scholarly journals Magnetoelastic plane waves in rotating media in thermoelasticity of type II (G-N model)

2004 ◽  
Vol 2004 (71) ◽  
pp. 3917-3929 ◽  
Author(s):  
S. K. Roychoudhuri ◽  
Manidipa Banerjee (Chattopadhyay)
Keyword(s):  
Magnetic Field ◽  
Energy Loss ◽  
Phase Velocity ◽  
Specific Energy ◽  
Thermal Field ◽  
Plane Waves ◽  
Transverse Magnetic ◽  
Thermal Parameters ◽  
First Order ◽  
Specific Energy Loss

A study is made of the propagation of time-harmonic plane waves in an infinite, conducting, thermoelastic solid permeated by a uniform primary external magnetic field when the entire medium is rotating with a uniform angular velocity. The thermoelasticity theory of type II (G-N model) (1993) is used to study the propagation of waves. A more general dispersion equation is derived to determine the effects of rotation, thermal parameters, characteristic of the medium, and the external magnetic field. If the primary magnetic field has a transverse component, it is observed that the longitudinal and transverse motions are linked together. For low frequency (χ≪1,χbeing the ratio of the wave frequency to some standard frequencyω∗), the rotation and the thermal field have no effect on the phase velocity to the first order ofχand then this corresponds to only one slow wave influenced by the electromagnetic field only. But to the second order ofχ, the phase velocity, attenuation coefficient, and the specific energy loss are affected by rotation and depend on the thermal parameterscT,cTbeing the nondimensional thermal wave speed of G-N theory, and the thermoelastic couplingεT, the electromagnetic parametersεH, and the transverse magnetic fieldRH. Also for large frequency, rotation and thermal field have no effect on the phase velocity, which is independent of primary magnetic field to the first order of (1/χ) (χ≫1), and the specific energy loss is a constant, independent of any field parameter. However, to the second order of (1/χ), rotation does exert influence on both the phase velocity and the attenuation factor, and the specific energy loss is affected by rotation and depends on the thermal parameterscTandεT, electromagnetic parameterεH, and the transverse magnetic fieldRH, whereas the specific energy loss is independent of any field parameters to the first order of (1/χ).

The effect of boundaries on wave propagation in a liquid-filled porous solid: VI. Love waves in a double surface layer

1964 ◽  
Vol 54 (1) ◽  
pp. 417-423
Author(s):  
H. Deresiewicz
Keyword(s):  
Wave Propagation ◽  
Surface Layer ◽  
Dispersion Relation ◽  
Energy Loss ◽  
Classical Solution ◽  
Specific Energy ◽  
Classical Case ◽  
Specific Energy Loss ◽  
Double Surface ◽  
The One

abstract The classical solution of Stoneley and Tillotson is generalized by considering the outer one of the pair of layers to be porous. Although the dispersion relation turns out, for practical purposes, to be identical with the one governing the classical case, the motion in the present instance is shown to be dissipative and the expression is exhibited for the specific energy loss.

A semianalytical solution for the propagation of electromagnetic waves in 3‐D lossy orthotropic media

Geophysics ◽  
2001 ◽  
Vol 66 (4) ◽  
pp. 1141-1148 ◽  
Author(s):  
José M. Carcione ◽  
Fabio Cavallini
Keyword(s):  
Magnetic Field ◽  
Plane Wave ◽  
Electromagnetic Waves ◽  
Plane Waves ◽  
Computer Experiment ◽  
Transverse Magnetic ◽  
Wave Analysis ◽  
Helmholtz Equations ◽  
Magnetic Surfaces ◽  
Time Histories

We derive an analytical solution for electromagnetic waves propagating in a 3‐D lossy orthotropic medium for which the electric permittivity tensor is proportional to the magnetic permeability tensor. The solution is obtained through a change of coordinates that transforms the spatial differential operator into a pure Laplace operator and the differential equations for the electric and magnetic field components into pure Helmholtz equations. A plane‐wave analysis gives the expression of the slowness and attenuation surfaces as a function of frequency and propagation direction. The transverse electric and transverse magnetic surfaces degenerate to one repeated sheet so that, in any direction, the two differently polarized plane waves have the same slowness. A computer experiment with realistic geophysical parameters has shown that the anisotropic propagation and dissipation properties emerging from plane‐wave analysis agree with the different time histories of the magnetic field computed at a number of representative receiver locations.

Magneto-thermo-elastic plane waves

1965 ◽  
Vol 61 (4) ◽  
pp. 939-944 ◽  
Author(s):  
C. M. Purushothama
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Shear Wave ◽  
Wave Velocity ◽  
Compression Wave ◽  
Thermal Field ◽  
Plane Waves ◽  
Elastic Plane ◽  
Magnetic Diffusivity ◽  
The Magnetic Field

AbstractThe combined effects of uniform thermal and magnetic fields on the propagation of plane waves in a homogeneous, initially unstressed, electrically conducting elastic medium have been investigated.When the magnetic field is parallel to the direction of wave propagation, the compression wave is purely thermo-elastic and the shear wave is purely magneto-elastic in nature. For a transverse magnetic field, the shear waves remain elastic whereas the compression wave assumes magneto-thermo-elastic character due to the coupling of all the three fields—mechanical, magnetic and thermal. In the general case, the waves polarized in the plane of the direction of wave propagation and the magnetic field are not only coupled but are also influenced by the thermal field, once again exhibiting the coupling of the three fields. The shear wave polarized transverse to the plane retains its magneto-elastic character.Notation.Hi = primary magnetic field components,ht = induced magnetic field components,To = initial thermal field,θ = induced thermal field,C = compression wave velocity.S = shear wave velocity,ui = displacement components,cv = specific heat at constant volume,k = thermal conductivity,η = magnetic diffusivity,μe = magnetic permeability,λ, μ = Lamé's constants,β = ratio of coefficient of volume expansion to isothermal compressibility.

Particle identification

2020 ◽  
pp. 543-580
Author(s):  
Hermann Kolanoski ◽  
Norbert Wermes
Keyword(s):  
Energy Loss ◽  
Specific Energy ◽  
Charged Particles ◽  
High Energy ◽  
Particle Identification ◽  
Specific Energy Loss ◽  
Quantum Numbers ◽  
Decay Products ◽  
High Energy Electrons ◽  
Shower Development

The identity of a particle is fixed by its mass, lifetime and quantum numbers such as charge, spin, parity and flavour. A particle’s identity can be inferred by observing its interactions in matter, as for example the shower development of an electron or a photon, the specific energy loss of charged particles, the emission of radiation by a particle or the penetration capability of a muon. The mass of a particle can be determined by measurements of specific energy loss, time-of-flight or Cherenkov radiation when combined with a momentum measurement. High energy electrons can be separated from heavier particles through transition radiation. For particles which decay in the detector the mass can often be kinematically reconstructed from the decay products and the lifetime can be determined by the reconstruction of secondary vertices.

scholarly journals Magneto-viscoelastic plane waves in rotating media in the generalized thermoelasticity II

2005 ◽  
Vol 2005 (11) ◽  
pp. 1819-1834 ◽  
Author(s):  
S. K. Roy Choudhuri ◽  
Manidipa Banerjee (Chattopadhyay)
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Dispersion Equation ◽  
Plane Waves ◽  
Generalized Thermoelasticity ◽  
Viscoelastic Parameters ◽  
Specific Energy Loss ◽  
General Dispersion ◽  
Effects Of Rotation ◽  
Propagation Of Waves

A study is made of the propagation of time-harmonic magneto-thermoviscoelastic plane waves in a homogeneous electrically conducting viscoelastic medium of Kelvin-Voigt type permeated by a primary uniform external magnetic field when the entire medium rotates with a uniform angular velocity. The generalized thermoelasticity theory of type II (Green and Naghdi model) is used to study the propagation of waves. A more general dispersion equation for coupled waves is derived to ascertain the effects of rotation, finite thermal wave speed of GN theory, viscoelastic parameters and the external magnetic field on the phase velocity, the attenuation coefficient, and the specific energy loss of the waves. Limiting cases for low and high frequencies are also studied. In absence of rotation, external magnetic field, and viscoelasticity, the general dispersion equation reduces to the dispersion equation for coupled thermal dilatational waves in generalized thermoelasticity II (GN model), not considered before. It reveals that the coupled thermal dilatational waves in generalized thermoelasticity II are unattenuated and nondispersive in contrast to the thermoelastic waves in classical coupled thermoelasticity (Chadwick (1960)) which suffer both attenuation and dispersion.

The propagation of magneto-thermo-viscoelastic plane waves in a parallel union of the Kelvin and Maxwell bodies

1971 ◽  
Vol 70 (2) ◽  
pp. 343-350 ◽  
Author(s):  
D. S. Chandrasekhariah
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Electromagnetic Field ◽  
Wave Propagation ◽  
Thermal Field ◽  
Plane Waves ◽  
Viscoelastic Body ◽  
Longitudinal Component ◽  
Transverse Component ◽  
Wave Travel

AbstractThe propagation of plane waves in a viscoelastic body representing a parallel union of the Kelvin and Maxwell bodies placed in a magneto-thermal field is investigated. It is shown that the longitudinal component of the wave is in general coupled with a transverse component and the wave travels in two families. In particular if the primary magnetic field is either parallel or perpendicular to the direction of wave propagation, the three components of the wave travel unlinked, with either the longitudinal component or the transverse components unaffected by the presence of the electromagnetic field. If the electrical conductivity of the solid is infinite the effect of the primary magnetic field is to increase the values of the material constants. The effect of wave propagation on magnetic permeability is equivalent to an anisotropic rescaling of the primary magnetic field. Some of the results obtained in the earlier works are obtained as particular cases of the more general results derived here.

Non-linear constant-profile plane waves in a cold plasma under an applied magnetic field

1967 ◽  
Vol 1 (1) ◽  
pp. 55-74 ◽  
Author(s):  
Yves J. Alloucherie
Keyword(s):  
Magnetic Field ◽  
Perturbation Methods ◽  
Plane Waves ◽  
Local Magnetic Field ◽  
Field Energy ◽  
First Order ◽  
Non Linear ◽  
Field Energy Density ◽  
Vlasov Plasma ◽  
Periodic Plane

Periodic plane waves propagating in a homogeneous cold Vlasov plasma under the influence of an external magnetic field B0 have been studied in this paper. Non-linear coupled differential equations for the two transverse components of the local magnetic field have been obtained for any angle α between B0 and the wave vector. Starting from the previously obtained exact solution for α = 90° and the zeroth-order solution for α = 0, two perturbation methods are used to obtain first-order solutions for α = 0 and intermediate angles. A numerical example has been worked out in detail for a specific value of the field energy density; although it is not possible to match the two sets of results rigorously, they seem to converge smoothly to the same limit.

Electromagneto-Thermoelastic Plane Waves in Solids With Thermal Relaxation

1972 ◽  
Vol 39 (1) ◽  
pp. 108-113 ◽  
Author(s):  
A. H. Nayfeh ◽  
S. Nemat-Nasser
Keyword(s):  
Magnetic Field ◽  
Relaxation Time ◽  
Thermal Field ◽  
Plane Waves ◽  
Electric Displacement ◽  
Thermal Relaxation ◽  
Displacement Current ◽  
Perturbation Techniques ◽  
Thermoelastic Waves ◽  
The Magnetic Field

Perturbation techniques are used to study the influence of small thermoelastic and magnetoelastic couplings on the propagation of plane electromagneto-thermoelastic waves in an unbounded isotropic medium. The thermal relaxation time of heat conduction, and the electric displacement current are included in the analysis. It is found that the thermal field may affect transverse motions, and that the magnetic field may affect motions that occur parallel to its line of action.

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