On Boussinesq-type models for long longitudinal waves in elastic rods

In this paper we revisit the derivations of model equations describing long nonlinear longitudinal bulk strain waves in elastic rods within the scope of the Murnaghan model in order to derive a Boussinesq-type model, and extend these derivations to include axially symmetric loading on the lateral boundary surface, and longitudinal pre-stretch. We systematically derive two forced Boussinesq-type models from the full equations of motion and non-zero surface boundary conditions, utilising the presence of two small parameters characterising the smallness of the wave amplitude and the long wavelength compared to the radius of the waveguide. We compare the basic dynamical properties of both models (linear dispersion curves and solitary wave solutions). We also briefly describe the laboratory experiments on generation of bulk strain solitary waves in the Ioffe Institute, and suggest that this generation process can be modelled using the derived equations.Comment: 19 pages, 5 figures, submitted to the Special Issue of Wave Motion, "Nonlinear Waves in Solids", in Memory of Professor Alexander M. Samsono

Saint Petersburg as a global coastal city: positioning in the Baltic Region

The Baltic region consists of coastal areas of nine countries - Russia, Estonia, Latvia, Lithuania, Poland, Germany, Denmark, Sweden, and Finland. The region's hubs are the port cities located along the Baltic Sea coast. However, Peter Taylor and Saskia Sassen's classification identifies higher status cities and "global cities", which are to be considered in the global context. Seven coastal regions are distinguished within this region, whose organising centers are the global coastal cities of Stockholm, Copenhagen, Helsinki, Riga, Tallinn, St. Petersburg, and Malmö. The concept of a "global city-region" (Sassen) can be used as a methodological framework for analyzing this connection. Within this hierarchy, the dominant alpha group global city is Stockholm. The authors argue that, as a global coastal city, St. Petersburg forms the St. Petersburg coastal region, which can be defined as a typical "global city region". The index method shows that the position of St. Petersburg in the system of global coastal cities of the Baltic region is relatively favorable in view of its transport, logistics, and demographic potential and the advantageous geo-economic situation. St. Petersburg has certain competitive advantages in the region brought about by its demographic potential, port freight capacity, and the favorable geo-economic position of the "sea gate" of Russia. However, the level of high-tech services and "new economy" development is not sufficient for the port to become a match for the top three cities (Stockholm, Helsinki, and Copenhagen). This is increasingly important because transboundary global city networks demonstrate that global cities are functions of global networks. Saint Petersburg is just starting to integrate into these networks through the Pulkovo airline hub and seaports of Ust-Luga, Primorsk, and Saint Petersburg

Вступ до спеціальності: робоча програма нормативної навчальної дисципліни

Робоча програма навчальної дисципліни «Вступ до спеціальності» для студентів напряму «Дошкільна освіта». Мета вивчення курсу – розкриття перед студентами перспективи і шляхів оволодіння професійною діяльністю педагога, сприяння підготовці першокурсників до педагогічної практики

Формування готовності дітей до школи: робоча програма нормативної навчальної дисципліни

Робоча програма навчальної дисципліни «Формування готовності дітей до школи» для студентів напряму 6.010101 «Дошкільна освіта». Мета вивчення курсу – розкрити суть готовності дитини до шкільного навчання; визначити завдання підготовки до школи; проаналізувати роль сім’ї та дошкільного закладу у формування готовності до шкільного навчання; обґрунтування шляхів формування готовності дитини до навчання у школі

Педагогіка дошкільна: робоча програма нормативної навчальної дисципліни

Програма навчальної дисципліни «Педагогіка дошкільна» для студентів cпеціальності 6.01010101 «Дошкільна освіта»

Nanocrystalline Ti Produced by Cryomilling and Consolidation by Severe Plastic Deformation

We report on a study of the nanocrystalline structure in Ti, which was produced by cryogenic milling followed by subsequent consolidation via severe plastic deformation using high pressure torsion. The mechanisms that are believed to be responsible for the formation of grains smaller than 40 nm are discussed and the influence of structural characteristics, such as nanometric grains and oxide nanoparticles, on Ti hardening is established

MANAGEMENT OF PERSONNEL INITIATIVE AS THE AS THE ACTIVITIES OF THE MODERN ORGANIZATION

The urgency of using personal and organizational mechanisms for activating the personnel initiative for the effective functioning and development of the company is determined. The essence of the potential of proactive employee as a source of individual initiative is revealed, the characteristic of its basic elements and forms of manifestation is given. The goals and principles of managing the initiative of personnel are formulated, and the main elements of the organizational environment that facilitate the mobilization of personnel initiatives are identified. The model of personnel initiative management based on mobilization mechanisms, concentrated in the organization management system, human resource management system, as well as specific infrastructural mechanisms, purposefully and consistently providing a positive impact on the potential of proactive employee is presented

Separation of Q from carbon in CR meteorites during stepped combustion

Introduction: The nature of the planetary noble gas carrier (Q) in meteorites remains uncertain. It is known that it is likely to be carbonaceous, but represents only a small fraction of the total macromolecular material. Q is oxidisible with nitric and other oxidizing acids. It seems to be partly destroyed with pyridine and may have an organic structure. Previously, we have shown that during parent body thermal metamorphism Q is less affected than the majority of other carbonaceous materials. If organic matter is graphitized, as has happened in the enstatite chondrite parent bodies, Q remains unaffected. In the present study we have found that Q is also separable from the majority of carbon in type 2 and 3 CR chondrites during stepped combustion. It is possible that this is because Q has become encased within the matrix, in contrast to other carbon phases, during parent body metamorphism