Ceiling fan be used to reduce the stratification of warm air in a room by forcing it down to affect both occupants' sensations and thermostat readings, thereby improving climate control energy efficiency. Punkah-type ceiling fans date back to 500 BC, and are native to India. Unlike modern rotary fans, these punkah fans move air by moving to and fro, and were operated manually by cord. The first rotary ceiling fans appeared in the early 1860s and 1870s in the United States. At that time, they were not powered by any form of electric motor. Instead, a stream of running water was used,
Spectrum of a C*-algebra representations of separable type I C*-algebras and correspondingly of separable locally compact groups of type I. Since a C*-algebra "A" is a ring, we can also consider the set of primitive ideals of "A", where "A" is regarded algebraically. For a ring an ideal is primitive if and only if it is the annihilator of a simple module. It turns out that for a C*-algebra "A", an ideal is algebraically primitive if and only if it is primitive in the sense defined above. This is the Corollary of Theorem 2.9.5 of the Dixmier reference. If "G" is a locally compact