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Submitted on: 03 April 1998.
Revised on: 03 June 1998.
Accepted on: 22 July 1998.
___________________JOURNAL OF COLD REGIONS ENGINEERING
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Submitted on: 01 March 2006.
Revised on: 01 June 2006.
Accepted on: 20 June 2006.
___________________JOURNAL OF COLD REGIONS ENGINEERING
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