ON CALCULATION OF OXYGEN BALANCE OF MULTICOMPONENT THERMOBARIC EXPLOSIVE SUBSTANCE

Most modern military confrontations take place near or directly in inhabited area. The use in such conditions of munition (warheads) which hit typical targets based on fragmentation (high-explosive) or cumulative action is impractical due to insufficient “selectivity” of hitting targets with such munition. At present, modern world tendency is the development of the latest munition (warheads) with increased properties of “destruction selectivity”. One of the directions is the development of munition based on thermobaric explosives. Such munitions can cause maximum damage due to high temperature and the impact of a shock wave with a low level of collateral damage, since thermobaric munition, especially in the open area, have a clearly defined or even limited area of effective damage, which determines the significance of their further development. Since modern thermobaric explosives include a large number of chemical elements (including chemically active metals), there is a need to calculate the physical balance of oxygen and oxygen coefficient to take into account the physical characteristics of modern multicomponent thermobaric explosives. The oxygen balance of multicomponent thermobaric explosives largely determines the nature of the reaction of its explosive transformation, i.e the composition of the explosive products and, consequently, the value of thermodynamic characteristics such as heat, temperature, volume and pressure of gas-like explosive products. The calculated ratio and coefficients for complex multicomponent thermobaric explosives should be calculated during the development of explosives, taking into account the composition of components and elements and their possible chemical reactions during the explosion. The abovementioned improved calculations of oxygen balance and oxygen coefficient of thermobaric explosives, which include aluminum, allows taking into account the physical characteristics of destruction of typical targets by thermobaric munitions.

Copper Flash Smelting Process Balance Modeling

Process control in flash smelting is based on mass and energy balance from which the operational parameters (oxygen coefficient, oxygen enrichment, and flux demand) are obtained to achieve matte and slag with defined compositions and at defined temperatures. Mineral compositions of copper concentrates, and their blends, have been used in order to optimize the heat process balance. The classical balance methodology has been improved by using equations for molecular ratios and distribution coefficients that have been calculated using FactSage™. This paper describes the development of balance equations and compares their theoretical (equilibrium) results with industrial data logs of the smelting process.

Sensitivity Analysis and Optimization of Operating Parameters of an Oxyfuel Combustion Power Generation System Based on Single-Factor and Orthogonal Design Methods

The main purpose of this paper is to quantitatively analyze the sensitivity of operating parameters of the system to the thermodynamic performance of an oxyfuel combustion (OC) power generation system. Therefore, the thermodynamic model of a 600 MW subcritical OC power generation system with semi-dry flue gas recirculation was established. Two energy consumption indexes of the system were selected, process simulation was adopted, and orthogonal design, range analysis, and variance analysis were used for the first time on the basis of single-factor analysis to conduct a comprehensive sensitivity analysis and optimization research on the changes of four operating parameters. The results show that with increasing oxygen purity, the net standard coal consumption rate first decreases and then increases. With decreasing oxygen concentration, the recirculation rate of dry flue gas in boiler flue gas ( χ 1 ) and an increasing excess oxygen coefficient, the net standard coal consumption rate increases. The net electrical efficiency was just the opposite. The sensitivity order of two factors for four indexes is obtained: the excess oxygen coefficient was the main factor that affects the net standard coal consumption rate and the net electrical efficiency. The influence of oxygen concentration and oxygen purity was lower than that of excess oxygen coefficient, and χ 1 has almost no effect.

Investigation of Chemical-looping Gasification Characteristics of Chinese Western Coals with Hematite-CuO Oxygen Carrier

In order to realize highly efficient conversion of Chinese western bituminous coals into syngas, a series of chemical-looping gasification experiments was conducted with hematite-CuO oxygen carrier in a laboratory-scale fluidized-bed reactor. The results indicated that the gasification rate of Chinese western bituminous increased by 2-3 times after addition of a hematite-CuO oxygen carrier. Meanwhile, the syngas yields of Chinese western bituminous ranged from 1.84–2.04 m3/kg, three times higher than that of lignite. This shows that the combination of chemical-looping technology and gasification of coal can achieve efficient conversion of Chinese/western bituminous coals. The temperature and the supply oxygen coefficient (O/C) all demonstrated a clear effect on the gasification rates and the gas yields. 10 cycles of redox experiments indicated that the hematite-CuO oxygen carriers have good recycled reaction characteristics. Those results provide theoretical guidance for the efficient conversion of Chinese western bituminous coals into syngas via chemical-looping gasification.

HOMEOSTASIS CHANGE IN THE SMALL INTESTINE WITH DISTURBED REGIONAL BLOOD FLOW IN EARLY POSTNATAL ONTOGENESIS

Objective: A study of the ischemic damage course and regeneration in the small intestine with disturbed regional blood flow in early postnatal ontogenesis.Materials and Methods: The experiments were carried out on 30 puppies at the age from 1 to 4 weeks. The state of regional blood flow in the ischemic area of the small intestine was investigated by blood filling of tissues, metabolism - by redox potential, oxygen pressure and diffusion oxygen coefficient, lipid peroxidation activity and catalase activity. Database formation and statistical calculations were performed using the applied programmes "Microsoft Excel", "ANOVA" for "Windows".Results: The performed research showed that in animals of early age pronounced microcirculatory disorders were observed. About this evidenced significant tissue bloodfilling in the ischemic region of the small intestine. Essential disorder of the blood supply in the organ naturally led to a pronounced fall in the redox potential, the oxygen pressure, and the diffusion oxygen coefficient in the tissues.On a level with the disturbances in the electrogenesis and tissue oxygenation, we found a significant diminution in their antioxidant capacity, as evidenced by a pronounced increase in lipid peroxidation and a decrease in catalytic activity. Insufficient oxygen supply of tissues caused the development of irreversible changes in the intestinal wall, the disorder of the organ motility with frequent appearance of small intestinal intussusception.Conclusions: A significant disturbance of the small intestine blood supply at the early age, caused by an operating trauma, leads to a pronounced decrease in electrical activity and oxygenation of the organ tissues, accompanied by marked metabolic disorders.Oxygen starvation of tissues in the ischemic region of the small intestine at the early age contributes to the development of irreversible changes in the intestinal wall, and frequent disruption of the regeneration process in this area. Keywords: small intestine; local ischemia; early age

Application of Distribution of Oxygen Coefficient in Explosive Neutron Detection

Oxygen coefficients of 396 explosives, including liquid and solid explosives, 177 dangerous materials, including oxidants, combustible substances, chemical hazards and narcotics, and 9 common packing materials were collected and compared. It can be seem that the explosives can be distinguished from non-explosives by oxygen coefficient with boundary 0.3 to 1.2. This result can support a convincing proof for explosive neutron detection.

Spectrophotometric method for rapid estimation of the oxygen stoichiometry in YBCO superconducting samples

Abstract Detailed investigations on the possibility for determination of the oxygen stoichiometry in YBa2Cu3Oy superconducting samples by measuring the absorbance of the colored Co(III)-EDTA and Cu(II)-EDTA complexes in one solution have been performed. The absorptivity of the complexes at pH 2.5 and 4.9 as well as Beer’s law have been studied. The content of the solution for the sample dissolving has been established. The stoichiometry of the oxidation-reduction reaction between Cu(III) from the sample and Co(II) in the solution has been proved. The possibility to dissolve the sample in air has been tested. As a result a simple and rapid spectrophotometric method for the determination of the δ non-stoichiometric oxygen coefficient in YBa2Cu3O6.5+δ samples has been developed without precise measurement of the sample mass. The standard deviation of the δ- and y-coefficient results is 0.017. The reproducibility of the y-values in relative units (sr ) is 0.2%. The accuracy of the results has been confirmed by the method, which is based on the absorbance measurement of the I 3−-starch compound. Graphical abstract