No abstract

Global warming is causing a major ice retreat from the North Pole. From now on, this retreat allows almost permanent movement between East and West off the coast of the Russian Federation along the Northern Sea Route (NSR). For a long time, navigators have been trying to use this route which significantly reduced the distance between continents. The amount of freight that currently travels on the NSR will inevitably increase in the coming years. To reduce environmental risks, one possible option is not to supply ships with heavy fuel oil. The ships could then be electrically powered and navigate in stages from one port to another along the route to refuel for energy. This electrical energy can be produced on site from renewable energy sources. In this article, a first feasibility analysis is outlined, taking into account the tonnage constraints for navigating on a possible route for the NSR, the cost of energy production and the possible location of several ports of call. Under current economic conditions, the solution would not be profitable as it stands, but should become so at a later stage, which justifies starting to think about a future full electrification of navigation on the NSR, which will also contribute to the economic development of the Russian Federation northernmost regions.

No abstract

Freeze-drying is often used as a final stage to produce three-dimensional porous matrices for medicine. Because a pure solvent crystallizes first during freezing, it acts as a pore-forming agent. The size of the solvent crystals primarily depends on the cooling rate and the composition of the material to be frozen. Ultrasonic treatment also affects the size of crystals and can be used to control the structure of a porous matrix. This article describes the effect of ultrasound (40 kHz, 50 W) applied at the preliminary freezing stage of polysaccharide solutions (alginate, chitosan, alginate–chitosan and alginate–gelatin) on the finished matrix properties. The most attention was paid to the effect of ultrasound on the size and shape of crystals formed during freezing, which leads to a change in the porous structure of the matrices after solvent sublimation. As a result of changes in the microstructure, a number of differences in the vibrational spectra of the molecules and the values of pore volume, sorption capacity, permeability and degradation of matrices were identified. Such changes in the structure of materials, as well as the emerging directionality of pores, together can affect the process of cell cultivation in these polysaccharide matrices, which can be useful in solving problems of tissue engineering.

This paper presents modern methods of mathematical modeling, which are widely used in the development of new inhalation and intranasal drugs, including those necessary for the treatment of socially significant diseases, which include: tuberculosis, bronchial asthma, and mental and behavioral disorders. Based on the conducted studies, it was revealed that the methods of mathematical modeling used in the development of drugs are fragmented, and there is no single approach that would combine the existing methods. The results presented in the work should contribute to the development of a unified multiscale model as a new approach in mathematical modeling that contributes to the accelerated development and introduction to the market of new drugs with high bioavailability and the required therapeutic efficacy.