Two-temperature model of gas combustion in a model burn device of the cylindrical form

The two-temperature model of gas combustion in a porous body of cylindrical heat-generator has been offered and numerically analyzed. Heat exchange between solid frame and gas; burning products interaction with heat-exchanger; distinction of diffusion speeds and heat conductivity in the gas phase are considered in the model. The influence of model parameters on characteristics of stationary modes of gas combustion for various heat exchange conditions of porous torch with heat exchanger is investigated. The results of numerical research do not contradict with observable laws that indicates the opportunity of model use for statement and solving the problem of work optimization of the real burning device

A behavior model of the viscoelastic system with a melting component under load

A numerical investigation of a stressed-strain state powder mixture with a melting component is carried out for the conditions of one-axial loading and nonstationary heating. The state of plane stress was assumed. The influence of the coupling between thermal and mechanical processes on temperature, stress and strains fields was investigated

Subthreshold and near-threshold kaon and antikaon production in proton-nucleus reactions

The differential production cross sections of K^+ and K^- mesons have been measured at the ITEP proton synchrotron in p+Be, p+Cu collisions under lab angle of 10.5^0, respectively, at 1.7 and 2.25, 2.4 GeV beam energies. A detailed comparison of these data with the results of calculations within an appropriate folding model for incoherent primary proton-nucleon, secondary pion-nucleon kaon and antikaon production processes and processes associated with the creation of antikaons via the decay of intermediate phi mesons is given. We show that the strangeness exchange process YN->NNK^- gives a small contribution to the antikaon yield in the kinematics of the performed experiment. We argue that in the case when antikaon production processes are dominated by the channels with KK^- in the final state, the cross sections of the corresponding reactions are weakly influenced by the in-medium kaon and antikaon mean fields.Comment: 24 pages. accepted for publication at J.Phys.

ВИДЕОСПЕКТРАЛЬНАЯ СИСТЕМА ДЛЯ ДИСТАНЦИОННОГО ЗОНДИРОВАНИЯ ЗЕМЛИ С БОРТА МЕЖДУНАРОДНОЙ КОСМИЧЕСКОЙ СТАНЦИИ

A videospectral system for Earth's remote sensing from space has been developed. The operating principle, optical scheme, basic and assist modules of the system are described. The specific requirements to device for ecological monitoring tasks at space experiments are presented. The main optical parameters of the experimental prototype have been analyzed. The method of gratings astigmatism correction has been developed. Optical parameters of the system have been improved.Разработана видеоспектральная система для дистанционного зондирования Земли из космоса. В работе описаны принцип работы, оптическая схема, основные и вспомогательные системы прибора, изложены основные требования к прибору для специфических задач экологического мониторинга в рамках космических экспериментов. Исследованы основные технические характеристики созданного образца. Разработаны методы улучшения оптических характеристик.

An algebraic approach to the Tavis-Cummings problem

An algebraic method is introduced for an analytical solution of the eigenvalue problem of the Tavis-Cummings (TC) Hamiltonian, based on polynomially deformed su(2), i.e. su_n(2), algebras. In this method the eigenvalue problem is solved in terms of a specific perturbation theory, developed here up to third order. Generalization to the N-atom case of the Rabi frequency and dressed states is also provided. A remarkable enhancement of spontaneous emission of N atoms in a resonator is found to result from collective effects.Comment: 13 pages, 7 figure

Study of in-medium ω\omega meson properties in Ap, pA and AA collisions

We propose to investigate the in-medium properties of vector $\omega$ mesons at the normal nuclear density in Ap(pA) collisions and at higher density in AA collisions at the ITEP accelerator facility TWAC. Using of the inverse Ap kinematics will permit us to study the $\omega$ meson production in a wide momentum interval included the not yet explored range of small meson momenta relative to the projectile nuclei where the mass modification effect in nuclear matter is expected to be the strongest. Momentum dependence of the in-medium $\omega$ meson width will be studied in the traditional pA kinematics. We intend to use the electromagnetic calorimeter for reconstruction of the $\omega$ meson invariant mass by detecting photons from the $\omega \to \pi^{0}\gamma \to 3\gamma$ decay. The model calculations and simulations with RQMD generator show feasibility of the proposed experiment. Available now intensity of the ion beams provides a possibility to collect large statistics and make decisive conclusion about the $\omega$ meson properties at density of normal nuclei. At the second stage of the investigation the $\omega$ meson properties will be studied in AA collisions at higher density. Interpretation of these measurements will be based on the results obtained in Ap(pA) interactions. Further investigation of the in-medium properties of light unflavored and charmed mesons can be performed at ITEP and at GSI(FAIR) where higher ion energies will be accessible in near future.Comment: 26 pages, 10 figures, 2 table