A more familiar common use is in silver-coloured modern circulation coins. A typical mix is 75% copper, 25% nickel, and a trace amount of manganese. In the past, true silver coins were debased with cupronickel. Despite high copper content, cupronickel is dark bronze in colour when in storage, but is a light copper colour when polished. Thermocouples and resistors whose resistance is stable across changes in temperature contain the 55% copper-45% nickel alloy constantan.
For the past 3 months, I've been taking several popular nootropics in relatively recommended dosages. The results have been generally positive (mental stamina, desire to learn, impressive thoughts at times), however, I am experiencing the following unwelcome side-effects. -Rash and skin irritation.
Smart drugs and designer drugs. Nootropics, also commonly referred to as smart drugs, are drugs that are claimed to improve human cognitive abilities. Nootropics are used to improve memory, concentration, thought, mood, learning, and many other things.