scholarly journals Upward LED Lighting from the Base Suppresses Senescence of Lower Leaves and Promotes Flowering in Indoor Rose Management

HortScience ◽  
2021 ◽  
pp. 1-7
Author(s):  
Namiko Yamori ◽  
Yoriko Matsushima ◽  
Wataru Yamori
Keyword(s):  
Leaf Senescence ◽  
Light Emitting Diode ◽  
Plant Management ◽  
Indoor Environments ◽  
Flower Buds ◽  
Flower Bud ◽  
Light Emitting ◽  
Led Lighting ◽  
Dim Light ◽  
Supplemental Lighting

In indoor environments such as hotels, the light intensity is generally insufficient for managing plants, and flower buds often fail to open. Lamps placed above (downward lighting) take up space. We assessed the applicability of lighting from underneath (upward lighting) for the indoor management of roses. We grew plants indoors in dim light for 2 weeks under three conditions: 1) without supplemental lighting, 2) with downward light-emitting diode (LED) lighting, and 3) with LED lighting. We quantified photosynthetic components (chlorophyll and rubisco) and the maximum quantum yield of photosystem II (Fv/Fm, an indicator of plant health) to determine the effects of each treatment on the quality and photosynthetic abilities of the leaves. We determined the ratios of dead and opened flower buds to elucidate the effects of supplemental lighting on flower bud maturation. Management without supplemental lighting decreased the number of flowers and resulted in lower-leaf senescence. Downward LED lighting promoted blooming but also resulted in lower-leaf senescence. However, upward LED lighting promoted blooming and maintained the photosynthetic abilities of the leaves, including the lower leaves. This study shows a strong case for using upward LED lighting in appropriate settings for indoor plant management and LED-based horticulture.

scholarly journals Continuous LED Lighting Enhances Yield and Nutritional Value of Four Genotypes of Brassicaceae Microgreens

Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 176
Author(s):  
Tatjana G. Shibaeva ◽  
Elena G. Sherudilo ◽  
Alexandra A. Rubaeva ◽  
Alexander F. Titov
Keyword(s):  
Antioxidant Enzymes ◽  
Nutritional Value ◽  
Light Emitting Diode ◽  
Leaf Mass Per Area ◽  
Guaiacol Peroxidase ◽  
Enzymatic Antioxidants ◽  
Light Spectrum ◽  
Light Emitting ◽  
Led Lighting ◽  
Nutritional Benefits

The effect of continuous lighting (CL, 24 h) and light spectrum on growth and nutritional quality of arugula (Eruca sativa), broccoli (Brassica oleracea var. italic), mizuna (Brassica rapa. var. nipposinica), and radish (Raphanus sativus var. radicula) were investigated in growth chambers under light-emitting diode (LED) and fluorescent lighting. Microgreens were grown under four combinations of two photoperiods (16 h and 24 h) providing daily light integral (DLI) of 15.6 and 23.3 mol m−2 day−1, correspondingly) with two light spectra: LED lamps and fluorescent lamps (FLU). The results show that fresh and dry weights as well as leaf mass per area and robust index of harvested arugula, broccoli, mizuna, and radish seedlings were significantly higher under CL compared to 16 h photoperiod regardless of light quality. There were no visible signs of leaf photodamage. In all CL-treated plants higher chlorophyll a/b and carotenoid-to-chlorophyll ratios were observed in all plants except mizuna. CL treatment was beneficial for anthocyanin, flavonoid, and proline accumulation. Higher activities of antioxidant enzymes (catalase, superoxide dismutase, ascorbate peroxidase, and guaiacol peroxidase) were also observed in CL-treated plants. In most cases, the effects were more pronounced under LED lighting. These results indicate that plants under mild oxidative stress induced by CL accumulated more non-enzymatic antioxidants and increased the activities of antioxidant enzymes. This added nutritional value to microgreens that are used as functional foods providing health benefits. We suggest that for arugula, broccoli, mizuna, and radish, an LED CL production strategy is possible and can have economic and nutritional benefits.

scholarly journals Optimized LED-Integrated Agricultural Facilities for Adjusting the Growth of Water Bamboo (Zizania latifolia)

2020 ◽  
Vol 10 (4) ◽  
pp. 1330
Author(s):  
Vincent K. S. Hsiao ◽  
Teng-Yun Cheng ◽  
Chih-Feng Chen ◽  
Hao Shiu ◽  
Yong-Jin Yu ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Winter Season ◽  
Lighting System ◽  
Zizania Latifolia ◽  
Light Emitting ◽  
Led Lighting ◽  
Led Light ◽  
Bamboo Leaves

We investigated a light emitting diode (LED) lighting system applied to a water bamboo field during winter season at night, and the results indicated that this lighting system can prevent the stunting of water bamboo leaves and further assist its growth. Compared with previous LED systems, in which the LED bulbs were placed directly above water bamboo leaves, our LED lighting system presents the benefit of easy handling during harvest. To prevent the inhomogeneous coverage of LED light patterns, a new design of LED lenses was also incorporated.

Design of Light Emitting Diodes (LEDs) Lighting System and Its Application in Garden Landscape Decoration

2020 ◽  
Vol 15 (6) ◽  
pp. 734-742
Author(s):  
Hailiang Liu ◽  
Jiade Cheng ◽  
Asnidar Hanim Yusuf
Keyword(s):  
Control System ◽  
Large Scale ◽  
Light Emitting Diode ◽  
Image Data ◽  
Junction Temperature ◽  
Lighting System ◽  
Light Emitting ◽  
Led Lighting ◽  
Arm Processor ◽  
Control Node

Light Emitting Diode (LED) is widely used in garden landscape decoration because of its small size, low power, concentrated light, and the capability of showing more vivid colors. While designing the LED lighting system, considering that a single Advanced RISC Machine (ARM)-based control system cannot achieve large-scale LED display, and a single Field Programmable Gate Array (FPGA)-based control system cannot control the lighting system well, an LED system with the combination of ARM processor-FPGA is proposed. In this system, the ARM processor is used as the major control component. The Linux system realizes remote monitoring and intelligent management of image data. In addition, FPGA is used for LED data output. The lighting system consists of a major control node and a lighting node. The nodes are connected in parallel through a chain network. The major control node uses an ARM Cortex processor and is equipped with a Linux operating system. The lighting node uses ARM + FPGA hardware architecture. During the experiments, the LED lighting system is tested first. The results show that the reading and writing speed is fast. The LED display screen meets the lighting requirements. This LED lighting system is used for night lighting of garden landscapes. During the brightness test, the brightness of lighting objects and the background is used as research objects. Experiments have proved that the ratio of the lighting object brightness to the background brightness between (Yu, M. and Li, X., 2012. A little current k-factor method for measuring junction temperature of aviation lighting power led. Guangxue Jishu/Optical Technique, 38(3), pp.371–375; Monas, A., Verma, A., Gawari, A. and Paswan, R. S., 2016. Portable network monitor using arm processor. Procedia Computer Science, 92, pp.493–497.) is suitable for night lighting of garden landscape decoration, which will not bring discomfort to people who enjoy night scenery.

scholarly journals Comparison of Intracanopy Light-emitting Diode Towers and Overhead High-pressure Sodium Lamps for Supplemental Lighting of Greenhouse-grown Tomatoes

2013 ◽  
Vol 23 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Celina Gómez ◽  
Robert C. Morrow ◽  
C. Michael Bourget ◽  
Gioia D. Massa ◽  
Cary A. Mitchell
Keyword(s):  
High Pressure ◽  
Energy Consumption ◽  
Energy Savings ◽  
Light Emitting Diode ◽  
Significant Proportion ◽  
Fruit Production ◽  
Light Sources ◽  
Node Number ◽  
Light Emitting ◽  
Supplemental Lighting

Electric supplemental lighting can account for a significant proportion of total greenhouse energy costs. Thus, the objectives of this study were to compare high-wire tomato (Solanum lycopersicum) production with and without supplemental lighting and to evaluate two different lighting positions + light sources [traditional high-pressure sodium (HPS) overhead lighting (OHL) lamps vs. light-emitting diode (LED) intracanopy lighting (ICL) towers] on several production and energy-consumption parameters for two commercial tomato cultivars. Results indicated that regardless of the lighting position + source, supplemental lighting induced early fruit production and increased node number, fruit number (FN), and total fruit fresh weight (FW) for both cultivars compared with unsupplemented controls for a winter-to-summer production period. Furthermore, no productivity differences were measured between the two supplemental lighting treatments. The energy-consumption metrics indicated that the electrical conversion efficiency for light-emitting intracanopy lighting (LED-ICL) into fruit biomass was 75% higher than that for HPS-OHL. Thus, the lighting cost per average fruit grown under the HPS-OHL lamps was 403% more than that of using LED-ICL towers. Although no increase in yield was measured using LED-ICL, significant energy savings for lighting occurred without compromising fruit yield.

Thermal Performance of Domestic Replacement A19 LED Lighting Products

2016 ◽  
Author(s):  
Thomas Storey ◽  
Robin Rackerby ◽  
Heather Dillon ◽  
Lydia Gingerich
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Research Process ◽  
Light Emitting ◽  
Led Lighting ◽  
Proper Design ◽  
The Cost

In an effort to create a Light Emitting Diode (LED) lighting system that is as efficient as possible, the heat dissipation system must be accurately measured for proper design and operation. Because LED lighting technology is new, little optimization has been performed on typical cooling system required for most A19 replacement products. This paper describes the research process for evaluating the thermal performance of over 15 LED lighting products and compares their performance to traditional lighting sources, namely incandescent and compact fluorescent (CFL). This process uses radiation and convection to model typical cooling mechanisms for domestic A19 type replacement LED products. The A19 products selected for this investigation had input wattages ranging between 7 to 60 Watts, with outputs ranging from 450 to 1100 lumens. The average LED tested dissipated 43% (± 5%) of the total heat generated in the lighting product through the heat exchanger. The best thermal performance was observed in an LED product that dissipated approximately 58% of the total product heat through the heat exchanger. Results indicate that significant improvements to the current LED heat exchanger designs are possible, which will help lower the cost of future LED products, improve performance, and reduce the environmental footprint of the products.

Analysis of Modified Current Controller and its Implementation in Automotive LED

2017 ◽  
Vol 6 (04) ◽  
pp. 01-06
Author(s):  
Prof. Bhushan Thakre, Dr. R.M Thakre
Keyword(s):  
Supply Voltage ◽  
Light Emitting Diode ◽  
Control Voltage ◽  
Process Technology ◽  
Light Emitting ◽  
Led Lighting ◽  
Current Controller ◽  
Dimming Control ◽  
Simulation Purpose ◽  
The One

A novel highly dimmable current controller which is a linear one is employed in the application of low power automotive is discussed here. Light Emitting Diode is the one which drives current that is linearly controlled to decrease the intensity of LED to limit the destruction of the LED and improve its reliability. Although many dimming techniques for LED lighting are available, our proposed method outperforms the existing methods in terms of power consumption and the no. of transistors used in the proposed design. This emits 100mA and decrease the LED current which is going linearly based on the theory of dimming control voltage. Toggling of LED is avoided finally in comparison with the existing system. This circuit is developed in 0.18μm process technology and Cadence ADE with Spectre is employed for simulation purpose. The proposed method utilizes a maximum power of 392.85 mW when the supply voltage is 4V and the control voltage is 4V at the temperature of 27oC.

Effects of Light-Emitting Diode (LED) Lighting on the Ergosterol Content of Beech Mushrooms (L yophyllum ulmarium )

2013 ◽  
Vol 38 (4) ◽  
pp. 1926-1931 ◽  
Author(s):  
Su-Yeon Kim ◽  
Jihye Son ◽  
Y. Martin Lo ◽  
Chan Lee ◽  
Bokyung Moon
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Led Lighting ◽  
Ergosterol Content

scholarly journals Supplemental LED lighting increases pansy growth

2015 ◽  
Vol 33 (4) ◽  
pp. 428-433
Author(s):  
Nezihe Koksal ◽  
Meral Incesu ◽  
Ahmet Teke
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Plant Biomass ◽  
Light Emitting Diode ◽  
Low Light ◽  
Light Emitting ◽  
Led Lighting ◽  
Light Levels ◽  
Long Day ◽  
Number Of Branches

ABSTRACT: Pansy (Viola cornuta) is a facultative long-day plant that flowers from October until March in Turkey. During the winter months, low light levels can limit plant growth and development. Light emitting diodes (LEDs) can provide supplemental lighting in greenhouses which produce same light intensity with less energy than conventional incandescent lighting. Light emitting diode technologies have enabled affordable and efficient light systems to be installed in greenhouses and plastic tunnels in the field. In this experiment we evaluated the effects of supplemental red-orange LED lightening on the growth and development of pansy cv. Blue Blotch grown in plastic tunnels. The energy, which LEDs are to consume, was provided through a solar panel system with the aim of drawing attention to the cleanliness of solar energy source. Five hours of supplement LED lighting was applied after dusk starting from November to February. Pansy growth and development parameters were compared with non-light supplied control plants. Supplemental LED lighting significantly increased plant biomass weight, flower number and leaves number at the rate of 52%, 72%, and 47%, respectively. Moreover, LED lighting increased plant growth rate (0.109 and 0.306 g of fresh weight), compared with the no light control. LED lighting, however, had no effect on length of stems, number of branches and the diameter of flowers. Thus, this study indicated that pansies are light limited during the winter months and supplemental LED lighting can significantly increase pansy growth and development.

scholarly journals Using Social Marketing to Spur Residential Adoption of ENERGY STAR®-Certified LED Lighting

2015 ◽  
Vol 21 (2) ◽  
pp. 61-78 ◽  
Author(s):  
P. Wesley Schultz ◽  
Julie Colehour ◽  
Jill Vohr ◽  
Lara Bonn ◽  
Ashlee Bullock ◽  
...  
Keyword(s):  
Social Marketing ◽  
Light Emitting Diode ◽  
Lessons Learned ◽  
Control Group ◽  
Light Emitting ◽  
Energy Star ◽  
Led Lighting ◽  
Incandescent Bulb ◽  
Star Program ◽  
Led Lights

Recent technological advancements in lighting have produced light bulbs that are dramatically more efficient than the traditional incandescent bulb. Yet despite these benefits, the marketplace has been slow to adopt these newer and more efficient bulbs. To help facilitate this change, the Environmental Protection Agency’s ENERGY STAR program conducted a series of pilot behavior change campaigns to encourage residents to purchase and install ENERGY STAR-certified light-emitting diode (LED) lights. Campaigns were conducted with Duke Energy and Efficiency Vermont aimed at encouraging residents to purchase and install certified LED lighting in their homes. The campaigns used community-based social marketing (CBSM) as the platform for developing the overarching strategy and were developed to highlight the benefits of certified LED lights and to decrease the barriers. In Vermont, a school-based fund-raiser was used to promote certified LED bulbs, and in North Carolina, special in-store lighting events were held at Home Depot and Costco retail locations. Both programs were implemented using a control group, and quantitative outcomes were tracked. Reported results highlight the increase in sales of certified LEDs associated with the campaigns. Survey data are also reported from participants in the two campaigns, along with tests for spillover of the newly adopted behavior into other lighting purchases and behaviors. The lessons learned from these two CBSM pilots are synthesized into turnkey materials that can be adopted by other organizations looking to promote the adoption of LED lights.

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