Total energy, ultrasonic system

Power is the total energy irradiated by an ultrasonic system per unit of time (J s or W). Power is very important in ultrasound applications, due to the fact that the greater the power applied in a medium, the higher are the observed ultrasound effects. In general, it is convenient to relate the level of applied energy with the size of the considered system, thereby reporting the ultrasonic energy in a relative form. Thus, the ultrasonic intensity is defined by the power applied per unit of treated area (W m ). The ultrasonic intensity, I, is related to the acoustic pressure. Pa, by... 

Ultrasounds can be applied to chemical systems by using ultrasonic baths or probes. Although baths are more widely used, probes are more efficient as a result of (a) the lack of uniformity in the transmission of ultrasounds (in baths, only a small fraction of the total liquid volume in the immediate vicinity of the ultrasound source experiences the effects of cavitation) and (b) the decline in power with time, which leads to exhaustion of the energy applied to baths. Both phenomena result in substantially decreased experimental repeatability and reproducibility. For this reason, the use of baths should be restricted to cleaning operations and removal of dissolved gases, their intended applications. A wide variety of commercially available ultrasonic baths exists ranging from laboratory to industrial-scale models. 

Concentration using aCi8 SPE Continuous-flow (methanol), high-temperature (65°C), sonicated extraction system to isolate APEO metabolites from sediment samples (low-power ultrasonic energy) sediment extraction was complete after 7 min with a total solvent consumption of 3.5 ml/sample two-step cleanup, normal-phase SPE, reversed-phase... 

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