On some algebraic examples of Frobenius manifolds

We construct some explicit quasihomogeneous algebraic solutions to the associativity (WDVV) equations by using analytical methods of the finite gap integration theory. These solutions are expanded in the uniform way to non-semisimple Frobenius manifolds.Comment: 14 page

Material for Radiation Protection. Stretching-reducing of the Powder Composition “Al-B”

The fiber composite material (FCM) aluminum-boron is used in rocket-space, aviation technique. The scheme is proposed for utilization of elements from this material by crushing, grinding in a disintegrator to production of powders with particle sizes of 100-15

Stabilization of dipole solitons in nonlocal nonlinear media

We address the stabilization of dipole solitons in nonlocal nonlinear materials by two different approaches. First, we study the properties of such solitons in thermal nonlinear media, where the refractive index landscapes induced by laser beams strongly depend on the boundary conditions and on the sample geometry. We show how the sample geometry impacts the stability of higher-order solitons in thermal nonlinear media and reveal that dipole solitons can be made dynami-cally stable in rectangular geometries in contrast to their counterparts in thermal samples with square cross-section. Second, we discuss the impact of the saturation of the nonlocal nonlinear response on the properties of multipole solitons. We find that the saturable response also stabi-lizes dipole solitons even in symmetric geometries, provided that the input power exceeds a criti-cal value.Comment: 29 pages, 8 figures, to appear in Phys. Rev.

Influence of structural damping on the durability of a crane metal construction

The durability of the metal structure of a clamshell crane is predicted in two ways: by the hypothesis of linear summation of damage and using the model of cyclic degradation of the static properties of the material. In the second case, a conservative estimate of longevity is obtained for a quasi-random stress spectrum at the dangerous point of the span beam. A significant influence of structural damping on the service life of the crane has been revealed. Calculations by the developed algorithm are performed on an ordinary personal computer with a small expenditure of computer time. © 2018 Author(s)

The choice of the optimal experimental model of myocardial infarction

Nowadays myocardial infarction has a high percentage of mortality [12], and is widespread inUkraine and Western countries [1, 2, 3]. Such a situation calls for the development of a new model of myocardial infarction, which would be as simple and effective as possible. In this article, a model of myocardial infarction with the use of inhalation anesthesia with chloroform is proposed

Stabilization of higher-order vortices and multi-hump solitons in media with synthetic nonlocal nonlinearities

We address the evolution of higher-order excited states, such as vortex and multi-hump solitons, in nonlocal media with synthetic, competing focusing and defocusing nonlinearities with different nonlocal transverse scales. We reveal that introduction of suitable competing effects makes possible the stabilization of vortex solitons with topological charge m>2, as well as one-dimensional multi-hump solitons with number of humps p>4, all of which are highly unstable in natural nonlocal materials with focusing nonlinearities.Comment: 14 pages, 5 figures, to appear in Physical Review

The boundary value problem of determining hydrogen concentration and the stress state in a titanium shell

Decreasing physical and mechanical properties of materials in contact with an aggressive environment is one of the factors determining the strength and service life of various structures. In this paper, the effect of a hydrogen-containing medium on the mechanical properties and stress state of a titanium alloy shell is shown. For this purpose, the diffusion boundary-value problem is solved and the distribution of hydrogen concentration over the shell wall thickness is determined. Then the boundary-value problem of statics is solved, and the stress state of the shell structure is determined before and after hydrogenation. The object of study is presented in the form of a shell of revolution loaded with internal pressure and working in a hydrogen-containing medium. © 2019 Author(s)