Arturo F. Méndez-Sánchez

Particle image velocimetry of the unstable capillary flow of a micellar solution

The unstable capillary flow of the micellar system formed by cetylpyridinium chloride 100 mM/sodium salicylate 60 mM (CPyCl/NaSal) in tridistilled water was studied in this work using a combination of particle image velocimetry (PIV) and rheometrical measurements. The experiments were run in a pressure controlled capillary rheometer at a temperature of 26 °C and covered all the different flow regimes occurring in the nonmonotonic flow curve characteristic of micellar solutions. First, we show the suitability of the PIV technique to study the unstable capillary flow of this micellar system. Then, and more important, we provide evidence of the development of shear banding and the velocity profiles for the different flow regimes, including the transition to the high shear branch because of spurt. The velocity profiles at low shear rates exhibited a Newtonian behavior, followed by a still Newtonian with apparent slip up to the onset of spurt. There was a jump of one order of magnitude in the shear rate with a...

Effect of Active and Nonactive Fluxes on the Mechanical Properties and Microstructure in Submerged-Arc Welds of A-36 Steel Plates

A study of the effect of active and nonactive fluxes on the mechanical properties and microstructure of submerged-arc welds for steel plates was carried out for the Submerged-Arc Welding (SAW) of A-36 Steel Plates. The nonactive flux promoted the formation of pearlite and ferrite in the weld having the highest toughness and ductility. In contrast, the active fluxes with Cr and Mo promoted the formation of acicular ferrite and fine carbides in the welds showing the highest tensile strength and hardness.

JERARQUIZACIÓN DE COMPETENCIAS ESPECÍFICAS EN EL PROGRAMA DE FÍSICA DE LA ESCUELA SUPERIOR DE FÍSICA Y MATEMÁTICAS DEL IPN-MÉXICO UTILIZANDO LA MATRIZ DE MORGANOV-HEREDIA

In this paper, the so-called Morganov-Heredia matrix was employed to obtain a hierarchy of competencies for physics graduates in Physics at the Higher Scholl of Physics and Mathematics of the National Polytechnic Institute in Mexico. The study is done in the context of the effort of the institution to implement Competence-Based Educational Model on its curricula. The Morganov-Heredia matrix allowed identifying and grouping competences by their characteristics, such as labor disciplinary and social competences. Also, the matrix allowed organizing the proposed competences from the most basic one to the final competence goal.