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Article
Publication date: 21 March 2023

Manjeet Kumar, Pradeep Kaswan, Nantu Sarkar, Xu Liu and Manjeet Kumari

The purpose of this article is to investigate the propagation characteristics (such as particle motion, attenuation and phase velocity) of a Rayleigh wave in a nonlocal…

Abstract

Purpose

The purpose of this article is to investigate the propagation characteristics (such as particle motion, attenuation and phase velocity) of a Rayleigh wave in a nonlocal generalized thermoelastic media.

Design/methodology/approach

The bulk waves are represented with Helmholtz potentials. The stress-free insulated and isothermal plane surfaces are taken into account. Rayleigh wave dispersion relation has been established and is found to be complex. Due to the presence of radicals, the dispersion equation is continuously computed as a complicated irrational expression. The dispersion equation is then converted into a polynomial equation that can be solved numerically for precise complex roots. The extra zeros in this polynomial equation are eliminated to yield the dispersion equation’s roots. These routes are then filtered for inhomogeneous wave propagation that decays with depth. To perform numerical computations, MATLAB software is used.

Findings

In this medium, only one mode of Rayleigh wave exists at both isothermal and insulated boundaries. The thermal factors of nonlocal generalized thermoelastic materials significantly influence the particle motion, attenuation and phase velocity of the Rayleigh wave.

Originality/value

Numerical examples are taken to examine how the thermal characteristics of materials affect the existing Rayleigh wave’s propagation characteristics. Graphical analysis is used to evaluate the behavior of particle motion (such as elliptical) both inside and at the isothermal (or insulated) flat surface of the medium under consideration.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 11 April 2022

Manjeet Kumar, Xu Liu, Manjeet Kumari and Poonam Yadav

The purpose of this paper is to investigate propagation characteristics of seismic waves at the welded interface of an elastic solid and unsaturated poro-thermoelastic solid.

Abstract

Purpose

The purpose of this paper is to investigate propagation characteristics of seismic waves at the welded interface of an elastic solid and unsaturated poro-thermoelastic solid.

Design/methodology/approach

A theoretical formulation of partially saturated poro-thermoelastic solid is used in this study established by Zhou et al. (2019). The incidence of two primary waves (P and SV) is taken. The incident wave from the elastic solid induces two reflected waves and five refracted waves. Due to viscous pore fluids, partially saturated poro-thermoelastic solid behave dissipative, whereas elastic solid behaves non-dissipative. As a result, both reflected and incident waves are homogeneous. However, all the refracted waves are inhomogeneous. A non-singular system of linear equations is formed by the coefficients of reflection and refraction for a specified incident wave. The energy shares of various reflected and refracted waves are determined by using these reflection and refraction factors. Finally, a sensitivity analysis is performed, and the effect of critical variables on energy partitioning at the interface is observed. The numerical example shows that throughout the process of reflection/refraction, the energy of incidence is conserved at all angles of incidences.

Findings

This study demonstrated two refracted (homogeneous) and five refracted (inhomogeneous) waves due to the incident wave from elastic solid. The reflection and refraction coefficients and partitioning of incident energy are acquired as a part of diverse physical parameters of the partially saturated poro-thermoelastic media. The interference energies between unlike pairs of refracted waves have been discovered due to the dissipative behavior of unsaturated poro-thermoelastic solid.

Originality/value

The sensitivity of different energy shares to various aspects of the considered model is graphically analyzed for a specific numerical model. The energy balance is maintained by combining interaction energy and bulk wave energy shares.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 25 May 2023

Manjeet Kumar, Jai Bhagwan, Pradeep Kaswan, Xu Liu and Manjeet Kumari

The purpose of this study is to investigate the reflection of plane waves in a double-porosity (DP) thermoelastic medium.

Abstract

Purpose

The purpose of this study is to investigate the reflection of plane waves in a double-porosity (DP) thermoelastic medium.

Design/methodology/approach

To derive the theoretical formulas for elastic wave propagation velocities through the potential decomposition of wave-governing equations. The boundary conditions have been designed to incorporate the unique characteristics of the surface pores, whether they are open or sealed. This approach provides a more accurate and realistic mathematical interpretation of the situation that would be encountered in the field. The reflection coefficients are obtained through a linear system of equations, which is solved using the Gauss elimination method.

Findings

The solutions obtained from the governing equations reveal the presence of five inhomogeneous plane waves, consisting of four coupled longitudinal waves and a single transverse wave. The energy ratios of reflected waves are determined for both open and sealed pores on the stress-free, the thermally insulated surface of DP thermoelastic medium. In addition, the energy ratios are compared for the cases of a DP medium and a DP thermoelastic medium.

Originality/value

A numerical example is considered to investigate the effect of fluid type in inclusions, temperature and inhomogeneity on phase velocities and attenuation coefficients as a function of frequency. Finally, a sensitivity analysis is performed graphically to observe the effect of the various parameters on propagation characteristics, such as propagation/attenuation directions, phase shifts and energy ratios as a function of incident direction in double-porosity thermoelasticity medium.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 5 September 2021

Manjeet Kumar, Xu Liu, Kapil Kumar Kalkal, Virender Dalal and Manjeet Kumari

The purpose of this paper is to study the propagation of inhomogeneous waves in a partially saturated poro-thermoelastic media through the examples of the free surface of such…

Abstract

Purpose

The purpose of this paper is to study the propagation of inhomogeneous waves in a partially saturated poro-thermoelastic media through the examples of the free surface of such media..

Design/methodology/approach

The mathematical model evolved by Zhou et al. (2019) is solved through the Helmholtz decomposition theorem. The propagation velocities of bulk waves in partially saturated poro-thermoelastic media are derived by using the potential functions. The phase velocities and attenuation coefficients are expressed in terms of inhomogeneity angle. Reflection characteristics (phase shift, loci of vertical slowness, amplitude, energy) of elastic waves are investigated at the stress-free thermally insulated boundary of a considered medium. The boundary can be permeable or impermeable. The incident wave is portrayed with both attenuation and propagation directions (i.e. inhomogeneous wave). Numerical computations are executed by using MATLAB.

Findings

In this medium, the permanence of five inhomogeneous waves is found. Incidence of the inhomogeneous wave at the thermally insulated stress-free surface results in five reflected inhomogeneous waves in a partially saturated poro-thermoelastic media. The reflection coefficients and splitting of incident energy are obtained as a function of propagation direction, inhomogeneity angle, wave frequency and numerous thermophysical features of the partially saturated poro-thermoelastic media. The energy of distinct waves (incident wave, reflected waves) accompanying interference energies between distinct pairs of waves have been exhibited in the form of an energy matrix.

Originality/value

The sensitivity of propagation characteristics (velocity, attenuation, phase shift, loci of vertical slowness, energy) to numerous aspects of the physical model is analyzed graphically through a particular numerical example. The balance of energy is substantiated by virtue of the interaction energies at the thermally insulated stress-free surface (opened/sealed pores) of unsaturated poro-thermoelastic media through the bulk waves energy shares and interaction energy.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 19 June 2017

Manjeet Singh and Surender Kumar Soni

This paper aims to discuss a comprehensive survey on fuzzy-based clustering techniques. The determination of an appropriate sensor node as a cluster head straightforwardly affects…

Abstract

Purpose

This paper aims to discuss a comprehensive survey on fuzzy-based clustering techniques. The determination of an appropriate sensor node as a cluster head straightforwardly affects a network’s lifetime. Clustering often possesses some uncertainties in determining suitable sensor nodes as a cluster head. Owing to various variables, selection of a suitable node as a cluster head is a perplexing decision. Fuzzy logic is capable of handling uncertainties and improving decision-making processes even with insufficient information. Then, state-of-the-art research in the field of clustering techniques has been reviewed.

Design/methodology/approach

The literature is presented in a tabular form with merits and limitations of each technique. Furthermore, the various techniques are compared graphically and classified in a tabular form and the flowcharts of important algorithms are presented with pseudocodes.

Findings

This paper comprehends the importance and distinction of different fuzzy-based clustering methods which are further supportive in designing more efficient clustering protocols.

Originality/value

This paper fulfills the need of a review paper in the field of fuzzy-based clustering techniques because no other paper has reviewed all the fuzzy-based clustering techniques. Furthermore, none of them has presented literature in a tabular form or presented flowcharts with pseudocodes of important techniques.

Details

Sensor Review, vol. 37 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 18 October 2022

Vipin Gupta, Rajesh Kumar, Manjeet Kumar, Vijayata Pathania and M.S. Barak

This paper aims to study the variation of energy ratios of different reflected and transmitted waves by calculating the amplitude ratios.

Abstract

Purpose

This paper aims to study the variation of energy ratios of different reflected and transmitted waves by calculating the amplitude ratios.

Design/methodology/approach

This investigation studied the reflection and transmission of plane waves on an interface of nonlocal orthotropic piezothermoelastic space (NOPHS) and fluid half-space (FHS) in reference to dual-phase-lag theory under three different temperature models, namely, without-two-temperature, classical-two-temperature, and hyperbolic-two-temperature with memory-dependent derivatives (MDDs).

Findings

The primary (P) plane waves propagate through FHS and strike at the interface x3 = 0. The results are one wave reflected in FHS and four waves transmitted in NOPHS. It is noticed that these ratios are observed under the impact of nonlocal, dual-phase-lag (DPL), two-temperature and memory-dependent parameters and are displayed graphically. Some particular cases are also deduced, and the law of conservation of energy across the interface is justified.

Research limitations/implications

According to the available literature, there is no substantial research on the considered model incorporating NOPHS and FHS with hyperbolic two-temperature, DPL and memory.

Practical implications

The current model may be used in various fields, including earthquake engineering, nuclear reactors, high particle accelerators, aeronautics, soil dynamics and so on, where MDDs and conductive temperature play a significant role. Wave propagation in a fluid-piezothermoelastic media with different characteristics such as initial stress, magnetic field, porosity, temperature, etc., provides crucial information about the presence of new and modified waves, which is helpful in a variety of technical and geophysical situations. Experimental seismologists, new material designers and researchers may find this model valuable in revising earthquake estimates.

Social implications

The researchers may classify the material using the two-temperature parameter and the time-delay operator, where the parameter is a new indication of its capacity to transmit heat in interaction with various materials.

Originality/value

The submitted manuscript is original work done by the team of said authors and each author contributed equally to preparing this manuscript.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 May 2013

Rana Haq

This paper aims to present the challenges facing women in India due to the intersectionality of gender and other forms of identities impacting on their personal and professional…

6519

Abstract

Purpose

This paper aims to present the challenges facing women in India due to the intersectionality of gender and other forms of identities impacting on their personal and professional lives by exploring the intersection of gender, colour, caste, ethnicity, religion, marital status, and class as sources of discrimination against women in Indian society and workplaces.

Design/methodology/approach

The approach is discussing the socio‐cultural traditions leading up to the complexities of multiple intersections of identity for women living and working in India, offering a paradigm shift from Western issues of gender equality towards understanding women's empowerment issues within the Indian context.

Findings

Indian women are marginalized in their access to education and healthcare, and they are also compromised in their personal and professional development by being undervalued, underemployed and under‐rewarded. The social implications are the impact of awareness, changing attitudes and corporate social responsibility interventions towards improving the quality of life of women in India. Multinational corporations as well as Indian organizations may be influenced to implement diversity policies and practices beyond individual identities to incorporate the complex intersectionality that is the reality and dilemma of the challenges faced by Indian women in society, in professional careers and within organizations.

Originality/value

Readers will find originality and value in understanding the complexities of gender equality issues in India as compared to other countries and contexts. It can inform researchers, academics, practitioners and policy makers on how to address the disparities and discrimination against women and guide comparative discourses between India and other countries towards eliminating discrimination against women.

Details

Gender in Management: An International Journal, vol. 28 no. 3
Type: Research Article
ISSN: 1754-2413

Keywords

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