Measuring bench for investigation of mixing process in ultrasonic mass-transfer apparatus
In the article the laboratory measuring equipment for investigation of mixing in the ultrasonic mass-transfer apparatus is described. The experimental results of testing the equipment during dissolving of crystalline substance in liquid medium with the help of high-intensity ultrasonic vibrations are considered.
Cavitation produced by Ultrasonics
The problem of cavitation produced by ultrasonic vibration is examined theoretically. Equations are developed which describe the motion of a gas-filled cavitation bubble in a liquid medium subjected to alternating pressure; the case of an empty cavity is also considered Information is obtained concerning the distribution of fluid pressures and velocities in the medium near the bubble surface during the motion It is suggested that these theoretical conclusions may be used to show how the intensity of the various effects of cavitation will depend on ultrasonic frequency and intensity. In particular, it is predicted that all cavitation phenomena will diminish and finally disappear as the frequency is raised The important part played by the nucler from which the cavitation bubbles grow is emphasized.
How Does the Keyword Method Affect Vocabulary Comprehension and Usage? Report from the project on Studies in Language: Reading and Communication. Working Paper No. 278.
THE KEYWORD METHOD of vocabulary learning involves forming a linkage between a to-be-learned vocabulary word and a familiar English word that sounds like part of the to-be-learned item (the keyword). Then the learner forms an interactive image between the keyword and definition referents. In previous research, the keyword method has been found to facilitate students' recall of definitions, given vocabulary items. In this study, use of the method was also shown to increase comprehension of English vocabulary in context, as well as usage of that vocabulary in a novel context.