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In view of the new emission regulations seeking to lower the particle cut-off size down to the current 23 nm, an extensive comprehension on the nature of sub-23 nm particles is crucial. In this regard, a new challenge lies ahead considering an even more massive use of biofuels. The objective of this research study was to characterize the sub-23 nm particles and to evaluate their volatile organic fraction (VOF) from a high performance, 1.8 L gasoline direct injection (GDI) engine under the Worldwide harmonized Light vehicles Test Cycle (WLTC). Particle emissions were measured through an Engine Exhaust Particle Sizer (EEPS) capable of particle sizing and counting in the range 5.6 - 560 nm. The sampling and conditioning were performed by both a single diluter and the Dekati Engine Exhaust Diluter (DEED) a Particle Measurement Programme (PMP) compliant sample conditioning system. The temperature of the dilution air at the first dilution stage and of the evaporation chamber in the DEED were varied to promote nucleation and condensation phenomena thus allowing to distinguish the VOF. The effect of ethanol at 10 %v/v (E10) and 85 %v/v (E85) blend on particle emissions was analyzed. The weight of sub-23 particles on the total emissions was assessed at each phase of the cycle. Main results highlighted that sub-23 nm particles give an important contribution to the total particle emissions. A strong reduction of particle concentration as the ethanol content in the fuel increases was observed. Moreover, the test performed at low dilution temperature showed a large number of su-23 nm particles thus revealing a large fraction of volatile components in specific phases of the cycle.

This work had partial financial support of the Portuguese Foundation for Science and Technology (FCT) under the Strategic Project for the Centre of Territory, Environment and Construction of the School of Engineering, University of Minho, Portugal. The Cluster computing facilities are provided by the Project ‘Search-ON2: Revitalisation of HPC infrastructure of UMinho’ (NORTE-07-0162-FEDER-000086), co-funded by the North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). We also would like to thank the two anonymous reviewers.

A wider use of biofuels in internal combustion engines could reduce the emissions of pollutants and greenhouse gases from the transport sector. In particular, due to stringent emission regulatory programs, compression ignition engine requires interventions aimed at reducing their polluting emissions. Ethanol, a low carbon fuel generally produced from biomass, is a promising alternative fuel applicable in compression ignition engines to reduce CO2 and soot emissions. In this paper, the application of a dual fuel diesel-ethanol configuration in a light-duty compression ignition engine has been numerically investigated. Ethanol is injected into the intake port, while diesel fuel is directly injected into the combustion chamber of the analyzed engine. CFD simulations have been carried out by means of the AVL Fire 3-D code. The operation at given engine load and speed has been simulated considering different diesel injection timings. Numerical results of both the diesel spray development and the dual fuel combustion process have been validated against available experimental data. 3-D analysis allowed to deeply investigate the evolution of the combustion process, particularly the transition between premixed and diffusive phase. The influence of diesel fuel direct injection timing, combustion chamber geometry, and EGR on the combustion process development, hence on engine performance and emission levels, have been highlighted. One of the main results of the use of dual fuel, diesel-ethanol configuration, is a significant reduction of soot and carbon dioxide emissions with respect to diesel-only operation.

Luengo Frades, J.; Garcia Barba, J.; Negro, V.; Martin-Anton, M., and Soriano, J., 2020. Blue economy: Compatibility between the increasing offshore wind technology and the achievement of the SDG. In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1490–1494. Coconut Creek (Florida), ISSN 0749-0208.In 2015, the UN impulsed an ambitious initiative called the Sustainable Development Goals (SDG), including 17 Goals and 169 Targets, to be accomplished in the 2015-2030 period. At the same time, offshore wind industry has taken the great leap towards the ocean. Such wind farms hold more and more wind turbines (>100), depths increase leaving shallow waters (almost 100 m deep), and the power installed is increasing at a dramatic rate not thought to be possible only one decade ago (currently reaching 400 MW). These facts are ones of the great advances of the XXI century, but so far, it has not been done a deep reflection on the impact of the offshore wind on the aforementioned SDG, and on how the offshore wind is going to accomplish all the challenges happening when trying to reach such SDG. The achievement of some of the SDG and the offshore wind technology progress go, with no doubt, hand in hand. This is the case of Goal 12 (Responsible consumption and production), Goal 13 (Climate action), or Goal 14 (Life below water). But there are also other SDG that deserve a special attention, in order to ensure that offshore wind power technology effectively will contribute to reach them, and will not, on the contrary, act to the detriment of them. This is the case of Goal 7 (Affordable and clean energy), Goal 8 (Decent work and economic growth), or Goal 10 (Reducing inequalities). In this paper, the great contribution of the offshore wind technology to achieve the SDG is commented, making special emphasis on the possible weaknesses that could appear, and on how to solve them. All of it to make by 2030 the world, in general, and the energy in particular, become more blue.