Recent content by Polyamorph

I've done it this way, it works! Thanks to both of you for your help.

Thanks for your reply. Yes at V=V0 the pressure is zero (ambient pressure).

Hello, https://www.physicsforums.com/lib/Eqn026.pngI have the pressure (P)-volume (V) Birch-Murnaghan equation of state coeffcients (V_{0},K_{0}, K^{'}_{0}, K^{''}_{0}) for a number of different compositions. I'm interested in the volume at very specific pressures only and ideally I would like...

Yes, looks like you're right. Thanks for spotting that.

Sure, I got the second equation from this paper: http://www.homepages.ucl.ac.uk/~ucfbdxa/pubblicazioni/PRL05161.pdf

OK, I've worked out that due to symmetry, XY=YX, YZ=ZY, ZX=XZ, so the tensor reduces from 9-components to 6. So that explains my second question (note typo when I wrote "what about yx, zx, yx?" should have said "what about yx, zy, xz?" But I still don't understand why the first equation is...

Hello! In this paper https://pdfs.semanticscholar.org/e8a2/02f25555cd8c4f947bbbdff5a61a0ea0efd2.pdf the authors use VASP to determine MgSiO3 viscosity using the Green-Kubo relation ## \eta = \frac{V}{3k_{\rm{B}}T}\int_{0} \left<\sum_\limits{i<j}\sigma_{ij}(t+t_{0}).\sigma_{ij}(t_{0})\right>dt##...

I used Rhenium spheres with diameters of 100-150 μm in a silicate melt, which has a viscosity of about 0.05 Pa s using white beam x-ray radiography with a very fast CCD camera. I just wanted to know the special case when the sphere didn't reach terminal velocity, which happened a couple of times...

Thanks. I've done this, solving Newton's 2nd law to find v as a function of time, taking into account gravitational force, bouyancy and drag force. The resulting function v(t) can then be fitted to the experimental data using a least square fit to find the optimum η. My remaining question the is...

Hello, I have recently conducted an experiment to measure the viscosity of some liquids using the falling sphere method and a high speed camera. For most of the measurements this is fine since the spheres reach terminal velocity and so it is easy to calculate the viscosity from: v =...

Hi, thanks for all your replies. Basically if I do a search there are literally thousands of hits. I don't know where to start and who to trust. The google host sounds interesting. the problem is it will be located at the: https://sites.google.com/site/ url whereas I'd like my own personal...

Hi fellow physicists, I'd like to create my own website. I already have my own webpages currently hosted on a university server but my account will soon be deactivated and I will no longer be able to use that server. So I would like to transfer my personal webpages elsewhere. The trouble is...

Yes this is true but you don't need to apply pressure to experience what are known as phosphenes (the experience of seeing light without light actually entering the eye). So it is one explanation but closed-eye hallucinations ( see this article...

I don't think use of a Geiger counter in a movie makes it a bad movie! As long as they are using it correctly.

If that doesn't work it shouldn't be too difficult or expensive to replace them, provided you can find a supplier that stocks identical parts.