Primary Ionization Density Produced by Charged Fragments in the Working Volume of the Fission Chambers

The question of the spatial distribution of ion pairs created by 235U fission fragments in the active volume of the fission chamber has been studied. The formulas of the spatial distribution of ion pairs in cylindrical fission chambers are proposed, which allows you to evaluate correctly the density of ion pairs in any point in the sensitive volume of the fission chamber

Integrability of One Bilinear Equation: Singularity Analysis and Dimension

The integrability of a four-dimensional sixth-order bilinear equation associated with the exceptional affine Lie algebra D(1)4 is studied by means of the singularity analysis. This equation is shown to pass the Painlevé test in three distinct cases of its coefficients, exactly when the equation is effectively a three-dimensional one, equivalent to the BKP equation.

Inter-event Times Statistic in Stationary Processes: Nonlinear ARMA Modeling of Wind Speed Time Series

The random sequence of inter-event times of a level-crossing is a statistical tool that can be used to investigate time series from complex phenomena. Typical features of observed series as the skewed distribution and long range correlations are modeled using non linear transformations applied to Gaussian ARMA processes. We investigate the distribution of the inter-event times of the level-crossing events in ARMA processes in function of the probability corresponding to the level. For Gaussian ARMA processes we establish a representation of this indicator, prove its symmetry and that it is invariant with respect to the application of a non linear monotonic transformation. Using simulated series we provide evidence that the symmetry disappears if a non monotonic transformation is applied to an ARMA process. We estimate this indicator in wind speed time series obtained from three different databases. Data analysis provides evidence that the indicator is non symmetric, suggesting that only highly non linear transformations of ARMA processes can be used in modeling. We discuss the possible use of the inter-event times in the prediction task.

Structure of the plane waves for a spin 3/2 particle, massive and massless cases, gauge symmetry

The structure of the plane waves solutions for a relativistic spin 3/2 particle described by 16-component vector-bispinor is studied. In massless case, two representations are used: Rarita – Schwinger basis, and a special second basis in which the wave equation contains the Levi-Civita tensor. In the second representation it becomes evident the existence of gauge solutions in the form of 4-gradient of an arbitrary bispinor. General solution of the massless equation consists of six independent components, it is proved in an explicit form that four of them may be identified with the gauge solutions, and therefore may be removed. This procedure is performed in the Rarita – Schwinger basis as well. For the massive case, in Rarita – Schwinger basis four independent solutions are constructed explicitly.

Turbulent Dispersion Simulation of Radioactive Aerosol Applied to the Infrastructure of the NPP-2006 Industrial Site

The goal of this work is to simulate the processes of transport and deposition of aerosol particles in a turbulent flow, taking into account the infrastructure of the industrial site of the NPP. The developed model for calculating the dynamics of the spread of the pollutant emissions in emergency situations is presented, the limits of applicability of turbulence models are determined and the main mechanical and thermal sources of turbulence in the NPP infrastructure are analyzed. The mechanisms of radioactive substances deposition for emergency situations have been assessed taking into account turbulent effects. According to the results of the numerical modeling, the zones of predominant deposition of radioactive aerosols on the characteristic surfaces of the NPP infrastructure have been determined, which is the basis for emergency actions planning and assessment of the personnel doses.

Stochastic Generalization of the Epidemiological SIR Model

In this paper we propose stochastic modification of well-known in epidemiology SIR model. This modification allows us to simulate various scenarios of infection and can be used for the risk management.

Influence of Structural, Electronic and Spin Properties of ND[NV] - Surface Group Conjugates on Formation of Their Biological Activity: Quantum Chemical Simulations

To estimate possible biological activity of conjugates based on nanodiamond with an NV center inside (ND[NV]), with various functional groups located on its surface, their structural, electronic, and spin properties were calculated using the PM6 method. The energy gap between HOMO and LUMO of the complex was used as a main indicator of biological activity. It has been shown that complexes with OH or H groups attached to the (111) surface are most stable in an aqueous medium. Analysis of spin density and HOMO and LUMO localization shows that complexes ND[NV] may be not just an inert carrier of a biologically active drug or means of visualizing drug delivery, but are also directly involved in the formation of the biological activity of the conjugate.

Bremsstrahlung Calculations of Single Gauge-Boson Production on Linear Colliders in Context of "New Physics" Searching

Differential and total cross sections of single gauge boson production in high energy electron-photon collisions obtained within the Standard Model in leading order and next-to-leading order are presented. Soft photon bremsstrahlung as well as hard photon bremsstrahlung parts were considered using the dimensional regularization procedure. Special features of receiving the hard bremsstrahlung convergent contribution are discussed. The corresponding anomalous gauge boson couplings were studied in the effective Lagrangian approach. Best conditions for registration of effects beyond the Standard Model are determined.

Effective Color Charge at A0 Background

In SU(2) gluodynamics, in the background Feynman gauge the effective charge ğ2(A0) is calculated in the presence of the A0 condensate which is spontaneous generated at high temperature. It is determined from a two-loop effective potential W(A0). Temperature dependence in a wide interval is investigated.

PMMA – C60 composite: thermal decomposition experiments in mass spectrometer and quantum chemical modeling

Mass-spectrometric thermal decomposition experiments with submicron films of neat polymethylmethacrylate (PMMA), and PMMA-fullerene composite (PMMA-C60) after UV irradiation are discussed. The experiment registers thermal desorption mass spectra (TDMS), that is the monomer desorption rate versus time upon gradual heating the PMMA films in a given heating regime. The spectra provide information on the amount of the monomer desorbed at different decomposition stages upon heating the given amount of film material as well as on the spectral shape changes. It is shown that both amount of monomer and the TDMS spectral shape are sensitive to the presence of fullerene and UV irradiation. The experimental results are discussed in terms of quantum chemical models of binding. The DFT/B3LYP-D3/def2/J RIJCOSX level of theory was used. The MMA-C60 structures which can yield different amounts of monomer have been compared.