A 2d-Numerical Study on Slot Jet Applied to a Wind Turbine as a Circulation Control Technique

The file attached to this record is the author's final peer reviewed version.A study on the feasibility of the Circulation Control (CC) technique for wind turbines is proposed. The CC was born in aeronautic field to improve the lift force on the wings, allowing the short take-off and landing of aircraft. It consists in blowing air at a relatively high speed over a rounded trailing edge. The thin jet of air remains attached to the convex curved surface, imposing a certain curvature to the outer streamlines, and, hence, increasing the lift force of the airfoil. Aim of this study is to numerically investigate the advantages on a wind turbine, based on the S809 airfoil, taking into account the energy related considerations, as the cost of the jet production. The paper, after a thorough evaluation of the increase of the generated power, finds that this technique could be promising in the energy harvesting aim

The Hydrothermal Carbonization Process for Waste Valorisation: a Study on the Effect of Process Conditions on the Yield and Properties of Hydrochars from Municipal Solid Waste

Hydrothermal carbonization (HTC) has received considerable attention in recent years for its potential to process heterogeneous organic wastes with high moisture contents. Unlike other thermochemical processes, HTC does not require drying of the feedstock as a pre-treatment. Performed in aqueous conditions at moderate temperatures under autogenous pressure, HTC produces a carbon rich solid phase, referred to as hydrochar, which can be directly used as a solid fuel, or it can be better exploited for new applications. In the present work the potential valorization by HTC of a waste stream from mechanical biological treatment of mixed municipal solid waste, namely the under-sieve fraction from the mechanical treatment stage, was explored. This stream does not have any potential for material recovery, and it is usually landfilled after aerobic biostabilization. HTC tests were carried out in a laboratory-scale reactor. The joint effect of different process parameters on the yield and physicochemical properties of the hydrochar produced was investigated. The design of experiments (DoE) / response surface methodology (RSM) approach was used for the analysis of the influence of temperature, time and solid load on the mass yield and properties of hydrochar. Quantitative relationships between responses and process parameters were determined. The results obtained demonstrated the feasibility of HTC for mixed municipal solid waste, suggesting HTC as a promising alternative treatment path to current waste management

Reproduction, energy storage and metabolic requirements in a mesophotic population at the gorgonian Paramuricea macrospina

This study examined the sexual reproductive cycle, energy storage and metabolic requirements of a Mediterranean gorgonian in a mesophotic ecosystem (~70 m depth). Paramuricea macrospina resulted to be a gonochoric internal brooding species with a 1:1 population sex ratio. Oogenesis lasted ~12-14 months, whereas spermatogenesis was significantly shorter, only lasting 6 months. Fertilization occurred during late summer (August) and larval release occurred during autumn (September-October). The organic matter and total lipid content showed a slight seasonal variability. Stable isotopic composition remained constant throughout the year, reflecting a general stability in gorgonian food sources. Conversely, the free fatty acid composition varied seasonally, reflecting changes in P. macrospina energetic demands probably related to gametogenesis and larval brooding. The reproductive ecology and biochemical composition of P. macrospina significantly differ from shallow coastal gorgonian species, reflecting the higher environmental stability of deeper environments

Reproductive ecology of Lophelia pertusa in Mingulay Reef and the Logachev mounds (North East Atlantic): a multi‐scale comparison

This paper presents the results of a multi-scale comparison in the reproductive stage of the cold-water coral Lophelia pertusa in two areas of the North-east Atlantic: The Mingulay Reef and the Logachev Mounds. The study was carried out during the Research cruise “Changing Oceans” on board of the RRV James Cook, conducted in May-June 2012. The comparative study between the two geographical areas revealed higher fecundity for the colonies analysed from Mingulay Reef compared to the colonies from the Logachev mounds. Moreover the development stage of the oocytes was more advanced in the colonies sampled from Mingulay than in the ones collected from Logachev. The comparison between single colonies and within the same colony from the Mingulay Reef did not show any differences in the maturity stage of the oocytes, nevertheless the analyses of the reproductive stage between mesenteries within the same polyps showed high variability, which indicates that the gametogenic development within each mesentery undergoes a prolonged period of oocyte production. This probably results in a protracted spawning period, which might improve the reproductive success of the species. This work has been developed under the framework of the UKOA program (United Kingdom Ocean Acidification program) and has been supported by the National Environmental Research Council (NERC, UK)