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The present comment concerns some doubtful results included in the above paper.

The document titled "Comment on Vishalakshi et al. MHD Hybrid Nanofluid Flow over a Stretching/Shrinking Sheet with Skin Friction: Effects of Radiation and Mass Transpiration" criticizes two errors in a previous publication. The first error is related to an incorrect gravity term in an equation, which violates the known physics principle that gravity acts in the vertical direction. The second error involves a dimensional inconsistency in an equation, where some parameters are dimensionless while one parameter is dimensional. The document concludes by stating that the authors have no conflicts of interest. [Extracted from the article]

The flow induced by a sphere rotating inside an incompressible, non-Newtonian, Carreau fluid has been investigated numerically. The rotating sphere is enclosed in a concentric cubic box with solid boundaries. The fluid power-law index varied between 0.2 and 2 thereby covering both shear-thinning and shear-thickening fluids, the Reynolds number varied between 0.01 and 1000 and the Carreau number varied between 1 and 1000. The torque applied on the sphere has been calculated and is presented in tables and figures. It was found that at low Reynolds numbers the torque is independent of the Reynolds number and increases with increasing the power-law index. As the Carreau number increases the torque decreases in shear-thinning fluids and increases in shear-thickening fluids. In all cases, four vortices appear at the vertical plane passing through the sphere centre. [ABSTRACT FROM AUTHOR]

The cited article incorrectly treats a non-similar problem as a similar one. Other anomalies are indicated. Key words: Jeffery-Hamel, similarity, non-similar, second-grade, channel. L'article cite traite incorrectement un probleme non-similaire comme un probleme similaire. Nous soulignons d'autres anomalies. [Traduit par la Redaction] Mots-cles: Jeffery-Hamel, similarite, non similaire, fluide de grade 2, canal., The transformed momentum equation solved in ref. 1 is the following ((21) of ref. 1). F''([eta]) + 4[a.sup.2]F'([eta]) + 2aRe F([eta])F'([eta]) + 4De[F([eta])F ''([eta]) + 4[a.sup.2]F([eta])F'([eta])] = 0 (1) where [...]