[en] Highlights: • Prediction of the properties of PVD/CVD coatings with the use of (FEM) analysis. • Stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N coatings. • The experimental values of stresses were determined on X-ray diffraction patterns. • An FEM model was established for the purpose of building a computer simulation. - Abstract: The aim of this paper is to present the results of the prediction of the properties of PVD/CVD coatings with the use of finite element method (FEM) analysis. The possibility of employing the FEM in the evaluation of stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N, Ti/(Ti,Si)N/(Ti,Si)N, and Ti/DLC/DLC coatings by taking into account their deposition conditions on magnesium alloys has been discussed in the paper. The difference in internal stresses in the zone between the coating and the substrate is caused by, first of all, the difference between the mechanical and thermal properties of the substrate and the coating, and also by the structural changes that occur in these materials during the fabrication process, especially during the cooling process following PVD and CVD treatment. The experimental values of stresses were determined based on X-ray diffraction patterns that correspond to the modelled values, which in turn can be used to confirm the correctness of the accepted mathematical model for testing the problem. An FEM model was established for the purpose of building a computer simulation of the internal stresses in the coatings. The accuracy of the FEM model was verified by comparing the results of the computer simulation of the stresses with experimental results. A computer simulation of the stresses was carried out in the ANSYS environment using the FEM method. Structure observations, chemical composition measurements, and mechanical property characterisations of the investigated materials has been carried out to give a background for the discussion of the results that were recorded during the modelling process.

[en] Highlights: • SiO2 NPs were obtained by sol-gel. • PVP and PVP/SiO2 composite nanofibers were obtained by electrospinning method. • The effect of process parameters on their morphology was investigated. • The effect of SiO2 NPs presence on their optical properties were investigated. - Abstract: The aim of the research was to create thin, nanofibrous composite mats with a polyvinylpyrrolidone (PVP) matrix, with the reinforcing phase in the form of silicon oxide (SiO₂) nanoparticles. SiO₂ nanopowder was obtained using the zol-gel method with a mixture of tetraethyl orthosilicate (TEOS, Si (OC2H5)), hydrochloric acid (HCl), ethanol (C3H5OH) and distilled water. The produced colloidal suspension was subjected to a drying process and a calcination process at 550 °C, resulting in an amorphous silica nanopowder with an average particle diameter of 20 nm. The morphology and structure of the manufactured SiO₂ nanoparticles was tested using transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Then, using the electrospinning method with a 15% (weight) solution of PVP in ethanol and a 15% solution of PVP/EtOH containing the produced nanoparticles equivalent to 5% of the mass concentration relative to the polymer matrix, polymer PVP nanofibres and PVP/SiO₂ composite nanofibres/SiO₂ nanoparticles were produced. The morphology and chemical composition of the produced polymer and composite nanofibres were tested using a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS). The analysis of the impact of the reinforcing phase on the absorption of electromagnetic radiation was conducted on the basis of UV–vis spectra, based on which the rated values of band gaps of the produced thin fibrous mats were assessed.

[en] Highlights: • None of the additives show the tendency to As, Ni, Sb and Zn capture in the ash. • Ammonium sulphate captures and immobilises Cr and Cu in the bottom ash. • Halloysite is effective in Cd, Co, V and Mn capture in the bottom ash. • Kaolinite is the most effective in Pb capture. -- Abstract: Up to now, a few studies on the efficiency of heavy metal(-oid)s capture by a sorbent directly mixed with fuel, have been performed. For this reason, the main objective of the study is to determine whether or not such a solution is effective when RDF is incinerated. The paper presents a two-step analysis of the impact of three sorbents (ammonium sulphate, kaolinite and halloysite) in three dosages (2, 4 and 8 wt%) on heavy metal(-oid)s retention in the bottom ash. 12 heavy metal(-oid)s were taken into consideration - As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, V and Zn. Samples were incinerated in a lab-scale tubular reactor at two temperatures - 900 °C and 1100 °C. The first step of investigation constitutes ICP analysis of heavy metal(-oid)s content in the bottom ash, coupled with SEM/EDS analysis. Afterwards, the second step was to determine the stability of formed additive-heavy metal(-oid)s complexes via leachability tests in neutral and acid environments. The performed research has shown that ammonium sulphate is effective in Cr, Cu and Hg capture, halloysite – in Cd, Co, V and Mn capture, whereas kaolinite – in Pb capture.

[en] Highlights: • KCl not associated with ash components does not influence ash melting behaviour. • Influence of KCl in ash deposits is higher at lower temperatures. • Temperature is the main factor enhancing steel oxidation. • SEM-EDS investigation of corrosion was used to determine corrosion mechanism. • K₂CO₃ thermal decomposition was observed at temperature around 600 °C. -- Abstract: The main aim of this work was to determine the influence of KCl-rich ash deposits on 10CrMo9-10 steel oxidation rate. Two agricultural biomass samples: oat and rye straw, clean and doped with KCl were tested in this study. The addition of KCl does not decrease the melting temperature of the ash when KCl is not incorporated with mineral matter components. Corrosion experiments were performed at 550 °C and 600 °C, with corrosion coupons covered with real and synthetic biomass ash under oxidising conditions. The nonuniform distribution of KCl in ash affected the results and the effect of potassium concentration on oxidation rate was not observed in all cases. More severe influence of ash rich in KCl was observed at lower temperature, the reason is lower protective oxide scale formation rate and higher influence of ashes on steel material and scale. The temperature increase by 50 °C doubled the corrosion rate. At 550 °C KCl was most aggressive salt, but at 600 °C the influence of eutectic mixture KCl+K₂SO₄ was the highest. Even at lower temperature thermal decomposition of K₂CO₃ was observed affecting the results. It might be concluded that temperature and eutectic mixture formation are essential parameters in corrosion prediction.