The article demonstrates a computer model of a fiber-optic sensor implemented on the basis of a two-frequency optoelectronic generator (OEG) for measuring lateral pressure. In the loop of the optoelectronic generator, a fiber Bragg grating (FBG) with a phase shift is applied to which a transverse pressure is applied to guide the birefringence and create two orthogonally polarized transparency windows, which leads to the generation of two optical frequencies. The difference frequency of the beats between the two optical frequencies lies in the microwave range and depends on the magnitude of the pressure applied to the FBG. It was modeled that the sensitivity and the minimum detectable pressure are ~ 10 GHz / (N / mm) and 2.5 × 104 (N / mm), respectively. The high frequency and stability of the generated microwave component of the optoelectronic generator provide an extremely reliable and highly accurate measurement. Frequency survey allows the system to operate at high speed. In addition, the measurements are insensitive to changes in the ambient temperature and the wavelength of the optical carrier.
Keywords: transverse pressure, fiber optic sensor, fiber Bragg grating with phase shift, birefringence, optoelectronic generator, two-frequency optical signal with microwave frequency difference frequency
In the present article the current state and the main problems of nondestructive control methods of working shovels of turbomachines are considered, scopes of nondestructive control methods in a flowing part of turbomachines are defined. The main control methods are considered; the reasons limiting possibilities of these methods are defined; the geometry of shovels, stream parameters, the main defects are defined; are considered hot and cold start-up; gasdynamic control methods are analysed; acoustic control methods, the systems of scanning of a cut of a nozzle are defined; the analysis of systems capable to exercise control of operability of a flowing part of turbomachines is carried out; the mathematical models describing acoustic processes in a flowing part of turbomachines and a way of their improvement are designated. The current state of works on creation of the methods and control devices aimed at improvement of metrological characteristics and expansion of functionality of an acoustic method of nondestructive control of working shovels of a flowing part of turbomachines on a nozzle cut is analysed. For control of working shovels of a flowing part of turbomachines it is necessary to use informative and reliable parameters in complex structure of their understanding. Defects in working shovels of a flowing part of turbomachines are found in operation at surveys by various devices therefore development of the minimum defect to greatest possible can happen for a short time interval that will lead to an emergency. The existing means of regular control прогар shovels don't come to light because of the depth or a sektornost for the reason that defects of motionless parts is insignificant a little influence vibration characteristics of the engine in general. Whereas defects in mobile parts can be revealed also sensors of vibration.
Keywords: distributed fiber systems, аero acoustic control, acoustic field, process simulation, recovery
The present article is devoted to development and a research of the distributed fiber systems of aero acoustic control of parameters of an air-gas stream on a cut of a nozzle of turbomachines. The main emphasis is placed on development and to a research of the distributed fiber systems on the basis of control methods the using multiplexed fiber-optical sensors of control of parameters of an air-gas stream on a cut of a nozzle of the turbomachines using advantages of optical methods of information transfer and the device for his realization. The principles of creation of the complex systems of aero acoustic cartography complemented with methods and measuring instruments of gasdynamic parameters of a stream in a flowing part and on a cut of a nozzle of the turbomachines directed to increase in informational content and level of algorithmization of nondestructive control of a condition of working shovels and providing data acquisition in the conditions of parametrical and structural uncertainty of an air-gas stream as on controlled internal sections of a flowing part, and on output section on a turbomachine cut are defined. Problems of placement of points of control and restoration of spatial distribution of the field of measurements in discrete set of points separately are considered. Restoration of the acoustic field of turbomachines is implemented according to measurements at the exit of WATERS, only using statistical approach. Restoration of the field is presented in the form of continuous functions of spatial coordinates by results of measurement in discrete set of points in the presence of aprioristic information on properties of the measured fields. Statistical approaches for determination of coordinates of sensors and an error of restoration on the example of one model problem of control of the field of the radiation created by the continuous exclusive radiator are used. Results of calculations show that existence of correlation between coefficients of decomposition of the field of radiation on functions, leads to reduction, necessary for achievement of the set accuracy of restoration of number of sensors.
Keywords: distributed fiber systems, аero acoustic control, acoustic field, process simulation, recovery
The article describes the use of high-intensity magnetic stimulation (IUD) apparatus in patients with sarcopenia who underwent total knee arthroplasty. For this purpose, the magnetic stimulator “Neuro-MS” and the electroencephalographic apparatus “Neuron-Spectrum-5” were used. Based on electroencephalography, the dominant spectral peak (DSP) of the alpha rhythm and theta rhythm of the motor area of the patient’s brain was determined. The use of the device allows you to reduce swelling, the intensity of pain, restore muscle strength, increase the range of motion in the operated joint.
Keywords: High-intensity magnetic stimulation, HIMC, sarcopenia, total knee arthroplasty, TKR
A method, a device and an experimental model were developed to control the cooling and providing effective low temperatures during cryosurgical treatment of bone tumors. Using the developed device, a range of effective temperatures was determined under the action of liquid nitrogen on the model of the bone cavity. Two ways of cooling the residual bone cavity, instillation and contact, were compared. During the experiment it was proved that the contact method of cryoexposure on the residual bone cavity model is more effective than the instillation of liquid nitrogen according to the characteristics of the temperature field. The proposed experimental model of the residual bone cavity makes it possible to study the temperature field, determine the rate of freezing and thawing both with the contact method and with the instillation of liquid nitrogen into the bone cavity. The results obtained allow to develop preliminary recommendations on the technique of carrying out cryosurgical ablation of bone tumors.
Keywords: cryoprobe, experimental model, tumors of bones, cryosurgery
At present, the problem of measures of the protection against distortion of measured and calculated parameters by signals corresponding to the third harmonic of the mains frequency is quite acute, which is the main parasitic signal entering the distribution networks.The purpose of this study is to develop a technique for reducing distortion caused by the third harmonic frequency in distribution networks.This is achieved by the fact that in each half of the period of the frequencies of the electric network are additionally determined by the times corresponding to 5/6, 4/6, 2/6,1/6 of its part, measure the value of the measured signal at each additional time, sum the values obtained in the main and additional moments in n adjacent halves of the period, calculate the average amplitude value of the signal for n adjacent half periods, and the average amplitude value of the measured signal is obtained by dividing the obtained value by a coefficient equal to 1+√3/2+ 1/2.
Keywords: measurement error, distribution grid, third frequency harmonic, device for measurement and calculation of electrical parameters
Modern distributed temperature control systems are used today everywhere, in particular, in the telemetry of oil and gas wells. Thus, when creating a distributed fiber-optic temperature sensor based on Raman scattering (DTS) for these purposes, the problem of improving its metrological characteristics always remains urgent. They are in turn determined by the known SNR (signal-to-noise ratio, SNR from English Signal-to-Noise Ratio). To achieve this goal, it is proposed to use a promising method of increasing the SNR in the DTS based on encoding the probing sensor signal by the Hadamard code sequences (simplex coding). For this purpose, a numerical experiment is carried out to implement this coding method using the DTS model and taking into account the noise of the photodetector device. The article presents the simulation results, confirms the effectiveness of the coding method, and summarizes the results of the simulation.
Keywords: distributed fiber optic temperature sensor, Raman scattering, photodetector device, noise, signal-to-noise ratio, optical pulse encoding, Hadamard code, simplex coding
The article proposes the use of a table processor to reduce the complexity of applying the probabilistic paper. Based on the written methodology, the measurement results were processed. Further ways of developing the methodology are suggested.
Keywords: metrological assurance, probabilistic paper, normal distribution law, OpenOffice Calc, MS Excel
The article considers the application of criteria for assessing the quality of segmentation of digital images of sputum stained by the method of Ziehl–Neelsen to select the optimal parameter "Sigma" wavelet transform Mexican Hat. 830 digital images obtained by sputum smear microscopy were used as the study material. To assess the optimal selection of the parameter σ, we used the average number of objects selected in the images, the proportion of missed acid-resistant mycobacteria in the images, the homogeneity criterion and 3 complex criteria for assessing the quality of image segmentation. The analysis showed that with an increase in the parameter σ there is a slight decrease in the value of the homogeneity criterion. At the same time, the parameter σ increases from 2.4 and more according to the complex criteria, and the image segmentation quality improves. Thus, the most optimal values of the σ parameter of the Mexican Hat wavelet for segmentation of digital images of sputum stained by the cyl-Nielsen method are values in the range from 2.90 to 3.09.
Keywords: method Ziehl-Nielsen, image segmentation, quality evaluation criteria, wavelet transform, Mexican Hat
The multi-advantageous fiber Bragg gratings (FBG) have attracted considerable interest from developers of various optical systems, including communication systems with spectral and code multiplexing, as well as fiber-optic and radio-photon sensor systems. The complexity and high cost of multiplexing and interrogation of complex fiber-optic sensors (CFOS) is still the main limitation for the widespread introduction of sensory systems, both distributed and quasi-distributed, and point-type.This article proposes a new multiplexing method that takes advantage of both broadband fiber-optic and dual-frequency or polyharmonic radio-photon sensor systems. The simplest broadband radiator is taken from the first, but a complex and expensive system of spectrometry is not used to determine the central wavelength of the FBG. From the second, a recording system is used at the beat frequency between two components, but an expensive system for generating two- or polyharmonic sounding systems is not used. The multiplexing parameter is determined by the frequency of separation between two identical over-narrow-band FBGs, which differs by a certain amount from each of the CFOS and, in fact, generates its address. At the same time, FBG-based structures remain a sensitive element of the systems. Thus, a new class of sensitive elements is formed - address fiber Bragg structures (AFBS).
Keywords: radio-photon sensor system, address fiber Bragg structure, integrated fiber-optic sensor, interrogation, multiplexing, two identical over-narrow-band fiber Bragg gratings, frequency spacing, address
In this paper, it is shown that the noise of the photodetector device (PD) is the dominant factor limiting the metrological characteristics in real distributed fiber-optic temperature sensors based on Raman scattering (RDTS), which contribute significantly to the process of signal noise using the example of the RDTS taking into account the noise of the PD, which was chosen as the avalanche photodiode (APD). The analysis of the main types of noise in the model of an APD in the model, including both basic PD noise, and characteristic for APDs, for example, their influence on the signal-to-noise ratio (SNR). The graphs of the dependence of the influence of noise on the RDTS, derived from the SNR ratio, are given and conclusions are drawn about the predominance of some noise over others under different conditions, based on their.
Keywords: distributed fiber optic temperature sensor, avalanche photodiode, shot noise, dark noise, thermal noise, amplitude noise, signal-noise ratio, random number distribution law
In this paper proposed a statistical model of the optoacoustic transformation in the moving liquid medium using nanoparticles for a noninvasive blood analysis system. Since to increase the accuracy of measurements should take into account the probabilistic nature of the distribution of nanoscale objects as contrast agents in the blood stream in the human cardiovascular system. To determine the statistical characteristics of the component of the sound signal formed by a conglomerate of nanoscale objects using Monte Carlo simulation. Main static characteristics were calculated and the density distribution of the probability of the normalized amplitude of the sound signal was determined for a series of numerical experiments.
Keywords: optoacoustics, optoacoustic effect, flow cytometry, acoustic signal, carbon nanotubes, laser sound excitation, statistical analysis
The article considers the data of experimental studies of vibroacoustic characteristics of cranes on the railway track. The conducted researches helped to reveal identical regularities in the spectral composition of noise in cranes on the railway run of various models, which allows to develop a general approach to modeling of vibro-acoustic dynamics of these nodes.
Keywords: cranes on the railway run, working conditions, harmful and dangerous production factors
This article presents a new two-frequency method for determining the center frequency of a resonant microwave sensor for monitoring the curing reactions of thermosetting and thermoplastic resins and adhesives. The results show that non-invasive, continuous and continuous monitoring of the dielectric properties of polymers can be realized, which will allow to control the adequate evolution of the curing process according to known initial conditions. Examples of experimental measurements during the cure reaction of polyurethane adhesives were selected to illustrate the effect of the method. In comparison with the known methods, this method allows to increase the signal-to-noise ratio of measurements and their accuracy by performing the measurement procedure for the maximum signal and to the region of the minimal noises of the envelope detector. As a method development, in the conclusion, a method of variation of the difference frequency and microwave sensors in forbidden bands was proposed, which is due to the obtained results only from the measurement of the central frequency and the existing need to make measurements in real time and in a complicated interference situation, taking into account the changing quality factor and the reflection coefficient of the resonance sensor. The article did not focus on the simplicity and cost of the implemented device. However, the obviousness of this allows us to use the system as a means of control both for the production of polymers and for their laboratory research.
Keywords: microwave technologies, thermosetting and thermoplastic polymers, microwave measurements, resonance sensor, two-frequency symmetric probing, beat envelope, central frequency, dielectric constant, degree of curing
In this paper, we present a new two-frequency method for determining the resonant frequency, transmission bandwidth, reflection coefficient, and quality factor of a resonant microwave sensor for monitoring the curing reactions of thermosetting and thermoplastic resins and adhesives. The method was named - the method of variation of the difference frequency. The results show that non-invasive, continuous and continuous monitoring of the dielectric properties of polymers can be realized, which makes it possible to control the adequate evolution of the process of their curing by known initial conditions. The questions of the realization of the method are considered in the case of variations in the difference and mean frequencies of the probing oscillation, as well as the option for fixed sounding, provided that all four components of the two two-frequency oscillations are in the spectral band of the microwave sensor. In addition, an estimate is given for determining the error in measuring the resonance frequency when probing different zones of the spectral characteristics of the sensors from 0.1 to 0.707 of the maximum reflection value. The universality of the method makes it possible to use a measurement system based on it as a means of monitoring both the production of polymers and for laboratory research
Keywords: Microwave technology, thermosetting and thermoplastic polymers, microwave measurements, resonance sensor, difference frequency variation method, beat envelope, resonant frequency, Q-factor, bandwidth, reflection coefficient, dielectric constant, degree of
The magnetic type of control is used to detect discontinuities (cracks, non-magnetic inclusions and other defects) in the surface layers of parts made of ferromagnetic materials and to reveal ferromagnetic inclusions in details from non-ferromagnetic materials. Methods based on the investigation of magnetic scattering fields after their magnetization have become widely used to detect discontinuities in the material of the base metal of pipes and welded joints of the main and auxiliary equipment of oil and gas producing complexes. In places of discontinuity, redistribution of the magnetic flux and a sharp change in the nature of the magnetic scattering field occur. The nature of the magnetic field of scattering is determined by the magnitude and shape of the defect, the depth of its occurrence, and its orientation relative to the direction of the magnetic flux. Surface defects such as cracks, oriented perpendicular to the magnetic flux, cause the appearance of the most pronounced magnetic scattering fields. Defects oriented along the magnetic flux practically do not cause the appearance of scattering fields. The review and analysis of existing external magnetic scanners - flaw detectors showed that when examining auxiliary equipment tubes for longitudinal and transverse defects, at least five scanner models - three for longitudinal and two for lateral scanners - should be available. As a result of the accumulated experience, the enterprise of LLC ""Antenor"", in Yoshkar-Ola, initiated scientific research to develop a competitive product that provides high operational efficiency of the main and auxiliary equipment of oil and gas production complexes on the basis of non-destructive technologies for monitoring the technical condition of pipeline transport. For this purpose, a prototype of a dry magnetic flaw detector (SMD) from a series of non-destructive testing instruments for magnetic flaw detection of metallurgical, construction and operational defects in the material of a pipeline element made of steel, its alloys and other ferromagnetic materials. Taking into account the peculiarities of the magnetic control of discontinuities in the surface layers of parts made of ferromagnetic materials, the main task in the design of the SMD-T ""SATURN"" was to provide a sufficiently powerful magnetic field capable not only to magnetize the pipe body, but also to provide sufficient force to hold the scanner at the object of investigation.
Keywords: pipeline, diagnostics, magnetic flaw detector, auxiliary equipment, gas and oil pipeline, prototype, testing, scanning, magnetic field
The article presents the results of an experimental study of methods and means of technical diagnostics of the engine cylinder-piston group during cold, idle scrolling of the crankshaft
Keywords: cylinder piston group, gas flow from the crankcase, technical conditions of the experiment
It refers to the field of medicine, namely, to ophthalmology and to the field of medical instrument making. The problem of documentary fixation of the pattern of the fundus observed with the help of such devices with the purpose of assessing the long-term dynamics of pathological changes and determining the degree of success of the therapy is still relevant. The purpose of the development is to realize the possibility of automatic and semi-automatic documentary photo fixation of the results of the study of the internal structures of the eye performed with the help of a hand-held mobile ophthalmoscope while preserving the possibility of direct examination of the internal structures of the eye. The goal is achieved by adding to the ophthalmoscope optical, electromechanical and electronic components, which allow photographic fixation of the observed picture of the internal structures of the eye being examined. Advantages and positive effect of the complex being developed: 1. The possibility of automated photographic fixation of the observed image of the fundus allows improving the quality of eye pathology diagnostics by simplifying the documentation of its condition and facilitating the monitoring of the dynamics of this condition. 2. The non-contact nature of measurements determines the reduced requirements for disinfection of the device and for anesthetizing the eye; 3. Automation of the process of photographic fixation allows to reduce time costs for them and to shorten the time necessary for training personnel to work with the complex; 4. Communication of the photophthalmoscope with a PC provides a wide range of local and centralized storage, processing and systematization of research results.
Keywords: Ophthalmoscope, ophthalmoscopy, photographic fixation, eye fundus
The analysis of a two-dimensional scanner lens based on a triple lens system for a laser with a wavelength of 1.06 μm is performed. The first chapter indicates the scope and features of f-theta lenses. In the second chapter the initial conditions for the design of f-theta lens are given. In the third part, the simulation results, showing the parameters and efficiency of the system for 2 types of construction are given. The parameters and efficiency of the system are demonstrated. For each system, the optimal parameters are calculated, and the technical criteria for the possible application are outlined. The geometrical characteristics of the systems are shown, lens materials are described. A variant with a distortion of 0.0035% with a maximum focal spot of 24.9 μm was obtained.
Keywords: scanning system, f-theta lens, optical design, laser engraving, galvo
It refers to the field of medicine, namely, to ophthalmology and to the field of medical instrument making. In the field of ophthalmology, the actual task is to study the state of the vascular system of the eye, the changes of which are observed in many diseases. Currently, there are no non-invasive devices that allow performing an automated direct measurement of pressure in the vascular system of the eye and evaluation of the mechanical characteristics of the vascular wall of the eye vessels. The purpose of the work: the development of a hardware-software complex for eye pneumovazotonometry. The goal is achieved by synthesizing the circuit of a combined measuring device that combines the functions of measuring hemodynamics in the OCA and the IOP level. The complex includes a measuring module and external software for the PC, designed to work with this module. In the measuring module, a microprocessor control system can be distinguished; pneumatic system; ultrasound system; system of video registration; system of indication and control; system of communication with PC; power supply system.
Keywords: Anterior ciliary arteries, pressure, measurement, ophthalmopneumovasotonometry
Modelling and experimental research of narrow band filter on opposing rods was made. Center frequency is 1010 MHz. In the far zone the filter has blocking more than 100 dB. The pass band width on the Level minus 3 dB from the maximum is 13 MHz, and losses in the pass band are 8 dB.
Keywords: Filter on opposing rods, modelling, experiment, amplitude-frequency characteristics, pass band
As a solution eliminating the disadvantage of wired home theaters - the multiplicity of signal and feed wires - a method of wireless power transmission is proposed to charge the batteries of the side and rear speakers at a frequency of 2.45 GHz. The energy of the microwave radiation is converted into energy for charging the batteries by means of a special receiving module. The receiver module includes a receiving antenna, a rectifier and a power controller. This article discusses the calculation of the receiving antenna for this system in the structure of a wireless home theater. For the simulation, an antenna of the Yagi-Uda type was chosen, for which the gain and the beamwidth were determined. During the first stage of the simulation, antenna parameters were obtained that were unsatisfactory in the width of the directional pattern. At the second stage, the antenna design was modernized and a re-simulation was performed. Based on the results of this, it can be concluded that the parameters of the receiving antenna improved by 1.5 times, while the gain factor increased by 13%.
Keywords: wireless home theater, wireless microwave power transmission, receiving module, Yagi-Uda antenna, simplified Landtapo dipole, patch antenna, antenna efficiency indicator, radiation pattern, gain factor, reflection coefficient
Models of wireless communication systems with phase modulation formats and various channel models are considered; The influence of phase fluctuations on the level of errors in communication channels with phase modulation formats is analyzed.
Keywords: modulation, sinal/noise, jitter, the Rayleigh channel, the Rician channel, the simbol and bith errors