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Advancements in Pressure Retarded Osmosis (PRO) technology are enhancing the feasibility of evaluating its economic viability against other renewable energy production methods. This is done using the Levelized Cost of Energy (LCOE) as a metric. The study focuses on three PRO scenarios designed to minimize environmental impact and promote sustainable energy. These scenarios utilize a spiral-wound membrane module combined with hyper-saline solutions from Reverse Osmosis (RO) and wastewater from demineralization processes. Experimental results using a commercial spiral-wound membrane in the PRO system yielded LCOE values of USD 0.0702/kWh for a draw solution (DS) concentration of 36.2 g/l, USD 0.0563/kWh for 44.2 g/l, and USD 0.0721/kWh for 51.8 g/l. The study also evaluated environmental viability by considering the cost of CO2emissions. This comprehensive comparison highlighted PRO's competitiveness with fossil fuels, showing it to be a reasonable alternative to coal and oil but less practical than natural gas. Specifically, the environmental analysis revealed that PRO is approximately 25.2 % more competitive than coal and 9.76 % more competitive than oil but 27.16 % less competitive compared to natural gas in terms of CO2emission costs. This underscores the importance of considering carbon emission mitigation in energy generation.

•An oxopropane derivative namely “1-(2-ethylamino-1,3,4-thiadiazol-5-yl)−3-phenyl-3-oxopropan ” of have been synthesized and fully characterized.•The inhibition efficiency of 1-(2-ethylamino-1,3,4-thiadiazol-5-yl)−3-phenyl-3-oxopropan (ETO) have been studied for mild steel corrosion in 1 M HCl.•ETO acted as mixed type inhibitor and obeyed Langmuir adsorption isotherm.•The inhibition efficiency increased with increasing ETO concentration.•The adsorption of ETO on mild steel surface is physical and chemical adsorption.

In the present work, quinoxaline (0.002 M) as a corrosion inhibitor for copper in 1.5 M HNO3has been investigated at different temperatures. Weight loss, regression, and density functional theory (DFT) were used in the experimental, mathematical, and quantum chemical studies, respectively. Experimental studies show that the corrosion rate of copper increases with temperature, according to the Arrhenius equation. On the other hand, the percentage of inhibitor efficiency increased as temperature decreased, approaching a maximum value of 91 % at 25 °C. Kinetic studies showed that the corrosion reaction was zero-order. Corrosion rate data was fitted to a second-order mathematical model with a 0.974 correlation coefficient. The effect of inhibitor concentration on the corrosion rate was studied at low and high levels of temperature. The corrosion rate decreases with an increase in an increase in inhibitor concentration. The adsorption on the copper surface was spontaneous and followed the Langmuir adsorption isotherm. The theoretical quantum chemical calculation was used to support the experimental study. These calculations showed that the inhibitor molecules were the donors of electrons, while the metal surface was the acceptor. In addition, Mulliken charge data showed that the negative charges of quinoxaline are mainly concentrated on the nitrogen and carbon atoms. On the other hand, all hydrogen atoms have positive charges. This indicates a lack of hydrogen bond formation with the copper surface. This extensive study not only confirms quinoxaline’s efficacy as a corrosion inhibitor but also advances our knowledge of how it interacts with copper, opening the way to the creation of more focused and effective corrosion inhibitors that follow the rules of molecular design.

Most organic corrosion inhibitors have polar groups through which the molecule can be adsorbed strongly or specifically on the metal surface. In this investigation, terephthalo- hydrazide and isophthalohydrazide were synthesized as corrosion inhibitors, and their corrosion-inhibiting properties on mild steel were evaluated in a corrosive environment by weight loss measurements. The results of corrosion experiments revealed that terephthalohydrazide and isophthalohydrazide as inhibitors controlled or reduced corrosion through adsorption mechanism and showed inhibitive efficiencies of 96.4 % and 97.2 %, respectively, at the optimum concentration of 0.5 mM. The surface morphology of the metal was evaluated by scanning electron microscopy. The terephthalohydrazide or isophthalohydrazide molecules were adsorbed on the mild steel surface, and the process of adsorption follows chemical adsorption. Quantum chemical calculations of the tested corrosion inhibitors were consistent with the experimental observations.

Background: The phthalocyanines a series of compounds involves four iso-indole units linked by aza nitrogen atoms bonded with metal atoms that are normally located in the center a phthalocyanines ring. Some of the central metal-phthalocyanines can be excited by ultraviolet light and emit a fluorescence in far-red region. Objective: To synthesize a derivative of phthalocyanines namely 4,4',4' '-tri-(dodecenyl succinic anhydride)- 4' ' '-(5-amino salicylic acid) zinc phthalocyanine with a zinc central metal. Materials and Methods: The reaction of 4- nitro Phthalonitrile and 4- amino Phthalonitrile with ZnCl2 in the presence of dimethyl amino ethanol afforded 4,4',4' '-triamino-4' ' '-nitro zinc phthalocyanine. This product reacted with 5-amino salicylic acid to yield tetra-(5-amino salicylic acid) zinc phthalocyanine. A dodecenyl succinic anhydride was added on the amine group of benzoic rings to afford 4,4',4' '-tri-(dodecenyl succinic anhydride)-4' ' '-(5-amino salicylic acid) zinc phthalocyanine(I), the target compound. Results and Discussion: Compound I is successfully synthesized with a yield of 72% from tetra-(5-amino salicylic acid) zinc phthalocyanine with dodecenyl succinic anhydride. Conclusion: The newly synthesized molecule of 4,4',4' '-tri-(dodecenyl succinic anhydride)-4' ' '-(5-amino salicylic acid) zinc phthalocyanine (I), tetra-(5-amino salicylic acid) zinc phthalocyanine(E) and 4,4',4' '- triamino-4' ' '-nitro zinc phthalocyanine (S). The reaction of 4- nitro Phthalonitrile and 4- amino and the structure of compound I is confirmed and its formation was proven.

AbstractThis study attempted to use zinc oxide (ZnO) nanoparticles in membrane photocatalytic reactor (MPR) for industrial dye wastewater treatment. Performance comparison of nanofiltration (NF) and ultrafiltration (UF) in the MPR system were investigated to produce cleaner discharge and to retain the ZnO for reuse. From the results, the optimum operational condition of MPR occurred under pH 11 and 0.1 g L−1of ZnO loading. NF membrane performance improved after the addition of ZnO nanoparticles in the wastewater; in terms of normalized flux reduction (65%), colour removal (100%), chemical oxygen demand (92%), turbidity reduction (100%) and total suspended solid rejection (100%). In contrast, UF membrane showed worse performance, due to the permeation of dye molecules and nanosized ZnO across the UF membrane pores. Membrane characterizations of field emission scanning electron microscopy and energy dispersive X-ray results confirmed that the ZnO nanoparticles and NF membrane application has a great potential for improving MPR system in industrial wastewater treatment.

This study attempted to use zinc oxide (ZnO) nanoparticles in membrane photocatalytic reactor (MPR) for industrial dye wastewater treatment. Performance comparison of nanofiltration (NF) and ultrafiltration (UF) in the MPR system were investigated to produce cleaner discharge and to retain the ZnO for reuse. From the results, the optimum operational condition of MPR occurred under pH 11 and 0.1g L−1of ZnO loading. NF membrane performance improved after the addition of ZnO nanoparticles in the wastewater; in terms of normalized flux reduction (65%), colour removal (100%), chemical oxygen demand (92%), turbidity reduction (100%) and total suspended solid rejection (100%). In contrast, UF membrane showed worse performance, due to the permeation of dye molecules and nanosized ZnO across the UF membrane pores. Membrane characterizations of field emission scanning electron microscopy and energy dispersive X-ray results confirmed that the ZnO nanoparticles and NF membrane application has a great potential for improving MPR system in industrial wastewater treatment.

Simple sol-gel route was used to synthesis the TiO2 nanoparticles and examined by X-ray diffraction (XRD). The small particle size and uniform morphology of the TiO2 were found at different calcination temperatures. The kinetic study of phase changes from the anatase to rutile using the X-ray diffraction data with Avrami equation was investigated. The transformation of anatase to rutile was started after 500 °C and above by decreasing of XRD peaks intensity of anatase with rutile increased. The activation energy of the rutile phase was found lower which indicated that uniform shape and morphology of TiO2 nanoparticles. At same time, changes of activation energy value depended on the experimental conditions was observed.

Tremendous efforts are being made to produce polymer electrolyte membrane (PEM) for fuel cell using advanced materials in order to replace Nafion due to the high costs and its complicated synthesis procedures. One of the efforts include an extensive research on natural polymer to produce biopolymer based electrolyte membranes with desirable properties such as high proton conductivity, as well as good chemical and thermal stabilities. The examples of biopolymer that have been used are polysaccharide (e.g. cellulose, starch and glycogen), chitin and chitosan. This paper presents an overview of the types of biopolymer used to produce a PEM, comprised also their chemical and physical properties, and its performances in fuel cell applications.

Abstract: The experimental conditions for the synthesis of ZnO nanoparticles to produce minimal size were optimized using the D-optimal design. The influence of process parameters involves molar ratio of the starting materials, pH and the calcination temperature on the particle size were evaluated using the polynomial regression. The optimum conditions revealed by the model for obtaining a minimum particle size of ZnO were predicted to have a molar ratio of 1.76, pH of 1.50 and calcination at 402.2°C. The obtainable particle size upon applying the model is 22.9nm in compare to experimental result of 18±2nm was obtained. [Copyright &y& Elsevier]

An innovative approach to the material science has demonstrated that photocatalytic activity may be conferred to cement-based construction materials, such as concrete, mortars, paints, etc. Photocatalyst is needed for a cleaner environment and a better quality of life that leads to thoughts of a more eco-compatable use of light. Addition of photocatalytic materials to the RC structure during its construction phase could reduce the corrosion problem of RC materials. This material hinders calcium oxide to form acidic compound. In this study, cement-based mixed photocatalytic material has been presented, which would adjustable with RC material for enhancing oxidization process and reducing corrosion problem.

AbstractThis study investigates the feasibility of using a pilot-scaled sequencing batch biofi lm reactor (SBBR) with an option for granular activated carbon (GAC), at different hydraulic retention times (HRT) for the post-treatment of treated recycled paper industry wastewater containing potentially persistent and toxic pollutants, especially adsorbable organic halides (AOX). The environmental problems associated with AOX include their accumulation in the food chain and their persistence in nature. The pilot plant consists of a high-density polyethylene (HDPE) biofi lm reactor with a diameter of 1.2 m, and a maximum water depth of 1.8 m, that is packed with 1111 g/L of 2–3 mm granular activated carbon (coconut shells). The effect of HRT on AOX (specifi cally PCP) and COD removal was investigated at varying hydraulic loading rates of 0.3– 0.8 m3/(m2 day). The HRT was investigated at three diff erent levels varying from 1 to 3 days and the most suitable retention time, resulting in maximum overall removal of COD and PCP, was determined. The study demonstrated that at a workable HRT of 3 days and an average organic loading rate of 0.008 kg COD/m3d, the PCP and COD removal efficiencies of the reactors were 100% and 86.9 ± 2.4%, respectively, at optimum pH of 7–8 and DO of 4–6 mg/L.

This study investigates the feasibility of using a pilot-scaled sequencing batch biofilm reactor (SBBR) with an option for granular activated carbon (GAC), at different hydraulic retention times (HRT) for the post-treatment of treated recycled paper industry wastewater containing potentially persistent and toxic pollutants, especially adsorbable organic halides (AOX). The environmental problems associated with AOX include their accumulation in the food chain and their persistence in nature. The pilot plant consists of a high-density polyethylene (HDPE) biofilm reactor with a diameter of 1.2 m, and a maximum water depth of 1.8 m, that is packed with 1111 g/L of 2-3 mm granular activated carbon (coconut shells). The effect of HRT on AOX (specifically PCP) and COD removal was investigated at varying hydraulic loading rates of 0.30.8 m3/(m2day). The HRT was investigated at three different levels varying from 1 to 3 days and the most suitable retention time, resulting in maximum overall removal of COD and PCP, was determined. The study demonstrated that at a workable HRT of 3 days and an average organic loading rate of 0.008 kg COD/m3d, the PCP and COD removal efficiencies of the reactors were 100% and 86.9 ± 2.4%, respectively, at optimum pH of 7-8 and DO of 4-6 mg/L.

Abstract: Quantum chemical calculations were performed on ten thio compounds using semi-empirical method PM3 within program package of Material Studio 5.5. The effect of molecular structure on the corrosion inhibition efficiency was investigated using the quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, (LUMO–HOMO) energy gap, dipole moment (λ) and fraction of electron transfer (ΔN) were calculated and discussed. A relationship between the corrosion inhibition efficiency and several quantum parameters was established with coefficient correlation (R 2) of 0.8894. [Copyright &y& Elsevier]

The organic material named 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT) was studied as inhibitor for mild steel corrosion in 1.0 M HCl at 30 oC. The effects of turbulent flow on the inhibition process were characterized using open circuit potential (OCP), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Turbulent flow condition experiments were simulated by Rotating Cylinder Electrode (RCE). Results obtained from changes of open circuit potential (OCP) with immersion time, potentiodynamic polarization, and impedance measurements all are in good agreement and indicated that the formation and the development of the inhibitor film were flow rate dependence. The scanning electron micrograph confirmed film structure is dependence of flow condition.

The production of polyaniline films on mild steel from sulfuric acid was carried out using cyclic voltammetry. Corrosion protection of the coating was observed in 3.5% NaCl using electrochemical impedance spectroscopy, (EIS) and potentiodynamic polarization measurements. Results showed that the polyaniline layer has the potential to protect mild steel by stabilizing the oxide layer formed on the steel surface and thus prevent the metal dissolution process.

A study concerned to overpotentials analysis has been performed in fuel cell based on solid acid electrolyte to investigate the losses produced namely activation, concentration and ohmic losses. The used equations are the semi-empirical equations (exchange current density) or the mathematical and material balance equations. The cesium dihydrogen phosphate, CsH2PO4, was used as the electrolyte membrane and its proton conductivity was calculated based on the Arrhenius law at 230 ° C temperature. The combination of semi-empirical equations, mathematical and Nernst equations were also used to represent one model for the formulation of voltage versus current density in order to indicate overpotential losses. The utilization of the power differentiation to current density, a non-linear equation was obtained in order to determine the optimum current or voltage, via Matlab’s F-solve nonlinear program. Two main factors electrocatalyst layer and pressure are influence in limiting current density and resulting increase of solid acid fuel cell performance.

Electrode performance is the most important part in proton exchange membrane fuel cell system because all electrochemical processes and chemical conversions into energy occur via electrode interface. However the main problem in widespread proton exchange membrane fuel cells (PEMFCs) applications is the cost of the catalyst and life time of electrode, due to different parameters effects. Intense research imply in reducing the cost with increase the activity of catalyst in additional to other parameters (components) to make electrode for PEM more efficient with reasonable cost. This paper review recent research for the most parameters affecting performance of (Pt/C and Pt/C/M ) electrode for proton exchange membrane fuel cells (PEMFCs) such as Catalyst oxidation (degradation), and life time of the electrode using Pt/C, gas diffusion layer (GDL) thickness, and loading of PTFE in the diffusion layer, Nafion@ solution in the catalyst layer, methods of fabrication of electrode as spraying, casting, and electro deposition methods. Then the link between these parameters to achieve high performance and avoid the electrode degradation by optimized these parameters.

Catalysis is the major process involved in fuel cell technology to generate electricity which is known renewable. Generally, fuel cell electrodes utilize platinum supported carbon to catalyze the reactions at both cathode and anode. However, cheaper substitution materials such as nitrogen-doped carbon catalyst have attracted greater attention in recent year due to its significant catalytic activity at cathode in fuel cell. Nitrogen-doped CNT (N-CNT) is believed to allow oxygen reduction reaction (ORR) at cathode to take place which play a role as n-type dopant for electrical conductivity. The objective of this paper is to understand the mechanism of oxygen adsorption on N-CNT using the density-functional theory (DFT). N-CNT with two configurations involve sp2 and sp3 hybridized nitrogen are studied and compared in order to find the most thermodynamically stable N-CNT for sustainable ORR activity in fuel cell. The structural stability is studied through the binding energies of each configurations and the metallic behavior is examined through the energy gaps from the HOMO-LUMO studies. Finally, the adsorption energies and deformation energies of oxygen on N-CNT is discussed. Results revealed that sp3 hybridized N-CNT gives the most stable structure with compatible oxygen adsorption ability.

Polymer electrolyte membrane based on Nafion and zirconium oxide (ZrO2) was developed via film casting method. The content of ZrO2 (1.0, 2.0, and 3.0 wt.%) was incorporated with Nafion solution to prepare Nafion-ZrO2 composite membranes. Recast Nafion membrane was used as reference material. All of the prepared membranes have been subjected to both physical and chemical characterizations such as Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) analysis, water uptake rate (WUR) and conductivity measurements. The Nafion-ZrO2 composite membranes were found to possess high thermal stability (Tg= 188 - 192°C) and conductivity (0.30 – 0.93 S cm-1). This study demonstrates the possibility of developing Nafion-ZrO2 composite membrane as promising polymer electrolyte membrane for fuel cell operated at medium temperature and low humidity.

The solar photocatalytic degradation of 2,4-dicholrophenol in aqueous solution was carried out direct solar radiation without any collector. A slurry reactor with TiO2 nanoparticles catalyst was used. The catalyst sample was prepared by sol-gel method from titanium tetra-isopropoxide as raw material and calcinated at 400°C. The photocatalytic activity of TiO2 nanoparticles were evaluated by photocatalytic degradation of initial concentration (50 mgl-1) 2,4-dicholrophenol under solar irradiation. The average solar intensity of ultra violet (UV) was recorded as 23 Wm-2. HPLC was used for monitoring the concentration of 2,4-dicholrophenol in solution at different time intervals during the experiment. The degradation efficiency of 2,4-dicholrophenol removal was 93.8% at pH solution of 6, irradiated for 1 h and using optimum amount of catalyst 2gl-1 .

Elastic polyester from glycerol and azelaic acid with different molar ratio was synthesized by simple catalyst-free esterification reaction. The ratio of azelaic acid to glycerol used in this experiment was 1:2, 1:1 and 2:1. The polyester with ratio 1:2 and 1:1 appear as clear, bubble free, non tacky and flexible after 48 hours at 125°C while the polyester with the ratio of 2:1 was cured after extension of 60 hours. The formation of ester bonds of the polyester produced is detected on the monomer molecular ratio and also on the efficiency of water removal during esterification process.

The protonic conductivity of cesium dihydrogen phosphate nanocrystals (CDP) was studied utilizing electrochemical impedance spectroscopy (EIS) technique. CDP was synthesized using Cetyl Trimethyl Ammonium Bromide (CTAB) and Polyoxyethylene-Polyoxypropylene (F-68) as an individual component and also F-68+CTAB as a mixture. Results showed that the conductivity of CDP has sharp increase from 5.6 × 10-5 to 1.89 × 10-2Ω 1-cm-1 at the transition temperature of 230 oC. The conductivity of CDP (CTAB) increased slightly to 260 oC while the conductivity of CDP (F-68) and CDP (0.5F-68+0.5CTAB) decreased with the temperature above 230 oC.

This review paper discusses the temperature behavior and thermal event of cesium dihydrogen phosphate (CsH2PO4) in both ambient and high pressure atmosphere. A complete transition from the room-temperature to a high-temperature of CsH2PO4 (monoclinic to cubic phase) occurs between 230 to 240 °C, even in the absence of humid conditions and the superprotonic transition precedes the onset of the dehydration/chemical decomposition of the title compound. Decomposition or dehydration can be avoided by either keeping the sample under a H2O-saturated atmosphere, or subjecting the sample to a pressure of 1.0 ± 0.2 GPa.

Inhibition of galvanic corrosion was carried out using 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT) as corrosion inhibitor. The couple metals were aluminium alloy (Al2024) and mild steel. The galvanic potential and the galvanic current were measured in absence and presence of 0.4 mM of APTT. FT-IR was used to characterise the adsorbed inhibitor film technique. The result showed that the galvanic current was reduced from 286 to 8.9 μA cm –2 with addition of APTT. FTIR result confirmed the adsorption of APTT on mild steel surface.

The corrosion of aluminum alloy (6262) in artificial sea water under flow condition was evaluated using electrochemical impedance spectroscopy (EIS) and potentiodynamic methods. The flow condition experiments were simulated using rotating cylinder electrode (RCE). Results showed that the increasing of the flow velocity enhances the corrosion kinetic of the system and changes the corrosion mechanism. Limiting current density was increased with increasing in the flow velocity. This behavior was due to the presence of a mixed control on the corrosion process related with the formation and stabilization of corrosion product layers on the electrode surface.

Electrochemical polarization and electrochemical impedance spectroscopy (EIS) were involved to study the corrosion inhibition of aluminum alloy 2024 in 2.5M H2SO4 solution by 4-amino-5-phenyl-4H-1, 2, 4-triazole-3-thiol (APTT) at 30 ○C. Potentiodynamic polarization results were comparable with those obtained by impedance measurements. Results showed that APTT performed as inhibitor for aluminum alloy 2024 corrosion in 2.5M H2SO4 solution and it attains an efficiency of more than 32% at 4×10- 4 M at 30 ○C . The inhibition efficiency increases with an increase in the concentration of APTT. Polarization curves show that APTT is a mix-type inhibitor. Changes in impedance parameters (charge transfer resistance, Rct, and double layer capacitance, Cdl) were indicative of adsorption of APTT on the aluminum alloy 2024 surface, leading to the formation of protective films

In this paper, hybrid organic–inorganic membranes were prepared using three different solvents and characterized. The hybrid membranes were fabricated using sol–gel technique, which had polymethyl‐methacrylate (PMMA) and tetraethyl orthosilicate (TEOS) as materials, with 80/20 ratio. The thin films were then characterized using FTIR, SEM, EDX, and mapping techniques. From the preliminary characterization, hybrid membranes were found to have nano and ultra scale tight‐pores ranges, which was influenced by the solvent used. The SEM images clearly show that hybrid membranes have homogenous and smooth surface. FTIR spectroscopy uncovered all the signature peaks characteristic of silicate structures in the near‐surface regions. Fingerprints of Si&bond;O&bond;Si groups in cyclic and linear molecular substructures were also present. From DSC analysis, the Tg value of the PMMA moieties in hybrids membranes was in the order H‐15‐Toluene < Pure PMMA < H‐15‐THF < H‐15‐DMF. Furthermore, from TGA analysis it was found that the hybrid membranes have higher thermal stability compared with that of pure PMMA. EDX and mapping analysis showed that the composition and distribution of particles in the membranes were different and dependent on the solvents used. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006

Abstract: The temperature dependence of the diffusion coefficient of ethanol-soluble substances from ground cloves (particle size 250 μm) during extraction was estimated by fitting batch extraction data at several temperatures (27.8, 40, 50, and 60C) to a previously developed mass transfer model. The model was based on spherical geometry of particles. Nonlinear regression analysis was used to develop an equation that describes the diffusivity as a function of temperature. The temperature dependence ofD A was of the Arrhenius type.

The temperature dependence of the diffusion coefficient of ethanol-soluble substances from ground cloves (particle size 250 µm) during extraction was estimated by fitting batch extraction data at several temperatures (27.8, 40, 50, and 60°C) to a previously developed mass transfer model. The model was based on spherical geometry of particles. Nonlinear regression analysis was used to develop an equation that describes the diffusivity as a function of temperature. The temperature dependence ofDAwas of the Arrhenius type.

The laminar 2-D blended convection of the nanofluids at different volume fractions has gained interest in the last decade due to an enormous application in technology. The laminar-flow stream system can be further modified by changing the geometry of the channel, adding an external heating source, and changing the initial conditions at which the stream is being influenced. The investigation of this system includes the variation of the geometrical parameters of the channel, Reynolds number, Nusselt number, and type of the nanoparticles used in preparing the nanofluid with water as the base fluid. These parameters constitute a very successful leading to utilize the numerical solutions by using a finite volume method. Regarding heat flow, one side of the channel was supplied by the heat while the temperature of the other side was kept steadily. The upstream walls of the regressive confronting step were considered as adiabatic surfaces. The nanofluids were made by adding aluminum oxide (Al2O3), copper oxide (CuO), silicon dioxide (SiO2), or zinc oxide (ZnO) nanoparticles to various volume fractions in the scope of 1 to 4% and diverse nanoparticle diameters of 25 to 80 nm. The calculations were performed with heat flux, Reynolds numbers (Re), and step height (S) at a range of 100 <  < 600 W/m2, 100 <  Re< 500, and 3 ≤ S≤ 5.8, respectively. The numerical study has shown that the nanofluid with SiO2has the highest value of the Nusselt number (Nu). The distribution area and the Nuincrease as Reynolds number increases and diminish as the volume fraction diminishes with the increase of the nanoparticle diameter. The outcome of this paper has shown that assisting flow has shown superiority over the opposing flow when Nuincreases.