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.
Zirconium is very poor at absorbing neutrons. It is therefore useful in nuclear energy applications such as in the cladding (outer layer) of fuel rods through which it is important that neutrons can travel easily. Zirconium is used as to make surgical instruments and is used in steel alloys as a hardening agent. As a result of its exceptional corrosion resistance, zirconium is used extensively in the chemical industry in corrosive environments where zirconiumâs alloys can be found in pipes, fittings and heat exchangers.