Total natural gas rig count in the US (including conventional gas drilling) Shale gas is natural gas that is found trapped within shale formations. Shale gas has become an increasingly important source of natural gas in the United States since the start of this century, and interest has spread to potential gas shales in the rest of the world.
A stressor is a chemical or biological agent, environmental condition, external stimulus or an event that causes stress to an organism.[1]
depressor nerve. 1. a nerve that lessens the activity of an organ. 2. an afferent nerve whose stimulation causes a fall in blood pressure. efferent nerve any nerve that carries impulses from the central nervous system toward the periphery, such as a motor nerve.See also neuron.otor nerves, or efferent nerves, transmit impulses from the brain and spinal cord to the muscles. Mixed nerves are composed of both motor and sensory fibers, and transmit messages in both directions at once.