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Traditional helicopter blades are subject to significant deformations, which influence control forces and moments, as well as the helicopter aeroelastic and aeroacoustic behavior. Thus, the knowledge of rotor elastic states could help improving flight control efficiency, and reducing vibration level and acoustic emissions of next-generation helicopters. This paper presents an original and computationally efficient modal approach aimed at dynamic shape sensing of helicopter rotor blades. It is based on strain measurements in a limited number of points over the blade surface. Although the algorithm is based on the cascaded solution of linear algebraic equations, much like other modal-based algorithms, it is able to reconstruct nonlinear, moderate lag, flap and torsional deflections, which are typical in helicopter structural dynamics. The algorithm is tested on non-rotating and rotating hingeless blades through numerical simulations based upon a multibody dynamics solver for general nonlinear comprehensive aeroelastic analysis. Its capabilities are assessed against those of classical modal approaches. Numerical investigations show that the proposed algorithm is reliable, accurate and robust to measurement noise. [ABSTRACT FROM AUTHOR]

The energy sector of the European Union (EU) is expected to progress fast towards a fully-fledged dependency on renewable sources. In such a goal-driven approach, a prospective assessment framework is designed to simulate the environmental consequences engendered by the gradual penetration of a novel biowaste-based energy technology in the EU energy production market. This is done by building a dynamic input-output model reflecting the implementation of the technology over time, following future energy scenarios and hypothetical targets for the EU (number of plants operating in 2030 and 2050). Total impacts, calculated for global warming, photochemical oxidation, acidification, eutrophication and human toxicity are calculated for these scenarios, and for a counterfactual scenario, represented by the same economic system operating without opting for such novel technology. The output of the simulation shows that the technology could bring carbon savings of 220–250 Mt CO 2 eq up to 2050 and significant changes in the economy structure such as a reduction of fossil phosphorus production and corresponding generation of revenues from phosphorus recovery in the order of 100–150 billion €. In a more general fashion and beside the case study, the factors affecting the model output, sources of uncertainty and assumptions are presented in order to appraise scope, applicability and limitations of the proposed assessment framework and to prepare its use in decision making. [Display omitted] • Studies related to prospective sustainability analysis are reviewed comprehensively. • A novel bio-waste-based energy technology in the EU energy production market is modeled. • Input-output tables are combined with LCA and dynamic scenarios up to 2050. • The model output shows carbon savings and positive economic impact due to phosphorus recovery. • An analysis of the model sensitive factors, uncertainty and assumptions is robustly discussed. [ABSTRACT FROM AUTHOR]

The ability of microalgae to sequester carbon and at the same time synthesise valuable compounds with potential applications in nutraceutical, pharmaceutical and cosmetic industries makes them attractive for commercial deployment, especially in view of a blue bioeconomy. Among microalgae, the diatom Phaeodactylum tricornutum is considered as an important potential source of omega-3 polyunsaturated fatty acids, such as eicosapentanoic acid, an essential polyunsaturated fatty acid with anti-inflammatory and antimicrobial properties. The aim of this study was to perform the Life Cycle Assessment of the cultivation of P. tricornutum - at semi-industrial scale in photobioreactor - for the production of high-quality bioactive compounds comparing synthetic carbon dioxide supply to a supply with waste carbon dioxide from a biogas upgrading process hypothesizing industrial symbiosis network. The effect of renewable energy use instead of the European electricity mix was also examined. Primary data on the production process, including the stages of cleaning and sterilisation, cultivation, harvesting and freeze-drying, were used. The midpoint impact categories recommended in the ILCD Handbook were used for performing the impact assessment. A sensitivity analysis was also performed on algal productivity, culture medium recirculation factor and amount of solvents per cleaning cycle. Firstly, results indicate in general cultivation and freeze-drying as the most contributing stages to the impacts. Secondly, they demonstrate in the comparative assessment that the use of carbon dioxide from the biogas upgrading is a feasible and attractive alternative to the synthetic one, as it allows for the improvement of the environmental performance of the production process in all the analysed impact categories. Finally, sensitivity analysis suggests that the environmental performance could be further improved by acting on other key factors, such as electricity source, nutrients culture medium and cleaning solutions. Unlabelled Image • Cultivation and Freeze-drying are the most contributing stages to the impacts. • Substitution of synthetic CO 2 with waste CO 2 brings measurable environmental benefits. • Larger improvements can be obtained acting on electricity source and nutrients reuse. [ABSTRACT FROM AUTHOR]

Abstract This paper presents an original approach to structural health monitoring of helicopter rotors based on strain measurement on the blades. Three algorithms are presented, one in the time domain and two in the frequency domain. They are based on the analysis of the discrepancies between the strains on damaged and undamaged blades. Two damage types are considered: a mass unbalance at the tip, and a localized stiffness reduction. The performance of the proposed methods is assessed by numerical simulation using a multibody dynamic solver for comprehensive aeroelastic analysis of rotorcraft. The numerical investigation has highlighted the capability of all the presented techniques to detect damages in the blades, even of small entity, in both steady-flight and soft maneuvers. The reduced prediction accuracy in aggressive maneuvered flight suggests the use of these methods only in steady or quasi-steady flight conditions. [ABSTRACT FROM AUTHOR]

Global energy demand is lowering its growth, but it is still expected to increase by 30% between now and 2040. To decrease greenhouse gas emissions a shift to more sustainable renewable energy sources is fundamental. Among the renewable energy sources, biomasses already have the largest share in Europe and their future demand for biorefinery plants will increase at global level. This study provides a comprehensive and exportable categorization of the residual biomasses (RB) from different supply sectors. Thanks to the individual descriptive and quantitative parameters introduced in the paper, an estimate of the theoretical and techno-economic potential is presented for a well-industrialized, agricultural-oriented and environmentally advanced European Region. Results are presented as recoverable biogas or biomethane, considering also the seasonal availability. In a relatively small region like Emilia Romagna (Italy), 106 different types of residual biomasses belonging to 6 main groups have been characterized. Over half of the total residues come from the agro-industrial and food businesses (58) followed by the agricultural sector (33). The estimate reveals a theoretical potential of 3544 ± 291 Gg/year of total solids for thermochemical valorisation and 3460 ± 639 Gg/year of total solids suitable for biological treatment. In terms of unused potential, the quantities decrease respectively to 2120 ± 298 and 915 ± 167 Gg/year. The estimates indicate stable results over the years from 2014 to 2016. The seasonal availability shows two evident peaks from August to October, while a significant shortage is present from April to June for the residues suitable for thermochemical valorisation. The theoretical potential that can be obtained from the Region's residues corresponds to about 1.8–2.3 million TOE/year, corresponding to 13–17% of the total regional consumption. Unused residues contribute to 0.9–1.2 million TOE/year. Image 1 • A fully comprehensive and exportable categorization of the RBs is developed. • 106 residual biomasses have been identified and estimated in Emilia Romagna Region. • About 1.5 Mg/year/capita of total solids is produced in the Region. • The theoretical RB potential covers the 13–17% of the regional energy consumption. • The unused RB potential decrease to 7–9% of the annual regional energy consumption. [ABSTRACT FROM AUTHOR]