Research Of Technological Properties Of The Styrene-Butadiene Rubber By The Method Of Mathematical Modeling

On the basis of production experiments and analysis of literary sources, the influence of molecular weight on the resulting copolymers on one of the important technological parameters of synthetic rubber - Mooney viscosity was established. In this paper a dependence is obtained that relates the Mooney viscosity and the molecular weight characteristics of the resulting product – the number-average and weight-average molecular weight. Molecular weight characteristics were determined by the modeling of the copolymerization process on the basis of Monte Carlo method. In this paper, we obtained a dependence linking the molecular weight characteristics of the resulting styrene-butadiene copolymer and the Mooney viscosity of the rubber specimen. For the derivation, the logarithmic regression dependence was used, which was applied to the results of modeling the process of styrene-butadiene copolymerization carried out in accordance with the conduct of this process in an industrial environment. The deviation of the data obtained as a result of applying the derived dependence to the simulation results from the production was no more than 8%

On Soliton Interactions for the Hierarchy of a Generalised Heisenberg Ferromagnetic Model on Symmetric Space

We consider an integrable hierarchy of nonlinear evolution equations (NLEE) related to linear bundle Lax operator L. The Lax representation is ℤ2× ℤ2reduced and can be naturally associated with the symmetric space SU(3)/S(U(1) × U(2)). The simplest nontrivial equation in the hierarchy is a generalization of Heisenberg ferromagnetic model. We construct the N-soliton solutions for an arbitrary member of the hierarchy by using the Zakharov-Shabat dressing method with an appropriately chosen dressing factor. Two types of soliton solutions: quadruplet and doublet solitons are found. The one-soliton solutions of NLEEs with even and odd dispersion laws have different properties. In particular, the one-soliton solutions for NLEEs with even dispersion laws are not traveling waves while their velocities and amplitudes are time dependent. Calculating the asymptotics of the N-soliton solutions for t → ± ∞ we analyze the interactions of quadruplet solitons

Assessment of Climatic Conditions for Siberian Reindeer Herding on the Basis of Heat Balance Modelling

The purpose of the research is to assess suitable climatic conditions for traditional herding of reindeer by Indigenous people in different areas of Siberia. A сomputer simulation model allowed us to calculate reindeer’s heat balance according to a number of meteorological indices; it was used to assess climatic conditions in 70 localities. To show the impact of climatic conditions on reindeer’s well-being, we introduce the notion of the thermal comfort index (Kt). The best environmental conditions for reindeer are in the areas where Kt takes the highest values in winter and the lowest ones in summer. We showed the results of the reindeer heat balance computer simulation on two maps visualising the average Kt values in summer and in winter. Finally, using official statistics, we calculated the number of reindeer per 100 km2 in areas with different types of traditional reindeer herding. The territories with the largest domesticated reindeer populations per 100 km2 in the two major tundra reindeer breeding areas (Samoed and Chukchi-Koriak types of reindeer herding) are located in the regions with the relatively low value of Kt in summer and high in winter. In the taiga, Kt is relatively high in summer, and reindeer herding (Tungus and Saian types) is developed mostly in highlands, where the summer Kt is lower than in flatlands because of the vertical temperature gradient. The results obtained prove that thermal conditions are extremely important for traditional reindeer herding.L’objectif de cette recherche consiste à évaluer les conditions climatiques convenables à l’élevage traditionnel des rennes par les peuples indigènes de différentes régions de la Sibérie. Au moyen d’un modèle de simulation informatisé, nous avons calculé le bilan thermique des rennes en fonction de plusieurs indices météorologiques. Nous avons évalué les conditions climatiques de 70 localités. Pour illustrer les incidences des conditions climatiques sur le bien-être des rennes, nous avons introduit la notion de l’indice du confort thermique (Kt). Pour le renne, les meilleures conditions environnementales sont celles pour lesquelles Kt a les plus grandes valeurs en hiver, et les moins grandes valeurs en été. Nous avons illustré les résultats de la simulation informatisée du bilan thermique du renne sur deux cartes permettant de visualiser les valeurs Kt moyennes de l’été et de l’hiver. Pour terminer, à l’aide de statistiques officielles, nous avons calculé le nombre de rennes par 100 km2 dans des zones ayant différents types d’élevage traditionnel de rennes. Les territoires comptant les plus grandes populations de rennes domestiqués par tranche de 100 km2 dans les deux grands secteurs de reproduction de la toundra (les types d’élevage Samoed et Chukchi-Koriak) se situent dans les régions où la valeur Kt est relativement basse l’été et élevée en hiver. Dans la taïga, le Kt est relativement élevé pendant l’été, et l’élevage des rennes (de types Tungus et Saian) est surtout développé dans les hautes terres, où la valeur Kt d’été est moins élevée que dans les plaines en raison du gradient thermique vertical. Les résultats obtenus prouvent que les conditions thermiques jouent un très grand rôle dans l’élevage traditionnel des rennes.Цель исследования состоит в оценке климатических условий для традиционного оленеводства коренных народов в разных областях Сибири. Использование имитационной компьютерной модели позволило по ряду метеорологических показателей рассчитать значения теплового баланса северного оленя для 70 географических пунктов. Чтобы отразить влияние климатических условий на организм оленя, мы ввели понятие коэффициент теплового комфорта (Kt). Самые благоприятные для северного оленя условия там, где Kt принимает наиболее высокие значения зимой и самые низкие значения летом. Мы отразили результаты компьютерного моделирования теплового баланса оленя на двух картах, отражающих средние значения Kt в летний и зимний периоды. Для интерпретации результатов мы рассчитали количество оленей на 100 км2 в ареалах с различными типами традиционного оленеводства, использовав данные официальной статистики. Оказалось, что в двух крупнейших областях тундрового оленеводства (самоедский и чукотско-корякский типы оленеводства) территории, с наибольшим числом домашних оленей на 100 км2, расположены в районах с относительно низкими значениями Kt летом и высокими зимой. В тайге (в ареалах тунгусского и саянского типов оленеводства) значения Kt летом сравнительно велики. Оленеводство здесь развивается в основном в районах, где есть высокие горы и из-за вертикального градиента температуры значения Kt летом понижены. Полученные результаты подтверждают значимость температурных условий для традиционного оленеводства

Relativistic theory of the double photoionization of helium-like atoms

A fully relativistic calculation of the double photoionization of helium-like atoms is presented. The approach is based on the partial-wave representation of the Dirac continuum states and accounts for the retardation in the electron-electron interaction as well as the higher-order multipoles of the absorbed photon. The electron-electron interaction is taken into account to the leading order of perturbation theory. The relativistic effects are shown to become prominent already for the medium-Z ions, changing the shape and the asymptotic behaviour of the photon energy dependence of the ratio of the double-to-single photoionization cross section

Experimental and Numerical Investigation of Near-field Rotor Aeroacoustics

This work presents comparisons between experimental and numerical estimates of near-field rotor aeroacoustics in hover. The experiments took place at the Kazan National Research Technical University named after A. N. Tupolev (Kazan Aviation Institute). A set of rotor blades with NACA-0012 aerofoil sections was used to obtain the sound pressure distribution using a linear array of microphones. It is shown that CFD and experimental results are in good agreement suggesting that the obtained test data can be useful as a validation case for development of CFD tools

On Soliton Interactions for a Hierarchy of Generalized Heisenberg Ferromagnetic Models on SU(3)/S(U(1) ×\times U(2)) Symmetric Space

We consider an integrable hierarchy of nonlinear evolution equations (NLEE) related to linear bundle Lax operator L. The Lax representation is Z2 \times Z2 reduced and is naturally associated with the symmetric space SU(3)/S(U(1) \times U(2)). The simplest nontrivial equation in the hierarchy is a generalization of Heisenberg ferromagnetic model. We construct the N-soliton solutions for an arbitrary member of the hierarchy by using the Zakharov-Shabat dressing method with an appropriately chosen dressing factor. Two types of soliton solutions: quadruplet and doublet solitons are found. The one-soliton solutions of NLEEs with even and odd dispersion laws have different properties. In particular, the one-soliton solutions for NLEEs with even dispersion laws are not traveling waves; their velocities and their amplitudes are time dependent. Calculating the asymptotics of the N-soliton solutions for t \rightarrow \pm \infty we analyze the interactions of quadruplet solitons

Rational Bundles and Recursion Operators for Integrable Equations on A.III-type Symmetric Spaces

We analyze and compare the methods of construction of the recursion operators for a special class of integrable nonlinear differential equations related to A.III-type symmetric spaces in Cartan’s classification and having additional reductions

Development of Algorithm for Calculating Data Packet Transmission Delay in Software-Defined Networks

The relevance of this type of network is associated with the development and improvement of protocols, methods, and tools to verify routing policies and algorithmic models describing various aspects of SDN, which determined the purpose of this study. The main purpose of this work is to develop specialized methods to estimate the maximum end-to-end delay during packet transmission using SDN infrastructure. The methods of network calculus theory are used to build a model for estimating the maximum transmission delay of a data packet. The basis for this theory is obtaining deterministic evaluations by analyzing the best and worst-case scenarios for individual parts of the network and then optimally combining the best ones. It was found that the developed method of theoretical evaluation demonstrates high accuracy. Consequently, it is shown that the developed algorithm can estimate SND performance. It is possible to conclude the configuration optimality of elements in the network by comparing the different possible configurations. Furthermore, the proposed algorithm for calculating the upper estimate for packet transmission delay can reduce network maintenance costs by detecting inconsistencies between network equipment settings and requirements. The scientific novelty of these results is that it became possible to calculate the achievable upper data delay in polynomial time even in the case of arbitrary tree topologies, but not only when the network handlers are located in tandem. Doi: 10.28991/ESJ-2022-06-05-010 Full Text: PD