Low Frequency Sound Absorption in Sea Water: A New Chemical Relaxation Mechanism.
Abstract
This document presented the oral and visual presentation entitled 'Low Frequency Sound Absorption in Sea Water: A New Chemical Relaxation Mechanism?,' presented at the 101st Meeting of the Acoustical Society of America, 18-22 May 1981, in Ottawa, Ontario, Canada. Excess sound absorption in sea water arises mainly from chemical relaxations involving MgS04 and B(OH)3. The high-frequency (100 kHz) MgS04 relaxation has been identified as a multistep ion-pair process. The low frequency (1 kHz) and B(OH)3 relaxation apparently involves more complex interactions with other constituents. To investigate B(OH)3 interactions in a simpler system, we measured absorption in NH3 solution using the resonator method. We have found alpha max to be proportional to the product of NH(+) and B(OH)4(-) concentrations; however, the magnitude is much too large to be caused by the ion pair. The mechanism, probably similar to that in sea water, resembles catalysis, the absorption being governed by the large volume change of the faster NH3/NH4(+) equilibrium and the relaxation frequency by the slower B(OH)3/B(OH)4(-) equilibrium. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1981
- Accession Number
- ADA103912
Entities
People
- D. G. Browning
- R. H. Mellen
- V. P. Simmons
Organizations
- Naval Underwater Systems Center