The paper presents the results of the calculation of optical and energy parameters of the flat-plate solar collector (FSC) with two glass transparent covers. The author of this paper carried out the calculations taking into account a number of structural and optical parameters of the FSC for the worst weather conditions observed in the 15 January 2014.  Firstly, the angles of refraction of sunlight were found considering the diurnal variation of the angle of incidence of sunlight on the surface of the FSC. Secondly, it were defined the reflectance of interfaces, transmittance of a transparent coating of FSC taking into account only the reflectance, and only the absorbability, and, lastly, total transmittance. The paper identifies the reflectance, transmittance and absorbability, as well as hourly and daily averages of FSC efficiency with and without the influence of dust and shading on transparent cover. It was found that the cumulative effect of virtually dust and shading coefficients on the optical and thermal power settings FSC does not exceed 5 ÷ 6% and radiation efficiency varies in the range of 57 ÷ 143 W / m² under the conditions of the Absheron Peninsula, in normal service.

The review has analyzed the papers relative to heteropoly compounds, as solid proton conductors, for modification of polymer proton exchange membranes for their usage as low temperature fuel cells. The electrolyte functions and requirements, the structure and transport properties of perfluorinated proton exchange membranes which are the main candidates for practical applications are briefly considered. The main disadvantages of these membranes limiting their use are also highlighted. A special attention is given to the structure and properties of heteropoly compounds. The properties of heteropoly acids (phospho- and silicotungstic) containing anion with Keggin structure are discussed in details. In the main part of the review the methods of the preparation of the composite membranes based on perfluorinated and aromatic polymers and heteropoly compounds, the influence of the nature and content of the heteropoly compounds on their transport properties are analyzed. It is shown that the modification of polymer membranes by heteropoly compounds is one of the most promising methods to improve membranes performance. Due to its own high proton conductivity introduction of heteropoly compounds into polymer electrolytes in some cases can significantly improve proton conductivity, particularly at elevated temperatures, and reduce the methanol permeability. In the final part of the review the data on the use of composite polymer electrolytes with heteropoly compounds in the fuel cells and the influence of heteropoly compounds on the performance of the electrochemical devices are analyzed. It is shown that introduction of dopants inside of membrane can significantly increase both the operating temperature and performance of the fuel cell.

In the cathode active layer of a fuel cell with a solid polymer electrolyte, process of current generation takes place in support grains. The speed of this process essentially depends on a degree of support grains pores filling with water. Calculations show that the overall current value in the cathode active layer with the pores of support grains completely filled with water are much less than with pores partially filled or even without water. The last variant is realized when the rate of moisture evaporation from the pores of the support grains exceeds the rate of flooding them in the current generation process. In order to increase the overall current, a degree of heating-up of the cathode active layer is necessary to increase.  It is desirable that the temperature of the active layer T_s as much as possible exceed the temperature T, which the fuel cell operates. In this study by method of computer simulation, a specific example of determining the overall current value in the cathode active layer is presented. It is shown that if the pores of support grains are completely filled with water, then overall current I = 0.223 A/cm², and if the pores of the support grains are filled with water only about 10 percent then I = 1.151 A/cm².

 

The statistical theory of atomic ordering, long- and short-range, in ternary substitutional solid solutions AB₃+C with fcc crystal lattice L1₂ of the Cu₃Au type has been elaborated within the quasi-chemical approximation on the assumption that C atoms are located in the sites of both types, legal for A and B atoms. On the basis of molecular-kinetic concepts using some simplifying assumptions the free energy of the fcc substitutional alloy in dependence on the composition, temperature, correlation parameters and energetic constants has been found as a result of the calculations. The quasichemical method, the approximation of pair-interaction of the nearest neighboring atoms have been used in calculations taking into account short-range ordering. The correlation parameters has been calculated depending on the temperature, alloy composition, degree of long-range order and energy constants, their functional dependences have been elucidated, the plots have been constructed. The calculation results have been compared with the published experimental data for these alloys. The performed study of the correlation parameters in ternary substitutional solid solutions has showed that the addition of a third component C to the alloy АВ₃ can substantially affect the degree of short-range order in the atoms arrangement and, therefore, lead to changes in its physical properties. The knowledge from independent experiments of energetic parameters of atomic interaction in the alloy can allow by the use of derived formulae to calculate the required amount of impurity of the certain type necessary to produce alloy with the predetermined degree of short- and long-range order.

The paper shows the opportunity and gives the concrete results of the application of the method of tenzoimpulse regulation of physical and chemical processes in the nonequilibrium condensed mediums to the kinetics analysis for the definition purpose of difficult electrochemical transformations mechanisms on the example of chromato-sulfate galvanic chromium plating. Regulation of macroscopically heterogeneous processes in the condensed mediums provides synchronization of the self-organizing dissipative structures without affecting the mechanism, thermodynamics and kinetic topology of controlled processes. It is observed the selective resonant increase of speed constant along the corresponding trajectory of chemical reaction with essential acceleration of mass and heat exchange. Moreover, this paper explicates the mechanism of electrolytic cathodic chrome restoration which does not assume spontaneous dissociation of the solution components. The authors of this study consider the solvated electron, delivered via the cathode in solution by the electromotive force (EMF source), as a complete reagent. The paper explains the mechanism of the trivalent chrome compounds emergence during electrolysis and shows their role in the general cathodic process, function of the allocated hydrogen in the general mechanism of electrolytic chromic acid restoration, catalytic effect of sulfuric acid, growth of chrome exit on current at decrease of electrolyte temperature and increase of cathodic current density, and also at reduction of chromic anhydride concentration in electrolyte. The paper is intended for process engineers, research associates, experts in the field of materials science, various areas of physical and applied chemistry, and also everybody who is interested in electrochemistry problems.

The paper deals with the experimental study of the heat transfer bodies enhancement partially submerged in the fluidized bed or floating on its surface by directing heterogeneous jets on the exposed surface of the body (mixture of solid particles with air). Heterogeneous jets were generated directly by the fluidized bed by tubes which placed in the bed and directed to the heat transfer surface. The study shows that the use of heterogeneous jets generated by the fluidizing medium itself, leads to extension of the average surface body area on heat transfer coefficient without altering the energy required on the fluidization process. Reducing the difference in the intensity of the heat transfer process for the body parts which contact with different environments, improves the quality of heat-treatable products.