Thermodynamic properties of <Emphasis Type="Italic">p</Emphasis>-Sm<Subscript>2</Subscript>Zr<Subscript>2</Subscript>O<Subscript>7</Subscript>

The isobaric heat capacity of p-Sm₂Zr₂O₇ (pyrochlore phase) has been determined in the temperature range 10–1400 K using adiabatic, differential scanning, and relaxation calorimetry, and its enthalpy increment, entropy, and reduced Gibbs energy have been calculated with allowance for the contributions of its low-temperature magnetic transformations.     

Length of the Pre-Detonation Region in Plastic-Bonded HMX Samples as a Function of the Velocity and Size of a Spherical Impactor

Combustion, Explosion, and Shock Waves - Experimental results on the parameters of detonation process formation in plastic-bonded HMX as functions of the velocity and size of spherical impactors...     

Effect of nature of fibrous substrate of composite membranes on their structure,conductive properties,and selectivity

The effect of fibers selected for investigation on the kinetics of synthesis and curing of the polymer matrix has been revealed; structural features of Polikon K materials formed on polyacrylonitrile, polyester, and novolac phenol–formaldehyde fibers have been studied; and the performance characteristics of the materials have been determined.     

Crystallographic and Low Frequency Conductivity Studies of the Spinel Systems CuFe_2O_4 and Cu_（1-x）Zn_xGa_（0.1）Fe_（1.9）O_4

Spinel solid solutions of CuFe2O4 and Cu1-xZnxGa0.1Fe1.9O4 with (0.0≤x≤0.5) are synthesized. Crystallographic phase transformation from tetragonal-to-cubic occurred at x=0.2. The derived structural parameters manifest that Zn occupies the tetrahedral A-site while Cu and Ga occupy the octahedral B-site and Fe distributes among A- and B-sites. Electrical conductivity measurements of these materials as a function of temperature and frequency revealed semiconducting behavior except CuFe2O4 sample, which has a metallic behavior at low frequency and at high frequency, metallic -to- semiconductor transition occurred as temperature increases. The metallic behavior in this sample is attributed to cation-cation interactions at B-site while, the semiconductor behavior in Cu1-xZnxGa0.1Fe1.9O4 compounds is due to the cation- anion -cation interactions at the same site in the spinel lattice. All compositions exhibit transition with change in the slope of conductivity versus temperature curve. This transition temperature (Tc) decreases linearly with increasing Zn content x. The relation of the universal exponent s with temperature gives evidence that over large polaron OLP and correlated barrier hopping CBH conduction mechanisms are presented in CuFe2O4 and Cu1-xZnxGa0.1Fe1.9O4 compounds respectively.     

Development of high-efficiency chemisorption filters for water treatment. Part 1

The effect of oxidized PAN fibre on the kinetics of synthesis and hardening of the polymer matrix was investigated. it was shown that synthesis and polymer matrix formation in the structure and on the surface of oxidized PAN fibre take place with a higher initial rate. The effect of fibre fillers on the structure of the ion-exchange matrix was investigated. The possibility of direct regulation of the structural characteristics of the ion-exchange matrix was demonstrated. It was shown that the chemisorbents developed can be used in treatment of waste water to remove heavy metal cations. Oxidized PAN fibre is a promising fibre filler in production of Polikon composite chemisorption fibre materials for treatment of wastewaters.     

Study and modeling of hydrogen release from Ti,Zr, Ni,Pd, Pt during linear heating

New the experimental results of thermally stimulated hydrogen release (TCHR) from plane-parallel plates of Ti, Zr, Ni, Pd, Pt metals with various thicknesses (0.05–1 mm), pre-saturated with hydrogen, under linear heating (1 °C s^?1) presented. The electrolytic and Sieverts method for saturate were used. Theoretical models for diffusion and desorption hydrogen release from flat metal samples into vacuum with linear heating were developed. In this case, the processes of diffusion and thermal desorption were taken into account to select the optimal conditions and experimental methods. The TSHR spectra simulated using the MATLAB software package to test the consistency of theory with experiment. By modeling in MATLAB using both the developed models and experimental TSHR spectra, the activation energies of desorption, diffusion and decomposition of hydrides, as well as the preexponential factors in the diffusion and kinetic equations, were determined.     

Thermal expansion and heat capacity of Sm2ScTaO7 – A promising material for thermal barrier coatings

The experimental results presented for Sm₂ScTaO₇ pyrochlore in this study, temperature dependence of heat capacity and retaining the pyrochlore structure with the temperature variation, as well as the constant value of the thermal expansion coefficient in a wide temperature range, can be considered as evidences for the absence of a previously reported phase transition in the high-temperature region for this compound. This means that Sm₂ScTaO₇ pyrochlore is no doubt a promising material for thermal barrier coatings.     

Dependence of the surface roughness on the cutting energy in abrasive superfinishing

The roughness of the machined surface is considered in relation to the cutting energy in superfinishing. The cutting energy is a generalized characteristic of superfinishing and depends in a complex manner on numerous factors.