Recent content by jet10

  1. J

    Uniaxial Plate Bending vs Beam Bending: What's the Difference?

    I can see here that the stiffness really depends on the width to length ratio, and the factors derived analytically are only approximations. The diagram is illuminating.
  2. J

    The Relationship Between Dielectric Function and Joint Density of States

    I noticed that there is a factor of 1/E^2 in the \varepsilon_2 equation. Since \varepsilon_2 is dependent on E, isn't the JDOS rather *almost* proportional to E^2\varepsilon_2?
  3. J

    Uniaxial Plate Bending vs Beam Bending: What's the Difference?

    Thanks a lot for the help. I will see if I can find such a plot in a paper somewhere. Your note is a nice summary. Thanks for that too
  4. J

    Uniaxial Plate Bending vs Beam Bending: What's the Difference?

    What are the criteria for the fraction to be nonnegligible? Is it just a matter of definition?
  5. J

    Uniaxial Plate Bending vs Beam Bending: What's the Difference?

    Just one more question: at which width does a beam become a plate?
  6. J

    Uniaxial Plate Bending vs Beam Bending: What's the Difference?

    Thanks very much. Yes, I think it does answer my question. So it is like two thin layers that are glued together. The top tries to expand and the bottom tries to contract. None of them succeeds because the other is doing the opposite.
  7. J

    Uniaxial Plate Bending vs Beam Bending: What's the Difference?

    I have checked with Timoshenko's Theory of Plates and Shells. There is no mistake in what I wrote. It even says "The lateral strain in the y-direction must be zero in order to maintain continuity in the plate during bending.." This follows from Hooke's law that...
  8. J

    Uniaxial Plate Bending vs Beam Bending: What's the Difference?

    I would appreciate it if some one could help me with this. I read from Timoshenko's book Theory of Elasticity that for prismatical beam bending (uniaxial), the assumption is \sigma_x>>\sigma_z,\sigma_y=0 where \sigma_x is stress in the direction parallel to the deflection curve. And for...
  9. J

    The Relationship Between Dielectric Function and Joint Density of States

    Thanks for your clear answer. Just one more question. I see that the formula for Epsilon in books are normally given for isotropic material. What changes in the integral of the formula if we want to know Epsilon in a certain direction for anisotropic material? There is a polarisation vector e in...
  10. J

    The Relationship Between Dielectric Function and Joint Density of States

    Hi. I have been looking at some lecture notes. What is not so clear for me is, how the imaginary part of the dielectric function is related to the joint density of states. Is the "amplitude" of the epsilon2 directly proportional to JDOS? or is JDOS some kind of derivative of epsilon2? Thanks
  11. J

    Where can i find a page to get laser simulations or laser models?

    you might want to try www.las-cad.com. Don't know if this is what you re looking for.
  12. J

    How do composite bosons behave in a Bose-Einstein condensate?

    I am not very familiar with theory of Cooper pairs. Maybe I just have to read it up. It is a little hard for me to imagine it. About a composite boson: Let's say you have |k_1, up> - |-k_1, down> and |k_2, up> - |-k_2, down>. They are two bosons or Cooper pairs made up of 2 electrons...
  13. J

    How do composite bosons behave in a Bose-Einstein condensate?

    A few questions about BEC: A) When these bosons condensate, many particles fill the ground state. I read from textbooks that this would imply that they occupy the same position. -1- experiments are done with Rb atoms, which consist of protons, neutrons and electrons. Wouldn't the electrons...
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