The sustainable environment in Ajman: A journey towards a green future in the United Arab Emirates
subject: Awareness; Environmental challenges; Innovation; Partnerships; Sustainability; Technology
description: Ajman, a rapidly developing emirate in the United Arab Emirates, is embarking on a journey toward a sustainable future amidst environmental challenges. This paper explores the current environmental situation in Ajman, analyzing challenges such as pollution, waste management issues, resource depletion, and impacts of climate change. It evaluates ongoing environmental innovation initiatives, including projects addressing these challenges and their impact on the local environment. Additionally, the paper examines the latest environmental technologies and innovations deployed in Ajman, along with efforts to promote environmental awareness among the local community. Furthermore, it delves into partnerships between the government and private sectors and international collaborations to advance sustainability goals. Finally, the paper identifies future challenges and development opportunities, reviews existing environmental policies and legislation, and provides recommendations for fostering a greener and more sustainable future in Ajman. 2025 by Nova Science Publishers, Inc. All rights reserved.
creator: Sebihi, Ahmed; Jain, Piyush K.; Jain, Rahul
source: Advancements in Sustainability Systems II;pp.1-20
publisher: Nova Science Publishers Inc.
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISBN: 979-889530654-3; 979-889530562-1;
language: English
type: Book chapter
coverage: Sebihi A., Skyline University College, Sharjah, United Arab Emirates; Jain P.K., Christ University, Bengaluru, India; Jain R., De Montfort University, Dubai, United Arab Emirates

Adolescents considering approval from others as a contributor to self-worth
subject: Approval from others; Contingencies of self worth; Self esteem
description: Adolescence is a period that starts from biological puberty till the individual is legally adult. This stage of life is filled with confusion, energy, and curiosity. As much as education is going to determine their future, the self-worth they have plays a critical role in choosing the future path. In India, the adolescents are dependent on their parents and guardians financially. They need approval from others to be acceptable. This study focuses on the effective support from others have on their self-worth. RJPT All right reserved.
creator: Seema Rani B.N.; Reddy J.
source: Research Journal of Pharmacy and Technology, Vol-10, No. 10, pp. 3337-3338.
publisher: Research Journal of Pharmacy and Technology
date: 2017-01-01
rights: Restricted Access
relation: ISSN: 9743618
format: Online
language: English
type: Article
coverage: Seema Rani B.N., AMET University, 135, East Coast Road, Kanathur, Chennai, India; Reddy J., Institute of Management, Christ University, Bangalore, India

Surface Effects Study: A Continuum Approach from Fundamental Modes to Higher Modes and Topological Polarization in Orthotropic Piezoelectric Materials
subject: electromechanical coupling factor; group velocity; impact; laminates; multiple modes; strain gradient theory; stress analysis; structures; surface effect; vibration; wave controlling; wave propagation
description: The primary goal of the current work is to investigate how wave propagation influences the performance of surface acoustics wave (SAW) macro-and nano-sensors. Therefore, shear horizontal (SH) waves use the surface piezoelectricity theory to explore SH waves in an orthotropic piezoelectric quasicrystal (PQC) layer overlying an elastic framework (Model I), a piezoelectric substrate, and an orthotropic PQC substrate (model II). This study employs a variable-separable technique. The theoretical forms are constructed and used to present the wavenumber of surface waves in any direction of the piezoelectric medium, based on the differential equations and matrix formulation. In addition, we take into account the surface elasticity theory in order to obtain the phase velocity equation. Two configurations are examined: An orthotropic piezoelectric material layer over an elastic framework and a piezoelectric material half-space with a nanosubstrate. Analytical expressions for frequency equations are derived for both symmetric and antisymmetric waves. This study investigates the effects of surface elastic constants, surface density, anisotropic piezoelectric constant, and symmetric and antisymmetric modes on phase velocity. This study is confined to only linear wave propagation. Additionally, the analysis is based on idealized material properties, surface properties, and characteristic length of the material. Copyright 2024 by ASME.
creator: Seema, Seema; Singhal, Abhinav
source: Journal of Applied Mechanics;Volume;92;Issue;1;Article No.;11008;
publisher: American Society of Mechanical Engineers (ASME)
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 218936; CODEN: JAMCA
format: online
language: English
type: Article
coverage: Seema S., Department of Mathematics, Christ University, Bengaluru, Karnataka, 560029, India; Singhal A., Department of Mathematics, Christ University, Bengaluru, Karnataka, 560029, India

Continuum Mechanics Analysis of Surface Vibrations in Piezomagnetic Laminates on Manifold Substrates
subject: heterogeneous half-space; impact analysis; Love-type wave; piezomagnetic materials; semiconductors; viscous liquid
description: Abstract: This work investigates Love-type wave transmission in a multilayered piezomagnetic (PM) and heterogeneous half-space (HHS) structure with a viscous liquid layer (VL) on top. Wave transmission behavior is investigated in both magnetically open (MO) and magnetically closed (MS) circuit boundary circumstances. The primary study focuses on the scattering behavior of phase velocity in a Love-type wave as influenced by the combination of VL, PM, and HHS. The dispersion relation for Love-type waves was calculated analytically, and phase velocity graphs were displayed and evaluated using Mathematica software. A detailed investigation was undertaken to determine the influence of important variables on phase velocity, such as material heterogeneity, piezomagnetic coupling, and viscous liquid layer thickness. The research results demonstrate the influence of VL, PM, and HHS materials on phase velocity in MO and MS conditions. Graphical comparisons reveal that piezomagnetic coupling causes significant changes in phase velocity, highlighting its role in wave propagation. The open and short circuit conditions exhibited approximately similar phase velocities, suggesting that boundary constraints had a negligible effect on wave propagation. The model only considers linear wave transmission and excludes nonlinear effects. Furthermore, the technique is predicated on idealized material properties that account for heterogeneity. The findings can be used to design and develop energy harvesters, sensors, and wave manipulation instruments using PM with viscous liquid coatings. Understanding the behaviour of surface waves, including phase velocity, is essential for efficient application in these frameworks. Pleiades Publishing, Ltd. 2025.
creator: Seema; Abhinav Singhal
source: Acoustical Physics;Volume;71;Issue;4;pp.569-579
publisher: Pleiades Publishing
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 10637710;
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Abhinav Singhal, Christ University, Bengaluru, 560029, India

Shearhorizontal wave transmission in prestressed rotating piezoelectricpiezomagnetic cylinders with imperfect interfaces: analytical modeling and parametric insights
description: This study develops an analytical framework to investigate shearhorizontal (SH) wave transmission in layered multiferroic cylinders composed of concentric piezoelectric (PE) and piezomagnetic (PM) materials under prestress and rotation. Both bi-layer and tri-layer configurations are examined, with the latter including a fiber-reinforced core, while the interfaces are modeled as mechanically, electrically, or magnetically imperfect using spring-type conditions. Closed-form dispersion relations are derived for electrically open/magnetically short and electrically short/magnetically open boundary cases. Numerical simulations are conducted to assess the influence of interfacial compliance, thickness ratio, rotation speed, and initial stress on phase and group velocities, as well as electromechanical coupling efficiency. The findings reveal that mechanical imperfection exerts a stronger influence on SH wave dispersion than electrical or magnetic defects, while PE/PM stiffening leads to monotonic phase velocity enhancement. Rotation and prestress are shown to significantly modify dispersion behavior, with PE layers more sensitive than PM layers. The novelty of this work lies in its unified treatment of multiferroic cylinders with simultaneous rotation, prestress, and multifield interface imperfections, bridging theoretical predictions with practical design considerations. Although the analysis assumes linear material behavior and neglects nonlinear dissipation or thermal coupling, it provides physically consistent predictions validated against limiting cases from prior literature. The results offer valuable guidelines for the design of piezoelectricpiezomagnetic devices such as SAW gyroscopes, rotation sensors, and magnetically controlled transducers, where interfacial integrity and prestress management are critical for performance optimization. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2025.
creator: Seema; Alamoudi, Manal; Saeed, Abdulkafi Mohammed; Alahmadi, Reham A.; Chaudhary, Anjali; Ganie, Abdul Hamid
source: Acta Mechanica;Volume;237;Issue;3;pp.1089-1109
publisher: Springer
date: 01-01-2026
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 15970; CODEN: AMHCA
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Alamoudi M., Department of Mathematics, College of Sciences and Humanities, Imam Abdulrahman Bin Faisal University, Jubail, Saudi Arabia; Saeed A.M., Department of Mathematics, College of Science, Qassim University, Buraydah, 51452, Saudi Arabia; Alahmadi R.A., Basic Science Department, College of Science and Theoretical Studies, Saudi Electronic University, Riyadh, 11673, Saudi Arabia; Chaudhary A., Department of Management, College of Business Administration, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh, 11671, Saudi Arabia; Ganie A.H., Basic Science Department, College of Science and Theoretical Studies, Saudi Electronic University, Riyadh, 11673, Saudi Arabia

Mathematical modelling and mechanics of acoustic waves in piezoelectric layers between n-type semiconductor plates: an irreducible Cardano method coupled with a functional iteration scheme
description: This study presents a comprehensive analyticalnumerical investigation of acoustic wave dispersion, attenuation, and energy dissipation in piezoelectricsemiconductor heterostructures composed of SiPZTSi and GePZTGe layers. The governing electromechanicaldiffusive equations for the coupled media are formulated with full continuity conditions, leading to a cubic characteristic equation solved using a hybrid irreducible Cardano method and functional iteration scheme. A detailed convergence analysis demonstrates stable, monotonic residual decay for both symmetric and asymmetric modes, confirming the robustness of the adopted solver. Numerical results reveal strong sensitivity of phase velocity, attenuation, and specific loss to wave number, semiconductor mobility, convergence and carrier concentration. GePZTGe consistently exhibits higher phase velocity, reduced attenuation, and lower dissipative losses than SiPZTSi, primarily due to the higher carrier mobility and weaker acoustoelectric drag in Ge. Additional parametric plots highlight the influence of semiconductor quality and PZT layer thickness on acoustic energy confinement. The findings provide actionable design guidelines for optimizing SAW-based filters, delay lines, sensors, and signal-processing devices, where low loss, high velocity, and efficient energy trapping are critical. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2026.
creator: Seema; Radhakrishnan, G.V.; Saeed, Abdulkafi Mohammed; Banerjee, Dyuti; Hundekari, Sheela; Chaudhary, Anjali
source: Acta Mechanica;
publisher: Springer
date: 01-01-2026
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 15970; CODEN: AMHCA
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Radhakrishnan G.V., KIIT School of Management (KSOM), Bhubaneswar, India; Saeed A.M., Department of Mathematics, College of Science, Qassim University, Buraydah, 51452, Saudi Arabia; Banerjee D., Department of Artificial Intelligence and Data Science, Koneru Lakshmaiah Education Foundation, Andhra Pradesh, Green Fields, Vaddeswaram, India; Hundekari S., School of Computer Applications, Pimpri Chinchwad University, Pune, India; Chaudhary A., Department of Management, College of Business Administration, Princess Nourah Bint Abdulrahman University, P. O. Box 84428, Riyadh, 11671, Saudi Arabia

Shear wave interaction with cylindrical magneto-electro-elastic structures
description: The present study develops an extended analytical framework for investigating Love-type wave propagation in multilayered magneto-electro-elastic (MEE) composites while accounting for nanoscale electrical, magnetic, and mechanical interfacial imperfections. The primary purpose is to establish a generalized dispersion relation that unifies classical Love-wave theory with coupled-field effects and imperfect interface conditions. The methodology employs the complex function approach in conjunction with the Helmholtz equation and wavefield superposition theory. Interfacial imperfection factors are introduced via a spring-type boundary model, leading to an infinite system of equations. A systematic truncation procedure ensures convergence of the analytical solution, and numerical simulations are performed to illustrate the influence of imperfections, thickness ratio, and coupling coefficients on dispersion, attenuation, and coupling efficiency. Findings reveal that imperfections significantly suppress phase velocity, with electrical defects producing stronger effects than magnetic ones, while mechanical bonding imperfections accelerate attenuation. Combined imperfections exhibit a synergistic nonlinear influence, producing dispersion shifts more severe than the sum of individual effects. Comparisons between EMO and EMS boundary conditions highlight that stress-driven EMS interfaces are more sensitive to imperfections than displacement-driven EMO boundaries. Additionally, increasing the guiding layer thickness enhances wave confinement, raising phase velocity and partially mitigating defect influence. Validation is achieved by demonstrating that the model naturally reduces to the classical Love-wave solution in the absence of coupling and imperfections, showing excellent agreement with previously published results. The novelty of the work lies in providing the first comprehensive formulation that integrates piezoelectric, piezomagnetic, and imperfection effects within a un…
creator: Seema; Radhakrishnan, Ganesh V.; Saeed, Abdulkafi Mohammed; Khan, Mohiuddin Ali; Singhal, Abhinav; Chaudhary, Anjali
source: Acta Mechanica;Volume;236;Issue;12;pp.6975-7003
publisher: Springer
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 15970; CODEN: AMHCA
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Radhakrishnan G.V., Department of Economics and Finance, KIIT School of Management (KSOM), KKIT University, Bhubaneswar, India; Saeed A.M., Department of Mathematics, College of Science, Qassim University, Buraydah, 51452, Saudi Arabia; Khan M.A., Department of Electrical & Electronics Engineering, Jazan University, Jazan, Saudi Arabia; Singhal A., Christ University, Bengaluru, 560029, India; Chaudhary A., Department of Management, College of Business Administration, Princess Nourah Bint Abdulrahman University, P.O.Box 84428, 11671, Riyadh, Saudi Arabia

Surface acoustic waves in a layered piezoelectric plate with considered surface effects
subject: Electromechanical coupling factor; Multiple modes; Nonlinear surface effect; Polarization; Surface wave interaction; Wave controlling
description: In an attempt to remove such impediments in the technological revolution of surface acoustics waves (SAW) sensors, the main objective of the current work is to study how wave propagation direction effects the performance of SAW macro- and nano-sensors. In order to investigate the propagation of shear horizontal (SH) and anti-plane SH waves in piezoelectric materials with surface effects, a model has been presented. The wavenumber of surface waves in any direction of the piezoelectric medium is presented using the theoretical forms that are generated. To get the phase velocity equation from the wavenumber expression, we additionally use surface elasticity theory. To account for surface phenomena at the nanoscale, the model includes permittivity, surface elasticity, and piezoelectricity. Two configurations are investigated: a piezoelectric material half-space with a nano-substrate and an orthotropic piezoelectric material layer atop an elastic framework. Frequency equations for both symmetric and anti-symmetric waves are determined analytically. The crucial thickness of the piezoelectric layer, where surface energy greatly affects dispersion properties, is highlighted by numerical results. Analysis of the impact of density and surface elasticity on wave velocity reveals a boundary-like spring force. The objective of this study is to investigate the SH wave transmission behavior in anisotropic, transversely isotropic piezoelectric nanostructures. Summaries of recent theoretical work aid in the construction of more effective surface acoustic wave sensors, and the study findings may be valuable in building SAW devices and piezoelectric sensors. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
creator: Seema; Saeed, Abdulkafi Mohammed; Singhal, Abhinav; Das, Soumik
source: International Journal of Dynamics and Control;Volume;13;Issue;1;Article No.;38;
publisher: Springer Science and Business Media Deutschland GmbH
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 2195268X;
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Saeed A.M., Department of Mathematics, College of Science, Qassim University, Buraydah, 51452, Saudi Arabia; Singhal A., Christ University, Bengaluru, 560029, India; Das S., School of Physical Sciences, Amrita Vishwa Vidyapeetham, Mysuru Campus, Karnataka, Mysore, 570026, India

Study of surface wave velocity in distinct rheological models with flexoelectric effect in piezoelectric aluminium nitride structure
subject: KelvinVoigt model; Love wave analysis; Maxwell model; Newton model; Visco-piezoelectric substrate
description: This study investigates the propagation of surface seismic waves at the loosely bonded interface of a visco-piezoelectric composite structure, incorporating the flexoelectric effect. The structure consists of a viscoelastic layer placed over a piezoelectric substrate, with the upper layer's shear stiffness modelled using the KelvinVoigt approach. An analytical method based on the separation of variables is employed to derive the complex dispersion relations for both electrically open- and short-circuit boundary conditions. Numerical simulations reveal the significant influence of various parameters on the wave's phase velocity and attenuation coefficient. Furthermore, a graphical comparison of three rheological modelsMaxwell, Newton, and KelvinVoigtis presented. The results show that the attenuation is lower in the Maxwell and Newton models compared to the KelvinVoigt model. Key findings include the bonding parameter's direct proportionality with phase velocity and inverse relationship with attenuation, and the pronounced impact of flexoelectricity on both phase velocity and attenuation. This theoretical framework offers insights into the piezo-flexoelectric coupling, with potential applications in designing sensors, actuators, energy harvesters, and nano-electronic devices. The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering 2024.
creator: Seema; Singhal A.
source: Journal of the Brazilian Society of Mechanical Sciences and Engineering, Vol-47, No. 1
publisher: Springer Science and Business Media Deutschland GmbH
date: 2025-01-01
rights: Restricted Access
relation: ISSN: 16785878
format: Online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

Analysis of imperfect interfaces in cobalt ferrite plates using a linear spring model: a comparative study with terfenol-D
subject: Cobalt ferrite; Direct sturm-liouville; Heterogeneity; Imperfect interface; Love-type waves; Terfenol-D
description: Purpose: This research aims to explore the transmission of seismic surface waves through a two magneto-strictive materials i.e. cobalt ferrite and Terfenol-D when embedded in a plate-substrate configuration with non-ideal interface. The study focuses on understanding the impact of width of the plates, imperfect parameter, heterogeneity parameter on both the materials cobalt ferrite and Terfenol-D under magnetically open and short conditions. Methodology: To achieve this, the study employs a variable-separable technique following Direct Sturm-Liouville method and appropriate boundary conditions to derive frequency relations for both magnetically open and short circuit scenarios. Numerical simulations are conducted to investigate the effects of width of the plates, imperfect parameter, heterogeneity parameter on both the materials cobalt ferrite and Terfenol-D under magnetically open and short conditions. Findings: The research findings indicate that the phase velocity is increasing more in Terfenol-D as compared to Cobalt ferrite, either the case magnetically open or closed. Graphical comparisons highlight the impact of width plates, imperfect parameter, heterogeneity parameter on the characteristics on wave propagation clearly. Research limitations: The study is confined to linear wave propagation and does not consider nonlinear effects. Additionally, the analysis is based on idealized material properties and interface conditions. Practical implications: The results of this research can contribute to the design and optimization of sensors, energy harvesters, and wave manipulation devices utilizing piezomagnetic materials. Understanding the behaviour of surface waves in these structures is crucial for their effective application. Originality: This study offers a comprehensive analysis of surface wave propagation in two different types of piezomagnetic composite structure by considering heterogeneity and interface conditions. The comparative study of different piezoma…
creator: Seema; Singhal A.
source: Discover Materials, Vol-4, No. 1
publisher: Discover
date: 2024-01-01
rights: All Open Access; Gold Open Access
relation: ISSN: 27307727
format: Online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

Examining three distinct rheological models with flexoelectric effect to investigate Love-type wave velocity in bedded piezo-structure
description: The transference of the surface seismic wave at the loosely bonded common interface of a visco-piezo composite structure is examined in the current work. With the flexoelectric effect taken into account, the structure is composed of a viscoelastic layer embedded on a piezoelectric substrate. The shear stiffness of the upper layer is thought to be described by a KelvinVoigt model. An analytical separable of variable method is used to derive the complex dispersion relation for both electrically open and short circuit scenarios. A numerical example is presented to demonstrate the significant influence of several influencing parameters on the wave's phase velocities and attenuation coefficients. Additionally, a graphic comparison of three rheological models the Maxwell, Newton and KelvinVoigt models is covered. Results indicate that the attenuation curve pertaining to the Maxwell and Newton model is lowest than on the KelvinVoigt model. Some major outcomes are highlighted here as: the prominent influence of bonding parameter is well-proportional to the phase velocity and inversely proportional to the attenuation coefficient, and flexoelectricity has an intensive impact on both phase velocity and attenuation coefficient curves. This theoretical study leads to understanding the piezo-flexo coupling and its potential application to design the sensors, actuators, energy harvesters and nano-electronics. 2024 Wiley-VCH GmbH.
creator: Seema; Singhal A.
source: ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik, Vol-104, No. 11
publisher: John Wiley and Sons Inc
date: 2024-01-01
rights: Restricted Access
relation: ISSN: 442267
format: Online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, India; Singhal A., Christ University, Bengaluru, India

Theoretical investigation of SH wave transmission in magneto-electro-elastic structure having imperfect interface using approximating method
subject: Asymptotic approach; Contact analysis; Imperfection parameters; Love-type wave; Quasi-classical approach; WentzelKramersBrillouin
description: Assuming different types of imperfect interfaces composed of a magnetoelectroelastic (MEE) structure, the current work investigates the transmission of a Love-type wave in a MEE solid cylindrical structure. The spatially variable quasi-classical technique is applied to derive the analytical solution of the layers. The substantial impact of factors related to the imperfect interface on the wave phase velocities is illustrated numerically. The Love-type wave's dispersion relation has been established as the determinant for electrically and magnetically open and short cases. Moreover, the article investigates the consequences of six different imperfect parameters namely mechanical imperfection, electrical imperfection, magnetic imperfection, magneto-mechanical imperfection, electro-mechanical imperfection, and magneto-electrical imperfection parameters in magnetically and electrically open and short scenarios are covered. The findings demonstrate that, in comparison to the short case, the electric and magnetic open case has a higher phase velocity. Here are some key findings: imperfection parameters strongly affect the phase velocity and attenuation coefficient curves and the bonding parameter's prominent influence is inversely proportional to the attenuation coefficient and well-proportional to the phase velocity. Identifying the piezoelectric and piezomagnetic connection and its possible use in the construction of sensors, actuators, energy harvesters, and nano-electronics is the result of this theoretical investigation. This is the first time that a polar coordinate system was used in the quasi-classical method of solving differential equations. The results argue that the outcomes of this specific model have an immense ability to deal with various commercial and industrial applications in acoustical engineering, geotechnical design, ultrasonic technology, and SAW devices. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature…
creator: Seema; Singhal A.
source: Applied Physics A: Materials Science and Processing, Vol-130, No. 8
publisher: Springer Science and Business Media Deutschland GmbH
date: 2024-01-01
rights: Restricted Access
relation: ISSN: 9478396; CODEN: APAMF
format: Online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

Mechanics of SH and anti-plane SH waves in orthotropic piezoelectric quasicrystal with multiple surface effect
description: Significant restrictions have been found in the selection of piezoelectric materials and the direction of wave propagation in earlier studies on surface acoustic wave sensors. The primary goal of the current work is to investigate how wave propagation direction influences the performance of SAW macro- and nano-sensors in an effort to remove such barriers in the technological revolution of SAW sensors. A proposed model is established to study Shear Horizontal (SH) and anti-plane SH wave propagation in piezoelectric materials with surface effects. The theoretical forms are constructed and used to present the wavenumber of surface waves in any direction of the piezoelectric medium, based on the Extended Stroh formalism. In addition, we take into account surface elasticity theory in order to obtain the phase velocity equation based on the wavenumber expression. The model incorporates surface elasticity, piezoelectricity, and permittivity to account for nanoscale surface phenomena. Two configurations are examined: an orthotropic piezoelectric material layer over an elastic framework and a piezoelectric material half-space with a nano substrate. Analytical expressions for frequency equations are derived for both symmetric and anti-symmetric waves. Numerical results highlight the critical thickness of the piezoelectric layer, where surface energy significantly influences dispersion properties. The effects of surface elasticity and density on wave velocity are analyzed, revealing a spring force-like influence on boundaries. The research investigates SH wave transmission in anisotropic, transversely isotropic piezoelectric nanostructures. The findings could aid in designing SAW devices and piezoelectric sensors, as well as producing more effective surface acoustic wave sensors, based on recent theoretical work summaries. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2024.
creator: Seema; Singhal A.
source: Acta Mechanica
publisher: Springer
date: 2024-01-01
rights: Restricted Access
relation: ISSN: 15970; CODEN: AMHCA
format: Online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

Transference of Love-type Wave Through Cobalt Ferrite Cofe2O4 Layer Structure, Governed by an Imperfect Interface
description: An analytical discussion of the wave transmission in a piezomagnetic (Cobalt ferrite) thin plate resting on an elastic substrate is presented in the problem. It is presumed that the geometrys interface is not ideal. The flaw of the considered structure is used to describe by following the linear spring model. The calculative method of the upper material is Direct Sturm-Liouville. Dispersion relations are drived for each of the magnetically open and magnetically short cases. Love-type wave velocity profiles have been depicted on graphs for various influencing factors, such as heterogeneity in the substrate, layer thickness, and interface imperfections. It has been demonstrated that raising these parameters raises the Love waves phase velocity. Furthermore, it is found that compared to substrate heterogeneity, layer thickness has less of an impact on the waves velocity profile. Additionally, it has been shown how the aforementioned cases compare when imperfect parameters are varied. It is discovered that the velocity in the open case is greater than that in the short case. The results have potential applications in the design of piezomagnetic semiconductor devices controlled by electric fields and are of great significance for developing surface acoustic wave (SAW) gyroscopes. 2024 American Institute of Physics Inc.. All rights reserved.
creator: Seema; Singhal A.
source: AIP Conference Proceedings, Vol-3242, No. 1
publisher: American Institute of Physics
date: 2024-01-01
rights: Restricted Access
relation: ISSN: 0094243X
format: Online
language: English
type: Conference paper
coverage: Seema, Christ University, Karnataka, Bengaluru, 560029, India; Singhal A., Christ University, Karnataka, Bengaluru, 560029, India

Surface energy transmission in dry long bones: A continuum mechanics approach with initial stress and rotation
description: This study examines the effect of the initial stress and a magnetic field on wave propagation in a dry long bone, modeled as an orthotropic hollow cylinder. The governing equations of motion are formulated in terms of displacements, capturing the anisotropic nature of the bone materials. A continuum mechanics approach with differential equations is utilized to compute phase velocity and vibration frequencies of harmonic wave propagation through the medium. Mathematica software is used for plotting the graphs. The current study discussed two cases: Case I is without rotation, and Case II is with rotation. Comparison analysis is also done for both cases. Graphical representations demonstrate the impact of initial stress, magnetic field, and surface span on wave behavior, emphasizing the sensitivity of phase velocity to these parameters. The findings contribute to theoretical knowledge of wave transmission in orthotropic bone structure, with possible implications in noninvasive diagnostics, including bone integrity and fracture healing rates. Moreover, the study provides the groundwork for future orthopedic research by shedding light on the dynamic behavior of long bones under mechanical and magnetic forces. The novelty of the study lies in its exploration of the combined effects of initial stress and a magnetic field on wave propagation in dry long bones, modeled as an orthotropic hollow cylinder. 2025 Wiley-VCH GmbH.
creator: Seema; Singhal, Abhinav
source: ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik;Volume;105;Issue;5;Article No.;e70101;
publisher: John Wiley and Sons Inc
date: 01-01-2025
rights: All Open Access; Bronze Open Access
relation: ISSN: 442267;
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, India; Singhal A., Christ University, Bengaluru, India

Coupling study of surface energy transmission in piezomagnetic tetrahedral laminate: a continuum mechanics analysis across a manifold substrate loaded by viscous gel
subject: Heterogeneity; Impact analysis; Semiconductors; Sensors; Stress analysis; Vibration; Viscous loading; Wave controlling
description: This paper examines Love-type energy transmission in a multilayered piezomagnetic tetrahedral structure (PMTS) and heterogeneous semi-space bar (HSS) structure with a viscoelastic gel (VL) on top. Energy transmission behaviour is examined in two physically important cases i.e. magnetically open (MO) and magnetically short (MS) circuit boundary. The main study focuses on the dispersion behaviour of phase velocity of a Love-type energy influenced by the combination of VL, PMTS and HSS. The dispersion relation for Love-type waves was determined analytically, and phase velocity graphs were plotted and analysed using numerical simulations using Mathematica software. A comprehensive study was conducted to acquire the effects of significant variables on phase velocity, including material heterogeneity, piezomagnetic coupling, and viscoelastic layer thickness. The research findings indicate the attenuation properties of the VL, PMTS and HSS materials in MO and MS conditions. Graphical comparisons highlight the piezomagnetic coupling caused the phase velocity curves to change consistently, demonstrating its significance in wave propagation. There was almost no difference in phase velocity between the magnetically open and short circuit scenarios, indicating that boundary constraints dont much affect how waves propagate. Phase velocity affects the PM coupling parameter. Higher material density leads to reduced phase velocity, emphasizing the role of density in influencing wave propagation. The model is confined to linear wave transmission and does not consider nonlinear influence. Moreover, the analysis is based on idealized material properties following heterogeneity. The design and advancement of energy harvesters, sensors, and wave manipulation instruments that employ PMTS with viscoelastic gel coatings can be aided by the studys conclusions. Effective usage of surface waves in these structures requires an understanding of their behaviour. This study offers a comprehensive…
creator: Seema; Singhal, Abhinav
source: Applied Physics A: Materials Science and Processing;Volume;131;Issue;4;Article No.;255;
publisher: Springer Science and Business Media Deutschland GmbH
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 9478396; CODEN: APAMF
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

Mechanics of SH and anti-plane SH waves in orthotropic piezoelectric quasicrystal with multiple surface effect
description: Significant restrictions have been found in the selection of piezoelectric materials and the direction of wave propagation in earlier studies on surface acoustic wave sensors. The primary goal of the current work is to investigate how wave propagation direction influences the performance of SAW macro- and nano-sensors in an effort to remove such barriers in the technological revolution of SAW sensors. A proposed model is established to study Shear Horizontal (SH) and anti-plane SH wave propagation in piezoelectric materials with surface effects. The theoretical forms are constructed and used to present the wavenumber of surface waves in any direction of the piezoelectric medium, based on the Extended Stroh formalism. In addition, we take into account surface elasticity theory in order to obtain the phase velocity equation based on the wavenumber expression. The model incorporates surface elasticity, piezoelectricity, and permittivity to account for nanoscale surface phenomena. Two configurations are examined: an orthotropic piezoelectric material layer over an elastic framework and a piezoelectric material half-space with a nano substrate. Analytical expressions for frequency equations are derived for both symmetric and anti-symmetric waves. Numerical results highlight the critical thickness of the piezoelectric layer, where surface energy significantly influences dispersion properties. The effects of surface elasticity and density on wave velocity are analyzed, revealing a spring force-like influence on boundaries. The research investigates SH wave transmission in anisotropic, transversely isotropic piezoelectric nanostructures. The findings could aid in designing SAW devices and piezoelectric sensors, as well as producing more effective surface acoustic wave sensors, based on recent theoretical work summaries. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2024.
creator: Seema; Singhal, Abhinav
source: Acta Mechanica;Volume;236;Issue;1;Article No.;106565;pp.439-456
publisher: Springer
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 15970; CODEN: AMHCA
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

Analysis of Rayleigh-type wave energy transmission in piezoelectric substrate following GreenNaghdi type III, MooreGibsonThompson and three-phase-lag theories
description: This study investigates the propagation of Rayleigh-type surface waves in a homogeneous, transversely isotropic piezoelectric half-space under various boundary conditionsspecifically, stress-free, electrically open- or short-circuited, and thermally insulated or isothermal surfaces. We analyze the problem within the framework of the GreenNaghdi type III (GN-III) and three-phase-lag thermoelastic models named as model I. Also, studies carry the comparative study with Rayleigh surface wave propagation in piezoelectric media influenced by thermal effects and the presence of voids where this has analytical solutions for Rayleigh wave propagation in a nonlocal piezo-thermoelastic medium with voids, employing the MooreGibsonThompson thermoelasticity theory that incorporates memory-dependent effects named as model II. Plane harmonic wave solutions are employed to determine mechanical displacements, electric potential and temperature variations. Using these results, expressions for stress, electric displacement and temperature gradient are derived. Four secular equations corresponding to different boundary conditions are formulated for the considered half-space. The trajectories of surface particles are shown to follow elliptical paths in a vertical plane parallel to the direction of wave propagation, with the eccentricity of these ellipses explicitly calculated. When there is no phase difference between the vertical and horizontal displacement components, the particle motion degenerates into a straight-line path. A previously established analysis is recovered as a special case of the present model. The effects of various wave characteristicsincluding phase velocity, attenuation coefficient and specific lossare illustrated graphically for both the GN-III and three-phase-lag models, using cadmium selenide (a 6-mm class, hexagonally symmetric material) as the representative medium. The findings of this study highlight several distinct scenarios that enhance the understanding …
creator: Seema; Singhal, Abhinav
source: Acta Mechanica;Volume;236;Issue;11;pp.6743-6772
publisher: Springer
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 15970; CODEN: AMHCA
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

https://archives.christuniversity.in/items/show/21866
title: Investigation of surface and interface effects of piezoelectric quasicrystal different models with propagation of shear horizontal and anti-plane shear horizontal wave; [??????????????????????????????????]
subject: Anti-plane SH waves; Antisymmetric and symmetric modes; Imperfect interface; Piezoelectric quasicrystal material; SH wave; Surface effect; Surface topography
description: Based on the theoretical representation of piezoelectric quasicrystal, a generalized dynamic model is built to represent the transmission of wave aspects in surface acoustic pulse nano-devices. Surface elasticity, surface piezoelectricity, and surface permittivity help to include the surface effect, which equals additional thin sheets. It is shown that, under certain assumptions, this generalized dynamic model may be simplified to a few classical examples that are appropriate for both macro and nano-scale applications. In the current work, surface piezoelectricity is used to develop a theoretical model for shear horizontal (SH) waves where it contains the surface piezoelectricity theory and a linear spring model to quantitatively and qualitatively explore SH waves in an orthotropic piezoelectric quasicrystal layer overlying an elastic framework (Model I), a piezoelectric quasi-crystal nano substrate, and an orthotropic piezoelectric quasicrystal half-space (Model II). The theoretical model stimulates the numerical results, which establish the critical thickness. As the piezoelectric layers thickness gets closer to nanometres, surface energy must be included when analyzing dispersion properties. Furthermore, the effects of surface elasticity and density on wave velocity are investigated individually. The authors establish a parameter, precisely the ratio of the physical modulus along the width direction to along the direction of wave travel. The surface effects impact on the general characteristics of piezoelectric structures is seen as a spring force acting on bulk boundaries. Analytical presentation of frequency equations for both symmetric and anti-symmetric waves pertains to the case of an electrical short circuit in Model II. The project aims to analyze SH waves in orthogonal anisotropic, transversely isotropic piezoelectric layered nanostructures, providing a practical mathematical tool for surface effects analysis and adaptability to other wave types, includin…
creator: Seema; Singhal, Abhinav
source: Acta Mechanica Sinica/Lixue Xuebao;Volume;41;Issue;11;Article No.;524389;
publisher: Springer Verlag
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 5677718; CODEN: AMSNE
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India

Study of surface wave velocity in distinct rheological models with flexoelectric effect in piezoelectric aluminium nitride structure
subject: KelvinVoigt model; Love wave analysis; Maxwell model; Newton model; Visco-piezoelectric substrate
description: This study investigates the propagation of surface seismic waves at the loosely bonded interface of a visco-piezoelectric composite structure, incorporating the flexoelectric effect. The structure consists of a viscoelastic layer placed over a piezoelectric substrate, with the upper layer's shear stiffness modelled using the KelvinVoigt approach. An analytical method based on the separation of variables is employed to derive the complex dispersion relations for both electrically open- and short-circuit boundary conditions. Numerical simulations reveal the significant influence of various parameters on the wave's phase velocity and attenuation coefficient. Furthermore, a graphical comparison of three rheological modelsMaxwell, Newton, and KelvinVoigtis presented. The results show that the attenuation is lower in the Maxwell and Newton models compared to the KelvinVoigt model. Key findings include the bonding parameter's direct proportionality with phase velocity and inverse relationship with attenuation, and the pronounced impact of flexoelectricity on both phase velocity and attenuation. This theoretical framework offers insights into the piezo-flexoelectric coupling, with potential applications in designing sensors, actuators, energy harvesters, and nano-electronic devices. The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering 2024.
creator: Seema; Singhal, Abhinav
source: Journal of the Brazilian Society of Mechanical Sciences and Engineering;Volume;47;Issue;1;Article No.;29;
publisher: Springer Science and Business Media Deutschland GmbH
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 16785878;
format: online
language: English
type: Article
coverage: Seema, Christ University, Bengaluru, 560029, India; Singhal A., Christ University, Bengaluru, 560029, India