An Energy-Saving Control System for an Orbital Electric Driver of a Press Coupler

A control system for the orbital electric drive of a press coupler capable of reducing energy consumption is considered. Because the stator is not completely overlapped by rotors, it is proposed to reduce the power consumption by means of turning off the power supply from the unused part of the rotor. This requires use of a rotor-positioning sensor as well as an algorithm for determining the overlap area depending on the position of the rotors. A calculation algorithm, which can be applied to orbital electric drives of different configurations, is presented. The algorithm creates rotor and stator maps depending on the angle and the sought overlap area is obtained by overlapping one map on another. This allows applying the optimization methods for finding an optimal control algorithm.     

Magnetic separators for cleaning of cutting-oil fluids in application and utilization systems

A modernized unit represented as a magnetic disk separator is proposed for the removal of mechanical impurities from cutting-oil fluids.     

Diffraction of H0m and E0m modes by a system of axially symmetric discontinuities in a coaxial circuit

Diffraction of axially symmetric H _0m and E _0m modes by a system of annular slots in the hollow inner conductor of a coaxial waveguide is considered. The space inside a slot and between the slots is filled with a dielectric. Diffraction of H _0m and E _0m modes by the end of a semiinfinite circular waveguide placed coaxially in a circular waveguide of larger diameter is solved as the key problem. The obtained solution is used in the analysis of structures with a finite number of equispaced discontinuities. The solution is obtained with the operator approach. Dependences of the reflection coefficient of this structure on the slot width and the spacing of discontinuities are analyzed.     

Influence of production parameters on greenhouse-gas emissions in ferrous metallurgy

The influence of the production parameters on greenhouse-gas emissions in ferrous metallurgy is demonstrated. Relevant factors include change in plant output, product range, the technology for steel smelting and casting, and the composition in ingot casting. The replacement of open-hearth technology by converters will reduce carbon-dioxide emissions and the energy consumption in steel production only if continuous casting is introduced and the hot-metal consumption in converter smelting is reduced.     

Spin Dynamics in Narrow-Gap Semiconductor Epitaxial Layers

We report on investigation of the spin dynamics in InAs and InSb films grown on GaAs at a temperature range from 77 K to 290 K. For both materials, the large lattice mismatch with the GaAs substrate results in the formation of an interface accumulation layer with a large defect concentration, which strongly affects the spin relaxation in these areas. Moreover, the native surface defect in the InAs films resulted in an additional charge accumulation layer with high conductivity, but very short spin lifetime. In contrast, in InSb layers, the surface states introduce a depletion region. We have correlated the spin relaxation with a multi-layer analysis of the transport properties, and find that in a 1 μm thick InAs film, approximately 70% of the total current flows through the interface and surface accumulation layers, which have sub-picosecond lifetimes, whereas in InSb films of the same thickness, the semiconducting layer carries more than 90% of the total current, and the spin lifetime in the accumulation layer is only slightly less than that of the central semiconducting layer. We suggest that InSb could be a more attractive candidate for spintronic applications than InAs.     

The dislocation anharmonicity in silicon

The effect of the dislocation anharmonicity on the Young modulus in bending silicon single crystals was studied. It is shown that changes in the Young modulus are caused by the contribution of dislocations to the fourth-order elasticity moduli. It is revealed experimentally that the bending deformation in both donor and acceptor silicon crystals favors the appearance mainly of the edge dislocations with the axes forming an angle θ∼90° with the Burgers vector.