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

  Polypyrrole is a perspective material for gas sensors. Property of polymeric chains can vary largely depending on their packing. Power characteristics are studied. Features of a structure and power tetramers thiophenes with methyl, ethyl, propyl substitutions in position 3 pyrroles a cycle are investigated. The most perspective and stable tetramers are revealed from the thermodynamic point. The estimation of laws of formation of a polymeric chain is spent.  Influence of the assistant on stability tetramers is considered.

Keywords: Polypyrrole, quantum-chemical research, influence of alkyl substituents, tetramer, cycle, polymeric chain, power tetramers

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

  Work is connected with the synthesis of information behavior of groups of autonomous intelligent agents of biomedical research, and machine learning methods to ensure the reliability of the forecast increase in their behavior using multi-agent systems based on the use of bionic principles, methods and models of swarm intelligence. Developed multi-agent system simulates the behavior of groups of autonomous intelligent agents developed methods to meet the proposed criteria of reliability, differing form the structure of the system and developed a set of specialized agents that provides the capability to model a group of biomedical robotics using autonomous intelligent agents. Classifier of stabilographic signals on the basis of Parzen method was developed. These data indicate that the auxiliary symptoms resulting from multidimensional scaling much more informative initial attributes.

Keywords: Intelligent agent, multidiagnostics, Parzen classifier

The features of circuit engineering and results of chip computer simulation which consists of 4-channel operational amplifier (op amp) and 2-channel electrometric voltage follower, designed for pre-processing of sensors signals in high-energy physics are considered. 
The characteristic properties of designed op amp are the absence of current source in the input differential stage and the use of parallel high-frequency channel for increasing of the bandwidth and slew rate.
The results of experimental research that have confirmed the low sensitivity of the parameters of designed integrated circuits created on the field programmable gate array "FGPA-1.3" without the horizontal p-n-p transistors to the influence of gamma-irradiation and electrons with energy of 4 MeV are given.  

Keywords: operational amplifier, field programmable gate array, voltage follower, sensor, sensing element, radiation resistance.

  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

  The purpose of investigation is to examine the effect of adaptation to difficult-house physical stress on the regulation of the vertical posture of man. For the analysis of the ability to maintain a vertical position used stabilographic hardware-software complex "Stabilan-1-02" (JSK Rhythm ", Russia). The ability to maintain a vertical position was evaluated in two static positions: 1) the main stand (OS) in the presence and absence of visual information, and 2) dip (PP) in the presence of visual information. Revealed that an increase of physical performance ability to maintain balance in static positions, especially in the complicated conditions (deprivation of visual information and static muscle tension) increases.

Keywords: Sports stabilometry, adaptation, vertical pose

  Regarding the structural evaluation of the instrumental error of bio MIS tool software package was developed that allows to take into account the error in the analysis of clinical diagnostic measurement in hematology research. It allows to analyze the results of hematological measurements with the measurement error and issue you with a message that characterizes getting results within normal or unreliability. Nanoparticles in biomedical analytical measurements are used as contrast agents, since, being immobilized specific proteins with adhesion to the diseased cells and bacteria. Register ultrasonic signal produced when the laser blood flow to the entered nanoparticles allows the detection and enumeration of diseased cells. The block diagram of analytical studies was designed to prove its basic metrological characteristics. Research is conducted in the centers for collective use of the Southern Federal University "Nanotechnology" and "Laser Technology", equipped with modern and unique nanotechnology research equipment.

Keywords: Bio MIS, nanoparticles, hematological measurements

Technique for measurement of inductances (L) about 1 nanohenry or less one, is discussed. Two measurements of inductance L are executed. First one is executed for stub length l0, another - for stub length, shortened into N times. Formula for calculation of unknown inductance’ error has been obtained, where determination of unknown L with error closed to meter error has been succeeded by choice of parameters. It is shown that required measurement’s error of initial stub length for N=2 and N=5 is in tens micrometers’ range. Techniques for error’s diminishing have been considered. Estimation for basic stub length of 6,6 mm and 8,3 mm for N=2 and N=5 respectively has been executed. 

Keywords: inductance, least-squares procedure, meter error, stub base

The influence of fine-dispersed mineral adds on the properties of cement stone and concrete has been investigated. The possibility of production of necessary strength concrete with small sand without increasing of standard expenditure of cement has been designed.

Keywords: concrete, strength, small sand, add, mineral powder, cement, reduction, expenditure

Submitted manufacturing operations performed at the landfill site TOP, their main types of negative impacts on the environment. The conditions of formation and emission of biogas generated in the interior of the landfill body and having a pronounced toxic effects. The dependence of the specific biogas yield for the period of his active stable generation.

Keywords: Solid waste consumption, landfill disposal TOP, biogas, wet waste, environmental safety

In article it is spoken about use of logistic approach at tariff setting on city passenger transport

Keywords: Logistic approach, tariff, tariff setting, passenger transportation, passenger transport

The paper discusses the features of method of extension of circuit’s operating frequency range of the source and the classical emitter voltage follower (VF). The features of this method based on the effect of the mutual compensation of the parasitic impedances are considered. Problem of improving operation speed of VF with output capacitance and reducing the time of establishment of transient at pulsed input voltage are discussed.
The simulation results of VF in Cadence on model of SiGe integrated transistors are given. This shows that with capacitive load high-frequency cutoff, the time of establishment of transient and the slew rate improved to tens - hundreds of times. 
The results of investigate complement of methods of improving operation speed of the classical stage with a common drain and common collector.

Keywords: operating frequency range, source follower, emitter follower, operational speed, broadband amplifier

In work infinitesimal bendings surfaces of positive curvature with edge, subordinates on edge of external communication of the mixed type are studied. It is established quasicorrectness such external communication provided that the vector field belongs to a surface

Keywords: a surface of positive curvature, infinitesimal bendings, a field of displacement, a field of rotations, own vector field, modelling problem