FIG. 7.
Representative top-view images of post-deposition spreading along the PA solution subphase with increasing time for aerosolized 0.1% w/w tyloxapol solution delivered at a 300 mL/min carrier gas flow rate. (A) Before delivery, (B) 0 sec (at the end of delivery), (C) 10 sec, (D) 1 min, (E) 2 min, (F) 5 min, and (G) 10 min after the end of delivery. Grayscale figures were inverted, with the presence of fluorescein tracer dye indicated by black pixels to facilitate viewing. (H) Image intensity value for spreading dye along the tube averaged across the width of the tube. Every 15th pixel is plotted to make viewing easier. (I) Distance moved by tyloxapol aerosol front shown in (A–G) and that by surfactant-free fluorescein solution (both with delivered volume ∼0.22 μL).