Figure 12.
Interiors of NPG, (a) and (c), and LPG, (b) and (d), that were immersed in pH 0.5 acid solution.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.