Broadband potential optimisation of a full scale acoustic metawindow performance

Noise control and airflow in duct-like systems are among some of the most interesting applications to conjugate AMMs innovation and sustainability. Specifically applied to the built environment, they opened up a new field of research supporting indoor wellbeing, sanitised environments, and public activities. Previous research conducted by the authors has proved AMM based window to be a resourceful way to address both natural ventilation and reduce the incoming noise propagation; however, the effective spectral range did not cover lower frequencies (50-350 Hz). For this reason, in the presented paper, implementation in the AMM unit geometry was performed over a full-scale acoustic metawindow (AMW). The resonating volume has been enhanced (by 200% of the original one) and coupled with a set of lateral flanks. Numerical analysis through FEM proved that on a range of opening ratio from 3 to 33%, the TL related to the window is improved overall of the 70% on the frequency range from 50 to 350 Hz. Such results encourage the use of new AMMs ergonomic windows in place of standard ones to achieve both natural ventilation and noise attenuation from 50 to 5k Hz, being resourceful for domestic, sanitary, and public applications

Full-scale metamaterial window for building application

The research on acoustic metamaterials (AMMs) has progressed rapidly over the last decades. One of the applications is for noise control and airflow in duct-like systems. These are useful features for natural ventilation window design; however, the visual impact between indoor and outdoor environment, as another key factor of windows, makes the existing AMMs not directly useable for this application due to their geometrical complexity and size limitations. In this research, an AMM previously developed by the authors is exploited for full-scale window design. The AMM is packed only in the window frame so that the window transparency is not compromised. A broadband attenuation performance is obtained by the resonant unit cells constituting the AMM. The effect of the geometric variation on the window performance in terms of both acoustics and the airflow is analysed numerically through Finite Element Method (FEM) models. The performances of different AMM windows are evaluated and compared with those of conventional window designs. The simulation results show that this new AMM-based window design can overcome the limitations of the conventional windows, with great potential in real applications

Effect of dietary supplementation with malt extracts on milk production

The transition period of a cow is characterized by marked changes in metabolism as the cow prepares for parturition and lactogenesis. Aim of the present study was the evaluation of the effect of feeding dairy cows with malt extracts on milk production. Ten days before calving, 22 multiparous Holstein dairy cows were divided in two groups and received for four months the same base diet added with an experimental concentrate (1.5 kg/cow/day) containing either corn starch and malt extracts (ME) or only corn starch (CS) as the main energy source. Dry matter intake was not influenced by treatment and averaged 21.7 kg of DM/cow/day. The use of malt extracts determined a numerical increase of milk yield (+0.7 kg/cow/day, i.e. +2.5%) but this difference did not reach the significance level. Milk quality parameters were not influenced by treatment. Further studies will be needed to assess if feeding diets rich in very high fermentable carbohydrates to transition dairy cows can be a valuable strateg

Guidelines for the LTO Noise Assessment of Future Civil Supersonic Aircraft in Conceptual Design

One of the most critical regulatory issues related to supersonic flight arises from limitations imposed by community noise acceptability. The most efficient way to ensure that future supersonic aircraft will meet low-noise requirements is the verification of noise emissions from the early stages of the design process. Therefore, this paper suggests guidelines for the Landing and Take-Off (LTO) noise assessment of future civil supersonic aircraft in conceptual design. The supersonic aircraft noise model is based on the semi-empirical equations employed in the early versions of the Aircraft NOise Prediction Program (ANOPP) developed by NASA, whereas sound attenuation due to atmospheric absorption has been considered in accordance with SAE ARP 866 B. The simulation of the trajectory leads to the prediction of the aircraft noise level on ground in terms of several acoustic metrics (LAmax, SEL, PNLTM and EPNL). Therefore, a dedicated validation has been performed, selecting the only available supersonic aircraft of the Aircraft Noise and Performance database (ANP), that is, the Concorde, through the matching with Noise Power Distance (NPD) curves for LAmax and SEL, obtaining a maximum prediction error of +/- 2.19%. At least, an application to departure and approach procedures is reported to verify the first noise estimations with current noise requirements defined by ICAO at the three certification measurement points (sideline, flyover, approach) and to draw preliminary considerations for future low-noise supersonic aircraft design

A metawindow with optimised acoustic and ventilation performance

Crucial factors in window performance, such as natural ventilation and noise control, are generally conceived separately, forcing users to choose one over the other. To solve this dualism, this study aimed to develop an acoustic metamaterial (AMM) ergonomic window design to allow noise control without dependence on the natural ventilation duration and vice versa. First, the finite element method (FEM) was used to investigate the noise control performance of the acoustic metawindow (AMW) unit, followed by anechoic chamber testing, which also served as the validation of the FEM models. Furthermore, FEM analysis was used to optimise the acoustic performance and assess the ventilation potential. The numerical and experimental results exhibited an overall mean sound reduction of 15 dB within a bandwidth of 380 to 5000 Hz. A good agreement between the measured and numerical results was obtained, with a mean variation of 30%. Therefore, the AMW unit optimised acoustic performance, resulting in a higher noise reduction, especially from 50 to 500 Hz. Finally, most of the AMW unit configurations are suitable for natural ventilation, and a dynamic tuned ventilation capacity can be achieved for particular ranges by adjusting the window’s ventilation opening. The proposed designs have potential applications in building acoustics and engineering where natural ventilation and noise mitigation are required to meet regulations simultaneously

Feeding dehydrated alfalfa increases polyunsaturated fatty acids concentration in Marchigiana beef muscle

Beef meat is a low fat food (<5% fat). However, the fatty acid composition of beef is relatively saturated (approximately 45-50%). The polyunsaturated/saturated fatty acids (P/S) ratio in beef is approximately 0.1, the ideal being about 0.4 (Department of Health, 1994). This can cause critical comments to beef meat related to human health

Space systems engineering tools for technology roadmapping activities: TrIS, technology roadmapping strategy, and HyDaT, database on hypersonic transportation systems

A technology roadmap is the output of the technology roadmapping process, a complex and continuously evolving process, which aims at selecting technologies, mission concepts, capabilities and building blocks to pursue incremental paths to increase the Technology Readiness Level, according to specific strategic plans. Technology roadmaps are crucial not only to illustrate the technologies' procurement plan for specific missions in the future, but also the achievement for Europe of technological milestones enabling operational capabilities, essential for current and future space missions. Coordination of requirements and funding sources among all European stakeholders (ESA, EU, National Agencies, Industries) is one of the objectives of technology roadmaps. The paper presents the results of a research activity carried out by Politecnico di Torino in support to the work on-going at ESA to elaborate technology roadmaps for the hypersonic and (re-)entry space transportation systems' domain. Traditionally the approach has always been based on workshops and brainstorming. The idea at the basis of the research activity has been the development of a flexible and rational methodology to generate technology roadmaps to better support strategic decisions in combination with traditional methods. The research activity thus focuses on the development of an innovative methodology to derive, track and manage the technology roadmaps' basic pillars (Technology Areas, Operational Capabilities, Mission Concepts and Building Blocks) and on the implementation of the methodology itself into two ad-hoc tools: TRIS, Technology Roadmapping Strategy, and HYDAT, Database on Hypersonic and (re-entry) transportation systems. TRIS is a versatile software tool that implements the objective methodology for technology roadmaps' derivation and update. HYDAT is a smart database, able to collect, categorize and analyze data to support technology roadmaps for (re-)entry missions and reusability applications. In addition, HYDAT can support hypersonic and (re-)entry conceptual design activities. First, the paper describes the main settings of the database that manages all relevant initiatives for technological development of hypersonic and (re-)entry systems, categorizing them according to the roadmap pillars. Secondly, the paper presents TRIS, the tool used to derive, track and manage the pillars and consequently to generate the technology roadmaps. Eventually, the paper presents and discusses the results obtained by the application of HYDAT and TRIS to IXV (Intermediate eXperimental Vehicle), analysing main activities expected in the near and far future to enhance hypersonic and (re-)entry technologies and proposing a TRL increase path in terms of missions and activities to perform, and in which schedule to carry out them

Using the ESA exploration technology roadmaps in support of new mission concepts and technology prioritization

Exploration technology roadmaps have been developed by ESA in the past few years and the edition of 2015 has just been released. In the context of Moon exploration initiatives and using HERACLES mission as case study, the authors will apply methodologies studied to simulate technology roadmapping activities and technologies prioritization processes. In particular, the roadmaps for the procurement of technologies required for the HERACLES mission are here presented through its main building blocks

Innovative time-based separation procedures for civil RPAS integration

Purpose: This paper aims to suggest feasible solutions to overcome the problem of unmanned aerial vehicles integration within the existing airspace. Design/methodology/approach: It envisages innovative time-based separation procedures that will enhance the integration in the future air traffic management (ATM) system of next generation of large remotely piloted aircraft system (RPAS). 4D navigation and dynamic mobile area concepts, both proposed in the framework of Single European Sky ATM Research program, are brought together to hypothesize innovative time-based separation procedures aiming at promoting integration of RPAS in the future ATM system. Findings: Benefits of proposed procedures, mainly evaluated in terms of volume reduction of segregated airspace, are quantitatively analyzed on the basis of realistic operational scenarios focusing on monitoring activities in both nominal and emergency conditions. Eventually, the major limits of time-based separation for RPAS are investigated. Practical implications: The implementation of the envisaged procedures will be a key enabler in RPAS integration in future ATM integration. Originality/value: In the current ATM scenario, separation of RPAS from air traffic is ensured by segregating a large amount of airspace areas with fixed dimensions, dramatically limiting the activities of these vehicles

Precision livestock farming, automats and new technologies: possible applications in extensive dairy sheep farming

Precision livestock farming (PLF) technologies are becoming increasingly common in modern agriculture. They are frequently integrated with other new technologies in order to improve human–livestock interactions, productivity and economical sustainability of modern farms. New systems are constantly being developed for concentrated farming operations as well as for extensive and pasture-based farming systems. The development of technologies for grazing animals is of particular interest for the Mediterranean extensive sheep farming sector. Dairy sheep farming is a typical production system of the area linked to its historical and cultural traditions. The area provides roughly 40% of the world sheep milk, having 27% of the milk-producing ewes. Developed countries of the area (France, Italy, Greece and Spain – FIGS) have highly specialized production systems improved through animal selection, feeding techniques and intensification of production. However, extensive systems are still practiced alongside intensive ones due to their lower input costs and better resilience to market fluctuations. In the current article, we evaluate possible PLF systems and their suitability to be incorporated in extensive dairy sheep farming as practiced in the FIGS countries. Available products include: electronic identification systems (now mandatory in the EU) such as ear tags, ruminal boluses and sub-cutaneous radio-frequency identification; on-animal sensors such as accelerometers, global positioning system) and social activity loggers; and stationary management systems such as walk-over-weights, automatic drafter (AD), virtual fencing and milking parlour-related technologies. The systems were considered according to their suitability for the management and business model common in dairy sheep farming. However, adoption of new technologies does not take place immediately in small and medium scale extensive farmer. As sheep farmers usually belong to more conservative technology consumers, characterized by average age of 60 and a very transparent community, dynamics which does not favour financial risk taking involved with new technologies. Financial barriers linked to production volumes and resource management of extensive farming are also a barrier for innovation. However, future prospective could increase the importance of technology and promote its wider adoption. Trends such as global sheep milk economics, global warming, awareness to animal welfare, antibiotics resistance and European agricultural policies could influence the farming practices and stimulate wider adoption of PLF systems in the near future