAs) that were irradiated with a light emitting diode (LED) light curing unit (LCU) and a halogen LCU. II. Materials and methods The halogen LCU and the LED LCU used in this study were a VIP(Bisco, Schaumburg, IL, USA) and an Elipar Freelight(3M ESPE, St Paul, MN, USA) respectively. For the VIP, $400mW{\cdot}cm-2$ intensity mode was used to adjust to the intensity of the LED LCU. The DBAs used in this study were Scotchbond Multipurpose (3M ESPE), Single Bond (3M ESPE), One-step(Bisco), Clearfil SE Bond(Kuraray), and Adper Prompt(3M ESPE).(omitted)

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