Improving the heat resistance of polymer electrical insulation systems for the modernization of induction motors

Ensuring high power, efficiency and reliability of induction motor operation while providing small weight–size parameters represents an up-to-date problem. One of the factors limiting the reduction of weight–sizeparameters when increasing capacities of induction motors is the failure of the insulation system. Therefore, thereis a strong need for studying the issues of slot fill when designing an induction motor, taking into account anincrease in the heat resistance class of electrical insulation systems. The purpose of the present research is todevelop a polymeric electrical insulation system of increased heat resistance for the modernization of aninduction medium-capacity motor to reduce weight–size parameters and to evaluate the possible savings ofwinding material. The paper deals with an analysis on the stator–slot fill for the induction motor. Modernconductor and insulation materials were selected. The necessary calculations for a medium–power inductionmotor of different heat resistance classes were performed. The usage of the proposed electrical insulation systemwas substantiated. The analysis shows the possibility of increasing the heat resistance of the polymer electricalinsulation systems to save winding material for induction motors without reducing the specified quality level

Reactive SPS of Al2O3–RE:YAG (RE = Ce; Ce+Gd) composite ceramic phosphors

Ultrafine-grained Al2O3–rare earth:yttrium aluminium garnet (Al2O3–RE:YAG) (RE = Ce; Ce+Gd) composite ceramics were obtained for the first time by reactive spark plasma sintering (SPS) using commercially available initial oxide powders. The effect of key sintering parameters (temperature, dwell time, and external pressure (Pload)) on densification peculiarities, structural-phase states, and luminescent properties of composites was studied comprehensively. Differences in phase formation and densification between Ce-doped and Ce,Gd-codoped systems were shown. Parameters of reactive SPS, at which there is partial melting with the formation of near-eutectic zones of the Al2O3–YAG system/coexistence of several variations of the YAG-type phase, were established. Pure corundum–garnet biphasic ceramics with an optimal balance between microstructural and luminescence performance were synthesized at 1425 ℃/30 min/30–60 MPa. The external quantum efficiency (EQE) of the phosphor converters reached 80.7% and 72% with close lifetime of ~63.8 ns, similar to those of commercial Ce:YAG materials, which is promising for further applications in the field of high-power white light-emitting diodes (WLEDs) and laser diodes (LDs)

Analysis of Social Networks Using an Information and Analytical System

The subject of the study is the analysis of social networks and the construction of an information and analytical system to automate data monitoring and mining. Modern social network analysis systems are reviewed, and the distinguishing features of these systems are given. Various methods of social network analysis and tasks that can be solved using these methods are described. The effectiveness of the methods to determine the text sentiment is compared

The new stage of preparing the European Congress of Psychology (ECP2019)

July 1–14, 2017 Amsterdam, Holland, the 16th European Congress of Psychology (ECP2019) to be held in Moscow, Russia, on July 2–5, 2019, is presented within the 15th European Congress of Psychology (ECP2017

Development and Performing of a Method of Comparative Flammability Tests of Magnesium Alloys

Magnesium alloys find their application in aviation technology for manufacturing of structural elements in uninhabited compartments and outside areas with increased fire hazard. At the stage of development of magnesium alloys with low fire hazard, it is advisable to perform comparative tests on relatively small samples so that all test equipment can be located in a laboratory. A method has been developed for conducting flammability tests when exposed to a flame with a temperature of 1,100 ° C for samples of magnesium alloys of small sizes. Comparative tests of two magnesium alloys - the standard ML5 and the new experimental one with increased fire safety - have been carried out. Significant differences have been established in the flammability and extinguishing ability of various grades of magnesium alloys - it is shown that the samples of the experimental magnesium alloy, in comparison with the ML5 alloy, are more difficult to ignite and in most cases can self-extinguish rapidly, while the weight loss of the sample practically does not occur

Influence of natural production conditions on efficient operation of wheel tractors

For the zones of “risky farming” characteristic of the Far East of the Russian Federation, the natural production conditions of the region are an important problem in preparing the soil for further basic agricultural work. So, when carrying out early spring agricultural work, due to presence of a solid underlying layer in the form of permafrost, they shall be completed in operational terms no more than 10 days, until the permafrost base thaws and the soil has not lost its bearing capacity. In addition, due to the peculiarities of the relief, the soil does not thaw equally in depth everywhere, which reduces the quality of field work and harrowing, as the most common operation, namely. This article provides theoretical and experimental studies on the adaptation of a wheeled tractor as part of a machine-tractor unit (MTU) used in harrowing to natural production conditions by installing a device that automatically regulates the load on the working body of the disc harrow or on the propellers of the energy device, depending on the conditions of use or the state of the motion surface

Mathematical Modeling of Production Processes of Discrete Machine-Building Enterprises Based on the Interaction of Simulation Systems and Operational Planning Systems

Analysis of production systems (PS) of discrete multi-nomenclature machine-building enterprises is a complex task, its solution is necessary to support decision-making during technical re-equipment, modernization or technological preparation of production. The paper shows a concept of joint use of operational scheduling systems and simulation modeling systems to improve the efficiency and adequacy of PS analysis. The problem of determining the deviation of the planned state of the PS from the simulated state and evaluating the level of stability and stability of the PS behaviour on its basis is considered. It is revealed that the proposed approach allows us to more adequately determine the timing of the production program, assess the stability of the PS behaviour when using various planning logics and algorithms, and choose the best one for subsequent use in a real PS