+ 0.25

+ 0.03

In iron, the stable low-temperature phase (the a phase) has a body-centered-cubic (bcc) structure that transforms to the face-centered-cubic (fcc) y phase at 1185 K. Since the fcc crystal is close-packed whereas the bcc lattice is more open, the specific volume change of the a o y transition, Ava-Y, is negative. In addition, Aha-Y is positive, so Eq (5.15) shows that the transition temperature decreases with increasing pressure. The y o L phase-change (i.e., melting) temperature increases with increasing pressure because, according to Eq (5.15), this is the behavior expected when both Avtr and Ahtr are positive. For either the solid-solid phase change or melting, the pressure effect is small because the volume changes associated with the transitions are small.

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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