Cryogenics

Abstract

This is the third article on Cryogenics to appear in this series. As in pre vious years, attention has been confined to a small number of topics. Those selected this year are the Third Law of Thermodynamics, the Liquid Helium Temperature Scale, and Antiferromagnetism.

Chapter 1. Hydrogen and Solar Hydrogen

“…Diatomic gases composed of heavier atoms, such as N 2 , do not have such widely spaced levels and do not exhibit the same effect. 15 Hydrogen can also react with oxygen to generate electricity in a ''fuel cell'', a concept that was first proposed in 1838 by Scho¨nbein. Soon afterwards, in 1842, Grove introduced the first ''gas voltaic battery'', using a design (Figure 1.6) that is remarkably similar to today's fuel cell designs.…”