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.
(A) Insulation layer: a shower cap (B) Semi-conducting layer: paper layer (C) A piece of thin paper dampened with saline placed on top of the insulation layer (D) A picture with all channels blocked (E) Sandwich diagram of construction (F) Unblocking one channel.
