Development of Aquatic Bioassay with Lemna minor and Spirodela polirhiza for Screening of Waters Contaminated with Tritium

The work is aimed at studying morphometric parameters of the aquatic plants Lemna minor and Spirodela polyrhiza to develop a bioassay for water bodies contaminated with tritium. A considerable increase is noted of Lemna minor plants with the greatest biomass and area at high specific activity of tritium (3700 Bq/l) in natural water objects. A reliable Spirodela polyrhiza species dependence on specific tritium activity is not observed. Keywords: Tritium, bioindication, freshwater body, Lemna minor, Spirodela polyrhiz

Justification of Filter Selection for Robot Balancing in Conditions of Limited Computational Resources

The paper considers the problem of mathematical filter selection, used for balancing of wheeled robot in conditions of limited computational resources. The solution based on complementary filter is proposed

Radiation tolerance studies of silicon microstrip sensors for the CBM Silicon Tracking System

Double-sided silicon microstrip sensors will be used in the Silicon Tracking System of the CBM experiment. During experimental run they will be exposed to a radiation field of up to 1x1014 1 MeV neq cm-2. Radiation tolerance studies were made on prototypes from two different vendors. Results from these prototype detectors before and after irradiation to twice that neutron fluence are discussed

Schwinger production of scalar particles during and after inflation from the first principles

By using the first-principles approach, we derive a system of three quantum kinetic equations governing the production and evolution of charged scalar particles by an electric field in an expanding universe. Analyzing the ultraviolet asymptotic behavior of the kinetic functions, we found the divergent parts of the electric current and the energy-momentum tensor of the produced particles and determined the corresponding counterterms. The renormalized system of equations is used to study the generation of electromagnetic fields during and after inflation in the kinetic coupling model $\mathcal{L}_{\rm EM}=-(1/4)f^{2}(\phi)F_{\mu\nu}F^{\mu\nu}$ with the Ratra coupling function $f=\exp(\beta\phi/M_{p})$. It is found that the electric current of created particles is retarded with respect to the electric field. This leads to an oscillatory behavior of both quantities in agreement with the results obtained previously in phenomenological kinetic and hydrodynamical approaches.Comment: 22 pages, 4 figure

Hydrodynamical approach to chirality production during axion inflation

We study chirality production in the pseudoscalar inflation model of magnetogenesis taking into account the Schwinger effect and particle collisions in plasma in the relaxation time approximation. We consider the Schwinger production of one Dirac fermion species by an Abelian gauge field in two cases: (i) the fermion carries only the weak charge with respect to the U(1) group and (ii) it is also charged with respect to another strongly coupled gauge group. While the gradient-expansion formalism is employed for the description of the evolution of gauge field, plasma is described by hydrodynamical approach which allows us to determine the number, energy density, and chirality of produced fermions. It is found that while chirality production is very efficient for both, weakly and strongly interacting fermions, the resulting gauge field is typically stronger in the case of strongly interacting fermions due to suppression of the Schwinger conductivity by particle collisions.Comment: 16 pages, 6 figure

Justification of Filter Selection for Robot Balancing in Conditions of Limited Computational Resources

The paper considers the problem of mathematical filter selection, used for balancing of wheeled robot in conditions of limited computational resources. The solution based on complementary filter is proposed