The entire cyclical freeze front sweep/defrost/extract process may be performed on contaminated regions that are unconfined, or such regions that are confined, such as by {TAIL ~ frozen earth barriers} of the type disclosed in {HEAD ~ the incorporated references} 
The entire cyclical freeze front sweep / defrost / extract process may be performed on contaminated regions that are unconfined , or such regions that are confined , such as by { TAIL ~ frozen earth barriers } of the type disclosed in { HEAD ~ the incorporated references }
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