Closure to “Estimation of Critical Velocity for Slurry Transport through Pipeline Using Adaptive Neuro-Fuzzy Interference System and Gene-Expression Programming” by H. Md. Azamathulla and Z. Ahmad

IntroductionThe discussers would like to thank the authors for proposing a newequation [Eq. (21)] for the estimation of critical velocity based onthe gene-expression programming (GEP) and using the availabledata, and would like to draw attention to some points.As mentioned by the authors, the GEP model is preferred overthe ANFIS model, as the latter does not produce an explicitformula. Explicit formulas are useful for the practitioners intheestimationofcriticalvelocityinapipeline.Manyinvestigatorshave proposed explicit equations for the estimation of the criticalflow velocity, and the authors also aim to propose a new equationbased on the gene-expression programming (GEP). However, thesteps and the results of a scientific research should be repeatableand reproducible.The authors haveused experimental data for the critical velocitypresentedbyHepyetal.(2008)intheirresearch.Asummaryofthisdata set is presented as Table 1 in the original paper, but this is notenough to show the performance of proposed Eq. (21). Thus it isessential to provide suitable tabulated experimental data forV