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Date submitted2022-03-22
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Date accepted2022-11-17
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Date published2023-02-27
Development of composition and study of sorbent properties based on saponite
The development of a comprehensive approach to preventing the pollution of natural objects is necessary due to the high requirements of environmental legislation for the discharge of industrial wastewater. Adsorbents are used in various industries to extract heavy metals from wastewater. In this study the possibility of using saponite clay as a raw material for the production of sorbent for the extraction of copper ions Cu 2+ from industrial wastewater is considered, a recipe and technology of sorbent production are developed, and its chemical composition is established. It has been established that the optimum temperature for heat treatment of the sorbent and corresponds to 550 ºC, since at this temperature saponite extrudates acquire strength (strength 34.1 kg/mm 2 ) and textural properties (specific surface area of pellets 22.803 m 2 /g), allowing them to be used as sorbents. The kinetics of molecular adsorption was studied using model solutions of copper (II) sulfate. The extraction efficiency of copper (II) ions from the model solutions is 93 %. Extraction efficiency of copper (II) ions from copper plating wastewater reaches 94 %. SEM results confirm the presence of metal on the sorbent surface.
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Date submitted2022-03-14
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Date accepted2022-06-20
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Date published2022-11-10
Model of a walking sampler for research of the bottom surface in the subglacial lake Vostok
Technologies and technical means for investigation of subglacial lakes in Antarctic is a new developing scientific and technical direction, which today has no clearly established methodology. Based on the developed technology of drilling a new access well to lake Vostok and its penetration as well as analysis of existing methods and devices for bottom sediment sampling, a basic model of a sampler with a walking-type mover, capable of moving along different trajectories and operating in a wide technological range, is proposed. The proposed device model is equipped with different actuators for sampling the bottom surface with different physical and mechanical properties. Based on the presented basic model of the walking sampler, a mathematical model of the device was developed, which was based on the theoretical mechanics methods. As a result of conducted research the dependencies were obtained, which allow making a scientifically justified choice of optimal values for geometric and force parameters of the walking sampler. A conceptual design of the walking sampler has been developed, taking into account the mutual location and coupling of its main components, the overall dimensions of the delivery tool, as well as the esthetic component of the device.
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Date submitted2022-03-17
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Date accepted2022-10-04
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Date published2022-11-10
Improving the reliability of 3D modelling of a landslide slope based on engineering geophysics data
Landslides are among the most dangerous geological processes, posing a threat to all engineering structures. In order to assess the stability of slopes, complex engineering surveys are used, the results of which are necessary to perform computations of the stability of soil masses and assess the risks of landslide development. The results of integ-rated geological and geophysical studies of a typical landslide slope in the North-Western Caucasus spurs, composed of clayey soils, are presented. The purpose of the work is to increase the reliability of assessing the stability of a landslide mass by constructing a 3D model of the slope, including its main structural elements, identified using modern methods of engineering geophysics. Accounting for geophysical data in the formation of the computed 3D model of the slope made it possible to identify important structural elements of the landslide, which significantly affected the correct computation of its stability.
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Date submitted2021-04-23
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Date accepted2021-09-07
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Date published2021-12-16
Development of the concept of an innovative laboratory installation for the study of dust-forming surfaces
Currently, the determination of the emission rate of suspended solids from a unit of the surface area of a man-made mass at various parameters of the wind flow is not sufficiently described. The analysis of the world experience of researchers shows that existing laboratory installations have various design features that do not allow to correctly determine the mass of the dust being flapped and wind-blown. Based on the analysis results, the concept of an innovative laboratory installation for the study of dust-forming surfaces has been developed. It takes into account the influence of wind shadows, the deturbulization of an artificially created air flow, the possibility of regulating not only the flow velocity mode, but also the creation of a vacuum or disturbance in the area of sample placement, as well as the formation of a certain angle of wind flow attack relative to the surface. The concept provides for the possibility of determining the volume of dust emissions by the values of the lost dust masses in the sample and by the values of dust concentrations in the outgoing stream. The calculation of the main basic elements of the installation using the ANSYS FLUENT software package was carried out. The model and configuration of the wind tunnel have been developed and calculated, the main geometric parameters and functional elements for the possibility of use in scientific work have been determined. For practical use of the empirical roughness value of the underlying surface, its values are recommended in a wide range – from zero for the water surface to 0.44 for large cities with tall buildings and skyscrapers.
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Date submitted2020-05-18
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Date accepted2020-06-16
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Date published2021-04-26
Traction asynchronous electric drive of mine electric locomotivesimulation model structure improvement
The article discusses the solution to the problem of underground railway transport slipping in dynamic modes, which occurs when there is a significant difference in the speeds of the driving and driven pairs of wheels. The state of the rail surfaces largely determines the coefficient of adhesion, therefore, using a mathematical model, the condition for the dependence of the magnitude of slipping and tractive effort is selected. For effective acceleration and deceleration of an electric locomotive, it is necessary to control the coefficient of adhesion at a certain level. A simulation model of rolling stock has been created, which for the first time takes into account a mechanical system with distributed parameters. In the structural diagram of the automatic control system of traction electric drives with frequency regulation, such factors as the volume of goods being moved, rolling friction, slope (rise) levels and the state of the rail track are taken into account. The simulation results show the features of the movement and stops of the freight train not only by the diagrams of speed and forces in the modes of acceleration-deceleration and uniform movement, but also the positions of the plungers and tractive forces on the couplings of the electric locomotive and all trolleys involved in the movement of goods. The practical application of the proposed method lies in the possibility of starting a heavily laden train from its place on the ascent section in conditions of insufficient adhesion coefficient with contaminated roads.
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Date submitted2018-09-08
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Date accepted2018-10-27
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Date published2019-02-22
Special strategy of treatment of difficulty-profile conical screw surfaces of single-screw compressors working bodies
- Authors:
- A. S. Vasilev
- A. A. Goncharov
The article deals with the problems arising during the shaping of complex profile tapered helical surfaces. These surfaces form the geometry of the working bodies of single-screw miniature compressors, which have great prospects for use in mobile miniature compressor plants, which is especially important for medical and space technology, robotics, oil and gas and mining industries. Due to the fact that the capabilities of existing CAD systems do not allow obtaining three-dimensional models of these surfaces, the problem of preparing a control program for a CNC machine arises, since the calculation of the tool path in CAM systems when processing complex surfaces is impossible without a three-dimensional surface model. To solve the problem, an automated programming system was developed that implements a formalized toolpath calculation in accordance with the proposed special processing strategy for conical helical surfaces. As the initial data for calculating the toolpath, the system needs information about the tool geometry and the helical surface in a parametric form, which makes it possible to abandon the construction of a three-dimensional surface model. The results of processing prototypes for the proposed strategy are given.
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Date submitted2009-08-03
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Date accepted2009-10-30
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Date published2010-02-01
Geotechnical engineering features of the estimation of stability of heavy constructions of designed cement works in Novorossiysk
- Authors:
- Yu. V. Khaliullina
In the paper possibilities of constructing industrial heavy structures near slopes are described. The influence of tectonics, seismicity, a relief, deposit rocks thicknesses, their physical properties of geotechnical engineering feature are analyzed. The law of marls durability change is established. Positions of the most probable surfaces of sliding in cracked monoclonal deposit thickness are shown. The estimation of stability of the loaded slopes is made. Some recommendations for maintenance of structure stability are given.
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Date submitted2009-07-20
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Date accepted2009-09-20
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Date published2010-04-22
Problematic aspects in rock movement
The paper considers the existing standards in the field of rock movement and protection of engineer constructions from harmful influence of mining operations. It is emphasized the necessity in revision of some standards in compliance with the real mining production.