A technique for measuring the frequency spectrum of the complex permittivity of soil

A technique for measuring the complex-permittivity spectra of moist soils in the microwave band with the use of a coaxial measuring container is proposed. A calibration procedure for the measuring waveguide circuit is developed. This procedure assumes measuring scattering matrices S of two empty containers with different lengths. Measurement errors are analyzed. Experimental results for the complex permittivity of a moist loamy soil at positive and negative temperatures are presented.     

Errors in Results and Measurement Provisions

The relative and reduced errors of measurement provisions and the relative errors of measurements are considered. Analytical expressions are provided that make it possible to evaluate the errors in question. Conclusions and practical recommendations are given.Translated from Izmeritel’naya Tekhnika, No. 3, pp. 71–72, March, 2005.     

Infinite Point Group Quasicrystals: Symmetry Basis for Noncrystalline Diamond-like Materials

The construction of a diamond-like tetracoordinated quasicrystal (possible only in the infinite point group R) is considered in the framework of algebraic geometry. The physical and materials research applications of this approach are discussed.     

Genetic algorithms to reduce diagnostic information

A new genetic algorithm-based approach to the problem of reducing the diagnostic information acquired by testing discrete devices was proposed. Consideration was given to minimization and optimization of the diagnostic information for which the corresponding fitness functions and chromosome structures used in the genetic algorithms were suggested. Statistical data corroborating efficiency of the developed genetic algorithms for the problems under consideration were presented.     

Microstructure evolution during warm working of Ti–6Al–4V with a colony-α microstructure

A high-resolution electron backscatter diffraction technique was employed to investigate microstructure evolution during warm working of Ti–6Al–4V with a colony-α microstructure. Particular emphasis was paid to the specific mechanisms governing this process. Microstructure development was found to be driven mainly by the geometrical requirements of the imposed strain and by the kinking of α lamellae. For the most part, the lamellar microstructure was surprisingly stable during straining, with limited globularization observed only in kinked α colonies. The kinking process was shown to be closely linked with the development of shear bands within the colonies. These observations suggest that changes in strain path may be beneficial in promoting globularization during warm working.     

Cyclic degradation of material in vehicle components

A nonstandard approach to the fatigue strength of materials and structures is proposed, within the framework of the complete-diagram method. The use of the cyclic-degradation model in calculating the life of vehicle components is illustrated. In supercritical cycling, linear summation of the damage is possible in some situations.     

Effect of boundary conditions on the heat transfer law for a turbulent boundary layer

The heat transfer at an impermeable plate has been experimentally investigated under various boundary conditions. The conservativeness of the heat transfer law St₀=f(Re _T ^** ) is demonstrated for a monotonic increase of temperature and heat flux along the surface.