Using the magnetic tape recorder in reading, listening, and oral language in the elementary classroom.

Thesis (Ed.M.)--Boston Universit

Marine energy exploitation in the mediterranean region: steps forward and challenges

This works aims to describe current perspectives for marine energy exploitation in the Mediterranean basin, highlighting challenges and opportunities as well as the factors that still limit its market deployment. Technologies for the conversion of Marine Energy (ME) into electricity are now ready for full-scale deployment in farms of devices, making the final step from demonstration to operability and commercial exploitation. Although marine energy is more abundant along the Atlantic and Nordic European coasts, significant resources are also available in the Mediterranean Sea, opening up new perspectives for sustainable energy production in sensitive coastal areas and for the economic development of Southern Europe. The implementation of ME converters in the Mediterranean is in fact liable to induce significant technological advancements leading to product innovation, due to the local low energy levels which impose more restrictive constraints on device efficiency and environmental compatibility. In addition, the milder climate allows the testing of concepts and prototypes in the natural environment at more affordable costs, lowering capital risks for new and innovative small and medium enterprises. Research institutions and industrial players in Mediterranean countries have already taken up the challenge, despite the numerous limiting factors that still need to be removed. In particular, the ME sector adds up to the many different traditional maritime activities and to the new ocean-related industries that are developing, potentially exacerbating the competition for the use of marine space in the Mediterranean region and threatening its environmental status. The ME sector needs therefore to design suitable instruments to involve all the relevant stakeholders in a participative public debate as to how to best manage the maritime space. As the prospective sea use patterns are rapidly changing, an adequate international legal and policy framework needs to be designed for the coherent management of sea space, and Marine Spatial Planning needs to be finally implemented by EU Member States also in the Mediterranean area. To this end, the creation of transnational clusters of stakeholders is expected be an effective catalyzer, especially as they can foster the exchange of knowledge and best practices both across European countries and between the North and the South shore of the Mediterranean basin

On the intermittent energy transfer at viscous scales in turbulent flows

In this letter we present numerical and experimental results on the scaling properties of velocity turbulent fields in the range of scales where viscous effects are acting. A generalized version of Extended Self Similarity capable of describing scaling laws of the velocity structure functions down to the smallest resolvable scales is introduced. Our findings suggest the absence of any sharp viscous cutoff in the intermittent transfer of energy.Comment: 10 pages, plain Latex, 6 figures available upon request to [email protected]

Delineation of the Native Basin in Continuum Models of Proteins

We propose two approaches for determining the native basins in off-lattice models of proteins. The first of them is based on exploring the saddle points on selected trajectories emerging from the native state. In the second approach, the basin size can be determined by monitoring random distortions in the shape of the protein around the native state. Both techniques yield the similar results. As a byproduct, a simple method to determine the folding temperature is obtained.Comment: REVTeX, 6 pages, 5 EPS figure

High resolution simulations of freely decaying shallow water turbulence on a rotating sphere

Results of high-resolution, long-time numerical integrations of the unforced shallow-water equations on a rotating sphere are presented. A new accurate and efficient grid point method is used for these simulations, that allows to easily reach very high spatial resolutions (up to an equivalent T680 spectral truncation). It is found that, for small values of the Rossby deformation radius LD, the final quasi-steady states of the free evolution are characterized by the formation of robust westward (retrograde) equatorial jets, whose strengths and widths depend on LD and on the rotation speed. It is also shown that the presence of a westward equatorial jet is related to the global prevalence of anticyclonic vorticity

Generalized scaling in fully developed turbulence

In this paper we report numerical and experimental results on the scaling properties of the velocity turbulent fields in several flows. The limits of a new form of scaling, named Extended Self Similarity(ESS), are discussed. We show that, when a mean shear is absent, the self scaling exponents are universal and they do not depend on the specific flow (3D homogeneous turbulence, thermal convection , MHD). In contrast, ESS is not observed when a strong shear is present. We propose a generalized version of self scaling which extends down to the smallest resolvable scales even in cases where ESS is not present. This new scaling is checked in several laboratory and numerical experiment. A possible theoretical interpretation is also proposed. A synthetic turbulent signal having most of the properties of a real one has been generated.Comment: 25 pages, plain Latex, figures are available upon request to the authors ([email protected], [email protected]