one of the most important issues that faced cities in developing countries with a crisis is expanding informal settlement in them. these settlements with differences in definition are known as occupational, changing, marginal, self-made and uncontrolled housing. it is estimated that about 1 billion man in all over the world live in such kinds of places. these zones are the texture for creation ...

<p class="Abstract">Security or protection systems at generators, substations, transmission, and housing others, especially to overcome lightning disturbances leakage currents, the earthing system must meet required standards. For each part of system, from substation residential electricity utilization as well other parts, standard earth resistance is not same, for example a maximum 5 Ω, ...