Comments on “Overflow characteristics of streamlined weirs based on model experimentation” by Bagheri S. and Kabiri-Samani A

In this paper the stage-discharge equation of a streamlined weir is theoretically deduced applying the Π-Theorem of dimensional analysis and the self-similarity theory. The coefficients of the new stage-discharge relationship are estimated using the experimental results by Bagheri and Kabiri-Samani.     

Comments on “Micro-scale abrasive wear testing of PVD coatings on curved substrates” [by K.L. Rutherford and I.M. Hutchings]

Previously published expressions for the wear volume in the micro-scale abrasion test for curved specimen surfaces (K.L. Rutherford and I.M. Hutchings, Tribology Letters 2 (1996) 1–11) were based upon erroneous assumptions about the wear-scar geometry. Accurate volumes have now been computed, and the errors in the use of the original analytical equations are shown to be negligibly small (<0.5% error) for all practical cases. This revised version was published online in August 2006 with corrections to the Cover Date.     

Comments on “Mean velocity and turbulent characteristics of flow over half-cycle cosine sharp-crested weirs” by Salehi S., Esmaili K., Azimi A.H.

In this paper the stage-discharge equation of a half-cycle cosine weir is theoretically deduced applying the Π-Theorem of dimensional analysis and the self-similarity theory. The coefficients of the new stage-discharge relationships are estimated using the results of the experimental runs by Salehi et al..     

Comments on “Influence of chemical reaction and viscous dissipation on MHD mixed convection flow” by K. Das [JMST 28 (5) (2014) 1881~1885] and “Cu-water nanofluid flow and heat transfer over a shrinking sheet” by K. Das [JMST 28 (12) 5089~5094]

In this letter, we submit our comment on the following recently published papers by Kalidas Das: (1) “Influence of chemical reaction and viscous dissipation on MHD mixed convection flow,” Journal of Mechanical Science and Technology 28 (5) (2014) 1881-1885; and (2) “Cu-water nanofluid flow and heat transfer over a shrinking sheet,” Journal of Mechanical Science and Technology 28 (12) (2014) 5089-5094. The authors attempt to present the similarity solutions in both papers. We comment that the similarity transformations considered in Refs. [1, 2] are incorrect. Thus, the results presented by Kalidas Das lead to invalid conclusions.     

Comments on “Study and application of discharge calibration for submerged radial gates” by Guo X., Guo Y., Wang T., Fu H., Li J. Flow Meas. Instrum. 78 (2021) 101912, https://doi.org/10.1016/j.flowmeasinst.2021.101912

This paper discusses the capability of Guo et al.'s (2021) equations to determine the discharge of radial gates under submerged flow conditions. It was concluded that Guo et al.'s (2021) equations are associated with error reduction compared to the Incomplete Self-Similarity (ISS) theory and the calibration method. However, it does not have a significant advantage over Energy-Momentum (E-M) approach. Employing E-M principles, new equations were proposed to determine the discharge of radial gates, which has some advantages compared to Guo et al. (2021), such as (1) error reduction under partially and fully submerged flow conditions, (2) least dependence on the empirical constants, (3) uniformity of form over the entire submerged condition, and (4) no need to classify the submerged flow. Field calibration showed that the proposed equations in the present study for a single gate predict the discharge of parallel radial gates with a mean absolute error of less than 4.5% subject to the submerged operation of all open gates.     

Retraction notice to: “Characteristics of recursive backstepping algorithm and active damping of oscillations in feedback linearization for electromechanical system with extended stability analysis and perturbation rejection” [ISA Trans. 64C (2016) 365-372]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted by agreement between the authors and the Editor-in-Chief. A request by the authors to add additional authors to the paper after publication resulted in an agreement to retract the paper by the Authors and Editor-in-Chief.