The work contains a description of a developed experimental and theoretical method of modeling of solid waste combustion in a device equipped with a moving grate and capability to optimize the work of waste incineration plant. Implementation of this issue was based on results of experimental studies made on a laboratory scale boiler. This was possible by defining and testing indicators of quantitative assessment of combustion such as: reaction front rate, ignition rate, the rate of combusted mass loss and the heat release rate. These indicators as measurable "criteria indicators" allow transfer of parameters from a laboratory-scale unit, working in the transient regime into an industrial full scale grate device working continuously in stable determined conditions. This allows for wide optimization possibilities in the operation of a waste incineration plant, in particular the combustion chamber, equipped with a moving grate system.

An emerging ultrasonic technology aims to control high-pressure industrial processes that use liquids at pressures up to 800 MPa. To control these processes it is necessary to know precisely physicochemical properties of the processed liquid (e.g., Camelina sativa oil) in the high-pressure range. In recent years, Camelina sativa oil gained a significant interest in food and biofuel industries. Unfortunately, only a very few data characterizing the high-pressure behavior of Camelina sativa oil is available. The aim of this paper is to investigate high pressure physicochemical properties of liquids on the example of Camelina sativa oil, using efficient ultrasonic techniques, i.e., speed of sound measurements supported by parallel measurements of density. It is worth noting that conventional low-pressure methods of measuring physicochemical properties of liquids fail at high pressures. The time of flight (TOF) between the two selected ultrasonic impulses was evaluated with a cross-correlation method. TOF measurements enabled for determination of the speed of sound with very high precision (of the order of picoseconds). Ultrasonic velocity and density measurements were performed for pressures 0.1–660 MPa, and temperatures 3–30XC. Isotherms of acoustic impedance Za, surface tension σ and thermal conductivity k were subsequently evaluated. These physicochemical parameters of Camelina sativa oil are mainly influenced by changes in the pressure p, i.e., they increase about two times when the pressure increases from atmospheric pressure (0.1 MPa) to 660 MPa at 30XC. The results obtained in this study are novel and can be applied in food, and chemical industries.

The investigation of Nida Valley water aimed to assess fluctuations in physicochemical properties. In this study, environmental monitoring method was utilized to evaluate the changes in physicochemical properties of water. Over a 24-month period, from June 2021 to May 2023, a total of 228 water samples were collected from 10 sampling sites, with a monthly sampling frequency. Statistical analyses were utilized including the Shapiro–Wilk test (α = 0.05), Kruskal–Wallis test and Wilcoxon (Mann–Whitney) rank sum test (α = 0.05), Pearson correlation analysis (α = 0.001) and principal component analysis (PCA). Statistical analyses revealed significant differences between months in GW samples for for temperature, dissolved oxygen, pH, total nitrogen, total phosphorus, chloride, manganese, and zinc in GW samples and for T and DO in SW samples. Pearson correlation coefficient analysis (α = 0.001) identified strong positive correlations within the SW dataset. Similarly, significant positive correlations were observed among the GW dataset. Noteworthy positive correlations were also detected between the GW and SW datasets. Principal component analysis (PCA) revealed a substantial dissimilarity between GW2 samples compared to others, characterized by elevated manganese, iron, and Sulfate content. Two distinct groups emerged: Group 1 included samples at GW1, GW2, GW3, GW5, and SW2, while Group 2 comprised all other samples. This study demonstrated the stability in the physicochemical properties of SW and underscore a discernible correlation between the hydrochemical compositions of both SW and GW in the riparian area. Outstanding characteristics in hydrochemical component of sample waters have been indicated.