No abstract

No abstract

Low levels of natural light in greenhouses and a short winter day require additional irradiation, and artificial maintenance of temperature and humidity, due to the significant cost of non-renewable energy. It is known that about half of the cost of production is accounted for by electricity. Therefore, the state level is gaining issues of conservation of electricity spent on lighting and irradiation of plants. One of the ways to reduce the cost of electricity for light crops is to improve the methods of calculating photosynthetic irradiation, followed by automatic maintenance of the effective level of irradiation. One of the ways to reduce energy consumption for photoculture of plants in protected ground structures and increase their productivity is to improve methods for determining and maintaining optimal illumination values with radiation of a given range, which will provide the most effective level of photosynthetic process of plant development with a subsequent increase in its productivity. In the given article, the modeling of the electromagnetic field of the optical spectrum at the level of plant leaf formation, which takes into account the scattered radiation and reflected by the surfaces of the walls and ceiling, is carried out. The proposed method increases the accuracy of determining the actual value of irradiance by taking into account the features of the brightness of the coating on the walls and ceiling and their reflection coefficient as a function of spatial coordinates. An example is given of using this method to determine and automatically maintain the actual photosynthetic irradiation in accordance with the standard value of light intensity in the production room of the greenhouse, which ensures effective plant development and, accordingly, maximum productivity.

MgB2 thin films have been coated on Nb substrates without any buffer layers. An in situ pulsed laser deposition (PLD) method was used to prepare the coating. The interface between films and substrates has been characterized by scanning electron microscopy (SEM). Surface impedance has been measured for the MgB2 films on Nb substrates. The results were discussed with regard to the potential large scale applications in superconducting RF cavities.

No abstract