APPLICATIONS Horn antennas are widely used as satellite dishes and radio telescopes. Antennas 6 2. PARABOLIC ANTENNAS A parabolic antenna is an antenna that uses a parabolic reflector, a curved surface with the cross-sectional shape of a parabola, to direct the radio waves.
Flu (influenza). Flu is usually infectious a day before symptoms start and remains infectious for about five to six days. Children and people with lowered immune systems may be infectious for a few days longer.
Many people with influenza illness will continue shedding influenza virus 24 hours after their fevers go away, but at lower levels than during their fever. Shedding of influenza virus, as detected by RT-PCR, can be detected for 10 days or more in some cases.