X-Message-Number: 16450 From: "Brett Bellmore" <> References: <> Subject: Re: 16436 Date: Wed, 6 Jun 2001 18:55:43 -0400 " On another note: Eugene Leitl on the Extropain list recently said that cryonics may become much more difficult because of changes in manufacturing methods. Anyone have comments on this?" Well, it's true that liquid nitrogen is amazingly cheap because it's an industrial byproduct of gas separation. And this could certainly change. You could look at the percentage of storage expenses accounted for by LN, and assume that that represented the degree of vulnerability, but that's an exageration in the long run. LN expenditure per patient isn't fixed, but is a compromise between competing values. Portability, LN expenses, capital expenses. Geometric constraints for small storage facilities, comparable in scale to the thickness of the insulation, tend to favor high LN expenditures over high capital expenditures, as each unit of thicker insulation represents a more than linear increase in expense. (As a first order approximation, anyway.) When a storage facility becomes large compared to the thickness of the insulation, added insulation scales more linearly, shifting the equilibrium towards less LN usage, thicker insulation. LN expenditure also scales as the square of facility size, while storage capacity scales as the cube. These general factors mean that LN expenditures per patient should decline as our patient load increases, offsetting the increase in LN costs. Of course, the question is when we switch to a new storage technology, such as a fixed instalation using conventional insulation. It's not like we can make the transition continuously. Brett Bellmore Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=16450