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Showing 1 to 20 of 36 for “"210Pb"”.
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The biogeochemistry of 210Pb and 210Po in fresh waters and sediments
The focus of this work was geochemical cycling of 210Pb in lakes, including the water column, sediments, and their interactions with each other. A special goal was to elucidate processes that might influence the distribution and fluxes of the radionuclide in ways that could effect 210Pb sediment …
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Mobilité physique et chimique du 10Be, 137Cs et 210Pb (xs) dans les sols : rôle des caractéristiques pédologiques.
… cinétique basée sur les profils verticaux de 210Pb (xs), 10Be et 137Cs a été développée pour les Luvisols, dans lesquels les transferts solubles peuvent être négligés. Les limites d’applicabilité de ce type d’approche n’ont cependant pas été testées. Dans ce travail, nous avons analysé le …
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Avaliação do potencial de acumulação de 210Pb pela Tillandsia recurvata L. para fins de biomonitoração da qualidade do ar.
… que evidenciem a eficiência de acumulação de 210Pb na espécie T. recurvata L. Com base nisto, o presente trabalho avaliou a aplicabilidade da Tilandsia recurvata L. para determinação do 210Pb, investigando o potencial de acumulação deste biomonitor em condições laboratoriais e quando exposto …
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Levantamento dos níveis de radioatividade natural no estuário do complexo industrial de Suape no estado de Pernambuco
… as concentrações do 238U, 226Ra, 232Th, 40K e 210Pb em amostras de solos, sedimentos, peixes e folhas de mangue coletadas no percurso dos rios Ipojuca Massangana e Tatuoca localizados na Região Estuarina do Complexo Industrial de SUAPE, devido à instalação de uma refinaria de petróleo e à …
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Investigating the ocean’s biological pump using thorium-235 and polonium-210
… the two radioisotope pairs 234Th/238U and 210Po/210Pb are utilized. Chapter 2 is an update of the 234Th/238U measurement method which simplifies the protocol, and allows for expansion of use. Chapter 3 presents an unprecedentedly extensive, non-steady state study of 234Th/238U to assess POC and …
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Radioactivity of Fossil Fuel Waste Products and Associated Environmental Implications
… 228Ra and 238U and its decay products 226Ra and 210Pb were measured in coals and CCRs from the majors coal producing basins in the United States as well as in coals and CCRs from high-U coal producing basins in China. 228Ra and 226Ra were measured in OGW from the Appalachian Basin in the United …
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The mineralogical deportment of radionuclides in South Australian Ca-Au-(U) ores
… sorb products of 238U decay, notably 226Ra and 210Pb, whereas U remains in solution. Many APS phases, particularly those that are Pb-bearing, are stable over a wide range of pH and Eh conditions and at temperatures up to 450 °C. As such, synthetic APS phases represent viable candidates not only …
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Quantifying Rates of Autocompaction in the Pearl River Marsh, Louisiana
… the following data: age control, using 137Cs and 210Pb, and sedimentary variables, specifically, particulate organic carbon, bulk density, median grain size, porosity, and water content. An upper and an underlying sedimentary unit (named the 137Cs and 210Pb units) were defined between radiometric …
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Geomorphic Analysis of A Rural Fluvial System During Pre-Dam Removal Conditions: A Case Study In Eastern Virginia
… one from each reservoir created by the dams, for 210Pb analysis using a slope regression (SR) model and the constant rate of supply (CRS) model. Estimated average sediment accumulation rates for Core 1 are 0.1665 (SR) and 0.1882 g cm-2yr-1 (CRS), and for Core 2 are 0.1335 (SR) and 0.1725 g …
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Sedimentation on a mixed siliciclastic/carbonate continental margin over decadal to millennial timescales: Gulf of Papua
… sediment mass accumulation and inventory-derived 210Pb fluxes display regional variations, decreasing seaward, and along isobaths seaward from the northeastern shelf edge. The amount of terrigenous sediment load being discharged annually from the shelf and accumulating in Pandora Trough is …
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Aminosäure-D/L-Verhältnisse in biogenen Carbonaten als Schlüssel zur Datierung holozäner Sedimentationsvorgänge im norddeutschen Küstenraum
… vermischt das ursprüngliche Signal, z.B. von 210Pb, und führt so zu scheinbar homogenen Sedimentaltern. Auf der anderen Seite bietet sich eine Datierung mit Hilfe der 14C-Methode aufgrund des Reservoireffekts von Sedimenten, die jünger als 400 Jahre sind, ebenfalls nicht an. Eine mögliche …
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The Paleolimnology of Sodus Bay
… into 1 cm samples, which were freeze dried and 210Pb dated. Coverslips were prepared using Battarbee trays. Diatom valves, some as old as 338 years, were examined in transects of mounted coverslips. Phosphorus concentrations of digested samples were determined using a Technicon Auto-analyzer. …
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Fechado de sedimentos marinos para determinar tasas de sedimentación en el Golfo de Fonseca, La Unión, El Salvador
… mediante el uso del método de fechado con 210Pb. Durante el período estudiado, las tasas de acumulación y sedimentación en el núcleo GF04 variaron entre 0.03 a 0.40 g cm-2 año-1, y 0.03 a 0.57 cm año-1 respectivamente, determinadas por el modelo de CRS (tasa de suministro constante, por sus …
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Environmental Impacts on the Development and Dune Activity of Oxbow Lake along the Southwest Coast of Lake Michigan at Saugatuck, Michigan USA
… and lake level are correlated individually with 210Pb/137Cs/7Be dated sand deposits from core samples taken in a small lake in the lee side of a dune ridge near Saugatuck, Michigan. Linear regressions were run to evaluate the strength of their relationship year-by-year, and offsets of one to two …
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Plutonium isotopes in the North Atlantic
… significant. A large suite of sedimentary Pu and 210Pbex inventory data are also examined from the Northwest Atlantic shelf, slope and deep-sea sediments. Comparisons between Pu and 210Pb are of interest since both isotopes are predominantly supplied by atmospheric delivery to coastal waters, and …
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Geological recognition of abrupt marine invasions in two coastal areas of Portugal
… macrofossils analysis, geochemical analysis and 210Pb and Optically Stimulated Luminescence dating. The investigated areas (e.g. Lagoa de Óbidos (Central Portugal) and Martinhal (South Portugal)) were affected by the AD 1755 tsunami. The locations have similar geomorphological features and are …
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Genomic adaptation to a century of environmental change in zooplankton from the Canadian Shield
… methods, such as high-resolution 210Pb dating and extraction of organic material from lake sediment cores, combined with recently developed whole genome sequencing protocols for individual Daphnia resting embryos. It addresses questions about the predictability and repeatability of …
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Sediment Deposition in the Deep Sea: from Seamounts to the Hadal Trenches
… observed via a radionuclide approach (234Th and 210Pb) in terms of assessing the control mechanism of carbon deposition to the seafloor. It is understood that topographical features alter the path of hydrological flow and these, in return, alter the sedimentary environment, biochemistry and …
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Glacial isostatic adjustment and relative sea level change over the last earthquake cycle in upper Cook Inlet, Alaska, USA
… methods used comprise a multi-method approach: 210Pb, 137Cs, stable lead (206Pb/207Pb) ratios, pollutants associated with the history of regional gold mining and development, tephrochronology and AMS 14C wiggle match dating. The research highlights some of the limitations of applying some of …
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