The Reconstruction Finance Corporation (RFC) was established during the Hoover administration with the primary objective of providing liquidity to, and restoring confidence in the banking system. The banking system experienced extensive pressure during the economic contraction of 1929-1933.
Typical materials used for electromagnetic shielding include sheet metal, metal screen, and metal foam. Any holes in the shield or mesh must be significantly smaller than the wavelength of the radiation that is being kept out, or the enclosure will not effectively approximate an unbroken conducting surface.
1. A mechanical wave needs a medium for its propagation. An electromagnetic wave can travel through vacuum and it has the highest speed as it moves through the vacuum. Sound wave is a mechanical wave and light is an electromagnetic wave. 2. A mechanical wave can be both transverse and longitudinal but an electromagnetic wave is a transverse wave. 3. The particles of the medium vibrate, when a mechanical wave passes through it. In an electromagnetic wave the oscillating parameters are the electric and magnetic field.