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
Profit margin is defined as a ratio of profits earned to total costs over a defined period (e.g. a quarter, a year, etc.). Each industry generally has its own average profit margin due to the differences in costs and materials needed for different products and services. There are two types of profit margin that small businesses might find useful: