Use of piezoelement in ultrasound generation

Abstract

At present, ultrasonic (piezoelectric) transducers are the most promising electromechanical transducers for use in miniature electronic devices. However, the calculation of the piezoelectric element for an ultrasonic environment poses certain problems due to the large number of problems to be solved and its nonlinearity. The article describes the principles of operation of the piezoelectric element, analyzes their advantages and disadvantages, gives the characteristics of the piezoelectric elements, as well as proposes an algorithm for calculating the frequency characteristics of the piezoelectric element based on the electrical model of the piezoelectric element.

Study of the composition of useful plant extracts

“…In order to optimize the extraction conditions, the method of mathematical-statistical planning of the experiment was used. The influence of various factors (the concentration of ethyl alcohol in the extractant; the duration of preliminary infusion and extraction of raw materials; the extraction temperature) on the yield of extractive substances has been studied [13][14][15][16]. The optimal composition of extracting mixtures and the duration of extraction were established: the ratio of raw material/extractant was 1,0:7,0 by weight; the ratio of alcohol and water in extractive mixtures is 1:1 by volume; extraction time, 70-80 h; the temperature of the solid-liquid system is 30-35 °С.…”

“…The mass fraction of organic acids was estimated by the titrimetric method [9][10][11][12][13][14][15][16][17]. The content of flavonols was determined by the spectrophotometric method (λ=410 nm) according to the reaction of complex formation of flavonols with aluminum chloride [18,19].…”

Analysis of dairy whey food functional modules based on resource-saving technologies

“…Technologies of such products can be implemented at larger enterprises with volumes of dairy whey from 50 tons per shift and more and imply application of energy-intensive processes (vacuum evaporation, drying) in combination with high-tech processes allowing to save energy resources. In this way, the loss, discharge and sale of whey in its natural form becomes negligible [15]. 3.…”