جستجوی مقالات مرتبط با کلیدواژه « راندمان » در نشریات گروه « میان رشته ای »

Nowadays, due to the increase in the amount of environmental pollutants and the electricity production price of energy carriers, the use of renewable energy sources for electricity production is increasing. Among renewable energy systems, photovoltaic systems, due to their stability, long lifetime, and low maintenance costs, are very popular. Utilization of these systems requires an accurate evaluation and understanding of various aspects of their performance, and ignoring this important issue is not only ineffective, but it may also lead to irrecoverable economic costs. To prevent this problem, several simulator applications are available for pre-construction testing of power generation units. In this paper, in order to simulate and assess the possibility of installing a photovoltaic production unit in the study environment, PVsyst application and accurate meteorological data such as annual radiation rate and environmental temperature have been used. Since solar arrays are installed in both movable and fixed forms, in this paper, the performance of both is examined separately and the model that had lower losses in practice and consequently higher efficiency is introduced. The simulation results showed that in the study environment, using the fixed type of solar panel for generating electrical energy is more appropriate than using the mobile type.

For study of the effect of planting dates and irrigation intervals on quality and quantity performance of Nutrifeed Millet, an experiment was conducted as split plot in a randomized complete block design with three replications on four planting dates (22nd May, 2nd June, 13th June, 24th June) and three levels of irrigation (8, 11 and 14 days) in Neyshabour Agricultural College fields in 2019. Forage crop in the first and second harvest were assessed according to quantity characteristics (fresh and dry forage, leaf to stem ratio, number of tillers per plant, number of tillers in m2) and quality characteristics (total protein content, ash percent). The results indicated that by reducing the irrigation period time distance, fresh forage yield increased per unit area. With any delay in planting date, performance of fresh forage yield per unit area decreased. A decrease in the number of tillers at the second harvest caused an increase in protein and ash percentage because of the increase in leaf to stem ratio. Total dry matter, protein percentage, number of tillers in plant, weight of fresh stem decreased when time distance of irrigation periods increased. In addition, total dry matter, fresh leaf weight, protein performance value and fresh leaf weight decreased with delays in planting date.