Questions relating to the stable functioning and restoration of soil-vegetation systems in zones with increased aridity are considered. New methodological possibilities of mathematical models in the form of ordinary differential equation systems and a calculating experiment are demonstrated.

Retrospective analysis of sickness rate of infectious diseases demanding realization of measures for sanitary protection of the Russian Federation territory and actual high contagious nosologies that epidemic manifestations can form an epidemiological emergency situation is carried out on the basis of the data of World Health Organization and Federal Service for Surveillance on Consumers’ Rights Protection and Human Wellbeing with use of a technique for organization of sanitary anti-epidemic support of mass actions with the international participation (МR 3.1.0079/2-13). It is established that human flu caused by a new virus subtype, cholera, Lassa fever, illnesses caused by Ebola and Marburg viruses and also measles, rubella and acute enteric virus infections forming the external epidemiological risk during the XXIX Winter Universiade 2019 in Krasnoyarsk city represent the greatest threat. High risk of the disease importations demanding realization of actions for sanitary protection of Russian territory is connected with the countries of Eastern, Southern and South Eastern Asia, Africa (except for the Continent south) and also North America.

The use of current-collecting contact elements with an extended service life is one of the most economical and least costly ways to ensure reliable, economical and environmentally friendly power transmission to the rolling stock. To assess and predict the service life, Omsk State Transport University developed and successfully tested a methodology for conducting experimental studies of contact inserts for pantographs, including bench tests of each pair of contact materials. The obtained test results are the initial data for predicting the wear of elements of contact pairs and assessing their service life in real operating conditions. Prediction of wear and service life of contact elements is carried out using mathematical modeling of wear processes, taking into account the maximum possible number of factors that negatively affect the elements. The purpose of this article is to improve the method for predicting wear, taking into account high speeds. The use of a mathematical model in forecasting makes it possible to reduce time and labor costs by 2.5 - 3 times for conducting experimental studies and assessing the resource of an element of a contact pair.

The key directions of intensification of the transportation process are described and their influence on the infrastructure is indicated. The concept of long irregularities of the longitudinal profile is defined and a method is proposed that allows one to study the geometric parameters and the growth rate of long irregularities. An assessment of the influence of long irregularities on energy consumption during the traction of trains is given.In the article, much attention is paid to the influence of long irregularities of the longitudinal profile on traffic safety. The article presents the results of the state analysis of the railway track section, where there was a derailment of the freight cars. The results of calculations of the level of forces arising in the automatic coupling and the coefficients of the vertical dynamics of the first stage of suspension for cars in a train when moving uphill along long irregularities are presented. Based on the results of the research, the main conclusions are formulated and the direction of further research is proposed.

Increasing axial loads including the development of heavy movement on Russian railroads network require the best solutions for improvement of the railway track structure. Research by Russian and international scientists indicates that rail elastic pads reduce vibrations transferred from reinforced concrete sleepers to crashed stone, including the joint area. This study examines possibilities of using rail pads for reducing the dynamic effects of the rolling stock on the track in the joint area. Assessment of the rail pads construction material shock-absorbing properties was conducted considering the elastic properties of the rail support with static and dynamic loads. Results of mode ling the elastic properties of the rail support with rail pads of different rigidities using the software complex “Universal mechanism” are presented. The results were used as basis for calculation of indicators of dynamic interaction of the track and rolling stock at the joint using the coeffi cient establishing the link between bendings of the solid rail and the rail with joint. The expediency of using rail pads at the place of the joint is justifi ed based on assessment of the results.This study reveals that elastic rail pads based on isoprene rubbers are suitable for track structures that improve indicators of the track and rolling stock interaction. When using rubber pads, the growth of accelerations on the sleeper is less dependent on the speed, causing the track stability to increase. The results are supported by tests consistent with calculations and justify the necessity for further studies in this fi eld.