Update README.md

README.md

@@ -22,7 +22,9 @@ so we're targeting filter material able to block particles with minimum ~0.25um
     - plaque assay: plaque forming units (pfu) - virus infected cell will lyse and infect other cells, then form the plaque which can be counted manually visually or by optical microscope, takes days for virus to infect (time depending on virus)
     -   focus forming assay (FFA) - similar to pfu/mL but instead of waiting for cell to lyse add reagents to highlight infected cells, less time but more costly with equipment
     -   fifty-percent tissue culture infective dose (TCID_50) - amount of virus required to kill 50% of infected hosts. 0.69 pfu = 1 TCID bc poisson distribution 
-
+- measuring aerosol particles:
+    - MMAD: mean mass aerodynamic diameter
+    - CMAD: count median aerodynamic diameter
 
 
 ### conventional test methods
@@ -46,10 +48,10 @@ performance difference between pleated hydrophobic filters and electrostatic fil
 [^aerodynamics]: [Aerodynamic Characteristics of RNA concetration of SARS-CoV-2](https://www.biorxiv.org/content/10.1101/2020.03.08.982637v1.abstract)
 [^VFEreport]: [Nelson Laboratories: Viral Filtration Efficiency (VFE) at increased challenge level](https://gitlab.cba.mit.edu/pub/coronavirus/tracking/uploads/164d119b5a7a5751c685a6677378668a/ER_2235600_Attachment_5_Viral_Filtration_Efficiency.pdf)
 [^nelson]: [Nelson lab filtration test](https://www.nelsonlabs.com/testing/bacterial-viral-filtration-efficiency-bfe-vfe/?industry=medical-devices&category=protective-barriers-material-performance)
-
+[^nebulizer_selection]: [Nebulizer selection from CH tech](http://chtechusa.com/Manuals/Selecting%20the%20Model%20and%20Configuration%20Instructions.pdf)
 
 ## needed for testing apparatus 
-- nebulizer for aerosolization 
+- nebulizer for aerosolization [^nebulizer_selection]
     -   three-jet Collison nebulizer? 
 - impinger for collection 
 - wet and dry thermometer / hygrometer for humidity