A Critical Analysis on the Current Design Criteria for Cathodic Protection of Ships and Superyachts

Classification Society and ISO standard regulate the design of cathodic protection (CP) plans of ships and superyachts. However, due to shipyards’ long experience, the hull vessel protection plans often rely on an adaptation of previous CP designs for similar ships. This simple practice could expose ships to low protection or overprotection. Here, the protection plan of an existing 42 m superyacht is considered to highlight critical CP design issues. The numerical analysis gives evidence of discrepancies between the CP design proposed in accordance with ISO standard and the protection plan that was actually implemented. Indeed, for a proper protection plan, the anode weight according to the ISO standard is 2.7 kg, whereas the real protection plan uses a 7 kg anode. The numerical optimization highlights an optimal anode mass of 5 kg (−28.5% in weight). It provides sufficient protection for the expected lifetime, and will preserve the system in cases of damage to the hull and a consequent increase in the breakdown factor. This new solution underlines the importance and necessity of improving cathodic protection plan design

Characterisation of La0.6Sr0.4Co0.2Fe0.8O3-\u3b4- Ba0.5Sr0.5Co0.8Fe0.2O3-\u3b4composite as cathode for solid oxide fuel cells

Mixture of La0.6Sr0.4Co0.2Fe0.8O3-\u3b4 and Ba0.5Sr0.5Co0.8Fe0.2O3-\u3b4, was investigated as promising cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The two perovskites possess high catalytic activity for the oxygen reduction (ORR), although some problems related to their chemical and structural stability have still to be overcome in view of improving durability of the cell performance. The achievement of a stable and high-performing composite material is the aim of this study. In principle, chemical equilibrium at the LSCF-BSCF interface may be reached through ions interdiffusion during the sintering process, resulting in the chemical stabilization of the material. The composite-cathode deposited on Ce0.8Sm0.2O2-\u3b4 electrolyte was then investigated by Electrochemical Impedance Spectroscopy (EIS) as a function of temperature, overpotential and time. The results exhibited an interesting electrochemical behavior of the electrode toward oxygen reduction reaction. XRD analysis was performed to detect structural modification during thermal or operation stages and it was found that after the sintering the two starting perovskites were no longer present; a new phase with a rhombohedral La0,4Sr0,6FeO3-type structure (LSF) is formed. An improvement in composite cathode durability has been detected under the considered operating conditions (200 mAcm-2, 700 \ub0C) in comparison with the pure BSCF electrode. The results confirmed this new electrode as promising system for further investigation as IT-SOFC cathode

DRIHM - An Infrastructure To Advance Hydro-Meteorological Research

One of the main challenges in hydro-meteorological research (HMR) is predicting the impact of weather and climate changes on the environment, society and economy, including local severe hazards such as floods and landslides. At the heart of this challenge lies the ability to have easy access to hydro-meteorological data and models, and facilitate the collaboration across discipline boundaries. Within the DRIHM project (Distributed Research Infrastructure for Hydro-Meteorology, www.drihm.eu, EC funded FP7 project 2011-2015) we develop a prototype e-Science environment to facilitate this collaboration and provide end-to-end HMR services (models, datasets, and post-processing tools) at the European level, with the ability to expand to global scale. The objectives of DRIHM are to lead the definition of a common long-term strategy, to foster the development of new HMR models, workflows and observational archives for the study of severe hydro-meteorological events, to promote the execution and analysis of high-end simulations, and to support the dissemination of predictive models as decision analysis tools. For this we implement a service portal to construct heterogeneous simulation workflows that can include deterministic and ensemble runs on a heterogeneous infrastructure consisting of HPC, grid and Windows cloud resources. Via another FP7 project called DRIHM2US (www.drihm2us.eu) we collaborate with the NSF funded SCIHM project (www.scihm.org) to build a wider international collaborative network. This contribution will provide a sketch of the DRIHM architecture and show some use cases such as the November 2011 Genoa flooding

Towards A Grid Infrastructure For Hydro-Meteorological Research

The Distributed Research Infrastructure for Hydro-Meteorological Study (DRIHMS) is a coordinatedaction co-funded by the European Commission. DRIHMS analyzes the main issuesthat arise when designing and setting up a pan-European Grid-based e-Infrastructure for researchactivities in the hydrologic and meteorological fields. The main outcome of the projectis represented first by a set of Grid usage patterns to support innovative hydro-meteorologicalresearch activities, and second by the implications that such patterns define for a dedicatedGrid infrastructure and the respective Grid architecture

Hydrometeorological multi-model ensemble simulations of the 4 November 2011 flash flood event in Genoa, Italy, in the framework of the DRIHM Project

The e-Science environment developed in the framework of the EU-funded DRIHM project was used to demonstrate its ability to provide relevant, meaningful hydrometeorological forecasts. This was illustrated for the tragic case of 4 November 2011, when Genoa, Italy, was flooded as the result of heavy, convective precipitation that inundated the Bisagno catchment. The Meteorological Model Bridge (MMB), an innovative software component developed within the DRIHM project for the interoperability of meteorological and hydrological models, is a key component of the DRIHM e-Science environment. The MMB allowed three different rainfall-discharge models (DRiFt, RIBS and HBV) to be driven by four mesoscale limited-area atmospheric models (WRF-NMM, WRF-ARW, Meso-NH and AROME) and a downscaling algorithm (RainFARM) in a seamless fashion. In addition to this multi-model configuration, some of the models were run in probabilistic mode, thus giving a comprehensive account of modelling errors and a very large amount of likely hydrometeorological scenarios (> 1500). The multi-model approach proved to be necessary because, whilst various aspects of the event were successfully simulated by different models, none of the models reproduced all of these aspects correctly. It was shown that the resulting set of simulations helped identify key atmospheric processes responsible for the large rainfall accumulations over the Bisagno basin. The DRIHM e-Science environment facilitated an evaluation of the sensitivity to atmospheric and hydrological modelling errors. This showed that both had a significant impact on predicted discharges, the former being larger than the latter. Finally, the usefulness of the set of hydrometeorological simulations was assessed from a flash flood early-warning perspective

Parallel Compression of 3D Meshes for Efficient Distributed Visualization

none3In a distributed visualization environment transmission time is dominant because of the amount of data to be moved and the limitations of available bandwidth. In this paper we address the problem to speed up the compression operation of large Triangulated Irregular Networks (TIN) using commodity clusters. In our case TINs represent isosurfaces extracted from volumetric data sets. The proposed parallel compression algorithm is based on Edgebreaker [ 1], one of the most powerful connectivity compression algorithm, and it exploits mesh partitioning produced during the parallel isosurface extraction operation. In this way a high speed-up of the compression module and a considerable improvement of the visualization system are obtained.A.CLEMATIS; V. GIANUZZI; D. D'AGOSTINOClematis, A.; Gianuzzi, Vittoria; D'Agostino, D

Solid polymer electrolyte as an alternative approach for the electrochemical removal of herbicide from groundwater

Groundwater represents one of the primary freshwater sources, but their pollution is rapidly increasing, and the development of tailored processes is mandatory. In this scenario, electrochemical advanced oxidation processes (EAOPs) represent a promising alternative to face this issue. Their application to groundwater is limited by low electrical conductivity, which directly affects cell voltage and then operating costs. In this paper, three different approaches to overcome this constrain are compared using a BDD anode and a Ti/RuO2 cathode. The first is the addition of a supporting electrolyte as sodium sulfate (Na2SO4); despite its efficacy to increase conductivity, some new problems are introduced in water source management and treatment plant for the electrolyte removal. An alternative approach is the reduction of gap-electrode from 5 mm up to some microns, equivalent to the thickness of a plastic mesh, used to avoid electrodes short-circuit. The third innovative method proposed here is the substitution of insulated mesh with an ionic conductor layer, a solid polymer electrolyte (SPE), like Nafion\uae117 sandwiched between the electrodes. This modification allows increasing electrochemical performance such as herbicide and COD removal, preserving energy consumptions. Moreover, SPE does not show any performance deterioration in the first 30 h of utilisation. The results suggest that the usage of SPE can be a promising approach for the treatment of groundwater

Electro-Fenton, solar photoelectro-Fenton and UVA photoelectro-Fenton: Degradation of Erythrosine B dye solution

The treatment of Erythrosine B, selected as a model compound, has been comparatively studied by electrochemical advanced oxidation processes (EAOPs) such as electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Experiments are performed in a one-compartment cell with a BDD anode, and a commercial carbon felt cathode at pH = 3, treating a volume of 0.3 L in each test. The irradiation plays a crucial role in the increasing of hydroxyl radical production and in the recover of iron catalyst. A faster colour and COD removal degradation are achieved under the light application. UVA photoelectro-Fenton and solar photoelectro-Fenton processes allow degrading COD entirely in 90 min, while a conventional electro-Fenton does not reach 90% COD removal after 2 h. Energy consumptions are a substantial factor in process selection. Photo electro-Fenton with a UVA-100 W lamp has one of the best removal performance, but it becomes not suitable for application due to high energy demand, up to 515.6 kWh m 123, and the UVA system requires the main fraction of this energy. Possible alternatives are proposed to contain costs: the first is the reduction of UVA lamp power to 25 W, maintaining a high-performance removal with an Ec decreasing to 187.9 kWh m 123. Nevertheless, the lowest and competitive energy demands is obtained working with a solar photoelectro-Fenton system, where energy consumption are only related to the electrochemical process (20.9 kWh m 123), and removal is complete