The rule is that a sample is safe when its radioactivity has dropped below detection limits. And that occurs at 10 half-lives. So, if radioactive iodine-131 (which has a half-life of 8 days) is injected into the body to treat thyroid cancer, itâll be âgoneâ in 10 half-lives, or 80 days.
The term 'ratchet' has no less than two distinct meanings. As an adjective, it describes a person, usually a woman, or activity, who is out of hand, out of control, generally whack in some way, dirty, ghetto, unattractive, Crucian, or just generally disliked.
ratchet effect. Definition. The implication for a variable that (like a ratchet) can move one direction but not the other. Thus if wages or prices are are inflexible downward but not upward, then fluctuations in the economy will only cause them, intermittently, to rise. Use ratchet effect in a sentence. â 1  You should try and make sure to find a way to use the ratchet effect in your favor if that is at all possible. â 2  For awhile, it seemed crude oil was in a ratchet effect as the dollar continued to deteriorate, since prices of barrels only seemed to go up.