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Enthalpy

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  1. Bassoon balancer v3. The string coming from the boot joint is redirected by a loop that now has its ends parallel to the body, while the ring perpendicular to the body passes straight over the loop. This v3 is much easier to build and to adjust. Still adhesive tape, about 3 plies. At the loop, two foldings give 90° each, and an added short tape part neutralizes the sticking side. V3 too provides perfect roll balance and leaves some weight on the left hand, since an attempt with perfect pitch balance was unplayable. The adhesive tape always separates from the concave portion of the tenor joint, so instead of sticking it there, this time I gave it roughly the loose length left by the spacing to the bass joint. Marc Schaefer, aka Enthalpy
  2. Nasa and Esa consider a mission to bring Mars samples back to Earth. The sunheat engine makes it much easier and enables a more ambitious mission. The artist rendering I saw recently suggest ion propulsion with big solar panels and small thrust. The sunheat engine brings a specific impulse similar to ion engines and a much stronger thrust for the same sunlight collecting area, so a heavier spacecraft can manoeuvre faster. I won't detail that.
  3. The Atecopol collective spreads doubt about the hydrogen amount needed by airliners blogs.mediapart.fr (in French) "10 000 wind turbines just to feed the planes starting from Roissy" (France's biggest airport), so here are my figures. Some 240 000 airliners a year start from Roissy, needing about 10Mt kerosene that produce 0.4EJ heat. The better efficiency of fuel cells needs 0.2EJ/year from hydrogen. Engines that burn the hydrogen, as Safran would like, are nonsense. A 5MW terrestrial wind turbine produces mean 1.3GW or 40TJ/year. 50% yield to hydrogen takes 10 000 wind turbines, OK. Germany has already 30 000. These wind turbines cost 14G€ and save yearly 80 000 000 barrels kerosene. Crude oil at 40usd costs yearly 3G€, kerosene 7G€. The production pays the investment in 2 years, after that it's all profit. Very few investments bring money that quickly. This single operation would reduce France's trade deficit by 1/20th.
  4. Hi MacSwell, thanks for your interest! I don't know any existing translation. The French document is a student's thesis. Google Translate maybe? Much of the document is verbose and loosely related with the innovation, so maybe the drawings can tell you where to let translate. Searching for "Luc Armant" or for "aile d'eau" on youtube brings nice videos, easier to grasp and containing much the same information. In addition to what I proposed later than he did, Luc Armant also conceived and experimented successfully human-free regulators for the sail and the centreboard, impressive achievement.
  5. Luc Armant proposed the same idea before I did: leaving only the centreboard in the water augredelair.fr (36MB in French with drawings) and he's a member of the Syroco team. Best wishes to the project!
  6. The Syroco speedcraft tries to develop what I proposed, here are their Youtube channel and main description video: UC1-4BeVLyF-g_qb3i4HoM9g - Blb2S6Ytngg Their options (on the video, I suppose the craft doesn't exist yet, so many choices can evolve): Flexible sail, this differs from my proposal. Eases the start. Less efficient. Centreboard tied stiffly to the hull, this differs from my proposal. Floating hull near the water with the crew. Eases the start. Less safe than a hull at the wing. The centreboard is not swept. It would have helped avoid cavitation. The sail and centreboard nearly perpendicular to the line joining them is a usual speedcraft design since Bernard Smith proposed it half a century ago. Leaving only the centreboard in the water is my idea, I believe. Much of the rest is from them, especially the design, while I only proposed a bare idea. But I'd have felt elegant of them to cite me. Anyway, I'm happy that someone tries it.
  7. A part of a car or truck turbocharger could be a makeshift centrifugal pump. It's not optimized against cavitation nor for liquids. It still needs difficult bearings and a quick electric motor. But it's very cheap and immediately available.
  8. Hi JC! D-D reactors, including fusors, achieve fusion. But they are energy consumers, not producers. I've suggested smaller tokamaks fed with D only that consume energy to produce radioisotopes, especially for hospitals http://www.scienceforums.net/topic/107732-tokamak-produces-radioisotopes/ Though, ITER claims to explore the way to energy production, then not with the too difficult D-D but with D-T. The link to my estimates was in my message of November 30, 2014 but the website is closed meanwhile. So here is the full text, minimally rewritten. ========== Examples here of pollutant production at a Pb–Li coolant meant to regenerate tritium. Doc in the Handbook of Chemistry and Physics and in Peter Reimer 's PhD thesis: kups.ub.uni-koeln.de [In this folder] 204Pb makes 1.4% of natural Pb. The neutron doubling process is efficient (2.1b over 5.3b at 14MeV) and leaves 203Pb, decaying in 2.2 days by electron capture of 0.97MeV with γ emission. 206Pb makes 24% of natural Pb. When hit by a 14MeV neutron, it can emit an α to leave 203Hg, decaying in 47 days by β− with a 0.28MeV γ. Section for this production is only 0.7mb over 5.3b at 14MeV but 206Pb is abundant. Investigating more would bring more cases. 1.4% abundance or 0.7mb reaction section may look rather small, but: 235U produces 131I in 2.8% and 137Cs in 6.1% of the fission events; Fission of 235U brings 200MeV. It takes 8× more D–T and n–Li reactions to produce as much heat. Combine both, you get as much 203Pb as 131I per MW. Now, one may argue that isotopes 204 and 206 could be removed from Pb… Well, no. Never completely. Changing a concentration by a factor of 10 is already a big effort. But 10× less pollutants is still far too much. I'm confident other pollutants are produced by 207Pb and 208Pb, like 204Tl. I only checked neutrons with 14MeV as they're emitted. As they thermalise before being used by 6Li, more reactions occur. Such reactions look inherent to tritium regeneration. In a leak of hot coolant, I imagine the 16% lithium ignite in air (or don't they?), with the fire releasing in the atmosphere the contained pollutants. Marc Schaefer, aka Enthalpy
  9. General knowledge, it doesn't need a specific citation.
  10. On my old French bassoon, I bored a second piano hole just under the first one at the bocal, closed by the same long pad, hoping to ease and raise C#, D on second register and ease C#, D, Eb, E, F on the 4th octave. It did that more or less. The less expected effects: 4th octave E became as easy as the A below. 4th octave D became impossible. Good reason, I tapped the second hole. But the much easier E confirms it: one lone hole per semitone will let my pianolike system add a half or full octave to the bassoon at identically easy emission. Oboes and flutes should improve similarly. Marc Schaefer, aka Enthalpy
  11. For suborbital rockets too, be it science or tourism, liquid propellants and electric pumps are an interesting option. >100km altitude needs efficient engines, and optimizing solids takes much development, while liquids provide naturally a good ejection speed. Roll control is easier too. In many cases, one liquid stage can replace two solids. The same propellants selection applies: oxygen, helium, and a storable fuel like Pmdeta. Electric pumps and batteries outperform the simpler pressurized tanks.
  12. For suborbital rockets too, be it science or tourism, pressure-fed liquids are an interesting option. >100km altitude needs efficient engines, and optimizing solids takes much development, while liquids provide naturally a good ejection speed. Roll control is easier too. In many cases, one liquid stage can replace two solids. The same propellants selection applies: oxygen, helium, and a storable fuel, better an amine like Pmdeta. And here too, graphite fibre tanks outperform steel tanks. Electric pumps and batteries would outperform pressurized tanks.
  13. More fusion reactions exist, yes. But D-T is the only accessible to tokamaks presently. It's far less difficult than any other one because only one proton in D repels one proton in T. D-D reacts too but produces little heat as it releases the less stable 3He or T, and the reaction rate is 100 times less than D-T. Other fuels like Li or 3He are hugely more difficult. They work in hydrogen bombs, in some inertial confinement setups, but as a means of controlled net energy production they are out of reach. ========== After ITER got >10 years late because of Covid-19, some sort of assembly was celebrated recently (2020, who cares about the month meanwhile). As for the cost, present figures by the promoters fluctuate between 20 and 30G€. But the DOE, not significantly involved in this huge squandering, includes also the hardware developed by the participating countries and brought to ITER, to get >60G€ instead. For an energy source as polluting as uranium fission and available half a century after wind turbines, ITER is an expensive scam.
  14. Ammonium nitrate can detonate without a fuel. This is perfectly known. My source is a book is two thick volumes that deals only with explosives. But Wiki tells it too: "While ammonium nitrate is stable at ambient temperature and pressure under many conditions, it may detonate from a strong initiation charge. It should not be stored near high explosives or blasting agents." https://en.wikipedia.org/wiki/Ammonium_nitrate Starting a detonation in ammonium nitrate is uneasy, but a local part tainted with some fuel suffices. The molecule undergoes detonation, that is, propagation of the decomposition by the shock wave rather than by heat, without passing by ammonia and nitric acid. ========== The products released are not quite clear to me. In the detonation itself, the Propep software finds exclusively N2, H20, O2. The molar composition after expansion from 1 000 bar or 10 000 bar is: 0.46 H2O 0.29 N2 0.14 O2 0.12 H2O liquid Zilch, nada, niente -> Everything else, including N2O, NO, NO2 Though, some powder is dispersed without detonation, which might provide other decomposition products making the NO2 colour seen at Beirut. Red smoke was reported over an other ammonium nitrate explosion, I wish I saw colour pictures. ========== Video of the damage in Beirut by the explosion of 4 August 2020 https://www.youtube.com/watch?v=FMvBg7YIDAA impressive damage, impressive pilot skills. ========== If ammonium nitrate in thousands of tons were stored at Beirut's port, inevitably some Lebanese faction used it to make bombs. In the morning of 4 August 2020 before 11h CET (9h UT), a small dozen of big four-propellers military cargo planes flew over my home near Ramstein (US base in Germany). About as many flew (back?) spread over the 5 and 6 of August. That's usual before military operations. Several countries have developed laser weapons. The US demonstrated (and abandoned) a jumbojet-sized one to destroy missiles 500km away, and more recently smaller lasers to destroy at less distance a drone approaching a ship. Because igniting a fire is much easier than destroying a missile, inevitably these lasers serve for arson too. Accountability would justify the heavy means despite one missile from one combat plane would obtain the same result. Less expectedly, the French secret services tell me to shut up about this, rather than the US ones.
  15. Wide variety of materials. What has become extremely common is "reconstructed leather", which is a plastic resin loaded with fibres from leftovers of real leather. Goods manufacturers use it as a cheap replacement and label it "leather" with absolutely no distinctive word nor label. Possibly, legislation allow that when the mass proportion exceeds 50%. The polymer matrix is often polyurethane, which interferes with our hormone mechanisms. It can also be other polymers, very often loaded with plasticizers to imitate leather's bendability, and these plasticizers use to be toxic and migrate out of the polymer over time. So consumers can legitimately dismiss reconstructed leather, as well as leather-free polymer imitates. Alas, they are very difficult to distinguish from true leather. On a picture, it's about impossible. Where leather is bent, especially goat leather, it makes finer wrinkles than reconstructed leather. Under the fingers, true leather is tackier, quite different. The odour differs too, for those people who knew true leather. Because consumers can legitimately dismiss reconstructed leather but have nearly no means to distinguish it on a picture, I wish legislation to impose different words and logos for reconstructed leather.
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