[Stoves] ***SPAM*** Re: ***SPAM*** RE: Stoves Digest, Vol 93, Issue 5

[Philip Lloyd]

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. 

 

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.

 

Hope that gives some clarity

 

Philip

 

 

 

From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Xavier Brandao
Sent: Thursday, May 24, 2018 6:27 PM
To: 'Discussion of biomass cooking stoves' <stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] ***SPAM*** Re: ***SPAM*** RE: Stoves Digest, Vol 93, Issue 5

 

Dear Philip,

 

OK, thanks for the precisions.

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?

Not sure I understood right.

 

Best,

 

Xavier

 

 

De : Stoves [ <mailto:stoves-bounces at lists.bioenergylists.org> mailto:stoves-bounces at lists.bioenergylists.org] De la part de  <mailto:plloyd at mweb.co.za> plloyd at mweb.co.za
Envoyé : mardi 22 mai 2018 09:01
À : Discussion of biomass cooking stoves
Objet : Re: [Stoves] ***SPAM*** Re: ***SPAM*** RE: Stoves Digest, Vol 93, Issue 5

 

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.
This was publshed back in about 1974, research by the gold mining industry in Johannesburg.
Philip

Sent from my Huawei Mobile

 

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