نتایج جستجو برای: stable isotopes

تعداد نتایج: 276152  

Journal: Geopersia 2020

Stable isotopes (Deuterium and Oxygen-18) have a broad application in many of water related sciences. Precipitation is the most important input to the water cycle which shows considrable spatial and temporal variability in its isotope content. To study the precipitation isotope content, 51 samples from August 2015 to July 2016 have been collected mainly on a monthly basis with few events based ...

Journal: Geopersia 2014

For more than half a century isotopes have been employed as a powerful tool in studying various aspects of water resources in a largenumber of countries. However, in developing countries like Iran the application of such techniques is in its infancy. The first research inIran was carried out in 1975 to identify the source of saline groundwaters in south Iran, and the first national conference o...

Journal: :Ecological applications : a publication of the Ecological Society of America 2014
Clark S Rushing Thomas B Ryder James F Saracco Peter P Marra

Patterns of migratory connectivity are a vital yet poorly understood component of the ecology and evolution of migratory birds. Our ability to accurately characterize patterns of migratory connectivity is often limited by the spatial resolution of the data, but recent advances in probabilistic assignment approaches have begun pairing stable isotopes with other sources of data (e.g., genetic and...

2008

A range of isotopic methods (using radioactive and stable isotopes) have been used to investigate groundwater processes and to determine the sources and pathways for groundwater contamination. Methods using stable isotopes of nitrogen have been applied in a variety of Australian and international groundwater studies. Isotopic methods have involved either application of tracer isotopes or studyi...

2012
S Bouillon

Stable isotopes have been extensively used to trace element cycles and their incorporation into food webs. This chapter provides a brief introduction to the principles of using stable isotopes as natural or deliberate tracers in estuarine systems, with a focus on (1) assessing the origin and cycling of organic and inorganic elements (mainly carbon and nitrogen), (2) defining estuarine food webs...

2016
Takanori NAKANO

The ratios of stable isotopes of certain elements in rocks and minerals have strong regional characteristics that are reflected in atmospheric components, in water, and in the living organisms that form Earth's surface environment as well as in agricultural and fishery products. Geologically derived stable isotope ratios can be used as a tracer for the source of many kinds of substances, with c...

Journal: :Clinical science 1994
J F Barrett P G Whittaker J D Fenwick J G Williams T Lind

1. Stable isotope methods are being used to investigate the absorption of dietary iron. In order to be certain that this new methodology is accurate, we have compared results obtained using stable isotopes and inductively coupled plasma mass spectrometry with those determined using a radioisotope and whole body counting. 2. The stable isotope 54Fe (2.8 mg) was given to 10 healthy non-pregnant w...

2018
Daniel James Wilkinson

Over a century ago, Frederick Soddy provided the first evidence for the existence of isotopes; elements that occupy the same position in the periodic table are essentially chemically identical but differ in mass due to a different number of neutrons within the atomic nucleus. Allied to the discovery of isotopes was the development of some of the first forms of mass spectrometers, driven forward...

2016
Niels J de Winter Christophe Snoeck Philippe Claeys

The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared w...

Journal: :Journal of the Mass Spectrometry Society of Japan 1964

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