You may need a backup method of birth control if you have vaginal intercourse during the seven days after a missed pill. Some backup methods are the condom, female condom, diaphragm, or sponge. You can also use emergency contraception (morning after pill) up to five days after unprotected intercourse.
Strontium-90, a radioactive isotope, is a by-product of nuclear reactors and present in nuclear fallout. It has a half-life of 28 years. It is absorbed by bone tissue instead of calcium and can destroy bone marrow and cause cancer. However, it is also useful as it is one of the best high-energy beta-emitters known. It can be used to generate electricity for space vehicles, remote weather stations and navigation buoys.
Uses. Zirconium is used in a number of industrial applications because it is so resistant to corrosion. It is used in pumps and valves and the cores of nuclear reactors. Zirconium oxide is used to make laboratory crucibles and to line furnaces.nother feature of zirconium is that it does not absorb neutrons (unlike hafnium, which absorbs neutrons, and is also found in zirconium deposits). This makes it useful in nuclear applications, where it is used as fuel cladding in nuclear reactors, and as a coating on nuclear fuel parts.