The nadir (UK: /ËnÃ¦dÉªÉr/), (US: /ËneÉªdÉªÉr/) (from Arabic: ÙØ¸ÙØ±ââ / ALA-LC: naáºÄ«r, meaning counterpart) is the direction pointing directly below a particular location; that is, it is one of two vertical directions at a specified location, orthogonal to a horizontal flat surface there.
Asymmetric hydrogenation is a chemical reaction that adds two atoms of hydrogen preferentially to one of two faces of an unsaturated substrate molecule, such as an alkene or ketone.ne of these is in the asymmetric hydrogenation of N-unfunctionalized imines to give primary amines. Such species can be difficult to selectively reduce because they tend to exist in complex equilibria of imine and enamine tautomers, as well as (E) and (Z) isomers.
magmatic differentiation. (petrology). The process by which the different types of igneous rocks are derived from a single parent magma. The process by which ores are formed by solidification from magma.Also known as magmatic segregation.1  Facebook.2  Twitter.petrology). The process by which the different types of igneous rocks are derived from a single parent magma. The process by which ores are formed by solidification from magma. Also known as magmatic segregation.