scholarly journals Tritium and 14C in Tree Rings of the Last Three Decades

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 766-770 ◽  
Author(s):  
Kristóf Kozák ◽  
Bogomil Obelić ◽  
Nada Horvatinčić
Keyword(s):  
Tree Rings ◽  
Catalytic Reaction ◽  
Water Samples ◽  
Proportional Counter ◽  
Liquid Scintillation ◽  
Global Scale ◽  
Scintillation Counting ◽  
Published Data ◽  
The Past ◽  
Free Hydrogen

Tree rings spanning the past three decades were collected from Picea spp trees grown in Matra, northern Hungary. Cellulose was prepared from the wood and samples were separately combusted for tritium and 14C analyses. Methane was synthesized from CO2 obtained by sample combustion via catalytic reaction with tritium-free hydrogen. 14C activity was measured by proportional counter. The exchangeable tritium was removed from cellulose samples used for tritium analysis. Water samples produced by combustion were measured by liquid scintillation counting. The distribution of tritium and 14C activities in tree rings are shown for years 1956–1986. Results are compared with published data on global-scale distribution of 14C and HTO. A comparison of tritium activity in precipitation and wine samples from the same region is presented.

scholarly journals Comparison of 14C Ages Between LSC and AMS Measurements of Choukai Jindai Cedar Tree Rings at 2600 cal BP

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 895-900 ◽  
Author(s):  
Yui Takahashi ◽  
Hirohisa Sakurai ◽  
Kayo Suzuki ◽  
Taiichi Sato ◽  
Shuichi Gunji ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tree Rings ◽  
Liquid Scintillation ◽  
Measurement Methods ◽  
Scintillation Counting ◽  
Age Difference ◽  
Data Sets ◽  
Data Set ◽  
The Difference ◽  
Good Agreement

Radiocarbon ages of Choukai Jindai cedar tree rings growing in the excess era of 14C concentrations during 2757–2437 cal BP were measured using 2 types of 14C measurement methods, i.e. liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The difference between the 2 methods is 3.7 ± 5.2 14C yr on average for 61 single-year tree rings, indicating good agreement between the methods. The Choukai data sets show a small sharp bump with an average 14C age of 2497.1 ± 3.0 14C yr BP during 2650–2600 cal BP. Although the profile of the Choukai LSC data set compares well with that of IntCal04, having a 14C age difference of 4.6 ± 5.3 14C yr on average, the Choukai LSC 14C ages indicate variability against the smoothed profile of IntCal04.

scholarly journals Packard Instrument Company Radiocarbon Dates I

Radiocarbon ◽  
1965 ◽  
Vol 7 ◽  
pp. 200-204 ◽  
Author(s):  
Sandra J. Kowalski
Keyword(s):  
Water Samples ◽  
Liquid Scintillation Counting ◽  
Small Area ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Radiocarbon Dates ◽  
Low Level ◽  
Area 6

The Low Level Counting Laboratory of Packard Instrument Company was organized and began operations in the fall of 1963 with the development and construction of the Packard Tri-carb® Benzene Synthesizer. This instrument is designed to consolidate into a small area (6 ft × 8 ft) the equipment necessary to quickly and efficiently convert carbon-containing material or tritium water samples into benzene—an ideal solvent for liquid scintillation counting.

scholarly journals Applications of PERALS-Alpha Spectrometry for the Investigation of Radionuclides in Water Samples

2021 ◽  
Author(s):  
Markus Raymond Zehringer ◽  
Franziska Kammerer ◽  
Anja Pregler
Keyword(s):  
Water Samples ◽  
Mineral Water ◽  
Liquid Scintillation ◽  
Sea Water ◽  
Selective Extraction ◽  
Scintillation Counting ◽  
Water Drinking ◽  
Extraction Step ◽  
Proper Setting

In this paper, experiences of the last 20 years with the PERALS-technique are described. PERALS stands for Photo Electron Rejecting Alpha Liquid Scintillation. This LSC-technique was developed by Jack McDowell in the 70ies and is a powerful technique for the analyses of many natural alpha nuclides. The principle is based on a selective extraction of the radionuclide from the water phase by means of a complexing or ion pair reagent. The extractant contains also a suitable cocktail for the scintillation counting. Therefore, the extract can be analysed directly after the extraction step. After removing quenchers, such as oxygen, and the proper setting of a pulse shape discriminator, alpha pulses can be counted with a photomultiplier. The paper describes the development of robust analysis schemes for the determination of traces of polonium, radon, radium, strontium, thorium, uranium and other actinides in water samples (groundwater, rain water, river water, drinking water, mineral water, sea water).

scholarly journals The New Nagoya Radiocarbon Laboratory

Radiocarbon ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Yasushi Muraki ◽  
Grant Kocharov ◽  
Tooru Nishiyama ◽  
Yukiko Naruse ◽  
Takuya Murata ◽  
...  
Keyword(s):  
High Precision ◽  
Tree Rings ◽  
Liquid Scintillation Counting ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Terrestrial Environment

A liquid scintillation counting apparatus that enables highly accurate measurements of 14C has been constructed at the Solar-Terrestrial Environment Laboratory, Nagoya University. The main aim of the project is high precision year-by-year measurements of the 14C content in tree rings of an old cedar tree from Yaku Island, Japan. We present the results of 14C measurements on tree rings from the Agematsu region for recent decades to confirm the validity of the system.

Tree-rings δ13C different responses to environmental factors in angiosperms and gymnosperms at global scale

2021 ◽  
Author(s):  
Xiaozhen Li ◽  
Guo Chen ◽  
Wenyi Qin ◽  
Peng Wang ◽  
Xiang Wang
Keyword(s):  
Tree Rings ◽  
Industrial Revolution ◽  
Isotope Composition ◽  
Environmental Parameters ◽  
Global Scale ◽  
Published Data ◽  
Atmospheric Concentration ◽  
Machine Learning Methods ◽  
Relationship Of ◽  
Climatic Information

<p>Tree-rings, was an extraordinary information base of climate. The global climatic change has been modifying ecosystem, it is important to understand mechanism of how plants respond to climate change. The carbon isotope composition of tree-rings corrected to the value before industrial revolution (δ<sup>13</sup>C<sub>ring</sub>) can provide climatic information and carbon and water balance relationship of plants. However, it was still a challenge to disentangle the influence of different environmental parameters on δ<sup>13</sup>C<sub>ring</sub> among different tree types. We collected published data of δ<sup>13</sup>C<sub>ring</sub> from published papers and study how angiosperms and gymnosperms responsed to different environmental parameters. The results showed that the δ<sup>13</sup>C<sub>ring </sub>of angiosperms and gymnosperms were significantly different and there was a decrasing trend in δ<sup>13</sup>C<sub>ring</sub> of angiosperms and gymnosperms. In this study, we found that atmospheric concentration (C<sub>a</sub>) was not the mainly factor to influence the δ<sup>13</sup>C<sub>ring</sub>, and the MAT and PRE were the most important environmental parameters to influence the decreasing trend of δ<sup>13</sup>C<sub>ring</sub> for angiosperms and gymnosperms, respectively. Additionally, the global isoscapes of δ<sup>13</sup>C<sub>ring</sub> were not established, in this study, three machine learning methods to predict the spatial distribution of δ<sup>13</sup>C<sub>ring</sub> were done, the results showed that RF was the best model to established the isoscapes of δ<sup>13</sup>C<sub>ring</sub>.</p>

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