Discuss the methods and technology used in damping buildings when Essay

Discuss the methods and technology used in damping buildings when resonance leads to SHM caused by the wind and earthquakes - Essay Example The amplitude of these oscillations is time dependent and is inversely proportional to the time. Higher damping means that the oscillations reduce in their size (Fang et al. 1999). In physics’ terms, the tendency of a system to oscillate at amplitude that is greater at certain frequencies as compared to others is called resonance. This situation occurs when the system has the capacity to stockpile and shift energy easily between more than two modes of storage. The losses that happen at the process of this cycle are called damping. With small damping, the resonance frequency tends to be the same as the natural frequency of the system. There are cases where systems have multiple resonance frequencies that are distinct (Kijewski-Correa and Pirnia, 2007). Damping is hence the physical phenomenon of reducing motion through dissipation of energy. In tall buildings, damping is important due to various reasons. The tall buildings are known to vibrate at natural frequencies that are low. This is a factor that makes the buildings to be very susceptible to dynamic resonance in cases of earthquake and wind. Wind energy is usually at its highest when the frequencies are low. Additionally, to the response to the wind gustiness, there is a common form of dynamic wind response that is due to vortex shedding. The circumstances mentioned results to the creation of movements of the structure that is at right angles to the course of the storm (Terman, 1992). Damping in tall buildings is mainly caused by intrinsic and supplementary sources. Intrinsic damping comes from connections, cladding, friction and seismic motion; in this case, this paper is interested in the seismic causes of the damping which is earthquakes. Supplementary damping is due to engineered devices such as friction devices, viscous and slosh dampers and tuned mass dampers (Katsuhiko, 2005). There are broad methods that have been largely

Discuss the different outlooks and experiences of Native Americans and Essay

Discuss the different outlooks and experiences of Native Americans and the Spanish Conquistidors during the colonial period of american history - Essay Example For the Indians part, the arrival of the Spaniards was originally thought to be the return of a god, Quetzalcoatl. This is indicated in many reports by the Spanish that tend to highlight the naivetà © of the Indians, but is also mentioned in the written record of the Indians: â€Å"It was as if he [Motecuhzoma] thought the new arrival was our prince Quetzalcoatl. This is what he felt in his heart: He has appeared! He has come back! He will come here, to the place of his throne and canopy, for that is what he promised when he departed!† (Leon-Portilla, year). However, while the Spanish insisted that this impression was long-lasting, the Indians themselves indicate that they quickly understood that this was not the god they had expected. While those in Tenochititlan understood this as the Spaniards proceeded to burn all their sacred treasures with eyes filled with greed, the Cibola tribes and other plains tribes similarly could not submit their own religious beliefs and lives t o the greed and domination of the Spaniards. For their part, the Spanish seem not to have been completely unsympathetic to the plight of the Indians that had been encountered. Juan Jaramillo (1896) describes his expedition with some detail, indicating highly practical Indian populations who had not only two-story houses, but innovative constructions such as hot rooms built underground against the chill of the winters and the hide-covered constructions (teepees) that others used as a means of portable housing to follow the herds of buffalo. While he does not indicate these people were rich by any means, he does indicate that they were courteous, welcoming and content with their lives upon their first encounter. However, investigations into reports of â€Å"cruelties† committed by the Spaniards turned out an interview of Juan Troyano, whose testimony seemed somewhat puzzled as to why the Indians would not immediately and peacefully surrender everything they