Measurements of the CMB properties is an actual problem of modern astronomy. The aim of the present paper is the numerical modeling of the two-frequency planar cross-slot antenna designed for operation in the receiving system of the orbital telescope Cosmic Origins Explorer (COrE), developed by the European Space Agency to measure the CMB.

The proposed antenna is a planar metal layer on the dielectric substrate, and comprising a set of four slots intersecting each other at right angles. The composition also includes a set of microstrip lines for transmitting a signal from the resonant slots to cold-electron bolometers, and a lens for forming the main beam of the radiation diagram. Calculation of the antenna system is made by electrodynamic modeling software package CST Microwave Studio. As a result of the modeling, the radiation diagram of the antenna in two frequency channels as well as its frequency characteristics are obtained.

The calculation gives the following characteristics of the receiving system on the basis of cross-slot antenna: width of the main beam of the radiation diagram – 24.3° and 19.5°, the ellipticity of the beam – 4.2 % and 0.3 %, the bandwidth – 14.9 GHz and 19.0 GHz, polarization resolution – 23.4 dB and 29.6 dB, where the former value refers to the 75 GHz channel, and the latter refers to 105 GHz channel.

It is proposed to use a cross-slot antenna in dual-frequency mode together with resonant cold-electron bolometers to work in the receiving system of the orbital telescope COrE. Comparison of the calculated antenna characteristics with the requirements set by the European Space Agency, have shown the possibility of using this type of antenna as part COrE mission.

The challenges of designing simple, reliable, and high sensitivity graviinertial sensors are investigated. The sensor comprises a proof mass (PM) and is fixed with the housing by the elastic torsion suspension. PM makes small rotations under the action of gravitational forces or inertial forces.

The distinctive features of the sensor are that the differential electrostatic system provides simultaneous reading of the desired signal and a control the torsional rigidity of suspension. In addition, the PM's rotational angular velocity transforms in the alternating current flowing through the capacitors. The presence of аlternating current (AC) voltage sources allows to get the parametric amplification of AC and significantly to improve the sensitivity of the sensor. In the simplest case, the sensor does not contain any feedback circuits.

As an example, calculations of the micromechanical linear accelerations confirm that the periodic modulation of the coefficient of elastic stiffness of the suspension can significantly increase the sensitivity in the low frequency range, even in the absence of parametric resonance.

Conditions for suppressions of background current participating in the output signal from a parametric pumping due to the asymmetry of the differential circuits are set. The frequency characteristics calculations of the sensor were carried out. It is expected, that the proposed sensor design ensures minimum noise level, which can be achievable in the graviinertial sensors. This design and the constructed theory can serve as a basis for creating a wide range of graviinertial devices operating on a movable base, for example, linear and angular accelerometer, gravity gradiometer, gravimeters, and inclinometers, which can be realized in the hybrid and in the micromechanical versions.

In this paper, we report of the solving the actual problem of control the air gap in the hydrogenerators. The aim of the study was development of a computerized information-measuring system for measuring the air gap in the hydrogenator, which used two capacitive sensors with parallel coplanar electrodes, and the method of determining the shape of the envelope parameters hydrogenerator rotor poles relative to the center axis of rotation, using the measurement results of the air gap.

In practical studies of the sensor circuit it has been shown that its use allows for the informative value of the sensor capacitance conversion function to obtain a high accuracy and resolution measurement with digital linearization of converting function of the sensor with use program utility. To determine the form deviations of the envelope line of the rotor pole from the ideal cylinder, which is one of the main structural defects of the technological errors as results the distortion of the shape of the air gap in the hydrogenator, when the machine was manufacture and assembly. It is proposed to describe the shape of the envelope to use a Fourier transform. Calculation of the coefficients of the Fourier series is performed using the method of least squares as the regression coefficients.

Application of this method in processing the measuring data in a computerized information-measuring system the developed with the primary converter with coplanar parallel electrodes allowed attaining the high measurement accuracy and resolution informative in magnitude of the capacity.

Providing quality and reliable operation as well as temperature monitoring of modern systems are directly related on the use of innovative fiber optic technology based on the concept of so-called distributed and quasi-distributed sensors having large linear dimensions, in which the optical fiber is both sensor and data channel. Existing fiber optic sensors based on stimulated Raman scattering and stimulated Brillouin scattering have relatively high measurement error, long and complicated measurement method, high cost. The purpose of this paper was to develop an automated quasi-distributed fiber optic recirculating temperature measurement system using wavelength division multiplexing technology. Measurement method based on the registration arising due to temperature changes of the frequency of single optical pulses recirculating at adjacent wavelengths. Thus there is a periodic signal restoration on waveform, amplitude and duration. The sensing element is a segment of a multimode silica fiber coated with metal, separated spectrally selective elements, which are mainly offered to use dichroic mirrors. With the help of the developed mathematical model that takes into account the temperature dependence of the coefficient of linear expansion and Young’s modulus of the fiber, the spectral and temperature dependence of the refractive index, the chemical composition of the fibers, the type of metal coating system response function was calculated, which allows to evaluate the sensitivity and measurement accuracy. These studies determined: number of measuring sections (8), the maximal measured temperature (500 °C), the sensitivity (3,28 Hz/°C), the measurement error (±0,2 °C), and the optimum beginning time measurement after starting circulation (15 min), and counting time of the frequency meter (1 s). Carried out estimations have shown that the proposed measuring system can outperform existing analogues on set specifications.

The main object of the work was developed the device based on GaInAsSb diodes for measurement water content in oil. Optical absorption method was used in this device. Three LEDs emitting in the range from 1.6 to 2.4 μm, and one wide-band GaSb/GaInAsSb/GaAlAsSb photodiode were used as sources of radiation and detectors.

The device was developed on the basis of selective optical absorption method of detection for measuring water content in oil. As sources of radiation, LEDs emitting in the range from 1.6 to 2.4 μm were used. The results of the experiments showed that the method used makes it possible to measure the water concentration in oil in the range from 0.2 to 40% with an relative error of not more than 2 %.

The technical requirements and operating parameters of the used light and photodiodes were established. Investigations of the dependence of the luminescence spectra of LEDs on temperature have shown the importance of using thermal control on the sources and detectors of radiation. The possibility of using one device for different types of oil, as well as oil products during preliminary calibration were shown in the paper. The importance of using a rotary pump for mixing and pumping the analyzed medium and a flow cell was established.

Measuring the amplitude-phase distribution of the radiation field of complex antenna systems on a certain surface close to the radiating aperture allows solving the problem of reconstructing the free-space diagram in the far field and also helps in determining the influence of various structural elements and defects of radiating surfaces on formation of directional diagram. The purpose of this work was to develop a universal hardware-software complex of a modular design aimed for determining the characteristics of wide range of antenna systems in respect of measurements of the amplitude-phase distribution of the radiation field in the near zone.

The equations that connect the structure of radiation fields of the antenna system at various distances from it in planar, cylindrical and spherical coordinate systems as well as structural diagrams of the hardware part of measuring complexes have been analyzed.

As a result, the concept of constructing a universal hardware-software complex for measuring the radiation field of various types of antenna systems with any type of measurement surface for solving a wide range of applied problems has been developed. A modular structure of hardware and software has been proposed; it allows reconfiguring the complex rapidly in order to measure the characteristics of any particular antenna system at all stages of product development and testing, and also makes the complex economically accessible even for small enterprises and organizations.

The most promising for mass use in gas analysis equipment are semiconductor gas sensors due to their high reliability, easy operation and relatively low cost. Power consumption in the single-sensor mode, constant heating is from 250 to 600 W average and in pulsed mode heating – ≤ 20 W. The aim of this work was to study the effectiveness of the pulsed heating for multisensor microsystems consisting of two sensors on the substrate of the nanostructured aluminum oxide, compared with the mode of constant heating.

For sensitive layers were chosen compositions: SnO2+Pt+Pd at the first sensor of the microsystem and In₂O₃+Al₂O₃+Pt on the second. Measuring the sensor response in the pulse heating mode was carried out as follows. Power on each sensor microsystem was installed 1.3 mW. Then the short-term heating (t_heat.. = 5 s) was performed at the power 61 mW. The detected gases CO and NO₂ with the concentration 200 ppm and 4 ppm, correspondingly, were submitted to the microsystem after 15 minutes. The resistance values for each of the sensor were fixed. According to the results determine the sensitivity (sensor response) the maximum value is after 60 s for the sensor with a sensing layer SnO2+Pt+Pd when exposed to CO was 670 %, and for the sensor with In₂O₃+Al₂O₃+Pt – 380 %.

Advantages of using pulsed heating from the point of view of a power consumption multisensor microsystem mW-range and high performance sensors on substrates of nanostructured alumina were established.

System in the form of a circular cylindrical piezoceramic transducer near a flat acoustic screen was analyzed. The aim of the work was to solve the problem of receiving plane sound waves by «cylindrical piezoceramic transducer – flat acoustically soft screen» system.

Considered system was characterized by a violation of the radial symmetry of the radiation load of the transducer while maintaining the radial symmetry of the electric load. At the same time, the energy perceived by the system under consideration is distributed between all modes of oscillation of the transducer, while the conversion of mechanical energy into electric is realized only at zero mole of oscillations.

Special attention was paid to the method of coupled fields in multiply connected domains using the imaging method. The design model of the «transducer–creen» system was formulated taking into account the interaction of acoustic, mechanical and electric fields in the process of energy conversion, the interaction of a cylindrical transducer with a flat screen and the interaction of a converter with elastic media outside and inside it. The physical fields of the system under consideration were determined by following solutions: the wave equation; equations of motion of thin piezoceramic cylindrical shells in displacements; equations of stimulated electrostatics for piezoceramics for given boundary conditions, conditions for coupling fields at interfaces and electrical conditions.

A general conclusion was made concerning solving of an infinite system of linear algebraic equations with respect to the unknown coefficients of the expansion of the fields. As an example of the application of the obtained relations, a calculation was made and an analysis of the dependences of the electric fields of the system under consideration for various parameters of its construction on the direction of arrival on the plane wave system was conducted.

Speckle fields are widely used in optical diagnostics of biotissues and evaluation of the functional state of bioobjects. The speckle field is formed by laser radiation scattered from the object under study. It bears information about the average dimensions of the scatterers, the degree of surface roughness makes it possible to judge the structural and biophysical characteristics of individual tissue cells (particles), on the one hand, and the integral optical characteristics of the entire biological tissue. The aim of the study was – the determination of connections between the biophysical and structural characteristics of the biotissue and the light fields inside the biotissues.

The model developed of the medium gives a direct relationship between the optical and biophysical parameters of the biotissue. Calculations were carried out using known solutions of the radiation transfer equation, taking into account the multilayer structure of the tissue, multiple scattering in the medium, and multiple reflection of irradiation between the layers.

With the increase wavelength, the size of speckles formed by the non-scattered component (direct light) of laser radiation increases by a factor of 2 from 400 to 800 μm in the stratum corneum and 5 times from 0.6 to 3 μm for the epidermis and from 0.27 to 1.4 μm to the dermis. Typical values of sizes of speckles formed by the diffraction component of laser radiation for the stratum corneum and epidermis range from 0.02 to 0.15 μm. For the dermis typical spot sizes are up to 0.03 μm. The speckle-spot size of the diffusion component in the dermis can vary from ±10 % at 400 nm and up to ±23 % for 800 nm when the volume concentration of blood capillaries changes. Characteristic dependencies are obtained and biophysical factors associated with the volume concentration of blood and the degree of it’s oxygenation that affect the contrast of the speckle structure in the dermis are discussed.

The of speckles׳ size in the layers of tissue varies from a share of micrometer to millimeter. The established dependence makes it possible to determine the depth of penetration of light into the biotissue based on the dimensions of speckles. Calculation of the contrast of the speckle structure of scattered light in visible spectral range at different depths in the biotissue made it possible to establish the dependence of the contrast value of the interference pattern on the degree of oxygenation of the blood and the volume concentration of capillaries in the dermis.

An experimental instrument complex which includes hardware for performing complex procedures using electrical shock massager frictional action was performed. The aim of the study was to influence the additional vibration effect on the efficiency of the procedure of electrostimulation.

In order to increase the efficiency of the procedure electrostimulation authors proposed to carry it out with using of massager shock-friction action. The changes of muscular indicator on different stimulation treatments was shown after a series of seven treatments .

Results of the processing of the experimental data and its subsequent analysis found that the use of the vibration exposure is accompanied by increase of load parameters in untrained volunteers. The increase in contact area due to decrease in the distance between the nozzle and the axis of rotation of the tumbler body surface, increases the electrical efficiency of the procedure.

On the basis of a generalized analysis of data reflecting the effect of inappropriate electrical stimulation, it was established that, in order to achieve the best results, oscillatory systems providing shock-friction mode of its interaction with the skin surface, in particular a shock-frictional massager, were used.