Modeling the signature of sulfur mass-independent fractionation produced in the Archean atmosphere [PDF]
, 2014 Minor sulfur isotope anomalies indicate the absence of O2 from the Archean atmosphere. A rich dataset showing large variations in magnitude and sign of Δ33S and Δ36S, preserved in both sulfates and sulfides, suggests that further constraints on Archean ...
Claire, Mark +10 more
core +1 more source
Stable isotope dilution techniques for assessing vitamin A status and bioefficacy of provitamin A carotenoids in humans. [PDF]
, 2005 Vitamin A deficiency is a major global public health problem. Among the variety of techniques that are available for assessing human vitamin A status, evaluating the provitamin A nutritional values of foodstuffs and estimating human vitamin A ...
Judy D Ribaya-Mercado +19 more
core +1 more source
Stable isotope analysis provides new information on winter habitat use of declining avian migrants that is relevant to their conservation [PDF]
, 2012 Winter habitat use and the magnitude of migratory connectivity are important parameters when assessing drivers of the marked declines in avian migrants. Such information is unavailable for most species.
Newton, J. +11 more
core +2 more sources
Nickel and osmium isotope and trace element geochemistry of organic-rich sedimentary rocks: The first investigation of Ni isotope systematics in marine sediments [PDF]
, 2012 Understanding the chemical composition of organic-rich marine sediments has the potential to: 1) allow evaluation of variations in ocean chemistry, enabling assessment of changes in global processes throughout geological time; and 2) provide an increased
PORTER, SARAH,JULIE
core
Probing stratospheric transport and chemistry with new balloon and aircraft observations of the meridional and vertical N2O isotope distribution [PDF]
, 2006 A comprehensive set of stratospheric balloon and aircraft samples was analyzed for the position-dependent isotopic composition of nitrous oxide (N2O). Results for a total of 220 samples from between 1987 and 2003 are presented, nearly tripling the number
Kaiser, Jan +11 more
core +2 more sources
Intraspecific variation modulates patterns of resource use by species, potentially affecting the structure and stability of food webs. In human-modified landscapes, habitat disturbance modifies trophic interactions and intraspecific niche variation ...
Environmental Isotope Studies, E
core +1 more source
Organic produce and production system conformity assessments : eggs and isotope analysis [PDF]
, 2008 Eggs were analysed for stable isotope composition, as a measure for organic produce ...
van Ruth, S.M. +2 more
core
On-line isotope separation at the hilac [PDF]
Nuclear Instruments and Methods, 1970 Abstract An one-line isotope separator was developed at the HILAC. The heavy ion beams impinges on a thin target, and the recoiling product nuclei are stopped in a solid or liquid catcher. They diffuse out of this catcher at high temperatures and are ionized by a rotating electron cloud. The ions are focused with a rf quadrupole lens into a Paul mass
openaire +2 more sources
A consistent molecular hydrogen isotope chemistry scheme based on an independent bond approximation [PDF]
, 2009 The isotopic composition of molecular hydrogen (H<sub>2</sub>) produced by photochemical oxidation of methane (CH<sub>4</sub>) and Volatile Organic Compounds (VOCs) is a key quantity in the global isotope budget of (H<sub>2 ...
Sub Atmospheric physics and chemistry +8 more
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An investigation into the archaeological application of carbon stable isotope analysis used to establish crop water availability: solutions and ways forward [PDF]
, 2011 Carbon stable isotope analysis of charred cereal remains is a relatively new method employed by archaeological scientists to investigate ancient climate and irrigation regimes. The aim of this study was to assess the effect of environmental variables
Jenkins, Emma L. +2 more
core +3 more sources