Some features of the fabrication of multilayer fiber composites by explosive welding

The fabrication of multilayer fiber composites by explosive welding is characterized by intense plastic deformation of the matrix material as it fills the spaces between fibers and by high velocity of the collision between matrix layers due to acceleration in the channels between fibers. The plastic deformation of the matrix layers and fiber-matrix friction provide mechanical and thermal activation of the contact surfaces, which contributes to the formation of a bond. An important feature of the process is that the fiber-matrix adhesion strength can be varied over a wide range by varying the parameters of impulsive loading

Spatial and structural patterns in the distribution of R&D, innovation and production activities in Russia

A modern innovative economy relies on the continual integration of knowledge and tech­nologies into production, monitoring, and management processes. Therefore, territorial proximity and sectoral complementarity of the activities of scientific, technological and industrial organisations are crucial factors in fostering innovation. This article aims to assess the relationship between a region’s economic and scientific specialisation and the level of its innovative development. The object of the study is the industrial and research profile of Russian regions’ economies with a focus on the strength of connections between them. We identified and measured Russian regions’ industry-specific research, technolog­ical and economic specialisations. Additionally, we described the spatial and structural patterns of interregional distribution and concentration of research, technological and in­novative activities. Methodologically, we compared data on the product output by industry, using the OKVED classification subgroups and information on the costs and implemen­tation of R&D. To gather the latter data, we employed our methodology, which involved juxtaposing GRNTI and OKVED codes. Overall, we analysed data from 17.3 thousand re­search, development and technological projects conducted between 2017 and 2021 across 18 fields. Specialisation coefficients for both the supply and demand of R&D outcomes and production were computed for each region. The econometric analysis made it possible to distinguish four clusters of regions based on their research and industrial specialisation: agro-industrial regions, mechanical engineering regions, precision engineering regions and diversified regions. The study demonstrated a correlation between a region’s innova­tive product output and the structure of its innovative economy

Innovative development of Russian coastal regions: North–south divergence

Coastal regions are territorial social systems whose socio-economic and innovative development is strongly influenced by the factor of coastalisation. The effect of movement to the sea determines the dynamics of settlement systems as well as their economic and infrastructure development. This holds for transport, logistics, information and communications, industrial, and other infrastructure. Coastal regions are so diverse that it is impossible to construct a development model that will fit all of them. One can speak only of general trends. This study focuses on identifying differences between the innovation systems of northern and southern coastal regions within the same country. The geographical scope of the study is four Russian coastal territories: Murmansk and Arkhangelsk in the Baltic Sea region and Rostov and Krasnodar in the Azov-Black Sea region. Methodologically, this study carries out a comparative assessment of heterogeneity of innovative development at municipal and interregional levels, using four groups of indicators: human capital, economic growth and clustering, innovation and digitalisation, and quality and standards of living. All these components are vital for regional innovative development. A statistical assessment is supplemented by a qualitative analysis of spatial patterns of innovation capital accumulation; the agglomeration factor is taken into account. It is shown that northern and southern coastal regions perform very differently on innovative development, the latter doing better than the former. Three main models of innovation generation, implementation, and accumulation of coastal regions are described. Each is associated with a different way to benefit from proximity to the sea. These are maritime activities, maritime transport, and the economic use of recreational, natural and climatic resources

Knowledge and innovation dynamics of the Northwest Russia under geopolitical changes

Over the past 25 years, Russia has faced several economic and geopolitical challenges, including the 2008 global financial crisis, sanctions imposed in 2014, and the COVID-19 pandemic. To remain resilient in the face of these challenges, Russia needs to adopt a flexible development strategy and transition to a new path of development. This transition requires the development of new knowledge-intensive industries, expansion into promising markets, strengthening trade and economic partnerships, and achieving technological sovereignty. This study examines the innovation system in Northwest Russia and identifies factors that are critical for its sustainability and innovation security in the face of geopolitical instability. The study uses an integrated approach to trace the knowledge production and innovation process from research findings to the commercialization of new technologies. The study finds that there are strong correlations between innovation activity and R&D investment, patent activity, and the number of innovative organisations. The study also identifies three types of regional innovation systems in Northwest Russia: core, semi-periphery, and periphery. The nature of the regions' involvement in R&D determines the dynamics and specialization of their publications and patents. The study also finds that there is a positive correlation between the volume of innovative products and quantitative factors in the functioning of subsystems involved in knowledge generation and innovation. Finally, the study examines the geography and structure of the international research network that the regions of Northwest Russia had formed by 2022. It shows that the geopolitical transformation requires a significant part of cooperation ties with unfriendly countries to be restructured

Exact computation of one-loop correction to energy of pulsating strings in AdS_5 x S^5

In the present paper, which is a sequel to arXiv:1001:4018, we compute the one-loop correction to the energy of pulsating string solutions in AdS_5 x S^5. We show that, as for rigid spinning string elliptic solutions, the fluctuation operators for pulsating solutions can be also put into the single-gap Lame' form. A novel aspect of pulsating solutions is that the one-loop correction to their energy is expressed in terms of the stability angles of the quadratic fluctuation operators. We explicitly study the "short string" limit of the corresponding one-loop energies, demonstrating a certain universality of the form of the energy of "small" semiclassical strings. Our results may help to shed light on the structure of strong-coupling expansion of anomalous dimensions of dual gauge theory operators.Comment: 49 pages; v2: appendix F and note about antiperiodic fermions added, typos corrected, references adde

Single and Double Bundle Arthroscopic Reconstruction of Anterior Cruciate Ligament (Review of Literature)

Researches performed in the past 20 years show the necessity of the restoration of anatomic position of anterior cruciate ligament as the main stabilizing structure of the joint in combination with the restoration of other injured elements and correction of deformities, which affect the outcomes of the treatment.Complexity of the restoration of anatomic position of torn anterior cruciate ligament is caused by its wide area of contact in combination with relatively small sectional area through the joint cavity. More detailed study of topographic anatomy of anterior cruciate ligament allowed the researchers to explain this phenomenon, which pushed them closer to the solution of the problem.Systemic anatomy of anterior cruciate ligament include two bundles - anteromedial bundle and posterolateral bundle. Double bundle plasty of anterior cruciate ligament restored anatomy to its nearly normal condition, but single bundle plasty is used much more often because of its simpler technique. However, the researchers still cannot reach a consensus in the choosing of single or double beam plasty at the restoration of anterior cruciate ligament