c	Concentration (mol $·$ m${}^{-3}$)
D	Diameter (m)
F	Volume fraction (%v/v)
I	Light intensity (W $·$ m${}^{-2}$)
L	Length (m)
m	Mass (kg)
$\dot{m}$	Mass flow rate (kg $·$ s${}^{-1}$)
p	Fraction of caloric production due to protein metabolism (%)
P	Pressure (Pa)
t	Time (s)
T	Period (s)
T	Temperature (°C)
T	Transmittance (-)
$\dot{V}$	Volumetric flow rate (m${}^3·$ s${}^{-1}$)
$\epsilon$	Relative error (%)
$ϵ$	Molar absorption coefficient (m${}^2·$ mol${}^{-1}$)
µ	Dynamic viscosity (Pa $·$ s)