Neutron spectrum at the center of a cylindrical caisson in the KVANT criticality test stand

An activation method is used to measure and calculate the neutron spectrum inside a cylindrical caisson in the KVANT criticality test stand. This is compared with the neutron spectrum near the inner surface of the core housing of the test stand.     

Densification of the granular medium by the low amplitude shock waves

The process of the granular medium densification by multiple low amplitude shock-wave treatment is studied. The granular media are alumina based nanopowders. The mathematical model of the process describes the energy dissipation that is governed by the powder densification work being made and also connected with the non-ideality of the shock waves reflection from the discontinuity surfaces on the borders of the body being compacted. The maximum possible densification limit upon the multiple shock treatment on the granular medium at the conditions of fixed starting velocity of the striker is determined analytically. The shock-wave densification of the nanopowders depending on the number of the shock actions is calculated numerically. The influence of such parameters as individual characteristics of the powder, powder and striker masses, striker speed, and wave resistances of the contacting materials on the process is analyzed.     

Self-action of Counterpropagating Axially Symmetric Light Beams in a Transparent Cubic-nonlinearity Medium

Abstract

The stationary effect of self-action of counterpropagating axially symmetric light beams in a medium with cubic nonlinearity is discussed. Self-similar solutions for initial radiation parameters and nonlinear medium characteristics in the case of slowly varying amplitudes of beams are found. The analysis of approximate solutions obtained on the basis of motion constants is carried out and results are compared with numerical experimental data.     

Effect of external force fields on the domain structure of equiatomic CuAu alloy

Peculiarities of the ordered-structure formation in the equiatomic CuAu alloy, which are caused by changes in the sample dimensions and by an applied external force field, have been studied. The rate of the microstructure transformation in the ordered alloy has been found to increase with increasing thickness of the sample. It has been shown that tensile stresses applied during heat treatment can affect the growth direction of c domains and, thus, makes it possible to avoid the low-temperature cracking of the material.     

Kinetics of atomic ordering of Cu-49 at % Pd alloy after severe plastic deformation

Resistometry has been employed to study kinetics of the disorder → order phase transformation in the Cu-49 at % Pd alloys in as-quenched and deformed (to various degrees of deformation) states. Diagrams of transformation kinetics upon isothermal annealing have been plotted and the activation energy of atomic ordering after severe plastic deformation has been estimated (? ≈ 7.1). The possibility of achieving a single-phase ordered state with an extremely low electrical resistivity in the alloy studied has been demonstrated.     

Optimizing pump-drive operation to improve the energy-efficiency of oil extraction

Equivalent systems (analogs) are employed in developing a model of the drive mechanism in a sucker-rod borehole pump. Normal and emergency pump operation is simulated on the basis of Matlab-Simulink software. The rod column is regarded as a coupled sequence of active quadrupoles. The results of the simulation are compared with experimental data, and recommendations are made for reducing the energy consumption.