A comparison of measurement techniques for acoustic cavitation
A comparison of measurement techniques for acoustic cavitation
Light emission, acoustic pressure, surface erosion/corrosion and sonochemical rates are compared in a number of different ultrasonic systems representing “idealised” and “real world” scenarios. The spatial correlation between the measurements is shown.
An electrochemical sensor based on surface erosion/corrosion of a passive metallic solution/metal interface is developed and shown to be applicable to a number of environments. Counting of discrete surface erosion/corrosion events on either an aluminium or titanium electrode is used to investigate cavitation activity as a function of position within an ultrasonic reactor with up to 4 x 105 events being recorded in 30s. The technique represents a 4 orders of magnitude increase in sensitivity compared to similar weight loss techniques. To conduct measurements in the “real world” environment (e.g. an ultrasonic cleaning vessel) a new unipolar linear optocoupled current follower is described and its performance analysed. The application of this current follower reduces the noise signal recorded from > 100 μA to < 0.1 μA. This allows measurement of erosion/corrosion events in situations that would otherwise be precluded. The processes that lead to erosion/corrosion on the surface of an electrode are investigated using high-speed photography with particular reference to the difference between sharp “primary” and rounded “secondary” peaks.
A stable and reproducible electrochemical flow cell is used to make sonochemical measurements as a function of position. It is found that mass transfer within ultrasonic vessels made spatial resolved measurements unrealistic with this system. A bi-polar optocoupled current follower is constructed to allow the electrochemical measurement of sonochemical activity under adverse conditions and used to show a rate of I3- generation of 1.3 nM s-1 in an ultrasonic cleaning bath.
University of Southampton
Vian, Christopher James Bradshaw
83ce28b4-b58e-4b98-a0c6-1aa98a3a00b8
2007
Vian, Christopher James Bradshaw
83ce28b4-b58e-4b98-a0c6-1aa98a3a00b8
Vian, Christopher James Bradshaw
(2007)
A comparison of measurement techniques for acoustic cavitation.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Light emission, acoustic pressure, surface erosion/corrosion and sonochemical rates are compared in a number of different ultrasonic systems representing “idealised” and “real world” scenarios. The spatial correlation between the measurements is shown.
An electrochemical sensor based on surface erosion/corrosion of a passive metallic solution/metal interface is developed and shown to be applicable to a number of environments. Counting of discrete surface erosion/corrosion events on either an aluminium or titanium electrode is used to investigate cavitation activity as a function of position within an ultrasonic reactor with up to 4 x 105 events being recorded in 30s. The technique represents a 4 orders of magnitude increase in sensitivity compared to similar weight loss techniques. To conduct measurements in the “real world” environment (e.g. an ultrasonic cleaning vessel) a new unipolar linear optocoupled current follower is described and its performance analysed. The application of this current follower reduces the noise signal recorded from > 100 μA to < 0.1 μA. This allows measurement of erosion/corrosion events in situations that would otherwise be precluded. The processes that lead to erosion/corrosion on the surface of an electrode are investigated using high-speed photography with particular reference to the difference between sharp “primary” and rounded “secondary” peaks.
A stable and reproducible electrochemical flow cell is used to make sonochemical measurements as a function of position. It is found that mass transfer within ultrasonic vessels made spatial resolved measurements unrealistic with this system. A bi-polar optocoupled current follower is constructed to allow the electrochemical measurement of sonochemical activity under adverse conditions and used to show a rate of I3- generation of 1.3 nM s-1 in an ultrasonic cleaning bath.
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Published date: 2007
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Local EPrints ID: 466450
URI: http://eprints.soton.ac.uk/id/eprint/466450
PURE UUID: b377512f-6c41-4fee-85d4-eeef96ce3ddd
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Date deposited: 05 Jul 2022 05:17
Last modified: 16 Mar 2024 20:42
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Author:
Christopher James Bradshaw Vian
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