a numerical model for simulating residence time distribution (rtd) of turbulent flows in helical static mixers is proposed and developed to improve the understanding of static mixers. the results of this model is presented in terms of different volumetric flow rate to illustrate the complicated flow patterns that drive the mixing process in helical static mixers. the computed results are also u...

brand plays an important role in contacting customers. even from the customer’s viewpoint, it is a symbol of product quality. measuring the brand equity in order to determine the brand position is of remarkable significance for companies, in particular iranian ones. the purpose of this article is to investigate the parameters that influence brand equity and provide a mathematical model for meas...

this paper presents a multi-criteria vehicle routing problem with soft time windows (vrpstw) to mini-mize fleet cost, routes cost, and violation of soft time windows penalty. in this case, the fleet is heterogene-ous. the vrpstw consists of a number of constraints in which vehicles are allowed to serve customers out of the desirable time window by a penalty. it is assumed that this relaxation a...

the results of batch settling tests (bst) are used to investigate settling behavior of solids suspension, which contribute to sizing thickeners. conventional methods in analyzing bst on the basis of visual and graphical procedures lead to sub-optimally sized and selected thickeners. a computational approach based on quantitative analysis of bst can be beneficial. about 300 settling experiments ...