Figure 7.
Ultrasonic waveforms with respect to different hydrogen-charging times: (a) overall signal; (b) secondary echo signal; and (c) amplitude of secondary echo signal.
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.