Results 141 to 150 of about 7,713 (173)

Gamma decay of 40K levels

Nuclear Physics A, 1971
Abstract Electromagnetic transition rates between states in 40 K up to 2.6 MeV excitation were investigated. The reaction 37 Cl(α, nγ) 40 K was used for lifetime measurements with the DSAM, and the reaction 40 Ar(p, nγ) 40 K for the derivation of spins and mixing ratios from angular distributions.
R. Wechsung, W. Strassheim, R. Bass
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In situ 40K–40Ca ‘double-plus’ SIMS dating resolves Klokken feldspar 40K–40Ar paradox

Earth and Planetary Science Letters, 2010
Abstract The 40K–40Ca decay system has not been widely utilized as a geochronometer because quantification of radiogenic daughter is difficult except in old, extremely high K/Ca domains. Even these environments have not heretofore been exploited by ion microprobe analysis due to the very high mass resolving power (MRP) of 25,000 required to separate ...
T. Mark Harrison, Matthew T. Heizler, Kevin D. McKeegan, Axel K. Schmitt   +3 more
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Half-life determination of 40K by LSC

Applied Radiation and Isotopes, 2002
The long-lived radioisotope 40K is one of the isotopes applied by geologists to date rocks hundreds or even thousands of millions of years old. Knowing the half-life of 40K, the potassium-argon (K-Ar) method gives an estimate of the date of the rock's formation by measuring the quantity of the daughter stable isotope 40Ar.
Malonda A, Grau, Carles A, Grau
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LSC measurements of the half-life of 40K

Applied Radiation and Isotopes, 2004
Liquid scintillation counting techniques combined with the CIEMAT/NIST method have been applied to measure the specific activity of natural potassium salts. Samples have been prepared with three different scintillators. The individual atomic composition as well as the density of the cocktails have been taken into account for the efficiency calculation.
K, Kossert, E, Günther
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The electron capture decay of 40K

Nuclear Physics A, 1967
Abstract The Auger and K X-ray electron capture peak of 40 K has been observed, free from source absorption and background effects, using internal source, scintillation counter methods. The (L+M+N)/K electron capture ratio has been determined to be 0.34±0.08.
M.F. McCann, G.M. Lewis, K.M. Smith
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The 39K(n, γ)40K reaction

Nuclear Physics, 1966
Abstract The gamma radiation from the 39K(n, γ)40K reaction has been studied using a Ge(Li) spectrometer. A total of 65 transitions was observed with an average precision of 3 keV. The neutron separation energy was found to be 7797±3 keV. A detailed comparison with (d, p) results reveals that the M1 and E1 strengths are almost equal as are the ...
T.J. Kennett, L.B. Hughes, W.V. Prestwich   +2 more
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40K emission in energy production from straw

Journal of Radioanalytical and Nuclear Chemistry Articles, 1990
Straw has the highest concent/ation of the natural radioisotope 40K in comparison with other biofuels such as peat, wood, wood chips, and energy forest. Concentrations of 40K have been measured in the ash remaining after wheat straw was burnt in a water heating plant. Samples were also taken of the wheat ears, straw, and surrounding earth.
Robert Hedvall, Bengt Erlandsson
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The 40K/40Ar and 40Ar/39Ar Methods

2020
The 40K/40Ar method and its variant, 40Ar/39Ar, are based on the natural radioactive decay of 40K, one of the isotopes of potassium, in 40Ar, one of the isotopes of argon. 40K decreases in 40Ar* (the * symbol indicates that this is a radiogenic isotope) with a period of 1.25 × 109 years, according to the law of radioactive decay N = N0 e−λt.
Guillou, Hervé, Nomade, Sébastien, Scao, Vincent   +2 more
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Superconductivity at 40K in Cesium Doped C₆₀

MRS Proceedings, 1994
ABSTRACTWe report superconductivity in Cs3 C60 at 40K using ac susceptibility measurements under hydrostatic conditions up to 15 kbar. Cs3 C60 was prepared by reaction of C60 with Cs in liquid ammonia, followed by heating at 150°C. This route circumvents formation of the energetically more stable CSl C60 and Cs4 C60 phases.
T.T.M. Palstra, O. Zhou, Y. Iwasa, P.E. Sulewski, R.M. Fleming, B.R. Zegarski   +5 more
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PEGylated Interferon-α2b: A Branched 40K Polyethylene Glycol Derivative

Pharmaceutical Research, 2005
The conjugation of interferon-alpha2b (IFN-alpha2b) to a branched-chain (40,000) polyethylene glycol (PEG2,40K) was studied.We studied the conjugation of IFN-alpha2b at different pH values (6.5, 7, and 8), using the PEG2,40K reagent in either solution or solid state. MonoPEGylated interferon was isolated by ion-exchange chromatography and characterized
Jose, Ramon, Vivian, Saez, Reynier, Baez, Raymersy, Aldana, Eugenio, Hardy   +4 more
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