The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform
J Hilton - One of the best experts on this subject based on the ideXlab platform.
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Determination of thorium-234/Uranium-238 disequilibrium in freshwater systems
Analyst, 1994Co-Authors: H W Morris, F R Livens, L Nolan, J HiltonAbstract:The use of 234Th/238U disequilibrium measurements is well established in marine systems and is potentially very valuable in determining the settling velocity of particles in freshwater systems. However, the much lower Uranium concentrations in fresh waters prevent established techniques from being used. An alternative approach, based on a combination of Cerenkov and liquid scintillation counting and α-spectrometry has improved the sensitivity of the technique so that freshwater samples can be measured.
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determination of thorium 234 Uranium 238 disequilibrium in freshwater systems
Analyst, 1994Co-Authors: H W Morris, F R Livens, L Nolan, J HiltonAbstract:The use of 234Th/238U disequilibrium measurements is well established in marine systems and is potentially very valuable in determining the settling velocity of particles in freshwater systems. However, the much lower Uranium concentrations in fresh waters prevent established techniques from being used. An alternative approach, based on a combination of Cerenkov and liquid scintillation counting and α-spectrometry has improved the sensitivity of the technique so that freshwater samples can be measured.
H W Morris - One of the best experts on this subject based on the ideXlab platform.
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Determination of thorium-234/Uranium-238 disequilibrium in freshwater systems
Analyst, 1994Co-Authors: H W Morris, F R Livens, L Nolan, J HiltonAbstract:The use of 234Th/238U disequilibrium measurements is well established in marine systems and is potentially very valuable in determining the settling velocity of particles in freshwater systems. However, the much lower Uranium concentrations in fresh waters prevent established techniques from being used. An alternative approach, based on a combination of Cerenkov and liquid scintillation counting and α-spectrometry has improved the sensitivity of the technique so that freshwater samples can be measured.
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determination of thorium 234 Uranium 238 disequilibrium in freshwater systems
Analyst, 1994Co-Authors: H W Morris, F R Livens, L Nolan, J HiltonAbstract:The use of 234Th/238U disequilibrium measurements is well established in marine systems and is potentially very valuable in determining the settling velocity of particles in freshwater systems. However, the much lower Uranium concentrations in fresh waters prevent established techniques from being used. An alternative approach, based on a combination of Cerenkov and liquid scintillation counting and α-spectrometry has improved the sensitivity of the technique so that freshwater samples can be measured.
A Taylor - One of the best experts on this subject based on the ideXlab platform.
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Uranium 238 decay chain data
Science of The Total Environment, 1993Co-Authors: G A Sutton, S T Napier, M John, A TaylorAbstract:BNFL Springfields Works and the MAFF Fisheries Radiological Inspectorate regularly monitor silt from the River Ribble and its estuary to assess the radiological impact of the BNFL liquid discharges on the local environment. It is generally accepted that due to its short half-life, 234mPa should be in secular equilibrium with its precursor 234Th. Measured results do not support this theory but show instead an average factor of 1.8:1 to exist between 234mPa and 234Th. Both laboratories use the United Kingdom Chemical Nuclear Data Library as the basis for their gamma line identification process and would expect better agreement. A search of current nuclear data libraries has identified some inconsistencies in reported gamma line intensities for this decay chain. This paper is a report on the work carried out at BNFL and MAFF to confirm the correct intensities for 234Th and 234mPa.
William W Au - One of the best experts on this subject based on the ideXlab platform.
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distribution of Uranium 238 in environmental samples from a residential area impacted by mining and milling activities
Environmental Toxicology and Chemistry, 1998Co-Authors: Marc A Mcconnell, V Sadagopa M Ramanujam, Nancy W Alcock, Gary J Gabehart, William W AuAbstract:The northern region of Karnes County, Texas, USA, has been the site of extensive mining/milling of Uranium for over 30 years. A previous study in our laboratory indicates that residents living near these facilities have increased chromosomal aberrations and a reduced DNA repair capacity. In this study, the long-lived radionuclides Uranium-238 (238U) and thorium-232 (232Th) were measured in order to evaluate the extent of contamination from mining/milling facilities. 232Th was quantified simultaneously and served as a reference. Soil samples (n = 70) were collected from the yards of previously studied households and adjacent areas near former mining and mining/milling sites at the surface and 30 cm subsurface. Additionally, samples from drinking water wells (n = 6) were collected from selected households. Sites located over 14 km from the study area with no known history of mining/milling served as the control. In the control area, 238U concentrations in soil were consistent between surface (0.13–0.26 mg/kg) and subsurface (0.13–0.23 mg/kg) samples. Near mining/milling sites, 238U in surface soil (0.34–15.71 mg/kg) was found to be consistently and statistically higher (p < 0.05) than corresponding subsurface samples (0.17–2.11 mg/kg). Near mining-only areas, 238U in surface soil (1.11–1.97 mg/kg), however, was not significantly increased over subsurface soil (0.96–1.68 mg/kg). As expected, 238U was much higher overall in the mining/milling and mining-only areas compared to the control sites. No trends were detected in the distribution of 232Th. The concentration of 238U was up to six times higher in a drinking water well near a former mining/milling operation, indicating possible leaching into the groundwater, while 232Th concentrations were low and uniform. Furthermore, lead isotope ratio analysis indicates contamination from the interstate shipping of ore by rail to and from a mining/milling facility. These data indicate contamination of the environment by the mining/milling activities in a residential area.
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Distribution of Uranium‐238 in environmental samples from a residential area impacted by mining and milling activities
Environmental Toxicology and Chemistry, 1998Co-Authors: Marc A Mcconnell, V Sadagopa M Ramanujam, Nancy W Alcock, Gary J Gabehart, William W AuAbstract:The northern region of Karnes County, Texas, USA, has been the site of extensive mining/milling of Uranium for over 30 years. A previous study in our laboratory indicates that residents living near these facilities have increased chromosomal aberrations and a reduced DNA repair capacity. In this study, the long-lived radionuclides Uranium-238 (238U) and thorium-232 (232Th) were measured in order to evaluate the extent of contamination from mining/milling facilities. 232Th was quantified simultaneously and served as a reference. Soil samples (n = 70) were collected from the yards of previously studied households and adjacent areas near former mining and mining/milling sites at the surface and 30 cm subsurface. Additionally, samples from drinking water wells (n = 6) were collected from selected households. Sites located over 14 km from the study area with no known history of mining/milling served as the control. In the control area, 238U concentrations in soil were consistent between surface (0.13–0.26 mg/kg) and subsurface (0.13–0.23 mg/kg) samples. Near mining/milling sites, 238U in surface soil (0.34–15.71 mg/kg) was found to be consistently and statistically higher (p < 0.05) than corresponding subsurface samples (0.17–2.11 mg/kg). Near mining-only areas, 238U in surface soil (1.11–1.97 mg/kg), however, was not significantly increased over subsurface soil (0.96–1.68 mg/kg). As expected, 238U was much higher overall in the mining/milling and mining-only areas compared to the control sites. No trends were detected in the distribution of 232Th. The concentration of 238U was up to six times higher in a drinking water well near a former mining/milling operation, indicating possible leaching into the groundwater, while 232Th concentrations were low and uniform. Furthermore, lead isotope ratio analysis indicates contamination from the interstate shipping of ore by rail to and from a mining/milling facility. These data indicate contamination of the environment by the mining/milling activities in a residential area.
F R Livens - One of the best experts on this subject based on the ideXlab platform.
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Determination of thorium-234/Uranium-238 disequilibrium in freshwater systems
Analyst, 1994Co-Authors: H W Morris, F R Livens, L Nolan, J HiltonAbstract:The use of 234Th/238U disequilibrium measurements is well established in marine systems and is potentially very valuable in determining the settling velocity of particles in freshwater systems. However, the much lower Uranium concentrations in fresh waters prevent established techniques from being used. An alternative approach, based on a combination of Cerenkov and liquid scintillation counting and α-spectrometry has improved the sensitivity of the technique so that freshwater samples can be measured.
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determination of thorium 234 Uranium 238 disequilibrium in freshwater systems
Analyst, 1994Co-Authors: H W Morris, F R Livens, L Nolan, J HiltonAbstract:The use of 234Th/238U disequilibrium measurements is well established in marine systems and is potentially very valuable in determining the settling velocity of particles in freshwater systems. However, the much lower Uranium concentrations in fresh waters prevent established techniques from being used. An alternative approach, based on a combination of Cerenkov and liquid scintillation counting and α-spectrometry has improved the sensitivity of the technique so that freshwater samples can be measured.
