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A new method of electroprometry has been proposed that allows continuous investigation of extended sections of a hollow fiber membrane. Samples of polysulfone hollow fiber membranes with different porous structures were obtained: finger-shaped and spongy. These membranes were examined on a laboratory electroprometric apparatus with continuous scanning along the length of the hollow fiber membrane sample at a high voltage of 15 kV. Defects were detected in these hollow fiber membranes by the proposed method of electroporometry, the nature of which was then investigated using scanning electron microscopy. A correlation was found between the size of the detected defect and the magnitude of the corona discharge current signal: the larger the defect, the greater the absolute value of the current. It is shown that the proposed method can be effectively used as an express method to study the homogeneity of the porous structure of hollow fiber membranes in extended areas with geometrical localization of possible defects.

Background: At present, the diagnosis of lymphoproliferative disorders is based on the combination of blood or bone marrow smear morphology and immunophenotyping by flow cytometry. Immunophenotypic testing by flow cytometry technique is available only in big medical centers, which is not always convenient for a patient. Therefore, development of an available method for preliminary diagnosis of lymphoproliferative diseases not requiring special equipment seems relevant.Materials and methods: Peripheral blood mononuclear cells from 17 patients admitted to the hospital with suspicion of a lymphoproliferative disorder, and 17 healthy donors were studied on a cell biochip for determination of proportions of cells positive for various surface CD antigens. The diagnosis was verified by flow cytometry.Results: Compared to healthy controls and patients with T-cell lymphoproliferative disorders (TCLPD), the patients with B-cell lymphoproliferative disorders (BCLPD) had significantly lower proportion of CD7+ cells (medians, 7% and 73% respectively, p=2×10-6 for comparison with healthy controls; median 7% and 93% for comparison with TCLPD, p=0.032). In addition, the patients with BCLPD had higher proportion of peripheral СD19+ mononuclear cells, compared to that in the patients with TCLPD and healthy donors (medians 84% and 13% for comparison between BCLPD and healthy control, p=2×10-5; 84% and 3% for comparison of BCLPD and TCLPD, p=0.033). The patients with B-cell chronic lymphocytic leukemia had significantly higher CD5+ cells in the cell biochip compared to the patients with other BCLPD (medians 72% and 9%, p=0.024). The patients with TCLPD had significantly lower proportion of CD19+ cells than the healthy controls (medians, 3% and 13%, respectively, р=0.042).Conclusion: The study has demonstrated the potential to use the previously developed cell biochip for diagnosis of lymphoproliferative diseases. The biochip makes it possible to sort out white blood cells according to their surface differentiation antigen for their further morphological analysis. The cell biochip allows for the differential diagnosis between BCLPD and TCLPD and determination the lymphocyte clones based on the expression of immunoglobulin light chains.

The most important information for the practical use of flexible-chain polymers is the change in structure in the presence of external influences. A conformational model for calculating the mean square of the dipole moment of a macromolecule is constructed in this work, provided that there is no correlation between the conformations of monomer units in a heterogeneous temperature field.

The design and dimensional characteristics of the spinneret affect not only the geometry of the hollow fiber, but also the transport properties of the hollow fiber membranes. In the literature available today, there is a limited number of works in which the influence of the design and dimensional characteristics of the spinneret is studied. In this work, using the example of polysulfone hollow fiber membranes, it was shown that the use of a spinneret with smaller annular diameters leads to an increase in the gas permeability of the hollow fiber membrane with a decrease in the value of the ideal selectivity for the He/CO2 gas pair. It was found that using the spinneret with large annular diameters, the hollow fiber membrane is obtained with a smaller value of the average pore size of the flow, which is in agreement with the obtained data on gas permeability.

An important practical and fundamental problem in the production of porous polymer membranes is the study of the porous structure and the detection of "defects" or large pores in the area of ​​the membrane. Known porosimetry methods cannot solve this problem. This work proposes a new non-destructive express method for studying the porous structure of asymmetric polymer membranes in high-intensity electric fields. This method can be successfully implemented on both flat sheet and hollow fiber membranes with a known porous structure. On the example of hollow fiber membranes made of polyacrylonitrile and polysulfone an assessment of the chemical structure effect of the membrane material on the high-voltage discharge currents in a highly inhomogeneous electric field through hollow fiber membranes with a given pore size was made. Under normal conditions and an average intensity of an inhomogeneous electric field E = 5 kV/cm, the results obtained allow us to conclude about a certain practical potential of the developed express method.

In the article, within the framework of the conformational approach, the problem of averaging the square of vector quantities of complex polymers is presented. This approach is based on determining the average values of the square of the dipole moment for the µ-th monomeric unit of the chain, which is a unique parameter of the supramolecular structure of the polymer, depending on the product of the rotation matrices. A generalization of the matrix method of averaging the product of several tensor quantities over possible conformations within the entire macromolecule is considered.

In the work, the methods of formalized modeling assessed the profitability of a possible Internet resource. The model makes it possible to carry out by public means (using spreadsheets) a comprehensive analysis of profits, taking into account possible competitors and their production volumes, demand for products, and to form a plan for the sale of products. The model clearly demonstrates the possibilities of a systematic approach in solving problems of financing Internet resources.

The paper analyzes the change in the entropy production of an open thermodynamic forest ecosystem, in which processes associated with the entry of a negative entropy flow into it can be realized. Using the example of computer modeling of the dynamics of effective specific entropy production for a single-pedigree stand, it is shown for the first time that the specific entropy production as a function of time corresponds to the Prigogine-Glensdorf principle, and the time to reach a stationary state coincides with experimental values from forestry tables.

The paper considers the "observer effect" on the example of an analysis of the results of an experiment to determine the power of emission bands by hydrogen, helium and argon atoms by different experimenters using the same equipment. To obtain atomic spectra, a gas discharge tube and a universal UM-2 monochromator have used. The results of the work performed showed that, in accordance with the chosen estimation technique, the magnitude of the radiation power is largely determined by the accuracy of measuring the bandwidth, which varies greatly among observers.

In Lake Amut (the Verkhnyaya Angara drainage basin) the third population of Arctic charr Salvelinus alpinus (L.) in Baikal basin was found, a presumed invader from the Lena basin; besides, one more representative of Lena ichthyofauna was recorded—sculpin Cottus cf. poecilopus Heckel. This lake is situated close to the divide with the Pravaya Mama River (the Vitim basin), not far from its main channel. The relief structure of the watershed area, in which Lake Amut is located, indicates high probability of the invasion of Lena species into Baikal basin at this place. Data on morphology, age, growth and diet of Arctic charr from Lake Amut are presented and compared with the data on other charr from Baikal basin. New records are discussed in the context of Pleistocene paleogeography of the Baikal region relevant to the history of its fish fauna formation.

The analysis of the current practice of financial monitoring in Russia is given. A study of the main directions, methods and forms of its implementation in the budgetary sphere and commercial organizations was carried out. The procedure for its implementation, participants, methods and techniques of verification are considered. On the basis of the comparison, common features and differences of external financial monitoring in commercial organizations and the budgetary sphere were identified, conclusions were formulated.

The draw ratio (DR) is an important parameter in the process of spinning hollow fiber membranes, by which their separation and performance characteristics can be controlled over a wide range of values. For the first time, a method for determining the DR using a roller movable in the vertical direction is described, which makes it possible to establish the ratio of the dope extrusion linear flow rate to the take-up speed. In the course of the work, polysulfone hollow-fiber membranes were obtained at various DR values. The influence of the draw ratio on the morphology and geometric and gas transport properties of the resulting polysulfone hollow fiber membranes has been examined.

The spinning solution properties (viscosity, chemical composition) can be varied depending on the method of its preparation. These variations might cause changes in the thermodynamics and kinetics of the phase separation process during the membrane formation. In this work, the influence of various modes of spinning solution preparation on the morphology, geometric and gas transport properties of the resulting polysulfone (PSf) hollow fiber membranes was investigated. The differences in methods of solution preparation were the temperature and time of stirring. It was found that with the transition to the lower-temperature stirring of the spinning solution the outer diameter and wall thickness of the fiber increase, and the thickness of the selective layer decreases. The highest ideal selectivity values are observed with the solution stirring for 5 hours at temperature 120 °С (3.1 for pair He/CO2). The maximum values of the gas permeability are achieved in the mode of the solution stirring for 24 hours at temperature 50 °C (P/l (He) = 201 m3/( m2∙h∙atm); P/l (CO2) = 83 m3/( m2∙h∙atm)).

The article discusses the concept of “regulatory guillotine” and how its realization in the Russian Federation will affect on the field of assurance of measurement uniformity. According to the principles of the “guillotine”, regulatory requirements that negatively affect the existence and development of entrepreneurial activity should be identified and either completely eliminated or maximally simplified. The Government of the Russian Federation has developed an action plan (“roadmap”) for the realization of the “regulatory guillotine” mechanism, according to which all obsolete regulations will be repealed or no longer valid in the territory of the Russian Federation, and new ones will be developed in their place, corresponding to actual trends and realities . In addition, new systems of legal regulation will be built in the relevant areas of activity, based on the principles of openness, scientific and technical soundness, risk-based orientation, proportionality and feasibility. Since field of assurance of measurement uniformity is inextricably linked with most fields: from production and labor productivity, to ensuring defense capabilities and national security, any reforms will affect on the country's social and economic development.

In recent decades, the Russian Federation has seen an increase in the incidence of the population, including children and adolescents.Objective: to identify trends in the incidence and “to chronize” the pathology of young men in the Russian Federation. Using the method of descriptive statistics, the authors analyzed the overall and for the first time recorded incidence in 15–17-year-old men in 2000–2017. The authors noted a 35,8% increase in the overall incidence rate and a 35,4% increase in the for the first time recorded incidence rate. The maximum increase in the overall incidence is observed in the following classes: neoplasms (2,6 times), blood and bloodforming organs diseases (2 times), congenital anomalies (malformations; 1,8 times), circulatory system diseases (1,7 times), the musculoskeletal system and connective tissue diseases (1,6 times), endocrine and metabolic disorders (1,5 times). Based on theoverall and for the first time registered incidence the authors calculated the “chronicity” of diseases. With a general growth rate of this indicator of 0,3% there is a significant growth of this indicator for certain diseases: mental disorders and behavioral disorders (2,1 times), congenital anomalies (malformations; 1,9 times), endocrine system diseases, metabolic disorders (1,5 times).

This article deals with the initial data coming from the Ivolga Fortress archaeological site located in the Trans-Baikal area. Multidisciplinary investigations were performed, including palynological and archaeozoological studies. Palynological data reflects the palaeovegetation of the region and shows the abundance of forested landscapes in the past. The fauna was made of molluscs (7 taxa), fishes (14 taxa), amphibians (3 taxa), reptiles (1 taxon), and wild mammals (18 taxa). The species composition and environmental data show the mosaic character of landscapes surrounding the ancient settlement: taiga and forest, steppe and forest-steppe biotopes, as well as meadows in the Selenga valley with the prevalence of open steppe spaces. In the era of the Xiongnu Empire 209 BC – 48 AD (Kradin, 2001) the climate was less arid than it is now.

The influence of parameters of the dry-jet wet spinning process was studied on properties of porous polysulfone hollow fiber membranes. The air gap distance, the dope extrusion pressure, bore fluid pressure and temperature were chosen as the studied parameters. Their effect on the geometric and morphological properties of membranes was investigated. The optimal parameters were revealed for the formation of polysulfone hollow fiber membranes, promising for use as porous supports of composite membranes. High gas permeability were achieved with pore sizes providing the Knudsen flow regime: carbon dioxide permeability P/l(CO2) = 48.3 m3 m–2 h–1 atm–1, and values of ideal selectivity α = 2.63 and 0.87 for He/CO2 and CO2/N2 gas pairs, respectively.

The paper considers the option to reduce power consumption in the operation of the underloaded trunk pipeline by engaging additional pump units with lower rotor r.p.m. control using variable frequency drive. Under these conditions, the operating point of the pumps (delivery rate, head) approaches to the rated output, thus increasing the efficiency of the pumps and decreasing the electricity power consumption for pumping operations. The paper presents comparative calculations of operating conditions for a section of the trunk pipeline with a specified pumping capacity of 35 million t/year (60 % of the design load) when one, two and three main line pumps with variable frequency drives are engaged. The power consumption for pumping is calculated using the dependence of the variable frequency drive and motor efficiencies on the electric motor load and rotational speed. Based on the results of calculations, the electric energy saving is determined when additional pumping units are engaged. The experience has shown that when the second main line pump was engaged, the electric energy saving for pumping was 3.7% compared to the condition with one pump running. However, if the third pump is engaged, the saving is only 1.9 % – the decrease is due to lower motor and variable frequency drive efficiencies in the underloaded condition.

Production of steel rolled products by using traditional metallurgical technologies are rather material- and energyintensive and its concentration at gigantic steel plants resulted in the increased expenses for transportation of raw materials and finished products. To solve the problems, a practice of comparatively small metallurgical plants (mini-mills) construction is becoming widespread in the world steel industry. The mini-mills include modern electric arc furnaces, ladle steel treatment facilities and steel continuous casters combined with continuous rolling mills. The review complied from materials of international conferences, taken place in 2015–2019. In the review achievements in equipment and technology of metal products at mini-mills development considered, as well as analysis of modern economical methods of steel coils presented. It was shown, that the methods of strips endless rolling, widely used already at industrial scale in several countries, enable producing rather thin hot-rolled strips from liquid steel. Universal casting-rolling aggregates (CRA) developed, by which high quality strips of rather wide assortment can be produced. For a mass production of rather thin (down to 0.8 mm) hot-rolled strips, which can in many applications substitute more expensive coldrolled ones, compact aggregates of endless casting-rolling are recommended, which provide the yield of up to 98%. Concepts of the CRA elaborated for production of steel strips of wide assortment, from ultrathin strips to thick (25 mm) ones. The concepts include application of thermomechanical treatment to increase the mechanical properties of the rolled products from various steels, including low-alloyed ones.

In this Letter, we studied the photoresponse in multilayer graphene on a lithium niobate (LiNbO3) crystal under the conditions of an electric potential applied to graphene and transmission of a surface acoustic wave. The acoustoelectric current in graphene when irradiated with light is shown to either increase or decrease depending on the polarity of the potential applied to graphene. A surface acoustic wave causes the appearance of a periodic charge lattice in graphene that enhances the interaction with incident light, which leads to an increase in the photoresponse.

The paper presents the problem of averaging the squared vector quantities of complex polymers, based on the determination of the average values of the dipole moment squared for the μ-th monomer unit of the chain and the subsequent averaging over possible conformations within the whole macromolecule within the framework of the conformational approach.

Results are presented from experimental studies of the change in the polarization of polydimethylsiloxane upon adding 0.5% methyl and vinyl groups (grade СKТВ-1 synthetic rubber) according to currents of polarization measured upon crystallization in an inhomogeneous temperature field. A ratio that includes the polarization of flexible polymers and parameters of crystallization in an inhomogeneous temperature field is proposed, based on an analysis of experimental results.