Coal the heat and pressure of deep burial causes the loss of water, methane and carbon dioxide and an increase in the proportion of carbon. Thus first lignite (also called "brown coal"), then sub-bituminous coal, bituminous coal, and lastly anthracite (also called "hard coal" or "black coal") may be formed. The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants—this coal is presumed to
Electro Scientific Industries to MKS Instruments, Inc. The deal was expected to close in the first quarter of 2019. ESI was founded in 1944 as Brown Engineering, later becoming Brown Electro-Measurement Corporation (BECO). In 1953, BECO's Douglas C. Strain and three other investors bought out Strain's partners at Brown and formed a new company, Electro-Measurements Inc., which used the brand name "ESI" in marketing. The acronym stood for "excellent scientific instruments", but the company's name remained Electro Measurements Inc. until 1959, when it was changed to "ESI, Inc." and finally in 1960 to Electro Scientific Industries, Inc. (ESI). Prior to about 2000, the