HALF-LIVES OF Rb94, Sr94, Y94, Rb93, Sr95, Y95

1961 ◽  
Vol 39 (3) ◽  
pp. 675-680 ◽  
Author(s):  
K. Fritze ◽  
T. J. Kennett ◽  
W. V. Prestwich
Keyword(s):  
Fission Product ◽  
Half Life ◽  
Strontium Isotopes ◽  
Upper Limit ◽  
Direct Measurements

The existence of a new rubidium isotope, Rb94, has been established and its half-life measured. The half-life of this fission product was determined using the technique of timed precipitations. The value obtained for Rb94 was 2.9 ± 0.3 seconds. With this same technique only an upper limit of 2.5 seconds could be assigned to Rb95. The half-lives of the strontium and yttrium daughters were also determined. The strontium isotopes were studied both by timed precipitations and direct measurements. The half-lives of Sr94 and Sr95 were found to be 1.36 ± 0.06 minutes and 0.8 ± 0.15 minute, respectively. Direct measurements lead to half-lives of 20.35 ± 0.20 minutes for Y94 and 10.9 ± 0.2 minutes for Y95.

THE IDENTIFICATION AND HALF LIVES OF FISSION-PRODUCT Rb92 AND Rb93

1960 ◽  
Vol 38 (12) ◽  
pp. 1614-1622 ◽  
Author(s):  
K. Fritze ◽  
T. J. Kennett
Keyword(s):  
Fission Product ◽  
Decay Rate ◽  
Half Life ◽  
Fission Products ◽  
Strontium Isotopes ◽  
A Value ◽  
Γ Ray ◽  
Rubidium Isotopes

The existence of two new rubidium isotopes, Rb92 and Rb93, has been established and their half lives measured. The half lives of these short-lived fission products were determined using a technique of timed precipitations. The values obtained for Rb92 and Rb93 were 5.3 ± 0.5 sec and 5.6 ± 0.5 sec respectively. The half lives of the strontium and yttrium daughters were also determined. The strontium isotopes were studied by observing the decay rate of a characteristic γ-ray peak. For Sr92, the decay of the 1.37-Mev line gave a value of 2.71 ± 0.02 hr. A γ-ray peak at 590 kev, which was found to be associated with Sr93, decayed with a half life of 7.54 ± 0.06 min. The half lives of the yttrium daughters were determined by β counting. The values found for Y92 and Y93 were 3.53 ± 0.02 hr and 10.1 ± 0.1 hr respectively.

scholarly journals Facile incorporation of technetium into magnetite, magnesioferrite, and hematite by formation of ferrous nitrate in situ: precursors to iron oxide nuclear waste forms

2018 ◽  
Vol 47 (30) ◽  
pp. 10229-10239 ◽  
Author(s):  
Wayne W. Lukens ◽  
Sarah A. Saslow
Keyword(s):  
Iron Oxide ◽  
Fission Product ◽  
Nuclear Waste ◽  
Half Life ◽  
Fission Yield ◽  
Waste Forms ◽  
Nuclear Waste Forms

The fission product, 99Tc, presents significant challenges to the long-term disposal of nuclear waste due to its long half-life, high fission yield, and to the environmental mobility of pertechnetate (TcO4−), the stable Tc species in aerobic environments.

scholarly journals Searching for Neutrinoless Double-Beta Decay of130Te with CUORE

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
D. R. Artusa ◽  
F. T. Avignone ◽  
O. Azzolini ◽  
M. Balata ◽  
T. I. Banks ◽  
...  
Keyword(s):  
Beta Decay ◽  
Energy Resolution ◽  
Confidence Level ◽  
Half Life ◽  
Average Energy ◽  
Neutrinoless Double Beta Decay ◽  
Lepton Number ◽  
Double Beta Decay ◽  
Current Status ◽  
Upper Limit

Neutrinoless double-beta (0νββ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0νββdecay of130Te using an array of 988 TeO2crystal bolometers operated at 10 mK. The detector will contain 206 kg of130Te and have an average energy resolution of 5 keV; the projected 0νββdecay half-life sensitivity after five years of livetime is 1.6 × 1026 y at 1σ(9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.

Thermochemical Comparison of the Systems Re-O and Tc-O

1988 ◽  
Vol 127 ◽  
Author(s):  
H. Migge
Keyword(s):  
Fission Product ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Nuclear Waste ◽  
Half Life ◽  
Thermodynamic Data ◽  
Thermochemical Treatment ◽  
Oxide Phase

Technetium is a hazardous fission product with a long half-life. In vitrification of nuclear waste, technetium tends to be lost substantially by evaporation [1], and the formation of gaseous Tc oxides is assumed to be the reason. Reliable thermochemical treatment of the problem is difficult, since data on the Tc-O system are surprisingly scarce [2]. Therefore, the system Re-O is treated for comparison. Key thermodynamic data for the condensed rhenium oxides exist [3,4,5] as well as measurements on the sublimation and the evaporation of the oxides [6–11]. Consistency of the different data is investigated by assessing the sublimation data of solid Re2O7, using them to calculate other sublimation equilibria and to compare the results with published measurements. Then a predominance area diagram is constructed and discussed with respect to the pressures of the gaseous oxides and their dependence on the temperature, oxygen partial pressure, and condensed oxide phase present. Predominance area diagrams of the Tc-O system are calculated and critically discussed. Owing to the small amout of available data, the possible existence of solid TcO3 is discussed. Comparison with the system Re-O is used to clarify, where further investigations need to be done.

Measurements of Entrainment by Acoustically Pulsed Axisymmetric Air Jets

1986 ◽  
Vol 108 (3) ◽  
pp. 479-484 ◽  
Author(s):  
P. J. Vermeulen ◽  
V. Ramesh ◽  
Wai Keung Yu
Keyword(s):  
Strouhal Number ◽  
Exit Plane ◽  
Downstream Distance ◽  
Air Jets ◽  
Upper Limit ◽  
Direct Measurements

Direct measurements of entrainment by acoustically pulsed axisymmetric air jets flowing into surrounding air have been made for a range of orifice sizes, Strouhal numbers, and excitation powers. The entrainment was considerably increased, by up to 5.8 times at distances greater than 15 diameters axially downstream of the orifice exit plane. The entrainment of the excited jet varied linearly with downstream distance. The jet response varied nonlinearly with excitation strength, indicating that there may be a practical upper limit to the acoustic augmentation of entrainment. The response depends on Strouhal number and appears to be optimum at about 0.25.

THE DECAY OF Au193 AND LEVEL SCHEME OF Pt193

1957 ◽  
Vol 35 (5) ◽  
pp. 672-692 ◽  
Author(s):  
G. T. Ewan
Keyword(s):  
Excited State ◽  
Electron Capture ◽  
Level Scheme ◽  
Half Life ◽  
Internal Conversion ◽  
Upper Limit ◽  
First Excited State ◽  
Γ Rays ◽  
Γ Ray ◽  
Conversion Spectrum

Au193 has been produced as the daughter of Hg193 formed by the reaction Au197(p, 5n)Hg193 in the McGill synchrocyclotron. The internal conversion spectrum and unconverted γ-ray spectrum have been examined using β-ray spectrometers, Nal spectrometers, and coincidence techniques. Au193 decays by electron capture to Pt193 with a half-life of 17.5 ± 0.2 hr. An upper limit of 0.08% per disintegration has been placed on the probability of emission of positrons in this decay. Twenty-eight γ-rays, all below 500 kev., have been observed associated with the decay of Au193. The first excited state of Pt193 has been shown to be at 12.7 kev. and the lifetime of this state measured as (2.2 ± 0.8) × 10−9sec. A level scheme is proposed for Pt193.

THE MASS SPECTROMETER DETERMINATION OF THE HALF-LIFE OF Kr85

1953 ◽  
Vol 31 (4) ◽  
pp. 517-519 ◽  
Author(s):  
R. K. Wanless ◽  
H. G. Thode
Keyword(s):  
Fission Product ◽  
High Precision ◽  
Mass Spectrometer ◽  
Half Life

The half-life of Kr85 has been redetermined using the high precision mass spectrometer method. Several samples of krypton gas extracted from fission product material have been investigated over a period of seven years. The half-life of Kr85 has been found to be 10.27 ± 0.18 years.

scholarly journals A large accumulation of non-muscle myosin occurs at first entry into M phase in rat vascular smooth-muscle cells

1991 ◽  
Vol 277 (1) ◽  
pp. 145-151 ◽  
Author(s):  
D J Grainger ◽  
T R Hesketh ◽  
J C Metcalfe ◽  
P L Weissberg
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Half Life ◽  
Muscle Cells ◽  
S Phase ◽  
Direct Measurements ◽  
M Phase ◽  
Muscle Myosin

Vascular smooth-muscle cells (VSMCs) from rat aortae contained very little non-muscle myosin heavy chain (MHC) immediately after dispersal, and the protein did not accumulate if the cells were held in G0/G1 phase by withholding serum or were held in first S phase by the addition of bromodeoxyuridine (BrdU). However, non-muscle MHC accumulated by greater than 20-fold per cell during first M phase, when over 80% of the cells divided between 48 h and 72 h after addition of serum. Delaying the addition of serum caused a delay in the accumulation of the non-muscle MHC until the cells subsequently entered M phase. If the cells were held in M phase at the metaphase/anaphase boundary by nocadazole, the accumulation of non-muscle myosin still occurred, although division was blocked. When the cells were pulse-labelled with [35S]methionine, it was found that non-muscle MHC was one of the major proteins being made and that its synthesis occurred at similar rates throughout the cell cycle. This implied that the rate of degradation of the protein before first M phase was much faster than in M phase, when the protein accumulated rapidly. This was confirmed by direct measurements of the rate at which [35S]methionine-labelled non-muscle MHC disappeared from the cells, which gave a half-life for the protein of about 8 h before M phase but about 5 days in post-mitotic cells, i.e. an increase of approx. 15-fold. These data are consistent with the hypothesis that there is a mechanism in VSMCs which shortens the half-life of the protein before first M phase and that the accumulation of non-muscle MHC which results from the increase in half-life at first M phase may be necessary for division of these cells.

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