Fig. 1
From: Gaseous emissions from brake wear can form secondary particulate matter
(a) Total number concentration in the flow reactor over the tribometer running time. Solid light blue and magenta lines represent the equivalent ambient ages of 7 days (condition I) and 9 days (condition II), respectively, whereas the dashed lines are the repeat for each equivalent age. The dash-dotted dark blue line represents a control experiment where the tribometer was run without a brake pin. (b) Corresponding number size distribution over time for an experiment performed at 9 days equivalent age. The times highlighted in yellow indicate the period when the tribometer was turned on (i.e. when wear emissions were generated).
