The crystal structure of the ternary intermetallic compounds τ1 in the Pd–(Cu, Ag, Au)–Sn systems has been determined. It has been found that in the silver and gold systems, these compounds crystallize in a body-centered tetragonal cell with atomic ordering corresponding to the Al3Ti structural type, whereas in the copper system, the τ1 phase adopts the VRh2Sn structure, which is an additionally ordered derivative of the Al3Ti type. The available literature data and the authors’ findings on the structures of binary and ternary compounds, which are ordered derivatives of the Cu-type structure, in Pd systems with Group 11 elements and non-transition metals In and Sn have been summarized and analyzed. It is shown that these compounds form at specific values of the electron concentration (e/a): compounds with AuCu or Al3Zr structural types at e/a = 0.75, with Al3Ti or VRh2Sn structural types at e/a = 0.8–1, and with the AuCu3 structural type at e/a = 1. The size factor influences the direction and extent of the phase homogeneity regions.

CALPHAD modelling of the Ag–Pd–Sn ternary system has been performed. The disordered phases, the melt and the fcc phase were described using the substitutional solution model. Sublattice models were used to describe intermetallic compounds and the ternary phase. The two-sublattice model (Ag,Pd) 4 (Ag, Sn) used for the ternary phase made it possible to reproduce the inclination of its homogeneity range. The results of the thermodynamic calculation of the Ag–Pd–Sn system are in good agreement with the experimental data on phase equilibria and enthalpies of formation of the liquid. The agreement with the data on the partial Gibbs energy of tin in the liquid is somewhat worse.

Phase equilibria in Ag–In–Pd ternary system were studied using Scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX) and X-Ray diffraction method (XRD). The solubilities of the third components in Ag–In and In–Pd binary phases were established, as well as composition ranges (from 4 to 17.5 at % Ag at 25 at % In) and crystal structure of τ ternary compound (Al 3 Ti). New thermodynamic assessment of Ag–In–Pd ternary system was performed, basing on the published experimental data and those obtained in the present work. Good agreement was achieved between the calculation results and the experimental data on phase equilibria and thermodynamic properties of the phases. The results of the calculation reproduce well experimental DTA/DSC data of three samples (the data were not included into the optimization). This additionally supports the correctness of the obtained thermodynamic description.

The paper focuses on a manned aircraft landing control system. It is known that actuator level and rate limitations can cause pilot-induced oscillations. This phenomenon occurs during intensive pilot control in a closed-loop system under certain initiating conditions associated with both the influence of the external environment and changes in the system dynamics. Oscillations appear unintentionally and unexpectedly for the pilot, which jeopardizes flight safety. The study shows the possibility of preventing aircraft oscillations using the method of nonlinear correction of systems by sequential introduction of a pseudo-linear correcting device into the control loop, the phase-frequency characteristic of the device not depending on the amplitude of the input signal. The airplane-pilot closed-loop system for various parameters of the input signal is analyzed by calculating the generalized function of sensitivity and the excitation index. The results of the study are presented in the form of angle and the pitch rate time processes, and landing trajectories.

New CALPHAD assessment of experimental data on phase equilibria and thermodynamic properties of phases in the Ag–Pd binary is performed. The results provide good description of experimental data, excepting one thermodynamic dataset which had to be excluded from calculation due to incompatibility. Results of optimization provides good description of data of phase equilibria, enthalpy of formation and activities of components obtained from 1906 to 2020 in whole range of concentrations and at temperatures from 560 to 1700 K. Differing from the results of published assessment, no artifacts (spurious miscibility gaps) were detected. The value of excess entropy for the composition Ag69.7Pd30.3 obtained from the heat capacity measured from 5 to about 560 K was not included to optimization but was used as independent test of results; the agreement seems to be well within experimental errors.

The partial isothermal section of the Pd-Cu-In system at 500 degrees C with 0-50 at. % In was plotted experimentally using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD). The addition of the third components significantly stabilizes binary compounds beta PdCu and eta' Cu2In. The solubility of copper in the InPd phase is close to 10 at.%. The phases InPd2, In3Pd5, and In3Pd2 do not dissolve any significant amount of copper. The new ternary compound InPd2Cu is found at about 25 at. % In from 3 to approx. 29 at. % Cu. This compound crystallizes in tetragonal structure of the VRh2Sn type. Its crystal structure, parameters of unit cell, as well as the distribution of atoms over crystallographic positions have been established by Rietveld method. (C) 2020 Elsevier B.V. All rights reserved.

Solidus and liquidus temperatures of solid solutions with the face centered cubic lattice (α-phase) in Pd—Au—Sn and Pd—Cu—Sn ternary systems were determined. The liquidus surface projections for the α-phase were constructed, and position of the binary eutectic reaction L → α + Pd3Sn in the studied ternary systems was predicted.

The solubility of tin in the phases of Pd–Au–Sn and Pd–Cu–Sn ternary systems and a Pd–Au–Cu–Sn quaternary system with a fixed Pd: Au: Cu ratio of 11.1: 1: 4.6 is studied via microstructural, X-ray diffraction, and energy dispersive analysis. It is found that a quaternary alloy in equilibrium with a solid solution based on Pd, Au, and Sn contains a τ1 compound with structure which is derivative of the In type. It contains ~15 at % Sn and is a solid solution of the same compounds identified earlier in Pd–Au–Sn and Pd–Cu–Sn ternary systems. In addition, a quaternary alloy with a content of 20 at % Sn also contains a τ2 compound with the Pd2CuSn own type and can barely dissolve gold. The obtained data are used to construct a three-dimensional model of the Pd-rich part of the isothermal tetrahedron of the Pd–Au–Cu–Sn system and diagrams of the tin solubility isolines in palladium-rich alloys of the quaternary system at 500°С.

The galactic cosmic ray (GCR) particle flux model has been developed by using the experimental data obtained during the solar cycles 21-24. The model calculates fluxes of GCR particles (with charge z from 1 to 28 and energy E from 80 up to 10(5) MeV/nucleon) in the interplanetary space (ecliptic plane) as a function of solar activity (sunspot number) and the heliocentric distance. GCR proton fluxes computed by the model for the case of a possible decrease in solar activity during solar cycles 25 and 26 are discussed.

Phase equilibria in Ag–Au–In system at 500°C are investigated by means of electron microscopy, electron probe microanalysis, and X-ray powder diffraction. The part of the system’s isothermal cross section with an indium content of up to 50 at % is constructed.

This work reports thermophysical properties measurements of binary mixtures of N,N-dimethylacetamide with 2-propanol and 2-butanol. Density, ρ, speed of sound, u, refractive index, nD, and kinematic viscosity, ν, were measured over the whole composition range at the temperatures (283.15, 298.15 and 313.15) K and at atmospheric pressure p = 0.1 MPa. Experimental data were used to calculate the following properties: excess molar volume, VE, excess isentropic compressibility, κSE,refractive index deviation, ΔnD, and viscosity deviation, Δη. These properties were correlated with the Redlich-Kister equation. Excess molar volumes were positive for both mixtures. Refractive index deviations were positive for N,N-dimethylacetamide + 2-propanol and negative for N,N-dimethylacetamide + 2-butanol. Excess isentropic compressibilities and viscosity deviations were negative for the two systems. Finally, the results obtained were interpreted based on both structural and energetic effects.

An improved thermodynamic model of the Fe–Co phase diagram has been achieved by incorporating new experimental data that was obtained via containerless processing. Fe–Co samples were prepared with 30, 40, and 50 at% cobalt, and they were processed via electrostatic levitation (ESL). The samples were levitated, melted, and allowed to cool and solidify in a vacuum. If sufficient undercooling was achieved, the metastable phase was observable after the first recalescence, which gives information on the location of the projected metastable phase lines on the phase diagram. Based on these new results, several parameters were adjusted so that the phase lines better represented the experimental metastable data, while the rest of the phase diagram continues to accurately predict previously accepted experimental results. The improved phase diagram allowed for evaluation of key solidification parameters including the partitioning coefficient of the metastable phase, as well as the thermal driving potential for the solidification of the stable phase from the metastable phase.

A combination of physicochemical analysis methods is used to study the phase equilibria in the Cu-In-Pd system. An isothermal section at 800°C has been constructed. The copper solubility in the binary phases of the In-Pd system is determined.

The article discusses the progress made in studying space radiation in the heliosphere using SINP MSU instruments on board a spacecraft built by the Lavochkin Association, in predicting flight radiation conditions, and in studying the radiation resistance of spacecraft components.

The isothermal section of Fe-Cr-V ternary at 900°С is plotted experimentally. New CALPHAD assessment of equilibria of α and σ phases in the temperature range of 700 to 1150°С is performed basing on both own and assessed published experimental data.

We have made a generalization of experimental data on the fluxes of trapped protons that were detected by various instruments on three low-orbit satellites (NOAA-17, Universitetskii-Tatiana, and CORONAS-F) during April of 2005. Based on these data, a new quantitative model is suggested to describe the fluxes of trapped protons. It allows one, using analytical expressions, to predict the fluxes of protons with energy from 30 keV to 140 MeV under quiet geomagnetic conditions in the period close to the solar activity minimum at drift shells L = 1.14–1.4. The suggested model establishes differential directional fluxes of protons as a function of pitchangle on the geomagnetic equator and takes into account the anisotropy of trapped particles on the lower boundary of the Earth’s radiation belt.