Photons may occur in the form of x-rays, gamma rays, or quanta of light. The energy (E) of a photon is expressed as the product of its frequency (v) and Planck's constant (h), as in the equation E = hv. X-ray photons occur in frequencies of 10 18 to 10 21 Hz and energies that range upward from 1 KeV.
Confidence votes 52.5K. In the US, the standards called General Industry Standards are the OSHA standards at 29 CFR 1910 and are sometimes called Part 1910.
The Global Industry Classification Standard (GICS) is an industry taxonomy developed in 1999 by MSCI and Standard & Poor's (S&P) for use by the global financial community. The GICS structure consists of 11 sectors, 24 industry groups, 68 industries and 157 sub-industries into which S&P has categorized all major public companies. The system is similar to ICB (Industry Classification Benchmark), a classification structure maintained by FTSE Group.