Measurements of angular distribution annihilation photons (ADAP) were applied to investigate the behavior of point defects in the annealed, plastically deformed and the irradiated titanium alloys. It is shown that irradiation by protons with E=30 MeV is accompanied by formation of vacancy clusters in titanium alloys. The presence of the deformation defects and alloying elements in the initial structure of the material leads to considerable changes in radiation damage spectra. It is determined that the role of the initial defects in the radiation damage of titanium alloys caused by a proton irradiation becomes apparent not only in the deceleration of the swelling process, but also in the evolution, transformation and the redistribution of the initial defects. These findings confirm once again a necessity of taking into account the presence of impurity atoms and preliminarily created structural damages in an irradiated material.

This study focuses on analyzing the influence of varying concentrations of polyethylene terephthalate filler on both the tensile strength and elongation at break properties of polyimide films when subjected to uniaxial tension, aiming to determine how polyethylene terephthalate filler impacts the mechanical performance and durability of these films under stress. The mechanical behavior of polyimide films and their homogeneous composites with polyethylene terephthalate under uniaxial tension were investigated. The samples were prepared by mechanically mixing polyimide varnish solutions with polyethylene terephthalate, which serves as a reinforcing filler. The results demonstrate that, for all sample types, an initial mechanical load until induces a sharp ~3% increase in relative elongation, attributed to the rotation of globules and alignment of matrix macromolecules into extended chains along the load direction. The additive dependence of viscosity observed in the study further supports that no chemical bonds are formed between the polyimide and polyethylene terephthalate macromolecules, and that no conformational changes take place within the composite.

Measurements of angular distributions of annihilation photons are applied to investigating structural defects and hydrogen behavior in annealed, plastically deformed, and irradiated stainless steels. It is determined that the whole cycle of investigations performed by positron diagnostics helped in tracing the formation and evolution of the defect structure and hydrogen behavior in different kinds of steels being subjected to complex physical–mechanical influences such as plastic deformation, hydrogenation and irradiation by fission neutrons. The high sensitivity of the electron–positron annihilation method allowed understanding even of details of the changes of the crystalline structure of multi-component materials.