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Nonlinear stability and dynamics of RayleighBard convection in variable viscosity ferromagnetic liquids
RayleighBard convection in ferromagnetic liquids provides a fundamental framework for understanding magneto-thermal transport in systems where buoyancy, magnetic forces and material properties interact. Most nonlinear studies of ferroconvection, however, assume constant viscosity, even though in practical ferrofluids viscosity may vary with temperature and be influenced by an applied magnetic field. In this work, we examine the stability and nonlinear dynamics of a Newtonian ferromagnetic liquid confined between rigid isothermal boundaries and subjected to a uniform vertical magnetic field, while explicitly accounting for viscosity variations arising from thermal and magnetic effects. Linear stability analysis is carried out using a truncated Galerkin approach, leading to an analytical expression for the stationary critical Rayleigh number that incorporates the viscosity-dependence parameter and magnetic numbers. To investigate post-onset behavior, a generalized Lorenz-type system is derived through a minimal FourierGalerkin truncation, allowing steady, oscillatory and irregular convection states to be explored within a low-dimensional nonlinear framework. Heat transport is interpreted through a Nusselt number formulation expressed in terms of the reduced system variables, with time-averaged values used in non-steady regimes. The model recovers established constant-viscosity ferroconvection results in the appropriate limiting case and demonstrates how viscosity variation modifies stability thresholds, amplitude saturation and convective transport trends. The present formulation provides a compact theoretical basis for assessing the combined influence of thermorheological and magnetorheological effects on convection dynamics in ferrofluid layers relevant to magnetic thermal control applications. The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2026. -
GraphDrift-net: a dynamic graph-based framework for concept drift detection in short unstructured text streams
Detecting concept drift in text streams is challenging due to the rapid evolution of language, shifting user behavior, and temporal dependencies. Issues like data sparsity, high dimensionality, lack of labeled data, and multimodal drift further complicate real-time detection and adaptation. This paper proposes GraphDrift-net, a novel dynamic graph-based framework for detecting and adapting to concept drift in evolving text streams. The model comprise of the following components: evolving Time BERT (EvoTimeBERT), which captures temporal language evolution via historical token memory and multi-scale temporal convolutions, hierarchical temporal graph network with dynamic topics and adaptive memory (HTGN-DTAM), a heterogeneous graph neural network that dynamically constructs topic-aware graphs to track changing semantics and Chronograph Detection, a time-series-based drift detection method leveraging graph statistics such as node centrality and clustering coefficient changes. In addition, graph neural reinforcement learning framework (GNRL), a reinforcement learning-based adaptive learning module, enables model adaptability by word embedding update, memory decay rate tuning, and few-shot adaptation. Experimental evaluations over various real-world datasets, including Twitter-1, Twitter-2, Enron, and News20, demonstrate that GraphDrift-net outperforms other methods in accuracy, F1-score, and drift detection sensitivity. The model achieves accuracy as high as 99.7%, is able to identify more drift points, and is more stable with computational efficiency, making it extremely appropriate for real-time text stream applications. The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025. -
Wave scattering and dynamic stress concentration in piezoelectric half-planes with semi-elliptical notches under SH-wave excitation
This study presents a comprehensive analytical framework for investigating the scattering and dynamic stress response of semi-elliptical notches in piezoelectric half-planes subjected to anti-plane shear (SH) waves. The primary objective is to unify the treatment of notches, cracks, and circular holes within a rigorous wavedefect interaction model while explicitly incorporating piezoelectric coupling and nanoscale surface/interface effects. The methodology employs the complex function method in conjunction with the Helmholtz equation and wavefield superposition theory, leading to an infinite system of equations that rigorously satisfies continuity and boundary conditions; a systematic truncation strategy is then applied to achieve convergent solutions. Results demonstrate that surface/interface effects significantly suppress the dynamic stress concentration factor, particularly under vertical SH-wave disturbance, while resonance peaks become sharper at low modulus ratios and higher piezoelectric constants such as PZT-5H and BaTiO3. Importantly, the formulation naturally recovers classical elasticity results in the absence of piezoelectric effects, providing strong theoretical consistency. Validation is achieved through analytical recovery of benchmark cases (semicircular notch and edge crack), graphical comparisons with established results, and rapid convergence of the truncated system, confirming both accuracy and robustness. The practical implications of these findings extend to structural health monitoring, non-destructive evaluation, and the optimal design of advanced piezoelectric composites, where accurate prediction of defect evolution and stress amplification is critical. While the present work is restricted to semi-elliptical notches under SH-wave excitation in half-plane geometries, the approach is readily extensible to more general defect shapes and mixed-mode disturbances. The novelty of this study lies in its ability to capture piezoelectric surface/interface effects within an exact analytical framework, providing predictive capability for defect-induced stress concentrations and offering a reliable basis for the design and reliability assessment of high-performance piezoelectric materials. The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025. -
Viscosity dissipation and BrinkmanBard convection with thermal anisotropy: stability studies in both linear and nonlinear
This study presents both linear and nonlinear stability analyses of BrinkmanBard convection in a porous medium, considering the effects of thermal anisotropy. The flow occurs between two walls maintained at uniform but different temperatures. The critical Rayleigh number is examined, including variations in the Darcy number, porosity, Prandtl number, and anisotropic thermal conductivity, with both linear and nonlinear stability regimes analyzed. Contour plots of streamlines and isotherms are provided to visualize fluid and heat flow directions. The results demonstrate that the presence of the porous medium inhibits convection and reduces the cell size at the onset of instability. Additionally, thermal anisotropy stabilizes the system, with the region of subcritical instability shrinking as the anisotropy parameter increases. While the linear stability analysis does not reveal any significant impact of viscous dissipation, the nonlinear stability analysis shows that viscous dissipation destabilizes the system. These findings contribute to a deeper understanding of the interplay between thermal anisotropy, porosity, and convection behavior in porous media, with implications for various engineering and geophysical applications. The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025. -
A comparative heat transfer analysis of rectangular fin through LTE and LTNE model
The objective of this research is to compare the thermal performance of rectangular porous fins through the Local Thermal Equilibrium and the Local Thermal Non-Equilibrium models. The thermal interactions between the solid and fluid phases are represented by two distinct energy equations in the Local Thermal Non-Equilibrium model. Whereas, heat transfer is governed by a single energy equation in the Local Thermal Equilibrium model. The governing equations describing the temperature distribution inside the fin system are developed using basic heat transfer principles. To enhance thermal conductivity and total effectiveness of heat transmission, the fluid phase of water is amalgamated with Al2O3 and TiO2 nanoparticles. The governing nonlinear ordinary differential equations are nondimensionalized, and the RungeKutta Fehlberg fourth-fifth order (RKF45) method is employed to solve these equations numerically. The accuracy and dependability of the obtained solution are confirmed by comparing it with previous findings. The influence of pertinent parameters on the thermal characteristics of the permeable fin is depicted graphically, and the rate of heat transfer is analyzed by Response surface methodology. It has been determined that, for the capturing of phase-wise thermal variations, Local Thermal Non-Equilibrium model performs better, particularly in permeable media with no heat conduction differences. The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025. -
The novel inhibitive action of the N-(p-ethylphenyl)thiobenzohydroxamic acid for mild steel in 1M HCl medium: electrochemical, thermodynamic, DFT, and MD simulation study
In this study, a reasonably priced inhibitor of N-(p-ethylphenyl)thiobenzohydroxamic acid (NTHA) is presented to stop steel from corroding in HCl solution. NTHA is investigated as a potential corrosion inhibitor, and the corrosion protectionactivityofmildsteelis evaluated in 1M HCl asacorrosionmedium.Manycharacterization techniques, including weight loss (WL)measurement,scanningelectronmicroscopy(SEM), electrochemical measurements, molecular dynamics (MD) simulations study, and density functional theory (DFT), have been applied to prove the inhibition performance of NTHA against the corrosion of mild steel. Langmuir adsorption isotherm confirms the prevention of mild steel from the attack of corrosive chloride ions (Cl?) by adsorbing on the metal surface. EIS investigation favors that the NTHA works as a mixed inhibitor. The morphological changes on the mild steel surface have been investigated using surface characterization techniques, i.e., scanning electron microscopy and electron dispersion spectroscopy (EDS). The weight loss study indicates a high inhibition efficiency of NTHA of 93.69% in its optimal concentration of 0.2g/L at 298K. DFT analyses show good electron donor property of NTHA, followed by the formation of the chelating complex with metal cations. The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025. -
Loop-corrected scalar potentials and late-time acceleration in f(R) gravity
We construct an analytic f(R) gravity model that unifies early-time inflation with late-time cosmic acceleration within a single covariant framework. At high curvature, the model reproduces a Starobinsky-like inflationary plateau, while at low curvature it asymptotes to a stable dark energy-dominated phase. In the scalar-tensor representation, this construction yields a hilltop-type potential in the Jordan frame, which maps to an exponential potential in the Einstein frame. To account for radiative effects, we introduce a logarithmic correction to the Einstein-frame potential inspired by one-loop effective field theory, producing a late-time flattening without requiring fine-tuning. The resulting scalaron dynamics reduce the effective mass to O(H0), inducing a thawing regime that deviates from a cosmological constant at the sub-percent levels. A joint background likelihood analysis using Pantheon+SH0ES and BAO+CC datasets (within the CPL parametrization) yields H0=73.40.6 km/s/Mpc and ?m=0.2530.007, consistent with local expansion rate measurements. The best-fit scalar field parameters are ?0?0.027MPl and ??0.010MPl, corresponding to a present-day dark energy equation of state w0?-0.985. While compatible with ?CDM within current observational bounds, the model satisfies GR recovery at low curvature and exhibits attractor-like behavior, thereby minimizing sensitivity to initial conditions. The Author(s) 2025. -
Cosmic structure growth and perturbation analysis in logarithmic f(Q) gravity
In this work, we explore a cosmological model within the framework of modified gravity, specifically a logarithmic form of f(Q) gravity. Using recent observational datasets including RSD and DESI, we constrain the model parameters via Markov Chain Monte Carlo (MCMC) techniques. Our analysis focuses on both background and perturbation-level cosmological diagnostics, evaluating the evolution of cosmographic parameters and the growth rate of structure through f?8. The results demonstrate consistency with observational data, particularly supporting a quintessence-like accelerated expansion. Additionally, the model addresses the S8 tension and provides insights into the late-time behavior of dark energy. The Author(s) 2025. -
Rumination, existential anxiety and professional quality of life among palliative care professionals in India
Objective: Palliative care enhances the quality of life for individuals with life-limiting illnesses, but frequent exposure to death and suffering poses emotional challenges for professionals. This study examines ruminations role in the relationship between existential anxiety (EA) and professional quality of life (ProQOL) among palliative care professionals in India. Methods: A mixed-method research design was employed. Quantitative data were collected from 500 palliative care professionals using the Event-Related Rumination Inventory, EA Questionnaire and ProQOL scale. In-depth interviews were conducted with 27 professionals with high rumination scores. Correlation and regression analyses were used for quantitative data, while thematic analysis was applied to qualitative data. Results: Persistent rumination heightened mortality awareness, exacerbated EA and negatively impacted ProQOL. Rumination partially mediated the relationship between EA and ProQOL. Four key themes emerged: (1) brooding rumination, (2) reflective rumination, (3) impact of rumination on ProQOL and (4) impact of rumination on EA. Individual differences in ruminations intensity and duration were notable. Conclusions: Findings highlight cultural and contextual challenges faced by Indian palliative care professionals, underscoring the need for targeted mental health interventions. This study supports Sustainable Development Goals 3, 8 and 4 by advocating for healthcare worker well-being, job satisfaction and improved mental health training. Author(s) (or their employer(s)) 2026. No commercial re-use. See rights and permissions. Published by BMJ Group. -
Sociocultural aspects of the medicalisation of infertility: A comparative reading of two illness narratives
This paper is a comparative reading of variations in the medicalisation of infertility caused by sociocultural aspects, in two illness narratives by patients: Elizabeth Katkin's Conceivability (2018), a story of navigating a fertility industry with polycystic ovarian syndrome and antiphospholipid syndrome in America and Rohini Rajagopal's What's a Lemon Squeezer Doing in My Vagina (2021), a discussion from India of a growing awareness of medicalisation in treatment of unexplained infertility. For this purpose, it first charts scholarship on illness narratives and medicalisation, noting a historical association. Following this, it shows how infertility, a physiological symptom of reproductive incapacity or failure to show clinical pregnancy, is generally medicalised. This paper reads the texts as showing hitherto unaddressed sociocultural aspects of infertility's medicalisation. At the same time, drawing from existing sociological and anthropological scholarship, it shows how a reading of sociocultural aspects in medicalised infertility nuances understanding of it's medicalisation. This comparative reading attends to sociocultural values and norms within the texts, including pronatalism, fetal personhood, kinship organisation, purity/pollution, individual reliance, sacred duty and so forth. It draws from scholarship on embodiment, rhetorical strategies and the language of medicine. It also shows how a patient's non-medicalised, affective history of 'deep' sickness caused by the biographical disruption of infertility is not that of a 'poor historian'. In laying out the particularisation of such sociocultural values and norms across America and India, medicalisation's migration from its origins to the margins reveals subjectivised, stratified reproduction in infertility illness narratives. This paper is part of a turn in scholarship away from understanding the medicalisation of infertility as naturalised and decontextualised. Author(s) (or their employer(s)) 2025. No commercial re-use. See rights and permissions. Published by BMJ Group. -
Tandem Neat Synthesis of Substituted Pyrano[3,2-c]chromen-5-ones: Unraveling the Camphor-10-sulfonic Acid Catalysis
Abstract: Camphor-10-sulfonic acid (CSA) is valued for its wide range of solubility, user friendliness, cost effectiveness, and catalytic activity. This work presents a catalytic approach using a minimal amount of CSA to promote a one-pot reaction between aromatic aldehydes, acetophenones, and 4-hydroxycoumarin. This tandem neat strategy delivers the desired 2,4-diarylpyrano[3,2-c]chromen-5-one derivatives in excellent yields (6592%). The product identity was confirmed by 1H and 13C NMR and LCMS characterization. The scalability of the method is demonstrated by achieving consistent yields in gram-scale reactions, highlighting its potential for industrial applications. Mechanistic insights were gained through controlled experiments, providing a valuable understanding of the role of CSA in catalyzing the formation of the target compounds. Pleiades Publishing, Ltd. 2025. -
Investigation of GaSb (p+) Pocket doped GaSb/Si Vertical TFETs for High-Frequency Analog Circuits
Abstract: This paper reports on the design, modelling, and performance analysis of a GaSb/Si Heterojunction Vertical Tunnel Field-Effect Transistors (HVTFETs), employing band-to-band tunneling (BTBT). The device structure includes a p+-GaSb source and an intrinsic Si-channel/drain, forming a heterojunction that enhances tunneling efficiency due to the staggered band alignment. The obtained ON and OFF currents are 1 105 and 1 1018 A/?m. The saturation drain current (IDSat) rises with gate voltage, measured as: 2.7 108 A for VG = 0.5 V, 3.4 108 A for VG = 0.6 V and 3.9 108 A for VG = 0.7 V. The off-state current (IOFF) is very low (~1019 A) for all the VG values, indicating effective suppression of leakage current. The derived gm values for gate voltages of 0.5, 0.6, and 0.7 V are 5.4 105, 5.5 105, and 5.6 105 S, respectively, indicating effective gate control and transconductive efficiency for signal amplification. The combination of these characteristics would enable high fT and fmax, making the device suitable for broadband and millimeter-wave applications in the radio frequency (RF). The suggested GaSb/Si heterojunction vertical TFET has commendable analog/RF attributes, featuring a peak cutoff frequency (fT) of 8.91 GHz and a maximum oscillation frequency (fmax) of 5.8 GHz. The device demonstrates an intrinsic gain (Av) of 11.2 and a gain-bandwidth product (GBW) of 99.79 GHz, indicating substantial promise for RF front-end applications, including low-noise amplifiers, mixers, and voltage-controlled oscillators, as well as energy harvesting applications. Pleiades Publishing, Ltd. 2026. -
Continuum Mechanics Analysis of Surface Vibrations in Piezomagnetic Laminates on Manifold Substrates
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. -
Analysis of the Viscous Dissipation and Nonlinear Velocity Slip Effect on the Thin Film Nanofluid Flow
Abstract: In the contemporary study, the dynamics of the nanofluid thin film is investigated by considering the viscous dissipation and chemical reaction effects. Additionally, the surface is assumed to have a nonlinear slip rather than the conventional no-slip conditions. This helps in better flow and heat transfer characteristics. This nonlinear velocity slip at the boundary is modelled using the idea proposed by Thompson and Troian. Also, the presence of viscous dissipation in the energy equation, depicts the loss of energy due to the internal friction. Hence, the viscous dissipation turns out to be a critical factor in determining the thermal properties of the nanofluid thin film. The chemical reactions take place within the system because of the presence of nanoparticles, that in turn will have a significant impact on the mass transfer characteristics of the thin film nanofluid. The incorporation of the similarity transformation helps in converting the partial differential equations (PDEs) that govern the fluid flow into a system of nonlinear ordinary differential equations (ODEs). This resulting system is then solved using the BVP package in python whose accuracy is assessed through residual analysis. By this error analysis, convergence of residues was confirmed. Thus validating the method and the results obtained. The outcomes of the study are interpreted through the graphs which highlighted the intensification of heat transfer for the increase in the Eckert number while the magnetic field confirmed its flow controlling feature. Also, the streamlines and contours were plotted to understand and visulaise the flow, all these contours showed the significance of the presence of nonlinear velocity slip at the boundary. Pleiades Publishing, Ltd. 2025. -
Conformal Invariance and Phase Transitions: Implications for Stable Black Hole Horizons?
Abstract: The behavior of black hole horizons under extreme conditionssuch as near collapse or phase transitionsremains less understood, particularly in the context of soft hair and Aretakis instabilities. We show that the breakdown of conformal symmetry during the balding phase induces a topological reorganization of the horizon, leading to divergent entropy corrections and emergent pressure terms. These corrections exhibit universal scaling laws, analogous to quantum phase transitions in condensed matter systems, with extremal limits functioning as quantum critical points. Interestingly, by employing quasi-equilibrium boundary conditions, one could stabilize horizon dynamics without explicitly introducing ad hoc higher-order corrections, further limiting the universal applicability of conformal invariance in black hole physics. Pleiades Publishing, Ltd. 2025. -
Exploring Microplastic Pollution in Bellandur and Madiwala Lakes of Bangalore: A Preliminary Study
Abstract: Microplastics are plastic debris/fragments measuring less than 5 mm, either produced as such or obtained due to the weathering and fragmentation of bigger plastics. They are an emerging pollutant that have already caused great havoc on aquatic organisms and are a major environmental concern. Microplastics are also found in the human body, but the extent of their harmful effects is not yet fully understood. The sources of microplastic entry into humans include food, water, and air. This study assesses the microplastic occurrence in water and bank sediment of Bellandur (L1) and Madiwala (L2) lakes in Bangalore. The lakes are surrounded by urban areas and are affected by sewage inlet, waste dumping, and commercial boating. The microplastics in the bank sediment and water samples were segregated using the Wet Peroxide Oxidation process. There were no visible microplastics obtainable from the water samples of both lakes. However, microplastics were segregated from the bank sediment of both lakes. The scanning electron micrographs of the microplastics segregated from the bank sediment of L1 were found to be like sheaths and in uneven form and shape. The microplastics retrieved from L2 bank sediment were uneven and sheaths of globular masses when observed using SEM. The EDAX analysis majorly showed the presence of carbon and oxygen in both samples. From the FTIR analysis, the microplastics derived from L1 bank sediment had characteristic peaks of Acrylonitrile Butadiene Styrene (ABS), and Polystyrene (PS). Whereas, the microplastics from L2 had unique peaks corresponding to both Polypropylene (PP), PS and ABS as identified by the absorption peaks pertaining to both CH3 bending (1366 cm1) and aromatic CH (2922 cm1) stretching vibrations. Similarly, in XRD, the 2? values around 20 could be seen in both samples. These peaks correspond to some form of crystallinity, but the microplastics may have degraded due to several factors in the environment leading to changes in their structural form. The SEM, EDAX, FTIR and XRD data confirm the presence of microplastics in both the samples. This is the first reported study of microplastics in these lakes of Bangalore and it implies the need to focus on mitigation strategies for retrieval of microplastics that continues to accumulate in these lakes. Pleiades Publishing, Ltd. 2025. -
Spectrometric Analysis of Decrease in Sodium Dodecyl Sulfate (SDS) Concentration by Klebsiella Species Using the Stains-All Dye
Abstract: Sodium dodecyl sulfate (SDS)-degrading bacteria were isolated from soil and water samples from multiple locations using basal media with 0.05% SDS as the only carbon source. The bacteria were identified using 16S rRNA sequencing and deposited in the NCBI database with specific accession numbers and strain name. There were six bacteria iidentified as Klebsiella variicola MSK86, Klebsiella sp. MSK86, K. quasipneumoniae MSK86, and three K. pneumoniae strains, MSK86, MSK25, and NET12. The potential for decrease in SDS concentration by the bacteria was assessed using Stains-all. The SDS standard graph was plotted with different SDS concentration of 0 to 0.06%. The SDS-Stains-all complex exhibited a peak with maximum absorbance at 440 nm. The absorbance of the bacteria-inoculated samples was monitored at 440 nm on every 24 h until the sixth day of incubation. The decrease in concentration of SDS in the medium on day 6 of incubation by K. pneumoniae MSK86, K. variicola MSK86, and Klebsiella sp. MSK86 was found to be 86, 84, and 84%, respectively. K. pneumoniae NET12 demonstrated 76% of decrease. K. pneumoniae MSK25 and K.quasipneumoniae MSK86 were able to survive in the SDS medium, with decrease of 20 and 40%, respectively. The focus of this investigation was finding bacteria that can breakdown SDS, that may contribute to the decrease in the amount of detergent pollution in water. Pleiades Publishing, Ltd. 2025. -
Rayleigh-Type Surface Waves in Piezo-Thermoelastic Materials: A Comparative Study Using GreenNaghdi III and Three-Phase-Lag Models with Machine-Learning Surrogates
Abstract: In this work, the GreenNaghdi type III (GN-III) and Three-Phase-Lag (TPL) thermoelastic theories are used to investigate Rayleigh-type surface wave propagation in a transversely isotropic piezo-thermoelastic half-space. Phase velocity, attenuation, and specific loss may be thoroughly evaluated thanks to the derivation of secular equations for electrically open/shorted and thermally insulated/isothermal boundary conditions. The findings indicate that attenuation and loss show a substantial dependency on boundary restrictions and the chosen thermoelastic model, but phase velocity increases with inclination angle and stabilises for high wave numbers. The TPL framework predicts somewhat greater velocities and damping because of thermal relaxation effects, while electrically shorted isothermal surfaces produce the lowest dissipation. By explicitly incorporating governing equations into its loss function, a Physics-Informed Neural Network (PINN) is utilised to overcome the computational burden of solving difficult transcendental equations. The PINN provides an effective stand-in for optimisation and real-time diagnostics in SAW sensors, ultrasonic devices, and smart piezoelectric materials by precisely reconstructing dispersion trends from sparse analytical data. Pleiades Publishing, Ltd. 2025. -
Continuum Mechanical Study of Love-Wave Propagation in Fibre-Reinforced Plate Over an Orthotropic Substrate with Interfacial Imperfection
Abstract: This paper aims to analyse the propagation of Love-type waves in a fibre-reinforced composite (FRC) over a pre-stressed orthotropic substrate. The upper fibre-reinforced layer is imperfectly bonded to the lower orthotropic half-space. The structure considered has a mechanical imperfection (MI). The purpose is to investigate the integrated effect of fibre reinforcement, initial stress, and flawed interface on the dispersion and attenuation of Love-type waves. The dispersion relation is derived analytically using the boundary condition. The phase velocity of the Love-type wave has been discussed in its typical cases: (i) in the infusion of reinforcement and absence of initial stress, (ii) in the presence of reinforcement subjected to initial stress, considering scenarios with and without the flawed coupling. The numerical computation of the analytical finding was performed and plotted using MATLAB, showing the impact of the parameters considered. It is observed that the interfacial imperfection positively influences the phase velocity of the Love-type wave in the model considered. The increase in the reinforcement parameter and the decrease in lead to attenuation in phase velocity. In engineering, fibres are considered to be oriented in two or more directions, and the study assumes only bidirectional fibres. The results highlight the combined influence of mechanical anisotropy, pre-stress, and interface quality on guided wave characteristics, offering valuable insights for the design and optimisation of layered composites, acoustic sensors, and structural health monitoring systems. Pleiades Publishing, Ltd. 2025. -
Mathematical Modelling of Love-Type Wave Transmission in Magnetostrictive Smart Materials with Imperfect Interface
Abstract: The purpose of this study is to investigate the propagation of Love-type surface acoustic waves through two magnetostrictive materials, NiFe2O4 (Nickel Ferrite) and Terfenol-D, embedded in a plate-substrate configuration with an imperfect interface. The study aims to investigate the effect of plate thickness, imperfect parameter, and heterogeneity parameter on both the materials under magnetically open and short scenarios. Methodology: To accomplish this, the study uses a variable-separable approach with the Direct Sturm-Liouville technique along with suitable boundary conditions, to construct frequency relations for both magnetically open and short-circuit conditions. Numerical simulations are carried out to explore the impacts of plate thickness, imperfect parameter, and heterogeneity parameter on Terfenol-D and NiFe2O4 materials under magnetically open and short circumstances. These results have been discussed through graphs that are plotted with the help of Mathematica software. Findings: The results of the study show that the phase velocity increases greater in Terfenol-D than in NiFe2O4, regardless of whether the case is magnetically open or closed. Graphical comparisons clearly demonstrate the impact of width plates, faulty parameters, and heterogeneity parameters on wave propagation characteristics. Research Limitations: The study is limited to linear wave propagation and excludes non-linear effects. Furthermore, the research is based on the attributes of the idealized material and the contact conditions. Practical implications: The findings of this study can help with the design and optimization of sensors, energy harvesters, and wave manipulation devices that use piezomagnetic materials. Understanding the behaviour of surface waves in these structures is critical for their proper use. Originality: This paper provides a complete investigation of surface wave propagation in two types of piezomagnetic composite structures, taking into account heterogeneity and interface circumstances. The comparison of several piezomagnetic models, as well as the addition of heterogeneity and contact circumstances, contribute to the researchs originality. Pleiades Publishing, Ltd. 2025.