In this article, we examine a gravitational theory including a fermion field that is non-minimally coupled to metric f(R) gravity in (2+1) dimensions. We give the field equations for fermion fields and Friedmann equations. In this context, we study cosmological solutions of the field equations using these forms obtained by the existent of Noether symmetry.

This work dedicated to the investigation cosmological models based on tachyon field. It was showed that Einstein’s field equations for spatially flat, homogeneous and isotropic Friedman-Robertson-Walker space-time have form-invariance of symmetry, obtained by form-invariance of transformations. The form-invariance of transformations is specified in the general case by the ...

The size and interposition of particles is a key parameter for the practical application of metallic nanostructures which requires the development of a synthesis method with precise control over their parameters. In this work the method for the synthesis of gold nanostructures in the pores of silicon dioxide from a gold sulfite complex and a gold chloride solution via wet ...

The aim of this paper is to study the effect of variation in the component ratio of (1−x)Si3N4 - xAl2O3 ceramics on the phase composition, strength and thermal properties of ceramics. To obtain ceramics and their further study, the solid-phase synthesis method combined with thermal annealing of samples at a temperature of 1500 ◦C typical for the initialization of phase ...

The aim of this work was to study the effect of samarium oxide doping on a SrTiO3 perovskite ceramic. After analyzing the data obtained on the morphological features of the synthesized structures, it was found that an increase in the dopant concentration led not only to a change in the morphological features, but also in the density of the ferroelectrics. Using the X-ray ...

This article addresses the issue of information security in the Industrial Internet of Things (IIoT) environment. Information security risk assessment in the IIoT is complicated by several factors: the complexity and heterogeneity of the system, the dynamic nature of the system, the distributed network infrastructure, the lack of standards and guidelines, and the increased ...

In this investigation, we explore the existence and intriguing features of matter-wave smooth positons in a non-autonomous one-dimensional Bose–Einstein condensate (BEC) system with attractive interatomic interactions. We focus on the Gross–Pitaevskii (GP) equation/nonlinear Schrödinger-type equation with time-modulated nonlinearity and trap potential, which govern nonlinear ...

The paper presents the results of the use of iron nanotubes as the anode material of lithiumion batteries. To assess the degradation of the morphology of nanostructures after different numbers of cycles of life tests, the method of scanning electron microscopy, Mossbauer spectroscopy, and X-ray diffraction analysis were applied. It is shown that the decrease in discharge capacity ...