Isotonic exercises involve moving your joints and muscles rhythmically and repetitively through their ranges of motion using low resistance, while isometric exercises are static and require you to contract your muscles without joint motion.
Substations are normally outdoors and are enclosed by a wire fence. However in residential or high density areas, the substation may be indoors and housed inside a building to restrict the humming noise of the huge transformers. slide 2 of 6 View of a Substation
A substation is a high-voltage electric system facility. It is used to switch generators, equipment, and circuits or lines in and out of a system. It also is used to change AC voltages from one level to another, and/or change alternating current to direct current or direct current to alternating current.tep-down transmission substations are located at switching points in an electrical grid. They connect different parts of a grid and are a source for subtransmission lines or distribution lines. The step-down substation can change the transmission voltage to a subtransmission voltage, usually 69 kV.