Generation of coal-based electricity is always associated with the origination of large amount of combustion waste. The presented article is a review concerning the possibilities of innovative directions of management for one of the by-products of coal combustion: fly ash. The storage of these waste products is associated with their negative impact on the environment. This is why research has been undertaken worldwide on the implementation of the concept of a circular economy. This article includes the examination of basic physical, chemical, and mineralogical properties of the most valuable components of fly ash (microspheres, magnetic fraction, and glass). It contains the examination of methods of separating these components and indicates the prospective directions of their use, e.g. as light fillers for polymers, sorbents, catalysts, composite materials, light ceramics, lightweight concretes, thermal insulation materials, biomaterials, raw material for the synthesis of zeolites or geopolymers. The paper also presents the components of fly ash, which can be treated as an alternative source of valuable elements, including critical elements. Moreover, it points to the necessity of capturing flammable substances from combustion by-products in order to obtain raw material characterised by a high degree of purity. It has been demonstrated that this way of ash management can lead to high recycling rates and bring valuable materials back to the economy. Such actions fit perfectly into global efforts for sustainable development and the circular economy.

Iron oxide nanoparticles were incorporated to form composite microspheres of SiO2 and Fe2O3 for magnetic separation of the particles after adsorption or photochemical decomposition. Economic material, sodium silicate, was purified by ion exchange to prepare aqueous silicic acid solution, followed by mixing with iron oxide nanoparticles. Resulting aqueous dispersion was emulsified, and composite microspheres of SiO2 and Fe2O3 was formed from the emulsion droplets as micro-reactors during heating. Removal of methylene blue using the composite microspheres was performed by batch adsorption process. Synthesis of composite microspheres of silica containing Fe2O3 and TiO2 nanoparticles was also possible, the particles could be separated using magnets efficiently after removal of organic dye.

Developing an effective and safe cancer therapy could significantly reduce the number of deaths and improve the quality of life of treated patients. Nowadays medicine has developed a wide range of anticancer chemotherapeutics but at the same time there is a lack of effective drug delivery methods. Therefore, the development of the targeted drug delivery system which will selectively release drug into the cancer cells is a key challenge of modern medicine.
The main aim of the presented research was to investigate the targeting effect of a drug delivery system based on the controlled release of dextran nanoparticles containing the anticancer drug – doxorubicin from the alginate microspheres coated with chitosan multilayers.
During the research the physicochemical properties of the alginate microspheres and its stability in the physiological environment were investigated. Moreover, the kinetics of the nanoparticles with doxorubicin release from the alginate microspheres covered with chitosan multilayers was characterized, depending on the thickness of the chitosan layer. Further, the cytotoxicity study of the alginate microspheres covered with chitosan multilayer and containing nanoparticles was performed to determine the therapeutic effect of the released nanoparticles with doxorubicin on the HeLa cells during the in vitro cell culture.

The process of obtaining alginate microspheres (AMs) by emulsification method was optimized by applying statistical analysis software. Ten batches of microspheres were prepared using the fractional plan 3 ^(K-p). AMs were obtained with two different methods: an ultrasonic homogenization (UH) process and a rotor-stator mechanical homogenization (MH). The amount of a cross-linking agent (CaCl ₂), calcium chloride rate addition, and the sonication amplitude (UH) or the speed of rotor rotation (MH) were selected as formulation variables. All the batches were evaluated in terms of stability and size of the alginate microspheres. Approximation profiles were developed. As a result of the conducted research, stable alginate microspheres with sizes ranging from 10 to 30 micrometres were obtained. The obtained results showed that the quality of AMs was mainly affected by the concentration and the rate of calcium chloride addition into the system. Therefore, the role of calcium ions in the mechanisms of shell structuring was discussed. Lactobacillus casei bacteria were encapsulated into the batches found to be optimum. The high encapsulation efficiency (EE) of the bacteria (72-94%) depending on the form) and their viability over time were obtained. The model developed in the study can be effectively utilized to achieve the AMs formulations.

The present work has the objective of studying the effect of shot peening with glass microspheres on SAE 1020 steel in its resistance to fatigue. Fatigue tests were carried out by rotary bending with load control and loading on balance in specimens with and without shot peening. A rotation speed of approximately 750 rpm (12.5 Hz) was employed in the fatigue tests. Vickers microhardness tests were performed in order to verify the surface hardening produced by shot peening with glass microspheres. Analysis of the steel surface and fatigue fractures was performed using scanning electron microscopy (SEM). Fatigue tests were performed in order to obtain S-N curves (Wöhler curves). It was observed that shot peening with glass microspheres improved the fatigue strength of the steel at high cycle.

This study is devoted to synthesis and characterization of uranium dioxide microspheres (Ø < 100 µm) and pellets by application of powder-free process called the Complex Sol-Gel Process. The precursors of prepared sols were ascorbic acid solution with dissolved a freshly precipitated ammonium diuranate. The microspheres of uranyl-ascorbate gel were obtained using the ICHTJ Process. The pellets were formed by pressing and sintering of uranium dioxide powder. Studies allowed determining an optimal heat treatment of calcination, reduction and sintering processes at temperatures of 700°C, 900°C and 1300°C, respectively. The main parameters which play a key role in the process of synthesis method and features of the pellets and microspheres of uranium dioxide are described in this article.