Техническое обслуживание малоинтенсивных железных дорог в современных условиях

The article is devoted to clarification of the structure of maintenance of low-intensity railways by optimising infrastructure maintenance operational personnel using the example of Mikunsky infrastructure section of the Northern Infrastructure Directorate of Russian Railways. As an example of the distance for operation of infrastructure, the article considers Berlin section of infrastructure of German railways. The task of organising the activities of the infrastructure linear enterprise of the track complex, including track section workers (PC), signalling, centralisation and blocking (SCB) maintenance section personnel working within enlarged teams and emergency repairs teams equipped with service trains and KamAZ vehicles, is considered. For the analysis of information uncertainty, an information model is proposed, for which the risk is considered in the form of determining losses. At the stage of preliminary calculations, a change in the number of maintenance personnel will make it possible to obtain a reduction in operating costs.Статья посвящена структуре технического обслуживания малоинтенсивных железных дорог за счёт уточнения эксплуатационного штата по содержанию инфраструктуры на примере Микуньской дистанции инфраструктуры Северной Дирекции инфраструктуры. Примером дистанции по эксплуатации инфраструктуры в статье рассматривается Берлинская дистанция инфраструктуры железных дорог Германии. Рассмотрена постановка задачи по организации деятельности инфраструктурного линейного предприятия путевого комплекса, включающего работников дистанции пути (ПЧ), персонал по обслуживанию сигнализации, централизации иблокировки (СЦБ), работающих по системе укрупнённых бригад ибригад по неотложным работам, оснащённых путеремонтными летучками, хозяйственными поездами и автомобилями КамАЗ. Для анализа информационной неопределённости предлагается информационная модель, для которой риск рассматривается ввиде определения потерь. На стадии предварительных расчётов изменение численности обслуживающего персонала позволит получить сокращение эксплуатационных расходов на полигоне МЖЛ за счёт экономии фонда заработной платы

Influence of tree-crown density on dominant plant species of the herb-shrub stratum in the zone of mixed forests

Forest ecosystems are among the most complex and dynamic biological systems of our planet. They play an important role in sustaining biodiversity, regulating the climate, and preserving water resources. Furthermore, they serve as natural filters, improving the quality of soil and air, and also preventing erosive processes. Forests create unique conditions for life of various species of plants and animals, which contributes to maintenance of the natural biodiversity and supports the stability of the ecosystem. Likewise, forests are important for the carbon cycle. They absorb a large amount of carbon, thus hindering global warming. Therefore, forest ecosystems are of paramount ecological value and their preservation is crucial for a balanced functioning of the planet. Our studies were carried out in the forest ecosystems of the Desna-Starohutskyi National Park, which is in the Ukrainian Polissia. The materials and methods of the study included systematic collection of the data on density of tree crowns, and also records of diversity of plants of the herb-shrub stratum in the chosen forest areas. Those data were analyzed using statistical methods. The study results revealed that the crown density has a significant effect on diversity of herb-shrub plants in the lower forest strata. Increase in crown density correlated with decrease in the light availability in the herb-shrub stratum. Change in the crown density towards increase significantly altered the conditions for competition between herbaceous and shrub species. Decrease in light availability led to shift in the competition ratio between the species, promoting dominance of more shade-loving species. Increase in crown density, which often reached 100%, made the competition more severe, especially for key resources (light, water, and nutrients). Because of this, species diversity in the herb-shrub stratum of the forest ecosystems was observed to decrease, and less adapted species were extruded. In general, change in tree-crown density in the forest ecosystem had a significant effect on the dynamics of herbaceous and shrub species, changing competitive relations and the structure of those plant communities. The results we obtained expand the knowledge about interactions between crown density and the structure of herb-shrub stratum, which gives perspectives for more efficient management of forest resources, and can also improve scientific identification and implementation of measures for protection of forest ecosystems

Mechanisms of water-salt metabolism disturbances in dogs subjected to six month hypokinesia

Water-salt metabolism in dogs during prolonged restricted motor activity (hypokinesia) was investigated. It was found that hydration occurred and fluid was redistributed between the extra- and intra-cellular sectors. Also, electrolyte excretion rose, and magnetism and calcium metabolism changed significantly. It is concluded that the forces caused by muscle strain proper (which was decreased under conditions of hypokinesia) influence the state of bone metabolism

The effect of hypodynamia on mineral and protein metabolism in calcified tissues of the maxillodental system (experimental radioisotope study)

Mineral and protein metabolism was studied in experiments on 60 white rats, using P-32 and Ca-45 uptake in the mineral fractions, 2C-14-glycine in the protein fractions, and P-32 in both fractions of calcified tissues as indices over a 100 day period of experimental hypodynamia. Combined alterations in mineral and protein metabolism occurred in the calcified tissues of the experimental animals. The most pronounced changes were found in P-32 and 2C-14-glycine metabolism. In the incisors and femoral bones, these alterations occurred in two phases: P-32 and 2C-14-glycine uptake first increased, then decreased. Changes in Ca-45 metabolism were less pronounced, particularly in the initial period of the experiment. A marked reduction in P-32, Ca-45, and 2C-14-glycine uptake was found in various fractions of the calcified tissues on the 100th day of experimental hypodynamia