The horse, the cowboy and the lightning modeling: A case study on a farm in the State of Minas Gerais, Brazil
Lightning provoke fear, fright and many material and personal losses in the urban environment, corroborated by the agglomeration of people and concentration of high buildings. No less terrified, however, are the inhabitants of the countryside, including the animals, in the occurrences of atmospheric discharges. This article deals with the action of lightning that victimized a horse and a cowboy, on a farm, by simulating the propagation of potentials in the soil.
Electrical resistance of work shoes
ANSI/IEEE Std. 80-1986 states that the electrical resistance of shoes is uncertain and that it may be very low for damp leather. Therefore, for purposes of the guide, the electrical resistance of shoes is assumed to be zero. It is believed that the use of zero ohms is unduly conservative for electric utility employees working at job sites where workshoes are required and results in unrealistic work restrictions. Present day work shoes utilize a rubber-based compound in the outer sole of the shoe that is especially moisture and oil resistant. Based on these considerations, Niagara Mohawk Power Corporation (USA) has established a conservative, but more realistic, shoe resistance of 2000 ohms for calculation of step and touch potentials for employees working on or near overhead electric lines.
Lightning risk analysis: Case study of endandgered animals
In January 2012, two highly endangered Mountain Bongo's were killed by lightning in the National Zoological Gardens of South Africa. These animals are on the critically endangered list and therefore as many risks should be mitigated where possible. Understanding and calculating the risk associated with lightning to animals within the enclosure is performed using IEC 62305-2 methods. In addition an alternate method is proposed looking at lightning current parameters and lightning ground flash data to determine a median lethal limit for a particular environment. From this a lethal area percentage for an outdoor environment can be determined. This is found to be approximately 75% for the enclosure. This would indicate that lightning protection measures should be put in place in order to prevent further losses as a result of lightning.