The publisher of Multidiscipline Modeling in Materials and Structures wishes to inform the readers that, due to a production error, Jha BK, Yahaya JD, Yusuf T (2026), “Transient generalized Taylor – Couette flow with suction and injection: a semi-analytical approach”. Multidiscipline Modeling in Materials and Structures, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/MMMS-02-2018-0032, was accepted in 2018 but not published until now. The publisher of the journal sincerely apologizes to the authors of this article and the readers of the journal.

Purpose This study investigates the optimization of (Unmanned Aerial Vehicle) UAV-based illumination systems using experimental design, Dialux simulations, and image processing methods, with a focus on maximizing lighting performance while minimizing energy consumption. Design/methodology/approach A full factorial experimental design with four factors (circuit status, spot angle, height, and spot efficiency) at multiple levels was employed. Dialux software was used to calculate horizontal and vertical illuminance values and homogeneity indices, while Python-based image processing (OpenCV and polynomial regression) extracted detailed illumination profiles. Response Surface Methodology (RSM) was applied in Minitab to evaluate factor significance and to determine the optimal parameter set. Findings The results showed that spot efficiency was the most dominant factor (p < 0.001) across all responses, while height significantly influenced horizontal average illuminance (p = 0.000). The maximum horizontal illuminance (Eyavg) of 7.10 lux was achieved at 10 m with narrow beam efficiency, whereas the minimum specific lighting energy consumption - Ey (SLEC Ey) was 0.010 W/lux under the same conditions. RSM optimization yielded a composite desirability of 1.000, indicating perfect agreement with the target objectives. Model reliability was confirmed with high coefficients of determination (R2 = 86–99%). Originality/value This study introduces a novel optimization framework for UAV-based illumination systems by integrating experimental lighting performance data with RSM. Unlike previous research that mainly focused on communication or surveillance aspects of drones, our work emphasizes quantitative analysis of lighting efficiency and energy consumption under varying operational factors. The combination of ANOVA modeling, surface plots, and desirability functions provides statistically robust results and identifies the optimum operational parameters with high accuracy.

Purpose The study aims to address the limitation of conventional thermoelastic models that assume constant material properties by investigating the effects of temperature-dependent material parameters. It seeks to enhance the accuracy of thermoelastic modeling and better represent the interaction between internal heat generation and evolving material behavior under thermal variations. Design/methodology/approach The research introduces the modified extended mapping method (MEMM) as an analytical technique for solving nonlinear partial differential equations within the Green–Lindsay (G-L) thermoelastic framework. The method incorporates temperature-dependent material characteristics and generates exact analytical solutions (exponential, Jacobi elliptic, rational and hyperbolic) to model complex thermoelastic responses. Findings The results reveal that incorporating temperature-dependent properties significantly improves the realism and accuracy of thermoelastic simulations. Exponential solutions effectively capture rapid, diffusiondominated thermal responses, while hyperbolic solutions are well-suited for localized, steady thermoelastic wave behavior under nonlinear effects. Graphical analyses highlight the intricate coupling between displacement, temperature fields, and thermal stresses. Practical implications The generated solution structures and enhanced modeling accuracy provide engineers and researchers with more reliable tools for predicting material performance under thermal loads. This can improve design and assessment processes involving heat-sensitive materials in applications such as aerospace mechanical systems, and high-temperature structural components. Originality/value The study advances thermoelastic analysis by integrating temperature-dependent material properties into the G-L theory using the innovative MEMM. It represents a significant methodological contribution by delivering exact analytical solutions to nonlinear thermoelastic systems and improving the depth and precision of thermal-mechanical modeling.

Purpose A comprehensive insight into bioheat transfer and the coupled thermomechanical response within tissues is vital for the precise application of thermal medical interventions. In the proposed model, the tissue surface is assumed to be traction-free and subjected to a time-dependent, exponentially diminishing heat flux. Design/methodology/approach This study explores the thermoelastic behavior of viscoelastic biological tissues exposed to thermal stimuli, employing the Green and Naghdi framework both with and without including energy dissipation mechanisms, as relevant to hyperthermia therapy. This is the first application of the eigenvalue approach in GN-III modeling of viscoelastic tissues. Findings To obtain exact solutions to the governing field equations, the generalized biothermoelastic formulation is addressed using Laplace transformation techniques in conjunction with an eigenvalue-based approach. Originality/value Graphical results for displacement, temperature and stress distributions are presented and a subsequent parametric investigation is carried out to identify optimal design variables that enhance the precision and therapeutic effectiveness of thermal treatments.

Purpose This study aims to quantify the effects of damper design parameters, building height, and seismic input types on the seismic response of reinforced concrete frames retrofitted with tension-compression resilient slip friction dampers. Despite their growing application, the performance of these dampers across different structural configurations and earthquake scenarios remains underexplored. By addressing this gap, the research seeks to provide data-driven insights to optimize retrofit strategies and enhance seismic resilience. The goal is to inform future design standards and contribute to more effective implementation of friction-based damping systems in earthquake-prone regions. Design/methodology/approach This study presents a parametric investigation using nonlinear time-history analysis in OpenSeesPy to assess the seismic performance of reinforced concrete moment-resisting frames retrofitted with tension-compression resilient slip friction dampers. Three damper configurations with varying friction thresholds and stiffness levels are evaluated across 3-, 5-, and 7-story building frames. Sixty ground motion records are considered, equally divided into pulse-like near-fault, non-pulse-like near-fault and far-field categories. Key structural response parameters, including peak roof displacement, interstory drift ratios, base shear forces and roof acceleration, are examined. The study aims to clarify how damper properties and structural characteristics influence seismic response outcomes. Findings The study reveals that damper effectiveness significantly depends on the interplay between damper properties, building height and earthquake type. Retrofitted frames exhibited substantial reductions in peak roof displacement, interstory drift and base shear compared to the unretrofitted model, particularly under near-fault pulse-like motions. Damper configurations with moderate friction thresholds and balanced stiffness offered optimal performance across scenarios. Additionally, taller frames benefited more noticeably from damping interventions. These results emphasize the importance of tailored damper parameterization for different structural and seismic contexts, providing robust evidence to guide the seismic retrofit of existing reinforced concrete structures using friction-based systems. Originality/value This study provides a novel contribution by systematically evaluating the seismic performance of reinforced concrete frames retrofitted with tension-compression resilient slip friction dampers under a wide range of structural configurations and earthquake types. Unlike previous research that focused on limited scenarios, this work integrates multiple damper designs, building heights, and categorized ground motion records to offer statistically robust insights.

Purpose Continuous SiC fiber-reinforced SiC matrix composites (SiCf/SiC) have a wide application prospect in aerospace fields due to their excellent high-temperature performance, corrosion resistance and oxidation resistance. SiCf/SiC composites face significant challenges under extreme aerothermal environments, which will cause oxidation-induced interphase degradation, thermal stress and surface ablation damage. The paper aims to investigate the ablation behavior of SiCf/SiC composites by using the arc wind tunnel test for the application of the material. Design/methodology/approach SiCf/SiC composites are subjected to single and five cycles of ablation by using the arc wind tunnel tests. The influence of machining processes on ablation resistance is investigated via comparative analysis of mechanical properties. Microstructural evolution before and after ablation is characterized using scanning electron microscopy, and the ablation mechanism is further revealed. Findings The results reveal that after single ablation, the composites exhibit negligible changes in tensile and flexural strengths. After five-cycle ablations, the tensile strength exhibits a substantial enhancement. Microstructural analysis suggests that passive oxidation predominantly occurred during the process of ablation, resulting in low ablation rates and the formation of dense oxide layers. These oxide layers effectively seal surface pores and microcracks, leading to maintain or even improve the mechanical properties. Originality/value This research provides essential experimental data and theoretical insights for understanding the ablation mechanisms of SiCf/SiC composites in high-temperature gas flow environments, while also offering technical support for their advanced aerospace applications.

PurposeThis study proposes a novel algorithm based on the finite volume method for simulating groundwater flows and presents the practical application of this method in geotechnical engineering.Design/methodology/approachThe matrix-free implicit iteration method based on the finite volume method and preconditioning conjugate gradient algorithm was used to discretize and solve the groundwater seepage governing equation. Implicit residual smoothing and GPU parallel techniques were utilized to speed up the computation with the solver.FindingsThe new method was assessed and evaluated using benchmark and typical infiltration cases. Both the analytical solutions and solutions of the commercial software GEO-Studio were used to verify the accuracy of the proposed algorithm. The speedup performance of the GPU parallel algorithm was also well reflected.Originality/valueThe results demonstrate that the new algorithm is simple and practical, with fast convergence and high accuracy and can satisfy engineering application requirements.

PurposeHybrid nanofluids have remarkable characteristics for improving the process of heat transfer. The findings suggest hybrid nanofluids are beneficial heat transfer fluids for industrial uses. Therefore, this article aims to investigate the Darcy–Forchheimer flow of Zn-TiO2/H2O hybrid nanofluids through a vertically porous shrinking cylinder.Design/methodology/approachThe thermal transportation phenomenon of radiated hybrid nanomaterials is studied subject to linear thermal radiation and chemical species with the consequence of non-uniform heat source/sink influence. The controlling flow and energy equations in the form of governing hybrid nanofluids are developed and then converted into ODEs by operating appropriate resemblance variables. Using the impacts of controlling parameters, the behaviors of flow constraints are interpreted graphically.FindingsThe current study’s outcomes reveal that the water-based hybrid nanomaterials show a promising upsurge in heat transfer rate. Similarly, as the mass transfer rate grows, the drag coefficient and energy transfer rate boost, while due to curvature relations, it tends to diminish for drag friction. In an upper branch solution, the flow field is improved by greater porosity parameter values, whereas in a lower branch solution, it deteriorates. Furthermore, the velocity profile depicts the opposite trend for upper and lower branches due to a boost in the mixed convection parameter.Originality/valueIn light of already conducted studies, the relation of internal heat source varying regarding thermal and space in the rheology of hybrid TiO2-Zn/H2O nanofluid possesses intriguing utilization in energy production strategies due to the exhibition of extensive heat energy. The most typical examples of this phenomenon can be observed in nuclear and chemical-reactor power stations, solar power plants for heating and cooling systems, combustion analysis equipment and so on. The current study is devoted to predicting the effect of a varied heat source on the thermal energy characteristics of mixed convective hybrid TiO2-Zn/H2O nanofluid flow through the vertical cylinder.

PurposeThis paper aims to investigate the steady-state creep of the multilayer Silver-Tin transient liquid phase (AgSn-TLP) interconnects of the power modules using experiments and constitutive modeling.Design/methodology/approachA series of engineered creep tests is executed at different temperatures and stress levels to produce creep strain versus time data. Accordingly, steady-state creep parameters are acquired through nonlinear regressions. Two steady-state creep relations, including hyperbolic sine and power laws, are created, and validated with measured data. Afterwards, numerical studies are executed to examine the thermomechanical response of the AgSn-TLP interconnects compared to other bond materials.FindingsGenerally, the AgSn- TLP interconnections showed higher resistance to the accumulation of creep strains, indicating their potential to perform efficiently in high temperature applications.Originality/valueThis paper models the steady-state creep response of the silver-tin TLP bonds using hyperbolic sine and power laws. These models are important for stress and strain analysis using numerical simulations.

PurposeThis article presents a numerical study of the heat transfer properties of a nanofluid created using engine oil as the common fluid and Fe3O4 nanoparticles within a square cavity embedded with porous media using the LTNE model in the presence of a Cattaneo–Christov heat flux. To obtain the governing boundary layer equations, the Boussinesq approximation and Darcy model are employed.Design/methodology/approachBy applying the Finite Element method, the modeling equations for dimensionless vorticity, stream function and temperature contours with conforming boundary and initial conditions are scrutinized.FindingsOne important finding is that streamlines create a core vortex that is oriented centrally and has longer thermal relaxation times. In contrast, solid state isotherms are hardly affected by growth in thermal relaxation parameter values when compared to fluid state isotherms.Originality/valueThe research work carried out in this work is original and no part is copied from others.