×

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

  • The effect of some mineral additives on the properties of fine-aggregate concrete

    The results of studies of the effect of mineral additives of natural and man-made origin on some properties of fine-aggregate concrete with the introduction of a mineral additive from 10 to 25% of the cement weight instead of either a part of cement with an increase in the value of W/ C, or a part of sand with a constant value of the value of W / C are presented. A slight, up to 3%, change in the average density of concrete was revealed. A decrease in the E-modulus from 4 to 14% was recorded when replacing a part of cement, while an increase in the flexural strength, depending on the dosage, was up to 26% (marshallite) and 6% (chemical water treatment sludge), and a decrease in the compressive strength was from 10 to 22%. When replacing part of the sand, an increase of up to 10% of the E-modulus, the flexural strength from 19 to 38% (marshallite) and up to 11% (chemical water treatment sludge) was recorded. The increase in the compressive strength, depending on the type and dosage of the additive, ranged from 8 to 20%. No significant effect of additives on the porosity of cement stone was revealed.

    Keywords: mineral additive, fine-aggregate concrete, flexural strength, E-modulus, shrinkage, water absorption

  • Analysis of curves that cannot be represented by the intersection of two surfaces in architectural bionics

    The article is devoted to the study of curves that are not representable by the intersection of two surfaces. In modern architectural practice, they very often depart from classical forms, replacing them with complex surfaces. Recently, there has been the development of such an architectural style as architectural bionics or bio-tech. Faced with the challenges of sustainable development and its impact on the environment, the construction sector faces the necessary need for innovation. Architecture is presented as one of the promising areas of knowledge use based on biological research. And it is able to respond to current environmental problems. Indeed, many species of animals and plants know how to apply adaptation strategies to the environment and its transformations, forming together with it a sustainable ecosystem. Technological advances in very small-scale observation allow for deeper knowledge of how nature works and offer a new source of knowledge and inspiration for architecture.

    Keywords: architecture, spatial curves, axonometric projections of curves, narrowed curves, bionics, biomimicry, eco-innovation

  • Redevelopment of industrial areas according to Fitwel's eco-standard

    The increase in the population of large cities leads to the need for residential buildings, office space, leisure facilities, etc. leads to an increase in new construction. The city cannot constantly develop in terms of space as it is limited by the territory allocated to it in the framework of the cadastral division of the territory and it cannot grow indefinitely in breadth. That is why there are various programs for urban development, such as renovation, redevelopment of industrial areas and reconstruction of existing buildings. Also in recent years it has become popular to use different environmental standards in the design and construction of new or reconstructed buildings. This article will focus on the redevelopment of industrial areas with the development of underground space from the perspective of Fitwel ecological standard.

    Keywords: Fitwel, green standard, redevelopment, industrial areas, renovation, industrial buildings, industrial facilities, new construction, development of underground space, integrated development of the territory

  • Catalysts for the synthesis of hydrocarbons based on ZVM zeolite

    The influence of the content of the zeolite component in the composition of cobalt catalysts for the synthesis of hydrocarbons on their physico-chemical properties is investigated. The catalysts were obtained by impregnation of a zeolite-containing carrier with subsequent heat treatment. The obtained samples with a concentration of ZVM zeolite of 30-70% were characterized by the methods of BET, TPR, TPD H2. The results of the analysis show that an increase in the concentration of the zeolite component of the catalyst contributes to an increase in the specific surface area, dispersion and a decrease in the recovery temperature of the deposited cobalt.

    Keywords: applied catalyst, cobalt, zeolite, dispersion, specific surface area, active component, synthetic fuel, degree of reduction

  • Dependence of the stationary current in the ferroelectric ceramics (1-x)Ва0.95Pb0.05TiO3+xCo2O3 on doping with cobalt under the action of radiation in the optical range

    The article presents the results of a study of the photoelectric response of cobalt-containing ferroelectric ceramics (1-x)Ва0.95Pb0.05TiO3+xCo2O3, synthesized at the Institute of Solid State Physics of the University of Latvia using conventional ceramic technology. Ceramics was exposed to optical radiation at room temperature. Before applying light radiation to the cellular electrode of the ceramic sample located in the measuring cell, zero current was recorded for 0.5 minutes in the absence of illumination using a high sensitivity digital electrometer. Then, the photoresponse was recorded during the time until its value remained constant (since the anomalous photovoltaic effect manifests itself in the form of constant currents flowing along the polar directions) and only then the light flux was turned off. A significant effect of the concentration of cobalt oxide on the value of the photovoltaic current is shown, which manifests itself in a decrease in the value of the stationary current with an increase in the content of the impurity of cobalt oxide. It is assumed that a possible reason for the decrease in the stationary current is deep charge traps, which is due to an increase in the cobalt concentration in the ceramic. The influence of the incident radiation wavelength, as well as the aging factor on the photoelectric response for ceramics with the highest concentration of cobalt oxide, is established.

    Keywords: mobile robots, polarization, depolarization, ferroelectrics, polarization current, remanent polarization, dielectric losses, electrical load, domain structure, electrical breakdown, mechanical failure

  • The effect of the carrier composition on the properties of the cobalt catalyst

    The article presents the results of a study of the physicochemical and catalytic properties of cobalt catalysts on a mixed zeolite-containing carrier. Samples of catalysts containing 10% cobalt and from 30 to 70% high-silica zeolite ZVM were prepared by impregnation with subsequent heat treatment. Methods of IR spectroscopy, scanning electron microscopy (SEM) in combination with energy dispersion analysis (EMF) were used to study the physicochemical properties of catalysts. The catalytic properties were studied in a reactor with a fixed layer at a temperature of 240 °C, a pressure of 20 MPa, a volumetric gas velocity (OSG) of 1000 h-1, H2 / CO = 2. As a result of IR spectroscopy, the presence of Si-O, Al–OH, Co–O, etc. functional groups was detected, SEM–EMF images confirmed the uniform distribution of cobalt on the surface of catalysts. The dependences of the catalytic characteristics depending on the content of zeolite were established, the maximum activity was recorded for a sample containing 70% of ZVM zeolite.

    Keywords: catalysts, Fischer-Tropsch synthesis, cobalt, zeolite, carrier, IR spectroscopy

  • The method of numerical calculation of water flow in multi-node sections of rivers

    The method of numerical calculation of the parameters of the river channel in the arms is given. The method of nonlinear programming for analysis of dissipative systems with concentrated parameters is used. The technique is focused on computer modeling in the environment of engineering package MathCad. The results of the experiment are given.

    Keywords: Distribution of water flow, calculation method, multi-node sections of rivers, water flow

  • Secondary use of ash and slag waste in road construction

    The increasing problem of the formation of ash dumps in the Rostov region dictates the need to search for environmentally friendly methods of waste disposal in the heat and power sector. In this article, the ash and slag waste of the Novocherkassk GRES is considered. We analyzed the chemical and fractional compositions of the ash-slag mixture formed at a coal-fired thermal power plant and proposed the use of ash waste with a size of 10-100 microns in road construction as a micro-filler. To study the strength of the road surface using ash microparticles, we manufactured and tested cubes of modified concrete mixture for compression using a press machine. The obtained result showed that the use of ash as a micro-filler in concrete does not affect its strength in any way. The tests of control samples with the use of ash wastes showed an improvement in the water resistance and frost resistance of concrete while maintaining its strength.

    Keywords: ash and slag waste, micro-filler, concrete mix, road construction

  • Application of machine learning and natural language processing to develop a recommendation system for the selection of perfumery products

    The paper discusses the use of machine learning in relation to natural language processing (sentiment analysis, semantic proximity analysis) to build a recommendation system for the choice of perfumery products. The topic of the work is relevant in view of the growth of the range of manufactured perfumery products and the complexity of its choice by consumers and promotion by manufacturers. The proposed approaches are relevant for solving this problem due to the accumulated textual reviews and reviews of perfumery products on various websites, including online stores.

    Keywords: machine learning, natural language, sentiment analysis, distributive semantics, word2vec, recommender systems

  • Air quality monitoring for building environmentally friendly routes

    Many sources of environmental pollution affect human health. The concentration of harmful substances constantly changes during the day when the weather conditions change in different parts of the territory. Residents can repeatedly enter and leave areas of increased pollution without noticing it with their senses when moving around the city. The authors analyzed the existing solutions for monitoring the quality of atmospheric air, as well as key sources of pollution and their distribution in the air. The interrelation of distribution of pollutants with weather conditions is noted. Preparation of data on the presence of harmful substances on the example of the city of Volgograd has been carried out. A method for organizing monitoring of harmful substances in the atmosphere using a software and hardware complex is proposed. The developed method was applied to create a specialized web application. The implemented solution allows to monitor the state of the environment using sensors and build routes around areas with a high concentration of harmful substances.

    Keywords: environment, air quality, air pollution, ecology, monitoring, web application, eco-route, spatial data, route building, cartographic visualization

  • Evaluation of the operational efficiency of road trains-chip trucks

    The paper presents an evaluation of the efficiency of the use of road trains for transporting fuel chips during operation in real natural and industrial conditions through the variability of the coefficient of adhesion weight (kst). The authors of the paper note that the transport and transposing aspect of the technological process is especially important in the formation of efficient technological chains for the production of biofuels and, in particular, wood chips for energy purposes. The analysis showed that it is rational to use wood chip trucks based on all-wheel drive vehicles (6x6) to ensure movement in all modes when operating in complicated and challenging conditions on road surfacing in an unsatisfactory condition. Vehicles for transporting wood chips for energy purposes, manufactured in Russia and Belarus, are at the level of foreign analogues in terms of the main technical and economic indicators, and in some cases surpass them.

    Keywords: forest bioenergy, transportation of fuel chips, wood chip trucks, cohesive weight coefficient, cross-country ability

  • Application of modern digital tools for precision determination of microhardness results on the surface under study

    The application of the results of hardness measurements and its modeling in CAD as a 3D model is considered. Different welding modes were applied and electrodes CT-15, OZL-8 and CL-11 were used as consumables. The test material is a hot-rolled pipe with a diameter of 159 mm made of corrosion-resistant steel 12X18N10T with a thickness of 6 mm. The electrodes were fused to half its length and removed from the electrode holder, after cooling the remainder of the electrode, it was reused. For scanning measurement of microhardness of samples with a load of 100 g, the scanning step was applied 0.5 mm. The use of modern software was able to more accurately simulate the test results on a 3D model. The samples are welded with CT-15 electrodes at a maximum current of 100 A. the hardness is over 450-550 HV, regardless of what the passage was. Similarly, when welding with OZL-8 brand electrodes, but only at low currents, the hardness exceeds 450 HV. In both electrodes, the hardness is increased. When using OZL-8 electrodes, samples welded at high currents have less hardness than at low currents. When welding with these electrodes, it is possible to use them in certain passages, for example, when surfacing the root layer of the seam. In the case of full penetration in high-current modes with CT-15 electrodes, the result differs little as in low modes.

    Keywords: steel 12X18N10T, multi-pass welding, welding of austenitic steels, pipe, coated electrodes, welding modes, mechanical properties, macrostructure. Excel, Autodesk Inventor, CT-15, OZL-8, CL-11, amperage

  • Development of a method for searching for clinical trials by including factors

    The results of clinical trials are the main source of information in the implementation of medical activities in accordance with the principles of evidence-based medicine. At the moment, there are no information systems that would allow a doctor to select clinical studies within the framework of nosology that best match the profile of a particular patient, in order to further analyze their results and select therapy. The aim of the study was to improve the existing process of searching for clinical trials by using the prioritization method according to the inclusion criteria set by the doctor during the selection. To achieve this goal, the following tasks were implemented, namely, the process of selecting and searching for clinical trials by doctors was studied and the method of searching for clinical trials by doctors and the allocation of the necessary criteria was worked out. The team of authors proposed an algorithm for searching for clinical trials according to inclusion criteria, which in turn will significantly increase the effectiveness and reduce the time for searching and choosing therapy.

    Keywords: clinical studies, criteria search algorithms, criteria search methods, including factors, search for the nearest class, services

  • Comparative analysis of the stability of steel and polymer pipelines to seismic impact

    The seismic activity of the zones through which the pipelines are laid has always caused serious concern. The analysis of emergency situations on pipeline systems caused by an earthquake revealed factors affecting their stability: longitudinal and transverse displacement of the soil, the effect of soil liquefaction, faults resulting in open cracks and shear deformations. To prevent damage to pipelines during seismic impact, it is necessary to take into account the nature of the impact on the pipeline structure, the required level of safety for this seismic impact. Currently, special attention is paid to structural solutions and materials from which pipelines are made. The conducted studies allow us to form an approach to assessing the operability of polyethylene and steel pipelines in earthquake-prone areas, and on the basis of a comparative analysis of their stability, to make recommendations on the use of pipelines under specified conditions.

    Keywords: hydrocarbons, analysis, pipeline, reliability, seismic impact, deformation, composite materials

  • Volumetric modeling of a microwave liquid heater

    This work is devoted to modeling the absorption of microwave electromagnetic field energy in a device for milk pasteurization. Using CAD FEKO, a 3D model of the device was built and its operation was simulated. A study was made of the influence of the tilt angle of quartz tubes on the distribution of the electromagnetic field in the waveguide. The influence of the diameter and material of the tubes is also considered. The distributions of the electric field and the specific power absorbed per kg of dielectric in the waveguide are obtained. The accuracy of the results was assessed.

    Keywords: pasteurization, microwave, heat treatment of dielectrics