Hives on dark skin. Hives are a skin reaction that causes red or white itchy welts. The welts vary in size and appear and fade repeatedly as the reaction runs its course. Chronic hives are a condition in which the welts last more than six weeks or recur over months or years.Chronic hives usually aren't life-threatening. But the condition can be very uncomfortable and interfere with sleep and daily activities. Often, the cause of chronic hives is not clear.In some cases, chronic hives are a sign of an underlying health problem, such as thyroid disease or lupus. You can try various treatments to relieve your symptoms. For many people, antihistamine and anti-itch medications provide relief from chronic hives.hronic hives are a condition in which the welts last more than six weeks or recur over months or years. Chronic hives usually aren't life-threatening. But the condition can be very uncomfortable and interfere with sleep and daily activities. Often, the cause of chronic hives is not clear.
longitudinal magnetization. 1  of a material or medium in a manner in which the magnetic flux is essentially parallel to the long axis of the influencing field. 2  In magnetic recording, 3  of a material or medium essentially in the same direction as the material or medium is traveling.
Polarization (also polarisation) is a property of some types of waves. Some waves have motion in another direction as well as the direction of the wave.In water, for instance, the wave will move across the water, but something on the surface of the water will move up and down.f both the electric field and magnetic field are perpendicular to the direction of the wave, the wave is called TEM (transverse electromagnetic). Linear, circular, and elliptical polarizations are specific cases of TEM polarization.