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DeTRacted

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  1. In Europe perhaps Peter, but dwarfed by China who are expanding coal generation : https://www.chinadialogue.net/blog/10761-China-is-building-coal-power-again/en Note they currently have 993GW of coal capacity - rather makes UK gesture-politics look completely futile doesn't it considering our grid only has around 50GW from all sources.
  2. DeTRacted

    365 photos in 365 days

    ... or you might get the apprentice instead....Mort wasn't it?
  3. DeTRacted

    1938 Practical Mechanics magazine

    I wonder whether the YouTube info will still be around - and more to the point readable - in 80 years time? Storage methods and media formats change so quickly now that unless things are constantly being moved to the latest one, the data soon becomes inaccessible, either because you can no longer read the media or the encoding method is out of use.
  4. DeTRacted

    Mystery object

    I have a vague recollection that its an exhaust-pipe repair device, used in conjuction with a resin 'bandage'. Used to have to resort to 'gun-gum' myself in my impoverished youth....
  5. DeTRacted

    Well done Toyota

    You do still have the question of where the hydrogen comes from. Most of it is currently produced by 'cracking' natural gas - in which case I guess you might just as well run the car on LPG and cut out all the lossy intermediate steps.
  6. DeTRacted

    Well done Toyota

    Ideally yes John, but there are significant problems with hydrogen storage that makes me wonder whether it will ever be practical for mass application. Storage as a liquid needs a maintained temperature of <20Kelvin and even then the energy per unit volume is only 1/4 that of of petrol so you need four times as much for the equivalent range (doesn't matter if the vehicle is to use it in an internal combustion engine or an electric fuel cell - the same sort of restriction applies though the percentages will differ). Compressed gas is even worse as you need over 2500 times the volume which means it must be compressed to a really high level to get it to fit in a car. Practical vessels use up to 10,000psi which is only about 650 times compression and are necessarily robustly constructed, hence weighty even if made of composites. (Would you be happy to ride around in a car with something like that on board?) Factor in the energy expended in cooling or compressing it in the first place and its really not that efficient. The inspection and maintenance of such pressure or cryogenic systems to ensure continued safety would also seem to be a major problem when used in millions under relatively uncontrolled conditions. Hydrogen embrittlement or cracking of steels and other metals has been a problem in the past. There are other means of storage such as a hydride of some substrate material like Lithium but that is adding real complication. Perhaps that is the way Toyota are intending going? Rob
  7. DeTRacted

    O2

    Net system redundancy perhaps John - but all the 'net needs mains power so if the electrical generating or distribution network is taken out, you lose everything in the area affected. Grid power distribution systems are controlled using electronics these days and in England and Wales It's all run from one point in Wokingham. I hope that system is emp-proof ('hardened' is the term used).
  8. ...and the same here in Berkshire. Glad I'm retired now otherwise I would have been trying to get to work in it. Just been out clearing the shared driveway in case anyone needs to get to my even-more-aged neighbours in hurry. I hope that vortex doesn't slip to the right a bit - perhaps that's what happened in '63?
  9. Re your question Hamish - looks like some version of a Cromwell tank to me.
  10. DeTRacted

    First post

    Welcome Pete - glad you made it. RobH
  11. DeTRacted

    Prices

    Yep that's the original type Hamish AFAIK - same on mine. Looks like he is maybe selling a repro part with an original box.
  12. DeTRacted

    Penta bits...

    Well since hex keys are ten-a-penny and I have a fair few gash rusty ones I shall never use as intended, it wasn't quite like that Paul. Plus there's two ends on a hex key so you could modify one end without really losing anything....
  13. DeTRacted

    Penta bits...

    When I needed a triangular key in a hurry I just attacked a spare hex-key with the bench grinder to make one. Worked a treat.
  14. DeTRacted

    Research Report

    Several tables available on the web give the shear modulus for 'carbon steel' as 77GPa, so that number looks believable John. The number varies a bit with temperature anyway.
  15. DeTRacted

    Heathrow parking bandits

    Thanks John, but its not the fact which is the problem (to be expected for all of us at some time) its the apparent exploitation of people when they are most vulnerable. I don't think being short of cash excuses that cynicism. The parking in question has been franchised to a parking company so I expect only a fraction of the money actually goes to the hospital anyway. Most hospitals I have experience of could save a fortune just by turning the heating down a couple of degrees. Rob
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