There are three main types of volcano-composite or strato, shield and dome. Composite Volcanoes. Composite volcanoes, sometimes known as strato volcanoes, are steep sided cones formed from layers of ash and [lava] flows. The eruptions from these volcanoes may be a pyroclastic flow rather than a flow of lava.
A vagal episode or vasovagal response or vasovagal attack (also called neurocardiogenic syncope) is a malaise mediated by the vagus nerve. When it leads to fainting, also known as a syncope, it is called a vasovagal syncope, which is the most common type of fainting.
Free radical halogenation is a reaction that substitutes a chlorine or a bromine for a hydrogen on an alkane. This reaction is a photochemical one. That is, it occurs only when performed in the presence of uv light (abbreviated hv).Typically, free radical reactions are described in three steps: initiation steps, propagation steps, and termination steps (described below).hat is, it occurs only when performed in the presence of uv light (abbreviated hv). Typically, free radical reactions are described in three steps: initiation steps, propagation steps, and termination steps (described below).