The beginning of the amazing events at Krakatoa in 1883 date to May 20 when there were initial rumblings and venting from the volcano, which had been dormant for about 200 years.
A refinery margin is the revenue associated with refining petroleum, expressed as a value per volume (e.g. $/L), net of the cost of the crude oil input. The simplest refining
Margin in business is expressed as a ratio of the difference between what it costs to produce a good or service and the amount of payment received for that good or service. Operating margin illustrates a company's operating efficiency in relation to its net sales.