Circulation

From Freepedia

The word circulation can mean the following:

• The transport of blood through the circulatory system. See circulation (physiology).
• Movement of gas or fluid through a physical circuit, such as air through ventilated building. See also Atmospheric circulation.
• imaginary circuit, such as money through the economy
• The readership of a periodical.
• In fluid dynamics, circulation is the line integral of fluid velocity around a closed curve