Stable multiple-charged localized optical vortices in cubic-quintic nonlinear media

The stability of two-dimensional bright vortex solitons in a media with focusing cubic and defocusing quintic nonlinearities is investigated analytically and numerically. It is proved that above some critical beam powers not only one- and two-charged but also multiple-charged stable vortex solitons do exist. A vortex soliton occurs robust with respect to symmetry-breaking modulational instability in the self-defocusing regime provided that its radial profile becomes flattened, so that a self-trapped wave beam gets a pronounced surface. It is demonstrated that the dynamics of a slightly perturbed stable vortex soliton resembles an oscillation of a liquid stream having a surface tension. Using the idea of sustaining effective surface tension for spatial vortex soliton in a media with competing nonlinearities the explanation of a suppression of the modulational instability is proposed.Comment: 4 pages, 3 figures. Submitted to Journal of Optics A. The proceedings of the workshop NATO ARW, Kiev 2003 Singular Optics 200

To the question of the level of readiness and the degree of motivation of the student of the pedagogical higher education institution to professional activity

The article deals with the problem of the level of professional readiness of the student to work in conjunction with the level of his motivation. These multifactorial processes interdepend each otherВ статье рассматривается проблема уровня профессиональной готовности студента к деятельности во взаимосвязи с уровнем его мотивированности. Эти многофакторные процессы взаимообуславливают друг друг

Digital holographic camera for plankton monitoring

A submersible digital holographic camera for measuring plankton and other particles is described. The camera provides underwater recording of digital holograms of water volume containing plankton followed by automatic restoration of holographic images of plankton species, determination of their sizes, shapes, and concentrations, and their recognition and classification. Particles with sizes of 200 μm and larger are analyzed. The water volume registered per exposure is about 1 L. The special features of the software for automatic information retrieval from digital holograms are discussed. Examples of application of the camera as an integral part of the hardware-software complex for field measurements are given. Prospects for application of this complex for ecological monitoring are discussed. The recognition criterion of the digital holographic camera and the data volume and the averaging time required for obtaining statistically reliable data on plankton species are also given

Stability of two-dimensional spatial solitons in nonlocal nonlinear media

We discuss existence and stability of two-dimensional solitons in media with spatially nonlocal nonlinear response. We show that such systems, which include thermal nonlinearity and dipolar Bose Einstein condensates, may support a variety of stationary localized structures - including rotating spatial solitons. We also demonstrate that the stability of these structures critically depends on the spatial profile of the nonlocal response function.Comment: 8 pages, 9 figure

Oral agreement juridical technique at the stage of contract signing: features and composition

Objective: to analyze the oral contractual legal technique and its component tools, to identify the features of technical and legal tools used at the stage of negotiating a contract.Methods: the dialectical approach to cognition of the legal phenomenon, allowing to analyze it from the point of view of the general theory of law, knowledge of individual branches of law and humanities; formal legal method (analysis of doctrinal provisions and practice of contractual law application), analysis, synthesis, comparison, classification, and other general scientific methods of cognition.Results: based on the analysis of theoretical and legal structures, legislation and practice of its application, conclusions are drawn about the existence of oral contractual legal technology and the criteria for distinguishing its legal tools from those of a non-legal nature. The legal tools of oral contractual legal techniques are expressed in the presence of specific rules for performing certain legally significant actions. These rules are characterized by: a) relative stability; b) direct focus on generating the main legal result: the emergence of rights and obligations in order to meet certain needs of the parties; c) dependence of the tools on the content of the contractual process stage. By the example of negotiating a contract as an important stage of the contractual process, one may regard good faith as the most significant rule in negotiations. The general model of signing a contract is also stable (sending a proposal to sign a contract, agreeing/disagreeing with the offer/agreeing to change the terms of the offer, sending a response to the offer, and signing the contract as a result). Negotiations can be organized in two ways: a) directly (based on the general provisions of Chapter 28 of the Russian Civil Code) and b) step-by-step (by signing an agreement on the procedure for conducting negotiations).Scientific novelty: oral contractual legal techniques rarely become the subject of scientific research. The proposed approach to the analysis of its tools is new for the Russian theory of legal technique.Practical significance: the main provisions and conclusions of the article contribute to the development of the legal technique theory aimed at improving the methods of professional legal activity, including in the field of contract signing

Organizational work on revision the resolutions of industrial safety expertise

The issues of examination of industrial safety as a tool for conformity of industrial equipment with the requirements of regulatory documents are considered. It’s underlined that at present, the regulatory framework for industrial safety is intensively developing. It’s proved that in order to ensure the quality of the preparation of the resolutions of industrial safety expertise the development of a standard for expert organization that will set the requirements for the structure and content of report documentation would be expedientРассматриваются вопросы экспертизы промышленной безопасности как инструмента подтверждения соответствия промышленного оборудования требованиям нормативной документации. Подчеркивается, что в настоящее время нормативная база по промышленной безопасности интенсивно развивается. Доказывается, что для обеспечения качества при подготовке заключений по результатам экспертизы промышленной безопасности целесообразна разработка стандарта экспертной организации, устанавливающего требования к составу и содержанию отчетной документаци