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[en] Full text : In paper the change of electric strength of high-voltage transformers insulation at the effect of partial discharges with space charge accumulation was investigated. It is revealed that the effect of partial discharges of insulation materials results the reduction of their pulsing electric strength which can restore the own initial value at releasing of saved charge the volume of a material under condition of absence the ineversible structural changes in it. Researches of high-voltage transformers insulation's non-failure operation conditions show, that at increasing of insulation work time in a strong electrical field the reduction of average breakdown voltages with simultaneous increasing of spread in discharge voltage values takes place. It authentically testifies to reduction of short-time discharge voltage of insulation materials during their electrical aging. As the basic reason of insulation electrical aging the partial discharges occurring in gas cavities inside insulation were considered. It is known that the space charges will be formed in insulation elements of high-voltage devices which effects in dielectrical property of these elements including the electric strength and the space charge formation can occur also at partial discharges in an alternating voltage while the service of high-voltage transformers. In the given work the experiments in revealing separate influence partial discharges in pulsing electric strength of insulation materials at presence and at absence inside them the space charge were spent
[en] Theoretical and experimental outcomes of investigation of the strength and radiation damage of some polymer materials under electron radiation are considered. A theoretical model of the strength evaluation, applying the strength values of the main atomic bonds in polymers, is proposed. Theoretical description of radiation damage of polymers is made taking into account the radiation yield factors of destruction and linking processes occurring in the same time. In addition, the concentration of ruptured bonds is evaluated using the cascade-probability method
[en] We introduce the generalized rumor spreading model and analytically investigate the epidemic spreading for this model on scale-free networks. To generalize the standard rumor spreading model (rumor model in which each node's infectivity equals its degree and all links have a uniform connectivity strength), we introduce not only the infectivity function to determine the simultaneous contacts that a given node (individual) establishes to its connected neighbors but also the connectivity strength function (CSF) for the direct link between two connected nodes that lead to degree-biased propagation of rumors. In the case of nonlinear functions, the generalization enters the infectivity's exponent α and the CSF's exponent β into the analytical rumor model. We show that one can adjust the exponents α and β to control the epidemic threshold which is absent for the standard rumor spreading model. In addition, we obtain the critical threshold for the generalized model on the finite scale-free network and compare our results with the standard model on the same network. We show that the generalized model has a greater threshold than the standard model. (author)
[en] We study the phase synchronization in one way coupled self-mode-locked Nd:YAG laser system in which the frequency of the master laser (Fotoma, YAG-22) is 133 MHz and that of the slave laser (Hambit Laser, HBC-250) is 138 MHz. Non-synchronization develops to phase synchronization as the coupling strength increase. We analyze the characteristic behavior by the difference dynamics of two laser output.
[en] A new and model-independent experimental method has been developed to determine the energy dependence of the photon strength function. It is designed to study statistical feeding from the quasi continuum to individual low-lying discrete levels. This new technique is presented and results for 95Mo are compared to data from the University of Oslo. In particular, questions regarding the existence of the low-energy enhancement in the photon strength function are addressed.
[en] The strength function of Gamow-Teller giant resonance is calculated. The role of the isobar degrees of freedom in 48Ca was tested. About 20% reduction is found from including the isobar degrees of freedom