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.
The main types of electromagnetic radiation. Radio wavesradio waves: Low frequency electromagnetic radiation used to transmit information such as television and radio programmes. have the lowest frequencies and longest wavelengths, while gamma waves have highest frequencies and shortest wavelengths.