tried to fix CR's   
      
      
   > >   
   >   
   > > Wiki says that the volume fraction is about 45%, and an erythrocyte is   
   >   
   > >   
   >   
   > > about 6 or 8 microns across, so the mean free path is something like   
   >   
   > >   
   >   
   > >   
   >   
   > >   
   >   
   > > MFP ~ 6 um/(0.45)**1/ ~ 7 um,   
   >   
   > >   
   >   
   > >   
   >   
   > >   
   >   
   > > which is somewhat unrealistically generous since it ignores the volume   
   >   
   > >   
   >   
   > > taken up by the blood cells themselves.   
   >   
   > >   
   >   
   > >   
   >   
   > >   
   >   
   > > So your 1 mm of blood will scatter the light not once but over 100   
   >   
   > >   
   >   
   > > times.  In other words, it's completely diffuse.   
   >   
   >   
   >   
   > Phil, Thanks for your analysis of scattering. I wanted to return to this   
   issue of diffuse transmission to see what you think of the following analysis   
   on a photon per photon basis, involving superposition. We are looking for a   
   number about the presence of absorbing particles, about 1% v/V, and the rbc's   
   or their lysed ghosts, are 50%.   
   >   
   >   
   >   
   > In one thought-picture is the light being elastically scattered through the   
      
   >   
   > 1 mm cuvette. Most is scattered out of the optical path that reaches the PD,   
    but some manages to get through, call it X number of photons.   
      
   >   
   >   
   >   
   > In another picture, we have just a few absorbing particles present in a 1 mm   
   path along with above scenario. At 1% v/V, a photon NOT getting scattered will   
   encounter about 1 of these inelastic absorbers. And IF a photon gets through   
   the scattering media to reach the PD, it also has had a chance of sncountering   
      
   an absorber, call it P.   
      
   >   
   >   
   >   
   > So, the signal seen is X-P, where P has the signal information.   
      
   >   
   >   
   >   
   > What do you think of this analysis?   
      
   >   
   >   
   >   
   > TIA,   
   >   
   > JB   
      
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