The activity concentrations of ²³⁴U and ²³⁸U in thermal groundwater, deep well water and river water samples from Central Poland were determined. Concentration of ²³⁴U and ²³⁸U in the examined waters varied from <0.013 (LLD) to 16.8 mBq/dm³ and from <0.013 (LLD) to 45.5 mBq/dm³ respectively. The highest uranium activity concentrations were measured in the thermal groundwater from Mszczonow and Cieplice, while the lowest were observed in thermal ground water from Uniejow and Poddebice. In thermal groundwater from Skierniewice, uranium activity concentrations were below lower limit of detection (0.013 mBq/dm³). The ²³⁴U/²³⁸U activity ratio varied from 0.37 (Cieplice) to 1.30 (Poddebice well water).

The article describes the mechanism of oxidation of polyunsaturated fatty acid esters and presents the effect of temperature as one of the factors accelerating this process. The consequences of aging for ester-based biofuels are discussed extensively. The article presents the results of aging of FAMEs obtained from frying oil and of FAMEs derived from unrefined rapeseed oil to examine the influence of temperature as a factor accelerating aging. Acid, peroxide and anisidine values were determined for each sample; additionally, IR spectra were measured. Based on the results, it was confirmed that temperature has a significant effect on the degradation of FAMEs. These changes are best represented by the anisidine value and the change in IR spectra. The paper presents the relationship between acid, peroxide and anisidine values. This paper also highlights the beneficial effect of natural antioxidants in the form of β–carotene, which is found in FAMEs derived from unrefined rapeseed oil.

The paper determines the properties of geopolymer pastes based on metakaolin and soda-lime waste glass. The density, alkaline activity, strength and microstructure of the reference geopolymer, as well as geopolymers with a 10%, 30% and 50% soda-lime waste glass content instead of metakaolin, were tested. The experimental results indicate that the properties of the geopolymers with waste glass largely depend on the ratio of the liquid to solid substance. Increasing the content of waste glass causes an increase in the fluidity of the geopolymer paste, which in turn allows the amount of water glass, i.e., an activator during the obtaining of geopolymers, to be reduced. On the basis of the conducted tests, it was found that the strength of geopolymers can be increased by adding up to 50% of soda-lime waste glass instead of metakaolin and by having a lower content of water glass.

A method for the determination of uranium and ²¹⁰Po in high salinity water samples has been elaborated. Both radionuclides are preconcentrated from 0.5 dm³ saline media by co-precipitation with hydrated manganese dioxide, followed by dissolution of the precipitate in 200 mL of 1 M HCl. Uranium isotopes ²³⁵U and ²³⁸U can be directly determined by ICP MS method with a detection limit of 0.01 ppb for ²³⁸U. Prior to a selective determination of ²¹⁰Po, the majority of other naturally occurring α-emitting radionuclides (uranium, thorium and protactinium) can be stripped from this solution by their extraction with a 50% solution of HDEHP in toluene. Finally, ²¹⁰Po is simply separated by direct transfer to an extractive scintillator containing 5% of trioctylphosphine oxide in Ultima Gold F cocktail and determined by an α/β separation liquid scintillation technique with detection limit below 0.1 mBq/dm³.

The uranium (²³⁴U/²³⁸U) and radium (²²⁸Ra/²²⁶Ra) activity ratios and ⁸⁷Sr/⁸⁶Sr isotopic ratio in thermal groundwater, subsurface water (groundwater) and river water from Poddebice and Uniejow were determined. The uranium and radium activity ratios and strontium isotopic ratio varied from 0.629 to 1.471, from 0.396 to 4.961 and from 0.708438 to 0.710344, respectively. The results for the thermal groundwater samples showed that the radiometric method together with mass spectrometry stable strontium isotope ratio measurements can be used for underground water transport studies. On the basis of the uranium and radium activity and the strontium isotopic ratio differences in subsurface water (groundwater) and in river water, any possible water influx between these adjacent reservoirs can be observed. The obtained results exclude any water transport from surface and subsurface water to thermal ground water reservoirs in this region of Poland.