[en] The notion of uniform filtration in an annular dense layer at the side feed of fluid has been transformed to a two-dimensional potential flow. The dynamic conditions on the layer side surfaces leading to a uniform filtration are found. They help to solve the optimization problem of determining the configuration of distributing and discharging channels and layer end faces. The problem solved provides for a maximal flow rate through the layer and a unifrom filtration under the fixed pressure drop

No abstract available

[en] The phase equilibria and the thermodynamics of coexisting phases in the Pr--Fe--O system were studied using static and dynamic methods for attaining equilibrium with subsequent annealing and identification of the condensed phases by x-ray analysis. Equilibrium phase diagrams were constructed to define the changes that take place in the Pr--Fe--O system on variation of the partial oxygen pressure, the temperature, and the composition of the initial mixture of oxides. An isothermal cross section at 1300⁰K and equilibrium diagrams of the type Po₂ = f(composition) with T = constant, Po₂ = f(1/T) with one composition parameter fixed and T = f(composition) with P o₂ = constant have been constructed. It was shown in the Pr--Fe--O system that only one ternary compound with perovskite structure, PrFeO₃, is formed, and furthermore, it is stable no matter how high the partial oxygen pressure

[en] Hydrodynamics and thermal physics of two-phase flows in monodisperse sphere-pac beds are investigated in view of long-term application of spherical nuclear fuel microelements cooled by water directly in water boiling reactor core. The same water vapor structures and flows can be in WWER and LWR when malfunctions. Questions of evaporation, boiling and initiation of boiling crisis are discussed

[en] X-ray and microstructural analysis methods were used to study the possibility of cationic nonstoichiometry in intermediate phases of the ferroperovskite--ferrogarnet type of the Eu₂O₃--Fe₂O₃ system. It is shown that at 1350⁰C europium ferroperovskite has a narrow range of nonstoichiometry in the direction of excess iron oxide. The character of phase changes in the Eu--Fe--O system during changes in Po₂ has been studied; the equilibrium pressure of oxygen on ferrogarnet and magnetite has been calculated, and an equilibrium phase diagram of the type log Po₂ = f(composition) at 1473⁰K has been constructed. The relative stability of europium ferroperovskite and ferrogarnet has been evaluated

No abstract available

[en] A study has been made of conditions under which solid solutions are formed of the type of ferrogarnet and ferroperovskite in Eu-Ce-Fe-O and Eu-Pr-Fe-O systems. Regions of their existence have been determined and isothermal phase diagrams of quasi-ternary sections plotted for Eu₃Fe₅O₁₂-Ce₃Fe₅O₁₂-Pr₃Fe₅O₁₂ (1380 deg C) and EuFeO₃-CeFeO₃-PrFeO₃ (1000 deg C). Phase composition and lattice parameters of solid solutions of ferrogarnets are given

No abstract available

No abstract available

[en] It is shown that in the Ce--Fe--O system only one ternary compound with a perovskite structure, the orthoferrite CeFeO₃, is formed. The crystallographic properties of cerium ferroperovskite are defined more accurately. The thermodynamics of its oxidation and reduction over a temperature range of 900 to 1200⁰C are studied using the emf method with a solid electrolyte. It is shown that the free energy of cerium orthoferrite formation from the oxides according to the reaction 1/2Ce₂O₃ + 1/2Fe₂O₃ = CeFeO₃, derived from data on the equilibrium oxidation of CeFeO₃, differs very little from the value of ΔG⁰, calculated from the magnitude of the equilibrium pressure of oxygen over the orthoferrite and reduction products coexisting with it. Phase equilibria and the thermodynamics of coexisting phases in the Ce--Fe--O system were investigated. Equilibrium diagrams are constructed which define the character of the changes taking place in the Ce--Fe--O system during changes in partial oxygen pressure, temperature, and composition of the initial oxide mixture. Thus, we have equilibrium diagrams of the type Po₂ = f(composition) with T = constant; Po₂ = f(1/T) with one composition parameter fixed; and T = f(composition) with Po₂ = constant