Science and technics

The network of foreign partner universities of Russian scientific community is set to increase further.

This September, a new academic year has begun and, with the start of the new school year, traditional discussions on the role of education and universities in Russia have once again resumed.

A number of Finnish universities is keen on cooperating with higher education institutions of St. Petersburg. Why would they do so?

Lapis lazuli is a mineral that very rarely takes the form of individual crystals but rather often forms dense granular masses. As per colour, the mineral can be turquoise, aquamarine, purple, at times also blue or green.

Russian scientists have made a brand new discovery – a physical phenomenon that will improve the efficiency of intercontinental ballistic missile control and allow building the spacecraft capable of flying under extreme conditions of the outer space.

The research and educational center will be established at the premises of Saint-Petersburg Mining University.

In Ancient Greece, extraction of gemstones was considered a matter of national importance. At times, the war could start at the territories if they were rich in precious stones. One such location was the city of Chalcedon, situated on the shore of the Sea of Marmara. Numerous stones of various colors and shades were mined there. Local people called them ”chalcedony”, which gave the name to the mineral itself.

The balance of electricity consumption a significant part is occupied by the production of compressed air at the mining enterprises. Many compressor stations of enterprises are equipped with automated parameter management systems that allow reliable, uninterrupted and safe operation of the compressor facilities. But the majority of automation systems at compressor stations do not perform the function of monitoring the energy efficiency indicators of the operation of a compressor station.

The article analyzes the effectiveness of anti-friction coatings obtained by finishing anti-friction non-abrasive treatment (FANT), including processing in metal-clad technological media, in order to improve the performance of machine parts. The analysis of the application of coating technologies FANT on materials operating at elevated temperature and at high pressure, as well as with high values of energy fluxes in the environment, was carried out.

The paper addresses issues of using the active rectifier in partially loaded variable frequency drive as active filter in the conditions of non-sinusoidal current and voltage disturbances caused by the presence of high-power nonlinear load in the grid. The topology of transformless three-level converter for 6-10 kV suitable for proposed solution has been presented and its mathematical model has been de-rived. Based on the model, the direct power control algorithm with ability to compensate non-linear currents has been designed. The investigation of active rectifier efficiency was performed depending on the relation between linear and non-linear load currents of the grid node, as well as on active power load of the active rectifier. Efficiency analysis was based on the developed computer model of the grid node with connected non-linear load simultaneously with the variable frequency drive with active rectifier.