Scheme 2.
Toroid nucleation and growth with equal outward and inward growth from the nucleation loop. The black circle on the proto-toroid (second from right) and the fully grown toroid (right) illustrates the size of the nucleation loop.
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.