Christmas tree (oil well) — Oil well Christmas tree In petroleum and natural gas extraction, a Christmas tree, or tree , (not wellhead as sometimes incorrectly referred to) is an assembly of valves, spools, and fittings used for an oil well, gas well, water injection well,… … Wikipedia
Well temperament — (also circular or circulating temperament) is a type of tempered tuning described in 20th century music theory. The term is modelled on the German word wohltemperiert which appears in the title of J.S. Bach s famous composition, The Well Tempered … Wikipedia
Non-conventional oil — is oil produced or extracted using techniques other than the traditional oil well method. Currently, non conventional oil production is less efficient and some types have a larger environmental impact relative to conventional oil production. Non… … Wikipedia
Non-tariff barriers to trade — (NTBs) are trade barriers that restrict imports but are not in the usual form of a tariff. Some common examples of NTB s are anti dumping measures and countervailing duties, which, although they are called non tariff barriers, have the effect of… … Wikipedia
Non-fiction — (or nonfiction) is the form of any narrative, account, or other communicative work whose assertions and descriptions are understood to be fact. This presentation may be accurate or not that is, it can give either a true or a false account of the… … Wikipedia
Non-small-cell lung carcinoma — Classification and external resources Micrograph of a squamous carcinoma, a type of non small cell lung carcinoma. FNA specimen. Pap stain. MedlinePlus … Wikipedia
Non-volcanic passive margins — (NVPM) constitute one end member of the transitional crustal types that lie beneath passive continental margins; the other end member being volcanic passive margins (VPM). Transitional crust welds continental crust to oceanic crust along the… … Wikipedia
Non-lethal weapon — Pepper spray demonstration Non lethal weapons, also called less lethal weapons, less than lethal weapons, non deadly weapons, compliance weapons, or pain inducing weapons are weapons intended to be less likely to kill a living target than are… … Wikipedia
Non-coding RNA — A non coding RNA (ncRNA) is a functional RNA molecule that is not translated into a protein. Less frequently used synonyms are non protein coding RNA (npcRNA), non messenger RNA (nmRNA) and functional RNA (fRNA). The term small RNA (sRNA) is… … Wikipedia
Non-standard cosmology — Physical cosmology Universe · Big Bang … Wikipedia
Well-ordering principle — In mathematics, the well ordering principle states that every non empty set of positive integers contains a smallest element. [cite book |title=Introduction to Analytic Number Theory |last=Apostol |first=Tom |authorlink=Tom M. Apostol |year=1976… … Wikipedia