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.
Smaller particle accelerators are used in a wide variety of applications, including particle therapy for oncological purposes, radioisotope production for medical diagnostics, ion implanters for manufacture of semiconductors, and accelerator mass spectrometers for measurements of rare isotopes such as radiocarbon.
Particle bombardment is a technique which can be used to introduce foreign DNA to a cell culture. Over the past several years, particle bombardment has progressed into a valuable tool for molecular biologists, permitting direct gene transfer to a broad wide range of cell and tissue types.