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The paper presents two methods for identifying microstructural heterogeneities on the surface of OFAM-K and OPMN-P nanofiltration membranes. Optical microscopy in combination with the AutoCad 2016 computer-aided design system and standard Microsoft Excel 2010 tools allows one to investigate microstructural heterogeneities of initial samples of OPMN-P and OFAM-K nanofiltration membranes. A method that enables the automated calculation of the average diameter of the fouling of semi-permeable membranes and the fouling coefficient of porous bodies is also developed. Using the capabilities of the Matlab 2017 software package, the application of modern tools to accomplish the set goal of the work is shown. Practical implementation of the method is exemplified by the nanofiltration process with semi-permeable polymer membranes of OFAM-K and OPMN-P types. The automated method combining optical microscopy studies, Otsu image processing, and software implementation in Matlab 2017 and optical microscopy in combination with the AutoCad 2016 computer-aided design system and standard Microsoft Excel 2010 tools, which more accurately reveals the structural heterogeneities of OFAM-K and OPMN-P nanofiltration membranes, are compared.

Electrochemical and transport characteristics of systems equipped with OPMN-P and OFAM-K membranes during operation in electronanofiltration cell are studied experimentally. The reasons for changes in the characteristics of membrane systems under the influence of various factors in the process of electronanofiltration of solutions that simulate the ionic composition of the ammonium-nitrate- and potassium-sulfate-containing solutions from electroplating and mineral fertilizers production, as well as the process media of the Livshits АО ТАGAT electroplating plant, are revealed. The change in the local conductivity of the solution in the intermembrane channel and, as a consequence, the increase in current density at the studied solution electronanofiltration is shown to be connected with the flow restriction in the electrochemical cell and the solution heating. Analysis of the systems’ electrochemical characteristics during the electronanofiltration the galvanic-production process media gave the degradation range of the OPMN-P semi-permeable membrane active layer (15–30 V) because of surplus of the operation range certified value pH > 12. Improving of the transport characteristics of membrane systems during electronanofiltration of aqueous solutions (ammonium nitrate, and potassium sulfate) is associated with the increase in the pressure differential. Increase of the voltage in the electronanofiltration cell leads to decrease in the outlet flow for the near-anodic membrane OFAM-K and increase in the outlet flow for the near-cathoduc membrane OPMN-P. This is associated with the displacement of the pH value of the near-anodic permeate toward acidic environment; of the near-cathodic permeate, toward alkaline environment. It is found that during the electronanofiltration of the electroplating process media the surface of the near-cathodic membrane OPMN-P is coated with the Fe(OH)2 and Fe(OH)3 precipitates due to supersaturation. The precipitates act as an absorber of Zn2+, [Zn(OH)4]2–, and other ions at a constant pressure differential P = 1.6 MPa, which leads to the dynamic membrane formation. Empirical equations for the calculating of the specific outlet flux and the retention coefficient are proposed basing on the analysis of experimental data obtained during the membrane separation of the studied solutions under the action of the pressure differential and voltage.

A design of a tubular electrobaromembrane apparatus for cleaning industrial solutions of chemical plants is developed. An optimized version of the apparatus with an effective solution separating area is presented and the volume of the body components and the mass of the body are calculated. The economic merits of the materials for fabrication of the apparatus for electrobaromembrane and baromembrane separation are compared. The merits of the developed apparatus design are enlarged solution separation area, increased throughput, improved solution separation quality, and reduced material content per unit volume of the apparatus.

Experimental studies and analysis of the effect of transmembrane pressure on the composite porous film material of OFAM-K, OPMN-P membranes and their components by differential scanning calorimetry (DSC), X-ray diffraction analysis and optical microscopy are presented. Investigations of nanofiltration composite materials by differential scanning calorimetry make it possible to study thermal effects that cause changes in the structure and phase transformations with increasing temperature in the membrane sample. X-ray diffraction analysis of the crystalline and amorphous regions of composite films using the radial distribution function allow the change in the unit cells in the membrane polymer sample due to an increase in the interatomic distances to be established. The crystallinity in a membrane sample exposed to transmembrane pressure increases from 44 to 55% due to the appearance of an additional crystalline phase in the film. Optical microscopy studies of the membrane substrate show a morphological feature that resembles fiber compaction, as well as the presence of microscopic voids, which can ultimately be explained by the presence of more knitted fibers in some areas of the membrane.

An efficient design of the flat-chamber-type electrobaromembrane apparatus was developed and based on it a calculation method that allows to determine the total working area of the membranes, the useful area of the near-cathode, near-anode membranes and the volume of the solution to be separated per unit volume of the developed apparatus.

A design is proposed for an electrobaric membrane system of coil type for use in the separation of solutions. The effective total working area of the membranes is calculated. The volume of solution that may be separated by the refined system here proposed is compared with that for the prototype system (described in the literature).

The article describes a method for calculating the heating temperature of the automobile brake disc. The brake disc is considered as a finite set of "cells" located in several layers. In thermal calculation, according to the proposed method, the heating of the disk surface is taken into account not only from the absorption of the vehicle kinetic energy, but also from the generated electric currents that cause micro-explosions between the irregularities of the disk surface and the brake pads. The cooling of the disk during the time between braking due to heat exchange with air is also taken into account. This method provides the ability to calculate the temperature of the brake disc, both on its surface and inside.

The article provides substantiation for the possibility of diagnozing latent damage to car tyres by comparing the average value of the static tyre rate at different points. The degree of uneven static stiffness of the tyre along its circumference was estimated by the size of the tyre contact spot with the support surface. An original method for approximate determination of the tyre spot area contacting with the supporting surface is proposed. The results of determining the area of the tyre contact spot at various points with several values of air pressure in the tyre are presented.

The design of a tubular-type electrobaromembrane apparatus for cleaning process solutions of chemical plants is developed. The principle of operation of the apparatus is explained and the volume of the solution separation chambers is calculated. The merits of the developed design are increased rate of near-anode and near-cathode permeate removal and reduced permeate heating temperature and absence of stagnant zones in the permeate withdrawal path.

A flat-chamber type of electrobaromembrane separation equipment is designed. A method is developed to calculate the effective separation area of the equipment that enables determination of the total performing area of the membranes for separating solutions and the usable area of cathode- and anode-adjoining membranes.

A flat-chamber electrobaromembrane apparatus with improved design and technological characteristics for wastewater treatment and differentiated ion extraction from industrial water systems was developed. A method allowing the total working area of the anodic and cathodic membranes, the sizes of the anodic and cathodic outlet flows, and other parameters of the membrane process to be calculated was presented. The design and technological parameters of the chamber and electrobaromembrane apparatus as a whole were calculated.

In this work, experimental data on the rejection coefficient and the specific output flux are obtained. Based on the studies, graphical dependencies of the rejection coefficient on the specific output flux were constructed and analyzed. During the analysis, it was noted that with an increase in the output specific flow of the solvent, the rejection coefficient decreases. The reason for this is the boundary layers of fat and protein formed in the near-membrane layers, which prevents the passage of protein molecules through the pores of the membrane. For the theoretical calculation of the rejection coefficient and specific output flux, mathematical expressions are developed and numerical values of the values of empirical coefficients are obtained. The developed mathematical expressions describe the experimental data with good confidence. The obtained experimental and calculated data can be used with great reliability in the calculations of mass-transported flows of substances through semipermeable membranes, as well as in engineering methods for calculating and predicting the effectiveness of the use of membrane processes for the concentration of whey.

We present the results of a large series of experiments aimed at the study of laws of damage accumulation and fracture in highly filled polymer materials under loading conditions of various types: monotone, repeated, low- and high-cycle, with varying type of stress state, dynamic (in general, more than 50 programs implemented on specimens from one lot of material). The data obtained in these test allow one to make conclusions about the constitutive role of the attained maximum of strain intensity when estimating the accumulated damage in the process of uniaxial tension by various programs (in particular, an additional cyclic deformation below the preliminary attained strain maximum does not affect the limit values of strain and stress in the subsequent active extension), about the strong influence of the stress state on the deformation and fracture, about the specific features of the nonlinear behavior of the material under the shock loading conditions and its influence on the repeated deformation.

Determination of mechanical characteristics of filled polymer materials in shock wave processes is of interest in calculations of the strength of these materials. The standard computation methods are based on the use of the linear theory of viscoelasticity, where there is no distinction between the active and passive deformation processes. In the present paper, dynamical experiment and theoretical modeling are used to illustrate the important role played by the sharp decrease in the resistance of a filled polymer material in unloading (in the millisecond time range). The higher the degree of filling of this material, the more significant this effect is.

We study composite polymer materials with a high degree of dispersion filling (several tens of percent in volume). A tensor generalization of the previously developed variant of the geroendochronic theory of viscoelastic materials is obtained, which allows us to pose and solve initialboundary value problems using this model. A numerical solution algorithm is proposed, which is realized as the UMAT subroutine for the ABAQUS finite element software package.

Material fracture experiments on specimens and structures testify that materials can resist greater stresses in local stress concentration regions than in regions with a nearly homogeneous stress state. Taking this fact into account in design stress analysis permits one to reveal additional structure loading and/or service life margins. One approach aimed at taking into account the increased strength in local stress concentration regions is to use averaged limit characteristics parametrically depending on the characteristic size L of the averaging region. One version of this approach is the concept of “elementary block” of a material [1, 2]. The averaged limit characteristics are determined by an experiment-calculation method involving the analysis of the stress-strain state of a material specimen with a stress concentrator at the time when the specimen attains the limit state preceding macrofracture. In [3], the dependence of the averaged limit separation stresses on the size of the averaging region was determined on the basis of numerical analysis of the singular stress state of the specimen used to determine the standard characteristics of the adhesion strength of a filled polymer material. In the present paper, we generalize the above approach to the case of a viscoelastic material. For the limit characteristics of the material in the local stress concentration region we take the volume-averaged components of the specific work of internal forces [4, 5] (the averaged specific absorbed energy and the averaged specific instantaneously reversible energy). The introduction of two limit energies originates from the fact that, to initiate the process of macrofracture, it is necessary to satisfy the following two conditions simultaneously: the material must be “damaged” sufficiently strongly by the preceding loading, and the “damaged” material must be loaded sufficiently strongly. As an example of determining the material averaged limit energy characteristics in a local stress concentration region, we consider the problem about the strain of a viscoelastic specimen used to determine the standard adhesion strength characteristics. The problem is solved numerically under the following assumptions: the specimen material is assumed to be linearly viscoelastic, and the specific absorbed energy in the stress concentration region is assumed to coincide in magnitude with the specific scattered energy. To estimate the accuracy of the numerical method, we use the solution of the model problem about the action of a plane circular die on a half-space consisting of a linearly viscoelastic incompressible material.