Solitary electromagnetic waves propagation in the asymmetric oppositely-directed coupler

We consider the electromagnetic waves propagating in the system of coupled waveguides. One of the system components is a standard waveguide fabricated from nonlinear medium having positive refraction and another component is a waveguide produced from an artificial material having negative refraction. The metamaterial constituting the second waveguide has linear characteristics and a wave propagating in the waveguide of this type propagates in the direction opposite to direction of energy flux. It is found that the coupled nonlinear solitary waves propagating both in the same direction are exist in this oppositely-directed coupler due to linear coupling between nonlinear positive refractive waveguide and linear negative refractive waveguide. The corresponding analytical solution is found and it is used for numerical simulation to illustrate that the results of the solitary wave collisions are sensible to the relative velocity of the colliding solitary waves.Comment: 9 pages,5 figure

Response evolution of a tetrachiral metamaterial unit cell under architectural transformations

This paper studies a mechanical metamaterial with tetrachiral topology by mathematical modeling. Chirality is the property of an object that makes the object distinguishable from its mirror image; chirality can be left‐ or right‐handed. The mechanical response of two metamaterial unit cells with different configurations (patterns A and B) is investigated. It is found that the cubic cell with a regular pattern A exhibits orthotropic mechanical behavior under loading along three coordinate axes. An irregular pattern B differs from pattern A in that the upper face of the unit cell has an opposite chirality. This architectural transformation is considered as a topological defect, which enhances the twisting effect in the loaded metamaterial. Analysis of displacements and stresses shows that the mechanical behavior of the pattern B cell is described by the model of a transversely isotropic material. The orthotropic and transversely isotropic behavior of the cells of given configurations is also confirmed by the values of the effective elastic constants. Microstructural geometry and mechanical deformation of metamaterials are shown to be closely related. It is shown that a topological defect in a unit cell of a tetrachiral metamaterial strongly determines its twisting behavior

Assessment of the reliability of the locomotive based on statistical methods of quality management

The lack of reliability of the diesel locomotive operation leads to a decrease in the technical and economic efficiency of using the locomotive service of the enterprise. During the experiment which aimed at assessing the reliability of repair and maintenance of a diesel locomotive in one of the railway divisions of OJSC "Russian Railways", it was found that the failures may be distributed by types of equipment, based on the failures for 12 months of 2017. Statistical quality management methods were used to identify the most problematic types of locomotive equipment and specific causes of failures. © Published under licence by IOP Publishing Ltd

Design of professional career by future experts in the sphere of art and culture

The problem of planning of professional life is discussed by experts in the field of art and culture, experience of application of active forms of education with use of presentation during psychology and pedagogical lessons is described in the article, aspects of efficiency of their realization in training of students of higher education institution are considered, possibilities of application of modern means of presentation in the course of professional formation of future specialist producer are revealed. Problems of design of a professional way of a personality in the context of modern social and economic conditions are complicated by unstable conditions, characterized by social, economic and political changes, prompt transformations in the sphere of values and purposes of personality that predetermines essentially new requirements to psychological structure of the personality which would provide the most effective self-realization and success in professional activity. That means that actual tendencies of process of vocational training of future experts in the sphere of art are ways of application of means of modern technologies in the course of training. We believe that use of active forms of education with use of presentation, and also analysis of perceived phenomena by students will form readiness of future experts of the sphere of art and culture for design of own professional future.peer-reviewe