Search results for "Ocean"

The SO2F2 quasi-spherical top: Correspondence between tensorial and Watson's formalisms

2006

Abstract The SO2F2 quasi-spherical top molecule with C2v symmetry is considered as a distorted spherical top deriving from the SO 4 2 − tetrahedral ion. We present here a detailed correspondence between the tensorial formalism using the Td⊃C2v reorientation and the usual Hamiltonian of Watson. We have also performed ab initio calculations in order to determine the centrifugal distorsion constants in the vibrational ground state.

Recupero dei fondali degradati del Golfo di Palermo: studio preliminare di riforestazione con Posidonia oceanica

2011

Selection of spawning substratum by European river lampreys (Lampetra fluviatilis) in experimental tanks

2014

The selection of spawning substratum by the river lamprey (Lampetra fluviatilis) was studied in two experimental tanks with different flow conditions. In both tanks, four gravel sizes mixed with 15% sand were available to the test animals. In the tank with the lower current speed, lampreys selected in favour of the finest (2–8 mm) gravel size available against gravel sizes 4–20 mm and 8–40 mm. Selection was also significantly different in the tank with higher current speed where selection against the medium-sized substratum (4–20 mm) was evident, but there were no differences between selection for gravel sizes 2–8 mm, 2–40 mm and 8–40 mm relative to availability. Substratum selection and ob…

Standardization of Road Danger Signs in the European Union

2015

The aim of this research is to find a solution for the standardization of road signs in the EU zone by a comparative analysis of different national sign systems to establish a common set from a single country. This work is based on the idea that road sign standardization might increase the safety level of transnational journeys and foster the relationships among the various members of the EU Community. This paper presents the outcome of the first step of the research, which focuses on the harmonization of danger signs. In more detail, a multicriteria approach is applied to rank 19 EU Member States on the basis of three main aspects: the installation cost of new signs, new sign learning issu…

Improving the Downwind Sail Design Process by Means of a Novel FSI Approach

2021

The process of designing a sail can be a challenging task because of the difficulties in predicting the real aerodynamic performance. This is especially true in the case of downwind sails, where the evaluation of the real shapes and aerodynamic forces can be very complex because of turbulent and detached flows and the high-deformable behavior of structures. Of course, numerical methods are very useful and reliable tools to investigate sail performances, and their use, also as a result of the exponential growth of computational resources at a very low cost, is spreading more and more, even in not highly competitive fields. This paper presents a new methodology to support sail designers in ev…

Towards a framework for assessment and management of cumulative human impacts on marine food webs

2015

Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the fo…

First Evidence of Contourite Drifts in the North-Western Sicilian Active Continental Margin (Southern Tyrrhenian Sea)

2021

We present the results of an integrated geomorphological and seismo-stratigraphic study based on high resolution marine data acquired in the north-western Sicilian continental margin. We document for the first time five contourite drifts (marked as EM1a, EM2b, EM2, EM3a, and EM3b), located in the continental slope at depths between ca. 400 and 1500 m. EM1a,b have been interpreted as elongated mounded drifts. EM1a,b are ca. 3 km long, 1.3 km wide, and have a maximum thickness of 36 m in their center that thins northwards, while EM1b is smaller with a thickness up to 24 m. They are internally characterized by mounded seismic packages dominated by continuous and parallel reflectors. EM2 is loc…

Modelling the relationship between sexual reproduction and rhizome growth in Posidonia oceanica (L.) Delile

2006

The relationship between flowering and growth performance of Posidonia oceanica (L.) Delile in meadows distributed along the south-eastern coast of Sicily (Italy) was investigated by means of a statistical model (generalized linear mixed model) combined with the lepidochronological analysis. Over a 28-year period, 67 floral stalk remains were observed. The highest flowering index was recorded in lepidochronological year 1998 (10.1%) and the Inflorescence Frequency per age showed a clear decrease corresponding to 15-year-old shoots. The sexual reproductive event had positive effects on rhizome elongation (cm year−1) and leaf production (no. leaves year−1) in the same flowering year, whilst n…

Uso di sistemi acustici ad alta risoluzione nel monitoraggio del limite inferiore di Posidonia oceanica nel Golfo di Palermo

2011

Multi‐specific small‐scale fisheries rely on few, locally essential, species: Evidence from a multi‐area study in the Mediterranean

2022

Achieving sound management of small-scale fisheries (SSFs) is globally recognized a key priority for sustaining livelihoods, local economies, social wealth and cultural heritage in coastal areas. The paucity of information on SSFs often prevents the proper assessment of different socio-ecological aspects, potentially leading to draw inappropriate conclusions and hampering the development and adoption of effective policies to foster SSF sustainability. To respond to the growing global call to assess these fisheries, we carried out a multi-disciplinary and data-rich assessment of SSFs at 11 areas in 6 Mediterranean EU countries, combining the analysis of 1292 SSF fishing operations and 149 se…