(plural ring topologies) (computing) A network topology in which, in the physical case, every node of a network is connected to exactly two other nodes: one node designated as upstream and the other as downstream. A given node receives data from its upstream node and sends data to its downstream node.
Image copyright. The price of Brent crude oil has fallen below $50 a barrel for the first time since May 2009. It fell more than a dollar to $49.92 a barrel in early trading on Wednesday before edging back above the $50 mark. Slowing global growth and increased supply of oil and gas have pushed prices sharply lower in recent weeks.
The amount of crude oil these countries produce determines the price of a barrel of oil. Crude-oil prices averaged around $35 per barrel (1 barrel = 42 gallons or 158.99 L) in 2004.