Advanced Materials Research Vol. 1084

Abstract: The experimental study of the kinetics of styrene monomer accumulation in polyvinylidene fluoride films with radiation-chemical grafting of styrene monomer is presented. It is proved that the degree of grafting depends on the absorbed dose of helium ions, temperature and composition of the grafting solution.

Abstract: The article contains an analytical overview of techniques used for UF₆ purification. Structures of respective devices have been considered. Their advantages and drawbacks have been outlined. It has been shown that heat discharge desublimators and multi-chamber devices with two heated walls are the most efficient in UF₆ purification.

Abstract: This paper presents the results of a pilot study of the process of hydrocarbonic gas conversion in microwave plasma discharge at atmospheric pressure. A microwave plasmatron of the waveguide type with the power of up to 3 kW was developed and used as a plasma source. Hydrocarbonic gas is both a chemical reagent and a plasma-forming environment in this plasmatron. A peculiarity of the developed microwave plasmatron is the presence of an active system for initiating and maintaining microwave discharge in its structure. It has been demonstrated that a high (up to 70%) degree of conversion of hydrocarbonic gases can be attained in microwave plasma discharge. The products of plasmochemical reaction are hydrogen and a carbon material. The carbon material contains up to 60% of carbon nanotubes. The phase structure of the material and the cross sizes of carbon nanotubes are provided herein.

Abstract: Severe plastic deformation is a widely used technique to modify common structural materials for obtaining ultra-fine grained microstructure. One kind of this technique is equal channel angular pressing. Many testing methods are applied to investigate the internal structure of materials after deformation. Recently developed microtomography is a promising method allowing testing volumetrical structure of a sample non-destructively. In this paper, we present preliminary results of studying light alloys microstructure after severe plastic deformation by using microtomography applied to such kind materials for the first time.

Abstract: This work describes the technology of growing crystal metamaterials spinel ferrites. Metamaterials is one of the most promising classes of materials for use in optical devices in the microwave range and features, which can be used for creation of controlled attenuators, phase shifters, and other devices.

Abstract: The paper presents the theoretical foundations of carbon nanotubes, as well as the methods of the saturation of carbon materials containing nanotubes with hydrogen from the gaseous phase. The dependences of hydrogen storage concentration on the pressure (between 0 and 8 atmospheres) at the same temperature for adsorption (–30 degrees Celsius) and different temperatures for desorption have been obtained. Obviously, at 8 atmospheres the concentration of hydrogen storage varies with the change of the temperature. Particular attention was paid to the influence of the temperature on the rate of desorption.

Abstract: This work presents the results of studies of electromagnetic properties of nanocomposites based on opal matrices in the millimeter wavelength range. It is shown that the application of an external magnetic field changes the transmission and reflection coefficients. Magnetic resonance was studied in nanocomposite particles of spinel ferrites or metals. Magnetic resonance spectra were restored. We considered the parameters of nanocomposites required for using in microwave devices.

Abstract: This article is devoted to the simulation of the uranium crystallization process. Emphasis is placed on developing a mathematical model of the crystal growth using the cellular automata theory. It is used quantities such as dislocation density and crystal orientation as state variables. Cellular automata are defined on two-dimensional lattice. Physics of the process are taken into consideration in this approach. It is allowed setting complex boundary conditions, consider the complex phase transitions with intermediates, and hypothesize regarding phase’s formation and concentration and temperature fields distribution. Optimization of uranium crystallization process is accepted to get especially pure nuclear materials.

Abstract: The article provides a mathematical description of the thermal processes in the experimental electrolyzer. We have performed computer simulation and verified the adequacy of the model obtained. All thermal processes occurring in the installation during its operation have been identified. The data are currently being used in the synthesis of automatic control systems (ACS).

Abstract: The paper describes the advantages and characteristics of the fluoride technology applicable for the recovery of oxides of rare earth elements with the help of a fluorinating agent of elemental fluorine. A metallurgical mixture (2.5 m²/g) of rare earth elements oxides of the cerium subgroup, containing % wt.: CeO₂ - 50-55; La₂ O₃ - 23-25; Pr₆O₁₁ - 6-9, and Nd₂O₃ - 13-16 were studied. It has been shown, that using fluoride technology allows recovering mixture of rare earth elements with outlet no less than 98.9 %.