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Technologies for direct injection of fuel in compression ignition engines are in continuous development. One of the most investigated components of this system is the injector; in particular, main attention is given to the nozzle characteristics as hole diameter, number, internal shape, and opening angle. The reduction of nozzle hole diameter seems the simplest way to increase the average fuel velocity and to promote the atomization process. On the other hand, the number of holes must increase to keep the desired mass flow rate. On this basis, a new logic has been applied for the development of the next generation of injectors. The tendency to increase the nozzle number and to reduce the diameter has led to the replacement of the nozzle with a circular plate that moves vertically. The plate motion allows to obtain an annulus area for the delivery of the fuel on 360 degrees; while the plate lift permits to vary the atomization level of the spray. The experimental activities have been performed on a single-cylinder metal engine in order to evaluate the new injector concept functionality in typical engine working conditions. Then a deeper investigation of injector the characteristics has been performed in an optical single-cylinder diesel engine via high speed digital imaging in order to catch information on its operation. The results have shown a good response of the injector fuel delivery control but penalties in terms of emissions and efficiency compared to multihole nozzles. Images of the injection process showed that the fuel assumed an asymmetric shape at the exit of the injector affecting the mixing quality and, then, the combustion efficiency.

As of mid-2017, there were ~7500 metric tons of mass in orbit around the Earth, of which about 95% concentrated in almost 6700 intact spacecraft and orbital stages. Among them, nearly 80% were abandoned and more than 90% could not be maneuvered. The intact objects abandoned in LEO above ~650 km, i.e. with a typical residual lifetime of more than 25 years, represent the main potential mass reservoir for the generation of new detrimental orbital debris in case of mutual collisions with the existing debris environment. A practicable strategy to assess the latent long-term environmental impact of an orbiting object is to devise a ranking scheme based on simplified and reasonable inferences. Several ranking schemes have been proposed by different authors during the last decade. Various "criticality indexes" have been devised by us (at ISTI-CNR) in the last few years, and they have been applied to evaluate the environmental impact of many families of rocket bodies and selected spacecraft. A couple of the most complete indexes formulated by us are herein applied to assess the potential criticality of the most massive objects abandoned in LEO.

The potential impacts of climate change on human health in sub-Saharan Africa are wide-ranging, complex, and largely adverse. The region's Indigenous peoples are considered to be at heightened risk given their relatively poor health outcomes, marginal social status, and resource-based livelihoods; however, little attention has been given to these most vulnerable of the vulnerable. This paper contributes to addressing this gap by taking a bottom-up approach to assessing health vulnerabilities to climate change in two Batwa Pygmy communities in rural Uganda. Rapid Rural Appraisal and PhotoVoice field methods complemented by qualitative data analysis were used to identify key climate-sensitive, community-identified health outcomes, describe determinants of sensitivity at multiple scales, and characterize adaptive capacity of Batwa health systems. The findings stress the importance of human drivers of vulnerability and adaptive capacity and the need to address social determinants of health in order to reduce the potential disease burden of climate change.

Waste management contributes to sustainable development since waste can be transformed into valuable resources and commodities. Moreover, it helps resolve the concerns related to the limitation and scarcity of natural resources. Improving waste management means carrying out activities such as prevention, reuse, recycling and recovery, in the perspective of circularity, to minimize waste. Some methodologies and indicators may support sustain and monitor waste, such as the material flow and cost accounting, the life cycle assessment, and the carbon and water footprint.

Abstract Mediterranean islands have the advantage of favourable climatic conditions to use different marine renewable energy sources. Remote sensing can provide data to determine wind energy production potential and observational activity to identify, assess and detect suitable points in large marine areas. In this paper, a new combined model has been developed to integrate wind speed assessment, mapping and forecasting using Sentinel 1 satellite data through images processing and Adaptive Neuro-Fuzzy Inference System and the Bat algorithm. Synthetic Aperture Radar (SAR) satellite images from the Sentinel 1 satellite have been used in order to detect offshore and nearshore wind potential. Particularly, Sentinel 1 images have been analysed by means of the SNAP software. Then, to extract data about wind speed and direction, a GIS software for mapping the wind climate has been used. This new methodology has been applied to the North-Central coasts of Sardinia Island and then focused on six main small islands of La Maddalena archipelago. Furthermore, ten Hot Spots (HSs) have been identified as interesting because of their high-energy potential and the possibility to be considered as sites for future implementation of Wind Turbine Generators (WTGs). Finally, the ten identified HS have been used as input data to train and test the proposed forecast model.

L’articolo affronta gli aspetti generali della riqualificazione energetica degli edifici esistenti, mettendo in luce come le politiche di incentivazione e la strutturazione di alcuni percorsi tecnologici abbiano prodotto un circolo vizioso del retrofit, che agisce come un freno alla diffusione delle riqualificazioni energetiche. La prima parte si focalizza sulla letteratura internazionale, isolando alcune dimensioni utili alla ricostruzione dello stato dell’arte in Italia; la seconda parte analizza le politiche nel contesto italiano, i meccanismi che ne depotenziano gli effetti e le motivazioni della assenza di interventi di riqualificazione su scala medio-grande nelle città italiane; la terza parte affronta il tema dal punto di vista dei percorsi tecnologici, mettendo in luce alcuni aspetti inerenti la difficile strutturazione del campo organizzativo del retrofit energetico e la perdurante incertezza attorno ai dispositivi di efficienza e risparmio. Nelle conclusioni vengono fornite alcune indicazioni di policy, mettendo in luce come le politiche urbane agiscano in modo più marcato sull’efficienza energetica che sul risparmio energetico, depotenziando i sistemi di incentivazione adottati su scala nazionale.

In the present work, the supercritical water gasification (SCWG) of biomass is analyzed with a view to outlining the possible thermodynamic constraints that must be taken into account to develop this new process. In particular, issues concerning the formation of solid carbon and the process heat duty are discussed. The analysis is conducted by means of a two-phase non-stoichiometric thermodynamic model, based on Gibbs free energy minimization. Results show that char formation at equilibrium only occurs at high biomass concentrations, with a strong dependence on biomass composition. As regards the process heat duty, SCWG is mostly endothermic when biomass concentration is low, although a very small amount of oxidizing agent is able to make the process exothermic, with only a small loss in the heating value of the syngas produced.