Surface Waves in Thermoelasticity with Relaxation Times

The aim of the present investigation is to study the effects of magnetic field, relaxation times, and rotation on the propagation of surface waves with imperfect boundary. The propagation between an isotropic elastic layer of finite thickness and a homogenous isotropic thermodiffusive elastic half-space with rotation in the context of Green-Lindsay (GL) model is studied. The secular equation for surface waves in compact form is derived after developing the mathematical model. The phase velocity and attenuation coefficient are obtained for stiffness, and then deduced for normal stiffness, tangential stiffness and welded contact. The amplitudes of displacements, temperature, and concentration are computed analytically at the free plane boundary. Some special cases are illustrated and compared with previous results obtained by other authors. The effects of rotation, magnetic field, and relaxation times on the speed, attenuation coefficient, and the amplitudes of displacements, temperature, and concentration are displayed graphically.

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Surface waves in porous thermoelastic medium with two relaxation times

Mechanics Based Design of Structures and Machines ◽

10.1080/15397734.2020.1831532 ◽

2020 ◽

pp. 1-19

Author(s):

Abdush Salam Pramanik ◽

Siddhartha Biswas

Keyword(s):

Surface Waves ◽

Relaxation Times ◽

Thermoelastic Medium

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Surface Wave Propagation in a Microstretch Thermoelastic Diffusion Material under an Inviscid Liquid Layer

Advances in Acoustics and Vibration ◽

10.1155/2014/518384 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11

Author(s):

Rajneesh Kumar ◽

Sanjeev Ahuja ◽

S. K. Garg

Keyword(s):

Surface Waves ◽

Half Space ◽

Liquid Layer ◽

Relaxation Times ◽

Wave Number ◽

Normal Velocity ◽

Thermoelastic Diffusion ◽

Inviscid Liquid ◽

Surface Wave Propagation ◽

The Mathematical Model

The present investigation deals with the propagation of Rayleigh type surface waves in an isotropic microstretch thermoelastic diffusion solid half space under a layer of inviscid liquid. The secular equation for surface waves in compact form is derived after developing the mathematical model. The dispersion curves giving the phase velocity and attenuation coefficients with wave number are plotted graphically to depict the effect of an imperfect boundary alongwith the relaxation times in a microstretch thermoelastic diffusion solid half space under a homogeneous inviscid liquid layer for thermally insulated, impermeable boundaries and isothermal, isoconcentrated boundaries, respectively. In addition, normal velocity component is also plotted in the liquid layer. Several cases of interest under different conditions are also deduced and discussed.

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Secular Equation of Magnetic Field and Gravity Variation on Propagation of Surface Waves in Fibre-Reinforced Anisotropic Thermoelastic Solid with Two Relaxation Times

Journal of Computational and Theoretical Nanoscience ◽

10.1166/jctn.2014.3648 ◽

2014 ◽

Vol 11 (11) ◽

pp. 2339-2355 ◽

Cited By ~ 3

Author(s):

S. M. Abo-Dahab ◽

E. Edfawy

Keyword(s):

Magnetic Field ◽

Surface Waves ◽

Secular Equation ◽

Relaxation Times ◽

Gravity Variation ◽

Thermoelastic Solid

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Effects of Rotation and Gravity Field on Surface Waves in Fibre-Reinforced Thermoelastic Media under Four Theories

Journal of Applied Mathematics ◽

10.1155/2013/562369 ◽

2013 ◽

Vol 2013 ◽

pp. 1-20 ◽

Cited By ~ 5

Author(s):

A. M. Abd-Alla ◽

S. M. Abo-Dahab ◽

A. Al-Mullise

Keyword(s):

Surface Waves ◽

Rayleigh Waves ◽

Relaxation Times ◽

Type Ii ◽

Physical Domain ◽

Stoneley Waves ◽

Harmonic Vibrations ◽

Effects Of Rotation ◽

Analytical Expressions ◽

Thermoelastic Theory

Estimation is done to investigate the gravitational and rotational parameters effects on surface waves in fibre-reinforced thermoelastic media. The theory of generalized surface waves has been firstly developed and then it has been employed to investigate particular cases of waves, namely, Stoneley waves, Rayleigh waves, and Love waves. The analytical expressions for surface waves velocity and attenuation coefficient are obtained in the physical domain by using the harmonic vibrations and four thermoelastic theories. The wave velocity equations have been obtained in different cases. The numerical results are given for equation of coupled thermoelastic theory (C-T), Lord-Shulman theory (L-S), Green-Lindsay theory (G-L), and the linearized (G-N) theory of type II. Comparison was made with the results obtained in the presence and absence of gravity, rotation, and parameters for fibre-reinforced of the material media. The results obtained are displayed by graphs to clear the phenomena physical meaning. The results indicate that the effect of gravity, rotation, relaxation times, and parameters of fibre-reinforced of the material medium is very pronounced.

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An emerging technology: Nuclear magnetic resonance microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010706x ◽

1988 ◽

Vol 46 ◽

pp. 1000-1001

Author(s):

M.J. Hennessy ◽

E. Kwok

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Relaxation Times ◽

Basic Research ◽

Local Environment ◽

Magnetic Resonance Images ◽

Nmr Microscopy ◽

Mri Scans ◽

Temperature Relaxation ◽

Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

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