i heard a story about varnish factory that failed quality checks after one old guy got fired, he was a smoker and used to spit in the main reactor. some enzyme from saliva made it shinier

it will vary, just after distillation (or RO/ion exchange) it should be closer to 7 then it goes down as carbon dioxide gets absorbed. that’s why it’s buffered everywhere where it matters

in my case the size of the system was so small they didn’t have that excuse, yet they were only ever able to get correct results after experimental data was handed over to them, zero predictive power, useless

seeing that jargon file has an extensive page on retrocomputing feels like figuring out that there were archeologists in ancient egypt

some people would tell you that we can simulate small bits of chemistry but it’s flat out wrong (i might be biased as i’ve wrangled for a year with computational chemists about results that don’t conform to reality) and even then errors are so large that’s it’s useless

and then some bozo says that biology is just complicated chemistry and chemistry is just complicated physics and we can simulate physics

curious thing is that i never hear biologists or chemists saying that, only some physicists and techbros. just trying to simulate your way out of small organic chemistry problems will make you even more hopelessly lost than you were before

maybe it introduces some critical contaminant (many such cases)

that’s a weird metric to look at because drug approval happens only like, 5-15 years after end of preclinical research, sometimes longer

clinical trials also take fuckton of money but this might be also post-2008 cuts that we only see effects of now

there’s a lot of complicated tubes in refinery, each with hideous lead time

they did a whoopsie, lead 210 comes from uranium 238. every 220 years radioactivity drops 1000x which means that 200-300 year old lead is mostly fine. copper notably doesn’t have this problem, is dense and is refined to high degree, at scale. it’s good enough to shield most of relatively low energy radiation from that isotope (less than 50kev gammas). couple mm of copper should be plenty for many applications

different tool for a different purpose. water has a large heat of evaporation which is something that allows for more compact turbines

big advantage is that molten salt allows for energy storage for nighttime

i’m guessing it wasn’t abducted by aliens

dropped as cleanup-only, not allowed by their policies

i suspect that it might be vibecoded, too

it also happened with tramadol before (different plant)

Adding to that, logistics are such that direct impact will be felt strongest in places like India that rely heavily on Qatari LNG to make fertilizer, but many places have other sources of both gas and fertilizer. Americas, EU, Russia and China will get by because they have their own supply and will be only affected by price increase

without synthetic nitrogen fertilizer there’s only enough reactive nitrogen going around for something like 1-1.5B people. yea mate very sustainable to retvrn to traditional farming and starve 80% of the planet in the process

i was thinking more like, thin external plastic shell and empty cells inside, perhaps with another thin plastic shell on inside, and internal metal shell (on plastic support?) fitting in snugly, for mechanical stability, idk 3dprinting

keeping leads short and nonmagnetic (dramatic reduction in skin layer depth) would be a good thing because of losses, but the longest object in capacitor would be just capacitor plates, and either way in wavelength terms it’s rather small. more precisely you can model it as open transmission line stub with some weird and low impedance, but it’s so small that you don’t have to. you can also make capacitor shorter and wider, or even add more layers like how vacuum variables are made. in nesting design you can get taper effect just by making inner layers longer

Found a piece about RFI and baluns, http://audiosystemsgroup.com/RFI-Ham.pdf multiple turns on ferrite aren’t really an option for VHF and up, ended up ordering extra beads (non-split)

The dielectric between the plates in this case is 0.4mm of ABS plastics (+ a bit of air in the 3d print layer lines).

in terms of losses, PP or PE is a bit better than ABS, teflon or FEP is a bit better than PP, but air is superior to either (this is part of the reason why foam coax is a thing). not sure which ones are printable, or whether it’s practical at this size, but try to introduce as many voids as possible (perhaps requires larger thickness of dielectric). it doesn’t matter much in your case, because of low power (warping of plastic because of excessive heat is probably not a problem). if your coax has solid dielectric, then by introducing enough air in 3d-print your variable might become less lossy than that

The Capacitors allows my 80cm diameter loop to tune from 20Mhz to 37Mhz. Sweeping the whole range is a bit slow due to the low RPM of the motor and takes about 6min. But that is kinda nice when fine adjusting to a frequency.

you have probably noticed that position vs resonant frequency relationship is rather nonlinear. you can get higher sweep speeds at lower end without losing much accuracy at higher end by tapering end of side plates into a triangle shape (it will get longer overall). it doesn’t matter much in your case, because it’s all approx monoband, but if you want to go multiband with this, then it’ll be a nice enhancement. similar effect happens when air variable capacitors have moving plates shaped in such a way that one end is longer than the other, and external edge has shape roughly like a section of logarithmic spiral. precise movement of variables like this is done by use of worm drive with large wheel

I am not sure what is causing this, but i assume it could be due to increase of dielectric losses in the capacitor getting bigger when more of the plates overlap because then the electric field has to flow thru a bigger area of dielectric, increasing the potential for losses.

loss tangent of dielectric is material property, that is ratio of equivalent loss resistance to capacitance should remain constant at given frequency. so i guess that losses should remain roughly the same, if dielectric is to blame, but at any rate lossy capacitor should make bandwidth broader and SWR lower. my guess would be that it’s a matter of coupling loop becoming wrong-sized or wrong-positioned at some point with change in frequency (try moving it up or down? there’s gotta be some optimum position for your entire range of interest)