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Re: PLEUROCOELOUS VERTEBRAE IN SAUROPODS



Date: Thu, 14 Nov 1996 14:21:45 -0500 (EST)
Reply-To: swf@ElSegundoCA.NCR.COM
Sender: owner-dinosaur@usc.edu
Precedence: bulk
From: Stan Friesen  <swf@ElSegundoCA.NCR.COM>
To: dinosaur@usc.edu
Subject: Re: PLEUROCOELOUS VERTEBRAE IN SAUROPODS

From: "Jonathan R. Wagner" <znc14@ttacs1.ttu.edu>
 >         1: Does heat loss progress at a different rate than heat gain,
 > ceteris paribus?

Probably, if for no other reason than that the specific heat of air
is quite different than the specific heat of flesh (and bone). I
beleive the specific heat of flesh is not too far below 1.  I rather
suspect that the specific heat of air is well below 0.5. (I haven't
had time to check the exact figures, but flesh, being mostly water,
should have a specific heat close that of water, namely 1, and water
is said to have a rather high specific heat).

Also, the shifting of the blood supply would change the effective
specific heat somewhat, as well as changing the rate of temperature
change at the surface. (With blood flowing to the surface from the
interior, the surface temperature will change much slower than if
surface blood flow is reduced).

Also, see the answer to question #2.

 > If so, is it possible to guesstimate a ballpark figure of
 > the coefficient for a big sauropod?

This depends not only on the actual specific heats, but also on the rate
effects of blood flow, and relative temperatures.

 >         2: Is rate of heat loss dependant on outside temperature?

Yes.  The greater the temperature difference, the faster the heat
flows (in *or* out).

Overall, I suspect the blood flow and temperature difference factors
will dominate the equations.

[ Yeah, that's another thing I neglected to mention in my comment in
  Russ' message -- many of the thermal resistances should be modeled
  as actively variable.  -- MR ]

swf@elsegundoca.ncr.com         sarima@ix.netcom.com

The peace of God be with you.