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Search results for: NONLINEAR WAVE THEORY
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Nonlinear impedance as a function of A.C. voltage of Bi2VO5.5 ceramic of thickness 2.91 mm was measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic of thickness 2.91 mm was measured by impedance spectroscopy method.
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Non-Linear Interaction of Harmonic Waves in a Quasi-Isentropic Flow of Magnetic Gas
PublicationThe diversity of wave modes in the magnetic gas gives rise to a wide variety of nonlinear phenomenaassociated with these modes. We focus on the planar fast and slow magnetosound waves in the geometryof a flow where the wave vector forms an arbitrary angleθwith the equilibrium straight magnetic field.Nonlinear distortions of a modulated signal in the magnetic gas are considered and compared to thatin unmagnetised gas. The case of...
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Instantaneous Heating and Cooling Caused by Periodic or Aperiodic Sound of Any Characteristic Duration in a Gas with Vibrational Relaxation
PublicationThermodynamic relaxation of internal degrees of a molecule's freedom in a gas occurs with some characteristic time. This makes wave processes in a gas behave differently depending on the ratio of characteristic duration of perturbations and the relaxation time. In particular, generation of the secondary non-wave modes by intense sound in a nonlinear flow dependens on frequency. These kinds of interaction are considered in this...
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Nonlinear impedance of 58(2Bi2O3-V2O5)-42SrB4O7 glass heat-treated for 3 hours at 693 K, measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrcial properties of partially crystallized 58(2Bi2O3-V2O5)-42SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 58(2Bi2O3-V2O5)-42SrB4O7 glass heat-treated for 10 hours at 693 K, measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrcial properties of partially crystallized 58(2Bi2O3-V2O5)-42SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrcial properties of 50(Bi2VO5.5)-50SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 35Bi2VO5.5-65SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 35Bi2VO5.5-65SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 30Bi2VO5.5-70SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 30Bi2VO5.5-70SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50(Bi2VO5.5)-50SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 45Bi2VO5.5-55SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 45Bi2VO5.5-55SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance as a function of A.C. voltage and temperature for Bi2VO5.5 ceramic of thickness 2.52 mm (after first heat-treatment at 913 K) was measured at different frequencies with impedance spectroscopy method
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic of thickness 2.52 mm was measured by impedance spectroscopy method.
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Nonlinear impedance of as-quenched 40Bi2VO5.5-60SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrical properties of as-quenched 40Bi2VO5.5-60SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of Bi2VO5.5 ceramic of thickness 2.52 mm (after second heat-treatment at 913 K) was measured at high temperature range with impedance spectroscopy method
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic of thickness 2.52 mm (after second heat-treatment at 913 K) was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 annealed glass at 593 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50Bi2VO5.5-50SrB4O7 annealed glass was measured by impedance spectroscopy method.
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Nonlinear impedance of Bi2VO5.5 ceramic prepared by traditional melt quenching technique was measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic prepared by traditional melt quenching technique was measured by impedance spectroscopy method.
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Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-Cooling Function
PublicationThe nonlinear phenomena which associate with magnetoacoustic waves in a plasma are analytically studied. A plasma is an open system with external inflow of energy and radiation losses. A plasma’s flow may be isentropically stable or unstable. The nonlinear phenomena occur differently in dependence on stability or instability of a plasma’s flow. The nonlinear instantaneous equation which describes dynamics of nonwave entropy mode...
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Computationally Effcient Solution of a 2D Diffusive Wave Equation Used for Flood Inundation Problems
PublicationThis paper presents a study dealing with increasing the computational efficiency in modeling floodplain inundation using a two-dimensional diffusive wave equation. To this end, the domain decomposition technique was used. The resulting one-dimensional diffusion equations were approximated in space with the modified finite element scheme, whereas time integration was carried out using the implicit two-level scheme. The proposed...
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Discussion of “Development of an Accurate Time integration Technique for the Assessment of Q-Based versus h-Based Formulations of the Diffusion Wave Equation for Flow Routing” by K. Hasanvand, M.R. Hashemi and M.J. Abedini
PublicationThe discusser read the original with great interest. It seems, however, that some aspects of the original paper need additional comments. The authors of the original paper discuss the accuracy of a numerical solution of the diffusion wave equation formulated with respect to different state variables. The analysis focuses on nonlinear equations in the form of a single transport equation with the discharge Q (volumetric flow rate)...
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Simulation of unsteady flow over floodplain using the diffusive wave equation and the modified finite element method
PublicationWe consider solution of 2D nonlinear diffusive wave equation in a domain temporarily covered by a layer of water. A modified finite element method with triangular elements and linear shape functions is used for spatial discretization. The proposed modification refers to the procedure of spatial integration and leads to a more general algorithm involving a weighting parameter. The standard finite element method and the finite difference...
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Designing a ship course controller by applying the adaptivebackstepping method
PublicationThe article discusses the problem of designing a proper and efficient adaptive course-keeping control system for a seagoingship based on the adaptive backstepping method. The proposed controller in the design stage takes into account thedynamic properties of the steering gear and the full nonlinear static maneuvering characteristic. The adjustable parametersof the achieved nonlinear control structure were tuned up by using the...
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On the Nonlinea Distortions of Sound and its Coupling with Other Modes in a Gasesous Plasma with Finite Electric Conductivity in a Magnetic Field
PublicationNonlinear phenomena of the planar and quasi-planar magnetoacoustic waves are considered. We focus on deriving of equations which govern nonlinear excitation of the non-wave motions by the intense sound in initially static gaseous plasma. The plasma is treated as an ideal gas with finite electrical conductivity permeated by a magnetic field orthogonal to the trajectories of gas particles. This introduces dispersion of a flow. Magnetoacoustic...
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Nonlinear impedance of 45Bi2VO5.5-55SrB4O7 fully crystallized glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 45Bi2VO5.5-55SrB4O7 fully crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 35Bi2VO5.5-65SrB4O7 fully crystallized glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 35Bi2VO5.5-65SrB4O7 fully crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 30Bi2VO5.5-70SrB4O7 fully crystallized glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 30Bi2VO5.5-70SrB4O7 fully crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 40Bi2VO5.5-60SrB4O7 annealed glass at 593 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrical properties of 40Bi2VO5.5-60SrB4O7 glass annealed at 593 K was measured by impedance spectroscopy method.
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Nonlinear impedance of as-quenched glass 40Bi2VO5.5-60SrB4O7 after full crystallization was measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of as-quenched glass 40Bi2VO5.5-60SrB4O7 afetr full crystallization was measured by impedance spectroscopy method.
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Nonlinear impedance of annealed and next fully crystallized 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of annealed and next fully crystallized 50Bi2VO5.5-50SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of Bi2VO5.5 ceramic prepared by traditional melt quenching technique was measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic prepared by traditional melt quenching technique was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 fully crystallized glass at 813 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50Bi2VO5.5-50SrB4O7 fully crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 partially crystallized glass at 613 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50Bi2VO5.5-50SrB4O7 partially crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance as a function of A.C. voltage for fully crystallized 35Bi2VO5.5-65SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties as a function of A.C. voltage for fully crystallized 35Bi2VO5.5-65SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 40Bi2VO5.5-60SrB4O7 annealed glass at 473 K for 3 h measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrical properties of 40Bi2VO5.5-60SrB4O7 glass annealed at 473 K for 3h was measured by impedance spectroscopy method.
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Nonlinear impedance as a function of A.C. voltage for fully crystallized 45Bi2VO5.5-55SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties as a function of A.C. voltage for fully crystallized 45Bi2VO5.5-55SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized was measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized was measured by impedance spectroscopy method.
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Nonlinear impedance as a function of A.C. voltage for annealed and next fully crystallized 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties as a function of A.C. voltage for annealed and next fully crystallized 50Bi2VO5.5-50SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of glass 40Bi2VO5.5-60SrB4O7 annealed at 473 K for 3h and next fully crystallized was measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized was measured by impedance spectroscopy method.
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Magnetoacoustic heating in a quasi-isentropic magnetic gas
PublicationThe nonlinear heating of a plasma which associates with the transfer of energy of magnetoacoustic waves into that of the entropy mode, is analytically studied. A plasma is uniform and motionless at equilibrium. Perturbations in a plasma are described by a system of ideal magnetohydrodynamic equations. The equilibrium straight magnetic strength and the wave vector form a constant angle which varies from 0 to π/2. There exist four...
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Nonlinear impedance as a function of A.C. voltage for glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties as a function of A.C. voltage for annealed at 593 K and next fully crystallized 40Bi2VO5.5-60SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance as a function of A.C. voltage for glass 40Bi2VO5.5-60SrB4O7 annealed at 473 K for 3h and next fully crystallized measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties as a function of A.C. voltage for annealed at 473 K for 3h and next fully crystallized 40Bi2VO5.5-60SrB4O7 glass was measured by impedance spectroscopy method.
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MAGNETOACOUSTIC HEATING AND STREAMING IN A PLASMA WITH FINITE ELECTRICAL CONDUCTIVITY
PublicationNonlinear effects of planar and quasi-planar magnetosound perturbations are discussed. Plasma is assumed to be an ideal gas with a finite electrical conductivity permeated by a magnetic filed orthogonal to the trajectories of gas particles. the excitation of non-wave modes in the filed of intense magnetoacoustic perturbations, i.e., magnetoaciustic heating and streaming, is discussed. The analysis includes a derivation if instantaneous...
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Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
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Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
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Rapid Design Tuning of Miniaturized Rat-Race Couplers Using Regression-Based Equivalent Network Surrogates
PublicationA simple technique for fast design tuning of compact rat-race couplers is presented. Our approach involves equivalent circuit representation, corrected by nonlinear functions of frequency with coefficients extracted through nonlinear regression. At the same time, the tuning process connects two levels of coupler representation: EM simulation of the entire circuit and re-optimization of the coupler building blocks (slow-wave cells...
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Analysis of the correlation between instantaneous resistance-increase in waves and ship motion for reducing fuel consumption
PublicationReducing fuel consumption is crucial for greening water transport. Wind, waves and currents affect fuel usage, with wave-induced resistance being significant. Typically, added resistance is estimated as the time average of resistance increase in waves over calm water. However, this average lacks real-time utility for engine adjustments. This study analyses time-series correlations between wave-induced resistance-increase and ship...
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Detection of Objects Buried in the Sea Bottom with the Use of Parametric Echosounder
PublicationThe paper contains results of a in situ research main task of which was to detect objects buried, partially or completely, in the sea bottom. Object detecting technologies employing acoustic wave sources based on nonlinear interaction of elastic waves require application of parametric sound sources. Detection of objects buried in the sea bottom with the use of classic hydroacoustic devices such as the sidescan sonar or multibeam...
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Curves of thermodynamic states in some fluids with dispersion
Publicationvariations in the thermodynamic state of a dispersive medium, caused by sound, are studied. A bubbly liquid and a Maxwell fluid are considered as examples. Curves in the plane of thermodynamic states are plotted. They are in fact pictorial images of linear relations of excess pressure and excess density in the acoustic wave which reflect irreversible attenuation of the sound energy. The curves account for the nonlinear generation...
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PROJEKTOWANIE WIELOWYMIAROWEGO REGULATORA BACKSTEPPING W UKŁADZIE DYNAMICZNEGO POZYCJONOWANIA STATKU
PublicationW komercyjnych systemach dynamicznego pozycjonowania statku, pomimo znacznego wzrostu poziomu automatyzacji, wykorzystywane jest nadal sterowanie typu PID. Poprawę jakości procesu pozycjonowania może umożliwić wykorzystanie bardziej efektywnych algorytmów, oferujących zaawansowane nieliniowe techniki sterowania. W artykule przedstawiono zagadnienie projektowania regulatora pozycji i kursu dla układu dynamicznego pozycjonowania...
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The study of acoustic climate of the Southern Baltic
PublicationThis paper presents the statistical characteristics of seawater properties, which are necessary for predicting the propagation of acoustic waves in selected areas of the Baltic Sea. The statistics were elaborated based on long-term measurements of vertical distributions of sound speed, temperature, and salinity, and the nonlinearity parameter B/A. Nonlinear properties of the environment are considered, in connection...
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Acoustic Heating Produced in the Thermoviscous Flow of a Shear-Thinning Fluid
PublicationThis study is devoted to the instantaneous acoustic heating of a shear-thinningfluid. Apparent viscosity of a shear-thinning fluid depends on the shear rate. Thatfeature distinguishes it from a viscous Newtonian fluid. The special linear combi-nation of conservation equations in the differential form makes it possible to derivedynamic equations governing both the sound and non-wave entropy mode inducedin the field of sound. These...
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Balance errors generated by numerical diffusion in the solution of non-linear open channel flow equations
PublicationThe paper concerns the untypical aspect of application of the dissipative numerical methods to solve nonlinear hyperbolic partial differential equations used in open channel hydraulics. It is shown that in some cases the numerical diffusion generated by the applied method of solution produces not only inaccurate solution but as well as a balance error. This error may occur even for an equation written in the conservative form not...