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 presentation of the four cell system. (A) In a four cell system the configuration can be either a running of the signal from one end through the whole system (left side in A) or from the middle to the borders (right hand side in A). (B) The single responses from the individual cells. (C) The sum of all (bold line) gives the observed signal. It is slightly different from that of a single cell given as gray trace for comparison.
