Monday, February 11, 2008

How Cool is That?!

Today was one of those days that I live for at school. Full of excitement and adventure and really cool things. The coolest thing of all (if you grok the engineering mind) was that I got to use a Scanning Electron Microscope to examine some of the diesel soot particles exhaled by my dear Thumper. You can see the zoom-in in the series of photos below. The magnifications go from 200x to 10,000x. For reference there is a little bar that shows a distance scale. 1µm is a thousandth of a millimeter. For reference, one of your hairs is about 50µm across. The fibers you see in the pictures are glass fibers that make up the filter paper I trapped the soot in. We're zooming progressively in on the particle slightly left of center in the first image.




Incidentally, the smaller soot particles less than 2µm across (the individual clumps in the last image) are perfect for delivering carcinogenic compounds deep into your lungs. When they clump together like the one shown above, then your nose filters it out, but if they remain small (and hard to see, which is good for visibility but bad for lungs) they pass right on down and deposit all sorts of wonderful benzene and other toxics straight into you most sensitive tissues. This is actually a special concern for bike commuters, who tend to breathe deeply right next to the exhaust pipes of trucks and buses. For that reason I try to ride on road where the diesels don't go...
I guess that sort of explains part of why I'm doing what I am in graduate school. Hope you thought this was a neat as I did.

3 comments:

Tracee said...

that is really awesome and really scary.

Jenny said...

Oh wow! I never got to use an SEM...and I admit I'm totally jealous!!

Louisa said...

cool! We just learned about SEM in one of my bio classes....

Have you ever gotten to play with flourescent proteins? That's MY story of the week ... to be posted soon I hope :).