Concept

Géochimie isotopique

Publications associées (234)

Proto-Planetary Disk Chemistry Recorded By D-Rich Organic Radicals In Carbonaceous Chondrites

Insoluble organic matter (IOM) in primitive carbonaceous meteorites has preserved its chemical composition and isotopic heterogeneity since the solar system formed similar to 4.567 billion years ago. We have identified the carrier moieties of isotopically ...

2009

Multiproxy evidence of Little Ice Age palaeoenvironmental changes in a peat bog from northern Poland

Mariusz Lamentowicz

‘Little Ice Age’ (LIA) climatic deteriorations have been abundantly documented in various archives such as ice, lake sediments and peat bog deposits. Palaeoecological analyses of peat samples have identified these climatic deteriorations using a range of t ...

2009

Apparent Transverse Relaxation Rates in Systems with Scalar-Coupled Protons

Geoffrey Bodenhausen

The modulation of spin echoes by homonuclear scalar couplings render the determination of transverse relaxation rates of individual spins difficult, in particular for molecules that are isotopically enriched in 13C or 15N, and for all molecules with scalar ...

2009

Modeling groundwater and benzene discharge to a river from an alluvial aquifer subject to strong interactions with surface water

Jordi Batlle-Aguilar

Modeling groundwater flow and contaminant transport in industrialized and urbanized alluvial plains is challenging because of the dynamic nature of the strongly interacting river – groundwater system and the scarcity of data. An original combined regional ...

2009

Improved ¹H-[¹³C] and ¹H NMR methods for in vivo measurement of cerebral metabolism

Lijing Xin

Nuclear magnetic resonance (NMR) spectroscopy can be applied in vivo to measure static or dynamic biochemical information, e.g., concentrations of metabolites and metabolic fluxes, using various nuclei such as 1H, 13C, 31P and 15N. The work of this thesis ...

EPFL2009

Diffusional and microbial isotope fractionation of methane during gas push–pull tests

Graciela Gonzalez Gil

A field method called gas push–pull test (GPPT) was previously developed for in-situ quantification of methane (CH4) oxidation by soil microorganisms. We examined whether natural-abundance stable carbon-isotope analysis of CH4, a common approach used to me ...

2008

Last millennium palaeoenvironmental changes from a Baltic bog (Poland) inferred from stable isotopes, pollen, plant macrofossils and testate amoebae

Edward Mitchell, Mariusz Lamentowicz

The Baltic coast of Northern Poland is a region of considerable potential interest for paleoclimatic studies because this region is under the influence of both oceanic and continental climates and that these two influences have likely changed through time. ...

2008

Transport of methane and noble gases during gas push−pull tests in variably saturated porous media

Graciela Gonzalez Gil

The gas push−pull test (GPPT) is a single-well gas-tracer method to quantify in situ rates of CH4 oxidation in soils. To improve the design and interpretation of GPPT field experiments, gas component transport during GPPTs was examined in abiotic porous me ...

2008

Comparison of optimised germanium gamma spectrometry and multicollector inductively coupled plasma mass spectrometry for the determination of 134Cs, 137Cs and 154Eu single ratios in highly burnt UO2

Rakesh Chawla, Stefano Caruso, Fabian Jatuff

Non-destructive and destructive methods have been compared to validate their corresponding assessed accuracies in the measurement of 134Cs/137Cs and 154Eu/137Cs isotopic concentration ratios in four spent UO2 fuel samples with very high (52 and 71 GWd/t) a ...

Elsevier Science B.V.2008

Non-invasive quantification of brain glycogen absolute concentration

Rolf Gruetter, Lijing Xin, Hongxia Lei, Ruud van Heeswijk, Hanne Frenkel, Sabrina Laus

The only currently available method to measure brain glycogen in vivo is C-13 NMR spectroscopy. Incorporation of C-13-labeled glucose (Glc) is necessary to allow glycogen measurement, but might be affected by turnover changes. Our aim was to measure glycog ...

Wiley-Blackwell2008

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