Relative yield of xenon isotopes in neutron fission of Pu239 and U233

1972 ◽  
Vol 33 (2) ◽  
pp. 826-827 ◽  
Author(s):  
K. A. Petrzhak ◽  
M. G. Pan'yan ◽  
V. F. Teplykh ◽  
M. Ya. Kondrat'ko
Keyword(s):  
Relative Yield ◽  
Neutron Fission ◽  
Xenon Isotopes

SOME CUMULATIVE YIELDS OF ISOTOPES FORMED IN THE THERMAL NEUTRON FISSION OF Pu239

1956 ◽  
Vol 34 (3) ◽  
pp. 227-232 ◽  
Author(s):  
D. M. Wiles ◽  
J. A. Petruska ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Mass Spectrometer ◽  
Isotope Dilution ◽  
Neutron Fission ◽  
Thermal Neutron Fission ◽  
Xenon Isotopes ◽  
The Absolute

The relative yields of the isotopes of cesium, cerium, neodymium, and samarium produced by the thermal neutron fission of Pu239 have been determined with a mass spectrometer. Preliminary values of the absolute yields of 16 isotopes of these elements together with four yields of the xenon isotopes have been assigned by means of isotope dilution techniques.

THE CUMULATIVE YIELDS OF THE KRYPTON AND XENON ISOTOPES PRODUCED IN THE FAST NEUTRON FISSION OF Th232

1957 ◽  
Vol 35 (8) ◽  
pp. 969-979 ◽  
Author(s):  
T. J. Kennett ◽  
H. G. Thode
Keyword(s):  
Fine Structure ◽  
Fast Neutron ◽  
Isotope Dilution ◽  
Yield Curve ◽  
Mass Yield ◽  
Neutron Fission ◽  
Xenon Isotopes ◽  
Induced Fission ◽  
The Absolute ◽  
Fission Yields

The relative fission yields for mass chains ending in stable krypton and xenon isotopes have been measured for the fast neutron-induced fission of Th232. Isotope dilution techniques were used to determine the krypton/xenon ratio to assist in obtaining the absolute fission yields for these mass chains. The absolute yields were determined by the use of two methods, both giving results which were in excellent agreement. The fine structure observed for the Th232 mass–yield curve is compared with that of heavier fissile nuclides.

FISSION YIELDS OF THE STABLE AND LONG-LIVED ISOTOPES OF CESIUM, RUBIDIUM, AND STRONTIUM AND NUCLEAR SHELL STRUCTURE

1953 ◽  
Vol 31 (3) ◽  
pp. 419-431 ◽  
Author(s):  
D. R. Wiles ◽  
B. W. Smith ◽  
R. Horsley ◽  
H. G. Thode
Keyword(s):  
Thermal Neutron ◽  
Shell Structure ◽  
Neutron Capture ◽  
Half Life ◽  
Neutron Fission ◽  
Thermal Neutron Fission ◽  
Xenon Isotopes ◽  
Nuclear Shell ◽  
Fission Yields ◽  
Shell Region

The relative yields of the isotopes of cesium, rubidium, and strontium from thermal neutron fission of U235 have been determined mass spectrometrically. The cesium isotope yields are combined with those obtained previously for the xenon isotopes to give high precision yields for mass chains from 131 to 137. In this work neutron capture reactions have been considered and corrections made where these take place to an appreciable extent. The results give further evidence of abnormal yields in the 82 neutron shell region. The half-life of Cs137 was determined and found to be 33 ± 2 years.

Thermo-Oxidative Decomposition of Lovage (Levisticum officinale) and Davana (Artemisia pallens) Essential Oils under Simulated Tobacco Heating Product Conditions

2020 ◽  
Vol 29 (1) ◽  
pp. 27-43
Author(s):  
Emma Jakab ◽  
Zoltán Sebestyén ◽  
Bence Babinszki ◽  
Eszter Barta-Rajnai ◽  
Zsuzsanna Czégény ◽  
...  
Keyword(s):  
Low Temperature ◽  
Essential Oils ◽  
Relative Yield ◽  
Gas Chromatography Mass Spectrometry ◽  
Intramolecular Rearrangement ◽  
Oxidation Reactions ◽  
Pyrolysis Gas ◽  
Oxidative Decomposition ◽  
Oxidative Pyrolysis ◽  
Artemisia Pallens

SummaryThe thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]

Assessment of a compton-suppressed spectrometer for measurement of radioactive xenon isotopes

2021 ◽  
Vol 172 ◽  
pp. 109669
Author(s):  
Yuanqing Fan ◽  
Qi Li ◽  
Ying Wang ◽  
Yungang Zhao ◽  
Xinjun Zhang ◽  
...  
Keyword(s):  
Xenon Isotopes ◽  
Radioactive Xenon

scholarly journals High probability of yield gain through conservation agriculture in dry regions for major staple crops

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Su ◽  
Benoit Gabrielle ◽  
Damien Beillouin ◽  
David Makowski
Keyword(s):  
Management Practices ◽  
Crop Yields ◽  
Positive Impact ◽  
Relative Yield ◽  
Conservation Agriculture ◽  
Conventional Tillage ◽  
Machine Learning Algorithms ◽  
Agricultural Practice ◽  
Crop Species ◽  
Yield Gain

AbstractConservation agriculture (CA) has been promoted to mitigate climate change, reduce soil erosion, and provide a variety of ecosystem services. Yet, its impacts on crop yields remains controversial. To gain further insight, we mapped the probability of yield gain when switching from conventional tillage systems (CT) to CA worldwide. Relative yield changes were estimated with machine learning algorithms trained by 4403 paired yield observations on 8 crop species extracted from 413 publications. CA has better productive performance than no-till system (NT), and it stands a more than 50% chance to outperform CT in dryer regions of the world, especially with proper agricultural management practices. Residue retention has the largest positive impact on CA productivity comparing to other management practices. The variations in the productivity of CA and NT across geographical and climatical regions were illustrated on global maps. CA appears as a sustainable agricultural practice if targeted at specific climatic regions and crop species.

Cumulative yields of stable and long-lived isotopes of tin in neutron-induced fission

1983 ◽  
Vol 61 (11) ◽  
pp. 1490-1497 ◽  
Author(s):  
K. J. R. Rosman ◽  
J. R. De Laeter ◽  
J. W. Boldeman ◽  
H. G. Thode
Keyword(s):  
Stable Isotopes ◽  
Fine Structure ◽  
Fission Product ◽  
Mass Spectrometer ◽  
Smooth Curve ◽  
Mass Region ◽  
Neutron Fission ◽  
Source Mass ◽  
Induced Fission ◽  
Fission Yields

The relative cumulative fission yields of the six stable isotopes of tin (117Sn,118Sn, 119Sn, 120Sn, 122Sn, and 124Sn) and the long-lived isotope 126Sn have been measured in the thermal and epicadium neutron fission of 233U and 235U, and the epicadium neutron fission of 238U. Nanogram-sized fission product tin samples were extracted from irradiated uranium samples and analyzed in a solid source mass spectrometer. In each case a smooth curve can be drawn through the yield points of the seven isotopes of tin. There is, therefore, no evidence of "fine structure" in the 117 ≤ A ≤ 126 portion of the symmetric mass region.

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