Proton exchange membrane fuel cells and direct alcohol fuel cells have been extensively studied over the last three decades or so. They have emerged as potential systems to power portable applications, providing clean energy, and offering good commercial viability. Ethanol is considered one of the most interesting fuels in this field. Herein, platinum-rare earth (Pt-RE) binary alloys (RE = Ce, Sm, Ho, Dy, nominal composition 50 at.% Pt) were produced and studied as anodes for ethanol oxidation reaction (EOR) in alkaline medium. A Pt-Dy alloy with nominal composition 40 at.% Pt was also tested. Their electrocatalytic performance was evaluated by voltammetric and chronoamperometric measurements in 2 M NaOH solution with different ethanol concentrations (0.2–0.8 M) in the 25–45 °C temperature range. Several EOR kinetic parameters were determined for the Pt-RE alloys, namely the charge transfer and diffusion coefficients, and the number of exchanged electrons. Charge transfer coefficients ranging from 0.60 to 0.69 and n values as high as 0.7 were obtained for the Pt0.5Sm0.5 electrode. The EOR reaction order at the Pt-RE alloys was found to vary between 0.4 and 0.9. The Pt-RE electrodes displayed superior performance for EOR than bare Pt, with Pt0.5Sm0.5 exhibiting the highest electrocatalytic activity. The improved electrocatalytic activity in all of the evaluated Pt-RE binary alloys suggests a strategy for the solution of the existing anode issues due to the structure-sensitive EOR.

In this study, three-dimensional finite element models based on the specific anatomy of a patient presenting a femoroacetabular impingement of the "cam" type were developed. The finite element meshes were obtained from arthrographic magnetic resonance images captured before and after hip arthroscopy. All soft tissues were considered linear elastic and isotropic and the bones were assumed as rigid. Physiological loads and rotational motions were applied. Stresses and contact pressures were evaluated in these patient specific models in order to better interpret the mechanism of aggression of the cartilages and of the labrum and to evaluate the effectiveness of the surgery. The results of the analyses are presented and discussed. The values obtained for the stresses and contact pressures in the pathological hip were similar to those reported by other models based on idealised geometries or similar reconstruction methodologies and were larger than the ones obtained in the same hip after the surgical treatment. The surgical treatment effectively reduces the intra-articular pressures and stresses approaching the values of a normal hip. Thus, early surgical treatment may help to prevent, or delay, the joint degeneration.