Sentences with phrase «13c isotopic»

Measurement of the 13C isotopic signature of methane emissions from Northern European wetlands.

This enabled a direct measurement of the 12C / 13C isotopic ratio for the Orion hot core of 14 + / - 1 and an estimated maximum value of 21.

Not exact matches

In diamond at room temperature, Maurer et al. (p. 1283) show that a spin - based qubit system comprised of an isotopic impurity (13C) in the vicinity of a color defect (a nitrogen - vacancy center) could be manipulated to have a coherence time exceeding one second.

The authors also monitored the isotopic 13C composition of CO2, which serves as a fingerprint of emissions from coal - fired power plants and matched it to that of the local coal.

The information about oxygen concentration comes from the isotopic composition of carbon or rather from the ratio between the stable carbon isotopes 12C and 13C.

Because carbon cycle processes such as photosynthesis fractionate the heavy isotope 13C from the lighter 12C, isotopic analysis can usually be used to «trace» sources and sinks of carbon.

More than likely, the isotopic signal (the distribution of 13C - depleted carbon that invaded the atmosphere) indicates that carbon should have been «mined» from the Southern ocean as a result of the displacement of southern winds, sea ice, and perturbations to the ocean's biological pump (e.g., Anderson et al., 2009).

Until recently, analytical issues in the ice core measurements provided a limitation on assessing the deglacial isotopic evolution of 13C.

Rob, David — Notwithstanding the limitations in the precision of isotopic measurements, no source sufficient to explain the increasing CO2 trend has been identified that produces the observed: (1) decreasing O2 / N2 (2) decreasing 14C / 12C (3) decreasing 13C / 12C (4) increasing pH of the oceans

«THE stable carbon isotopic (13C / 12C) record of twentieth - century tree rings has been examined1 - 3 for evidence of the effects of the input of isotopically lighter fossil fuel CO2 (δ 13C ~ -25 ‰ relative to the primary PDB standard4), since the onset of major fossil fuel combustion during the mid-nineteenth century, on the 13C / 12C ratio of atmospheric CO2 (δ 13C ~ -7 ‰), which is assimilated by trees by photosynthesis.

Curiously, the PETM was accompanied by an exceptionally large change to the global carbon cycle as indicated by a large drop in the isotopic ratio of 13C to 12C in the ocean and on land.

If he wanted to apply his scientific credentials to a scientific matter in climate, he might turn to what the isotopic ratio of carbon (13C / 12C) needs to be in atmospheric CO2 concentration to constitute a fingerprint of human origin.

Truth n ° 3 The amount of CO2 in the air from anthropic emissions is today no more than 6 % of the total CO2 in the air (as shown by the isotopic ratios 13C / 12C) instead of the 25 % to 30 % said by IPCC