scholarly journals Preliminary Investigation of LED Lighting as Growth Light for Seedlings from Different Tree Species in Growth Chambers

2012 ◽  
Vol 40 (2) ◽  
pp. 31 ◽  
Author(s):  
Stefania ASTOLFI ◽  
Chiara MARIANELLO ◽  
Stefano GREGO ◽  
Rosanna BELLAROSA
Keyword(s):  
Plant Species ◽  
Light Quality ◽  
Prunus Avium ◽  
Light Emitting Diode ◽  
Preliminary Investigation ◽  
Holm Oak ◽  
Fluorescent Light ◽  
Shoot Height ◽  
Led Light ◽  
Chlorophyll Contents

The influence of light quality on growth and metabolic activity during pre-cultivation (in miniplug containers) of beech (Fagus sylvatica L.), holm oak (Quercus ilex L.) and wild cherry (Prunus avium) plants was investigated. Seedlings were grown in a growth chamber for a month under light-emitting diode (LED) light or fluorescent light. The LED lamps (Valoya) used in this study emitted a continuous spectrum thanks to a mixture of blue, green, red and far-red LEDs. Our results showed that plant response to light quality seems to be related to the plant species. In particular, in beech seedlings fresh and dry weight, shoot height and leaf area were greatest when plants were cultured under LED light, and lowest under fluorescent lamps. Furthermore, we found that LED-induced reduction of chlorophyll contents in beech and holm oak leaves resulted in an increase of the carboxylase capacity of Rubisco in the same plant species suggesting an improvement of light-use-efficiency in these plants. These results indicate that LED light may be suitable for the culture of plants in tightly controlled environments. The comparison of malondialdehyde levels between LED and fluorescent grown plants strongly supports this idea.

scholarly journals Changes in Beneficial C-glycosylflavones and Policosanol Content in Wheat and Barley Sprouts Subjected to Differential LED Light Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1502
Author(s):  
Muthusamy Muthusamy ◽  
Jong Hee Kim ◽  
Suk Hee Kim ◽  
Joo Yeol Kim ◽  
Jeong Wook Heo ◽  
...  
Keyword(s):  
Light Quality ◽  
Higher Plants ◽  
Light Emitting Diode ◽  
Growth Period ◽  
Light Irradiation ◽  
Fluorescent Light ◽  
Light Conditions ◽  
Wheat Seedlings ◽  
Blue Led ◽  
Led Light

The spectral quality and intensity of light, photoperiodism, and other environmental factors have profound impacts on the metabolic composition of light-dependent higher plants. Hence, we investigate the effects of fluorescent light (96 μmol m−2s−1) and white (100 μmol m−2s−1), blue (100 μmol m−2s−1), and red (93 μmol m−2s−1) light-emitting diode (LED) light irradiation on the C-glycosylflavone and policosanol contents in young seedlings of wheat and barley. Ultra-high-performance liquid chromatography (UHPLC) analyses of C-glycosylflavone contents in barley reveal that the saponarin content is significantly enhanced under blue LED light irradiation. Under similar conditions, isoorientin and isoschaftoside contents are improved in wheat seedlings. The contents of these C-glycosylflavones differed along with the light quality and growth period. The highest accumulation was observed in sprouts after three days under blue LED light irradiation. GC/MS analyses of policosanol contents showed that 1-hexacosanol (C26:o–OH) in barley and 1-octacosanol (C28:o–OH) in wheat seedlings were reduced under LED light irradiation, compared to seedlings under fluorescent light conditions. Nonetheless, the policosanol contents gradually improved with the extension of growth times and treatments, irrespective of the light quality. Additionally, a positive correlation was observed between the expression pattern of biosynthesis-related genes and the respective metabolite content in barley. This study demonstrates that blue LED light irradiation is useful in maximizing the C-glycosylflavone content in barley and wheat sprouts.

scholarly journals Growth of Impatiens, Petunia, Salvia, and Tomato Seedlings under Blue, Green, and Red Light-emitting Diodes

HortScience ◽  
2014 ◽  
Vol 49 (6) ◽  
pp. 734-740 ◽  
Author(s):  
Heidi Marie Wollaeger ◽  
Erik S. Runkle
Keyword(s):  
Light Quality ◽  
Light Emitting Diode ◽  
Red Light ◽  
Morphological Characteristics ◽  
Photon Flux ◽  
Fluorescent Light ◽  
Flower Bud ◽  
Specialty Crops ◽  
Light Emitting ◽  
Shoot Weight

Plant growth and architecture are regulated in part by light quality. We performed experiments to better understand how young plants acclimate to blue (B), green (G), and red (R) light and how those responses can be used to produce plants with desirable morphological characteristics. We grew seedlings of impatiens (Impatiens walleriana), salvia (Salvia splendens), petunia (Petunia ×hybrida), and tomato (Solanum lycopersicum) under six sole-source light-emitting diode (LED) treatments or one cool-white fluorescent treatment that each delivered a photosynthetic photon flux (PPF) of 160 µmol·m−2·s–1 for 18 h·d−1. Leaf number was similar among treatments, but plants grown under 25% or greater B light were 41% to 57% shorter than those under only R light. Plants under R light had 47% to 130% greater leaf area and 48% to 112% greater fresh shoot weight than plants grown under treatments with 25% or greater B. Plants grown under only R had a fresh shoot weight similar to that of those grown under fluorescent light for all species except tomato. In impatiens, flower bud number at harvest generally increased with B light, whereas in tomato, the number of leaflets with intumescences decreased with B light. This research discusses how light quality can be manipulated for desired growth characteristics of young plants, which is important in the production of specialty crops such as ornamentals, herbs, and microgreens.

Evaluation of Color Rendering Index for LED and Fluorescent Light Sources

2015 ◽  
Vol 731 ◽  
pp. 22-26
Author(s):  
Huan Jiang ◽  
Min Huang ◽  
Fu Song Yang ◽  
Yu Liu
Keyword(s):  
Light Emitting Diode ◽  
Fluorescent Light ◽  
Light Sources ◽  
Light Emitting ◽  
Led Light ◽  
Color Science ◽  
Color Rendering Index ◽  
Different Color ◽  
Color Rendering

In order to assess the performances of different color rendering index (Ra, CRI, CQS, nCRI, R96a). The LED (light-emitting diode), fluorescent light sources and 30 printed color samples were used in our experiment. 20 observers were organized to carry out the color preference experiment, the visual data were accumulated to test the performances of the light sources and the results indicated that existing color rendering index have some deficiencies to assess the quality of the light source, which were needed to be modified for the theory of color science and industry application. The new CQS additional scales were calculated and the improvements were still insufficient for the LED light sources.

scholarly journals Design of a Secondary Freeform Lens of UV LED Mosquito-Trapping Lamp for Enhancing Trapping Efficiency

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 335 ◽  
Author(s):  
Wei-Hsiung Tseng ◽  
Diana Juan ◽  
Wei-Cheng Hsiao ◽  
Cheng-Han Chan ◽  
Hsin-Yi Ma ◽  
...  
Keyword(s):  
Light Intensity ◽  
Intensity Distribution ◽  
Light Emitting Diode ◽  
Trapping Efficiency ◽  
Axially Symmetric ◽  
Light Intensity Distribution ◽  
Light Emitting ◽  
Led Light ◽  
Uv Led ◽  
Freeform Lens

In this study, our proposed ultraviolet light-emitting diode (UV LED) mosquito-trapping lamp is designed to control diseases brought by insects such as mosquitoes. In order to enable the device to efficiently catch mosquitoes in a wider area, a secondary freeform lens (SFL) is designed for UV LED. The lens is mounted on a 3 W UV LED light bar as a mosquito-trapping lamp of the new UV LED light bar module to achieve axially symmetric light intensity distribution. The special SFL is used to enhance the trapping capabilities of the mosquito-trapping lamp. The results show that when the secondary freeform surface lens is applied to the experimental outdoor UV LED mosquito-trapping lamp, the trapping range can be expanded to 100π·m2 and the captured mosquitoes increased by about 300%.

scholarly journals Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang
Keyword(s):  
Light Source ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Distribution ◽  
Light Sources ◽  
Led Light ◽  
High Power Led ◽  
Distribution Requirement ◽  
Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

scholarly journals Virulence of Aerial Conidia of Beauveria bassiana Produced under LED Light to Ctenocephalides felis (Cat Flea)

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Sarayut Pittarate ◽  
Malee Thungrabeab ◽  
Supamit Mekchay ◽  
Patcharin Krutmuang
Keyword(s):  
Beauveria Bassiana ◽  
Adult Mortality ◽  
Ctenocephalides Felis ◽  
Fluorescent Light ◽  
Malt Extract ◽  
Led Light ◽  
Red Led ◽  
Aerial Conidia ◽  
Different Color

Ctenocephalides felis is an ectoparasitic flea species commonly found on dogs and cats. The current study verified the in vitro virulence of conidia of the entomopathogenic fungus Beauveria bassiana produced under different color LED light (red, blue, purple, green, yellow, and white) to adults of C. felis. The fungal isolates were cultivated on malt extract agar (MEA). Bioassay treatments used aerial conidia in test tubes. Adult fleas were obtained from a house cat in Chiang Mai province, Thailand. The experiments were composed of one control and eleven treatment groups. All of the treatments with B. bassiana conidia caused adult mortality after an exposure of 12 h. Among the conditions used in this study, B. bassiana cultured under red LED and fluorescent light were the most effective in causing mortality (100 %) in adult fleas after 36 h. The experimental results indicate that these aerial conidia of B. bassiana have promising potential for use in control of C. felis adult stages.

scholarly journals An RNA-Seq Analysis of Grape Plantlets Grown in vitro Reveals Different Responses to Blue, Green, Red LED Light, and White Fluorescent Light

2017 ◽  
Vol 8 ◽  
Author(s):  
Chun-Xia Li ◽  
Zhi-Gang Xu ◽  
Rui-Qi Dong ◽  
Sheng-Xin Chang ◽  
Lian-Zhen Wang ◽  
...  
Keyword(s):  
Fluorescent Light ◽  
Rna Seq ◽  
Led Light ◽  
Red Led

Reliability of High-Power Light Emitting Diode Attached With Different Thermal Interface Materials

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xin Li ◽  
Xu Chen ◽  
Guo-Quan Lu
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Temperature Cycling ◽  
Fluorescent Light ◽  
Light Sources ◽  
Light Emitting ◽  
Die Attach ◽  
Nanosilver Paste ◽  
Interconnection Material

As a solid electroluminescent source, white light emitting diode (LED) has entered a practical stage and become an alternative to replace incandescent and fluorescent light sources. However, due to the increasing integration and miniaturization of LED chips, heat flux inside the chip is also increasing, which puts the packaging into the position to meet higher requirements of heat dissipation. In this study, a new interconnection material—nanosilver paste is used for the LED chip packaging to pursue a better optical performance, since high thermal conductivity of this material can help improve the efficiency of heat dissipation for the LED chip. The bonding ability of this new die-attach material is evaluated by their bonding strength. Moreover, high-power LED modules connected with nanosilver paste, Sn3Ag0.5Cu solder, and silver epoxy are aged under hygrothermal aging and temperature cycling tests. The performances of these LED modules are tested at different aging time. The results show that LED modules sintered with nanosilver paste have the best performance and stability.

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