A facile novel green methodology is presented for the synthesis of highly stable and well-dispersed copper oxide nanoparticles using aqueous wheat seed extract. Under optimal reaction conditions, the wheat seed extract-derived electron-rich biomolecules were functioned as a reducing and capping/ stabilizing agent. The ultraviolet-visible absorption peak at 300 nm was confirmed the formation of copper oxide nanoparticles. Fourier-transform infrared spectroscopy analysis determined Cu–O bonds in nanosample, indicating the active role of functional groups in the wheat seed extract in bio-reduction of Cu cations. X-ray diffraction pattern results demonstrated the monoclinic structure of highly pure biosynthesized copper oxide nanoparticles with a crystallite size of 20.76 nm. The stability of copper oxide nanoparticles was confirmed after 3 months’ storage of product with no sedimentation or suspension. Transmission electron microscopy results showed the spherical shape of nano-particle with an average size of 22 ± 1.5 nm. X-ray photo-electron spectroscopy analyses revealed only copper and oxygen elements in the sample, confirming the purity of copper oxide nanoparticles. Bio-assisted copper oxide nanoparticles demonstrated significant catalytic efficiency and reusability toward 4-nitrophenol removal by an average of 97.6% from aqueous solutions after successive 5 days’ exposure to UV irradiation.

A 3D computational fluid dynamics method is used in the current study to investigate the hybrid nanofluid (HNF) flow and heat transfer in an annulus with hot and cold rods. The chief goal of the current study is to examine the influences of dissimilar Reynolds numbers, emissivity coefficients, and dissimilar volume fractions of nanoparticles on hydraulic and thermal characteristics of the studied annulus. In this way, the geometry is modeled using a symmetry scheme. The heat transfer fluid is a water, ethylene–glycol, or water/ethylene–glycol mixture-based Cu-Al2O3 HNF, which is a Newtonian NF. According to the findings for the model at Re = 3000 and ϕ1 = 0.05, all studied cases with different base fluids have similar behavior. ϕ1 and ϕ2 are the volume concentration of Al2O3 and Cu nanoparticles, respectively. For all studied cases, the total average Nusselt number (Nuave) reduces firstly by an increment of the volume concentrations of Cu nanoparticles until ϕ2 = 0.01 or 0.02 and then, the total Nuave rises by an increment of the volume concentrations of Cu nanoparticles. Additionally, for the case with water as the base fluid, the total Nuave at ϕ2 = 0.05 is higher than the values at ϕ2 = 0.00. On the other hand, for the other cases, the total Nuave at ϕ2 = 0.05 is lower than the values at ϕ2 = 0.00. For all studied cases, the case with water as the base fluid has the maximum Nuave. Plus, for the model at Re = 4000 and ϕ1 = 0.05, all studied cases with different base fluids have similar behavior. For all studied cases, the total Nuave reduces firstly by an increment of the volume concentrations of Cu nanoparticles until ϕ2 = 0.01 and then, the total Nuave rises by an increment of the volume concentrations of Cu nanoparticles. The Nuave augments are found by an increment of Reynolds numbers. Higher emissivity values should lead to higher radiation heat transfer, but the portion of radiative heat transfer in the studied annulus is low and therefore, has no observable increment in HNF flow and heat transfer.

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This research paper aims to determine of the rate equation for the reaction that is described in this article.Experiments carried out by using iodometric method for determine the concentration of potassium permanganate at different times. The results are very similar to the results of the UV-Visible spectrophotometric method. These results showed that order of reaction for acetone, potassium permanganate and sulfuric acid were 1, 1 and 1, respectively. Therefore, the rate equation is according to the chemical equation. In addition, it was demonstrated that there was no relationship between products concentration and rate of reaction. A suitable mechanism is also suggested. Thus, the reaction rate law implies a complicated reaction mechanism with low acetone concentrations. In addition, elevated temperature and reactants concentrations are required for a fast acetone oxidation. A reaction mechanism in good consistent with the kinetic results will be suggested and discussed.