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
Nothing in the world is perfect. This is also true in materials research. In computer simulations, one often represents a system in a highly idealized way; for example, one calculates the properties that an absolutely perfect ...
Nanophysics
Aug 29, 2023
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Research and development of organic electronics such as organic solar cells and organic light-emitting diodes is rapidly advancing. The "shape" of the electron orbitals of organic molecules (molecular orbitals) is crucial ...
Analytical Chemistry
Jun 26, 2023
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Electric space propulsion systems use energized atoms to generate thrust. The high-speed beams of ions bump against the graphite surfaces of the thruster, eroding them a little more with each hit, and are the systems' primary ...
Space Exploration
Jan 31, 2023
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An international research team led by Skoltech scientists has identified the best artificial intelligence algorithm for determining the synthesis conditions that favor the formation of carbon nanotubes with properties tailored ...
Nanomaterials
Dec 8, 2022
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Oak Ridge National Laboratory researchers serendipitously discovered when they automated the beam of an electron microscope to precisely drill holes in the atomically thin lattice of graphene, the drilled holes closed up. ...
Nanomaterials
Dec 8, 2022
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A research team from Skoltech, Aalto University, and Kurnakov Institute has recently developed a new, versatile and simple approach to using carbon nanotubes for manufacturing carbon nanotube-polymer nanocomposites. The method ...
Nanomaterials
Nov 25, 2022
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Lawrence Livermore National Laboratory (LLNL) scientists are scaling up the production of vertically aligned single-walled carbon nanotubes (SWCNT) that could revolutionize diverse commercial products ranging from rechargeable ...
Nanophysics
Oct 25, 2022
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Nanodiamonds' repertoire of applications expands constantly, including everything from ultra-fine coatings to precise drug delivery.
Bio & Medicine
Jul 27, 2022
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The migration of carbon atoms on the surface of the nanomaterial graphene was recently measured for the first time. Although the atoms move too swiftly to be directly observed with an electron microscope, their effect on ...
Nanomaterials
Jun 24, 2022
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Russian scientists have synthesized a new ultra-hard material consisting of scandium containing carbon. It consists of polymerized fullerene molecules with scandium and carbon atoms inside. The work paves the way for future ...
Nanomaterials
May 6, 2022
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