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.
Symptoms can begin about 1 to 4 days, or an average of 2 days, after a person is first exposed to the influenza virus. Fever and other symptoms can usually last up to 7 to 10 days, but the cough and weakness may last 1 to 2 weeks longer. What is the home treatment? If you get sick with influenza, home treatment can help ease symptoms. Follow the self-care advice below: Get plenty of rest. Drink extra fluids to replace those lost from fever.