112,781 research outputs found
Numerical modelling of the quantum tail effect on fusion rates at low energy
No full textResults of numerical simulations of fusion rate d(d,p)t, for low-energy deuteron beam, colliding with deuterated metallic matrix (Phys. Lett. B 547 (2002) 193; Ear. Phys. J. A 13 (2002) 377) confirm analytical estimates given in M. Coraddu et al. (Quantum-tail effect in low energy d+d reaction in deuterated metals, Physica A, this issue), taking into account quantum tails in the momentum distribution function of target particles, and predict an enhanced astrophysical factor in the 1 keV region in qualitative agreement with experiments
Static and collective properties of dusty non-equilibrium plasmas
No full textThe static dielectric function and dust acoustic waves are considered of non-equilibrium dusty plasmas. The
dynamic characteristics are considered using an effective potential applicable at elevated pressure, but this is
not a limitation. A three-species model capable of describing the collective processes is suggested, and a first
order phase transition in such systems is previewed. The OCP static characteristics are calculated within the
HNC approach.This work was partially supported by the Russian Foundation for Basic Research (project No. 12-02-01177-a), the President of the Russian Federation (project no. NSh-2447.2012.2 for Support of Leading Scientific Schools) and the Spanish Ministerio de Ciencia e Innovacion (Grant No. ENE2010-21116-C02-02). I. M. T. is also grateful to the UPV for the sabbatical leave he was granted.Filippov, AV.; Starostin, AN.; Tkachenko Gorski, IM.; Fortov, VE. (2013). Static and collective properties of dusty non-equilibrium plasmas. Contributions to Plasma Physics. 53(4-5):442-449. https://doi.org/10.1002/ctpp.201200128S442449534-5Filippov, A. V., Starostin, A. N., Tkachenko, I. M., Fortov, V. E., Ballester, D., & Conde, L. (2010). Dust acoustic waves in a nonequilibrium dusty plasma. JETP Letters, 91(11), 558-565. doi:10.1134/s0021364010110044Filippov, A. V., Starostin, A. N., Tkachenko, I. M., & Fortov, V. E. (2011). Dust acoustic waves in complex plasmas at elevated pressure. Physics Letters A, 376(1), 31-38. doi:10.1016/j.physleta.2011.10.030Adamyan, V. M., & Tkachenko, I. M. (2003). Sum rules and exact relations for quantal Coulomb systems. Contributions to Plasma Physics, 43(56), 252-257. doi:10.1002/ctpp.200310020I. M. Tkachenko Yu. V. Arkhipov A. Askaruly “The Method of Moments and its Applications in Plasma Physics”, Lambert Acad. Publ., Saarbrücken, Germany, 2012.Dolgov, O. V., Kirzhnits, D. A., & Maksimov, E. G. (1981). On an admissible sign of the static dielectric function of matter. Reviews of Modern Physics, 53(1), 81-93. doi:10.1103/revmodphys.53.81Maksimov, E. G., Dolgov, O. V., & Dolgov, O. V. (2007). Physics-Uspekhi, 50(9), 933. doi:10.1070/pu2007v050n09abeh006213M. G. Krein A. A. Nudel'man “The Markov moment problem and extremal problems”, Trans. of Math. Monographs 50 , Amer. Math. Soc., Providence, R. I., 1977.N. I. Akhiezer “The Classical Moment Problem”, Hafner Publishing Company, New York, 1965.A. A. Abrikosov L. P. Gorkov I. E. Dzyaloshinski “Methods of Quantum Field Theory in Statistical Physics”, Pergamon Press, 1965.A. N. Starostin in Proceedings of IXth International Conference on Phenomena in Ionized Gases (Bucharest, 1969), p. 366.Starostin, A. N., Roerich, V. C., & More, R. M. (2003). How correct is the EOS of weakly nonideal hydrogen plasmas? Contributions to Plasma Physics, 43(56), 369-372. doi:10.1002/ctpp.200310048Starostin, A. N., & Roerich, V. C. (2005). A converging equation of state of a weakly nonideal hydrogen plasma without mystery. Journal of Experimental and Theoretical Physics, 100(1), 165-198. doi:10.1134/1.1866208Fasolino, A., Parrinello, M., & Tosi, M. P. (1978). Static dielectric behavior of charged fluids near freezing. Physics Letters A, 66(2), 119-121. doi:10.1016/0375-9601(78)90013-0Ng, K. (1974). Hypernetted chain solutions for the classical one‐component plasma up to Γ=7000. The Journal of Chemical Physics, 61(7), 2680-2689. doi:10.1063/1.1682399Baus, M. (1980). Statistical mechanics of simple coulomb systems. Physics Reports, 59(1), 1-94. doi:10.1016/0370-1573(80)90022-
Approximating ideal shapes with tight elements
No full textA variational approach is applied to the problem of finding the shortest curves in space separated
by constant distance. Among particular extremal solutions are straight line, circular arc and double
helix. Various knots and links may be assembled from these elements. It turns out that the structures so
created may serve as very good approximations of the ideal shapes. Explicit construction of the trefoil
knot and link 421
furnishes the examples
In Fond Memory of Scholar and a Good Man (To the 80 anniversary since the birth of P.N. Starostin)
No full textIt is a dedication to the 80th birthday anniversary since the birth of prominent Kazan archaeologist Petr N. Starostin (24.07.1936 – 4.07.2012), an outstanding researcher of Volga and Kama archaeological cultures, who made an invaluable contribution to the studies of the Pyany Bor, Azelino and Imenkovo cultures
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
On the perfect hexagonal packing of rods
No full textIn most cases the hexagonal packing of fibrous structures or rods extremizes the energy of interaction between strands. If the strands are not straight, then it is still possible to form a perfect hexatic bundle. Conditions under which the perfect hexagonal packing of curved tubular structures may exist are formulated. Particular attention is given to closed or cycled arrangements of the rods like in the DNA toroids and spools. The closure or return constraints of the bundle result in an allowable group of automorphisms of the cross-sectional hexagonal lattice. The structure of this group is explored. Examples of open helical-like and closed toroidal-like bundles are presented. An expression for the elastic energy of a perfectly packed bundle of thin elastic rods is derived. The energy accounts for both the bending and torsional stiffnesses of the rods. It is shown that equilibria of the bundle correspond to solutions of a variational problem formulated for the curve representing the axis of the bundle. The functional involves a function of the squared curvature under the constraints on the total torsion and the length. The Euler?Lagrange equations are obtained in terms of curvature and torsion and due to the existence of the first integrals the problem is reduced to the quadrature. The three-dimensional shape of the bundle may be readily reconstructed by integration of the Ilyukhin-type equations in special cylindrical coordinates. The results are of universal nature and are applicable to various fibrous structures, in particular, to intramolecular liquid crystals formed by DNA condensed in toroids or packed inside the viral capsids
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