The main symptoms of vascular dementia include: 1  Abrupt onset (in some, but not all patients). 2  Progressive deterioration of intellectual abilities, processing speed, cognitive and motor abilities. 3  Progressive memory loss. 4  Slow, unsteady gait. 5  Fluctuating course (in some patients).
Although radio frequency is a rate of oscillation, the term radio frequency or its abbreviation RF are used as a synonym for radio â i.e., to describe the use of wireless communication, as opposed to communication via electric wires. The energy in an RF current can radiate off a conductor into space as electromagnetic waves (radio waves); this is the basis of radio technology. 2  RF current does not penetrate deeply into electrical conductors but tends to flow along their surfaces; this is known as the skin effect.
The RF part of the electromagnetic spectrum is generally defined as that part of the spectrum where electromagnetic waves have frequencies in the range of about 3 kilohertz (3 kHz) to 300 gigahertz (300 GHz).he frequency of an RF signal is usually expressed in terms of a unit called the hertz (Hz). One Hz equals one cycle per second. One megahertz (MHz) equals one million cycles per second. Different forms of electromagnetic energy are categorized by their wavelengths and frequencies.