Victoria Akmaldinova

The impact of technological downtime during the reloading of isothermal containers on the economic efficiency of temperature-sensitive cargoes multimodal transportation was investigated. The features of the cold chain functioning are considered in the conditions of maritime and rail transport interaction, where the reloading process is tracked by a temporary loss of power supply to containers. The mathematical model of non-stationary heat transfer has been developed, taking into account the interaction of the "environment - container - cargo" system and allows to assess the change in temperature over time. The modeling was performed for different cargo types (chilled beef, poultry, seafood) taking into account seasonal factors, in particular summer and winter operation conditions. The exponential nature of temperature changes have been established and the maximum time for containers to remain without power supply have been determined. An approach to the economic assessment of losses based on the relationship between temperature deviations, the duration of their impact and the reduction in product quality is substantiated. It has been shown that even short-term downtime can lead to significant economic losses associated with decrease in goods commodity value. It has been confirmed that ensuring continuity of temperature control and optimizing reloading operations are the key factors in increasing efficiency of multimodal transportation.

The article is devoted to the analysis of existing methods of calculation of rigid heliport coverings, both domestic and foreign. Considerable attention is paid to the geometric dimensions in the plan and layout; location and orientation of heliports. Types of helipads are considered; materials used in the construction of heliports; type of structures (panels), designed for the construction of helicopter pads at the surface level (on any dense surface or ordinary soil), that successfully replace concrete, as well as for the reconstruction of worn and damaged concrete helicopter pads on rooftops and other heliport modifications; possible locations of helicopter pads, which may be different in size and configuration: mobile, off-road, ground, on the roofs of buildings and structures, on pontoons, on sea or river vessels and yachts, on offshore drilling platforms, by individual projects. Approaches to the improvement of the existing method of calculation and design of rigid helipads are analyzed.A comparative analysis of ICAO, FAA, SNiP 2.05.08-85 regulatory documentation and recommendations, which do not provide a clear idea of ​​the method of calculating the thickness of rigid heliports, do not separate the calculation of heliports from the calculation of aerodrome pavements, do not consider any critical cross sections in calculating the load from helicopters and the main differences in designing coverings for helicopters from those for aircraft maintenance, connected with the dynamics of the takeoff and landing operations.As the weight of modern helicopters varies widely, it has been established that different types of coverings must be used for different weight categories (from structures raised above the ground level for light and medium-weight helicopters to cement concrete coverings for heavy helicopters).

Фахове видання. Педагогічні науки. Філософські науки.