scholarly journals Statistical Optimization of a Hyper Red, Deep Blue, and White LEDs Light Combination for Controlled Basil Horticulture

2021 ◽  
Vol 11 (19) ◽  
pp. 9279
Author(s):  
Silvia Barbi ◽  
Francesco Barbieri ◽  
Alessandro Bertacchini ◽  
Monia Montorsi
Keyword(s):  
Mathematical Models ◽  
Indoor Environment ◽  
Predictive Power ◽  
Growth Parameters ◽  
White Led ◽  
Light Conditions ◽  
White Leds ◽  
Deep Blue ◽  
Germination And Growth ◽  
Germination Parameters

This study aims to optimize artificial LEDs light conditions, for “Genovese” basil germination and growth in an indoor environment suitable for horticulture. Following a previous study on the synergic effect of LEDs light and a tailored fertilizer, in this study, the effect of white LED in combination with hyper red and deep blue, as well the plants–lights distance, was correlated to 14 growth and germination parameters, such as height, number of plants, etc. A design of experiments approach was implemented, aiming to derive mathematical models with predictive power, employing a restrained number of tests. Results demonstrated that for the germination phase, it is not possible to derive reliable mathematical models because almost the same results were found for all the experiments in terms of a fruitful germination. On the contrary, for the growth phase, the statistical analysis indicates that the distance among plants and lights is the most significant parameter. Nevertheless, correlations with LED light type emerged, indicating that white LEDs should be employed only to enhance specific growth parameters (e.g., to reduce water consumption). The tailored models derived in this study can be exploited to further enhance the desired property of interest in the growth of basil in horticulture.

Superior Performance of Dye-Sensitized versus Conventional TiO2 Nanoparticles for Promoting Germination and early Growth of Barley: From Photovoltaic to Biotechnological Application

2015 ◽  
Vol 35 ◽  
pp. 77-91
Author(s):  
Hasan Mir ◽  
Ahmad Gholamalizadeh Ahangar ◽  
Noshin Mir
Keyword(s):  
Growth Parameters ◽  
Dye Sensitized Solar Cells ◽  
Negative Influence ◽  
Superior Performance ◽  
Dye Sensitized ◽  
Vigor Index ◽  
Common Strategy ◽  
Germination And Growth ◽  
Sensitized Solar Cells ◽  
Germination Parameters

TiO2 nanoparticle is one of the most fascinating materials for stimulating germination and growth of various seeds. However, the low capacity of these materials in absorbing sunlight is a challenging issue which should be taken into consideration. Sensitization of TiO2 nanoparticles is already a common strategy for improving its visible light absorption and it is mainly used in dye-sensitized solar cells. In this study, a set of experiments were conducted to investigate the influences of dye-sensitized TiO2 nanoparticles on germination and growth of barley seeds (Hordeum vulgare L.). Fluorescein was used as the sensitizer with high extinction coefficient in the visible regions. It was shown that different growth parameters including seedling fresh and dry weights, root and shoot lengths, chlorophyll-a, and chlorophyll-b were increased by 59.2% and 85.7%, 330%, 100%, 45% and 50% relative to the control, respectively. Moreover, the results confirmed that dye-sensitized TiO2 nanoparticles do not have any negative influence on germination parameters and are beneficial for increasing vigor index I.

Study of High-Power White LED's Lifetime Based on Accelerated Life Test

2013 ◽  
Vol 800 ◽  
pp. 205-209 ◽  
Author(s):  
De Sheng Li ◽  
Nian Yu Zou ◽  
Yun Cui Zhang ◽  
Xiao Yang He ◽  
Yi Yang
Keyword(s):  
High Power ◽  
Accelerated Life Test ◽  
Reliability Test ◽  
White Led ◽  
Life Test ◽  
Arrhenius Model ◽  
White Leds ◽  
Accelerated Life ◽  
Temperature Levels

The study of LED reliability becomes more and more important with LED widely used in various areas, and accelerated life test (ALT) as an element of reliability test is widely used to predict the lifetime of LED. In this paper, ALTs have been carried out at various current levels and various temperature levels. In the current ALT experiment, three kinds of stressing currents were demonstrated for 1W white LEDs and lumen flux of the tested LEDs were studied, and based on Eyting model, lifetime of the tested LEDs is calculated about 6.86×105h. In the temperature ALT experiment, two kinds of stressing temperature were demonstrated for the same type of white LEDs and lumen flux were also studied, and based on Arrhenius model, lifetime of the tested LEDs is calculated about 7.41×105h. In addition, the color shifting velocity is faster than lumens depreciation velocity was observed in our experiment, which means the lifetime evaluating of white LED should be paid more attention.

scholarly journals Germination and seedling structure of Ruprechtia laxiflora Meissn. (Polygonaceae)

2017 ◽  
Vol 39 (2) ◽  
pp. 243
Author(s):  
Rafael Espanhol Müller ◽  
Luiz Antonio De Souza ◽  
Lindamir Hernandez Pastorini ◽  
Mariza Barion Romagnolo
Keyword(s):  
Experimental Design ◽  
Light Condition ◽  
Cotyledonary Node ◽  
Plant Anatomy ◽  
Light Conditions ◽  
Continuous Darkness ◽  
Germination Speed ◽  
Forest Remnants ◽  
Mean Time ◽  
Germination Parameters

Germination of diaspores and the seedling structure of Ruprechtia laxiflora Meissn. (Polygonaceae) which is a secondary species frequent in forest remnants are described. Seedlings were embedded in hydroxymethacrylate and sectioned in a rotary microtome according to usual techniques in plant anatomy. For bioassays of germination, the experimental design was completely randomized in a 3x2 bifactorial arrangement, corresponding to three temperatures (20, 25 and 30°C) and two light conditions (photoperiod and continuous darkness) for the diaspores newly harvested and in a 4x2 bifactorial arrangement, corresponding to four temperatures (15, 20, 25 and 30°C) and two light conditions (photoperiod and continuous darkness) for diaspores analyzed after storage. There was no interaction between the factors light condition and temperature for germination parameters analyzed. However, the temperature affected the germination and diaspores maintained at 25°C showed a shorter mean time and higher germination speed index. Seedlings are phanerocotylar and epigeal with tetrarch root, intermediate-low type of root-stem transition and trilacunar cotyledonary node.

scholarly journals ALLELOPATHIC POTENTIAL OF WEED SPEICES AGERATUM CONYZOIDES L. AND CLEOME VISCOSA L. ON GERMINATION AND GROWTH OF SESAMUM INDICUM L

2015 ◽  
Vol 2 (2) ◽  
pp. 114-117
Author(s):  
Anbarasan R ◽  
Prabhakaran J
Keyword(s):  
Growth Parameters ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Sesamum Indicum ◽  
Weed Species ◽  
Ageratum Conyzoides ◽  
Allelopathic Potential ◽  
Germination And Growth ◽  
Cleome Viscosa

Various concentrations (5%, 10%, 15% and 20%) of aqueous extracts prepared from two weed species namely Ageratum conyzoides L. and Cleome viscosa L. and used for the present experiments to determine their allelopathic potential on growth and developmental changes on sesame (Sesamum indicum L.). The weed extracts showed an inhibitory effect on germination percentage, root and shoot growth, and fresh and dry weight of sesame seedlings. The extracts of A.conyzoides had more inhibitory effect at 20%concentration,than that of C.viscosa on growth parameters of sesame.

Growth and Light Properties of Fluorescent SiC for White LEDs

2012 ◽  
Vol 717-720 ◽  
pp. 87-92
Author(s):  
Mikael Syväjärvi ◽  
Rositza Yakimova ◽  
Motoaki Iwaya ◽  
Tetsuya Takeuchi ◽  
Isamu Akasaki ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
White Light ◽  
Energy Savings ◽  
Red Light ◽  
Visible Range ◽  
White Led ◽  
Light Emitting ◽  
Blue Led ◽  
White Leds ◽  
New Type

The LED technology started to developed many years ago with red light emitting diodes. To achieve the blue LED, novel growth technologies and process steps were explored, and made it possible to demonstrate efficient blue LED performance from nitrides. The efficiency was further developed and blue LEDs were commercially introduced in the 1990’s. The white LED became possible by the use of the blue LED and a phosphor that converts a part of the blue light to other colors in the visible range to combine into white light. However, even today there are limitations in the phosphor-based white LED technology, in particular for general lighting, and new solutions should be explored to speed the pace when white LEDs will be able to make substantial energy savings. In this paper we overview gallium nitride materials evolution and growth concepts for LEDs. We describe the fluorescent silicon carbide material prepared by a novel growth technology for a new type of white LED in general lighting with pure white light. This paper introduces an interesting research in fundamental growth and optical properties of light emitting silicon carbide.

HERBICIDAL ACTIVITY OF Ageratum conyzoides AGAINST PARTHENIUM

2020 ◽  
Vol 27 (2) ◽  
pp. 137-146
Author(s):  
Nimra Javaid ◽  
Arshad Javaid ◽  
Mukhtar Hussain Shah ◽  
Iqra Haider Khan ◽  
Syed Muhammad Waleed
Keyword(s):  
Root Length ◽  
Plant Biomass ◽  
Growth Parameters ◽  
Shoot Length ◽  
Herbicidal Activity ◽  
Ageratum Conyzoides ◽  
Stem Extract ◽  
Noxious Weed ◽  
Germination And Growth ◽  
Laboratory Bioassays

This study was carried out to explore herbicidal potential of an asteraceous weed Ageratum conyzoides against an exotic noxious weed parthenium (Parthenium hysterophorus L.). Different concentrations (0, 2, 4, 6, 8 and 10%) of aqueous extracts of various parts of the tested weed were used in laboratory bioassays. ANOVA revealed the significant effect of plant part bioassay and extract concentration on germination as well as various root and shoot growth parameters. Leaf extract was found the most herbicidal where a 10% extract completely inhibited the germination and growth of parthenium. Root and inflorescence extracts were also highly inhibitory in suppressing the germination up to 89% and 95%, shoot length up to 80% and 89%, root length up to 86% and 91%, and plant biomass up to 89% and 98%, respectively. Stem extract showed the least herbicidal activity causing up to 46%, 59%, 73% and 37% reduction in germination, shoot length, root length and plant biomass, respectively. This study concludes that leaf, root and inflorescence extracts of A. conyzoides possess strong herbicidal potential against germination and growth of parthenium.

An excellent cyan-emitting orthosilicate phosphor for NUV-pumped white LED application

2017 ◽  
Vol 5 (47) ◽  
pp. 12365-12377 ◽  
Author(s):  
Yongfu Liu ◽  
Jack Silver ◽  
Rong-Jun Xie ◽  
Jiahua Zhang ◽  
Huawei Xu ◽  
...  
Keyword(s):  
High Performance ◽  
Luminescence Properties ◽  
White Led ◽  
White Leds ◽  
Promising Application

The Ba9Lu2Si6O24:Ce3+cyan phosphor has excellent luminescence properties and displays promising application in NUV-based white LEDs with high performance.

scholarly journals Simultaneously Improve White LED Omni-Directional Package Efficacy and Spatial Color Uniformity on Scattered Photon Extraction Technology

Crystals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 21 ◽  
Author(s):  
Tsung-Xian Lee ◽  
Yun-Chieh Huang
Keyword(s):  
Extraction Efficiency ◽  
Critical Index ◽  
Light Extraction Efficiency ◽  
Color Temperature ◽  
Scattered Photon ◽  
Lens Design ◽  
White Led ◽  
Extraction Technology ◽  
White Leds ◽  
Color Uniformity

The Scattered Photon Extraction (SPE™) based on the concept of TIR lens combined with remote phosphor is proven to be one of the effective solutions for improving white LED efficiency, and it provides the omnidirectional light distribution for luminaire design. Not only the light extraction efficiency (LEE) is important, but also the angular uniformity of correlated color temperature (CCT) is a critical index in the evaluation of high-quality white LEDs. A non-optimized SPE™ will cause an increase in the angular CCT deviation (ACCTD) and ultimately affect lighting quality. Two possible ways using lens design are proposed to reduce the ACCTD and even improve its efficiency. Among them, using the concept of light guiding to design the lens can minimum the deviation of forward and backward CCT from 2720 K to 657 K, and the overall efficiency can be further enhanced by 12% compared to typical SPE™ lens.

Narrow band red emitting europium complexes and their application in smart white LEDs and vapoluminescent sensors

2020 ◽  
Vol 49 (19) ◽  
pp. 6205-6219 ◽  
Author(s):  
Rachna Devi ◽  
Sivakumar Vaidyanathan
Keyword(s):  
Narrow Band ◽  
White Led ◽  
Acid Base ◽  
Europium Complexes ◽  
White Leds ◽  
Color Rendering Index ◽  
Color Rendering

The synthesized molecular Eu-complex based hybrid white LED showed superior color rendering index. In addition, the complex also showed on-off-on luminescence with exposure to acid–base vapours.

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