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  • Comparison of cold hardiness performance of heavy concrete class B35 obtained by vibrating and centrifuging

    By centrifuging it is possible to manufacture a wide range of building structures and products from reinforced concrete. Such products have several advantages, being relevant in modern construction, however, it requires careful compliance and quality control of the process. The frost resistance of concrete is one of the main indicators characterizing the durability of such building structures as reinforced concrete pillars of power transmission lines and contact network. The analysis of the literature and a series of experimental studies in the laboratory. The influence of the technology of manufacturing products from heavy concrete on the indicator of their cold resistance has been identified and determined.

    Keywords: Racks of power transmission poles, racks of supports of the contact network, centrifugation, vibrating, frost resistance, heterogeneity of concrete, variotropy

  • Experience of using blast furnace slag as an artificial foundation for the foundation of a building

    The experience of using blast furnace slag as an artificial foundation of the building foundation is considered. In the process of construction and installation works, the displacement of the columnar foundations was revealed due to changes in the initial properties of the blast-furnace slag. The chemical composition of the slag belonged to the group of inert materials. In fact, after layer-by-layer compaction, the process of disintegration of its initial properties began. The analysis of the conducted studies showed that in the regulatory and scientific literature there are no unambiguous recommendations on the use of this material as the base of buildings and structures. The recommendations that are available relate exclusively to its use in road foundations. From experience it follows: the use of slag in construction is possible, subject to confirmation of its compliance with specific construction conditions.

    Keywords: blast-furnace slag, artificial base, layer-by-layer compaction of the soil, hydraulic activity and inertness, modulus of basicity, calcium oxides, manganese oxides, particle size distribution, inert material, chemical decomposition

  • The use of gentle technologies in the reconstruction of cultural heritage

    The use of benign technologies in the reconstruction of a building that is an object of cultural heritage is analyzed on a concrete example. Conclusions on the use of selected technology

    Keywords: cultural heritage, cultural heritage object, preservation of cultural heritage objects, monument, sparing technologies, restoration, soil, consolidation, foundation, foundation, deformation, inspection

  • Assessment of the impact of low-pressure water storage units on the environment

    The article provides materials for research and assessment of the effect of reservoir hydro-systems on the environment. A detailed analysis of the causes and parameters of the influence of hydroelectric small hydropower stations on the hydrobtological resources of rivers. The results of the study and the assessment of the pollution level of the bottom sediments of the head node of the Kashkhatau HPP are given, which confirmed a slight excess of the permissible concentration level in terms of the content of cadmium and oil products. The main factors influencing the low-pressure reservoirs on the natural environment and on the restoration of fish river resources of small rivers are determined. According to the results of engineering and environmental studies, a comparative characteristic of soil pollution by oil products in relation to the permissible level was established, analyzing the results obtained, it was concluded that the content of oil products in the collected soil samples is within the established standards. A comprehensive assessment of pollution of water resources and soils of coastal water protection zones is given.

    Keywords: reservoir waterworks, small hydropower plant, aquatic and biological resources, solid runoff, river pollution, flood waters, background concentrations, heavy metals, hydraulic structures

  • Analysis and systematization of the causes of bridge structures destruction

    The paper presents the classification of the main causal aspects of the occurrence of catastrophes of large-span bridge structures, given with elements of the analysis of actual examples of the destruction of structures of various types. Also are described the innovative developments applicable in the field.

    Keywords: fatigue failure, bridge, large-span bridge, failure of structures, destruction of bridge structures, accident in construction, resonance, wear, aerodynamics of bridge structures, stiffness beam, bolted joint

  • Compensation of additive temperature error of the Hall transducer

    In the article we discuss temperature errors caused by non-stationary thermal processes in a thin-film Hall transducer. When solving the heat conduction equation we show the significant influence of effects of Peltier and Seebeck on the Hall voltage measurement results in the current switching mode. A new twenty-step switching currents algorithm for the Hall transducer is proposed. In this algorithm the additional voltages are measured at the absence of current through the transducer. From the additional voltages we estimate the contribution of the temperature drift. It was experimentally shown that for the PHE602117 converter the additive temperature error decreases by 30 times in comparison with the four-step algorithm while reducing performance by 20%.

    Keywords: Hall transducer, additive error, Peltier effect, non-stationary processes, thermo-emf., magnetic measurements, current switching

  • The main methods of increasing the stability and rigidity of large-span cable-stayed and hanging bridge structures

    The paper presents the systematization of the main methods for increasing the rigidity and stability of the cable-stayed and hanging types bridge structures , its given in conjunction with the analysis of the real objects. Among the methods presented are such techniques as: improving the quality of the material; additional structural elements that perceive vibrations; modification of the main elements of the design scheme. Also in the paper innovative developments applicable in the field of study are described.

    Keywords: transport structure, bridge, cable-stayed bridge, suspension bridge, bridge construction, guyed, pylon, rigidity of the bridge structure, stability of the bridge structure, operational safety of the bridge, aerodynamics of the bridge

  • Effect of oxide additives on the structural properties of the cobalt catalyst for the synthesis of hydrocarbons

    The structural properties of cobalt catalysts and their active component are studied. The influence of metal oxides on the specific surface area, pore volume and size, the average crystallite size and the active surface area of the catalyst Co-Al2O3/SiO2 was studied.

    Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, cobalt, promoter, carrier, specific surface, porous structure, catalytic activity, degree of reduction, active surface area

  • Effect of modification of aluminum oxide on cobalt catalyst of Fischer-Tropsch synthesis promoted by manganese oxide

    The physical and chemical properties of cobalt catalysts promoted by manganese oxides for the synthesis of hydrocarbons by the Fischer-Tropsch method are studied. The influence of polymorphic modifications of the alumina carrier on the specific surface area, pore volume, degree of reduction, size of cobalt crystallites,catalytic activity, dispersion degree of catalyst reduction is considered.

    Keywords: Synthesis of Fischer-Tropsch, synthetic hydrocarbons, the cobalt catalyst, promoter MnO2, the carrier of Al2O3, specific surface area, the degree of recovery of the catalytic activity, dispersion, and the crystallites of cobalt

  • Improving the performance and performance properties of coatings formed under vibration mechanochemical action

    The article presents an analysis of promising research on the formation of vibrational mechanochemical coatings from the point of view of practical use in the real sector of the economy

    Keywords: combined methods of treatment, vibration treatment, the vibration mechano-chemical (chemical-mechanical) coverage webrevolve technological system, mechanical coating, fragmentary nature, plastic deformation, uniform coating, vibrowave impact, microstructu

  • Problems of safety of traffic

    Article is devoted problems of safety of traffic. In given article are sounded a number of the reasons of occurrence of failures on highways. In article questions of influence of psychophysiological features of drivers on occurrence accidents are considered. The special attention is given that use of cellular telephones by drivers (despite prohibition by traffic regulations), and also every possible advertising materials in sight of drivers do not promote concentration of attention on driving process. Also in article questions of increase of safety of pedestrians, as participants of traffic are mentioned. In article the interrelation between road conditions and safety of traffic is investigated. That fact is marked, the reasons of adverse influence of road conditions can be obvious and hidden. In article the developed practice of roads design is analyzed. The given practice, in a due measure, does not consider requirements of landscape designing. Which, in turn, though are registered in the arch of rules, but have recommendatory character. Also in article questions of use of the minimum parameters of highways are mentioned at its designing.

    Keywords: Safety of traffic, accidents , a highway, the driver, the pedestrian, roads design, a road condition, road conditions, intensity of movement, the road maintenance, landscape design of road

  • Application of logistics approaches to the use of cable cars on the example of the mountain resort "ROSA KHUTOR»

    In the article the features of application of logistic approaches of the organization of movement of the cable cars, as well as the method of selecting the cable car and the slopes at various characteristics of the operation of the complex. The results of experimental research on the network of cable cars of the mountain resort "Rosa Khutor"are offered. The paper uses the methods of monitoring the movement of passengers on cable cars by means of identification by ski pass and GPS

    Keywords: transport mobility, route network, public transport, automated monitoring of passenger traffic, logistics approach, cable car, monitoring of cable car congestion on-line, traffic volume, digital transport management system

  • Calculation of the main beam of the production building

    The problem of calculating rods for vector perturbations consisting of five components is solved: 1. kinematic transverse vibrations of the left end; 2. kinematic transverse vibrations of the right end; 3. dynamic bending moment at the left end; 4. dynamic bending moment at the right end; 5 dynamic uniformly distributed lateral load along the length of the rod. The transfer functions from each disturbance are obtained separately. Using these functions, we obtained the elements of the spectral matrix for stationary random processes, taking into account their correlation. The most common types of processes are considered: exponentially correlated random process; process with latent periodicity (with characteristic frequency); truncated white noise. The formula for obtaining the dispersion of displacement of sections is shown.

    Keywords: rod, harmonic oscillations, natural frequency, kinematic disturbances, dynamic disturbances, transfer function, correlation matrix, random process, delta-correlated random process, latent periodicity, truncated white noise

  • Estimation of the mathematical expectation of the insulation resource in problems of increasing the reliability of electrical equipment

    The model of the occurrence of failures as a result of aging of insulation materials of power cable lines is considered. It is shown that the residual life depends on the ratio of the safety margin and the ultimate strength of the materials used. A simulation of the resource actuation processes was carried out using a mathematical model of the insulation state that relates the time and probability of its trouble-free operation with certain parameters of it. The model allows to predict the state of the insulation and the service life of the power cable lines.

    Keywords: Reliability, life, insulation materials, heat aging

  • Analysis of the influence of the color of the object and the spectral composition of its illumination on the noise of the CCD matrix of the video camera of the vision system

    The paper considers an optical laser-free system for express analysis of vibration state, which includes a dedicated backlight and a videocamera of vision system, which is a displacement sensor. The problem of determining the degree of mutual influence of the reflecting properties of the surface and the spectral composition of the radiation of the light source on the noise level of the CCD matrix is ​​solved. Using dispersion analysis of the results of a field experiment, it was determined that the spectral composition of the backlight is the most significant factor; the best combinations of parameters were identified. Comparison of the noise level with the real vibration signal showed the crucial role of the selection of combinations of the backlight and the type of the reflecting surface.

    Keywords: noise CCD, dispersion analysis, vision system, vibration control, optical measurement, reflective properties, spectral composition, backlight, vibration