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Particleboard with veneer. Particle board, also known as particleboard or chipboard, is an engineered wood product, belonging to the wood-based panels, manufactured from wood chips and a synthetic, mostly formaldehyde-based resin or other suitable binder, which is pressed under a hot press, batch- or continuous- type, and produced. [1]
The Arithmometer, invented in 1820 as a four-operation mechanical calculator, was released to production in 1851 as an adding machine and became the first commercially successful unit; forty years later, by 1890, about 2,500 arithmometers had been sold [16] plus a few hundreds more from two arithmometer clone makers (Burkhardt, Germany, 1878 ...
Chipboard may refer to: Particle board, a type of engineered wood known as chipboard in some countries; See also. White-lined chipboard, a grade of paperboard;
The length of day and night could be re-programmed every day in order to account for the changing lengths of day and night throughout the year. [11] 1235 Persian astronomer Abi Bakr of Isfahan invented a brass astrolabe with a geared calendar movement based on the design of Abū Rayhān al-Bīrūnī's mechanical calendar analog computer. [12]
The stepped reckoner was based on a gear mechanism that Leibniz invented and that is now called the Leibniz wheel. It is unclear how many different variants of the calculator were made. Some sources, such as the drawing to the right, show a 12-digit version. [5] This section describes the surviving 16-digit prototype in Hanover. Leibniz wheel
The Guinness Book of World Records listed him as "Fastest Human Calculator" [4] in 2001 and 2003, [6] after he broke the record for adding the same number to itself more times in 15 seconds than someone could do with a calculator. [7] In 1999 he invented a 13-month calendar using zero as a day, month, and year, which he called "The Human ...
The true story is that it was invented utterly by accident one fateful day more than 70 years ago, when a Raytheon engineer named Percy Spencer was testing a military-grade magnetron and suddenly ...
The Harvard Mark III, also known as ADEC (for Aiken Dahlgren Electronic Calculator) was an early computer that was partially electronic and partially electromechanical.It was built at Harvard University under the supervision of Howard Aiken for use at Naval Surface Warfare Center Dahlgren Division.