спектральний аналіз

In this work, we propose a study of the mean annual rainfall time series in order to evaluate the climate changes pattern over time.  If the analysis of this time series is carried out correctly, it can contribute to improve planning and policy development.  That is why we consider the problem of mathematical modeling and analysis of the mean annual rainfall of Morocco between 1901 and 2020 using descriptive statistics, structure changes analysis, spectral analysis and a nonlinear Exponential Autoregressive (EXPAR) processes to reproduce the behavior of this time series

Analysis of the literature database connected with the usage of an electro-spark alloying (ESA) for tool hardening has been carried out in the article.

Necessity of developing a new tungstenless electrode materials with eutectic structure for improvement of an electro-spark alloying technologies has been proved. Therefore, the structure of a new eutectic Fe-Mn-C-B-Si-Cr-Li alloy system has been developed and manufacturing techniques of an alloying by a sintering method has been offered.