scholarly journals Effect of combined light-emitting diodes on the accumulation of glucosinolates in Brassica microgreens

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Oday Alrifai ◽  
Lili Mats ◽  
Ronghua Liu ◽  
Xiuming Hao ◽  
Massimo F. Marcone ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Average Concentration ◽  
Mass Spectrometry Data ◽  
Vegetable Production ◽  
Light Spectrum ◽  
Light Emitting ◽  
Highly Sensitive ◽  
Health Promoting ◽  
Controlled Environments ◽  
The Individual

AbstractAs of recent, microgreen vegetable production in controlled environments are being investigated for their bioactive properties. Phytochemicals like glucosinolates (GLS) are highly sensitive to varying spectral qualities of light, especially in leafy greens of Brassica where the responses are highly species-dependent. The accumulation of bioactive GLS were studied under 8 different treatments of combined amber (590 nm), blue (455 nm), and red (655 nm) light-emitting diodes (rbaLED). A semi-targeted metabolomics approach was carried out to profile common intact-GLS in microgreen extracts of Brassica by means of LC-HRMS/MS. Thirteen GLS were identified, among them were 8 aliphatic, 4 indolic and 1 aromatic GLS. Mass spectrometry data showed sinigrin had the highest average concentration and was highest in B. juncea, progoitrin was highest in B. rapa and glucobrassicin in R. sativus. The individual and total GLS in the microgreens of the present study were largely different under rbaLED; B. rapa microgreens contained the highest profile of total GLS, followed by R. sativus and B. juncea. Sinigrin was increased and gluconasturtiin was decreased under rbaLED lighting in most microgreens, glucoalyssin uniquely increased in R. sativus and decreased in B. rapa and glucobrassicin uniquely decreased in both B. rapa and B. juncea. The present study showed that rbaLED contributed to the altered profiles of GLS resulting in their significant modulation. Optimizing the light spectrum for improved GLS biosynthesis could lead to production of microgreens with targeted health-promoting properties. Graphical Abstract

Micro-optics in lighting applications

2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Wolfgang Mönch
Keyword(s):  
Light Emitting Diodes ◽  
Light Sources ◽  
Large Area ◽  
Light Emitters ◽  
Optical Elements ◽  
Optical Components ◽  
Light Emitting ◽  
Reflection And Refraction ◽  
Automotive Lighting ◽  
The Individual

AbstractThe intention of this article is to give a concise overview on current applications of micro-optical components in lighting, including general lighting, automotive lighting, projection, and display backlighting. Regarding the light sources, the focus of this paper is on inorganic light-emitting diodes (LEDs) and the characteristic problems encountered with them. Lasers, laser diodes, and organic light-emitting diodes (OLEDs) are out of scope of this paper. Micro-optical components for current applications of inorganic LEDs may be categorized essentially into three classes: First, components for light shaping, i.e., adjusting the intensity distribution to a desired target; second, components for light homogenization with respect to space and color, and third, large-area micro-optical elements. These large-area elements comprise micro-optical slabs and sheets for guiding, reflection, and refraction of light and are designed without regard to particular details of type, design, arrangement, and layout of the individual light emitters. References are given to textbooks and review articles to guide the interested reader to further and more detailed studies on the problems discussed here.

scholarly journals 200 Comparison of Spinach Growth and Development Under Broad- and Narrow-spectrum Lighting Sources

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 425D-425
Author(s):  
Gregory D. Goins ◽  
Neil C. Yorio ◽  
Lynn V. Lewis
Keyword(s):  
Broad Spectrum ◽  
Growth And Development ◽  
Light Emitting Diodes ◽  
Leaf Growth ◽  
Light Sources ◽  
Light Emitting ◽  
Narrow Spectrum ◽  
Controlled Environments ◽  
Photosynthetic Responses ◽  
Light Spectral Quality

Various electric lamp sources have been proposed for growing plants in controlled environments. Although it is desirable for any light source to provide as much photosynthetically active radiation (PAR) as possible, light spectral quality is critical in regard to plant development and morphology. Light-emitting diodes (LEDs) and microwave lamps are promising light sources that have appealing features for applications in controlled environments. Light-emitting diodes can illuminate a narrow spectrum of light, which corresponds with absorption regions of chlorophyll. The sulfur-microwave lamp uses microwave energy to excite sulfur and argon, which produces a bright, continuous broad-spectrum white light. Compared to conventional broad-spectrum sources, the microwave lamp has higher electrical efficiency, and produces limited ultraviolet and infrared radiation. Experiments were conducted with spinach to test the feasibility of using LEDs and microwave lamps for spinach production in controlled environments. Growth and development comparisons were made during 28-day growth cycles with spinach grown under LED (at various red wavelengths), microwave, cool-white fluorescent, or high-pressure sodium lamps. Plant harvests were conducted at 14, 21, and 28 days after planting. At each harvest under all broad-spectrum light sources, spinach leaf growth and photosynthetic responses were similar. Major differences were observed in terms of specific leaf area and weight between spinach plants grown under 700 and 725 nm LEDs as compared to plants grown under shorter red wavelengths.

White and Unsaturated Color Organic Light Emitting Diodes

1995 ◽  
Vol 413 ◽  
Author(s):  
A. Dodabalapur ◽  
M. Strukelj ◽  
R. H. Jordan ◽  
L. J. Rothberg ◽  
T. M. Miller
Keyword(s):  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Optically Active ◽  
Organic Light Emitting Diodes ◽  
Maximum Luminance ◽  
Light Emitting ◽  
Active Layers ◽  
Organic Light ◽  
Emission Color ◽  
The Individual

ABSTRACTWe describe the principles of operation and device characteristics of novel organic light emitting diodes in which the emission originates in a number of optically active layers. The effective emission color can be controlled by adjusting the thicknesses of the individual layers, and in this manner white and other unsaturated color LEDs with external quantum efficiency > 0.5% have been fabricated. The maximum luminance that has been achieved is ∼4,700 Cd/m2.

EFFECTS OF RED LIGHT AT 640 nm FROM LIGHT EMITTING DIODES ON THE RESPIRATORY BURST OF HUMAN NEUTROPHILS

2008 ◽  
Vol 01 (02) ◽  
pp. 285-294 ◽  
Author(s):  
MIN WU ◽  
LING ZHU ◽  
BINA HU ◽  
TIMON CHENG-YI LIU ◽  
DONG-LIANG RONG ◽  
...  
Keyword(s):  
Respiratory Burst ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Polymorphonuclear Neutrophils ◽  
Human Neutrophils ◽  
Long Distance ◽  
Light Emitting ◽  
Long Distance Running ◽  
Human Pmns ◽  
The Individual

Photobiomodulation (PBM) has been reported to have effects on respiratory burst of polymorphonuclear neutrophils (PMNs), but little focus was on the individual differences of human PMNs. The latter was investigated in this study. The PMNs were isolated from peripheral blood of 13 volunteers (10 ordinary persons, 3 athletes) and treated by red light (640 ± 15 nm) from light emitting diodes (RLED) at 50, 100, 300, 500 and 1000 J/m2 for 100 seconds, respectively. Blood samples of athletes were extracted at different running stages in 10 km non-interrupted long-distance running, before running, 1 hour after running began, just finishing the running, resting for 1 hour and 2 hours after running. The PMN respiratory burst was assessed by the nitroblue tetrazolium test. It was found that there were three types of RLED PBM on the respiratory burst of 3 types of PMNs, respectively, inducing for the subactivated PMNs, inhibiting for the overactivated PMNs and none for the PMNs in homeostasis. It was then concluded that there may be RLED PBM on dysfunctional human PMNs while none on those in homeostasis, and RLED at 300 J/m2 for 100 seconds may have bi-direction modulation on PMN respiratory burst.

In situ investigation of energy transfer in hybrid organic/colloidal quantum dot light-emitting diodes via magneto-electroluminescence

2016 ◽  
Vol 18 (32) ◽  
pp. 22373-22378 ◽  
Author(s):  
Lixiang Chen ◽  
Qiusong Chen ◽  
Yanlian Lei ◽  
Weiyao Jia ◽  
De Yuan ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Quantum Dot ◽  
Efficient Method ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Inorganic Composites ◽  
Highly Sensitive ◽  
In Situ Investigation ◽  
Colloidal Quantum Dot

Magneto-electroluminescence (MEL) could be a highly sensitive fingerprint for energy transfer, which provides a facile and efficient method for thein situinvestigation of fundamental processes in the hybrid organic/colloidal QD-LEDs and other organic/inorganic composites.

scholarly journals Simultaneous bifunctional application of solid-state lighting and ratiometric optical thermometer based on double perovskite LiLaMgWO6:Er3+ thermochromic phosphors

RSC Advances ◽  
2019 ◽  
Vol 9 (13) ◽  
pp. 7189-7195 ◽  
Author(s):  
Weiguang Ran ◽  
Hyeon Mi Noh ◽  
Sung Heum Park ◽  
Bo Ram Lee ◽  
Jung Hwan Kim ◽  
...  
Keyword(s):  
Solid State ◽  
Light Emitting Diodes ◽  
Double Perovskite ◽  
Solid State Lighting ◽  
Light Emitting ◽  
Highly Sensitive ◽  
Optical Thermometer

Both efficient light emitting diodes and highly sensitive (2.24% K−1) ratiometric thermometer were obtained based on the LiLaMgWO6:Er3+ thermochromic phosphor.

Injecting Inter-Layers and the Built-in Potential of Blue Polymer Light-Emitting Diodes

2000 ◽  
Vol 660 ◽  
Author(s):  
Thomas M. Brown ◽  
Ian S. Millard ◽  
David J. Lacey ◽  
Jeremy H. Burroughes ◽  
Richard H. Friend ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Basic Structure ◽  
Thin Layers ◽  
Carrier Injection ◽  
Semiconducting Polymer ◽  
Light Emitting ◽  
Physical Mechanisms ◽  
Organic Solid ◽  
Polymer Light Emitting Diodes

ABSTRACTThe semiconducting-polymer/injecting-electrode heterojunction plays a crucial part in the operation of organic solid state devices. In polymer light-emitting diodes (LEDs), a common fundamental structure employed is Indium-Tin-Oxide/Polymer/Al. However, in order to fabricate efficient devices, alterations to this basic structure have to be carried out. The insertion of thin layers, between the electrodes and the emitting polymer, has been shown to greatly enhance LED performance, although the physical mechanisms underlying this effect remain unclear. Here, we use electro-absorption measurements of the built-in potential to monitor shifts in the barrier height at the electrode/polymer interface. We demonstrate that the main advantage brought about by inter-layers, such as poly(ethylenedioxythiophene)/poly(styrene sulphonic acid) (PEDOT:PSS) at the anode and Ca, LiF and CsF at the cathode, is a marked reduction of the barrier to carrier injection. The electro- absorption results also correlate with the electroluminescent characteristics of the LEDs.

Sign in / Sign up

Export Citation Format

Share Document