Cutting-edge theories and techniques for LCI in the context of CALL

Language-Learner Computer Interactions - Language Studies, Science and Engineering ◽

10.1075/lsse.2.01caw ◽

2016 ◽

pp. 1-13

Author(s):

Catherine Caws ◽

Marie-Josée Hamel

Keyword(s):

Cutting Edge

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Plastic Deformation in Microtomed Sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066346 ◽

1971 ◽

Vol 29 ◽

pp. 458-459

Author(s):

J. Temple Black

Keyword(s):

Plastic Deformation ◽

Plastic Strain ◽

Applied Stress ◽

Elastic Strain ◽

High Strain ◽

Tool Material ◽

Cutting Edge ◽

Material Structure ◽

Geometrical Constraints

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.

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