Radiocarbon dating (sometimes simply known as carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (C) to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" (BP), "Present" being defined as 1950. Such raw ages can be calibrated to give calendar dates. One of the most frequent uses of radiocarbon dating is to estimate the age of organic remains from archaeological sites. When plants fix atmospheric carbon dioxide (CO2) into organic material during photosynthesis they incorporate a quantity of C that approximately matches the level of this isotope in the atmosphere (a small difference occurs because of isotope fractionation, but this is corrected after laboratory analysis). After plants die or they are consumed by other organisms (for example, by humans or other animals) the C fraction of this organic material declines at a fixed exponential rate due to the radioactive decay of C. Comparing the remaining C fraction of a sample to that expected from atmospheric C allows the age of the sample to be
Nanostructures made of carbon are extremely versatile. They can absorb ions in batteries and supercapacitors, store gases and desalinate water. How well they cope with the task at hand depends largely on the structural features ...
Nanomaterials
Mar 14, 2019
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Scientists at the University of Waterloo have created a powder that can capture CO2 from factories and power plants.
Environment
Dec 19, 2018
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Brown University researchers have shown a way to use graphene oxide (GO) to add some backbone to hydrogel materials made from alginate, a natural material derived from seaweed that's currently used in a variety of biomedical ...
Nanomaterials
Nov 21, 2018
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152
Using the energy from the sun and graphene applied to the surface of cubic silicon carbide, researchers at Linköping University, Sweden, are working to develop a method to convert water and carbon dioxide to the renewable ...
Nanomaterials
Nov 08, 2018
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485
A new research article introduces a nanofiber material produced by the electrospinning device at the Laboratory of Polymers and Textile Technology in Tallinn University of Technology, and a range of applications. The article, ...
Nanomaterials
Nov 01, 2018
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Graphene has been hailed as the material of the future. As yet, however, little is known about whether and how graphene affects our health if it gets into the body. A team of researchers from Empa and the Adolphe Merkle Institute ...
Nanomaterials
Oct 18, 2018
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85
Research by Robert Hudson, a doctoral student in mechanical engineering, and Alok Sinha, professor of mechanical engineering, conducted in the Penn State Department of Mechanical and Nuclear Engineering, has resulted in computationally ...
Nanomaterials
Aug 20, 2018
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7
If you're ever unlucky enough to have a car with metal tires, you might consider a set made from a new alloy engineered at Sandia National Laboratories. You could skid—not drive, skid—around the Earth's equator 500 times ...
Materials Science
Aug 16, 2018
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2323
Fullerenes are composed of 60 carbon atoms joined together in hexagonal rings to form a sphere that resembles a soccer ball. Fullerenes are of great interest to materials scientists because their interesting electronic properties ...
Nanomaterials
May 10, 2018
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The surfaces of materials can have an enormous influence on their function. If the external properties are changed, this also expands the range of possible applications. This is why materials scientists at Friedrich Schiller ...
Condensed Matter
Apr 16, 2018
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