Welcome to Citizendium

Natural Sciences           Social Sciences           Humanities     Arts           Applied Arts and Sciences           Recreation

Welcome! We are an encyclopedia project — and more! We are a different sort of Web 2.0 wiki: We aim at credibility and quality, not just quantity. Both the general public and credentialed experts are encouraged to get involved. We use our real names, not pseudonyms. We're both collegial and congenial. We have added [[:Category:CZ Live|over Template:Articles number articles]] (and many subpages), and over six million words. New announcement: the Citizendium Makes it Easier for Authors to Submit Articles. How? Simply join us and then send your articles in word processor format to cz-wikiformat@mail.citizendium.org!. For more details: CLICK HERE. Sidebar expanded! There are many more links on the left, including links that you used to be able to find here. Comments? Contribute to Citizendium! New authors and editors welcome! Accounts usually approved within a few hours. Why Citizendium?‎ Start here. Learn about us For readers: About the Citizendium For authors: The Author Role For editors: The Editor Role For the press: Press The Monthly CZ News Report, The Citizen (No. 3!) Initiatives Core Articles - tackle high priority topics Eduzendium - students write CZ articles for credit Recruitment - help invite others to join Subpages - add other types of info to CZ Support us We're a 501(c)(3) non-profit, and we need your support. If you shop at Amazon.com or Barnes & Noble, do so through our links! We'll get donations at no cost to you. (read more) - Search All Products. Link to us. Help increase our page rank by linking to us.

Some of our finest [ about ] Approved Articles Developed Articles (over 700) Article of the Week [ about ] (PD) Photo: U.S. Environmental Protection Agency Tosco refinery in Northern California. Petroleum refining processes are those chemical engineering processes and other facilities used in petroleum refineries (also referred to as oil refineries) to transform crude oil into useful products such as liquefied petroleum gas (LPG), gasoline or petrol, kerosene, jet fuel, diesel oil and fuel oils. Petroleum refineries are very large industrial complexes that involve a great many different processing units and auxiliary facilities such as utility units and storage tanks. Each refinery has its own unique arrangement and combination of refining processes largely determined by the refinery location, desired products and economic considerations. There are most probably no two refineries that are identical in every respect. [more...] New Draft of the Week [ about ] © Photo: ledzeppelin.com (l. to r.) Jimmy Page, John Bonham, Robert Plant, and John Paul Jones, c 1975. Led Zeppelin were a highly rated British blues-rock outfit and statistically regarded as one of the most successful rock bands of the seventies. They first formed in 1968 from the remaining members of The Yardbirds, and consisted of Jimmy Page (b. 1946, guitar), Robert Plant (b. 1948, vocals), John Paul Jones (b. 1946, bass guitar / keyboards), and John Bonham (1948-1980, drums). They are considered one of the most influential bands in the world, becoming closely associated with the "album-oriented rock" (AOR) format and progenitors of a style of rock music called "heavy metal", although the band's musical output transcended heaviness with a strong blues, folk, psychedelia, classical, Celtic, and world music flavour in their recordings, and acoustic live performances. The band also eschewed traditional promotional avenues in the industry, focussing on albums and concerts, without reliance on singles or television performances. The interaction of all four musicians on stage gave their live performances a visual counterpoint to voluminous intertwined harmonic and rhythmic structures of their compositions. [more...]