Effect of various LED lighting on the growth and development of garden strawberry Fragariaxananassa Duch. and groundcover rose Rosa hybrida L. at greenhouse conditions

The purpose of this study was to determine the role of various LED (light-emitting diode) light units in ensuring high-quality growth and development of plants, as well as to obtain high-quality seedlings of strawberries and ground cover rose. We studied the physiological reactions of garden strawberry (“Melga” variety) and ground cover rose (“Fairy” variety) plants under controlled conditions and obtained the data on the effect of light quality on plant biological productivity, dynamics of growth processes, photosynthesis rate and transpiration. Regardless of the type of studied crops, the tallest plants were obtained under conditions of supplementary lighting by the lamp with blue/green/red ratio in the spectrum 17/29/54 % (option 1) and the lamp with ratio 18/45/37 % (option 2). At the same time, the dry weight of leaves and roots, as well as the biological productivity of strawberry plants in experimental options 1 and 2 exceeded by 41% than in the control plants (under high pressure sodium lamp). For garden strawberry we recommend the LED in the option 2, for the ground cover rose optimal is the option 1.

Light regulating metabolic responses of Cyanobium sp. (Cyanobacteria)

Cyanobacteria are an important group of microorganisms of significant economic interest due to, for ex- ample, the antioxidant capacity of their metabolites. Cyanobium sp. LEGE 06113 is a marine cyanobacterium poorly studied, but with promising future applications. The aim of this study was to optimize the light conditions (both source and irradiance) and nutrient (N and P) concentration for Cyanobium sp. production as a source of high-valued com- pounds. The optimization of the processing parameters was performed using two different light sources (fluorescent and low-pressure sodium lamp), four irradiances (50, 100, 200 and 300 μmol photons m–2 s–1) and two variations of BG11 medium (BG11 and BG11+, with the second containing double amounts of phosphates and nitrates). The effects of the three factors were evaluated on the biomass production, photosynthetic activity, biochemical composition and antioxidant capacity. A synergistic effect between the light source, light intensity, and medium was observed for all measured parameters, with the greatest impact of light irradiance on the metabolism of Cyanobium sp. The combination of the SOX lamp, BG11+ medium, and a light irradiance of 200 μmol photons m–2 s–1 was optimal for the cultivation of Cyanobium sp. This work reports the tools for the production of Cyanobium sp. as a source of high-value products, thus increasing its biotechnological potentials.

Quantification of Spectral Perception of Plants with Light Absorption of Photoreceptors

Although plant responses to artificial lighting spectra often produce abnormal morphogenesis and reduced productivity, no quantification method to determine how plants perceive and respond to light has been available. Our objective in this study was to test whether a plant’s spectral perception can be quantified using the light absorption of its major photoreceptors, phytochrome, cryptochrome, and phototropin. We developed an artificial solar lamp and three different light sources, based on a high-pressure sodium lamp, a fluorescent lamp, and red and blue light-emitting diodes, whose absorption by photoreceptors was equal to that of the standard solar spectrum. Cucumber plants grown under the artificial solar and developed light sources showed normal photomorphogenesis and were indistinguishable from each other. Plants grown under unmodified commercial light sources had abnormal photomorphogenesis that made them short and small. The photosynthetic rate was higher under the unmodified light sources; however, dry masses were highest under the artificial solar and modified light sources, indicating that the cucumber plants are optimized to the solar spectrum. Our results clearly demonstrate that the spectral perceptions of plants can be quantified using the light absorption of their photoreceptors, not visual color or spectra. We expect that our findings will contribute to a better understanding of plant perceptions of and responses to light quality, and improve the productivity of plants cultivated under artificial light.

Neural network identification of a nonlinear model of a high-pressure sodium lamp

The article is devoted to the identification of a high-pressure sodium lamp nonlinear model parameters based on neural network technologies. Identification was carried out using a dynamic neural network. The model had 17 parameters based on second order differential equations. As a result, out of 17 parameters, four were selected that accurately reflect the real picture of the model.

DESIGNING A SINGLE PHASE INVERTER TO CALCULATE PUBLIC ROADS LIGHTING EFFICIENCY USING SODIUM LAMP TYPES

An inverter is a circuit which converts the AC voltage into DC voltage. Current use of inverters is very large, especially in industries, offices and housing. Even though now there are many inverter markets, but many are used for household loads, no one uses an inverter for roads lighting system namely sodium lamp because it requires a high frequency and voltage Then the surveyors placed a single phase inverter from the sodium lamp. Single phase inverter tool designed produces a voltage of 10,000 V, Amperage current of 0.20 A and 2000 w Power when tested against overloaded and not overloaded inverter, the results are quite good but in the design and manufacture of a single phase inverter is still lacking, which is only able to start the initial lighting of the sodium lamp because the current is small and the resulting voltage is unstable. Keywords: Single phase inverter, electrical energy, public road lighting, sodium lamp.