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louis wu

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  • Interests
    Building a creature, hiding from lynch mobs (why do they have to have flaming torches and pitchforks?, I hate that).
  • College Major/Degree
    Chemistry Physics
  • Favorite Area of Science
  • Biography
    Experimental and theoretical scientist working in the nuclear field
  • Occupation
    Nuclear Scientist


  • Meson

louis wu's Achievements


Meson (3/13)



  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. love the name, great books...

  11. 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.
  12. 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.
  13. Are the cracks embedded or surface breaking?
  14. 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.
  15. 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.
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