Abdulrahman Aljabri

This study examines synergy between Mechanical Engineering (ME) and Materials Science (MS) as a driver of high-tech industrial development, analyzing five stakeholder categories across nine economies (Germany, Japan, South Korea, USA, EU, China, India, Turkey, Saudi Arabia). The global lightweight materials market grows at a 4.1-4.6% CAGR, reflecting its economic significance. Barriers to ME-MS integration and enablers co-patents, co-publications, shared testbeds, cross-domain certification, and cross-sectoral governance are identified as priorities for accelerating co-innovation. This conceptual, synthesis-based study develops the SIDM framework and a qualitative case-based assessment, proposing convergence forecasting and a concrete empirical agenda for future cross-country validation.

Magnetorheological (MR) fluids are smart materials that can change their rheological properties when a magnetic field is applied. This makes them useful in adaptive engineering systems like rehabilitation devices, robotics, and vibration control systems. It is important to accurately describe how MR fluids flow in a field-dependent way in order to design these kinds of systems well. However, regular rheometers are often limited by their high cost, large sample volume requirements, and limited ability to see internal flow phenomena. This study shows a magnetically induced micro channel flow platform that was made as a small measurement system to study Bingham-plastic MR fluids under controlled magnetic excitation. The platform uses a modified Hagen–Poiseuille model to estimate shear stress by combining electromagnetic field generation, microfluidic flow control, and pressure-based measurement. We took experimental measurements at set flow rates and magnetic field strengths and compared them to reference data from a commercial parallel-plate rheometer. The results show that they are within 20% of each other at lower flow velocities. At higher velocities, the differences are due to flow instability and particle aggregation. The proposed platform offers a cheap and low-volume way to characterize that can help with the design and improvement of adaptive rehabilitation devices that use MR fluids.

Magnetorheological fluids (MRFs) are renowned for their rapid, field-dependent rheological changes under an external magnetic field. This unique feature gives them a remarkable ability for advanced applications in smart materials, adaptive systems, and diverse industrial sectors. Accordingly, this mini-review provides a comprehensive overview of the methodologies utilized for the characterization of MRFs. The mini-review systematically categorizes the characterization processes into two distinct groups: pre-synthesis and post-synthesis. Pre-synthesis characterization focuses on the analysis of individual components, including the morphological and magnetic properties of particles and the viscosity of the base carrier fluid. Meanwhile, post-synthesis characterization investigates the performance of the final MRF formulation, with a detailed examination on techniques such as rheometry, essential for quantifying yield stress and field-dependent viscosity, as well as magnetic properties and sedimentation stability testing. Beyond cataloging established techniques, this review critically addresses persistent challenges in MRF characterization, including issues of accuracy, reproducibility, and scalability. By highlighting current practices and identifying future directions, this mini-review aims to contribute as an academic resource for researchers to standardize characterization protocols and accelerate the development of next-generation MRFs. Lastly, the applications of MRFs across various industries, such as aerospace engineering, automotive industry, and biomedical systems, are discussed.

The adoption of lubricants in metal forming processes at high temperatures holds particular significance. This practice facilitates reducing friction and wear, enhances metal formability, prevent seizure and galling, and extends tool life. However, elevated temperatures cause changes in lubricant properties, making it difficult to maintain effective lubrication. These changes may negatively affect the quality and efficiency of the forming process. Given the severity undergone at high temperatures, several solid inorganic salts are reported as an alternative to exhibit favourable lubrication performance. In this study, the lubrication performance of environmentally friendly albite (NaAlSi ₃ O ₈ ) was evaluated through ball-on-disc tests at elevated temperatures ranging from 550 to 950°C. The results demonstrate that albite can effectively decrease friction and wear loss across the tested temperature range, with a more pronounced effect at higher temperatures (890 and 950°C). The high-temperature lubrication mechanism of albite is attributed to the formation of a thick layer containing Na, Si, and O elements within the tribo-interface, which prevents direct contact between rubbing surfaces.

Purpose: This study investigates the coupled thermal–mechanical behaviour in micro flexible cold rolling, an advanced forming process aimed at producing micro-thin metal strips with variable thickness distributions to enhance load-bearing performance in miniaturised systems. Design/methodology/approach: A detailed three-dimensional finite element model was developed for 304 stainless steel strips with initial thicknesses between 100 and 500 µm, employing three modelling frameworks, specifically an athermal-mechanical model, a thermal-mechanical model incorporating deformational and frictional heat generation and a modified thermal–mechanical model that includes convective heat transfer and temperature-dependent specific heat capacity. The simulations capture the evolution of temperature and thermal stress and their influence on thickness directional springback, with parametric optimisation performed using the Taguchi method supported by intuitive and variance analyses. Findings: The results reveal that thinner thickness regions exhibit higher peak temperatures, which increase with decreasing strip thickness and rising friction coefficient, while rolling speed has minimal impact, and the inclusion of convective effects and temperature-dependent specific heat capacity leads to 15.4 and 10.6% reductions in peak temperature and peak thermal–mechanical stress, respectively. Although the synergistic thermal effect causes only minor fluctuations in the springback ratio within ±5.7%, it significantly alters the relative importance of influencing parameters, particularly initial strip thickness and interface friction coefficient, while the optimal conditions for minimising springback remain consistent across varying thickness regions. Originality/value: This work presents the first fully integrated thermal–mechanical analysis of micro flexible cold rolling and offers a theoretical foundation for process optimisation and quality enhancement in precision micro-manufacturing applications.

The dynamic relationship between current and pressure in magnetorheological (MR) valves is essential for the design of adaptive rehabilitation devices aimed at health rehabilitation for disabled individuals, yet it remains under-explored in existing modeling approaches. Accurately capturing this relationship is vital to predict the pressure drop response to current variations, facilitating the development of effective control systems in such rehabilitation applications. This study employs a linear black-box modeling approach to characterize the current–pressure dynamics of an annular MR valve. Experimental data are used to develop a set of transfer function models, with parameters identified through MATLAB’s system identification tools, utilizing invariant variable regression and the Levenberg–Marquardt (LM) iteration. The modeling yielded a 14th-order transfer function, labeled TF14, which closely aligns with experimental data, achieving a root mean square error of 12.64%. These findings contribute valuable insights into the current–pressure dynamics of MR valves and establish a foundational model for adaptive rehabilitation devices designed for individuals with disabilities.

This study explores the adsorption efficiency of biochar derived from palm trees and Ficus nitida for the removal of various contaminants, including Cu(II), Pb(II), iodine, and chlorpyrifos from aqueous solutions. Biochar was prepared using a two-step pyrolysis process for date palm biochar and single-step pyrolysis for Ficus nitida biochar. Characterization techniques such as SEM, EDX, and FTIR revealed a significant surface area and a variety of functional groups in both types of biochar, essential for effective adsorption. The date palm biochar exhibited superior adsorption capacities for Cu(II) and Pb(II) ions, achieving efficiencies up to 99.9% and 100%, respectively, due to its high content of oxygen-containing functional groups that facilitated strong complexation and ion exchange mechanisms. Conversely, Ficus nitida biochar demonstrated a higher adsorption capacity for iodine, reaching 68% adsorption compared to 39.7% for date palm biochar, owing to its greater surface area and microporosity. In the case of chlorpyrifos, Ficus nitida biochar again outperformed date palm biochar, achieving a maximum adsorption efficiency of 87% after 24 h of incubation, compared to 50.8% for date palm biochar. The study also examines the effect of incubation time on adsorption efficiency, showing that the adsorption of chlorpyrifos by date palm biochar increased significantly with time, reaching a maximum of 62.9% after 48 h, with no further improvement beyond 12 h. These results highlight the importance of biochar characteristics, such as surface area, pore structure, and functional groups, in determining adsorption efficiency. The findings suggest that optimizing pyrolysis conditions and surface modifications could further enhance the performance of biochar as a cost-effective and sustainable solution for water purification and environmental remediation.

This study addresses the environmental and health hazards posed by Pb(II) and iodine, two significant contaminants. The objective was to explore the adsorption of these substances from aqueous solutions using biochar derived from the leaf midribs of the date palm through a slow pyrolysis process. The pyrolysis was conducted in two stages within a vacuum furnace: initially at 300 °C for 1 h followed by overnight cooling, and then at 600 °C with a similar cooling process. The resulting biochar was characterized for its microstructural features and functional groups using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. It exhibited a porous structure with large numbers of pores (20 to 50 μm in size) and functional groups including O-H, C-H, and C=C, which are integral to its adsorption capabilities. For the adsorption studies, a 100 ppm Pb(II) ion solution was treated with varying amounts of biochar (20, 40, 60, and 80 mg) for 24 h. In parallel, iodine adsorption was tested, with biochar quantities ranging from 0.1 to 0.4 g/50 mL. Both treatments were followed by filtration and analysis using atomic absorption spectroscopy to determine the remaining concentrations of Pb(II) and iodine. The study also explored the effect of varying incubation periods (up to 30 h) on iodine adsorption. The results were significant; 100% adsorption of Pb(II) was achieved with the addition of 60 mg of biochar per 10 mL of solution. In contrast, for iodine, a maximum adsorption of 39.7% was observed with 30 mg or 40 mg of biochar per 50 mL. These findings demonstrate the potential of date palm-derived biochar as an effective and sustainable material for the removal of Pb(II) and iodine from contaminated water, offering valuable insights for environmental remediation strategies.

Heavy metals such as copper, often discharged from industrial processes and agricultural activities, pose significant environmental and health risks due to their toxicity, particularly in the soluble form of Cu (II). This study investigates the effectiveness of biochar produced from date palm leaf midrib waste via a two-step pyrolysis process, as a sustainable and economical adsorbent for removing Cu (II) from aqueous solutions The biochar was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) surface area analysis. Adsorption experiments were conducted to evaluate the effects of pH, adsorbent dosage, contact time, and initial Cu (II) concentration. The maximum adsorption capacity was observed at pH 6, with a capacity of 70 mg/g. The adsorption data were best described by the pseudo-second-order kinetic model, indicating chemisorption as the primary mechanism. Thermodynamic studies indicated that the adsorption process was spontaneous and exothermic, with a Gibbs free energy change (ΔG) of −1.245 kJ/mol at 25 °C, enthalpy change (ΔH) of −15.71 kJ/mol, and entropy change (ΔS) of 48.36 J/mol·K. Reusability tests demonstrated that the biochar retained over 85% of its initial adsorption capacity after five cycles, with capacities of 60 mg/g in the first cycle, decreasing to 52 mg/g by the fifth cycle. This study highlights the potential of biochar derived from date palm waste as an efficient, sustainable adsorbent for the removal of Cu (II) from wastewater, contributing to both environmental management and waste valorization. Future research should focus on optimizing the biochar production process and exploring its application for the removal of other contaminants.