Excitation of controllable perturbations in the three-dimensional boundary layer using plasma actuators

Two versions of the structure of a multi-discharge plasma actuator intended to excite boundary layer perturbations in the neighborhood of the leading swept-wing edge are suggested. The actuator must prevent from appearance and development of the crossflow instability modes leading to laminarturbulent transition under the normal conditions. In the case of flow past a swept wing, excitation of controllable perturbations by the plasma actuator is simulated numerically in the steady-state approximation under the typical conditions of cruising flight of a subsonic aircraft. The local body force and thermal impact on the boundary layer flow which is periodic along the leading wing edge is considered. The calculations are carried out for the physical impact parameters realizable in the near-surface dielectric barrier discharge.     

Study of Light Neutron-Rich Nuclei Using a Multilayer Semiconductor Setup

The characteristics of two modifications of the semiconductor (s.c.d.) setup consisting of telescopes on the basis of silicon detectors are presented. These settings allow performing a precision measurement of energy in a large dynamic range (from a few to hundreds of MeV) and particle identification in a wide range of masses. The issues of measurement of the characteristics of s.c.d. telescopes and their impact on the quality of the obtained experimental data are considered. Considerable attention is paid to the use of created semiconductor devices for the search for and spectroscopy of light exotic nuclei on the accelerators of PNPI (Gatchina) and LANL (Los Alamos).     

Hydrophobic ionic liquids in plasticized membranes of ion-selective eletctrodes

Ionic liquids with substituted imidazole, pyridine, and pyrrolidine cations and hydrophobic anions are studied as ionophores of PVC membranes of ion-selective electrodes plasticized with 2-nitrophenyloctyl ether. These membranes show a response to hydrophobic organic cations. In solutions of cationic surfactants, the slope of the electrode function is close to the theoretical one and the limit of detection does not exceed n × 10⁻⁶ M. Ion-selective electrodes for anions are developed using a trioctylmethylammonium salicylate ionic liquid. The electrode on its basis shows a stable potentiometric response to the salicylate anion in a wide range of concentrations and is characterized by good selectivity in the presence of foreign anions.     

The dynamics of macroparticles in a direct current glow discharge plasma under microgravitation conditions

The dynamics of large-sized (70-180 μm) spherical bronze particles in a direct current glow discharge plasma was studied experimentally under microgravitation conditions. The temperatures, velocities, pair correlation functions, and self-diffusion coefficients of macroparticles were measured at various discharge currents. The charges of dust particles (on the order of 10⁶ e) corresponded to high surface potentials of about 30–40 V. The experimental data were in close agreement with the simulation data on Yukawa systems with weak screening of dust charges. The influence of macroparticles on equilibrium ionization in a dense dust cloud was considered.     

Generalization of a multicriteria shortest path problem in an oriented graph

A partial order relation is introduced on the set of all paths. An algorithm for determination of the shortest paths is considered providing an additional condition on the partial order is assumed.