Arabian Journal for Science and Engineering最新文献

Compact heat exchangers in HVAC and automotives rely upon plain, wavy, and louver fins to achieve required airside performance under limited volume limits. Most prior studies have evaluated one fin family or dry operation, which has limited the design transfer to humid conditions and proper comparison. Consistent comparisons under condensation with unified metrics are scarce. This study compared plain, wavy and louver fins. Forty-eight geometries with three fin types were modeled using FreeCAD scripts and simulated in ANSYS Fluent using 3D Volume of Fluid with species transport over Re = 250–4000. Wet Colburn “j”, Fanning “f”, compactness-based indices, and constant pumping power per unit area were evaluated. This study further compared the thermal–hydraulic performance of these three fin types under similar geometric conditions, as well as through a cluster-based comparison. Louver fins delivered the highest heat transfer with high friction losses, governed by louver angle and the louver-to-fin pitch ratios. Wavy fins achieved intermediate heat transfer with moderate friction losses, controlled by amplitude to wavelength and other geometric parameters. Plain fins performed the worst, while delta winglet vortex generators raised heat transfer at low to intermediate pumping power with a geometry-dependent rise in friction losses. Unified wet-surface correlations for “j” and “f” were developed, as functions of Reynolds number and non-dimensional geometry ratios. The correlations predicted within about 10 percent across all fin types and proposed ready-to-use correlations for prediction.

The novel hypercross-linked porous ionic polymers combine the advantages of ionic liquids, hydrogen-bond donors and hypercross-linked polymers. In this regard, imidazolium-based ionic liquids with different hydrogen-bond donors (hydroxyl and carboxyl groups) were grafted on hypercross-linked polymers by taking advantage of the easier functionalization of ionic liquids. With the introduction of ionic liquids, the CO₂ adsorption capacity of HCP-CH₂IL-COOH was increased to 13.86 wt % (273 K, 1 bar). The catalytic performance of HCP-CH₂IL-OH and HCP-CH₂IL-COOH with containing hydrogen-bond donors was found better than that of HCP-CH₂IL-Et without hydrogen-bond donor. In addition, HCP-CH₂IL-OH showed the highest CO₂ conversion efficiency after 48 h with a high yield (up to 94%) at room temperature and pressure due to high specific surface area, high CO₂ adsorption capacity and the catalytic activity of ionic liquid, which achieved efficient CO₂ conversion by metal-free catalytic system under mild conditions. The TON and TOF values were found to be up to 292 and 6 h⁻¹, and the efficiency was comparable to that of the current metal-free heterogeneous catalytic systems. In addition, the catalyst can efficiently convert different terminal epoxides and show good universality. More interestingly, the catalytic activity of this catalyst was retained after five cycles, which endorse its recycling stability.

Arsenic in rice grains presents a food safety concern, with potential adverse effects to humans. Despite the presence of numerous publications on arsenic in rice grains, arsenic uptake by rice grains, regional variation, health risks and its mitigation strategies need better understanding. In this study, mechanisms of arsenic uptake in rice grains, variation of inorganic arsenic (iAs) in rice grains, and human exposure and risk were investigated for all continents. Human exposure and risk analyses were performed following the probabilistic concept to incorporate uncertainty. Rice plants primarily absorb arsenic through silicon and phosphate transport pathways, with arsenite [As(III)] and arsenate [As(V)] being the predominant forms. The iAs concentrations in rice grains vary significantly around the globe. Several Asian countries, particularly Bangladesh and China, showed elevated iAs concentrations in rice grains, averaging 121 ± 93.5 µg/kg. The highest average of cancer risk was observed in Asia (2.39 × 10⁻⁴), followed by Oceania (8.87 × 10⁻⁵) and South America (8.82 × 10⁻⁵) while Europe exhibited the lowest risk (1.59 × 10⁻⁵). Various mitigation approaches including mineral supplementation, advanced soil amendments, water management practices, biotechnological interventions and genetic modification were investigated. The advanced soil amendments showed significant reduction in iAs accumulation in rice grains (biochar: 30–72% reduction, nanoparticles: up to 90% reduction, layered double hydroxides [LDH]: 69–88% reduction). The genetic modification strategies targeting specific genes (OsHAC1;1, OsHAC1;2, OsABCC1) showed 20–75% reduction in grain arsenic accumulation. Overall, this research presents valuable insights in developing effective strategies to minimize arsenic accumulation in rice grains.

Porosity is a physical property of a material that indicates the presence of voids within it, which alters the way the material interacts mechanically with its surroundings. There are many reasons why metals become porous, and these reasons depend primarily on the method by which the metal was manufactured. Porous steel alloys are used in bearings, gears, and other components that experience sliding or rolling contact. This review consolidates recent findings on how porosity fraction, size, and morphology shape the tribological response of porous steels produced by powder metallurgy (PM), metal injection molding (MIM), and laser-based additive routes. Across most studies, increasing porosity elevates surface roughness and reduces hardness, concentrating stresses at pore rims and lowering the real load-bearing area. Consequently, friction coefficients and wear rates generally rise with porosity. Some exceptions occur when pores are fine, closed, or deliberately oil-impregnated, where pores can act as micro-reservoirs that stabilize boundary films, trap debris, and intermittently reduce friction and scuffing—especially under conformal contacts and wet environments at dissimilar tribo-pair. For similar tribo-pairs (porous steel against the same steel), porosity tends to be detrimental even under lubrication. At similar tribo-pair contacts, adhesive wear mechanism dominate, but with dissimilar tribo-pair contacts, abrasive and delamination wear dominate as pores act as crack initiators; under lubricated gears and pins, debris sequestration and self-lubrication can offset part of the hardness penalty. The paper also reviews strategies to improve performance: surface densification (rolling/burnishing), thermochemical treatments (carburizing/nitriding) tailored to porous substrates, solid lubricant or hard coatings (e.g., MoS₂/graphite, high-entropy or hard alloy overlays), ultrasonic nanocrystal surface modification, and purposeful pore design or oil impregnation. Collectively, the evidence supports a design window in which low-to-moderate porosity with controlled pore size and appropriate surface treatment can balance weight reduction and damping with acceptable friction and wear.

Sustainable agricultural development is constrained by water resources and ongoing reduction in arable land. Agrivoltaic systems, which integrate solar energy with agricultural activities on same land, offer a sustainable solution by enhancing the synergy between energy and food production, thereby maximizing productivity per unit land area. This review explores design considerations, technological advancements, implementation strategies, and economic drivers of agrivoltaic with focus on potential deployment in the Middle East. Review also identifies potentials and climate-resilient strategies of agrivoltaic implementation on water consumption, increased crop yield, and land-use efficiency. Challenges, like regional constraints, regulatory hurdles, policies and incentives, and the trade-off between crop yield and energy production are also discussed. Finally, a techno-economic analysis of an agrivoltaic system is performed for Eastern Saudi Arabian climate using quasi-steady-lumped modeling to assess the economic viability and life cycle assessment. Agrivoltaic configurations outperforms the independent stationary systems, achieving land-use efficiency of 35–73%, with land equivalent ratio ranging from 1.04 to 2.05. Results show that the product efficiency can be enhanced by 60–70% through agrivoltaic systems utilization. The techno-economic analyses show that the agrivoltaic technology demonstrates a practical viability, particularly in arid regions such as Eastern Saudi Arabian climate, highlighting levelized electricity and crop yield costs of 0.048 $/kWh and 0.50 $/kg for agrivoltaic system and 0.059 $/kWh and 0.651 $/kg for the independent stationary systems, respectively. Conclusively, the research underscores the need for a comprehensive understanding of economic, technological, and policy factors to promote widespread adoption of agrivoltaic technologies.

Biodegradable materials and soft robotics have each shown significant promise in advancing minimally invasive surgery (MIS), yet current literature lacks an integrated analytical perspective on how these two domains converge to create next-generation medical devices. This review addresses that gap by critically synthesizing research on biodegradable polymers, metals, and composites within the functional context of soft robotic actuation, sensing, and surgical interaction. The analysis highlights how degradation behavior, mechanical compliance, and biocompatibility influence device performance during and after MIS procedures, while identifying limitations in current prototypes, including stability, long-term controllability, and clinically relevant load handling. By comparing design strategies, material–structure interactions, and emerging clinical demonstrations, this work delineates the technological barriers, such as inconsistent biodegradation kinetics and limited multifunctional integration, that must be overcome for real-world translation. The review contributes a structured framework for understanding how biodegradable soft robotic systems can minimize secondary surgeries, improve patient safety, and expand the functional capabilities of MIS tools. It also outlines specific research directions required to bridge engineering advances with clinical adoption, establishing a clearer roadmap for future interdisciplinary development.

This review examines how artificial intelligence (AI) including machine learning (ML), deep learning (DL), and the Internet of Things (IoT) is transforming operations across exploration, production, and refining in the Middle Eastern oil and gas sector. Using a systematic literature review approach, the study analyzes AI adoption in upstream, midstream, and downstream activities, with a focus on predictive maintenance, emission monitoring, and digital transformation. It identifies both opportunities and challenges in applying AI to achieve environmental and economic goals. Although adoption levels vary across the region, countries such as Saudi Arabia, the UAE, and Qatar are leading initiatives that align with global sustainability targets. Overall, the findings highlight AI’s potential to improve productivity, lower carbon footprints, and support the transition toward more efficient and sustainable energy systems. This work provides strategic insights for stakeholders seeking to align technological advancement with sustainable energy transition objectives.

The increasing demand for mass customization poses significant challenges for traditional manufacturing systems, which frequently lack the flexibility and cost-effectiveness to make highly tailored components. Hybrid manufacturing, specifically the integration of additive manufacturing (AM) and metal forming, has emerged as an attractive approach for overcoming these limitations by combining AM's geometric freedom with the mechanical robustness and productivity of forming procedures. This review presents an in-depth investigation of hybrid techniques that combine powder bed fusion (PBF) or directed energy deposition (DED) with sheet and bulk metal forming. The article begins by providing a conceptual framework that includes definitions and systematic classifications of hybrid processes. It then investigates two main process sequences: forming before additive deposition and AM followed by forming. Case studies of alloys such as titanium, stainless steel, and aluminum alloys have been reviewed to show how hybrid techniques can refine microstructures, reduce porosity, and improve mechanical performance. Enabling procedures, such as interlayer rolling, hammering, and heat treatments, are reviewed as well for their effectiveness in reducing residual stresses and improving part quality. Key challenges are identified, such as sequence sensitivity, residual stress development, interfacial bonding, and anisotropic material behavior. Research gaps have been found in predictive multiphysics modeling, interface optimization, qualification criteria, and sustainability assessment. The review underlines the need to expand investigations to include a wider range of materials, as well as to incorporate data-driven and intelligent process control systems. Finally, this work provides a road map for advancing AM–forming hybrids toward industrial adoption, underlining their potential to develop reliable and customized components for high-performance applications.

The increase in atmospheric carbon dioxide (CO₂) levels, which are regarded as a significant greenhouse gas (GHGs), exerts a pivotal influence on global warming and climate change. In addition to the reduction of CO₂ emissions from anthropogenic activities, the active removal of CO₂ from the atmosphere is a more urgent necessity. Carbon capture and storage (CCS) represent a technically feasible but economically costly technology for the removal of CO₂ from the flue gases of coal-fired power plants. Conversely, the sequestration of CO₂ by biological methods demonstrates promise and offers the additional benefit that the biomass produced from the fixed CO₂ can then be utilized for other purposes. Nevertheless, the technology for mitigating CO₂ through biological means remains in its infancy, as the efficiency of CO₂ capture and fixation is currently insufficient to make it a viable option for industrial applications. The use of environmentally friendly technology, such as carbonic anhydrase as an enzyme to capture and utilize CO₂, has the potential to reduce CO₂ emissions and mitigate the effects of climate change and global warming. Carbonic anhydrase (CA) enzymes play an essential role in the capture of CO₂ through a rapid reaction with bicarbonate ions. This enzymatic mechanism accelerates the hydration of CO₂ in water-based solutions, converting CO₂ into bicarbonate ions and back again. CA enzymes exhibit a high turnover rate, which allows them to enhance CO₂ capture, conversion and utilization, making them a promising solution for the remediation of carbon-containing contaminants. However, little is investigated into the modification of CA to enhance CO₂ uptake. Therefore, this review aims at addressing the mitigation of CO₂ by modified microbial Carbonic anhydrase enzyme thereby filling in this gap.

This paper presents an advanced adaptive barrier function sliding mode controller (ABF-SMC) for the efficient management of hybrid energy storage systems (HESS) in electric vehicles (EVs). The proposed controller is designed to manage energy distribution in EVs that use multiple energy storage devices (ESDs), such as battery, supercapacitor (SC), fuel cell (FC), and photovoltaic (PV) panel. The primary goal of the controller is to regulate the HESS and ensure the global stability of the system using Lyapunov criteria. Additionally, ABF-SMC is compared with the conventional sliding mode controller (SMC), and simulation tests of the proposed system are performed using MATLAB/Simulink R2024b. Hardware in loop (HIL) experiments (OPAL-RT 5700 testbed) is also conducted to assess the performance of the proposed controller. The results validate the system’s stability, robustness, and effective performance under varying operating conditions. An in-depth comparison of the two controllers shows that ABF-SMC outperforms SMC, as confirmed by the results.