Medical Dictionary. brachial plexus. noun. Medical Definition of brachial plexus. : a complex network of nerves that is formed chiefly by the lower four cervical nerves and the first thoracic nerve, lies partly within the axilla, and supplies nerves to the chest, shoulder, and arm.
Nonrenewable Sources of Energy. Most of the energy we use comes from fossil fuels, such as coal, natural gas and petroleum. Uranium is another nonrenewable source, but it is not a fossil fuel.Uranium is converted to a fuel and used in nuclear power plants.Once these natural resources are used up, they are gone forever.nergy is the power we use for transportation, for heat and light in our homes and for the manufacture of all kinds of products. There are two sources of energy: renewable and nonrenewable energy.
Nuclear fuel. Nuclear fuel is a substance that is used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile elements that are capable of nuclear fission, such as uranium-235 or plutonium-239. When the unstable nuclei of these atoms are hit by a slow-moving neutron, they split, creating two daughter nuclei and two or three more neutrons. These neutrons then go on to split more nuclei. This creates a se