(Or how to bury your work so deeply that no-one will ever know it existed in the first place!)
If there’s one piece of advice I’d give myself as a young researcher, it would probably be “never agree to write a book chapter!”
Of course, there are plenty of good academic book chapters around. But over the years I’ve sadly come to realize that this is the fastest way to make my work inaccessible to people who might otherwise benefit from it — partly because academic books are so expensive that few people can afford to read them!
However, I’ve just come across an even more effective way of ensuring no-one has a hope in hell of benefiting from your research: publishing a chapter in a book which is then dropped from subsequent editions.
Back in the late 1990’s, a close colleague and friend Dr. Paul Baron developed the “Aerosol Calculator” — an Excel spreadsheet that contained pretty much every equation imaginable (at the time) related to airborne particle behavior.
The Aerosol Calculator became legend, and an essential tool for anyone working in aerosol science. It contained over 100 equations for calculating aerosol behavior, drawing from the books Aerosol Measurement (edited by Baron and Willeke, and later Kulkarni, Baron and Willeke), and the equally legendary Aerosol Technology by Bill Hinds.
A frame from the first of the 2009 Nano Cubes visualizations showing the relationship between number, surface area and mass
Those nano-geeks amongst you with long memories may remember that, back in 2009, I played around with a couple of visualizations of the relationship between particle number, surface area, and mass. Those of you with even longer memories may recall that the origins of these visualizations goes all the way back to 2002.
As I was digging through some old files this morning, I came across my original work here, and was caught off-guard by a wave of nostalgia.
Back in the early 2000’s I was working on ways of measuring the surface area of collections of nanoparticles, and giving an increasing number of talks about how particle surface area, number and mass are related.
The challenge was that, at the time, the standard way of assessing health impact from exposure to airborne particles was to measure the mass concentration of material depositing in the lungs. Yet research was beginning to show that, for fine particles, health impact was potentially associated with the surface area, or even the number, of inhaled particles.
This was a problem, as at the nanoscale, this would potentially lead to mass concentration measurements dangerously underestimating the risks of airborne nanomaterials.
At the time, I was using the platform Mathematica for a lot of my modeling work, and decided to play around with it to see if I could come up with a simple visualization of the relationship between particle number, surface area and mass.
Here, I should say that Mathematica — at least at the time — was a powerful but gnarly math platform that no sane person would use to create complex animations. But that didn’t stop me relishing the challenge, and so I started to play around.
The first iteration — from March 2002 according to my archives – was a video visualization of a cube being progressively split four times:
This was a good start, but it lacked any quantitative information. So the next iteration was to add information on the number, surface area and mass of the cubes:
Back in the early 2000’s I taught a graduate course at the University of Cincinnati on aerosol dynamics. It was an introductory course that covered the basics of airborne particle physics, including how they behave, what affects this behavior, and how to sample and characterize them.
With the growing coronavirus-inspired interest in face masks and respirators–especially DIY ones–I dug my course notes out, and was surprised at how detailed they are.
And so, just in case anyone’s looking for a crash course in aerosol dynamics, either because they are simply curious, or they want to build a better face mask, here are those notes:
These were written for the class participants rather than for public consumption, and so they are a little clunky in places. And of course, the state of the science has moved on since they were last updated in 2004. Yet the notes still do a surprisingly good job of covering the basics of aerosol behavior in a way that remains relevant today.
Please feel free to share and use – they are provided under a Creative Commons CC- BY-SA license
UPDATE: One of the key resources for this course was an Excel spreadsheet developed by a good friend and colleague Paul Baron that included an exceptionally comprehensive set of calculations for determining, predicting and modeling aerosol behavior. That “aerosol calculator” can be downloaded here.
Despite having spent years working at the cutting edge of engineered nanomaterial safety, I’m not that involved in the field these days — having moved on to broader challenges and opportunities associated with emerging and converging technologies. But I recently had the chance to work with a group of colleagues on what I think is an important paper that systematically reviews the state of knowledge on workplace carbon nanotube exposure assessment.
Guseva Canu, I., K. Batsungnoen, A. Maynard and N. B. Hopf (2020). “State of knowledge on the occupational exposure to carbon nanotube.” International Journal of Hygiene and Environmental Health 225: 113472. DOI: 10.1016/j.ijheh.2020.113472
