scholarly journals Karakterisasi Sumber Cahaya Menggunakan Spektrofotometer Vis-Nir untuk Optimasi Optical Non-Contact Speedometer

2021 ◽  
Vol 10 (1) ◽  
pp. 69-72
Author(s):  
Johan Iskandar ◽  
Yunita Rahma ◽  
Sindy Andiani
Keyword(s):  
Light Source ◽  
Light Sources ◽  
Ocean Optics ◽  
Adc Value ◽  
Color Changes ◽  
Peak Point ◽  
Red Led ◽  
Working Principle ◽  
Optimum Wavelength ◽  
Absorbance Peak

Characterization the light source has been carried out using a Vis-Nir spectrophotometer with the Ocean Optics DTmini-2 model. The purpose of this characteristic is to obtain the optimum wavelength as a light source in making a digital optical non-contact speedometer model. There are 5 light sources tested, namely blue, green, yellow, red and white light. From the characterization results, the wavelengths were blue (450 nm), green (540 nm), yellow (570 nm), red (640 nm) and white (550 nm). In making the digital optical non-contact speedometer model, a photodiode sensor is used which has an absorbance peak point at 479 nm, 680, and 900 nm. The working principle of the prototype is to detect changes in light intensity as a result of the reflectance by the wheel. The sensor reads every color changes on the wheel and the results will be sent to the microcontroller for further processing. The results obtained are that the red LED is excellent to this prototype because it has the highest ADC value compared to other light sources tested. This is consistent with the results of the sensor spectrophotometer characterization.

scholarly journals Artificial light source selection in seaweed production: growth of seaweed and biosynthesis of photosynthetic pigments and soluble protein

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11351
Author(s):  
Shitao Huang ◽  
Ke Li ◽  
Yaoru Pan ◽  
Yan Yu ◽  
Thomas Wernberg ◽  
...  
Keyword(s):  
Light Source ◽  
Photosynthetic Pigments ◽  
Soluble Protein ◽  
Residual Energy ◽  
Ulva Pertusa ◽  
Artificial Light ◽  
Light Sources ◽  
Sargassum Fusiforme ◽  
Source Selection ◽  
Red Led

Seaweed growth is often limited by light. Artificial light supply has been well studied in terrestrial agriculture, however, much less is known about its effect in seaweed aquaculture. In this study, the effects of four artificial light sources (white, red, green, and blue LEDs light) on a brown alga Sargassum fusiforme and a green alga Ulva pertusa were investigated. Seaweed growth, accumulation of photosynthetic pigments (chlorophyll a and carotenoid), and soluble protein were evaluated. White LED light was the optimal supplementary light when cultivating Ulva pertusa and Sargassum fusiforme, because it promoted seaweed growth while maintaining protein production. Meanwhile, red LED was unfavored in the cultivation of S. fusiforme, as it affected the seaweed growth and has a lower residual energy ratio underneath the water. LEDs would be a promising supplementary light source for seaweed cultivation.

scholarly journals Effect of Integrating LED Lighting With Fiber Membranes On The Restoration of Eutrophic Waterbody And Its Optimal Application

2021 ◽  
Author(s):  
Aimin Hao ◽  
Qi Mi ◽  
Kai He ◽  
Dong Xia ◽  
Bingjun Liu ◽  
...  
Keyword(s):  
Water Quality ◽  
Light Source ◽  
Water Bodies ◽  
Light Sources ◽  
Led Light ◽  
Eutrophic Water ◽  
Red Led ◽  
Fiber Membranes ◽  
Do Concentration ◽  
Study Laboratory

Abstract In this study, laboratory experiments were used to compare the effects of two LED light sources (blue and red) combined with fiber membranes on the increase of Dissolved Oxygen (DO) in eutrophic water bodies for improvement of water quality. The results showed that the application of these two LED light sources can increase the DO concentration and oxidation-reduction potential (ORP), and eliminate the NH4+-N in water bodies and the phosphorus release from the sediment, resulting in the improvement of sediment. Specifically, the blue LED light source is more benefitable to the increase of the DO concentration than the red LED light source. After 28 days, the DO concentration increases to 10 mg/L, and the redox potential is higher than 50 mV with the elimination of NH4+-N. This study illustrated that LED light sources can significantly increase the DO and effectively improve the water quality in eutrophic water bodies.

scholarly journals Light sources and culture media in the in vitro growth of the Brazilian orchid Microlaelia lundii

2017 ◽  
Vol 38 (4) ◽  
pp. 1775 ◽  
Author(s):  
Vanessa Favetta ◽  
Ronan Carlos Colombo ◽  
José Fernando Mangili Júnior ◽  
Ricardo Tadeu de Faria
Keyword(s):  
Chlorophyll Content ◽  
Light Source ◽  
Culture Media ◽  
Growth Parameters ◽  
Seedling Survival ◽  
Light Sources ◽  
In Vitro Growth ◽  
Red Led ◽  
Specific Care

The Brazilian micro-orchid Microlaelia lundii enchants by its beautiful blooms in winter, but its cultivation is still a challenge, requiring specific care. The objectiv of this work was to evaluate the influence of light sources and culture media on in vitro growth and ex vitro survival of this micro-orchid. M. lundii seedlings were transferred to flasks containing the culture medium ½ MS and Simplified Medium, consisting of 5 mL L-1 of Biofert Plus® NPK fertilizer (09-08-09) and 60 g L-1 of ‘Nanica’ banana pulp. These flasks were placed in a growth chamber composed of seven environments, characterized by types of lighting: L1) LEDtube 4000K; L2) LEDtube 6500K; L3) L1 + L2; L4) L1 + L1; L5) red LED; L6) blue LED; L7) fluorescent lamp (control). After 200 days of cultivation, biometric growth parameters and leaves chlorophyll content were evaluated together with the percentage of seedling survival when acclimatized. At the end of the experiment, an analysis of individual variances and a combined analysis of the environments were carried out. The simplified medium led to higher seedlings, especially for light source L6. Light sources L1, L2, L3 and L4 promoted an increase in the seedlings root system in the simplified medium. As for the chlorophyll content, L4 and L7 showed higher contents of chlorophyll a and b. The simplified medium led practically to 100% of seedling survival, regardless of the light source used. Results shown that the simplified medium for light sources L1, L2, L3 and L4 is recommended for the in vitro propagation of M. lundii.

Organic Light Emitting Diodes - Innovative Light Sources

2019 ◽  
pp. 101-107
Author(s):  
Sergei A. Stakharny
Keyword(s):  
Light Source ◽  
Organic Light Emitting Diodes ◽  
Organic Leds ◽  
Light Sources ◽  
High Quality ◽  
Light Emitting ◽  
Organic Light ◽  
Lighting Systems ◽  
Physical Principles ◽  
Prospects Of Application

This article is a review of the new light source – organic LEDs having prospects of application in general and special lighting systems. The article describes physical principles of operation of organic LEDs, their advantages and principal differences from conventional non-organic LEDs and other light sources. Also the article devoted to contemporary achievements and prospects of development of this field in the spheres of both general and museum lighting as well as other spheres where properties of organic LEDs as high-quality light sources may be extremely useful.

scholarly journals Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang
Keyword(s):  
Light Source ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Distribution ◽  
Light Sources ◽  
Led Light ◽  
High Power Led ◽  
Distribution Requirement ◽  
Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

scholarly journals Towards the Optimum Light Source Spectrum

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Chalmers ◽  
Snjezana Soltic
Keyword(s):  
Light Source ◽  
Large Scale ◽  
Source Spectrum ◽  
Light Sources ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Spectral Bands ◽  
Good Energy ◽  
Lighting Systems ◽  
Colour Rendering

This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes). Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.

Hybrid-Light-Source Stereolithography for Fabricating Macro-Objects With Micro-Textures

2021 ◽  
Author(s):  
Wenxuan Jia ◽  
Yuen-Shan Leung ◽  
Huachao Mao ◽  
Han Xu ◽  
Chi Zhou ◽  
...  
Keyword(s):  
Light Source ◽  
Dimensional Accuracy ◽  
Beam Width ◽  
Surface Structures ◽  
Light Sources ◽  
Scanning Method ◽  
Hardware System ◽  
Building Area ◽  
Micro Features ◽  
Display Resolution

Abstract Microscale surface structures are commonly found on macroscale bodies of natural creatures for their unique functions. However, it is difficult to fabricate such multi-scale geometry with conventional stereolithography processes that rely on either laser or digital micromirror device (DMD). More specifically, the DMD-based mask projection method displays the image of a cross-section of the part on the resin to fabricate the entire layer efficiently; however, its display resolution is limited by the building area. In comparison, the laser-based vector scanning method builds smooth features using a focused laser beam with desired beam-width resolution; however, it has less throughput for its sequential nature. In this paper, we studied the hybrid-light-source stereolithography process that integrates both optical light sources to facilitate the fabrication of macro-objects with microscale surface structures (called micro-textures in the paper). The hardware system uses a novel calibration approach that ensures pixel-level dimensional accuracy across the two light sources. The software system enables designing the distribution and density of specific microscale textures on a macro-object by generating projection images and laser toolpaths for the two integrated light sources. Several test cases were fabricated to demonstrate the capability of the developed process. A large fabrication area (76.8 mm × 80.0 mm) with 50 μm micro-features can be achieved with a high throughput.

scholarly journals Photobiocatalytic alcohol oxidation using LED light sources

2017 ◽  
Vol 19 (2) ◽  
pp. 376-379 ◽  
Author(s):  
M. Rauch ◽  
S. Schmidt ◽  
I. W. C. E. Arends ◽  
K. Oppelt ◽  
S. Kara ◽  
...  
Keyword(s):  
Light Source ◽  
Photocatalytic Oxidation ◽  
Alcohol Oxidation ◽  
Light Sources ◽  
Blue Led ◽  
Led Light

The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported.

scholarly journals Effect of Supplementary Light Source on Quality of Grafted Tomato Seedlings and Expression of Two Photosynthetic Genes

Agronomy ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 207 ◽  
Author(s):  
Hao Wei ◽  
Jiangtao Hu ◽  
Chen Liu ◽  
Mengzhao Wang ◽  
Jin Zhao ◽  
...  
Keyword(s):  
Light Source ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Sources ◽  
Seedling Production ◽  
White Leds ◽  
Tomato Seedlings ◽  
Photosynthetic Genes ◽  
Supplementary Lighting

Supplementary lighting is commonly used in high-quality seedling production. In this study, grafted tomato seedlings were grown for 10 days in a glasshouse with 16-h daily supplementary lighting at 100 μmol·m−2·s−1 PPFD (Photosynthetic photon flux density) from either high-pressure sodium (HPS), metal halide (MH), far-red (FR), white LEDs (Light emitting diodes) (W), or mixed LEDs (W1R2B1, where the subscript numbers indicate the ratio of the LED chips) to determine which light sources improve the seedling quality. The control seedlings did not receive any supplementary light. Physiological parameters and the expression of genes related to photosynthesis were analyzed. The results showed that root length, biomass, number of leaves, chlorophyll (SPAD), scion dry weight to height ratio (WHR), and specific leaf weight (SLW) were the greatest for grafted seedlings grown in W1R2B1. The level of root ball formation was the greatest for seedlings grown in W1R2B1, followed by those grown in W, HPS, and MH. Seedlings grown in FR did not fare well, as they were very thin and weak. Moreover, the expression of two photosynthetic genes (PsaA and PsbA) was significantly increased by W1R2B1 and W, which suggests that the plastid or nuclear genes might be regulated. The overall results suggest that W1R2B1 was the most suitable light source to enhance the quality of grafted tomato seedlings. The results of this study could be used as a reference for seedling production in glasshouses, and may provide new insights in the research on lights affecting the development of plants.

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