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The authors have shown in previous contributions that reduced order modeling with optimal cubature applied to finite element square (FE2) techniques results in a reliable and affordable multiscale approach, the HPR-FE2 technique. Such technique is assessed here for an industrial case study of a generic 3D reinforced composite whose microstructure is represented by two general microcells accounting for different deformation mechanisms, microstrucural phases and geometry arrangement. Specifically, in this approach the microstrain modes used for building the reduced order model (ROM) are obtained through standard proper orthogonal decomposition (POD) techniques applied over snapshots of a representative sampling strain space. Additionally, a reduced number of integration points is obtained by exactly integrating the main free energy modes resulting from the sampling energy snapshots. The outcome consists of a number of dominant strain modes integrated over a remarkably reduced number of integration points which provide the support to evaluate the constitutive behavior of the microstructural phases. It is emphasized that stresses are computed according to the selected constitutive law at the reduced integration points and, therefore, the strategy inherits advantageous properties such as model completeness and customization of material properties. Overall results are discussed in terms of the consistency of the multiscale analysis, customization of the microscopic material parameters and speedup ratios compared to high-fidelity finite element (HF) simulations., Comment: Computer Methods in Applied Mechanics and Engineering, 2021

In the framework of black hole spectroscopy, we extend the results obtained for a charged black hole in an asymptotically flat spacetime to the scenario with non vanishing negative cosmological constant. In particular, exploiting Hamiltonian techniques, we construct the area spectrum for an AdS Reissner-Nordstrom black hole., Comment: 21 pages, enhanced conclusions, references added

Ridge morphometrices on placoid scales from 12 galeoid shark species were examined in order to evaluate their potential value for frictional drag reduction. The geometry of the shark scales is similar to longitudinal grooved surfaces (riblets) that have been previously shown to give 8 percent skin-friction reduction for turbulent boundary layers. The present study of the shark scales was undertaken to determine if the physical dimensions of the ridges on the shark scales are of the right magnitude to be used by the sharks for drag reduction based on previous riblet work. The results indicate that the ridge heights and spacings are normally maintained between the predicted optimal values proposed for voluntary and burst swimming speeds throughout the individual's ontogeny. Moreover, the species which might be considered to be the faster posses smaller and more closely spaced ridges that based on the riblet work would suggest a greater frictional drag reduction value at the high swimming speeds, as compared to their more sluggish counterparts.