As far as the tile roofs, they last a long time. It isn't the tile that is the issue, it's the felt (or paper) underneath that gets replaced. Mine is 25 years old, has not been replaced yet. Some neighbors have had theirs redone, but many have not as yet. 04-06-2011, 12:00 AM.
Particle Accelerators Could Be Used to Produce Energy (and Plutonium) Particle accelerators, which are not renowned for their real-world applications, could in fact be used to produce energy, according to a 34-year-old research paper that resurfaced this week.
Particle therapy is a form of external beam radiotherapy using beams of energetic protons, neutrons, or positive ions for cancer treatment. The most common type of particle therapy as of 2012 is proton therapy. Although a photon, used in x-ray or gamma ray therapy, can also be considered a particle, photon therapy is not considered here. Additionally, electron therapy is generally put into its own category.