The article presents theoretical calculations and studies of the possibility of parametric oscillations and parametric resonance arising in a polymer self-supporting thermoplastic pipe "Furanflex". The Furanflex thermoplastic, polymer liner is offered as a variant of a separate gas exhaust trunk during the reconstruction of boiler rooms and thermal power plants by heat generating companies.The article provides a detailed description and analysis of the occurrence of parametric oscillations. Examples of symmetric and asymmetric parametric oscillations are considered.Information and conclusions of the presented work are intended for a different range of readers, teachers, designers, students of construction specialties.This article should be of interest to utility managers and heat generating companies .

Keywords: chimney, ventilation duct, corrosion, repair, restoration of the chimney, condensate,protection of the chimney, lining, furanflex, thermoplastic liner,perimetric oscillation

The equations of multiple regression of air quality from factors affecting external sources of emission in the urban environment are obtained. A prototype of a forced air supply ventilation valve with air purification, placed in the outer wall of the building, using various sorbents together with a photocatalytic filter (a thin porous plate coated with titanium dioxide next to two UV lamps, UV-A range, 365 nm, 6 W each) was developed. Full-scale studies of five options for purifying the supply air were carried out. High quality of outdoor air purification from pollutants has the following options: shungite; zeolite; silica gel; photocatalytic filter, its purification efficiency was 96.39-99.98% for carbon oxide (II), 96.39-97.89% for phenol, 95.76-97.78% for formaldehyde, and 93.97-95.12% for aliphatic hydrocarbons (C1-C5). The results obtained can be used in multi-storey construction.

Keywords: forced air supply valve, prototype, pollutants, sorbent, shungite, zeolite, silica gel, photocatalytic filter

In this paper, we propose the option of constructing a multi-channel system of quantum key distribution with frequency coding, based on an electro-optical scheme of a system of quantum key distribution (hereinafter QKD) with pairs of amplitude modulator and phase modulator on the Alice side, and pairs of phase modulator and amplitude modulator on the Bob side ( hereinafter referred to as AMPM-PMAM), using a Comb generator, a multiplexer and a demultiplexer to form multiple parallel quantum subchannels.

Keywords: quantum cryptography, quantum key distribution; frequency coding, electro-optical photon modulation, amplitude-phase tandem modulation

The article provides a study and calculation of the dependence of the hazardous area resulting from the operation of the flare equipment on the height of the flare at which service equipment and personnel can operate

Keywords: flare unit, radiation intensity, safe operation zone, thermal voltage

he article presents the results of evaluating the ability of activated sludge, saturated with anammox bacteria, to adapt to mesophilic and lower temperature operating conditions. As the main temperature regimes, temperatures of 30, 25, 15, and 13 ° C were selected. The system showed stable operation at temperatures up to 15 ° С with the highest degree of purification with respect to ammonium nitrogen - 0.33 mg / dm3. At the same time, the concentration of nitrites taking into account forced nitritation reached 0.07 mg / dm3. An additional increase in the efficiency of the system requires structural changes in the adopted technological scheme of the bioreactor, however, the introduction of an internal recirculation system of attached biomass (with load) inside the anammox department is considered as an essential element of the system that ensures stability

Keywords: nitrification, denitrification, activated sludge, aeration tank, anammox, biological treatment, domestic wastewater, low-oxygen treatment method, energy saving, resource saving, ecology

The issues of organization of works with the use of expanding concrete, which are reinforced with carbon fiber, are raised. An example of the use of modern technologies in construction is considered. It describes the solution of some specific problems that arise when maintaining the quality of construction of complex buildings, attention is paid to the peculiarities of improving the quality of work performed.

Keywords: organization of construction; quality of construction and installation works

The article considers the results of development of water treatment technology for household drinking water in Semey, presents a comparative analysis of widely used disinfectants, and considers technological schemes for water disinfection with chlorine dioxide and a combined disinfectant " chlorine dioxide and chlorine".

Keywords: household drinking water, disinfectants, chlorine

This article presents the results of a parameters study on a piezoelectric flexible transducer of a beam type. The analysis was performed by the finite element method using the ANSYS Multiphysics software package. It is shown that there are optimal parameters ratios of the structural elements of the transducer under study for which it is the most effective

Keywords: bending-type piezoelectric transducer, piezoelectric element, elastic plate, resonance frequency, conversion coefficient, Electromechanical coupling coefficient

An impact on mechanochemical activation on morphology and structure of wood cellulose was examined. A comparative analysis of structure of sheet cellulose and fluffed cellulose was made using infrared spectroscopy and scanning microscopy. It was given that the cellulose I tranformed into a modification of cellulose II with more reacting power as a result of pulping. It ascertained that mechanochemical activation of the cellulose can increase the physical and chemical indicators of technical carboxymethylcellulose.

Keywords: cellulose, mechanochemical activation, carboxymethylcellulose

The equations of spinodal decay in binary systems in which there is a phase transition-improper decay are obtained. For the first time, spinodal equations for a phase transition with one multicomponent order parameter (two one-component) are obtained.

Keywords: binary solutions, spinodal decay, structural phase transition

The paper considers the results of research on the use of various types of approximations of concrete deformation diagrams on the example of calculating a large-span reinforced concrete truss with a length of 18 m. calculations were performed taking into account the physical nonlinearity of concrete and reinforcement. The following concrete deformation diagrams were used : bilinear, trilinear , and curved with a descending branch. The result of the calculation was the forces in the truss rods, the displacement and the width of the crack opening. Conclusions were made about the influence of the choice of the concrete deformation diagram on the calculation results.

Keywords: concrete, deformation diagram, approximation, physical nonlinearity, stress-strain state, longitudinal force, bending moment, displacement, crack resistance , truss

The article deals with the reducing issues the time spent of making informed decisions by automating the workplace of a transport engineer on the basis of the development and use of methods for selecting and calculating the number of vehicles for servicing remote objects. A specific example based on the transport service of electric power facilities, which can be implemented in any software of the organization, is considered

Keywords: Workplace automation, transport operation engineer, transport service, electric power facility, calculation of the number of vehicles.

The article presents the results of a study of the deflections of a monolithic flat floor with a different grid of columns with prestressed reinforcement without adhesion to concrete. To analyze the deflections, numerical studies of slabs with different rectangular columns and thicknesses were performed. The studies were performed using the LIRA CAD software package. The aspect ratio of rectangular cells of monolithic flat floors is determined, for which the application of prestressing is ineffective on the short side of the cell or most effective on the long side. It was revealed that the use of high-strength reinforcement of the "monostrand" type is most effective for a grid of columns 5x9m from the volume of the studied cell sides. It was found that the application of post-tension on the short side of the slab cell practically does not affect the total deflection of the cell - with the aspect ratio a / b> 1.2. The conclusion is drawn about the increase in the efficiency of using contour reinforcement with an increase in the deflections that affect the amount of rope repulsion. The results can be used in the design of slabs using prestressed reinforcement without adhesion to concrete of the "monostrand" type.

Keywords: rope, high-strength reinforcement, finite element, monostrand, repulse, prestressing, post-stressing, deflection

The article presents a program of comprehensive construction and technical expertise of the structures of an industrial building. The features of the construction and technical expertise of the structures of the agricultural warehouse of mineral fertilizers are described. An algorithm of the sequence of actions for the technical expertise of the structures of the object is developed. Measures have been developed to repair and restore the working condition of damaged structures

Keywords: construction and technical expertise, defects, bearing capacity, structural repair, property management

The publication is devoted to the task of developing a demo-genetic model of the adaptation of pests to transgenic and hybrid agricultural crops, taking into account the type of taxis. An assumption is introduced that the dynamics of hybrid agricultural crops can be investigated using demo-genetic models. A description of the problem is given in accordance with the characteristics of the growth of biomass of agricultural crops and the dynamics of pests, as well as taxis species. The modeling of the processes of fast and slow taxis depending on the behavior of pests at a particular point in time is described in detail, taking into account the type of their genotypes that affect the acquisition of mutations. The paper describes the features of the physiological structure and life cycle of insect pests, affecting the prediction of their spatial concentration and, accordingly, the prediction of productivity; the possibilities of their application in mathematical modeling.

Keywords: demo-genetic model, taxis, transgenic agriculture, hybrid, pest, biomass, diffusion