Neurotransmitters and hormones are the chemicals which control every system and process within the body. Norepinephrine is both a neurotransmitter and a hormone. As a result, its role within the body is essential to normal body and brain function.orepinephrine's role as a brain and body stimulant requires a certain level of this chemical to be present to achieve normal mental and emotional function. Its primary mechanism is that of arousal.
A normal diamond pickaxe has 1562 durability so it may get you as much stone with that pickaxe. With Unbreaking III however, that may quadruple your mining count, or around 6248 stone. Efficiency enchantment just makes mining faster and does not improve durability. Sources: http://minecraft.gamepedia.com/Pickaxe
The average engagement ring has a center diamond of about one carat and a total carat weight of approximately one and a half carats. An engagement ring around two carats or above would be considered 'big' for the average girl's standards, and anything three carats or above would likely elicit some serious jaw dropping. Besides carat weight, several other factors, like the shape and cut of a diamond, can affect how large it appears.