Glossary

Embolism:: A blockage of an artery in the lungs by fat, air, tumour tissue or blood.

Fracture mechanics:: An approach to the understanding of strength and mechanical failure in materials that is based on a consideration of the influence of cracks (size, geometry and rate of growth) in the material, including at the surface.
Fracture toughness:: When a material breaks, due to the extension of pre-existing cracks, two factors influence the amount of energy absorbed. These are (i) the energy needed to create the new surfaces and (ii) the energy absorbed, for example in polymeric materials, by viscous flow of the molecules at the crack tip. The latter causes the material to be tough.

For a crack of original length 2 c, the breaking stress, ? _b is given by the expression:

The term K ₁ is known as the fracture toughness and is a measure of the resistance to growth of pre-existing cracks.

Hank s Balanced salt solution:: A solution with the following composition (mmol dm ^?3):

NaCl

130

KH ₂PO ₄

0.44

MgSO ₄.7H ₂O

0.811

CaCl ₂

1.26

NaHCO ₃

4.1

NaHPO ₄

0.33

KCl

5.3

Glucose

5.5

pH=7.4

Ringer s solution:: A solution with the following composition (mmol dm ^?3):

NaCl

137

KCl

5.64

CaCl ₂

2.16

NaHCO ₃

2.38

pH=7.2

It is isotonic with...

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The Chemistry of Medical and Dental Materials