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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'>It is difficult conceptually to even think about the mechanism whereby submicron particles interact with matter. I have suggested to you it is a question of momentum. At the sub-micron scale “surfaces” are a moosh of electrons – that’s all you can see as you approach the surface. You may be lucky, and be riding a particle which is looking for an electron, but even so with that excess of surface electrons you are likely to get repulsed. Alternatively you may be going fast enough (Boltzmann allows it) to dash through the Coulomb barrier. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'>These probabilities are calculable and lead to low adsorption at less than 0.5 micron. I’ve given you a mechanistic, Newtonian interpretation, which is a good enough first approximation. Being more exact gets fun but some of the approximations you have to make are hairy.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'>Hope that gives some clarity<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'>Philip<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt'>From:</span></b><span style='font-size:11.0pt'> Stoves [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Xavier Brandao<br><b>Sent:</b> Thursday, May 24, 2018 6:27 PM<br><b>To:</b> 'Discussion of biomass cooking stoves' <stoves@lists.bioenergylists.org><br><b>Subject:</b> Re: [Stoves] ***SPAM*** Re: ***SPAM*** RE: Stoves Digest, Vol 93, Issue 5<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'>Dear Philip,<o:p></o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'>OK, thanks for the precisions.<o:p></o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'>But don’t the recent studies found, or suspect, that below a certain size, like below 0.1µ, retention increases since the nanoparticles cross the cell membranes?<o:p></o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'>Not sure I understood right.<o:p></o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'>Best,<o:p></o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'>Xavier<o:p></o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:11.0pt;color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span lang=FR style='font-family:"Tahoma",sans-serif'>De :</span></b><span lang=FR style='font-family:"Tahoma",sans-serif'> Stoves [</span><a href="mailto:stoves-bounces@lists.bioenergylists.org"><span lang=FR style='font-family:"Tahoma",sans-serif'>mailto:stoves-bounces@lists.bioenergylists.org</span></a><span lang=FR style='font-family:"Tahoma",sans-serif'>] <b>De la part de</b> </span><a href="mailto:plloyd@mweb.co.za"><span lang=FR style='font-family:"Tahoma",sans-serif'>plloyd@mweb.co.za</span></a><span lang=FR style='font-family:"Tahoma",sans-serif'><br><b>Envoyé :</b> mardi 22 mai 2018 09:01<br><b>À :</b> Discussion of biomass cooking stoves<br><b>Objet :</b> Re: [Stoves] ***SPAM*** Re: ***SPAM*** RE: Stoves Digest, Vol 93, Issue 5<o:p></o:p></span></p></div><p class=MsoNormal><span lang=FR><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR style='font-size:12.0pt;font-family:"Times New Roman",serif'>We measured retention of silica dust as a function of particle size. The human filter scavenged everything above 10 micron very well. Between 10 & 2.5 there was degradation and increasing quantities were retained. Below 2.5 down to about 0.8 retention increased. Below about 0.6retention dropped rapidly ,and was effectively nil from 0.3.</span><span lang=FR><br>This was publshed back in about 1974, research by the gold mining industry in Johannesburg.<br>Philip<br><br>Sent from my Huawei Mobile<o:p></o:p></span></p><div><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=FR style='font-size:12.0pt;font-family:"Times New Roman",serif'><o:p> </o:p></span></p></div></div></body></html>