Plasticization of neutron-irradiated LiF crystals upon thermal stimulation of a single-system dislocation glide

It has been shown that post-radiation annealing of LiF crystals irradiated by high neutron fluences (10¹⁵–10¹⁸ neutrons/cm²) at comparative low temperatures (300–400°C) creates optimal conditions for single-system dislocation glide, which favors a complete recovery of the plasticity with conservation of a significant fraction of radiation hardening.     

Effect of magnetic field on the polarization of LiF crystals during microindentation

The polarization and depolarization processes in a LiF crystal during indentation after exposure to a dc magnetic field (B = 0.9 T, t = 30 min) have been studied. It has been shown that the potential difference appearing due to movement of charged dislocations in the exposed crystal increases more than two-fold as compared to the initial sample, and the subsequent charge equilibrium in the samples is established approximately 1.5 times faster. These developments demonstrate significant increase in the concentration of free cation vacancies due to action of a magnetic field.     

PECVD of Carbon Nanostructures in Hydrocarbon‐Based RF Plasmas

Different aspects of the plasma‐enhanced chemical vapor deposition of various carbon nanostructures in the ionized gas phase of high‐density, low‐temperature reactive plasmas of Ar+H₂+CH₄ gas mixtures are studied. The growth techniques, surface morphologies, densities and fluxes of major reactive species in the discharge, and effects of the transport of the plasma‐grown nanoparticles through the near‐substrate plasma sheath are examined. Possible growth precursors of the carbon nanostructures are also discussed. In particular, the experimental and numerical results indicate that it is likely that the aligned carbon nanotip structures are predominantly grown by the molecular and radical units, whereas the plasma‐grown nanoparticles are crucial components of polymorphous carbon films. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Alkaloid and phenolic compounds of Galanthus caucasicus, Magnolia obovata, Cocculus laurifolius, and Veratrum lobelianum grown in Georgia

A collection of plants from the country of Georgia (Galanthus caucasicus, Magnolia obovata, Cocculus laurifolius, and Veratrum lobelianum) has been studied for their alkaloid content. Our studies led to the isolation and identification of 24 alkaloids, three of which are being identified and reported for the first time.     

Poincaré oscillations and geostrophic adjustment in a rotating paraboloid

Free liquid oscillations (Poincaré oscillations) in a rotating paraboloid are investigated theoretically and experimentally. Within the framework of shallow-water theory, with account for the centrifugal force, expressions for the free oscillation frequencies are obtained and corrections to the frequencies related with the finiteness of the liquid depth are found. It is shown that in the rotating liquid, apart from the wave modes of free oscillations, a stationary vortex mode is also generated, that is, a process of geostrophic adjustment takes place. Solutions of the shallow-water equations which describe the wave dynamics of the adjustment process are presented. In the experiments performed the wave and vortex modes were excited by removing a previously immersed hemisphere from the central part of the paraboloid. Good agreement between theory and experiment was obtained.