Decay of a weak gap and wave propagation in a nonlocal environment with a source
... fourth-order wave equation with a source is considered. The results are set out in terms of the heat transfer theory. The temperature derivative of the source function is positive (a technical source) or negative (a source in biological tissue). The wave velocity (subsonic, sonic, supersonic) is determined with respect to the velocity of propagating heat perturbations. We give examples of the exact solving the problem of disintegration of a weak discontinuity in the temperature field. This problem ...
On asymptotic expression for velocity field of atmosphere gas perturbed by 1D acoustic wave
... problem at half space . The atmosphere is modeled as a multi-layer gas with an exponential structure of density in each layer. The boundary conditions at determine the direction of propagation, by link between dynamic variables (pressure, density, and velocity) of the wave. It defines the dynamic projection operators on the subspaces of z-evolution for each layer. The universal formulas for the perturbation of atmospheric variables in an arbitrary layer are derived in frequency and time domains....
The The Variability of Bottom Friction Velocity and the Suspended Particle Propagation along the Pathway of Saline Inflow into the Baltic Sea
... inflow and non-inflow cases. For these time intervals, I identified processes prevalent in the bottom layer dynamics at specific points on the pathway of the inflow waters propagation in the Baltic Sea. An analysis of the variability of bottom friction velocity made it possible to estimate the likelihood of bottom sediment resuspension at these points and to predict propagation pathways.
1. Blumberg A. F., Mellor G. L. A Description of a Three-Dimensional Coastal Ocean Circulation Model. Washington,...
The dynamics of the dispersible particle which is blown off from a flat level by the laminar Couette layer
Character of influence Saffmena force on the particles out of the layer is detected. The longitudinal velocity of the particle can be more fluid speed, then the power Saffmena will be directed to the surface. In these circumstances we need a big initial vertical velocity of the particle to reach the outer layer of the border.
1. Великанов ...
Rotation of the cylinder in the flowing stream
The features of modeling the dynamics of the rotational movement of a cylindrical rod in a homogeneous flow of a viscous liquid are considered. The angle of attack, the angle of rotation, and the angular velocity of the rod are studied numerically. The results of solving the boundary value problem using the numerical method in Mathcad are presented. Graphs are presented in dimensionless variables. It is obtained that the angular velocity of the rod ...
Normal range of liver stiffness measurement in healthy people
... measuring by transient elastography (FibroScan, Echosens); 2.4—6.2 kPa on measuring by point shear wave elastography (iU elite, Philips); 2.6—6.2 kPa on measuring by 2D shear wave elastography (Aixplorer, Supersonic Imagine). The liver shear wave velocity varies in the range of 0.71—1.71 m/s on measuring by the point shear wave elastography. The given data of the normal liver stiffness measurement and shear wave velocity in healthy people could not be taken as the reference data for assessing ...
The internal friction in longitudinal oscillations of the wire rope
A velocity model of internal friction is considered. It is shown that the use of a linear velocity model of internal friction makes it possible to describe the results of published experimental studies of longitudinal damped oscillations of cargo on a short ...
Simulating of non-stationary processes in the ionospheric plasma
A model of distribution of concentration, velocities and temperatures of ions along a geomagnetic flux tube is considered. The model also examines the main processes of chemical kinetics, ambipolar diffusion, influence of horizontal neutral wind and plasma heating by superthermal electrons. The ...
Dynamics of a cargo lift system
... increase in the weight of the load is reduced the steady-state rotation speed of the drum, the settling time varies slightly. The calculation of the oscillation frequency of the cable relative to the vertical. It is established that change of the angular velocity deviations correspond to oscillations of mathematical pendulum with variable length strings. Reducing the axial moment of inertia of the drum, ceteris paribus, affects neither the steady-state angular velocity of rotation of the drum or the value ...
A new way of solving the problem of the sinusoidal waves on the surface of a homogeneous perfect fluid
... consider a new way of solving the problem of the sinusoidal wave on the surface of a homogeneous perfect fluid. Its feature is used instead of the potential speed of the original characteristics of wave motion: horizontal and vertical components of the velocity and pressure. It is noted that it will generalize the problem under consideration in the event of a multi-layer liquid. The results, including the dispersion relation, fully consistent with the known. Specially considered long-wave approximation....
2D modeling of ion shadow behind a charged satellite by the method of molecular dynamics
... the interaction of a charged micro satellite and thermal plasma. The method of molecular dynamics used as a modeling method. Ion concentration distributions near SC were calculated for 10 and 102 protons in cm2 and the two values of relative satellite velocity and plasma were considered — 8 and 20 km s-1, respectively. It is shown that an increase in velocity and concentration of particles of ion shadow behind the satellite becomes more expressed.
1. Katz I., Mandell M. L. Differential charging ...
Propagation of sine waves in a two-layer density-stratified fluid
... boundary conditions. The dispersion relation for long waves is found. The frequency value for sinusoidal waves in a stratified fluid is obtained.
Zaitsev A. A., Rudenko A. I., Alekseeva S. M.
two-layer liquid, sine wave, dispersion relation, phase velocity, Boussinesq approximation
95-106
On mechanical resonances and anti-resonances
... Parallel and sequential connections of elements of a mechanical system with a source of force or a source of speed as a source of external mechanical harmonic action are considered. Four modes are described — resonances and antiresonances of forces and velocities. The use of the symbolic (complex) method has significantly simplified the study of resonance and near-resonance phenomena, in particular, it has made it possible to deeply unify and formalize the consideration of various mechanical systems....
Liver shear wave elastography: the problem of accuracy and reproducibility
...
Izranov V.A., Kazantseva N.V., Stepanyan I.A., Martinovich M.V., Gordova V.S., But-Gusaim V.I.
ultrasound, stiffness of the liver, measurement area, body mass index, operator skills, the minimum required number of measurements, shear wave velocity
67-88
Towards a Theory of Barotropic Geostrophic Currents
... polar coordinate system. The polar system is preferable for analysing geostrophic currents, since radial symmetry is intrinsic to these currents. We obtained ratios between the general hydrodynamic properties. The expressions of geostrophic current velocity components in terms of pressure were the most important among them. The procedure of deriving the expression of vorticity in terms of pressure was carried out. We determined that isobaths coincided with streamlines in stationary barotropic geostrophic ...
Measurement of liver volume using imaging techniques of various modalities
... Conventional B-Mode Ultrasonography, and Computed Tomography for Measuring Liver Size // Ultrashall in Med. 2010. Vol. 31. P. 31—36.
13. Bulut M. D., Özdemir H., Bora A. et al. Comparison of computed tomography densitometry and shear wave elastography velocity measurements for evaluation of the liver volume in the nonalcoholic fatty liver disease // Int. J. Clin. Exp. Med. 2016. Vol. 9(6). P. 10159—10169.
14. Chaubal G., Borkar V. V., Shetty G. et al. Estimation of liver volume in the western Indian ...
An analysis of sinusoidal waves in two-layer liquid
... многослойной вращающей жидкости // Физика атмосферы и океана. 1967. Т. 111, № 3. С. 284—290.
Zaitsev A., Kulakov P.
two-layer liquid, sinusoidal waves, dispersion relations, Boussinesq approximation, phase velocity of short and long waves, new technique
32-43
Dynamics of falling rotating particle. Part 2
... числах Рейнольдса // Моделирование в механике. 1992. Т. 6(23), № 4. С. 150—156.
2. Naumov V. A., Solomenko A. D., Yatsenko V. P. Influence of the Magnus force on the motion of a spherical solid with a large angular velocity // Journal of Engineering Physics and Thermophysics. 1993. Vol. 65, № 3. P.852—855.
3. Великанов Н .Л., Корягин С. И. Проблемы эксплуатации и ремонта металлических и железобетонных ...
Dynamics of falling rotating particle. Part 1
... Magnus force on a rotating sphere at low Reynolds numbers // J. Fluids Engin. 1985. Vol. 107, № 4. P. 484—488.
8. Naumov V. A., Solomenko A. D., Yatsenko V. P. Influence of the Magnus force on the motion of a spherical solid with a large angular velocity // J. Engin. Phys. and Thermophys. 1993. Vol. 65, № 3. P. 852—855.
9. Наумов В. А. Динамика вращающихся сферических частиц, падающих в неподвижной жидкости // Вестник ...
Semi-geodetic transformation of temporary images
Often while seismic data processing one gets time dependent images (time cuts, time migration), in which time plays the role of the «depth» variable. If in some approximation the wave propagation velocity is known, these images can be transformed into the true ones. In this article for this purpose it is proposed to use semi-geodesic transform associated with the normal to the boundary rays. The results of simulations are presented.
1. Громол ...
Numerical modeling of wave processes in 3D fractured media
... 50, № 4. С. 341—362.
2. Schoenberg M., Douma J. Elastic wave propagation in media with parallel fractures and aligned cracks // Geophysical Prospecting. 1988. Vol. 36, Iss. 6. P. 571—590.
3. Berryman J. G. Modeling high-frequency acoustic velocities in patchy and partially saturated porous rock using differential effective medium theory // International Journal of Multiscale Computational Engineering. 2004. № 2. P. 115—131.
4. Петров И. Б., Квасов И. Е. Численное ...
Simulating of ion and electron trajectories in thermal plasma in electric field of a satellite by the molecular dynamic method
A three-dimensional model of the interaction of a charged micro satellite and thermal plasma was considered. The ion and electron trajectories for different initial velocities and directions are shown. The calculated particle trajectories have some deviations from the classical trajectories in crossed electric and magnetic fields. The examples of closed trajectories of electrons are discussed.
1. Гальперин ...
The lithodynamic and geomorphological features of a terraced underwater slope of the Sambian peninsula (South-East Baltic)
... nearshore to the basinal environment in the southern Baltic Sea: I. Processes and mass estimates// Journal of Marine Systems. 2002. Vol. 35, № 3—4. P. 133—150.
11. Jönsson A., Danielsson A., Rahm L. Bottom type distribution based on wave friction velocity in the Baltic Sea // Continental Shelf Research. 2005. Vol. 25, 3. P. 419—435.
12. Айбулатов Н. А., Долотов Ю. С., Орлова Г. А. и др. Некоторые черты динамики отмелого песчаного ...
Implementation persistent scatterers interferometry in MATLAB environment on a high performance computer cluster
... processing of multi-time measurements made by radar ALOS/PALSAR in 2007—2011 is described. For processing software package developed used high-precision evaluation of the displacement of man-made objects. The technology publication of displacement velocity of terrestrial surface on the basis of GeoServer and Google Maps services is offered.
1. Комаров С. А., Миронов В. Л., Романов А. Н. и др. Методы дистанционного зондирования техногенных ...
Modeling of Wave Processes in High Speed Impacts with Smoothed Particle Hydrodynamics Method
... модели процессов. М
., 2002.
С
. 72—78.
3.
Parshikov A. N., Medin S. A., Loukashenko I. I. and so on.
Improvements in SPH methods by means of interparticle contact algorithm and analysis of perforation tests at moderate projectile velocities // International Journal of Impact Engineering.
2000.
Vol
.
24.
P
. 779—796.
Potapov A. P., Petrov I. B.
SPH, elastic-plastic, discontinuity, 3D algorithm.
49-55
10.5922/2223-2095-2009-10-3
Non-stationary polar wind in presence of magnetosphere convection
... density profiles measured with IMAGE radio plasma imager // J. Geophys. Res. 2004. Vol. 109, №A7.
Р
. 7206.
17.
Horwitz J. L. Zeng W.
Physics-based formula representations of high-latitude ionospheric outflows: H
+
and O
+
densities, flow velocities, and temperatures versus soft electron precipitation, wave-driven transverse heating, and solar zenith angle effects // J. Geophys. Res
. 2009.
Vol
. 114, №
A
1. Р. 1308.
18.
Григорьев С. А., Зинин Л. В., Василенко ...
Structural features of upwelling in South-East Baltic
... gale were simulated by 3D numerical model, based on the Princeton Ocean Model (POM). By means of numerical simulation it was conformed that features of upwelling space structure depend upon bottom topography in an area of observation, strength of wind velocity and its duration. The dependence of the
upwelling scenario on the Froude number was obtained.
1.
Андросов А.
А., Вольцингер Н.
Е.
Проливы мирового океана. Общий подход к моделированию....
The conservation laws in the Euler problem about two attractive centers and the integration of the dynamic equations
The article establishes that Euler’s problem of two attractive centres contains another conservation law alongside with the energy conservation
one, which is also quadratic in velocities. These conservation laws and elliptic coordinates considerably simplify the procedure of trajectory equations generation.
1. Euler L. Probleme. Un corps ètant attirè en raison rèciproque quarrèe des distances vers deux points fixes ...
The interaction between an anticyclone and barrier
...
А., Шабат Б.
В.
Проблемы гидродинамики и их математические модели. М., 1973.
Zaitsev A. A., Ivanov S. N., Yudina A. V.
two-dimensional vortex, anticyclone, interaction, trajectory,
flow velocity, streamline.
17-20
10.5922/2223-2095-2009-4-3