+ 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.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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