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Californium was first made at University of California Radiation Laboratory, Berkeley, by physics researchers Stanley Gerald Thompson, Kenneth Street Jr., Albert Ghiorso, and Glenn T. Seaborg, about February 9, 1950. [28] It was the sixth transuranium element to be discovered; the team announced its discovery on March 17, 1950. [29] [30]
Smoke detectors are usually powered by battery while some are connected directly to power mains, often having a battery as a power supply backup in case the mains power fails. The first automatic electric fire alarm was co-invented in 1890 by Francis Robbins Upton and Fernando J. Dibble. Upton and Dibble were issued U.S. patent #436,961.
A fire alarm system is a building system designed to detect, alert occupants, and alert emergency forces of the presence of fire, smoke, ...
Smoke detector mounted on a ceiling. A smoke detector is a device that senses smoke, typically as an indicator of fire.Smoke detectors/alarms are usually housed in plastic enclosures, typically shaped like a disk about 125 millimetres (5 in) in diameter and 25 millimetres (1 in) thick, but shape and size vary.
Two early fire siren manufacturers were William A. Box Iron Works, who made the "Denver" sirens as early as 1905, and the Inter-State Machine Company (later the Sterling Siren Fire Alarm Company) who made the ubiquitous Model "M" electric siren, which was the first dual tone siren.
The first elemental metal with a clearly identifiable discoverer is cobalt, discovered in 1735 by Georg Brandt, by which time the Scientific Revolution was in full swing. [6] (Even then, cobalt might have been prepared before the 13th century by alchemists roasting and reducing its ore, but,in any case, its distinct nature was not recognised.) [7]
More than 800 people have lost their lives in jail since July 13, 2015 but few details are publicly released. Huffington Post is compiling a database of every person who died until July 13, 2016 to shed light on how they passed.
A fire alarm box, fire alarm call box, or fire alarm pull box is a device used for notifying a fire department of a fire or a fire alarm activation. Typically installed on street corners or on the outside of commercial buildings in urban areas, they were the main means of summoning firefighters before the general availability of telephones.