Abstract.The article presents a model of economic evaluation and selection of explosion-relief constructions (ERC), as well as determination of explosion protection efficiency of buildings and structures provided on a stage of construction. It has been shown that definition of economic efficiency of ERС is the evaluation of its application for buildings with remote or automatically controlled production. It has been determined that an important role in design of explosive industrial facilities is played by selection of the economically feasible and effective materials for ERC. When selecting materials it is necessary to consider probability and yield of explosions. Necessity to create the methods allow considering such probability has been revealed.Amount of damages caused to the company as a result of explosion of combustible gases, vapors and dusts inside the building with explosive production depends on the effectiveness of explosion safety measures [1, 2].The results of inspection of emergency explosion consequences and calculation of explosion loadings for separate buildings, which external protection was designed taking into account the installation of explosion-relief constructions (ERC), have shown that the main protecting and bearing structures of affected buildings and, sometimes, adjacent buildings can be damaged together with destruction of ERC [3].The measures proposed to ensure explosion protection of industrial facilities differ from existing differentiated approach to choice of types and number of ERC for each specific case [4][5][6][7][8][9]. Besides, manufacture of ERC, except the specially designed covering elements, does not require additional expenses because the offered constructions are standard and produced on an industrial scale. Application of ERC in the cladding of buildings could limit the damaged area by sizes of destroyed construction. Such destructions minimize the amount of damage due to the absence of additional costs for restoration of the process equipment and the main building structures [10][11][12][13]. This can sharply reduce the costs for rescue and recovery operations and decrease the losses from temporary termination of the productive activity.It should be noted that implementation of explosion safety measures for industrial facilities, which technological processes connected with generation of combustible gases,

Abstract.The work provides a cause analysis for major industrial explosions and a review of the causes of combustive air-gas mixture generation in a production environment. It has been established that during operation of explosive production facilities, it is process equipment that, as a rule, creates explosive environment inside the floor area. A qualitative method for determination of a potential accident has been reviewed. Analysis of the nature of explosion effect on building structures and equipment has shown that exposions characterised by absence of equipment and building structure disintegration normally have a localized character. It has been identified that during explosions inside process equipment, the largest structural damage occurs in spots hit by equipment debris. Complete destruction of building structures and equipment is caused by explosions inside equipment containing large quantities of combustible products. It has been identified that most explosions are accompanied by partial or total destruction of building structures and equipment. Therefore, measures taken to protect equipment and buildings from explosion effects lack efficiency.In most cases, generation of explosive gas-air mixture within a building is related to leakages and accidental releases of combustible gases to the atmosphere of the floor area. Thus, out of 1,200 industrial explosions registered in the US over a five-year's period, 50% are accounted for by the use of combustible gas/steam-air mixtures in production [1][2][3]. According to the analysis conducted by the American Insurance Association, the causes of major explosions are distributed as follows: equipment breakdown: 31%, process order violations: 17%, incorrect estimation of explosiveness of products used in the production process: 20% [4]. Moreover, the most frequent cause of combustible substance leakages and releases (50% of all cases) is breakdown or technical failures of process line equipment; 20% can be attributed to errors and negligence of operations personnel during equipment operation.The examined causes of combustible gas-air mixture generation in a production floor atmosphere have necessitated development of the following explosion-safety measures: prevention of gas leakages or of their movement in an inadvertent direction; implementation of complex production mechanization and automated remote control.

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Abstract. The influence of non-uniformity on mass transfer processes in open channels have been investigated under the action of urbanization factors. The study is related to the urgent problem of environmental degradation of water objects in urbanized areas. It is known that the water quality in the water objects depends on the manner in which the contaminants spread how they mix with the river water and diluted by it. The main results of the study consist of recommendations to incorporate non-uniformity factor to the calculation of diffusion dilution of wastewater and prediction of river processes. So the effect of the flow non-uniformity on the diffusion model of pollutants dilution and diffusion coefficient have been investigated. Formulas for the concentration profiles calculating and the average concentration of fine particulate matter in nonuniform gradually varied flow were presented. The deposition length of suspended contaminants were received, based on the hydraulic resistance laws of nonuniform gradually varied flow.

Abstract. The traditional concept of wetted cross-section, wetted perimeter and hydraulic radius seems fairly simple and clear, especially in the case of smooth boundaries of the flow. However, for the rough boundary surface covered with randomly arranged roughness the definition of the wetted cross-section as a normal to all elementary streams becomes notably problematic. More controversial seems the concept of wetted perimeter. This issue is of particular importance for the beds with high-dimensional roughness for which the geometric dimensions of the flow and the roughness elements are of the same order. The article shows that topological features of the boundary surfaces for the natural channels allow definitely refer them to fractals. Further study of the bed roughness based on its fractal nature can form a new approach to methodological soundness of main hydraulic parameters and open up new opportunities for their description.