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Thermal spraying technologies are an effective way to ensure surface protection against destructive effects of wear, corrosion and oxidizing phenomena which can be applied in majority industrial sectors for improving properties of new parts or for reconditioning worn out parts technology. The powders used in this study are mainly used in the repair of cast iron parts (e.g. engine blocks) and in build - up of press tools for car bodies, threads, turbine-guided vanes, rotating valves and shafts in eccentric presses. Three types of tubular composites based on WC powders were studied which demonstrated that this technology improved their properties.

The paper proposes a new method for direct measurement of human alkaline phosphatase (ALP) and interleukin-6 and -8 (IL-6, IL-8) content using titania nanotubes (TNT) film as sensitive electrode. Under polarization, the interface characteristics are modified by the specific adhesion of proteins to the electrode surface, as shown by confocal fluorescence microscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) investigations for all 3 biomarkers. These changes can be measured by electrochemical impedance spectroscopy (EIS). A thin and uniform gold plating is beneficial for electrochemical sensitivity toward the investigated biomarkers. This electrode reflects the low levels of human ALP in water and in dilute solutions of human serum (HS) and total protein extract (TPE) by EIS. Good calibrations were obtained for the enzyme activities of 50, 100 and 125 U/L, which go below the detection limit obtained by classical methods. Calibration of IL-6 was performed in the concentration range of 0.165 ÷ 1.645 nM. The paper demonstrates that the annealed and in vacuum gold plated TNT/Ti electrode with 50 nm diameter is a new and credible candidate for a highly stable sensor to be used in the human ALP and IL-6 direct determination.

The purpose of this experimental laboratory work is to obtain composite membranes having carbon and gold nanoparticles in the matrix. Consideration was made of using graphene oxide, a material which, under certain conditions, can generate membranes by a self-assembly process under vacuum in an aqueous or organic medium. The cellulose acetate (CA) - graphene oxide (GO) composite membranes have been functionalized with gold nanoparticles (AuNP) by two technological processes: thermal evaporation and ultrasonic mixing of stable graphene oxide and gold suspensions. The stable suspensions containing gold nanoparticles were obtained by chemical reduction of aqueous solutions of Tetrachloroauric acid trihydrate (HAuCl4) precursors with sodium citrate under high temperature conditions. Dispersibility of carbon nanostructures and precious metal nanoparticles has been studied with a DLS granulometer - Malvern Instruments Zetasizer ZS90. It was determined the mean particle size and Zeta potential function of the suspensions pH. The graphite based membranes were further subjected to various characterizations techniques. It was found that both the surfaces and the cross-sections were functionalized with gold particles. The presence of Au particles was revealed both on the membrane surface and also inside its structure. Hydrophilic tests demonstrate that the membrane filters have potential to be used in various applications.