3,151 research outputs found
Integrability of the symmetry reduced bosonic dynamics and soliton generating transformations in the low energy heterotic string effective theory
Integrable structure of the symmetry reduced dynamics of massless bosonic
sector of the heterotic string effective action is presented. For string
background equations that govern in the space-time of dimensions ()
the dynamics of interacting gravitational, dilaton, antisymmetric tensor and
any number of Abelian vector gauge fields, all depending only on two
coordinates, we construct an \emph{equivalent} matrix
spectral problem (). This spectral problem provides the base for the
development of various solution constructing procedures (dressing
transformations, integral equation methods). For the case of the absence of
Abelian gauge fields, we present the soliton generating transformations of any
background with interacting gravitational, dilaton and the second rank
antisymmetric tensor fields. This new soliton generating procedure is available
for constructing of various types of field configurations including stationary
axisymmetric fields, interacting plane, cylindrical or some other types of
waves and cosmological solutions.Comment: 4 pages; added new section on Belinski-Zakharov solitons and new
expressions for calculation of the conformal factor; corrected typo
Effect of ionic ordering in conductivity experiments of DNA aqueous solutions
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
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
Pозробка методу контролю елементів конструкції планеру повітряних суден в умовах експлуатації
The paper proposes to use a method of infrared pulse-echo inspection to control airframe designelements, made of polymeric composite materials under operators` conditions. The following is described:skeleton operation diagram of the given method, device structure and results of the preliminary researchesconfirming operation capacity of the method offeredПредложено использовать инфракрасный эхо-импульсный метод для контроля элементов конструкции планера, изготовленного из полимерных композицитных материаловЗапропоновано використовувати інфрачервоний ехо-імпульсний метод для контролю елементів конструкціїпланера, виготовленого з полімерних композитних матеріалі
Accuracy of one-dimensional collision integral in the rigid spheres approximation
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
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