Indirect methods sonication

Rieke obtained activation of metals by an indirect method, the reduction of salts, most of the time the chlorides, with potassium or lithium.18 The method was further improved by effecting the reduction with lithium under sonication,19 which avoids the use of potassium, prolonged heating at relatively high temperatures, and a possible deactivation of the metal slurry by annealing. 

Capacity. Pumps deHver a certain capacity, Q, sometimes referred to as flow, which can be measured directly by venturi, orifice plate (11), or magnetic meters (12) (see Flow measurement). The indirect way to determine capacity is often used. Whereas this method is less accurate than applying a flow meter, it often is the only method available in the field. The total head is measured and the capacity found from the pump head—capacity (H— curve (Fig. 2). More recently, sonic flow meters (13) have been used, which can be installed on the piping without the need for pipe disassembly. These meters are simple to use, but require relatively clean single-phase Hquid for reHable measurements. 

Descriptions of sulfuric acid analytical procedures not specified by ASTM are available (32,152). Federal specifications also describe the requited method of analysis. Concentrations of 78 wt % and 93 wt % H2SO4 are commonly measured indirectly by determining specific gravity. Higher acid concentrations are normally determined by titration with a base, or by sonic velocity or other physical property for plant control. Sonic velocity has been found to be quite accurate for strength analysis of both filming and nonfuming acid. 

Digestion Ultrasound irradiation. High-grade titanium alloy sonotrode indirectly irradiate water samples. Sonication time 2 min. Recovery values of real wastewater samples lie between 50% and 60% of the values obtained with the conventional semimicro method... 

---