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Contamination of natural groundwater by arsenic (As) is a serious problem that appears in some areas of Northern Central Mexico (NCM). In this research, As was removed from NCM wells groundwater by the electrocoagulation (EC) technique. Laboratory-scale arsenic electroremoval experiments were carried out at continuous flow rates between 0.25 and 1.00 L min−1using current densities of 5, 10, and 20 A m−2. Experiments were performed under galvanostatic conditions during 5 min, at constant temperature and pH. The response surface methodology (RSM) was used for the optimization of the processing variables (flow rate and current density), response modeling, and predictions. The highest arsenic removal efficiency from underground water (99%) was achieved at low flow rates (0.25 L min−1) and high current densities (20 A m−2). The response models developed explained 93.7% variability for As removal efficiency.

The magnetorheological fluids have the ability to modify their viscosity quickly by subjecting it to a magnetic field, a quality that classifies them in the category of intelligent materials. Such fluids include three main components; the base fluid that is generally mineral or synthetic oil, magnetizable particles which are dispersed in the base fluid and the additives or stabilizers that prevent agglomeration and sedimentation of the particles, as well as the degradation induced by the carrier medium. The main challenge of these fluids is to maintain the rheological response to the magnetic field, as well as avoid the chemical and microstructural instability of the magnetoreological fluids. In the present investigation an exhaustive bibliographic review was carried out to understand the main aspects of these types of materials, their properties as well as the main applications in the different branches of industry and medicine. The most recent contributions focused on the chemical stability of magnetic particles through the application of surface coatings are discussed.

The austenite to ferrite transformation start temperature was measured in two low-C, Si-Al grain nonoriented electrical steels using in situ x-ray diffraction and the direct comparison method with the (111) c and (110) a diffracted intensities. It was shown that increasing Al content from 0.2 to 0.6 wt.% in a 0.06 wt.% C, 0.6 wt.% Si and 0.5 wt.% Mn steel increases the Ae 3 temperature from 928 to 955°C. The results are supported by microstructural observations of isothermally transformed samples and used to discuss the loss of ductility during high temperature deformation (e.g. hot rolling) of this type of materials.

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