Development of the method of an electrohydrodynamic force effect on a boundary layer for active control of aerodynamic flows

The results of investigations on the possibility of an electrohydrodynamic force effect on a gas flow implemented with the help of a barrier discharge are presented. A new method of controlling the laminar flow around a base with suppression of instabilities of the incoming flow due to electrohydrodynamic force action on the boundary layer near the forward edge of a swept wing is proposed. An efficient multidischarge actuator system is developed and created for active control of aerodynamic flows with induced-air-flow characteristics exceeding the world analogues.     

Field-effect transistor structures on the basis of poly(3-hexylthiophene), fullerene derivatives [60]PCBM, [70]PCBM,and nickel nanoparticles

Organic field-effect transistor (OFET) structures with the active layers on the basis of composite films of semiconductor polymer poly(3-hexylthiophene) (P3HT), fullerene derivatives [60]PCBM, [70]PCBM, and nickel (Ni) nanoparticles are obtained, and their optical, electrical, and photoelectrical properties are studied. It is shown that introducing Ni nanoparticles into P3HT: [60]PCBM and P3HT: [70]PCBM films leads to an increase in the absorption and to quenching of photoluminescence of the composite in the 400–600 nm spectral band due to the plasmon effect. In P3HT: [60]PCBM: Ni and P3HT: [70]PCBM: Ni OFET structures at the P3HT: [60]PCBM and P3HT: [70]PCBM concentrations of ~1: 1 and Ni concentrations of ~3–5 wt %, current–voltage (I–V) characteristics typical of ambipolar OFETs with the dominant hole conduction are observed. The charge-carrier (hole) mobilities calculated from the I–V characteristic at V_G =–10 V were found to be ~0.46 cm²/(V s) for P3HT: [60]PCBM: Ni and ~4.7 cm²/(V s) for P3HT: [70]PCBM: Ni, which means that the mobility increases if [60]PCBM in the composition is replaced with [70]PCBM. The effect of light on the I–V characteristics of P3HT: [60]PCBM: Ni and P3HT: [70]PCBM: Ni OFETs is studied.     

On the question of the magnitude of day-night asymmetry for solar neutrinos

The effect of flavor day-night asymmetry is considered for solar neutrinos of energy about 1 MeV under the assumption that the electron-density distribution within the Earth is approximately piecewise continuous on the scale of the neutrino-oscillation length. In this approximation, the resulting asymmetry factor for beryllium neutrinos does not depend on the structure of the inner Earth’s layers or on the properties of the detector used. Its numerical estimate is on the order of ?4 × 10^?4, which is far beyond the reach of present-day experiments.     

A new method for separation of 97Ru from irradiated by α-particles molybdenum for nuclear medicine

Russian Chemical Bulletin - A new method for separation of 97Ru radionuclide from irradiated by a-particles molybdenum, which potentially could be applied in nuclear medicine, is proposed....     

Elastic properties of two-dimensional two-phase composites with isotropic phases

Formal series of powers of Fourier coefficients for the effective elastic constants of a heterogeneous material (Herring’s series) are considered. It is demonstrated that, on their basis, all the known exact solutions of an elastic problem for a two-dimensional two-phase composite can be found. It is also shown how a full renormalization of the series for the inverse bulk modulus can be carried out. A general expression for Young’s modulus is deduced, leading to considerable simplifications in some special cases. All results have been obtained without any restrictions on the Fourier coefficients of local parameters of the composite.     

On the solution of the kinetic equation for a heat flux between concentric spheres

The problem of calculating a heat flux in a spherical layer is considered. The results are obtained in terms of the Bhatnagar-Gross-Krook model and the Boltzmann collision integral. A general (independent of the form of the kinetic equation and the solution method) expression for the heat flux as a function of the energy accommodation coefficient is derived. The results are compared with the experiment and the analytical results obtained previously.     

Kinetic resistance of borofluoride complexes of dipyrrolylmethenes to acids

The trends of kinetic resistance of borofluoride complexes of alkyl- and sulfo-substituted dipyrrolylmethene (Bodipy) to protolytic and solvoprotolytic dissociation in organic solvents and aqueous solutions are studied. It is established that among dipyrrolylmethene complexes with d elements, Bodipy is notable for its superresistance to acids. The rate of the dissociation reaction increases with increasing acidity of protonating mixtures or decreasing effective charge of the coordinating nitrogen atoms of the ligand. Dissociation of the complexes occurs in accordance with a second-order rate equation. A kinetic model of the process is proposed; its kinetic and activation parameters are determined. The energy profiles of the initial stages of protolytic dissociation reactions are calculated using quantum-chemical methods for two suggested variants of the transient state; the energetically preferable pathway is recognized.     

Protolytic dissociation of copper(II) and nickel(II) dipyrrolylmethenates in benzene solutions of acetic acid

Protolytic dissociation of copper(II) and nickel(II) dipyrrolylmethenates in benzene solutions of acetic acid has been studied. The results have completed the knowledge of kinetics of dipyrrolylmethene complexes dissociation in acidic medium. The effect of the nature of complex forming atom, ligand, and other factors on the complexes kinetic stability has been analyzed.