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.
It does not cause epidemics and does not have the severe public health impact that influenza types A and B do. The typical incubation period for influenza is 1 to 4 days, with an average of 2 days. Adults can be infectious from the day before symptoms begin through approximately 5 days after illness onset.Children can be infectious for.t does not cause epidemics and does not have the severe public health impact that influenza types A and B do. The typical incubation period for influenza is 1 to 4 days, with an average of 2 days. Adults can be infectious from the day before symptoms begin through approximately 5 days after illness onset.