It is considered a centrally symmetric stress-strain state of the rock mass near the underground spherical cavity taking into account the technological heterogeneity of the rocks of the near-edge region. The mathematical model was developed and analytical solutions were found for this problem. The technological heterogeneity of the elastic properties of the rock mass material was modeled by a radially inhomogeneous coefficient of elasticity at a constant Poisson's ratio. The variable coefficient of elasticity for heterogeneous rocks was approximated by a generalized polynomial with undetermined coefficients. On the basis of experimental data, a numerical calculation of the stress-strain state components for the problem was carried out, and characteristic effects were detected.
Keywords: stress-strain state, rock mass with technological heterogeneity, underground spherical cavity, mathematical model
investigated the concept of competition and competitiveness of construction organizations. Analyzed the main and specific factors of competitiveness of construction organizations. The ways to improve the competitiveness of construction organizations, taking into account the main and specific factors, are proposed.
Keywords: competition, competitiveness, competitiveness improvement, competitiveness factors, construction organization
A dynamic model of the process of internal corrosion of pipelines of heating networks is considered. Model include five level: the level of the wall thickness of the pipeline, the level of slowing down of thinning of the wall of the pipeline from pH, the level of accelerating of thinning of the wall of the pipeline from temperature, the level of accelerating of thinning of the wall of the pipeline from the oxygen concentration, the level of slowing down of thinning of the wall the pipeline from the carbonate index. The composition of variables includes one level of state, thar characterize the process of thinning the wall of the pipeline due to internal corrosion, and four levels, that characterize the performance of network water. Six rates of changing of the physical indicators, that characterize the growth (dynamics) of the ongoing process, are taken into account. Four dependencies of influence are connect the subsystems of the complex into a single whole. The results of the evaluation of the dynamics of the pipe wall thinning process in the process of internal corrosion for a period of 1 year and 5 years presented. The software implementation in the Mathcad environment is considered.
Keywords: dynamic model, internal corrosion of pipelines, corrosion of the heat network, corrosion factor
This paper presents two methods of computer simulation (quantum chemical analysis and molecular dynamics) of the interaction of additives with the iron surface. Quantum chemical interaction of silicate and phosphate additives with iron surface was carried out. The plate model was used for quantum chemical analysis, calculations were carried out in the DFT approximation. The method of molecular dynamics is based on the calculation of the evolution of the system of interacting particles of atoms and molecules by integrating the equations of their motion. It is shown that the oxidation of the surface leads to a decrease in the adhesion energy of both individual additives and their combinations, allowing to find the influencing factors on the behavior of tribosystems.
Keywords: lubricant, method, quantum chemical analysis, molecular dynamics, tribology, friction, computer simulation
Assessment of influence of speech intelligibility and reverberation time on the quality of acoustics Determination by theoretical method and computer simulation method of reverberation time in the modern audience and the audience, built more than 10 years ago. Determination of sound absorption coefficients of surface materials in both classrooms. Modernize of classrooms using wood fiber panels to increase sound absorption and reduce reverberation time. As a result, the reverberation time of the upgraded audiences has become less than one at all frequencies. This ensures good speech quality and efficiency of the educational process.
Keywords: acoustics, classroom acoustics, reverberation time, speech intelligibility, sound absorption coefficient, computer simulation, wood fiber
The article provides an overview of the methods of automatic abstracting and annotating documents. The description of classification of methods of annotation and abstracting on various criteria is presented. The algorithm of automatic annotation is described in detail, the key step of which is the transformation of all words in the text into lemmas (lemmatization). The developed program sets the upper limit of the output annotation in order to avoid receiving the abstract instead of the annotation.
Keywords: annotation, abstracting, lemmatization, algorithm, software implementation, database, text analysis
The technique of improving the quality of remote diagnostics of cars is proposed. This method makes it possible to learn real-time and real-time information about the status of the functional units of the car, thereby assessing its technical condition.
Keywords: remote diagnostics, car service, car
Progressive collapse - or, in particular, an understanding of the mechanics of this phenomenon and the development of ways to consider it in the framework of structural design - can be regarded as a relatively new topic in building science. The article describes the background to the emergence of this topic, ranging from local examples of the collapse of buildings and ending with the well-known collapse of the World Trade Center. Analyzed the latest world research in this area and revealed inconsistencies in the requirements of regulatory documentation and the real work of the building frame in case of progressive collapse
Keywords: progressive collapse, durability, steel frame, multi-storey buildings, connections stiffness, ductility
The urgency of estimating the content of nitrates in food products to ensure environmental safety at an individual level is discussed in the article. Data on the negative effect of increased nitrate content in plant foods on human health are given. The results of the study on the determination of the content of nitrates in food products using a household nitrate counter "Soek nuk-019-2" are discussed. This device makes a conclusion about the concentration of nitrates by comparing the reference electrical conductivity of different types of vegetables / fruits with the electrical conductivity of a particular controlled product. It is determined that exceeding the MPC is observed in potatoes and onions, which are sold through a network of stores that occupy leading positions in the prevalence in Taganrog. Excess of MAC in carrots is observed only in its central part (core). Based on the results obtained, practical recommendations are given to ensure the safety of food consumption.
Keywords: food safety, food, nitrate content, household nitrate
The problem of synthesis of the speed regulation law and the angle of rotation of a crawler platform with DC electric drives in a nondeterministic medium is discussed. The solution of the task is achieved by using a synergetic controller with a hierarchical control principle. The crawler platform control is considered on the basis of the mathematical model of platform motion and electric drives
Keywords: synergetic control theory, ACAR method, hierarchical method, integral adaptation, crawler platform, DC electric drive
Noise pollution is an ecological problem of big cities. Noise can reduce the working capacity of city residents and cause various diseases, so combating it is the most important event for ecologists, doctors, builders and other stakeholders. Studying the ability of plants to absorb noise will allow you to plan the future of the city’s territory. Examining the ability of green roofs to absorb noise will solve the noise problem in places where creating additional landscaping is possible. As a result of studies revealed green cement capable of reducing the noise level in the premises to 1.5 dB greater than the conventional roof. Based on the work carried out, a systematic approach has been proposed to solve the problem of noise pollution in the urban environment in the North by creating various types of green roofs on roofs with a slope level of less than 30 °.
Keywords: noise pollution, plants, green roofs, noise-attenuating ability
The article describes the algorithm of recognition of schematic diagrams in the framework of structural design of complex technical objects. It is specified that at statement of a problem of development of the specialized vectorizer it is necessary to define: software subsystems of the simplest tracer; algorithms of the analysis of images; formats of representation of the end result; initial data (formats) for recognition. As a result, it was concluded that for structural and circuit design, during which the vertex of the final portrait of the graph of the projected system is replaced, obtained after optimization by the criterion of the set of the smallest external stability, it is necessary to recognize images of graphic elements. The proposed algorithm allows for adequate recognition of the elements of electronic circuits, which further makes it possible to automatically replenish the database of elements with new elements in a given format.
Keywords: vectorization, concept recognition algorithm, structural design, graphic, element, raster image, electronic circuits, semi-graphical display, block-the functional distribution of the tracer
The article highlights the use of information technologies in modern education. The opinion of modern didacts has been generalized and presented, and the methodology for presenting information allows the most effective presentation of educational material. The economic component of application of information technologies in higher educational institutions is considered. The peculiarities of the realization of the educational process are considered taking into account the impact of computer radiation on human health. The most important indicators of the effectiveness of the use of information technology are revealed.
Keywords: information technology, distance learning, communication technology, economic component of IT, aim IT, quality
The article examines the problems of construction and design of buildings and structures in tropical areas of Vietnam, formulated the principles of their construction. It demonstrates that the comfort principles are correlated with the corresponding composition techniques and methods are implemented in a system architecture approach Urbanized shaping medium using methods lighting calculations that take into account parameters of the light and climate conditions insolation simulation method for building layouts.
Keywords: construction, design, tropical areas, solar radiation, insolation, sun protection devices, light climate, cloud statistics, structures, architecture, design
This article describes the relevance of geodetic control. Briefly describes the existing and proposed methods of geodetic control. Also the special device for geodetic researches of industrial buildings and constructions is offered. This device is attached to the geodetic rail, it is fixed laser rangefinder. With this device it is possible to perform geodetic survey of building structures of an industrial building or structure without fixing reference points. The technical task of the claimed device is the joint use (fixation) of the standard laser rangefinder and geodetic rack due to the constructive execution of the device, in the production of geodetic works to determine the deflections of supporting structures of industrial, public and residential buildings. For verification of the claimed device was carried out surveying work for determining deflections of the roof trusses of an industrial enterprise. Conclusion: labor costs of geodetic works were reduced in comparison with traditional methods by an average of 20 – 30%.
Keywords: geodesy, laser rangefinder, survey rail, survey, device, building, structure, plate, bolt, thread, size