Scopus Research — Mohsin-Oleiwi Naser Al-khafaji

The electrochemical reduction of CO2 into valuable products is a potential approach to reduce carbon emissions and meet energy concerns. Herein, we report the synthesis and use of MnNi-P/ZIF8@CNT, a composite electrocatalyst with high activity, selectivity, and stability for reducing CO2 to CO. Structural and morphological characterizations using SEM, XRD, and Raman spectroscopy demonstrated that MnNi-P and ZIF8 are uniformly integrated on CNTs. Electrochemical techniques, including linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry, confirmed its high catalytic activity. MnNi-P/ZIF8@CNT exhibited a low onset potential of −355 mV (vs. RHE) and an overpotential of −616 mV at −8 mA cm−2 in a 0.5 M KHCO3 solution saturated with CO2, outperforming ZIF8@CNT and MnNi-P@CNT. It achieved a high faradaic efficiency for CO (FECO) of over 93 % at −0.8 V (vs. RHE), surpassing many catalysts reported in the literature. Stability tests showed that MnNi-P/ZIF8@CNT maintained a stable current over 24 h without remarkable performance loss (<2 %), compared to 4.6 % and 8.4 % losses for ZIF8@CNT and MnNi-P@CNT, respectively. This work highlights the synergistic effects of MnNi-P and ZIF8, providing a robust platform for designing efficient, durable, and scalable catalysts for CO2 electroreduction. © 2025 Elsevier B.V.

This study explored the performance of magnetic fluids in couplings, focusing on optimizing torque and rotational transfer. It investigated how variations in mass fraction, oil film thickness, and cylinder diameter impacted the efficiency and torque transfer capabilities of the system. The research aimed to identify the optimal combination of these parameters for improved performance under magnetic field conditions. The study employed both experimental and numerical simulation methods. Cylinders with diameters of 80 mm, 105 mm, and 130 mm were tested to analyze the dynamics of fluid flow between internal and external cylinders. Numerical simulations predicted optimal system performance, and the results were validated through laboratory experiments. Key metrics included torque transfer, rotational velocity, oil film thickness, and shear stress applied to the cylinder walls. The findings show that reducing oil film thickness enhanced torque and rotational transfer. The 80 mm cylinder performed poorly at low mass fractions, while the 105 mm cylinder achieved effective performance at a 60 % mass fraction. The 130 mm cylinder demonstrated superior performance across all mass fractions due to its thinner oil film and higher shear stress. However, torque transfer plateaued at magnetic field intensities above 0.33 T, indicating limitations in system control. In conclusion, optimizing mass fraction and cylinder diameter enabled significant improvements in torque and rotational transfer. The system achieved a maximum torque of 2.75 N.m and a peak rotational speed of 820 rpm with a 130 mm cylinder at a 60 % mass fraction. © 2025 Elsevier Ltd

The development of electronic equipment depends on the performance of their processors, which themselves require operating at low temperatures. So, solutions that can keep their temperatures low are significant for the advancement of this valuable industry. This study attempts to find an effective solution to this problem in a practical case, which is the ASUS GT 730 silent graphics card. The working condition of this processor's heatsink is simulated by a heat source with 1.7- and 2.1-W heat flow rates. To cool down the system, a new experimental setup is proposed, in which the heatsink is placed inside an aluminum box where water flows through a copper pipe. In addition, two phase change materials (PCM), including Lauric Acid and Paraffin wax, with different volume percentages, are separately injected into the box to examine the influence of the properties of these materials on energy storage. Hence, 18 modes are obtained based on heat flux, PCM type, and their volume percentages. To compare the effectiveness, a dimensionless number is introduced as a special measure based on the time duration recorded for each mode, named dimensionless melting time efficiency (DMTE). This number, which adapts to the physics of the process, is defined as the ratio of the total heat input to the total heat capacity of PCM (sensible and latent). This new setup, together with the definition of the dimensionless number, provides an appropriate tool for achieving the best arrangement selection for higher thermal energy absorption. The results show that the presence of phase change materials, regardless of their type, will increase the efficiency of the system. Furthermore, using the maximum volume percentage of the phase change material will maximize the cooling efficiency of the system, where DMTE can be reduced by around 64 % for both PCMS and both input heat flow rates from 25 % volume percentage to full. Also, it is concluded that the choice of Lauric acid as phase material change for this case can enhance the performance of the system, where DMTE of Lauric acid decreases by 6.25 % for an input heat flow rate of 1.7 W and 9.68 % for 2.1 W than paraffin wax when the volume percentage of PCMs is maximum. © 2025 Elsevier Ltd

This study investigates the thermal performance of evaporators in vapour compression refrigeration systems, with a focus on the design, experimental analysis, and impact of various operating parameters. The evaporator used in the experiments was tested in the Air Condition Laboratory at Al-Mustaqbal University, with key specifications including a total tube length of 19.2 meters, tube diameter of 7 mm, and fin geometry configured for optimal heat transfer. The experimental setup included measuring the evaporator’s performance under various conditions, specifically with refrigerant R-22. The average evaporator temperature was maintained at 5℃, with the refrigerant entering at -1.6℃ and exiting at 3.6℃. The pressure within the evaporator was recorded at 584 kPa, while the condenser operated at 40℃ and 1533.5 kPa. Key thermodynamic parameters, such as the overall heat transfer coefficient (0.466 kJ/m²·s·℃ for copper), were calculated and analyzed. Key findings from the experiments include a direct relationship between the evaporator’s area and its cooling capacity, as expressed by the equation Q=U×Θm×A. Additionally, it was observed that the refrigeration capacity increases with the temperature difference between the refrigerant and the air. The study also found that the coefficient of performance (COP) of the refrigeration cycle improves with an increase in the evaporator’s effect, though it decreases as the evaporator temperature rises. The study concludes that the presence of lubricating oil within the system complicates heat transfer and pressure drop, making the thermal design of the evaporator challenging. Furthermore, it was determined that high-pressure refrigerants enhance evaporator capacity, and the heat transfer capacity is significantly influenced by the temperature differential between the refrigerant and the medium being cooled. The findings contribute to a better understanding of evaporator design and optimization for improved system performance. Copyright: ©2025 The authors. This article is published by IIETA and is licensed under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/).

Thanks to their unique attributes, potassium-ion batteries (KIBs) have aroused the interest of researchers in the field of energy storage. Developing KIBs with high performance has become significant with an increase in energy demands, which has also urged many research groups to aim at designing and fabricating novel materials with high capacity. Within this piece of research, the possibility of using a graphyne-like boron nitride monolayer (G-BNyenML) as an electrode in KIBs was investigated. N and B and N have been considered to be complementary options to be used as anode materials since the complement each other. The DFT calculations revealed that G-BNyenML had a structure with reliable mechanical attributes. The great conductance of the G-BNyenML was further substantiated by DOS calculations. The binding energy of the potassium atom was −1.29 eV, which was due to the charge transport of 0.49e from the potassium to the G-BNyenML. The specific capacity of G-BNyenML reached 1374 mAhg−1. Based on the CI-NEB calculations, the adatoms migrated easily via the anode and thew energy barrier and the diffusion coefficient were 0.56 eV and 5.14 × 10−14 cm2/s respectively. The obtained working voltage was very low (0.38 V), which demonstrated that the operation was safe and cyclability was good. Hence, the theoretical results revealed that G-BNyenML can be used a promising anode in KIBs. © 2024 Elsevier Ltd

This research investigates the predictive modeling of a dataset containing parameters denoted by r(m), z(m), and T(K) which is temperature. The considered process is a membrane distillation (MD) for separation of compounds based on temperature gradient. A membrane contactor is used for the process, and the computations are performed in the context of computational fluid dynamics (CFD) and machine learning. The dataset, which is generated by CFD modeling and encompasses over 5,000 data points, is analyzed using three distinct regression models: Support Vector Machine (SVM), Deep Neural Network (DNN), and Kernel Ridge Regression (KRR). Hyperparameter tuning is performed employing the Stochastic Fractal Search (SFS) algorithm. Our findings unraveled the nuanced intricacies of each model's performance, gauged through a comprehensive set of metrics. The RMSE, MAPE, and R2 score collectively offer a robust evaluation framework. The Deep Neural Network (DNN) exhibits a compelling RMSE of 7.7001E-01, a remarkably low MAPE of 2.05131E-03, and an impressive R2 score of 0.97054. Meanwhile, the Support Vector Machine (SVM) showcases a notable RMSE of 1.7215E-01, a minimal MAPE of 2.90820E-04, and a remarkably high R2 score of 0.99839. On the other hand, the Kernel Ridge Regression (KRR) model presents an RMSE of 1.3588E + 00, a MAPE of 2.63550E-03, and an R2 score of 0.90042. © 2024 Elsevier B.V.

The use of fresh water to produce green hydrogen fuel through the water electrolysis process can exacerbate the challenges of water scarcity. Using non-potable water for this purpose can lead to the design of a process with high security, reliability and sustainability. This paper develops the conceptual design and techno-economic evaluation of an innovative hydrogen energy production process from a solid oxide electrolyzer (SOE) integrated with a water treatment and recovery process. Accordingly, purified wastewater and waste heat of flue gases of the power plants have been utilized as feedstocks for the electrolysis process. Two different scenarios were assumed to supply the required thermal energy of the electrolyzer: the first scenario is the use of a preheater based on fossil energies, while in the latter scenario the required thermal energy is supplied through parabolic trough collectors, PTCs,-based solar farm. The integrating fossil fuels-driven power plants with evolving green technologies can mitigate the greenhouse gas emission crisis in addition to reducing the limitations of fossil energies. The outcomes indicated that the Levelized cost of hydrogen (LCH) for the second scenario increases by almost 38.7% compared to the first scenario. The reason for the high value of LCH for the second scenario is the high capital cost of solar collectors. Furthermore, the overall conversion efficiency for the proposed hydrogen production process was calculated as 53.26%. The introduced system can be competitive and reliable from the point of view of saving water consumption. The net potential energy saving and carbon emissions of the process was also determined. © 2023 The Institution of Chemical Engineers

Background: This study analyses turbulent flow and heat transfer characteristics of a three-dimensional perforated finned heat sink using computational fluid dynamics (CFD) and response surface methodology (RSM) methods. Methods: The effects of perforation geometry, including size (1.85 ≤ σ ≤ 2) and cross-sectional shape (square, circular, hexagonal, and triangular), as well as the Reynolds number (25, 000 ≤ Re ≤ 40, 000) as design variables, on parameters such as friction drag force, pressure drag force, total drag force, and Nusselt number were investigated. In addition, using the well-known RSM technique, three accurate models were proposed for the percentage of heat transfer enhancement (PHTE), percentage of drag reduction (PDR), and percentage of weight reduction (PWR) as the most significant design objectives for any heat sink. RSM models served as the foundation for two- and three-objective optimizations. Significant Findings: Results indicate that fins with square perforations in high σ and fins with circular perforations in low σ could achieve exceptional thermal performance (PHTE > 70%). Compared to solid fins, fins with square perforations demonstrated improved PDR performance with a 20–40% reduction in total drag force. In addition, using fins with circular perforations can reduce the heat sink's weight by 45–65% compared to solid fins. Moreover, the optimal condition for the perforated finned heat sink can be attained by considering the values 40,000 and 1,946 for Reynolds number and σ, respectively, and by selecting a circular shape for the perforations. PHTE, PDR, and PWR increase in the optimal case by 68.98%, 35.87%, and 58.86%, respectively, compared to the base case (solid fin). © 2023 Taiwan Institute of Chemical Engineers

Near the suction/injection area, a scientific definition for laminar boundary layer flow and heat transfer of an incompressible viscous flow over a stretching cylinder is given. In the study, differential equations with partial derivatives are converted into dimensionless coupled equations using numerical and analytical methods of Akbari- Ganji and Finite Elements Methods. The goal of this first stage of research and research on this topic is to use simplified forms to simplify equations using derivatives of simplified forms; the analysis of the displacement of the heat flux and the velocity gradient will be done using the changes of the Prandtl number. Based on the results obtained on this issue, it is found that the suction process increments surface firmness and quality, whereas the injection decreases surface skin friction. Also, at the points where the water and oil are attached to the surface of the cylinder, the heat has reached its maximum value, and as the distance increases along the Y axis, the temperature decreases. The highest temperature gradient is observed for water fluid. This shows that the use of water fluid around the cylinder accelerates the process of heat transfer from the surface to the outside of the boundary layer. One of the differences between the use of oil and water fluid around the cylinder according to the 2D contours is the difference in the temperature gradient of the two fluids. So that the highest temperature gradient is observed for water fluid. © 2023 The Authors

The poor heat transfer properties of the base fluid are the first effective obstacle to improving heat exchangers' efficiency. The key point of using very high conductivity of solid particles (in nanometer dimension) is hundreds of times more than common fluids in heat transfer in the composition of these fluids. Therefore, adding nanoparticles (NPs) to base fluids has been a solution to increase the heat transfer (HT) properties of common energy-carrying fluids. On the other hand, adding surfactants prevents the sedimentation and instability of NPs and improves the thermal performance of nanofluids (NF). So, this study surveyed the thermal properties of water-copper NF with/without surfactant molecules in a rectangular nanochannel using molecular dynamics (MD) simulation. Cetryltrimethylammoniu Bromide (CTAB) molecules were used as surfactants, copper structure as NPs, and water molecules as a base fluid in this simulation. In the present study, the effect of nanochannel wall temperature, copper nanoparticle (NP) size, and force field type (DREIDING, Universal Force-Field (UFF), and CHARM) on thermal conductivity (Knf) of water-copper NF were studied. The results show that as the wall temperature decreased from 80 to 30 K, Knf decreased from 0.783 to 0.753 Wm-1K−1. On the other hand, by increasing the radius of NPs from 0.5 to 2 nm, Knf and heat flux (HF) increase from 0.77 to 0.798 Wm-1K−1 and 5734 to 6352 W.m−2, respectively. One of the important purposes of researchers and engineers in various industries is to increase efficiency and reduce the systems' size. Therefore, it is expected that the results of this study will be effective in many different thermal industries. © 2022 Elsevier B.V.

The present study numerically investigated the simulation of two-phase nanofluid (NF) flow to examine the thermal performance of Cu–water NF within an enhanced tube with W- and C-shaped ribs in the heat exchangers (HEX). In this research, the effect of volume fraction (φ = 0.2, 0.4, 0.6, and 0.8%), and diameter (15, 20, 25 and 30 nm) of copper nanoparticles and the type and size of the turbulators (TRB) (W- and C-shaped ribs together), which were designed for the first time on Heat transfer (HT), were discussed. Heat transfer flow (HTF) entered the test section at Tin = 290 K in various velocities related to different Reynolds numbers (Re) 5000, 10000, 15000 and 20000. Based on the Eulerian-Eulerian two-phase method, the governing equations were solved. Different rib geometrical parameters were determined, and the optimization was performed to achieve the maximum performance evaluation criteria (PEC). According to obtained results, the PECs were more than 1, which indicated that these TRB were impressive from a hydraulic-thermal performance. Furthermore, the PEC variations of C- and W-shaped models were not similar. For the C-shaped configuration, the PEC values always enhanced with Re enhancement, while for the W-shaped model, the PEC values enhanced till Re = 10000, and then decreased till Re = 20000. The PEC values of the optimum model (W-shaped, NB = 6 and R = 15 mm) filled by NF at φ = 0.8% and dnp = 30 nm in Re = 5000, 10000, 15000 and 20000 are 1.491, 1.498, 1.482 and 1.469, respectively. © 2023 The Authors

Desiccant systems, as a promising air conditioning technology have opened new aspects as a replacement for vapor compression systems. The liquid desiccant energy exchanger system with natural convection flow is proposed here; the system is a loop with two hollow fiber membrane air-desiccant exchanger of shell-and-tube type that works as the humidifier and regenerator. The LiCl aqueous solution as desiccant directed over the fibers and the air is inside the fibers; the water stream flows outside the modules to provide the required heat exchange. The heat sink and source as merged subparts of the exchangers have a major influence on system performance. The system is examined from the energetic and exergetic viewpoints at different heat sink and heat source temperatures. Keeping the fixed air flow rate and using the standard air properties, the cold and hot water temperatures of 15–25 °C and 50–70 were employed and the effectiveness coefficients including the latent, sensible and total and 2nd law efficiency evaluated. It was shown that the values of NTU and Cr* depend on each other and attenuating effect of NTU reduction is higher than enhancing effect of Cr* increase on effectiveness values. The prominent factor on exergy performance which hinders the effect of the other parameters is the solution flow rate. Also, the highest and lowest values of 2 nd law efficiency are 81% and 5% which are for temperature pairs of (52, 20) and (65,25), respectively. © 2023 The Authors

A boron nitride (BN) plate was investigated in this work for adsorbing the formaldehyde (Frm) substance by performing the density functional theory (DFT) calculations. The singular models of BN and Frm were optimized first, and their combinations were re-optimized next to obtain Frm@BN complexes; F1 and F2 were found. To manage the interaction processes, an iron (Fe) atom was inserted in the center of a small plate. The results showed the benefits of such atomic insertion for approaching the goal of this work. Details of interactions were analyzed, and the results show the existence of two interactions for each of obtained Frm@BN bimolecular models. The model with O…Fe, and H…N interactions (F1) was placed at a higher level of strength than the model with the existence of H…Fe and H…N interactions (F2). Accordingly, energy levels of characteristic frontier molecular orbitals and their related features affirmed the impacts of complex formations leading to the possibility of running diagnostic processes. Additionally, the role of the Fe-doped region was dominant in conducting the adsorption processes, and the results of both F1 and F2 complexes revealed such importance. Consequently, the stabilized models regarding the energies and interactions details affirmed this achievement for proposing the formations of Frm@BN complexes for environmental applications. © 2023, AMG Transcend Association. All rights reserved.

In this work, argon flow within different microchannels with square cross-section is simulated by the molecular dynamics simulation (MDS) method. The first simulation is done within ideal microchannel and then, internal surfaces of this microchannel are roughened by cone, cubic and spherical barriers respectively to report influences of roughness with different geometries on the distribution of fluid flows. It is reported that cone and spherical geometry of barriers do not strongly affect flow characteristics of argon fluid within the microchannel, while the cubic geometry of barriers delays density distribution of argon flow in the middle region of the microchannel due to their destructive role against translocation of fluid particles between lateral and central layers of the microchannel. For the density results, it is reported that two physical phenomenon of thermal and external energies play important roles on the distribution of fluid particles in different sections of microchannel due to their different applying directions. Moreover, it is observed that the temperature profile of fluid flow within microchannel with cubic barriers touched a maximum temperature of 420 K at the central layers which are in the highest temperature level among all cases studied. Results of this study are applicable for practical application in small scale designs such as medical probes to inject destructive fluid for destroying tumors in cold surgeries. © 2023 THE AUTHORS

In this paper the amount of partitioning while the simultaneous use of THIS and a KHI inhibitors is examined and, results were investigated. The effects of adding oil, alcohols and salts on the efficiency of kinetic inhibitors were investigated using UV spectrometry and Beer-Lamberdt law. Samples of the mentioned inhibitors were prepared using a kinetic inhibitor (Poly Vinyl Pyrrolidone) and then spectrometry was conducted. Results indicated positive impacts whenever salt was added to the solution; since salt addition caused stronger bonds between kinetic inhibitor and water molecules. It was found that between salts NaNO3 with 70% had the highest and KCl with 39% had the lowest percentage of partitioning. Addition of oil showed fewer negative impacts. Bangestan oil with 2% of partitioning had the least negative effect and n-heptane with 7% had the most negative effect. Normal butanol (16%), acetone(11%) and ethylene glycol with 18% did not have major negative influences. © 2022 The Authors

In friction stir welding, tool shoulder diameter and its rotational speed are the major influencing parameters than others. A simple novel correlation is proposed to select the optimum range of tool shoulder diameter with respect to the chosen rotational speed and vice versa. The conditions to apply derived correlation were defined through process heat index number as the joint efficiency in the friction stir welding depends on the effective heat supply to the volume of material deformed in the stir zone. Weld speed is the key parameter through which generated heat can be regulated towards optimum heat supply to attain defect-free weld in the stir zone. Effective heat input also has obvious effect on grain growth and corresponding property eradication in the heat affected zone. The experimental study was carried out on AA2024-T3 plates to understand the effect of process heat index on the prescribed optimum range of tool shoulder and rotational speed defined in the correlation. Eventually, a novel relationship was attained between the first order process influencing parameters to deliver maximum joint efficiency. © 2022 Stephen Leon Joseph Leon et al.