An Analytical Model of the Counter-Current Heat Exchange Phenomena

An analytical model for the counter-current heat exchange mechanism in animals has been formulated and a solution has been obtained. The nondimensional parameters that govern the mechanism have been determined in terms of the properties of the animal. The normalized temperatures are functions of normalized distance and, in general, three nondimensional heat transfer conductances. Graphical results are presented for two representative physiological systems. These results allow a delineation of those situations in which counter-current heat transfer is important, and also a quantitative prediction of the heat transfer and temperature distributions. The theory is compared to the available experimental results.     

Treatment of Basal Cell Carcinoma by Curettage and Electrosurgery

One hundred and forty-eight basal cell carcinomas were treated by curettage and electrosurgery. Twenty-six recurrent carcinomas were treated and 24 did not recur during a minimum two-year follow-up. Seventy-two newly diagnosed carcinomas were treated by the same method, and a two-year recurrence-free rate of 97.4% was obtained. About 50 new and recurrent lesions were treated in three patients in whom extensive cutaneous changes from actinic atrophy and previous therapy made the distinction between new and recurrent lesions difficult or impossible. This technique has a particular place in the management of multiple lesions. Patient acceptance is good. Lesions at some sites, e.g. on the nose, where closure of a wound is difficult, are better managed by this method than by surgical excision. Secondary infection is rare and the cosmetic results are excellent.