In this article the basic parameters required for residual life assessment and life extension of the technical condition of water or long operated facilities. Inlet water or prolonged use many facilities design elements out of order it - complete destruction of concrete structures water conveyance structures, the formation of defects, normal operational performance of the design water conveyance facilities, such as violation of butt joints, as well as the destruction of the individual elements of the structure, etc. During the development of methods for extending the life cycle of water conveyance structures are obtained by the use of impervious geotextile cover that make for a correct evaluation of residual life of structures may extend its operational life cycle. The question arises of the need for correct and timely manner and to assess the remaining amount of the carrying capacity of water conveyance structures, to evaluate the technical condition and extend its life cycle. To do this, we can apply the proposed impervious geotextile cover.
Keywords: hydraulic structures, water-conducting structures, life cycle, residual life, technical condition
The article describes the method to assess the social and economic efficiency of bringing workplaces to the requirements of standard of health and safety. The article considers the possibility of calculating the individual groups of social and economic indicators in accordance with the evaluation of various schemes.
Keywords: social and economic efficiency, assessment methodology workplaces, standard of labor protection, labor conditions
The article describes one of the possible ways to improve the durability of roofing bitumen-emulsion mastics used in the repair and new construction due to the introduction of surfactant inhibitors.
Keywords: SAW inhibitors, roofing, mastics, durability, modifiers
Considers the most important sources of material pollution of urban territories. A comprehensive approach to studying properties of pollutants, based on the theory of disperse systems. Built block diagram of systematization of parameters that determine the behavior of contaminants from the position of theory of disperse systems. The dependence between the behavior of pollutant aerosol and parameters of its stability.
Keywords: Contaminant dispersion system, the parameters of pollutant properties, stability of pollutant aerosol
This paper presents key capital structure determinants of construction companies and their impact on fund raising and financing mix formation in accordance with the conditions of construction activity. It was found that profitability and tangibility have a positive effect on leverage, risk - the negative and the effect of company size, assets growth rate and taxes is ambiguous.
Keywords: capital structure determinants, profitability, risk, taxes, tangibility, construction companies
The article describes the main problems of circuit simulation. The problem of solving ill-conditioned systems of linear algebraic equations (SLAE) of large dimension. The modified algorithm is a linear algebraic solutions. Described a hybrid evolutionary algorithm for solving linear systems based on the proposed modified method. The results of the pilot study and comparison of the algorithm with the algorithms based on the traditional methods for solving linear algebraic equation, which confirm the advantages of the hybrid evolutionary algorithm.
Keywords: Genetic operators, evolutionary algorithm, the system of linear algebraic equations, computer-aided design.
The establishment of automated air monitoring systems is a promising way of the air monitoring devices development. The comparative analysis of literature has shown that thin films based on semiconductor metal oxides are effective and widely used material for air monitoring systems creation. In order to create effective and more sensitive sensors it is important to research processes that occur on the surface of the gas sensitive material when it contacts with different substances. The processes that proceed on the surface of gas sensitive material based on SiO2SnOxCuOy during the interaction with molecules of nitrogen dioxide. Quantum chemical calculations have shown that there are three possible mechanisms of interaction between the molecules of nitrogen dioxide with a surface of gas sensitive material.
Keywords: multitouch system of the monitoring, gas-sensitive material, molecules of dioxide of nitrogen
The mathematical model of the potential distribution in the semiconductor surficial region in the presence of deep-lying levels in its forbidden zone which specified by multiple-charge impurity centers has been developed. The simulation results can be used for the width of the space charge region estimation, for the prognostication of the most probable mechanism of the charge carriers transfer in metal-semiconductor structure with multiple-charge deep-lying levels and also for the prognostication of the barrier capacitance value. It can be used in the development of solid-state electronic devices with improved values of some parameters.
Keywords: Poisson’s equation, multiple-charge impurity center, potential distribution, deep-lying levels
Results of researches of gas sensitive properties of zinc oxide films grown by reactive rf magnetron sputtering was shown. Process parameters, affected on the gas-sensitive ratio, response time, recovery time and the type of electrical conductivity of obtained films were identified. Optimal modes of magnetron sputtering of zinc oxide for implementing gas sensors (RF sputtering Zn target in a gas mixture of oxygen and argon at a concentration of 80% oxygen, a chamber pressure of 0.8 Pa and the magnetron power 100 W) were established. Avarage response time on NO2 gas was 5-15 sec. The obtained values of the gas-sensitivity were in the range 30-67% for NO2 concentrations from 20 to 100 ppm, CO and CO2 from 50 to 100 ppm and 81-97% for higher gas concentrations from 500 to 1000 ppm.
Keywords: Nanotechnology, magnetron sputtering, zinc oxide, thin films, gas sensitivity
In this work researches of structural and electrophysical properties of ferroelectric films of lead zirconate titanate (PZT) which afterwards is planned to apply in hybrid sensor systems are done. Values of capacities of the received samples are in the range from 200 to 1100 pF, the range of thickness of the received films is 300-1000 nanometers. X-ray analysis showed direct dependence of the quantitative maintenance of crystalline PZT in film structure from partial pressure of oxygen in the camera. By results of research the range of polarization of samples are in the range 0,06 – 2,2 µC/cm2, and values of calculated piezoelectric modules are in the range 0,04*10-12 – 13,3*10-12 C/N.
Keywords: sensors, segnetoelektric films, touch systems, piezoelectric modules.
The article investigates the impact on the normal stresses of inequality of the young modulus for tension and compression in the bending of reinforced beams. Obtained formulas for determination of the bending moments that arise in the fixture, compressed and stretched zone of the aggregate. Found the formula for the normal stresses arbitrarily supported reinforced beams, arbitrary cross section and arbitrarily loaded bending loads. For example, reinforced beams of rectangular cross-section shows the determination of the neutral line and maximum stresses.
Keywords: reinforced beam, elastic modulus, stress, normal concrete
Cracking of reinforced-concrete elements with holes is examined. Comparison of theoretical and experiment moments of crack’s formation during torsion, and during intensive torsion with twist. Formula for practical calculations of cracking of reinforced-concrete elements with holes during torsion and formula for estimate of cracking of reinforced-concrete elements with holes during intensive torsion with twist is suggested.
Keywords: Crack, twist, torsion, reinforced-concrete, elements, hole, beam
A principle of spectrometric systems of gas sensors was described. A model and a method of numerical modeling of spectrometric gas sensor with the combined radiator-receiver of infrared radiation on the basis of the punched semiconductor thermoresistor were proposed.
Keywords: spectrometric gas sensor, model, method of modeling
Classical implementation of active selective amplifiers (SA) are usually associated with design sophisticated active elements (operational amplifiers) that consume relatively large power from their universality. This paper present the active SA based on an analog array chip ABMK_1_3, that have high level of radiation resistance to the flow of neutrons and accumulated dose of radiation. This SA implemented on the basis of a voltage-to-current converter with a minimum number of transistors and low consumption static current. Efficient use of current amplifier can be explained by use frequency dependent symmetric chains in a feedback loop. This property provides the independence of the pole frequency f0 = fp on the gain of the active element, as well as maximizing the quality factor.
The basic analytical expressions that establish the relationships between the SA and the characteristics of active and passive components are given. The relations that help minimize sensitivity of parameters SA to instability properties of the components are considered. Simulation results of desired SA are shown.
Keywords: selective amplifier, bandpass filter, active RC-filter, analog array chip, radiation hardness
The requirements to be met by a data acquisition system in terms of each of the problems to be solved. Presented electric concept developed biopotential amplifier with a total gain of 2000. The theoretical model of the spectrum of RR intervals and changes depending on the running processes. The analysis revealed that the resulting spectrum satisfies the conditions considered in the theoretical model, and can be further analyzed with fractal characteristics.
Keywords: Instrumental amplifier, biopotential, fractal index