scholarly journals Light-Emitting Diodes (LED): A Promising Street Light System to Reduce the Attraction to Light of Insects

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 89
Author(s):  
Beatriz Martín ◽  
Héctor Pérez ◽  
Miguel Ferrer
Keyword(s):  
Light Emitting Diodes ◽  
Ecological Impacts ◽  
Light Emitting ◽  
Light System ◽  
Wide Range ◽  
Lower Light ◽  
Lighting Systems ◽  
Negative Impacts ◽  
Short Wavelength Light ◽  
Led Lights

Currently, there is a demand for more energy-efficient lighting sources, however, light emitted by different lighting systems differs in primary properties such as intensity, propagation direction, and wavelength spectrum, among others, and these properties may affect insect light attraction. Despite the energetic benefits of light-emitting diodes (LED) as street light systems, their ecological impacts on insects have not yet been tested on a wide range of taxa. Using an experimental approach, we showed that LED street lights lead to a reduction in the total number of insects captured with light traps in a wide range of families. Coleoptera and Lepidoptera orders were the most sensitive groups to ecological light pollution in the study area. We suggest that LED was the least attractive light system for most of the affected groups both because of its very little emitted short-wavelength light and because of its lower light intensity. We expect that the more and more widespread use of LED lights as a measure to reduce economic costs of outdoor lighting should lead to a lower attraction to street lights in most of the affected insect taxa and to diminish the negative impacts of artificial light attraction on the ecosystems.

Testing of Various Monochromatic LED Lights Used in Supplemental Irradiation of Lettuce in Modern Urban Rooftop Polytunnels

2019 ◽  
Vol 35 (3) ◽  
pp. 439-452
Author(s):  
Chung-Liang Chang ◽  
Kuang-Pi Chang ◽  
Wei-Lun Fu
Keyword(s):  
Light Emitting Diodes ◽  
Environmental Parameters ◽  
Quality Parameters ◽  
Urban Heat Islands ◽  
Direct Access ◽  
Urban Farming ◽  
Light Emitting ◽  
Fresh Vegetables ◽  
Lighting Systems ◽  
Led Lights

Abstract. Urban farming could provide both vegetable growers and urban dwellers with more direct access to various fresh vegetables. Nevertheless, certain challenging problems associated with urban farming, including a lack of cultivation space and the effects of urban heat islands, must still be solved. Relatedly, a grower must, in some cases, also know how to utilize various forms of technology, such as lighting systems, as well as factors such as water availability. In this study, an original rooftop polytunnel design for lettuce ( cv. Lollo Rosso) cultivation equipped with a hydroponic system and light emitting diodes (LEDs) is proposed. Various monochromatic lights were also tested for their effects on different quality parameters of lettuce. Specifically, supplemental red (655 nm), blue (445 nm), green (520 nm), and ultraviolet (380 nm) LED lights were used at night to apply photon fluxes of 150, 150, 150, and 20 µmol.m-2.s-1, respectively. The resulting effects of these different colored LEDs on the pigment concentration and growth response of the lettuce grown inside the roof polytunnel were then investigated. The experiment was then repeated several times with different environmental parameters in order to compare the effects of the different light wavelengths under higher temperatures and higher natural irradiation conditions.The results indicated that supplemental red or blue light at night could be strategically employed to maintain low nitrate levels and enhance the nutritional value and growth of lettuce grown in roof polytunnels. Keywords: Light emitting-diodes, LEDs, Hydroponic, Red lettuce, Rooftop polytunnel, Urban agriculture.

Assessing the impact of the transition to Light Emitting Diodes based solar lighting systems in India

2013 ◽  
Vol 17 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Santosh M. Harish ◽  
Shuba V. Raghavan ◽  
Milind Kandlikar ◽  
Gireesh Shrimali
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Solar Lighting ◽  
Lighting Systems ◽  
The Impact

Inserting a AlN Electron Blocking Layer for InGaN/GaN Blue Light-Emitting Diodes

2020 ◽  
Vol 1014 ◽  
pp. 126-130
Author(s):  
Wan Sheng Zuo ◽  
Yin Xi Niu ◽  
Liu Yang ◽  
Xiu Zhen Chi ◽  
Jin Jin Liu ◽  
...  
Keyword(s):  
Blue Light ◽  
Barrier Layer ◽  
Light Emitting Diodes ◽  
Electrostatic Discharge ◽  
Blocking Layer ◽  
Optical Performance ◽  
Spreading Effect ◽  
Electron Blocking Layer ◽  
Light Emitting ◽  
Wide Range

In this study, the advantages of the AlN electron blocking layer (EBL) for InGaN/GaN blue light-emitting diodes (LEDs) were investigated. The LEDs with the AlN EBL exhibited better optical performance over a wide range of carrier concentration due to the suppression of electron overflow. Furthermore, the AlN EBL with a thicker last barrier layer was investigated. The thicker last barrier layer was used to enhance Electrostatic Discharge (ESD) characteristic by the better current spreading effect.

scholarly journals Spectrally Wide-Range-Tunable, Efficient, and Bright Colloidal Light-Emitting Diodes of Quasi-2D Nanoplatelets Enabled by Engineered Alloyed Heterostructures

2020 ◽  
Vol 32 (18) ◽  
pp. 7874-7883 ◽  
Author(s):  
Yemliha Altintas ◽  
Baiquan Liu ◽  
Pedro Ludwig Hernández-Martínez ◽  
Negar Gheshlaghi ◽  
Farzan Shabani ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Wide Range

scholarly journals The Influence of Artificial Lighting Systems on the Cultivation of Algae: The Example of Chlorella vulgaris

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5994
Author(s):  
Beata Brzychczyk ◽  
Tomasz Hebda ◽  
Norbert Pedryc
Keyword(s):  
Chlorella Vulgaris ◽  
Light Emitting Diode ◽  
Radiant Energy ◽  
Biodiesel Production ◽  
Light Emitting ◽  
Artificial Lighting ◽  
Single Side ◽  
Biological Compounds ◽  
Lower Light ◽  
Lighting Systems

Microalgae are a practical source of biological compounds for biodiesel production. This study examined the influence of three different light-emitting diode (LED) systems on the biomass production of green algae Chlorella vulgaris BA0002a. The cultivation was carried out in a photobioreactor illuminated from the bottom with a single side light jacket (PBR I), in a photobioreactor illuminated from the bottom with a double side light jacket (PBR II) and in a photobioreactor illuminated only from the top (PBR III). Research has shown that the intensification of algae cell production and growth depends on the light distribution and exposure time of a single cell to radiation. In the experiment, the highest growth of algae cells was obtained in the photobioreactor with double jacket and lower light panel. The lowest cell growth was observed in the photobioreactor illuminated only from above. For cultures raised in the PBR I and PBR II photobioreactors, increased oxygen production was observed, which was directly related to the increased production of biomass, which in turn was dependent on the increased amount of radiant energy.

Cost-Effective Light-Mixing Module for Solar-Lighting System Appended With Auxiliary RGBW Light-Emitting Diodes

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
An Chi Wei ◽  
Shih Chieh Lo ◽  
Ju-Yi Lee ◽  
Hong-Yih Yeh
Keyword(s):  
Light Source ◽  
Light Emitting Diodes ◽  
Cylindrical Tube ◽  
Cost Effective ◽  
Lighting System ◽  
Optical Efficiency ◽  
Light Emitting ◽  
Solar Lighting ◽  
Lighting Systems ◽  
Main Components

A light-mixing module consisting of a compound parabolic concentrator (CPC) and a light-mixing tube is proposed herein to realize a uniform and efficient solar-lighting system. In this lighting system, the sunlight collected into a fiber and then guided to an indoor destination is the principal light source, while an auxiliary light source including multiple red, green, blue, and white (RGBW) light-emitting diodes (LEDs) is controlled by an auto-compensating module. To mix the principal and the auxiliary sources and to realize the uniform illumination, the light-mixing tube was coated with BaSO4 and optimized as a cylindrical tube. The design of the light-mixing tube is described and discussed in this article. According to the simulated results, the uniformity and the optical efficiency of the designed light-mixing tube are 82.9% and 85.7%, respectively, while from the experimental results, the uniformity of 85.9% and the optical efficiency of 83.3% have been obtained. In terms of the common indoor-lighting standards and the specifications of commercial components used in lighting systems, the proposed light-mixing module has demonstrated the high uniformity and acceptable optical efficiency. Additionally, since the main components of the light-mixing module can be designed as plastic optics, a cost-effective light-mixing module and a profitable lighting system can be realized. Thus, the performance and the price of the proposed light-mixing module fit the demands of the illumination market, while the proposed system shows the potential for indoor solar-lighting applications.

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