Raman spectroscopy has been used for characterization of commercial nanosized TiO2 powder with declared grain size of 5 nm. The Raman spectra measured in Stokes and anti-Stokes regime confirm the anatase phase of TiO2 powder in temperature range 25-1173K. It is shown that phonon-confinement (due to small grain size) and nonstoichiometry (caused by laser irradiation in vacuum) have a great influence on blueshift and broadening of the main Eg Raman mode at low temperatures, while the influence of the strong anharmonic effect becomes dominant at higher temperatures. The phonon confinement effect decreases due to the crystallite growth at temperatures above 673K

The paper describes the mechanical properties and the corrosion behaviour of three Al-Si alloys in 0.5 M NaCl solution. The alloys have exhibited similar values of hardness, but the highest tensile strength and the lowest elongation have shown the specimens of alloy with 11.38 % of silicon. Higher content of both copper and magnesium has contributed to better tensile strength and lower elongation of as-cast hypoeutectic alloys. The harmful effects of iron on mechanical properties of all alloys have been reduced to some extent by nickel and cobalt addition. The differences in the values of the open circuit potential of the examined alloys were insignificant. The thickness of the protective oxide layer has increased over time, and the layer has become very compact. Slight differences in the values of the corrosion potential of the alloys were determined, whereas the lowest value of the corrosion current was indicated for the hypereutectic alloy. The presence of intermetallic phases in the alloys has shown that the oxide film was not consistent. The severe pits have not been found at the surface of the corroded samples. Based on the obtained results, the examined alloys may be used for the manufacturing of the internal combustion engine parts.

Biosorption of cadmium from aqueous solutions using fermented grape marc is investigated in this paper as well as influence of the most important factors, such as: contact time, granulation of biosorbent and the initial concentration of metal ions, is investigated in this paper. The equilibrium sorption of cadmium ions is achieved after 15-20 min., depending on the initial concentration of metal ions. Such a short time needed to achieve the equilibrium indicates that mass sorption is dominate process. Langmuir, Freundlich and Dubinin-Radushkevich isotherm were used to describe the equilibrium sorption process, while Langmuir model was found to be the most conveniente. Maximum of sorption capacity is 20 mg g1. EDS spectrum analysis showed that the process of ion exchange is one of the main sorption mechanism. Minor changes observed in the FTIR spectrum of grape marc after the sorption of Cd(II) ions indicate forming a band between metal ions and partially ionized carboxyl and phenol groups from the biomass. The results of this study confirmed that the fermented grape marc, due to the porous structure and characteristic chemical composition, is good sorption material.

Microstructural examinations of Al-Si alloys intended to manufacture IC engine components revealed a complex phase composition in all samples. Polyhedral crystals of primary silicon were detected in Al-12.5Si alloy, besides the ?-Al phase, eutectic silicon, and several intermetallic phases, identified in the cast samples of both alloys. Better tensile properties were found for samples of Al-11Si. Predominantly intercrystalline fracture with features of ductile failure was observed in both alloys. In as-cast specimens of Al-11Si alloy, the cracks were formed by the decohesion mechanism between the particles of the intermetallic phase AlCuFeNi and ?-Al phase. The microcracks initiated on the interface were spread along the branches of ?-Al15(Fe,Mn,Cu)3Si2 particles. After T6 treatment of Al-11Si alloy, almost half the intermetallics quantity presented Al3Ni phase, while the iron-based phases were observed in a small amount. Spheroidized eutectic silicon, less portion of Al5Cu2Mg8Si6, and a more considerable quantity of Al3(Fe,Mn,Cu,Ni,Co) were detected for T6 specimens of Al-12.5Si alloy. The rounded crystals of eutectic silicon contributed to the improvement of their tensile properties. Larger and deeper dimples of mostly polygonal shapes were observed in the samples of Al-11Si alloy after T6 treatment. The microcracks have occurred at the boundary of the intermetallic phase/?-Al solid solution.

Analyzing the production and consumption of non-ferrous metals in the world, it can be stated that aluminum and its alloys are in the first place in the term of a growth rate. The accelerated rate of nonferrous metals consumption, demands for high-quality castings, as well as the economic aspect, certainly have influenced some changes, certain improvements and innovations in casting technologies and their application in corrosive environments. In this sense the aluminum alloys with copper and magnesium occupy a significant place. Stability corrosion tests often use the Tafel's method of potentiodynamic polarization, as well as the electrochemical impedance measurements. Also, a certain corrosion stability enhancements and reducing the metal corrosion rates can be achieved with the addition of small quantities of inhibitors in the aggressive corrosion ambience. A proper selection of inhibitors is very important for effective enhancement of the corrosion protection, bearing in mind that some types of the inhibitors slow down the corrosion only in a particular solution/metal system. Inhibitors are mainly used to improve the corrosion protection of metal parts in solvents and spaces of limited volume, such as: chemical devices, steam boilers, storage and etching equipment and similar devices. The inhibitors used in this study belong to anodic corrosion inhibitors whose role is to slow down the anodic process of metal dissolution, through creating an insoluble protective layer with the primary corrosion products that firmly adheres to the metal surface and thereby reduces the anodic surface.