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Potassium-Argon and Argon-40/Argon-39 Dating
1994Potassium is an alkali metal of Group IA in which its companions are lithium, sodium, rubidium and caesium. It is highly reactive with a relative density of 0·86 and a melting point of 62·3° C, an atomic weight of 39·0983 and an atomic number of 19; it has 18 isotopes.
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2018
Argon–argon dating is a radioisotopic method based on the natural, spontaneous radioactive decay of an isotope of potassium, 40K, at a known rate to produce an isotope of argon, 40Ar. This method is one of the most versatile, precise and accurate of all radioisotopic dating tools applied to volcanic materials.
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Argon–argon dating is a radioisotopic method based on the natural, spontaneous radioactive decay of an isotope of potassium, 40K, at a known rate to produce an isotope of argon, 40Ar. This method is one of the most versatile, precise and accurate of all radioisotopic dating tools applied to volcanic materials.
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Physical Review Letters, 1996
The total cross section ${\ensuremath{\sigma}}_{T}$ for orthopositronium (o-Ps) scattering from argon gas has been measured directly for the first time using a variable energy o-Ps beam in the range 16--95 eV. The cross section is found to rise from a value of approximately $9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}$ to $15\ifmmode ...
, Zafar +3 more
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The total cross section ${\ensuremath{\sigma}}_{T}$ for orthopositronium (o-Ps) scattering from argon gas has been measured directly for the first time using a variable energy o-Ps beam in the range 16--95 eV. The cross section is found to rise from a value of approximately $9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}$ to $15\ifmmode ...
, Zafar +3 more
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American Journal of Ophthalmology, 1976
Argon laser photomydriasis was used to enlarge 20 miotic pupils in 18 open-angle glaucoma patients, with beneficial visual results in patients properly selected before treatment. During eight months of observation, significant complications such as persistent iritis and lens changes did not occur.
W A, James +3 more
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Argon laser photomydriasis was used to enlarge 20 miotic pupils in 18 open-angle glaucoma patients, with beneficial visual results in patients properly selected before treatment. During eight months of observation, significant complications such as persistent iritis and lens changes did not occur.
W A, James +3 more
openaire +2 more sources