Preliminary design of a supercritical CO2 wind tunnel

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Weakly polydisperse systems: Perturbative phase diagrams that include the critical region

The phase behaviour of a weakly polydisperse system, such as a colloid with a small spread of particle sizes, can be related perturbatively to that of its monodisperse counterpart. I show how this approach can be generalized to remain well-behaved near critical points, avoiding the divergences of existing methods and giving access to some of the key qualitative features of polydisperse phase equilibria. The analysis explains also why in purely size polydisperse systems the critical point is, unusually, located very near the maximum of the cloud and shadow curves.Comment: 4.1 pages. Revised version, as published: expanded discussion of Fisher renormalization for systems with non-classifical critical exponents; coefficients "a" and "b" re-defined to simplify statement of critical point shifts and cloud/shadow curve slope

On the parameter B = Re/KC = D²/vT

The article of record as published may be located at http://dx.doi.org/10.1016/j.jfluidstructs.2005.08.007This brief communication is a summary of the facts regarding the universalization in 1976 of a parameter b to fully nonlinear unsteady separated flows about bluff bodies nearly 125 years after its first appearance in a linearized analysis of unseparated viscous flow with very slow oscillations about a cylindrical rod and sphere by Sir George Gabriel Stokes [1851. On the effect of the internal friction of fluids on the motion of pendulums. Transactions of the Cambridge Philosophical Society 9(II), 8–106]. The primary purpose of Stokes was to show that ‘‘the index of friction’’ (the kinematic viscosity), in the equations of motion may be deduced from experiments for the vindication of the heuristic reasoning that went into the derivation by Navier [1827. Me´moire sur les lois du movement des fluides. Me´moires de l’Acade´mie de Sciences 6, 389–416.], Poisson [1831. Nouvelle the´orie de l’action capillaire Bachelier, Paris.], de Saint- Venant [1843. Note a´ joindre un memoire sur la dynamique des fluides. Comptes Rendus 17, 1240–1244.] and Stokes [1845. On the theories of internal friction of fluids in motion. Transactins of the Cambridge Philosophical Society 8, 287–305.] of what are now called the Navier–Stokes equations

Letter from [John Muir] to B. Re, [ca. 1909].

Helen L.Mr B. Re [diacritic]Crockett, Cal.Dear Sir:After considering Valona leases for next year we have considered that it would probably be better for all parties that you should continue to lease the same part of the ranch as formerly instead of all of it, as you proposed.As I informed you when you were here the other day your rent for next year will be seven hundred dollars payable semi-annually in advance -When you come up to make first payment we will make out a new lease.Trusting this will prove satisfactoryI am yrs truly0922

Transferring elements of a density matrix

We study restrictions imposed by quantum mechanics on the process of matrix elements transfer. This problem is at the core of quantum measurements and state transfer. Given two systems \A and \B with initial density matrices $\lambda$ and $r$, respectively, we consider interactions that lead to transferring certain matrix elements of unknown $\lambda$ into those of the final state ${\widetilde r}$ of \B. We find that this process eliminates the memory on the transferred (or certain other) matrix elements from the final state of \A. If one diagonal matrix element is transferred, ${\widetilde r}_{aa}=\lambda_{aa}$, the memory on each non-diagonal element $\lambda_{a\not=b}$ is completely eliminated from the final density operator of \A. Consider the following three quantities \Re \la_{a\not =b}, \Im \la_{a\not =b} and \la_{aa}-\la_{bb} (the real and imaginary part of a non-diagonal element and the corresponding difference between diagonal elements). Transferring one of them, e.g., \Re\tir_{a\not = b}=\Re\la_{a\not = b}, erases the memory on two others from the final state of \A. Generalization of these set-ups to a finite-accuracy transfer brings in a trade-off between the accuracy and the amount of preserved memory. This trade-off is expressed via system-independent uncertainty relations which account for local aspects of the accuracy-disturbance trade-off in quantum measurements.Comment: 9 pages, 2 table