Breaking in computers
Article Abstract:
Scientists have found a way to demonstrate brittleness and ductility at the atomic level of solids. The setting for their calculation is a model block of copper that contains 35 million atoms. The atoms were arranged so that the copper will have a crack in it while the computer was instructed to pull on the top and bottom of the block and follow the consequences for 25 x 10(supra -12) seconds. Unlike color and conductivity which are easily evident when a solid is subjected to very weak external forces, brittleness and ductility only become apparent in the presence of forces large enough to rip atoms apart.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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Unlocking dislocation secrets
Article Abstract:
Bulatov and colleagues have studied how collaboration of atoms leads to change on major scales. Investigations look into the appearance of barriers to plastic flow in a crystal, followed by the destruction of the barrier. A case study provides insights into complicated phenomena at the atomic scale, with their transformation into quantitative accounts of whirlpools and vortices, enabling metals to deform. Vortices are known as dislocations, and the link between vortices in liquids and solids is illustrated.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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Energetic developments in fracture
Article Abstract:
The application of small amounts of energy to a crack tip cuts the material into two parts. The crack tip becomes unstable and develops many ramified zones of damaged material beneath the visible fracture surface on subjecting it to energy fluxes above a critical value. A study on Plexiglas shows that the energy required to create the ramified branching structures is in agreement with the fracture theory predictions.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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