Ok, to exclude further speculations around Dv and Da and to close our discussion I will rewrite those equations in terms of integral breadths:
<D> = 0.5/Beta + 0.25(2BetaL*Beta)^-0.5 sigma<D> = <D>(BetaL/Beta - 1/4) where Beta and BetaL are the total and Lorentzian integral breadths of TCH pV fitted to size-broadened profile. For simulated data (lognorm or gamma distribution with 0.05<c<0.4) these equations reproduced both <D> and sigma<D> within 10%. I included respective simulated profiles into new DDM package: http://icct.krasn.ru/eng/content/persons/Sol_LA/ddm102.zip (folder SIZE) All the best, Leonid > Leonid, > The lognormal distribution for particle size is not my modeling > (unfortunately), but if you insist, let see once again your > equations. > > <D> = Da + 0.25(DaDv)^0.5 and sigma<D> = <D>(Dv/Da - 1/2)/2 > > For lognormal distribution first equation becomes: > 2=(4/3)(1+c)**2+(1/4)sqrt[2*(1+c)**5] > For c=0.05 we obtain: 2=1.87, for c=0.4, 2=3.43 > > The second equation becomes: > sqrt(c)=[(9/8)(1+c)-1/2] > For c=0.05, 0.22=0.68, for c=0.4, 0.63=1.75 > > Well, taking account that the world is not ideal I'm ready to > accept that, then I think is time to close our discussion. __________________________________ Do you Yahoo!? Plan great trips with Yahoo! Travel: Now over 17,000 guides! http://travel.yahoo.com/p-travelguide
