Is this article simulation of statistical measurements is performed on the basis of which the analysis of the standard deviation of the obtained results is carried out. It is shown that the standard deviation is minimum and independent from measurement duration while an object is in the state of equilibrium. For objects in a stationary non-equilibrium state the standard deviation depends on the duration measurements and the parameters of the state. The influence of these factors on the standard deviation is assessed with equation which includes the relaxation time. The value of the relaxation time is determined by approximating the energy spectrum of the studied signals. The analysis of energy spectra showed that the spectrum of white noise is inherent in objects in equilibrium; the flicker component of the spectrum occurs when the state of the object deviates from equilibrium.

One of the main causes of road pavement distress are low temperatures, and hence the need to thoroughly study the low temperature performance of all bituminous materials used in road construction. The purpose of this studywas to determine the performance of alternative and conventional bituminous mixtures in the temperature range between –25˚C and –10˚C using for this purpose the Tensile Creep Test (TCT). The low-temperature performance data were evaluated using the Burgers model, a tool that is widely used for evaluation of bituminous mixtures. This research focuses on bridge paving mixtures. These included both conventional (mastic asphalt) and alternative (SMAMA) materials. It was established, based on the test results and their analysis, that low temperature performance of a bituminous mixture is influenced, in the first place, by the characteristics of the asphalt binder it contains. Furthermore, SMA-MA mixtures showed better low temperature performance than conventional, mastic asphalt type mixtures.

Results of the ab initio molecular dynamics calculations of silicon crystals are presented by means of analysis of the velocity autocorrelation function and determination of mean phonon relaxation time. The mean phonon relaxation time is crucial for prediction of the phonon-associated coefficient of thermal conductivity of materials. A clear correlation between the velocity autocorrelation function relaxation time and the coefficient of thermal diffusivity has been found. The analysis of the results obtained has indicated a decrease of the velocity autocorrelation function relaxation time t with increase of temperature. The method proposed may be used to estimate the coefficient of ther-mal diffusivity and thermal conductivity of the materials based on silicon and of other wide-bandgap semiconductors. The correlation between kinetic energy fluctuations and relaxation time of the velocity autocorrelation function has been calculated with the relatively high coefficient of determination R2 = 0.9396. The correlation obtained and the corresponding approach substantiate the use of kinetic energy fluctuations for the calculation of values related to heat conductivity in silicon-based semiconductors (coefficients of thermal conductivity and diffusivity).

In this topic review the results of the X-band electron paramagnetic resonance (EPR) measurements of Mn, Co, Cr, Fe ions in YAlO₃ (YAP) crystals and Fe ions in LiNbO₃ (LNO) crystals and of chromium doped Bi₁₂GeO₂₀ (BGO) and Ca₄GdO(BO₃)₃ single crystals, are presented. It is well known that the oxide crystals (for example:YAP, LNO, BGO) are one of the most widely used host materials for different optoelectronic applications. The nature of point defect of impurities and produced in the oxide crystal after irradiation by bismuth ions and after irradiation by the ²³⁵U ions with energy 9.47 MeV/u and fluency 5 × 10¹¹ cm⁻¹ is discussed. The latter is important for applications of these oxide crystal as laser materials.