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Thin films of nickel hydroxide were prepared using the cathodic template method and were tested in different electrolytes. The electrolytes were 0.1 M KOH and 0.1 M KOH with the addition of 0.1, 0.3 and 1 mM K2WO4. The test revealed, that the presence of tungstate can have a significant effect on electrochemical and electrochromic characteristics of Ni(OH)2 films. The initial sample, cycled in 0.1 M KOH showed different characteristics from those cycled in tungstate-containing electrolytes: significant difference between current densities of cathodic and anodic peaks and presence of the current plateau on the cyclic voltamperometry curve. However, the initial sample demonstrated the highest coloration degree of 74 %. On the other hand, the sample showed degradation of the coloration degree past initial growth.The samples cycled in the tungstate-containing electrolyte showed better electrochemical characteristics – sharper cathodic and anodic peaks, with the lesser difference between peak values. The dynamics of the absolute coloration degree of the samples cycled in tungstate-containing electrolyte showed a constant increase. The sample tested in a solution with 1 mM tungstate had the lowest value of the absolute coloration degree – 60 %. For tungstate concentrations of 0.1 and 0.3 mM, the absolution coloration degree at the last cycle was 72 and 71 % respectively.The samples tested in a solution with tungstate additive had a significantly lower bleaching time – 40–50 s in comparison to 360 s of the sample cycled in 0.1 М KOH.A possible mechanism that explains such differences in behavior was proposed

This paper outlines the prospect of obtaining water from atmospheric air by cooling it to the dew point temperature using refrigeration machines in order to partially reduce water scarcity in the arid regions of our planet. To minimize energy costs in the systems for obtaining water from atmospheric air, it is proposed to utilize solar energy with absorption refrigeration units (ARUs) acting as a source of artificial cold. The characteristic thermodynamic processes have been analyzed in a modernized ARU, capable of working at a lower thermal energy source's temperature than its analogs. The possibility has been studied to reduce the temperature of the heat source by including a solution vaporizer in the ARU scheme. The analysis involved an authentic method based on the balance of specific streams of ARU working body components and actual boundary conditions at characteristic points of the cycle. A limit was shown for the level of a minimum boiling temperature in the ARU generator (from 90 °C) when the systems for obtaining water from atmospheric air are operated under current climatic conditions. The simulation of heat-and-mass exchange processes during contact interaction between a steam-gas mixture and ammonia water solution was carried out. Based on variant calculations, it has been shown that the proposed ARU structure with an adiabatic solution vaporizer could work as part of systems to obtain water from atmospheric air at a hot spring temperature above 100 °C and constructively enough fits into the element base of standard models. It has been proposed to use two types of solar thermal energy sources to operate ARU. In a tropical climate, with vacuum solar collectors or solar energy hubs; in a temperate climate zone, with solar collectors with water as a heat carrier

We have investigated the process of constructing the charts of electrical load, as well as electricity consumption, of many-storied apartment houses in a city's neighborhood, taking into consideration the fractal structure and the existence of a long-term dependence, inherent to self-affine stochastic processes. The results from studying daily, weekly, monthly, yearly charts have shown the presence of fractal properties and the existence of short-term and long-term memory. This makes it possible, in order to efficiently predict and control power consumption, to apply a fractal analysis, which establishes the dependence of future values on retrospective information. Feature of the current study is determining a critical value for the Hurst exponent, approaching which leads to that the system loses stability and enters an unstable state under which the parameters are changing rapidly. The Hurst exponent can be transformed into fractal dimensionality, which is a measure for the complexity of a load chart. In the theory of fractal sets and fractal geometry, of significant importance are the self-similar and fractal sets. By using the specified properties of the fractal, this study has proven the existence of a fractal principle in the formation of the dynamics of electrical load on civilian targets using the example of power consumption by many-storied apartment houses within a city's neighborhood. The calculation of the Hurst exponent has made it possible to determine that the series is persistent and suitable for adequate prediction and efficient energy consumption management. The relevance of the current research is predetermined by the application of a fractal analysis to electricity consumption pattern particularly by civilian objects, since the scientific literature analyzes and predicts the processes that form electric load structure on energy systems, at industrial enterprises

Energy consumption, environmental issues, product quality are actual problems related to grain drying processes. It is necessary to pay attention to designing new structures of energy-efficient grain dryers. A structure of an energy-efficient grain dryer based on thermosiphons has been designed; its energy consumption is 3.5...6.8 MJ/kg depending on surface temperature and air flow rate. The dryer includes a layer heater, a drying chamber, a heat generator, a heater, a noria for loading the product, and fans. The structural features of the dryer allow the drying process to be carried out without direct contact between the combustion gases and the product. The efficiency of the designed structure was evaluated for such indicators as heat transfer coefficients to the grain flow, specific energy costs, moisture content, the relative humidity of the air leaving the dryer. The values of coefficients of the heat transfer to the grain flow vary within 36...58 W/m2K at speeds 2.5...8 mm/s. An increase in the flow rate by 3.2 times leads to an increase in the heat transfer coefficient by 1.6 times. The moisture content of the air at the outlet of the dryer reaches 60 g/kg, while the relative humidity is 90 %, which is several times higher than the parameters for convective mine grain dryers. Energy consumption for drying at the surface temperature of thermosiphons Ts=142.9 °C for various grain flow rates is close to a minimum. The energy consumption is lower than in existing convective dryers. 21 % is spent on heating grain in the dryer; 54 % ‒ on moisture evaporation; and 23.6 % are losses. If we consider the energy spent on moisture evaporation usable, the efficiency of convective dryers is only 40 % while that of dryers based on thermosiphons is 54.1 %. It is expected that the designed structure could be a solution for small farmers in the post-harvest drying process

This work is focused on the numerical simulations of gas-solid flow in an industrial cyclone-calciner furnace. «ANSYS Fluent 15» software was used for numerical simulation. The computer model allows us to investigate modes of work with different fractional composition of material. For different boundary conditions of inlet gas flow, the trajectory of the particles and residence time in the apparatus, as well as hydrodynamic flow structure were determines. In addition the influence of additional revolving flow in the furnace on a distribution of particles was investigated too. The simulation results show good agreement between predicted and experimental data. This means that the behaviour of complex furnace system can be predicted using the CFD. The obtained results will be used in the future to optimize the design of the furnace and determination of optimal modes of operation.

We have experimentally investigated the patterns in the influence of opening angle of the scraper unit, inclination angle of scrapers, and motion speed of the scraper unit, on specific energy consumption by the improved scraper unit. We have experimentally substantiated the hourly schedule of manure accumulation and a schedule for turning the scraper unit on; it is proposed to remove manure 5 times during 24 hours: at 7, 9, 14, 18, 22, which would significantly reduce resource consumption and energy costs associated with the launch of a conveyor. Experimental study enabled determining the structural (opening angle of the scraper unit and inclination angle of the working surfaces of scratchers) and technological (motion speed of the scraper unit) parameters, at which the improved scraper unit would demonstrate minimum specific energy consumption. The optimal parameters for a scraper unit, at which the improved scraper unit would have minimum specific energy consumption, are the scraper unit opening angle in the range of 105 to 115°; inclination angle of the working surface of scrapers is 60°, motion speed of the scraper unit is 0.13 m/s. Based on these indicators, we assembled the developed scraper unit for manure removal. We have conducted comparative experimental study into operation of the developed scraper unit for manure removal and the prototype, commercially available scraper unit USG-3. This study demonstrated the advantage of the developed scraper unit compared to USG-3; specific energy consumption reduces by the amount of 44 to 48 % to 0.34‒0.36 kW h/t. The established rational parameters and operating modes of the scraper unit reduce energy consumption of the scraper unit required, while maintaining the required quality for cleaning a manure channel, which confirms the feasibility of its industrial production. The research results reported here could be applied when designing the bulldozers and other melioration equipment.

The key directions of the development and improvement of the fuel supply system for internal combustion engines with ignition from compression of the fuel/air mixture were pointed out. The need for the comprehensive implementation of electromechanical principles of fuel injection control in accordance with the various conditions of diesel engines operation was proved. The relevance of further development and modernization of the hydromechanical fuel systems on the background of ever-increasing interest in their electro-controllable analogues was highlighted. The unused potential possibilities of hydromechanical fuel equipment to improve the conditions of the fuel supply process were listed. To intensify fuel injection, it was proposed to use the electromechanical device that is mounted in the fuel discharge pipeline and modifies the phase-amplitude characteristic of the wave process of propagation of a single supplying pulse between the high-pressure fuel pump and the hydromechanical nozzle. We highlighted the important aspects of the procedure for constructing the calculation model of the switchgear-type fuel system of direct action with a new device for fuel supply intensification. It was proposed to consider the fuel injection process at some stages, taking into consideration the characteristics of functioning of a particular hydraulic node of the fuel system, including the proposed technical means of intensification. The systems of differential and analytical equations that make it possible to perform mathematical modeling of the process of propagation and mutual influence of the pressure waves in the pressure-pumping tract were presented. The resulting systems make it possible to obtain characteristics of a change in hydraulic pressure in different fuel volumes, the kinematics of motion of shut-off elements in a high-pressure pump and nozzle, etc. In the course of a comparative study, carried out on the basis of the presented calculation model, the fuel injection process for the standard and improved fuel system for a turbo-diesel, a significant improvement of the injection quality by a large number of indicators was revealed. According to the results of calculations, the existence of high-rate character of increasing and decreasing of injection pressure at the initial and final phase of the process of fuel supplyi to the cylinders of a diesel engine is observed. It was noted that the rate of pressure change can reach 170 MPa/deg, maximum, and average injection pressure increases up to 75 MPa and 30...40 MPa, respectively. Calculation studies were carried out with the employment of the numerical method of integration – the Adams interpolation method, the choice of which is caused by the necessity of obtaining consistent solutions when solving the described systems of differential equations, which belong to the category of the rigid

The study has substantiated the choice of components of manganese–containing electrolytes and their rational concentrations as well as determined the current density range for one–step plasma electrolytic oxidation of the VT1–0 alloy. Oxidation with mixed oxides produced coatings of different compositions and surface morphology. It has been shown that control over the chemical and phase compositions of coatings, the surface topography, and the grain size as well as incorporation of manganese oxides into a coating can be achieved by varying the concentration of the electrolyte and the oxidation parameters. Adding manganese sulfate to a pyrophosphate electrolyte has proved to be valuable for enhancing the content of the alloying component in the oxide layer and for reducing the concentrations of potassium and impurities. An increase in the current density of plasma electrolytic oxidation has been found to promote the formation of the oxide layer with a more developed surface area that is characterized by alternating torus–like inclusions and nanoporous sections. By studying the distribution of the content elements throughout the thickness of the oxide coating, it has been determined that manganese is uniformly distributed in the surface layer, but phosphorus is mainly located at the oxide–solution interface. It has been found that the synthesized mixed oxide coatings of manganese and titanium are highly resistant to abrasion. Incorporation of manganese has proved to reduce the grain size and improve the surface development, which facilitates catalytic activities in the oxidation reactions of carbon monoxide. The resulting materials can be used in process systems of catalytic purification.