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.
Detecting and Avoiding Step Voltage Hazards
Uncontrolled flow of electrical current in the earth may have a range of effects, from barely perceptible to dangerous electrical shocks, or unintended electrical heating resulting in fires. This paper promotes awareness of hazards from ground-potential rise and briefly describes the root causes of voltage in the ground. It is proven that the values of ground potential can be above permissible limits if a voltage as small as 220 V ac is applied into the ground. The step voltage hazards depend on the distance of the fault as well as from the step length. Ground resistivity also affects ground-potential rise. A wearable device is proposed for avoiding injuries. The device warns and protects the user of the step voltage hazards.
Die Populationsdynamik Von Canthocampt Us Staphylinus (Jurine) (Copepoda, Harpacticoida) Im Litoral Des Bodensees
The population dynamics of Canthocamptus staphylinus in the littoral zone of Lake Constance are described (fig. 2). Adult animals aestivate as cysts. The main part of the population emerges from the cysts in autumn. During the resting stage and the first spell after emerging, mortality is very low (fig. 3). Reproduction, expressed as numbers of ovigerous females, begins in November and reaches its maximum in January. The new generation becomes adult in May/June and encysts without previous reproduction. According to Sarvala (1979) it may be possible, that in littoral populations dormancy is induced by long day periods and temperatures of over 12° C (figs. 1, 2). In the profundal zone C. staphylinus also forms cysts, however, both light and temperature are not likely to induce this stage in depths of over 60 m.