Absolute Disintegration Rate of Finite Gold Sample: Determination by Coincidence Techniques

1968 ◽  
Vol 22 (6) ◽  
pp. 722-725
Author(s):  
John A. Dooley
Keyword(s):  
Gold Foil ◽  
Disintegration Rate ◽  
Gold Sample ◽  
Nuclear Parameter ◽  
Pulse Timing ◽  
The Absolute

A method has been developed for absolute disintegration rate determination of finite-sized, radioactive samples. Measurements were made on a 15-mg gold foil. The average disintegration rate was 2.163X105 for 24 determinations with a precision of 2.3%. Subsequent measurements yielded precisions as low as 0.5%. Conditions of bias settings, decay corrections, and coincidence resolving times were widely varied. The scintillation, coincidence equipment, including novel pulse timing, are mentioned. Data corrections, including accidentals and particle A in detector B are discussed. It is shown that the corrections are empirical and do not limit the absolute nature of the measurements. Some of the nuclear parameter requirements and spectroscopic implications are indicated.

DETERMINATION OF THE ABSOLUTE FISSION YIELD OF Ba140 IN THERMAL NEUTRON FISSION OF U235

1954 ◽  
Vol 32 (11) ◽  
pp. 1017-1024 ◽  
Author(s):  
L. Yaffe ◽  
H. G. Thode ◽  
W. F. Merritt ◽  
R. C. Hawkings ◽  
F. Brown ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Neutron Monitor ◽  
Half Life ◽  
Fission Yield ◽  
Disintegration Rate ◽  
Neutron Fission ◽  
Before And After ◽  
Thermal Neutron Fission ◽  
The Absolute

The absolute fission yield of Ba140 in the thermal neutron fission of U235 has been determined to be (6.32 ± 0.24)%. The reaction B10(n, α)Li7 was used as a neutron monitor and the B10/B11 ratio determined mass spectrometrically before and after neutron bombardment. The Ba140 disintegration rate was determined using 4π counting techniques. The half-life of La140 has been found to be 40.31 ± 0.06 hr.

Polarity Determination in Sphalerite and Wurtzite Structures

1990 ◽  
Vol 48 (2) ◽  
pp. 500-501
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Opposite Polarity ◽  
Single Domain ◽  
Polar Material ◽  
Electron Microscopic ◽  
Dynamical Interaction ◽  
X Ray ◽  
Polarity Determination ◽  
The Absolute ◽  
Microscopic Techniques

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.

A DORIS determination of the absolute velocities of the Sorsdal and Mellor glaciers in Antarctica

2010 ◽  
Vol 45 (12) ◽  
pp. 1523-1534 ◽  
Author(s):  
R. Govind ◽  
J.J. Valette ◽  
F.G. Lemoine
Keyword(s):  
The Absolute

scholarly journals Rapid Organocatalytic Chirality Analysis of Amines, Amino Acids, Alcohols, Amino Alcohols and Diols with Achiral Iso(thio)cyanate Probes

2021 ◽  
Author(s):  
Eryn Nelson ◽  
Jeffrey S. S. K. Formen ◽  
Christian Wolf
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Rapid Determination ◽  
Amino Alcohols ◽  
Enantioselective Synthesis ◽  
Widespread Occurrence ◽  
Chiral Compounds ◽  
New Methods ◽  
The Absolute

The widespread occurrence and significance of chiral compounds does not only require new methods for their enantioselective synthesis but also efficient tools that allow rapid determination of the absolute configuration,...

scholarly journals Preparative-scale HPLC Resolution of Metallacyclic η3-Allyltricarbonyliron Complexes and Determination of the Absolute Configuration by X-Ray Crystal Structure Analysis

1999 ◽  
Vol 23 (9) ◽  
pp. 578-579
Author(s):  
Rainer Schobert ◽  
Hermann Pfab ◽  
Jutta Böhmer ◽  
Frank Hampel ◽  
Andreas Werner
Keyword(s):  
Crystal Structure ◽  
Silica Gel ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
Preparative Scale ◽  
X Ray ◽  
The Absolute

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.

scholarly journals Migration of mineral oil in elastomers

2021 ◽  
Author(s):  
Tobias Förster ◽  
Artur Blivernitz
Keyword(s):  
Diffusion Coefficients ◽  
Mineral Oil ◽  
Activation Energies ◽  
Concentration Profiles ◽  
Small Reservoir ◽  
Experimental Procedure ◽  
Mineral Oils ◽  
The Absolute ◽  
Suitable Measure

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.

Asymmetric Total Synthesis and Determination of the Absolute Configuration of (+)-Srilankenyne via Sequence-Sensitive Halogenations Guided by Conformational Analysis

2021 ◽  
Vol 23 (4) ◽  
pp. 1321-1326
Author(s):  
Hongjun Jang ◽  
Soo Yeon Kwak ◽  
Dongjoo Lee ◽  
Juan V. Alegre-Requena ◽  
Hyoungsu Kim ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Conformational Analysis ◽  
Absolute Configuration ◽  
Asymmetric Total Synthesis ◽  
The Absolute
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