The present work is aimed to assess the capability of a numerical code based on the solution of the Rey- nolds averaged Navier-Stokes equations for the study of propeller functioning in off design conditions; this aspect is becoming of central interest in naval hydrodynamics research because of its crucial impli- cations on design aspects and performance analysis of the vessel during its operational life. A marine pro- peller working in oblique flow conditions is numerically simulated by the unsteady Reynolds averaged Navier-Stokes equations (uRaNSe) and a dynamically overlapping grid approach. The test case consid- ered is the CNR-INSEAN E779A propeller model. Two different loading conditions have been analyzed at different incidence angles (10-30°) in order to characterize the propeller performance during idealized off-design conditions, similar to those experienced during a tight manoeuvre. The main focus is on hydro- dynamic loads (forces and moments) that act on a single blade, on the hub and on the complete propeller; peculiar characteristics of pressure distribution on the blade and downstream wake will be presented as well. Verification of the numerical computations have been assessed by grid convergence analysis

The dynamics of extended bodies endowed with multipolar structure up to the mass quadrupole moment is investigated in the Schwarzschild background according to Dixon's model, extending previous works. The whole set of evolution equations is numerically integrated under the simplifying assumptions of constant frame components of the quadrupole tensor and that the motion of the center of mass be confined on the equatorial plane, the spin vector being orthogonal to it. The equations of motion are also solved analytically in the limit of small values of the characteristic length scales associated with the spin and quadrupole with respect to the background curvature characteristic length. The results are qualitatively and quantitatively different from previous analyses involving only spin structures. In particular, the presence of the quadrupole turns out to be responsible for the onset of a nonzero spin angular momentum, even if initially absent.

The gravitational field of a static body with the quadrupole moment is described by an exact solution found by Erez and Rosen. Here, we investigate the role of the quadrupole in the motion, deflection and lensing of a light ray in the above metric. The standard lensing observables such as image positions and magnification have been explicitly obtained in the weak-field and small quadrupole limit. In this limit, the spacetime metric appears as the natural generalization to quadrupole corrections of the metric form adopted also in current astrometric models. Hence, the corresponding analytical solution of the inverse ray tracing problem and the consistency with other approaches are also discussed.

The optical medium analogy of a radiation field generated by either an exact gravitational plane wave or an exact electromagnetic wave in the framework of general relativity is developed. The equivalent medium of the associated background field is inhomogeneous and anisotropic in the former case, whereas it is inhomogeneous but isotropic in the latter. The features of light scattering are investigated by assuming the interaction region to be sandwiched between two flat spacetime regions, where light rays propagate along straight lines. Standard tools of ordinary wave optics are used to study the deflection of photon paths due to the interaction with the radiation fields, allowing for a comparison between the optical properties of the equivalent media associated with the different background fields.

We evaluate the modifications to the cosmic microwave background anisotropy spectrum that result from a semiclassical expansion of the Wheeler-DeWitt equation. Recently, such an investigation in the case of a real scalar field coupled to gravity has led to the prediction that the power at large scales is suppressed. We make here a more general analysis and show that there is an ambiguity in the choice of solution to the equations describing the quantum gravitational effects. Whereas one of the two solutions describes a suppression of power, the other one describes an enhancement. We investigate possible criteria for an appropriate choice of solution. The absolute value of the correction term is in both cases of the same order and currently not observable. We also obtain detailed formulas for arbitrary values of a complex parameter occurring in the general solution of the nonlinear equations of the model. We finally discuss the modification of the spectral index connected with the power spectrum and comment on the possibility of a quantum-gravity induced unitarity violation.

We complete the analytical determination, at the 4th post-Newtonian approximation, of the main radial potential describing (within the effective one-body formalism) the gravitational interaction of two bodies. The (non logarithmic) coefficient $a_5(\nu)$ measuring this 4th post-Newtonian interaction potential is found to be linear in the symmetric mass ratio $\nu$. Its $\nu$-independent part $a_5(0)$ is obtained by an analytical gravitational self-force calculation that unambiguously resolves the formal infrared divergencies which currently impede its direct post-Newtonian calculation. Its $\nu$-linear part $a_5(\nu)-a_5(0)$ is deduced from recent results of Jaranowski and Schaefer, and is found to be significantly negative.

Protected areas are continuously subjected to ecological change due to anthropic pressures. Analyses of changes in the extent and intensity of pressures over time are essential for adaptive management, yet such analyses are rarely conceptualized or performed in a well-defined, standardized way, with a frequent lack of clarity in development, definition and measurement. Over-time remote sensing data has great potential for mapping spatial pattern of pressures and their impacts. Some pressures can be mapped directly (e.g. land use dynamics, some invasive species), whereas for others the nature, intensity and spatial pattern of impacts can be used to infer on pressures. This paper develops a framework within which remote sensing datasets in combination with GIS and ecological modeling may be used to identify potential pressure growth through either direct detection or indirect monitoring of impacts on landscapes, land cover/habitat types, communities and species through multi-temporal remote sensing image series. The use of this framework is illustrated through categorization of pressure-derived impacts on protected areas in six countries - Greece, Italy, Portugal, Wales, The Netherlands, and India - located in diverse biogeographic, environmental and social-ecological contexts, and facing a different range of pressures. The framework is conceptually robust, geographically invariant, scalable and spatially-explicit, connecting to the growing data sets from remote sources, and we urge it to be tested over a wide range of pressures and social-ecological settings.

Volume di 368 pagine, stampato nell'ambito delle pubblicazioni edite per i 90 anni del CNR. Contiene il carteggio intercorso tra Mario G. Salvadori e Mauro Picone e una serie di documenti utili a ricostruire la figura di Salvadori e i suoi rapporti con l'IAC. Il carteggio è preceduto da una presentazione di Luigi Nicolais e da un ampio saggio (pagg. 11-74) scritto dai tre curatori.

Storia dei maggiori progetti sviluppati da Mauro Picone per costruire in Italia un calcolatore elettronico prima della CEP. A questi progetti segue la collaborazione allo sviluppo della CEP tramite la realizzazione di un simulatore della calcolatrice pisana sulla Ferranti Mark 1* dell'INAC (FINAC). Invine, si accenna alla collaborazione con Olivetti per realizzare la serie ELEA 9004.

Storia delle soluzioni meccaniche inventate dal Seicento alla prima metà del Novecento per eseguire moltiplicazioni e divisioni. Ci si sofferma in particolare su alcune macchine che risolvono direttamente il problema e non ricorrono ad algoritmi di addizione o sottrazione ripetuta.

Schede tecniche e storiche delle calcolatrici meccaniche esposte nel nuovo allestimento del Museo degli Strumenti di Calcolo della Fondazione Galileo Galilei a Pisa

This paper investigates the use of time series of ALOS/PALSAR-1 and COSMO-SkyMed data for the soil moisture retrieval (mv) by means of the SMOSAR algorithm. The application context is the exploitation of mv maps at a moderate spatial and temporal resolution for improving flood/drought monitoring at regional scale. The SAR data were acquired over the Capitanata plain in Southern Italy, over which ground campaigns were carried out in 2007, 2010 and 2011. The analysis shows that the mv retrieval accuracy is 5%-7% m^3/m^3 at L- and X band, although the latter is restricted to a use over nearly bare soil only.