Recent content by minerva

  1. M

    Smoothing 3d prints with acetone

    You said you're using PLA, so acetone won't do anything as it doesn't dissolve PLA. This technique is commonly used with acetone on ABS, not on PLA. Having concave surfaces or cavities won't matter. The object is not immersed into liquid solvent, it's immersed into the saturated vapor phase...
  2. M

    Power Over Fiber for Small Sensors

    "Power-over-fibre" systems which provide small power supplies with very strong galvanic isolation in floating HV systems are discussed a little bit in Horowitz and Hill's The Art of Electronics 'X-Chapters', chapter 9x.23. Broadcom make photovoltaic fibre-coupled devices designed for exactly...
  3. M

    What to do with 1 year+ expired bleach?

    It's not going to hurt anything. Flush it down the drain with ample water. That's what happens to bleach when using it to clean the toilet or other household applications, isn't it? Sodium hypochlorite bleach decomposes over time, and you'll gradually end up with less available chlorine in the...
  4. M

    Sealants without Methyl Ethyl Ketoxime

    Typical silicone sealants usually either come in "acetic cure" or "neutral cure". Acetic ones will say on the label that they release acetic acid during the reaction of methyl triacetoxysilane, and will release the characteristic vinegar scent of acetic acid. Sometimes this acetic acid is...
  5. M

    Can Na2PdCl4 be used as a substitute for PdCl2 in electroless copper plating?

    These videos show an electroless Cu deposition process onto a printed circuit board. I don't care about actually making a PCB, so the other steps such as PCB drilling, photolithography and electroplating thicker Cu aren't relevant. I'm only interested in the steps of electroless Cu...
  6. M

    I Where Can I Find Data on the IR Transmission of Silicon and Germanium?

    I'm looking for a table of data in electronic format, for optical transmission of Si in the mid infrared at say a wavelength range of 1-15um. Something like a text file or CSV file from a public source? Also looking for Germanium - the same spectrum. Any suggestions where I could get this?
  7. M

    The Nuclear Power Thread

    "I would open the containment (say, by blowing up a hole in its wall)" It's a massive structure of reinforced solid concrete. Stick a brick of C4 on it if you like - it will hardly do much. Cutting open the reactor building, for refurbishments and the like, is a massive engineering...
  8. M

    The Nuclear Power Thread

    "i think we will come back to Nuclear Power sometime in the future" Will it be - as Bernard Cohen titled his book - before it's too late?
  9. M

    The Nuclear Power Thread

    You're right, but I think you do have to have a little bit of regulation to guide the free market capitalism within certain boundaries to some extent. You can't just have everything "sensitive to investors" or they'll completely drive the climate and the environment into the ground with coal and...
  10. M

    Metal thin film adhesion, Au-Si deposition

    What protocol should I use to get a good stable 100nm Au adhesion onto a Si substrate using electron beam evaporation? I've heard talk of primer layers of either Cr or Ti at around 5nm thickness, as the typical way to do it. Which material should I choose? What the advantages or disadvantages...
  11. M

    Calculate mass or number of atoms based on MBq?

    If you've got some nuclide of interest, say Tc99m, then you can look up the "specific activity" for that nuclide. This gives you Bq per gram. (Then I'll let you convert grams to atoms, as an exercise for the reader.) But this assumes that you've got nothing but pure 100% Tc-99m in your sample...
  12. M

    A Can Relative Permittivity of Aluminum Be Calculated from Its Plasma Frequency?

    Consider a metal such as Al. How do we look up or determine the relative permittivity of the metal? Suppose we have some known incident frequency, say about c/500nm for visible light. We can look up the bulk plasma frequency (3.7 PHz for Al), can it be calculated from that? For context, what I...
  13. M

    Fukushima How will they end the Fukushima disaster?

    As far as I'm aware, that has not actually happened.
  14. M

    Max Neutron Output from Fusion: Power Requirements & Comparisons

    I really do not see any merit in accelerator-driven reactors. You need to add a very large, powerful proton synchrotron (typically on the order of 10 mA proton beam at 1 GeV) to the reactor, so you're adding non-trivial extra complexity and cost. And for what? What does it give you, relative...
  15. M

    Nuclear plant refueling and temporary workers

    You should remember that everything around a nuclear power plant is very well monitored for the presence of radioactive contamination, with very sensitive instruments. Look up the case of Stanley Watras, for an interesting demonstration of the implications of this. As another example, if you...
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