Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Entire DC Network
Membrane Inlet Mass Spectrometry Method (Reox/Mims) To Measure 15n-Nitrate In Isotope-Enrichment Experiments, Xianbiao Lin, Kaijun Lu, Amber K. Hardison, Et Al
Membrane Inlet Mass Spectrometry Method (Reox/Mims) To Measure 15n-Nitrate In Isotope-Enrichment Experiments, Xianbiao Lin, Kaijun Lu, Amber K. Hardison, Et Al
VIMS Articles
Using 15N stable isotope as a tracer to quantify N transformation rates in isotope-enrichment experiments improves understanding of the N cycle in various ecosystems. However, measuring 15N-nitrate (15NO3−) in small volumes of water for these experiments is a major challenge due to the inconvenience of preparing samples by traditional techniques. We developed a “REOX/MIMS” method by applying membrane inlet mass spectrometry (MIMS) to determining 15NO3− concentrations in a small volumes of water from isotope-enrichment experiments after converting the dissolved inorganic N to N2. The nitrates (NO3− …
Extraordinary Human Energy Consumption And Resultant Geological Impacts Beginning Around 1950ce Initiated The Proposed Anthropocene Epoch, Jaia Syvitsk, Colin N. Waters, John Day, John D. Milliman, Et Al
Extraordinary Human Energy Consumption And Resultant Geological Impacts Beginning Around 1950ce Initiated The Proposed Anthropocene Epoch, Jaia Syvitsk, Colin N. Waters, John Day, John D. Milliman, Et Al
VIMS Articles
Growth in fundamental drivers—energy use, economic productivity and population—can provide quantitative indications of the proposed boundary between the Holocene Epoch and the Anthropocene. Human energy expenditure in the Anthropocene, ~22 zetajoules (ZJ),exceeds that across the prior 11,700 years of the Holocene (~14.6 ZJ), largely through combustion of fossil fuels. The global warming effect during the Anthropocene is more thanan order of magnitude greater still. Global human population, their productivity and energy consumption, and most changes impacting the global environment, are highly correlated. This extraordinary outburst of consumption and productivity demonstrates how the Earth System has departed from its Holocene state …
Temporal Variability Of Delta C-14, Delta C-13, And C/N In Sinking Particulate Organic Matter At A Deep Time Series Station In The Northeast Pacific Ocean, J Hwang, Erm Druffel, S Griffin, Kl Smith, Rj Baldwin, Je Bauer
Temporal Variability Of Delta C-14, Delta C-13, And C/N In Sinking Particulate Organic Matter At A Deep Time Series Station In The Northeast Pacific Ocean, J Hwang, Erm Druffel, S Griffin, Kl Smith, Rj Baldwin, Je Bauer
VIMS Articles
A 6-year time series of Delta(14) C, delta(13) C, and C/N measurements in deep sinking particulate organic matter ( POM) is presented for an abyssal site, Station M in the northeast Pacific Ocean. The Delta(14)C values revealed that sinking POM at 3450 m depth ( 650 m above bottom) contained old carbon despite its presumed short transit time in the water column. The isotopic and chemical properties of the sinking POM varied with time and appear to be controlled by more than one major process. In 1993, 1994, and late 1996, isotopic signatures and C/N molar ratios indicate negligible or …
Transport Of Particles Across Continental Shelves, Ca Nittrouer, Ld Wright
Transport Of Particles Across Continental Shelves, Ca Nittrouer, Ld Wright
VIMS Articles
Transport of particulate material across continental shelves is well demonstrated by the distributions on the seabed and in the water column of geological, chemical, or biological components, whose sources are found farther landward or farther seaward. This paper addresses passive (incapable of swimming) particles and their transport across (not necessarily off) continental shelves during high stands of sea level. Among the general factors that influence across-shelf transport are shelf geometry, latitudinal constraints, and the timescale of interest. Research studies have investigated the physical mechanisms of transport and have made quantitative estimates of mass flux across continental shelves. Important mechanisms include …