9 research outputs found
Influence of ecological farming on the community structure of epigeic arthropods in crops Triticum aestivum and T. spelta
Soil is an irreplaceable natural resource that enables the production of food and raw materials, forms agricultural and forest landscapes, filters and maintains water, ensures the cycle of substances in the ecosystem and contributes to maintaining biodiversity. Agricultural intensification is one of the most important factors for biodiversity loss. Spatial dispersion of epigeic arthropods reflects the ecological status of habitats and points to its quality. The aim of our research was to point out the differences in epigeic arthropod diversity in the examined crops Triticum aestivum, T. spelta and the influence of their ecotones on epigeic arthropods. Between the years 2019 to 2021 an investigation using the pitfall trap method recorded 5,232 individuals belonging to 13 taxonomic groups. The crop T. aestivum was represented by 2493 individuals and 13 taxa while in T. spelta we recorded 2739 individuals and 11 taxa. We observed significantly more taxa in the crop T. aestivum than in the crop T. spelta. We also confirmed the ecotone rule only for the T. aestivum crop. We confirmed the significant influence of crops and environmental variables (pH, potassium, phosphorus, nitrogen) on the spatial dispersion of individuals around pitfall traps. On the basis of our results, both ecological farming and their ecotone systems are important for epigeic arthropods and with topical and trophic conditions, which is important for the production of biomass and also affects crop. In any anthropogenic activity, it is important to give priority to less invasive procedures with non-toxic effects on organisms and to use effective technologies in land management
A sensorless initial rotor position's estimation for permanent magnet synchronous machines
Permanent magnet synchronous motors for the effective start require information about the initial position of a rotor. In this regard, most systems use position sensors, which substantially increase entirely a cost of an electrical drive [1-3]. The aim of this article is to develop a new method, allowing determining the absolute angular position of the permanent magnet synchronous motors' rotor [4,5]. With a certain voltage pulses applied to the motor, its stator is magnetized by currents leakage in the windings. This allows using a special algorithm to calculate the absolute position of the rotor without using any motor parameters [6]. Simulation results prove the simplicity and efficiency of this method for determining an initial position of the permanent magnet synchronous motors' rotor. Thus, this method can be widely used in the electrical industry
Assessment of soil quality in agroecosystems based on soil fauna
Soil arthropods respond sensitively to land management practices and correlate with beneficial soil functions. The aim of this research was to determine soil quality using the QBS index in different types of crops and influence of soil variables (pH soil, soil moisture, potassium, phosphorus and nitrogen) on soil arthropods. Between the years 2018 and 2020, we studied different types of crops (Brassica napus, Pisum sativum, Triticum aestivum, T. spelta, Zea mays, Grass mixture and Hordeum vulgare) and recorded 14 taxa. Our results suggest a higher QBS index value in crops grass mixture, Pisum sativum, Triticum aestivum, T. spelta. The EMI value grew with increasing values of soil moisture, soil pH, phosphorus, potassium and nitrogen; indicating the presence of soil arthropods occurring in higher quality soil. Our results suggest that agricultural intensification affects soil arthropods, which are important for the production of biomass, which also affects crop yields
The influence of relief morphometric characteristics upon the occurrence of the species Cordulegaster bidentata in the particular conditions of the Western Carpathians
The study concerns a monitoring survey of Cordulegaster bidentata Selys, 1843 (Odonata, Cordulegastridae), which is considered near threatened in the European Red List of Dragonflies, in order to show its habitat preferences and clarify the influence of slope and orientation of slopes on the occurrence of the species. Investigations of water habitats were carried out during the period from 2019 to 2020 in the Kysuce Region in northwest Slovakia. The protocol consists of looking for larvae and characterizing larval micro-habitat of C. bidentata so as to show their habitat preferences and clarify the influence of slope and orientation of slopes on the occurrence of the species. We sampled 32 watercourses (epicrenal, hypocrenal, rheocren, heleocren, epirhithral, metarhithral) at altitudes 420–950 m above sea level. A total of 79 larvae and 10 imagines (7♂ 3♀) of C. bidentata were found at 12 streams. In the present study, C. bidentata clearly preferred first-order stream sections, the slopes were steep and the proportion of small sediment grain sizes was high. The results show that the number of C. bidentata larvae grew with the increasing percentage of forests around streams. We also confirmed the trend for the number of C. bidentata larvae to increase with increasing values of slope and altitude of watercourses. Most of the individuals were recorded at the south and southwest oriented streams; we did not record larvae on the north and northwest oriented slopes. We assume that more suitable conditions for development of population exist in the streams on the south and southwest oriented slopes. The preference for watercourses oriented south and southwest ensures optimal conditions for the development of the population of this dragonfly species. The finding of larvae at the stages of instars shows the permanent occurrence of the species in the Kysuce Region
A sensorless initial rotor position's estimation for permanent magnet synchronous machines
Permanent magnet synchronous motors for the effective start require information about the initial position of a rotor. In this regard, most systems use position sensors, which substantially increase entirely a cost of an electrical drive [1-3]. The aim of this article is to develop a new method, allowing determining the absolute angular position of the permanent magnet synchronous motors' rotor [4,5]. With a certain voltage pulses applied to the motor, its stator is magnetized by currents leakage in the windings. This allows using a special algorithm to calculate the absolute position of the rotor without using any motor parameters [6]. Simulation results prove the simplicity and efficiency of this method for determining an initial position of the permanent magnet synchronous motors' rotor. Thus, this method can be widely used in the electrical industry