Highly efficient and dual broad emitting light convertor: an option for next-generation plant growth LEDs

2019 ◽  
Vol 7 (12) ◽  
pp. 3617-3622 ◽  
Author(s):  
Mingcai Li ◽  
Xuejie Zhang ◽  
Haoran Zhang ◽  
Weibin Chen ◽  
Li Ma ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Plant Growth ◽  
Blue Light ◽  
Red Light ◽  
Light Sources ◽  
Full Width ◽  
Half Maximum ◽  
Next Generation ◽  
Led Light ◽  
Generation Plant

At present, blue-red composite LED light sources used for plant lighting are mainly composed of blue light and red light; the blue light is provided by gallium nitride LED chips, but the full-width at half-maximum (FWHW) is only approximately 25 nm, while the blue light required by plants for photosynthesis is wider.

scholarly journals Single Wavelengths of LED Light Supplement Promote the Biosynthesis of Major Cyclic Monoterpenes in Japanese Mint

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1420
Author(s):  
Takahiro Ueda ◽  
Miki Murata ◽  
Ken Yokawa
Keyword(s):  
Blue Light ◽  
Solid Phase ◽  
Glandular Trichomes ◽  
Red Light ◽  
Glandular Trichome ◽  
Pulse Amplitude ◽  
Light Treatment ◽  
Led Light ◽  
Trichome Formation ◽  
Japanese Mint

Environmental light conditions influence the biosynthesis of monoterpenes in the mint plant. Cyclic terpenes, such as menthol, menthone, pulegone, and menthofuran, are major odor components synthesized in mint leaves. However, it is unclear how light for cultivation affects the contents of these compounds. Artificial lighting using light-emitting diodes (LEDs) for plant cultivation has the advantage of preferential wavelength control. Here, we monitored monoterpene contents in hydroponically cultivated Japanese mint leaves under blue, red, or far-red wavelengths of LED light supplements. Volatile cyclic monoterpenes, pulegone, menthone, menthol, and menthofuran were quantified using the head-space solid phase microextraction method. As a result, all light wavelengths promoted the biosynthesis of the compounds. Remarkably, two weeks of blue-light supplement increased all compounds: pulegone (362% increase compared to the control), menthofuran (285%), menthone (223%), and menthol (389%). Red light slightly promoted pulegone (256%), menthofuran (178%), and menthol (197%). Interestingly, the accumulation of menthone (229%) or menthofuran (339%) was observed with far-red light treatment. The quantification of glandular trichomes density revealed that no increase under light supplement was confirmed. Blue light treatment even suppressed the glandular trichome formation. No promotion of photosynthesis was observed by pulse-amplitude-modulation (PAM) fluorometry. The present result indicates that light supplements directly promoted the biosynthetic pathways of cyclic monoterpenes.

scholarly journals Identification and expression of the trehalose-6-phosphate synthase gene family members in tomato exposed to different light spectra

2017 ◽  
Vol 69 (1) ◽  
pp. 93-101
Author(s):  
Zexiong Chen ◽  
Juan Lou
Keyword(s):  
Plant Growth ◽  
Blue Light ◽  
White Light ◽  
Growth And Development ◽  
Light Quality ◽  
Red Light ◽  
Floral Transition ◽  
Stem Length ◽  
Pcr Analysis ◽  
Phosphate Synthase

Light is the source of energy for plants. Light wavelengths, densities and irradiation periods act as signals directing morphological and physiological characteristics during plant growth and development. To evaluate the effects of light wavelengths on tomato growth and development, Solanum lycopersicum (cv. micro-Tom) seedlings were exposed to different light-quality environments, including white light and red light supplemented with blue light (at ratios of 3:1 and 8;1, respectively). Tomatoes grown under red light supplemented with blue light displayed significantly shorter stem length, a higher number of flower buds and rate of fruit set, but an extremely late flowering compared to white-light-grown plants. To illustrate the mechanism underlying the inhibition of stem growth and floral transition mediated by red/blue light, 10 trehalose-6-phosphate synthase (TPS) genes were identified in tomato, and bioinformatics analysis was performed. qRT-PCR analysis showed that SlTPSs were expressed widely throughout plant development and SlTPS1 was expressed at extremely high levels in stems and buds. Further analysis of several flowering-associated genes and microRNAs showed that the expressions of SlTPS1, SlFT and miR172 were significantly downregulated in tomato grown under red and blue light compared with those grown under white light, whereas miR156 transcript levels were increased. A regulatory model underlying vegetative growth and floral transition regulated by light qualities is presented. Our data provide evidence that light quality strongly affects plant growth and phase transition, most likely via the TPS1-T6P signaling pathway.

scholarly journals Blue light attracts nocturnally migrating birds

The Condor ◽  
2020 ◽  
Vol 122 (2) ◽  
Author(s):  
Xuebing Zhao ◽  
Min Zhang ◽  
Xianli Che ◽  
Fasheng Zou
Keyword(s):  
Blue Light ◽  
Field Experiments ◽  
Red Light ◽  
Light Pollution ◽  
Artificial Light ◽  
Light Sources ◽  
Rapid Urbanization ◽  
Phototactic Response ◽  
Migrating Birds ◽  
The Impact

Abstract Light pollution is increasing and artificial light sources have great impacts on animals. For migrating birds, collisions caused by artificial light pollution are a significant source of mortality. Laboratory studies have demonstrated that birds have different visual sensitivities to different colors of light, but few field experiments have compared birds’ responses to light of different wavelengths. We used 3 monochromatic lights (red, green, and blue) and polychromatic yellow light to study the impact of wavelength on phototaxis at 2 gathering sites of nocturnally migrating birds in Southwest China. For both sites, short-wavelength blue light caused the strongest phototactic response. In contrast, birds were rarely attracted to long-wavelength red light. The attractive effect of blue light was greatest during nights with fog and headwinds. As rapid urbanization and industrialization cause an increase in artificial light, we suggest that switching to longer wavelength lights is a convenient and economically effective way to reduce bird collisions.

InGaN/AlGaN Double-Heterostructure Blue Leds

1994 ◽  
Vol 339 ◽  
Author(s):  
Shuji Nakamura
Keyword(s):  
Blue Light ◽  
Full Width ◽  
Half Maximum ◽  
Ingan Layer ◽  
Peak Wavelength ◽  
Forward Voltage ◽  
High Brightness ◽  
Light Emitting ◽  
Double Heterostructure ◽  
First Time

ABSTRACTHigh-brightness InGaN/AlGaN double-heterostructure (DH) blue-light-emitting diodes (LEDs) with a luminous intensity of 1.2 cd were fabricated successfully for the first time. As an active layer, a Zn-doped InGaN layer was used. The peak wavelength and the full width at half-maximum of the electroluminescence were 450 nm and 70 nm, respectively. The forward voltage was as low as 3.6V at 20 mA.

Performance Optimization of Blue-light Blocking Lens Through Analysis of Blue Light Emitted from LED Light Sources

2016 ◽  
Vol 21 (4) ◽  
pp. 393-400 ◽  
Author(s):  
Younghyun Son ◽  
Seok-Jun Yang ◽  
Chang Jin Kim ◽  
Gyeong Sun Lee ◽  
Su Mi Choi ◽  
...  
Keyword(s):  
Blue Light ◽  
Performance Optimization ◽  
Light Sources ◽  
Led Light

scholarly journals Virtual Plant Tissue: Building Blocks for Next-Generation Plant Growth Simulation

2017 ◽  
Vol 8 ◽  
Author(s):  
Dirk De Vos ◽  
Abdiravuf Dzhurakhalov ◽  
Sean Stijven ◽  
Przemyslaw Klosiewicz ◽  
Gerrit T. S. Beemster ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Tissue ◽  
Building Blocks ◽  
Next Generation ◽  
Growth Simulation ◽  
Virtual Plant ◽  
Generation Plant

Narrow-band red emitting oxonitridosilicate phosphor La4−xSr2+xSi5N12−xOx:Pr3+ (x ≈ 1.69)

2021 ◽  
Vol 57 (31) ◽  
pp. 3761-3764
Author(s):  
Hong-Wei Zheng ◽  
Xiao-Ming Wang ◽  
Heng-Wei Wei ◽  
Yu Zheng ◽  
Cong-Ling Yin ◽  
...  
Keyword(s):  
Blue Light ◽  
Narrow Band ◽  
Full Width ◽  
Half Maximum ◽  
Red Emission

The new oxonitridosilicate phosphor La2.31Sr3.69Si5N10.31O1.69:Pr3+could be excited with near-UV and blue light, and shows a narrow-band red emission peaking at 625 nm with a full width at half-maximum of 40 nm.

scholarly journals Spectral Effects of Three Types of White Light-emitting Diodes on Plant Growth and Development: Absolute versus Relative Amounts of Blue Light

HortScience ◽  
2013 ◽  
Vol 48 (4) ◽  
pp. 504-509 ◽  
Author(s):  
Kevin R. Cope ◽  
Bruce Bugbee
Keyword(s):  
Plant Growth ◽  
Blue Light ◽  
Plant Development ◽  
Growth And Development ◽  
Stem Elongation ◽  
Leaf Expansion ◽  
Light Sources ◽  
Plant Growth And Development ◽  
Light Emitting ◽  
White Leds

Light-emitting diodes (LEDs) are a rapidly developing technology for plant growth lighting and have become a powerful tool for understanding the spectral effects of light on plants. Several studies have shown that some blue light is necessary for normal growth and development, but the effects of blue light appear to be species-dependent and may interact with other wavelengths of light as well as photosynthetic photon flux (PPF). We report the photobiological effects of three types of white LEDs (warm, neutral, and cool, with 11%, 19%, and 28% blue light, respectively) on the growth and development of radish, soybean, and wheat. All species were grown at two PPFs (200 and 500 μmol·m−2·s−1) under each LED type, which facilitated testing the effect of absolute (μmol photons per m−2·s−1) and relative (percent of total PPF) blue light on plant development. Root and shoot environmental conditions other than light quality were uniformly maintained among six chambers (three lamp types × two PPFs). All LEDs had similar phytochrome photoequilibria and red:far red ratios. Blue light did not affect total dry weight (DW) in any species but significantly altered plant development. Overall, the low blue light from warm white LEDs increased stem elongation and leaf expansion, whereas the high blue light from cool white LEDs resulted in more compact plants. For radish and soybean, absolute blue light was a better predictor of stem elongation than relative blue light, but relative blue light better predicted leaf area. Absolute blue light better predicted the percent leaf DW in radish and soybean and percent tiller DW in wheat. The largest percentage differences among light sources occurred in low light (200 μmol·m−2·s−1). These results confirm and extend the results of other studies indicating that light quantity and quality interact to determine plant morphology. The optimal amount of blue light likely changes with plant age because plant communities balance the need for rapid leaf expansion, which is necessary to maximize radiation capture, with prevention of excessive stem elongation. A thorough understanding of this interaction is essential to the development of light sources for optimal plant growth and development.

PHOTOTHERAPY FOR MILD TO MODERATE ACNE VULGARIS WITH PORTABLE BLUE AND RED LED

2011 ◽  
Vol 04 (01) ◽  
pp. 45-52 ◽  
Author(s):  
GUANGDA LIU ◽  
CHANGE PAN ◽  
KAI LI ◽  
YUAN TAN ◽  
XUNBIN WEI
Keyword(s):  
Side Effects ◽  
Light Emitting Diode ◽  
Acne Vulgaris ◽  
Red Light ◽  
Light Sources ◽  
Light Emitting ◽  
Led Light ◽  
Led Phototherapy ◽  
Red Led ◽  
Complete Treatment

In this paper, we studied portable blue and red light-emitting-diode (LED) light sources in phototherapy for mild to moderate acne vulgaris to evaluate the efficacy and tolerance of patients. Patients, randomly divided into blue and red groups, received either blue or red LED phototherapy twice a week for four weeks. After complete treatment, the number of lesions reduced by 71.4% in the blue group, in contrast to 19.5% in the red group. No obvious side effects were observed during and one month after the treatment, except for some mild dryness mentioned by several patients.

An intelligent VegeCareAI tool for next generation plant growth management

2021 ◽  
Vol 14 ◽  
pp. 100381
Author(s):  
Makoto Ikeda ◽  
Natwadee Ruedeeniraman ◽  
Leonard Barolli
Keyword(s):  
Plant Growth ◽  
Growth Management ◽  
Next Generation ◽  
Generation Plant
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