The objective of this study was to ascertain the socioeconomic and geospatial traits responsible for little or no usage of tractors for land clearing and cultivation by rural farmers in Ogun State, Nigeria. Data were obtained on the study objec-tives with use of interview guide, in-depth discussion and field observation a randomly selected 247 arable crop farmers. The obtained data were subjected to frequency count and binominal analysis of variance. Results showed factors such as farmers’ inability to afford tractor acquisition and/or hire tractors services (prop = 1.00, p < 0.05) as the major economic traits encumbering tractor usage for land preparation. The social traits included inadequate available of tractors to serve the farmers (prop = 0.76, p < 0.05), and farmers’ apprehension of possible destruction of soil structure and/or farm land (prop= 0.64, p < 0.05) as a result of tractor usage for land preparation. The geospatial traits were stump/tree distribution (prop = 0.97, p < 0.05) and land fragmentation (prop = 0.92, p < 0.05). It was thus concluded that both socioeconomic and farmgeospatial traits interactively encumbered farm tractorisation in the study area. It was recommended that farmers should be supported technically and financially by stakeholders in agro-development so as to enable them to afford tractor usage for land cultivation.

The paper presents a thermodynamic optimization of supercritical coal fired power plant. The aim of the study was to optimize part of the thermal cycle consisted of high-pressure turbine and two chosen highpressure feed water heaters. Calculations were carried out using IPSEpro software combined with MATLAB, where thermal efficiency and gross power generation efficiency were chosen as objective functions. It was shown that the optimization with newly developed framework is sufficiently precise and its main advantage is the reduction of computation time on comparison to the classical method. The calculations have shown the tendency of the increase in efficiency, with the rise of a number of function variables.

The aim of the study was to determine the extent to which created and functioning beaver dams contribute to increasing water retention in the Łąki Soleckie facility (Mała River valley). Changes in the plant cover of meadow habitats within the range of beaver dams were also determined. During the growing periods in 2020–2022, measurements of the periodic levels and water retention of the Mała River and the adjacent ditches (R-27, R-29) were closely related to the activity of beavers and precipitation. The maximum volume of water retained in the Mała riverbed in 2020–2022 was 1,300, 1,700, and 1,200 m³; the maximum retention of the R-29 ditch was 270, 210, and 200 m³, respectively. In 2021–2022, the R-27 ditch collected the most water – 270 m³and 250 m³. Starting from June 2022, due to beaver dams D2 and D3, the water level in the river and water retention have stabilised at a high level, despite slight rainfall. The activity of beavers contributed to the transformation of communities of wet habitats located on organic soils (Calthion) into communities of periodically wet habitats (Caricetum gracilis). In places where natural habitat 6510 occurs, the coverage of species of the Festuca genus has increased, and the value of the biodiversity index has increased by an average of 9%. High stability in the community of expansive species (Deschampsia caespitosa and Veronica longifolia) and their increasing cover may make it difficult to maintain the proper condition of natural habitat 6510.