Comparison of extensometric results measured in the Vyhne Tidal Station (Slovakia) and in the Sopronbánfalva Geodynamic Observatory (Hungary)

Two extensometer stations have been set up at the margin of the Pannonian Basin to monitor tectonic movements as well as Earth tides and related phenomena. Because the Sopronbánfalva Geodynamic Observatory (SGO) in Hungary and the Vyhne Tidal Station (VTS) in Slovakia are located in different geological, topographic, and tectonic environments, the analysis and comparison of the extensometer data measured here provides a useful opportunity to interpret the observed data. The tectonic deformation at the SGO shows an average contraction of: −2.94 μstr y−1 (1 μstr is 10−6 relative deformation) which can be explained by the uplift of the Alps and the anticlockwise motion of the Adria microplate, causing compression in the Eastern Alps. At the VTS an average compression of −14.8 nstr y−1 (1 nstr is 10−9 relative deformation) was measured which can be explained by the NW compression direction in this area. The measured deformations in both observatories show a good agreement with the results of GPS measurements. The deformation at the VTS is characterized by small dilatation anomalies caused by the different topographic, tectonic environment and probably by the high heat flow in the area of the station. At this station the calculated amplitude factors for O1, P1, K1, M2 are 1.01482, 1.21691, 0.83173, 1.09392 and the ocean load corrected values are 1.10817, 1.35717, 0.92809, 1.28812, respectively. At the SGO the calculated amplitude factors for the same tidal components are 0.58776, 0.38967, 0.41548, 1.00564 and the ocean load corrected values are 0.98893, 1.89117, 1.00430, 1.04962, respectively. These results show that the effect of the ocean tide loading is greater at Sopronbánfalva, than at Vyhne. Based on the comparison, we can say that the result of the local strain measurement can be considered realistic.

Comparison of forecast estimates of seabed subsidence of the Yuzhno-Kirinskoye field

The geodynamic consequences of the field development process include the subsidence of the earth’s surface. Monitoring of deformations in offshore fields is difficult and it is necessary to evaluate them by various methods. It is important to investigate how much the calculated amplitude of the seabed subsidence is reduced by taking into account changes in the porosity and compressibility of the pore space with a decrease in reservoir pressure. The analysis of changes in the petrophysical parameters of the reservoirs of the Daginsky horizon during the projected development of the Yuzhno-Kirinskoye hydrocarbon field for depletion and a decrease in formation pressure by 10 MPa showed that the porosity decrease will be 0.038 absolute percent, the compressibility of the pore space will decrease by 0,08 10-3 1/MPa. With the help of the Petrel software, changes in the thickness of the productive layer from 80 to 120 cm were obtained, which can be taken as an estimate of the seabed subsidence in the area of the field. The application of the genetic model of the deformable formation by Kuzmin Yu showed that the maximum amplitude of the seabed subsidence to be 101 cm. Comparison of these estimates of the seabed subsidence indicates their proximity. Taking into account the dynamics of tectonophysical and petrophysical characteristics due to the long-term development of hydrocarbon deposits significantly changes the intensity of the deformation state of the rock mass and the earth’s surface above the field.

OPTIMIZATION IN SPEED OF THE RELAY-MODAL CONTROL SYSTEM OF THE SERVO DRIVE BASED ON THE STUDY OF THE MATHEMATICAL MODEL

Positional control systems are characterized by the limitation of intermediate coordinates in transients. Such restrictions are implemented by a system with cascading controllers. The N-i switching method provides optimization of the speed of such control systems. In this paper, we study the three-loop system of subordinate regulation. The parameters of the relay-modal controllers were varied based on a change in the calculated amplitude of the control action without changing its real value. The parametric synthesis of such a system is based on optimal trajectories in terms of speed. The study of the control system at various settings revealed a different degree of deviation of transitional trajectories from the calculated one. This effect is due to the replacement of optimal regulator settings with modal ones in order to give the system a margin of stability. The obtained families of transient characteristics make it possible to construct empirical dependences of the duration of regulation on the relative value of the calculated amplitude of the control action. Such dependencies have pronounced extremes, which makes it possible to tune the system to a near optimal speed by preventing the regulators from entering the sliding mode prematurely. The performed simulation of the positional system with extremal settings confirms the effectiveness of the proposed methodology for the correction of dynamic characteristics. The results of the study open up the prospects of the practical implementation of relay-modal control algorithms for cascading systems, the synthesis of which is based on the N-i switching method.

Simulation of the Flat-parallel Movement of a Bridge Agricultural Unit with an Articulated Frame

The work presents foundations of the dynamics of the flat-parallel movement of a bridge agricultural unit in a horizontal with the kinematic method of its control (turning the wheels) by changing the position of one of its parts relative to the other. The analysis of assessment of the degree of impact of the scheme and parameters of the investigated agricultural tool upon its controllability and stability of movement is based on the amplitude and phase frequency characteristics. The mathematical models of the movement of the bridge agricultural unit are presented in a differential and an operator form of recording. Based on mathematical models, the calculated amplitude and phase frequency characteristics of the dynamic control system of the control impact, presented as the angular displacement of its half-frames ψ, are constructed for various parameters and operating modes. The constructed mathematical models, amplitude and phase frequency characteristics make it possible to assess the impact of the control parameter of the bridge agricultural unit, as well as its design and other parameters upon the controllability of the movement.

Implementation of the Spectral Method for Determining of Measuring Instruments' Dynamic Characteristics

The spectral method for establishing dynamic response of measuring instruments basically requires determining the amplitude spectrum of the signal in its informative part that includes the amplitude spectrum at zero frequency. The operating frequency range of existing low-frequency spectrum analyzers is above zero frequency that leads to an uncertainty in dynamic response of measuring instruments determined by the spectral method. The purpose of this paper is to develop a program for calculating the signal amplitude spectrum, starting from zero frequency, to implement a spectral method for determining the dynamic response of measuring instruments on computers equipped with the MatLab package.To implement the spectral method for determining the dynamic response of measuring instruments, we developed a program in the MatLab 2013b environment that determines the signal amplitude spectrum from zero Hertz. The program reads the source data from Excel tables and presents the calculated amplitude spectrum as a chart and a report table.It is shown that the developed program calculates the signal amplitude spectrum with a standard deviation of not more than 3.4 % in the frequency range of 0 to 10 rad/s. The calculated amplitude spectrum allows determining the time constant of first-order aperiodic measuring instruments with an uncertainty of not more than 0.166 % at any noise level, if their frequencies are outside the information part of the spectrum.We demonstrated the claimed advantage of the spectral method for determining dynamic response using the developed program by the example of a high-frequency noise in the transient response of some measuring instruments.

Numerical investigation of wall pressure fluctuations downstream of concentric and eccentric blunt stenosis models

Pressure fluctuations that cause acoustic radiation from vessel models with concentric and eccentric blunt stenoses are investigated. Large eddy simulations of non-pulsatile flow condition are performed using OpenFOAM. Calculated amplitude and spatial-spectral distribution of acoustic pressures at the post-stenotic region are compared with previous experimental and theoretical results. It is found that increasing the Reynolds number does not change the location of the maximum root mean square wall pressure, but causes a general increase in the spectrum level, although the change in the shape of the spectrum is not significant. On the contrary, compared to the concentric model at the same Reynolds number, eccentricity leads to an increase both at the distance of the location of the maximum root mean square wall pressure from the stenosis exit and the spectrum level. This effect becomes more distinct when radial eccentricity of the stenosis increases. Both the flow rate and the eccentricity of the stenosis shape are evaluated to be clinically important parameters in diagnosing stenosis.

K2 observations of the sdBV + dM/bd binaries PHL 457 and EQ Psc

ABSTRACT We present an analysis of two pulsating subdwarf B stars PHL 457 and EQ Psc observed during the K2 mission. The K2 light curves of both stars show variation consistent with irradiation of a cooler companion by the hot subdwarf. They also show higher frequency oscillations consistent with pulsation. Using new spectroscopic data, we measured the radial velocity, effective temperature, surface gravity, and helium abundance of both hot subdwarfs as a function of orbital phase. We confirm the previously published spectroscopic orbit of PHL 457, and present the first spectroscopic orbit of EQ Psc. The orbital periods are 0.313 and 0.801 d, respectively. For EQ Psc, we find a strong correlation between Teff and orbital phase, due to contribution of light from the irradiated companion. We calculated amplitude spectra, identified significant pulsation frequencies, and searched for multiplets and asymptotic period spacings. By means of multiplets and period spacing, we identified the degrees of several pulsation modes in each star. The g-mode multiplets indicate subsynchronous core rotation with periods of 4.6 d (PHL 457) and 9.4 d (EQ Psc). We made spectral energy disctribution (SED) fits of PHL 457 and EQ Psc using available broad-band photometry and Gaia data. While the SED of PHL 457 shows no evidence of a cool companion, the SED for EQ Psc clearly shows an infrared (IR) access consistent with a secondary with a temperature of about 6800 K and a radius of 0.23 R⊙. This is the first detection of an IR access in any sdB + dM binary.

Calculation the production cross-section of the BSM boson via photon fusion reaction

The production cross-section of the beyond the standard model (BSM) scalar boson (S-boson) have been considered it the article. Scalar boson produced via photon fusion reaction in the deep inelastic scattering of a charged particle (proton or electron) on heavy nucleus of the target. This process is one of the possible mecha- nisms of BSM boson production at the SHiP (Search for Hidden Particles) experiment at the CERN LHC and may be dominating among others processes due to large nuclear charge. In a low-energy case for which virtual photon wavelength similar or bigger nuclear size one can consider nucleus as an elementary particle with the charge Z. Corresponding amplitude is proportional to Z and the cross-section proportional to Z^2. Due to this the alpha_{EM}^2 suppression of the production cross-section is approximately compensated by the charge number factor Z^2. The mass of boson cannot exceed 4 MeV for the incident proton (or less than 80 MeV for electron). We calculated amplitude and the production cross-section of this reaction directly without using equivalent photon approximation. Interaction between photon and neutral boson is described by triangular diagrams with the loop containing all charged leptons, quarks and W-bosons. For this interaction we used effective lagrangian. The found cross-section was analyzed for the case of proton scattering on the lead nucleous and compared with the production cross-section in the decay of Ds mesons. It was found that the photon fusion reaction becomes effective only with a S-boson mass less than 0.1 keV.

Dynamics of a Carriage System of Comparator for Calibrating the Line Standards of Length

This paper presents research dynamic properties of a calibration comparator which is used to calibrate high precision line standards of length. For this purpose, multi-body dynamic and mathematical models of a carriage system of the comparator were presented. Calculated amplitude-frequency responses and modes of oscillations allowed a determination of resonant frequencies of the system.