Cogeneration or combined heat and power ( CHP) is the use of a heat engine Cogeneration and Cogeneration Schematic, www.clarke-energy.com, retrieved 26.11.11 or power station to simultaneously generate electricity and useful heat. Trigeneration or combined cooling, heat and power ( CCHP) refers to the simultaneous generation of electricity and useful heating and cooling from the combustion of a fuel or a solar heat collector. A plant producing electricity, heat and cold is called a trigeneration or poly..
Witchcraft (also called witchery or spellcraft) broadly means the practice of, and belief in, magical skills and abilities that are able to be exercised individually, by designated , or by persons with the necessary esoteric secret knowledge. Witchcraft is a complex concept that varies culturally and societally, therefore it is difficult to define with precision definition&ots=aw4oz13kOS&sig=2CWBjLB2TIsUt1aNz_nyUPxOf5E&redir_esc=y#v=onepage&q=witchcraft definition&f=false Witchcraft in the Middle Ages, ..
