The aim of the study was to evaluate the shielding properties of selected building materials against gamma radiation and to analyze the impact of their density and composition on the effectiveness of beam attenuation. Linear attenuation coefficients were determined based on spectrometric measurements for various materials using Cs-137 and Co-60 sources. Steel and concrete with lead additives proved to be the most effective, while other additives did not significantly improve protective properties.
A review, with 17 refs., of chem. methods used for decontamination of radionuclides 137Cs and 90Sr in the environment and on technical surfaces. Mechanisms of sorption, ion exchange, precipitation, and complexation were discussed, together with the application of advanced sorbents (zeolites, metal ferrocyanides, graphene, MOFs, nanocellulose) in comparison with classical approaches. Key factors affecting performance (pH, ionic competition, diffusion limits) and field experience from Chernobyl and Fukushima were summarized, highlighting the need for selective sorbents and hybrid systems.
The design of a flow extractor for obtaining active substances from plant material and examplary exptl. results were presented. Optimization of the process parameters, i.e. time, temp. and speed of liq. flow through plant fragments, were detd. The temp. range at which satisfactory concns. of cannabidiol (CBD) and cannabidiolic acid (CBDA) were achieved in the extracts, were detd. The results will be used for further work on the development of a centrifugal extractor.
Drops of sulfur mustard were applied on the exterior of 3 types of protective materials and the time after which this agent permeate through the fabric was detd. The static method using UV-Vis and the dynamic method using GC were used to det. the breakthrough time of the material. A test stand for testing using the dynamic method was designed and built. Dynamic method was more accurate and gave less scatter of results.
Three potentially stable methods for generating tabun vapor were compared using (i) a capillary, (ii) solns. of tabun in suitable aliphatic solvents and (iii) a metal vessel and liquid tabun. The best results were obtained for the method (iii), which showed high repeatability and stability of the generated tabun concn. over time and was characterized by increased work safety. The limit of detn. of tabun vapor generation was established via GC with a dual FPD detector at 1x10-5 g/m(3).
