Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Stable isotope


Related Topics

In the News (Sat 20 Apr 19)

  
  Stable isotope overview
Among stable isotopes the most useful as biological tracers are the heavy isotopes of carbon and nitrogen.
Isotopes of the same element take part in the same chemical reactions, but because the atoms of different isotopes are of different sizes and different atomic weights they react at different rates.
Stable isotope analysis gives an independent measure of fractionation such that if, for instance, a sample is 1.5% heavier in 13C than "modern standard carbon" through the effects of fractionation, then it will be 3% heavier in 14C than it would have been had fractionation not taken place.
www.uga.edu /~sisbl/stable.html   (2022 words)

  
  Isotope - Wikipedia, the free encyclopedia
Isotopes are forms of an element whose nuclei have the same atomic number–-the number of protons in the nucleus--but different atomic masses because they contain different numbers of neutrons.
The word isotope, meaning at the same place, comes from the fact that all isotopes of an element are located at the same place on the periodic table.
In scientific nomenclature, isotopes (nuclides) are specified by the name of the particular element by a hyphen and the number of nucleons (protons and neutrons) in the atomic nucleus (e.g., helium-3, carbon-12, carbon-14, iron-57, uranium-238).
en.wikipedia.org /wiki/Isotope   (954 words)

  
 CONK! Encyclopedia: Stable_isotope   (Site not responding. Last check: )
Isotopes that are not radioactive are called stable.
Stable isotopes of the same element have the same chemical characteristics and therefore behave almost identically.
For example, the difference in mass between the two stable isotopes of hydrogen H-1 (1 proton, no neutron) and H-2 (also known as deuterium, 1 proton, 1 neutron) is almost 100%.
www.conk.com /search/encyclopedia.cgi?q=Stable_isotope   (169 words)

  
 AllRefer.com - isotope (Physics) - Encyclopedia
The concept of isotope was introduced by F. Soddy in explaining aspects of radioactivity; the first stable isotope (of neon) was discovered by J. Thomson.
Thus isotopes of a given element have identical chemical properties but slightly different physical properties and very different half-lives, if they are radioactive (see half-life).
Radioactive isotopes of many common elements, such as carbon and phosphorus, are used as tracers in medical, biological, and industrial research.
reference.allrefer.com /encyclopedia/I/isotope.html   (371 words)

  
 Stable isotope -- Facts, Info, and Encyclopedia article   (Site not responding. Last check: )
Those isotopes that are not (Click link for more info and facts about radioactive) radioactive are called stable.
While stable isotopes of the same element maintain the same chemical characteristics and therefore react in the same way, the mass difference as a result of an extra few neutrons results in partial separation of the light from heavy isotopes during chemical reactions (isotopic fractionation).
For example, the difference in mass between the two main isotopes of hydrogen H-1 (1 proton, no neutron) and H-2 (also known as (An isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)) deuterium; 1 proton, 1 neutron) is almost 100%.
www.absoluteastronomy.com /encyclopedia/s/st/stable_isotope.htm   (174 words)

  
 Isotope Geochemistry - Module 8   (Site not responding. Last check: )
Several elements which show variations in their stable isotope compositions (particularly; hydrogen, carbon, oxygen and sulphur) are very important in terms of their participation and abundance in rock-forming, ore-forming, water-rock interaction and life-processes.
This applies to all stable isotope systems, but is particularly important in the case of H, C, N, O and S isotopes as biologic processes are intimately involved in the biogeochemical cycles of these elements.
The extent of stable isotope fractionation is inversely proportion to the square of the relative mass difference between two isotopes.
www.huxley.ic.ac.uk /Local/EarthSciUG/ESFirstYr/EarthMaterials/mrpalmer/EarthMaterials/Iso/module8/m8.html   (1149 words)

  
 USGS -- Isotope Tracers -- Resources -- Isotope Geochemistry
Isotopes are atoms of the same element that have the same numbers of protons and electrons but different numbers of neutrons.
The so-called stable isotopes are nuclei that do not appear to decay to other isotopes on geologic timescales, but may themselves be produced by the decay of radioactive isotopes.
Reaction rates depend on the ratios of the masses of the isotopes and their vibrational energies; as a general rule, bonds between the lighter isotopes are broken more easily than the stronger bonds between the heavy isotopes.
wwwrcamnl.wr.usgs.gov /isoig/res/funda.html   (1607 words)

  
 What are stable isotopes? Colorado Plateau Stable Isotope Laboratory
Isotopes are atoms of the same element that differ in atomic mass, due to differences in the number of neutrons contained in the atoms' nuclei.
Stable isotopes of carbon, nitrogen, sulfur, oxygen, and hydrogen - those most commonly used in ecological and environmental research - are measured by gas isotope-ratio mass spectroscopy.
Other stable isotope techniques rely on adding trace amounts of compounds that are artificially enriched in the rare (heavy) isotope of the element of interest.
www4.nau.edu /cpsil/isotopes.htm   (1057 words)

  
 Geochron Laboratories / Krueger Enterprises: Stable Isotope Ratio Analysis
Stable isotope ratio analysis is the precise measurement of the abundance ratio of two stable isotopes of a particular element.
In the stable isotope laboratory at Geochron, we prepare and analyze a variety of materials for their nitrogen, sulfur, carbon, oxygen, and hydrogen stable isotope compositions.
Samples with significant isotopic depletion or enrichment with respect to natural levels should be discussed with us in advance, and may be subject to additional analytical charges.
www.geochronlabs.com /stable.html   (257 words)

  
 Spectra Stable Isotopes - An Introduction
Spectra Stable Isotopes, a division of Spectra Gases, was formed by the acquisition of the Martek Stable Isotope Group by Spectra Gases, Inc.
Stable isotope biochemicals are materials such as amino acids, carbohydrates, lipids and nucleic acids in which the naturally abundant isotopes of hydrogen, carbon and nitrogen (
Incorporation of stable isotopes into proteins, carbohydrates and nucleic acids facilitates their structural determination at the atomic level.
www.spectrastableisotopes.com /Home.asp   (91 words)

  
 Stable isotope - Wikipedia, the free encyclopedia
Different isotopes of one chemical element may have different radioactive properties.
For example, the difference in mass between the two main isotopes of hydrogen H-1 (1 proton, no neutron) and H-2 (also known as deuterium; 1 proton, 1 neutron) is almost 100%.
Commonly analysed stable isotopes include oxygen, carbon, hydrogen and sulfur.
www.bucyrus.us /project/wikipedia/index.php/Stable_isotope   (244 words)

  
 A Brief Early History of Stable Isotope (
An isotope of oxygen of mass 17 in the Earth's atmosphere.
Two landmark papers published on the theory of stable isotope fractionation and the Urey puts forth the idea of oxygen isotope paleothermometry.
Reviews recent investigations on the isotopic composition of terrestrial carbon, and notes that progress made in the study of carbon isotopes is a contribution to the discovery of the most primitive organisms.
epswww.unm.edu /facstaff/zsharp/505/abrief.htm   (351 words)

  
 Stable Isotope Techniques in human nutritional studies   (Site not responding. Last check: )
The use of stable isotopes is a potential technique to study the bioavailability of nutrients or active compounds.
The bioavailability of iron is measured by the dual stable isotope technique, in which absorption is calculated from the incorporation of both isotopes in haemoglobin.
The dual stable isotopes technique using urinary monitoring, is a potentially useful method for measuring selenium absorption and is now under development.
www.voeding.tno.nl /Go/Prodvoe301e.htm   (648 words)

  
 Center for Isotope Geochemistry: Stable Isotope Laboratory
The Center for Isotope Geochemistry stable isotope laboratory conducts basic and applied geochemical research using the isotope ratios of light elements including hydrogen, carbon, nitrogen, oxygen and chlorine.
Stable isotope facilities include a dual-inlet VG Prism Series II isotope ratio mass spectrometer with automated prep systems for measuring the isotope ratios of carbonate minerals and oxygen and hydrogen isotope ratios of waters.
In addition, there are both conventional and laser fluorination lines for analyzing the oxygen isotope compositions of silicate and oxide minerals, and vacuum lines used for extraction of water from soil and plant material and off-line preparation of samples for carbon and nitrogen isotope measurements.
www-esd.lbl.gov /CIG/stableisotope/sil.html   (173 words)

  
 Stable Isotope Ratio Mass Spectrometer (SIRMS) Laboratory, University at Albany
The Stable Isotope Ratio Mass Spectrometer (SIRMS) Laboratory is the main analytical facility in the Department of Earth and Atmospheric Sciences dedicated to global paleoclimatological and paleoenvironmental research.
The carbon dioxide that is evolved during acid digestion of the carbonate material, or the carbon dioxide or hydrogen that has equilibrated with the water sample, enters a side port in the same needle and passes through a water trap prior to being frozen into cold fingers in the mass spectrometer's dual inlet.
The evolved carbon dioxide or equilibrated carbon dioxide or hydrogen is analyzed by comparing its stable isotopic composition to that of reference carbon dioxide or hydrogen repeatedly during a 7-minute analysis.
www.albany.edu /geosciences/sirmslab.html   (871 words)

  
 Stable Isotope Laboratory
We are New Zealand's national stable isotope facility with established techniques and skilled researchers.
Our website provides information on the stable isotopes of carbon 13, nitrogen 15, oxygen 18, sulphur 34, deuterium, and hydrogen.
A competitive price for the analysis of each of the isotopes is also given, based on the type of sample submitted.
www.gns.cri.nz /stable/index.html   (114 words)

  
 Chapter 2: Fundamentals of Isotope Geochemistry
Stable isotopes are nuclides that do not appear to decay to other isotopes on geologic time scales, but may themselves be produced by the decay of radioactive isotopes.
Stable isotopes are analyzed either on gas- or solid-source mass spectrometers, depending on both the masses of the isotopes and the existence of appropriate gaseous compounds stable at room temperature.
The isotopic compositions of waters and solutes can be significantly affected by the concentration and types of salts because the isotopic compositions of waters in the hydration spheres of salts and in regions farther from the salts are different (see Horita (1989) for a good discussion of this topic).
wwwrcamnl.wr.usgs.gov /isoig/isopubs/itchch2.html   (13621 words)

  
 Dr. R.V. Krishnamurthy, Faculty Home Page
I apply known stable isotope techniques to geochemical, hydrological and related environmental studies and also go hunting for new and novel applications.
I also spend time in developing techniques that will make a stable isotope geochemist's life a bit easy, and look for collaborative research.
The stable isotope laboratory under my direction is equipped with a Micromass Optima isotope ratio mass spectrometer, various vaccum extraction lines, constant temperature bath and a microwave sample digestion system.
www.wmich.edu /geology/faculty/krishnamurthy.html   (185 words)

  
 Stable Isotope Laboratory
The stable isotope laboratory has a number of extraction lines for the measurement of stable isotope ratios of O, C, and H in rock (silicates and carbonates), mineral and water samples.
R Diamond "A stable isotope study of the hot springs of the Western part of the Cape Fold Belt".
P Macey "A stable isotope study of fluid movement during the deformation of the Zerrissene turbidites in north western Namibia".
web.uct.ac.za /depts/geolsci/facilities/stable_isotopes.htm   (489 words)

  
 Stable isotope   (Site not responding. Last check: )
Whilst stable isotopes the same element maintain the same chemical and therefore react in the same way mass difference as a result of an few neutrons results in partial separation of light from heavy isotopes during chemical reactions fractionation).
For example the difference in mass the two main isotopes of hydrogen H1 proton no neutron) and H2 (also known deuterium; 1 proton 1 neutron) is almost Therefore a significant fractionation will occur.
These isotope systems have been investigation for many years as they are simple to measure.
www.freeglossary.com /Stable_isotope   (415 words)

  
 Stable Isotope   (Site not responding. Last check: )
After another four weeks the grassland was exposed to a particular form of carbon dioxide (a stable isotope of carbon, 13C) for 7 hours, a technique called...
The forensic stable isotope testing was done by the Dunedin company Iso-trace New Zealand Limited.
Falkowski's team used the relative abundances of a stable isotope of carbon in deep-sea cores to calculate how much oxygen was in the atmosphere at that time.
www.wikiverse.org /stable-isotope   (306 words)

  
 Controls on methane concentration and stable isotope (δ2H-CH4 and δ13C-CH4) distributions in the water ...
We derive open-system kinetic isotope effect equations and use a one-dimensional (vertical) stable isotope box model that, along with isotope budgets developed using radiocarbon, permits a quantitative treatment of the stable isotope differences.
We show that two main factors control the CH concentration and stable isotope differences: (1) the depth distributions of the input of CH from seafloor seeps and (2) anaerobic oxidation of CH under open-system steady state conditions in the Black Sea and open-system non-steady-state conditions in the Cariaco Basin.
Index Terms: 4870 Oceanography: Biological and Chemical: Stable isotopes (0454, 1041); 4820 Oceanography: Biological and Chemical: Gases; 4802 Oceanography: Biological and Chemical: Anoxic environments (0404, 1803, 4834, 4902); 4219 Oceanography: General: Continental shelf and slope processes (3002).
www.agu.org /pubs/crossref/2006/2005GB002571.shtml   (363 words)

  
 Carbon and Nitrogen Stable Isotope Literature
Abend, A.G., and Smith, T.D. Differences in ratios of stable isotopes of nitrogen in long-finned pilot whales (Globicephalus melas) in the western and eastern North Atlantic.
Investigating trophic relationships of pinnipeds in Alaska and Washington using stable isotope ratios of nitrogen and carbon.
Thompson, D.R., and Furness, R.W. Stable isotopes ratios of carbon and nitrogen in feathers indicate seasonal dietary shifts in northern fulmars.
epswww.unm.edu /facstaff/zsharp/carbon_nitrogen_literature.htm   (3201 words)

  
 Development and use of stable isotope techniques to investigate the functional ecology of invertebrates
Objectives: To determine intra and interspecific variation in C and N stable isotope ratios as novel means of determining feeding relationships and ecosystem functions of dominant soil invertebrate groups in contrasting farm systems.
In Action 4, enriched stable isotope tracer methods (15N and 13C) will be used as one tool to study the functional significance of altered biodiversity.
Isotope analyses for the Ag-Biota project will be carried out at the Stable Isotopes Unit, Scottish Crop Research Institute, Dundee DD2 5DA, Scotland, with which strong collaborative research links exist.
www.ucd.ie /agbiota/studies/stable_isotopes.htm   (278 words)

  
 NERC Research Funding - NERC STABLE ISOTOPE FACILITY
Located at Grange-over-Sands in Cumbria, the stable isotope facility is based within the Institute of Terrestrial Ecology's research station and carries out stable isotope analyses directed toward the terrestrial and freshwater scientific communities.
The introduction of gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) into the Stable Isotope Facility at ITE Merlewood has created the potential for exciting new research opportunities to be developed and applied to the field of terrestrial and freshwater sciences.
Additionally, due to recent improvements in analytical techniques, the volumes of sample required for the isotopic analyses of the trace gases (carbon dioxide, methane and nitrous oxide) at ambient concentrations and natural abundance, has fallen by nearly 3 orders of magnitude.
www.nerc.ac.uk /funding/services/15nsif.shtml   (1103 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.