Ultrasonic processes cleaning

The polystyrene samples were used as received. Examination by XPS showed only carbon on the surface (XPS does not detect hydrogen). The pyrolytic carbon samples were prepared by a "steady state" fluidized bed process (j ). The carbon samples were polished by the manufacturer using 7-alumina. Before use in this study the pyrolytic carbon samples were ultrasonically cleaned in reagent grade methanol for five minutes. Examination by XPS of both the as received and ultrasonic methanol cleaned samples showed removal of small amounts of chlorine, magnesium, silicon, and sulfur by the cleaning procedure. 

Versatile ultrasonic precision cleaning system for aqueous or semi-aqueous processes with all-in-one rinse and dry operations... 

SNC-Research Inc., Continuous Cementation of Selenium Using Aluminum Pellets and Ultrasonic Auto-cleaning Process Feasibility (in French), Technical Report prepared for Noranda. CEZinc Division by SNC-Research Inc.. Montreal, Canada, November 1995. 

For processes other than immersion, there are many technologies offered for aqueous cleaning that are designed to split or separate. These often leave materials floating on the surface of the wash tank—rarely a good choice for immersion processes. Cleaning technology providers often have specialty materials (noted with a US for ultrasonic) for these immersion processes. These materials minimize evaporation losses of the water component however, this separation characteristic is a fatal flaw for immersion applications. 

Rules for the welded fabrication of pressure vessels cover welding processes, manufacturer s record keeping on welding procedures, welder qualification, cleaning, fit-up alignment tolerances, and repair of weld defects. Procedures for postweld heat treatment are detailed. Checking the procedures and welders and radiographic and ultrasonic examination of welded joints are covered. 

Deep-bed condensate polishers are commonly used for nuclear reactor power plants. Due to the extreme operating conditions, the resin is sometimes taken out of service as frequently as every 3 weeks for ultrasonic cleaning. This process removes the iron oxides and other particulates filtered out by the resin media. 

Procedure 10% aqueous solution of potassium iodide, KI, when exposed to sunlight, liberated I2 due to the photolytic decomposition and gave blue colour with freshly prepared starch solution. The intensity of blue coloured complex with the starch increased many fold when the same solution was kept in the ultrasonic cleaning bath. As an extension of the experiment, the photochemical decomposition of KI could be seen to be increasing in the presence of a photocatalyst, Ti02, showing an additive effect of sonication and photocatalysis (sono-photocatalysis) However, the addition of different rare earth ions affect the process differently due to the different number of electrons in their valence shells. 

Work by Ono et al. [66] has been specifically directed at ultrasonic control of product-selectivity in electroreductions. Using a lead cathode, in dilute methanolic sulphuric acid, at a constant current of 20 mA cm , Ono electroreduced benzaldehyde under stirred, unstirred and ultrasonic conditions (Fig. 6.17). In an unstirred system, benzyl alcohol (two-electron process) was the major product, while mechanical stirring reversed the position in favour of the hydrodimer (one-electron product). Ultrasonic irradiation from a cleaning bath (100 W, 36 kHz) so strongly favoured the hydrodimer that the alcohol was barely evident (Tab. 6.16). 

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