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Purpose. The substantiation of accounting the deformation-strength characteristics of the collapsed rocks and the rocks consolidating near the reusable preparatory mine working of the mined-out space to optimize the loading parameters of its fastening and security systems. Improving the research adequacy and recommendations reliability.Methods. By means of computational experiments based on the finite-element method, the influence has been studied of rigidity of the collapsed rocks and consolidating rocks in the mined-out space on the level of intensity of the load-bearing elements of the fastening and security systems of mine working. The analysis has been performed of the stress-strain state of the geomechanical system load-bearing elements, as well as comparative mine research.Findings. The research results and analysis are represented of the stress-strain state of the fastening and security systems elements in the preparatory mine workings with different degree of rigidity of the collapsed and consolidated rocks of the mined-out space. The patterns of the rigidity influence of the collapsed roof rocks on the stable state of preparatory mine workings have been assessed. Originality.A different-valued relation has been established between the deformation-strength characteristics of the collapsed rocks in the mined-out space and the elements of fastening and security systems of mine working, which should be considered when optimizing the modes of their operation. It has been revealed that the increased loading on the combined roof-bolting system elements protects the frame support from the increased rock pressure, which contributes to reducing the section losses of mine working. Practical implications.The research performed is the basis for the parameters optimization when maintaining the preparatory mine workings for their repeated use and also for the rational parameters search of the combined roof-bolting system in order to develop a method for choosing its parameters depending on mining and geological conditions.

Today considerable experience in the development of tar sands is accumulated. However, well-known mining technologies do not cover the entire depth range of natural bitumen deposits. In addition, there are significant energy-intensive technologies and negative environmental impacts. In view of this, the purpose of this work is to improve the method of extracting natural bitumen in site for a deposit interval of 75 – 200 m and to substantiate the basic technological scheme of this method. The proposed method of extracting bitumen from poorly cemented reservoirs in the depth range of 50 – 400 m provides: creation of artificial mine working; the transfer of the rock into the water mixture composition under the action of high pressure jets of a heated mixture of water, a hydrocarbon solvent and a flotation agent; separation from the rock and concentration of bitumen in the production as a result of its heating, dissolution and flotation; selection of depleted bitum slurry from the mine working by gas lift method. The proposed method of extracting bitumen is the transfer of the rock at the site of its occurrence to the suspension condition on the excavation created by the hydraulic production method, separation and concentration of bitumen by dissolving it with a heated hydrocarbon solvent and a flotation agent (hydrocarbon reagents), and extraction in the composition of depleted rock slurry to the surface by the gas lift method. As the preliminary calculations show, the proposed method will allow the efficient extraction of bitumen and highly viscous oil from weakly cemented reservoirs in the depth range of 50 – 400 m. Also, the proposed technology creates the preconditions for the development of oil sands at a depth of 75 – 200 m since there is currently no effective technology for the interval. In addition, it can significantly reduce energy costs, environmental pollution and greenhouse gas emissions.

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The purpose of paper is to develop an algorithm for designing the half-masks of air-purifying respirators and assessment of their safety factor of insulation. To create a 3D model of a head, two-parameter NIOSH tables (National Institute for Occupational Safety and Health) were used. The model drawings were made with the use of Solid works software package. Differential geometrical method based on applying the moving Frénet trihedral was used to design half-masks. Two designs of the respirator half-mask were developed based on the averaged length and width of face (Modification 1), and length of face and lips (Modification 2). As a result of modeling test, the area and perimeter of the mask contact line have been defined. The safety factor of half-mask insulation was calculated theoretically. It has been established that the safety factor of Modification 1 half-mask is 2.5 times higher.

Purpose. To rate the main factors and indicators of the national economic security, in particular the degree of the country's provision with primary natural resources which determine the global energy consumption trends.Methods. Analysis of components comprising the fuel and energy complex of Ukraine in view of survivability and heuristic algorithm for finding economically feasible reserves. The problem of finding the optimal flow distribution is solved by graphs.Findings. Emergencies are ranked in the descending order of optimal flows in the normal mode, the sorting sequence is defined, which results in the optimal solution via a minimum number of the algorithm computational steps. Originality.A universal algorithm for the development of fuel and energy complex of Ukraine has been designed. Practical implications.It was found that the vitality of integrated energy systems can be defined as the property to resist a large scale external disturbance, maintaining the ability to operate with acceptable performance and backup indicators. When considering large energy systems, the levels of the industry reserve can be reduced due to interchangeability of energy resources.

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