drilling efficiency
81Coal — Sedimentary Rock Anthracite coal Composition Primary carbon Secondary hydrogen, sulfur …
82Light pollution — This article is about light pollution in the visible spectrum. For information on pollution in the radio spectrum, see radio spectrum pollution. This time exposure photo of New York City at night shows skyglow, one form of light pollution …
83Renewable energy — Burbo Bank Offshore Wind Farm, at the entrance to the River Mersey in North West England …
84Code for Sustainable Homes — The Code for Sustainable Homes is an environmental impact rating system for housing in England and Wales, setting new standards for energy efficiency (above those in current building regulations)[1] and sustainability which are not mandatory… …
85United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …
86Convent Schools (Great Britain) — • Convent education is treated here not historically but as it is at the present day (Article written in 1908.) Catholic Encyclopedia. Kevin Knight. 2006. Convent Schools (Great Britain) Convent Schools (Great Br …
87ECONOMIC AFFAIRS — THE PRE MANDATE (LATE OTTOMAN) PERIOD Geography and Borders In September 1923 a new political entity was formally recognized by the international community. Palestine, or Ereẓ Israel as Jews have continued to refer to it for 2,000 years,… …
88Cyprus — This article is about the island sovereign state. For other uses, see Cyprus (disambiguation). Republic of Cyprus Κυπριακή Δημοκρατία (Greek) Kypriakí Dimokratía Kıbrıs Cumhuriyeti (Turkish) …
89List of Chinese inventions — A bronze Chinese crossbow mechanism with a buttplate (the wooden components have …
90Comparison of United States presidential candidates, 2008 — This article compares the presidential candidates in the United States 2008 presidential election. It does not cover previous elections. Because of ballot access restrictions in the United States, not all candidates appeared on the ballots in all …
