×

You are using an outdated browser Internet Explorer. It does not support some functions of the site.

Recommend that you install one of the following browsers: Firefox, Opera or Chrome.

Contacts:

+7 961 270-60-01
ivdon3@bk.ru

  • Overview of the evolution of facades of buildings and structures

    The article discusses the architectural and artistic properties of facade cladding materials, which can be used to shape facade solutions. The main architectural and artistic properties and components of finishing materials are revealed, as well as ways of detailing them on a facade structure or element. As a result of the study, it was revealed that the artistic properties of facade materials depend on the expressive features of the surface and ways to change its structure, along with the variety of shapes and ways of its deformation, and the architectural properties lie in the constructive variety of installation and placement of material on the facade plane, as well as in its geometric variability.

    Keywords: facade, surface, form, shaping, facing materials, artistic properties

  • Determination of stiffness and curvature of two-layer reinforced concrete beams with concrete of frame structure in the compressed zone

    Based on the research conducted by the authors, data on the stiffness and curvatures of reinforced concrete beams with a layer of various heights of concrete with frame structure are presented. Stiffness, curvature and deflections are given for cases of absence and presence of cracks in the tensile zone of beam. Formulas for describing changes in the stiffness and curvature of sections depending on the magnitude of the moment are obtained. The influence of the thickness of the layer of concrete with frame structure and the diameter of the working reinforcement on the change in the stiffness of the sections is established. The regularity of changing the position of the neutral axis for single and double-layer beams depending on the beam parameters.

    Keywords: concrete of frame structure, stiffness, curvature, deflection, layered structures, bending moment, neutral axis

  • Sand for construction works and technogenic sands

    One of the important components of building mixtures and concretes is sand. Sand is the most readily available raw material. In many countries sand mining is environmentally damaging or in short supply. Some countries have to buy sand. To replace building sands, various wastes are offered during crushing and grinding, screenings of concrete and brick scrap. Desert sand is not always suitable for building mixes due to its physical properties. Technogenic sands are very different in their origin, formation conditions, chemical and mineral composition, structure and properties. To determine the applicability of a sand substitute, it is required to conduct research on technogenic sand and products based on it.

    Keywords: sand extraction, technogenic sands, concrete scrap crushing screening, brick scrap crushing screening, enrichment waste

  • On the issue of regulatory and legal regulation in the field of fire safety of shopping and entertainment complexes and centers

    This article discusses various aspects of the design, construction and operation of shopping centers and shopping and entertainment complexes from the point of view of fire safety. Examples of existing structural and space-planning solutions that do not fall under the regulations governing fire safety, but pose a danger to visitors and staff of the shopping center and shopping mall in the event of a fire. Ways to eliminate these shortcomings are proposed.

    Keywords: fire safety, children's play area, shopping-entertainment area, normative legal acts

  • Research of issues of strengthening of wooden structures

    The main reasons for the weakening of wooden structures, as well as the main requirements for strengthening wooden structures, are considered. Various methods for strengthening structures are being analyzed. Strengthening with carbon fiber is highlighted separately, the main advantages and disadvantages of this method are considered.

    Keywords: analysis, causes, methods, reinforcement, wooden structures, wood, reconstruction, carbon fiber, composite, strength, deformability

  • Preservation of manor churches (on the example of St. Petersburg province)

    Church occupied an important place in life of the manor owners. It became a place of christening, wedding and repose. Having lost their historical significance, manors and churches have become a ""monument of history and culture"" and are often in disrepair. The article examines the main characteristics of the churches of the ""estates of the highest nobility"" of the St. Petersburg province, the essence of their identity. The recommendations for the preservation of churches in the estates ""Maryino"", ""Ropsha"", ""Pyataya Gora"", based on the analysis of spatial, urban planning and value characteristics, are described.The purpose of the work is to offer reasonable recommendations for the preservation of the most valuable manor churches of the St. Petersburg province. The tasks of the research were: 1. Consideration of the main characteristics of manor churches. 2. Identification of the three most valuable churches for specific estates and for the Leningrad region as a whole. 3. Giving recommendations for the preservation of chosen churches based on the analysis of individual characteristics. The researched material allows us to conclude that the importance of churches in estates is great. Today it is important to preserve the small proportion of manor churches, which remained as evidence of the lost culture. At the same time, do it comprehensively, in conjunction with the park structure and other manor buildings. The preservation of the estate heritage is justified from the point of view of preserving national identity and creating developed cultural spaces. The proposed recommendations for the preservation of the ruined churches in the estates ""Maryino"", ""Ropsha"" and ""Pyataya Gora"" will form the basis of a comprehensive project proposal during the master's thesis and will attract attention to the estate heritage from the society, security agencies and investors.

    Keywords: manor churches, ruined churches, estates of the highest nobility, St. Petersburg province, Marino, Ropsha, Fifth Mountain, preservation

  • Multidisciplinary research

  • Methodological foundations for the formation of a data bank on the sources of atmospheric pollution in the region

    In the article, the object of the study is the spread of pollutants from the sources of their release. During the calculations, the sources of atmospheric pollution were combined with the allocation of groups taking into account the height of the mouth of the emission source. To reduce time-consuming calculations using the method of combining sources of atmospheric pollution, the program has been created that provides fast processing of a large amount of information. A data bank on the main sources of pollution of the Rostov region has been compiled; systematization and reduction of these sources to a single coordinate system has been carried out. A trial estimation calculation of the regional transport of pollutants from the combined sources of emissions with the construction of maps of pollution isolines was made.

    Keywords: harmful emissions, sources of pollution, the method of unification, data bank, maps of pollution isolines

  • Influence of supply voltage on the speed of flight of domains in the Gunn diode

    Mathematical modeling of processes in the crystal structures of the Gunn diode and modeling of the operation of the diode itself in various electrical circuits are relevant for monitoring the operation of electronic devices The paper investigates the effect of low-frequency pickups in the power supply circuit of the Gunn diode on the Fourier spectrum of the generated microwave signal. To study the processes of formation and motion of a domain in a crystal structure, the local field model of the Gunn diode is used, based on the assumption that the average drift velocity of electrons depends on the instantaneous value of the electric field, and the diffusion coefficient does not depend on the applied electric field. A serial circuit for switching on a diode with a power source and a resistive load is simulated. As a result of the simulation of the program, the distribution of stresses inside the crystal along its length at a selected moment of time is obtained; graphs of the movement of domains are plotted based on these data. Based on the data obtained, a Fourier transform is performed, and the resulting spectrum is constructed. The correctness of the program operation is confirmed by the spectrum obtained by the 3A703B diode on the S4-27 spectrum analyzer. The shape of the inhomogeneities in the crystal lattice, given the same width, does not affect the formation of domains. Rectangular, parabolic and gradient functions of dopant concentration variation are investigated. If the function changes more smoothly, then the maximum amplitude of the domain strengths will be greater, but the domain will take a little longer to form. The resulting model can be used to calculate fields with different loads in an electrical circuit.

    Keywords: Gunn diode, microwave, simulation of physical processes, Fourier spectrum, radar systems

  • Investigation of stress concentration at special cross-section points of structural elements reinforced with coatings

    The points of stress concentration in the sections of structural elements are considered. These include, in particular, crack tips that may appear both during operation and as a result of a violation of their production technology. The values of stress intensity factors in the vicinity of cracks in the considered sections with contour corner points are obtained. In addition, the study of indicators in the asymptotic solution of the elasticity theory problem for bodies made of isotropic materials in the vicinity of the structure rod element corner point of the section, where the sides (or one of them) are supported by a thin coating, was carried out. On the other side of the corner region, various conditions for its reinforcement are assumed, including the presence of a thin elastic coating. Mathematically, the solution of the problem is reduced to the transcendental characteristic equation solution, that is, to the problem of finding the equation roots that is constructed from the condition for the existence of a non-zero solution to a linear homogeneous equations system. The characteristics of the stress components were determined for various combinations of boundary conditions, physical and geometric parameters. Qualitative conclusions are made. In particular, values these parameters are established combinations , at which the behavior of stresses at the section corner point becomes singular.

    Keywords: stress intensity factor, isotropic elastic bodies, structural element, section corner point , crack, thin elastic coating, boundary conditions, characteristic equation, stress concentration

  • Simulation model of the pressure digital automatic control system in the pressure compensator of the reactor plant

    Reducing the risk of human-made disasters is directly related to the trouble-free operation of nuclear power plants. Analysts name the human factor like a one of the causes of accidents at the nuclear power plants, which mainly determines both the probability of their occurrence and the consequences. Minimizing of the human factor impact suggests a number of actions, including automation and digitalization, the applying of which on the plant is impossible without of mathematical models of technological processes. A simulation model of a digital automatic control system (SAR) of pressure in a pressure compensator used to maintain pressure in the first circuit of the nuclear power plant is presented in this article. As a result of modeling are the charts of transition process which are used for calculating of the digital ACS quality indicators. The ACS simulation model is implemented in a classical way, but in practice such classical regulators do not provide the predefined quality indicators. In this connection, a model of adaptive ACS with a neuroregulator is proposed to improve the qualitative characteristics of the system.

    Keywords: nuclear power plant, reactor, compensator, pressure, temperature, perturbation, regulator, valve, gate valve, turbine, model, circuit, neural network, optimization.

  • Development of unmanned transport and technological systems for industrial forest management

    The article considers aspects of industrial forest management based on automation of control of local positioning, engineering and information technology of unmanned industry. Original algorithms for automatic control of unmanned technical systems and contact elements of technological equipment under the forest canopy, directly implementing the operations of the technological process, have been created and tested. Software complexes for data collection and control of information flows, providing stable functioning of the last generation local positioning means, have been developed and registered. The designs, methods and architecture of unmanned ground, suspended and airborne systems for industrial forest management, forest maintenance, located in specially protected natural areas and industries indirectly related to forest or forest land have been proposed.

    Keywords: automation, digitalisation, method, algorithm, synthesis, technology, positioning, control method, digital model, modelling

  • Radiative Changes in Concrete in the Shaft of Water-Water Power Reactors during the Extension of NPP Operation

    Computational and analytical studies of the influence of the duration of operation of nuclear power plants during the extension of their operation on the radiation changes in the concrete of the shaft of water-water power reactors (VVER) on various aggregates have been carried out. The studies were carried out using the existing experimentally tested methods for the analytical determination of radiation changes in concrete and their components. It has been established that during the extension of the operation of nuclear power plants with VVER reactors, the radiation changes in the concrete of the reactor shaft can be commensurate with the allowable changes in concrete or exceed them. It is shown that the radiation changes in the concrete of the reactor shaft increase with an increase in the duration of operation and depend on the power of the reactor (440 or 1000 MW), the thickness of the "dry" shield around the reactor, and the material of the concrete filler used. Radiation changes in all concrete of the NPP shaft with VVER-440 reactors will be more significant than in the concrete of the NPP shaft with VVER-1000 reactors. It has been established that the radiation changes in the concrete of the reactor shaft and the maximum duration of operation when using aggregates from various rocks differ significantly. It is noted which concretes (on which aggregates) have the smallest, largest and intermediate radiation changes. It is shown that with an increase in the operating temperature, the radiation changes in concrete will decrease, and the allowable operating time of the NPP will increase.

    Keywords: radiation changes, reactor shaft concretes, concrete aggregates, rocks, water-water power reactors VVER-440 and VVER-1000, extension of NPP operation

  • Study of the effect of technological LED lighting conditions on the growth and productivity of cucumber plants

    The article presents the results of evaluation of photobiological efficiency of technological LED lighting in growing cucumber plants Svyatogor F1 variety under light culture conditions. In the experiment phyto-irradiators (FI) with high-pressure sodium lamps of DNAT type (control variant), as well as LED FI of combined spectrum were used. On the basis of photobiological experiments it was found that the emission of OP2 (where radiation with  = 730 nm was 3.1 times more and radiation with  = 660 nm 1.23 times less than in the emission spectrum of OP3) was more effective, providing not only better quality of cucumber seedlings but also higher productivity. The practical significance of the obtained results is shown.

    Keywords: phyto-irradiator, LED light source, light-culture, photobiological research, radiation spectrum, photosynthetically active radiation, photosynthetic photon irradiation, cucumber plant