Phase evolution studies in Al-Cu-Fe quasicrystals to tailor the mechanical properties of quasicrystal-polymer composites prepared by spark plasma sintering

Main contributions of this thesis are findings on the formation of the QC phase from equilibrium phases through a peritectic reaction directly by mechanical alloying in order to eliminate the costly process of melting and rapid solidification.The QCs are further employed on the preparation and characterization of quasicrystalline-polymer composites for the use in biomedical applications.The role of the interphase between the QC particles and the polymer is discussed. Finally,the possibility of using SPS technique to process the powders into bulk form suitable for applications is investigated

Influence of Technological Parameters on the Evolution of Nickel Films Deposited by Electrolysis

The influence of technological parameters on the structure of nickel layers electrodeposited on a copper substrate in a Watts bath has been studied. The complex influence of current densities, temperature and pH values on the formation of the deposition layers are compared. The surface morphology of the nickel films was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray diffraction (XRD) was used to investigate the crystallinity of the prepared samples. The increase in the current density leads to fine crystallized films, while layers obtained at even higher current density have dendritic structures. The temperature increasing results in a structure change from fine to coarse

DISTRIBUTION OF INVASIVE PLANT AILANTHUS ALTISSIMA (MILL) SWINGLE IN THE DANUBE SPA - BAZIAS - IRON GATE

Originary from China, Ailanthus altissima was first introduced in our country like un ornamental tree and in urban area possible due to its tolerance of polluants and resistance to drought. In present the tree of haven is one of the few invasive tree species from our country maybe because its huge capacity of vegetative and generative reproduction, fact that contribute to its spread. Research made in the Danube SPA - Bazias - Iron Gate (“Iron Gate” Natural Park) showed that the species is not found in the forest land but occupy large surface along the Danube river, between Socol and Berzasca towns