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, this paper is based on the roof deformation delay theory of the dangerous formation of dynamic phenomena and the elastic resonance spectrum characteristics of artificial acoustic signals. According to the research of artificial acoustics prediction of the dangerous dynamic phenomena in Russia for many years, the test results and the latest requirements of safety regulations have developed the automated system САКСМ for acoustic monitoring of rock mass conditions and prediction of dynamic phenomena, and has been tested and applied in production mines. The results of the system operation show that: at different deformation stages of the roof rock formation, the stress and strain state of the rock mass near the working face is different, and the corresponding artificial acoustic signal has different spectral characteristics, it can be use to evaluate the development position and weakening degree of the softened contact surface in the roof rock layer according to the resonance frequency, amplitude and dynamics of the artificial acoustic signal, and to analyze the deformation state of the rock mass near the working face and the risk of dynamic phenomena. The relative stress coefficient monitors the state of the rock mass near the working face, reflects the deformation delay and potential accumulation level, represents the severity of the danger of the dynamic phenomenon; the relative stress coefficient increases significantly near the working face, and the maximum value exceeds 2 times the background value, which can reliably predict the mine pressure rise zone in front of the working face. When the working face is more than 7 m away from the geological damage, the geological damage coefficient significantly increases and exceeds its critical value, reaching more than 3 times the background value, which can reliably predict the geological damage in front of the work. The relative stress coefficient has a linear and inverse relationship with the gas concentration of the return air flow, the gas concentration of the return air flow decreases with the increase of the relative stress coefficient, and increases with the decrease of the relative stress coefficient, the stress state of the rock mass near the working face controls the gas emission.

The electrorotation velocity of spherical colloidal polystyrene particles suspended in an electrolyte solution is calculated with the help of a network simulation method. The findings are in good agreement with the existing theoretical results when applicable, and they extend to ranges where these theories cannot be applied.

A numerical method is used to solve the electric potential ion number concentration, and fluid velocity distributions induced by an ac electric field applied to a cell suspended in an electrolyte solution is presented. Here, the dependence of the rotation spectra cells with some of the parameters is considered.