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CONSTRUCTION BIOCOMPOSITES USING WOODWORKING WASTE.
PART 4 (DETERMINATION OF DESIGN STRENGTH BIOLOGICALLY
ACTIVATED CHARACTERISTICS SAWDUST CONCRETE)
Authors: V.V. Belov
Abstract: The possibility of using biologically activated sawdust concrete in low-rise construction is justified. The values of the normative initial and long-term deformation modules are calculated within the standard values of temperature and humidity for the developed low-energy compositions of sawdust concrete. Design strength characteristics of sawdust concrete on biologically active aggregate determined in this work make it possible to recommend it for use in enclosing structures of buildings for various purposes.
Keywords: biologically activated sawdust concrete, compositions, design strength characteristics.
EXPERIMENTAL STUDY OF BENDING BEARING CAPACITY OF GLUED AERATED CONCRETE LINTELS
Authors: A.V. Levikov, A.V. Gavrilenko
Abstract: The article gives a brief description of several variants of lintels over openings in non-load-bearing walls and partitions made of aerated concrete blocks, their disadvantages are indicated. The variant of the lintel is described, which is an element made of several blocks glued at the ends with masonry glue-foam. The description of made samples of such lintels is given, the methodology and results of their bending tests are considered. It is shown that lintels of 1.1 m span with cross-section dimensions 100 × 250 mm, made of D400 blocks of strength class B2.5, are able to withstand distributed load up to 100 kg/m, but their destruction is brittle, in connection with which their use in practice at the moment cannot be fully recommended. Possible directions for improving the design of glued lintels are presented.
Keywords: газобетон, клей-пена, перемычка, испытание на изгиб, несущая способность.
SELF-COMPACTING CONCRETE BASED ON MAN-MADE WASTE
Authors: A.S. Mitskevich, Yu.Yu. Kuryatnikov
Abstract: The article presents the results of the development of self-compacting concrete (SCB) for the manufacture of small architectural forms (SAF). It is noted that at the organisation of SAF production due to small sizes, thin walls and complex geometric shape of products it is difficult to use traditional concrete mixtures with coarse aggregate, therefore in factory conditions for SAF production it is expedient to use vibration-free technology of high-moving self-compacting mixtures, and as mineral raw materials to use technogenic wastes (fine and coarse aggregate from concrete scrap) to reduce the cost price.
Keywords: self-compacting concrete, concrete scrap, man-made waste, ground blast furnace slag, modifiers.
STANDARDIZATION OF ADDITIVE TECHNOLOGIES
IN CONSTRUCTION
Authors: Yu.N. Moskvina
Abstract: The article gives a brief overview of the development of 3D printing technologies, the main directions of technical regulation and the formation of the regulatory and technical regime of additive construction production.
Keywords: additive technologies, construction, national standard, standardization.
EFFICIENT ROAD AND AIRPORT PAVEMENTS
FOR CONSTRUCTION IN THE NORTH
Authors: V.I. Trofimov
Abstract: . The article concerns the current problem of increasing the efficiency of road and airfield cement concrete pavements in the Arctic zone. To do this, it is necessary to take into account the harsh natural and climatic conditions of construction, the permafrost condition of the soil and the high cost of work. The article discusses issues of improving the technology and design of road and airfield slabs. It is proposed to use multilayer slab technology using composite materials and polymer-based products to produce road slabs with increased operational reliability. The design of the prefabricated road slab is justified - two-layer or three-layer, where the lower and upper layers are made of a ready-made polymer composite slab. Positive results of complex tests on models were obtained.
Keywords: arctic zones, crack resistance, polymer composite slab, reinforcement, prefabricated road slab.
MODIFIED CONCRETE FOR WATER RECLAMATION CONSTRUCTION
Authors: Yu.S. Filimonova, E.V. Tkach, T.V. Susanina
Abstract: Within the framework of research the questions related to modification of heavy concrete composition on the basis of polydisperse binder with complex modifier and its influence on the formation of structure and properties of cement stone, as well as hardened concrete are considered. The possibility of obtaining effective heavy concrete for hydromeliorative construction with improved performance properties in terms of strength and hydrophysical characteristics has been substantiated. The influence of three-level disperse composition of clinker component of cement particles on the reduction of inter-particle emptiness and increase of cement stone strength has been investigated. It is noted that the obtained performance indicators make it possible to recommend the modified concrete for the production of building products and structures operating under severe operating conditions, in particular for irrigation system flumes. It is indicated that the prospects for further development of scientific research lie in improving the composition of modified heavy concrete on the basis of polydisperse binder with complex modifier by searching for new types of modifiers and micro reinforcing fillers to reduce the cost of production and study the possibilities of its application in hydraulic structures of the zone of variable water level.
Keywords: modified concrete, dispersed composition of the clinker component, complex modifier, durability.
ANALYSIS OF THE INFLUENCE OF GENERATORS
OF THERMAL POWER PLANTS ON THE OPERATING MODES
OF THE POWER GRID OF A LARGE RUSSIAN CITY
Authors: P.G. Ivanov, K.B. Korneev
Abstract: The article describes the results of calculations of the operation of power grids of a large city in different schemes. The problems that may arise in the absence of generation sources within the city power supply system are considered. The variants of their solution are offered. Possible variants of development of events for conducting the regime under normal and repair schemes, as well as variants of imposing emergency shutdowns on repairs are calculated.
Keywords: power grid operation mode, repair scheme, emergency shutdown, substation, emergency automation.
INFLUENCE OF METEOROLOGICAL CONDITIONS
UPON THE ELECTRICAL CONDUCTIVITY OF THE PRECIPITATION
IN TVER DURING 2016–2022 YEARS
Authors: F.V. Kachanovsky
Abstract: Analysis had made of the precipitation′s electrical conductivity (atmospheric precipitation had fallen in Tver in 2016–2022 years) and factors of the influence on it. Time series models of the electrical conductivity were examined. Сubic model has considered as adequate.
Keywords: conductivity, acidity, acid rain, precipitation, model, time series, trend, cycle component, seasonal component, correlation.
VERIFICATION FOR THE CORRESPONDENCE TO THE TRUTH OF THE LAWS OF THERMAL RADIATION OF GAS VOLUMES. PART I. EXAMPLES OF CALCULATIONS ACCORDING TO THE LAWS OF QUANTUM THERMAL RADIATION OF CYLINDRICAL GAS VOLUMES
Authors: A.N. Makarov
Abstract: Examples of calculations of heat exchange of gas volumes with heating surfaces according to the laws of thermal radiation of cylindrical gas volumes are given. Examples of calculations confirm the validity of the five laws of thermal radiation of gaseous volumes of electric arcs and torches. Researchers and readers are invited to check the truth of the laws of quantum thermal radiation of gas volumes on a computer using the Compass program.
Keywords: thermal radiation, laws, gas volumes, torch, electric arc, furnaces, combustion chambers.
CHECKING THE LAWS OF THERMAL RADIATION OF GAS VOLUMES FOR THE CORRESPONDENCE TO THE TRUTH. PART II. EXAMPLES
OF CALCULATIONS ACCORDING TO THE LAWS OF THERMAL
RADIATION OF CYLINDRICAL AND SPHERICAL GAS VOLUMES
Authors: A.N. Makarov
Abstract: Examples of calculations of heat transfer of gas volumes of electric arcs and torches with heating surfaces according to the laws of thermal radiation of cylindrical and spherical gas volumes are given. It is noted that the examples of calculations confirm the truth of the five laws of thermal radiation of gas volumes. It is indicated that the gas volume in the furnace of a steam boiler fills the entire furnace and has the shape of a rectangular parallelepiped; when modeling the radiation of a gas volume in the form of a rectangular parallelepiped by radiation of a cylindrical gas volume, the calculation error does not exceed 3 %. It is concluded that the error in calculations when modeling the radiation of a gas volume in the form of a rectangular parallelepiped by the radiation of several hundred spherical gas volumes inscribed in a parallelepiped is 0,9–0,4 %.
Keywords: thermal radiation, gas volume, laws, torch, electric arc, furnaces, furnaces, combustion chambers.
THEOREM ON THE CENTER OF n-SYMMETRY
OF A CONVEX SPATIAL BODY
Authors: Al.A. Shum, A.M. Vetoshkin
Abstract: The concept of the center of n-symmetry of a spatial body is considered. It is indicated that special cases of this general concept are the center of s-symmetry (the center of 0-symmetry) and the center of c-symmetry (the center of 1-symmetry). The following theorem is proved: in any convex region of space, it is possible to determine the density function so that the center of the n-symmetry of the resulting body will be located at any predetermined internal point of this body (special cases of this theorem corresponding to the values n = 0 and n = 1 were previously known).
Keywords: symmetry, c-symmetry, s-symmetry, n-symmetry, center of symmetry, density function, convex body, mass, center of mass, electric bus.
SYNTHESIS OF GEOPOLYMER COMPOSITIONS BASED ON ALKALINE TECHNOGENIC PRODUCTS OF FUEL STATIONS
Authors: D.D. Babaev, V.B. Petropavlovskaya, T.B. Novichenkova, K.S. Petropavlovskii, M.Yu. Zavadko
Abstract: The problem of waste disposal resulting from the operation of thermal power plants in Russia is considered. The main attention is paid to the issues of recycling and reducing the impact on the environment. As one of the solutions, it is proposed to use innovative technologies – geopolymers. The compressive and bending strength of geopolymer solutions with the addition of ash of class C, as well as the effect of curing conditions on their characteristics, are considered. The authors proposed a new approach to the description of the porous structure of materials based on fractal geometry. The results showed that with an optimal activator module, maximum compressive strength and the lowest porosity can be achieved. The use of ground granulated blast furnace slag as raw materials for the production of geopolymers with the addition of fly ash is also described. The influence of various factors, including activation by various alkaline solutions and the curing temperature, on the mechanical properties of the obtained materials has been investigated.
Keywords: геополимеры, золы ТЭС, доменный гранулированный шлак, щелочная активация, промышленные отходы.
TECHNOLOGICAL ASPECTS OF ENVIRONMENTALLY SAFE DISPOSAL
OF WASTE OILS
Authors: О.P. Filippova, S.Z. Kalaeva, E.S. Tskhovrebov, Е.S. Sergeev
Abstract: It is noted that in recent years, the amount of waste oils generated, accumulated and stored at enterprises has been significantly increasing. Based on the analysis of chemical composition, physico-chemical parameters and comparison of infrared spectra, the possibility of using spent mineral, industrial and edible oils for the preparation of preservative lubricants, the production of anticorrosive coatings is substantiated. It is concluded that separate collection, isolated, environmentally safe accumulation, industrial processing and disposal of waste oils contribute to the implementation of measures to protect the population and territories of the regions from environmental hazards created by the negative impact of industrial waste on the environment.
Keywords: used oil, anticorrosive coating, dispersion medium, recycling, waste, environ-mental safety.
RESEARCH CHANGES IN ELASTIC PULSE' SPECTRAL COMPOSITION
DURING REFLECTION AND PASSAGE THROUGH A SAPROPEL
Authors: G.N. Ivanov, I.V. Krivenko, M.A. Smirnova, S.R. Ispiryan
Abstract: The current topic of increasing the capabilities of sonar survey of sapropel deposits is considered. Mathematical modeling of the spectra of reflected and refracted pulses has been carried out, taking into account the characteristic dependence of the absorption coefficient on the frequency characteristic of various types of mineral soils, since the study of the spectra of reflected and refracted signals arising from sonar sounding of its layers provides information about the quantitative and qualitative composition of the layer. As a result of computational experiments, the dependences of the intensity of such signals on the frequency were obtained, which make it possible to distinguish sapropel from other types of soil. It is indicated that the research results can be used to determine the power and quality of the underlying layers without sampling by appropriately changing the parameters of the receiving channel of the equipment and decoding the spectra of the above-mentioned signals.
Keywords: sapropel, mineral soils, seismoacoustic methods, sonar, mathematical modeling, dependence, absorption coefficient, frequency, spectrum, reflected signal, refracted signal.
DEVELOPMENT OF METHODS FOR IN VITRO BIOTESTING OF LYSOZYME-CONTAINING SUBSTANCES TO IMPROVE THE PRODUCTION TECHNOLOGIES OF DRUGS WITH ANTIMICROBIAL ACTIVITY
Authors: S.A. Smirnova, I.A. Lyubkevich, A.I. Zorin, E.A. Mironov, V.P. Molchanov
Abstract: The paper presents the results of the development of a new biotechnological methodology for testing the activity of an in vitro solution of the enzyme lysozyme, belonging to the class of hydrolases, and various substances produced on its basis. The methodology for determining the activity of lysozyme is based on its lytic effect on the Micrococcus Luteus test culture. The proposed technique can be used in pharmaceutical, biotechnological and food enterprises for laboratory quality control of finished preparations with antimicrobial activity, as well as in research practice.
Keywords: lysozyme, biotesting, in vitro, lytic action, Micrococcus Luteus, test culture, enzymatic activity, antimicrobial activity, quality control.