According to statistics, one of the most common causes of vehicle fires is the fire hazard of operating onboard electrical networks - 35%. The most common causes of vehicle fires, during their operation, are malfunctions of electrical equipment (short circuit and overload of on-board electrical wiring) and fuel systems. In this regard, the problem arose to identify the cause and establish the involvement of the ignition of the on-board electrical system and the electrical equipment of the vehicle by studying the microstructures of the conductive elements of the power grid. Microstructures were studied using a method of metallographic and X-ray spectral analysis, using a scanning electron microscope with an X-ray microanalysis system. The microstructure of the reference model of the wire is a copper polycrystal, which is elongated in the direction of deformation. It should be noted that after etching the microstructural heterogeneity is detected, it is observed on both longitudinal and transverse slices. The passage of a direct current through a wire significantly changes its microstructure: in it there are local areas of the globular shape, indicating the melting and subsequent rapid crystallization, resulting in the formation of separate sections in the form of round inclusions. It should be noted that under the influence of short-circuit currents, the gullet form is formed on the surface of the wires, and the dimensional characteristics of the melting regions become larger. In the complex action of the short-circuit of the direct current and the open flame of the model focus on the regions of the melting it becomes noticeable that from the action of the current, due to the sharp heating of the metal formed fine-grained structure, and with the subsequent action of the open flame in the wires formed a large-grained structure, and the action of the flame It is manifested in the fact that the oxidation of the grain boundaries occurs, which results in the destruction of the material of the wire along the grain boundaries. Performing research using the method of local X-ray spectral analysis enables us to determine the oxygen content of copper conductors by the principle of individuality of the spectra and provides sufficiently accurate data on its content in the structure of the conductor, depending on the heating conditions, which confirms the expediency of its use to detect the involvement of the conductors of the onboard electrical grids prior to the occurrence of fires.

The technological units of electric arc steel remelting are among the most energy-intensive consumers for whom the problem of energy saving is extremely urgent. The proposed reconstruction of the electric-arc steel furnace is aimed at reducing the amount of electricity consumption. The feasibility study makes it possible to assess the technical and economic parameters of project of an electric-arc steel furnace reconstruction. The simulation results of the reconstructed electric furnace showed that due to the optimal placement of electric arcs in the electric furnace space, the duration of the metal melting stage can be reduced by approximately 19 min. Cost-effectiveness calculations for the implementation of the innovative solution showed that reducing the duration of steel remelting in a reconstructed furnace reduces the electricity consumption by approximately 28% per process. The article takes into account only the reduction of electricity consumption, but does not take into account the possibility of improving the productivity of the furnace by increasing the number of technological processes per shift. References 7, figures 3, table 1.

Welcome to this introductory tutorial on wavelet transforms. The wavelet transform is a relatively new concept (about 10 years old), but yet there are quite a few articles and books written on them. However, most of these books and articles are written by math people, for the other math people; still most of the math people don't know what the other math people are

For any metric space $X$ endowed with the action of a group $G$, and two $n$-gons $\vec x=(x_1,\dots,x_n)\in X^n$ and $\vec y=(y_1,\dots,y_n)\in X^n$ in $X$, we introduce the $G$-deviation $d(G\vec x,\vec y\,)$ of $\vec x$ from $\vec y$ as the distance in $X^n$ from $\vec y$ to the $G$-orbit $G\vec x$ of $\vec x$ in the $n$-th power $X^n$ of $X$. For some groups $G$ of affine transformations of the complex plane, we deduce simple-to-apply formulas for calculating the $G$-deviation between $n$-gons on the complex plane. We apply these formulas for defining new measures of asymmetry of triangles. These new measures can be applied in Electric Power Engineering for evaluating the quality of 3-phase electric power. One of such measures, namely the affine deviation, is espressible via the unbalance degree, which is a standard characteristic of quality of three-phase electric power.