It was renamed Functional Discourse Grammar in the 1990s, but the theory can go by either name. This theory is called functional because it states that all constituents, whether affixes, words, phrases, or sentences, have semantic, syntactic, and pragmatic functions.he most famous of these is Systemic Functional Grammar, which was first published by British linguist Michael Halliday in 1961. Other functional grammars include Danish Functional Linguistics, lexical functional grammar, and Role and Reference Grammar.
The head of a Hemispherical combustion chamber. A hemispherical combustion chamber is a type of combustion chamber in a reciprocating internal combustion engine with a domed cylinder head. The hemispherical shape provides a number of advantages over a reverse-flow cylinder head but comes up short in others, particularly in carbureted engines.
How combustion chamber design relates to engine performance. Most aspects of a cylinder head are relatively straightforward and easily grasped. Valve size, deck thickness and combustion chamber volume are often topics of discussion and qualify the designâs ability to be a player. But there is much more to be considered. The characteristics of the combustion chamber will dictate the engineâs power, octane tolerance and brake specific fuel consumption (BSFC). So if you thought the shape of the combustion chamber had little to do with a cylinder headâs performance, you will be surprised. Authorâs note: Due to the nature of this story, references to cylinder heads from manufacturers other than Pontiac are used to demonstrate different combustion chamber technologies.