International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Due to various interferences arising from the tropospheric propagation of radio waves over big water basins, it is necessary to study in detail the mechanisms of propagation and to improve the existing models for determining propagation factor or path loss profiles at different frequencies, especially in UHF bands, caused by the growing interest of mobile communications and especially 5G technologies. To get enough information about radio wave propagation over the Black sea area, the state of atmosphere above points of interest is studied in detail and the results are compared with real measured radio signals distributed between those points. The results are compared with basic theoretical computed models. The results showed more than 10 dB and from 6 to10 dB difference respectively for VHF and UHF between measurement and computed with Three way path loss model EMF levels for the favorable cases which might be due to additional ray in the receiver. A clear relationship between received EMF levels and wind speed but in combination with different abnormal tropospheric environments and relationship between absolute value of modified refractivity and the levels of received signals for the surveyed regions

Sol gel TiO2-ZrO2 composite films were dip coated on stainless steel substrates and treated at 300, 400 and 500oC. The morphology and surface features were examined by Scanning electron microscopy (SEM) and X ray photoelectron spectroscopy (XPS). Xray diffraction analyses (XRD) was applied to investigate the phase composition. The corrosion resistances of the coatings were studied by evaluation of the weight loss in NaCl medium. According to XRD while the Zr-Ti composites are amorphous after treatment even at 500oC. The surfaces of the coatings possess typical island structure. The coatings, treated at 500oC ehxibit higher corrosion resistance than the other two type of samples. This could be explained by the amorphous structure of the composites, which lowers ion and electron conduction, high hydrophobicity and lower oxygen content.