Field induced evolution of regular and random 2D domain structures and shape of isolated domains in LiNbO₃ and LiTaO₃

The shapes of isolated domains produced by application of the uniform external electric field in different experimental conditions were investigated experimentally in single crystalline lithium niobate LiNbO3 and lithium tantalate LiTaO3. The study of the domain kinetics by computer simulation and experimentally by polarization reversal of the model structure using two-dimensional regular electrode pattern confirms applicability of the kinetic approach to explanation of the experimentally observed evolution of the domain shape and geometry of the domain structure. It has been shown that the fast domain walls strictly oriented along X directions appear after domain merging

Equation of state SAHA-S meets stellar evolution code CESAM2k

We present an example of an interpolation code of the SAHA-S equation of state that has been adapted for use in the stellar evolution code CESAM2k. The aim is to provide the necessary data and numerical procedures for its implementation in a stellar code. A technical problem is the discrepancy between the sets of thermodynamic quantities provided by the SAHA-S equation of state and those necessary in the CESAM2k computations. Moreover, the independent variables in a practical equation of state (like SAHA-S) are temperature and density, whereas for modelling calculations the variables temperature and pressure are preferable. Specifically for the CESAM2k code, some additional quantities and their derivatives must be provided. To provide the bridge between the equation of state and stellar modelling, we prepare auxiliary tables of the quantities that are demanded in CESAM2k. Then we use cubic spline interpolation to provide both smoothness and a good approximation of the necessary derivatives. Using the B-form of spline representation provides us with an efficient algorithm for three-dimensional interpolation. The table of B-spline coefficients provided can be directly used during stellar model calculations together with the module of cubic spline interpolation. This implementation of the SAHA-S equation of state in the CESAM2k stellar structure and evolution code has been tested on a solar model evolved to the present. A comparison with other equations of state is briefly discussed. The choice of a regular net of mesh points for specific primary quantities in the SAHA-S equation of state, together with accurate and consistently smooth tabulated values, provides an effective algorithm of interpolation in modelling calculations. The proposed module of interpolation procedures can be easily adopted in other evolution codes.Comment: 8 pages, 5 figure

Nutritional habits of combat athletes

The review presents modern data characterizing the features of the energy exchange of athletes engaged in combat sport. The general principles of diet formation for combat athletes taking into account the basis of optimal nutrition, dependence on the period of sports activity (training, competition, and recovery), the duration and intensity of physical exertion are described. Based on results of recent studies published by Russian and foreign authors, the substantiation for the energy density of chemical composition of the diet (the content of proteins, fats, carbohydrates, vitamins, macro- and microelement) and hydration regime of combat athletes is given. The issues of food distribution during the day are affected, depending on the training and competitive process. Particular attention is paid to the use of specialized products and dietary supplements, as well as personalization of nutrition, which is based on individual studying of the nutritional status of combat athletes

СОВРЕМЕННОЕ СОСТОЯНИЕ И ПРОБЛЕМы ОБОГАЩЕНИЯ ТИТАНОЦИРКОНИЕВОГО СыРЬЯ В УКРАИНЕ

В природе известно 70 минералов, в различных количествах содержащих титан. На сегодняшний день промышленными источниками титанового сырья являются месторождения, содержащие ильменит, рутил, лейкоксен и, в послед-нее время, анатаз. Львиная (около 90%) часть ильменитовых, лейкоксеновых и рутиловых концентратов используются для производства диоксида титана. Из ильменитовых концентратов получают синтетический рутил и титановые шла-ки, которые можно использовать как для производства губчатого титана, так и диоксида титана. На производство металлического титана используется 7-10% сырья. Природный рутил, кроме того, используется частично и для обмазки сварочных электродов. Наиболее богатыми по содержанию диоксида титана являются рутиловые концентраты (93-96%), ильменитовые содержат 44-70% диоксида титана, а концентраты из лейкоксеновых руд содержат до 90% TiO

MuSR method and tomographic probability representation of spin states

Muon spin rotation/relaxation/resonance (MuSR) technique for studying matter structures is considered by means of a recently introduced probability representation of quantum spin states. A relation between experimental MuSR histograms and muon spin tomograms is established. Time evolution of muonium, anomalous muonium, and a muonium-like system is studied in the tomographic representation. Entanglement phenomenon of a bipartite muon-electron system is investigated via tomographic analogues of Bell number and positive partial transpose (PPT) criterion. Reconstruction of the muon-electron spin state as well as the total spin tomography of composed system is discussed.Comment: 20 pages, 4 figures, LaTeX, submitted to Journal of Russian Laser Researc

The Role of Birds as Potential Reservoirs of West Nile Virus in the Territory of the Russian Federation

Submitted are the materials on epizootiology of West Nile Fever in birds, taking into account their migration. Described are the characteristics of WNF in wild and synanthropic birds. Ecological relationships between birds, mosquitoes, ticks and West Nile virus are analyzed. Main autumn bird migratory directions are characterized and the data on WNF monitoring in birds in different geographical regions of Russia are presented

Local electromechanical properties of barium strontium titanate based glass-ceramics

The equipment of the Ural Center for Shared Use “Modern Nanotechnology” Ural Federal University was used. The research was made possible by Russian Foundation for Basic Research (Grant 18-52-53032)