Daniel Rutherford Essay Example | Topics and Well Written Essays - 500 words

Daniel Rutherford - Essay Example Daniel Rutherford, from Holl, 1804 It was a natural academic progression to attend the University of Edinburgh where his father was a professor of medicine. Daniel would also graduate with a degree in medicine, but it was the experiments he conducted as a student that helped unlock the mysteries of combustion, life, and the composition of 'vital air' ("Daniel Rutherford"). At the time, it was known that a quantity of air that had been subjected to combustion would no longer support life. It was mistakenly believed that the only gas left was carbon dioxide (CO2), and it was considered noxious because of its in inability to support life. Rutherford, through a series of experiments, was able to extract the CO2 and found that it still would not combust or support life. Though he is credited for isolating nitrogen, a more accurate portrayal is that he discovered that air was a mixture of many gases and there was the existence of 'vital air', that would later be known as oxygen. In 1772, he published his thesis titled On A ir Said to be Fixed or Mephitic (Daintith 467). This enabled other scientists that were doing similar research to be moved down the path of discovery. Rutherford's thesis helped guide the current thinking and has been credited with spawning many of Joseph Priestley's later experiments.(Daintith 467).

Fuel cells Essay Example | Topics and Well Written Essays - 1000 words

Fuel cells - Essay Example This is then used to run a turbine to produce electricity. Thus there are many intermediate steps each with certain efficiency (always less than 100%) associated with each of them. This is because thermal energy is the worst form of energy with maximum entropy and therefore can never be converted fully into useful work. Now the overall efficiency of chemical potential energy to electricity conversion is a product of efficiency of each of the intermediate steps and therefore is much smaller. The best thermal power plants operate at maximum conversion efficiency of about 40%. Also, the combustion products are highly polluting adding to carbon emission and global warming. Fuel cells on the other hand convert the chemical potential energy directly into electricity and thus have very high conversion efficiency which is typically 70%. Besides, the reaction products are relatively harmless and in many cases completely harmless. Thus fuel cells are being seen as power plants of future and a tangible potential solution for containing the menace of carbon emission and therefore, global warming. These are already into many specialized and high end applications. In this report the basic principle, related developments and current and potential applications of fuel cells are briefly discussed. A fuel cell is like a galvanic cell. It directly converts chemical energy into electricity and is highly efficient. It is now possible to make such cells in which reactants are fed continuously to the electrodes and products are removed continuously from the electrolyte compartment. Galvanic cells that are designed to convert the energy of combustion of fuels like hydrogen, methane, methanol, etc. directly into electrical energy are called fuel cells. Such a fuel cell was used for providing electrical power in the Apollo space program. The water vapors produced during the reaction were