• No results found

nitrogen isotope ratio

Determination of Subsurface Nitrogen Contamination using Tree Leaves and Stable Nitrogen Isotope Ratios.

Determination of Subsurface Nitrogen Contamination using Tree Leaves and Stable Nitrogen Isotope Ratios.

... heavier isotope to become more positive in the substrate, while the newly formed product will be isotopically more enriched with the lighter isotope or more negative than the parent material (Kendall and ...

195

Nitrogen isotope ratios identify nitrate contamination sources

Nitrogen isotope ratios identify nitrate contamination sources

... 615Nconcentratlonswlth depth for Inorganic fertilizer, animal feedlot, septic tank on-site sewage disposal and natural soil organic matter sites In the Davis area southern Sacramento Val[r] ...

5

Variability in δ15N, δ13C and Kjeldahl nitrogen of soils from islands with and without seabirds in the Marlborough Sounds, New Zealand

Variability in δ15N, δ13C and Kjeldahl nitrogen of soils from islands with and without seabirds in the Marlborough Sounds, New Zealand

... Kjeldahl nitrogen (TKN) and carbon and nitrogen isotope ratios of soils from islands with and without seabirds in the Marlborough Sounds, New Zealand, to investigate one means by which seabirds may ...

6

Stable isotopes and dynamic diets : the Mesolithic-Neolithic dietary transition in terrestrial Central Europe

Stable isotopes and dynamic diets : the Mesolithic-Neolithic dietary transition in terrestrial Central Europe

... Stable isotope data in this context have thrown up controversial results, famously such as the ‘sharp shift’ from marine to terrestrial resources along the Atlantic façade of Europe (Richards et ...stable ...

18

Insights into nitrogen allocation and recycling from nitrogen elemental analysis and 15N isotope labelling in 14 genotypes of willow

Insights into nitrogen allocation and recycling from nitrogen elemental analysis and 15N isotope labelling in 14 genotypes of willow

... Short rotation coppice willow is known to recycle resources before the winter from leaves to stems, stools and roots to provide reserves for re-growth in the spring (Bollmark et al. 1999, Cooke and Weih 2005, Karp and ...

12

Natural Isotopic Composition of Particulate Organic Nitrogen in the Eastern and Central Arabian Sea

Natural Isotopic Composition of Particulate Organic Nitrogen in the Eastern and Central Arabian Sea

... for nitrogen isotopic composition of natural PON at eighteen Stations using Niskin bottles, mounted on a CTD rosette from various depths, mostly up to ~100 m, however, at two Stations (1 and 2) up to 1500 ...

9

Rapid CO2 mineralisation into calcite at the CarbFix storage site quantified using calcium isotopes

Rapid CO2 mineralisation into calcite at the CarbFix storage site quantified using calcium isotopes

... initial isotope ratio of the basalt, the isotope ratios and Ca con- centrations of the measured fluid samples, the fluid-calcite frac- tionation factor and the water flow ...metal isotope ...

8

Assessment of the authenticity of fruit spirits by gas chromatography and stable isotope ratio analyses

Assessment of the authenticity of fruit spirits by gas chromatography and stable isotope ratio analyses

... by isotope ratio mass spectrometry – IRMS analysis as well as SNIF–NMR analysis of (D/H)I and (D/H)II ratios in ethanol are prospective analytical methods which can be used for checking the authenticity of ...

8

Hagfish feeding habits along a depth gradient inferred from stable isotopes

Hagfish feeding habits along a depth gradient inferred from stable isotopes

... C:N ratio in this study was ...little nitrogen, so it is possible that the high C:N ratios observed in this study could also be due to high levels of this com- ...

13

Continuous-flow isotope ratio mass spectrometry method for carbon and hydrogen isotope measurements on atmospheric methane

Continuous-flow isotope ratio mass spectrometry method for carbon and hydrogen isotope measurements on atmospheric methane

... It is crucial that the system can be stabilized at different temperatures with only small temperature gradients in the unit. Figure 3a and b illustrate the concept of two developed HSD units. The two units use liquid ...

15

High precision isotope ratio measurements of uranium and plutonium in the environment

High precision isotope ratio measurements of uranium and plutonium in the environment

... introduced at the top of the stratosphere would have a longer residence time than would plutonium from weapons testing which was mainly introduced to the lower parts. Besides the location of injected particles, other ...

187

On the interference of Kr during carbon isotope analysis of methane using continuous-flow combustion–isotope ratio mass spectrometry

On the interference of Kr during carbon isotope analysis of methane using continuous-flow combustion–isotope ratio mass spectrometry

... form molecules or adducts (Leckrone and Hayes, 1998; Ses- sions et al., 2001), which then could provide the necessary m/z 44, m/z 45 and m/z 46 signals. The other hypothesis as- sumes scattering processes lead to broader ...

21

Distribution and rates of nitrogen fixation in the western tropical South Pacific Ocean constrained by nitrogen isotope budgets

Distribution and rates of nitrogen fixation in the western tropical South Pacific Ocean constrained by nitrogen isotope budgets

... Frank, I., Bode, A., Bonnet, S., Boström, K. H., Böttjer, D., Capone, D. G., Carpenter, E. J., Chen, Y. L., Church, M. J., Dore, J. E., Falcón, L. I., Fernández, A., Foster, R. A., Fu- ruya, K., Gómez, F., Gundersen, K., ...

10

Recent advances in the application of stable isotope ratio analysis in forensic chemistry

Recent advances in the application of stable isotope ratio analysis in forensic chemistry

... The paper details the analysis of 26 samples of semtex H, which contains 80% pentaerythritol tetranitrate (PETN) and cyclotrimethylenetrinitramine (RDX) and 20% of polymeric matrix. Four different statistical methods ...

9

Stable Isotope Traces of Nitrogen Sources to the Neuse River, North Carolina

Stable Isotope Traces of Nitrogen Sources to the Neuse River, North Carolina

... Stable nitrogen isotopic analyses (6%)2 were conducted on dissolved nitrate in surface water samples collected over a two year period from the lower Neuse River, North Carolina, to ass[r] ...

36

STUDIES ON THE EFFECTS OF SALINISATION ON NODULATION AND NITROGEN FIXATION IN PEA (PISUM SAT/VUM L.)

STUDIES ON THE EFFECTS OF SALINISATION ON NODULATION AND NITROGEN FIXATION IN PEA (PISUM SAT/VUM L.)

... The nodule nitrogen, total plant nitrogen and the ratio of plant dry matter to plant nitrogen indicated reduced nitrogen fixation by the plants growing under saline cond iti[r] ...

6

An analytical system for stable isotope analysis on carbon monoxide using continuous-flow isotope-ratio mass spectrometry

An analytical system for stable isotope analysis on carbon monoxide using continuous-flow isotope-ratio mass spectrometry

... CO isotope analysis was carried out with of- fline extraction systems, which require large amounts of air (Brenninkmeijer, 1993; Stevens and Krout, 1972), but in re- cent years, continuous-flow techniques have ...

10

Experimental investigation of potential biological nitrogen provisioning by freshwater

Experimental investigation of potential biological nitrogen provisioning by freshwater

... 15 N stable isotope analysis in investigating biological nitrogen provisioning via nitrate reduction 191. to ammonium in freshwater insects[r] ...

22

Microbial diversity on Icelandic glaciers and ice caps

Microbial diversity on Icelandic glaciers and ice caps

... We were also able to confirm the presence of archaea in our samples. Currently, only very few studies have documented the presence of archaea in glacial environments. They have been found in a glacial stream in Austria ...

17

John Bremner 1922-2007

John Bremner 1922-2007

... the nitrogen fertilizer research and outreach area because the last large ammonium nitrate production facility for manufacture of explosives during World War II was ...Since nitrogen fertilizer production ...

27

Show all 10000 documents...

Related subjects