Classical element to use the term "element (στοιχεῖον, "stoicheion")" in reference to air, fire, earth, and water. The ancient Greek word for element, "stoicheion" (from "stoicheo", "to line up") meant "smallest division (of a sun-dial), a syllable", as the composing unit of an alphabet it could denote a letter and the smallest unit from which a word is formed. A similar alphabetic metaphor may be the origin of the equivalent Latin word "elementum" (from which the English word comes), possibly based on the names of the letters 'l', 'm', and 'n', though the validity of this idea is debated. In his "On
Homogeneous charge compression ignition development. Examples include: Homogeneous charge compression ignition Homogeneous charge compression ignition (HCCI) is a form of internal combustion in which well-mixed fuel and oxidizer (typically air) are compressed to the point of auto-ignition. As in other forms of combustion, this exothermic reaction releases energy that can be transformed in an engine into work and heat. HCCI combines characteristics of conventional gasoline engine and diesel engines. Gasoline engines combine "homogeneous charge" (HC) with "spark ignition" (SI), abbreviated as HCSI. Diesel engines combine "stratified charge" (SC) with "compression ignition" (CI), abbreviated as SCCI. As in HCSI, HCCI injects fuel during the intake