2,757 research outputs found

    Effect of ionic ordering in conductivity experiments of DNA aqueous solutions

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    The effects of ionic ordering in DNA water solutions are studied by conductivity experiments. The conductivity measurements are performed for the solutions of DNA with KCl salt in the temperature range from 28 to 70 C. Salt concentration vary from 0 to 2 M. The conductivity of solutions without DNA but with the same concentration of KCl salt are also performed. The results show that in case of salt free solution of DNA the melting process of the double helix is observed, while in case of DNA solution with added salt the macromolecule denaturation is not featured. For salt concentrations lower than some critical one (0.4 M) the conductivity of DNA solution is higher than the conductivity of KCl water solution without DNA. Starting from the critical concentration the conductivity of KCl solution is higher than the conductivity of DNA solution with added salt. For description of the experimental data phenomenological model is elaborated basing on electrolyte theory. In framework of the developed model a mechanism of counterion ordering is introduced. According to this mechanism under the low salt concentrations electrical conductivity of the system is caused by counterions of DNA ion-hydrate shell. Increasing the amount of salt to the critical concentration counterions condense on DNA polyanion. Further increase of salt concentration leads to the formation of DNA-salt complexes that decreases the conductivity of the system.Comment: 12 pages, 6figures. Ukr. J. Phys. (2014

    Decomposable representations and Lagrangian submanifolds of moduli spaces associated to surface groups

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    In this paper, we construct a Lagrangian submanifold of the moduli space associated to the fundamental group of a punctured Riemann surface (the space of representations of this fundamental group into a compact connected Lie group). This Lagrangian submanifold is obtained as the fixed-point set of an anti-symplectic involution defined on the moduli space. The notion of decomposable representation provides a geometric interpretation of this Lagrangian submanifold

    Accuracy of one-dimensional collision integral in the rigid spheres approximation

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    The accuracy of calculation of spectral line shapes in one-dimensional approximation is studied analytically in several limiting cases for arbitrary collision kernel and numerically in the rigid spheres model. It is shown that the deviation of the line profile is maximal in the center of the line in case of large perturber mass and intermediate values of collision frequency. For moderate masses of buffer molecules the error of one-dimensional approximation is found not to exceed 5%.Comment: LaTeX, 24 pages, 8 figure

    Solvability of a multivalued filtering problem in a heterogeneous environment with a distributed source

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    In this paper we formulate a generalized filtering problem in a heterogeneous environment in the presence of a source distributed along a line. Incompressible fluids obey a multivalued law with a linear growth at infinity. In this study we use the additive singularity extraction in the right-hand side of the problem constraint. We represent the pressure field as the sum of a known solution to a certain linear problem and an unknown "additive term". We reduce the problemunder consideration to a variational inequality of the second kind in a Hilbert space (with respect to the mentioned "additive term") and prove its solvability. © 2011 Allerton Press, Inc

    A nonperturbative model for the strong running coupling within potential approach

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    A nonperturbative model for the QCD invariant charge, which contains no low-energy unphysical singularities and possesses an elevated higher loop corrections stability, is developed in the framework of potential approach. The static quark-antiquark potential is constructed by making use of the proposed model for the strong running coupling. The obtained result coincides with the perturbative potential at small distances and agrees with relevant lattice simulation data in the nonperturbative physically-relevant region. The developed model yields a reasonable value of the QCD scale parameter, which is consistent with its previous estimations obtained within potential approach.Comment: 14 pages, 4 figure

    Educational Inequality and Professional Motivation of a Future Teacher

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    The professional motivation and interest of the teacher in the students’ educational results are the key resources that allow educational institutions to minimize the existing inequality of educational opportunities for members of different social groups. On this point, one of the important issues of professional training of future teachers is the formation of motivation for their professional activity regarded as a factor that ensures the equality of educational opportunities for students from different social groups. Based on the results of empirical studies of different years, the article analyzes the changes that occurred in the professional motivation of students after the Ussuriysk State Pedagogical Institute joined the Far Eastern Federal University (FEFU) in 2011 as the School of Education. The use of the same measuring instruments made it possible to conduct a comparative analysis of the professional motivation of students in different periods

    METHODOLOGICAL APPROACH TO CONDUCTING CORPORATE TECHNOLOGICAL FORESIGHT AND AN EXAMPLE OF ITS USE FOR A COMPANY IN THE OIL AND GAS SECTOR OF RUSSIA

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    A methodological approach for conducting a technological foresight at the corporate level has been proposed. A corporate foresight based on general methodological approaches used in world practice should take into account a number of additional factors imposed by the specifics of the industry and organization in order to obtain a list of priority technologies and technological directions relevant to the company’s activities. Methodological approach is based on the concept “Markets-Trends-Technologies”. Global markets research allows us to determine key problems and trends of society evolution in economic, social, political and other arears. The transition to the corporate level is carried out by identifying trends in the company’s industry. The methodology have described in detail the methods of attracting experts to assess the power of mutual influence of trends and technologies. The results of the assessment can be used for subsequent technological mapping in scientific and technical forecasting and strategic planning

    Defect loops in gauged Wess-Zumino-Witten models

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    We consider loop observables in gauged Wess-Zumino-Witten models, and study the action of renormalization group flows on them. In the WZW model based on a compact Lie group G, we analyze at the classical level how the space of renormalizable defects is reduced upon the imposition of global and affine symmetries. We identify families of loop observables which are invariant with respect to an affine symmetry corresponding to a subgroup H of G, and show that they descend to gauge-invariant defects in the gauged model based on G/H. We study the flows acting on these families perturbatively, and quantize the fixed points of the flows exactly. From their action on boundary states, we present a derivation of the "generalized Affleck-Ludwig rule, which describes a large class of boundary renormalization group flows in rational conformal field theories.Comment: 43 pages, 2 figures. v2: a few typos corrected, version to be published in JHE
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