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This paper reports the generalized results of computer simulation of physical processes at a rotor-disk film evaporating plant. Optimization of the operation mode cannot be achieved without establishing patterns in the course of physical processes. We have proposed a computer model of hydrodynamics that accounts for all the features, initial and boundary conditions. The results of computer simulations make it possible to adequately assess the effectiveness of using a rotor-disk film evaporating plant (RDFVP) for the concentration of heat-labile materials. We have established patterns in the course of physical processes within a structure of RDFVP by using computer simulation of hydrodynamics in the programming environment ANSYS and applying a k-e turbulence model. The result of simulation is the derived velocity fields of the concentrated fluid (w max =0.413 m/s) and the gas phase (w max =8.176 m/s), as well as the magnitude of values for shear stress τ=0.94·10 -6 Pa. It was established that the gas heat-carrier is characterized by the highly-turbulent flows with maximum values for kinetic energy TKE max =8.985·10 -1 m 2 /s 2 . The reliability of results is ensured by the correctness, completeness, and adequacy of physical assumptions when stating the problem and while solving it using the computer aided design system ANSYS. It has been established that the proposed structure is an effective alternative to equipment for the concentration of solutions. The data obtained could be used when designing heat-and-mass-exchange equipment for the highly efficient dehydration of thermolabile materials

The problems of environmental pollution in the conditions of high dust content in the air during the development of coal mines in the territory of the Czech Republic are considered. A mechanism for making managerial decisions was developed using an integrated approach using the new technological process Nastup Tušimice (DNT) aimed at eliminating pollutant emissions and managing workers in dusty conditions in mining operations. The recommendations of active and passive measures aimed at reducing dustiness in the process of coal mining have also been developed.

Bridges in Ukraine are one of the most important components of the infrastructure, requiring attention from government agencies and constant funding. The object of the study was the methodology for quantifying the condition of bridge components. The Artificial Neural Network-based (ANN) tool was developed to quantify the technical condition of bridge components. The literature analysis showed that in most cases the datasets were obtained during the inspection of bridges to solve the problems of assessing the current technical condition. The lack of such a database prompted the creation of a dataset on the basis of the Classification Tables of the Operating Conditions of the Bridge Components (CT). Based on CTs, five datasets were formed to assess the condition of the bridge components: bridge span, bridge deck, pier caps beam, piers and abutments, approaches. The next step of this study was creating, training, validating and testing ANN models. The network with ADAM loss function and softmax activation showed the best results. The optimal values of MAPE and R2 were achieved at the 100th epoch with 64 neurons in the hidden layer and were equal to 0.1% and 0.99998, respectively. The practical application of the ANN models was carried out on the most common type of bridge in Ukraine, namely, a road beam bridge of small length, made of precast concrete. The novelty of this study consists of the development of a tool based on the use of ANN model, and the proposal to modify the methodology for quantifying the condition of bridge components. This will allow minimizing the uncertainties associated with the subjective judgments of experts, as well as increasing the accuracy of the assessment.

AbstractThe presented synthesis of the title compounds (II), (IV), (VI) and (VIII) is extremely simple and highly efficient without the use of any chromatographic purification.

Micro hydro power plants (µHPP) are typically used to supply electric energy to microgrids outside the national power grids taking care of the frequency control of the isolated system. A conventional way to maintain the load balance in the system is to use thyristor switched AC-AC converters controlled dump loads. A disadvantage of the AC-AC converters is their reactive power consumption decreasing the power factor at the generator output. To avoid this problem the authors have earlier proposed two converter topologies utilizing symmetrical switching scheme resulting to zero reactive power consumption. The objective of this paper is to evaluate the frequency regulation loop performance of the dump load controlled single generator system by using the symmetrically switched converter structures. Evaluation is carried out by analyzing the performances of different converter structures in a simulator representing the operation of a Cuban µHPP “Los Gallegos”. The results showed that the frequency regulation loop performance using each proposed converter structure satisfied the Cuban standard of frequency regulation, but with the symmetrically switched structures reactive power consumption was reduced resulting to reduced losses and improved effective current delivery capacity of the generator.

Nail polish, in particular gel nail polish, is the most used cosmetic product. The components of the gel polish, which determine both toxicity and consumer color properties, are pigments. Zn-Al layered double hydroxides intercalated with anionic food dyes are promising pigments for use in gel polish. The parameters of the samples of Orange Yellow S-intercalated Zn-Al (Zn:Al=4:1 and Zn:Al=2:1) hydroxides synthesized at pH=8 and pH=11 were studied. The crystal structure of the samples was studied by X-ray phase analysis and thermogravimetry, and the pigment properties – by the method of measuring and calculating color characteristics in the CIELab and XYZ systems. The color characteristics of gel nail polish samples prepared using synthesized pigments were studied in a similar way. X-ray phase analysis and thermogravimetry showed that Zn-Al-Orange Yellow S pigments synthesized at both Zn:Al ratios and pH were layered double hydroxides with the α-Zn(OH) 2 structure. The phenomenon of the decomposition of Zn-Al LDH to ZnO during the synthesis was revealed. As a result, all Zn-Al-Orange Yellow S pigment samples contained both layered double hydroxide and zinc oxide. It was shown that all samples of the Zn-Al-Orange Yellow S pigment obtained at pH 8 and 11 and the ratios Zn:Al=4:1 and Zn:Al=2:1 had high pigment characteristics and are promising for use in gel polish. The samples of gel nail polish with synthesized pigments have a red-orange color (сolor tone 595–604 nm) with high monochromaticity (color purity 63–75 %) and color saturation (48.7–58.3)

Sugarcane biorefineries, despite their contribution to sustainable transportation fuels and mitigation of carbon emissions in the mobility sector, produce a large amount of carbon dioxide in their conversion processes. According to the Paris climate agreement, a carbon neutral energy system has to be launched in the years to come, and in this scenario, greenhouse gases emission free industrial processes and alternative carbon sources will be needed. Therefore, this paper presents the evaluation of carbon mass balance of a typical Brazilian ethanol mill to better understand its potential for energy and carbon yield improvement. Due to the fact that Brazilian sugarcane mills are evolving from first generation to integrated first and second generation plant, four different scenarios were analysed. For a first generation plant without (S-I) and with conversion of straw to electricity (S-II) and for the integrated plant (S-III), results of carbon mass balance showed that the harvested sugarcane carbon was mainly converted into CO2 and in a smaller proportion into ethanol. In the modelled cases S-I to S-III the conversion of sugarcane carbon into CO2 and ethanol ranged from 41% to 53% and 17%-22%, respectively. Because this carbon amount in the CO2 flows provides an interesting platform to both increase the bioenergy produced and the harvested carbon-to-fuels ratio, a fourth scenario (S-IV) that studies the integration of power-to-gas (PtG) technologies into the mill was also considered. PtG can increase the sugarcane fuels energy content from 9.3 kW/ha to 33.6 kW/ha using 1361.3 MWe of electricity, increasing the amount of sugarcane carbon transformed into sugarcane based fuels to 54% and converting CO2 into a high value added product.