Recent comments in /f/science

WeylandsWings t1_j7ck4sy wrote

> A new fuel is methane, which is used in multiple rocket engines under development by major launch companies. The emissions products of methane are as yet poorly understood.

????? What? The combustion byproducts of a methalox rocket is mostly H2O and CO2.

And it isn’t poorly characterized. The report authors just don’t look into it. NASA has a wonderful piece of software/web site that you can run Computational Chemical Equilibrium simulations, even simulated rocket engines. And it is pretty accurate.

And for a 300 bar , sea level methalox engine it spits out the following mass fractions of various species at the Comustion Chamber, the throat, and most importantly for this discussion the Exit. (Forgive the formatting, on mobile)

Species. Chamber Throat Exit

*CO 0.22048 0.20984 0.13790

*CO2 0.27689 0.29368 0.40681

COOH 0.00009 0.00005 0.00000

*H 0.00071 0.00060 0.00001

HCO 0.00004 0.00002 0.00000

HO2 0.00028 0.00016 0.00000

*H2 0.00681 0.00644 0.00695

HCOOH 0.00002 0.00001 0.00000

H2O 0.41879 0.42748 0.44829

H2O2 0.00008 0.00004 0.00000

*O 0.00481 0.00356 0.00000

*OH 0.04585 0.03779 0.00005

*O2 0.02515 0.02032 0.00000

So as you can see, the vast majority of the exhaust is Water, Carbon Dioxide, and Carbon Monoxide. Now there will be other trace components because the system assumes the LOX and Methane are totally pure, but even then those will be trace.

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Igotz80HDnImWinning t1_j7cjesz wrote

The VA ships it to your house. Also, this goes beyond a simple effect to show 1. A dose-dependent improvement (argues more strongly for a necessary or sufficient effect) and 2. A physiological model supporting their hypothesis because darker skinned folks have less vit D from the same amount of sun, and it had a larger effect in black veterans. I don’t love epidemiology, but this is far better than your average retrospective study and clearly points for a large randomized trial to be done to confirm.

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GrowsOnGraves t1_j7ci2ac wrote

In my husband's family no man has made it to 60 (in at least 3 gens as far as I know) because of heart issues. My father in law was still body building at 55 and had a heart attack. 70 isn't so bad

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