Parametric variation in linguistic theory refers to the systematic grammatical variation permitted by the human language faculty. Although still widely assumed, the parametric theory of variation has in recent years been subject to re-evaluation and critique. The Null Subject Parameter, which determines among other things whether or not a language allows the suppression of subject pronouns, is one of the best-known and most widely discussed examples of a parameter. Nevertheless its status ...

Rock Blasting and Explosives Engineering covers the practical engineering aspects of many different kinds of rock blasting. It includes a thorough analysis of the cost of the entire process of tunneling by drilling and blasting in comparison with full-face boring. Also covered are the fundamental sciences of rock mass and material strength, the thermal decomposition, burning, shock initiation, and detonation behavior of commercial and military explosives, and systems for charging explosive...