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Hydrogen Properties for Energy Research (HYPER) Laboratory Cool. Fuel.

Decorating The Thermodynamic Property Tree

At the 18th Symposium on Thermophysical Properties Eric Lemmon and Vince Arp had a presentation on the Gruneisen (Γ) and Phase Identification Parameter (Π) as useful properties for fitting Equations of State. In that talk they showed a slide titled “The Thermodynamic Property Tree”:Thermodynamic Property Tree

The exact origins of the tree are unknown and this was the first version I’ve personally seen. Unlike our Christmas trees that are ready to come down, this tree is just beginning. For example, the Helmholtz Free Energy (A) at the top is actually at the same … » More …

The colors of hydrogen

Two ways to color sort hydrogen have become popular. Although this post was originally developed with the physical colors that hydrogen fluoresces in mind, the community has since developed a color coordinated renewability scheme which is shown after the physical color scheme.

Hydrogen has signature colors that appear when the atoms are excited. This image from NASA-Ames shows a hydrogen arc lamp fluorescing:

Neils Bohr used the emission spectra of hydrogen to develop his model of the atom. In short, quantized energy levels release specific bands of light with unique colors. A description of the physics is … » More …