Experimental grounding of the efficiency of the use of elastic operating elements in the devices for pre-sowing seed treatments

The article is devoted to the experimental studies of the effect of elastic operating elements of a mixer-dresser on seeds. Conducted experimental studies have shown the effectiveness of using the elastic operating elements for pre-sowing seed treatments. The proposed device is intended for the intensification of the process of mixing and dressing, excluding the traumatizing of seeds, and the harmful effect of protectant preparations on maintenance workers, while simplifying and reducing the cost of construction without additional power inputs. Experimental studies have confirmed the hypothesis, that the use ofshells, made of elastic materials,in the function of mixing devices, significantly reduces the time of preparation of homogeneous mixtures, due to the ability to accumulate the potential energy and to transfer it to the granular material,in the form of kinetic energy of mixed particles motion. Based on the performed researches, 3D model of the device for pre-sowing seed treatments has been developed. Hybrid elastic mixer-dressers can be used in agricultural enterprises, dealing with the issues of obtaining multicomponent granular mixtures and seed dressing.Web of Science97S74273

Factorization effects in a model of unstable particles

The effects of factorization are considered within the framework of the model of unstable particles with a smeared mass. It is shown that two-particle cross section and three-particle decay width can be described by the universal factorized formulae for an unstable particles of an arbitrary spin in an intermediate state. The exact factorization is caused by the specific structure of the model unstable-particle propagators. This result is generalized to complicated scattering and decay-chain processes with unstable particles in intermediate states. We analyze applicability of the method and evaluate its accuracy.Comment: 13 pages, 7 figure

Temperature operating mode of the CuBr+Ne+H2(HBr)-laser at change of pumping

The analysis of a temperature mode of the laser on copper bromide vapour using active additives of hydrogen (bromhydrogen) at change of pumping parameters has been carried out. It is shown that introduction of the optimal additive increases the discharge tube wall temperature from 620 up to 720 °С. The increase of wall temperature 50...60 °С more can occur at change of buffer gas pressure from 3,3 to 13,3 kPa, as well as at increase working capacity twice. It is stated that introduction of the additive raises pressure of working substance vapours in the active media of the laser of average diameter 6,7 Pa more due to interaction of bromine, bromhydrogen with copper atoms settled on the tube wall. The peculiarities of laser thermal mode at high frequencies of pulse sequences (up to 100 kHz) have been considered

Radiotomography based on monostatic interference measurement with controlled oscillator

The method of three-dimensional tomography based on radioholography measurements with the reference signal transmitted by the transmitter in the near zone and the receiver near zone. We solve the problem of repairing the object signal phase due to the reference signal in the near field in a wide frequency band and the consideration of analytical signals. Here are presented results of experimental studies on application of a tunable YIG (yttrium iron garnet) oscillator in the frequency range from 6.5 to 10.7 GHz for radio tomography of metal objects in air. Holographic principle is applied on the basis of measuring of the interference field amplitude by the detector diode. The interference occurs with the direct wave and waves scattered by the object. To restore the radio images the method of aperture synthesis and extraction of quadrature components at all frequencies sensing are applied. Experimental study on test object shows resolution about 15 mm

3D Radiotomography of objects hidden behind dielectrically inhomogeneous shields

A method for the reconstruction of 3D radio images of objects that are hidden behind a priori known dielectrically inhomogeneous shields is based on the results of multiposition ultrabroadband radio sounding. Direct and inverse problems are solved in the Kirchhoff approximation and the scalar approximation of single scattering. Numerical simulation and experimental study are performed at frequencies ranging from 4 to 14 GHz. It is demonstrated that distortions of reconstructed images of hidden objects can be eliminated with allowance for the diffraction by dielectric shields

Analytical device model for graphene bilayer field-effect transistors using weak nonlocality approximation

We develop an analytical device model for graphene bilayer field-effect transistors (GBL-FETs) with the back and top gates. The model is based on the Boltzmann equation for the electron transport and the Poisson equation in the weak nonlocality approximation for the potential in the GBL-FET channel. The potential distributions in the GBL-FET channel are found analytically. The source-drain current in GBL-FETs and their transconductance are expressed in terms of the geometrical parameters and applied voltages by analytical formulas in the most important limiting cases. These formulas explicitly account for the short-gate effect and the effect of drain-induced barrier lowering. The parameters characterizing the strength of these effects are derived. It is shown that the GBL-FET transconductance exhibits a pronounced maximum as a function of the top-gate voltage swing. The interplay of the short-gate effect and the electron collisions results in a nonmonotonic dependence of the transconductance on the top-gate length.Comment: 12 pages, 7 figure