• 제목/요약/키워드: Light of the sun

검색결과 1,938건 처리시간 0.028초

Characteristics Investigation of Organic Light Emitting Diodes Using Numerical Device Simulation

  • Lee, Yang-Soo;Park, Jae-Hoon;Choi, Jong-Sun
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
    • /
    • pp.28-31
    • /
    • 2003
  • We have investigated the electrical characteristics of the organic light emitting diodes (OLEDs) using the numerical device simulation. The current-voltage characteristics, the charge carrier concentrations, and the recombination rate profiles are presented. The simulation results of the effects of the various device parameters on the device characteristics are discussed.

  • PDF

Advanced Organic LED Materials for the Excellent Organic LED Displays

  • Enokida, Toshio;Gwon, Tae-Sun
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2001년도 International Meeting on Information Display
    • /
    • pp.189-190
    • /
    • 2001
  • In this paper, we explain the materials of the advanced organic light emitting diode(OLED) for the excellent OLED displays. We have been designed the various kinds of organic materials like as the hole-injecting materials (HIMs), the hole transporting materials(HTMs). the light emitting materials(LEMs), and the electron injecting materials(EIMs). As the results, we found the excellent materials and their combinations for the OLED displays.

  • PDF

A Novel Light Guide Plate with Micro-prisms for an Edge-lit LED Backlight

  • Kwon, Jae-Joong;Kim, Hyoung-Joo;Shim, Sung-Kyu;Baek, Seung-In;Hwang, In-Sun;Jang, Tae-Seok
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
    • /
    • pp.1193-1195
    • /
    • 2008
  • We propose a novel light guide plate for an edge-lit LED backlight. Properly designed micro-prisms enable light to go out of the LGP in near vertical direction and luminance fluctuations in front of the LEDs to be invisible.

  • PDF

Experiment Investigation of Partial Rotor Rub

  • Park, Yeon-Sun
    • Journal of Mechanical Science and Technology
    • /
    • 제14권11호
    • /
    • pp.1250-1256
    • /
    • 2000
  • Rubbing occurs when a rotor contacts with a stator during whirling motion of the rotor. Compared to full annular rub, partial rub against a nonrotating part is more common in practice. In this study, several partial rubbing phenomena of superharmonic and subharmonic vibrations and jump phenomenon are demonstrated experimentally for the cases of light and heavy rub for a flexible rotor. The orbit patterns of forward or backward whirling are also calculated using directional spectrum analysis. The occurrence if subharmonic vibration during heavy rub is demonstrated as one impact per two rotations both experimentally and numerically.

  • PDF

CMP 공정이 ITO 박막의 전기적.광학적 특성에 미치는 영향 (Electrical and Optical Properties of ITO Thin Film by CMP Process Parameter)

  • 최권우;서용진;이우선
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
    • /
    • pp.354-355
    • /
    • 2005
  • Indium tin oxide (ITO) thin film was polished by chemical mechanical polishing (CMP) by the change of process parameters for the improvement of electrical and optical properties of ITO thin film. Light transparent efficiency of ITO thin film was improved after CMP process at the optimized process parameters compared to that before CMP process.

  • PDF

차즈기(Perilla frutescens var. acuta)의 생육에 미치는 생장억제제의 영향 (Effect of Growth Retardants on the Growth of Periila fuetescens var. acuta)

  • 이종석;박영민
    • 한국환경복원기술학회지
    • /
    • 제7권2호
    • /
    • pp.1-11
    • /
    • 2004
  • The purpose of this study was to determine usability as potted flowers and garden plants by controlled plant height using growth retardants. There was no significant difference on the dwarfing effect according to the degree of exposure the sun, but growth was well under full exposure to the sun. The plant height was decreased by application of Cycocel (CCC), Bonzi (paclobutrzol), Ancymidol, and Uniconazole compared to the control group, and treatment of Bonzi $5mg{\cdot}L^{-1}$ was most dwarfing effect for both full sun exposure or 70% controlled shading condition. No consistent different was found in stem diameter, leaf color change, the content of chlorophyll and anthocyanin when the concentration of plant growth retardants was altered. These factors were affected only by light intensity. In comparison to the results of the control group, leaf length, leaf width, plant width and petiole length were all reduced by the application of growth retardants.

광활성 유무가 치아미백과 치아표면 및 치수 내 온도에 미치는 영향 (Tooth bleaching effect by light activation on the tooth surface and intra-pulpal temperature: an in vitro study)

  • 심연수;우희선
    • 한국치위생학회지
    • /
    • 제14권4호
    • /
    • pp.585-591
    • /
    • 2014
  • Objectives : The purpose of this study was to investigate of the color change, tooth surface and intra-pulpal temperature of tooth bleaching by light activation Methods : Forty-eight extracted bovine teeth were immersed into a tea solution for 24 hours. The specimens were randomly divided into four groups(n=15):(G1) 15% HP + without light activation, (G2) 15% HP + light activation, (G3) 25% HP + without light activation, (G4) 25% HP + light activation. All specimens were bleached for 15 minutes three times. The spectrophotometer (CM-2600d, Konica Minolta, Osaka, Japan) was used including before bleaching, immediately after bleaching, 1 week, 1 and 3 months after the end of bleaching. The temperature rise were measured in the pulpal chamber and tooth surface with a digital thermocouple thermometer(Termopar Digital Multimeter, Tektronix DMM916, USA). Between the tested time points, the specimens were stored in distilled water. The data were analyzed by ANOVA, t-test and Tukey's post hoc test set at 0.05. Results : There was no significant color change by the use of light after the bleaching treatment(p>0.05). The dental bleaching treatments of teeth with 15% HP and 25% HP did not seem to be more effective when light source was used. There was no difference in color stability between groups within three month(p>0.05). There was an increase in tooth surface and pulp temperature, but it was not sufficient to cause damage to the pulp. Conclusions :The use of light activation has no obvious effective impact on the tooth bleaching effect.

고에너지 전자선 측정을 위한 광섬유 방사선 센서에서의 체렌코프 빛 측정 및 분석 (Measurements and characterizations of cerenkov light in fiber-optic radiation sensor irradiated by high energy electron beam)

  • 장경원;조동현;정순철;전재훈;이봉수;김신;조효성;박성용;신동호
    • 센서학회지
    • /
    • 제15권3호
    • /
    • pp.186-191
    • /
    • 2006
  • In general, Cerenkov light is produced by a charged particle that passes through a medium with a velocity greater than that of visible light. Although the wavelength of Cerenkov light is very broad, the peak is in the almost visible range from 400 to 480 nm. Therefore, it always causes a problem to detect a real light signal that is generated in the scintillator on the fiber-optic sensor tip for dose measurements of high-energy electron beam. The objectives of this study are to measure, characterize and remove Cerenkov light generated in a fiber-optic radiation sensor tip to detect a real light signal from the scintillator. In this study, the intensity of Cerenkov light is measured and characterized as a function of incident angle of electron beam from a LINAC, and as a function of the energy of electron beam. As a measuring device, a photodiode-amplifier system is used, and a subtraction method using a background optical fiber is investigated to remove Cerenkov light.

Synthesis and Characterization of Poly[9,10-diphenylanthracene-4$^\prime$, 4$^\prime^\prime$-ylenevinylene-3,6-(N-2-ethylhexyl)carbazole]

  • 김윤미;박기민;권순기
    • Bulletin of the Korean Chemical Society
    • /
    • 제22권9호
    • /
    • pp.975-978
    • /
    • 2001
  • A novel poly[9,10-diphenylanthracene-4',4"-ylenevinylene-3,6-(N-2-ethyl hexyl)carbazole] containing alternate diphenylanthracene and carbazole unit was synthesized by the Wittig reaction. The obtained polymer was soluble in common organic solvents and thermally stable up to 380 $^{\circ}C.$ The polymer gives rise to bright blue fluorescence both in solution and in thin solid films. The light emitted from the device (ITO/polymer/Al) was greenish-blue in color and clearly visible in daylight.