Methylphenidate is a commonly prescribed psychostimulant and works by increasing the activity of the central nervous system. It produces such effects as increasing or maintaining alertness, combating fatigue, and improving attention. The short-term benefits and cost effectiveness of methylphenidate are well established.
(image copied from here). 1  Igneous Rocks: form by crystallizing melted material (magma). 2  They can form either on the surface (extrusive igneous rocks), or deep in the crust (intrusive or plutonic igneous rocks).
Igneous Rocks. Igneous rocks form as a result of the cooling of magma. When magma cools and solidifies underground, the resulting igneous rock is plutonic. These types of rocks may be surfaced through weathering processes or the movement of plate tectonics.gneous rocks form as a result of the cooling of magma. When magma cools and solidifies underground, the resulting igneous rock is plutonic. These types of rocks may be surfaced through weathering processes or the movement of plate tectonics.