• 제목/요약/키워드: White Light

검색결과 1,626건 처리시간 0.029초

The effects of LEDs and duty ratio on the growth and physiological responses of Silene capitata Kom., endangered plant, in a plant factory

  • Park, Jae-Hoon;Lee, Eung-Pill;Han, Young-Sub;Lee, Soo-In;Cho, Kyu-Tae;Hong, Yong-Sik;You, Young-Han
    • Journal of Ecology and Environment
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    • 제42권4호
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    • pp.174-182
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    • 2018
  • Background: In this study, we observed their growth and physiological responses using a variety of duty ratio under the mixed light using red, blue, and white lights. The red+blue mixed light was treated with 95%, 90%, 85%, 80%, and 75% duty ratios and red+blue+white mixed light with 85% and 70% duty ratios. We examined the width and length of leaves, total number of leaves, and number of shoots to examine their growth responses. The physiological responses were studied by measuring their photosynthetic rate, transpiration rate, stomatal conductance, water use efficiency, chlorophyll content, and fluorescence ($F_o$, $F_m$, and $F_v/F_m$). Results: We found that lower duty ratio caused the length and width of the leaves to grow longer under red+blue mixed light but that it did not cause any difference in the red+blue+white mixed light condition. In addition, there was no difference in the number of leaves and shoots among all treatments. In the red+blue mixed light condition, the photosynthetic rate was no difference, but both transpiration rate and stomatal conductance were the highest at 95% duty ratio than in other ratios. Water use efficiency pattern was similar to that of photosynthetic rate; water use efficiency was no difference. Chlorophyll content was the highest at 95% duty ratios, and it was the least at 90%, 85%, and 75% duty ratio. $F_o$ and $F_m$ values were relatively high at 85% and 80% duty ratio and low at 90% duty ratio while $F_v/F_m$ showed no difference. Conclusions: Under the red+blue+white mixed light, all physiological items showed no difference between 70 and 85% treatments. But, photosynthetic rate, water use efficiency, chlorophyll content, and $F_v/F_m$ were relatively greater in the red+blue+white mixed light than in the red+blue mixed light. Therefore, red+blue+white mixed light treated with 70% duty ratio could lessen the environmental stress and save more power when cultivating Silene capitata in a plant factory.

The effect of different colored light emitting diode illumination on egg laying performance, egg qualities, blood hormone levels and behavior patterns in Brown Tsaiya duck

  • Su, Chin-Hui;Cheng, Chih-Hsiang;Lin, Jung-Hsin;Liu, Hsiu-Chou;Yu, Yen-Ting;Lin, Chai-Ching;Chen, Wei-Jung
    • Animal Bioscience
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    • 제34권11호
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    • pp.1870-1878
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    • 2021
  • Objective: The objective of this experiment was to investigate the effects of different colors produced by light emitting diode (LED) on Brown Tsaiya ducks. Methods: A total of 144 female Brown Tsaiya ducks were randomly allocated into three individual cage rearing chambers with different LED illumination colors as treatments. Three different treatments were: i) white color, ii) blue color, and iii) red color. The experiment periods were from ducks 21 to 49 weeks of age, determined traits included i) egg laying performance, ii) feed intake, iii) egg shell breaking strength, iv) egg shell thickness, v) egg Haugh unit, vi) egg weight, vii) serum Estradiol and Progesterone concentration, and viii) behavior pattern. Results: The results indicated that when compared with white and blue color, red color could stimulate ducks sexual maturation and raised the egg laying performance. The red light group was also observed to have the highest feed intake among three treatments. The blue treatment had the lowest egg shell breaking strength and the highest egg weight among three treatments, nevertheless, no significant difference was observed among three treatments on egg shell thickness and egg Haugh unit. The red light group had higher serum estradiol concentration than the white and blue groups, but no significant difference among treatments on the serum Progesterone concentration was found. The results of behavior pattern indicated that red light group showed more feeding and less resting behavior compared to the blue light group. Conclusion: We found a potential of applying red light illumination in the indoor laying duck raising system with positive results on egg laying performance and acceptable egg weight, equivalent egg qualities compared to white and blue light.

암면큐브를 이용한 육묘에서 LED 광질에 따른 파프리카 묘의 생육 특성 (Growth Characteristics of Paprika Seedlings Affected by Different LED Light Qualities Raising Seedlings Using Rockwool Cube)

  • 이세형;고바울;배종향;구양규;김호철
    • 생물환경조절학회지
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    • 제31권1호
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    • pp.60-66
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    • 2022
  • 본 연구는 파프리카 육묘 시 다양한 LED 광질(red:blue = 10:0, 8:2, 2:8, white)에 따른 생육변화에 대하여 구명하여 수경재배용 묘 생산을 위한 전용육묘장의 기반기술로 활용하고자 수행하였다. 초장과 줄기직경의 생육은 red 비율이 높을수록 유의하게 길거나 굵었고, 엽면적은 LED red:blue = 8:2에서 가장 넓었다. 건물 중량도 엽면적과 동일한 경향이었다. LED white에서는 모든 묘의 소질에서 다른 처리들보다 뚜렷하게 저조하였다. 상대생장률은 red 비율이 높을수록 높은 경향을 나타내었고 순동화율은 blue 비율이 높을수록 높은 경향을 나타내었다. 따라서 본 시험에서 LED를 활용한 파프리카 육묘 시 초장, 엽면적, 단위엽면적당 건물생산능력 등을 고려하였을 때 혼합광을 이용하는 것이 적합하고 특히, LED red:blue = 8:2가 가장 적합한 것으로 생각된다. 그리고 red와 blue 파장의 적절한 혼합 비율을 통해 파프리카 묘의 초장 및 절간장을 제어할 수 있을 것으로 생각된다.

플렉시블 무기EL 색변환 백색 발광 소자 제작 및 특성평가 (The Fabrication and Characteristics of White Emission using CCM on Flexible Substrate)

  • 김기령;안성일;금정훈;이흥렬;임태홍;이성의
    • 한국전기전자재료학회논문지
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    • 제21권10호
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    • pp.911-915
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    • 2008
  • EL (electro-luminescent) device as a light source has an advantage in embodying large area with great flexibility. On nickel foil as an electrode and backplane, we demonstrated a white EL flexible light source with blue phosphor layer combined with color change layer. A correlation between color change layer and color coordination was analyzed by Gaussian method, and then the color coordinate was controlled near to (0.33, 0.33) of pure white light.

고출력 조명용 White LED의 수명예측 (Lifetime Estimation of High Power White LED for Lighting Use)

  • 이명훈;신승중;곽계달
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1343-1348
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    • 2008
  • LEDs which have many merits are widely used in the field of light devices, and have rapidly replaced old light devices such as incandescent or fluorescent lamps. Long life, on the order of 50,000 to 100,000 hours, is one of the key features of light emitting diodes(LEDs) that has attracted the lighting community to this technology. High Power white LEDs have yet to demonstrate this capability. This paper planed accelerated life test that has two factor(temperature, current) and two levels. Finally, using ALTA programs, we estimated the common shape parameter of Weibull distribution, life-stress relationship, B10 life and accelerating factors.

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실내 가시광 통신 시스템의 성능 분석 (Performance Analysis of Indoor Visible Light Communication Systems)

  • 최재혁;김성일;김진영
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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    • pp.7-11
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    • 2008
  • Future electric lights will be composed of white LEDs (Light Emitting Diodes). Indoor wireless optical communication systems utilizing white LED lights have been studying about it. Generally, plural lights are installed in room. Therefore, their optical path difference must be considered. In this paper, the influence of an optical path difference has been investigated and two approaches against this problem are introduced. One uses OOK-RZ (On-Off Keying, Return-to-Zero) coding and the other uses optical OFDM (Orthogonal Frequency Division Multiplexing). From the results of computer simulations, we have found that these approaches are feasible for the wireless optical communication systems utilizing white LED lights.

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SMD 타입 태양전지 어레이를 이용한 white GaN LED용 전원 공급 장치 (Power Supply for White GaN LED by Using SMD Type Solar Cell Array)

  • 김성일;이윤표
    • 신재생에너지
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    • 제5권4호
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    • pp.34-37
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    • 2009
  • Using six SMD(surface mount device) type AlGaAs/GaAs single junction solar cells connected in series, a power source was fabricated for a white GaN LED. The electrical properties of the power source was measured and analyzed under one sun (100mW/$cm^2$) and various indoor light (300 - 900 lux) conditions. Under 600 lux indoor light condition, output power was 17.06 ${\mu}W$ and it was 30.75 ${\mu}W$ under 900 lux indoor light condition. Using the fabricated solar cell power supply, we have turned on the white GaN LED. It was worked well under 15 ${\mu}W$(at 480 lux) power supplied from solar cell array. This kind of solar cell power supply can be used as a power source for ubiquitous sensor network (USN).

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백색 발광다이오드의 특성에 대한 황색 형광체의 영향 (Effect of Yellow Phosphor on Characteristics of White Light Emitting Diode)

  • 장호정;손창식;허재성
    • 한국표면공학회지
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    • 제40권2호
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    • pp.103-106
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    • 2007
  • We have investigated the optical and electrical properties of surface mounted white light emitting diode (LED) chips prepared by using yellow phosphors on the blue LED chip. The yellow phosphor mixed with transparent epoxy was coated on the prepared LED chip. The optimum mixing conditions with epoxy and yellow phosphor is obtained at the mixing ratio of epoxy:yellow phosphor = 97:3 wt%. The maximum luminance and light emitting efficiency are above $80,000cd/m^2$ and 23.2 lm/W, respectively, at the bias voltage of 2.9 V. There was no distinct change in the luminance strength with changing of the yellow phosphor ratios. The current of the white LED chip is about 30 mA at 2.9 V.

BCP 전자수송층 두께가 백색 OLED의 효율 및 발광 특성에 미치는 영향 (Effects of BCP Electron Transport Layer Thickness on the Efficiency and Emission Characteristics of White Organic Light-Emitting Diodes)

  • 서유석;문대규
    • 한국전기전자재료학회논문지
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    • 제27권1호
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    • pp.45-49
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    • 2014
  • We have fabricated white organic light-emitting diodes (OLEDs) using several thicknesses of electron-transport layer. The multi-emission layer structure doped with red and blue phosphorescent guest emitters was used for achieving white emission. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was used as an electron-transport layer. The thickness of BCP layer was varied to be 20, 55, and 120 nm. The current efficiency, emission and recombination characteristics of multi-layer white OLEDs were investigated. The BCP layer thickness variation results in the shift of emission spectrum due to the recombination zone shift. As the BCP layer thickness increases, the recombination zone shifts toward the electron-transport layer/emission-layer interface. The white OLED with a 55 nm thick BCP layer exhibited a maximum current efficiency of 40.9 cd/A.

White-Light-Emitting Materials for Organic Electroluminescent Devices

  • Kim, Duck-Young;Kwon, Oh-Kwan;Kwon, Hyuck-Joo;Kim, Young-Kwan;Sohn, Byoung-Chung;Ha, Yun-Kyoung
    • 한국응용과학기술학회지
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    • 제18권1호
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    • pp.7-11
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    • 2001
  • White emission is important for applying organic EL devices to full-color flat panel display and backlight for liquid crystal display. In order to obtain white emission, the use of a light-emitting material which shows the white emission by itself is advantageous for these applications because of its high reliability and productivity. A chelate-metal complex such as zinc bis(2-(2-hydroxyphenyl) benzothiazolate) ($Zn(BTZ)_{2}$ was known to emit white light with a broad electroluminescence. In this study, the electroluminescent characteristics of $Be(BTZ)_{2}$ and $Mg(BTZ)_{2}$, as well as $Zn(BTS)_2$ were investigated using organic electroluminescent devices with the structure of ITO/TPD/ $Be(BTZ)_{2}$, $Mg(BTZ)_{2}$, or $Zn(BTZ)_{2}/Al$. It was found that the device containing $Be(BTZ)_{2}$ showed the highest power efficiency.