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The main object of the present paper is to examine and compare the improvement of flow and heat transfer characteristics between a rotating nanofluid and a newly discovered hybrid nanofluid in the presence of velocity slip and thermal slip. The influence of thermal radiation is also included in the present study. The system after applying the similarity transformations is solved numerically by using the bvp-4c scheme. Additionally, numerical calculations for the coefficient of skin friction and local Nusselt number are introduced and perused for germane parameters. The comparison between water, nanofluid and hybrid nanofluid on velocity and temperature is also visualized. It is observed that the velocity and temperature distributions are decreasing functions of the slip parameter. Temperature is boosted by thermal radiation and rotation. It is found that the heat transfer rate of the hybrid nanofluid is higher as compared to the traditional nanofluid.

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Flake graphite (FG) with high uranium(VI) entrapment efficiency was successfully fabricated via a simple and efficient nonthermal plasma treatment method. FG was modified with −NH 2 functional groups through nonthermal plasma with different treatment times under vacuum conditions. The modified FG samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transformed infrared spectroscopy (FT-IR spectra), thermogravimetric analysis (TGA), BET surface area measurements, and zeta potential. FG samples with different treatment times are used as contrast adsorbents for U(VI) entrapment. The adsorption experiments show that the modified FG has higher high U(VI) entrapment efficiency than others, and longer treatment time results in higher efficiency, demonstrating that the plasma treatment can greatly increase the active sites of FG samples and lead to the successful grafting of −NH 2 on FG surface. The −NH 2 modified FG with 2 h treatment time shows the highest adsorption capacity with 140.68 mg•g −1 among the five samples at 333.15 K. Thermodynamic studies reveal that the U(VI) entrapment process is spontaneous and entropy-driven endothermic. XPS studies reveal that the adsorption mechanism for U(VI) entrapment is achieved through the complexation of U(VI) with both −NH 2 and phenolic hydroxyl group on the surface of modified FG. Moreover, desorption studies exhibit that PTFG-4 can be used repeatedly and adsorption capacity only shows slight decrease after five cycles. Thus, it can be concluded that the nonthermal plasma treatment can be used as an effective method for the fabrication of adsorbents with great adsorption performance for heavy metals entrapment.

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This article addresses steady flow of Maxwell nanofluid induced by an exponentially stretching sheet subject to convective heating. The revised model of passively controlled wall nanoparticle volume fraction is taken into account. Numerical solutions of the arising non-linear boundary value problem (BVP) are obtained by using MATLAB built-in function bvp4c. Simulations are performed for various values of embedded parameters which include local Deborah number, Prandtl number, Biot number, Brownian motion parameter and thermophoresis parameter. The results are consistent with the previous studies in some limiting cases. It is found that velocity decreases and temperature increases when the local Deborah number is increased. Moreover the influence of Brownian diffusion on temperature and heat transfer rate is found to be insignificant.

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