Performance of Arabidopsis thaliana under different light qualities: comparison of light-emitting diodes to fluorescent lamp

2017 ◽  
Vol 44 (7) ◽  
pp. 727 ◽  
Author(s):  
Karin Köhl ◽  
Takayuki Tohge ◽  
Mark Aurel Schöttler
Keyword(s):  
Arabidopsis Thaliana ◽  
Light Source ◽  
Light Emitting Diodes ◽  
Seed Mass ◽  
Fluorescent Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Light Emitting ◽  
Led Light ◽  
Improve Energy Efficiency ◽  
Fluorescent Lamps

For precise phenotyping, Arabidopsis thaliana (L.) Heynh. is grown under controlled conditions with fluorescent lamps as the predominant light source. Replacement by systems based on light emitting diodes (LED) could improve energy efficiency and stability of light quality and intensity. To determine whether this affects the reproducibility of results obtained under fluorescent lamps, four Arabidopsis accessions and a phytochrome mutant were grown and phenotyped under two different LED types or under fluorescent lamps. All genotypes had significantly higher rosette weight and seed mass and developed faster under LED light than under fluorescent lamps. However, differences between genotypes were reproducible independent of the light source. Chlorophyll content, photosynthetic complex accumulation and light response curves of chlorophyll fluorescence parameters were indistinguishable under LED and fluorescent light. Principal component analysis of leaf metabolite concentrations revealed that the effect of a change from fluorescent light to LED light was small compared with the diurnal effect, which explains 74% of the variance and the age effect during vegetative growth (12%). Altogether, the replacement of fluorescent lamps by LED allowed Arabidopsis cultivation and reproduction of results obtained under fluorescent light.

scholarly journals Green-light Supplementation for Enhanced Lettuce Growth under Red- and Blue-light-emitting Diodes

HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1617-1622 ◽  
Author(s):  
Hyeon-Hye Kim ◽  
Gregory D. Goins ◽  
Raymond M. Wheeler ◽  
John C. Sager
Keyword(s):  
Plant Growth ◽  
Light Source ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Green Light ◽  
Light Sources ◽  
Natural Setting ◽  
Light Emitting ◽  
Fluorescent Lamps ◽  
Green Fluorescent

Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.

A novel optical panel photobioreactor for cultivation of microalgae

2013 ◽  
Vol 67 (11) ◽  
pp. 2543-2548 ◽  
Author(s):  
Hee-Jeong Choi ◽  
Jae-Min Lee ◽  
Seung-Mok Lee
Keyword(s):  
Flat Plate ◽  
Light Source ◽  
Cell Concentration ◽  
Fluorescent Light ◽  
Initial Cell Concentration ◽  
Light Emitting ◽  
Initial Cell ◽  
Fluorescent Lamps ◽  
Parametric Studies ◽  
Optical Panel Photobioreactor

In this study, a novel optical panel photobioreactor (OPPBR) equipped with a V-cut/or flat optical panel (OP) and a light source, i.e., light-emitting diodes (LEDs) was developed. The performance of this OPPBR was assessed using cultures of Chlorella vulgaris. Growth rates of biomass were compared in bioreactors operated separately using a V-cut OP, or a flat-plate OP both equipped with LEDs or a fluorescent light source without any OP. The experiments were conducted at neutral pH (7.2 ± 0.3) with an initial cell concentration of 0.15 ± 0.05 g L−1, at 23 ± 1 °C under dark and light cycles of 8 and 16 h, respectively, using LEDs and fluorescent lamps for 11 days. The results demonstrated that the amount of biomass produced using the V-cut OP was three times higher than the flat-plate OP and five times higher than without the OP. Parametric studies demonstrated that a distance of 3 mm between the OP and the LEDs produced the highest illumination uniformity, i.e., 65.7% for the flat-plate OP and 87.6% for the V-cut OP. The OPPBR system can be scaled up and could be used to enhance biomass production using an LED and OP combination.

scholarly journals Sugarcane micropropagation using light emitting diodes and adjustment in growth-medium sucrose concentration

2013 ◽  
Vol 43 (7) ◽  
pp. 1168-1173 ◽  
Author(s):  
Paulo Sérgio Gomes da Rocha ◽  
Roberto Pedroso de Oliveira ◽  
Walkyria Bueno Scivittaro
Keyword(s):  
Light Source ◽  
Growth Medium ◽  
Light Emitting Diodes ◽  
Sucrose Concentration ◽  
Saccharum Officinarum ◽  
Growth Media ◽  
Light Sources ◽  
Multiplication Rate ◽  
Light Emitting ◽  
Fluorescent Lamps

The aim of this research was to evaluate the use of light emitting diodes (LEDs) instead of white fluorescent lamps as light source and adequate growth-medium sucrose concentration for sugarcane micropropagation (Saccharum officinarum L.). Sugarcane (RB 872552 variety) bud explants were evaluated during the multiplication and rooting phases under controlled growth-room conditions. Different light sources (blue, red and green LEDs; Growlux and white fluorescent lamps) and different medium sucrose concentrations (0; 15; 30 and 45g L-1) were used, maintaining constant light intensity (20µmol m-2 s-1), photoperiod (16h) and temperature (25+2°C). The experiment was a completely randomized design, and treatments were arranged in a 5x4 factorial (five light sources and four medium sucrose concentrations) with six replications. Sugarcane bud growth was satisfactory under the three LED types studied. The presence of sucrose in growth media was essential for bud multiplication and rooting. Nevertheless, each light source requires the respective medium sucrose concentration adjustment for best results. Red LEDs provided a significantly high multiplication rate (although not the highest) with 8.5 buds per sub-culture and 34.9g L-1 of sucrose; also, the highest bud length (33.3mm) and the best plantlet acclimatization. Therefore, LED sources can advantageously substitute fluorescent lamps in laboratories of sugarcane micropropagation.

Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans

2011 ◽  
Vol 110 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Kathleen E. West ◽  
Michael R. Jablonski ◽  
Benjamin Warfield ◽  
Kate S. Cecil ◽  
Mary James ◽  
...  
Keyword(s):  
Short Wavelength ◽  
Healthy Subjects ◽  
Response Curve ◽  
Light Emitting Diodes ◽  
Fluorescent Light ◽  
Light Emitting ◽  
Blue Led ◽  
Led Light ◽  
Melatonin Suppression ◽  
Wavelength Light

Light suppresses melatonin in humans, with the strongest response occurring in the short-wavelength portion of the spectrum between 446 and 477 nm that appears blue. Blue monochromatic light has also been shown to be more effective than longer-wavelength light for enhancing alertness. Disturbed circadian rhythms and sleep loss have been described as risk factors for astronauts and NASA ground control workers, as well as civilians. Such disturbances can result in impaired alertness and diminished performance. Prior to exposing subjects to short-wavelength light from light-emitting diodes (LEDs) (peak λ = 469 nm; ½ peak bandwidth = 26 nm), the ocular safety exposure to the blue LED light was confirmed by an independent hazard analysis using the American Conference of Governmental Industrial Hygienists exposure limits. Subsequently, a fluence-response curve was developed for plasma melatonin suppression in healthy subjects ( n = 8; mean age of 23.9 ± 0.5 years) exposed to a range of irradiances of blue LED light. Subjects with freely reactive pupils were exposed to light between 2:00 and 3:30 AM. Blood samples were collected before and after light exposures and quantified for melatonin. The results demonstrate that increasing irradiances of narrowband blue-appearing light can elicit increasing plasma melatonin suppression in healthy subjects ( P < 0.0001). The data were fit to a sigmoidal fluence-response curve ( R2 = 0.99; ED50 = 14.19 μW/cm2). A comparison of mean melatonin suppression with 40 μW/cm2 from 4,000 K broadband white fluorescent light, currently used in most general lighting fixtures, suggests that narrow bandwidth blue LED light may be stronger than 4,000 K white fluorescent light for suppressing melatonin.

Light source with light emitting diodes. Determination of limited frequencies and of the crest factor of illuminance meters and luminance meters

1989 ◽  
Vol 20 (5) ◽  
pp. 205-217
Author(s):  
J Deforges ◽  
P Garcia ◽  
J Bastie ◽  
F Marandet ◽  
J Bernard ◽  
...  
Keyword(s):  
Light Source ◽  
Light Emitting Diodes ◽  
Crest Factor ◽  
Light Emitting

scholarly journals Utjecaj različitog tipa umjetnog osvjetljenja na klijavost sjemena matovilca i kres salate

2017 ◽  
Vol 40 (6) ◽  
pp. 70-76
Author(s):  
Tomislav Vinković ◽  
Monika Tkalec ◽  
Nada Parađiković ◽  
MIro Stošić ◽  
Krunoslav Zmaić ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Led Light

Cilj rada je bio utvrditi utjecaj LED (Light Emitting Diodes) i FLUO (fluorescentno svjetlo) osvjetljenja na klijavost i energiju klijanja sjemena te masu i visinu klijanaca matovilca i kres salate. Sjetva naturalnog sjemena provedena je u Petrijeve zdjelice u komori opremljenoj LED i FLUO lampama. LED lampe su bile opremljene crvenim (650-670 nm) i plavim (440-460 nm) LED diodama u omjeru 3:1. Istraživanje je provedeno u Laboratoriju za povrćarstvo, cvjećarstvo, ljekovito i začinsko bilje Poljoprivrednog fakulteta u Osijeku. Utvrđen je statistički opravdan utjecaj tipa osvjetljenja na energiju klijanja i klijavost sjemena matovilca, a veće vrijednosti utvrđene su uslijed primjene LED lampi. Suprotno, pod FLUO lampama je utvrđena značajno veća masa i visina klijanaca matovilca te visina klijanaca kres salate. Međutim, tip osvjetljenja nije značajno utjecao na klijavost i energiju klijanja te masu klijanaca kres salate. Prema tome, može se zaključiti da je odgovor na tip osvjetljenja uvjetovan biljnom vrstom već od samih početaka rasta i razvoja.

scholarly journals 310 nm UV-LEDs attenuate imiquimod-induced psoriasis-like skin lesions in C57BL/6 mice and inhibit IL-22-induced STAT3 expression in HaCaT cells

2020 ◽  
Vol 19 (8) ◽  
pp. 1009-1021
Author(s):  
Tae-Rin Kwon ◽  
Sung-Eun Lee ◽  
Jong Hwan Kim ◽  
You Na Jang ◽  
Su-Young Kim ◽  
...  
Keyword(s):  
Light Source ◽  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Skin Lesions ◽  
Hacat Cells ◽  
Light Emitting ◽  
Uv Leds ◽  
Ultraviolet Light Emitting Diodes

Ultraviolet light-emitting diodes (UV-LEDs) are a novel light source for phototherapy.

scholarly journals Compressive strength measurements of hybrid dental composites treated with dry heat and light emitting diodes (LED) post cure treatment

2014 ◽  
Vol 26 (3) ◽  
Author(s):  
Jenny Krisnawaty ◽  
Setiawan Natasasmita ◽  
Dudi Aripin
Keyword(s):  
Compressive Strength ◽  
Hybrid Composite ◽  
Light Emitting Diodes ◽  
Composite Resin ◽  
Hybrid Composites ◽  
Testing Machine ◽  
Dental Composite ◽  
Light Emitting ◽  
Led Light ◽  
Dry Heat

Hybrid composites are mostly used on large cavities as restorative dental materials, whether it is used directly or indirectly. The mechanical properties of composite resin shall increase if it is treated with post cure treatment. The aim of this study is to evaluate compressive strength differences between dry heat and Light Emitting Diodes (LED) treatment on the hybrid dental composite. A quasi-experimental was applied on this research with a total of 30 samples that were divided into two groups. Each sample was tested using LLOYD Universal Testing Machine with 1 mm/min speed to evaluate the compressive strength. The compressive strength results were marked when the sample was broken. The results of two groups were then analyzed using t-test statistical calculation. The results of this study show that post cure treatment on hybrid composite using LED light box (194.138 MPa) was lower than dry heat treatment (227.339 MPa), which was also significantly different from statistical analysis. It can be concluded that compressive strength of LED light box was lower than dry heat post-cure treatment on the hybrid composite resin.

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