RETRACTED: Optimal exergy-efficiency of a thermoacoustic cooler with a complex heat-transfer exponent

This article has been retracted. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).Reason: The Editors would like to confirm the retraction of this paper at the request of the Authors. This article was a duplication of a paper that had already appeared in Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, Vol. 221, 1339-1343 (2007) doi: 10.1243/09544062JMES739. The authors would like to apologize for this administrative error on their part.