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- Dec 18, 2019
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The article I linked in post #47 is about combustion only. Not the JT effect. I linked it to show the UV and IR combustion emissions only.Again, just an uniformed observation, but if the test state is combustion (ie: producing oh and h20), it would seem to imply that any thermal and ir/uv emission are a result of the combustion (ie: chemical reaction), not the expansion of the hydrogen.
The figure in Post #43 is about the Joule-Thomson coefficient, which is negative at temperatures above 200K (about -73C) for hydrogen. A negative coefficient means heating (not cooling) upon expansion through an orifice. A positive coefficient means cooling upon expansion through and orifice. Normal air (nitrogen and oxygen) will cool upon expansion, for all temperatures below 600K. You don't have to believe any of this, but you won't be able to liquefy helium, hydrogen or neon from simple orifice expansion, unless the compressed gas temperature is low enough that the Joule-Thomson coefficient is positive. https://en.wikipedia.org/wiki/Joule–Thomson_effect If you have an alternate informed opinion, with references, I'd be glad to hear it.