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
Net Profit Margin. Net profit margin (or profit margin, net margin) is a ratio of profitability calculated as after-tax net income (net profits) divided by sales (revenue). Net profit margin is displayed as a percentage. It shows the amount of each sales dollar left over after all expenses have been paid.et Profit Margin. Net profit margin (or profit margin, net margin) is a ratio of profitability calculated as after-tax net income (net profits) divided by sales (revenue). Net profit margin is displayed as a percentage. It shows the amount of each sales dollar left over after all expenses have been paid.