Share this page!

Enter URL or ID to Unroll

You can paste full URL like: https://x.com/threadreaderapp/status/1644127596119195649
or just the ID like: 1644127596119195649

How to get URL link on X (Twitter) App

  1. On the Twitter thread, click on or icon on the bottom
  2. Click again on or Share Via icon
  3. Click on Copy Link to Tweet
  4. Paste it above and click "Unroll Thread"!
  5. More info at Twitter Help
Nora Traviss, PhD Profile picture
@NoraTraviss
Jul 15, 2018 • 3 tweets • 2 min read • Read on X
Yes, I’m so happy to make bigger point and I know someday teens will appreciate the “live biology” lesson! Lots of fun crab and lobster catching and releasing #invertebratesaresexytoo
Teens are impressed! Success! #biologistsintraining #exploring Except when I explained about Chordata my son instantly broke into “Hakuna matata” from The Lion King. #smallvictories Image
Thank you 😊 @karencang 😘

• • •

Missing some Tweet in this thread? You can try to force a refresh
　

Keep Current with Nora Traviss, PhD

Nora Traviss, PhD Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @NoraTraviss

Nora Traviss, PhD Profile picture
Aug 8, 2020
Thread: so in this thread I am posting my results from a "chamber study" at the rural school I described in my earlier thread. Different room, smaller, no air flow. I used a Dylos DC 1100 and a TSI CPC 3007. The CPC is a much better instrument - picks up nanometer particles.
I basically used the smoke kits, 6 puffs, checked instruments after 10 seconds, wrote down "inlet" concentration and then put instruments on "clean" side of fan, about 1/2" from fan about 2 mins later. These are GRAB samples, so spot checks. Very quick and dirty!
Again, here is chicken scratch. Basically about a 23% to 50% reduction in smoke particles, depending on instrument. CPC results (~50% reduction) are more reliable. Other researchers have gotten up to 87% reduction in more controlled settings. Image
Read 4 tweets
Nora Traviss, PhD Profile picture
Aug 8, 2020
So I worked with a local school, rural area, NO HVAC, to check out natural ventilation, and setting up box fan configurations and [box fan + 20"x 20" x 1" filter combos]

Smoke Test - before, minimal ventilation, 800 ft2 classroom via @YouTube
I was really surprised with how the smoke just instantly rose just like those animations we have been seeing from aerosol scientists! We had a fan as an exhaust, so some air flow, but clearly not enough!
Then we moved the fans around and settled on this configuration which I have sketched by hand, in terrible chicken scratch, but time is of essence, not art. We settled on a cross flow ventilation, 1 fan as supply in window, 1 as exhaust, w/"box fan +filter" combo in the front. Image
Read 8 tweets
Nora Traviss, PhD Profile picture
Jul 3, 2020
Thread: So I’m a Jill of All Trades Scientist - doer of many things and master of none. But I measure particles in air most times. I broke out a textbook Exposure Analysis by Ott, Steinmann, Wallace. A virus is a very tiny particle so what if we treated it as such? 1/
2/ A tiny particle that weighs very little (an attogram according to Wikipedia 1 x 10^-18 of a gram) but still let’s assume the tiny mass is conserved (unlike particle number). With these and some “rule of thumb” or “back of the envelope” assumptions of the equation below: Image
3/then we can determine the max indoor air concentration of virus with some baseline assumptions. 1 person is an emitter in a 30x 40x 10ft class [~340 m^3]. A shedder if you will that emits 600 virus/particles per min while talking. Then the concentration in the room after ...
Read 13 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

Send Email!

:(