Papers by Keyword: Explosion

Abstract: The article presents a simulation model for determining the required area of easily removable structures to protect against progressive collapse. The simulation model allows you to calculate the area of easily removable structures depending on the input parameters, to obtain the dynamics of the change in the parameters of the combustible medium depending on the change in the properties of the combustible gases that are in the room.

Abstract: The study evaluates the method of investigation of soil contamination with heavy metals at the sites of explosions. Results of method application were obtained. Soil samples were collected in location selected as the typical place were explosions take place for explosive objects destruction. For the qualitative and quantitative analysis of soil samples, the "KBr tablets" method was used. Obtained pellets were investigated with spectral-analytical installation created on the basis of infrared-spectrometer IKS-21 and thermal imager LAND-814. IR spectrometric research was carried out in the most informative spectral range of wavelengths of 7.5...14 μm. Proposed method of investigation of soil contamination with heavy metals at the sites of explosions allowed to identify presence of such metals as Al, Cu, Fe, Mg, Ni and Zn in soil samples of explosion site. Mg, Ni and Zn show stable presence in the soil of explosion site with low amount. Al, Cu and Fe we have seen sharp decrease of logarithmic transmittance value at the depth of 10…15 cm which means that these elements are accumulated at these depths of soil after explosions.

Abstract: The sequence and development of the life cycle of a machine-building product are described. Metals recycling, specifically hard alloys, is considered one of the important economically profitable directions of production development. The evaluation of the efficiency of such a method is given in the example of the explosive processing of hard alloys.

Abstract: The sequence and development the impulse stamping goals and production objectives are described. A new idea development from a primitive “field” technology to modern integrated technologies that allow obtaining unique quality indicators of manufactured parts is shown. The article covers the description of pulse technologies for sheet stamping by the blasting agents explosion and an underwater high-voltage discharge.

Abstract: The analysis and necessity for studying of burning processes of systems formed by coal dust and methane for the purpose of development the effective activities on the enterprises of coal branch were shown. The results demonstrate the role of nonflammable components in the combustion processes of air suspension in heterogeneous systems. Also the dependence of the critical conditions creation for flame propagation in air suspension of sucrose from the average particle diameter at different temperatures of the ignition source is presented. The necessity of taking into account the experimental and methodological experience of other industries for the study of air suspension sensitivity to the initiating influence of the ignition source is explored. The requirements to the installation and methodology for studying the sensitivity of coal dust air suspension as one of the main factors preventing explosions of heterogeneous systems in the coal industry are formulated.

Abstract: This analysis is a part of the research devoted to the affect of energetic characteristics of explosives to strength properties of exploded mine rock pieces [1,7]. We show here the results of a model experiment how the energy of blast-hole can influence strength properties of mine rock pieces with respect to ruptured zones.

Abstract: A subsurface magazine has an explosive storage chamber, a horizontal passageway, and a vertical shaft for vent. It was proposed and legislated in Japan. The authors found that small amount of water on the floor of its storage chamber mitigated the blast pressure remarkably. The mechanism of the mitigation has been studied, however, it is not still well understood. In this study, the explosion in a transparent, square cross section, and straight tube was carried out to examine the mechanism of blast-wave mitigation by water. The arrangement and amount of water in the tube were varied for five ways. The dependence of mitigation effect on the arrangement and amount of water was evaluated by measuring the blast pressures in the tube and outside the tube. The results of this study concluded that the mitigation of blast wave by water is mainly due to the interaction between the explosion and the water very near the explosion point. On the contrary, the water at other part of the tube was found to strengthen the blast pressure.

Abstract: Today, especially after the several technical accidents, the last one in France Flamanville power station near Cherbour in January 2017 risks of the nuclear hazards due to technical, terrorist or military accidents continually rising. In this situation is of a great importance to start with a retrofit those of underground spaces that was decommissioned in last years and to start thinking about reuse of mining shafts as a fallout shelters for protection of civil population. And the first step is to start with selection of the identify spaces with a mathematical models for selection of the rocks massifs that can be useful for porpoise of the underground shelters. The need to utilise specific geological data, which project organisations usually do not have available. The physical-mathematical properties of rocks are not sufficiently portrayed in these methodologies, which complicates execution of calculations and reduces the credibility of these calculations. The methodology for calculating the stability of rocks around a mine works proposed in the article enables resolution of the task complexly for the conditions of individual deposits, utilising the generalised values of rock property indicators.

Abstract: The development of the new technologies has also brought new possibilities of the wood processing, wood shaping and wood materials tending. By reason of increased human need for wood products the industry has shifted from the production in the workshops throught manufactures up to fabrications. This fact also causes increasing of the wood dust amount in the spaces of the production shops or halls, and by that also increased danger of the explosion of the wood dust. At the adequate initiatory source, sufficient amount of flammable material, oxidant and essential pressure, the explosion can occur and last for several miliseconds, therefore people rescue in the endangered spaces in case of explosion is impossible. One of the parameters which influence properties of the flammable wood dust is its particle size. The article deals with the particle size influence of the wood dust at its minimal temperature of ignition in the stired state. On the basis of the experimental measures the influence of the minimal action of the thermal energy for the activation of the ignition process of the wood dust in the stired state at the reacting of pressure and variousness of grit size is assessed.

Abstract: The aim of the paper is to provide an expert opinion on the issue of charge size estimation of used explosion weight according to the caused damages on the sourronings buildings. The research is focused on the analytical approach of setting the weight of explosives used in explosive improvised devices, using a current state-of-art of blast pressure setting. The vice versa methodology is to estimate the weight of used explosive from maximal pressure of blast wave.