Recent content by Gilles

Thanks, I elaborated it a little bit more and have put a paper on arXiv http://arxiv.org/abs/1110.0239

I'm not sure that this has been discussed already : the neutrino cross section increases with energy. Assume that the energy composition changes during the rising and decaying phases of the beam. Then the beam would interact more en more with the detector, which means that the rising slope of...

I think the question of clock synchronization may be tricky. In GR, there is no absolute definition of simultaneity. Due to differences in gravitational potential, as mentioned, clocks evolves differently at different points. So you must periodically resynchronize them, but how ? there is no...

C2H2 = 26 , very close to the average molar mass of the air (29), no reason to separate.

sorry again if those videos have already been discussed, but have you seen that ? blue flashing light possibly showing localized criticality : http://www.youtube.com/watch?v=qRoIpMNTbcQ&feature=player_embedded analysis of the video of unit-4 showing that there is no water left in the pool...

how to say without saying... http://www.bloomberg.com/news/2011-03-30/record-high-levels-of-radiation-found-in-sea-near-crippled-nuclear-reactor.html they exclude the possibility of uncontrolled chain reactions , but not of chain reactions ! obvisously , if some occur, they can be only...

actually Na emits a well-known orange resonance line, you can get it with a small crystal of salt in a flame - that may just be the salt contained in some droplets of sea water that gave this color to the explosion.

and as I said it is a daughter nuclide of Mo-99, which has a longer half-life (66 h) so actually it rather tracks the presence of its parent. But still 66 h is a rather short period compared to 20 days.

yes, m stands for metastable - excited but somewhat stable nuclear spin states. What I don't know is if the half-life is given for beta decay only or for the some of all decay modes including transition to the stable Ag110 ? and Tc-99m is produced by the decay of Mo-99, which has a longer...

Sorry, I come here only from time to time (plus jet lag ..) and I may have missed part of the discussion, but it seems that interesting observations can be done on these graphs http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/v8/Main.html Obviously explosions happened after...

Astronuc, I was told that massive reaction of Zircaloy with water required 1200°C to produce hydrogen, do you confirm ? so at least this temperature has been reached, probably in all active reactors 1-3. Also, high temperatures of 300-400°C have been measured when the pressure was only a few...

a possible scenario (sorry I'm not an expert in nuclear reactors, I just try to imagine reasonable conditions ) : control bars have been damaged at least at the top of fuel assemblies, due to very high temperatures and/or chemical reaction with steam, and have been partially destroyed. The top...

so confirming again that a blending of I-134 and Co-56 lines has mysteriously become undetectable ... :confused:

yes but https://www.physicsforums.com/showpost.php?p=3213341&postcount=1602", we see that both I-134 and Co-56 have disappeared after the reanalysis, how is it explainable if there was a blending of two lines? hope this is not kind of "political" suppression... or may be as they were unable to...

seen on this report : Te-132 (3 days) : 2.2E-01 Bq/cm^3 I-232 (2hours) : 3.3 +00 Bq/cm^3 correct me if I'm wrong, but if I-232 is a https://www.physicsforums.com/showpost.php?p=3212764&postcount=1491", with a much shorter lifetime, shouldn't the activities be equal ? (because each Te-132...