fullsquare

have you? vietnam was backed by soviet union and china when these states were at peak performance, and north vietnamese government was genuinely popular. iran today is not it, who's gonna stand up for them, fucking north korea? mullah's regime doesn't seem to be popular either https://gamaan.org/wp-content/uploads/2020/09/GAMAAN-Iran-Religion-Survey-2020-English.pdf also iranian air defences were already shown to be unable of touching american aircraft last year, and nobody's talking about ground invasion

Skin depth is larger in aluminum but not enough to balance out its lower conductivity, copper is better material taking all into account, in practice both are good. If opposite was true we'd use lead or zinc for conductors. There are satellite microwave parts made out of aluminium (low weight) coated sequentially with zinc (bonding layer), copper (better conductivity), thin layer of silver (even better conductivity) and then gold (actually not thick enough to contribute, this one is for corrosion protection)

he's either out of fucks, or knows exactly what he's doing

also ignoring that natanz was actually effectively airgapped, and was knowingly infected by another country's contractor's usb stick, working on behalf of dutch intelligence service

the thing with using aluminum tape is that you can get away with very small thickness, because current flows only in top tens of micrometers depending on band. you can just roll up, say, 5cm wide, 0.5mm thick aluminum tape and have riveted/brazed/spot welded short length of 2mm thick bar to the ends for connecting capacitor. the problem is with mechanical stability of this setup, which is why you see pipes and thicker bars, bicycle rims etc, and here you would need some kind of horizontal bars for loop to more or less keep shape

with braid you get a lot of contacts between wires, and i'm not sure that resistance of them would be low unless tire is fully inflated. keep in mind that copper in contact with some grades of rubber develops copper sulfide film. maybe you can put short U-turn within loop at end opposite of capacitor and have adjustable shorting bar there. adjustable capacitor is more common by far, because if you can adjust it widely enough, you can get to different bands

if you're going for portable operation, wire dipole is probably the better way to go. cheaper, lighter, more efficient, you can roll it up and fit in your pocket. if you're operating out of a car, you don't need to fold magloop just lay it flat in the trunk

"has potential" and "could" but never "is"

90% of drugs that enter clinical trials, fail them

"All day Astronomy" seems to be a weird place to take medical news from

i'd expect shield to fray and core to bend with arrangement like this. if you just slide piece of pipe (can be rectangular, or U-shaped) it should be more durable. you'd be surprised at voltages developing there, even with 4W online calculators suggest something in 1kV range. 100W is over 5kV (voltage scales as square root of power)

btw if you don't need it collapsible, consider using bicycle rim as loop, or some kind of wide aluminum tape, as it has much higher equivalent diameter than coax (less losses)

you can add in parallel small adjustable capacitor, made from two or maybe four coax cores with some kind of sliding conductive sleeve around them all (piece of copper pipe moved by screw) this way you should be able to tune to any channel within cb band

additionally, you made your loop suitable for higher power than was previously (magloops tend to be limited by voltage across capacitor). if you use coax with foam core, capacitance per mm will be lower still. for adjusting, you can get away with only clipping away shield with nail clippers

it's a type of heat engine. heat engines require temperature difference to work, and the lower it becomes, the less energy is there in the first place and a very fundamental limitation, that is carnot cycle efficiency, goes down very quickly. in practice, all heat exchangers have some thermal resistance, and the lower temperature gradient you can afford to use up on this, the bigger heat exchanger becomes, making low grade heat powerplants extremely big and expensive on top of barely generating any electricity

i don't think there's a lot of energy to be squeezed from daily variations in air temperature vs lake temperature, you'd be better off just by using solar panels on the same area

take any aluminum can, cut it open, cut a plate fitting in your wallet, insert it there so that it sits on external surface if your walket, done, that's your yeehaw rfid blocking sleeve, extra mass 1g

if you want to scan bus pass you can put that card on external side of it

Because now you have to establish a complex supply chain and potentially large worker base in a place that’s potentially quite inconvenient for both, instead of a much simpler supply chain and smaller workforce.

i'm not sure why you think that it is the case. if you want to make aluminum, you just need a ship to come in and pile up alumina, then take up piled up aluminum. the process is decently automated these days and you avoid making hydrogen. if you want to make ammonia, then all you need is hydrogen that you use as soon as it's made and nitrogen which is separated from air on demand. nitrogen fertilizers account for something like 2% of global primary energy use so it's probably decently scalable. then you can ship out liquid pressurized ammonia, or convert it to ammonium nitrate which again you can pile up*. however with methanol you run into a Problem, because you need carbon dioxide, which means that you have to ship it from somewhere or capture in a massive installation. this immediately makes logistics of this entire enterprise harder. if you want to convert methanol to hydrocarbons then it takes some extra energy for little benefit (2x energy density) and some losses. to some degree, maybe it will make sense, but maybe it'll be easier to just build up renewables where people already live

in that scenario biofuels get to serve much smaller segment than today in the first place so maybe it's less of a problem. there are also things like biogas

I strongly feel that hydrogen is even more of a dead-end technology than these e-fuels. It is a right pain to store and transport and has rubbish energy density. There’s no future in the hydrogen economy. I’d bet we’re more likely to jump to artificial photosynthesis and fancy fuel cells than we are to see any substantial hydrogen infrastructure.

and you base that on what exactly other than vibes? there are applications where you need hydrogen directly as a reagent like ammonia synthesis, and these are probably most adaptable to this approach. methane is also proper PITA in terms of storage, yet we store it anyway because it's cheap as a fuel. if hydrogen is cheaper than that, then it will be used where applicable. it's easier to transport coal than electricity but not lignite; i don't know how it will play out with hydrogen, but either way you can imagine a situation where hydrogen is generated onsite, or within pipeline distance, and used immediately or maybe with some storage worth hours to days. this fits iron smelting (DRI) nicely, today the fuel used for it is methane because it's cheapest (process common in India). if hydrogen is cheaper than that, it will be used instead. other than that, applications where high heat is needed and where no electric heating can be used would be another use of hydrogen, like glassmaking and metal objects manufacture. hydrogen might be not disastrously bad option as fuel for transportation, because every step in manufacturing other fuels introduces losses; there are other tradeoffs

what do you want to fuel these fuel cells with? hydrogen is simplest option and most efficient (60% roundtrip efficiency or so). artificial photosynthesis is not a thing currently and strictly worse than combination of any energy source + conventional electrolyzer, because you have to combine not within single device but within single material something that will work as both. this also is only applicable to solar, not to wind or nuclear. some of these direct light to hydrogen schemes also only use UV only, and hydrogen is mixed with oxygen which is suboptimal, not to mention that main output of that work seems to be grant applications, while both electrolyzers and solar panels or wind turbines are available today, in bulk, straight from factory, and even more efficiently in decarbonization terms, these can replace coal-based electricity generation

regardless, main value of electrofuels today is in propaganda

* regular process starting from gas has carbon dioxide as a byproduct, so urea is another option, but with hydrogen it would have to be provided. it's more expensive even today. maybe liquefied gas carrier could provide carbon dioxide and load ammonia on return leg, with some other dry cargo ship picking up that urea at some other time

ftx also did something like that, but didn't release ad with matt damon