A regional system to forecast the social-economic development : the case of the RF regions

The world economy and the consumer culture of the population are changing rapidly. Informatization and high technologies have influenced the way of life on all spheres. In this environment the improvement of the mechanisms for regional development and the forecasting techniques to achive it has been characterized as one of the most important issues in regional economics. In these modern conditions, the development of a single regional policy should aim to achieve the key goals set by the Russian government in its attempt to improve the national regions by considering it as an integral part of the country’s development strategy.peer-reviewe

Electron-Pair Production in 158 AGeV/c Pb-Au Collisions from CERES

The CERES experiment is devoted to the measurement of low-mass electron pairs in proton and ion-induced collisions at the Super Proton Synchrotron accelerator. The main goal of the CERES experiment is to investigate modifications of hadron properties in hot and dense nuclear matter. A significant enhancement of dilepton pair yield with respect to expectations based on hadron decays was observed in the mass range 0.25~$<~$m$_{ee}~<$~0.7~GeV/c$^2$. This fascinating result can only be described by models invoking in-medium modifications of the $\rho$ meson. To distinguish between different theoretical explanations of the enhancement the experiment was upgraded in 1998 by the addition of a radial TPC to improve the mass resolution in the vector meson region. In this thesis, the analysis of the data sample taken in 2000 in 158~A~GeV/c Pb-Au collisions with the upgraded experimental setup is presented. The observed enhancement of the $e^+e^-$ pairs confirms previous results of CERES. The data, compared to the theoretical calculations based on dropping $\rho$ mass approach and in-medium $\rho$ spectral function modifications, favor the latter

Local de sondagem de Li+ difusão e concentração em materias de baterias de ions de litio via microscopia de varredura por sonda

Doutoramento em Ciência e Engenharia de MateriaisThis thesis presents the results of Scanning Probe Microscopy (SPM) study of Li-ion battery active materials. The measurements have been performed on LiMn2O4 cathodes and graphite anodes extracted from commercial Li batteries at different states of charge and health. The study has been focused on measurements of Li spatial distribution and transport properties in the active electrode materials. Special attention has been paid to influence of fatigue caused by high C rate cycling on Li spatial distribution and local diffusion coefficient. Electrochemical Strain Microscopy (ESM) has been used to access Li transport properties at the nanoscale in LiMn2O4 cathodes. Kelvin Probe Force Microscopy (KPFM) has been used to examine Li spatial distribution in graphite anodes. ESM has been implemented and used in a single frequency mode out of the contact resonance for the first time. Signal-to-noise ratio analysis has been performed for a number of single- and multi-frequency modes used in ESM. The analysis allowed to establish criteria for a proper cantilever choice and an experimental setup for the optimized detection of surface displacements via lock-in amplifier. Transport properties of Li+ mobile ions in fresh and fatigued LiMn2O4 battery cathodes have been studied at the nanoscale via ESM using time-and voltage spectroscopies. Both Vegard and non-Vegard contributions to ESM signal have been identified in electrochemical hysteresis loops obtained on the fresh and fatigued samples. In fresh cathodes the Vegard contribution dominates the signal, while in fatigued samples different shape of hysteresis loops indicates additional contributions. Non-uniform spatial distribution of the electrochemical loop opening in LiMn2O4 particles studied in the fatigued samples indicates stronger variation of Li diffusion coefficients in fatigued samples’ as compared to the fresh one. Time spectroscopy measurements have revealed suppressed local Li diffusivity in fatigued samples by more than two orders of magnitude as compared to the fresh one. We attributed such reduction of the diffusion coefficient to the accumulation of point defects induced by high C-rate cycling and accompanied structural instability. This mechanism can be specifically important for high C-rate cycling. Li spatial distribution in fresh and fatigued graphite cathodes has been accessed via KPFM using a 2-pass amplitude modulation mode. Core-shell and mosaic surface potential structures have been observed on the fatigued and fresh anodes, respectively. The observed surface potential distributions have been attributed to the apparent Li concentration profiles in graphite. The core-shell potential distribution has been attributed to the remnant Li ions stacked in graphite particles causing irreversible capacity loss. The mosaic potential distribution has been attributed to inactive Li inside graphite at the starting stage of cycling. The results corroborate the “radial” model used to explain the specific capacity fading mechanism at high C rate cycling in Li-ion batteries.Esta tese apresenta os resultados do estudo de Scanning Probe Microscopia (SPM) de materiais de baterias de ions de litio. As medidas foram executadas na cátodos de LiMn2O4 e ânodos de grafite extraidos de bateriais de litio comerciais em diferentes estados de carga e fadiga. O estudo concentrou-se na medição da distribuição de Li e propriedades de transporte dos materiais de eletrodo ativo. Especial atencao tem sido dada a influencia do ciclo de fadiga da elevada taxa C na distribuicao especial dos ions de Li e coeficiente de difusao. Microscopia de tensão eletroquímica (ESM) tem sido usada para acessar Li transporte propriedades em nanoescala em cátodos de LiMn2O4. Microscopia de força de sonda Kelvin (KPFM) tem sido usada para acessar a distribuição espacial de Li em anodos de grafite. ESM foi implementada e usada em um modo de única freqüência de ressonância o contato pela primeira vez. Análise de relação sinal-ruído foi feito para um número de monomodo e multimodo usados no ESM. A análise permite estabelecer critérios para um cantilever e uma instalação experimental para a detecção mais sensível de deslocamentos superficiais. Propriedades da mobilidade dos ions de lition em catodos de bateria LiMn2O4 frescos e fatigados foram estudados em nanoescala via ESM, espectroscopia de tempo e espectroscopia de tensão de transporte. Contribuições como sinal Vegard e non-Vegard ESM foram identificadas em ciclos de histerese eletroquímica obtidos em amostras frescas e fatigadas. Em cátodos frescos o sinal Vegard dominante, enquanto em amostras envelhecidas, a diferente ciclo de histerese indica contribuições adicionais. Distribuição espacial não-uniforme do ciclo aberto eletroquímico em partículas de LiMn2O4 foram estudadas nas amostras fatigadas indicando mais forte variação do coeficiente de difusão de Li das amostras fatigadas em microescala em comparação com a outra amostra. Medições de espectroscopia de tempo revelaram a ausencia de difusidade local em amostras fatigadas por mais de duas ordens de magnitude em comparação com a outra. Atribui-se tal redução do coeficiente de difusão o acúmulo de defeitos de ponto induzida pelo Ciclo de elevada taxa C e acompanhadas de instabilidade estrutural. Este mecanismo pode ser especialmente importante para ciclo de elevada taxa C. Distribuição espacial de Li em cátodos amostras fresca e fatigada grafite foi analisaa via KPFM no modo de modulação de amplitude 2-pass. Estruturas de superfícies potenciais core-shell e mosaico têm sido observadas em ânodos fatigados e frescos, respectivamente. As distribuições de superfícies potenciais observadas foram atribuídas para os perfis de concentração Li aparentes em grafite. Distribuição potencial core-shell tem sido atribuída para o ions remanescentes de Li empilhados em partículas de grafite, causando perda irreversível de capacidade. A distribuição de potencial de mosaico tem sido atribuída a Li inativo dentro do grafite na fase inicial do ciclo. Os resultados corroboram o modelo "radial" usado para explicar o mecanismo de desvanecimento de capacidade específica a alta taxa de C em baterias de íon-lítio

ПРОГНОЗУВАННЯ ВОЛЬТ-АМПЕРНОЇ ХАРАКТЕРИСТИКИ ВАРИСТОРІВ В ЗОНІ СТРУМІВ ВИТОКУ ЗА ДОПОМОГОЮ НЕЙРОННОЇ МЕРЕЖІ

На основі аналізу літературних джерел обрано тип нейронної мережі, розроблена її структура та проведено навчання. Розроблено нейронну мережу для прогнозування вольтамперних характеристик обмежувачів перенапруг нелінійних в зоні струмів витоку. Отримана нейронна мережа дає прийнятні похибки прогнозу вольт-амперної характеристики в зоні струму витоку.

On one approach to the numerical modeling of the strain-stress state of layered rock mass

According to the principle of virtual work for a system of elastic layers, a semi-analytical scheme for constructing the finite-dimensional analog of the variational equation was developed based on the well-known analytical solution in the Fourier series for a single layer. The solution of a test problem shows that the constructed numerical procedure of mathematical modeling ensures fairly accurate calculations and highly effective computer-aided realization. It was demonstrated that the proposed semi-analytical scheme for constructing the finite-dimensional analog of the variational equation can be effectively used for the assessment of safety conditions of the potash salt development within the Upper Kama salt deposit

Formation of human capital as a key factor in ensuring the national security of agriculture in the digital economy

Over the past few years in many literary sources and the media an issue of the digital economy is rapidly gaining popularity due to the qualitative technological changes in society. In current circumstances the qualitative component of labor resources called “human capital” is a priority value. The authors have identified the main realities of the development of agribusiness, studied the main directions of information support on the example of the agricultural sector of the economy and identified the root causes of the slowdown in the innovation development of agriculture in Russia, the features of using information technologies in agribusiness have been considered in detail.peer-reviewe

Ultraviolet inspection for diagnostics of coronary discharge on suspension insulators and lines of 35-110 kV

In this paper, the question of the correctness and sufficiency of using a UV camera for the diagnosis of insulators and 35-110 kV power lines is considered. As a result of the literary analysis, controversial moments and minuses are identified in the existing method. In addition, for its refinement and correction, an experiment was conducted at the laboratory of the TVN SPbPU. The analysis of the experiment showed features and nuances in the work of the camera, which must be taken into account in the UV survey