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What kind of conatiner keeps liquid hotter longer?
The standard of the industry is called a Dewar flask, named after the Scottish physicist and chemist who invented it. A Dewar flask consists of two flasks, one inside the other, separated by a vacuum. The vacuum reduces the transfer of heat from the outside.
It can be used for keeping things either hot or cold. A commercial version of it is made the the Thermos company.
Usually the surfaces of the glass facing the vacuum are coated with a thin layer of highly reflective metal, to reduce the rate of transmission of heat by infrared thermal radiation.
(published on 04/29/08)
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