Search results for " Isotopes"
showing 10 items of 460 documents
Back to the bases: Building a terrestrial water δ18O baseline for archaeological studies in North Patagonia (Argentina)
2020
Archaeology has been using stable oxygen as an isotopic tracer linked with water consumption for decades, and it has been demonstrated to be a powerful tool to assess paleomobility in bioarchaeology. Central-eastern North Patagonia (Argentina) is an especially appropriate region to apply it since it presents a high density of huntergatherer burials, it was a nodal zone criss-crossed by an extensive network of important routes, and it is characterized by a high environmental fragmentation due to the scarcity of fresh water sources. The aim of this paper is to build an empirical stable oxygen isotope baseline of terrestrial surface waters to assess the potentiality of tracing past human movem…
Laser spectroscopy of gallium isotopes beyond N = 50
2012
The installation of an ion-beam cooler-buncher at the ISOLDE, CERN facility has provided increased sensitivity for collinear laser spectroscopy experiments. A migration of single-particle states in gallium and in copper isotopes has been investigated through extensive measurements of ground state and isomeric state hyperfine structures. Lying beyond the N = 50 shell closure, 82Ga is the most exotic nucleus in the region to have been studied by optical methods, and is reported here for the first time. ispartof: pages:012071-6 ispartof: Journal of Physics: Conference Series vol:381 issue:1 pages:012071-6 ispartof: Rutherford Centennial Conference on Nuclear Physics location:Manchester, UK dat…
Production and investigation of neutron-rich Osmium isotopes with and around N=126 using gas flow transport method
2014
Neutron-rich isotopes of heavy nuclei are until now poorly studied. In this work we investigate neutron-rich osmium isotopes produced in multi-nucleon transfer reactions. The reaction 136Xe+208Pb at energy near Coulomb barrier is used for production of osmium isotopes. The CORSAR-V setup is used to record the characteristics of osmium isotopes. The separation of the reaction products is based on their respective volatility. Experimental results are presented and discussed. © Published under licence by IOP Publishing Ltd.
The second century CE Roman watermills of Barbegal Unraveling the enigma of one of the oldest industrial complexes
2018
Carbonate deposits provide insights into the operation of the earliest industrial utilization of hydropower by an ancient society.
New chronology for Ksâr ‘Akil (Lebanon) supports Levantine route of modern human dispersal into Europe
2015
Modern human dispersal into Europe is thought to have occurred with the start of the Upper Paleolithic around 50,000-40,000 y ago. The Levantine corridor hypothesis suggests that modern humans from Africa spread into Europe via the Levant. Ksâr 'Akil (Lebanon), with its deeply stratified Initial (IUP) and Early (EUP) Upper Paleolithic sequence containing modern human remains, has played an important part in the debate. The latest chronology for the site, based on AMS radiocarbon dates of shell ornaments, suggests that the appearance of the Levantine IUP is later than the start of the first Upper Paleolithic in Europe, thus questioning the Levantine corridor hypothesis. Here we report a seri…
Laminated carbonate deposits in Roman aqueducts: Origin, processes and implications
2013
Carbonate deposits in Roman aqueducts of Patara and Aspendos (southern Turkey) were studied to analyse the nature of their regular layering. Optical microscopy and electron-backscattered diffraction results show an alternation of dense, coarsely crystalline, translucent laminae composed of bundles and fans of elongate calcite crystals with their c-axes parallel to the long axis, and porous, fine-grained laminae with crystals at near-random orientation. The ?18O and ?13C data show a strong cyclicity and anti-correlation, whereby high and low ?18O values correspond to dense columnar and porous fine-grained laminae, respectively. Geochemical analyses show similar cyclic changes in carbonate co…
Pleistocene age paleo-groundwater inferred from water-stable isotope values in the central part of the Baltic Artesian Basin.
2016
A new data set of δ(2)H and δ(18)O in the groundwater from the central part of the Baltic Artesian Basin is presented. The hydrogeological section is subdivided into stagnation, slow exchange and active exchange zones. Na-Ca-Cl brine found at the deepest part - the stagnation zone - is characterized by δ(18)O values above -5 ‰ and δ(2)H values approaching -40 ‰ with respect to Vienna Standard Mean Ocean Water. The slow exchange zone where waters of mostly intermediate salinity reside is characterized by δ(18)O values around -11.7 ‰ and δ(2)H values around -85.3 ‰. Mean δ(18)O and δ(2)H values of the fresh groundwater in the active water exchange zone are -11.1 and -79.9 ‰, respectively. Cha…
A New Method to Reconstruct Quantitative Food Webs and Nutrient Flows from Isotope Tracer Addition Experiments
2020
Understanding how nutrients flow through food webs is central in ecosystem ecology. Tracer addition experiments are powerful tools to reconstruct nutrient flows by adding an isotopically enriched element into an ecosystem and tracking its fate through time. Historically, the design and analysis of tracer studies have varied widely, ranging from descriptive studies to modeling approaches of varying complexity. Increasingly, isotope tracer data are being used to compare ecosystems and analyze experimental manipulations. Currently, a formal statistical framework for analyzing such experiments is lacking, making it impossible to calculate the estimation errors associated with the model fit, the…
Characterisation of submarine groundwater discharge offshore south-eastern Sicily
2005
A complex approach in characterisation of submarine groundwater discharge (SGD) off south-eastern Sicily comprising applications of radioactive and non-radioactive tracers, direct seepage measurements, geophysical surveys and a numerical modelling is presented. SGD fluxes in the Donnalucata boat basin were estimated by direct seepage measurements to be from 4 to 12Ls(-1), which are comparable with the total SGD flux in the basin of 17Ls(-1) obtained from radon measurements. The integrated SGD flux over the Donnalucata coast estimated on the basis of Ra isotopes was around 60m(3)s(-1) per km of the coast. Spatial variations of SGD were observed in the Donnalucata boat basin, the average (222…
Application of ICP-MS for measuring soil metal cations from sequential extraction
2005
The present work is part of a collaboration between Palermo and Seville Universities to investigate the cations incorporated into calcite and its effect in the trace metal mobility in soils. The study area is located in the central part of Sicily. Calcite is usually greatly dispersed and has a major influence on the pH of soils and therefore on trace element behaviour. A great affinity for carbonates has been observed for a wide range of cations incorporated into calcite. in order to investigate the metal cations in soil carbonate, 1M MgCl2 was used to remove the exchangeable Ca. Sub-samples were treated with acid acetic 1M to quantify the total amount of Ca and metal cations in soil carbon…