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
What it is: Operating margin is a measure of profitability. It indicates how much of each dollar of revenues is left over after both costs of goods sold and operating expenses are considered. The formula is for calculating operating margin is: Operating Margin = Operating Earnings / Revenue.