American History and Society Through Music Research Paper

American History and Society Through Music - Research Paper Example The District judge and the Court of Appeal seemed to think that the school was in its right. The Supreme Court did not agree and reversed the decision with Mr. Justice Fortas giving the opinion of the court and Justice White and Stewart concurring. The majority based their opinions on the idea that the students could not be expected to leave what rights they had at the doors of the school and were not in any manner causing a disturbance. Those in dissent argued that the constitution did not protect students from any disruptive form of symbolic speech and Justice Black stated â€Å"And I repeat that if the time has come when pupils of state-supported schools, kindergartens, grammar schools, or high schools, can defy and flout orders of school officials to keep their minds on their own schoolwork, it is the beginning of a new revolutionary era of permissiveness in this country fostered by the judiciary.† (Tinker v. Des MoinesIndependent Community School District). Though Tinker has been used in various cases after it, courts are now beginning to take a view aside from that which was presented in this case.

Managing of Energy Assets Essay Example | Topics and Well Written Essays - 3000 words

Managing of Energy Assets - Essay Example In wind power generation, there are no harmful by-products left over since no chemical processes take place. Also, with wind power, pollution that can contaminate the environment is avoided. Since wind generation is a renewable source of energy, we will never run out of it. Farming and grazing can still take place on land occupied by wind turbines which can help in the production of biofuels. Wind farms can be built off-shore like that in Germany and at some states of the United States of America. Wind energy harnesses the power of the wind to propel the blades of wind turbines. A turbine is a machine powered by rotating blades. The rotation of turbine blades is converted into electrical current by means of an electrical generator. In the older windmills, wind energy was used to turn mechanical machinery to do physical work, like crushing grain or pumping water. Wind towers are usually built together on wind farms. Now, electrical currents are harnessed by large scale wind farms that are used by national electrical grids as well as small individual turbines used for providing electricity to isolated locations or individual homes (Layton, 2006).   History of Wind Power Technology In the beginning, wind power production did not have any impact on the power system control. When it started in the 1980’s production was a few tens of kW, and today, multi-MW range wind turbines are being installed. This also means that wind power production in the beginning did not have any impact on the power system control, but now they have to play an active part in the grid due to their size. The technology used in the past wind turbines was based on a squirrel-cage induction generator connected directly to the grid. With that, there is no control of the active and reactive power, which typically are important control parameters to regulate the frequency and the voltage. The power pulsations in the wind are almost directly transferred to the electrical grid. As there is a n increase in the power range of the turbines, the control parameters become more important and likewise, necessary to introduce power electronics as an interface between the wind turbine and the grid. The power electronics is changing the basic characteristic of the wind turbine from being an energy source to be an active power source. The electrical technology used in wind turbine is not new. It has been discussed for several years but now the price per produced kWh is so low, that solutions with power electronics are very attractive (Blaabjerg & Chen, 2005) . Wind Turbines Stored energy is referred to as potential energy, while energy in motion is called kinetic energy. Kinetic energy can be captured, just like the energy in the moving water that can be captured by the turbine in a hydroelectric dam. In the case of a wind turbine, the turbine blades are designed to capture the kinetic energy in wind. Modern wind turbines fall into two basic groups; the  horizontal-axis  varie ty, like the traditional farm windmills used for pumping water, and the  vertical-axis  design, like the eggbeater-style Darrieus model, named after its French inventor. Most large modern wind turbines are horizontal-axis turbines. In any wind-energy turbine, the three crucial parts are the rotor blades, the shaft, and the generator (Sudrai & Chindris, 2005). The rotor blades act as barriers to the wind, such that when the wind forces the blades to turn, kinetic energy is