Radioastronomical investigations of the small scale spatial inhomogeneities' motions and dimensions

Radioastronomical method for solar wind measurement

Acoustics of tachyon Fermi gas

We consider a Fermi gas of free tachyons as a continuous medium and find whether it satisfies the causality condition. There is no stable tachyon matter with the particle density below critical value $n_T$ and the Fermi momentum $k_F<\sqrt{\frac 32}m$ that depends on the tachyon mass $m$. The pressure $P$ and energy density $E$ cannot be arbitrary small, but the situation $P>E$ is not forbidden. Existence of shock waves in tachyon gas is also discussed. At low density $n_T<n<3.45n_T$ the tachyon matter remains stable but no shock wave do survive.Comment: 14 pages, 2 figures (color

Regional Investment Policy Under the Impact of Budget Limitations and Economic Sanctions

The article is devoted to the assessment of influence of budgetary restrictions and economic sanctions on investment policy of a region. The paper studies the bilateral negative effect on socio-economic development of regions from both the external sanctions and braking mechanism of economic development within the country. On the basis of the comparative and statistical analysis, the need to change focus of investment policy from the growth in volumes to qualitative perfecting is proved. The new direction of investment policy connected with the import substitution process realization, its combination with acceleration of innovative development on the certain example of Sverdlovsk region is analyzed. The conclusions and offers stated in the article are applicable to the public authorities of subjects of the Russian Federation, experts in the sphere of regional investment policy and improvement of investment climate, and also the specialized organizations specialized in attracting investment and work with investors in regions of Russia

White light-emitting diodes for optical stimulation of aluminium oxide in OSL dosimetry

The results of comparative investigations into the optically stimulated luminescence (OSL) of anion-defective corundum excited by radiation of blue and white light-emitting diodes (LEDs) are reported. The continuous-wave OSL (CW-OSL) measurements showed that the white LED (compared to the blue LED) and the chosen geometry allow the amplitude of the OSL response to increase by a factor of more than 40 and the dosimetric information readout time to decrease by a factor of 20. The effect of deep traps on the behavior of the CW-OSL curves of anion-defective corundum was studied. It was found that the filling of deep traps essentially increases the TL yield with a dosimetric peak at 450 K and the CW-OSL-yield under stimulation with blue and white LEDs. It was also found that this filling causes a considerable change in the shape of the OSL curve and the time parameters of the decay. © 2013 Elsevier Ltd. All rights reserved

Application of Hexagonal Conceptual Model for Solving Problem of Synchronization By Visual Designing of Complex Systems

In this article, solutions in the field of synchronous technology of the computer-aided design of complex systems on the example of the integral structure are discussed. The main attention is paid to the methods of conceptual and functional and logical design using the tools of visual presentation. The data transfer problem between the levels of design models have been analyzed. To synchronize design models at the system level, a hexagonal conceptual model is proposed for the visual presentation of information about the integrated structures and the VI-XML language – for the implementation of the synchronous modeling environment

Parametric frequency mixing in the magneto-elastically driven FMR-oscillator

We demonstrate the nonlinear frequency conversion of ferromagnetic resonance (FMR) frequency by optically excited elastic waves in a thin metallic film on dielectric substrates. Time-resolved probing of the magnetization directly witnesses magneto-elastically driven second harmonic generation, sum- and difference frequency mixing from two distinct frequencies, as well as parametric downconversion of each individual drive frequency. Starting from the Landau-Lifshitz-Gilbert equations, we derive an analytical equation of an elastically driven nonlinear parametric oscillator and show that frequency mixing is dominated by the parametric modulation of FMR frequency

Random raman fiber laser based on a twin-core fiber with FBGs inscribed by femtosecond radiation

Narrowband Raman lasing in a polarization-maintaining two-core fiber (TCF) is demonstrated. Femtosecond point-by-point inscription of fiber Bragg gratings (FBGs) in individual cores produces a half-open cavity with random distributed feedback. The laser linewidth in the cavity with a single FBG inscribed in one core of the TCF reduced by ∼2 times with respect to the cavity with a fiber loop mirror. It is shown that the inscription of two FBGs in different cores leads to the formation of a Michelson-type interferometer, leading to the modulation of generation spectra near threshold. This technique offers new possibilities for spectral filtering or multi-wavelength generation

Self-consistent Langmuir waves in resonantly driven thermal plasmas

The longitudinal dynamics of a resonantly driven Langmuir wave are analyzed in the limit that the growth of the electrostatic wave is slow compared to the bounce frequency. Using simple physical arguments, the nonlinear distribution function is shown to be nearly gaussian in the canonical particle action, with a slowly evolving mean and fixed variance. Self-consistency with the electrostatic potential provide the basic properties of the nonlinear distribution function including a frequency shift that agrees well with driven, electrostatic particle simulations. This extends earlier work on nonlinear Langmuir waves by Morales and O'Neil [G. J. Morales and T. M. O'Neil, Phys. Rev. Lett. 28, 417 (1972)], and could form the basis of a reduced kinetic treatment of Raman backscatter in a plasma.Comment: 11 pages, 4 figures, submitted to Physics of Plasma

Interaction between superconducting vortices and Bloch wall in ferrite garnet film

Interaction between a Bloch wall in a ferrite-garnet film and a vortex in a superconductor is analyzed in the London approximation. Equilibrium distribution of vortices formed around the Bloch wall is calculated. The results agree quantitatively with magneto-optical experiment where an in-plane magnetized ferrite-garnet film placed on top of NbSe2 superconductor allows observation of individual vortices. In particular, our model can reproduce a counter-intuitive attraction observed between vortices and a Bloch wall having the opposite polarity. It is explained by magnetic charges appearing due to discontinuity of the in-plane magnetization across the wall.Comment: 4 pages, 5 figure