gravity heating
61heavy oil and tar sand — Introduction crude oils (crude oil) below 20° API gravity are usually considered to be heavy. The lighter conventional crudes are often waterflooded to enhance recovery. The injection of water into the reservoir helps to maintain reservoir… …
62ionosphere and magnetosphere — ▪ atmospheric science Introduction regions of Earth s (Earth) atmosphere in which the number of electrically charged particles ions (ion) and electrons (electron) are large enough to affect the propagation of radio waves (electromagnetic… …
63technology, history of — Introduction the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek technē, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both… …
64Technological and industrial history of Canada — The technological and industrial history of Canada encompasses the country s development in the areas of transportation, communication, energy, materials, public works, public services (health care), domestic/consumer and defense technologies.… …
65Spacecraft propulsion — A remote camera captures a close up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Spacecraft propulsion is any method used to accelerate spacecraft and artificial… …
66Oil sands — The Athabasca oil sands in Alberta, Canada, are a very large source of bitumen, which can be upgraded to synthetic crude oil. Bituminous sands, colloquially known as oil sands or tar sands, are a type of unconventional petroleum deposit. The… …
67Friction — For other uses, see Friction (disambiguation). Classical mechanics …
68Plate tectonics — The tectonic plates of the world were mapped in the second half of the 20th century …
69Convective available potential energy — A skew T plot showing a morning sounding with a large hydrolapse followed by an afternoon sounding showing the cooling which occurred in the mid levels resulting in an unstable atmosphere as surface parcels have now become negatively buoyant. The …
70Timeline of Islamic science and engineering — This timeline of Islamic science and engineering covers the general development of science and technology in the Islamic world during the Islamic Golden Age, usually dated from the 7th to 16th centuries.From the 17th century onwards, the advances …
