A Computational Analysis of the Aerodynamics and Aeroacoustics of Jets with Fluid Injection

A detailed numerical analysis of fluidic injection as a tool to reduce noise emission is presented here. The noise reduction strategy, developed at the Pennsylvania State University, is based on injectors that blow air into the diverging section of the nozzle to emulate the effect of interior corrugation on the jet plume. The advantage is that the injection can be activated during takeoff and turned o_ during other phases of flight so that performance is not affected. Numerical simulations are performed on a military-style nozzle based on the GE F400-series engines, with a design Mach number of 1:65, for over-expanded jet conditions. The effectiveness of the fluidic injection as noise reduction technique is analyzed for heated and unheated jets. A high-order Large Eddy Simulation (LES) solver, developed originally at Purdue University, is used to analyze the flow-field and the acoustic field. New initial conditions and new boundary conditions are introduced. A set of Reynolds Averaged Navier-Stokes (RANS) simulations is used to set up the initial and boundary conditions for the LES runs. The numerical results are compared and validated with the outcome of experiments and RANS simulations performed at the Pennsylvania State University. The characteristics of unheated and heated jets are presented and compared. The higher temperatures do not modify the shock-cell structures, while they affect the jet development and the acoustic signature. The fluidic injection shows the potential of breaking down the shock-cells into smaller structures with lower strength, directly reducing the intensity of broadband shock associated noise. Moreover, the injectors are found to affect the development of the larger turbulent structures that generate the peak noise. For the cases tested the injectors reduce the peak noise by more than 1:5 dB for the unheated jet and by 3 dB for the heated jet, on the azimuthal plane in between two lines of injectors. The direction of maximum sound propagation moves from about 30_ to about 50_ as the jet gets heated. An analysis of the thrust changes due to activating the injectors is also presented for the heated and unheated jet conditions. The specific thrust is reduced by about 3% when the injectors are used

Consumer stated preferences for dairy products with carbon footprint labels in Italy

Abstract Carbon footprint (CF) labels on agri-food products represent one of the most important tools to convey information to consumers about the greenhouse gases emissions associated with their purchase behaviour. Together with the growing interest of consumers in CF labels, the subject has gained attention also in the scientific literature, and formal evaluations of consumer response to carbon labelling have been published. Studies in this area aim at analysing consumers' preferences for buying products with a lower CF label or their willingness to pay (WTP) for these products. The objective of this paper is twofold. First, the study proposes a review of the literature that so far has analysed consumer WTP for CF label, focusing on Italian consumers. Second, it uses the results of two surveys of consumers' attitudes towards dairy products with a lower CF label to analyse the factors determining a positive stated WTP. Results point out that a positive WTP for lower CF products is more likely to be declared by respondents who believe that buying products with less environmental impact can combat climate change. Conversely, highly price-sensitive consumers are less likely to be willing to pay more for CF-labelled products

Approaches for reducing wastes in the agricultural sector. An analysis of Millennials’ willingness to buy food with upcycled ingredients

Upcycled ingredients are one of the most significant current trends in the food industry aimed to tackle the challenge of solid food loss reduction. This study investigates the potential market among Millennial consumers for products enriched with upcycled ingredients in Italy. We surveyed a sample of 317 Italian Millennial consumers, using a web-based survey. 62% of respondents declared to be informed about the existence of food made from upcycled ingredients and 53% declared to be willing to buy this novel food. Also, 69% of respondents think that food enriched with upcycled ingredients can bring environmental benefits, while only 40% believe that it can bring health benefits. Using a logit model to analyse consumer preferences, we found that food neophobia and food technology neophobia negatively impact on the likelihood of being willing to buy food produced with upcycled ingredients. Also, consumers who give high importance to food certification are less likely to be willing to buy upcycled foods. Contrariwise, reading labels and believing that upcycled foods are healthier or more environmentally friendly positively impacts on the willingness of Millennial consumers to buy these foods. Results for the sample analysed eventually suggest that giving right information to consumers about the environmental and health characteristics of the products, through clear labelling, could increase their market uptake thus helping to reduce food loss and contributing to reaching circular economy objectives in the agricultural sector

Farms Employing Foreign Workers in Italy: An Analysis with Census Micro Data

Over the last decades, foreign workers have become a significant component of Italian agriculture workforce. Their presence and incidence are highly diversified with respect to farm typologies, type of contract and geographic location. A comprehensive representation of this complex phenomenon is thus the first step to understand the different problems and needs associated to the employment of foreign workforce. This study uses micro data from the 2010 Italian Agricultural Census to first describe what are the structural and geographical features of Italian farms employing foreign workers and then to group farms through a cluster analysis. Results give a detailed representation of the incidence of foreign workers employed, revealing which part of Italian agriculture relies more on foreign workers. The cluster analysis allows the definition of six groups: foreign workers are especially involved in livestock activities, both indoor and grazing and in farms specialized in permanent crops. Among major policy implications, analysing the presence of foreign workers can help targeting policies to agricultural production system needs

Key policy questions for ex-ante impact assessment of European agricultural and rural policies

Policies in the agricultural and rural sectors are of key importance in shaping their sustainable development. These policies are changing from market-based policies to policies that aim to influence farmers' decision-making. Thus, the scientific literature supporting evidence-based policy-making must develop models that simulate individual decision-making (IDM) by farmers. This study aims to understand key policy objectives, related policy questions and benchmark scenarios relevant to the European agricultural sector to define the research agenda for a suite of IDM models. This research goal has been addressed following a five-step process that involved different research tools and heterogeneous actors, including key stakeholders. Results suggest that environmental policy objectives are the most relevant for European agriculture in the coming decades. Thus, the scenario modelling exercise should focus mainly on the agri-environmental policies' impacts while properly considering the potential trade-offs between economic and environmental objectives

The role of economic and policy variables in energy-efficient retrofitting assessment. A stochastic Life Cycle Costing methodology

Abstract Energy saving is a major policy objective worldwide and in the EU in particular. Evaluating the convenience of energy-efficient investments, however, is complex. This paper aims to apply stochastic Life Cycle Costing to assess the economic value of energy-efficient building retrofitting investments. The proposed approach investigates how macroeconomic variables affect such an evaluation by explicitly taking into account their interdependent stochastic nature. Consequently, the economic evaluation of an investment is itself stochastic thus expressing both its expected value and its inherent uncertainty and risk. On this basis, an illustrative case-study is presented, where alternative designs of the energy-saving intervention are compared and a sensitivity analysis performed to identify the determinants of the LCC outcome and of its variability. In terms of policy implications, a tool providing a sounder evaluation of the convenience of such investments can suggest when and to what extent incentives may be appropriate to facilitate these investments and what possible financial instruments could be put forward in order to reduce the associated risk

A scoping review of the impact of agricultural, food, and environmental policies on the transition towards a safe and just operating space for EU agri-food systems

The transition of agri-food systems towards a safe and just operating space (SJOS) is a complex phe- nomenon, which implies finding proper pathways for satisfying human needs and social justice for all, while staying within the limits of the planet’s natural resources. In this context, public policies can play a key role in driving the transition. Thus, in this paper, we have carried out a scoping review of the literature on the relationships between some key public policies affecting agricultural and food and the SJOS dimensions, with the purpose of identifying the most important knowledge gaps. Following the most recent protocols proposed by the literature, we have reviewed papers published in the 20 0 0–23 period using the Web of Science database as the main reference. Our results show that the available evidence is somehow scattered across the SJOS thematic areas, with a clear prevalence of the environ- mental (safe operating space) with respect to the social [just operating space (JOS)] ones. Thus, there is a clear research gap in exploring the impact of public policies on JOS issues such as social equity, health, and nutrition security. Moreover, very few studies explore synergies and trade-offs between different SJOS dimensions. This is especially relevant in evaluating a complex policy mix such as the Green Deal of the European Union. Finally, from a methodological perspective, the available studies provide some interesting hints for extending the available toolkit for ex-ante policy modelling, which deserve further research

Immigrant workforce and labour productivity in Italian agriculture: a farm-level analysis

The objective of this paper is to detect stylized facts and put forward testable hypotheses on the presence and role of immigrant workforce in Italian agriculture. This research focuses on professional agriculture as represented by the Italian FADN over the period 2008-2015. Descriptive statistics show that immigrants are an important component of the workforce employed in professional agriculture over this period, even with wide disparities between regions, sectors and classes of economic size. Immigrants are concentrated in larger and more productive farms and their presence is positively correlated with farm’s labour productivity (LP). To understand whether they are more productive, or they are just occupied by more productive farms, the relationship between LP and their contribution to agricultural production, in terms of Annual Working Units (AWU), is modelled at the farm level, by assuming alternative model specifications. Results emphasize that, in many cases, statistically significant relationships between the contribution of immigrants and farm-level LP can result from model misspecifications. Accounting for farms’ heterogeneity can greatly influence the dimension of this link. Moreover, when assuming persistence of LP with a dynamic specification, this relationship disappears

The productivity and environment nexus with farm-level data. The Case of Carbon Footprint in Lombardy FADN farms

This paper aims to assess whether and to what extent environmental and productivity affect each other within heterogeneous farms. The analysis concerns the sample of FADN Lombardy farms observed from 2008 to 2013. Using the FADN information on production structures and activities, a productivity index (Total Factor Productivity - TFP) and an environmental indicator (Emission Intensity - EI) are properly reconstructed at the farm level. The nexus between TFP and EI is then investigated by admitting heterogenous behaviour across farm sizes and specializations. Results show that the relationship between TFP and EI is not univocal and suggest that the mitigation of GHG emission can be based on the diffusion of the best practices adopted by high-productivity farms of different size and specialization.

The productivity and environment nexus with farm-level data. The Case of Carbon Footprint in Lombardy FADN farms

This paper aims to assess whether and to what extent environmental and productivity affect each other within heterogeneous farms. The analysis concerns the sample of FADN Lombardy farms observed from 2008 to 2013. Using the FADN information on production structures and activities, a productivity index (Total Factor Productivity - TFP) and an environmental indicator (Emission Intensity - EI) are properly reconstructed at the farm level. The nexus between TFP and EI is then investigated by admitting heterogenous behaviour across farm sizes and specializations. Results show that the relationship between TFP and EI is not univocal and suggest that the mitigation of GHG emission can be based on the diffusion of the best practices adopted by high-productivity farms of different size and specialization.