The research reported in this paper involves the development and refinement of methods applicable to the measurement and analysis of infrasound signals generated by the operation of wind turbines. In particular, the presentation focuses on the use of a new system that is applied for simultaneous recording of acoustic signals in the low-frequency range emitted by wind farms in three independent and identical measurement setups. A comparative analysis of the proposed new system was made with the Brüel & Kjaer measurement, a commonly used methodology, which meets the requirements of the IEC 61400-11 standard. The paper focuses on the results of frequency and time-frequency analysis of infrasound signals recorded throughout the operation of a wind turbine with a rated capacity of 2 MW. The use of a correlated system with three simultaneous measurement systems can be a new and alternative measurement method that will eliminate the drawbacks of previous approaches.

In paper the influence of thermal oxidation on nano-modified transformer oil is analyzed. The probes of mineral transformer were doped with different content of C ₆₀ fullerenes from 0 mg/l to 512 mg/l. One set of probes were then aged for 64 hours in the temperature of 110°C with the presence of copper inhibitor. Oil parameters such us: resistivity, dielectric loss tangent and permittivity were measured for each probe set. The influence of C ₆₀ additive on individual characteristics of fresh and aged oil was analyzed.

In the paper, an innovative control system devoted to the stabilization of the parallel manipulator-type Hexapod is presented. The device consists of three main parts, allowing us to reach the desired location during various external disturbances. Indeed, the telescopic boom located on the car along with the system providing the correction of the boom column deflection as well as the gyroscopic self-leveling head constitute a complex tool covering a plethora of modern techniques and solutions. Through the application of advanced issues strictly derived from nonlinear identification and multivariable control theory branches, the dynamical behavior of the discussed device has been handled in order to achieve a proper reference operation. Naturally, it has been supported by a set of accompanying approaches related to the processes of the real-time measurement and robust data transmission. It should be emphasized that the proposed computer-aided system is intended for the film industry, where image stabilization plays a crucial role. Such a statement has additionally been confirmed by other innovative products introduced by a company placed in Opole, Poland, called MovieBird International.

This article identifies seasonality profiles for three stages of housing construction. The profiles were determined as average monthly values obtained for permits issued for the construction of new apartments, for apartments whose construction has begun, and for apartments put into operation. The research process showed that there are differences in seasonality profiles between investments carried out by individual investors and those who build apartments for sale or rent. The research clearly showed that the development of reports and analyses for the housing market should include a breakdown of the market for the activities of individual developers as well as those operating as investments. Unfortunately, at present, reports on the real estate market are developed in total terms, which significantly reduces their utilitarian application. Taking into account the recommendations of the research will allow for sustainable development of the housing market in such a way that the market will strengthen its resilience to the occurrence of cyclical fluctuations, among other things.

This research paper describes the development of a low-cost device for measuring wastewater flow rates in open channels, a significant advancement enabled by the evolution of microcomputers and processing techniques. A laboratory setup was constructed to validate the device’s accuracy against a standard flow measurement method, optimizing key parameters to achieve a linear relationship between detected and set flow rates, while considering hardware limitations and energy efficiency. The central focus of the research was developing a method to measure the velocity of contaminated fluid using ultrasonic signals, employing the cross-correlation method for signal delay analysis in a stochastic environment. This was complemented by a procedure to measure fluid levels, also based on ultrasonic signals. The device’s reliability was assessed through repeatability and uncertainty measurements, confirming its accuracy with an extended uncertainty not exceeding an average of 3.47% for flows above 40 L/min. The device has potential to provide valuable data on the operational dynamics of sanitary networks, crucial for developing and calibrating simulation models.