Spin-Orbital momentum decomposition and helicity exchange in a set of non-null knotted electromagnetic fields

We calculate analytically the spin-orbital decomposition of the angular momentum using completely non-paraxial fields that have certain degree of linkage of electric and magnetic lines. The split of the angular momentum into spin-orbital components is worked out for non-null knotted electromagnetic fields. The relation between magnetic and electric helicities and spin-orbital decomposition of the angular momentum is considered. We demonstrate that even if the total angular momentum and the values of the spin and orbital momentum are the same, the behaviour of the local angular momentum density is rather different. By taking cases with constant and non-constant electric and magnetic helicities, we show that the total angular momentum density present different characteristics during time evolution

Quaternary glacial evolution in the Central Cantabrian Mountains (Northern Spain)

Peer reviewedPostprin

Ground temperatures, landforms and processes in an Atlantic mountain. Cantabrian Mountains (Northern Spain)

This research was supported by the Formación de Profesorado Universitario FPU13/05837 (Ministerio de Educación Cultura y Deporte) program, by the OAPN 053/2010 (Organismo Autónomo Parques Nacionales, MAGRAMA) project, by the I + D + I CGL2015-68144-R (Ministerio de Economia y Competitividad) project, by the Leverhulme Trust International Network Grant IN-2012-140 and the Royal Geographical Society Dudley Stamp Memorial Award.Peer reviewedPostprin

Influence of the Compaction Pressure and Sintering Temperature on the Mechanical Properties of Porous Titanium for Biomedical Applications

In the present work, the use of porous titanium is proposed as a solution to the difference in stiffness between the implant and bone tissue, avoiding the bone resorption. Conventional powder metallurgical technique is an industrially established route for fabrication of this type of material. The results are discussed in terms of the influence of compaction pressure and sintering temperature on the porosity (volumetric fraction, size, and morphology) and the quality of the sintering necks. A very good agreement between the predicted values obtained using a simple 2D finite element model, the experimental uniaxial compression behavior, and the analytical model proposed by Nielsen, has been found for both the Young’s modulus and the yield strength. The porous samples obtained by the loose sintering technique and using temperatures between 1000 °C −1100 °C (about 40% of total porosity) are recommended for achieving a suitable biomechanical behavior for cortical bone partial replacement.Ministry of Economy and Competitiveness of the State General Administration of Spain grant MAT2015-71284-

EFFETTO DELLA SOLLECITAZIONE MECCANICA A FLESSIONE SUL COMPORTAMENTO A CORROSIONE DI LEGHE DI Al STRUTTURALI

The present work reports on the effect of constant bending load on the electrochemical behavior of structural aluminum alloys AA 2024-T3 (Al-Cu-Mg) and AA 7075-T6 (Al-Zn-Mg-Cu). The single cycle anodic polarization curves in 0.6 M NaCl (pH 6.5) were carried out using four-point bent beam specimens (4PBB). Lower propensity to localized corrosion has been indicated for compressive stresses. The effect of tensile stresses on the electrochemical response is more complex and depends on the alloy nature