Main Technological Parameters Research Articles

Biotechnology of groundwater purification for water supply systems, using Gallionella and Lepthothrix ferrobacteria

Aim. The aim of the study was to consider the possibility of using the consortia of chemolithoautotrophic ferrobacteria from Gallionella genus and heterotrophic bacteria from Lepthothrix genus for the biological method of groundwater purification. Methods. The photocolorimetric method to determine the concentrations of ammonium and iron ions, the titrimetric method to determine the hydrocarbon and total alkalinity, the method of determining the permanganate oxidizability using the Kubel method, the potentiometric method to determine the values of рН and Еh, the electronic microscopy using the X-ray spectral analysis of matrix structures of bio-minerals, microbiological and statistical methods. Results. The main technological parameters of the water deironing process were defined as follows: the filtration velocity of the bioreactor – 7–11 m/h, and of the filters – 3.5–5 m/h; the filter-cycle duration – 48 h. It was found that the application of the two-stage technology of biological deironing in the bioreactor and filters provided for the possible removal of Fe2+ compounds up to 5.0 mg/cdm, ammonium nitrogen — up to 1.5 mg/cdm, soluble organic substances by PO – up to 6.0 mg O2/cdm. It was determined that the optimal parameters for the process of biological purification of neutral groundwaters, containing increased concentrations of Fe2+ cations were as follows: рН 7.0–7.2; hydrocarbon alkalinity 2.5–2.2 mmol/cdm; content of soluble oxygen – 1.5–2.0 mg/cdm. The ability of concentrated (Dos 200 mg/cdm) matrix structures of Gallionella and Lepthothrix ferrobacteria to remove Cr6+ ions from natural groundwaters was determined. The study found no considerable differences in the efficiency of applying disinfectants, produced using polyhexamethylene guanidine chloride (PHMGchl) or polyhexamethylene biguanidine chloride (PHMBchl). In concentrations of 0.25–0.5 %, they effectively disinfect pathogenic microorganisms, including Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The same was found true for the bacteria, most common in the systems of technical reverse water supply, the systems of water circulation, plant watering, and fire tanks, including Aeromonas hydrophila, Aeromonas salmonicida, Pseudomonas sp., E. coli, Flavobacterium columnare, Micrococcus lysodeikticus. Conclusions. This was the first study on the possibility of applying the biotechnology of groundwater purification from excessive amounts of iron in conditions of uneven hydraulic burden, notable for the water supply systems of rural areas and most agricultural enterprises in the north-western and northern regions of Ukraine. The specificities and perspectives of PHMGchl application in the systems of water preparation were studied. It was found that from the standpoint of safety and efficiency, the use of the water deironing processes involving iron bacteria was reasonable in the systems of water consumption and technical water supply, and the disinfection of water using PHMG was possible only in the second case, due to some toxicity of the preparation. The optimal parameters for the process of biological purification of neutral groundwaters, containing increased concentrations of Fe2+ cations were determined.

Theoretical study of the working process of a multivariate cabbage harvester

BACKGROUND. A multi-variant cabbage harvester of a block-modular design is proposed for small-scale farming in vegetable growing. At the same time, it is planned to complete the cabbage harvester in three versions: with an elevator, with a lower longitudinal conveyor, with an elevator and an upper longitudinal conveyor. AIMS – modeling the working process of a multivariate cabbage harvester to identify its main technological parameters that ensure the efficiency of its operation. MATERIALS AND METHODS. The working process of a multivariate cabbage harvester is presented as the functioning of a certain physical system, the state of which changes during the technological process over time depending on stochastic factors. The process of sequential transition of a system from one state to another is considered on the basis of queuing theory depending on the intensity of movement of the flow of heads of cabbage λ in the technological line of the machine and the intensity of service μ of this flow. In this work, the limiting probabilities of the model states are determined and the stochastic indicators of its functioning are calculated. RESULTS AND DISCUSSION. Based on the results of calculations of stochastic indicators of the functioning of the model, the optimal number of service personnel people was established, when the maximum probability of servicing cabbage heads can be up to 0.934. CONCLUSIONS. The workflow of a multivariate cabbage harvester is modeled as a stationary stochastic queuing process. Based on the research results, it is recommended to take the number of service personnel at the combine refining table as .

TREATMENT OF COPPER FLUE DUST FROM FLASH FURNACE WASTE HEAT BOILER FOR IMPURITIES CONTROL

During the pyrometallurgical processing of copper sulphide raw materials, part of the charge leaves the furnace space together with the exhaust gases in the form of dust entrainment. Volatile components also pass into the dust-gas flow, due to which it is enriched with impurities, some of which are harmful to the technological process. The formed dust-gas flow passes through dust collection equipment, where the main part of it is captured. Most often, the captured dust is recirculated, which leads to a decrease in the productivity of the furnace unit and a gradual increase in the content of impurities in the condensed products of the smelting. To overcome these disadvantages, it is necessary to take part or all the recirculating dust out of the melting cycle and process it independently to extract the valuable metals and dispose of the harmful substances. In metallurgical practice, industrial application for the processing of recirculating dust entrainment has mainly been accomplished by hydrometallurgical methods based on treating the flue dust in aqueous solutions of acid or alkaline reagents. In the present research work, laboratory results on hydrometallurgical leaching of flue dust from a flash furnace waste heat boiler (FF-WHB) are presented. The effect of the main technological parameters affecting the degrees of recovery of the main metals in solution was studied. Based on the experimental results, the optimal conditionsfor hydrometallurgical treatment of the FF-WHB flue dust were determined. By treating the dust under optimal conditions, the main tasks of the research are achieved - removal of impurities harmful to the technological process and reduction of the amount of flue dust processed in the flash furnace.

Experiment Evaluation on the Porosity of Plasma Coating from Ceramic Al2O3 – TiO2 Using the Metallography

Background: The objective of this paper is an experimental investigation of the metallographic porosity of plasma coating using standard materials from the ceramic system Al2O3-TiO2 on the substrate of steel SS400 at laboratory scale Lab at the Research Institute of Mechanical Engineering. Contribution: The main contribution of the research is the evaluation of the porosity of the coating under the influence of the main technological parameters since the porosity plays a significant role in the performance of the working surface using the built-in Image Pro-Analyzer software in the Axiovert 25 MAT microscope. Method: The spraying material is Al2O3-TiO2 powder. The input parameters are: spraying distance (Lp; current of plasma stream (Ip); powder feed flow (Gp and spraying rate (Vp). Results: The findings show that the average porosity of the Al2O3-TiO2 plasma coating is inversely decreasing in the increasing direction of the distance: spray in the range Lp = 100–200 mm, increase proportional to the increase of the current plasma flow rate in the range Ip = 400–600 A, provided that the powder feed flow Gp = 1.7 kg/h and the spraying rate Vp = 50 mm/min. Conclusion: The degree of influence of the three main technological parameters (Lp, Ip, and Gp) in the survey limit domain may be due to the selected Lp spray distance within the relatively wide recommended range of the plasma spraying equipment supplier. It is recommended to conduct the experimental planning of the L27 type to localize the optimum area.

Glass frit and method of forming electrical insulating coatings on steel substrates of film heaters

Electric film heaters (EFHs) applied on flat steel substrates show promising potential in the production of heating devices. The basis for manufacturing EHFs is heat-resistant steel, the surface of which is coated with a heat-resistant electrical insulation coating. These coatings are glass crystalline and are applied mainly by screen printing. Compared to screen printing, the electrophoretic method of coating is more productive. In this work, glass in the MgO–CaO–B2O3–SiO2 oxide system was chosen for obtaining glass crystalline coatings. The paper provides a description of the material composition and the method used to prepare a suspension for еру electrophoretic deposition of coating. The main technological parameters for forming electrophoretic coatings with a specific thickness are determined based on experimental results. Utilizing calculated data on the properties of the selected glass, the study substantiates the most rational temperature and time regime for coating firing. These conditions promote crystallization and result in the production of heat-resistant coatings with sufficient electrical insulating properties for steel substrates of EFHs.

Влияние параметров плазменного упрочнения на качество поверхностного слоя тяжелонагруженных изделий

There has been studied the effect of the hardening current, the distance between the nozzle and the hardened surface of the product, the flow rate of the plasma-forming gas, the dependence of the cooling rate during plasma hardening on the speed of the plasma torch movement (treatment speed), and the diameter of the nozzle. Based on the theory of thermal processes, the cooling rates have been calculated for various values of the current strength. It has been shown that the ratings characterizing the significance of the main technological parameters of the plasma hardening mode for the depth and width of the hardened zone are practically the same. While the effect of the current strength on the dimensions (depth and width) of the plasma hardening zone significantly exceeds the effect of the other parameters of the hardening mode. This indicates that the arc current is the main controlled parameter of the plasma hardening process. There has been shown the possibility of regulating the mechanical properties of the hardened surface of the solid-rolled railway wheel rim depending on the required level of mechanical characteristics by means of controlling the speed of the wheelset.

A Review of Road Bitumen Modification Methods. Part 1 – Physical Modification

The information in this study is based on a thorough review of recent articles related to the production of binders for road construction and the improvement of their performance properties. The main attention is paid to the physical modification of road bitumen with polymer modifiers. The influence of the three main types of polymers (thermoplastics, elastomers, and thermoplastic elastomers) on the main physical and mechanical properties of bitumen-polymer compositions is shown. The main technological parameters and features of the physical modification of bitumen by different types of polymer modifiers have been determined.

Flow-through moisture meter for measuring grain moisture as part of an automated grain moisture control system

The methods of increasing the accuracy and efficiency of the production process, as well as ensuring high quality of final products in the grain processing industry, are investigated. It is shown that to solve the problem of insufficient quality control of grain materials, an automated system for monitoring the properties and characteristics of bulk granular materials is necessary. The features of the construction of automatic and automated systems for monitoring the properties and characteristics of bulk granular materials are considered. Measurement methods and control devices of the main technological parameters used in the management of grain processing facilities are briefly described. It is proposed to include a flow moisture meter in the automated grain moisture control system. The physical properties of grain and grain materials, measurement conditions and instrumentation for grain moisture control are analyzed. The use of devices based on the dielkometric method in the subsystem of an automated process control system is discussed. The application of intelligent sensors of a measuring system with a complex multilevel hierarchy is described. The structure of the interconnection of measuring devices for intellectual support of humidification processes and quality control of the studied materials is given. A functional diagram and metrological characteristics of a prototype grain moisture monitoring device, a flow moisture meter, are presented. The metrological characteristics of this device meet the requirements of the grain processing industry and allow it to be used as part of a humidity control system

Methodology for determining the design parameters of combined type plasma-chemical reactor for gasification of carbon-containing raw materials

The paper shows the advantages of combined type reactors for plasma-chemical allothermic processes of carbon-containing raw materials gasification. The methodology for determining the design parameters of combined type plasma-chemical reactor for gasification of carbon-containing raw materials is developed. Analytical dependences for determination of time and constructive parameters of the combined type plasma-chemical reactor are established. Dependences contain interrelation between the main technological parameters of the process of thermo-conversion of carbon-containing raw materials taking into account thermochemical reactions. Dependences of constructive parameters of reaction zone of combined type plasma-chemical reactor for steam plasma gasification of carbon-containing media are obtained. It is established that at steam gasification of carbon-containing raw materials with the maximum particle size of 150 microns and the temperature in the reaction zone of 5000 K the volume of the reaction zone depends on the productivity of carbon-containing raw materials, which has a significant effect on the design parameters of the reaction zone.

Development of the oil-contaminated wastewater treatment technology for trucking companies

Industrial activity of trucking companies belongs to environmentally dangerous processes, which leads to the pollution of natural ecosystems, both in local and regional scale. Currently, there are strict requirements for the quality of wastewater discharged from trucking companies and car-wash sites into the outer sewer or the storm water network. This erases the urgency of the installation of local treatment facilities and implementing of the water circulating supply systems with maximum water consumption and minimum discharge of wastewater into natural water bodies. The improved technology of wastewater treatment for the trucking companies with preliminary stage of the multilayer oil-trap treatment is presented. The modeling of sedimentation process of wastewater contaminated with petroleum products allowed determine structural parameters of the proposed oil trap. The main technological parameters of wastewater treatment according to the proposed technological scheme have been determined. Implementation of the proposed technology at the trucking company allows reduce the content of petroleum products and suspended solids according to Ukrainian normative standards for water quality. This improvement minimizes the impact of contaminated wastewater on neighboring water bodies and extends capacity for water reuse in the technological process of trucking companies.

Research on the extraction of rare earth elements from ash-slag waste

The research investigates the patterns of rare earth elements (REE) extraction from ash-slag waste of thermal power plants using sintering processes. The aim of the study was to determine the optimal parameters for the process: the composition of the flux, the ratio of the sintering flux to the waste, and the sintering temperature. It has been shown that the change in the type of sintering reagent, its ratio to the waste, and the process temperature significantly affect the degree of REE extraction from the insoluble form in ash-slag to the soluble form in sinter. The optimal sintering temperatures (300–4500C) for the extraction of REE from ash-slag waste have been determined. The influence of various sintering reagents on the process of REE extraction from ash-slag waste has been investigated. It has been shown that the use of sodium hydroxide as a sintering reagent allows increasing the degree of REE extraction from waste up to 100%. Based on the analysis of the obtained experimental data, the main technological parameters of REE extraction in sinter have been determined.

Evaluation of the activity of amine hardeners of epoxy resins

With the appearance of new epoxy resins and amines, which are widely used for hardening epoxy compositions using energy-saving technology (at "ordinary" temperatures), on the world market, the targeted selection of these materials to provide the desired technological and operational properties becomes relevant. In order to predictively choose amine hardeners for epoxy resins, their quantum-chemical calculations were performed using the semi-empirical parameterized 3 (PM3) method. The energy value of the highest occupied molecular orbital (HOMO) of amines and the absolute value of the energy gap || (the absolute difference in energies between the HOMO of amines and the lower vacant molecular orbital (LUMO) of epoxy resins) were used. The relationships between the absolute value of the energy gap || and the main technological parameters of the curing process of dian epoxy resin ED-20 with individual amines were established with pairwise correlation coefficients of not less than 0.977. The evaluation of the activity of modified polyamines and their mixtures in hardening epoxy resins is proposed to be carried out based on the maximum temperature of the exothermic reaction of interaction between the epoxy groups of resins and the amine groups of hardeners. The possibility of adjusting the temperature of the exothermic hardening reaction of epoxy compositions and their "viability" time by introducing epoxy-containing diluents with different values of the LUMO energy was shown.

Simulation and Optimization of Surface Roughness and Process Performance during Machining of HSS by Micro-WEDM Technology.

When machining high-speed steels (HSS) with micro-wire electrical discharge machining (micro-WEDM), high surface quality is achieved as standard. The value of the roughness parameter Ra is less than 0.2 μm. However, the problem is the performance of the electroerosion process (MRR), which is low. This problem is related to the mechanical and physical properties of the HSS in combination with the setting of the main technological parameters (MTP). The proposed solution to eliminate this problem relies on the selection of proper procedures for the determination of optimization criteria in relation to Ra and MTP, with the inclusion of properties of the machined material. The solution consisted in the identification of four significant physical (ρ, κ) and mechanical (Rm, HRC) indicators of HSS properties, on the basis of which a suitable combination of the process output parameters Ra and MRR can be determined through established mathematical regression models using simulation and optimization. In the next step, the proper values of the MTP output process parameter settings, which correspond to the optimized output parameters Ra and MRR during machining of HSS by micro-WEDM technology, were then obtained by the same approach.

Study of crucial factors for minimizing the roughness of chemical coatings with Ni – P and Ni – Cu – P alloys

The surface roughness of coatings has a significant impact on their functional properties and efficiency. We present the results of studying the effect of the main technological parameters on the roughness of chemical coatings with Ni – P and Ni – Cu – P alloys. The key factors affecting the roughness of coatings were determined by the Taguchi method. Parameters of the coating process were varied in the experiments: concentration of components in solution, pH, temperature, and the time of deposition. It is found that the surface roughness increases linearly with the thickness of coatings. The concentration of sodium hypophosphite and pH value have the greatest influence on the development of roughness. It is shown that the lowest roughness is observed at concentrations of sodium hypophosphite and copper salt 0.358 and 0.0012 mol/liter, pH 5.8 and temperature 90 °C. The rate of the surface roughness development for Ni – P and Ni – Cu – P coatings under optimal conditions is 0.68 and 0.97 %/μm (before optimization — 6.72 %/μm). The obtained results can be used to improve the methodology for reducing the roughness of coatings with Ni – P and Ni – Cu – P alloys and, accordingly, to improve the functionality, wear resistance and quality of coatings.

Valorization of wheat production in marginal areas: farmer-centric experimentation for variety choice and evolutionary population development

In Italy, from 2000 to 2010, 58% of farms in mountain areas were abandoned leading to a 33% decrease in available land for agriculture. This research aimed to restore value and competitiveness to the Apennine area, by proposing a balanced and sustainable agriculture model. Following the needs of farmers, underutilised cereals were selected as the ideal genetic material for the study and development of short local food supply chains. The field experiments were carried out in two organic farms located in the Emilia-Romagna Region (Italy). During two growing seasons, seven wheat genotypes, two wheat evolutionary populations and one einkorn mixture were cultivated under organic farming management. Results related to functional traits are presented along with the main agronomic and technological parameters that were determined. Several nutritional properties are included. Mean yield and stability performance over environments for each genotype were explored using the “Genotype and Genotype by Environment biplot” elaboration. Considering yield performances, “Benco” was closer to the ‘ideal’ genotype. All the results were evaluated with the farmers, who expressed their own preferences from field observations. The right coupling between environment and genotypes can discourage the abandonment of hilly and mountainous farms by enhancing the economic competitiveness of agriculture in these regions.

ВЛИЯНИЕ НА КАЧЕСТВО ПРОИЗВОДСТВА ШТУКАТУРНЫХ РАБОТ ПАРАМЕТРОВ РОБОТА-ШТУКАТУРА

The article considers the main aspects of studying the effective use of plastering machines and mixtures in construction through the use of automated and mechanized systems, units and robots. Theoretical aspect of the study of the process of plaster layer compaction with the help of a vibration platform of a robot plasterer with adjustable parameters. The main design and technological parameters of vibration compaction of the plaster layer and their influence on the efficiency of the process of compaction of vertical walls are revealed. The methods of experimental research are described, as well as experimental installations on which the laboratory experiment was carried out. The use of this technology allows to solve the problem of time costs and increase labor productivity indicators, as well as aspects of economic nature. When changing the physical and mechanical characteristics of the vibration platform its dependence of variation factors allows to form the most favorable conditions for the mechanical effect of vibrations on the efficiency of the process of plastering vertical walls. Plastering mixtures for obtaining a plaster layer are studied, the main physical and mechanical characteristics are analyzed, the requirements to be taken into account in the process of plastering are analyzed. The paper presents a comparison of physical and mechanical characteristics of the vibration platform, reveals the advantages and disadvantages of using different combinations of parameters. It is established that the use of a certain combination or change of one important parameter contributes to the increase of physical and mechanical characteristics in comparison with the traditional method of mechanical action.

Optimization of fuel and energy infrastructure for urban ground passenger transport system

Introduction. The influence of urban passenger transport on the formation of a comfortable urban environment is indicated. The role and place of the fuel and energy supply infrastructure as one of the subsystems in the urban ground passenger transport system is determined. The results of the review of scientific works in the field of designing the infrastructure of fuel and energy supply are presented. The insufficient degree of development of methodological support forming the integrated development of subsystems of urban passenger transport is noted. The purpose of the study is formulated, the tasks are defined, the solution of which ensures its achievement.Materials and methods. A brief description of the methodology for determining the main technological parameters of the fuel and energy infrastructure of the urban ground passenger transport system is presented. The sequence of use of the presented calculation formulas is determined, the main hypothesis underlying the research is described. The expected results are described.Results. As intermediate results of the conducted research, the data and functional dependencies obtained in the process of performing the research part of the work are presented. These data provide practical implementation of the developed methodology and allow modeling of the parameters of the projected infrastructure. The dependencies obtained as a result of modeling and which are the basis for the development of optimization measures are given. Discussion. It is noted that the logistics approach implemented in the development of the presented methods allows us to determine the design parameters of the fuel and energy infrastructure as one of the subsystems of urban passenger transport, which ensures the coordinated development of the system based on the conditions for achieving maximum efficiency.Conclusion. As a generalizing conclusion, it is noted that the practical implementation of the developed methodology within the framework of an integrated system approach makes it possible to achieve the set goal – to increase the efficiency of the urban ground passenger transport system.

Prediction of contact pressure during cold rolling of thin strips with predominance of front tension

The results of theoretical studies of the average relative contact stress during cold rolling of thin steel strips with a predominance of front tension are presented. The transition from symmetric to the asymmetric tension mode helps to reduce the contact stress by 6.4...13.5 %. This makes it possible to increase the service life of rolling rolls. A regression equation is obtained for predicting of the average relative contact stress for the studied range of change in the main technological parameters.

Расчет поливной нормы при капельном орошении древесно-плодовых культур в садовых насаждениях

Purpose: to develop the methodology for calculating irrigation rate for drip irrigation of tree-fruit crops, ensuring the formation of moistened soil contours in soil space with the required geometric and moisture parameters. Materials and methods. The empirical basis for the methodology development was the materials of the author's research devoted to determining the geometric dimensions (parameters) of soil moisture contours. The working hypothesis of the study involved determining the water supply rate for one emitter, one tree-fruit plant and a number of crops in the plantation, with further determining drip irrigation rate per unit area of drip-irrigated agricultural land, taking into account the number of drip micro-water outlets located on it. Results and discussion. When determining the geometric parameters of moisture contours and water supply rate, the main soil and technological parameters of drip irrigation and contour formation (physical clay content in soil, its lowest moisture capacity and bulk density, levels of pre-irrigation and after-irrigation soil moisture, specified depth soil profile moistening and dripper consumption) were considered as influence factors. The dependencies obtained by the author make it possible to determine the linear, areal and volumetric dimensions of local moisture contours and water supply rate, which, under appropriate conditions of drip irrigation, ensures the formation of a local, initially formed moisture contour with the required soil wetting depth in the soil layer. A study of the proposed methodology showed a deviation of the predicted parameters from the experimental soil moisture contours within ±10.0 %. Conclusions. A methodology allowing determining the irrigation rate for drip irrigation of agricultural land as the sum of the water supply rates of all drip water outlets irrigating 1 hectare of agricultural land with practical accuracy has been developed.

Расчет поливной нормы при капельном орошении древесно-плодовых культур в садовых насаждениях

Purpose: to develop the methodology for calculating irrigation rate for drip irrigation of tree-fruit crops, ensuring the formation of moistened soil contours in soil space with the required geometric and moisture parameters. Materials and methods. The empirical basis for the methodology development was the materials of the author's research devoted to determining the geometric dimensions (parameters) of soil moisture contours. The working hypothesis of the study involved determining the water supply rate for one emitter, one tree-fruit plant and a number of crops in the plantation, with further determining drip irrigation rate per unit area of drip-irrigated agricultural land, taking into account the number of drip micro-water outlets located on it. Results and discussion. When determining the geometric parameters of moisture contours and water supply rate, the main soil and technological parameters of drip irrigation and contour formation (physical clay content in soil, its lowest moisture capacity and bulk density, levels of pre-irrigation and after-irrigation soil moisture, specified depth soil profile moistening and dripper consumption) were considered as influence factors. The dependencies obtained by the author make it possible to determine the linear, areal and volumetric dimensions of local moisture contours and water supply rate, which, under appropriate conditions of drip irrigation, ensures the formation of a local, initially formed moisture contour with the required soil wetting depth in the soil layer. A study of the proposed methodology showed a deviation of the predicted parameters from the experimental soil moisture contours within ±10.0 %. Conclusions. A methodology allowing determining the irrigation rate for drip irrigation of agricultural land as the sum of the water supply rates of all drip water outlets irrigating 1 hectare of agricultural land with practical accuracy has been developed.