scholarly journals Determination of the effective operating hours of the intermittent lighting system for growing vegetables

2021 ◽  
Vol 935 (1) ◽  
pp. 012004
Author(s):  
N Kondrateva ◽  
D Filatov ◽  
R Bolshin ◽  
M Krasnolutskaya ◽  
A Shishov ◽  
...  

Abstract Around the world, one of the key challenges is the provision of food for a growing urbanized population. A vertical farming system will help solve this problem. Vertical farming in a controlled environment provides 4-6 times higher yields per unit area, but requires more electricity. The most economical light sources are light-emitting diodes but it is important to determine the rational operating mode of the lighting system. The aim of the study was to determine the specific operating hours of the intermittent lighting system to reduce the cost of electricity consumption when growing vegetables in vertical farming in a controlled environment. Continuous and periodic modes of operation of the lighting system with a total operating time of 16 hours per day were considered. In Russia, there are six price categories for consumed electricity. Research has shown that price level II is economically viable. and a rational operating mode: 8 hours of light/4 hours of darkness, etc. Thus, the intervals of operation of the lighting system are 11.00-19.00 and 23.00-7.00. The study of this regime for microgreening of Mitsun head cabbage showed that the productivity of the plants was preserved, since the length of the leaves did not change.

2020 ◽  
Vol 134 (8) ◽  
pp. 727-731
Author(s):  
A Das ◽  
S Mitra ◽  
P Agarwal ◽  
A Sengupta

AbstractObjectiveThe aim of this study was to assess change in temperature, audiometric outcomes and post-operative complications following exposure to different light sources during endoscopic ear surgery.MethodA total of 64 patients diagnosed with chronic otitis media with central perforation and pure conductive hearing loss underwent endoscopic type 1 tympanoplasty. The patients were randomised into two groups based on the light source used: xenon or light-emitting diode. Temperature was measured using a K type thermocouple at the promontory and round window niche. Mean temperature change with respect to operating time, mean audiometric change, incidence of vomiting in the first 24 hours, vertigo and tinnitus at the end of the first week were observed.ResultsMean temperature change showed a statistically significant difference with increasing length of operating time with the xenon light source and when the two light sources were compared for a particular time interval. Mean audiometric change showed statistically significant deterioration at higher frequencies (4, 6 and 8 kHz) with the xenon light source but only at 8 kHz for the light emitting diode source. When the mean audiometric change was compared between light sources for a particular frequency, statistical significance was found at 4, 6 and 8 kHz. Post-operative complications were vomiting, vertigo and tinnitus (p-values of 0.042, 0.099 and 0.147, respectively, between two groups).ConclusionLight emitting diodes are associated with less significant middle-ear temperature rises and audiometric changes at higher frequencies when compared to xenon light sources. Hence, xenon should be replaced with cooler light sources.


HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 1951-1956 ◽  
Author(s):  
Gioia D. Massa ◽  
Hyeon-Hye Kim ◽  
Raymond M. Wheeler ◽  
Cary A. Mitchell

Light-emitting diodes (LEDs) have tremendous potential as supplemental or sole-source lighting systems for crop production both on and off earth. Their small size, durability, long operating lifetime, wavelength specificity, relatively cool emitting surfaces, and linear photon output with electrical input current make these solid-state light sources ideal for use in plant lighting designs. Because the output waveband of LEDs (single color, nonphosphor-coated) is much narrower than that of traditional sources of electric lighting used for plant growth, one challenge in designing an optimum plant lighting system is to determine wavelengths essential for specific crops. Work at NASA's Kennedy Space Center has focused on the proportion of blue light required for normal plant growth as well as the optimum wavelength of red and the red/far-red ratio. The addition of green wavelengths for improved plant growth as well as for visual monitoring of plant status has been addressed. Like with other light sources, spectral quality of LEDs can have dramatic effects on crop anatomy and morphology as well as nutrient uptake and pathogen development. Work at Purdue University has focused on geometry of light delivery to improve energy use efficiency of a crop lighting system. Additionally, foliar intumescence developing in the absence of ultraviolet light or other less understood stimuli could become a serious limitation for some crops lighted solely by narrow-band LEDs. Ways to prevent this condition are being investigated. Potential LED benefits to the controlled environment agriculture industry are numerous and more work needs to be done to position horticulture at the forefront of this promising technology.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Marta Hornyák ◽  
Michał Dziurka ◽  
Monika Kula-Maximenko ◽  
Jakub Pastuszak ◽  
Anna Szczerba ◽  
...  

AbstractLight-emitting diodes (LEDs) and high-pressure sodium lamps (HPS) are among the most commonly used light sources for plant cultivation. The objective of this study was to evaluate the effect of two controlled-environment production systems differing in light sources on growth, photosynthetic activity, and secondary metabolism of common buckwheat. We hypothesized that LED light with the majority of red and blue waves would increase physiological and biochemical parameters compared to sunlight supplemented with HPS lamps. The experiment was performed in a phytotronic chamber (LEDs) and in a greenhouse (solar radiation supplemented with HPS lamps as a control). The effects were analyzed at the flowering phase with biometric measurements, leaf chlorophyll index, the kinetics of chlorophyll a fluorescence, content of soluble carbohydrates and phenolics in the leaves. Applied LED light decreased the biomass but stimulated the production of phenolics compared to control plants. In control plants, a positive correlation between flavonoid content and energy dissipation from photosystem II (DIo/CSm) was found, while in plants under LEDs total pool of phenolic content correlated with this parameter and the quantum yield of electron transport (φ Ro and ψ Ro) was lower than that of the control, probably affecting buckwheat biomass.


Author(s):  
Chen-Kang Huang ◽  
Jeng-Gang Sung

Benefited by the progress of material science, Light-Emitting Diodes (LED) with UV-emitting have been produced successfully. Like other LEDs, UV-LEDs exhibit several advantages, such as energy conservation, long life, compact, and quick response. The UV-LED application to microlithography is attractive. In contrast to point light sources requiring lens to generate parallel light beams, an array of UV-LEDs can emit nearly parallel light beams easily. UV-LEDs only need 3 to 4 voltages to ignite, which is much lower than that required by mercury short arc lamps. The cost of using UV-LEDs is also much lower than current solutions. In this study, we used UV-LEDs as the light source in the laboratory lithography system. LEDs, whose emitting spectrum distributed between 370 to 410 nm mostly, were displaced on the bottom of a heat sink. Two 10-by-10 cm2 test masks, where the smallest pattern was 20 μm, were used to examine the resolution ability of this combination. Each light module was utilized to exposure photosensitized printed circuit board (PCB). After etching, the printed patterns were observed under microscope. The minimum reproducible feature size was 100 μm. Through the 4” mask, the uniformity was decent, and could be improved by using LEDs from the same batch, collimator, or LED displacement optimization. In the future, standard g-line process can be performed, and further tests will be performed to check the limits of the UV-LED system. Based on these preliminary tests, it seems like the usage of UV-LEDs should be a feasible solution for microlithography.


Author(s):  
Dmitry Konstantinovich Glazyk ◽  
Vladimir Viktorovich Manitsyn ◽  
Rafail Ravilevich Simashov

The article considers the current methods of calculating norms of lubricating oil consumption by marine diesels that provide for three causes of oil loss: oil burning, evaporation rate, and replacement expense. According to the manual, the lubricating oil consumption for replacement is considered only in trunk diesel engines; in main crosshead diesel engines with capacity over 3000 kW it is not considered and not performed. The lubricating oil consumption norms are proposed to carry out in terms of burnout and evaporation, according to the methods of determining fuel consumption norms. To determine consumption norms, it is necessary to know the oil consumption characteristic in relation to the load of the diesels and the load distribution in the ship operating mode. In the low speed crosshead diesel engines the circulating oil is only consumed for evaporation, but the trunk diesel engines consume oil for evaporation, burnout and replacement. The diagram of dependence of the relative cylinder oil consumption on the relative load of the diesel engine in the helical characteristic mode is illustrated. A simplified technological scheme of low-tonnage regeneration of the used motor oils is presented. It is proposed to calculate the oil consumption by the lubrication pump according to a nonlinear dependence based on the speed of the crankshaft at a specific mode. The analysis of the evaporation and burnout is recommended to carry out using a linear relationship, subject to oil consumption in the idle mode. The cost of circulating oil replacement is recommended to calculate according to the diesel operating time. Application of the used lubricating oil regeneration by means of a ship small-sized plant allows to achieve the oil consumption reduction by 19-48% depending on the ship operating mo


2019 ◽  
pp. 97-105
Author(s):  
Mikhail M. Erokhin ◽  
Pavel V. Kamshilov ◽  
Vladislav G. Terekhov ◽  
Andrei N. Turkin

The present study comprises comprehensive research of red, green and blue light emitting diodes (LED), which are widely used in phytoirradiators for plant growing in protected ground in the environment of a photo-culture including their spectrum measurements within the wide range of current values at room temperature. Shifts of spectral peaks of radiation of red and green LEDs after increase of operating current were discovered. On the basis of the conducted study, recommendations for selection of current operating mode of light sources used in phytoirradiators for plant growing in the environment of photo-culture were worked out, and a model of a phytoirradiator was proposed and studied in this work with red, green and blue LEDs, which have their spectrum covering all regions of photosynthetic active radiation (PAR).


Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3370 ◽  
Author(s):  
János Hegedüs ◽  
Gusztáv Hantos ◽  
András Poppe

The advantages of light emitting diodes (LEDs) over previous light sources and their continuous spread in lighting applications is now indisputable. Still, proper modelling of their lifespan offers additional design possibilities, enhanced reliability, and additional energy-saving opportunities. Accurate and rapid multi-physics system level simulations could be performed in Spice compatible environments, revealing the optical, electrical and even the thermal operating parameters, provided, that the compact thermal model of the prevailing luminaire and the appropriate elapsed lifetime dependent multi-domain models of the applied LEDs are available. The work described in this article takes steps in this direction in by extending an existing multi-domain LED model in order to simulate the major effect of the elapsed operating time of LEDs used. Our approach is based on the LM-80-08 testing method, supplemented by additional specific thermal measurements. A detailed description of the TM-21-11 type extrapolation method is provided in this paper along with an extensive overview of the possible aging models that could be used for practice-oriented LED lifetime estimations.


2019 ◽  
pp. 101-107
Author(s):  
Sergei A. Stakharny

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.


2017 ◽  
Vol 4 (2) ◽  
Author(s):  
SANJEEV KUMAR ◽  
SHIVANI . ◽  
S. K. SAMAL ◽  
S. K. DWIVEDI ◽  
MANIBHUSHAN .

Integration of different components viz. livestock, fishery, horticulture, mushroom etc. along with field crops not only enhanced productivity but by-products (waste) of one component act as input for another component through resource recycling within the system. Six integrated farming systems models with suitable combinations of Crop, vegetables, fruit trees, fish, livestock, mushroom etc. were made and evaluated at the experimental farm of ICAR Research Complex for Eastern Region, Patna during 2012-16 for harness maximum income, nutrient recycling and employment. Among six combinations, crop + fish + duck + goat resulted as most profitable combination in terms of productivity (RGEY- 22.2t), net income (Rs. 2,15,900/ha), additional employment (170 days/year) with income sustainability index (ISI) by 90.2. Upon nutrient recycling prepared from different wastes from the system Crop + fish + duck + goat combination added N (56.5 kg), P (39.6 kg) and K (42.7 kg) into the soil and reduced the cost of cultivation by 24 percent and was followed by crop + fish + goat combination. Crops grown under IFS mode with different types of manures produced 31 percent higher yield over conventional rice- wheat system. The contribution of crops towards the system productivity ranged from 36.4 to 56.2 %, while fish ranged from 22.0-33.5 %; for goat 25.4-32.9 %; for poultry 38.7 %; for duck 22.0-29.0 %; for cattle 32.2% and for mushroom 10.3 %.


2019 ◽  
Vol 290 ◽  
pp. 02007
Author(s):  
Radu Dan Paltan ◽  
Cristina Biriş ◽  
Loredana Anne-Marie Rădulescu

Of many techniques that are used to optimize production and costs, the studies conducted within a profile company lead to our choice for testing the 6Sigma method (the most used method in the automotive industry) in view of the economic efficiency applied in the wood Industry company. This method measures how many flaws exist in a process and determines in a systematic way how to improve it by technical overhauling and eliminating or minimizing the process for efficiency. This research article aims to study the state of research on the optimization of the production process through technical overhauling for panels reconstituted from solid wood and ways to make production more efficient by cutting costs through technical overhauling. From preliminary research, we estimate that all the items founded and others that will result from further research will result in a significant decrease in production costs that are reflected in the cost of the finished product and consequently in increasing the yield of the company by maximizing its profit. At the same time it may be the basis of future research studies in the field. The easier it is to maximize profits, the lower the operating costs are and the higher recovery rate of investments are, that will result a change in the operating mode: “working smarter not harder”.


Sign in / Sign up

Export Citation Format

Share Document