Results 11 to 20 of about 95,714 (157)

Towards a global interpretation of dual nitrate isotopes in surface waters [PDF]

Journal of Hydrology X, 2019
Modern anthropogenic activities have significantly increased nitrate (NO3−) concentrations in surface waters. Stable isotopes (δ15N and δ18O) in NO3− offer a tool to deconvolute some of the human-made changes in the nitrogen cycle.
J.J. Venkiteswaran, P. Boeckx, D.C. Gooddy   +2 more
doaj   +3 more sources

Determination Methods and Distribution Characteristics of Nitrogen Isotopes in Different Nitrogenous Components of Crude Oil

Yankuang ceshi, 2023
BACKGROUNDThe distribution of nitrogen isotopes has important significance in paleoclimate, paleo-sedimentary and evolutionary characteristics. Nitrogen is one of the important heteroatomic elements in crude oil.
Min LI, Jing QIN, Yang BAI, Chen HE, Xuemin XU, Jianfa CHEN   +5 more
doaj   +1 more source

Presenting the Compendium Isotoporum Medii Aevi, a Multi-Isotope Database for Medieval Europe

Scientific Data, 2022
Measurement(s) Isotopes Technology Type(s) Mass Spectrometry Factor Type(s) Carbon isotopes • nitrogen isotopes • sulfur isotopes • oxygen isotopes • strontium isotopes Sample Characteristic - Organism Humans • Animals • Plants Sample Characteristic ...
Carlo Cocozza, Enrico Cirelli, Marcus Groß, Wolf-Rüdiger Teegen, Ricardo Fernandes   +4 more
doaj   +1 more source

Inter-Laboratory Comparison of Measuring Organic Carbon and Stable Nitrogen Isotopes in Marine Sediments by Elemental Analysis-Isotope Ratio Mass Spectrometry

Yankuang ceshi, 2020
BACKGROUND Organic carbon and nitrogen stable isotopes (δ13C, δ15N) in marine sediments are used as effective indicators to trace the changes of air, temperature, precipitation and other parameters in different geological time. Elemental analysis-isotope
CHANG Wen-bo, LI Feng, ZHANG Yuan-yuan, HE Xing-liang   +3 more
doaj   +1 more source

Sedimentary pyrite sulfur isotopes track the local dynamics of the Peruvian oxygen minimum zone

Nature Communications, 2021
To explore the importance of local vs. global sulfur-cycle controls on variations in pyrite sulfur isotopes, the authors couple carbon-nitrogen-sulfur concentrations and stable isotopes of sediments from the Peruvian oxygen minimum zone, identifying a ...
Virgil Pasquier, David A. Fike, Itay Halevy   +2 more
doaj   +1 more source

Isotopic Fingerprinting: A Promising Tool for Coffee Authenticity Checks

Proceedings, 2023
Almost every physical or chemical process in nature favors certain light stable isotopes over others, and thereby leaves an isotopic “fingerprint” on the substances involved.
Johannes Wintel, Corina Knipper, Mila Spross, Ronny Friedrich, Steffen Schwarz   +4 more
doaj   +1 more source

Interstellar nitrogen isotope ratios [PDF]

Symposium - International Astronomical Union, 1985
We report first results of a systematic study of the galactic interstellar nitrogen isotope ratios, based upon measurements of the (J,K) = (1,1) and (2,2) lines of the 14NH3 and 15NH3 molecules. We find significant deviations of the [14N]/[15N3] abundance ratio from the solar-system value (~270), with the most extreme enrichment in the galactic-center ...
R. Güsten, H. Ungerechts
openaire   +1 more source

A pilot study of stable isotope fractionation in Bombyx mori rearing

Scientific Reports, 2023
Hydrogen, oxygen, carbon, and nitrogen isotopes derived from three different strains of silkworms at different life stages involved in silkworm rearing, were measured to understand the fractionation characteristics of stable isotopes at different stages ...
Hao Li, Yujie He, Jinzhong Lu, Liling Jia, Yong Liu, Dan Yang, Shuai Shao, Gang Lv, Hailiang Yang, Hailing Zheng, Yang Zhou, Zhiqin Peng   +11 more
doaj   +1 more source

Effects of Upwelling Intensity on Nitrogen and Carbon Fluxes through the Planktonic Food Web off A Coruña (Galicia, NW Spain) assessed with Stable Isotopes

Diversity, 2020
The input of new nutrients by upwelling in shelf waters, and the associated carbon and nitrogen fluxes, can be traced by their stable isotope signatures in organic matter.
Antonio Bode, Angel F. Lamas, Carmen Mompeán   +2 more
doaj   +1 more source

LIBS plasma in atmospheric pressure argon, nitrogen and helium: Spatio-temporal distribution of plume emission and Hα linewidth

Nuclear Materials and Energy, 2023
Laser Induced Breakdown Spectroscopy (LIBS) method is considered for assessing the retention of hydrogen isotopes in the ITER plasma-facing components during the maintenance breaks when the reactor is filled with near atmospheric pressure nitrogen or ...
Indrek Jõgi, Jasper Ristkok, Jelena Butikova, Jüri Raud, Peeter Paris   +4 more
doaj   +1 more source