scholarly journals daughter product in radiochemistry

2008 ◽  
Keyword(s):  
Daughter Product

Oxidative alteration of Ce-rich pyrochlore: HRTEM/EELS investigation

1999 ◽  
Vol 556 ◽  
Author(s):  
Huifang Xu ◽  
Yifeng Wang
Keyword(s):  
Inner Mongolia ◽  
Diffusion Processes ◽  
Northern China ◽  
Alpha Decay ◽  
Daughter Product ◽  
Ore Deposit ◽  
Transmission Electron ◽  
Abundant Element ◽  
Electron Energy Loss ◽  
Aqueous Species

AbstractTransmission electron microscopy (TEM) and associated electron energy-loss spectroscopy (EELS) study show intergrowth of Ce4+-rich pyrochlore (metamict) and Ce3+-rich pyrochlore (partially metamict) in a Ce-rich pyrochlore from a rare earth element (REE) ore deposit of Inner Mongolia, Northern China. The partially metamict material is Ba-free and dominated by Ce3+. However, the metamict material is Ba-bearing and dominated by Ce3+,. The Ce4+-rich pyrochlore may result from radiation damage by alpha decay that also causes oxidation of Fe 2+ in titanite, and the interaction with a Ba-bearing oxidizing fluid. The oxidation of Ce3+ in the primary pyrochlore is accompanied by in the loss of REE, Ca, and Pb, a daughter product of U via alpha decay, during the alteration. However, most REE were incorporated in the alteration product, the Ce4+-rich pyrochlore. Based on EDS and EELS analyses, the chemical formulae of the partially metamict Ce3+-rich pyrochlore and metamict Ce4+-rich pyroeblore can be written as: (Ca, Ce3+, U, Pb) 2(Ti, Nb)2O7−x(OH)x, and (Ba, Ca, Ce4+, U)2 (Ti, Nb)2O7−y(OH)y, respectively. Ce is the most abundant element among all REE. It is proposed that the alteration takes place in solid-state with oxidizing fluid as a catalyst. The alteration kinetics is controlled by diffusion processes of aqueous species in metamict pyrochlore.

The Role of Daughter Product Plateout in Passive Radon Detection

1984 ◽  
Vol 7 (1-4) ◽  
pp. 115-119 ◽  
Author(s):  
J.P. McLaughlin ◽  
F.D. O'Byrne
Keyword(s):  
Daughter Product ◽  
Radon Detection

Bestimmung der Halbwertszeit von 210Pb

1969 ◽  
Vol 24 (4) ◽  
pp. 612-615 ◽  
Author(s):  
A. Höhndorf
Keyword(s):  
Isotope Dilution ◽  
Half Life ◽  
Specific Activity ◽  
Mass Spectrometric ◽  
Isotope Dilution Analysis ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Daughter Product ◽  
Pb Concentration

Abstract The half-life of 210Pb has been calculated from measurements of the specific activity and the 210Pb-concentration of a 210Pb-solution. The specific 210Pb-activity was determined by measuring the daughter product 210Po using an α-spectrometric isotope dilution method with 208Po as tracer. The 210Pb-concentration was measured by mass-spectrometric isotope dilution analysis. A half-life of 22.26 ± 0.22 ( = 2 σ) years has been obtained.

Tracking Recent DDT Contamination in a Northern New England Watershed

2021 ◽  
Author(s):  
Amanda May ◽  
Lisa Doner ◽  
Jeremiah Duncan ◽  
Stephen Hill
Keyword(s):  
New England ◽  
New Hampshire ◽  
Sediment Quality ◽  
Source Area ◽  
Daughter Product ◽  
Multiple Sources ◽  
Aquatic Life ◽  
Quality Guidelines ◽  
Northern New England ◽  
Lake Deposits

Abstract Ecological research since 2005 into potential causes of declines in loon population at Squam Lake, New Hampshire, U.S.A., revealed multiple potential causes, but no particular source of contaminants. In 2017, tributary sediment analyses revealed specific sub-watersheds transporting contaminants to the lake (Vogel, 2019). For this study, from 2018 to 2020, we used an approach to this problem that allowed for rapid source area determination of DDT using soil and sediment analyses. We find modern presence of p,p’ isomers of DDT and DDE within the Bennett Brook sub-watershed, arising from 60-year-old orchard applications and a former barn. Highest concentrations, 723 μg/kg p,p’ DDT and 721 μg/kg p,p’ DDE, occur near the barn’s foundation rubble. DDT exceeds that of the daughter product, DDE, in some of the sub-watershed’s soils, including but not limited to the barn site. In the soils where DDT>DDE, we infer delayed breakdown of DDT. DDT<DDE occurs in the streambed and lake deposits, as well as some soils. A Pb-210 dated sediment core, collected near the outlet of Bennet Brook, shows continuous accumulation of the daughter products, DDE and DDD, from 1951 to the present. Residuals are derived from multiple sources within the sub-watershed, including orchard soils, the barn site, and sediment accumulations in the stream. These DDT residues fall below mandatory soil remediation levels for the State of New Hampshire, but exceed some sediment quality guidelines for protection of aquatic life. Bioaccumulation of p,p’ DDE is evident in crayfish that reside in Bennett Brook.

scholarly journals Observations on the Absorption of Radioactive Strontium and Yttrium by Marine Algae

1949 ◽  
Vol 28 (3) ◽  
pp. 587-625 ◽  
Author(s):  
G. M. Spooner
Keyword(s):  
Marine Algae ◽  
Sea Water ◽  
Parent Substance ◽  
Ionic Exchange ◽  
Daughter Product ◽  
Fucus Serratus ◽  
Carrier Free

Certain marine algae were treated with sea water containing carrier-free radioactive strontium (mixture of Sr89 and Sr90), to test whether these ions were taken up by the weeds.At the same time the behaviour of radioactive yttrium (Y90), which occurred as a short-lived daughter-product of Sr90, was investigated by the expedient of studying the ‘decay’ characteristics of specimens of water and weed.Promising possibilities of this technique, by which an isotope is made available for study by applying its parent substance, are pointed out.Radioactive strontium is extracted from sea water by the brown sea-weeds, in particular by Fucus serratus.It is held that this effect is simply a result of ionic exchange, and that the algae regularly contain many times as much strontium in their cell fluids as exists in sea water.

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