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louis wu

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Everything posted by louis wu

  1. So the official EU wide definition of pressure vessels is irrelevant as to discounting a balloon as a pressure vessel. Well I disagree. Balloons are not pressure vessels, either when utilised in work environments or otherwise. BTW the official HSE position on conkers appears to be http://www.hse.gov.uk/myth/september.htm.
  2. Not according to the HSE Pressure vessel regulations (UK Pressure Equipment Directive (Directive 97/23/EC) (PED)). Only a contained pressure of 0.5 Bar or greater satisfies the requirements for a pressure vessel.
  3. The actual paper is here. https://arxiv.org/pdf/1607.04878.pdf The authors do not claim in any way to have proven any holographic principle. They do claim that some holographic models are consistent with the Planck satellite data and may be competitive with ΛCDM.
  4. Well the EPA is to be terminated according to a bill presented to congress. https://www.congress.gov/bill/115th-congress/house-bill/861/text?q=%7B%22search%22%3A%5B%22HR+861%22%5D%7D&r=1 US uncut link. http://usuncut.com/climate/epa-terminate/ This cannot be a good idea. It is not how I envisioned draining the swamp.
  5. The actual paper can be found here https://arxiv.org/ftp/arxiv/papers/1409/1409.0880.pdf A video is an important component of the paper and is found http://irfu.cea.fr/laniakea or http://vimeo.com/pomarede/laniakea I found the video mind blowing and beautiful. The method is the Cosmicflows-2 catalog of galaxy positions and velocities together with standard cosmology are used as prior distribution for variational Bayesian analysis. Wiener noisy signal processing is heavily used, in deriving the velocity and density flow data. The analysis used H0 = 75.2 km s−1 Mpc−1 : The Planck team found H0 = 67.3 km s−1 Mpc−1, I find the difference a little disturbing, but I am not really competent to criticise the paper. The paper claims that the difference should not affect the derived velocities.
  6. Why was it not achieved years ago? i think that is kind of unfair. The fig.1 phase diagram is the result of ongoing research by several competing teams. The production of metallic hydrogen is novel as far as I can tell, and may be a great leap forwards. Before this last weekend I had assumed that metallic hydrogen would be confined to the centre of gas giant planets, if found anywhere.
  7. A BBC news article on the discovery is here http://www.bbc.co.uk/news/science-environment-38768683 The paper is here https://arxiv.org/ftp/arxiv/papers/1610/1610.01634.pdf As described in the paper, the work should be easy to replicate and confirm. If the metallic hydrogen is metastable. and can be a RT superconductor that would be wonderful for many applications. There would be obvious difficulties in mass production of metallic hydrogen. That weird phase diagram (fig. 1) does imply the possibility of RT stability..
  8. If you have have not already found the answers for yourself I will supply some. Interstitial C in both FCC and BCC steel does produce local lattice strains and distortions. Too much carbon will produce a very brittle and essentially undesirable steel. I calculate the interstitial hole to be ~104 pm diameter in FCC iron. Interstitials and other lattice defects such as vacancies, edge and screw dislocations are not fixed in place permanently. Your blacksmithing is influencing, moving, concentrating, sometimes creating or eliminating these defects.
  9. Putin's detractors often come to unfortunate ends. Of course the esteemed statesman has no connection to these events.
  10. Well Geothermal Energy, as Captain Panic alludes above, is very much a good idea for a geology career. In many ways Geothermal is the free lunch of energy production. Ensuring the geological stability of radioactive waste repositories is another worthwhile goal. As is working out methods of disposing of radioactive waste into subduction zones. http://www.science20.com/tuff_guy/nuclear_waste_geologists_perspective NNC report on subduction For a geologist, finding fresh reserves of Uranium and possibly Thorium would be worthwhile.
  11. Well, the actual quote was 'water in direct contact with atmosphere', a condition that your pond fails to meet. To be specific, the algae and other organisms form an organic chemical layer on top of the pond. So the oxygen in air must pass through a barrier layer before reaching the water. This slows down the rate at which oxygen can penetrate into the water to a level where the lifeforms consume oxygen faster than it can be replenished. As the organisms die and decompose, the oxygen levels fall further. Stagnant fresh water is particularly prone to decomposing algae removing the oxygen. Algal blooms can act even on the open sea, by producing large amounts of toxins that kill any lifeforms present; resulting decomposition reduces oxygen levels over large dead areas. wiki lake scientist In the case of a clean garden pond, of shallow depth, the fish will not consume oxygen faster than it can be replenished. Obviously there will be a concentration gradient in replenishment, so the fish will reduce the oxygen level slightly. In water without any organic film the reduction will be trivial. Of more relevance to the actual opening post: I have designed and carried out many experiments in which exact dissolved oxygen levels had to be controlled and measured. The popular Orbisphere electrochemical sensors for measuring dissolved oxygen rely for their calibration on a beaker of water exposed to atmosphere. The dissolved oxygen at 25°C is 8.x ppm on a wt per Kg or litre basis, as I have verified all too often. http://shop.hach-lange.com/shop/action_q/highlights/highlight_id/1454/lkz/II/spkz/en/TOKEN/vAtZzeQkkE8dqTzPdOCaHtzmbhs/M/t1Dyvw Even large concentrations of dissolved ions do not affect oxygen solubility greatly. Full on seawater at 35000 ppm has only a fall in oxygen levels of 20%. Here is data, John Cuthber posted the link earlier. This information is accurate, mg/l is equivalent to ppm as commonly used by workers in this field. some oxygen solubility data I concur with other posters that the is an information shortage on the set-up from the opening post. Is the system some kind of bio-reactor? What has Mercury to do with the project? What exactly is depleting the oxygen? Without mains power I could generate oxygen using car batteries, though I would also be generating hydrogen. With some design work the hydrogen could be generated in a separate vessel, but I would still have to be monitored and stores or safely vented (to a flame trap?) Even knowledgeable people cannot solve a problem without sufficient information.
  12. Are the cracks embedded or surface breaking?
  13. Any water that is direct contact with atmosphere will contain dissolved oxygen at ~8ppm. The exact amount will vary with atmospheric pressure and the temperature. To obtain higher levels of dissolved oxygen: the oxygen content of the local environment can be raised, or compressed air can be used to pressurise a sealed vessel to a higher pressure than atmospheric. Indeed pure oxygen can be used to pressurise a sealed vessel (use of high oxygen gases requires special consideration to the vessel and piping materials, and pressure vessels themselves are the subject of safety legislation.
  14. Induction heating units are in theory tuned to match the application desired. When a unit is ordered the coils are claimed to have been designed to match the material to be heated (both its composition and size / shape). The power supply and water chiller will be standard off the shelf units, of capacity to match the intended application. In practice any conductive material will be heated by the equipment; some materials will heat better than others. Austenitic stainless steels and nickel alloys are relatively poor at heating whilst ferromagnetic steels are easily heated. Some power supplies are frequency tun-able and some are not. NMR states do not affect the process as far as I know: Rather it is the resistivity and magnetic properties of the material.
  15. View Postlouis wu, on 24 September 2011 - 09:33 PM, said: Based on the GPS distance of 730km from the paper being a great circle upon a sphere of the dimensions quoted, which are equatorial dimensions from the internet. The oblate spheroid nature of the Earth should not introduce any great error as the polar radius is 7357km so the chord calculated assuming the polar radius would actually be shorter.
  16. Well I did the the calculation. Taking the GPS distance as 730km, the Earth's circumference as 40070km, and the Earth's radius as 4378km. The shortened chord distance I get is 729.677km, which is 323m shorter, not the 20m claimed. Another bright idea bites the dust, probably. Anyone care to check my calc.
  17. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1987ApJ...319..136A&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES Here is a paper from soon after 1987a, which confirms that the neutrino burst arrived 3 hours before the visible light detection. That is good synchronisation after a travel time of ~165000 years.
  18. 'Death by snu snu' is the obvious choice.
  19. Despite the release of a long form certificate, some amongst the Birthers still have serious concerns.
  20. michel123456 You seem to be prone to the lack of rational consideration of risks that I was alluding to. 30000 people is one possible death toll from Chernobyl. This is spread out over many decades. This death toll is unacceptable to you, from an accident that occurs with a frequency of ~ 25 years: assuming that Fukushima releases about the same total radiation as Chernobyl (something that seems very unlikely). That fossil fuel power systems cause 10 times that number of preventable deaths each and every year seems OK by you. A simple, rational, risk assessment approach says that fossil fuels are far more risky; that getting the fossil fuel set-up to clean up their act will save far more lives than irrational concentration on nuclear power. A consideration of the numbers shows where the most human lives are to be saved.
  21. There seems to be some unwarranted hysteria on this thread about radiation releases in Japan. Chernobyl was by far the worst Civil Nuclear Power incident so far. The WHO estimated 4000-9000 deaths would be caused by Chernobyl. This is a low side estimate by the UN-led Chernobyl Forum back in 2006. The Greenpeace sponsored TORCH report estimated 30000-60000 deaths would be caused by Chernobyl. This would be a high end figure. http://www.greens-efa.org/cms/topics/dokbin/118/118559.torch_executive_summary@en.pdf In contrast the fossil fuel industry kills 300000 every year from particulate pollution, as outlined in an OECD 2008 report. http://www.rivm.nl/bibliotheek/rapporten/500113001.pdf http://m.economist.com/democracy-in-america-21016879.php So if you accept the Greenpeace figures of Chernobyl eventually killing between 30000 to 60000 people: we would need at least 5 Chernobyls a year to match the fatalities currently being caused by fossil fuels. Most of the radiation debates do not seem to include any rational consideration of the actual risks involved.
  22. Zircaloy will steam oxidise if it becomes hot enough, producing hydrogen.
  23. Kaku is an opponent of nuclear fission power. He has been doing some scaremongering because if you dislike nuclear power then this is a great time to give the nuclear industry a kicking. This article for example is blatant scaremongering. http://bigthink.com/ideas/31595 I think he has a new book out as well, so he needs to increase his public profile by any means possible.
  24. Well Swansont Without wishing to be too argumentative I think you are wrong. The information you have posted is for the main circulation system on the AP1000. This system would be powered from the grid in a reactor SCRAM. BWR emergency systems based on diesel generators do not run the main circulation pump, They are on totally different lines. See this diagram. The main circulation pump is not needed in a SCRAM because in the same second that the rods go in; the heat output from the fuel is reduced to 10% and drops quickly thereafter. The diesel generators will be hefty beasts, and sized so that a single one of them can cope with the job; however I think that they will be commercially available items rather than specials. I entirely agree with you emphasising the flooded switchroom. I believe that this was the single most important factor in changing the situation from an entirely controlled shut-down into a disaster. If 1 replacement diesel had been plumbed in during the 12 hours of battery power TEPCO would be telling us all about a vindication of the defence in depth strategy.
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