Comments by "SeanBZA" (@SeanBZA) on "Thunderf00t" channel.

  1. Another thing is that avionics grade PTFE wire is typically a foamed structure to reduce mass, so there would have been a large surface area available, but in a small volume. As Phil is in the EU there is no problems for him to look on Ebay for any cheap aircraft parts on auction, both from US origin, UK origin, French origin and ex Soviet era hardware, which almost always has PTFE wire involved in the construction. that will give a nice cross section of wire types and sizes, and of various ages and manufacture, to do a quick test. As a wire it is the correct form factor, and is not a pure PTFE, as typically the insulation used there has some filler or the other added to it to get it to extrude nicely onto the wire, which also has a nice silver plate on it to prevent any chemical reactions between the copper wire and the PTFE with time, contamination with chemicals and heat. The units are cheap in Euro prices, and shipping is very cheap as well. He will also get a good set of samples of the grades of aluminium alloys and stainless steels used in manufacture consistent with the era, for other tests.
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  2. More like " I once bought a Vodaphone phone and used it, till they cut me off for not paying the bill"
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  3. Thing is that they literally have the glue bond inside out, as the ring should have had an internal structure as well, to transfer the compression force from the carbon fibre to the inner titanium ring via the epoxy, not put a tensile pull on the epoxy join. That would lead to the carbon fibre delaminating with pressure cycles, and failing. They constructed that join surface as if the join was for a pipe with pressure inside, where the pressure will hold the epoxy onto the cap, not the other way round. Pipe shrank under pressure, and eventually some microscopic section of the join, likely with an embedded air bubble in it that had been compressed to have a sharp edge, caused a stress that started to propagate through the bulk resin, because there is no stress relief in the resin bond, and this then eventually grew to the outside, where water was able to fill the crack. Now the water is applying pressure to a section that can flex, and grows the crack into the joint further, aided by the tension in the epoxy join, and this then rapidly, basically the speed of sound in the epoxy as the growth speed, grew to open the joint to the inside. That joint should have had an inner and outer lip, and have been filled with epoxy with a slow cure time, and then have the shell pressed down into it, also with a coat of the epoxy on the surfaces, and then pressed together, with a few vent holes for the excess resin to flow out in the titanium, that later on would have a cap bolted and bonded to it. Or a thicker section that you put a setscrew in to fill the hole, while the resin is still not cured, after it has bottomed out, then left and heated to cure fully before removing the pressure. That join section should have been at least 3 times thicker, and longer, with a taper on the inside to allow a flexible sealer to be there, to allow the join to flex with pressure, not a solid non flex epoxy only. you want to not have stress risers, and a solid join with the different materials will have that stress riser. This hull was likely only going to last 3 cycles before you would have to replace it, they should have done testing, using a deep water area, and a cable and cage, to measure the number of cycles to failure first, not used the passengers as alpha testers.
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  4. Only the gem quality ones, the rest they sell for industrial use, or turn into diamond powder to be used for industry. They only sell the top grade big ones for gemstone use, and yes do have a century or more of stock in vaults while keeping the supply low, and also subtly pushing the myth to never buy a used stone.
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  5.  @ludoviclagouardette7020  Those misters typically run at up to 1MHz, so probably around the right ballpark for this. The 3 droplets connected are likely each made from a single pulse from the piezo disk, and will probably all have about the same volume as the energy imparted on them is the same. They explode as the energy is concentrated into them from the compression wave, as the energy is able to reflect inside to cause the sides to rupture as the energy exceeds the surface tension in small sections. Water tentacle is the lifted water from each pulse accumulating on each cycle, as the energy accelerating it is moving the water faster than it can fall under gravity or surface tension, causing the fountain. That it does so even with the soap on the sensor is because the soap conducts the sound, and there is still enough cohesion to hold it together for a few seconds till it all dissolves in the water.
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  6. Yes, aircraft engines can run on gravity feed of fuel, just ignoring that if the pumps pack up they will not run for more than a few seconds, mostly because the fuel flow is now not even enough to run them at idle, and the whole pesky injectors need enough pressure to put it in against the pressure in the combustion chamber. Now fuel tanks in the wings are there to have useful volume in the cargo space, plenty of aircraft can have tanks in the fuselage, often things like tankers, where that fuselage is used to carry fuel as the cargo. Airlines however have that pesky need to move things, like people, cargo and baggage, so need that room to fit them in, instead of them sitting cramped up in the wings. So instead they fit the tanks in the wings, using self sealing bladders so they do not leak all the fuel out in all the rivet holes, and then, to keep it sloshing about, they use open cell fibre foam to provide both support for the bladder material on top and bottom, and also prevent sloshing around, but still allow flow down to the fuel pick up points.
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  7.  @moeron9172  Yes do in the post combustion and post turbine exhaust, where the air is still hot enough, and has plenty of oxygen still to react with it. single injector there, cooled on the outside by the bypass air, and only energised with pressure when at altitude, so that it has enough time to cool off on the way down. Plus you can add in a purge valve, that will use compressed air to vent the line, and as the fuel likely will be solid at altitude, you would only need a little trace heater on the lines, that turns on after reaching 15000 feet altitude, and turns off and does the purge when descending again. Can be totally automatic as well, only a simple switch and light in the cockpit, or a message in the ECAM display, along with the others, and only flag a fault when it does have one. 20l of fuel will last quite a few flights as well, though the tank and pump will definitely need to be in a fire proof housing that will contain any leaks from damaging the airframe. Just going to be hard to fit, avionics bays tend not to have much spare volume these days, you can barely get in there to service them normally, and that space has to be there.
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  8.  @bdf2718  They could not replace it, nothing else has the ability to withstand the use case, so it was replaced with a blend with some inerting fillers so the flammable volume was less. You can't really use any other plastic there, and ceramics and glass or asbestos fibres are too brittle.
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  9.  @666wurm  Could be, I generally only met the expanded stuff as wire, and it was nice and flexible, but somewhat fragile with time. The solid PTFE cable though was very common in high temperature applications, along with polyamide, though that would turn to crumble long before the PTFE itself would.
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  10. I will bet that if you look there is a product nearly like this that has been sold for a few years already, just the took it, added the "condenser" to it, the UV LED to the front, and a fancier control panel with display, instead of the original simple timer.
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  11. Running it at 2W, when it is really rated at 0.5W is kind of overdriving it. However it is a proper UV LED, though with the amount of light it can give off at 0.5W of power it is not exactly going to be the biggest killer of germs, unless they are right by it in the unit.
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  12. We used to use the magnetron test load for the RADAR set as a pie warmer, as it would run typically at 150C at full pulse repetition rate. Put the cold pie on 5 minutes before lunch, and run your magnetron under test for the 5 minutes, and the pie is done.
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  13. Yes solar still works, and is cheap to make, and every place in Africa has both the brackish water, and enough discarded glass, to make them up.
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  14. Easiest way to get ignition is to have a second injector driven in parallel with the first, with the reservoir filled with distilled water. That will enure a nice jet of water with the sodium flame to ignite it, and also a cooling down of the flame front as well, so it might be easier to photograph as well.
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  15. You see, he is using "blessed" radio waves, those are the good ones.
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  16. Just remembere he is merely following the Deathstar method, getting paid by the government massive amounts to roll out service, yet taking the money and only rolling out part, then going back and demanding more to carry on with the part service. That got you a monopolistic market, and you being unable to choose except between crappy and worse, and then having throttled service, and paying to receive calls and texts.
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  17. Expensive coloured urine, as your kidneys are pretty effective at dumping the excess.
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  18.  @AlexBarbu  NaK also dissolves aluminium, and also will dissolve brass and bronzes as well. Very reactive, you need things like steel, which will only slowly dissolve, or stainless steel, which will survive longer due to the passivation layer that forms on it. NaK is used to cool nuclear reactors, where the entire cooling loop it is in is made from either ceramic or Hastalloy, which is pretty much only going to dissolve over centuries in it. Ceramic so they can use a magnetohydroynamic pump to circulate it without having to have moving parts in the liquid.
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  19.  @eno2870  That would be extra, as you then have to use medical grade oxygen, which has a much lower concentration of contaminants, most notable being nitrogen, which is pretty close in boiling point, so you have to do fractional distillation of the liquid, or use molecular filters to reduce the volume of contaminants. Expensive and slow, as you do need to keep a very precise control on the pressures and temperatures. For each passenger you would need around 3l of liquid oxygen, per flight, and probably around 15l of liquid nitrogen as well, so as to be able to make a one atmosphere environment, and simply dump all the exhaust out of the craft. Otherwise you need lithium hydroxide CO2 scrubbers to be able to recirculate the air, and then your gas needs are lower, but you do need a lot more mass in scrubbers. However the scrubbers need to be fed dry air, so you then need to extract almost all of the humidity out of the air first. So, probably a ton of scrubbers alone, another 2 tons of airconditioners, for the hundred passengers, to save the 1500kg of liquid nitrogen, but the LOX is not going to be much less. That assumes you want to have the passengers feel like they are in an aircraft, though you could get away with dropping cabin pressure to a bit lower, and increasing oxygen concentration, but having them need to spend an hour before and after each flight doing a decompression would probably not be a desired thing. After all, the space shuttle and ISS takes the best part of a day to get ready for EVA, because the low pressure in the space suits requires all nitrogen to be removed, and the time for the Starship will not be much less.
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  20. Don't forget the packaging probably has more carbon in it than the product could ever hope to absorb in it's lifetime, and just how much carbon can a clay bead absorb in any case when it is on your body, and gets clogged up with a blend of fat and dead skin. Then the mailer envelope, which is probably nice coated non recyclable paper, along with the nice brochure with non recyclable UV cure varnish, the plastic coated carrier and such, plus the shipping label with BPA to make the printing visible.
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  21. that is merely an illusion, brought about by him wanting to not be there as a regular cleaner, and wanting to be something else.
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  22.  @thejuggernautofspades9453  Not really going to help, heating past the glass transition temperature will just anneal the epoxy, releasing the residual stress in it, but will do nothing to make the portions where it has already got tiny bond failures any better, just making them seem to disappear, as the interface material now is contacting again. Only way would have been to have had the mandrel it was wound on be a strength member as well, able to handle the pressure, and the carbon fibre merely to reinforce it, though that would have made mass much too high, and made the need for carbon fibre moot anyway.
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  23.  @acrazedtanker1550  They have costed out towing icebergs there, and simply placing a plastic bag around them, so as to capture the melting ice water and use it. Lot less energy than desalination, and after all the fuel to move the ice there to the Saudi's is essentially free.
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  24. Yes, composite overwrapped pressure vessels are common, but have a limited life at full pressure, and also a cycle life. I have one used as a water purifier, and while it is 10 years past it's life, it also is only used at 1bar of water pressure, not the rating of 10bar, and 20 bar test pressure. Should have a near indefinite life at that pressure, especially as it generally is not under pressure unless I need to draw water. I will probably wear out the threads changing the resin first.
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  25. Easy to get stonkig 0-60 times with a regular truck as well, just remove the trailer. A plain truck tractor is way overpowered, I have seen them beating almost all vehicles in light to light, simply from the massive power to weight ratio.
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  26.  @YouCensored  Seen plenty of PTFE wire with a pink tinge or a pink stripe in the insulation, there generally on sealed assemblies like motors, to allow you to indicate polarity on the motor during further assembly. Though yes the tiny amount of dye will be totally insignificant here to overall burning of the wire in the pure oxygen atmosphere when it got an ignition source. With pure oxygen at atmospheric pressure and above, many things that are normally considered fine, like lubricant oils and greases, are forbidden, you have to use rather esoteric lubricants, like molybdenun sulphide, and powdered graphite, as lubricant, and even skin oil from handling is considered to be a contaminant. Even such things like crush washers are a problem, they have to be copper, or ultra pure aluminium, or nickel, as the first application of oxygen to the newly crushed surface exposed to it will nearly instantly form an oxide layer, so the pressure has to rise slowly, so the reaction is not too violent during this time, and the heat can be dissipated. Not so bad as handling fluorine gas, where you have to do this even more carefully, as literally the only thing that is keeping your entire apparatus from dissolving, is the thin film of metal fluoride that is coating all surfaces, from the initial introduction of gas. Oxygen is only slightly less reactive.
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  27.  @MarkShinnick  At least the front did, have not seen the rear bulkhead, but I would assume the failure was there, and it blew off the front during the pressure pulse from the implosion. They got the rear well mangled, so the implosion was likely that end, simply because the rear would have been turned into shreds if the pulse of pressure had come from the front, just the back is mangled likely from the collapse of the tube there.
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  28. Very high pressure, GDI engine, the one that needs a 100bar boost mechanical pump on the engine, to allow the injector pressure to exceed cylinder pressure by a fair amount, so that the injection into the actual cylinder can take place.
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  29.  @JoeOvercoat  Civilian aircraft cannot do inverted flight for long, only under around 10 seconds, before the fuel starvation stops the engines. Fighter aircraft have a fuel tank within the final feed tank, which allows inverted operation for a period of around 30 seconds at full afterburner, before it will start to run low. Yes it will gravity feed fuel to the LP pump, but after there it is pressurised, and fuel transfer from tank to tank in the airframe is done by pumps, generally self priming gear pumps, because the fuel in drop tanks, always below the fuselage, is always used first, so it has to be sucked up to the main fuel tanks, with overflow returning to the drop tanks till empty, then the shut off valves will stop that, along with the pumps. Lose the pumps and the engine stops in short order.
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  30.  @fmccloud  Yes, and as they are mostly made from stainless steel and steel alloys they will also only slowly dissolve in the NaK fuel. Just have to make sure the ones you start with do not have any brass parts in the fuel system as those will rapidly dissolve in the fuel. As a bonus they are also very similar to the existing injection nozzles in aircraft, so retrofitting will be a lot easier, just have to add in the tank and the high pressure pump to get it to the nozzle, plus make all the piping out of the usual aircraft grade line of stainless steel and PTFE for the flex parts.
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  31.  @markevans2294  Yes but in both cases the FADEC was operating, just with no input control, so it stayed at the last operate level under full control of the FADEC, and the fuel pumps controlled by the FADEC were still operational. Damaged engine you can still shut down by turning off all DC buses, and all AC buses, and before that use the fuel system valves to starve the engine of fuel, but that is something the pilots are never taught, as that is mostly done at depot service, to isolate an engine for removal with full fuel tanks.
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  32.  @dinobuddy  Is he being represented by the world's most famous copyright lawyers, Prenda law?
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  33. He would change his mind if he was the one going to travel on the first few launches though.
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  34. Plenty of bigger vacuum pumps though, you just have to look at the GAST catalogue to see them, and the smaller ones will pump that volume down to a reasonably low pressure in around 30 minutes. Bigger ones, which require a few horsepower on the drive motor, are common in industry, and will do that volume in under 10 minutes. Inlet diameters are in the inch size, and they are available in oiled and oil less versions. If you want cheaper then there are plenty of Chinese suppliers who will give you a clone that is a lot cheaper, and which will equal the performance in most respects.
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  35. That city looks like a very old Heinlein story about rolling roads. the estate might want to look into their copyright infringement as well.
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  36. Peter is just another AI bot.........
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  37. Little does she realise that that half kilo of face plaster that she has trowelled onto her face likely is made from clay contaminated with dioxin, and the inks she happily injected into her body is also a known carcinogen. Same for the lipstick, made with petroleum wax and dye, of which she eats at least a half kilogram a year on average.
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  38. Dreamliners with relatively small lithium battery packs, and there there were a few uncontained failures there that nearly resulted in airframe failures. So now the battery pack is now heavier because they had to add a fireproof container with venting, and any mass saving over the old nickel cadmium battery is lost.
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  39. Pretty sure that is a standard, though very large, water valve, intended for use on large water reticulation systems. About the only thing they have done is place a cover over the actuator, so that it will at least hold a vacuum, though I really doubt that cover is light, as it has to handle 400 tons of force on it, and it will flex somewhat.
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  40. Prenda law enters the fray........
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  41.  @UncleKennysPlace  So they are probably made from charcoal briquette then, as that is generally made from a mix of clay as binder and carbon. Probably the crummy cheap and nasty type that is more clay than carbon, that turns into around the same mass of white ash when it burns.
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  42. Hopes and dreams, plus lots of taxpayer money.....
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  43. About the only place this will work is in India, mostly because there is a shortage of power, and no shortage of people. Unfortunately the cost of making it is a lot more than they are able to pay, let alone are willing to pay.
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  44. Just remember there was stuff more than metal in there that was easier to ignite than the stainless steel. there was a lot of PTFE used for insulation, which was likely also generating a lot of gas as it burnt up in there as well, and which was involved in the beginning as the wire insulation that was lit. PTFE will burn nicely in pure oxygen, as proved by the Apollo one fire, which was mostly burning PTFE and which also resulted in a corrosive mix of by products and acids as well. Wonder if the next time will involve a piece of PTFE in addition to the steel wool, though this will need to be done outdoors or in a very good fume hood, because of the nasty flouride acid that will be generated.
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  45. I think they forgot the second unit off there. Instead of 500Watts that they were bragging about, they forgot to use the second word in the actual unit, it is a 500 watt second battery, or, more prosaically in the more normal SI nomenaclature that people are more familiar with, it has 500 joules of stored energy in it. Not 500 watt hours, which would actually make it a really compact and high capacity power source, with 1.8 MJ of stored energy, far more than your similar size lithium pouch cell pack of the same volume, but instead it will store roughly the same energy in the "easy to replace charge collection plates" ( bet nobody saw that small print and thought why the charge collection plates wear out, but not the sea water) as a single standard duty ( hardest thing to find these days, even the cheapest Chinese one is marketed as heavy duty) IEC standard ( yes there is a standard for a zinc carbon cell, basically to get the ability to market it with a size in the IEC nomenclature, you have to meet the dimensions, and capacity has to be greater than the minimum in the spec) zinc carbon internally depolarised AAA cell. I think the AAA cell is a lot cheaper as well, and easier to recycle, as it only has zinc, carbon, a drop of tar, some wood pulp soaked in manganese dioxide and ammonia, and a bit of plastic as sleeve and top cap.
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  46. Here is the real power cube, fits in your hand, and incredible power supply ability for a few minutes, plus a breakdown of how it works. https://www.youtube.com/watch?v=vs1paqSlpeg You can easily fit the parts into the rear shell of that TV set without any problem, as there is a lot of space dedicated to making the speakers sound better inside there.
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  47. Seems like a rehash of RA Heinlein's The Roads Must Roll, which he wrote in 1940. Same idea, same thing of a linear town based on long strips of road carrying all transport, and with photovoltaic cells in the top cover providing power for everything. Also has the mention of video calling, cellular phones, the split between elite and those who work, and also the rise of a servant class to provide all service to the elites who live in the lap of luxury.
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  48. That is because he was so dumb he was held back for a few years. In kindegarden he was the biggest child simply because he was 10 at the time, having failed remedial clay squishing so many times.
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  49. One thing with every video ever posted by Thunderfoot is that you will always learn at least one new thing that you never knew before, or he will show you that something you thought was dogma is actually wrong, and give you an explanation that is consistent as well.
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  50. Red glow is electron bombardment of the metal ball creating a plasma, as it strips off a few atoms off the surface.
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