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.

Mass Spectrometer Determination of the Half-Life ofXe133

1949 ◽  
Vol 75 (3) ◽  
pp. 532-533 ◽  
Author(s):  
J. Macnamara ◽  
C. B. Collins ◽  
H. G. Thode
Keyword(s):  
Mass Spectrometer ◽  
Half Life

Determination of the half-life of213Fr with high precision

2013 ◽  
Vol 88 (1) ◽  
Author(s):  
M. Fisichella ◽  
A. Musumarra ◽  
F. Farinon ◽  
C. Nociforo ◽  
A. Del Zoppo ◽  
...  
Keyword(s):  
High Precision ◽  
Half Life

Membrane Inlet Mass Spectrometer for Rapid High-Precision Determination of N2, O2, and Ar in Environmental Water Samples

1994 ◽  
Vol 66 (23) ◽  
pp. 4166-4170 ◽  
Author(s):  
Todd M. Kana ◽  
Christina. Darkangelo ◽  
M. Duane. Hunt ◽  
James B. Oldham ◽  
George E. Bennett ◽  
...  
Keyword(s):  
High Precision ◽  
Mass Spectrometer ◽  
Water Samples ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Precision Determination ◽  
High Precision Determination

THE CUMULATIVE FISSION YIELDS OF LIGHT MASS FRAGMENTS IN THE THERMAL NEUTRON FISSION OF Pu239

1959 ◽  
Vol 37 (8) ◽  
pp. 916-925 ◽  
Author(s):  
H. R. Fickel ◽  
R. H. Tomlinson
Keyword(s):  
Fission Product ◽  
Thermal Neutron ◽  
Mass Spectrometer ◽  
Isotope Dilution ◽  
Light Fragment ◽  
Neutron Fission ◽  
Fragment Mass ◽  
Thermal Neutron Fission ◽  
Fission Yields

The relative cumulative yields of 19 light mass fragments of rubidium, strontium, yttrium, zirconium, molybdenum, and ruthenium formed in the thermal neutron fission of Pu239 have been determined with a mass spectrometer using the isotope dilution technique.The yields of the fission product isotopes of these elements, together with the previously published relative yields of three krypton isotopes, have made possible the determination of the absolute yields of 22 light fragment mass chains.

Half-Life Determination of Carbon (14) with a Mass Spectrometer and Low Absorption Counter

1946 ◽  
Vol 70 (9-10) ◽  
pp. 772-773 ◽  
Author(s):  
L. D. Norris ◽  
M. G. Inghram
Keyword(s):  
Mass Spectrometer ◽  
Half Life ◽  
Carbon 14

A MASS SPECTROMETER INVESTIGATION OF THE ISOTOPES OF XENON AND KRYPTON RESULTING FROM THE FISSION OF U235 BY THERMAL NEUTRONS

1947 ◽  
Vol 25a (1) ◽  
pp. 1-14 ◽  
Author(s):  
H. G. Thode ◽  
R. L. Graham
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Fission Product ◽  
Mass Spectrometer ◽  
Half Life ◽  
Fission Products ◽  
Rare Gas ◽  
Thermal Neutrons ◽  
Yield Values ◽  
Fission Yields

Mass spectrometer investigations have been made of rare gas fission products extracted from uranium irradiated with thermal neutrons. The irradiated uranium rods were allowed to stand for various periods of time after irradiation to permit the decay of most fission product chains to stable isotopes. Four stable isotopes of xenon were found having mass numbers 131, 132, 134, and 136, and three stable isotopes of krypton with mass numbers 83, 84, and 86. Kr86, the most abundant of the latter group, is probably formed directly in fission. In addition a long lived krypton with mass 85 was discovered which is isomeric with a 4.0 hr. Kr85 reported previously.The relative abundances of these isotopes which are related directly to fission yields of the corresponding mass chains have been determined with an accuracy of 1% or better. The mass numbers of these fission chains can now be identified with certainty by comparing mass spectrometer abundance data with known yield values of the active chain members. Finally, the half-life of krypton 85 was determined by comparing its concentration to that of a stable isotope over a period of time.

On effects of non-systematic reflections on weak-beam images of partial dislocations

1991 ◽  
Vol 49 ◽  
pp. 688-689
Author(s):  
K. Z. Botros ◽  
S. S. Sheinin
Keyword(s):  
High Precision ◽  
Stacking Fault ◽  
Important Application ◽  
Stacking Fault Energy ◽  
Sharp Peak ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Deviation Parameter ◽  
Beam Diffraction

The main features of weak beam images of dislocations were first described by Cockayne et al. using calculations of intensity profiles based on the kinematical and two beam dynamical theories. The feature of weak beam images which is of particular interest in this investigation is that intensity profiles exhibit a sharp peak located at a position very close to the position of the dislocation in the crystal. This property of weak beam images of dislocations has an important application in the determination of stacking fault energy of crystals. This can easily be done since the separation of the partial dislocations bounding a stacking fault ribbon can be measured with high precision, assuming of course that the weak beam relationship between the positions of the image and the dislocation is valid. In order to carry out measurements such as these in practice the specimen must be tilted to "good" weak beam diffraction conditions, which implies utilizing high values of the deviation parameter Sg.

Comparative assessment of informational content of the equations of F.P. Hadlock and the computer program of V.N. Demidov in determination of term of gestation and fetal weight in the III trimester of gestation

2017 ◽  
Author(s):  
E.A. Derkach , O.I. Guseva
Keyword(s):  
Computer Program ◽  
High Precision ◽  
Gestational Age ◽  
Computer Programs ◽  
Comparative Assessment ◽  
Fetal Weight ◽  
Informational Content ◽  
Third Trimester ◽  
The Third

Objectives: to compare the accuracy of equations F.P. Hadlock and computer programs by V.N. Demidov in determining gestational age and fetal weight in the third trimester of gestation. Materials: 328 patients in terms 36–42 weeks of gestation are examined. Ultrasonography was performed in 0–5 days prior to childbirth. Results: it is established that the average mistake in determination of term of pregnancy when using the equation of F.P. Hadlock made 12,5 days, the computer program of V.N. Demidov – 4,4 days (distinction 2,8 times). The mistake within 4 days, when using the equation of F.P. Hadlock has met on average in 23,1 % of observations, the computer program of V.N. Demidov — 65,9 % (difference in 2,9 times). The mistake more than 10 days, took place respectively in 51,7 and 8,2 % (distinction by 6,3 times). At a comparative assessment of size of a mistake in determination of fetal mass it is established that when using the equation of F.P. Hadlock it has averaged 281,0 g, at application of the computer program of V.N. Demidov — 182,5 g (distinction of 54 %). The small mistake in the mass of a fetus which isn't exceeding 200 g at application of the equation of F.P. Hadlock has met in 48,1 % of cases and the computer program of V.N. Demidov — 64,0 % (distinction of 33,1 %). The mistake exceeding 500 g has been stated in 18 % (F.P. Hadlock) and 4,3 % (V.N. Demidov) respectively (distinction 4,2 times). Conclusions: the computer program of V.N. Demidov has high precision in determination of term of a gestation and mass of a fetus in the III pregnancy.

A Rapid Method for Determination of Buprenorphine and Norbuprenorphine in Urine by UPLC-MS/MS

2020 ◽  
Vol 16 ◽  
Author(s):  
Aykut Kul ◽  
Murat Ozdemir ◽  
Selma Ozilhan ◽  
Olcay Sagirli
Keyword(s):  
Forensic Science ◽  
Rapid Method ◽  
Proficiency Testing ◽  
Mass Spectrometer ◽  
Illicit Market ◽  
Analysis Methods ◽  
Accuracy And Precision ◽  
Lower Limits

Background: Buprenorphine is quite common in the illicit market. Buprenorphine-containing drugs abuse is frequently encountered in patients. The analysis methods used to determine the abuse of buprenorphine and norbuprenorphine are important for forensic science. Buprenorphine is metabolized to norbuprenorphine by the liver. Objective: Therefore, the determination of buprenorphine and norbuprenorphine in urine is one of the methods to determine the abuse of buprenorphine. Methods: In this study, we have developed a precise, simple, and rapid ultra-performance liquid chromatographytandem mass spectrometer method for the determination of buprenorphine and norbuprenorphine simultaneously. Results: The developed method was validated in terms of selectivity and linearity, which was in the range of 9–1800 ng/mL for both buprenorphine and norbuprenorphine. The intra-assay and inter-assay accuracy and precision were found within acceptable limits of the EMA guideline. Lower limits of quantitation were 9 ng/mL for both buprenorphine and norbuprenorphine. Conclusion: The developed method was successfully applied for the determination of both analytes in the proficiency testing samples.

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