The Upper Limit of the Separation Efficiency of a Gas Centrifuge

A general theory of isotopes separation in a gas centrifuge based on a radial averaging method has been developed. The ultimate upper limit for a centrifuge separative power is expressed as a function of its external parameters. This is a more accurate definition of the centrifuge efficiency upper limit than the well-known Dirac's estimation or estimations of his followers, because it takes into account the feed flow value (throughput) and it provides the way to a one-dimensional diffusion equation without a lot of assumptions. For the first time the problem of an energy efficient centrifuge is formulated and the solution is obtained. Two cases of a centrifuge internal flow optimization are compared. The optimal internal circulations for both optimization cases are calculated. The results help us to understand how far the modern centrifuges are from their highest possible effectiveness limit and to identify ways to improve centrifuge performance. © 2013 Copyright Taylor and Francis Group, LLC

Modeling of the future in the programs of political parties

The paper addresses the problem of modeling and planning of the future. It presents the problems of developing a model of the future due to the ideologies and strategies of some ruling political parties. The authors deal with the means of expression of the model of the future as one of the most important elements of the lingvo-mental image of political world in the context of program documents of the parties. The authors examine a program of a party as a part of political communication system and characterize the model of the future. On the basis of comparative study the authors determine common and specific features of the model of the future expression. A comparative study of the model of the future expression on the material of ruling parties of Russia and a variety of foreign countries (the United States, Great Britain, France, and Italy) is extremely relevant in the current period of global economic crisis. Such a research provides the basis for the optimal model of the future determination that can become a universal one for the electorate of different countries. Thus, the authors reveal the most advanced model of the future representation

Multicomponent separation potential. Elementary kinetic theory

A molecular model of a multicomponent separation process has been constructed. A general expression for the multicomponent separation potential (value function) has been derived from first principles. The general expression is not tied to a concrete cascade scheme and coincides with the classical expression for the case of a binary mixture. A peculiarity of the separation process, which leads to an infinite value of the potential for pure components of the mixture, has been revealed. © 2013 Springer Science+Business Media New York

Photon splitting in a laser field

Photon splitting due to vacuum polarization in a laser field is considered. Using an operator technique, we derive the amplitudes for arbitrary strength, spectral content and polarization of the laser field. The case of a monochromatic circularly polarized laser field is studied in detail and the amplitudes are obtained as three-fold integrals. The asymptotic behavior of the amplitudes for various limits of interest are investigated also in the case of a linearly polarized laser field. Using the obtained results, the possibility of experimental observation of the process is discussed.Comment: 31 pages, 4 figure

Optimal waveform estimation for classical and quantum systems via time-symmetric smoothing

Classical and quantum theories of time-symmetric smoothing, which can be used to optimally estimate waveforms in classical and quantum systems, are derived using a discrete-time approach, and the similarities between the two theories are emphasized. Application of the quantum theory to homodyne phase-locked loop design for phase estimation with narrowband squeezed optical beams is studied. The relation between the proposed theory and Aharonov et al.'s weak value theory is also explored.Comment: 13 pages, 5 figures, v2: changed the title to a more descriptive one, corrected a minor mistake in Sec. IV, accepted by Physical Review

Breakdown of the Migdal-Eliashberg theory in the strong-coupling adiabatic regime

In view of some recent works on the role of vertex corrections in the electron-phonon system we readress an important question of the validity of the Migdal-Eliashberg theory. Based on the solution of the Holstein model and inverse coupling constant expansion, we argue that the standard Feynman-Dyson perturbation theory by Migdal and Eliashberg with or without vertex corrections cannot be applied if the electron-phonon coupling constant $\lambda$ is larger than 1 for any ratio of the phonon and Fermi energies. In the extreme adiabatic limit of the Holstein model electrons collapse into self-trapped small polarons or bipolarons due to spontaneous translational-symmetry breaking when $\lambda$ is between 0.5 and 1.3 (depending on the lattice dimensionality). With the increasing phonon frequency the region of the applicability of the theory shrinks to lower values of the coupling constant.Comment: 4 pages, 1 figur

Compton Scattering from the Deuteron and Extracted Neutron Polarizabilities

Differential cross sections for Compton scattering from the deuteron were measured at MAX-lab for incident photon energies of 55 MeV and 66 MeV at nominal laboratory angles of $45^\circ$, $125^\circ$, and $135^\circ$. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and difference of the isospin-averaged nucleon polarizabilities, $\alpha_N + \beta_N = 17.4 \pm 3.7$ and $\alpha_N - \beta_N = 6.4 \pm 2.4$ (in units of $10^{-4}$ fm$^3$), have been determined. By combining the latter with the global-averaged value for $\alpha_p - \beta_p$ and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of $\alpha_n= 8.8 \pm 2.4$(total) $\pm 3.0$(model) and $\beta_n = 6.5 \mp 2.4$(total) $\mp 3.0$(model), respectively.Comment: 4 pages, 2 figures, revtex. The text is substantially revised. The cross sections are slightly different due to improvements in the analysi

Mixing quantum and classical mechanics and uniqueness of Planck's constant

Observables of quantum or classical mechanics form algebras called quantum or classical Hamilton algebras respectively (Grgin E and Petersen A (1974) {\it J Math Phys} {\bf 15} 764\cite{grginpetersen}, Sahoo D (1977) {\it Pramana} {\bf 8} 545\cite{sahoo}). We show that the tensor-product of two quantum Hamilton algebras, each characterized by a different Planck's constant is an algebra of the same type characterized by yet another Planck's constant. The algebraic structure of mixed quantum and classical systems is then analyzed by taking the limit of vanishing Planck's constant in one of the component algebras. This approach provides new insight into failures of various formalisms dealing with mixed quantum-classical systems. It shows that in the interacting mixed quantum-classical description, there can be no back-reaction of the quantum system on the classical. A natural algebraic requirement involving restriction of the tensor product of two quantum Hamilton algebras to their components proves that Planck's constant is unique.Comment: revised version accepted for publication in J.Phys.A:Math.Phy