Large-scale offshore wind production in the Mediterranean Sea

In recent years there has been a growing interest in offshore wind energy thanks to the various advantages it offers. The offshore wind energy is used for the production of electric energy above all in the shallow waters but different research activities and large-scale demonstrations are also under way for the deep waters with scientific and technological advances that open possibilities also for new markets such as the Mediterranean Sea. In this context, the present paper aims to estimate the large-scale offshore wind production of the Mediterranean Sea. The methodology uses an open GIS platform and considers bathymetric data, annual average wind speed data, environmental data, turbines technical characteristics and administrative information. Three depth categories have been considered. The overlap between depth categories and annual average wind speeds ranges has allowed to determine the areas potentially suitable for wind farms allocation. On the basis of optimal wind farm layouts and of the characteristic of the type of turbines considered, the theoretical maximum annual offshore wind production has been estimated for whole Mediterranean area and it is about 742 TWh/year. Moreover, for each depth category, the theoretical annual wind offshore production for each Mediterranean country has been estimated

Infrastructure Vulnerability Index of drinking water systems to terrorist attacks

Drinking water supply systems are vulnerable targets for which counter-terrorism measures have been raised worldwide. The threat of terrorist attacks to these systems has led to the need for the international scientific community to deal with the vulnerability assessment related to such events. In this context, this paper proposes an Infrastructure Vulnerability Index for drinking water distribution system with the aim of providing managers with a tool to assess system vulnerability to possible terrorist acts and to support the investments choice aimed at increasing security. This index is obtained using a set of indicators with reference to the structural parts of the system and considers both intentional contamination and physical damage. The index uses a hierarchic structure and decomposes the system into components and uses the Analytic Hierarchy Process to compute the weights. An application of the index was carried out for three water schemes of the Province of Crotone (Southern Italy) and the results obtained allowed to highlight the characteristics of the index and its usefulness

Sustainable Water Management Index,SWaM_Index

The present paper describes the Sustainable Water Management Index, SWaM_Index, useful for managers to measure the sustainability of water management and to assess the effects of the policies undertaken in the direction of sustainability. The structure of the proposed index has been derived from European legal framework of the water resources sector, and the index is obtained from elementary indicators of environmental, economic, social and institutional nature, subsequently aggregated in sub-themes, themes and pillars. The index is well applicable on a national, regional but also local scale and the sustainable management of water resources is assessed considering natural systems, artificial systems and socio-economic and institutional aspects

A methodological proposal for the evaluation of potable water use risk

Water shortages are due to a number of factors such as pollution of sources, decrease of water availability, climate change, wrong use of water resources and the inaccurate management of water systems, including the physiological dysfunctions of waterwork facilities. In order to improve the planning of emergency management, forecasting and prevention of this type of risk, it is helpful to address the study of the risk of potable water use. Through the analysis of water systems in all its components, key factors have been identified that influence the incorrect operation of systems and it was possible to define the risk for potable water use in order to formulate an initial proposal for an estimation method

Shifts in chain-melting transition temperature of liposomal membranes by polymer-grafted lipids

AbstractThe chain-melting transition temperature of dipalmitoyl phosphatidylcholine (DPPC) bilayer membranes containing poly(ethylene glycol)-grafted dipalmitoyl phosphatidylethanolamine (PEG-DPPE) was determined by optical turbidity measurements. The dependence on content, Xp, of PEG-DPPE lipid was studied for different polar headgroup sizes, np, of the polymer lipid, throughout the lamellar phase of the mixtures with DPPC. Mean-field theory for the polymer brush regime predicts that the downward shift in transition temperature should vary with polymer size and content as npXp5/3 (∼npXp11/6 for scaling theory). Any shift induced by the charge on PEG-lipids is independent of polymer size. These predictions are reasonably borne out for the longer polymer lipids (PEG molecular masses 750, 2000 and 5000 Da). Transition temperature shifts in the lamellar phase, before the onset of micellisation, are in the region of −1 to −2 °C (±0.1–0.2 °C) in reasonable accord with theoretical estimates of the lateral pressure exerted by the polymer brush. Shifts of this size are significant to the design of liposomes for controlled release of contents by mild hyperthermia

Interaction of human serum albumin with membranes containing polymer-grafted lipids: spin-label ESR studies in the mushroom and brush regimes

The adsorption of human serum albumin (HSA) to dipalmitoyl phosphatidylcholine (DPPC) bilayer membranes containing poly(ethylene glycol)-grafted dipalmitoyl phosphatidylethanolamine (PEG-DPPE) was studied as a function of content and headgroup size of the polymer lipid. In the absence of protein, conversion from the low-density mushroom regime to the high-density brush regime of polymer-lipid content is detected by the change in ESR outer hyperfine splitting, 2A(max), of chain spin-labelled phosphatidylcholine in gel-phase membranes. The values of 2A,; remain constant in the mushroom regime, but decrease on entering the brush regime. Conversion between the two regimes occurs at mole fractions X- PEG(m --> h) approximate to 0.04, 0.01-0.02 and 0.005-0.01 for PEG-DPPE with mean PEG molecular masses of 350, 2000 and 5000 Da, respectively, as expected theoretically. Adsorption of HSA to DPPC membranes is detected as a decrease of the spin label 2.4(max) hyperfine splitting in the gel phase. Saturation is obtained at a protein/lipid ratio of ca. 1:1 w/w. In the presence of polymer-grafted lipids, HSA adsorbs to DPPC membranes only in the mushroom regime, irrespective of polymer length. In the brush regime, the spin-label values of 2A(max) are unchanged in the presence of protein. Even in the mushroom regime, protein adsorption progressively becomes strongly attenuated as a result of the steric stabilization exerted by the polymer lipid. These results are in agreement with theoretical estimates of the lateral pressure exerted by the grafted polymer in the brush and mushroom regimes, respectively. (C) 2002 Elsevier Science B.V. All rights reserved

Modelling and optimization of least-cost water distribution networks with multiple supply sources and users

The proper allocation of water resources is a very important practical problem in the field of water network planning. Optimization models that are expeditious and easy to use for all stakeholders of the sector play an important role for water resource management. The present work resumes and reviews a least-cost optimization model proposed by our group (Maiolo and Pantusa in Water Sci Tech-W Sup. https://doi.org/10.2166/ws.2015.114, 2016), able to design a water distribution network with multiple supply sources and multiple users. This approach requires of solving an optimization problem based on a nonlinear objective function which is proportional to the cost of the water distribution network. The cost of pre-existing pipelines is considered null. A more realistic scenario, able to consider the maximum flow rate allowed for existing sources-users connections, is considered here. In order to illustrate the usefulness and flexibility of the proposed approach, an application of the model to the real case of the province of Croton, Southern Italy, is presented

Application of a coastal vulnerability index. A case study along the Apulian Coastline, Italy

The coastal vulnerability index (CVI) is a popular index in literature to assess the coastal vulnerability of climate change. The present paper proposes a CVI formulation to make it suitable for the Mediterranean coasts; the formulation considers ten variables divided into three typological groups: geological; physical process and vegetation. In particular, the geological variables are: geomorphology; shoreline erosion/accretion rates; coastal slope; emerged beach width and dune width. The physical process variables are relative sea-level change; mean significant wave height and mean tide range. The vegetation variables are width of vegetation behind the beach and posidonia oceanica. The first application of the proposed index was carried out for a stretch of the Apulia region coast, in the south of Italy; this application allowed to (i) identify the transects most vulnerable to sea level rise, storm surges and waves action and (ii) consider the usefulness of the index as a tool for orientation in planning strategies. For the case study presented in this work, the most influential variables in determining CVI are dune width and geomorphology. The transects that present a very high vulnerability are characterized by sandy and narrow beaches (without dunes and vegetation) and by the absence of Posidonia oceanica

Experimental study of the dynamic response of a spar buoy floating structure under wind and wave action

Floating Wind Turbines (F-WT) represent an important trade-off in terms of wind energy potential and economic feasibility. Among the floating concepts, Spar Buoy (SB) wind turbine is particularly suitable for deep waters. The motion response of such a structure depends on wind, wave and rotor conditions. Nowadays, only a limited number of experimental studies have been conducted on the dynamic response of F-WT even if the recent interest in renewable energies has increased the demand of quality physical model tests to optimize the design of innovative F-WT and to collect reliable and accurate data for further calibration and verification of numerical models. In the present work, the experience gained from the conduction of a 3D physical model experiment performed within the EU-Hydralab IV Integrated Infrastructure Initiative (http://hydralab.eu/) will be described. The objectives of the research activity have been mainly oriented: (i) to investigate the dynamic behavior of a SB floating structure and (ii) to overcome the limitation in the available public domain dataset. Observations of displacements of the floating structure and wave/wind induced tensions at the mooring lines have been carried out. In the present study, a frequency domain analysis is conducted in order to investigate the dynamic effects on the SB under co-directional and misaligned irregular waves/wind loads and extreme conditions. In particular, waves head in two directions, 0\ub0 and 20\ub0, respectively, with reference to the structure. The results show that the dynamic response of the SB wind turbine in coupled wave-wind-induced analyses is influenced by both wave and wind loads effects