Results 271 to 280 of about 3,969,104 (330)
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Stable carbon isotopes in marine porewaters
Earth and Planetary Science Letters, 1985Abstract We present centimeter-scale porewater δ 13 C profiles from four sites in the Central Equatorial Pacific Ocean, which reveal steep porewater δ 13 C gradients (up to −1.0‰ cm −1 ) at the deep-sea sediment—water interface. We describe the processes controlling porewater carbon isotopic composition and incorporate them into a model of the deep ...
Daniel C. McCorkle +2 more
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Journal of Forensic Sciences, 2008
Abstract: There remains significant uncertainty in illicit marijuana cultivation. We analyzed the δ13C and δ15N of 508 domestic samples from known U.S.A. counties, 31 seized from a single location, 5 samples grown in Mexico and Colombia, and 10 northwest border seizures. For a subset, inflorescences and leaves were analyzed separately.
Jason B, West +2 more
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Abstract: There remains significant uncertainty in illicit marijuana cultivation. We analyzed the δ13C and δ15N of 508 domestic samples from known U.S.A. counties, 31 seized from a single location, 5 samples grown in Mexico and Colombia, and 10 northwest border seizures. For a subset, inflorescences and leaves were analyzed separately.
Jason B, West +2 more
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Assessment of Carbon Allocation with Stable Carbon Isotope Labeling
Agronomy Journal, 1990AbstractLabeling plants with isotopic forms of C allows many processes important to agriculture and/or natural resource management to be studied. Most C‐labelling experiments have employed radioactive 14C, but in recent years regulatory constraints associated with use of radioactive materials appear to have curtailed studies which may have benefited ...
Tony J. Svejcar +2 more
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Behavior of Stable Carbon and Stable Nitrogen Isotopes during Hydrothermal Carbonization of biomass
Journal of Analytical and Applied Pyrolysis, 2018Abstract This work studied the changes of stable isotope compositions (C and N) of diverse biomass feedstocks (loblolly pine, cow manure, and sewage biosolids) as a result of hydrothermal carbonization (HTC), and provides insight into degradation pathways based on these changes.
M. Toufiq Reza +3 more
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The carbon stable isotope composition of pollen
Review of Palaeobotany and Palynology, 2004The d 13 C value of plant tissue is increasingly used to infer environmental and ecological conditions in modern and ancient environments. Isolation techniques and morphological descriptions have been established that characterize plant pollen for the greater part of the Phanerozoic eon.
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Stable Carbon and Oxygen Isotopes in Soils
2001The most common use of stable carbon (C) and oxygen (O) isotopes in archaeology is to infer paleodiet, artifact provenance, and paleoenvironment (Herz, 1990; Herz and Garrison, 1998).
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Stable Carbon Isotopes in the Dissolved Organic Matter of the Sea
Nature, 1968THERE have been several recent investigations concerned with 13C/12C ratios in marine phyto and zooplankters, with metabolic fractionation of these isotopes in laboratory phytoplankton cultures, and with the carbon isotopic composition of the biochemical constituents of oceanic plankton1–5.
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